1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 
  22 /*
  23  * Copyright (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
  24  */
  25 /*
  26  * Copyright (c) 2010, Intel Corporation.
  27  * All rights reserved.
  28  */
  29 /*
  30  * Copyright 2015 Joyent, Inc.
  31  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
  32  */
  33 
  34 #include <sys/types.h>
  35 #include <sys/thread.h>
  36 #include <sys/cpuvar.h>
  37 #include <sys/cpu.h>
  38 #include <sys/t_lock.h>
  39 #include <sys/param.h>
  40 #include <sys/proc.h>
  41 #include <sys/disp.h>
  42 #include <sys/class.h>
  43 #include <sys/cmn_err.h>
  44 #include <sys/debug.h>
  45 #include <sys/note.h>
  46 #include <sys/asm_linkage.h>
  47 #include <sys/x_call.h>
  48 #include <sys/systm.h>
  49 #include <sys/var.h>
  50 #include <sys/vtrace.h>
  51 #include <vm/hat.h>
  52 #include <vm/as.h>
  53 #include <vm/seg_kmem.h>
  54 #include <vm/seg_kp.h>
  55 #include <sys/segments.h>
  56 #include <sys/kmem.h>
  57 #include <sys/stack.h>
  58 #include <sys/smp_impldefs.h>
  59 #include <sys/x86_archext.h>
  60 #include <sys/machsystm.h>
  61 #include <sys/traptrace.h>
  62 #include <sys/clock.h>
  63 #include <sys/cpc_impl.h>
  64 #include <sys/pg.h>
  65 #include <sys/cmt.h>
  66 #include <sys/dtrace.h>
  67 #include <sys/archsystm.h>
  68 #include <sys/fp.h>
  69 #include <sys/reboot.h>
  70 #include <sys/kdi_machimpl.h>
  71 #include <vm/hat_i86.h>
  72 #include <vm/vm_dep.h>
  73 #include <sys/memnode.h>
  74 #include <sys/pci_cfgspace.h>
  75 #include <sys/mach_mmu.h>
  76 #include <sys/sysmacros.h>
  77 #if defined(__xpv)
  78 #include <sys/hypervisor.h>
  79 #endif
  80 #include <sys/cpu_module.h>
  81 #include <sys/ontrap.h>
  82 
  83 struct cpu      cpus[1];                        /* CPU data */
  84 struct cpu      *cpu[NCPU] = {&cpus[0]};    /* pointers to all CPUs */
  85 struct cpu      *cpu_free_list;                 /* list for released CPUs */
  86 cpu_core_t      cpu_core[NCPU];                 /* cpu_core structures */
  87 
  88 #define cpu_next_free   cpu_prev
  89 
  90 /*
  91  * Useful for disabling MP bring-up on a MP capable system.
  92  */
  93 int use_mp = 1;
  94 
  95 /*
  96  * to be set by a PSM to indicate what cpus
  97  * are sitting around on the system.
  98  */
  99 cpuset_t mp_cpus;
 100 
 101 /*
 102  * This variable is used by the hat layer to decide whether or not
 103  * critical sections are needed to prevent race conditions.  For sun4m,
 104  * this variable is set once enough MP initialization has been done in
 105  * order to allow cross calls.
 106  */
 107 int flushes_require_xcalls;
 108 
 109 cpuset_t cpu_ready_set;         /* initialized in startup() */
 110 
 111 static void mp_startup_boot(void);
 112 static void mp_startup_hotplug(void);
 113 
 114 static void cpu_sep_enable(void);
 115 static void cpu_sep_disable(void);
 116 static void cpu_asysc_enable(void);
 117 static void cpu_asysc_disable(void);
 118 
 119 /*
 120  * Init CPU info - get CPU type info for processor_info system call.
 121  */
 122 void
 123 init_cpu_info(struct cpu *cp)
 124 {
 125         processor_info_t *pi = &cp->cpu_type_info;
 126 
 127         /*
 128          * Get clock-frequency property for the CPU.
 129          */
 130         pi->pi_clock = cpu_freq;
 131 
 132         /*
 133          * Current frequency in Hz.
 134          */
 135         cp->cpu_curr_clock = cpu_freq_hz;
 136 
 137         /*
 138          * Supported frequencies.
 139          */
 140         if (cp->cpu_supp_freqs == NULL) {
 141                 cpu_set_supp_freqs(cp, NULL);
 142         }
 143 
 144         (void) strcpy(pi->pi_processor_type, "i386");
 145         if (fpu_exists)
 146                 (void) strcpy(pi->pi_fputypes, "i387 compatible");
 147 
 148         cp->cpu_idstr = kmem_zalloc(CPU_IDSTRLEN, KM_SLEEP);
 149         cp->cpu_brandstr = kmem_zalloc(CPU_IDSTRLEN, KM_SLEEP);
 150 
 151         /*
 152          * If called for the BSP, cp is equal to current CPU.
 153          * For non-BSPs, cpuid info of cp is not ready yet, so use cpuid info
 154          * of current CPU as default values for cpu_idstr and cpu_brandstr.
 155          * They will be corrected in mp_startup_common() after cpuid_pass1()
 156          * has been invoked on target CPU.
 157          */
 158         (void) cpuid_getidstr(CPU, cp->cpu_idstr, CPU_IDSTRLEN);
 159         (void) cpuid_getbrandstr(CPU, cp->cpu_brandstr, CPU_IDSTRLEN);
 160 }
 161 
 162 /*
 163  * Configure syscall support on this CPU.
 164  */
 165 /*ARGSUSED*/
 166 void
 167 init_cpu_syscall(struct cpu *cp)
 168 {
 169         kpreempt_disable();
 170 
 171 #if defined(__amd64)
 172         if (is_x86_feature(x86_featureset, X86FSET_MSR) &&
 173             is_x86_feature(x86_featureset, X86FSET_ASYSC)) {
 174                 uint64_t flags;
 175 
 176 #if !defined(__lint)
 177                 /*
 178                  * The syscall instruction imposes a certain ordering on
 179                  * segment selectors, so we double-check that ordering
 180                  * here.
 181                  */
 182                 ASSERT(KDS_SEL == KCS_SEL + 8);
 183                 ASSERT(UDS_SEL == U32CS_SEL + 8);
 184                 ASSERT(UCS_SEL == U32CS_SEL + 16);
 185 #endif
 186                 /*
 187                  * Turn syscall/sysret extensions on.
 188                  */
 189                 cpu_asysc_enable();
 190 
 191                 /*
 192                  * Program the magic registers ..
 193                  */
 194                 wrmsr(MSR_AMD_STAR,
 195                     ((uint64_t)(U32CS_SEL << 16 | KCS_SEL)) << 32);
 196                 wrmsr(MSR_AMD_LSTAR, (uint64_t)(uintptr_t)sys_syscall);
 197                 wrmsr(MSR_AMD_CSTAR, (uint64_t)(uintptr_t)sys_syscall32);
 198 
 199                 /*
 200                  * This list of flags is masked off the incoming
 201                  * %rfl when we enter the kernel.
 202                  */
 203                 flags = PS_IE | PS_T;
 204                 if (is_x86_feature(x86_featureset, X86FSET_SMAP) == B_TRUE)
 205                         flags |= PS_ACHK;
 206                 wrmsr(MSR_AMD_SFMASK, flags);
 207         }
 208 #endif
 209 
 210         /*
 211          * On 32-bit kernels, we use sysenter/sysexit because it's too
 212          * hard to use syscall/sysret, and it is more portable anyway.
 213          *
 214          * On 64-bit kernels on Nocona machines, the 32-bit syscall
 215          * variant isn't available to 32-bit applications, but sysenter is.
 216          */
 217         if (is_x86_feature(x86_featureset, X86FSET_MSR) &&
 218             is_x86_feature(x86_featureset, X86FSET_SEP)) {
 219 
 220 #if !defined(__lint)
 221                 /*
 222                  * The sysenter instruction imposes a certain ordering on
 223                  * segment selectors, so we double-check that ordering
 224                  * here. See "sysenter" in Intel document 245471-012, "IA-32
 225                  * Intel Architecture Software Developer's Manual Volume 2:
 226                  * Instruction Set Reference"
 227                  */
 228                 ASSERT(KDS_SEL == KCS_SEL + 8);
 229 
 230                 ASSERT32(UCS_SEL == ((KCS_SEL + 16) | 3));
 231                 ASSERT32(UDS_SEL == UCS_SEL + 8);
 232 
 233                 ASSERT64(U32CS_SEL == ((KCS_SEL + 16) | 3));
 234                 ASSERT64(UDS_SEL == U32CS_SEL + 8);
 235 #endif
 236 
 237                 cpu_sep_enable();
 238 
 239                 /*
 240                  * resume() sets this value to the base of the threads stack
 241                  * via a context handler.
 242                  */
 243                 wrmsr(MSR_INTC_SEP_ESP, 0);
 244                 wrmsr(MSR_INTC_SEP_EIP, (uint64_t)(uintptr_t)sys_sysenter);
 245         }
 246 
 247         kpreempt_enable();
 248 }
 249 
 250 /*
 251  * Multiprocessor initialization.
 252  *
 253  * Allocate and initialize the cpu structure, TRAPTRACE buffer, and the
 254  * startup and idle threads for the specified CPU.
 255  * Parameter boot is true for boot time operations and is false for CPU
 256  * DR operations.
 257  */
 258 static struct cpu *
 259 mp_cpu_configure_common(int cpun, boolean_t boot)
 260 {
 261         struct cpu *cp;
 262         kthread_id_t tp;
 263         caddr_t sp;
 264         proc_t *procp;
 265 #if !defined(__xpv)
 266         extern int idle_cpu_prefer_mwait;
 267         extern void cpu_idle_mwait();
 268 #endif
 269         extern void idle();
 270         extern void cpu_idle();
 271 
 272 #ifdef TRAPTRACE
 273         trap_trace_ctl_t *ttc = &trap_trace_ctl[cpun];
 274 #endif
 275 
 276         ASSERT(MUTEX_HELD(&cpu_lock));
 277         ASSERT(cpun < NCPU && cpu[cpun] == NULL);
 278 
 279         if (cpu_free_list == NULL) {
 280                 cp = kmem_zalloc(sizeof (*cp), KM_SLEEP);
 281         } else {
 282                 cp = cpu_free_list;
 283                 cpu_free_list = cp->cpu_next_free;
 284         }
 285 
 286         cp->cpu_m.mcpu_istamp = cpun << 16;
 287 
 288         /* Create per CPU specific threads in the process p0. */
 289         procp = &p0;
 290 
 291         /*
 292          * Initialize the dispatcher first.
 293          */
 294         disp_cpu_init(cp);
 295 
 296         cpu_vm_data_init(cp);
 297 
 298         /*
 299          * Allocate and initialize the startup thread for this CPU.
 300          * Interrupt and process switch stacks get allocated later
 301          * when the CPU starts running.
 302          */
 303         tp = thread_create(NULL, 0, NULL, NULL, 0, procp,
 304             TS_STOPPED, maxclsyspri);
 305 
 306         /*
 307          * Set state to TS_ONPROC since this thread will start running
 308          * as soon as the CPU comes online.
 309          *
 310          * All the other fields of the thread structure are setup by
 311          * thread_create().
 312          */
 313         THREAD_ONPROC(tp, cp);
 314         tp->t_preempt = 1;
 315         tp->t_bound_cpu = cp;
 316         tp->t_affinitycnt = 1;
 317         tp->t_cpu = cp;
 318         tp->t_disp_queue = cp->cpu_disp;
 319 
 320         /*
 321          * Setup thread to start in mp_startup_common.
 322          */
 323         sp = tp->t_stk;
 324         tp->t_sp = (uintptr_t)(sp - MINFRAME);
 325 #if defined(__amd64)
 326         tp->t_sp -= STACK_ENTRY_ALIGN;               /* fake a call */
 327 #endif
 328         /*
 329          * Setup thread start entry point for boot or hotplug.
 330          */
 331         if (boot) {
 332                 tp->t_pc = (uintptr_t)mp_startup_boot;
 333         } else {
 334                 tp->t_pc = (uintptr_t)mp_startup_hotplug;
 335         }
 336 
 337         cp->cpu_id = cpun;
 338         cp->cpu_self = cp;
 339         cp->cpu_thread = tp;
 340         cp->cpu_lwp = NULL;
 341         cp->cpu_dispthread = tp;
 342         cp->cpu_dispatch_pri = DISP_PRIO(tp);
 343 
 344         /*
 345          * cpu_base_spl must be set explicitly here to prevent any blocking
 346          * operations in mp_startup_common from causing the spl of the cpu
 347          * to drop to 0 (allowing device interrupts before we're ready) in
 348          * resume().
 349          * cpu_base_spl MUST remain at LOCK_LEVEL until the cpu is CPU_READY.
 350          * As an extra bit of security on DEBUG kernels, this is enforced with
 351          * an assertion in mp_startup_common() -- before cpu_base_spl is set
 352          * to its proper value.
 353          */
 354         cp->cpu_base_spl = ipltospl(LOCK_LEVEL);
 355 
 356         /*
 357          * Now, initialize per-CPU idle thread for this CPU.
 358          */
 359         tp = thread_create(NULL, PAGESIZE, idle, NULL, 0, procp, TS_ONPROC, -1);
 360 
 361         cp->cpu_idle_thread = tp;
 362 
 363         tp->t_preempt = 1;
 364         tp->t_bound_cpu = cp;
 365         tp->t_affinitycnt = 1;
 366         tp->t_cpu = cp;
 367         tp->t_disp_queue = cp->cpu_disp;
 368 
 369         /*
 370          * Bootstrap the CPU's PG data
 371          */
 372         pg_cpu_bootstrap(cp);
 373 
 374         /*
 375          * Perform CPC initialization on the new CPU.
 376          */
 377         kcpc_hw_init(cp);
 378 
 379         /*
 380          * Allocate virtual addresses for cpu_caddr1 and cpu_caddr2
 381          * for each CPU.
 382          */
 383         setup_vaddr_for_ppcopy(cp);
 384 
 385         /*
 386          * Allocate page for new GDT and initialize from current GDT.
 387          */
 388 #if !defined(__lint)
 389         ASSERT((sizeof (*cp->cpu_gdt) * NGDT) <= PAGESIZE);
 390 #endif
 391         cp->cpu_gdt = kmem_zalloc(PAGESIZE, KM_SLEEP);
 392         bcopy(CPU->cpu_gdt, cp->cpu_gdt, (sizeof (*cp->cpu_gdt) * NGDT));
 393 
 394 #if defined(__i386)
 395         /*
 396          * setup kernel %gs.
 397          */
 398         set_usegd(&cp->cpu_gdt[GDT_GS], cp, sizeof (struct cpu) -1, SDT_MEMRWA,
 399             SEL_KPL, 0, 1);
 400 #endif
 401 
 402         /*
 403          * If we have more than one node, each cpu gets a copy of IDT
 404          * local to its node. If this is a Pentium box, we use cpu 0's
 405          * IDT. cpu 0's IDT has been made read-only to workaround the
 406          * cmpxchgl register bug
 407          */
 408         if (system_hardware.hd_nodes && x86_type != X86_TYPE_P5) {
 409 #if !defined(__lint)
 410                 ASSERT((sizeof (*CPU->cpu_idt) * NIDT) <= PAGESIZE);
 411 #endif
 412                 cp->cpu_idt = kmem_zalloc(PAGESIZE, KM_SLEEP);
 413                 bcopy(CPU->cpu_idt, cp->cpu_idt, PAGESIZE);
 414         } else {
 415                 cp->cpu_idt = CPU->cpu_idt;
 416         }
 417 
 418         /*
 419          * alloc space for cpuid info
 420          */
 421         cpuid_alloc_space(cp);
 422 #if !defined(__xpv)
 423         if (is_x86_feature(x86_featureset, X86FSET_MWAIT) &&
 424             idle_cpu_prefer_mwait) {
 425                 cp->cpu_m.mcpu_mwait = cpuid_mwait_alloc(cp);
 426                 cp->cpu_m.mcpu_idle_cpu = cpu_idle_mwait;
 427         } else
 428 #endif
 429                 cp->cpu_m.mcpu_idle_cpu = cpu_idle;
 430 
 431         init_cpu_info(cp);
 432 
 433         /*
 434          * alloc space for ucode_info
 435          */
 436         ucode_alloc_space(cp);
 437         xc_init_cpu(cp);
 438         hat_cpu_online(cp);
 439 
 440 #ifdef TRAPTRACE
 441         /*
 442          * If this is a TRAPTRACE kernel, allocate TRAPTRACE buffers
 443          */
 444         ttc->ttc_first = (uintptr_t)kmem_zalloc(trap_trace_bufsize, KM_SLEEP);
 445         ttc->ttc_next = ttc->ttc_first;
 446         ttc->ttc_limit = ttc->ttc_first + trap_trace_bufsize;
 447 #endif
 448 
 449         /*
 450          * Record that we have another CPU.
 451          */
 452         /*
 453          * Initialize the interrupt threads for this CPU
 454          */
 455         cpu_intr_alloc(cp, NINTR_THREADS);
 456 
 457         cp->cpu_flags = CPU_OFFLINE | CPU_QUIESCED | CPU_POWEROFF;
 458         cpu_set_state(cp);
 459 
 460         /*
 461          * Add CPU to list of available CPUs.  It'll be on the active list
 462          * after mp_startup_common().
 463          */
 464         cpu_add_unit(cp);
 465 
 466         return (cp);
 467 }
 468 
 469 /*
 470  * Undo what was done in mp_cpu_configure_common
 471  */
 472 static void
 473 mp_cpu_unconfigure_common(struct cpu *cp, int error)
 474 {
 475         ASSERT(MUTEX_HELD(&cpu_lock));
 476 
 477         /*
 478          * Remove the CPU from the list of available CPUs.
 479          */
 480         cpu_del_unit(cp->cpu_id);
 481 
 482         if (error == ETIMEDOUT) {
 483                 /*
 484                  * The cpu was started, but never *seemed* to run any
 485                  * code in the kernel; it's probably off spinning in its
 486                  * own private world, though with potential references to
 487                  * our kmem-allocated IDTs and GDTs (for example).
 488                  *
 489                  * Worse still, it may actually wake up some time later,
 490                  * so rather than guess what it might or might not do, we
 491                  * leave the fundamental data structures intact.
 492                  */
 493                 cp->cpu_flags = 0;
 494                 return;
 495         }
 496 
 497         /*
 498          * At this point, the only threads bound to this CPU should
 499          * special per-cpu threads: it's idle thread, it's pause threads,
 500          * and it's interrupt threads.  Clean these up.
 501          */
 502         cpu_destroy_bound_threads(cp);
 503         cp->cpu_idle_thread = NULL;
 504 
 505         /*
 506          * Free the interrupt stack.
 507          */
 508         segkp_release(segkp,
 509             cp->cpu_intr_stack - (INTR_STACK_SIZE - SA(MINFRAME)));
 510         cp->cpu_intr_stack = NULL;
 511 
 512 #ifdef TRAPTRACE
 513         /*
 514          * Discard the trap trace buffer
 515          */
 516         {
 517                 trap_trace_ctl_t *ttc = &trap_trace_ctl[cp->cpu_id];
 518 
 519                 kmem_free((void *)ttc->ttc_first, trap_trace_bufsize);
 520                 ttc->ttc_first = NULL;
 521         }
 522 #endif
 523 
 524         hat_cpu_offline(cp);
 525 
 526         ucode_free_space(cp);
 527 
 528         /* Free CPU ID string and brand string. */
 529         if (cp->cpu_idstr) {
 530                 kmem_free(cp->cpu_idstr, CPU_IDSTRLEN);
 531                 cp->cpu_idstr = NULL;
 532         }
 533         if (cp->cpu_brandstr) {
 534                 kmem_free(cp->cpu_brandstr, CPU_IDSTRLEN);
 535                 cp->cpu_brandstr = NULL;
 536         }
 537 
 538 #if !defined(__xpv)
 539         if (cp->cpu_m.mcpu_mwait != NULL) {
 540                 cpuid_mwait_free(cp);
 541                 cp->cpu_m.mcpu_mwait = NULL;
 542         }
 543 #endif
 544         cpuid_free_space(cp);
 545 
 546         if (cp->cpu_idt != CPU->cpu_idt)
 547                 kmem_free(cp->cpu_idt, PAGESIZE);
 548         cp->cpu_idt = NULL;
 549 
 550         kmem_free(cp->cpu_gdt, PAGESIZE);
 551         cp->cpu_gdt = NULL;
 552 
 553         if (cp->cpu_supp_freqs != NULL) {
 554                 size_t len = strlen(cp->cpu_supp_freqs) + 1;
 555                 kmem_free(cp->cpu_supp_freqs, len);
 556                 cp->cpu_supp_freqs = NULL;
 557         }
 558 
 559         teardown_vaddr_for_ppcopy(cp);
 560 
 561         kcpc_hw_fini(cp);
 562 
 563         cp->cpu_dispthread = NULL;
 564         cp->cpu_thread = NULL;       /* discarded by cpu_destroy_bound_threads() */
 565 
 566         cpu_vm_data_destroy(cp);
 567 
 568         xc_fini_cpu(cp);
 569         disp_cpu_fini(cp);
 570 
 571         ASSERT(cp != CPU0);
 572         bzero(cp, sizeof (*cp));
 573         cp->cpu_next_free = cpu_free_list;
 574         cpu_free_list = cp;
 575 }
 576 
 577 /*
 578  * Apply workarounds for known errata, and warn about those that are absent.
 579  *
 580  * System vendors occasionally create configurations which contain different
 581  * revisions of the CPUs that are almost but not exactly the same.  At the
 582  * time of writing, this meant that their clock rates were the same, their
 583  * feature sets were the same, but the required workaround were -not-
 584  * necessarily the same.  So, this routine is invoked on -every- CPU soon
 585  * after starting to make sure that the resulting system contains the most
 586  * pessimal set of workarounds needed to cope with *any* of the CPUs in the
 587  * system.
 588  *
 589  * workaround_errata is invoked early in mlsetup() for CPU 0, and in
 590  * mp_startup_common() for all slave CPUs. Slaves process workaround_errata
 591  * prior to acknowledging their readiness to the master, so this routine will
 592  * never be executed by multiple CPUs in parallel, thus making updates to
 593  * global data safe.
 594  *
 595  * These workarounds are based on Rev 3.57 of the Revision Guide for
 596  * AMD Athlon(tm) 64 and AMD Opteron(tm) Processors, August 2005.
 597  */
 598 
 599 #if defined(OPTERON_ERRATUM_88)
 600 int opteron_erratum_88;         /* if non-zero -> at least one cpu has it */
 601 #endif
 602 
 603 #if defined(OPTERON_ERRATUM_91)
 604 int opteron_erratum_91;         /* if non-zero -> at least one cpu has it */
 605 #endif
 606 
 607 #if defined(OPTERON_ERRATUM_93)
 608 int opteron_erratum_93;         /* if non-zero -> at least one cpu has it */
 609 #endif
 610 
 611 #if defined(OPTERON_ERRATUM_95)
 612 int opteron_erratum_95;         /* if non-zero -> at least one cpu has it */
 613 #endif
 614 
 615 #if defined(OPTERON_ERRATUM_100)
 616 int opteron_erratum_100;        /* if non-zero -> at least one cpu has it */
 617 #endif
 618 
 619 #if defined(OPTERON_ERRATUM_108)
 620 int opteron_erratum_108;        /* if non-zero -> at least one cpu has it */
 621 #endif
 622 
 623 #if defined(OPTERON_ERRATUM_109)
 624 int opteron_erratum_109;        /* if non-zero -> at least one cpu has it */
 625 #endif
 626 
 627 #if defined(OPTERON_ERRATUM_121)
 628 int opteron_erratum_121;        /* if non-zero -> at least one cpu has it */
 629 #endif
 630 
 631 #if defined(OPTERON_ERRATUM_122)
 632 int opteron_erratum_122;        /* if non-zero -> at least one cpu has it */
 633 #endif
 634 
 635 #if defined(OPTERON_ERRATUM_123)
 636 int opteron_erratum_123;        /* if non-zero -> at least one cpu has it */
 637 #endif
 638 
 639 #if defined(OPTERON_ERRATUM_131)
 640 int opteron_erratum_131;        /* if non-zero -> at least one cpu has it */
 641 #endif
 642 
 643 #if defined(OPTERON_WORKAROUND_6336786)
 644 int opteron_workaround_6336786; /* non-zero -> WA relevant and applied */
 645 int opteron_workaround_6336786_UP = 0;  /* Not needed for UP */
 646 #endif
 647 
 648 #if defined(OPTERON_WORKAROUND_6323525)
 649 int opteron_workaround_6323525; /* if non-zero -> at least one cpu has it */
 650 #endif
 651 
 652 #if defined(OPTERON_ERRATUM_298)
 653 int opteron_erratum_298;
 654 #endif
 655 
 656 #if defined(OPTERON_ERRATUM_721)
 657 int opteron_erratum_721;
 658 #endif
 659 
 660 static void
 661 workaround_warning(cpu_t *cp, uint_t erratum)
 662 {
 663         cmn_err(CE_WARN, "cpu%d: no workaround for erratum %u",
 664             cp->cpu_id, erratum);
 665 }
 666 
 667 static void
 668 workaround_applied(uint_t erratum)
 669 {
 670         if (erratum > 1000000)
 671                 cmn_err(CE_CONT, "?workaround applied for cpu issue #%d\n",
 672                     erratum);
 673         else
 674                 cmn_err(CE_CONT, "?workaround applied for cpu erratum #%d\n",
 675                     erratum);
 676 }
 677 
 678 static void
 679 msr_warning(cpu_t *cp, const char *rw, uint_t msr, int error)
 680 {
 681         cmn_err(CE_WARN, "cpu%d: couldn't %smsr 0x%x, error %d",
 682             cp->cpu_id, rw, msr, error);
 683 }
 684 
 685 /*
 686  * Determine the number of nodes in a Hammer / Greyhound / Griffin family
 687  * system.
 688  */
 689 static uint_t
 690 opteron_get_nnodes(void)
 691 {
 692         static uint_t nnodes = 0;
 693 
 694         if (nnodes == 0) {
 695 #ifdef  DEBUG
 696                 uint_t family;
 697 
 698                 /*
 699                  * This routine uses a PCI config space based mechanism
 700                  * for retrieving the number of nodes in the system.
 701                  * Device 24, function 0, offset 0x60 as used here is not
 702                  * AMD processor architectural, and may not work on processor
 703                  * families other than those listed below.
 704                  *
 705                  * Callers of this routine must ensure that we're running on
 706                  * a processor which supports this mechanism.
 707                  * The assertion below is meant to catch calls on unsupported
 708                  * processors.
 709                  */
 710                 family = cpuid_getfamily(CPU);
 711                 ASSERT(family == 0xf || family == 0x10 || family == 0x11);
 712 #endif  /* DEBUG */
 713 
 714                 /*
 715                  * Obtain the number of nodes in the system from
 716                  * bits [6:4] of the Node ID register on node 0.
 717                  *
 718                  * The actual node count is NodeID[6:4] + 1
 719                  *
 720                  * The Node ID register is accessed via function 0,
 721                  * offset 0x60. Node 0 is device 24.
 722                  */
 723                 nnodes = ((pci_getl_func(0, 24, 0, 0x60) & 0x70) >> 4) + 1;
 724         }
 725         return (nnodes);
 726 }
 727 
 728 uint_t
 729 do_erratum_298(struct cpu *cpu)
 730 {
 731         static int      osvwrc = -3;
 732         extern int      osvw_opteron_erratum(cpu_t *, uint_t);
 733 
 734         /*
 735          * L2 Eviction May Occur During Processor Operation To Set
 736          * Accessed or Dirty Bit.
 737          */
 738         if (osvwrc == -3) {
 739                 osvwrc = osvw_opteron_erratum(cpu, 298);
 740         } else {
 741                 /* osvw return codes should be consistent for all cpus */
 742                 ASSERT(osvwrc == osvw_opteron_erratum(cpu, 298));
 743         }
 744 
 745         switch (osvwrc) {
 746         case 0:         /* erratum is not present: do nothing */
 747                 break;
 748         case 1:         /* erratum is present: BIOS workaround applied */
 749                 /*
 750                  * check if workaround is actually in place and issue warning
 751                  * if not.
 752                  */
 753                 if (((rdmsr(MSR_AMD_HWCR) & AMD_HWCR_TLBCACHEDIS) == 0) ||
 754                     ((rdmsr(MSR_AMD_BU_CFG) & AMD_BU_CFG_E298) == 0)) {
 755 #if defined(OPTERON_ERRATUM_298)
 756                         opteron_erratum_298++;
 757 #else
 758                         workaround_warning(cpu, 298);
 759                         return (1);
 760 #endif
 761                 }
 762                 break;
 763         case -1:        /* cannot determine via osvw: check cpuid */
 764                 if ((cpuid_opteron_erratum(cpu, 298) > 0) &&
 765                     (((rdmsr(MSR_AMD_HWCR) & AMD_HWCR_TLBCACHEDIS) == 0) ||
 766                     ((rdmsr(MSR_AMD_BU_CFG) & AMD_BU_CFG_E298) == 0))) {
 767 #if defined(OPTERON_ERRATUM_298)
 768                         opteron_erratum_298++;
 769 #else
 770                         workaround_warning(cpu, 298);
 771                         return (1);
 772 #endif
 773                 }
 774                 break;
 775         }
 776         return (0);
 777 }
 778 
 779 uint_t
 780 workaround_errata(struct cpu *cpu)
 781 {
 782         uint_t missing = 0;
 783 
 784         ASSERT(cpu == CPU);
 785 
 786         /*LINTED*/
 787         if (cpuid_opteron_erratum(cpu, 88) > 0) {
 788                 /*
 789                  * SWAPGS May Fail To Read Correct GS Base
 790                  */
 791 #if defined(OPTERON_ERRATUM_88)
 792                 /*
 793                  * The workaround is an mfence in the relevant assembler code
 794                  */
 795                 opteron_erratum_88++;
 796 #else
 797                 workaround_warning(cpu, 88);
 798                 missing++;
 799 #endif
 800         }
 801 
 802         if (cpuid_opteron_erratum(cpu, 91) > 0) {
 803                 /*
 804                  * Software Prefetches May Report A Page Fault
 805                  */
 806 #if defined(OPTERON_ERRATUM_91)
 807                 /*
 808                  * fix is in trap.c
 809                  */
 810                 opteron_erratum_91++;
 811 #else
 812                 workaround_warning(cpu, 91);
 813                 missing++;
 814 #endif
 815         }
 816 
 817         if (cpuid_opteron_erratum(cpu, 93) > 0) {
 818                 /*
 819                  * RSM Auto-Halt Restart Returns to Incorrect RIP
 820                  */
 821 #if defined(OPTERON_ERRATUM_93)
 822                 /*
 823                  * fix is in trap.c
 824                  */
 825                 opteron_erratum_93++;
 826 #else
 827                 workaround_warning(cpu, 93);
 828                 missing++;
 829 #endif
 830         }
 831 
 832         /*LINTED*/
 833         if (cpuid_opteron_erratum(cpu, 95) > 0) {
 834                 /*
 835                  * RET Instruction May Return to Incorrect EIP
 836                  */
 837 #if defined(OPTERON_ERRATUM_95)
 838 #if defined(_LP64)
 839                 /*
 840                  * Workaround this by ensuring that 32-bit user code and
 841                  * 64-bit kernel code never occupy the same address
 842                  * range mod 4G.
 843                  */
 844                 if (_userlimit32 > 0xc0000000ul)
 845                         *(uintptr_t *)&_userlimit32 = 0xc0000000ul;
 846 
 847                 /*LINTED*/
 848                 ASSERT((uint32_t)COREHEAP_BASE == 0xc0000000u);
 849                 opteron_erratum_95++;
 850 #endif  /* _LP64 */
 851 #else
 852                 workaround_warning(cpu, 95);
 853                 missing++;
 854 #endif
 855         }
 856 
 857         if (cpuid_opteron_erratum(cpu, 100) > 0) {
 858                 /*
 859                  * Compatibility Mode Branches Transfer to Illegal Address
 860                  */
 861 #if defined(OPTERON_ERRATUM_100)
 862                 /*
 863                  * fix is in trap.c
 864                  */
 865                 opteron_erratum_100++;
 866 #else
 867                 workaround_warning(cpu, 100);
 868                 missing++;
 869 #endif
 870         }
 871 
 872         /*LINTED*/
 873         if (cpuid_opteron_erratum(cpu, 108) > 0) {
 874                 /*
 875                  * CPUID Instruction May Return Incorrect Model Number In
 876                  * Some Processors
 877                  */
 878 #if defined(OPTERON_ERRATUM_108)
 879                 /*
 880                  * (Our cpuid-handling code corrects the model number on
 881                  * those processors)
 882                  */
 883 #else
 884                 workaround_warning(cpu, 108);
 885                 missing++;
 886 #endif
 887         }
 888 
 889         /*LINTED*/
 890         if (cpuid_opteron_erratum(cpu, 109) > 0) do {
 891                 /*
 892                  * Certain Reverse REP MOVS May Produce Unpredictable Behavior
 893                  */
 894 #if defined(OPTERON_ERRATUM_109)
 895                 /*
 896                  * The "workaround" is to print a warning to upgrade the BIOS
 897                  */
 898                 uint64_t value;
 899                 const uint_t msr = MSR_AMD_PATCHLEVEL;
 900                 int err;
 901 
 902                 if ((err = checked_rdmsr(msr, &value)) != 0) {
 903                         msr_warning(cpu, "rd", msr, err);
 904                         workaround_warning(cpu, 109);
 905                         missing++;
 906                 }
 907                 if (value == 0)
 908                         opteron_erratum_109++;
 909 #else
 910                 workaround_warning(cpu, 109);
 911                 missing++;
 912 #endif
 913         /*CONSTANTCONDITION*/
 914         } while (0);
 915 
 916         /*LINTED*/
 917         if (cpuid_opteron_erratum(cpu, 121) > 0) {
 918                 /*
 919                  * Sequential Execution Across Non_Canonical Boundary Caused
 920                  * Processor Hang
 921                  */
 922 #if defined(OPTERON_ERRATUM_121)
 923 #if defined(_LP64)
 924                 /*
 925                  * Erratum 121 is only present in long (64 bit) mode.
 926                  * Workaround is to include the page immediately before the
 927                  * va hole to eliminate the possibility of system hangs due to
 928                  * sequential execution across the va hole boundary.
 929                  */
 930                 if (opteron_erratum_121)
 931                         opteron_erratum_121++;
 932                 else {
 933                         if (hole_start) {
 934                                 hole_start -= PAGESIZE;
 935                         } else {
 936                                 /*
 937                                  * hole_start not yet initialized by
 938                                  * mmu_init. Initialize hole_start
 939                                  * with value to be subtracted.
 940                                  */
 941                                 hole_start = PAGESIZE;
 942                         }
 943                         opteron_erratum_121++;
 944                 }
 945 #endif  /* _LP64 */
 946 #else
 947                 workaround_warning(cpu, 121);
 948                 missing++;
 949 #endif
 950         }
 951 
 952         /*LINTED*/
 953         if (cpuid_opteron_erratum(cpu, 122) > 0) do {
 954                 /*
 955                  * TLB Flush Filter May Cause Coherency Problem in
 956                  * Multiprocessor Systems
 957                  */
 958 #if defined(OPTERON_ERRATUM_122)
 959                 uint64_t value;
 960                 const uint_t msr = MSR_AMD_HWCR;
 961                 int error;
 962 
 963                 /*
 964                  * Erratum 122 is only present in MP configurations (multi-core
 965                  * or multi-processor).
 966                  */
 967 #if defined(__xpv)
 968                 if (!DOMAIN_IS_INITDOMAIN(xen_info))
 969                         break;
 970                 if (!opteron_erratum_122 && xpv_nr_phys_cpus() == 1)
 971                         break;
 972 #else
 973                 if (!opteron_erratum_122 && opteron_get_nnodes() == 1 &&
 974                     cpuid_get_ncpu_per_chip(cpu) == 1)
 975                         break;
 976 #endif
 977                 /* disable TLB Flush Filter */
 978 
 979                 if ((error = checked_rdmsr(msr, &value)) != 0) {
 980                         msr_warning(cpu, "rd", msr, error);
 981                         workaround_warning(cpu, 122);
 982                         missing++;
 983                 } else {
 984                         value |= (uint64_t)AMD_HWCR_FFDIS;
 985                         if ((error = checked_wrmsr(msr, value)) != 0) {
 986                                 msr_warning(cpu, "wr", msr, error);
 987                                 workaround_warning(cpu, 122);
 988                                 missing++;
 989                         }
 990                 }
 991                 opteron_erratum_122++;
 992 #else
 993                 workaround_warning(cpu, 122);
 994                 missing++;
 995 #endif
 996         /*CONSTANTCONDITION*/
 997         } while (0);
 998 
 999         /*LINTED*/
1000         if (cpuid_opteron_erratum(cpu, 123) > 0) do {
1001                 /*
1002                  * Bypassed Reads May Cause Data Corruption of System Hang in
1003                  * Dual Core Processors
1004                  */
1005 #if defined(OPTERON_ERRATUM_123)
1006                 uint64_t value;
1007                 const uint_t msr = MSR_AMD_PATCHLEVEL;
1008                 int err;
1009 
1010                 /*
1011                  * Erratum 123 applies only to multi-core cpus.
1012                  */
1013                 if (cpuid_get_ncpu_per_chip(cpu) < 2)
1014                         break;
1015 #if defined(__xpv)
1016                 if (!DOMAIN_IS_INITDOMAIN(xen_info))
1017                         break;
1018 #endif
1019                 /*
1020                  * The "workaround" is to print a warning to upgrade the BIOS
1021                  */
1022                 if ((err = checked_rdmsr(msr, &value)) != 0) {
1023                         msr_warning(cpu, "rd", msr, err);
1024                         workaround_warning(cpu, 123);
1025                         missing++;
1026                 }
1027                 if (value == 0)
1028                         opteron_erratum_123++;
1029 #else
1030                 workaround_warning(cpu, 123);
1031                 missing++;
1032 
1033 #endif
1034         /*CONSTANTCONDITION*/
1035         } while (0);
1036 
1037         /*LINTED*/
1038         if (cpuid_opteron_erratum(cpu, 131) > 0) do {
1039                 /*
1040                  * Multiprocessor Systems with Four or More Cores May Deadlock
1041                  * Waiting for a Probe Response
1042                  */
1043 #if defined(OPTERON_ERRATUM_131)
1044                 uint64_t nbcfg;
1045                 const uint_t msr = MSR_AMD_NB_CFG;
1046                 const uint64_t wabits =
1047                     AMD_NB_CFG_SRQ_HEARTBEAT | AMD_NB_CFG_SRQ_SPR;
1048                 int error;
1049 
1050                 /*
1051                  * Erratum 131 applies to any system with four or more cores.
1052                  */
1053                 if (opteron_erratum_131)
1054                         break;
1055 #if defined(__xpv)
1056                 if (!DOMAIN_IS_INITDOMAIN(xen_info))
1057                         break;
1058                 if (xpv_nr_phys_cpus() < 4)
1059                         break;
1060 #else
1061                 if (opteron_get_nnodes() * cpuid_get_ncpu_per_chip(cpu) < 4)
1062                         break;
1063 #endif
1064                 /*
1065                  * Print a warning if neither of the workarounds for
1066                  * erratum 131 is present.
1067                  */
1068                 if ((error = checked_rdmsr(msr, &nbcfg)) != 0) {
1069                         msr_warning(cpu, "rd", msr, error);
1070                         workaround_warning(cpu, 131);
1071                         missing++;
1072                 } else if ((nbcfg & wabits) == 0) {
1073                         opteron_erratum_131++;
1074                 } else {
1075                         /* cannot have both workarounds set */
1076                         ASSERT((nbcfg & wabits) != wabits);
1077                 }
1078 #else
1079                 workaround_warning(cpu, 131);
1080                 missing++;
1081 #endif
1082         /*CONSTANTCONDITION*/
1083         } while (0);
1084 
1085         /*
1086          * This isn't really an erratum, but for convenience the
1087          * detection/workaround code lives here and in cpuid_opteron_erratum.
1088          */
1089         if (cpuid_opteron_erratum(cpu, 6336786) > 0) {
1090 #if defined(OPTERON_WORKAROUND_6336786)
1091                 /*
1092                  * Disable C1-Clock ramping on multi-core/multi-processor
1093                  * K8 platforms to guard against TSC drift.
1094                  */
1095                 if (opteron_workaround_6336786) {
1096                         opteron_workaround_6336786++;
1097 #if defined(__xpv)
1098                 } else if ((DOMAIN_IS_INITDOMAIN(xen_info) &&
1099                     xpv_nr_phys_cpus() > 1) ||
1100                     opteron_workaround_6336786_UP) {
1101                         /*
1102                          * XXPV Hmm.  We can't walk the Northbridges on
1103                          *      the hypervisor; so just complain and drive
1104                          *      on.  This probably needs to be fixed in
1105                          *      the hypervisor itself.
1106                          */
1107                         opteron_workaround_6336786++;
1108                         workaround_warning(cpu, 6336786);
1109 #else   /* __xpv */
1110                 } else if ((opteron_get_nnodes() *
1111                     cpuid_get_ncpu_per_chip(cpu) > 1) ||
1112                     opteron_workaround_6336786_UP) {
1113 
1114                         uint_t  node, nnodes;
1115                         uint8_t data;
1116 
1117                         nnodes = opteron_get_nnodes();
1118                         for (node = 0; node < nnodes; node++) {
1119                                 /*
1120                                  * Clear PMM7[1:0] (function 3, offset 0x87)
1121                                  * Northbridge device is the node id + 24.
1122                                  */
1123                                 data = pci_getb_func(0, node + 24, 3, 0x87);
1124                                 data &= 0xFC;
1125                                 pci_putb_func(0, node + 24, 3, 0x87, data);
1126                         }
1127                         opteron_workaround_6336786++;
1128 #endif  /* __xpv */
1129                 }
1130 #else
1131                 workaround_warning(cpu, 6336786);
1132                 missing++;
1133 #endif
1134         }
1135 
1136         /*LINTED*/
1137         /*
1138          * Mutex primitives don't work as expected.
1139          */
1140         if (cpuid_opteron_erratum(cpu, 6323525) > 0) {
1141 #if defined(OPTERON_WORKAROUND_6323525)
1142                 /*
1143                  * This problem only occurs with 2 or more cores. If bit in
1144                  * MSR_AMD_BU_CFG set, then not applicable. The workaround
1145                  * is to patch the semaphone routines with the lfence
1146                  * instruction to provide necessary load memory barrier with
1147                  * possible subsequent read-modify-write ops.
1148                  *
1149                  * It is too early in boot to call the patch routine so
1150                  * set erratum variable to be done in startup_end().
1151                  */
1152                 if (opteron_workaround_6323525) {
1153                         opteron_workaround_6323525++;
1154 #if defined(__xpv)
1155                 } else if (is_x86_feature(x86_featureset, X86FSET_SSE2)) {
1156                         if (DOMAIN_IS_INITDOMAIN(xen_info)) {
1157                                 /*
1158                                  * XXPV Use dom0_msr here when extended
1159                                  *      operations are supported?
1160                                  */
1161                                 if (xpv_nr_phys_cpus() > 1)
1162                                         opteron_workaround_6323525++;
1163                         } else {
1164                                 /*
1165                                  * We have no way to tell how many physical
1166                                  * cpus there are, or even if this processor
1167                                  * has the problem, so enable the workaround
1168                                  * unconditionally (at some performance cost).
1169                                  */
1170                                 opteron_workaround_6323525++;
1171                         }
1172 #else   /* __xpv */
1173                 } else if (is_x86_feature(x86_featureset, X86FSET_SSE2) &&
1174                     ((opteron_get_nnodes() *
1175                     cpuid_get_ncpu_per_chip(cpu)) > 1)) {
1176                         if ((xrdmsr(MSR_AMD_BU_CFG) & (UINT64_C(1) << 33)) == 0)
1177                                 opteron_workaround_6323525++;
1178 #endif  /* __xpv */
1179                 }
1180 #else
1181                 workaround_warning(cpu, 6323525);
1182                 missing++;
1183 #endif
1184         }
1185 
1186         missing += do_erratum_298(cpu);
1187 
1188         if (cpuid_opteron_erratum(cpu, 721) > 0) {
1189 #if defined(OPTERON_ERRATUM_721)
1190                 on_trap_data_t otd;
1191 
1192                 if (!on_trap(&otd, OT_DATA_ACCESS))
1193                         wrmsr(MSR_AMD_DE_CFG,
1194                             rdmsr(MSR_AMD_DE_CFG) | AMD_DE_CFG_E721);
1195                 no_trap();
1196 
1197                 opteron_erratum_721++;
1198 #else
1199                 workaround_warning(cpu, 721);
1200                 missing++;
1201 #endif
1202         }
1203 
1204 #ifdef __xpv
1205         return (0);
1206 #else
1207         return (missing);
1208 #endif
1209 }
1210 
1211 void
1212 workaround_errata_end()
1213 {
1214 #if defined(OPTERON_ERRATUM_88)
1215         if (opteron_erratum_88)
1216                 workaround_applied(88);
1217 #endif
1218 #if defined(OPTERON_ERRATUM_91)
1219         if (opteron_erratum_91)
1220                 workaround_applied(91);
1221 #endif
1222 #if defined(OPTERON_ERRATUM_93)
1223         if (opteron_erratum_93)
1224                 workaround_applied(93);
1225 #endif
1226 #if defined(OPTERON_ERRATUM_95)
1227         if (opteron_erratum_95)
1228                 workaround_applied(95);
1229 #endif
1230 #if defined(OPTERON_ERRATUM_100)
1231         if (opteron_erratum_100)
1232                 workaround_applied(100);
1233 #endif
1234 #if defined(OPTERON_ERRATUM_108)
1235         if (opteron_erratum_108)
1236                 workaround_applied(108);
1237 #endif
1238 #if defined(OPTERON_ERRATUM_109)
1239         if (opteron_erratum_109) {
1240                 cmn_err(CE_WARN,
1241                     "BIOS microcode patch for AMD Athlon(tm) 64/Opteron(tm)"
1242                     " processor\nerratum 109 was not detected; updating your"
1243                     " system's BIOS to a version\ncontaining this"
1244                     " microcode patch is HIGHLY recommended or erroneous"
1245                     " system\noperation may occur.\n");
1246         }
1247 #endif
1248 #if defined(OPTERON_ERRATUM_121)
1249         if (opteron_erratum_121)
1250                 workaround_applied(121);
1251 #endif
1252 #if defined(OPTERON_ERRATUM_122)
1253         if (opteron_erratum_122)
1254                 workaround_applied(122);
1255 #endif
1256 #if defined(OPTERON_ERRATUM_123)
1257         if (opteron_erratum_123) {
1258                 cmn_err(CE_WARN,
1259                     "BIOS microcode patch for AMD Athlon(tm) 64/Opteron(tm)"
1260                     " processor\nerratum 123 was not detected; updating your"
1261                     " system's BIOS to a version\ncontaining this"
1262                     " microcode patch is HIGHLY recommended or erroneous"
1263                     " system\noperation may occur.\n");
1264         }
1265 #endif
1266 #if defined(OPTERON_ERRATUM_131)
1267         if (opteron_erratum_131) {
1268                 cmn_err(CE_WARN,
1269                     "BIOS microcode patch for AMD Athlon(tm) 64/Opteron(tm)"
1270                     " processor\nerratum 131 was not detected; updating your"
1271                     " system's BIOS to a version\ncontaining this"
1272                     " microcode patch is HIGHLY recommended or erroneous"
1273                     " system\noperation may occur.\n");
1274         }
1275 #endif
1276 #if defined(OPTERON_WORKAROUND_6336786)
1277         if (opteron_workaround_6336786)
1278                 workaround_applied(6336786);
1279 #endif
1280 #if defined(OPTERON_WORKAROUND_6323525)
1281         if (opteron_workaround_6323525)
1282                 workaround_applied(6323525);
1283 #endif
1284 #if defined(OPTERON_ERRATUM_298)
1285         if (opteron_erratum_298) {
1286                 cmn_err(CE_WARN,
1287                     "BIOS microcode patch for AMD 64/Opteron(tm)"
1288                     " processor\nerratum 298 was not detected; updating your"
1289                     " system's BIOS to a version\ncontaining this"
1290                     " microcode patch is HIGHLY recommended or erroneous"
1291                     " system\noperation may occur.\n");
1292         }
1293 #endif
1294 #if defined(OPTERON_ERRATUM_721)
1295         if (opteron_erratum_721)
1296                 workaround_applied(721);
1297 #endif
1298 }
1299 
1300 /*
1301  * The procset_slave and procset_master are used to synchronize
1302  * between the control CPU and the target CPU when starting CPUs.
1303  */
1304 static cpuset_t procset_slave, procset_master;
1305 
1306 static void
1307 mp_startup_wait(cpuset_t *sp, processorid_t cpuid)
1308 {
1309         cpuset_t tempset;
1310 
1311         for (tempset = *sp; !CPU_IN_SET(tempset, cpuid);
1312             tempset = *(volatile cpuset_t *)sp) {
1313                 SMT_PAUSE();
1314         }
1315         CPUSET_ATOMIC_DEL(*(cpuset_t *)sp, cpuid);
1316 }
1317 
1318 static void
1319 mp_startup_signal(cpuset_t *sp, processorid_t cpuid)
1320 {
1321         cpuset_t tempset;
1322 
1323         CPUSET_ATOMIC_ADD(*(cpuset_t *)sp, cpuid);
1324         for (tempset = *sp; CPU_IN_SET(tempset, cpuid);
1325             tempset = *(volatile cpuset_t *)sp) {
1326                 SMT_PAUSE();
1327         }
1328 }
1329 
1330 int
1331 mp_start_cpu_common(cpu_t *cp, boolean_t boot)
1332 {
1333         _NOTE(ARGUNUSED(boot));
1334 
1335         void *ctx;
1336         int delays;
1337         int error = 0;
1338         cpuset_t tempset;
1339         processorid_t cpuid;
1340 #ifndef __xpv
1341         extern void cpupm_init(cpu_t *);
1342 #endif
1343 
1344         ASSERT(cp != NULL);
1345         cpuid = cp->cpu_id;
1346         ctx = mach_cpucontext_alloc(cp);
1347         if (ctx == NULL) {
1348                 cmn_err(CE_WARN,
1349                     "cpu%d: failed to allocate context", cp->cpu_id);
1350                 return (EAGAIN);
1351         }
1352         error = mach_cpu_start(cp, ctx);
1353         if (error != 0) {
1354                 cmn_err(CE_WARN,
1355                     "cpu%d: failed to start, error %d", cp->cpu_id, error);
1356                 mach_cpucontext_free(cp, ctx, error);
1357                 return (error);
1358         }
1359 
1360         for (delays = 0, tempset = procset_slave; !CPU_IN_SET(tempset, cpuid);
1361             delays++) {
1362                 if (delays == 500) {
1363                         /*
1364                          * After five seconds, things are probably looking
1365                          * a bit bleak - explain the hang.
1366                          */
1367                         cmn_err(CE_NOTE, "cpu%d: started, "
1368                             "but not running in the kernel yet", cpuid);
1369                 } else if (delays > 2000) {
1370                         /*
1371                          * We waited at least 20 seconds, bail ..
1372                          */
1373                         error = ETIMEDOUT;
1374                         cmn_err(CE_WARN, "cpu%d: timed out", cpuid);
1375                         mach_cpucontext_free(cp, ctx, error);
1376                         return (error);
1377                 }
1378 
1379                 /*
1380                  * wait at least 10ms, then check again..
1381                  */
1382                 delay(USEC_TO_TICK_ROUNDUP(10000));
1383                 tempset = *((volatile cpuset_t *)&procset_slave);
1384         }
1385         CPUSET_ATOMIC_DEL(procset_slave, cpuid);
1386 
1387         mach_cpucontext_free(cp, ctx, 0);
1388 
1389 #ifndef __xpv
1390         if (tsc_gethrtime_enable)
1391                 tsc_sync_master(cpuid);
1392 #endif
1393 
1394         if (dtrace_cpu_init != NULL) {
1395                 (*dtrace_cpu_init)(cpuid);
1396         }
1397 
1398         /*
1399          * During CPU DR operations, the cpu_lock is held by current
1400          * (the control) thread. We can't release the cpu_lock here
1401          * because that will break the CPU DR logic.
1402          * On the other hand, CPUPM and processor group initialization
1403          * routines need to access the cpu_lock. So we invoke those
1404          * routines here on behalf of mp_startup_common().
1405          *
1406          * CPUPM and processor group initialization routines depend
1407          * on the cpuid probing results. Wait for mp_startup_common()
1408          * to signal that cpuid probing is done.
1409          */
1410         mp_startup_wait(&procset_slave, cpuid);
1411 #ifndef __xpv
1412         cpupm_init(cp);
1413 #endif
1414         (void) pg_cpu_init(cp, B_FALSE);
1415         cpu_set_state(cp);
1416         mp_startup_signal(&procset_master, cpuid);
1417 
1418         return (0);
1419 }
1420 
1421 /*
1422  * Start a single cpu, assuming that the kernel context is available
1423  * to successfully start another cpu.
1424  *
1425  * (For example, real mode code is mapped into the right place
1426  * in memory and is ready to be run.)
1427  */
1428 int
1429 start_cpu(processorid_t who)
1430 {
1431         cpu_t *cp;
1432         int error = 0;
1433         cpuset_t tempset;
1434 
1435         ASSERT(who != 0);
1436 
1437         /*
1438          * Check if there's at least a Mbyte of kmem available
1439          * before attempting to start the cpu.
1440          */
1441         if (kmem_avail() < 1024 * 1024) {
1442                 /*
1443                  * Kick off a reap in case that helps us with
1444                  * later attempts ..
1445                  */
1446                 kmem_reap();
1447                 return (ENOMEM);
1448         }
1449 
1450         /*
1451          * First configure cpu.
1452          */
1453         cp = mp_cpu_configure_common(who, B_TRUE);
1454         ASSERT(cp != NULL);
1455 
1456         /*
1457          * Then start cpu.
1458          */
1459         error = mp_start_cpu_common(cp, B_TRUE);
1460         if (error != 0) {
1461                 mp_cpu_unconfigure_common(cp, error);
1462                 return (error);
1463         }
1464 
1465         mutex_exit(&cpu_lock);
1466         tempset = cpu_ready_set;
1467         while (!CPU_IN_SET(tempset, who)) {
1468                 drv_usecwait(1);
1469                 tempset = *((volatile cpuset_t *)&cpu_ready_set);
1470         }
1471         mutex_enter(&cpu_lock);
1472 
1473         return (0);
1474 }
1475 
1476 void
1477 start_other_cpus(int cprboot)
1478 {
1479         _NOTE(ARGUNUSED(cprboot));
1480 
1481         uint_t who;
1482         uint_t bootcpuid = 0;
1483 
1484         /*
1485          * Initialize our own cpu_info.
1486          */
1487         init_cpu_info(CPU);
1488 
1489         cmn_err(CE_CONT, "?cpu%d: %s\n", CPU->cpu_id, CPU->cpu_idstr);
1490         cmn_err(CE_CONT, "?cpu%d: %s\n", CPU->cpu_id, CPU->cpu_brandstr);
1491 
1492         /*
1493          * Initialize our syscall handlers
1494          */
1495         init_cpu_syscall(CPU);
1496 
1497         /*
1498          * Take the boot cpu out of the mp_cpus set because we know
1499          * it's already running.  Add it to the cpu_ready_set for
1500          * precisely the same reason.
1501          */
1502         CPUSET_DEL(mp_cpus, bootcpuid);
1503         CPUSET_ADD(cpu_ready_set, bootcpuid);
1504 
1505         /*
1506          * skip the rest of this if
1507          * . only 1 cpu dectected and system isn't hotplug-capable
1508          * . not using MP
1509          */
1510         if ((CPUSET_ISNULL(mp_cpus) && plat_dr_support_cpu() == 0) ||
1511             use_mp == 0) {
1512                 if (use_mp == 0)
1513                         cmn_err(CE_CONT, "?***** Not in MP mode\n");
1514                 goto done;
1515         }
1516 
1517         /*
1518          * perform such initialization as is needed
1519          * to be able to take CPUs on- and off-line.
1520          */
1521         cpu_pause_init();
1522 
1523         xc_init_cpu(CPU);               /* initialize processor crosscalls */
1524 
1525         if (mach_cpucontext_init() != 0)
1526                 goto done;
1527 
1528         flushes_require_xcalls = 1;
1529 
1530         /*
1531          * We lock our affinity to the master CPU to ensure that all slave CPUs
1532          * do their TSC syncs with the same CPU.
1533          */
1534         affinity_set(CPU_CURRENT);
1535 
1536         for (who = 0; who < NCPU; who++) {
1537                 if (!CPU_IN_SET(mp_cpus, who))
1538                         continue;
1539                 ASSERT(who != bootcpuid);
1540 
1541                 mutex_enter(&cpu_lock);
1542                 if (start_cpu(who) != 0)
1543                         CPUSET_DEL(mp_cpus, who);
1544                 cpu_state_change_notify(who, CPU_SETUP);
1545                 mutex_exit(&cpu_lock);
1546         }
1547 
1548         /* Free the space allocated to hold the microcode file */
1549         ucode_cleanup();
1550 
1551         affinity_clear();
1552 
1553         mach_cpucontext_fini();
1554 
1555 done:
1556         if (get_hwenv() == HW_NATIVE)
1557                 workaround_errata_end();
1558         cmi_post_mpstartup();
1559 
1560         if (use_mp && ncpus != boot_max_ncpus) {
1561                 cmn_err(CE_NOTE,
1562                     "System detected %d cpus, but "
1563                     "only %d cpu(s) were enabled during boot.",
1564                     boot_max_ncpus, ncpus);
1565                 cmn_err(CE_NOTE,
1566                     "Use \"boot-ncpus\" parameter to enable more CPU(s). "
1567                     "See eeprom(1M).");
1568         }
1569 }
1570 
1571 int
1572 mp_cpu_configure(int cpuid)
1573 {
1574         cpu_t *cp;
1575 
1576         if (use_mp == 0 || plat_dr_support_cpu() == 0) {
1577                 return (ENOTSUP);
1578         }
1579 
1580         cp = cpu_get(cpuid);
1581         if (cp != NULL) {
1582                 return (EALREADY);
1583         }
1584 
1585         /*
1586          * Check if there's at least a Mbyte of kmem available
1587          * before attempting to start the cpu.
1588          */
1589         if (kmem_avail() < 1024 * 1024) {
1590                 /*
1591                  * Kick off a reap in case that helps us with
1592                  * later attempts ..
1593                  */
1594                 kmem_reap();
1595                 return (ENOMEM);
1596         }
1597 
1598         cp = mp_cpu_configure_common(cpuid, B_FALSE);
1599         ASSERT(cp != NULL && cpu_get(cpuid) == cp);
1600 
1601         return (cp != NULL ? 0 : EAGAIN);
1602 }
1603 
1604 int
1605 mp_cpu_unconfigure(int cpuid)
1606 {
1607         cpu_t *cp;
1608 
1609         if (use_mp == 0 || plat_dr_support_cpu() == 0) {
1610                 return (ENOTSUP);
1611         } else if (cpuid < 0 || cpuid >= max_ncpus) {
1612                 return (EINVAL);
1613         }
1614 
1615         cp = cpu_get(cpuid);
1616         if (cp == NULL) {
1617                 return (ENODEV);
1618         }
1619         mp_cpu_unconfigure_common(cp, 0);
1620 
1621         return (0);
1622 }
1623 
1624 /*
1625  * Startup function for 'other' CPUs (besides boot cpu).
1626  * Called from real_mode_start.
1627  *
1628  * WARNING: until CPU_READY is set, mp_startup_common and routines called by
1629  * mp_startup_common should not call routines (e.g. kmem_free) that could call
1630  * hat_unload which requires CPU_READY to be set.
1631  */
1632 static void
1633 mp_startup_common(boolean_t boot)
1634 {
1635         cpu_t *cp = CPU;
1636         uchar_t new_x86_featureset[BT_SIZEOFMAP(NUM_X86_FEATURES)];
1637         extern void cpu_event_init_cpu(cpu_t *);
1638 
1639         /*
1640          * We need to get TSC on this proc synced (i.e., any delta
1641          * from cpu0 accounted for) as soon as we can, because many
1642          * many things use gethrtime/pc_gethrestime, including
1643          * interrupts, cmn_err, etc.  Before we can do that, we want to
1644          * clear TSC if we're on a buggy Sandy/Ivy Bridge CPU, so do that
1645          * right away.
1646          */
1647         bzero(new_x86_featureset, BT_SIZEOFMAP(NUM_X86_FEATURES));
1648         cpuid_pass1(cp, new_x86_featureset);
1649 
1650         if (boot && get_hwenv() == HW_NATIVE &&
1651             cpuid_getvendor(CPU) == X86_VENDOR_Intel &&
1652             cpuid_getfamily(CPU) == 6 &&
1653             (cpuid_getmodel(CPU) == 0x2d || cpuid_getmodel(CPU) == 0x3e) &&
1654             is_x86_feature(new_x86_featureset, X86FSET_TSC)) {
1655                 (void) wrmsr(REG_TSC, 0UL);
1656         }
1657 
1658         /* Let the control CPU continue into tsc_sync_master() */
1659         mp_startup_signal(&procset_slave, cp->cpu_id);
1660 
1661 #ifndef __xpv
1662         if (tsc_gethrtime_enable)
1663                 tsc_sync_slave();
1664 #endif
1665 
1666         /*
1667          * Once this was done from assembly, but it's safer here; if
1668          * it blocks, we need to be able to swtch() to and from, and
1669          * since we get here by calling t_pc, we need to do that call
1670          * before swtch() overwrites it.
1671          */
1672         (void) (*ap_mlsetup)();
1673 
1674 #ifndef __xpv
1675         /*
1676          * Program this cpu's PAT
1677          */
1678         pat_sync();
1679 #endif
1680 
1681         /*
1682          * Set up TSC_AUX to contain the cpuid for this processor
1683          * for the rdtscp instruction.
1684          */
1685         if (is_x86_feature(x86_featureset, X86FSET_TSCP))
1686                 (void) wrmsr(MSR_AMD_TSCAUX, cp->cpu_id);
1687 
1688         /*
1689          * Initialize this CPU's syscall handlers
1690          */
1691         init_cpu_syscall(cp);
1692 
1693         /*
1694          * Enable interrupts with spl set to LOCK_LEVEL. LOCK_LEVEL is the
1695          * highest level at which a routine is permitted to block on
1696          * an adaptive mutex (allows for cpu poke interrupt in case
1697          * the cpu is blocked on a mutex and halts). Setting LOCK_LEVEL blocks
1698          * device interrupts that may end up in the hat layer issuing cross
1699          * calls before CPU_READY is set.
1700          */
1701         splx(ipltospl(LOCK_LEVEL));
1702         sti();
1703 
1704         /*
1705          * Do a sanity check to make sure this new CPU is a sane thing
1706          * to add to the collection of processors running this system.
1707          *
1708          * XXX  Clearly this needs to get more sophisticated, if x86
1709          * systems start to get built out of heterogenous CPUs; as is
1710          * likely to happen once the number of processors in a configuration
1711          * gets large enough.
1712          */
1713         if (compare_x86_featureset(x86_featureset, new_x86_featureset) ==
1714             B_FALSE) {
1715                 cmn_err(CE_CONT, "cpu%d: featureset\n", cp->cpu_id);
1716                 print_x86_featureset(new_x86_featureset);
1717                 cmn_err(CE_WARN, "cpu%d feature mismatch", cp->cpu_id);
1718         }
1719 
1720         /*
1721          * We do not support cpus with mixed monitor/mwait support if the
1722          * boot cpu supports monitor/mwait.
1723          */
1724         if (is_x86_feature(x86_featureset, X86FSET_MWAIT) !=
1725             is_x86_feature(new_x86_featureset, X86FSET_MWAIT))
1726                 panic("unsupported mixed cpu monitor/mwait support detected");
1727 
1728         /*
1729          * We could be more sophisticated here, and just mark the CPU
1730          * as "faulted" but at this point we'll opt for the easier
1731          * answer of dying horribly.  Provided the boot cpu is ok,
1732          * the system can be recovered by booting with use_mp set to zero.
1733          */
1734         if (workaround_errata(cp) != 0)
1735                 panic("critical workaround(s) missing for cpu%d", cp->cpu_id);
1736 
1737         /*
1738          * We can touch cpu_flags here without acquiring the cpu_lock here
1739          * because the cpu_lock is held by the control CPU which is running
1740          * mp_start_cpu_common().
1741          * Need to clear CPU_QUIESCED flag before calling any function which
1742          * may cause thread context switching, such as kmem_alloc() etc.
1743          * The idle thread checks for CPU_QUIESCED flag and loops for ever if
1744          * it's set. So the startup thread may have no chance to switch back
1745          * again if it's switched away with CPU_QUIESCED set.
1746          */
1747         cp->cpu_flags &= ~(CPU_POWEROFF | CPU_QUIESCED);
1748 
1749         /*
1750          * Setup this processor for XSAVE.
1751          */
1752         if (fp_save_mech == FP_XSAVE) {
1753                 xsave_setup_msr(cp);
1754         }
1755 
1756         cpuid_pass2(cp);
1757         cpuid_pass3(cp);
1758         cpuid_pass4(cp, NULL);
1759 
1760         /*
1761          * Correct cpu_idstr and cpu_brandstr on target CPU after
1762          * cpuid_pass1() is done.
1763          */
1764         (void) cpuid_getidstr(cp, cp->cpu_idstr, CPU_IDSTRLEN);
1765         (void) cpuid_getbrandstr(cp, cp->cpu_brandstr, CPU_IDSTRLEN);
1766 
1767         cp->cpu_flags |= CPU_RUNNING | CPU_READY | CPU_EXISTS;
1768 
1769         post_startup_cpu_fixups();
1770 
1771         cpu_event_init_cpu(cp);
1772 
1773         /*
1774          * Enable preemption here so that contention for any locks acquired
1775          * later in mp_startup_common may be preempted if the thread owning
1776          * those locks is continuously executing on other CPUs (for example,
1777          * this CPU must be preemptible to allow other CPUs to pause it during
1778          * their startup phases).  It's safe to enable preemption here because
1779          * the CPU state is pretty-much fully constructed.
1780          */
1781         curthread->t_preempt = 0;
1782 
1783         /* The base spl should still be at LOCK LEVEL here */
1784         ASSERT(cp->cpu_base_spl == ipltospl(LOCK_LEVEL));
1785         set_base_spl();         /* Restore the spl to its proper value */
1786 
1787         pghw_physid_create(cp);
1788         /*
1789          * Delegate initialization tasks, which need to access the cpu_lock,
1790          * to mp_start_cpu_common() because we can't acquire the cpu_lock here
1791          * during CPU DR operations.
1792          */
1793         mp_startup_signal(&procset_slave, cp->cpu_id);
1794         mp_startup_wait(&procset_master, cp->cpu_id);
1795         pg_cmt_cpu_startup(cp);
1796 
1797         if (boot) {
1798                 mutex_enter(&cpu_lock);
1799                 cp->cpu_flags &= ~CPU_OFFLINE;
1800                 cpu_enable_intr(cp);
1801                 cpu_add_active(cp);
1802                 mutex_exit(&cpu_lock);
1803         }
1804 
1805         /* Enable interrupts */
1806         (void) spl0();
1807 
1808         /*
1809          * Fill out cpu_ucode_info.  Update microcode if necessary.
1810          */
1811         ucode_check(cp);
1812 
1813 #ifndef __xpv
1814         {
1815                 /*
1816                  * Set up the CPU module for this CPU.  This can't be done
1817                  * before this CPU is made CPU_READY, because we may (in
1818                  * heterogeneous systems) need to go load another CPU module.
1819                  * The act of attempting to load a module may trigger a
1820                  * cross-call, which will ASSERT unless this cpu is CPU_READY.
1821                  */
1822                 cmi_hdl_t hdl;
1823 
1824                 if ((hdl = cmi_init(CMI_HDL_NATIVE, cmi_ntv_hwchipid(CPU),
1825                     cmi_ntv_hwcoreid(CPU), cmi_ntv_hwstrandid(CPU))) != NULL) {
1826                         if (is_x86_feature(x86_featureset, X86FSET_MCA))
1827                                 cmi_mca_init(hdl);
1828                         cp->cpu_m.mcpu_cmi_hdl = hdl;
1829                 }
1830         }
1831 #endif /* __xpv */
1832 
1833         if (boothowto & RB_DEBUG)
1834                 kdi_cpu_init();
1835 
1836         /*
1837          * Setting the bit in cpu_ready_set must be the last operation in
1838          * processor initialization; the boot CPU will continue to boot once
1839          * it sees this bit set for all active CPUs.
1840          */
1841         CPUSET_ATOMIC_ADD(cpu_ready_set, cp->cpu_id);
1842 
1843         (void) mach_cpu_create_device_node(cp, NULL);
1844 
1845         cmn_err(CE_CONT, "?cpu%d: %s\n", cp->cpu_id, cp->cpu_idstr);
1846         cmn_err(CE_CONT, "?cpu%d: %s\n", cp->cpu_id, cp->cpu_brandstr);
1847         cmn_err(CE_CONT, "?cpu%d initialization complete - online\n",
1848             cp->cpu_id);
1849 
1850         /*
1851          * Now we are done with the startup thread, so free it up.
1852          */
1853         thread_exit();
1854         panic("mp_startup: cannot return");
1855         /*NOTREACHED*/
1856 }
1857 
1858 /*
1859  * Startup function for 'other' CPUs at boot time (besides boot cpu).
1860  */
1861 static void
1862 mp_startup_boot(void)
1863 {
1864         mp_startup_common(B_TRUE);
1865 }
1866 
1867 /*
1868  * Startup function for hotplug CPUs at runtime.
1869  */
1870 void
1871 mp_startup_hotplug(void)
1872 {
1873         mp_startup_common(B_FALSE);
1874 }
1875 
1876 /*
1877  * Start CPU on user request.
1878  */
1879 /* ARGSUSED */
1880 int
1881 mp_cpu_start(struct cpu *cp)
1882 {
1883         ASSERT(MUTEX_HELD(&cpu_lock));
1884         return (0);
1885 }
1886 
1887 /*
1888  * Stop CPU on user request.
1889  */
1890 int
1891 mp_cpu_stop(struct cpu *cp)
1892 {
1893         extern int cbe_psm_timer_mode;
1894         ASSERT(MUTEX_HELD(&cpu_lock));
1895 
1896 #ifdef __xpv
1897         /*
1898          * We can't offline vcpu0.
1899          */
1900         if (cp->cpu_id == 0)
1901                 return (EBUSY);
1902 #endif
1903 
1904         /*
1905          * If TIMER_PERIODIC mode is used, CPU0 is the one running it;
1906          * can't stop it.  (This is true only for machines with no TSC.)
1907          */
1908 
1909         if ((cbe_psm_timer_mode == TIMER_PERIODIC) && (cp->cpu_id == 0))
1910                 return (EBUSY);
1911 
1912         return (0);
1913 }
1914 
1915 /*
1916  * Take the specified CPU out of participation in interrupts.
1917  */
1918 int
1919 cpu_disable_intr(struct cpu *cp)
1920 {
1921         if (psm_disable_intr(cp->cpu_id) != DDI_SUCCESS)
1922                 return (EBUSY);
1923 
1924         cp->cpu_flags &= ~CPU_ENABLE;
1925         return (0);
1926 }
1927 
1928 /*
1929  * Allow the specified CPU to participate in interrupts.
1930  */
1931 void
1932 cpu_enable_intr(struct cpu *cp)
1933 {
1934         ASSERT(MUTEX_HELD(&cpu_lock));
1935         cp->cpu_flags |= CPU_ENABLE;
1936         psm_enable_intr(cp->cpu_id);
1937 }
1938 
1939 void
1940 mp_cpu_faulted_enter(struct cpu *cp)
1941 {
1942 #ifdef __xpv
1943         _NOTE(ARGUNUSED(cp));
1944 #else
1945         cmi_hdl_t hdl = cp->cpu_m.mcpu_cmi_hdl;
1946 
1947         if (hdl != NULL) {
1948                 cmi_hdl_hold(hdl);
1949         } else {
1950                 hdl = cmi_hdl_lookup(CMI_HDL_NATIVE, cmi_ntv_hwchipid(cp),
1951                     cmi_ntv_hwcoreid(cp), cmi_ntv_hwstrandid(cp));
1952         }
1953         if (hdl != NULL) {
1954                 cmi_faulted_enter(hdl);
1955                 cmi_hdl_rele(hdl);
1956         }
1957 #endif
1958 }
1959 
1960 void
1961 mp_cpu_faulted_exit(struct cpu *cp)
1962 {
1963 #ifdef __xpv
1964         _NOTE(ARGUNUSED(cp));
1965 #else
1966         cmi_hdl_t hdl = cp->cpu_m.mcpu_cmi_hdl;
1967 
1968         if (hdl != NULL) {
1969                 cmi_hdl_hold(hdl);
1970         } else {
1971                 hdl = cmi_hdl_lookup(CMI_HDL_NATIVE, cmi_ntv_hwchipid(cp),
1972                     cmi_ntv_hwcoreid(cp), cmi_ntv_hwstrandid(cp));
1973         }
1974         if (hdl != NULL) {
1975                 cmi_faulted_exit(hdl);
1976                 cmi_hdl_rele(hdl);
1977         }
1978 #endif
1979 }
1980 
1981 /*
1982  * The following two routines are used as context operators on threads belonging
1983  * to processes with a private LDT (see sysi86).  Due to the rarity of such
1984  * processes, these routines are currently written for best code readability and
1985  * organization rather than speed.  We could avoid checking x86_featureset at
1986  * every context switch by installing different context ops, depending on
1987  * x86_featureset, at LDT creation time -- one for each combination of fast
1988  * syscall features.
1989  */
1990 
1991 /*ARGSUSED*/
1992 void
1993 cpu_fast_syscall_disable(void *arg)
1994 {
1995         if (is_x86_feature(x86_featureset, X86FSET_MSR) &&
1996             is_x86_feature(x86_featureset, X86FSET_SEP))
1997                 cpu_sep_disable();
1998         if (is_x86_feature(x86_featureset, X86FSET_MSR) &&
1999             is_x86_feature(x86_featureset, X86FSET_ASYSC))
2000                 cpu_asysc_disable();
2001 }
2002 
2003 /*ARGSUSED*/
2004 void
2005 cpu_fast_syscall_enable(void *arg)
2006 {
2007         if (is_x86_feature(x86_featureset, X86FSET_MSR) &&
2008             is_x86_feature(x86_featureset, X86FSET_SEP))
2009                 cpu_sep_enable();
2010         if (is_x86_feature(x86_featureset, X86FSET_MSR) &&
2011             is_x86_feature(x86_featureset, X86FSET_ASYSC))
2012                 cpu_asysc_enable();
2013 }
2014 
2015 static void
2016 cpu_sep_enable(void)
2017 {
2018         ASSERT(is_x86_feature(x86_featureset, X86FSET_SEP));
2019         ASSERT(curthread->t_preempt || getpil() >= LOCK_LEVEL);
2020 
2021         wrmsr(MSR_INTC_SEP_CS, (uint64_t)(uintptr_t)KCS_SEL);
2022 }
2023 
2024 static void
2025 cpu_sep_disable(void)
2026 {
2027         ASSERT(is_x86_feature(x86_featureset, X86FSET_SEP));
2028         ASSERT(curthread->t_preempt || getpil() >= LOCK_LEVEL);
2029 
2030         /*
2031          * Setting the SYSENTER_CS_MSR register to 0 causes software executing
2032          * the sysenter or sysexit instruction to trigger a #gp fault.
2033          */
2034         wrmsr(MSR_INTC_SEP_CS, 0);
2035 }
2036 
2037 static void
2038 cpu_asysc_enable(void)
2039 {
2040         ASSERT(is_x86_feature(x86_featureset, X86FSET_ASYSC));
2041         ASSERT(curthread->t_preempt || getpil() >= LOCK_LEVEL);
2042 
2043         wrmsr(MSR_AMD_EFER, rdmsr(MSR_AMD_EFER) |
2044             (uint64_t)(uintptr_t)AMD_EFER_SCE);
2045 }
2046 
2047 static void
2048 cpu_asysc_disable(void)
2049 {
2050         ASSERT(is_x86_feature(x86_featureset, X86FSET_ASYSC));
2051         ASSERT(curthread->t_preempt || getpil() >= LOCK_LEVEL);
2052 
2053         /*
2054          * Turn off the SCE (syscall enable) bit in the EFER register. Software
2055          * executing syscall or sysret with this bit off will incur a #ud trap.
2056          */
2057         wrmsr(MSR_AMD_EFER, rdmsr(MSR_AMD_EFER) &
2058             ~((uint64_t)(uintptr_t)AMD_EFER_SCE));
2059 }