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9832 Original bug discovered as 9560 has friends IPv4 packets coming in as IPv6 creating chaos
    
      
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          --- old/usr/src/uts/common/io/mac/mac_sched.c
          +++ new/usr/src/uts/common/io/mac/mac_sched.c
   1    1  /*
   2    2   * CDDL HEADER START
   3    3   *
   4    4   * The contents of this file are subject to the terms of the
   5    5   * Common Development and Distribution License (the "License").
   6    6   * You may not use this file except in compliance with the License.
   7    7   *
   8    8   * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9    9   * or http://www.opensolaris.org/os/licensing.
  10   10   * See the License for the specific language governing permissions
  11   11   * and limitations under the License.
  12   12   *
  13   13   * When distributing Covered Code, include this CDDL HEADER in each
  
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  14   14   * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15   15   * If applicable, add the following below this CDDL HEADER, with the
  16   16   * fields enclosed by brackets "[]" replaced with your own identifying
  17   17   * information: Portions Copyright [yyyy] [name of copyright owner]
  18   18   *
  19   19   * CDDL HEADER END
  20   20   */
  21   21  /*
  22   22   * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
  23   23   * Use is subject to license terms.
  24      - * Copyright 2017 Joyent, Inc.
       24 + * Copyright 2018 Joyent, Inc.
  25   25   * Copyright 2013 Nexenta Systems, Inc. All rights reserved.
  26   26   */
  27   27  
  28   28  /*
  29   29   * MAC data path
  30   30   *
  31   31   * The MAC data path is concerned with the flow of traffic from mac clients --
  32   32   * DLS, IP, etc. -- to various GLDv3 device drivers -- e1000g, vnic, aggr,
  33   33   * ixgbe, etc. -- and from the GLDv3 device drivers back to clients.
  34   34   *
  35   35   * -----------
  36   36   * Terminology
  37   37   * -----------
  38   38   *
  39   39   * MAC uses a lot of different, but related terms that are associated with the
  40   40   * design and structure of the data path. Before we cover other aspects, first
  41   41   * let's review the terminology that MAC uses.
  42   42   *
  43   43   * MAC
  44   44   *
  45   45   *      This driver. It interfaces with device drivers and provides abstractions
  46   46   *      that the rest of the system consumes. All data links -- things managed
  47   47   *      with dladm(1M), are accessed through MAC.
  48   48   *
  49   49   * GLDv3 DEVICE DRIVER
  50   50   *
  51   51   *      A GLDv3 device driver refers to a driver, both for pseudo-devices and
  52   52   *      real devices, which implement the GLDv3 driver API. Common examples of
  53   53   *      these are igb and ixgbe, which are drivers for various Intel networking
  54   54   *      cards. These devices may or may not have various features, such as
  55   55   *      hardware rings and checksum offloading. For MAC, a GLDv3 device is the
  56   56   *      final point for the transmission of a packet and the starting point for
  57   57   *      the receipt of a packet.
  58   58   *
  59   59   * FLOWS
  60   60   *
  61   61   *      At a high level, a flow refers to a series of packets that are related.
  62   62   *      Often times the term is used in the context of TCP to indicate a unique
  63   63   *      TCP connection and the traffic over it. However, a flow can exist at
  64   64   *      other levels of the system as well. MAC has a notion of a default flow
  65   65   *      which is used for all unicast traffic addressed to the address of a MAC
  66   66   *      device. For example, when a VNIC is created, a default flow is created
  67   67   *      for the VNIC's MAC address. In addition, flows are created for broadcast
  68   68   *      groups and a user may create a flow with flowadm(1M).
  69   69   *
  70   70   * CLASSIFICATION
  71   71   *
  72   72   *      Classification refers to the notion of identifying an incoming frame
  73   73   *      based on its destination address and optionally its source addresses and
  74   74   *      doing different processing based on that information. Classification can
  75   75   *      be done in both hardware and software. In general, we usually only
  76   76   *      classify based on the layer two destination, eg. for Ethernet, the
  77   77   *      destination MAC address.
  78   78   *
  79   79   *      The system also will do classification based on layer three and layer
  80   80   *      four properties. This is used to support things like flowadm(1M), which
  81   81   *      allows setting QoS and other properties on a per-flow basis.
  82   82   *
  83   83   * RING
  84   84   *
  85   85   *      Conceptually, a ring represents a series of framed messages, often in a
  86   86   *      contiguous chunk of memory that acts as a circular buffer. Rings come in
  87   87   *      a couple of forms. Generally they are either a hardware construct (hw
  88   88   *      ring) or they are a software construct (sw ring) maintained by MAC.
  89   89   *
  90   90   * HW RING
  91   91   *
  92   92   *      A hardware ring is a set of resources provided by a GLDv3 device driver
  93   93   *      (even if it is a pseudo-device). A hardware ring comes in two different
  94   94   *      forms: receive (rx) rings and transmit (tx) rings. An rx hw ring is
  95   95   *      something that has a unique DMA (direct memory access) region and
  96   96   *      generally supports some form of classification (though it isn't always
  97   97   *      used), as well as a means of generating an interrupt specific to that
  98   98   *      ring. For example, the device may generate a specific MSI-X for a PCI
  99   99   *      express device. A tx ring is similar, except that it is dedicated to
 100  100   *      transmission. It may also be a vector for enabling features such as VLAN
 101  101   *      tagging and large transmit offloading. It usually has its own dedicated
 102  102   *      interrupts for transmit being completed.
 103  103   *
 104  104   * SW RING
 105  105   *
 106  106   *      A software ring is a construction of MAC. It represents the same thing
 107  107   *      that a hardware ring generally does, a collection of frames. However,
 108  108   *      instead of being in a contiguous ring of memory, they're instead linked
 109  109   *      by using the mblk_t's b_next pointer. Each frame may itself be multiple
 110  110   *      mblk_t's linked together by the b_cont pointer. A software ring always
 111  111   *      represents a collection of classified packets; however, it varies as to
 112  112   *      whether it uses only layer two information, or a combination of that and
 113  113   *      additional layer three and layer four data.
 114  114   *
 115  115   * FANOUT
 116  116   *
 117  117   *      Fanout is the idea of spreading out the load of processing frames based
 118  118   *      on the source and destination information contained in the layer two,
 119  119   *      three, and four headers, such that the data can then be processed in
 120  120   *      parallel using multiple hardware threads.
 121  121   *
 122  122   *      A fanout algorithm hashes the headers and uses that to place different
 123  123   *      flows into a bucket. The most important thing is that packets that are
 124  124   *      in the same flow end up in the same bucket. If they do not, performance
 125  125   *      can be adversely affected. Consider the case of TCP.  TCP severely
 126  126   *      penalizes a connection if the data arrives out of order. If a given flow
 127  127   *      is processed on different CPUs, then the data will appear out of order,
 128  128   *      hence the invariant that fanout always hash a given flow to the same
 129  129   *      bucket and thus get processed on the same CPU.
 130  130   *
 131  131   * RECEIVE SIDE SCALING (RSS)
 132  132   *
 133  133   *
 134  134   *      Receive side scaling is a term that isn't common in illumos, but is used
 135  135   *      by vendors and was popularized by Microsoft. It refers to the idea of
 136  136   *      spreading the incoming receive load out across multiple interrupts which
 137  137   *      can be directed to different CPUs. This allows a device to leverage
 138  138   *      hardware rings even when it doesn't support hardware classification. The
 139  139   *      hardware uses an algorithm to perform fanout that ensures the flow
 140  140   *      invariant is maintained.
 141  141   *
 142  142   * SOFT RING SET
 143  143   *
 144  144   *      A soft ring set, commonly abbreviated SRS, is a collection of rings and
 145  145   *      is used for both transmitting and receiving. It is maintained in the
 146  146   *      structure mac_soft_ring_set_t. A soft ring set is usually associated
 147  147   *      with flows, and coordinates both the use of hardware and software rings.
 148  148   *      Because the use of hardware rings can change as devices such as VNICs
 149  149   *      come and go, we always ensure that the set has software classification
 150  150   *      rules that correspond to the hardware classification rules from rings.
 151  151   *
 152  152   *      Soft ring sets are also used for the enforcement of various QoS
 153  153   *      properties. For example, if a bandwidth limit has been placed on a
 154  154   *      specific flow or device, then that will be enforced by the soft ring
 155  155   *      set.
 156  156   *
 157  157   * SERVICE ATTACHMENT POINT (SAP)
 158  158   *
 159  159   *      The service attachment point is a DLPI (Data Link Provider Interface)
 160  160   *      concept; however, it comes up quite often in MAC. Most MAC devices speak
 161  161   *      a protocol that has some notion of different channels or message type
 162  162   *      identifiers. For example, Ethernet defines an EtherType which is a part
 163  163   *      of the Ethernet header and defines the particular protocol of the data
 164  164   *      payload. If the EtherType is set to 0x0800, then it defines that the
 165  165   *      contents of that Ethernet frame is IPv4 traffic. For Ethernet, the
 166  166   *      EtherType is the SAP.
 167  167   *
 168  168   *      In DLPI, a given consumer attaches to a specific SAP. In illumos, the ip
 169  169   *      and arp drivers attach to the EtherTypes for IPv4, IPv6, and ARP. Using
 170  170   *      libdlpi(3LIB) user software can attach to arbitrary SAPs. With the
 171  171   *      exception of 802.1Q VLAN tagged traffic, MAC itself does not directly
 172  172   *      consume the SAP; however, it uses that information as part of hashing
 173  173   *      and it may be used as part of the construction of flows.
 174  174   *
 175  175   * PRIMARY MAC CLIENT
 176  176   *
 177  177   *      The primary mac client refers to a mac client whose unicast address
 178  178   *      matches the address of the device itself. For example, if the system has
 179  179   *      instance of the e1000g driver such as e1000g0, e1000g1, etc., the
 180  180   *      primary mac client is the one named after the device itself. VNICs that
 181  181   *      are created on top of such devices are not the primary client.
 182  182   *
 183  183   * TRANSMIT DESCRIPTORS
 184  184   *
 185  185   *      Transmit descriptors are a resource that most GLDv3 device drivers have.
 186  186   *      Generally, a GLDv3 device driver takes a frame that's meant to be output
 187  187   *      and puts a copy of it into a region of memory. Each region of memory
 188  188   *      usually has an associated descriptor that the device uses to manage
 189  189   *      properties of the frames. Devices have a limited number of such
 190  190   *      descriptors. They get reclaimed once the device finishes putting the
 191  191   *      frame on the wire.
 192  192   *
 193  193   *      If the driver runs out of transmit descriptors, for example, the OS is
 194  194   *      generating more frames than it can put on the wire, then it will return
 195  195   *      them back to the MAC layer.
 196  196   *
 197  197   * ---------------------------------
 198  198   * Rings, Classification, and Fanout
 199  199   * ---------------------------------
 200  200   *
 201  201   * The heart of MAC is made up of rings, and not those that Elven-kings wear.
 202  202   * When receiving a packet, MAC breaks the work into two different, though
 203  203   * interrelated phases. The first phase is generally classification and then the
 204  204   * second phase is generally fanout. When a frame comes in from a GLDv3 Device,
 205  205   * MAC needs to determine where that frame should be delivered. If it's a
 206  206   * unicast frame (say a normal TCP/IP packet), then it will be delivered to a
 207  207   * single MAC client; however, if it's a broadcast or multicast frame, then MAC
 208  208   * may need to deliver it to multiple MAC clients.
 209  209   *
 210  210   * On transmit, classification isn't quite as important, but may still be used.
 211  211   * Unlike with the receive path, the classification is not used to determine
 212  212   * devices that should transmit something, but rather is used for special
 213  213   * properties of a flow, eg. bandwidth limits for a given IP address, device, or
 214  214   * connection.
 215  215   *
 216  216   * MAC employs a software classifier and leverages hardware classification as
 217  217   * well. The software classifier can leverage the full layer two information,
 218  218   * source, destination, VLAN, and SAP. If the SAP indicates that IP traffic is
 219  219   * being sent, it can classify based on the IP header, and finally, it also
 220  220   * knows how to classify based on the local and remote ports of TCP, UDP, and
 221  221   * SCTP.
 222  222   *
 223  223   * Hardware classifiers vary in capability. Generally all hardware classifiers
 224  224   * provide the capability to classify based on the destination MAC address. Some
 225  225   * hardware has additional filters built in for performing more in-depth
 226  226   * classification; however, it often has much more limited resources for these
 227  227   * activities as compared to the layer two destination address classification.
 228  228   *
 229  229   * The modus operandi in MAC is to always ensure that we have software-based
 230  230   * capabilities and rules in place and then to supplement that with hardware
 231  231   * resources when available. In general, simple layer two classification is
 232  232   * sufficient and nothing else is used, unless a specific flow is created with
 233  233   * tools such as flowadm(1M) or bandwidth limits are set on a device with
 234  234   * dladm(1M).
 235  235   *
 236  236   * RINGS AND GROUPS
 237  237   *
 238  238   * To get into how rings and classification play together, it's first important
 239  239   * to understand how hardware devices commonly associate rings and allow them to
 240  240   * be programmed. Recall that a hardware ring should be thought of as a DMA
 241  241   * buffer and an interrupt resource. Rings are then collected into groups. A
 242  242   * group itself has a series of classification rules. One or more MAC addresses
 243  243   * are assigned to a group.
 244  244   *
 245  245   * Hardware devices vary in terms of what capabilities they provide. Sometimes
 246  246   * they allow for a dynamic assignment of rings to a group and sometimes they
 247  247   * have a static assignment of rings to a group. For example, the ixgbe driver
 248  248   * has a static assignment of rings to groups such that every group has exactly
 249  249   * one ring and the number of groups is equal to the number of rings.
 250  250   *
 251  251   * Classification and receive side scaling both come into play with how a device
 252  252   * advertises itself to MAC and how MAC uses it. If a device supports layer two
 253  253   * classification of frames, then MAC will assign MAC addresses to a group as a
 254  254   * form of primary classification. If a single MAC address is assigned to a
 255  255   * group, a common case, then MAC will consider packets that come in from rings
 256  256   * on that group to be fully classified and will not need to do any software
 257  257   * classification unless a specific flow has been created.
 258  258   *
 259  259   * If a device supports receive side scaling, then it may advertise or support
 260  260   * groups with multiple rings. In those cases, then receive side scaling will
 261  261   * come into play and MAC will use that as a means of fanning out received
 262  262   * frames across multiple CPUs. This can also be combined with groups that
 263  263   * support layer two classification.
 264  264   *
 265  265   * If a device supports dynamic assignments of rings to groups, then MAC will
 266  266   * change around the way that rings are assigned to various groups as devices
 267  267   * come and go from the system. For example, when a VNIC is created, a new flow
 268  268   * will be created for the VNIC's MAC address. If a hardware ring is available,
 269  269   * MAC may opt to reassign it from one group to another.
 270  270   *
 271  271   * ASSIGNMENT OF HARDWARE RINGS
 272  272   *
 273  273   * This is a bit of a complicated subject that varies depending on the device,
 274  274   * the use of aggregations, the special nature of the primary mac client. This
 275  275   * section deserves being fleshed out.
 276  276   *
 277  277   * FANOUT
 278  278   *
 279  279   * illumos uses fanout to help spread out the incoming processing load of chains
 280  280   * of frames away from a single CPU. If a device supports receive side scaling,
 281  281   * then that provides an initial form of fanout; however, what we're concerned
 282  282   * with all happens after the context of a given set of frames being classified
 283  283   * to a soft ring set.
 284  284   *
 285  285   * After frames reach a soft ring set and account for any potential bandwidth
 286  286   * related accounting, they may be fanned out based on one of the following
 287  287   * three modes:
 288  288   *
 289  289   *     o No Fanout
 290  290   *     o Protocol level fanout
 291  291   *     o Full software ring protocol fanout
 292  292   *
 293  293   * MAC makes the determination as to which of these modes a given soft ring set
 294  294   * obtains based on parameters such as whether or not it's the primary mac
 295  295   * client, whether it's on a 10 GbE or faster device, user controlled dladm(1M)
 296  296   * properties, and the nature of the hardware and the resources that it has.
 297  297   *
 298  298   * When there is no fanout, MAC does not create any soft rings for a device and
 299  299   * the device has frames delivered directly to the MAC client.
 300  300   *
 301  301   * Otherwise, all fanout is performed by software. MAC divides incoming frames
 302  302   * into one of three buckets -- IPv4 TCP traffic, IPv4 UDP traffic, and
 303  303   * everything else. Note, VLAN tagged traffic is considered other, regardless of
 304  304   * the interior EtherType. Regardless of the type of fanout, these three
 305  305   * categories or buckets are always used.
 306  306   *
 307  307   * The difference between protocol level fanout and full software ring protocol
 308  308   * fanout is the number of software rings that end up getting created. The
 309  309   * system always uses the same number of software rings per protocol bucket. So
 310  310   * in the first case when we're just doing protocol level fanout, we just create
 311  311   * one software ring each for IPv4 TCP traffic, IPv4 UDP traffic, and everything
 312  312   * else.
 313  313   *
 314  314   * In the case where we do full software ring protocol fanout, we generally use
 315  315   * mac_compute_soft_ring_count() to determine the number of rings. There are
 316  316   * other combinations of properties and devices that may send us down other
 317  317   * paths, but this is a common starting point. If it's a non-bandwidth enforced
 318  318   * device and we're on at least a 10 GbE link, then we'll use eight soft rings
 319  319   * per protocol bucket as a starting point. See mac_compute_soft_ring_count()
 320  320   * for more information on the total number.
 321  321   *
 322  322   * For each of these rings, we create a mac_soft_ring_t and an associated worker
 323  323   * thread. Particularly when doing full software ring protocol fanout, we bind
 324  324   * each of the worker threads to individual CPUs.
 325  325   *
 326  326   * The other advantage of these software rings is that it allows upper layers to
 327  327   * optionally poll on them. For example, TCP can leverage an squeue to poll on
 328  328   * the software ring, see squeue.c for more information.
 329  329   *
 330  330   * DLS BYPASS
 331  331   *
 332  332   * DLS is the data link services module. It interfaces with DLPI, which is the
 333  333   * primary way that other parts of the system such as IP interface with the MAC
 334  334   * layer. While DLS is traditionally a STREAMS-based interface, it allows for
 335  335   * certain modules such as IP to negotiate various more modern interfaces to be
 336  336   * used, which are useful for higher performance and allow it to use direct
 337  337   * function calls to DLS instead of using STREAMS.
 338  338   *
 339  339   * When we have IPv4 TCP or UDP software rings, then traffic on those rings is
 340  340   * eligible for what we call the dls bypass. In those cases, rather than going
 341  341   * out mac_rx_deliver() to DLS, DLS instead registers them to go directly via
 342  342   * the direct callback registered with DLS, generally ip_input().
 343  343   *
 344  344   * HARDWARE RING POLLING
 345  345   *
 346  346   * GLDv3 devices with hardware rings generally deliver chains of messages
 347  347   * (mblk_t chain) during the context of a single interrupt. However, interrupts
 348  348   * are not the only way that these devices may be used. As part of implementing
 349  349   * ring support, a GLDv3 device driver must have a way to disable the generation
 350  350   * of that interrupt and allow for the operating system to poll on that ring.
 351  351   *
 352  352   * To implement this, every soft ring set has a worker thread and a polling
 353  353   * thread. If a sufficient packet rate comes into the system, MAC will 'blank'
 354  354   * (disable) interrupts on that specific ring and the polling thread will start
 355  355   * consuming packets from the hardware device and deliver them to the soft ring
 356  356   * set, where the worker thread will take over.
 357  357   *
 358  358   * Once the rate of packet intake drops down below a certain threshold, then
 359  359   * polling on the hardware ring will be quiesced and interrupts will be
 360  360   * re-enabled for the given ring. This effectively allows the system to shift
 361  361   * how it handles a ring based on its load. At high packet rates, polling on the
 362  362   * device as opposed to relying on interrupts can actually reduce overall system
 363  363   * load due to the minimization of interrupt activity.
 364  364   *
 365  365   * Note the importance of each ring having its own interrupt source. The whole
 366  366   * idea here is that we do not disable interrupts on the device as a whole, but
 367  367   * rather each ring can be independently toggled.
 368  368   *
 369  369   * USE OF WORKER THREADS
 370  370   *
 371  371   * Both the soft ring set and individual soft rings have a worker thread
 372  372   * associated with them that may be bound to a specific CPU in the system. Any
 373  373   * such assignment will get reassessed as part of dynamic reconfiguration events
 374  374   * in the system such as the onlining and offlining of CPUs and the creation of
 375  375   * CPU partitions.
 376  376   *
 377  377   * In many cases, while in an interrupt, we try to deliver a frame all the way
 378  378   * through the stack in the context of the interrupt itself. However, if the
 379  379   * amount of queued frames has exceeded a threshold, then we instead defer to
 380  380   * the worker thread to do this work and signal it. This is particularly useful
 381  381   * when you have the soft ring set delivering frames into multiple software
 382  382   * rings. If it was only delivering frames into a single software ring then
 383  383   * there'd be no need to have another thread take over. However, if it's
 384  384   * delivering chains of frames to multiple rings, then it's worthwhile to have
 385  385   * the worker for the software ring take over so that the different software
 386  386   * rings can be processed in parallel.
 387  387   *
 388  388   * In a similar fashion to the hardware polling thread, if we don't have a
 389  389   * backlog or there's nothing to do, then the worker thread will go back to
 390  390   * sleep and frames can be delivered all the way from an interrupt. This
 391  391   * behavior is useful as it's designed to minimize latency and the default
 392  392   * disposition of MAC is to optimize for latency.
 393  393   *
 394  394   * MAINTAINING CHAINS
 395  395   *
 396  396   * Another useful idea that MAC uses is to try and maintain frames in chains for
 397  397   * as long as possible. The idea is that all of MAC can handle chains of frames
 398  398   * structured as a series of mblk_t structures linked with the b_next pointer.
 399  399   * When performing software classification and software fanout, MAC does not
 400  400   * simply determine the destination and send the frame along. Instead, in the
 401  401   * case of classification, it tries to maintain a chain for as long as possible
 402  402   * before passing it along and performing additional processing.
 403  403   *
 404  404   * In the case of fanout, MAC first determines what the target software ring is
 405  405   * for every frame in the original chain and constructs a new chain for each
 406  406   * target. MAC then delivers the new chain to each software ring in succession.
 407  407   *
 408  408   * The whole rationale for doing this is that we want to try and maintain the
 409  409   * pipe as much as possible and deliver as many frames through the stack at once
 410  410   * that we can, rather than just pushing a single frame through. This can often
 411  411   * help bring down latency and allows MAC to get a better sense of the overall
 412  412   * activity in the system and properly engage worker threads.
 413  413   *
 414  414   * --------------------
 415  415   * Bandwidth Management
 416  416   * --------------------
 417  417   *
 418  418   * Bandwidth management is something that's built into the soft ring set itself.
 419  419   * When bandwidth limits are placed on a flow, a corresponding soft ring set is
 420  420   * toggled into bandwidth mode. This changes how we transmit and receive the
 421  421   * frames in question.
 422  422   *
 423  423   * Bandwidth management is done on a per-tick basis. We translate the user's
 424  424   * requested bandwidth from a quantity per-second into a quantity per-tick. MAC
 425  425   * cannot process a frame across more than one tick, thus it sets a lower bound
 426  426   * for the bandwidth cap to be a single MTU. This also means that when
 427  427   * hires ticks are enabled (hz is set to 1000), that the minimum amount of
 428  428   * bandwidth is higher, because the number of ticks has increased and MAC has to
 429  429   * go from accepting 100 packets / sec to 1000 / sec.
 430  430   *
 431  431   * The bandwidth counter is reset by either the soft ring set's worker thread or
 432  432   * a thread that is doing an inline transmit or receive if they discover that
 433  433   * the current tick is in the future from the recorded tick.
 434  434   *
 435  435   * Whenever we're receiving or transmitting data, we end up leaving most of the
 436  436   * work to the soft ring set's worker thread. This forces data inserted into the
 437  437   * soft ring set to be effectively serialized and allows us to exhume bandwidth
 438  438   * at a reasonable rate. If there is nothing in the soft ring set at the moment
 439  439   * and the set has available bandwidth, then it may processed inline.
 440  440   * Otherwise, the worker is responsible for taking care of the soft ring set.
 441  441   *
 442  442   * ---------------------
 443  443   * The Receive Data Path
 444  444   * ---------------------
 445  445   *
 446  446   * The following series of ASCII art images breaks apart the way that a frame
 447  447   * comes in and is processed in MAC.
 448  448   *
 449  449   * Part 1 -- Initial frame receipt, SRS classification
 450  450   *
 451  451   * Here, a frame is received by a GLDv3 driver, generally in the context of an
 452  452   * interrupt, and it ends up in mac_rx_common(). A driver calls either mac_rx or
 453  453   * mac_rx_ring, depending on whether or not it supports rings and can identify
 454  454   * the interrupt as having come from a specific ring. Here we determine whether
 455  455   * or not it's fully classified and perform software classification as
 456  456   * appropriate. From here, everything always ends up going to either entry [A]
 457  457   * or entry [B] based on whether or not they have subflow processing needed. We
 458  458   * leave via fanout or delivery.
 459  459   *
 460  460   *           +===========+
 461  461   *           v hardware  v
 462  462   *           v interrupt v
 463  463   *           +===========+
 464  464   *                 |
 465  465   *                 * . . appropriate
 466  466   *                 |     upcall made
 467  467   *                 |     by GLDv3 driver  . . always
 468  468   *                 |                      .
 469  469   *  +--------+     |     +----------+     .    +---------------+
 470  470   *  | GLDv3  |     +---->| mac_rx   |-----*--->| mac_rx_common |
 471  471   *  | Driver |-->--+     +----------+          +---------------+
 472  472   *  +--------+     |        ^                         |
 473  473   *      |          |        ^                         v
 474  474   *      ^          |        * . . always   +----------------------+
 475  475   *      |          |        |              | mac_promisc_dispatch |
 476  476   *      |          |    +-------------+    +----------------------+
 477  477   *      |          +--->| mac_rx_ring |               |
 478  478   *      |               +-------------+               * . . hw classified
 479  479   *      |                                             v     or single flow?
 480  480   *      |                                             |
 481  481   *      |                                   +--------++--------------+
 482  482   *      |                                   |        |               * hw class,
 483  483   *      |                                   |        * hw classified | subflows
 484  484   *      |                 no hw class and . *        | or single     | exist
 485  485   *      |                 subflows          |        | flow          |
 486  486   *      |                                   |        v               v
 487  487   *      |                                   |   +-----------+   +-----------+
 488  488   *      |                                   |   |   goto    |   |  goto     |
 489  489   *      |                                   |   | entry [A] |   | entry [B] |
 490  490   *      |                                   |   +-----------+   +-----------+
 491  491   *      |                                   v          ^
 492  492   *      |                            +-------------+   |
 493  493   *      |                            | mac_rx_flow |   * SRS and flow found,
 494  494   *      |                            +-------------+   | call flow cb
 495  495   *      |                                   |          +------+
 496  496   *      |                                   v                 |
 497  497   *      v                             +==========+    +-----------------+
 498  498   *      |                             v For each v--->| mac_rx_classify |
 499  499   * +----------+                       v  mblk_t  v    +-----------------+
 500  500   * |   srs    |                       +==========+
 501  501   * | pollling |
 502  502   * |  thread  |->------------------------------------------+
 503  503   * +----------+                                            |
 504  504   *                                                         v       . inline
 505  505   *            +--------------------+   +----------+   +---------+  .
 506  506   *    [A]---->| mac_rx_srs_process |-->| check bw |-->| enqueue |--*---------+
 507  507   *            +--------------------+   |  limits  |   | frames  |            |
 508  508   *               ^                     +----------+   | to SRS  |            |
 509  509   *               |                                    +---------+            |
 510  510   *               |  send chain              +--------+    |                  |
 511  511   *               *  when clasified          | signal |    * BW limits,       |
 512  512   *               |  flow changes            |  srs   |<---+ loopback,        |
 513  513   *               |                          | worker |      stack too        |
 514  514   *               |                          +--------+      deep             |
 515  515   *      +-----------------+        +--------+                                |
 516  516   *      | mac_flow_lookup |        |  srs   |     +---------------------+    |
 517  517   *      +-----------------+        | worker |---->| mac_rx_srs_drain    |<---+
 518  518   *               ^                 | thread |     | mac_rx_srs_drain_bw |
 519  519   *               |                 +--------+     +---------------------+
 520  520   *               |                                          |
 521  521   *         +----------------------------+                   * software rings
 522  522   *   [B]-->| mac_rx_srs_subflow_process |                   | for fanout?
 523  523   *         +----------------------------+                   |
 524  524   *                                               +----------+-----------+
 525  525   *                                               |                      |
 526  526   *                                               v                      v
 527  527   *                                          +--------+             +--------+
 528  528   *                                          |  goto  |             |  goto  |
 529  529   *                                          | Part 2 |             | Part 3 |
 530  530   *                                          +--------+             +--------+
 531  531   *
 532  532   * Part 2 -- Fanout
 533  533   *
 534  534   * This part is concerned with using software fanout to assign frames to
 535  535   * software rings and then deliver them to MAC clients or allow those rings to
 536  536   * be polled upon. While there are two different primary fanout entry points,
 537  537   * mac_rx_fanout and mac_rx_proto_fanout, they behave in similar ways, and aside
 538  538   * from some of the individual hashing techniques used, most of the general
 539  539   * flow is the same.
 540  540   *
 541  541   *  +--------+              +-------------------+
 542  542   *  |  From  |---+--------->| mac_rx_srs_fanout |----+
 543  543   *  | Part 1 |   |          +-------------------+    |    +=================+
 544  544   *  +--------+   |                                   |    v for each mblk_t v
 545  545   *               * . . protocol only                 +--->v assign to new   v
 546  546   *               |     fanout                        |    v chain based on  v
 547  547   *               |                                   |    v hash % nrings   v
 548  548   *               |    +-------------------------+    |    +=================+
 549  549   *               +--->| mac_rx_srs_proto_fanout |----+             |
 550  550   *                    +-------------------------+                  |
 551  551   *                                                                 v
 552  552   *    +------------+    +--------------------------+       +================+
 553  553   *    | enqueue in |<---| mac_rx_soft_ring_process |<------v for each chain v
 554  554   *    | soft ring  |    +--------------------------+       +================+
 555  555   *    +------------+
 556  556   *         |                                    +-----------+
 557  557   *         * soft ring set                      | soft ring |
 558  558   *         | empty and no                       |  worker   |
 559  559   *         | worker?                            |  thread   |
 560  560   *         |                                    +-----------+
 561  561   *         +------*----------------+                  |
 562  562   *         |      .                |                  v
 563  563   *    No . *      . Yes            |       +------------------------+
 564  564   *         |                       +----<--| mac_rx_soft_ring_drain |
 565  565   *         |                       |       +------------------------+
 566  566   *         v                       |
 567  567   *   +-----------+                 v
 568  568   *   |   signal  |         +---------------+
 569  569   *   | soft ring |         | Deliver chain |
 570  570   *   |   worker  |         | goto Part 3   |
 571  571   *   +-----------+         +---------------+
 572  572   *
 573  573   *
 574  574   * Part 3 -- Packet Delivery
 575  575   *
 576  576   * Here, we go through and deliver the mblk_t chain directly to a given
 577  577   * processing function. In a lot of cases this is mac_rx_deliver(). In the case
 578  578   * of DLS bypass being used, then instead we end up going ahead and deliver it
 579  579   * to the direct callback registered with DLS, generally ip_input.
 580  580   *
 581  581   *
 582  582   *   +---------+            +----------------+    +------------------+
 583  583   *   |  From   |---+------->| mac_rx_deliver |--->| Off to DLS, or   |
 584  584   *   | Parts 1 |   |        +----------------+    | other MAC client |
 585  585   *   |  and 2  |   * DLS bypass                   +------------------+
 586  586   *   +---------+   | enabled   +----------+    +-------------+
 587  587   *                 +---------->| ip_input |--->|    To IP    |
 588  588   *                             +----------+    | and beyond! |
 589  589   *                                             +-------------+
 590  590   *
 591  591   * ----------------------
 592  592   * The Transmit Data Path
 593  593   * ----------------------
 594  594   *
 595  595   * Before we go into the images, it's worth talking about a problem that is a
 596  596   * bit different from the receive data path. GLDv3 device drivers have a finite
 597  597   * amount of transmit descriptors. When they run out, they return unused frames
 598  598   * back to MAC. MAC, at this point has several options about what it will do,
 599  599   * which vary based upon the settings that the client uses.
 600  600   *
 601  601   * When a device runs out of descriptors, the next thing that MAC does is
 602  602   * enqueue them off of the soft ring set or a software ring, depending on the
 603  603   * configuration of the soft ring set. MAC will enqueue up to a high watermark
 604  604   * of mblk_t chains, at which point it will indicate flow control back to the
 605  605   * client. Once this condition is reached, any mblk_t chains that were not
 606  606   * enqueued will be returned to the caller and they will have to decide what to
 607  607   * do with them. There are various flags that control this behavior that a
 608  608   * client may pass, which are discussed below.
 609  609   *
 610  610   * When this condition is hit, MAC also returns a cookie to the client in
 611  611   * addition to unconsumed frames. Clients can poll on that cookie and register a
 612  612   * callback with MAC to be notified when they are no longer subject to flow
 613  613   * control, at which point they may continue to call mac_tx(). This flow control
 614  614   * actually manages to work itself all the way up the stack, back through dls,
 615  615   * to ip, through the various protocols, and to sockfs.
 616  616   *
 617  617   * While the behavior described above is the default, this behavior can be
 618  618   * modified. There are two alternate modes, described below, which are
 619  619   * controlled with flags.
 620  620   *
 621  621   * DROP MODE
 622  622   *
 623  623   * This mode is controlled by having the client pass the MAC_DROP_ON_NO_DESC
 624  624   * flag. When this is passed, if a device driver runs out of transmit
 625  625   * descriptors, then the MAC layer will drop any unsent traffic. The client in
 626  626   * this case will never have any frames returned to it.
 627  627   *
 628  628   * DON'T ENQUEUE
 629  629   *
 630  630   * This mode is controlled by having the client pass the MAC_TX_NO_ENQUEUE flag.
 631  631   * If the MAC_DROP_ON_NO_DESC flag is also passed, it takes precedence. In this
 632  632   * mode, when we hit a case where a driver runs out of transmit descriptors,
 633  633   * then instead of enqueuing packets in a soft ring set or software ring, we
 634  634   * instead return the mblk_t chain back to the caller and immediately put the
 635  635   * soft ring set into flow control mode.
 636  636   *
 637  637   * The following series of ASCII art images describe the transmit data path that
 638  638   * MAC clients enter into based on calling into mac_tx(). A soft ring set has a
 639  639   * transmission function associated with it. There are seven possible
 640  640   * transmission modes, some of which share function entry points. The one that a
 641  641   * soft ring set gets depends on properties such as whether there are
 642  642   * transmission rings for fanout, whether the device involves aggregations,
 643  643   * whether any bandwidth limits exist, etc.
 644  644   *
 645  645   *
 646  646   * Part 1 -- Initial checks
 647  647   *
 648  648   *      * . called by
 649  649   *      |   MAC clients
 650  650   *      v                     . . No
 651  651   *  +--------+  +-----------+ .   +-------------------+  +====================+
 652  652   *  | mac_tx |->| device    |-*-->| mac_protect_check |->v Is this the simple v
 653  653   *  +--------+  | quiesced? |     +-------------------+  v case? See [1]      v
 654  654   *              +-----------+            |               +====================+
 655  655   *                  * . Yes              * failed                 |
 656  656   *                  v                    | frames                 |
 657  657   *             +--------------+          |                +-------+---------+
 658  658   *             | freemsgchain |<---------+          Yes . *            No . *
 659  659   *             +--------------+                           v                 v
 660  660   *                                                  +-----------+     +--------+
 661  661   *                                                  |   goto    |     |  goto  |
 662  662   *                                                  |  Part 2   |     | SRS TX |
 663  663   *                                                  | Entry [A] |     |  func  |
 664  664   *                                                  +-----------+     +--------+
 665  665   *                                                        |                 |
 666  666   *                                                        |                 v
 667  667   *                                                        |           +--------+
 668  668   *                                                        +---------->| return |
 669  669   *                                                                    | cookie |
 670  670   *                                                                    +--------+
 671  671   *
 672  672   * [1] The simple case refers to the SRS being configured with the
 673  673   * SRS_TX_DEFAULT transmission mode, having a single mblk_t (not a chain), their
 674  674   * being only a single active client, and not having a backlog in the srs.
 675  675   *
 676  676   *
 677  677   * Part 2 -- The SRS transmission functions
 678  678   *
 679  679   * This part is a bit more complicated. The different transmission paths often
 680  680   * leverage one another. In this case, we'll draw out the more common ones
 681  681   * before the parts that depend upon them. Here, we're going to start with the
 682  682   * workings of mac_tx_send() a common function that most of the others end up
 683  683   * calling.
 684  684   *
 685  685   *      +-------------+
 686  686   *      | mac_tx_send |
 687  687   *      +-------------+
 688  688   *            |
 689  689   *            v
 690  690   *      +=============+    +==============+
 691  691   *      v  more than  v--->v    check     v
 692  692   *      v one client? v    v VLAN and add v
 693  693   *      +=============+    v  VLAN tags   v
 694  694   *            |            +==============+
 695  695   *            |                  |
 696  696   *            +------------------+
 697  697   *            |
 698  698   *            |                 [A]
 699  699   *            v                  |
 700  700   *       +============+ . No     v
 701  701   *       v more than  v .     +==========+     +--------------------------+
 702  702   *       v one active v-*---->v for each v---->| mac_promisc_dispatch_one |---+
 703  703   *       v  client?   v       v mblk_t   v     +--------------------------+   |
 704  704   *       +============+       +==========+        ^                           |
 705  705   *            |                                   |       +==========+        |
 706  706   *            * . Yes                             |       v hardware v<-------+
 707  707   *            v                      +------------+       v  rings?  v
 708  708   *       +==========+                |                    +==========+
 709  709   *       v for each v       No . . . *                         |
 710  710   *       v mblk_t   v       specific |                         |
 711  711   *       +==========+       flow     |                   +-----+-----+
 712  712   *            |                      |                   |           |
 713  713   *            v                      |                   v           v
 714  714   *    +-----------------+            |               +-------+  +---------+
 715  715   *    | mac_tx_classify |------------+               | GLDv3 |  |  GLDv3  |
 716  716   *    +-----------------+                            |TX func|  | ring tx |
 717  717   *            |                                      +-------+  |  func   |
 718  718   *            * Specific flow, generally                 |      +---------+
 719  719   *            | bcast, mcast, loopback                   |           |
 720  720   *            v                                          +-----+-----+
 721  721   *      +==========+       +---------+                         |
 722  722   *      v valid L2 v--*--->| freemsg |                         v
 723  723   *      v  header  v  . No +---------+               +-------------------+
 724  724   *      +==========+                                 | return unconsumed |
 725  725   *            * . Yes                                |   frames to the   |
 726  726   *            v                                      |      caller       |
 727  727   *      +===========+                                +-------------------+
 728  728   *      v braodcast v      +----------------+                  ^
 729  729   *      v   flow?   v--*-->| mac_bcast_send |------------------+
 730  730   *      +===========+  .   +----------------+                  |
 731  731   *            |        . . Yes                                 |
 732  732   *       No . *                                                v
 733  733   *            |  +---------------------+  +---------------+  +----------+
 734  734   *            +->|mac_promisc_dispatch |->| mac_fix_cksum |->|   flow   |
 735  735   *               +---------------------+  +---------------+  | callback |
 736  736   *                                                           +----------+
 737  737   *
 738  738   *
 739  739   * In addition, many but not all of the routines, all rely on
 740  740   * mac_tx_softring_process as an entry point.
 741  741   *
 742  742   *
 743  743   *                                           . No             . No
 744  744   * +--------------------------+   +========+ .  +===========+ .  +-------------+
 745  745   * | mac_tx_soft_ring_process |-->v worker v-*->v out of tx v-*->|    goto     |
 746  746   * +--------------------------+   v only?  v    v  descr.?  v    | mac_tx_send |
 747  747   *                                +========+    +===========+    +-------------+
 748  748   *                              Yes . *               * . Yes           |
 749  749   *                   . No             v               |                 v
 750  750   *     v=========+   .          +===========+ . Yes   |     Yes .  +==========+
 751  751   *     v apppend v<--*----------v out of tx v-*-------+---------*--v returned v
 752  752   *     v mblk_t  v              v  descr.?  v         |            v frames?  v
 753  753   *     v chain   v              +===========+         |            +==========+
 754  754   *     +=========+                                    |                 *. No
 755  755   *         |                                          |                 v
 756  756   *         v                                          v           +------------+
 757  757   * +===================+           +----------------------+       |   done     |
 758  758   * v worker scheduled? v           | mac_tx_sring_enqueue |       | processing |
 759  759   * v Out of tx descr?  v           +----------------------+       +------------+
 760  760   * +===================+                      |
 761  761   *    |           |           . Yes           v
 762  762   *    * Yes       * No        .         +============+
 763  763   *    |           v         +-*---------v drop on no v
 764  764   *    |      +========+     v           v  TX desc?  v
 765  765   *    |      v  wake  v  +----------+   +============+
 766  766   *    |      v worker v  | mac_pkt_ |         * . No
 767  767   *    |      +========+  | drop     |         |         . Yes         . No
 768  768   *    |           |      +----------+         v         .             .
 769  769   *    |           |         v   ^     +===============+ .  +========+ .
 770  770   *    +--+--------+---------+   |     v Don't enqueue v-*->v ring   v-*----+
 771  771   *       |                      |     v     Set?      v    v empty? v      |
 772  772   *       |      +---------------+     +===============+    +========+      |
 773  773   *       |      |                            |                |            |
 774  774   *       |      |        +-------------------+                |            |
 775  775   *       |      *. Yes   |                          +---------+            |
 776  776   *       |      |        v                          v                      v
 777  777   *       |      |  +===========+               +========+      +--------------+
 778  778   *       |      +<-v At hiwat? v               v append v      |    return    |
 779  779   *       |         +===========+               v mblk_t v      | mblk_t chain |
 780  780   *       |                  * No               v chain  v      |   and flow   |
 781  781   *       |                  v                  +========+      |    control   |
 782  782   *       |               +=========+                |          |    cookie    |
 783  783   *       |               v  append v                v          +--------------+
 784  784   *       |               v  mblk_t v           +========+
 785  785   *       |               v  chain  v           v  wake  v   +------------+
 786  786   *       |               +=========+           v worker v-->|    done    |
 787  787   *       |                    |                +========+   | processing |
 788  788   *       |                    v       .. Yes                +------------+
 789  789   *       |               +=========+  .   +========+
 790  790   *       |               v  first  v--*-->v  wake  v
 791  791   *       |               v append? v      v worker v
 792  792   *       |               +=========+      +========+
 793  793   *       |                   |                |
 794  794   *       |              No . *                |
 795  795   *       |                   v                |
 796  796   *       |       +--------------+             |
 797  797   *       +------>|   Return     |             |
 798  798   *               | flow control |<------------+
 799  799   *               |   cookie     |
 800  800   *               +--------------+
 801  801   *
 802  802   *
 803  803   * The remaining images are all specific to each of the different transmission
 804  804   * modes.
 805  805   *
 806  806   * SRS TX DEFAULT
 807  807   *
 808  808   *      [ From Part 1 ]
 809  809   *             |
 810  810   *             v
 811  811   * +-------------------------+
 812  812   * | mac_tx_single_ring_mode |
 813  813   * +-------------------------+
 814  814   *            |
 815  815   *            |       . Yes
 816  816   *            v       .
 817  817   *       +==========+ .  +============+
 818  818   *       v   SRS    v-*->v   Try to   v---->---------------------+
 819  819   *       v backlog? v    v enqueue in v                          |
 820  820   *       +==========+    v     SRS    v-->------+                * . . Queue too
 821  821   *            |          +============+         * don't enqueue  |     deep or
 822  822   *            * . No         ^     |            | flag or at     |     drop flag
 823  823   *            |              |     v            | hiwat,         |
 824  824   *            v              |     |            | return    +---------+
 825  825   *     +-------------+       |     |            | cookie    | freemsg |
 826  826   *     |    goto     |-*-----+     |            |           +---------+
 827  827   *     | mac_tx_send | . returned  |            |                |
 828  828   *     +-------------+   mblk_t    |            |                |
 829  829   *            |                    |            |                |
 830  830   *            |                    |            |                |
 831  831   *            * . . all mblk_t     * queued,    |                |
 832  832   *            v     consumed       | may return |                |
 833  833   *     +-------------+             | tx cookie  |                |
 834  834   *     | SRS TX func |<------------+------------+----------------+
 835  835   *     |  completed  |
 836  836   *     +-------------+
 837  837   *
 838  838   * SRS_TX_SERIALIZE
 839  839   *
 840  840   *   +------------------------+
 841  841   *   | mac_tx_serializer_mode |
 842  842   *   +------------------------+
 843  843   *               |
 844  844   *               |        . No
 845  845   *               v        .
 846  846   *         +============+ .  +============+    +-------------+   +============+
 847  847   *         v srs being  v-*->v  set SRS   v--->|    goto     |-->v remove SRS v
 848  848   *         v processed? v    v proc flags v    | mac_tx_send |   v proc flag  v
 849  849   *         +============+    +============+    +-------------+   +============+
 850  850   *               |                                                     |
 851  851   *               * Yes                                                 |
 852  852   *               v                                       . No          v
 853  853   *      +--------------------+                           .        +==========+
 854  854   *      | mac_tx_srs_enqueue |  +------------------------*-----<--v returned v
 855  855   *      +--------------------+  |                                 v frames?  v
 856  856   *               |              |   . Yes                         +==========+
 857  857   *               |              |   .                                  |
 858  858   *               |              |   . +=========+                      v
 859  859   *               v              +-<-*-v queued  v     +--------------------+
 860  860   *        +-------------+       |     v frames? v<----| mac_tx_srs_enqueue |
 861  861   *        | SRS TX func |       |     +=========+     +--------------------+
 862  862   *        | completed,  |<------+         * . Yes
 863  863   *        | may return  |       |         v
 864  864   *        |   cookie    |       |     +========+
 865  865   *        +-------------+       +-<---v  wake  v
 866  866   *                                    v worker v
 867  867   *                                    +========+
 868  868   *
 869  869   *
 870  870   * SRS_TX_FANOUT
 871  871   *
 872  872   *                                             . Yes
 873  873   *   +--------------------+    +=============+ .   +--------------------------+
 874  874   *   | mac_tx_fanout_mode |--->v Have fanout v-*-->|           goto           |
 875  875   *   +--------------------+    v   hint?     v     | mac_rx_soft_ring_process |
 876  876   *                             +=============+     +--------------------------+
 877  877   *                                   * . No                    |
 878  878   *                                   v                         ^
 879  879   *                             +===========+                   |
 880  880   *                        +--->v for each  v           +===============+
 881  881   *                        |    v   mblk_t  v           v pick softring v
 882  882   *                 same   *    +===========+           v   from hash   v
 883  883   *                 hash   |          |                 +===============+
 884  884   *                        |          v                         |
 885  885   *                        |   +--------------+                 |
 886  886   *                        +---| mac_pkt_hash |--->*------------+
 887  887   *                            +--------------+    . different
 888  888   *                                                  hash or
 889  889   *                                                  done proc.
 890  890   * SRS_TX_AGGR                                      chain
 891  891   *
 892  892   *   +------------------+    +================================+
 893  893   *   | mac_tx_aggr_mode |--->v Use aggr capab function to     v
 894  894   *   +------------------+    v find appropriate tx ring.      v
 895  895   *                           v Applies hash based on aggr     v
 896  896   *                           v policy, see mac_tx_aggr_mode() v
 897  897   *                           +================================+
 898  898   *                                          |
 899  899   *                                          v
 900  900   *                           +-------------------------------+
 901  901   *                           |            goto               |
 902  902   *                           |  mac_rx_srs_soft_ring_process |
 903  903   *                           +-------------------------------+
 904  904   *
 905  905   *
 906  906   * SRS_TX_BW, SRS_TX_BW_FANOUT, SRS_TX_BW_AGGR
 907  907   *
 908  908   * Note, all three of these tx functions start from the same place --
 909  909   * mac_tx_bw_mode().
 910  910   *
 911  911   *  +----------------+
 912  912   *  | mac_tx_bw_mode |
 913  913   *  +----------------+
 914  914   *         |
 915  915   *         v          . No               . No               . Yes
 916  916   *  +==============+  .  +============+  .  +=============+ .  +=========+
 917  917   *  v  Out of BW?  v--*->v SRS empty? v--*->v  reset BW   v-*->v Bump BW v
 918  918   *  +==============+     +============+     v tick count? v    v Usage   v
 919  919   *         |                   |            +=============+    +=========+
 920  920   *         |         +---------+                   |                |
 921  921   *         |         |        +--------------------+                |
 922  922   *         |         |        |              +----------------------+
 923  923   *         v         |        v              v
 924  924   * +===============+ |  +==========+   +==========+      +------------------+
 925  925   * v Don't enqueue v |  v  set bw  v   v Is aggr? v--*-->|       goto       |
 926  926   * v   flag set?   v |  v enforced v   +==========+  .   | mac_tx_aggr_mode |-+
 927  927   * +===============+ |  +==========+         |       .   +------------------+ |
 928  928   *   |    Yes .*     |        |         No . *       .                        |
 929  929   *   |         |     |        |              |       . Yes                    |
 930  930   *   * . No    |     |        v              |                                |
 931  931   *   |  +---------+  |   +========+          v              +======+          |
 932  932   *   |  | freemsg |  |   v append v   +============+  . Yes v pick v          |
 933  933   *   |  +---------+  |   v mblk_t v   v Is fanout? v--*---->v ring v          |
 934  934   *   |      |        |   v chain  v   +============+        +======+          |
 935  935   *   +------+        |   +========+          |                  |             |
 936  936   *          v        |        |              v                  v             |
 937  937   *    +---------+    |        v       +-------------+ +--------------------+  |
 938  938   *    | return  |    |   +========+   |    goto     | |       goto         |  |
 939  939   *    |  flow   |    |   v wakeup v   | mac_tx_send | | mac_tx_fanout_mode |  |
 940  940   *    | control |    |   v worker v   +-------------+ +--------------------+  |
 941  941   *    | cookie  |    |   +========+          |                  |             |
 942  942   *    +---------+    |        |              |                  +------+------+
 943  943   *                   |        v              |                         |
 944  944   *                   |   +---------+         |                         v
 945  945   *                   |   | return  |   +============+           +------------+
 946  946   *                   |   |  flow   |   v unconsumed v-------+   |   done     |
 947  947   *                   |   | control |   v   frames?  v       |   | processing |
 948  948   *                   |   | cookie  |   +============+       |   +------------+
 949  949   *                   |   +---------+         |              |
 950  950   *                   |                  Yes  *              |
 951  951   *                   |                       |              |
 952  952   *                   |                 +===========+        |
 953  953   *                   |                 v subtract  v        |
 954  954   *                   |                 v unused bw v        |
 955  955   *                   |                 +===========+        |
 956  956   *                   |                       |              |
 957  957   *                   |                       v              |
 958  958   *                   |              +--------------------+  |
 959  959   *                   +------------->| mac_tx_srs_enqueue |  |
 960  960   *                                  +--------------------+  |
 961  961   *                                           |              |
 962  962   *                                           |              |
 963  963   *                                     +------------+       |
 964  964   *                                     |  return fc |       |
 965  965   *                                     | cookie and |<------+
 966  966   *                                     |    mblk_t  |
 967  967   *                                     +------------+
 968  968   */
 969  969  
 970  970  #include <sys/types.h>
 971  971  #include <sys/callb.h>
 972  972  #include <sys/sdt.h>
 973  973  #include <sys/strsubr.h>
 974  974  #include <sys/strsun.h>
 975  975  #include <sys/vlan.h>
 976  976  #include <sys/stack.h>
 977  977  #include <sys/archsystm.h>
 978  978  #include <inet/ipsec_impl.h>
 979  979  #include <inet/ip_impl.h>
 980  980  #include <inet/sadb.h>
 981  981  #include <inet/ipsecesp.h>
 982  982  #include <inet/ipsecah.h>
 983  983  #include <inet/ip6.h>
 984  984  
 985  985  #include <sys/mac_impl.h>
 986  986  #include <sys/mac_client_impl.h>
 987  987  #include <sys/mac_client_priv.h>
 988  988  #include <sys/mac_soft_ring.h>
 989  989  #include <sys/mac_flow_impl.h>
 990  990  
 991  991  static mac_tx_cookie_t mac_tx_single_ring_mode(mac_soft_ring_set_t *, mblk_t *,
 992  992      uintptr_t, uint16_t, mblk_t **);
 993  993  static mac_tx_cookie_t mac_tx_serializer_mode(mac_soft_ring_set_t *, mblk_t *,
 994  994      uintptr_t, uint16_t, mblk_t **);
 995  995  static mac_tx_cookie_t mac_tx_fanout_mode(mac_soft_ring_set_t *, mblk_t *,
 996  996      uintptr_t, uint16_t, mblk_t **);
 997  997  static mac_tx_cookie_t mac_tx_bw_mode(mac_soft_ring_set_t *, mblk_t *,
 998  998      uintptr_t, uint16_t, mblk_t **);
 999  999  static mac_tx_cookie_t mac_tx_aggr_mode(mac_soft_ring_set_t *, mblk_t *,
1000 1000      uintptr_t, uint16_t, mblk_t **);
1001 1001  
1002 1002  typedef struct mac_tx_mode_s {
1003 1003          mac_tx_srs_mode_t       mac_tx_mode;
1004 1004          mac_tx_func_t           mac_tx_func;
1005 1005  } mac_tx_mode_t;
1006 1006  
1007 1007  /*
1008 1008   * There are seven modes of operation on the Tx side. These modes get set
1009 1009   * in mac_tx_srs_setup(). Except for the experimental TX_SERIALIZE mode,
1010 1010   * none of the other modes are user configurable. They get selected by
1011 1011   * the system depending upon whether the link (or flow) has multiple Tx
1012 1012   * rings or a bandwidth configured, or if the link is an aggr, etc.
1013 1013   *
1014 1014   * When the Tx SRS is operating in aggr mode (st_mode) or if there are
1015 1015   * multiple Tx rings owned by Tx SRS, then each Tx ring (pseudo or
1016 1016   * otherwise) will have a soft ring associated with it. These soft rings
1017 1017   * are stored in srs_tx_soft_rings[] array.
1018 1018   *
1019 1019   * Additionally in the case of aggr, there is the st_soft_rings[] array
1020 1020   * in the mac_srs_tx_t structure. This array is used to store the same
1021 1021   * set of soft rings that are present in srs_tx_soft_rings[] array but
1022 1022   * in a different manner. The soft ring associated with the pseudo Tx
1023 1023   * ring is saved at mr_index (of the pseudo ring) in st_soft_rings[]
1024 1024   * array. This helps in quickly getting the soft ring associated with the
1025 1025   * Tx ring when aggr_find_tx_ring() returns the pseudo Tx ring that is to
1026 1026   * be used for transmit.
1027 1027   */
1028 1028  mac_tx_mode_t mac_tx_mode_list[] = {
1029 1029          {SRS_TX_DEFAULT,        mac_tx_single_ring_mode},
1030 1030          {SRS_TX_SERIALIZE,      mac_tx_serializer_mode},
1031 1031          {SRS_TX_FANOUT,         mac_tx_fanout_mode},
1032 1032          {SRS_TX_BW,             mac_tx_bw_mode},
1033 1033          {SRS_TX_BW_FANOUT,      mac_tx_bw_mode},
1034 1034          {SRS_TX_AGGR,           mac_tx_aggr_mode},
1035 1035          {SRS_TX_BW_AGGR,        mac_tx_bw_mode}
1036 1036  };
1037 1037  
1038 1038  /*
1039 1039   * Soft Ring Set (SRS) - The Run time code that deals with
1040 1040   * dynamic polling from the hardware, bandwidth enforcement,
1041 1041   * fanout etc.
1042 1042   *
1043 1043   * We try to use H/W classification on NIC and assign traffic for
1044 1044   * a MAC address to a particular Rx ring or ring group. There is a
1045 1045   * 1-1 mapping between a SRS and a Rx ring. The SRS dynamically
1046 1046   * switches the underlying Rx ring between interrupt and
1047 1047   * polling mode and enforces any specified B/W control.
1048 1048   *
1049 1049   * There is always a SRS created and tied to each H/W and S/W rule.
1050 1050   * Whenever we create a H/W rule, we always add the the same rule to
1051 1051   * S/W classifier and tie a SRS to it.
1052 1052   *
1053 1053   * In case a B/W control is specified, it is broken into bytes
1054 1054   * per ticks and as soon as the quota for a tick is exhausted,
1055 1055   * the underlying Rx ring is forced into poll mode for remainder of
1056 1056   * the tick. The SRS poll thread only polls for bytes that are
1057 1057   * allowed to come in the SRS. We typically let 4x the configured
1058 1058   * B/W worth of packets to come in the SRS (to prevent unnecessary
1059 1059   * drops due to bursts) but only process the specified amount.
1060 1060   *
1061 1061   * A MAC client (e.g. a VNIC or aggr) can have 1 or more
1062 1062   * Rx rings (and corresponding SRSs) assigned to it. The SRS
1063 1063   * in turn can have softrings to do protocol level fanout or
1064 1064   * softrings to do S/W based fanout or both. In case the NIC
1065 1065   * has no Rx rings, we do S/W classification to respective SRS.
1066 1066   * The S/W classification rule is always setup and ready. This
1067 1067   * allows the MAC layer to reassign Rx rings whenever needed
1068 1068   * but packets still continue to flow via the default path and
1069 1069   * getting S/W classified to correct SRS.
1070 1070   *
1071 1071   * The SRS's are used on both Tx and Rx side. They use the same
1072 1072   * data structure but the processing routines have slightly different
1073 1073   * semantics due to the fact that Rx side needs to do dynamic
1074 1074   * polling etc.
1075 1075   *
1076 1076   * Dynamic Polling Notes
1077 1077   * =====================
1078 1078   *
1079 1079   * Each Soft ring set is capable of switching its Rx ring between
1080 1080   * interrupt and poll mode and actively 'polls' for packets in
1081 1081   * poll mode. If the SRS is implementing a B/W limit, it makes
1082 1082   * sure that only Max allowed packets are pulled in poll mode
1083 1083   * and goes to poll mode as soon as B/W limit is exceeded. As
1084 1084   * such, there are no overheads to implement B/W limits.
1085 1085   *
1086 1086   * In poll mode, its better to keep the pipeline going where the
1087 1087   * SRS worker thread keeps processing packets and poll thread
1088 1088   * keeps bringing more packets (specially if they get to run
1089 1089   * on different CPUs). This also prevents the overheads associated
1090 1090   * by excessive signalling (on NUMA machines, this can be
1091 1091   * pretty devastating). The exception is latency optimized case
1092 1092   * where worker thread does no work and interrupt and poll thread
1093 1093   * are allowed to do their own drain.
1094 1094   *
1095 1095   * We use the following policy to control Dynamic Polling:
1096 1096   * 1) We switch to poll mode anytime the processing
1097 1097   *    thread causes a backlog to build up in SRS and
1098 1098   *    its associated Soft Rings (sr_poll_pkt_cnt > 0).
1099 1099   * 2) As long as the backlog stays under the low water
1100 1100   *    mark (sr_lowat), we poll the H/W for more packets.
1101 1101   * 3) If the backlog (sr_poll_pkt_cnt) exceeds low
1102 1102   *    water mark, we stay in poll mode but don't poll
1103 1103   *    the H/W for more packets.
1104 1104   * 4) Anytime in polling mode, if we poll the H/W for
1105 1105   *    packets and find nothing plus we have an existing
1106 1106   *    backlog (sr_poll_pkt_cnt > 0), we stay in polling
1107 1107   *    mode but don't poll the H/W for packets anymore
1108 1108   *    (let the polling thread go to sleep).
1109 1109   * 5) Once the backlog is relived (packets are processed)
1110 1110   *    we reenable polling (by signalling the poll thread)
1111 1111   *    only when the backlog dips below sr_poll_thres.
1112 1112   * 6) sr_hiwat is used exclusively when we are not
1113 1113   *    polling capable and is used to decide when to
1114 1114   *    drop packets so the SRS queue length doesn't grow
1115 1115   *    infinitely.
1116 1116   *
1117 1117   * NOTE: Also see the block level comment on top of mac_soft_ring.c
1118 1118   */
1119 1119  
1120 1120  /*
1121 1121   * mac_latency_optimize
1122 1122   *
1123 1123   * Controls whether the poll thread can process the packets inline
1124 1124   * or let the SRS worker thread do the processing. This applies if
1125 1125   * the SRS was not being processed. For latency sensitive traffic,
1126 1126   * this needs to be true to allow inline processing. For throughput
1127 1127   * under load, this should be false.
1128 1128   *
1129 1129   * This (and other similar) tunable should be rolled into a link
1130 1130   * or flow specific workload hint that can be set using dladm
1131 1131   * linkprop (instead of multiple such tunables).
1132 1132   */
1133 1133  boolean_t mac_latency_optimize = B_TRUE;
1134 1134  
1135 1135  /*
1136 1136   * MAC_RX_SRS_ENQUEUE_CHAIN and MAC_TX_SRS_ENQUEUE_CHAIN
1137 1137   *
1138 1138   * queue a mp or chain in soft ring set and increment the
1139 1139   * local count (srs_count) for the SRS and the shared counter
1140 1140   * (srs_poll_pkt_cnt - shared between SRS and its soft rings
1141 1141   * to track the total unprocessed packets for polling to work
1142 1142   * correctly).
1143 1143   *
1144 1144   * The size (total bytes queued) counters are incremented only
1145 1145   * if we are doing B/W control.
1146 1146   */
1147 1147  #define MAC_SRS_ENQUEUE_CHAIN(mac_srs, head, tail, count, sz) {         \
1148 1148          ASSERT(MUTEX_HELD(&(mac_srs)->srs_lock));                       \
1149 1149          if ((mac_srs)->srs_last != NULL)                                \
1150 1150                  (mac_srs)->srs_last->b_next = (head);                   \
1151 1151          else                                                            \
1152 1152                  (mac_srs)->srs_first = (head);                          \
1153 1153          (mac_srs)->srs_last = (tail);                                   \
1154 1154          (mac_srs)->srs_count += count;                                  \
1155 1155  }
1156 1156  
1157 1157  #define MAC_RX_SRS_ENQUEUE_CHAIN(mac_srs, head, tail, count, sz) {      \
1158 1158          mac_srs_rx_t    *srs_rx = &(mac_srs)->srs_rx;                   \
1159 1159                                                                          \
1160 1160          MAC_SRS_ENQUEUE_CHAIN(mac_srs, head, tail, count, sz);          \
1161 1161          srs_rx->sr_poll_pkt_cnt += count;                               \
1162 1162          ASSERT(srs_rx->sr_poll_pkt_cnt > 0);                            \
1163 1163          if ((mac_srs)->srs_type & SRST_BW_CONTROL) {                    \
1164 1164                  (mac_srs)->srs_size += (sz);                            \
1165 1165                  mutex_enter(&(mac_srs)->srs_bw->mac_bw_lock);           \
1166 1166                  (mac_srs)->srs_bw->mac_bw_sz += (sz);                   \
1167 1167                  mutex_exit(&(mac_srs)->srs_bw->mac_bw_lock);            \
1168 1168          }                                                               \
1169 1169  }
1170 1170  
1171 1171  #define MAC_TX_SRS_ENQUEUE_CHAIN(mac_srs, head, tail, count, sz) {      \
1172 1172          mac_srs->srs_state |= SRS_ENQUEUED;                             \
1173 1173          MAC_SRS_ENQUEUE_CHAIN(mac_srs, head, tail, count, sz);          \
1174 1174          if ((mac_srs)->srs_type & SRST_BW_CONTROL) {                    \
1175 1175                  (mac_srs)->srs_size += (sz);                            \
1176 1176                  (mac_srs)->srs_bw->mac_bw_sz += (sz);                   \
1177 1177          }                                                               \
1178 1178  }
1179 1179  
1180 1180  /*
1181 1181   * Turn polling on routines
1182 1182   */
1183 1183  #define MAC_SRS_POLLING_ON(mac_srs) {                                   \
1184 1184          ASSERT(MUTEX_HELD(&(mac_srs)->srs_lock));                       \
1185 1185          if (((mac_srs)->srs_state &                                     \
1186 1186              (SRS_POLLING_CAPAB|SRS_POLLING)) == SRS_POLLING_CAPAB) {    \
1187 1187                  (mac_srs)->srs_state |= SRS_POLLING;                    \
1188 1188                  (void) mac_hwring_disable_intr((mac_ring_handle_t)      \
1189 1189                      (mac_srs)->srs_ring);                               \
1190 1190                  (mac_srs)->srs_rx.sr_poll_on++;                         \
1191 1191          }                                                               \
1192 1192  }
1193 1193  
1194 1194  #define MAC_SRS_WORKER_POLLING_ON(mac_srs) {                            \
1195 1195          ASSERT(MUTEX_HELD(&(mac_srs)->srs_lock));                       \
1196 1196          if (((mac_srs)->srs_state &                                     \
1197 1197              (SRS_POLLING_CAPAB|SRS_WORKER|SRS_POLLING)) ==              \
1198 1198              (SRS_POLLING_CAPAB|SRS_WORKER)) {                           \
1199 1199                  (mac_srs)->srs_state |= SRS_POLLING;                    \
1200 1200                  (void) mac_hwring_disable_intr((mac_ring_handle_t)      \
1201 1201                      (mac_srs)->srs_ring);                               \
1202 1202                  (mac_srs)->srs_rx.sr_worker_poll_on++;                  \
1203 1203          }                                                               \
1204 1204  }
1205 1205  
1206 1206  /*
1207 1207   * MAC_SRS_POLL_RING
1208 1208   *
1209 1209   * Signal the SRS poll thread to poll the underlying H/W ring
1210 1210   * provided it wasn't already polling (SRS_GET_PKTS was set).
1211 1211   *
1212 1212   * Poll thread gets to run only from mac_rx_srs_drain() and only
1213 1213   * if the drain was being done by the worker thread.
1214 1214   */
1215 1215  #define MAC_SRS_POLL_RING(mac_srs) {                                    \
1216 1216          mac_srs_rx_t    *srs_rx = &(mac_srs)->srs_rx;                   \
1217 1217                                                                          \
1218 1218          ASSERT(MUTEX_HELD(&(mac_srs)->srs_lock));                       \
1219 1219          srs_rx->sr_poll_thr_sig++;                                      \
1220 1220          if (((mac_srs)->srs_state &                                     \
1221 1221              (SRS_POLLING_CAPAB|SRS_WORKER|SRS_GET_PKTS)) ==             \
1222 1222                  (SRS_WORKER|SRS_POLLING_CAPAB)) {                       \
1223 1223                  (mac_srs)->srs_state |= SRS_GET_PKTS;                   \
1224 1224                  cv_signal(&(mac_srs)->srs_cv);                          \
1225 1225          } else {                                                        \
1226 1226                  srs_rx->sr_poll_thr_busy++;                             \
1227 1227          }                                                               \
1228 1228  }
1229 1229  
1230 1230  /*
1231 1231   * MAC_SRS_CHECK_BW_CONTROL
1232 1232   *
1233 1233   * Check to see if next tick has started so we can reset the
1234 1234   * SRS_BW_ENFORCED flag and allow more packets to come in the
1235 1235   * system.
1236 1236   */
1237 1237  #define MAC_SRS_CHECK_BW_CONTROL(mac_srs) {                             \
1238 1238          ASSERT(MUTEX_HELD(&(mac_srs)->srs_lock));                       \
1239 1239          ASSERT(((mac_srs)->srs_type & SRST_TX) ||                       \
1240 1240              MUTEX_HELD(&(mac_srs)->srs_bw->mac_bw_lock));               \
1241 1241          clock_t now = ddi_get_lbolt();                                  \
1242 1242          if ((mac_srs)->srs_bw->mac_bw_curr_time != now) {               \
1243 1243                  (mac_srs)->srs_bw->mac_bw_curr_time = now;              \
1244 1244                  (mac_srs)->srs_bw->mac_bw_used = 0;                     \
1245 1245                  if ((mac_srs)->srs_bw->mac_bw_state & SRS_BW_ENFORCED)  \
1246 1246                          (mac_srs)->srs_bw->mac_bw_state &= ~SRS_BW_ENFORCED; \
1247 1247          }                                                               \
1248 1248  }
1249 1249  
1250 1250  /*
1251 1251   * MAC_SRS_WORKER_WAKEUP
1252 1252   *
1253 1253   * Wake up the SRS worker thread to process the queue as long as
1254 1254   * no one else is processing the queue. If we are optimizing for
1255 1255   * latency, we wake up the worker thread immediately or else we
1256 1256   * wait mac_srs_worker_wakeup_ticks before worker thread gets
1257 1257   * woken up.
1258 1258   */
1259 1259  int mac_srs_worker_wakeup_ticks = 0;
1260 1260  #define MAC_SRS_WORKER_WAKEUP(mac_srs) {                                \
1261 1261          ASSERT(MUTEX_HELD(&(mac_srs)->srs_lock));                       \
1262 1262          if (!((mac_srs)->srs_state & SRS_PROC) &&                       \
1263 1263                  (mac_srs)->srs_tid == NULL) {                           \
1264 1264                  if (((mac_srs)->srs_state & SRS_LATENCY_OPT) ||         \
1265 1265                          (mac_srs_worker_wakeup_ticks == 0))             \
1266 1266                          cv_signal(&(mac_srs)->srs_async);               \
1267 1267                  else                                                    \
1268 1268                          (mac_srs)->srs_tid =                            \
1269 1269                                  timeout(mac_srs_fire, (mac_srs),        \
1270 1270                                          mac_srs_worker_wakeup_ticks);   \
1271 1271          }                                                               \
1272 1272  }
1273 1273  
1274 1274  #define TX_BANDWIDTH_MODE(mac_srs)                              \
1275 1275          ((mac_srs)->srs_tx.st_mode == SRS_TX_BW ||              \
1276 1276              (mac_srs)->srs_tx.st_mode == SRS_TX_BW_FANOUT ||    \
1277 1277              (mac_srs)->srs_tx.st_mode == SRS_TX_BW_AGGR)
1278 1278  
1279 1279  #define TX_SRS_TO_SOFT_RING(mac_srs, head, hint) {                      \
1280 1280          if (tx_mode == SRS_TX_BW_FANOUT)                                \
1281 1281                  (void) mac_tx_fanout_mode(mac_srs, head, hint, 0, NULL);\
1282 1282          else                                                            \
1283 1283                  (void) mac_tx_aggr_mode(mac_srs, head, hint, 0, NULL);  \
1284 1284  }
1285 1285  
1286 1286  /*
1287 1287   * MAC_TX_SRS_BLOCK
1288 1288   *
1289 1289   * Always called from mac_tx_srs_drain() function. SRS_TX_BLOCKED
1290 1290   * will be set only if srs_tx_woken_up is FALSE. If
1291 1291   * srs_tx_woken_up is TRUE, it indicates that the wakeup arrived
1292 1292   * before we grabbed srs_lock to set SRS_TX_BLOCKED. We need to
1293 1293   * attempt to transmit again and not setting SRS_TX_BLOCKED does
1294 1294   * that.
1295 1295   */
1296 1296  #define MAC_TX_SRS_BLOCK(srs, mp)       {                       \
1297 1297          ASSERT(MUTEX_HELD(&(srs)->srs_lock));                   \
1298 1298          if ((srs)->srs_tx.st_woken_up) {                        \
1299 1299                  (srs)->srs_tx.st_woken_up = B_FALSE;            \
1300 1300          } else {                                                \
1301 1301                  ASSERT(!((srs)->srs_state & SRS_TX_BLOCKED));   \
1302 1302                  (srs)->srs_state |= SRS_TX_BLOCKED;             \
1303 1303                  (srs)->srs_tx.st_stat.mts_blockcnt++;           \
1304 1304          }                                                       \
1305 1305  }
1306 1306  
1307 1307  /*
1308 1308   * MAC_TX_SRS_TEST_HIWAT
1309 1309   *
1310 1310   * Called before queueing a packet onto Tx SRS to test and set
1311 1311   * SRS_TX_HIWAT if srs_count exceeds srs_tx_hiwat.
1312 1312   */
1313 1313  #define MAC_TX_SRS_TEST_HIWAT(srs, mp, tail, cnt, sz, cookie) {         \
1314 1314          boolean_t enqueue = 1;                                          \
1315 1315                                                                          \
1316 1316          if ((srs)->srs_count > (srs)->srs_tx.st_hiwat) {                \
1317 1317                  /*                                                      \
1318 1318                   * flow-controlled. Store srs in cookie so that it      \
1319 1319                   * can be returned as mac_tx_cookie_t to client         \
1320 1320                   */                                                     \
1321 1321                  (srs)->srs_state |= SRS_TX_HIWAT;                       \
1322 1322                  cookie = (mac_tx_cookie_t)srs;                          \
1323 1323                  (srs)->srs_tx.st_hiwat_cnt++;                           \
1324 1324                  if ((srs)->srs_count > (srs)->srs_tx.st_max_q_cnt) {    \
1325 1325                          /* increment freed stats */                     \
1326 1326                          (srs)->srs_tx.st_stat.mts_sdrops += cnt;        \
1327 1327                          /*                                              \
1328 1328                           * b_prev may be set to the fanout hint         \
1329 1329                           * hence can't use freemsg directly             \
1330 1330                           */                                             \
1331 1331                          mac_pkt_drop(NULL, NULL, mp_chain, B_FALSE);    \
1332 1332                          DTRACE_PROBE1(tx_queued_hiwat,                  \
1333 1333                              mac_soft_ring_set_t *, srs);                \
1334 1334                          enqueue = 0;                                    \
1335 1335                  }                                                       \
1336 1336          }                                                               \
1337 1337          if (enqueue)                                                    \
1338 1338                  MAC_TX_SRS_ENQUEUE_CHAIN(srs, mp, tail, cnt, sz);       \
1339 1339  }
1340 1340  
1341 1341  /* Some utility macros */
1342 1342  #define MAC_SRS_BW_LOCK(srs)                                            \
1343 1343          if (!(srs->srs_type & SRST_TX))                                 \
1344 1344                  mutex_enter(&srs->srs_bw->mac_bw_lock);
1345 1345  
1346 1346  #define MAC_SRS_BW_UNLOCK(srs)                                          \
1347 1347          if (!(srs->srs_type & SRST_TX))                                 \
1348 1348                  mutex_exit(&srs->srs_bw->mac_bw_lock);
1349 1349  
1350 1350  #define MAC_TX_SRS_DROP_MESSAGE(srs, mp, cookie) {              \
1351 1351          mac_pkt_drop(NULL, NULL, mp, B_FALSE);                  \
1352 1352          /* increment freed stats */                             \
1353 1353          mac_srs->srs_tx.st_stat.mts_sdrops++;                   \
1354 1354          cookie = (mac_tx_cookie_t)srs;                          \
1355 1355  }
1356 1356  
1357 1357  #define MAC_TX_SET_NO_ENQUEUE(srs, mp_chain, ret_mp, cookie) {          \
1358 1358          mac_srs->srs_state |= SRS_TX_WAKEUP_CLIENT;                     \
1359 1359          cookie = (mac_tx_cookie_t)srs;                                  \
1360 1360          *ret_mp = mp_chain;                                             \
1361 1361  }
1362 1362  
1363 1363  /*
1364 1364   * MAC_RX_SRS_TOODEEP
1365 1365   *
1366 1366   * Macro called as part of receive-side processing to determine if handling
1367 1367   * can occur in situ (in the interrupt thread) or if it should be left to a
1368 1368   * worker thread.  Note that the constant used to make this determination is
1369 1369   * not entirely made-up, and is a result of some emprical validation. That
1370 1370   * said, the constant is left as a static variable to allow it to be
1371 1371   * dynamically tuned in the field if and as needed.
1372 1372   */
1373 1373  static uintptr_t mac_rx_srs_stack_needed = 10240;
1374 1374  static uint_t mac_rx_srs_stack_toodeep;
1375 1375  
1376 1376  #ifndef STACK_GROWTH_DOWN
1377 1377  #error Downward stack growth assumed.
1378 1378  #endif
1379 1379  
1380 1380  #define MAC_RX_SRS_TOODEEP() (STACK_BIAS + (uintptr_t)getfp() - \
1381 1381          (uintptr_t)curthread->t_stkbase < mac_rx_srs_stack_needed && \
1382 1382          ++mac_rx_srs_stack_toodeep)
1383 1383  
1384 1384  
1385 1385  /*
1386 1386   * Drop the rx packet and advance to the next one in the chain.
1387 1387   */
1388 1388  static void
1389 1389  mac_rx_drop_pkt(mac_soft_ring_set_t *srs, mblk_t *mp)
1390 1390  {
1391 1391          mac_srs_rx_t    *srs_rx = &srs->srs_rx;
1392 1392  
1393 1393          ASSERT(mp->b_next == NULL);
1394 1394          mutex_enter(&srs->srs_lock);
1395 1395          MAC_UPDATE_SRS_COUNT_LOCKED(srs, 1);
1396 1396          MAC_UPDATE_SRS_SIZE_LOCKED(srs, msgdsize(mp));
1397 1397          mutex_exit(&srs->srs_lock);
1398 1398  
1399 1399          srs_rx->sr_stat.mrs_sdrops++;
1400 1400          freemsg(mp);
1401 1401  }
1402 1402  
1403 1403  /* DATAPATH RUNTIME ROUTINES */
1404 1404  
1405 1405  /*
1406 1406   * mac_srs_fire
1407 1407   *
1408 1408   * Timer callback routine for waking up the SRS worker thread.
1409 1409   */
1410 1410  static void
1411 1411  mac_srs_fire(void *arg)
1412 1412  {
1413 1413          mac_soft_ring_set_t *mac_srs = (mac_soft_ring_set_t *)arg;
1414 1414  
1415 1415          mutex_enter(&mac_srs->srs_lock);
1416 1416          if (mac_srs->srs_tid == NULL) {
1417 1417                  mutex_exit(&mac_srs->srs_lock);
1418 1418                  return;
1419 1419          }
1420 1420  
1421 1421          mac_srs->srs_tid = NULL;
1422 1422          if (!(mac_srs->srs_state & SRS_PROC))
1423 1423                  cv_signal(&mac_srs->srs_async);
1424 1424  
1425 1425          mutex_exit(&mac_srs->srs_lock);
1426 1426  }
1427 1427  
1428 1428  /*
1429 1429   * 'hint' is fanout_hint (type of uint64_t) which is given by the TCP/IP stack,
1430 1430   * and it is used on the TX path.
1431 1431   */
1432 1432  #define HASH_HINT(hint) \
1433 1433          ((hint) ^ ((hint) >> 24) ^ ((hint) >> 16) ^ ((hint) >> 8))
1434 1434  
1435 1435  
1436 1436  /*
1437 1437   * hash based on the src address, dst address and the port information.
1438 1438   */
1439 1439  #define HASH_ADDR(src, dst, ports)                                      \
1440 1440          (ntohl((src) + (dst)) ^ ((ports) >> 24) ^ ((ports) >> 16) ^     \
1441 1441          ((ports) >> 8) ^ (ports))
1442 1442  
1443 1443  #define COMPUTE_INDEX(key, sz)  (key % sz)
1444 1444  
1445 1445  #define FANOUT_ENQUEUE_MP(head, tail, cnt, bw_ctl, sz, sz0, mp) {       \
1446 1446          if ((tail) != NULL) {                                           \
1447 1447                  ASSERT((tail)->b_next == NULL);                         \
1448 1448                  (tail)->b_next = (mp);                                  \
1449 1449          } else {                                                        \
1450 1450                  ASSERT((head) == NULL);                                 \
1451 1451                  (head) = (mp);                                          \
1452 1452          }                                                               \
1453 1453          (tail) = (mp);                                                  \
1454 1454          (cnt)++;                                                        \
1455 1455          if ((bw_ctl))                                                   \
1456 1456                  (sz) += (sz0);                                          \
1457 1457  }
1458 1458  
1459 1459  #define MAC_FANOUT_DEFAULT      0
1460 1460  #define MAC_FANOUT_RND_ROBIN    1
1461 1461  int mac_fanout_type = MAC_FANOUT_DEFAULT;
1462 1462  
1463 1463  #define MAX_SR_TYPES    3
1464 1464  /* fanout types for port based hashing */
1465 1465  enum pkt_type {
1466 1466          V4_TCP = 0,
1467 1467          V4_UDP,
1468 1468          OTH,
1469 1469          UNDEF
1470 1470  };
1471 1471  
1472 1472  /*
1473 1473   * Pair of local and remote ports in the transport header
1474 1474   */
1475 1475  #define PORTS_SIZE 4
1476 1476  
1477 1477  /*
1478 1478   * mac_rx_srs_proto_fanout
1479 1479   *
1480 1480   * This routine delivers packets destined to an SRS into one of the
1481 1481   * protocol soft rings.
1482 1482   *
1483 1483   * Given a chain of packets we need to split it up into multiple sub chains
1484 1484   * destined into TCP, UDP or OTH soft ring. Instead of entering
1485 1485   * the soft ring one packet at a time, we want to enter it in the form of a
1486 1486   * chain otherwise we get this start/stop behaviour where the worker thread
1487 1487   * goes to sleep and then next packets comes in forcing it to wake up etc.
1488 1488   */
1489 1489  static void
1490 1490  mac_rx_srs_proto_fanout(mac_soft_ring_set_t *mac_srs, mblk_t *head)
1491 1491  {
1492 1492          struct ether_header             *ehp;
1493 1493          struct ether_vlan_header        *evhp;
1494 1494          uint32_t                        sap;
1495 1495          ipha_t                          *ipha;
1496 1496          uint8_t                         *dstaddr;
1497 1497          size_t                          hdrsize;
1498 1498          mblk_t                          *mp;
1499 1499          mblk_t                          *headmp[MAX_SR_TYPES];
1500 1500          mblk_t                          *tailmp[MAX_SR_TYPES];
1501 1501          int                             cnt[MAX_SR_TYPES];
1502 1502          size_t                          sz[MAX_SR_TYPES];
1503 1503          size_t                          sz1;
1504 1504          boolean_t                       bw_ctl;
1505 1505          boolean_t                       hw_classified;
1506 1506          boolean_t                       dls_bypass;
1507 1507          boolean_t                       is_ether;
1508 1508          boolean_t                       is_unicast;
1509 1509          enum pkt_type                   type;
1510 1510          mac_client_impl_t               *mcip = mac_srs->srs_mcip;
1511 1511  
1512 1512          is_ether = (mcip->mci_mip->mi_info.mi_nativemedia == DL_ETHER);
1513 1513          bw_ctl = ((mac_srs->srs_type & SRST_BW_CONTROL) != 0);
1514 1514  
1515 1515          /*
1516 1516           * If we don't have a Rx ring, S/W classification would have done
1517 1517           * its job and its a packet meant for us. If we were polling on
1518 1518           * the default ring (i.e. there was a ring assigned to this SRS),
1519 1519           * then we need to make sure that the mac address really belongs
1520 1520           * to us.
1521 1521           */
1522 1522          hw_classified = mac_srs->srs_ring != NULL &&
1523 1523              mac_srs->srs_ring->mr_classify_type == MAC_HW_CLASSIFIER;
1524 1524  
1525 1525          /*
1526 1526           * Special clients (eg. VLAN, non ether, etc) need DLS
1527 1527           * processing in the Rx path. SRST_DLS_BYPASS will be clear for
1528 1528           * such SRSs. Another way of disabling bypass is to set the
1529 1529           * MCIS_RX_BYPASS_DISABLE flag.
1530 1530           */
1531 1531          dls_bypass = ((mac_srs->srs_type & SRST_DLS_BYPASS) != 0) &&
1532 1532              ((mcip->mci_state_flags & MCIS_RX_BYPASS_DISABLE) == 0);
1533 1533  
1534 1534          bzero(headmp, MAX_SR_TYPES * sizeof (mblk_t *));
1535 1535          bzero(tailmp, MAX_SR_TYPES * sizeof (mblk_t *));
1536 1536          bzero(cnt, MAX_SR_TYPES * sizeof (int));
1537 1537          bzero(sz, MAX_SR_TYPES * sizeof (size_t));
1538 1538  
1539 1539          /*
1540 1540           * We got a chain from SRS that we need to send to the soft rings.
1541 1541           * Since squeues for TCP & IPv4 sap poll their soft rings (for
1542 1542           * performance reasons), we need to separate out v4_tcp, v4_udp
1543 1543           * and the rest goes in other.
1544 1544           */
1545 1545          while (head != NULL) {
1546 1546                  mp = head;
1547 1547                  head = head->b_next;
1548 1548                  mp->b_next = NULL;
1549 1549  
1550 1550                  type = OTH;
1551 1551                  sz1 = (mp->b_cont == NULL) ? MBLKL(mp) : msgdsize(mp);
1552 1552  
1553 1553                  if (is_ether) {
1554 1554                          /*
1555 1555                           * At this point we can be sure the packet at least
1556 1556                           * has an ether header.
1557 1557                           */
1558 1558                          if (sz1 < sizeof (struct ether_header)) {
1559 1559                                  mac_rx_drop_pkt(mac_srs, mp);
1560 1560                                  continue;
1561 1561                          }
1562 1562                          ehp = (struct ether_header *)mp->b_rptr;
1563 1563  
1564 1564                          /*
1565 1565                           * Determine if this is a VLAN or non-VLAN packet.
1566 1566                           */
1567 1567                          if ((sap = ntohs(ehp->ether_type)) == VLAN_TPID) {
1568 1568                                  evhp = (struct ether_vlan_header *)mp->b_rptr;
1569 1569                                  sap = ntohs(evhp->ether_type);
1570 1570                                  hdrsize = sizeof (struct ether_vlan_header);
1571 1571                                  /*
1572 1572                                   * Check if the VID of the packet, if any,
1573 1573                                   * belongs to this client.
1574 1574                                   */
1575 1575                                  if (!mac_client_check_flow_vid(mcip,
1576 1576                                      VLAN_ID(ntohs(evhp->ether_tci)))) {
1577 1577                                          mac_rx_drop_pkt(mac_srs, mp);
1578 1578                                          continue;
1579 1579                                  }
1580 1580                          } else {
1581 1581                                  hdrsize = sizeof (struct ether_header);
1582 1582                          }
1583 1583                          is_unicast =
1584 1584                              ((((uint8_t *)&ehp->ether_dhost)[0] & 0x01) == 0);
1585 1585                          dstaddr = (uint8_t *)&ehp->ether_dhost;
1586 1586                  } else {
1587 1587                          mac_header_info_t               mhi;
1588 1588  
1589 1589                          if (mac_header_info((mac_handle_t)mcip->mci_mip,
1590 1590                              mp, &mhi) != 0) {
1591 1591                                  mac_rx_drop_pkt(mac_srs, mp);
1592 1592                                  continue;
1593 1593                          }
1594 1594                          hdrsize = mhi.mhi_hdrsize;
1595 1595                          sap = mhi.mhi_bindsap;
1596 1596                          is_unicast = (mhi.mhi_dsttype == MAC_ADDRTYPE_UNICAST);
1597 1597                          dstaddr = (uint8_t *)mhi.mhi_daddr;
1598 1598                  }
1599 1599  
1600 1600                  if (!dls_bypass) {
1601 1601                          FANOUT_ENQUEUE_MP(headmp[type], tailmp[type],
1602 1602                              cnt[type], bw_ctl, sz[type], sz1, mp);
1603 1603                          continue;
1604 1604                  }
1605 1605  
1606 1606                  if (sap == ETHERTYPE_IP) {
1607 1607                          /*
1608 1608                           * If we are H/W classified, but we have promisc
1609 1609                           * on, then we need to check for the unicast address.
1610 1610                           */
1611 1611                          if (hw_classified && mcip->mci_promisc_list != NULL) {
1612 1612                                  mac_address_t           *map;
1613 1613  
1614 1614                                  rw_enter(&mcip->mci_rw_lock, RW_READER);
1615 1615                                  map = mcip->mci_unicast;
1616 1616                                  if (bcmp(dstaddr, map->ma_addr,
1617 1617                                      map->ma_len) == 0)
1618 1618                                          type = UNDEF;
1619 1619                                  rw_exit(&mcip->mci_rw_lock);
1620 1620                          } else if (is_unicast) {
1621 1621                                  type = UNDEF;
1622 1622                          }
1623 1623                  }
1624 1624  
1625 1625                  /*
1626 1626                   * This needs to become a contract with the driver for
1627 1627                   * the fast path.
1628 1628                   *
1629 1629                   * In the normal case the packet will have at least the L2
1630 1630                   * header and the IP + Transport header in the same mblk.
1631 1631                   * This is usually the case when the NIC driver sends up
1632 1632                   * the packet. This is also true when the stack generates
1633 1633                   * a packet that is looped back and when the stack uses the
1634 1634                   * fastpath mechanism. The normal case is optimized for
1635 1635                   * performance and may bypass DLS. All other cases go through
1636 1636                   * the 'OTH' type path without DLS bypass.
1637 1637                   */
1638 1638  
1639 1639                  ipha = (ipha_t *)(mp->b_rptr + hdrsize);
1640 1640                  if ((type != OTH) && MBLK_RX_FANOUT_SLOWPATH(mp, ipha))
1641 1641                          type = OTH;
1642 1642  
1643 1643                  if (type == OTH) {
1644 1644                          FANOUT_ENQUEUE_MP(headmp[type], tailmp[type],
1645 1645                              cnt[type], bw_ctl, sz[type], sz1, mp);
1646 1646                          continue;
1647 1647                  }
1648 1648  
1649 1649                  ASSERT(type == UNDEF);
1650 1650                  /*
1651 1651                   * We look for at least 4 bytes past the IP header to get
1652 1652                   * the port information. If we get an IP fragment, we don't
1653 1653                   * have the port information, and we use just the protocol
1654 1654                   * information.
1655 1655                   */
1656 1656                  switch (ipha->ipha_protocol) {
1657 1657                  case IPPROTO_TCP:
1658 1658                          type = V4_TCP;
1659 1659                          mp->b_rptr += hdrsize;
1660 1660                          break;
1661 1661                  case IPPROTO_UDP:
1662 1662                          type = V4_UDP;
1663 1663                          mp->b_rptr += hdrsize;
1664 1664                          break;
1665 1665                  default:
1666 1666                          type = OTH;
1667 1667                          break;
1668 1668                  }
1669 1669  
1670 1670                  FANOUT_ENQUEUE_MP(headmp[type], tailmp[type], cnt[type],
1671 1671                      bw_ctl, sz[type], sz1, mp);
1672 1672          }
1673 1673  
1674 1674          for (type = V4_TCP; type < UNDEF; type++) {
1675 1675                  if (headmp[type] != NULL) {
1676 1676                          mac_soft_ring_t                 *softring;
1677 1677  
1678 1678                          ASSERT(tailmp[type]->b_next == NULL);
1679 1679                          switch (type) {
1680 1680                          case V4_TCP:
1681 1681                                  softring = mac_srs->srs_tcp_soft_rings[0];
1682 1682                                  break;
1683 1683                          case V4_UDP:
1684 1684                                  softring = mac_srs->srs_udp_soft_rings[0];
1685 1685                                  break;
1686 1686                          case OTH:
1687 1687                                  softring = mac_srs->srs_oth_soft_rings[0];
1688 1688                          }
1689 1689                          mac_rx_soft_ring_process(mcip, softring,
1690 1690                              headmp[type], tailmp[type], cnt[type], sz[type]);
1691 1691                  }
1692 1692          }
1693 1693  }
1694 1694  
1695 1695  int     fanout_unaligned = 0;
1696 1696  
1697 1697  /*
1698 1698   * mac_rx_srs_long_fanout
1699 1699   *
1700 1700   * The fanout routine for VLANs, and for anything else that isn't performing
1701 1701   * explicit dls bypass.  Returns -1 on an error (drop the packet due to a
1702 1702   * malformed packet), 0 on success, with values written in *indx and *type.
1703 1703   */
1704 1704  static int
1705 1705  mac_rx_srs_long_fanout(mac_soft_ring_set_t *mac_srs, mblk_t *mp,
1706 1706      uint32_t sap, size_t hdrsize, enum pkt_type *type, uint_t *indx)
1707 1707  {
1708 1708          ip6_t           *ip6h;
1709 1709          ipha_t          *ipha;
1710 1710          uint8_t         *whereptr;
1711 1711          uint_t          hash;
1712 1712          uint16_t        remlen;
1713 1713          uint8_t         nexthdr;
1714 1714          uint16_t        hdr_len;
1715 1715          uint32_t        src_val, dst_val;
1716 1716          boolean_t       modifiable = B_TRUE;
1717 1717          boolean_t       v6;
1718 1718  
1719 1719          ASSERT(MBLKL(mp) >= hdrsize);
1720 1720  
1721 1721          if (sap == ETHERTYPE_IPV6) {
1722 1722                  v6 = B_TRUE;
1723 1723                  hdr_len = IPV6_HDR_LEN;
1724 1724          } else if (sap == ETHERTYPE_IP) {
1725 1725                  v6 = B_FALSE;
1726 1726                  hdr_len = IP_SIMPLE_HDR_LENGTH;
1727 1727          } else {
1728 1728                  *indx = 0;
1729 1729                  *type = OTH;
1730 1730                  return (0);
1731 1731          }
1732 1732  
1733 1733          ip6h = (ip6_t *)(mp->b_rptr + hdrsize);
1734 1734          ipha = (ipha_t *)ip6h;
1735 1735  
1736 1736          if ((uint8_t *)ip6h == mp->b_wptr) {
1737 1737                  /*
1738 1738                   * The first mblk_t only includes the mac header.
1739 1739                   * Note that it is safe to change the mp pointer here,
1740 1740                   * as the subsequent operation does not assume mp
1741 1741                   * points to the start of the mac header.
1742 1742                   */
1743 1743                  mp = mp->b_cont;
1744 1744  
1745 1745                  /*
1746 1746                   * Make sure the IP header points to an entire one.
1747 1747                   */
1748 1748                  if (mp == NULL)
1749 1749                          return (-1);
1750 1750  
1751 1751                  if (MBLKL(mp) < hdr_len) {
1752 1752                          modifiable = (DB_REF(mp) == 1);
1753 1753  
1754 1754                          if (modifiable && !pullupmsg(mp, hdr_len))
1755 1755                                  return (-1);
1756 1756                  }
1757 1757  
1758 1758                  ip6h = (ip6_t *)mp->b_rptr;
1759 1759                  ipha = (ipha_t *)ip6h;
1760 1760          }
1761 1761  
1762 1762          if (!modifiable || !(OK_32PTR((char *)ip6h)) ||
1763 1763              ((uint8_t *)ip6h + hdr_len > mp->b_wptr)) {
1764 1764                  /*
1765 1765                   * If either the IP header is not aligned, or it does not hold
1766 1766                   * the complete simple structure (a pullupmsg() is not an
1767 1767                   * option since it would result in an unaligned IP header),
1768 1768                   * fanout to the default ring.
1769 1769                   *
1770 1770                   * Note that this may cause packet reordering.
1771 1771                   */
1772 1772                  *indx = 0;
1773 1773                  *type = OTH;
1774 1774                  fanout_unaligned++;
1775 1775                  return (0);
1776 1776          }
1777 1777  
1778 1778          /*
1779 1779           * Extract next-header, full header length, and source-hash value
1780 1780           * using v4/v6 specific fields.
1781 1781           */
  
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1782 1782          if (v6) {
1783 1783                  remlen = ntohs(ip6h->ip6_plen);
1784 1784                  nexthdr = ip6h->ip6_nxt;
1785 1785                  src_val = V4_PART_OF_V6(ip6h->ip6_src);
1786 1786                  dst_val = V4_PART_OF_V6(ip6h->ip6_dst);
1787 1787                  /*
1788 1788                   * Do src based fanout if below tunable is set to B_TRUE or
1789 1789                   * when mac_ip_hdr_length_v6() fails because of malformed
1790 1790                   * packets or because mblks need to be concatenated using
1791 1791                   * pullupmsg().
1792      -                 *
1793      -                 * Perform a version check to prevent parsing weirdness...
1794 1792                   */
1795      -                if (IPH_HDR_VERSION(ip6h) != IPV6_VERSION ||
1796      -                    !mac_ip_hdr_length_v6(ip6h, mp->b_wptr, &hdr_len, &nexthdr,
     1793 +                if (!mac_ip_hdr_length_v6(ip6h, mp->b_wptr, &hdr_len, &nexthdr,
1797 1794                      NULL)) {
1798 1795                          goto src_dst_based_fanout;
1799 1796                  }
1800 1797          } else {
1801 1798                  hdr_len = IPH_HDR_LENGTH(ipha);
1802 1799                  remlen = ntohs(ipha->ipha_length) - hdr_len;
1803 1800                  nexthdr = ipha->ipha_protocol;
1804 1801                  src_val = (uint32_t)ipha->ipha_src;
1805 1802                  dst_val = (uint32_t)ipha->ipha_dst;
1806 1803                  /*
1807 1804                   * Catch IPv4 fragment case here.  IPv6 has nexthdr == FRAG
1808 1805                   * for its equivalent case.
1809 1806                   */
1810 1807                  if ((ntohs(ipha->ipha_fragment_offset_and_flags) &
1811 1808                      (IPH_MF | IPH_OFFSET)) != 0) {
1812 1809                          goto src_dst_based_fanout;
1813 1810                  }
1814 1811          }
1815 1812          if (remlen < MIN_EHDR_LEN)
1816 1813                  return (-1);
1817 1814          whereptr = (uint8_t *)ip6h + hdr_len;
1818 1815  
1819 1816          /* If the transport is one of below, we do port/SPI based fanout */
1820 1817          switch (nexthdr) {
1821 1818          case IPPROTO_TCP:
1822 1819          case IPPROTO_UDP:
1823 1820          case IPPROTO_SCTP:
1824 1821          case IPPROTO_ESP:
1825 1822                  /*
1826 1823                   * If the ports or SPI in the transport header is not part of
1827 1824                   * the mblk, do src_based_fanout, instead of calling
1828 1825                   * pullupmsg().
1829 1826                   */
1830 1827                  if (mp->b_cont == NULL || whereptr + PORTS_SIZE <= mp->b_wptr)
1831 1828                          break;  /* out of switch... */
1832 1829                  /* FALLTHRU */
1833 1830          default:
1834 1831                  goto src_dst_based_fanout;
1835 1832          }
1836 1833  
1837 1834          switch (nexthdr) {
1838 1835          case IPPROTO_TCP:
1839 1836                  hash = HASH_ADDR(src_val, dst_val, *(uint32_t *)whereptr);
1840 1837                  *indx = COMPUTE_INDEX(hash, mac_srs->srs_tcp_ring_count);
1841 1838                  *type = OTH;
1842 1839                  break;
1843 1840          case IPPROTO_UDP:
1844 1841          case IPPROTO_SCTP:
1845 1842          case IPPROTO_ESP:
1846 1843                  if (mac_fanout_type == MAC_FANOUT_DEFAULT) {
1847 1844                          hash = HASH_ADDR(src_val, dst_val,
1848 1845                              *(uint32_t *)whereptr);
1849 1846                          *indx = COMPUTE_INDEX(hash,
1850 1847                              mac_srs->srs_udp_ring_count);
1851 1848                  } else {
1852 1849                          *indx = mac_srs->srs_ind % mac_srs->srs_udp_ring_count;
1853 1850                          mac_srs->srs_ind++;
1854 1851                  }
1855 1852                  *type = OTH;
1856 1853                  break;
1857 1854          }
1858 1855          return (0);
1859 1856  
1860 1857  src_dst_based_fanout:
1861 1858          hash = HASH_ADDR(src_val, dst_val, (uint32_t)0);
1862 1859          *indx = COMPUTE_INDEX(hash, mac_srs->srs_oth_ring_count);
1863 1860          *type = OTH;
1864 1861          return (0);
1865 1862  }
1866 1863  
1867 1864  /*
1868 1865   * mac_rx_srs_fanout
1869 1866   *
1870 1867   * This routine delivers packets destined to an SRS into a soft ring member
1871 1868   * of the set.
1872 1869   *
1873 1870   * Given a chain of packets we need to split it up into multiple sub chains
1874 1871   * destined for one of the TCP, UDP or OTH soft rings. Instead of entering
1875 1872   * the soft ring one packet at a time, we want to enter it in the form of a
1876 1873   * chain otherwise we get this start/stop behaviour where the worker thread
1877 1874   * goes to sleep and then next packets comes in forcing it to wake up etc.
1878 1875   *
1879 1876   * Note:
1880 1877   * Since we know what is the maximum fanout possible, we create a 2D array
1881 1878   * of 'softring types * MAX_SR_FANOUT' for the head, tail, cnt and sz
1882 1879   * variables so that we can enter the softrings with chain. We need the
1883 1880   * MAX_SR_FANOUT so we can allocate the arrays on the stack (a kmem_alloc
1884 1881   * for each packet would be expensive). If we ever want to have the
1885 1882   * ability to have unlimited fanout, we should probably declare a head,
1886 1883   * tail, cnt, sz with each soft ring (a data struct which contains a softring
1887 1884   * along with these members) and create an array of this uber struct so we
1888 1885   * don't have to do kmem_alloc.
1889 1886   */
1890 1887  int     fanout_oth1 = 0;
1891 1888  int     fanout_oth2 = 0;
1892 1889  int     fanout_oth3 = 0;
1893 1890  int     fanout_oth4 = 0;
1894 1891  int     fanout_oth5 = 0;
1895 1892  
1896 1893  static void
1897 1894  mac_rx_srs_fanout(mac_soft_ring_set_t *mac_srs, mblk_t *head)
1898 1895  {
1899 1896          struct ether_header             *ehp;
1900 1897          struct ether_vlan_header        *evhp;
1901 1898          uint32_t                        sap;
1902 1899          ipha_t                          *ipha;
1903 1900          uint8_t                         *dstaddr;
1904 1901          uint_t                          indx;
1905 1902          size_t                          ports_offset;
1906 1903          size_t                          ipha_len;
1907 1904          size_t                          hdrsize;
1908 1905          uint_t                          hash;
1909 1906          mblk_t                          *mp;
1910 1907          mblk_t                          *headmp[MAX_SR_TYPES][MAX_SR_FANOUT];
1911 1908          mblk_t                          *tailmp[MAX_SR_TYPES][MAX_SR_FANOUT];
1912 1909          int                             cnt[MAX_SR_TYPES][MAX_SR_FANOUT];
1913 1910          size_t                          sz[MAX_SR_TYPES][MAX_SR_FANOUT];
1914 1911          size_t                          sz1;
1915 1912          boolean_t                       bw_ctl;
1916 1913          boolean_t                       hw_classified;
1917 1914          boolean_t                       dls_bypass;
1918 1915          boolean_t                       is_ether;
1919 1916          boolean_t                       is_unicast;
1920 1917          int                             fanout_cnt;
1921 1918          enum pkt_type                   type;
1922 1919          mac_client_impl_t               *mcip = mac_srs->srs_mcip;
1923 1920  
1924 1921          is_ether = (mcip->mci_mip->mi_info.mi_nativemedia == DL_ETHER);
1925 1922          bw_ctl = ((mac_srs->srs_type & SRST_BW_CONTROL) != 0);
1926 1923  
1927 1924          /*
1928 1925           * If we don't have a Rx ring, S/W classification would have done
1929 1926           * its job and its a packet meant for us. If we were polling on
1930 1927           * the default ring (i.e. there was a ring assigned to this SRS),
1931 1928           * then we need to make sure that the mac address really belongs
1932 1929           * to us.
1933 1930           */
1934 1931          hw_classified = mac_srs->srs_ring != NULL &&
1935 1932              mac_srs->srs_ring->mr_classify_type == MAC_HW_CLASSIFIER;
1936 1933  
1937 1934          /*
1938 1935           * Special clients (eg. VLAN, non ether, etc) need DLS
1939 1936           * processing in the Rx path. SRST_DLS_BYPASS will be clear for
1940 1937           * such SRSs. Another way of disabling bypass is to set the
1941 1938           * MCIS_RX_BYPASS_DISABLE flag.
1942 1939           */
1943 1940          dls_bypass = ((mac_srs->srs_type & SRST_DLS_BYPASS) != 0) &&
1944 1941              ((mcip->mci_state_flags & MCIS_RX_BYPASS_DISABLE) == 0);
1945 1942  
1946 1943          /*
1947 1944           * Since the softrings are never destroyed and we always
1948 1945           * create equal number of softrings for TCP, UDP and rest,
1949 1946           * its OK to check one of them for count and use it without
1950 1947           * any lock. In future, if soft rings get destroyed because
1951 1948           * of reduction in fanout, we will need to ensure that happens
1952 1949           * behind the SRS_PROC.
1953 1950           */
1954 1951          fanout_cnt = mac_srs->srs_tcp_ring_count;
1955 1952  
1956 1953          bzero(headmp, MAX_SR_TYPES * MAX_SR_FANOUT * sizeof (mblk_t *));
1957 1954          bzero(tailmp, MAX_SR_TYPES * MAX_SR_FANOUT * sizeof (mblk_t *));
1958 1955          bzero(cnt, MAX_SR_TYPES * MAX_SR_FANOUT * sizeof (int));
1959 1956          bzero(sz, MAX_SR_TYPES * MAX_SR_FANOUT * sizeof (size_t));
1960 1957  
1961 1958          /*
1962 1959           * We got a chain from SRS that we need to send to the soft rings.
1963 1960           * Since squeues for TCP & IPv4 sap poll their soft rings (for
1964 1961           * performance reasons), we need to separate out v4_tcp, v4_udp
1965 1962           * and the rest goes in other.
1966 1963           */
1967 1964          while (head != NULL) {
1968 1965                  mp = head;
1969 1966                  head = head->b_next;
1970 1967                  mp->b_next = NULL;
1971 1968  
1972 1969                  type = OTH;
1973 1970                  sz1 = (mp->b_cont == NULL) ? MBLKL(mp) : msgdsize(mp);
1974 1971  
1975 1972                  if (is_ether) {
1976 1973                          /*
1977 1974                           * At this point we can be sure the packet at least
1978 1975                           * has an ether header.
1979 1976                           */
1980 1977                          if (sz1 < sizeof (struct ether_header)) {
1981 1978                                  mac_rx_drop_pkt(mac_srs, mp);
1982 1979                                  continue;
1983 1980                          }
1984 1981                          ehp = (struct ether_header *)mp->b_rptr;
1985 1982  
1986 1983                          /*
1987 1984                           * Determine if this is a VLAN or non-VLAN packet.
1988 1985                           */
1989 1986                          if ((sap = ntohs(ehp->ether_type)) == VLAN_TPID) {
1990 1987                                  evhp = (struct ether_vlan_header *)mp->b_rptr;
1991 1988                                  sap = ntohs(evhp->ether_type);
1992 1989                                  hdrsize = sizeof (struct ether_vlan_header);
1993 1990                                  /*
1994 1991                                   * Check if the VID of the packet, if any,
1995 1992                                   * belongs to this client.
1996 1993                                   */
1997 1994                                  if (!mac_client_check_flow_vid(mcip,
1998 1995                                      VLAN_ID(ntohs(evhp->ether_tci)))) {
1999 1996                                          mac_rx_drop_pkt(mac_srs, mp);
2000 1997                                          continue;
2001 1998                                  }
2002 1999                          } else {
2003 2000                                  hdrsize = sizeof (struct ether_header);
2004 2001                          }
2005 2002                          is_unicast =
2006 2003                              ((((uint8_t *)&ehp->ether_dhost)[0] & 0x01) == 0);
2007 2004                          dstaddr = (uint8_t *)&ehp->ether_dhost;
2008 2005                  } else {
2009 2006                          mac_header_info_t               mhi;
2010 2007  
2011 2008                          if (mac_header_info((mac_handle_t)mcip->mci_mip,
2012 2009                              mp, &mhi) != 0) {
2013 2010                                  mac_rx_drop_pkt(mac_srs, mp);
2014 2011                                  continue;
2015 2012                          }
2016 2013                          hdrsize = mhi.mhi_hdrsize;
2017 2014                          sap = mhi.mhi_bindsap;
2018 2015                          is_unicast = (mhi.mhi_dsttype == MAC_ADDRTYPE_UNICAST);
2019 2016                          dstaddr = (uint8_t *)mhi.mhi_daddr;
2020 2017                  }
2021 2018  
2022 2019                  if (!dls_bypass) {
2023 2020                          if (mac_rx_srs_long_fanout(mac_srs, mp, sap,
2024 2021                              hdrsize, &type, &indx) == -1) {
2025 2022                                  mac_rx_drop_pkt(mac_srs, mp);
2026 2023                                  continue;
2027 2024                          }
2028 2025  
2029 2026                          FANOUT_ENQUEUE_MP(headmp[type][indx],
2030 2027                              tailmp[type][indx], cnt[type][indx], bw_ctl,
2031 2028                              sz[type][indx], sz1, mp);
2032 2029                          continue;
2033 2030                  }
2034 2031  
2035 2032  
2036 2033                  /*
2037 2034                   * If we are using the default Rx ring where H/W or S/W
2038 2035                   * classification has not happened, we need to verify if
2039 2036                   * this unicast packet really belongs to us.
2040 2037                   */
2041 2038                  if (sap == ETHERTYPE_IP) {
2042 2039                          /*
2043 2040                           * If we are H/W classified, but we have promisc
2044 2041                           * on, then we need to check for the unicast address.
2045 2042                           */
2046 2043                          if (hw_classified && mcip->mci_promisc_list != NULL) {
2047 2044                                  mac_address_t           *map;
2048 2045  
2049 2046                                  rw_enter(&mcip->mci_rw_lock, RW_READER);
2050 2047                                  map = mcip->mci_unicast;
2051 2048                                  if (bcmp(dstaddr, map->ma_addr,
2052 2049                                      map->ma_len) == 0)
2053 2050                                          type = UNDEF;
2054 2051                                  rw_exit(&mcip->mci_rw_lock);
2055 2052                          } else if (is_unicast) {
2056 2053                                  type = UNDEF;
2057 2054                          }
2058 2055                  }
2059 2056  
2060 2057                  /*
2061 2058                   * This needs to become a contract with the driver for
2062 2059                   * the fast path.
2063 2060                   */
2064 2061  
2065 2062                  ipha = (ipha_t *)(mp->b_rptr + hdrsize);
2066 2063                  if ((type != OTH) && MBLK_RX_FANOUT_SLOWPATH(mp, ipha)) {
2067 2064                          type = OTH;
2068 2065                          fanout_oth1++;
2069 2066                  }
2070 2067  
2071 2068                  if (type != OTH) {
2072 2069                          uint16_t        frag_offset_flags;
2073 2070  
2074 2071                          switch (ipha->ipha_protocol) {
2075 2072                          case IPPROTO_TCP:
2076 2073                          case IPPROTO_UDP:
2077 2074                          case IPPROTO_SCTP:
2078 2075                          case IPPROTO_ESP:
2079 2076                                  ipha_len = IPH_HDR_LENGTH(ipha);
2080 2077                                  if ((uchar_t *)ipha + ipha_len + PORTS_SIZE >
2081 2078                                      mp->b_wptr) {
2082 2079                                          type = OTH;
2083 2080                                          break;
2084 2081                                  }
2085 2082                                  frag_offset_flags =
2086 2083                                      ntohs(ipha->ipha_fragment_offset_and_flags);
2087 2084                                  if ((frag_offset_flags &
2088 2085                                      (IPH_MF | IPH_OFFSET)) != 0) {
2089 2086                                          type = OTH;
2090 2087                                          fanout_oth3++;
2091 2088                                          break;
2092 2089                                  }
2093 2090                                  ports_offset = hdrsize + ipha_len;
2094 2091                                  break;
2095 2092                          default:
2096 2093                                  type = OTH;
2097 2094                                  fanout_oth4++;
2098 2095                                  break;
2099 2096                          }
2100 2097                  }
2101 2098  
2102 2099                  if (type == OTH) {
2103 2100                          if (mac_rx_srs_long_fanout(mac_srs, mp, sap,
2104 2101                              hdrsize, &type, &indx) == -1) {
2105 2102                                  mac_rx_drop_pkt(mac_srs, mp);
2106 2103                                  continue;
2107 2104                          }
2108 2105  
2109 2106                          FANOUT_ENQUEUE_MP(headmp[type][indx],
2110 2107                              tailmp[type][indx], cnt[type][indx], bw_ctl,
2111 2108                              sz[type][indx], sz1, mp);
2112 2109                          continue;
2113 2110                  }
2114 2111  
2115 2112                  ASSERT(type == UNDEF);
2116 2113  
2117 2114                  /*
2118 2115                   * XXX-Sunay: We should hold srs_lock since ring_count
2119 2116                   * below can change. But if we are always called from
2120 2117                   * mac_rx_srs_drain and SRS_PROC is set, then we can
2121 2118                   * enforce that ring_count can't be changed i.e.
2122 2119                   * to change fanout type or ring count, the calling
2123 2120                   * thread needs to be behind SRS_PROC.
2124 2121                   */
2125 2122                  switch (ipha->ipha_protocol) {
2126 2123                  case IPPROTO_TCP:
2127 2124                          /*
2128 2125                           * Note that for ESP, we fanout on SPI and it is at the
2129 2126                           * same offset as the 2x16-bit ports. So it is clumped
2130 2127                           * along with TCP, UDP and SCTP.
2131 2128                           */
2132 2129                          hash = HASH_ADDR(ipha->ipha_src, ipha->ipha_dst,
2133 2130                              *(uint32_t *)(mp->b_rptr + ports_offset));
2134 2131                          indx = COMPUTE_INDEX(hash, mac_srs->srs_tcp_ring_count);
2135 2132                          type = V4_TCP;
2136 2133                          mp->b_rptr += hdrsize;
2137 2134                          break;
2138 2135                  case IPPROTO_UDP:
2139 2136                  case IPPROTO_SCTP:
2140 2137                  case IPPROTO_ESP:
2141 2138                          if (mac_fanout_type == MAC_FANOUT_DEFAULT) {
2142 2139                                  hash = HASH_ADDR(ipha->ipha_src, ipha->ipha_dst,
2143 2140                                      *(uint32_t *)(mp->b_rptr + ports_offset));
2144 2141                                  indx = COMPUTE_INDEX(hash,
2145 2142                                      mac_srs->srs_udp_ring_count);
2146 2143                          } else {
2147 2144                                  indx = mac_srs->srs_ind %
2148 2145                                      mac_srs->srs_udp_ring_count;
2149 2146                                  mac_srs->srs_ind++;
2150 2147                          }
2151 2148                          type = V4_UDP;
2152 2149                          mp->b_rptr += hdrsize;
2153 2150                          break;
2154 2151                  default:
2155 2152                          indx = 0;
2156 2153                          type = OTH;
2157 2154                  }
2158 2155  
2159 2156                  FANOUT_ENQUEUE_MP(headmp[type][indx], tailmp[type][indx],
2160 2157                      cnt[type][indx], bw_ctl, sz[type][indx], sz1, mp);
2161 2158          }
2162 2159  
2163 2160          for (type = V4_TCP; type < UNDEF; type++) {
2164 2161                  int     i;
2165 2162  
2166 2163                  for (i = 0; i < fanout_cnt; i++) {
2167 2164                          if (headmp[type][i] != NULL) {
2168 2165                                  mac_soft_ring_t *softring;
2169 2166  
2170 2167                                  ASSERT(tailmp[type][i]->b_next == NULL);
2171 2168                                  switch (type) {
2172 2169                                  case V4_TCP:
2173 2170                                          softring =
2174 2171                                              mac_srs->srs_tcp_soft_rings[i];
2175 2172                                          break;
2176 2173                                  case V4_UDP:
2177 2174                                          softring =
2178 2175                                              mac_srs->srs_udp_soft_rings[i];
2179 2176                                          break;
2180 2177                                  case OTH:
2181 2178                                          softring =
2182 2179                                              mac_srs->srs_oth_soft_rings[i];
2183 2180                                          break;
2184 2181                                  }
2185 2182                                  mac_rx_soft_ring_process(mcip,
2186 2183                                      softring, headmp[type][i], tailmp[type][i],
2187 2184                                      cnt[type][i], sz[type][i]);
2188 2185                          }
2189 2186                  }
2190 2187          }
2191 2188  }
2192 2189  
2193 2190  #define SRS_BYTES_TO_PICKUP     150000
2194 2191  ssize_t max_bytes_to_pickup = SRS_BYTES_TO_PICKUP;
2195 2192  
2196 2193  /*
2197 2194   * mac_rx_srs_poll_ring
2198 2195   *
2199 2196   * This SRS Poll thread uses this routine to poll the underlying hardware
2200 2197   * Rx ring to get a chain of packets. It can inline process that chain
2201 2198   * if mac_latency_optimize is set (default) or signal the SRS worker thread
2202 2199   * to do the remaining processing.
2203 2200   *
2204 2201   * Since packets come in the system via interrupt or poll path, we also
2205 2202   * update the stats and deal with promiscous clients here.
2206 2203   */
2207 2204  void
2208 2205  mac_rx_srs_poll_ring(mac_soft_ring_set_t *mac_srs)
2209 2206  {
2210 2207          kmutex_t                *lock = &mac_srs->srs_lock;
2211 2208          kcondvar_t              *async = &mac_srs->srs_cv;
2212 2209          mac_srs_rx_t            *srs_rx = &mac_srs->srs_rx;
2213 2210          mblk_t                  *head, *tail, *mp;
2214 2211          callb_cpr_t             cprinfo;
2215 2212          ssize_t                 bytes_to_pickup;
2216 2213          size_t                  sz;
2217 2214          int                     count;
2218 2215          mac_client_impl_t       *smcip;
2219 2216  
2220 2217          CALLB_CPR_INIT(&cprinfo, lock, callb_generic_cpr, "mac_srs_poll");
2221 2218          mutex_enter(lock);
2222 2219  
2223 2220  start:
2224 2221          for (;;) {
2225 2222                  if (mac_srs->srs_state & SRS_PAUSE)
2226 2223                          goto done;
2227 2224  
2228 2225                  CALLB_CPR_SAFE_BEGIN(&cprinfo);
2229 2226                  cv_wait(async, lock);
2230 2227                  CALLB_CPR_SAFE_END(&cprinfo, lock);
2231 2228  
2232 2229                  if (mac_srs->srs_state & SRS_PAUSE)
2233 2230                          goto done;
2234 2231  
2235 2232  check_again:
2236 2233                  if (mac_srs->srs_type & SRST_BW_CONTROL) {
2237 2234                          /*
2238 2235                           * We pick as many bytes as we are allowed to queue.
2239 2236                           * Its possible that we will exceed the total
2240 2237                           * packets queued in case this SRS is part of the
2241 2238                           * Rx ring group since > 1 poll thread can be pulling
2242 2239                           * upto the max allowed packets at the same time
2243 2240                           * but that should be OK.
2244 2241                           */
2245 2242                          mutex_enter(&mac_srs->srs_bw->mac_bw_lock);
2246 2243                          bytes_to_pickup =
2247 2244                              mac_srs->srs_bw->mac_bw_drop_threshold -
2248 2245                              mac_srs->srs_bw->mac_bw_sz;
2249 2246                          /*
2250 2247                           * We shouldn't have been signalled if we
2251 2248                           * have 0 or less bytes to pick but since
2252 2249                           * some of the bytes accounting is driver
2253 2250                           * dependant, we do the safety check.
2254 2251                           */
2255 2252                          if (bytes_to_pickup < 0)
2256 2253                                  bytes_to_pickup = 0;
2257 2254                          mutex_exit(&mac_srs->srs_bw->mac_bw_lock);
2258 2255                  } else {
2259 2256                          /*
2260 2257                           * ToDO: Need to change the polling API
2261 2258                           * to add a packet count and a flag which
2262 2259                           * tells the driver whether we want packets
2263 2260                           * based on a count, or bytes, or all the
2264 2261                           * packets queued in the driver/HW. This
2265 2262                           * way, we never have to check the limits
2266 2263                           * on poll path. We truly let only as many
2267 2264                           * packets enter the system as we are willing
2268 2265                           * to process or queue.
2269 2266                           *
2270 2267                           * Something along the lines of
2271 2268                           * pkts_to_pickup = mac_soft_ring_max_q_cnt -
2272 2269                           *      mac_srs->srs_poll_pkt_cnt
2273 2270                           */
2274 2271  
2275 2272                          /*
2276 2273                           * Since we are not doing B/W control, pick
2277 2274                           * as many packets as allowed.
2278 2275                           */
2279 2276                          bytes_to_pickup = max_bytes_to_pickup;
2280 2277                  }
2281 2278  
2282 2279                  /* Poll the underlying Hardware */
2283 2280                  mutex_exit(lock);
2284 2281                  head = MAC_HWRING_POLL(mac_srs->srs_ring, (int)bytes_to_pickup);
2285 2282                  mutex_enter(lock);
2286 2283  
2287 2284                  ASSERT((mac_srs->srs_state & SRS_POLL_THR_OWNER) ==
2288 2285                      SRS_POLL_THR_OWNER);
2289 2286  
2290 2287                  mp = tail = head;
2291 2288                  count = 0;
2292 2289                  sz = 0;
2293 2290                  while (mp != NULL) {
2294 2291                          tail = mp;
2295 2292                          sz += msgdsize(mp);
2296 2293                          mp = mp->b_next;
2297 2294                          count++;
2298 2295                  }
2299 2296  
2300 2297                  if (head != NULL) {
2301 2298                          tail->b_next = NULL;
2302 2299                          smcip = mac_srs->srs_mcip;
2303 2300  
2304 2301                          SRS_RX_STAT_UPDATE(mac_srs, pollbytes, sz);
2305 2302                          SRS_RX_STAT_UPDATE(mac_srs, pollcnt, count);
2306 2303  
2307 2304                          /*
2308 2305                           * If there are any promiscuous mode callbacks
2309 2306                           * defined for this MAC client, pass them a copy
2310 2307                           * if appropriate and also update the counters.
2311 2308                           */
2312 2309                          if (smcip != NULL) {
2313 2310                                  if (smcip->mci_mip->mi_promisc_list != NULL) {
2314 2311                                          mutex_exit(lock);
2315 2312                                          mac_promisc_dispatch(smcip->mci_mip,
2316 2313                                              head, NULL);
2317 2314                                          mutex_enter(lock);
2318 2315                                  }
2319 2316                          }
2320 2317                          if (mac_srs->srs_type & SRST_BW_CONTROL) {
2321 2318                                  mutex_enter(&mac_srs->srs_bw->mac_bw_lock);
2322 2319                                  mac_srs->srs_bw->mac_bw_polled += sz;
2323 2320                                  mutex_exit(&mac_srs->srs_bw->mac_bw_lock);
2324 2321                          }
2325 2322                          MAC_RX_SRS_ENQUEUE_CHAIN(mac_srs, head, tail,
2326 2323                              count, sz);
2327 2324                          if (count <= 10)
2328 2325                                  srs_rx->sr_stat.mrs_chaincntundr10++;
2329 2326                          else if (count > 10 && count <= 50)
2330 2327                                  srs_rx->sr_stat.mrs_chaincnt10to50++;
2331 2328                          else
2332 2329                                  srs_rx->sr_stat.mrs_chaincntover50++;
2333 2330                  }
2334 2331  
2335 2332                  /*
2336 2333                   * We are guaranteed that SRS_PROC will be set if we
2337 2334                   * are here. Also, poll thread gets to run only if
2338 2335                   * the drain was being done by a worker thread although
2339 2336                   * its possible that worker thread is still running
2340 2337                   * and poll thread was sent down to keep the pipeline
2341 2338                   * going instead of doing a complete drain and then
2342 2339                   * trying to poll the NIC.
2343 2340                   *
2344 2341                   * So we need to check SRS_WORKER flag to make sure
2345 2342                   * that the worker thread is not processing the queue
2346 2343                   * in parallel to us. The flags and conditions are
2347 2344                   * protected by the srs_lock to prevent any race. We
2348 2345                   * ensure that we don't drop the srs_lock from now
2349 2346                   * till the end and similarly we don't drop the srs_lock
2350 2347                   * in mac_rx_srs_drain() till similar condition check
2351 2348                   * are complete. The mac_rx_srs_drain() needs to ensure
2352 2349                   * that SRS_WORKER flag remains set as long as its
2353 2350                   * processing the queue.
2354 2351                   */
2355 2352                  if (!(mac_srs->srs_state & SRS_WORKER) &&
2356 2353                      (mac_srs->srs_first != NULL)) {
2357 2354                          /*
2358 2355                           * We have packets to process and worker thread
2359 2356                           * is not running. Check to see if poll thread is
2360 2357                           * allowed to process.
2361 2358                           */
2362 2359                          if (mac_srs->srs_state & SRS_LATENCY_OPT) {
2363 2360                                  mac_srs->srs_drain_func(mac_srs, SRS_POLL_PROC);
2364 2361                                  if (!(mac_srs->srs_state & SRS_PAUSE) &&
2365 2362                                      srs_rx->sr_poll_pkt_cnt <=
2366 2363                                      srs_rx->sr_lowat) {
2367 2364                                          srs_rx->sr_poll_again++;
2368 2365                                          goto check_again;
2369 2366                                  }
2370 2367                                  /*
2371 2368                                   * We are already above low water mark
2372 2369                                   * so stay in the polling mode but no
2373 2370                                   * need to poll. Once we dip below
2374 2371                                   * the polling threshold, the processing
2375 2372                                   * thread (soft ring) will signal us
2376 2373                                   * to poll again (MAC_UPDATE_SRS_COUNT)
2377 2374                                   */
2378 2375                                  srs_rx->sr_poll_drain_no_poll++;
2379 2376                                  mac_srs->srs_state &= ~(SRS_PROC|SRS_GET_PKTS);
2380 2377                                  /*
2381 2378                                   * In B/W control case, its possible
2382 2379                                   * that the backlog built up due to
2383 2380                                   * B/W limit being reached and packets
2384 2381                                   * are queued only in SRS. In this case,
2385 2382                                   * we should schedule worker thread
2386 2383                                   * since no one else will wake us up.
2387 2384                                   */
2388 2385                                  if ((mac_srs->srs_type & SRST_BW_CONTROL) &&
2389 2386                                      (mac_srs->srs_tid == NULL)) {
2390 2387                                          mac_srs->srs_tid =
2391 2388                                              timeout(mac_srs_fire, mac_srs, 1);
2392 2389                                          srs_rx->sr_poll_worker_wakeup++;
2393 2390                                  }
2394 2391                          } else {
2395 2392                                  /*
2396 2393                                   * Wakeup the worker thread for more processing.
2397 2394                                   * We optimize for throughput in this case.
2398 2395                                   */
2399 2396                                  mac_srs->srs_state &= ~(SRS_PROC|SRS_GET_PKTS);
2400 2397                                  MAC_SRS_WORKER_WAKEUP(mac_srs);
2401 2398                                  srs_rx->sr_poll_sig_worker++;
2402 2399                          }
2403 2400                  } else if ((mac_srs->srs_first == NULL) &&
2404 2401                      !(mac_srs->srs_state & SRS_WORKER)) {
2405 2402                          /*
2406 2403                           * There is nothing queued in SRS and
2407 2404                           * no worker thread running. Plus we
2408 2405                           * didn't get anything from the H/W
2409 2406                           * as well (head == NULL);
2410 2407                           */
2411 2408                          ASSERT(head == NULL);
2412 2409                          mac_srs->srs_state &=
2413 2410                              ~(SRS_PROC|SRS_GET_PKTS);
2414 2411  
2415 2412                          /*
2416 2413                           * If we have a packets in soft ring, don't allow
2417 2414                           * more packets to come into this SRS by keeping the
2418 2415                           * interrupts off but not polling the H/W. The
2419 2416                           * poll thread will get signaled as soon as
2420 2417                           * srs_poll_pkt_cnt dips below poll threshold.
2421 2418                           */
2422 2419                          if (srs_rx->sr_poll_pkt_cnt == 0) {
2423 2420                                  srs_rx->sr_poll_intr_enable++;
2424 2421                                  MAC_SRS_POLLING_OFF(mac_srs);
2425 2422                          } else {
2426 2423                                  /*
2427 2424                                   * We know nothing is queued in SRS
2428 2425                                   * since we are here after checking
2429 2426                                   * srs_first is NULL. The backlog
2430 2427                                   * is entirely due to packets queued
2431 2428                                   * in Soft ring which will wake us up
2432 2429                                   * and get the interface out of polling
2433 2430                                   * mode once the backlog dips below
2434 2431                                   * sr_poll_thres.
2435 2432                                   */
2436 2433                                  srs_rx->sr_poll_no_poll++;
2437 2434                          }
2438 2435                  } else {
2439 2436                          /*
2440 2437                           * Worker thread is already running.
2441 2438                           * Nothing much to do. If the polling
2442 2439                           * was enabled, worker thread will deal
2443 2440                           * with that.
2444 2441                           */
2445 2442                          mac_srs->srs_state &= ~SRS_GET_PKTS;
2446 2443                          srs_rx->sr_poll_goto_sleep++;
2447 2444                  }
2448 2445          }
2449 2446  done:
2450 2447          mac_srs->srs_state |= SRS_POLL_THR_QUIESCED;
2451 2448          cv_signal(&mac_srs->srs_async);
2452 2449          /*
2453 2450           * If this is a temporary quiesce then wait for the restart signal
2454 2451           * from the srs worker. Then clear the flags and signal the srs worker
2455 2452           * to ensure a positive handshake and go back to start.
2456 2453           */
2457 2454          while (!(mac_srs->srs_state & (SRS_CONDEMNED | SRS_POLL_THR_RESTART)))
2458 2455                  cv_wait(async, lock);
2459 2456          if (mac_srs->srs_state & SRS_POLL_THR_RESTART) {
2460 2457                  ASSERT(!(mac_srs->srs_state & SRS_CONDEMNED));
2461 2458                  mac_srs->srs_state &=
2462 2459                      ~(SRS_POLL_THR_QUIESCED | SRS_POLL_THR_RESTART);
2463 2460                  cv_signal(&mac_srs->srs_async);
2464 2461                  goto start;
2465 2462          } else {
2466 2463                  mac_srs->srs_state |= SRS_POLL_THR_EXITED;
2467 2464                  cv_signal(&mac_srs->srs_async);
2468 2465                  CALLB_CPR_EXIT(&cprinfo);
2469 2466                  thread_exit();
2470 2467          }
2471 2468  }
2472 2469  
2473 2470  /*
2474 2471   * mac_srs_pick_chain
2475 2472   *
2476 2473   * In Bandwidth control case, checks how many packets can be processed
2477 2474   * and return them in a sub chain.
2478 2475   */
2479 2476  static mblk_t *
2480 2477  mac_srs_pick_chain(mac_soft_ring_set_t *mac_srs, mblk_t **chain_tail,
2481 2478      size_t *chain_sz, int *chain_cnt)
2482 2479  {
2483 2480          mblk_t                  *head = NULL;
2484 2481          mblk_t                  *tail = NULL;
2485 2482          size_t                  sz;
2486 2483          size_t                  tsz = 0;
2487 2484          int                     cnt = 0;
2488 2485          mblk_t                  *mp;
2489 2486  
2490 2487          ASSERT(MUTEX_HELD(&mac_srs->srs_lock));
2491 2488          mutex_enter(&mac_srs->srs_bw->mac_bw_lock);
2492 2489          if (((mac_srs->srs_bw->mac_bw_used + mac_srs->srs_size) <=
2493 2490              mac_srs->srs_bw->mac_bw_limit) ||
2494 2491              (mac_srs->srs_bw->mac_bw_limit == 0)) {
2495 2492                  mutex_exit(&mac_srs->srs_bw->mac_bw_lock);
2496 2493                  head = mac_srs->srs_first;
2497 2494                  mac_srs->srs_first = NULL;
2498 2495                  *chain_tail = mac_srs->srs_last;
2499 2496                  mac_srs->srs_last = NULL;
2500 2497                  *chain_sz = mac_srs->srs_size;
2501 2498                  *chain_cnt = mac_srs->srs_count;
2502 2499                  mac_srs->srs_count = 0;
2503 2500                  mac_srs->srs_size = 0;
2504 2501                  return (head);
2505 2502          }
2506 2503  
2507 2504          /*
2508 2505           * Can't clear the entire backlog.
2509 2506           * Need to find how many packets to pick
2510 2507           */
2511 2508          ASSERT(MUTEX_HELD(&mac_srs->srs_bw->mac_bw_lock));
2512 2509          while ((mp = mac_srs->srs_first) != NULL) {
2513 2510                  sz = msgdsize(mp);
2514 2511                  if ((tsz + sz + mac_srs->srs_bw->mac_bw_used) >
2515 2512                      mac_srs->srs_bw->mac_bw_limit) {
2516 2513                          if (!(mac_srs->srs_bw->mac_bw_state & SRS_BW_ENFORCED))
2517 2514                                  mac_srs->srs_bw->mac_bw_state |=
2518 2515                                      SRS_BW_ENFORCED;
2519 2516                          break;
2520 2517                  }
2521 2518  
2522 2519                  /*
2523 2520                   * The _size & cnt is  decremented from the softrings
2524 2521                   * when they send up the packet for polling to work
2525 2522                   * properly.
2526 2523                   */
2527 2524                  tsz += sz;
2528 2525                  cnt++;
2529 2526                  mac_srs->srs_count--;
2530 2527                  mac_srs->srs_size -= sz;
2531 2528                  if (tail != NULL)
2532 2529                          tail->b_next = mp;
2533 2530                  else
2534 2531                          head = mp;
2535 2532                  tail = mp;
2536 2533                  mac_srs->srs_first = mac_srs->srs_first->b_next;
2537 2534          }
2538 2535          mutex_exit(&mac_srs->srs_bw->mac_bw_lock);
2539 2536          if (mac_srs->srs_first == NULL)
2540 2537                  mac_srs->srs_last = NULL;
2541 2538  
2542 2539          if (tail != NULL)
2543 2540                  tail->b_next = NULL;
2544 2541          *chain_tail = tail;
2545 2542          *chain_cnt = cnt;
2546 2543          *chain_sz = tsz;
2547 2544  
2548 2545          return (head);
2549 2546  }
2550 2547  
2551 2548  /*
2552 2549   * mac_rx_srs_drain
2553 2550   *
2554 2551   * The SRS drain routine. Gets to run to clear the queue. Any thread
2555 2552   * (worker, interrupt, poll) can call this based on processing model.
2556 2553   * The first thing we do is disable interrupts if possible and then
2557 2554   * drain the queue. we also try to poll the underlying hardware if
2558 2555   * there is a dedicated hardware Rx ring assigned to this SRS.
2559 2556   *
2560 2557   * There is a equivalent drain routine in bandwidth control mode
2561 2558   * mac_rx_srs_drain_bw. There is some code duplication between the two
2562 2559   * routines but they are highly performance sensitive and are easier
2563 2560   * to read/debug if they stay separate. Any code changes here might
2564 2561   * also apply to mac_rx_srs_drain_bw as well.
2565 2562   */
2566 2563  void
2567 2564  mac_rx_srs_drain(mac_soft_ring_set_t *mac_srs, uint_t proc_type)
2568 2565  {
2569 2566          mblk_t                  *head;
2570 2567          mblk_t                  *tail;
2571 2568          timeout_id_t            tid;
2572 2569          int                     cnt = 0;
2573 2570          mac_client_impl_t       *mcip = mac_srs->srs_mcip;
2574 2571          mac_srs_rx_t            *srs_rx = &mac_srs->srs_rx;
2575 2572  
2576 2573          ASSERT(MUTEX_HELD(&mac_srs->srs_lock));
2577 2574          ASSERT(!(mac_srs->srs_type & SRST_BW_CONTROL));
2578 2575  
2579 2576          /* If we are blanked i.e. can't do upcalls, then we are done */
2580 2577          if (mac_srs->srs_state & (SRS_BLANK | SRS_PAUSE)) {
2581 2578                  ASSERT((mac_srs->srs_type & SRST_NO_SOFT_RINGS) ||
2582 2579                      (mac_srs->srs_state & SRS_PAUSE));
2583 2580                  goto out;
2584 2581          }
2585 2582  
2586 2583          if (mac_srs->srs_first == NULL)
2587 2584                  goto out;
2588 2585  
2589 2586          if (!(mac_srs->srs_state & SRS_LATENCY_OPT) &&
2590 2587              (srs_rx->sr_poll_pkt_cnt <= srs_rx->sr_lowat)) {
2591 2588                  /*
2592 2589                   * In the normal case, the SRS worker thread does no
2593 2590                   * work and we wait for a backlog to build up before
2594 2591                   * we switch into polling mode. In case we are
2595 2592                   * optimizing for throughput, we use the worker thread
2596 2593                   * as well. The goal is to let worker thread process
2597 2594                   * the queue and poll thread to feed packets into
2598 2595                   * the queue. As such, we should signal the poll
2599 2596                   * thread to try and get more packets.
2600 2597                   *
2601 2598                   * We could have pulled this check in the POLL_RING
2602 2599                   * macro itself but keeping it explicit here makes
2603 2600                   * the architecture more human understandable.
2604 2601                   */
2605 2602                  MAC_SRS_POLL_RING(mac_srs);
2606 2603          }
2607 2604  
2608 2605  again:
2609 2606          head = mac_srs->srs_first;
2610 2607          mac_srs->srs_first = NULL;
2611 2608          tail = mac_srs->srs_last;
2612 2609          mac_srs->srs_last = NULL;
2613 2610          cnt = mac_srs->srs_count;
2614 2611          mac_srs->srs_count = 0;
2615 2612  
2616 2613          ASSERT(head != NULL);
2617 2614          ASSERT(tail != NULL);
2618 2615  
2619 2616          if ((tid = mac_srs->srs_tid) != NULL)
2620 2617                  mac_srs->srs_tid = NULL;
2621 2618  
2622 2619          mac_srs->srs_state |= (SRS_PROC|proc_type);
2623 2620  
2624 2621  
2625 2622          /*
2626 2623           * mcip is NULL for broadcast and multicast flows. The promisc
2627 2624           * callbacks for broadcast and multicast packets are delivered from
2628 2625           * mac_rx() and we don't need to worry about that case in this path
2629 2626           */
2630 2627          if (mcip != NULL) {
2631 2628                  if (mcip->mci_promisc_list != NULL) {
2632 2629                          mutex_exit(&mac_srs->srs_lock);
2633 2630                          mac_promisc_client_dispatch(mcip, head);
2634 2631                          mutex_enter(&mac_srs->srs_lock);
2635 2632                  }
2636 2633                  if (MAC_PROTECT_ENABLED(mcip, MPT_IPNOSPOOF)) {
2637 2634                          mutex_exit(&mac_srs->srs_lock);
2638 2635                          mac_protect_intercept_dynamic(mcip, head);
2639 2636                          mutex_enter(&mac_srs->srs_lock);
2640 2637                  }
2641 2638          }
2642 2639  
2643 2640          /*
2644 2641           * Check if SRS itself is doing the processing
2645 2642           * This direct path does not apply when subflows are present. In this
2646 2643           * case, packets need to be dispatched to a soft ring according to the
2647 2644           * flow's bandwidth and other resources contraints.
2648 2645           */
2649 2646          if (mac_srs->srs_type & SRST_NO_SOFT_RINGS) {
2650 2647                  mac_direct_rx_t         proc;
2651 2648                  void                    *arg1;
2652 2649                  mac_resource_handle_t   arg2;
2653 2650  
2654 2651                  /*
2655 2652                   * This is the case when a Rx is directly
2656 2653                   * assigned and we have a fully classified
2657 2654                   * protocol chain. We can deal with it in
2658 2655                   * one shot.
2659 2656                   */
2660 2657                  proc = srs_rx->sr_func;
2661 2658                  arg1 = srs_rx->sr_arg1;
2662 2659                  arg2 = srs_rx->sr_arg2;
2663 2660  
2664 2661                  mac_srs->srs_state |= SRS_CLIENT_PROC;
2665 2662                  mutex_exit(&mac_srs->srs_lock);
2666 2663                  if (tid != NULL) {
2667 2664                          (void) untimeout(tid);
2668 2665                          tid = NULL;
2669 2666                  }
2670 2667  
2671 2668                  proc(arg1, arg2, head, NULL);
2672 2669                  /*
2673 2670                   * Decrement the size and count here itelf
2674 2671                   * since the packet has been processed.
2675 2672                   */
2676 2673                  mutex_enter(&mac_srs->srs_lock);
2677 2674                  MAC_UPDATE_SRS_COUNT_LOCKED(mac_srs, cnt);
2678 2675                  if (mac_srs->srs_state & SRS_CLIENT_WAIT)
2679 2676                          cv_signal(&mac_srs->srs_client_cv);
2680 2677                  mac_srs->srs_state &= ~SRS_CLIENT_PROC;
2681 2678          } else {
2682 2679                  /* Some kind of softrings based fanout is required */
2683 2680                  mutex_exit(&mac_srs->srs_lock);
2684 2681                  if (tid != NULL) {
2685 2682                          (void) untimeout(tid);
2686 2683                          tid = NULL;
2687 2684                  }
2688 2685  
2689 2686                  /*
2690 2687                   * Since the fanout routines can deal with chains,
2691 2688                   * shoot the entire chain up.
2692 2689                   */
2693 2690                  if (mac_srs->srs_type & SRST_FANOUT_SRC_IP)
2694 2691                          mac_rx_srs_fanout(mac_srs, head);
2695 2692                  else
2696 2693                          mac_rx_srs_proto_fanout(mac_srs, head);
2697 2694                  mutex_enter(&mac_srs->srs_lock);
2698 2695          }
2699 2696  
2700 2697          if (!(mac_srs->srs_state & (SRS_BLANK|SRS_PAUSE)) &&
2701 2698              (mac_srs->srs_first != NULL)) {
2702 2699                  /*
2703 2700                   * More packets arrived while we were clearing the
2704 2701                   * SRS. This can be possible because of one of
2705 2702                   * three conditions below:
2706 2703                   * 1) The driver is using multiple worker threads
2707 2704                   *    to send the packets to us.
2708 2705                   * 2) The driver has a race in switching
2709 2706                   *    between interrupt and polling mode or
2710 2707                   * 3) Packets are arriving in this SRS via the
2711 2708                   *    S/W classification as well.
2712 2709                   *
2713 2710                   * We should switch to polling mode and see if we
2714 2711                   * need to send the poll thread down. Also, signal
2715 2712                   * the worker thread to process whats just arrived.
2716 2713                   */
2717 2714                  MAC_SRS_POLLING_ON(mac_srs);
2718 2715                  if (srs_rx->sr_poll_pkt_cnt <= srs_rx->sr_lowat) {
2719 2716                          srs_rx->sr_drain_poll_sig++;
2720 2717                          MAC_SRS_POLL_RING(mac_srs);
2721 2718                  }
2722 2719  
2723 2720                  /*
2724 2721                   * If we didn't signal the poll thread, we need
2725 2722                   * to deal with the pending packets ourselves.
2726 2723                   */
2727 2724                  if (proc_type == SRS_WORKER) {
2728 2725                          srs_rx->sr_drain_again++;
2729 2726                          goto again;
2730 2727                  } else {
2731 2728                          srs_rx->sr_drain_worker_sig++;
2732 2729                          cv_signal(&mac_srs->srs_async);
2733 2730                  }
2734 2731          }
2735 2732  
2736 2733  out:
2737 2734          if (mac_srs->srs_state & SRS_GET_PKTS) {
2738 2735                  /*
2739 2736                   * Poll thread is already running. Leave the
2740 2737                   * SRS_RPOC set and hand over the control to
2741 2738                   * poll thread.
2742 2739                   */
2743 2740                  mac_srs->srs_state &= ~proc_type;
2744 2741                  srs_rx->sr_drain_poll_running++;
2745 2742                  return;
2746 2743          }
2747 2744  
2748 2745          /*
2749 2746           * Even if there are no packets queued in SRS, we
2750 2747           * need to make sure that the shared counter is
2751 2748           * clear and any associated softrings have cleared
2752 2749           * all the backlog. Otherwise, leave the interface
2753 2750           * in polling mode and the poll thread will get
2754 2751           * signalled once the count goes down to zero.
2755 2752           *
2756 2753           * If someone is already draining the queue (SRS_PROC is
2757 2754           * set) when the srs_poll_pkt_cnt goes down to zero,
2758 2755           * then it means that drain is already running and we
2759 2756           * will turn off polling at that time if there is
2760 2757           * no backlog.
2761 2758           *
2762 2759           * As long as there are packets queued either
2763 2760           * in soft ring set or its soft rings, we will leave
2764 2761           * the interface in polling mode (even if the drain
2765 2762           * was done being the interrupt thread). We signal
2766 2763           * the poll thread as well if we have dipped below
2767 2764           * low water mark.
2768 2765           *
2769 2766           * NOTE: We can't use the MAC_SRS_POLLING_ON macro
2770 2767           * since that turn polling on only for worker thread.
2771 2768           * Its not worth turning polling on for interrupt
2772 2769           * thread (since NIC will not issue another interrupt)
2773 2770           * unless a backlog builds up.
2774 2771           */
2775 2772          if ((srs_rx->sr_poll_pkt_cnt > 0) &&
2776 2773              (mac_srs->srs_state & SRS_POLLING_CAPAB)) {
2777 2774                  mac_srs->srs_state &= ~(SRS_PROC|proc_type);
2778 2775                  srs_rx->sr_drain_keep_polling++;
2779 2776                  MAC_SRS_POLLING_ON(mac_srs);
2780 2777                  if (srs_rx->sr_poll_pkt_cnt <= srs_rx->sr_lowat)
2781 2778                          MAC_SRS_POLL_RING(mac_srs);
2782 2779                  return;
2783 2780          }
2784 2781  
2785 2782          /* Nothing else to do. Get out of poll mode */
2786 2783          MAC_SRS_POLLING_OFF(mac_srs);
2787 2784          mac_srs->srs_state &= ~(SRS_PROC|proc_type);
2788 2785          srs_rx->sr_drain_finish_intr++;
2789 2786  }
2790 2787  
2791 2788  /*
2792 2789   * mac_rx_srs_drain_bw
2793 2790   *
2794 2791   * The SRS BW drain routine. Gets to run to clear the queue. Any thread
2795 2792   * (worker, interrupt, poll) can call this based on processing model.
2796 2793   * The first thing we do is disable interrupts if possible and then
2797 2794   * drain the queue. we also try to poll the underlying hardware if
2798 2795   * there is a dedicated hardware Rx ring assigned to this SRS.
2799 2796   *
2800 2797   * There is a equivalent drain routine in non bandwidth control mode
2801 2798   * mac_rx_srs_drain. There is some code duplication between the two
2802 2799   * routines but they are highly performance sensitive and are easier
2803 2800   * to read/debug if they stay separate. Any code changes here might
2804 2801   * also apply to mac_rx_srs_drain as well.
2805 2802   */
2806 2803  void
2807 2804  mac_rx_srs_drain_bw(mac_soft_ring_set_t *mac_srs, uint_t proc_type)
2808 2805  {
2809 2806          mblk_t                  *head;
2810 2807          mblk_t                  *tail;
2811 2808          timeout_id_t            tid;
2812 2809          size_t                  sz = 0;
2813 2810          int                     cnt = 0;
2814 2811          mac_client_impl_t       *mcip = mac_srs->srs_mcip;
2815 2812          mac_srs_rx_t            *srs_rx = &mac_srs->srs_rx;
2816 2813          clock_t                 now;
2817 2814  
2818 2815          ASSERT(MUTEX_HELD(&mac_srs->srs_lock));
2819 2816          ASSERT(mac_srs->srs_type & SRST_BW_CONTROL);
2820 2817  again:
2821 2818          /* Check if we are doing B/W control */
2822 2819          mutex_enter(&mac_srs->srs_bw->mac_bw_lock);
2823 2820          now = ddi_get_lbolt();
2824 2821          if (mac_srs->srs_bw->mac_bw_curr_time != now) {
2825 2822                  mac_srs->srs_bw->mac_bw_curr_time = now;
2826 2823                  mac_srs->srs_bw->mac_bw_used = 0;
2827 2824                  if (mac_srs->srs_bw->mac_bw_state & SRS_BW_ENFORCED)
2828 2825                          mac_srs->srs_bw->mac_bw_state &= ~SRS_BW_ENFORCED;
2829 2826          } else if (mac_srs->srs_bw->mac_bw_state & SRS_BW_ENFORCED) {
2830 2827                  mutex_exit(&mac_srs->srs_bw->mac_bw_lock);
2831 2828                  goto done;
2832 2829          } else if (mac_srs->srs_bw->mac_bw_used >
2833 2830              mac_srs->srs_bw->mac_bw_limit) {
2834 2831                  mac_srs->srs_bw->mac_bw_state |= SRS_BW_ENFORCED;
2835 2832                  mutex_exit(&mac_srs->srs_bw->mac_bw_lock);
2836 2833                  goto done;
2837 2834          }
2838 2835          mutex_exit(&mac_srs->srs_bw->mac_bw_lock);
2839 2836  
2840 2837          /* If we are blanked i.e. can't do upcalls, then we are done */
2841 2838          if (mac_srs->srs_state & (SRS_BLANK | SRS_PAUSE)) {
2842 2839                  ASSERT((mac_srs->srs_type & SRST_NO_SOFT_RINGS) ||
2843 2840                      (mac_srs->srs_state & SRS_PAUSE));
2844 2841                  goto done;
2845 2842          }
2846 2843  
2847 2844          sz = 0;
2848 2845          cnt = 0;
2849 2846          if ((head = mac_srs_pick_chain(mac_srs, &tail, &sz, &cnt)) == NULL) {
2850 2847                  /*
2851 2848                   * We couldn't pick up a single packet.
2852 2849                   */
2853 2850                  mutex_enter(&mac_srs->srs_bw->mac_bw_lock);
2854 2851                  if ((mac_srs->srs_bw->mac_bw_used == 0) &&
2855 2852                      (mac_srs->srs_size != 0) &&
2856 2853                      !(mac_srs->srs_bw->mac_bw_state & SRS_BW_ENFORCED)) {
2857 2854                          /*
2858 2855                           * Seems like configured B/W doesn't
2859 2856                           * even allow processing of 1 packet
2860 2857                           * per tick.
2861 2858                           *
2862 2859                           * XXX: raise the limit to processing
2863 2860                           * at least 1 packet per tick.
2864 2861                           */
2865 2862                          mac_srs->srs_bw->mac_bw_limit +=
2866 2863                              mac_srs->srs_bw->mac_bw_limit;
2867 2864                          mac_srs->srs_bw->mac_bw_drop_threshold +=
2868 2865                              mac_srs->srs_bw->mac_bw_drop_threshold;
2869 2866                          cmn_err(CE_NOTE, "mac_rx_srs_drain: srs(%p) "
2870 2867                              "raised B/W limit to %d since not even a "
2871 2868                              "single packet can be processed per "
2872 2869                              "tick %d\n", (void *)mac_srs,
2873 2870                              (int)mac_srs->srs_bw->mac_bw_limit,
2874 2871                              (int)msgdsize(mac_srs->srs_first));
2875 2872                  }
2876 2873                  mutex_exit(&mac_srs->srs_bw->mac_bw_lock);
2877 2874                  goto done;
2878 2875          }
2879 2876  
2880 2877          ASSERT(head != NULL);
2881 2878          ASSERT(tail != NULL);
2882 2879  
2883 2880          /* zero bandwidth: drop all and return to interrupt mode */
2884 2881          mutex_enter(&mac_srs->srs_bw->mac_bw_lock);
2885 2882          if (mac_srs->srs_bw->mac_bw_limit == 0) {
2886 2883                  srs_rx->sr_stat.mrs_sdrops += cnt;
2887 2884                  ASSERT(mac_srs->srs_bw->mac_bw_sz >= sz);
2888 2885                  mac_srs->srs_bw->mac_bw_sz -= sz;
2889 2886                  mac_srs->srs_bw->mac_bw_drop_bytes += sz;
2890 2887                  mutex_exit(&mac_srs->srs_bw->mac_bw_lock);
2891 2888                  mac_pkt_drop(NULL, NULL, head, B_FALSE);
2892 2889                  goto leave_poll;
2893 2890          } else {
2894 2891                  mutex_exit(&mac_srs->srs_bw->mac_bw_lock);
2895 2892          }
2896 2893  
2897 2894          if ((tid = mac_srs->srs_tid) != NULL)
2898 2895                  mac_srs->srs_tid = NULL;
2899 2896  
2900 2897          mac_srs->srs_state |= (SRS_PROC|proc_type);
2901 2898          MAC_SRS_WORKER_POLLING_ON(mac_srs);
2902 2899  
2903 2900          /*
2904 2901           * mcip is NULL for broadcast and multicast flows. The promisc
2905 2902           * callbacks for broadcast and multicast packets are delivered from
2906 2903           * mac_rx() and we don't need to worry about that case in this path
2907 2904           */
2908 2905          if (mcip != NULL) {
2909 2906                  if (mcip->mci_promisc_list != NULL) {
2910 2907                          mutex_exit(&mac_srs->srs_lock);
2911 2908                          mac_promisc_client_dispatch(mcip, head);
2912 2909                          mutex_enter(&mac_srs->srs_lock);
2913 2910                  }
2914 2911                  if (MAC_PROTECT_ENABLED(mcip, MPT_IPNOSPOOF)) {
2915 2912                          mutex_exit(&mac_srs->srs_lock);
2916 2913                          mac_protect_intercept_dynamic(mcip, head);
2917 2914                          mutex_enter(&mac_srs->srs_lock);
2918 2915                  }
2919 2916          }
2920 2917  
2921 2918          /*
2922 2919           * Check if SRS itself is doing the processing
2923 2920           * This direct path does not apply when subflows are present. In this
2924 2921           * case, packets need to be dispatched to a soft ring according to the
2925 2922           * flow's bandwidth and other resources contraints.
2926 2923           */
2927 2924          if (mac_srs->srs_type & SRST_NO_SOFT_RINGS) {
2928 2925                  mac_direct_rx_t         proc;
2929 2926                  void                    *arg1;
2930 2927                  mac_resource_handle_t   arg2;
2931 2928  
2932 2929                  /*
2933 2930                   * This is the case when a Rx is directly
2934 2931                   * assigned and we have a fully classified
2935 2932                   * protocol chain. We can deal with it in
2936 2933                   * one shot.
2937 2934                   */
2938 2935                  proc = srs_rx->sr_func;
2939 2936                  arg1 = srs_rx->sr_arg1;
2940 2937                  arg2 = srs_rx->sr_arg2;
2941 2938  
2942 2939                  mac_srs->srs_state |= SRS_CLIENT_PROC;
2943 2940                  mutex_exit(&mac_srs->srs_lock);
2944 2941                  if (tid != NULL) {
2945 2942                          (void) untimeout(tid);
2946 2943                          tid = NULL;
2947 2944                  }
2948 2945  
2949 2946                  proc(arg1, arg2, head, NULL);
2950 2947                  /*
2951 2948                   * Decrement the size and count here itelf
2952 2949                   * since the packet has been processed.
2953 2950                   */
2954 2951                  mutex_enter(&mac_srs->srs_lock);
2955 2952                  MAC_UPDATE_SRS_COUNT_LOCKED(mac_srs, cnt);
2956 2953                  MAC_UPDATE_SRS_SIZE_LOCKED(mac_srs, sz);
2957 2954  
2958 2955                  if (mac_srs->srs_state & SRS_CLIENT_WAIT)
2959 2956                          cv_signal(&mac_srs->srs_client_cv);
2960 2957                  mac_srs->srs_state &= ~SRS_CLIENT_PROC;
2961 2958          } else {
2962 2959                  /* Some kind of softrings based fanout is required */
2963 2960                  mutex_exit(&mac_srs->srs_lock);
2964 2961                  if (tid != NULL) {
2965 2962                          (void) untimeout(tid);
2966 2963                          tid = NULL;
2967 2964                  }
2968 2965  
2969 2966                  /*
2970 2967                   * Since the fanout routines can deal with chains,
2971 2968                   * shoot the entire chain up.
2972 2969                   */
2973 2970                  if (mac_srs->srs_type & SRST_FANOUT_SRC_IP)
2974 2971                          mac_rx_srs_fanout(mac_srs, head);
2975 2972                  else
2976 2973                          mac_rx_srs_proto_fanout(mac_srs, head);
2977 2974                  mutex_enter(&mac_srs->srs_lock);
2978 2975          }
2979 2976  
2980 2977          /*
2981 2978           * Send the poll thread to pick up any packets arrived
2982 2979           * so far. This also serves as the last check in case
2983 2980           * nothing else is queued in the SRS. The poll thread
2984 2981           * is signalled only in the case the drain was done
2985 2982           * by the worker thread and SRS_WORKER is set. The
2986 2983           * worker thread can run in parallel as long as the
2987 2984           * SRS_WORKER flag is set. We we have nothing else to
2988 2985           * process, we can exit while leaving SRS_PROC set
2989 2986           * which gives the poll thread control to process and
2990 2987           * cleanup once it returns from the NIC.
2991 2988           *
2992 2989           * If we have nothing else to process, we need to
2993 2990           * ensure that we keep holding the srs_lock till
2994 2991           * all the checks below are done and control is
2995 2992           * handed to the poll thread if it was running.
2996 2993           */
2997 2994          mutex_enter(&mac_srs->srs_bw->mac_bw_lock);
2998 2995          if (!(mac_srs->srs_bw->mac_bw_state & SRS_BW_ENFORCED)) {
2999 2996                  if (mac_srs->srs_first != NULL) {
3000 2997                          if (proc_type == SRS_WORKER) {
3001 2998                                  mutex_exit(&mac_srs->srs_bw->mac_bw_lock);
3002 2999                                  if (srs_rx->sr_poll_pkt_cnt <=
3003 3000                                      srs_rx->sr_lowat)
3004 3001                                          MAC_SRS_POLL_RING(mac_srs);
3005 3002                                  goto again;
3006 3003                          } else {
3007 3004                                  cv_signal(&mac_srs->srs_async);
3008 3005                          }
3009 3006                  }
3010 3007          }
3011 3008          mutex_exit(&mac_srs->srs_bw->mac_bw_lock);
3012 3009  
3013 3010  done:
3014 3011  
3015 3012          if (mac_srs->srs_state & SRS_GET_PKTS) {
3016 3013                  /*
3017 3014                   * Poll thread is already running. Leave the
3018 3015                   * SRS_RPOC set and hand over the control to
3019 3016                   * poll thread.
3020 3017                   */
3021 3018                  mac_srs->srs_state &= ~proc_type;
3022 3019                  return;
3023 3020          }
3024 3021  
3025 3022          /*
3026 3023           * If we can't process packets because we have exceeded
3027 3024           * B/W limit for this tick, just set the timeout
3028 3025           * and leave.
3029 3026           *
3030 3027           * Even if there are no packets queued in SRS, we
3031 3028           * need to make sure that the shared counter is
3032 3029           * clear and any associated softrings have cleared
3033 3030           * all the backlog. Otherwise, leave the interface
3034 3031           * in polling mode and the poll thread will get
3035 3032           * signalled once the count goes down to zero.
3036 3033           *
3037 3034           * If someone is already draining the queue (SRS_PROC is
3038 3035           * set) when the srs_poll_pkt_cnt goes down to zero,
3039 3036           * then it means that drain is already running and we
3040 3037           * will turn off polling at that time if there is
3041 3038           * no backlog. As long as there are packets queued either
3042 3039           * is soft ring set or its soft rings, we will leave
3043 3040           * the interface in polling mode.
3044 3041           */
3045 3042          mutex_enter(&mac_srs->srs_bw->mac_bw_lock);
3046 3043          if ((mac_srs->srs_state & SRS_POLLING_CAPAB) &&
3047 3044              ((mac_srs->srs_bw->mac_bw_state & SRS_BW_ENFORCED) ||
3048 3045              (srs_rx->sr_poll_pkt_cnt > 0))) {
3049 3046                  MAC_SRS_POLLING_ON(mac_srs);
3050 3047                  mac_srs->srs_state &= ~(SRS_PROC|proc_type);
3051 3048                  if ((mac_srs->srs_first != NULL) &&
3052 3049                      (mac_srs->srs_tid == NULL))
3053 3050                          mac_srs->srs_tid = timeout(mac_srs_fire,
3054 3051                              mac_srs, 1);
3055 3052                  mutex_exit(&mac_srs->srs_bw->mac_bw_lock);
3056 3053                  return;
3057 3054          }
3058 3055          mutex_exit(&mac_srs->srs_bw->mac_bw_lock);
3059 3056  
3060 3057  leave_poll:
3061 3058  
3062 3059          /* Nothing else to do. Get out of poll mode */
3063 3060          MAC_SRS_POLLING_OFF(mac_srs);
3064 3061          mac_srs->srs_state &= ~(SRS_PROC|proc_type);
3065 3062  }
3066 3063  
3067 3064  /*
3068 3065   * mac_srs_worker
3069 3066   *
3070 3067   * The SRS worker routine. Drains the queue when no one else is
3071 3068   * processing it.
3072 3069   */
3073 3070  void
3074 3071  mac_srs_worker(mac_soft_ring_set_t *mac_srs)
3075 3072  {
3076 3073          kmutex_t                *lock = &mac_srs->srs_lock;
3077 3074          kcondvar_t              *async = &mac_srs->srs_async;
3078 3075          callb_cpr_t             cprinfo;
3079 3076          boolean_t               bw_ctl_flag;
3080 3077  
3081 3078          CALLB_CPR_INIT(&cprinfo, lock, callb_generic_cpr, "srs_worker");
3082 3079          mutex_enter(lock);
3083 3080  
3084 3081  start:
3085 3082          for (;;) {
3086 3083                  bw_ctl_flag = B_FALSE;
3087 3084                  if (mac_srs->srs_type & SRST_BW_CONTROL) {
3088 3085                          MAC_SRS_BW_LOCK(mac_srs);
3089 3086                          MAC_SRS_CHECK_BW_CONTROL(mac_srs);
3090 3087                          if (mac_srs->srs_bw->mac_bw_state & SRS_BW_ENFORCED)
3091 3088                                  bw_ctl_flag = B_TRUE;
3092 3089                          MAC_SRS_BW_UNLOCK(mac_srs);
3093 3090                  }
3094 3091                  /*
3095 3092                   * The SRS_BW_ENFORCED flag may change since we have dropped
3096 3093                   * the mac_bw_lock. However the drain function can handle both
3097 3094                   * a drainable SRS or a bandwidth controlled SRS, and the
3098 3095                   * effect of scheduling a timeout is to wakeup the worker
3099 3096                   * thread which in turn will call the drain function. Since
3100 3097                   * we release the srs_lock atomically only in the cv_wait there
3101 3098                   * isn't a fear of waiting for ever.
3102 3099                   */
3103 3100                  while (((mac_srs->srs_state & SRS_PROC) ||
3104 3101                      (mac_srs->srs_first == NULL) || bw_ctl_flag ||
3105 3102                      (mac_srs->srs_state & SRS_TX_BLOCKED)) &&
3106 3103                      !(mac_srs->srs_state & SRS_PAUSE)) {
3107 3104                          /*
3108 3105                           * If we have packets queued and we are here
3109 3106                           * because B/W control is in place, we better
3110 3107                           * schedule the worker wakeup after 1 tick
3111 3108                           * to see if bandwidth control can be relaxed.
3112 3109                           */
3113 3110                          if (bw_ctl_flag && mac_srs->srs_tid == NULL) {
3114 3111                                  /*
3115 3112                                   * We need to ensure that a timer  is already
3116 3113                                   * scheduled or we force  schedule one for
3117 3114                                   * later so that we can continue processing
3118 3115                                   * after this  quanta is over.
3119 3116                                   */
3120 3117                                  mac_srs->srs_tid = timeout(mac_srs_fire,
3121 3118                                      mac_srs, 1);
3122 3119                          }
3123 3120  wait:
3124 3121                          CALLB_CPR_SAFE_BEGIN(&cprinfo);
3125 3122                          cv_wait(async, lock);
3126 3123                          CALLB_CPR_SAFE_END(&cprinfo, lock);
3127 3124  
3128 3125                          if (mac_srs->srs_state & SRS_PAUSE)
3129 3126                                  goto done;
3130 3127                          if (mac_srs->srs_state & SRS_PROC)
3131 3128                                  goto wait;
3132 3129  
3133 3130                          if (mac_srs->srs_first != NULL &&
3134 3131                              mac_srs->srs_type & SRST_BW_CONTROL) {
3135 3132                                  MAC_SRS_BW_LOCK(mac_srs);
3136 3133                                  if (mac_srs->srs_bw->mac_bw_state &
3137 3134                                      SRS_BW_ENFORCED) {
3138 3135                                          MAC_SRS_CHECK_BW_CONTROL(mac_srs);
3139 3136                                  }
3140 3137                                  bw_ctl_flag = mac_srs->srs_bw->mac_bw_state &
3141 3138                                      SRS_BW_ENFORCED;
3142 3139                                  MAC_SRS_BW_UNLOCK(mac_srs);
3143 3140                          }
3144 3141                  }
3145 3142  
3146 3143                  if (mac_srs->srs_state & SRS_PAUSE)
3147 3144                          goto done;
3148 3145                  mac_srs->srs_drain_func(mac_srs, SRS_WORKER);
3149 3146          }
3150 3147  done:
3151 3148          /*
3152 3149           * The Rx SRS quiesce logic first cuts off packet supply to the SRS
3153 3150           * from both hard and soft classifications and waits for such threads
3154 3151           * to finish before signaling the worker. So at this point the only
3155 3152           * thread left that could be competing with the worker is the poll
3156 3153           * thread. In the case of Tx, there shouldn't be any thread holding
3157 3154           * SRS_PROC at this point.
3158 3155           */
3159 3156          if (!(mac_srs->srs_state & SRS_PROC)) {
3160 3157                  mac_srs->srs_state |= SRS_PROC;
3161 3158          } else {
3162 3159                  ASSERT((mac_srs->srs_type & SRST_TX) == 0);
3163 3160                  /*
3164 3161                   * Poll thread still owns the SRS and is still running
3165 3162                   */
3166 3163                  ASSERT((mac_srs->srs_poll_thr == NULL) ||
3167 3164                      ((mac_srs->srs_state & SRS_POLL_THR_OWNER) ==
3168 3165                      SRS_POLL_THR_OWNER));
3169 3166          }
3170 3167          mac_srs_worker_quiesce(mac_srs);
3171 3168          /*
3172 3169           * Wait for the SRS_RESTART or SRS_CONDEMNED signal from the initiator
3173 3170           * of the quiesce operation
3174 3171           */
3175 3172          while (!(mac_srs->srs_state & (SRS_CONDEMNED | SRS_RESTART)))
3176 3173                  cv_wait(&mac_srs->srs_async, &mac_srs->srs_lock);
3177 3174  
3178 3175          if (mac_srs->srs_state & SRS_RESTART) {
3179 3176                  ASSERT(!(mac_srs->srs_state & SRS_CONDEMNED));
3180 3177                  mac_srs_worker_restart(mac_srs);
3181 3178                  mac_srs->srs_state &= ~SRS_PROC;
3182 3179                  goto start;
3183 3180          }
3184 3181  
3185 3182          if (!(mac_srs->srs_state & SRS_CONDEMNED_DONE))
3186 3183                  mac_srs_worker_quiesce(mac_srs);
3187 3184  
3188 3185          mac_srs->srs_state &= ~SRS_PROC;
3189 3186          /* The macro drops the srs_lock */
3190 3187          CALLB_CPR_EXIT(&cprinfo);
3191 3188          thread_exit();
3192 3189  }
3193 3190  
3194 3191  /*
3195 3192   * mac_rx_srs_subflow_process
3196 3193   *
3197 3194   * Receive side routine called from interrupt path when there are
3198 3195   * sub flows present on this SRS.
3199 3196   */
3200 3197  /* ARGSUSED */
3201 3198  void
3202 3199  mac_rx_srs_subflow_process(void *arg, mac_resource_handle_t srs,
3203 3200      mblk_t *mp_chain, boolean_t loopback)
3204 3201  {
3205 3202          flow_entry_t            *flent = NULL;
3206 3203          flow_entry_t            *prev_flent = NULL;
3207 3204          mblk_t                  *mp = NULL;
3208 3205          mblk_t                  *tail = NULL;
3209 3206          mac_soft_ring_set_t     *mac_srs = (mac_soft_ring_set_t *)srs;
3210 3207          mac_client_impl_t       *mcip;
3211 3208  
3212 3209          mcip = mac_srs->srs_mcip;
3213 3210          ASSERT(mcip != NULL);
3214 3211  
3215 3212          /*
3216 3213           * We need to determine the SRS for every packet
3217 3214           * by walking the flow table, if we don't get any,
3218 3215           * then we proceed using the SRS we came with.
3219 3216           */
3220 3217          mp = tail = mp_chain;
3221 3218          while (mp != NULL) {
3222 3219  
3223 3220                  /*
3224 3221                   * We will increment the stats for the mactching subflow.
3225 3222                   * when we get the bytes/pkt count for the classified packets
3226 3223                   * later in mac_rx_srs_process.
3227 3224                   */
3228 3225                  (void) mac_flow_lookup(mcip->mci_subflow_tab, mp,
3229 3226                      FLOW_INBOUND, &flent);
3230 3227  
3231 3228                  if (mp == mp_chain || flent == prev_flent) {
3232 3229                          if (prev_flent != NULL)
3233 3230                                  FLOW_REFRELE(prev_flent);
3234 3231                          prev_flent = flent;
3235 3232                          flent = NULL;
3236 3233                          tail = mp;
3237 3234                          mp = mp->b_next;
3238 3235                          continue;
3239 3236                  }
3240 3237                  tail->b_next = NULL;
3241 3238                  /*
3242 3239                   * A null indicates, this is for the mac_srs itself.
3243 3240                   * XXX-venu : probably assert for fe_rx_srs_cnt == 0.
3244 3241                   */
3245 3242                  if (prev_flent == NULL || prev_flent->fe_rx_srs_cnt == 0) {
3246 3243                          mac_rx_srs_process(arg,
3247 3244                              (mac_resource_handle_t)mac_srs, mp_chain,
3248 3245                              loopback);
3249 3246                  } else {
3250 3247                          (prev_flent->fe_cb_fn)(prev_flent->fe_cb_arg1,
3251 3248                              prev_flent->fe_cb_arg2, mp_chain, loopback);
3252 3249                          FLOW_REFRELE(prev_flent);
3253 3250                  }
3254 3251                  prev_flent = flent;
3255 3252                  flent = NULL;
3256 3253                  mp_chain = mp;
3257 3254                  tail = mp;
3258 3255                  mp = mp->b_next;
3259 3256          }
3260 3257          /* Last chain */
3261 3258          ASSERT(mp_chain != NULL);
3262 3259          if (prev_flent == NULL || prev_flent->fe_rx_srs_cnt == 0) {
3263 3260                  mac_rx_srs_process(arg,
3264 3261                      (mac_resource_handle_t)mac_srs, mp_chain, loopback);
3265 3262          } else {
3266 3263                  (prev_flent->fe_cb_fn)(prev_flent->fe_cb_arg1,
3267 3264                      prev_flent->fe_cb_arg2, mp_chain, loopback);
3268 3265                  FLOW_REFRELE(prev_flent);
3269 3266          }
3270 3267  }
3271 3268  
3272 3269  /*
3273 3270   * mac_rx_srs_process
3274 3271   *
3275 3272   * Receive side routine called from the interrupt path.
3276 3273   *
3277 3274   * loopback is set to force a context switch on the loopback
3278 3275   * path between MAC clients.
3279 3276   */
3280 3277  /* ARGSUSED */
3281 3278  void
3282 3279  mac_rx_srs_process(void *arg, mac_resource_handle_t srs, mblk_t *mp_chain,
3283 3280      boolean_t loopback)
3284 3281  {
3285 3282          mac_soft_ring_set_t     *mac_srs = (mac_soft_ring_set_t *)srs;
3286 3283          mblk_t                  *mp, *tail, *head;
3287 3284          int                     count = 0;
3288 3285          int                     count1;
3289 3286          size_t                  sz = 0;
3290 3287          size_t                  chain_sz, sz1;
3291 3288          mac_bw_ctl_t            *mac_bw;
3292 3289          mac_srs_rx_t            *srs_rx = &mac_srs->srs_rx;
3293 3290  
3294 3291          /*
3295 3292           * Set the tail, count and sz. We set the sz irrespective
3296 3293           * of whether we are doing B/W control or not for the
3297 3294           * purpose of updating the stats.
3298 3295           */
3299 3296          mp = tail = mp_chain;
3300 3297          while (mp != NULL) {
3301 3298                  tail = mp;
3302 3299                  count++;
3303 3300                  sz += msgdsize(mp);
3304 3301                  mp = mp->b_next;
3305 3302          }
3306 3303  
3307 3304          mutex_enter(&mac_srs->srs_lock);
3308 3305  
3309 3306          if (loopback) {
3310 3307                  SRS_RX_STAT_UPDATE(mac_srs, lclbytes, sz);
3311 3308                  SRS_RX_STAT_UPDATE(mac_srs, lclcnt, count);
3312 3309  
3313 3310          } else {
3314 3311                  SRS_RX_STAT_UPDATE(mac_srs, intrbytes, sz);
3315 3312                  SRS_RX_STAT_UPDATE(mac_srs, intrcnt, count);
3316 3313          }
3317 3314  
3318 3315          /*
3319 3316           * If the SRS in already being processed; has been blanked;
3320 3317           * can be processed by worker thread only; or the B/W limit
3321 3318           * has been reached, then queue the chain and check if
3322 3319           * worker thread needs to be awakend.
3323 3320           */
3324 3321          if (mac_srs->srs_type & SRST_BW_CONTROL) {
3325 3322                  mac_bw = mac_srs->srs_bw;
3326 3323                  ASSERT(mac_bw != NULL);
3327 3324                  mutex_enter(&mac_bw->mac_bw_lock);
3328 3325                  mac_bw->mac_bw_intr += sz;
3329 3326                  if (mac_bw->mac_bw_limit == 0) {
3330 3327                          /* zero bandwidth: drop all */
3331 3328                          srs_rx->sr_stat.mrs_sdrops += count;
3332 3329                          mac_bw->mac_bw_drop_bytes += sz;
3333 3330                          mutex_exit(&mac_bw->mac_bw_lock);
3334 3331                          mutex_exit(&mac_srs->srs_lock);
3335 3332                          mac_pkt_drop(NULL, NULL, mp_chain, B_FALSE);
3336 3333                          return;
3337 3334                  } else {
3338 3335                          if ((mac_bw->mac_bw_sz + sz) <=
3339 3336                              mac_bw->mac_bw_drop_threshold) {
3340 3337                                  mutex_exit(&mac_bw->mac_bw_lock);
3341 3338                                  MAC_RX_SRS_ENQUEUE_CHAIN(mac_srs, mp_chain,
3342 3339                                      tail, count, sz);
3343 3340                          } else {
3344 3341                                  mp = mp_chain;
3345 3342                                  chain_sz = 0;
3346 3343                                  count1 = 0;
3347 3344                                  tail = NULL;
3348 3345                                  head = NULL;
3349 3346                                  while (mp != NULL) {
3350 3347                                          sz1 = msgdsize(mp);
3351 3348                                          if (mac_bw->mac_bw_sz + chain_sz + sz1 >
3352 3349                                              mac_bw->mac_bw_drop_threshold)
3353 3350                                                  break;
3354 3351                                          chain_sz += sz1;
3355 3352                                          count1++;
3356 3353                                          tail = mp;
3357 3354                                          mp = mp->b_next;
3358 3355                                  }
3359 3356                                  mutex_exit(&mac_bw->mac_bw_lock);
3360 3357                                  if (tail != NULL) {
3361 3358                                          head = tail->b_next;
3362 3359                                          tail->b_next = NULL;
3363 3360                                          MAC_RX_SRS_ENQUEUE_CHAIN(mac_srs,
3364 3361                                              mp_chain, tail, count1, chain_sz);
3365 3362                                          sz -= chain_sz;
3366 3363                                          count -= count1;
3367 3364                                  } else {
3368 3365                                          /* Can't pick up any */
3369 3366                                          head = mp_chain;
3370 3367                                  }
3371 3368                                  if (head != NULL) {
3372 3369                                          /* Drop any packet over the threshold */
3373 3370                                          srs_rx->sr_stat.mrs_sdrops += count;
3374 3371                                          mutex_enter(&mac_bw->mac_bw_lock);
3375 3372                                          mac_bw->mac_bw_drop_bytes += sz;
3376 3373                                          mutex_exit(&mac_bw->mac_bw_lock);
3377 3374                                          freemsgchain(head);
3378 3375                                  }
3379 3376                          }
3380 3377                          MAC_SRS_WORKER_WAKEUP(mac_srs);
3381 3378                          mutex_exit(&mac_srs->srs_lock);
3382 3379                          return;
3383 3380                  }
3384 3381          }
3385 3382  
3386 3383          /*
3387 3384           * If the total number of packets queued in the SRS and
3388 3385           * its associated soft rings exceeds the max allowed,
3389 3386           * then drop the chain. If we are polling capable, this
3390 3387           * shouldn't be happening.
3391 3388           */
3392 3389          if (!(mac_srs->srs_type & SRST_BW_CONTROL) &&
3393 3390              (srs_rx->sr_poll_pkt_cnt > srs_rx->sr_hiwat)) {
3394 3391                  mac_bw = mac_srs->srs_bw;
3395 3392                  srs_rx->sr_stat.mrs_sdrops += count;
3396 3393                  mutex_enter(&mac_bw->mac_bw_lock);
3397 3394                  mac_bw->mac_bw_drop_bytes += sz;
3398 3395                  mutex_exit(&mac_bw->mac_bw_lock);
3399 3396                  freemsgchain(mp_chain);
3400 3397                  mutex_exit(&mac_srs->srs_lock);
3401 3398                  return;
3402 3399          }
3403 3400  
3404 3401          MAC_RX_SRS_ENQUEUE_CHAIN(mac_srs, mp_chain, tail, count, sz);
3405 3402  
3406 3403          if (!(mac_srs->srs_state & SRS_PROC)) {
3407 3404                  /*
3408 3405                   * If we are coming via loopback, if we are not optimizing for
3409 3406                   * latency, or if our stack is running deep, we should signal
3410 3407                   * the worker thread.
3411 3408                   */
3412 3409                  if (loopback || !(mac_srs->srs_state & SRS_LATENCY_OPT) ||
3413 3410                      MAC_RX_SRS_TOODEEP()) {
3414 3411                          /*
3415 3412                           * For loopback, We need to let the worker take
3416 3413                           * over as we don't want to continue in the same
3417 3414                           * thread even if we can. This could lead to stack
3418 3415                           * overflows and may also end up using
3419 3416                           * resources (cpu) incorrectly.
3420 3417                           */
3421 3418                          cv_signal(&mac_srs->srs_async);
3422 3419                  } else {
3423 3420                          /*
3424 3421                           * Seems like no one is processing the SRS and
3425 3422                           * there is no backlog. We also inline process
3426 3423                           * our packet if its a single packet in non
3427 3424                           * latency optimized case (in latency optimized
3428 3425                           * case, we inline process chains of any size).
3429 3426                           */
3430 3427                          mac_srs->srs_drain_func(mac_srs, SRS_PROC_FAST);
3431 3428                  }
3432 3429          }
3433 3430          mutex_exit(&mac_srs->srs_lock);
3434 3431  }
3435 3432  
3436 3433  /* TX SIDE ROUTINES (RUNTIME) */
3437 3434  
3438 3435  /*
3439 3436   * mac_tx_srs_no_desc
3440 3437   *
3441 3438   * This routine is called by Tx single ring default mode
3442 3439   * when Tx ring runs out of descs.
3443 3440   */
3444 3441  mac_tx_cookie_t
3445 3442  mac_tx_srs_no_desc(mac_soft_ring_set_t *mac_srs, mblk_t *mp_chain,
3446 3443      uint16_t flag, mblk_t **ret_mp)
3447 3444  {
3448 3445          mac_tx_cookie_t cookie = NULL;
3449 3446          mac_srs_tx_t *srs_tx = &mac_srs->srs_tx;
3450 3447          boolean_t wakeup_worker = B_TRUE;
3451 3448          uint32_t tx_mode = srs_tx->st_mode;
3452 3449          int cnt, sz;
3453 3450          mblk_t *tail;
3454 3451  
3455 3452          ASSERT(tx_mode == SRS_TX_DEFAULT || tx_mode == SRS_TX_BW);
3456 3453          if (flag & MAC_DROP_ON_NO_DESC) {
3457 3454                  MAC_TX_SRS_DROP_MESSAGE(mac_srs, mp_chain, cookie);
3458 3455          } else {
3459 3456                  if (mac_srs->srs_first != NULL)
3460 3457                          wakeup_worker = B_FALSE;
3461 3458                  MAC_COUNT_CHAIN(mac_srs, mp_chain, tail, cnt, sz);
3462 3459                  if (flag & MAC_TX_NO_ENQUEUE) {
3463 3460                          /*
3464 3461                           * If TX_QUEUED is not set, queue the
3465 3462                           * packet and let mac_tx_srs_drain()
3466 3463                           * set the TX_BLOCKED bit for the
3467 3464                           * reasons explained above. Otherwise,
3468 3465                           * return the mblks.
3469 3466                           */
3470 3467                          if (wakeup_worker) {
3471 3468                                  MAC_TX_SRS_ENQUEUE_CHAIN(mac_srs,
3472 3469                                      mp_chain, tail, cnt, sz);
3473 3470                          } else {
3474 3471                                  MAC_TX_SET_NO_ENQUEUE(mac_srs,
3475 3472                                      mp_chain, ret_mp, cookie);
3476 3473                          }
3477 3474                  } else {
3478 3475                          MAC_TX_SRS_TEST_HIWAT(mac_srs, mp_chain,
3479 3476                              tail, cnt, sz, cookie);
3480 3477                  }
3481 3478                  if (wakeup_worker)
3482 3479                          cv_signal(&mac_srs->srs_async);
3483 3480          }
3484 3481          return (cookie);
3485 3482  }
3486 3483  
3487 3484  /*
3488 3485   * mac_tx_srs_enqueue
3489 3486   *
3490 3487   * This routine is called when Tx SRS is operating in either serializer
3491 3488   * or bandwidth mode. In serializer mode, a packet will get enqueued
3492 3489   * when a thread cannot enter SRS exclusively. In bandwidth mode,
3493 3490   * packets gets queued if allowed byte-count limit for a tick is
3494 3491   * exceeded. The action that gets taken when MAC_DROP_ON_NO_DESC and
3495 3492   * MAC_TX_NO_ENQUEUE is set is different than when operaing in either
3496 3493   * the default mode or fanout mode. Here packets get dropped or
3497 3494   * returned back to the caller only after hi-watermark worth of data
3498 3495   * is queued.
3499 3496   */
3500 3497  static mac_tx_cookie_t
3501 3498  mac_tx_srs_enqueue(mac_soft_ring_set_t *mac_srs, mblk_t *mp_chain,
3502 3499      uint16_t flag, uintptr_t fanout_hint, mblk_t **ret_mp)
3503 3500  {
3504 3501          mac_tx_cookie_t cookie = NULL;
3505 3502          int cnt, sz;
3506 3503          mblk_t *tail;
3507 3504          boolean_t wakeup_worker = B_TRUE;
3508 3505  
3509 3506          /*
3510 3507           * Ignore fanout hint if we don't have multiple tx rings.
3511 3508           */
3512 3509          if (!MAC_TX_SOFT_RINGS(mac_srs))
3513 3510                  fanout_hint = 0;
3514 3511  
3515 3512          if (mac_srs->srs_first != NULL)
3516 3513                  wakeup_worker = B_FALSE;
3517 3514          MAC_COUNT_CHAIN(mac_srs, mp_chain, tail, cnt, sz);
3518 3515          if (flag & MAC_DROP_ON_NO_DESC) {
3519 3516                  if (mac_srs->srs_count > mac_srs->srs_tx.st_hiwat) {
3520 3517                          MAC_TX_SRS_DROP_MESSAGE(mac_srs, mp_chain, cookie);
3521 3518                  } else {
3522 3519                          MAC_TX_SRS_ENQUEUE_CHAIN(mac_srs,
3523 3520                              mp_chain, tail, cnt, sz);
3524 3521                  }
3525 3522          } else if (flag & MAC_TX_NO_ENQUEUE) {
3526 3523                  if ((mac_srs->srs_count > mac_srs->srs_tx.st_hiwat) ||
3527 3524                      (mac_srs->srs_state & SRS_TX_WAKEUP_CLIENT)) {
3528 3525                          MAC_TX_SET_NO_ENQUEUE(mac_srs, mp_chain,
3529 3526                              ret_mp, cookie);
3530 3527                  } else {
3531 3528                          mp_chain->b_prev = (mblk_t *)fanout_hint;
3532 3529                          MAC_TX_SRS_ENQUEUE_CHAIN(mac_srs,
3533 3530                              mp_chain, tail, cnt, sz);
3534 3531                  }
3535 3532          } else {
3536 3533                  /*
3537 3534                   * If you are BW_ENFORCED, just enqueue the
3538 3535                   * packet. srs_worker will drain it at the
3539 3536                   * prescribed rate. Before enqueueing, save
3540 3537                   * the fanout hint.
3541 3538                   */
3542 3539                  mp_chain->b_prev = (mblk_t *)fanout_hint;
3543 3540                  MAC_TX_SRS_TEST_HIWAT(mac_srs, mp_chain,
3544 3541                      tail, cnt, sz, cookie);
3545 3542          }
3546 3543          if (wakeup_worker)
3547 3544                  cv_signal(&mac_srs->srs_async);
3548 3545          return (cookie);
3549 3546  }
3550 3547  
3551 3548  /*
3552 3549   * There are seven tx modes:
3553 3550   *
3554 3551   * 1) Default mode (SRS_TX_DEFAULT)
3555 3552   * 2) Serialization mode (SRS_TX_SERIALIZE)
3556 3553   * 3) Fanout mode (SRS_TX_FANOUT)
3557 3554   * 4) Bandwdith mode (SRS_TX_BW)
3558 3555   * 5) Fanout and Bandwidth mode (SRS_TX_BW_FANOUT)
3559 3556   * 6) aggr Tx mode (SRS_TX_AGGR)
3560 3557   * 7) aggr Tx bw mode (SRS_TX_BW_AGGR)
3561 3558   *
3562 3559   * The tx mode in which an SRS operates is decided in mac_tx_srs_setup()
3563 3560   * based on the number of Tx rings requested for an SRS and whether
3564 3561   * bandwidth control is requested or not.
3565 3562   *
3566 3563   * The default mode (i.e., no fanout/no bandwidth) is used when the
3567 3564   * underlying NIC does not have Tx rings or just one Tx ring. In this mode,
3568 3565   * the SRS acts as a pass-thru. Packets will go directly to mac_tx_send().
3569 3566   * When the underlying Tx ring runs out of Tx descs, it starts queueing up
3570 3567   * packets in SRS. When flow-control is relieved, the srs_worker drains
3571 3568   * the queued packets and informs blocked clients to restart sending
3572 3569   * packets.
3573 3570   *
3574 3571   * In the SRS_TX_SERIALIZE mode, all calls to mac_tx() are serialized. This
3575 3572   * mode is used when the link has no Tx rings or only one Tx ring.
3576 3573   *
3577 3574   * In the SRS_TX_FANOUT mode, packets will be fanned out to multiple
3578 3575   * Tx rings. Each Tx ring will have a soft ring associated with it.
3579 3576   * These soft rings will be hung off the Tx SRS. Queueing if it happens
3580 3577   * due to lack of Tx desc will be in individual soft ring (and not srs)
3581 3578   * associated with Tx ring.
3582 3579   *
3583 3580   * In the TX_BW mode, tx srs will allow packets to go down to Tx ring
3584 3581   * only if bw is available. Otherwise the packets will be queued in
3585 3582   * SRS. If fanout to multiple Tx rings is configured, the packets will
3586 3583   * be fanned out among the soft rings associated with the Tx rings.
3587 3584   *
3588 3585   * In SRS_TX_AGGR mode, mac_tx_aggr_mode() routine is called. This routine
3589 3586   * invokes an aggr function, aggr_find_tx_ring(), to find a pseudo Tx ring
3590 3587   * belonging to a port on which the packet has to be sent. Aggr will
3591 3588   * always have a pseudo Tx ring associated with it even when it is an
3592 3589   * aggregation over a single NIC that has no Tx rings. Even in such a
3593 3590   * case, the single pseudo Tx ring will have a soft ring associated with
3594 3591   * it and the soft ring will hang off the SRS.
3595 3592   *
3596 3593   * If a bandwidth is specified for an aggr, SRS_TX_BW_AGGR mode is used.
3597 3594   * In this mode, the bandwidth is first applied on the outgoing packets
3598 3595   * and later mac_tx_addr_mode() function is called to send the packet out
3599 3596   * of one of the pseudo Tx rings.
3600 3597   *
3601 3598   * Four flags are used in srs_state for indicating flow control
3602 3599   * conditions : SRS_TX_BLOCKED, SRS_TX_HIWAT, SRS_TX_WAKEUP_CLIENT.
3603 3600   * SRS_TX_BLOCKED indicates out of Tx descs. SRS expects a wakeup from the
3604 3601   * driver below.
3605 3602   * SRS_TX_HIWAT indicates packet count enqueued in Tx SRS exceeded Tx hiwat
3606 3603   * and flow-control pressure is applied back to clients. The clients expect
3607 3604   * wakeup when flow-control is relieved.
3608 3605   * SRS_TX_WAKEUP_CLIENT get set when (flag == MAC_TX_NO_ENQUEUE) and mblk
3609 3606   * got returned back to client either due to lack of Tx descs or due to bw
3610 3607   * control reasons. The clients expect a wakeup when condition is relieved.
3611 3608   *
3612 3609   * The fourth argument to mac_tx() is the flag. Normally it will be 0 but
3613 3610   * some clients set the following values too: MAC_DROP_ON_NO_DESC,
3614 3611   * MAC_TX_NO_ENQUEUE
3615 3612   * Mac clients that do not want packets to be enqueued in the mac layer set
3616 3613   * MAC_DROP_ON_NO_DESC value. The packets won't be queued in the Tx SRS or
3617 3614   * Tx soft rings but instead get dropped when the NIC runs out of desc. The
3618 3615   * behaviour of this flag is different when the Tx is running in serializer
3619 3616   * or bandwidth mode. Under these (Serializer, bandwidth) modes, the packet
3620 3617   * get dropped when Tx high watermark is reached.
3621 3618   * There are some mac clients like vsw, aggr that want the mblks to be
3622 3619   * returned back to clients instead of being queued in Tx SRS (or Tx soft
3623 3620   * rings) under flow-control (i.e., out of desc or exceeding bw limits)
3624 3621   * conditions. These clients call mac_tx() with MAC_TX_NO_ENQUEUE flag set.
3625 3622   * In the default and Tx fanout mode, the un-transmitted mblks will be
3626 3623   * returned back to the clients when the driver runs out of Tx descs.
3627 3624   * SRS_TX_WAKEUP_CLIENT (or S_RING_WAKEUP_CLIENT) will be set in SRS (or
3628 3625   * soft ring) so that the clients can be woken up when Tx desc become
3629 3626   * available. When running in serializer or bandwidth mode mode,
3630 3627   * SRS_TX_WAKEUP_CLIENT will be set when tx hi-watermark is reached.
3631 3628   */
3632 3629  
3633 3630  mac_tx_func_t
3634 3631  mac_tx_get_func(uint32_t mode)
3635 3632  {
3636 3633          return (mac_tx_mode_list[mode].mac_tx_func);
3637 3634  }
3638 3635  
3639 3636  /* ARGSUSED */
3640 3637  static mac_tx_cookie_t
3641 3638  mac_tx_single_ring_mode(mac_soft_ring_set_t *mac_srs, mblk_t *mp_chain,
3642 3639      uintptr_t fanout_hint, uint16_t flag, mblk_t **ret_mp)
3643 3640  {
3644 3641          mac_srs_tx_t            *srs_tx = &mac_srs->srs_tx;
3645 3642          mac_tx_stats_t          stats;
3646 3643          mac_tx_cookie_t         cookie = NULL;
3647 3644  
3648 3645          ASSERT(srs_tx->st_mode == SRS_TX_DEFAULT);
3649 3646  
3650 3647          /* Regular case with a single Tx ring */
3651 3648          /*
3652 3649           * SRS_TX_BLOCKED is set when underlying NIC runs
3653 3650           * out of Tx descs and messages start getting
3654 3651           * queued. It won't get reset until
3655 3652           * tx_srs_drain() completely drains out the
3656 3653           * messages.
3657 3654           */
3658 3655          if ((mac_srs->srs_state & SRS_ENQUEUED) != 0) {
3659 3656                  /* Tx descs/resources not available */
3660 3657                  mutex_enter(&mac_srs->srs_lock);
3661 3658                  if ((mac_srs->srs_state & SRS_ENQUEUED) != 0) {
3662 3659                          cookie = mac_tx_srs_no_desc(mac_srs, mp_chain,
3663 3660                              flag, ret_mp);
3664 3661                          mutex_exit(&mac_srs->srs_lock);
3665 3662                          return (cookie);
3666 3663                  }
3667 3664                  /*
3668 3665                   * While we were computing mblk count, the
3669 3666                   * flow control condition got relieved.
3670 3667                   * Continue with the transmission.
3671 3668                   */
3672 3669                  mutex_exit(&mac_srs->srs_lock);
3673 3670          }
3674 3671  
3675 3672          mp_chain = mac_tx_send(srs_tx->st_arg1, srs_tx->st_arg2,
3676 3673              mp_chain, &stats);
3677 3674  
3678 3675          /*
3679 3676           * Multiple threads could be here sending packets.
3680 3677           * Under such conditions, it is not possible to
3681 3678           * automically set SRS_TX_BLOCKED bit to indicate
3682 3679           * out of tx desc condition. To atomically set
3683 3680           * this, we queue the returned packet and do
3684 3681           * the setting of SRS_TX_BLOCKED in
3685 3682           * mac_tx_srs_drain().
3686 3683           */
3687 3684          if (mp_chain != NULL) {
3688 3685                  mutex_enter(&mac_srs->srs_lock);
3689 3686                  cookie = mac_tx_srs_no_desc(mac_srs, mp_chain, flag, ret_mp);
3690 3687                  mutex_exit(&mac_srs->srs_lock);
3691 3688                  return (cookie);
3692 3689          }
3693 3690          SRS_TX_STATS_UPDATE(mac_srs, &stats);
3694 3691  
3695 3692          return (NULL);
3696 3693  }
3697 3694  
3698 3695  /*
3699 3696   * mac_tx_serialize_mode
3700 3697   *
3701 3698   * This is an experimental mode implemented as per the request of PAE.
3702 3699   * In this mode, all callers attempting to send a packet to the NIC
3703 3700   * will get serialized. Only one thread at any time will access the
3704 3701   * NIC to send the packet out.
3705 3702   */
3706 3703  /* ARGSUSED */
3707 3704  static mac_tx_cookie_t
3708 3705  mac_tx_serializer_mode(mac_soft_ring_set_t *mac_srs, mblk_t *mp_chain,
3709 3706      uintptr_t fanout_hint, uint16_t flag, mblk_t **ret_mp)
3710 3707  {
3711 3708          mac_tx_stats_t          stats;
3712 3709          mac_tx_cookie_t         cookie = NULL;
3713 3710          mac_srs_tx_t            *srs_tx = &mac_srs->srs_tx;
3714 3711  
3715 3712          /* Single ring, serialize below */
3716 3713          ASSERT(srs_tx->st_mode == SRS_TX_SERIALIZE);
3717 3714          mutex_enter(&mac_srs->srs_lock);
3718 3715          if ((mac_srs->srs_first != NULL) ||
3719 3716              (mac_srs->srs_state & SRS_PROC)) {
3720 3717                  /*
3721 3718                   * In serialization mode, queue all packets until
3722 3719                   * TX_HIWAT is set.
3723 3720                   * If drop bit is set, drop if TX_HIWAT is set.
3724 3721                   * If no_enqueue is set, still enqueue until hiwat
3725 3722                   * is set and return mblks after TX_HIWAT is set.
3726 3723                   */
3727 3724                  cookie = mac_tx_srs_enqueue(mac_srs, mp_chain,
3728 3725                      flag, NULL, ret_mp);
3729 3726                  mutex_exit(&mac_srs->srs_lock);
3730 3727                  return (cookie);
3731 3728          }
3732 3729          /*
3733 3730           * No packets queued, nothing on proc and no flow
3734 3731           * control condition. Fast-path, ok. Do inline
3735 3732           * processing.
3736 3733           */
3737 3734          mac_srs->srs_state |= SRS_PROC;
3738 3735          mutex_exit(&mac_srs->srs_lock);
3739 3736  
3740 3737          mp_chain = mac_tx_send(srs_tx->st_arg1, srs_tx->st_arg2,
3741 3738              mp_chain, &stats);
3742 3739  
3743 3740          mutex_enter(&mac_srs->srs_lock);
3744 3741          mac_srs->srs_state &= ~SRS_PROC;
3745 3742          if (mp_chain != NULL) {
3746 3743                  cookie = mac_tx_srs_enqueue(mac_srs,
3747 3744                      mp_chain, flag, NULL, ret_mp);
3748 3745          }
3749 3746          if (mac_srs->srs_first != NULL) {
3750 3747                  /*
3751 3748                   * We processed inline our packet and a new
3752 3749                   * packet/s got queued while we were
3753 3750                   * processing. Wakeup srs worker
3754 3751                   */
3755 3752                  cv_signal(&mac_srs->srs_async);
3756 3753          }
3757 3754          mutex_exit(&mac_srs->srs_lock);
3758 3755  
3759 3756          if (cookie == NULL)
3760 3757                  SRS_TX_STATS_UPDATE(mac_srs, &stats);
3761 3758  
3762 3759          return (cookie);
3763 3760  }
3764 3761  
3765 3762  /*
3766 3763   * mac_tx_fanout_mode
3767 3764   *
3768 3765   * In this mode, the SRS will have access to multiple Tx rings to send
3769 3766   * the packet out. The fanout hint that is passed as an argument is
3770 3767   * used to find an appropriate ring to fanout the traffic. Each Tx
3771 3768   * ring, in turn,  will have a soft ring associated with it. If a Tx
3772 3769   * ring runs out of Tx desc's the returned packet will be queued in
3773 3770   * the soft ring associated with that Tx ring. The srs itself will not
3774 3771   * queue any packets.
3775 3772   */
3776 3773  
3777 3774  #define MAC_TX_SOFT_RING_PROCESS(chain) {                               \
3778 3775          index = COMPUTE_INDEX(hash, mac_srs->srs_tx_ring_count),        \
3779 3776          softring = mac_srs->srs_tx_soft_rings[index];                   \
3780 3777          cookie = mac_tx_soft_ring_process(softring, chain, flag, ret_mp); \
3781 3778          DTRACE_PROBE2(tx__fanout, uint64_t, hash, uint_t, index);       \
3782 3779  }
3783 3780  
3784 3781  static mac_tx_cookie_t
3785 3782  mac_tx_fanout_mode(mac_soft_ring_set_t *mac_srs, mblk_t *mp_chain,
3786 3783      uintptr_t fanout_hint, uint16_t flag, mblk_t **ret_mp)
3787 3784  {
3788 3785          mac_soft_ring_t         *softring;
3789 3786          uint64_t                hash;
3790 3787          uint_t                  index;
3791 3788          mac_tx_cookie_t         cookie = NULL;
3792 3789  
3793 3790          ASSERT(mac_srs->srs_tx.st_mode == SRS_TX_FANOUT ||
3794 3791              mac_srs->srs_tx.st_mode == SRS_TX_BW_FANOUT);
3795 3792          if (fanout_hint != 0) {
3796 3793                  /*
3797 3794                   * The hint is specified by the caller, simply pass the
3798 3795                   * whole chain to the soft ring.
3799 3796                   */
3800 3797                  hash = HASH_HINT(fanout_hint);
3801 3798                  MAC_TX_SOFT_RING_PROCESS(mp_chain);
3802 3799          } else {
3803 3800                  mblk_t *last_mp, *cur_mp, *sub_chain;
3804 3801                  uint64_t last_hash = 0;
3805 3802                  uint_t media = mac_srs->srs_mcip->mci_mip->mi_info.mi_media;
3806 3803  
3807 3804                  /*
3808 3805                   * Compute the hash from the contents (headers) of the
3809 3806                   * packets of the mblk chain. Split the chains into
3810 3807                   * subchains of the same conversation.
3811 3808                   *
3812 3809                   * Since there may be more than one ring used for
3813 3810                   * sub-chains of the same call, and since the caller
3814 3811                   * does not maintain per conversation state since it
3815 3812                   * passed a zero hint, unsent subchains will be
3816 3813                   * dropped.
3817 3814                   */
3818 3815  
3819 3816                  flag |= MAC_DROP_ON_NO_DESC;
3820 3817                  ret_mp = NULL;
3821 3818  
3822 3819                  ASSERT(ret_mp == NULL);
3823 3820  
3824 3821                  sub_chain = NULL;
3825 3822                  last_mp = NULL;
3826 3823  
3827 3824                  for (cur_mp = mp_chain; cur_mp != NULL;
3828 3825                      cur_mp = cur_mp->b_next) {
3829 3826                          hash = mac_pkt_hash(media, cur_mp, MAC_PKT_HASH_L4,
3830 3827                              B_TRUE);
3831 3828                          if (last_hash != 0 && hash != last_hash) {
3832 3829                                  /*
3833 3830                                   * Starting a different subchain, send current
3834 3831                                   * chain out.
3835 3832                                   */
3836 3833                                  ASSERT(last_mp != NULL);
3837 3834                                  last_mp->b_next = NULL;
3838 3835                                  MAC_TX_SOFT_RING_PROCESS(sub_chain);
3839 3836                                  sub_chain = NULL;
3840 3837                          }
3841 3838  
3842 3839                          /* add packet to subchain */
3843 3840                          if (sub_chain == NULL)
3844 3841                                  sub_chain = cur_mp;
3845 3842                          last_mp = cur_mp;
3846 3843                          last_hash = hash;
3847 3844                  }
3848 3845  
3849 3846                  if (sub_chain != NULL) {
3850 3847                          /* send last subchain */
3851 3848                          ASSERT(last_mp != NULL);
3852 3849                          last_mp->b_next = NULL;
3853 3850                          MAC_TX_SOFT_RING_PROCESS(sub_chain);
3854 3851                  }
3855 3852  
3856 3853                  cookie = NULL;
3857 3854          }
3858 3855  
3859 3856          return (cookie);
3860 3857  }
3861 3858  
3862 3859  /*
3863 3860   * mac_tx_bw_mode
3864 3861   *
3865 3862   * In the bandwidth mode, Tx srs will allow packets to go down to Tx ring
3866 3863   * only if bw is available. Otherwise the packets will be queued in
3867 3864   * SRS. If the SRS has multiple Tx rings, then packets will get fanned
3868 3865   * out to a Tx rings.
3869 3866   */
3870 3867  static mac_tx_cookie_t
3871 3868  mac_tx_bw_mode(mac_soft_ring_set_t *mac_srs, mblk_t *mp_chain,
3872 3869      uintptr_t fanout_hint, uint16_t flag, mblk_t **ret_mp)
3873 3870  {
3874 3871          int                     cnt, sz;
3875 3872          mblk_t                  *tail;
3876 3873          mac_tx_cookie_t         cookie = NULL;
3877 3874          mac_srs_tx_t            *srs_tx = &mac_srs->srs_tx;
3878 3875          clock_t                 now;
3879 3876  
3880 3877          ASSERT(TX_BANDWIDTH_MODE(mac_srs));
3881 3878          ASSERT(mac_srs->srs_type & SRST_BW_CONTROL);
3882 3879          mutex_enter(&mac_srs->srs_lock);
3883 3880          if (mac_srs->srs_bw->mac_bw_limit == 0) {
3884 3881                  /*
3885 3882                   * zero bandwidth, no traffic is sent: drop the packets,
3886 3883                   * or return the whole chain if the caller requests all
3887 3884                   * unsent packets back.
3888 3885                   */
3889 3886                  if (flag & MAC_TX_NO_ENQUEUE) {
3890 3887                          cookie = (mac_tx_cookie_t)mac_srs;
3891 3888                          *ret_mp = mp_chain;
3892 3889                  } else {
3893 3890                          MAC_TX_SRS_DROP_MESSAGE(mac_srs, mp_chain, cookie);
3894 3891                  }
3895 3892                  mutex_exit(&mac_srs->srs_lock);
3896 3893                  return (cookie);
3897 3894          } else if ((mac_srs->srs_first != NULL) ||
3898 3895              (mac_srs->srs_bw->mac_bw_state & SRS_BW_ENFORCED)) {
3899 3896                  cookie = mac_tx_srs_enqueue(mac_srs, mp_chain, flag,
3900 3897                      fanout_hint, ret_mp);
3901 3898                  mutex_exit(&mac_srs->srs_lock);
3902 3899                  return (cookie);
3903 3900          }
3904 3901          MAC_COUNT_CHAIN(mac_srs, mp_chain, tail, cnt, sz);
3905 3902          now = ddi_get_lbolt();
3906 3903          if (mac_srs->srs_bw->mac_bw_curr_time != now) {
3907 3904                  mac_srs->srs_bw->mac_bw_curr_time = now;
3908 3905                  mac_srs->srs_bw->mac_bw_used = 0;
3909 3906          } else if (mac_srs->srs_bw->mac_bw_used >
3910 3907              mac_srs->srs_bw->mac_bw_limit) {
3911 3908                  mac_srs->srs_bw->mac_bw_state |= SRS_BW_ENFORCED;
3912 3909                  MAC_TX_SRS_ENQUEUE_CHAIN(mac_srs,
3913 3910                      mp_chain, tail, cnt, sz);
3914 3911                  /*
3915 3912                   * Wakeup worker thread. Note that worker
3916 3913                   * thread has to be woken up so that it
3917 3914                   * can fire up the timer to be woken up
3918 3915                   * on the next tick. Also once
3919 3916                   * BW_ENFORCED is set, it can only be
3920 3917                   * reset by srs_worker thread. Until then
3921 3918                   * all packets will get queued up in SRS
3922 3919                   * and hence this this code path won't be
3923 3920                   * entered until BW_ENFORCED is reset.
3924 3921                   */
3925 3922                  cv_signal(&mac_srs->srs_async);
3926 3923                  mutex_exit(&mac_srs->srs_lock);
3927 3924                  return (cookie);
3928 3925          }
3929 3926  
3930 3927          mac_srs->srs_bw->mac_bw_used += sz;
3931 3928          mutex_exit(&mac_srs->srs_lock);
3932 3929  
3933 3930          if (srs_tx->st_mode == SRS_TX_BW_FANOUT) {
3934 3931                  mac_soft_ring_t *softring;
3935 3932                  uint_t indx, hash;
3936 3933  
3937 3934                  hash = HASH_HINT(fanout_hint);
3938 3935                  indx = COMPUTE_INDEX(hash,
3939 3936                      mac_srs->srs_tx_ring_count);
3940 3937                  softring = mac_srs->srs_tx_soft_rings[indx];
3941 3938                  return (mac_tx_soft_ring_process(softring, mp_chain, flag,
3942 3939                      ret_mp));
3943 3940          } else if (srs_tx->st_mode == SRS_TX_BW_AGGR) {
3944 3941                  return (mac_tx_aggr_mode(mac_srs, mp_chain,
3945 3942                      fanout_hint, flag, ret_mp));
3946 3943          } else {
3947 3944                  mac_tx_stats_t          stats;
3948 3945  
3949 3946                  mp_chain = mac_tx_send(srs_tx->st_arg1, srs_tx->st_arg2,
3950 3947                      mp_chain, &stats);
3951 3948  
3952 3949                  if (mp_chain != NULL) {
3953 3950                          mutex_enter(&mac_srs->srs_lock);
3954 3951                          MAC_COUNT_CHAIN(mac_srs, mp_chain, tail, cnt, sz);
3955 3952                          if (mac_srs->srs_bw->mac_bw_used > sz)
3956 3953                                  mac_srs->srs_bw->mac_bw_used -= sz;
3957 3954                          else
3958 3955                                  mac_srs->srs_bw->mac_bw_used = 0;
3959 3956                          cookie = mac_tx_srs_enqueue(mac_srs, mp_chain, flag,
3960 3957                              fanout_hint, ret_mp);
3961 3958                          mutex_exit(&mac_srs->srs_lock);
3962 3959                          return (cookie);
3963 3960                  }
3964 3961                  SRS_TX_STATS_UPDATE(mac_srs, &stats);
3965 3962  
3966 3963                  return (NULL);
3967 3964          }
3968 3965  }
3969 3966  
3970 3967  /*
3971 3968   * mac_tx_aggr_mode
3972 3969   *
3973 3970   * This routine invokes an aggr function, aggr_find_tx_ring(), to find
3974 3971   * a (pseudo) Tx ring belonging to a port on which the packet has to
3975 3972   * be sent. aggr_find_tx_ring() first finds the outgoing port based on
3976 3973   * L2/L3/L4 policy and then uses the fanout_hint passed to it to pick
3977 3974   * a Tx ring from the selected port.
3978 3975   *
3979 3976   * Note that a port can be deleted from the aggregation. In such a case,
3980 3977   * the aggregation layer first separates the port from the rest of the
3981 3978   * ports making sure that port (and thus any Tx rings associated with
3982 3979   * it) won't get selected in the call to aggr_find_tx_ring() function.
3983 3980   * Later calls are made to mac_group_rem_ring() passing pseudo Tx ring
3984 3981   * handles one by one which in turn will quiesce the Tx SRS and remove
3985 3982   * the soft ring associated with the pseudo Tx ring. Unlike Rx side
3986 3983   * where a cookie is used to protect against mac_rx_ring() calls on
3987 3984   * rings that have been removed, no such cookie is needed on the Tx
3988 3985   * side as the pseudo Tx ring won't be available anymore to
3989 3986   * aggr_find_tx_ring() once the port has been removed.
3990 3987   */
3991 3988  static mac_tx_cookie_t
3992 3989  mac_tx_aggr_mode(mac_soft_ring_set_t *mac_srs, mblk_t *mp_chain,
3993 3990      uintptr_t fanout_hint, uint16_t flag, mblk_t **ret_mp)
3994 3991  {
3995 3992          mac_srs_tx_t            *srs_tx = &mac_srs->srs_tx;
3996 3993          mac_tx_ring_fn_t        find_tx_ring_fn;
3997 3994          mac_ring_handle_t       ring = NULL;
3998 3995          void                    *arg;
3999 3996          mac_soft_ring_t         *sringp;
4000 3997  
4001 3998          find_tx_ring_fn = srs_tx->st_capab_aggr.mca_find_tx_ring_fn;
4002 3999          arg = srs_tx->st_capab_aggr.mca_arg;
4003 4000          if (find_tx_ring_fn(arg, mp_chain, fanout_hint, &ring) == NULL)
4004 4001                  return (NULL);
4005 4002          sringp = srs_tx->st_soft_rings[((mac_ring_t *)ring)->mr_index];
4006 4003          return (mac_tx_soft_ring_process(sringp, mp_chain, flag, ret_mp));
4007 4004  }
4008 4005  
4009 4006  void
4010 4007  mac_tx_invoke_callbacks(mac_client_impl_t *mcip, mac_tx_cookie_t cookie)
4011 4008  {
4012 4009          mac_cb_t *mcb;
4013 4010          mac_tx_notify_cb_t *mtnfp;
4014 4011  
4015 4012          /* Wakeup callback registered clients */
4016 4013          MAC_CALLBACK_WALKER_INC(&mcip->mci_tx_notify_cb_info);
4017 4014          for (mcb = mcip->mci_tx_notify_cb_list; mcb != NULL;
4018 4015              mcb = mcb->mcb_nextp) {
4019 4016                  mtnfp = (mac_tx_notify_cb_t *)mcb->mcb_objp;
4020 4017                  mtnfp->mtnf_fn(mtnfp->mtnf_arg, cookie);
4021 4018          }
4022 4019          MAC_CALLBACK_WALKER_DCR(&mcip->mci_tx_notify_cb_info,
4023 4020              &mcip->mci_tx_notify_cb_list);
4024 4021  }
4025 4022  
4026 4023  /* ARGSUSED */
4027 4024  void
4028 4025  mac_tx_srs_drain(mac_soft_ring_set_t *mac_srs, uint_t proc_type)
4029 4026  {
4030 4027          mblk_t                  *head, *tail;
4031 4028          size_t                  sz;
4032 4029          uint32_t                tx_mode;
4033 4030          uint_t                  saved_pkt_count;
4034 4031          mac_tx_stats_t          stats;
4035 4032          mac_srs_tx_t            *srs_tx = &mac_srs->srs_tx;
4036 4033          clock_t                 now;
4037 4034  
4038 4035          saved_pkt_count = 0;
4039 4036          ASSERT(mutex_owned(&mac_srs->srs_lock));
4040 4037          ASSERT(!(mac_srs->srs_state & SRS_PROC));
4041 4038  
4042 4039          mac_srs->srs_state |= SRS_PROC;
4043 4040  
4044 4041          tx_mode = srs_tx->st_mode;
4045 4042          if (tx_mode == SRS_TX_DEFAULT || tx_mode == SRS_TX_SERIALIZE) {
4046 4043                  if (mac_srs->srs_first != NULL) {
4047 4044                          head = mac_srs->srs_first;
4048 4045                          tail = mac_srs->srs_last;
4049 4046                          saved_pkt_count = mac_srs->srs_count;
4050 4047                          mac_srs->srs_first = NULL;
4051 4048                          mac_srs->srs_last = NULL;
4052 4049                          mac_srs->srs_count = 0;
4053 4050                          mutex_exit(&mac_srs->srs_lock);
4054 4051  
4055 4052                          head = mac_tx_send(srs_tx->st_arg1, srs_tx->st_arg2,
4056 4053                              head, &stats);
4057 4054  
4058 4055                          mutex_enter(&mac_srs->srs_lock);
4059 4056                          if (head != NULL) {
4060 4057                                  /* Device out of tx desc, set block */
4061 4058                                  if (head->b_next == NULL)
4062 4059                                          VERIFY(head == tail);
4063 4060                                  tail->b_next = mac_srs->srs_first;
4064 4061                                  mac_srs->srs_first = head;
4065 4062                                  mac_srs->srs_count +=
4066 4063                                      (saved_pkt_count - stats.mts_opackets);
4067 4064                                  if (mac_srs->srs_last == NULL)
4068 4065                                          mac_srs->srs_last = tail;
4069 4066                                  MAC_TX_SRS_BLOCK(mac_srs, head);
4070 4067                          } else {
4071 4068                                  srs_tx->st_woken_up = B_FALSE;
4072 4069                                  SRS_TX_STATS_UPDATE(mac_srs, &stats);
4073 4070                          }
4074 4071                  }
4075 4072          } else if (tx_mode == SRS_TX_BW) {
4076 4073                  /*
4077 4074                   * We are here because the timer fired and we have some data
4078 4075                   * to tranmit. Also mac_tx_srs_worker should have reset
4079 4076                   * SRS_BW_ENFORCED flag
4080 4077                   */
4081 4078                  ASSERT(!(mac_srs->srs_bw->mac_bw_state & SRS_BW_ENFORCED));
4082 4079                  head = tail = mac_srs->srs_first;
4083 4080                  while (mac_srs->srs_first != NULL) {
4084 4081                          tail = mac_srs->srs_first;
4085 4082                          tail->b_prev = NULL;
4086 4083                          mac_srs->srs_first = tail->b_next;
4087 4084                          if (mac_srs->srs_first == NULL)
4088 4085                                  mac_srs->srs_last = NULL;
4089 4086                          mac_srs->srs_count--;
4090 4087                          sz = msgdsize(tail);
4091 4088                          mac_srs->srs_size -= sz;
4092 4089                          saved_pkt_count++;
4093 4090                          MAC_TX_UPDATE_BW_INFO(mac_srs, sz);
4094 4091  
4095 4092                          if (mac_srs->srs_bw->mac_bw_used <
4096 4093                              mac_srs->srs_bw->mac_bw_limit)
4097 4094                                  continue;
4098 4095  
4099 4096                          now = ddi_get_lbolt();
4100 4097                          if (mac_srs->srs_bw->mac_bw_curr_time != now) {
4101 4098                                  mac_srs->srs_bw->mac_bw_curr_time = now;
4102 4099                                  mac_srs->srs_bw->mac_bw_used = sz;
4103 4100                                  continue;
4104 4101                          }
4105 4102                          mac_srs->srs_bw->mac_bw_state |= SRS_BW_ENFORCED;
4106 4103                          break;
4107 4104                  }
4108 4105  
4109 4106                  ASSERT((head == NULL && tail == NULL) ||
4110 4107                      (head != NULL && tail != NULL));
4111 4108                  if (tail != NULL) {
4112 4109                          tail->b_next = NULL;
4113 4110                          mutex_exit(&mac_srs->srs_lock);
4114 4111  
4115 4112                          head = mac_tx_send(srs_tx->st_arg1, srs_tx->st_arg2,
4116 4113                              head, &stats);
4117 4114  
4118 4115                          mutex_enter(&mac_srs->srs_lock);
4119 4116                          if (head != NULL) {
4120 4117                                  uint_t size_sent;
4121 4118  
4122 4119                                  /* Device out of tx desc, set block */
4123 4120                                  if (head->b_next == NULL)
4124 4121                                          VERIFY(head == tail);
4125 4122                                  tail->b_next = mac_srs->srs_first;
4126 4123                                  mac_srs->srs_first = head;
4127 4124                                  mac_srs->srs_count +=
4128 4125                                      (saved_pkt_count - stats.mts_opackets);
4129 4126                                  if (mac_srs->srs_last == NULL)
4130 4127                                          mac_srs->srs_last = tail;
4131 4128                                  size_sent = sz - stats.mts_obytes;
4132 4129                                  mac_srs->srs_size += size_sent;
4133 4130                                  mac_srs->srs_bw->mac_bw_sz += size_sent;
4134 4131                                  if (mac_srs->srs_bw->mac_bw_used > size_sent) {
4135 4132                                          mac_srs->srs_bw->mac_bw_used -=
4136 4133                                              size_sent;
4137 4134                                  } else {
4138 4135                                          mac_srs->srs_bw->mac_bw_used = 0;
4139 4136                                  }
4140 4137                                  MAC_TX_SRS_BLOCK(mac_srs, head);
4141 4138                          } else {
4142 4139                                  srs_tx->st_woken_up = B_FALSE;
4143 4140                                  SRS_TX_STATS_UPDATE(mac_srs, &stats);
4144 4141                          }
4145 4142                  }
4146 4143          } else if (tx_mode == SRS_TX_BW_FANOUT || tx_mode == SRS_TX_BW_AGGR) {
4147 4144                  mblk_t *prev;
4148 4145                  uint64_t hint;
4149 4146  
4150 4147                  /*
4151 4148                   * We are here because the timer fired and we
4152 4149                   * have some quota to tranmit.
4153 4150                   */
4154 4151                  prev = NULL;
4155 4152                  head = tail = mac_srs->srs_first;
4156 4153                  while (mac_srs->srs_first != NULL) {
4157 4154                          tail = mac_srs->srs_first;
4158 4155                          mac_srs->srs_first = tail->b_next;
4159 4156                          if (mac_srs->srs_first == NULL)
4160 4157                                  mac_srs->srs_last = NULL;
4161 4158                          mac_srs->srs_count--;
4162 4159                          sz = msgdsize(tail);
4163 4160                          mac_srs->srs_size -= sz;
4164 4161                          mac_srs->srs_bw->mac_bw_used += sz;
4165 4162                          if (prev == NULL)
4166 4163                                  hint = (ulong_t)tail->b_prev;
4167 4164                          if (hint != (ulong_t)tail->b_prev) {
4168 4165                                  prev->b_next = NULL;
4169 4166                                  mutex_exit(&mac_srs->srs_lock);
4170 4167                                  TX_SRS_TO_SOFT_RING(mac_srs, head, hint);
4171 4168                                  head = tail;
4172 4169                                  hint = (ulong_t)tail->b_prev;
4173 4170                                  mutex_enter(&mac_srs->srs_lock);
4174 4171                          }
4175 4172  
4176 4173                          prev = tail;
4177 4174                          tail->b_prev = NULL;
4178 4175                          if (mac_srs->srs_bw->mac_bw_used <
4179 4176                              mac_srs->srs_bw->mac_bw_limit)
4180 4177                                  continue;
4181 4178  
4182 4179                          now = ddi_get_lbolt();
4183 4180                          if (mac_srs->srs_bw->mac_bw_curr_time != now) {
4184 4181                                  mac_srs->srs_bw->mac_bw_curr_time = now;
4185 4182                                  mac_srs->srs_bw->mac_bw_used = 0;
4186 4183                                  continue;
4187 4184                          }
4188 4185                          mac_srs->srs_bw->mac_bw_state |= SRS_BW_ENFORCED;
4189 4186                          break;
4190 4187                  }
4191 4188                  ASSERT((head == NULL && tail == NULL) ||
4192 4189                      (head != NULL && tail != NULL));
4193 4190                  if (tail != NULL) {
4194 4191                          tail->b_next = NULL;
4195 4192                          mutex_exit(&mac_srs->srs_lock);
4196 4193                          TX_SRS_TO_SOFT_RING(mac_srs, head, hint);
4197 4194                          mutex_enter(&mac_srs->srs_lock);
4198 4195                  }
4199 4196          }
4200 4197          /*
4201 4198           * SRS_TX_FANOUT case not considered here because packets
4202 4199           * won't be queued in the SRS for this case. Packets will
4203 4200           * be sent directly to soft rings underneath and if there
4204 4201           * is any queueing at all, it would be in Tx side soft
4205 4202           * rings.
4206 4203           */
4207 4204  
4208 4205          /*
4209 4206           * When srs_count becomes 0, reset SRS_TX_HIWAT and
4210 4207           * SRS_TX_WAKEUP_CLIENT and wakeup registered clients.
4211 4208           */
4212 4209          if (mac_srs->srs_count == 0 && (mac_srs->srs_state &
4213 4210              (SRS_TX_HIWAT | SRS_TX_WAKEUP_CLIENT | SRS_ENQUEUED))) {
4214 4211                  mac_client_impl_t *mcip = mac_srs->srs_mcip;
4215 4212                  boolean_t wakeup_required = B_FALSE;
4216 4213  
4217 4214                  if (mac_srs->srs_state &
4218 4215                      (SRS_TX_HIWAT|SRS_TX_WAKEUP_CLIENT)) {
4219 4216                          wakeup_required = B_TRUE;
4220 4217                  }
4221 4218                  mac_srs->srs_state &= ~(SRS_TX_HIWAT |
4222 4219                      SRS_TX_WAKEUP_CLIENT | SRS_ENQUEUED);
4223 4220                  mutex_exit(&mac_srs->srs_lock);
4224 4221                  if (wakeup_required) {
4225 4222                          mac_tx_invoke_callbacks(mcip, (mac_tx_cookie_t)mac_srs);
4226 4223                          /*
4227 4224                           * If the client is not the primary MAC client, then we
4228 4225                           * need to send the notification to the clients upper
4229 4226                           * MAC, i.e. mci_upper_mip.
4230 4227                           */
4231 4228                          mac_tx_notify(mcip->mci_upper_mip != NULL ?
4232 4229                              mcip->mci_upper_mip : mcip->mci_mip);
4233 4230                  }
4234 4231                  mutex_enter(&mac_srs->srs_lock);
4235 4232          }
4236 4233          mac_srs->srs_state &= ~SRS_PROC;
4237 4234  }
4238 4235  
4239 4236  /*
4240 4237   * Given a packet, get the flow_entry that identifies the flow
4241 4238   * to which that packet belongs. The flow_entry will contain
4242 4239   * the transmit function to be used to send the packet. If the
4243 4240   * function returns NULL, the packet should be sent using the
4244 4241   * underlying NIC.
4245 4242   */
4246 4243  static flow_entry_t *
4247 4244  mac_tx_classify(mac_impl_t *mip, mblk_t *mp)
4248 4245  {
4249 4246          flow_entry_t            *flent = NULL;
4250 4247          mac_client_impl_t       *mcip;
4251 4248          int     err;
4252 4249  
4253 4250          /*
4254 4251           * Do classification on the packet.
4255 4252           */
4256 4253          err = mac_flow_lookup(mip->mi_flow_tab, mp, FLOW_OUTBOUND, &flent);
4257 4254          if (err != 0)
4258 4255                  return (NULL);
4259 4256  
4260 4257          /*
4261 4258           * This flent might just be an additional one on the MAC client,
4262 4259           * i.e. for classification purposes (different fdesc), however
4263 4260           * the resources, SRS et. al., are in the mci_flent, so if
4264 4261           * this isn't the mci_flent, we need to get it.
4265 4262           */
4266 4263          if ((mcip = flent->fe_mcip) != NULL && mcip->mci_flent != flent) {
4267 4264                  FLOW_REFRELE(flent);
4268 4265                  flent = mcip->mci_flent;
4269 4266                  FLOW_TRY_REFHOLD(flent, err);
4270 4267                  if (err != 0)
4271 4268                          return (NULL);
4272 4269          }
4273 4270  
4274 4271          return (flent);
4275 4272  }
4276 4273  
4277 4274  /*
4278 4275   * This macro is only meant to be used by mac_tx_send().
4279 4276   */
4280 4277  #define CHECK_VID_AND_ADD_TAG(mp) {                     \
4281 4278          if (vid_check) {                                \
4282 4279                  int err = 0;                            \
4283 4280                                                          \
4284 4281                  MAC_VID_CHECK(src_mcip, (mp), err);     \
4285 4282                  if (err != 0) {                         \
4286 4283                          freemsg((mp));                  \
4287 4284                          (mp) = next;                    \
4288 4285                          oerrors++;                      \
4289 4286                          continue;                       \
4290 4287                  }                                       \
4291 4288          }                                               \
4292 4289          if (add_tag) {                                  \
4293 4290                  (mp) = mac_add_vlan_tag((mp), 0, vid);  \
4294 4291                  if ((mp) == NULL) {                     \
4295 4292                          (mp) = next;                    \
4296 4293                          oerrors++;                      \
4297 4294                          continue;                       \
4298 4295                  }                                       \
4299 4296          }                                               \
4300 4297  }
4301 4298  
4302 4299  mblk_t *
4303 4300  mac_tx_send(mac_client_handle_t mch, mac_ring_handle_t ring, mblk_t *mp_chain,
4304 4301      mac_tx_stats_t *stats)
4305 4302  {
4306 4303          mac_client_impl_t *src_mcip = (mac_client_impl_t *)mch;
4307 4304          mac_impl_t *mip = src_mcip->mci_mip;
4308 4305          uint_t obytes = 0, opackets = 0, oerrors = 0;
4309 4306          mblk_t *mp = NULL, *next;
4310 4307          boolean_t vid_check, add_tag;
4311 4308          uint16_t vid = 0;
4312 4309  
4313 4310          if (mip->mi_nclients > 1) {
4314 4311                  vid_check = MAC_VID_CHECK_NEEDED(src_mcip);
4315 4312                  add_tag = MAC_TAG_NEEDED(src_mcip);
4316 4313                  if (add_tag)
4317 4314                          vid = mac_client_vid(mch);
4318 4315          } else {
4319 4316                  ASSERT(mip->mi_nclients == 1);
4320 4317                  vid_check = add_tag = B_FALSE;
4321 4318          }
4322 4319  
4323 4320          /*
4324 4321           * Fastpath: if there's only one client, we simply send
4325 4322           * the packet down to the underlying NIC.
4326 4323           */
4327 4324          if (mip->mi_nactiveclients == 1) {
4328 4325                  DTRACE_PROBE2(fastpath,
4329 4326                      mac_client_impl_t *, src_mcip, mblk_t *, mp_chain);
4330 4327  
4331 4328                  mp = mp_chain;
4332 4329                  while (mp != NULL) {
4333 4330                          next = mp->b_next;
4334 4331                          mp->b_next = NULL;
4335 4332                          opackets++;
4336 4333                          obytes += (mp->b_cont == NULL ? MBLKL(mp) :
4337 4334                              msgdsize(mp));
4338 4335  
4339 4336                          CHECK_VID_AND_ADD_TAG(mp);
4340 4337                          MAC_TX(mip, ring, mp, src_mcip);
4341 4338  
4342 4339                          /*
4343 4340                           * If the driver is out of descriptors and does a
4344 4341                           * partial send it will return a chain of unsent
4345 4342                           * mblks. Adjust the accounting stats.
4346 4343                           */
4347 4344                          if (mp != NULL) {
4348 4345                                  opackets--;
4349 4346                                  obytes -= msgdsize(mp);
4350 4347                                  mp->b_next = next;
4351 4348                                  break;
4352 4349                          }
4353 4350                          mp = next;
4354 4351                  }
4355 4352                  goto done;
4356 4353          }
4357 4354  
4358 4355          /*
4359 4356           * No fastpath, we either have more than one MAC client
4360 4357           * defined on top of the same MAC, or one or more MAC
4361 4358           * client promiscuous callbacks.
4362 4359           */
4363 4360          DTRACE_PROBE3(slowpath, mac_client_impl_t *,
4364 4361              src_mcip, int, mip->mi_nclients, mblk_t *, mp_chain);
4365 4362  
4366 4363          mp = mp_chain;
4367 4364          while (mp != NULL) {
4368 4365                  flow_entry_t *dst_flow_ent;
4369 4366                  void *flow_cookie;
4370 4367                  size_t  pkt_size;
4371 4368                  mblk_t *mp1;
4372 4369  
4373 4370                  next = mp->b_next;
4374 4371                  mp->b_next = NULL;
4375 4372                  opackets++;
4376 4373                  pkt_size = (mp->b_cont == NULL ? MBLKL(mp) : msgdsize(mp));
4377 4374                  obytes += pkt_size;
4378 4375                  CHECK_VID_AND_ADD_TAG(mp);
4379 4376  
4380 4377                  /*
4381 4378                   * Find the destination.
4382 4379                   */
4383 4380                  dst_flow_ent = mac_tx_classify(mip, mp);
4384 4381  
4385 4382                  if (dst_flow_ent != NULL) {
4386 4383                          size_t  hdrsize;
4387 4384                          int     err = 0;
4388 4385  
4389 4386                          if (mip->mi_info.mi_nativemedia == DL_ETHER) {
4390 4387                                  struct ether_vlan_header *evhp =
4391 4388                                      (struct ether_vlan_header *)mp->b_rptr;
4392 4389  
4393 4390                                  if (ntohs(evhp->ether_tpid) == ETHERTYPE_VLAN)
4394 4391                                          hdrsize = sizeof (*evhp);
4395 4392                                  else
4396 4393                                          hdrsize = sizeof (struct ether_header);
4397 4394                          } else {
4398 4395                                  mac_header_info_t       mhi;
4399 4396  
4400 4397                                  err = mac_header_info((mac_handle_t)mip,
4401 4398                                      mp, &mhi);
4402 4399                                  if (err == 0)
4403 4400                                          hdrsize = mhi.mhi_hdrsize;
4404 4401                          }
4405 4402  
4406 4403                          /*
4407 4404                           * Got a matching flow. It's either another
4408 4405                           * MAC client, or a broadcast/multicast flow.
4409 4406                           * Make sure the packet size is within the
4410 4407                           * allowed size. If not drop the packet and
4411 4408                           * move to next packet.
4412 4409                           */
4413 4410                          if (err != 0 ||
4414 4411                              (pkt_size - hdrsize) > mip->mi_sdu_max) {
4415 4412                                  oerrors++;
4416 4413                                  DTRACE_PROBE2(loopback__drop, size_t, pkt_size,
4417 4414                                      mblk_t *, mp);
4418 4415                                  freemsg(mp);
4419 4416                                  mp = next;
4420 4417                                  FLOW_REFRELE(dst_flow_ent);
4421 4418                                  continue;
4422 4419                          }
4423 4420                          flow_cookie = mac_flow_get_client_cookie(dst_flow_ent);
4424 4421                          if (flow_cookie != NULL) {
4425 4422                                  /*
4426 4423                                   * The vnic_bcast_send function expects
4427 4424                                   * to receive the sender MAC client
4428 4425                                   * as value for arg2.
4429 4426                                   */
4430 4427                                  mac_bcast_send(flow_cookie, src_mcip, mp,
4431 4428                                      B_TRUE);
4432 4429                          } else {
4433 4430                                  /*
4434 4431                                   * loopback the packet to a local MAC
4435 4432                                   * client. We force a context switch
4436 4433                                   * if both source and destination MAC
4437 4434                                   * clients are used by IP, i.e.
4438 4435                                   * bypass is set.
4439 4436                                   */
4440 4437                                  boolean_t do_switch;
4441 4438                                  mac_client_impl_t *dst_mcip =
4442 4439                                      dst_flow_ent->fe_mcip;
4443 4440  
4444 4441                                  /*
4445 4442                                   * Check if there are promiscuous mode
4446 4443                                   * callbacks defined. This check is
4447 4444                                   * done here in the 'else' case and
4448 4445                                   * not in other cases because this
4449 4446                                   * path is for local loopback
4450 4447                                   * communication which does not go
4451 4448                                   * through MAC_TX(). For paths that go
4452 4449                                   * through MAC_TX(), the promisc_list
4453 4450                                   * check is done inside the MAC_TX()
4454 4451                                   * macro.
4455 4452                                   */
4456 4453                                  if (mip->mi_promisc_list != NULL)
4457 4454                                          mac_promisc_dispatch(mip, mp, src_mcip);
4458 4455  
4459 4456                                  do_switch = ((src_mcip->mci_state_flags &
4460 4457                                      dst_mcip->mci_state_flags &
4461 4458                                      MCIS_CLIENT_POLL_CAPABLE) != 0);
4462 4459  
4463 4460                                  if ((mp1 = mac_fix_cksum(mp)) != NULL) {
4464 4461                                          (dst_flow_ent->fe_cb_fn)(
4465 4462                                              dst_flow_ent->fe_cb_arg1,
4466 4463                                              dst_flow_ent->fe_cb_arg2,
4467 4464                                              mp1, do_switch);
4468 4465                                  }
4469 4466                          }
4470 4467                          FLOW_REFRELE(dst_flow_ent);
4471 4468                  } else {
4472 4469                          /*
4473 4470                           * Unknown destination, send via the underlying
4474 4471                           * NIC.
4475 4472                           */
4476 4473                          MAC_TX(mip, ring, mp, src_mcip);
4477 4474                          if (mp != NULL) {
4478 4475                                  /*
4479 4476                                   * Adjust for the last packet that
4480 4477                                   * could not be transmitted
4481 4478                                   */
4482 4479                                  opackets--;
4483 4480                                  obytes -= pkt_size;
4484 4481                                  mp->b_next = next;
4485 4482                                  break;
4486 4483                          }
4487 4484                  }
4488 4485                  mp = next;
4489 4486          }
4490 4487  
4491 4488  done:
4492 4489          stats->mts_obytes = obytes;
4493 4490          stats->mts_opackets = opackets;
4494 4491          stats->mts_oerrors = oerrors;
4495 4492          return (mp);
4496 4493  }
4497 4494  
4498 4495  /*
4499 4496   * mac_tx_srs_ring_present
4500 4497   *
4501 4498   * Returns whether the specified ring is part of the specified SRS.
4502 4499   */
4503 4500  boolean_t
4504 4501  mac_tx_srs_ring_present(mac_soft_ring_set_t *srs, mac_ring_t *tx_ring)
4505 4502  {
4506 4503          int i;
4507 4504          mac_soft_ring_t *soft_ring;
4508 4505  
4509 4506          if (srs->srs_tx.st_arg2 == tx_ring)
4510 4507                  return (B_TRUE);
4511 4508  
4512 4509          for (i = 0; i < srs->srs_tx_ring_count; i++) {
4513 4510                  soft_ring =  srs->srs_tx_soft_rings[i];
4514 4511                  if (soft_ring->s_ring_tx_arg2 == tx_ring)
4515 4512                          return (B_TRUE);
4516 4513          }
4517 4514  
4518 4515          return (B_FALSE);
4519 4516  }
4520 4517  
4521 4518  /*
4522 4519   * mac_tx_srs_get_soft_ring
4523 4520   *
4524 4521   * Returns the TX soft ring associated with the given ring, if present.
4525 4522   */
4526 4523  mac_soft_ring_t *
4527 4524  mac_tx_srs_get_soft_ring(mac_soft_ring_set_t *srs, mac_ring_t *tx_ring)
4528 4525  {
4529 4526          int             i;
4530 4527          mac_soft_ring_t *soft_ring;
4531 4528  
4532 4529          if (srs->srs_tx.st_arg2 == tx_ring)
4533 4530                  return (NULL);
4534 4531  
4535 4532          for (i = 0; i < srs->srs_tx_ring_count; i++) {
4536 4533                  soft_ring =  srs->srs_tx_soft_rings[i];
4537 4534                  if (soft_ring->s_ring_tx_arg2 == tx_ring)
4538 4535                          return (soft_ring);
4539 4536          }
4540 4537  
4541 4538          return (NULL);
4542 4539  }
4543 4540  
4544 4541  /*
4545 4542   * mac_tx_srs_wakeup
4546 4543   *
4547 4544   * Called when Tx desc become available. Wakeup the appropriate worker
4548 4545   * thread after resetting the SRS_TX_BLOCKED/S_RING_BLOCK bit in the
4549 4546   * state field.
4550 4547   */
4551 4548  void
4552 4549  mac_tx_srs_wakeup(mac_soft_ring_set_t *mac_srs, mac_ring_handle_t ring)
4553 4550  {
4554 4551          int i;
4555 4552          mac_soft_ring_t *sringp;
4556 4553          mac_srs_tx_t *srs_tx = &mac_srs->srs_tx;
4557 4554  
4558 4555          mutex_enter(&mac_srs->srs_lock);
4559 4556          /*
4560 4557           * srs_tx_ring_count == 0 is the single ring mode case. In
4561 4558           * this mode, there will not be Tx soft rings associated
4562 4559           * with the SRS.
4563 4560           */
4564 4561          if (!MAC_TX_SOFT_RINGS(mac_srs)) {
4565 4562                  if (srs_tx->st_arg2 == ring &&
4566 4563                      mac_srs->srs_state & SRS_TX_BLOCKED) {
4567 4564                          mac_srs->srs_state &= ~SRS_TX_BLOCKED;
4568 4565                          srs_tx->st_stat.mts_unblockcnt++;
4569 4566                          cv_signal(&mac_srs->srs_async);
4570 4567                  }
4571 4568                  /*
4572 4569                   * A wakeup can come before tx_srs_drain() could
4573 4570                   * grab srs lock and set SRS_TX_BLOCKED. So
4574 4571                   * always set woken_up flag when we come here.
4575 4572                   */
4576 4573                  srs_tx->st_woken_up = B_TRUE;
4577 4574                  mutex_exit(&mac_srs->srs_lock);
4578 4575                  return;
4579 4576          }
4580 4577  
4581 4578          /*
4582 4579           * If you are here, it is for FANOUT, BW_FANOUT,
4583 4580           * AGGR_MODE or AGGR_BW_MODE case
4584 4581           */
4585 4582          for (i = 0; i < mac_srs->srs_tx_ring_count; i++) {
4586 4583                  sringp = mac_srs->srs_tx_soft_rings[i];
4587 4584                  mutex_enter(&sringp->s_ring_lock);
4588 4585                  if (sringp->s_ring_tx_arg2 == ring) {
4589 4586                          if (sringp->s_ring_state & S_RING_BLOCK) {
4590 4587                                  sringp->s_ring_state &= ~S_RING_BLOCK;
4591 4588                                  sringp->s_st_stat.mts_unblockcnt++;
4592 4589                                  cv_signal(&sringp->s_ring_async);
4593 4590                          }
4594 4591                          sringp->s_ring_tx_woken_up = B_TRUE;
4595 4592                  }
4596 4593                  mutex_exit(&sringp->s_ring_lock);
4597 4594          }
4598 4595          mutex_exit(&mac_srs->srs_lock);
4599 4596  }
4600 4597  
4601 4598  /*
4602 4599   * Once the driver is done draining, send a MAC_NOTE_TX notification to unleash
4603 4600   * the blocked clients again.
4604 4601   */
4605 4602  void
4606 4603  mac_tx_notify(mac_impl_t *mip)
4607 4604  {
4608 4605          i_mac_notify(mip, MAC_NOTE_TX);
4609 4606  }
4610 4607  
4611 4608  /*
4612 4609   * RX SOFTRING RELATED FUNCTIONS
4613 4610   *
4614 4611   * These functions really belong in mac_soft_ring.c and here for
4615 4612   * a short period.
4616 4613   */
4617 4614  
4618 4615  #define SOFT_RING_ENQUEUE_CHAIN(ringp, mp, tail, cnt, sz) {             \
4619 4616          /*                                                              \
4620 4617           * Enqueue our mblk chain.                                      \
4621 4618           */                                                             \
4622 4619          ASSERT(MUTEX_HELD(&(ringp)->s_ring_lock));                      \
4623 4620                                                                          \
4624 4621          if ((ringp)->s_ring_last != NULL)                               \
4625 4622                  (ringp)->s_ring_last->b_next = (mp);                    \
4626 4623          else                                                            \
4627 4624                  (ringp)->s_ring_first = (mp);                           \
4628 4625          (ringp)->s_ring_last = (tail);                                  \
4629 4626          (ringp)->s_ring_count += (cnt);                                 \
4630 4627          ASSERT((ringp)->s_ring_count > 0);                              \
4631 4628          if ((ringp)->s_ring_type & ST_RING_BW_CTL) {                    \
4632 4629                  (ringp)->s_ring_size += sz;                             \
4633 4630          }                                                               \
4634 4631  }
4635 4632  
4636 4633  /*
4637 4634   * Default entry point to deliver a packet chain to a MAC client.
4638 4635   * If the MAC client has flows, do the classification with these
4639 4636   * flows as well.
4640 4637   */
4641 4638  /* ARGSUSED */
4642 4639  void
4643 4640  mac_rx_deliver(void *arg1, mac_resource_handle_t mrh, mblk_t *mp_chain,
4644 4641      mac_header_info_t *arg3)
4645 4642  {
4646 4643          mac_client_impl_t *mcip = arg1;
4647 4644  
4648 4645          if (mcip->mci_nvids == 1 &&
4649 4646              !(mcip->mci_state_flags & MCIS_STRIP_DISABLE)) {
4650 4647                  /*
4651 4648                   * If the client has exactly one VID associated with it
4652 4649                   * and striping of VLAN header is not disabled,
4653 4650                   * remove the VLAN tag from the packet before
4654 4651                   * passing it on to the client's receive callback.
4655 4652                   * Note that this needs to be done after we dispatch
4656 4653                   * the packet to the promiscuous listeners of the
4657 4654                   * client, since they expect to see the whole
4658 4655                   * frame including the VLAN headers.
4659 4656                   */
4660 4657                  mp_chain = mac_strip_vlan_tag_chain(mp_chain);
4661 4658          }
4662 4659  
4663 4660          mcip->mci_rx_fn(mcip->mci_rx_arg, mrh, mp_chain, B_FALSE);
4664 4661  }
4665 4662  
4666 4663  /*
4667 4664   * mac_rx_soft_ring_process
4668 4665   *
4669 4666   * process a chain for a given soft ring. The number of packets queued
4670 4667   * in the SRS and its associated soft rings (including this one) is
4671 4668   * very small (tracked by srs_poll_pkt_cnt), then allow the entering
4672 4669   * thread (interrupt or poll thread) to do inline processing. This
4673 4670   * helps keep the latency down under low load.
4674 4671   *
4675 4672   * The proc and arg for each mblk is already stored in the mblk in
4676 4673   * appropriate places.
4677 4674   */
4678 4675  /* ARGSUSED */
4679 4676  void
4680 4677  mac_rx_soft_ring_process(mac_client_impl_t *mcip, mac_soft_ring_t *ringp,
4681 4678      mblk_t *mp_chain, mblk_t *tail, int cnt, size_t sz)
4682 4679  {
4683 4680          mac_direct_rx_t         proc;
4684 4681          void                    *arg1;
4685 4682          mac_resource_handle_t   arg2;
4686 4683          mac_soft_ring_set_t     *mac_srs = ringp->s_ring_set;
4687 4684  
4688 4685          ASSERT(ringp != NULL);
4689 4686          ASSERT(mp_chain != NULL);
4690 4687          ASSERT(tail != NULL);
4691 4688          ASSERT(MUTEX_NOT_HELD(&ringp->s_ring_lock));
4692 4689  
4693 4690          mutex_enter(&ringp->s_ring_lock);
4694 4691          ringp->s_ring_total_inpkt += cnt;
4695 4692          ringp->s_ring_total_rbytes += sz;
4696 4693          if ((mac_srs->srs_rx.sr_poll_pkt_cnt <= 1) &&
4697 4694              !(ringp->s_ring_type & ST_RING_WORKER_ONLY)) {
4698 4695                  /* If on processor or blanking on, then enqueue and return */
4699 4696                  if (ringp->s_ring_state & S_RING_BLANK ||
4700 4697                      ringp->s_ring_state & S_RING_PROC) {
4701 4698                          SOFT_RING_ENQUEUE_CHAIN(ringp, mp_chain, tail, cnt, sz);
4702 4699                          mutex_exit(&ringp->s_ring_lock);
4703 4700                          return;
4704 4701                  }
4705 4702                  proc = ringp->s_ring_rx_func;
4706 4703                  arg1 = ringp->s_ring_rx_arg1;
4707 4704                  arg2 = ringp->s_ring_rx_arg2;
4708 4705                  /*
4709 4706                   * See if anything is already queued. If we are the
4710 4707                   * first packet, do inline processing else queue the
4711 4708                   * packet and do the drain.
4712 4709                   */
4713 4710                  if (ringp->s_ring_first == NULL) {
4714 4711                          /*
4715 4712                           * Fast-path, ok to process and nothing queued.
4716 4713                           */
4717 4714                          ringp->s_ring_run = curthread;
4718 4715                          ringp->s_ring_state |= (S_RING_PROC);
4719 4716  
4720 4717                          mutex_exit(&ringp->s_ring_lock);
4721 4718  
4722 4719                          /*
4723 4720                           * We are the chain of 1 packet so
4724 4721                           * go through this fast path.
4725 4722                           */
4726 4723                          ASSERT(mp_chain->b_next == NULL);
4727 4724  
4728 4725                          (*proc)(arg1, arg2, mp_chain, NULL);
4729 4726  
4730 4727                          ASSERT(MUTEX_NOT_HELD(&ringp->s_ring_lock));
4731 4728                          /*
4732 4729                           * If we have a soft ring set which is doing
4733 4730                           * bandwidth control, we need to decrement
4734 4731                           * srs_size and count so it the SRS can have a
4735 4732                           * accurate idea of what is the real data
4736 4733                           * queued between SRS and its soft rings. We
4737 4734                           * decrement the counters only when the packet
4738 4735                           * gets processed by both SRS and the soft ring.
4739 4736                           */
4740 4737                          mutex_enter(&mac_srs->srs_lock);
4741 4738                          MAC_UPDATE_SRS_COUNT_LOCKED(mac_srs, cnt);
4742 4739                          MAC_UPDATE_SRS_SIZE_LOCKED(mac_srs, sz);
4743 4740                          mutex_exit(&mac_srs->srs_lock);
4744 4741  
4745 4742                          mutex_enter(&ringp->s_ring_lock);
4746 4743                          ringp->s_ring_run = NULL;
4747 4744                          ringp->s_ring_state &= ~S_RING_PROC;
4748 4745                          if (ringp->s_ring_state & S_RING_CLIENT_WAIT)
4749 4746                                  cv_signal(&ringp->s_ring_client_cv);
4750 4747  
4751 4748                          if ((ringp->s_ring_first == NULL) ||
4752 4749                              (ringp->s_ring_state & S_RING_BLANK)) {
4753 4750                                  /*
4754 4751                                   * We processed inline our packet and
4755 4752                                   * nothing new has arrived or our
4756 4753                                   * receiver doesn't want to receive
4757 4754                                   * any packets. We are done.
4758 4755                                   */
4759 4756                                  mutex_exit(&ringp->s_ring_lock);
4760 4757                                  return;
4761 4758                          }
4762 4759                  } else {
4763 4760                          SOFT_RING_ENQUEUE_CHAIN(ringp,
4764 4761                              mp_chain, tail, cnt, sz);
4765 4762                  }
4766 4763  
4767 4764                  /*
4768 4765                   * We are here because either we couldn't do inline
4769 4766                   * processing (because something was already
4770 4767                   * queued), or we had a chain of more than one
4771 4768                   * packet, or something else arrived after we were
4772 4769                   * done with inline processing.
4773 4770                   */
4774 4771                  ASSERT(MUTEX_HELD(&ringp->s_ring_lock));
4775 4772                  ASSERT(ringp->s_ring_first != NULL);
4776 4773  
4777 4774                  ringp->s_ring_drain_func(ringp);
4778 4775                  mutex_exit(&ringp->s_ring_lock);
4779 4776                  return;
4780 4777          } else {
4781 4778                  /* ST_RING_WORKER_ONLY case */
4782 4779                  SOFT_RING_ENQUEUE_CHAIN(ringp, mp_chain, tail, cnt, sz);
4783 4780                  mac_soft_ring_worker_wakeup(ringp);
4784 4781                  mutex_exit(&ringp->s_ring_lock);
4785 4782          }
4786 4783  }
4787 4784  
4788 4785  /*
4789 4786   * TX SOFTRING RELATED FUNCTIONS
4790 4787   *
4791 4788   * These functions really belong in mac_soft_ring.c and here for
4792 4789   * a short period.
4793 4790   */
4794 4791  
4795 4792  #define TX_SOFT_RING_ENQUEUE_CHAIN(ringp, mp, tail, cnt, sz) {          \
4796 4793          ASSERT(MUTEX_HELD(&ringp->s_ring_lock));                        \
4797 4794          ringp->s_ring_state |= S_RING_ENQUEUED;                         \
4798 4795          SOFT_RING_ENQUEUE_CHAIN(ringp, mp_chain, tail, cnt, sz);        \
4799 4796  }
4800 4797  
4801 4798  /*
4802 4799   * mac_tx_sring_queued
4803 4800   *
4804 4801   * When we are out of transmit descriptors and we already have a
4805 4802   * queue that exceeds hiwat (or the client called us with
4806 4803   * MAC_TX_NO_ENQUEUE or MAC_DROP_ON_NO_DESC flag), return the
4807 4804   * soft ring pointer as the opaque cookie for the client enable
4808 4805   * flow control.
4809 4806   */
4810 4807  static mac_tx_cookie_t
4811 4808  mac_tx_sring_enqueue(mac_soft_ring_t *ringp, mblk_t *mp_chain, uint16_t flag,
4812 4809      mblk_t **ret_mp)
4813 4810  {
4814 4811          int cnt;
4815 4812          size_t sz;
4816 4813          mblk_t *tail;
4817 4814          mac_soft_ring_set_t *mac_srs = ringp->s_ring_set;
4818 4815          mac_tx_cookie_t cookie = NULL;
4819 4816          boolean_t wakeup_worker = B_TRUE;
4820 4817  
4821 4818          ASSERT(MUTEX_HELD(&ringp->s_ring_lock));
4822 4819          MAC_COUNT_CHAIN(mac_srs, mp_chain, tail, cnt, sz);
4823 4820          if (flag & MAC_DROP_ON_NO_DESC) {
4824 4821                  mac_pkt_drop(NULL, NULL, mp_chain, B_FALSE);
4825 4822                  /* increment freed stats */
4826 4823                  ringp->s_ring_drops += cnt;
4827 4824                  cookie = (mac_tx_cookie_t)ringp;
4828 4825          } else {
4829 4826                  if (ringp->s_ring_first != NULL)
4830 4827                          wakeup_worker = B_FALSE;
4831 4828  
4832 4829                  if (flag & MAC_TX_NO_ENQUEUE) {
4833 4830                          /*
4834 4831                           * If QUEUED is not set, queue the packet
4835 4832                           * and let mac_tx_soft_ring_drain() set
4836 4833                           * the TX_BLOCKED bit for the reasons
4837 4834                           * explained above. Otherwise, return the
4838 4835                           * mblks.
4839 4836                           */
4840 4837                          if (wakeup_worker) {
4841 4838                                  TX_SOFT_RING_ENQUEUE_CHAIN(ringp,
4842 4839                                      mp_chain, tail, cnt, sz);
4843 4840                          } else {
4844 4841                                  ringp->s_ring_state |= S_RING_WAKEUP_CLIENT;
4845 4842                                  cookie = (mac_tx_cookie_t)ringp;
4846 4843                                  *ret_mp = mp_chain;
4847 4844                          }
4848 4845                  } else {
4849 4846                          boolean_t enqueue = B_TRUE;
4850 4847  
4851 4848                          if (ringp->s_ring_count > ringp->s_ring_tx_hiwat) {
4852 4849                                  /*
4853 4850                                   * flow-controlled. Store ringp in cookie
4854 4851                                   * so that it can be returned as
4855 4852                                   * mac_tx_cookie_t to client
4856 4853                                   */
4857 4854                                  ringp->s_ring_state |= S_RING_TX_HIWAT;
4858 4855                                  cookie = (mac_tx_cookie_t)ringp;
4859 4856                                  ringp->s_ring_hiwat_cnt++;
4860 4857                                  if (ringp->s_ring_count >
4861 4858                                      ringp->s_ring_tx_max_q_cnt) {
4862 4859                                          /* increment freed stats */
4863 4860                                          ringp->s_ring_drops += cnt;
4864 4861                                          /*
4865 4862                                           * b_prev may be set to the fanout hint
4866 4863                                           * hence can't use freemsg directly
4867 4864                                           */
4868 4865                                          mac_pkt_drop(NULL, NULL,
4869 4866                                              mp_chain, B_FALSE);
4870 4867                                          DTRACE_PROBE1(tx_queued_hiwat,
4871 4868                                              mac_soft_ring_t *, ringp);
4872 4869                                          enqueue = B_FALSE;
4873 4870                                  }
4874 4871                          }
4875 4872                          if (enqueue) {
4876 4873                                  TX_SOFT_RING_ENQUEUE_CHAIN(ringp, mp_chain,
4877 4874                                      tail, cnt, sz);
4878 4875                          }
4879 4876                  }
4880 4877                  if (wakeup_worker)
4881 4878                          cv_signal(&ringp->s_ring_async);
4882 4879          }
4883 4880          return (cookie);
4884 4881  }
4885 4882  
4886 4883  
4887 4884  /*
4888 4885   * mac_tx_soft_ring_process
4889 4886   *
4890 4887   * This routine is called when fanning out outgoing traffic among
4891 4888   * multipe Tx rings.
4892 4889   * Note that a soft ring is associated with a h/w Tx ring.
4893 4890   */
4894 4891  mac_tx_cookie_t
4895 4892  mac_tx_soft_ring_process(mac_soft_ring_t *ringp, mblk_t *mp_chain,
4896 4893      uint16_t flag, mblk_t **ret_mp)
4897 4894  {
4898 4895          mac_soft_ring_set_t *mac_srs = ringp->s_ring_set;
4899 4896          int     cnt;
4900 4897          size_t  sz;
4901 4898          mblk_t  *tail;
4902 4899          mac_tx_cookie_t cookie = NULL;
4903 4900  
4904 4901          ASSERT(ringp != NULL);
4905 4902          ASSERT(mp_chain != NULL);
4906 4903          ASSERT(MUTEX_NOT_HELD(&ringp->s_ring_lock));
4907 4904          /*
4908 4905           * The following modes can come here: SRS_TX_BW_FANOUT,
4909 4906           * SRS_TX_FANOUT, SRS_TX_AGGR, SRS_TX_BW_AGGR.
4910 4907           */
4911 4908          ASSERT(MAC_TX_SOFT_RINGS(mac_srs));
4912 4909          ASSERT(mac_srs->srs_tx.st_mode == SRS_TX_FANOUT ||
4913 4910              mac_srs->srs_tx.st_mode == SRS_TX_BW_FANOUT ||
4914 4911              mac_srs->srs_tx.st_mode == SRS_TX_AGGR ||
4915 4912              mac_srs->srs_tx.st_mode == SRS_TX_BW_AGGR);
4916 4913  
4917 4914          if (ringp->s_ring_type & ST_RING_WORKER_ONLY) {
4918 4915                  /* Serialization mode */
4919 4916  
4920 4917                  mutex_enter(&ringp->s_ring_lock);
4921 4918                  if (ringp->s_ring_count > ringp->s_ring_tx_hiwat) {
4922 4919                          cookie = mac_tx_sring_enqueue(ringp, mp_chain,
4923 4920                              flag, ret_mp);
4924 4921                          mutex_exit(&ringp->s_ring_lock);
4925 4922                          return (cookie);
4926 4923                  }
4927 4924                  MAC_COUNT_CHAIN(mac_srs, mp_chain, tail, cnt, sz);
4928 4925                  TX_SOFT_RING_ENQUEUE_CHAIN(ringp, mp_chain, tail, cnt, sz);
4929 4926                  if (ringp->s_ring_state & (S_RING_BLOCK | S_RING_PROC)) {
4930 4927                          /*
4931 4928                           * If ring is blocked due to lack of Tx
4932 4929                           * descs, just return. Worker thread
4933 4930                           * will get scheduled when Tx desc's
4934 4931                           * become available.
4935 4932                           */
4936 4933                          mutex_exit(&ringp->s_ring_lock);
4937 4934                          return (cookie);
4938 4935                  }
4939 4936                  mac_soft_ring_worker_wakeup(ringp);
4940 4937                  mutex_exit(&ringp->s_ring_lock);
4941 4938                  return (cookie);
4942 4939          } else {
4943 4940                  /* Default fanout mode */
4944 4941                  /*
4945 4942                   * S_RING_BLOCKED is set when underlying NIC runs
4946 4943                   * out of Tx descs and messages start getting
4947 4944                   * queued. It won't get reset until
4948 4945                   * tx_srs_drain() completely drains out the
4949 4946                   * messages.
4950 4947                   */
4951 4948                  mac_tx_stats_t          stats;
4952 4949  
4953 4950                  if (ringp->s_ring_state & S_RING_ENQUEUED) {
4954 4951                          /* Tx descs/resources not available */
4955 4952                          mutex_enter(&ringp->s_ring_lock);
4956 4953                          if (ringp->s_ring_state & S_RING_ENQUEUED) {
4957 4954                                  cookie = mac_tx_sring_enqueue(ringp, mp_chain,
4958 4955                                      flag, ret_mp);
4959 4956                                  mutex_exit(&ringp->s_ring_lock);
4960 4957                                  return (cookie);
4961 4958                          }
4962 4959                          /*
4963 4960                           * While we were computing mblk count, the
4964 4961                           * flow control condition got relieved.
4965 4962                           * Continue with the transmission.
4966 4963                           */
4967 4964                          mutex_exit(&ringp->s_ring_lock);
4968 4965                  }
4969 4966  
4970 4967                  mp_chain = mac_tx_send(ringp->s_ring_tx_arg1,
4971 4968                      ringp->s_ring_tx_arg2, mp_chain, &stats);
4972 4969  
4973 4970                  /*
4974 4971                   * Multiple threads could be here sending packets.
4975 4972                   * Under such conditions, it is not possible to
4976 4973                   * automically set S_RING_BLOCKED bit to indicate
4977 4974                   * out of tx desc condition. To atomically set
4978 4975                   * this, we queue the returned packet and do
4979 4976                   * the setting of S_RING_BLOCKED in
4980 4977                   * mac_tx_soft_ring_drain().
4981 4978                   */
4982 4979                  if (mp_chain != NULL) {
4983 4980                          mutex_enter(&ringp->s_ring_lock);
4984 4981                          cookie =
4985 4982                              mac_tx_sring_enqueue(ringp, mp_chain, flag, ret_mp);
4986 4983                          mutex_exit(&ringp->s_ring_lock);
4987 4984                          return (cookie);
4988 4985                  }
4989 4986                  SRS_TX_STATS_UPDATE(mac_srs, &stats);
4990 4987                  SOFTRING_TX_STATS_UPDATE(ringp, &stats);
4991 4988  
4992 4989                  return (NULL);
4993 4990          }
4994 4991  }
  
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