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