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 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #pragma ident "%Z%%M% %I% %E% SMI" 27 28 #include <sys/types.h> 29 #include <sys/thread.h> 30 #include <sys/cpuvar.h> 31 #include <sys/t_lock.h> 32 #include <sys/param.h> 33 #include <sys/proc.h> 34 #include <sys/disp.h> 35 #include <sys/mmu.h> 36 #include <sys/class.h> 37 #include <sys/cmn_err.h> 38 #include <sys/debug.h> 39 #include <sys/asm_linkage.h> 40 #include <sys/x_call.h> 41 #include <sys/systm.h> 42 #include <sys/var.h> 43 #include <sys/vtrace.h> 44 #include <vm/hat.h> 45 #include <sys/mmu.h> 46 #include <vm/as.h> 47 #include <vm/seg_kmem.h> 48 #include <sys/segments.h> 49 #include <sys/kmem.h> 50 #include <sys/stack.h> 51 #include <sys/smp_impldefs.h> 52 #include <sys/x86_archext.h> 53 #include <sys/machsystm.h> 54 #include <sys/traptrace.h> 55 #include <sys/clock.h> 56 #include <sys/cpc_impl.h> 57 #include <sys/chip.h> 58 #include <sys/dtrace.h> 59 #include <sys/archsystm.h> 60 #include <sys/fp.h> 61 #include <sys/reboot.h> 62 #include <sys/kdi.h> 63 #include <vm/hat_i86.h> 64 #include <sys/memnode.h> 65 #include <sys/pci_cfgspace.h> 66 #include <sys/cpu_module.h> 67 68 struct cpu cpus[1]; /* CPU data */ 69 struct cpu *cpu[NCPU] = {&cpus[0]}; /* pointers to all CPUs */ 70 cpu_core_t cpu_core[NCPU]; /* cpu_core structures */ 71 72 /* 73 * Useful for disabling MP bring-up for an MP capable kernel 74 * (a kernel that was built with MP defined) 75 */ 76 int use_mp = 1; 77 78 int mp_cpus = 0x1; /* to be set by platform specific module */ 79 80 /* 81 * This variable is used by the hat layer to decide whether or not 82 * critical sections are needed to prevent race conditions. For sun4m, 83 * this variable is set once enough MP initialization has been done in 84 * order to allow cross calls. 85 */ 86 int flushes_require_xcalls = 0; 87 ulong_t cpu_ready_set = 1; 88 89 extern void real_mode_start(void); 90 extern void real_mode_end(void); 91 static void mp_startup(void); 92 93 static void cpu_sep_enable(void); 94 static void cpu_sep_disable(void); 95 static void cpu_asysc_enable(void); 96 static void cpu_asysc_disable(void); 97 98 extern int tsc_gethrtime_enable; 99 100 /* 101 * Init CPU info - get CPU type info for processor_info system call. 102 */ 103 void 104 init_cpu_info(struct cpu *cp) 105 { 106 processor_info_t *pi = &cp->cpu_type_info; 107 char buf[CPU_IDSTRLEN]; 108 109 /* 110 * Get clock-frequency property for the CPU. 111 */ 112 pi->pi_clock = cpu_freq; 113 114 (void) strcpy(pi->pi_processor_type, "i386"); 115 if (fpu_exists) 116 (void) strcpy(pi->pi_fputypes, "i387 compatible"); 117 118 (void) cpuid_getidstr(cp, buf, sizeof (buf)); 119 120 cp->cpu_idstr = kmem_alloc(strlen(buf) + 1, KM_SLEEP); 121 (void) strcpy(cp->cpu_idstr, buf); 122 123 cmn_err(CE_CONT, "?cpu%d: %s\n", cp->cpu_id, cp->cpu_idstr); 124 125 (void) cpuid_getbrandstr(cp, buf, sizeof (buf)); 126 cp->cpu_brandstr = kmem_alloc(strlen(buf) + 1, KM_SLEEP); 127 (void) strcpy(cp->cpu_brandstr, buf); 128 129 cmn_err(CE_CONT, "?cpu%d: %s\n", cp->cpu_id, cp->cpu_brandstr); 130 } 131 132 /* 133 * Configure syscall support on this CPU. 134 */ 135 /*ARGSUSED*/ 136 static void 137 init_cpu_syscall(struct cpu *cp) 138 { 139 kpreempt_disable(); 140 141 #if defined(__amd64) 142 if (x86_feature & X86_ASYSC) { 143 144 #if !defined(__lint) 145 /* 146 * The syscall instruction imposes a certain ordering on 147 * segment selectors, so we double-check that ordering 148 * here. 149 */ 150 ASSERT(KDS_SEL == KCS_SEL + 8); 151 ASSERT(UDS_SEL == U32CS_SEL + 8); 152 ASSERT(UCS_SEL == U32CS_SEL + 16); 153 #endif 154 /* 155 * Turn syscall/sysret extensions on. 156 */ 157 cpu_asysc_enable(); 158 159 /* 160 * Program the magic registers .. 161 */ 162 wrmsr(MSR_AMD_STAR, ((uint64_t)(U32CS_SEL << 16 | KCS_SEL)) << 163 32); 164 wrmsr(MSR_AMD_LSTAR, (uint64_t)(uintptr_t)sys_syscall); 165 wrmsr(MSR_AMD_CSTAR, (uint64_t)(uintptr_t)sys_syscall32); 166 167 /* 168 * This list of flags is masked off the incoming 169 * %rfl when we enter the kernel. 170 */ 171 wrmsr(MSR_AMD_SFMASK, (uint64_t)(uintptr_t)(PS_IE | PS_T)); 172 } 173 #endif 174 175 /* 176 * On 32-bit kernels, we use sysenter/sysexit because it's too 177 * hard to use syscall/sysret, and it is more portable anyway. 178 * 179 * On 64-bit kernels on Nocona machines, the 32-bit syscall 180 * variant isn't available to 32-bit applications, but sysenter is. 181 */ 182 if (x86_feature & X86_SEP) { 183 184 #if !defined(__lint) 185 /* 186 * The sysenter instruction imposes a certain ordering on 187 * segment selectors, so we double-check that ordering 188 * here. See "sysenter" in Intel document 245471-012, "IA-32 189 * Intel Architecture Software Developer's Manual Volume 2: 190 * Instruction Set Reference" 191 */ 192 ASSERT(KDS_SEL == KCS_SEL + 8); 193 194 ASSERT32(UCS_SEL == ((KCS_SEL + 16) | 3)); 195 ASSERT32(UDS_SEL == UCS_SEL + 8); 196 197 ASSERT64(U32CS_SEL == ((KCS_SEL + 16) | 3)); 198 ASSERT64(UDS_SEL == U32CS_SEL + 8); 199 #endif 200 201 cpu_sep_enable(); 202 203 /* 204 * resume() sets this value to the base of the threads stack 205 * via a context handler. 206 */ 207 wrmsr(MSR_INTC_SEP_ESP, 0ULL); 208 wrmsr(MSR_INTC_SEP_EIP, (uint64_t)(uintptr_t)sys_sysenter); 209 } 210 211 kpreempt_enable(); 212 } 213 214 /* 215 * Multiprocessor initialization. 216 * 217 * Allocate and initialize the cpu structure, TRAPTRACE buffer, and the 218 * startup and idle threads for the specified CPU. 219 */ 220 static void 221 mp_startup_init(int cpun) 222 { 223 #if defined(__amd64) 224 extern void *long_mode_64(void); 225 #endif /* __amd64 */ 226 227 struct cpu *cp; 228 struct tss *ntss; 229 kthread_id_t tp; 230 caddr_t sp; 231 int size; 232 proc_t *procp; 233 extern void idle(); 234 235 struct cpu_tables *tablesp; 236 rm_platter_t *real_mode_platter = (rm_platter_t *)rm_platter_va; 237 238 #ifdef TRAPTRACE 239 trap_trace_ctl_t *ttc = &trap_trace_ctl[cpun]; 240 #endif 241 242 ASSERT(cpun < NCPU && cpu[cpun] == NULL); 243 244 if ((cp = kmem_zalloc(sizeof (*cp), KM_NOSLEEP)) == NULL) { 245 panic("mp_startup_init: cpu%d: " 246 "no memory for cpu structure", cpun); 247 /*NOTREACHED*/ 248 } 249 procp = curthread->t_procp; 250 251 mutex_enter(&cpu_lock); 252 /* 253 * Initialize the dispatcher first. 254 */ 255 disp_cpu_init(cp); 256 mutex_exit(&cpu_lock); 257 258 cpu_vm_data_init(cp); 259 260 /* 261 * Allocate and initialize the startup thread for this CPU. 262 * Interrupt and process switch stacks get allocated later 263 * when the CPU starts running. 264 */ 265 tp = thread_create(NULL, 0, NULL, NULL, 0, procp, 266 TS_STOPPED, maxclsyspri); 267 268 /* 269 * Set state to TS_ONPROC since this thread will start running 270 * as soon as the CPU comes online. 271 * 272 * All the other fields of the thread structure are setup by 273 * thread_create(). 274 */ 275 THREAD_ONPROC(tp, cp); 276 tp->t_preempt = 1; 277 tp->t_bound_cpu = cp; 278 tp->t_affinitycnt = 1; 279 tp->t_cpu = cp; 280 tp->t_disp_queue = cp->cpu_disp; 281 282 /* 283 * Setup thread to start in mp_startup. 284 */ 285 sp = tp->t_stk; 286 tp->t_pc = (uintptr_t)mp_startup; 287 tp->t_sp = (uintptr_t)(sp - MINFRAME); 288 289 cp->cpu_id = cpun; 290 cp->cpu_self = cp; 291 cp->cpu_mask = 1 << cpun; 292 cp->cpu_thread = tp; 293 cp->cpu_lwp = NULL; 294 cp->cpu_dispthread = tp; 295 cp->cpu_dispatch_pri = DISP_PRIO(tp); 296 297 /* 298 * cpu_base_spl must be set explicitly here to prevent any blocking 299 * operations in mp_startup from causing the spl of the cpu to drop 300 * to 0 (allowing device interrupts before we're ready) in resume(). 301 * cpu_base_spl MUST remain at LOCK_LEVEL until the cpu is CPU_READY. 302 * As an extra bit of security on DEBUG kernels, this is enforced with 303 * an assertion in mp_startup() -- before cpu_base_spl is set to its 304 * proper value. 305 */ 306 cp->cpu_base_spl = ipltospl(LOCK_LEVEL); 307 308 /* 309 * Now, initialize per-CPU idle thread for this CPU. 310 */ 311 tp = thread_create(NULL, PAGESIZE, idle, NULL, 0, procp, TS_ONPROC, -1); 312 313 cp->cpu_idle_thread = tp; 314 315 tp->t_preempt = 1; 316 tp->t_bound_cpu = cp; 317 tp->t_affinitycnt = 1; 318 tp->t_cpu = cp; 319 tp->t_disp_queue = cp->cpu_disp; 320 321 /* 322 * Bootstrap the CPU for CMT aware scheduling 323 * The rest of the initialization will happen from 324 * mp_startup() 325 */ 326 chip_bootstrap_cpu(cp); 327 328 /* 329 * Perform CPC intialization on the new CPU. 330 */ 331 kcpc_hw_init(cp); 332 333 /* 334 * Allocate virtual addresses for cpu_caddr1 and cpu_caddr2 335 * for each CPU. 336 */ 337 338 setup_vaddr_for_ppcopy(cp); 339 340 /* 341 * Allocate space for page directory, stack, tss, gdt and idt. 342 * This assumes that kmem_alloc will return memory which is aligned 343 * to the next higher power of 2 or a page(if size > MAXABIG) 344 * If this assumption goes wrong at any time due to change in 345 * kmem alloc, things may not work as the page directory has to be 346 * page aligned 347 */ 348 if ((tablesp = kmem_zalloc(sizeof (*tablesp), KM_NOSLEEP)) == NULL) 349 panic("mp_startup_init: cpu%d cannot allocate tables", cpun); 350 351 if ((uintptr_t)tablesp & ~MMU_STD_PAGEMASK) { 352 kmem_free(tablesp, sizeof (struct cpu_tables)); 353 size = sizeof (struct cpu_tables) + MMU_STD_PAGESIZE; 354 tablesp = kmem_zalloc(size, KM_NOSLEEP); 355 tablesp = (struct cpu_tables *) 356 (((uintptr_t)tablesp + MMU_STD_PAGESIZE) & 357 MMU_STD_PAGEMASK); 358 } 359 360 ntss = cp->cpu_tss = &tablesp->ct_tss; 361 362 if ((tablesp->ct_gdt = kmem_zalloc(PAGESIZE, KM_NOSLEEP)) == NULL) 363 panic("mp_startup_init: cpu%d cannot allocate GDT", cpun); 364 cp->cpu_gdt = tablesp->ct_gdt; 365 bcopy(CPU->cpu_gdt, cp->cpu_gdt, NGDT * (sizeof (user_desc_t))); 366 367 #if defined(__amd64) 368 369 /* 370 * #DF (double fault). 371 */ 372 ntss->tss_ist1 = 373 (uint64_t)&tablesp->ct_stack[sizeof (tablesp->ct_stack)]; 374 375 #elif defined(__i386) 376 377 ntss->tss_esp0 = ntss->tss_esp1 = ntss->tss_esp2 = ntss->tss_esp = 378 (uint32_t)&tablesp->ct_stack[sizeof (tablesp->ct_stack)]; 379 380 ntss->tss_ss0 = ntss->tss_ss1 = ntss->tss_ss2 = ntss->tss_ss = KDS_SEL; 381 382 ntss->tss_eip = (uint32_t)mp_startup; 383 384 ntss->tss_cs = KCS_SEL; 385 ntss->tss_fs = KFS_SEL; 386 ntss->tss_gs = KGS_SEL; 387 388 /* 389 * setup kernel %gs. 390 */ 391 set_usegd(&cp->cpu_gdt[GDT_GS], cp, sizeof (struct cpu) -1, SDT_MEMRWA, 392 SEL_KPL, 0, 1); 393 394 #endif /* __i386 */ 395 396 /* 397 * Set I/O bit map offset equal to size of TSS segment limit 398 * for no I/O permission map. This will cause all user I/O 399 * instructions to generate #gp fault. 400 */ 401 ntss->tss_bitmapbase = sizeof (*ntss); 402 403 /* 404 * setup kernel tss. 405 */ 406 set_syssegd((system_desc_t *)&cp->cpu_gdt[GDT_KTSS], cp->cpu_tss, 407 sizeof (*cp->cpu_tss) -1, SDT_SYSTSS, SEL_KPL); 408 409 /* 410 * If we have more than one node, each cpu gets a copy of IDT 411 * local to its node. If this is a Pentium box, we use cpu 0's 412 * IDT. cpu 0's IDT has been made read-only to workaround the 413 * cmpxchgl register bug 414 */ 415 cp->cpu_idt = CPU->cpu_idt; 416 if (system_hardware.hd_nodes && x86_type != X86_TYPE_P5) { 417 cp->cpu_idt = kmem_alloc(sizeof (idt0), KM_SLEEP); 418 bcopy(idt0, cp->cpu_idt, sizeof (idt0)); 419 } 420 421 /* 422 * Get interrupt priority data from cpu 0 423 */ 424 cp->cpu_pri_data = CPU->cpu_pri_data; 425 426 hat_cpu_online(cp); 427 428 /* Should remove all entries for the current process/thread here */ 429 430 /* 431 * Fill up the real mode platter to make it easy for real mode code to 432 * kick it off. This area should really be one passed by boot to kernel 433 * and guaranteed to be below 1MB and aligned to 16 bytes. Should also 434 * have identical physical and virtual address in paged mode. 435 */ 436 real_mode_platter->rm_idt_base = cp->cpu_idt; 437 real_mode_platter->rm_idt_lim = sizeof (idt0) - 1; 438 real_mode_platter->rm_gdt_base = cp->cpu_gdt; 439 real_mode_platter->rm_gdt_lim = sizeof (gdt0) -1; 440 real_mode_platter->rm_pdbr = getcr3(); 441 real_mode_platter->rm_cpu = cpun; 442 real_mode_platter->rm_x86feature = x86_feature; 443 real_mode_platter->rm_cr4 = cr4_value; 444 445 #if defined(__amd64) 446 if (getcr3() > 0xffffffffUL) 447 panic("Cannot initialize CPUs; kernel's 64-bit page tables\n" 448 "located above 4G in physical memory (@ 0x%llx).", 449 (unsigned long long)getcr3()); 450 451 /* 452 * Setup pseudo-descriptors for temporary GDT and IDT for use ONLY 453 * by code in real_mode_start(): 454 * 455 * GDT[0]: NULL selector 456 * GDT[1]: 64-bit CS: Long = 1, Present = 1, bits 12, 11 = 1 457 * 458 * Clear the IDT as interrupts will be off and a limit of 0 will cause 459 * the CPU to triple fault and reset on an NMI, seemingly as reasonable 460 * a course of action as any other, though it may cause the entire 461 * platform to reset in some cases... 462 */ 463 real_mode_platter->rm_temp_gdt[0] = 0ULL; 464 real_mode_platter->rm_temp_gdt[TEMPGDT_KCODE64] = 0x20980000000000ULL; 465 466 real_mode_platter->rm_temp_gdt_lim = (ushort_t) 467 (sizeof (real_mode_platter->rm_temp_gdt) - 1); 468 real_mode_platter->rm_temp_gdt_base = rm_platter_pa + 469 (uint32_t)(&((rm_platter_t *)0)->rm_temp_gdt); 470 471 real_mode_platter->rm_temp_idt_lim = 0; 472 real_mode_platter->rm_temp_idt_base = 0; 473 474 /* 475 * Since the CPU needs to jump to protected mode using an identity 476 * mapped address, we need to calculate it here. 477 */ 478 real_mode_platter->rm_longmode64_addr = rm_platter_pa + 479 ((uint32_t)long_mode_64 - (uint32_t)real_mode_start); 480 #endif /* __amd64 */ 481 482 #ifdef TRAPTRACE 483 /* 484 * If this is a TRAPTRACE kernel, allocate TRAPTRACE buffers for this 485 * CPU. 486 */ 487 ttc->ttc_first = (uintptr_t)kmem_zalloc(trap_trace_bufsize, KM_SLEEP); 488 ttc->ttc_next = ttc->ttc_first; 489 ttc->ttc_limit = ttc->ttc_first + trap_trace_bufsize; 490 #endif 491 492 /* 493 * Record that we have another CPU. 494 */ 495 mutex_enter(&cpu_lock); 496 /* 497 * Initialize the interrupt threads for this CPU 498 */ 499 cpu_intr_alloc(cp, NINTR_THREADS); 500 /* 501 * Add CPU to list of available CPUs. It'll be on the active list 502 * after mp_startup(). 503 */ 504 cpu_add_unit(cp); 505 mutex_exit(&cpu_lock); 506 } 507 508 /* 509 * Apply workarounds for known errata, and warn about those that are absent. 510 * 511 * System vendors occasionally create configurations which contain different 512 * revisions of the CPUs that are almost but not exactly the same. At the 513 * time of writing, this meant that their clock rates were the same, their 514 * feature sets were the same, but the required workaround were -not- 515 * necessarily the same. So, this routine is invoked on -every- CPU soon 516 * after starting to make sure that the resulting system contains the most 517 * pessimal set of workarounds needed to cope with *any* of the CPUs in the 518 * system. 519 * 520 * workaround_errata is invoked early in mlsetup() for CPU 0, and in 521 * mp_startup() for all slave CPUs. Slaves process workaround_errata prior 522 * to acknowledging their readiness to the master, so this routine will 523 * never be executed by multiple CPUs in parallel, thus making updates to 524 * global data safe. 525 * 526 * These workarounds are based on Rev 3.57 of the Revision Guide for 527 * AMD Athlon(tm) 64 and AMD Opteron(tm) Processors, August 2005. 528 */ 529 530 #if defined(OPTERON_ERRATUM_91) 531 int opteron_erratum_91; /* if non-zero -> at least one cpu has it */ 532 #endif 533 534 #if defined(OPTERON_ERRATUM_93) 535 int opteron_erratum_93; /* if non-zero -> at least one cpu has it */ 536 #endif 537 538 #if defined(OPTERON_ERRATUM_100) 539 int opteron_erratum_100; /* if non-zero -> at least one cpu has it */ 540 #endif 541 542 #if defined(OPTERON_ERRATUM_109) 543 int opteron_erratum_109; /* if non-zero -> at least one cpu has it */ 544 #endif 545 546 #if defined(OPTERON_ERRATUM_121) 547 int opteron_erratum_121; /* if non-zero -> at least one cpu has it */ 548 #endif 549 550 #if defined(OPTERON_ERRATUM_122) 551 int opteron_erratum_122; /* if non-zero -> at least one cpu has it */ 552 #endif 553 554 #if defined(OPTERON_ERRATUM_123) 555 int opteron_erratum_123; /* if non-zero -> at least one cpu has it */ 556 #endif 557 558 #if defined(OPTERON_ERRATUM_131) 559 int opteron_erratum_131; /* if non-zero -> at least one cpu has it */ 560 #endif 561 562 #if defined(OPTERON_WORKAROUND_6336786) 563 int opteron_workaround_6336786; /* non-zero -> WA relevant and applied */ 564 int opteron_workaround_6336786_UP = 0; /* Not needed for UP */ 565 #endif 566 567 #if defined(OPTERON_WORKAROUND_6323525) 568 int opteron_workaround_6323525; /* if non-zero -> at least one cpu has it */ 569 #endif 570 571 #define WARNING(cpu, n) \ 572 cmn_err(CE_WARN, "cpu%d: no workaround for erratum %d", \ 573 (cpu)->cpu_id, (n)) 574 575 uint_t 576 workaround_errata(struct cpu *cpu) 577 { 578 uint_t missing = 0; 579 580 ASSERT(cpu == CPU); 581 582 /*LINTED*/ 583 if (cpuid_opteron_erratum(cpu, 88) > 0) { 584 /* 585 * SWAPGS May Fail To Read Correct GS Base 586 */ 587 #if defined(OPTERON_ERRATUM_88) 588 /* 589 * The workaround is an mfence in the relevant assembler code 590 */ 591 #else 592 WARNING(cpu, 88); 593 missing++; 594 #endif 595 } 596 597 if (cpuid_opteron_erratum(cpu, 91) > 0) { 598 /* 599 * Software Prefetches May Report A Page Fault 600 */ 601 #if defined(OPTERON_ERRATUM_91) 602 /* 603 * fix is in trap.c 604 */ 605 opteron_erratum_91++; 606 #else 607 WARNING(cpu, 91); 608 missing++; 609 #endif 610 } 611 612 if (cpuid_opteron_erratum(cpu, 93) > 0) { 613 /* 614 * RSM Auto-Halt Restart Returns to Incorrect RIP 615 */ 616 #if defined(OPTERON_ERRATUM_93) 617 /* 618 * fix is in trap.c 619 */ 620 opteron_erratum_93++; 621 #else 622 WARNING(cpu, 93); 623 missing++; 624 #endif 625 } 626 627 /*LINTED*/ 628 if (cpuid_opteron_erratum(cpu, 95) > 0) { 629 /* 630 * RET Instruction May Return to Incorrect EIP 631 */ 632 #if defined(OPTERON_ERRATUM_95) 633 #if defined(_LP64) 634 /* 635 * Workaround this by ensuring that 32-bit user code and 636 * 64-bit kernel code never occupy the same address 637 * range mod 4G. 638 */ 639 if (_userlimit32 > 0xc0000000ul) 640 *(uintptr_t *)&_userlimit32 = 0xc0000000ul; 641 642 /*LINTED*/ 643 ASSERT((uint32_t)COREHEAP_BASE == 0xc0000000u); 644 #endif /* _LP64 */ 645 #else 646 WARNING(cpu, 95); 647 missing++; 648 #endif /* OPTERON_ERRATUM_95 */ 649 } 650 651 if (cpuid_opteron_erratum(cpu, 100) > 0) { 652 /* 653 * Compatibility Mode Branches Transfer to Illegal Address 654 */ 655 #if defined(OPTERON_ERRATUM_100) 656 /* 657 * fix is in trap.c 658 */ 659 opteron_erratum_100++; 660 #else 661 WARNING(cpu, 100); 662 missing++; 663 #endif 664 } 665 666 /*LINTED*/ 667 if (cpuid_opteron_erratum(cpu, 108) > 0) { 668 /* 669 * CPUID Instruction May Return Incorrect Model Number In 670 * Some Processors 671 */ 672 #if defined(OPTERON_ERRATUM_108) 673 /* 674 * (Our cpuid-handling code corrects the model number on 675 * those processors) 676 */ 677 #else 678 WARNING(cpu, 108); 679 missing++; 680 #endif 681 } 682 683 /*LINTED*/ 684 if (cpuid_opteron_erratum(cpu, 109) > 0) { 685 /* 686 * Certain Reverse REP MOVS May Produce Unpredictable Behaviour 687 */ 688 #if defined(OPTERON_ERRATUM_109) 689 690 /* workaround is to print a warning to upgrade BIOS */ 691 if (rdmsr(MSR_AMD_PATCHLEVEL) == 0) 692 opteron_erratum_109++; 693 #else 694 WARNING(cpu, 109); 695 missing++; 696 #endif 697 } 698 /*LINTED*/ 699 if (cpuid_opteron_erratum(cpu, 121) > 0) { 700 /* 701 * Sequential Execution Across Non_Canonical Boundary Caused 702 * Processor Hang 703 */ 704 #if defined(OPTERON_ERRATUM_121) 705 static int lma; 706 707 if (opteron_erratum_121) 708 opteron_erratum_121++; 709 710 /* 711 * Erratum 121 is only present in long (64 bit) mode. 712 * Workaround is to include the page immediately before the 713 * va hole to eliminate the possibility of system hangs due to 714 * sequential execution across the va hole boundary. 715 */ 716 if (lma == 0) { 717 /* 718 * check LMA once: assume all cpus are in long mode 719 * or not. 720 */ 721 lma = 1; 722 723 if (rdmsr(MSR_AMD_EFER) & AMD_EFER_LMA) { 724 if (hole_start) { 725 hole_start -= PAGESIZE; 726 } else { 727 /* 728 * hole_start not yet initialized by 729 * mmu_init. Initialize hole_start 730 * with value to be subtracted. 731 */ 732 hole_start = PAGESIZE; 733 } 734 opteron_erratum_121++; 735 } 736 } 737 #else 738 WARNING(cpu, 121); 739 missing++; 740 #endif 741 } 742 743 /*LINTED*/ 744 if (cpuid_opteron_erratum(cpu, 122) > 0) { 745 /* 746 * TLB Flush Filter May Cause Cohenrency Problem in 747 * Multiprocessor Systems 748 */ 749 #if defined(OPTERON_ERRATUM_122) 750 /* 751 * Erratum 122 is only present in MP configurations (multi-core 752 * or multi-processor). 753 */ 754 755 if (opteron_erratum_122 || lgrp_plat_node_cnt > 1 || 756 cpuid_get_ncpu_per_chip(cpu) > 1) { 757 /* disable TLB Flush Filter */ 758 wrmsr(MSR_AMD_HWCR, rdmsr(MSR_AMD_HWCR) | 759 (uint64_t)(uintptr_t)AMD_HWCR_FFDIS); 760 opteron_erratum_122++; 761 } 762 763 #else 764 WARNING(cpu, 122); 765 missing++; 766 #endif 767 } 768 769 #if defined(OPTERON_ERRATUM_123) 770 /*LINTED*/ 771 if (cpuid_opteron_erratum(cpu, 123) > 0) { 772 /* 773 * Bypassed Reads May Cause Data Corruption of System Hang in 774 * Dual Core Processors 775 */ 776 /* 777 * Erratum 123 applies only to multi-core cpus. 778 */ 779 780 if (cpuid_get_ncpu_per_chip(cpu) > 1) { 781 /* workaround is to print a warning to upgrade BIOS */ 782 if (rdmsr(MSR_AMD_PATCHLEVEL) == 0) 783 opteron_erratum_123++; 784 } 785 } 786 #endif 787 788 #if defined(OPTERON_ERRATUM_131) 789 /*LINTED*/ 790 if (cpuid_opteron_erratum(cpu, 131) > 0) { 791 /* 792 * Multiprocessor Systems with Four or More Cores May Deadlock 793 * Waiting for a Probe Response 794 */ 795 /* 796 * Erratum 131 applies to any system with four or more cores. 797 */ 798 if ((opteron_erratum_131 == 0) && ((lgrp_plat_node_cnt * 799 cpuid_get_ncpu_per_chip(cpu)) >= 4)) { 800 /* 801 * Workaround is to print a warning to upgrade 802 * the BIOS 803 */ 804 if (!(rdmsr(MSR_AMD_NB_CFG) & AMD_NB_CFG_SRQ_HEARTBEAT)) 805 opteron_erratum_131++; 806 } 807 } 808 #endif 809 810 #if defined(OPTERON_WORKAROUND_6336786) 811 /* 812 * This isn't really erratum, but for convenience the 813 * detection/workaround code lives here and in cpuid_opteron_erratum. 814 */ 815 if (cpuid_opteron_erratum(cpu, 6336786) > 0) { 816 int node; 817 uint8_t data; 818 819 /* 820 * Disable C1-Clock ramping on multi-core/multi-processor 821 * K8 platforms to guard against TSC drift. 822 */ 823 if (opteron_workaround_6336786) { 824 opteron_workaround_6336786++; 825 } else if ((lgrp_plat_node_cnt * 826 cpuid_get_ncpu_per_chip(cpu) >= 2) || 827 opteron_workaround_6336786_UP) { 828 for (node = 0; node < lgrp_plat_node_cnt; node++) { 829 /* 830 * Clear PMM7[1:0] (function 3, offset 0x87) 831 * Northbridge device is the node id + 24. 832 */ 833 data = pci_getb_func(0, node + 24, 3, 0x87); 834 data &= 0xFC; 835 pci_putb_func(0, node + 24, 3, 0x87, data); 836 } 837 opteron_workaround_6336786++; 838 } 839 } 840 #endif 841 842 #if defined(OPTERON_WORKAROUND_6323525) 843 /*LINTED*/ 844 /* 845 * Mutex primitives don't work as expected. 846 */ 847 if (cpuid_opteron_erratum(cpu, 6323525) > 0) { 848 849 /* 850 * problem only occurs with 2 or more cores. If bit in 851 * MSR_BU_CFG set, then not applicable. The workaround 852 * is to patch the semaphone routines with the lfence 853 * instruction to provide necessary load memory barrier with 854 * possible subsequent read-modify-write ops. 855 * 856 * It is too early in boot to call the patch routine so 857 * set erratum variable to be done in startup_end(). 858 */ 859 if (opteron_workaround_6323525) { 860 opteron_workaround_6323525++; 861 } else if ((x86_feature & X86_SSE2) && ((lgrp_plat_node_cnt * 862 cpuid_get_ncpu_per_chip(cpu)) >= 2)) { 863 if ((xrdmsr(MSR_BU_CFG) & 0x02) == 0) 864 opteron_workaround_6323525++; 865 } 866 } 867 #endif 868 return (missing); 869 } 870 871 void 872 workaround_errata_end() 873 { 874 #if defined(OPTERON_ERRATUM_109) 875 if (opteron_erratum_109) { 876 cmn_err(CE_WARN, 877 "BIOS microcode patch for AMD Athlon(tm) 64/Opteron(tm)" 878 " processor\nerratum 109 was not detected; updating your" 879 " system's BIOS to a version\ncontaining this" 880 " microcode patch is HIGHLY recommended or erroneous" 881 " system\noperation may occur.\n"); 882 } 883 #endif /* OPTERON_ERRATUM_109 */ 884 #if defined(OPTERON_ERRATUM_123) 885 if (opteron_erratum_123) { 886 cmn_err(CE_WARN, 887 "BIOS microcode patch for AMD Athlon(tm) 64/Opteron(tm)" 888 " processor\nerratum 123 was not detected; updating your" 889 " system's BIOS to a version\ncontaining this" 890 " microcode patch is HIGHLY recommended or erroneous" 891 " system\noperation may occur.\n"); 892 } 893 #endif /* OPTERON_ERRATUM_123 */ 894 #if defined(OPTERON_ERRATUM_131) 895 if (opteron_erratum_131) { 896 cmn_err(CE_WARN, 897 "BIOS microcode patch for AMD Athlon(tm) 64/Opteron(tm)" 898 " processor\nerratum 131 was not detected; updating your" 899 " system's BIOS to a version\ncontaining this" 900 " microcode patch is HIGHLY recommended or erroneous" 901 " system\noperation may occur.\n"); 902 } 903 #endif /* OPTERON_ERRATUM_131 */ 904 } 905 906 static ushort_t *mp_map_warm_reset_vector(); 907 static void mp_unmap_warm_reset_vector(ushort_t *warm_reset_vector); 908 909 /*ARGSUSED*/ 910 void 911 start_other_cpus(int cprboot) 912 { 913 unsigned who; 914 int cpuid = 0; 915 int delays = 0; 916 int started_cpu; 917 ushort_t *warm_reset_vector = NULL; 918 extern int procset; 919 920 /* 921 * Initialize our own cpu_info. 922 */ 923 init_cpu_info(CPU); 924 925 /* 926 * Initialize our syscall handlers 927 */ 928 init_cpu_syscall(CPU); 929 930 /* 931 * if only 1 cpu or not using MP, skip the rest of this 932 */ 933 if (!(mp_cpus & ~(1 << cpuid)) || use_mp == 0) { 934 if (use_mp == 0) 935 cmn_err(CE_CONT, "?***** Not in MP mode\n"); 936 goto done; 937 } 938 939 /* 940 * perform such initialization as is needed 941 * to be able to take CPUs on- and off-line. 942 */ 943 cpu_pause_init(); 944 945 xc_init(); /* initialize processor crosscalls */ 946 947 /* 948 * Copy the real mode code at "real_mode_start" to the 949 * page at rm_platter_va. 950 */ 951 warm_reset_vector = mp_map_warm_reset_vector(); 952 if (warm_reset_vector == NULL) 953 goto done; 954 955 bcopy((caddr_t)real_mode_start, 956 (caddr_t)((rm_platter_t *)rm_platter_va)->rm_code, 957 (size_t)real_mode_end - (size_t)real_mode_start); 958 959 flushes_require_xcalls = 1; 960 961 affinity_set(CPU_CURRENT); 962 963 for (who = 0; who < NCPU; who++) { 964 if (who == cpuid) 965 continue; 966 967 if ((mp_cpus & (1 << who)) == 0) 968 continue; 969 970 mp_startup_init(who); 971 started_cpu = 1; 972 (*cpu_startf)(who, rm_platter_pa); 973 974 while ((procset & (1 << who)) == 0) { 975 976 delay(1); 977 if (++delays > (20 * hz)) { 978 979 cmn_err(CE_WARN, 980 "cpu%d failed to start", who); 981 982 mutex_enter(&cpu_lock); 983 cpu[who]->cpu_flags = 0; 984 cpu_vm_data_destroy(cpu[who]); 985 cpu_del_unit(who); 986 mutex_exit(&cpu_lock); 987 988 started_cpu = 0; 989 break; 990 } 991 } 992 if (!started_cpu) 993 continue; 994 if (tsc_gethrtime_enable) 995 tsc_sync_master(who); 996 997 998 if (dtrace_cpu_init != NULL) { 999 /* 1000 * DTrace CPU initialization expects cpu_lock 1001 * to be held. 1002 */ 1003 mutex_enter(&cpu_lock); 1004 (*dtrace_cpu_init)(who); 1005 mutex_exit(&cpu_lock); 1006 } 1007 } 1008 1009 affinity_clear(); 1010 1011 for (who = 0; who < NCPU; who++) { 1012 if (who == cpuid) 1013 continue; 1014 1015 if (!(procset & (1 << who))) 1016 continue; 1017 1018 while (!(cpu_ready_set & (1 << who))) 1019 delay(1); 1020 } 1021 1022 done: 1023 workaround_errata_end(); 1024 1025 if (warm_reset_vector != NULL) 1026 mp_unmap_warm_reset_vector(warm_reset_vector); 1027 hat_unload(kas.a_hat, (caddr_t)(uintptr_t)rm_platter_pa, MMU_PAGESIZE, 1028 HAT_UNLOAD); 1029 } 1030 1031 /* 1032 * Dummy functions - no i86pc platforms support dynamic cpu allocation. 1033 */ 1034 /*ARGSUSED*/ 1035 int 1036 mp_cpu_configure(int cpuid) 1037 { 1038 return (ENOTSUP); /* not supported */ 1039 } 1040 1041 /*ARGSUSED*/ 1042 int 1043 mp_cpu_unconfigure(int cpuid) 1044 { 1045 return (ENOTSUP); /* not supported */ 1046 } 1047 1048 /* 1049 * Startup function for 'other' CPUs (besides boot cpu). 1050 * Called from real_mode_start (after *ap_mlsetup). 1051 * 1052 * WARNING: until CPU_READY is set, mp_startup and routines called by 1053 * mp_startup should not call routines (e.g. kmem_free) that could call 1054 * hat_unload which requires CPU_READY to be set. 1055 */ 1056 void 1057 mp_startup(void) 1058 { 1059 struct cpu *cp = CPU; 1060 extern int procset; 1061 uint_t new_x86_feature; 1062 1063 new_x86_feature = cpuid_pass1(cp); 1064 1065 /* 1066 * We need to Sync MTRR with cpu0's MTRR. We have to do 1067 * this with interrupts disabled. 1068 */ 1069 if (x86_feature & X86_MTRR) 1070 mtrr_sync(); 1071 1072 /* 1073 * Initialize this CPU's syscall handlers 1074 */ 1075 init_cpu_syscall(cp); 1076 1077 /* 1078 * Enable interrupts with spl set to LOCK_LEVEL. LOCK_LEVEL is the 1079 * highest level at which a routine is permitted to block on 1080 * an adaptive mutex (allows for cpu poke interrupt in case 1081 * the cpu is blocked on a mutex and halts). Setting LOCK_LEVEL blocks 1082 * device interrupts that may end up in the hat layer issuing cross 1083 * calls before CPU_READY is set. 1084 */ 1085 (void) splx(ipltospl(LOCK_LEVEL)); 1086 1087 /* 1088 * Do a sanity check to make sure this new CPU is a sane thing 1089 * to add to the collection of processors running this system. 1090 * 1091 * XXX Clearly this needs to get more sophisticated, if x86 1092 * systems start to get built out of heterogenous CPUs; as is 1093 * likely to happen once the number of processors in a configuration 1094 * gets large enough. 1095 */ 1096 if ((x86_feature & new_x86_feature) != x86_feature) { 1097 cmn_err(CE_CONT, "?cpu%d: %b\n", 1098 cp->cpu_id, new_x86_feature, FMT_X86_FEATURE); 1099 cmn_err(CE_WARN, "cpu%d feature mismatch", cp->cpu_id); 1100 } 1101 1102 /* 1103 * We could be more sophisticated here, and just mark the CPU 1104 * as "faulted" but at this point we'll opt for the easier 1105 * answer of dieing horribly. Provided the boot cpu is ok, 1106 * the system can be recovered by booting with use_mp set to zero. 1107 */ 1108 if (workaround_errata(cp) != 0) 1109 panic("critical workaround(s) missing for cpu%d", cp->cpu_id); 1110 1111 cpuid_pass2(cp); 1112 cpuid_pass3(cp); 1113 (void) cpuid_pass4(cp); 1114 1115 init_cpu_info(cp); 1116 1117 mutex_enter(&cpu_lock); 1118 procset |= 1 << cp->cpu_id; 1119 mutex_exit(&cpu_lock); 1120 1121 if (tsc_gethrtime_enable) 1122 tsc_sync_slave(); 1123 1124 mutex_enter(&cpu_lock); 1125 /* 1126 * It's unfortunate that chip_cpu_init() has to be called here. 1127 * It really belongs in cpu_add_unit(), but unfortunately it is 1128 * dependent on the cpuid probing, which must be done in the 1129 * context of the current CPU. Care must be taken on x86 to ensure 1130 * that mp_startup can safely block even though chip_cpu_init() and 1131 * cpu_add_active() have not yet been called. 1132 */ 1133 chip_cpu_init(cp); 1134 chip_cpu_startup(cp); 1135 1136 cp->cpu_flags |= CPU_RUNNING | CPU_READY | CPU_ENABLE | CPU_EXISTS; 1137 cpu_add_active(cp); 1138 mutex_exit(&cpu_lock); 1139 1140 add_cpunode2devtree(cp->cpu_id, cp->cpu_m.mcpu_cpi); 1141 1142 /* The base spl should still be at LOCK LEVEL here */ 1143 ASSERT(cp->cpu_base_spl == ipltospl(LOCK_LEVEL)); 1144 set_base_spl(); /* Restore the spl to its proper value */ 1145 1146 (void) spl0(); /* enable interrupts */ 1147 1148 /* 1149 * Set up the CPU module for this CPU. This can't be done before 1150 * this CPU is made CPU_READY, because we may (in heterogeneous systems) 1151 * need to go load another CPU module. The act of attempting to load 1152 * a module may trigger a cross-call, which will ASSERT unless this 1153 * cpu is CPU_READY. 1154 */ 1155 cmi_init(); 1156 1157 if (x86_feature & X86_MCA) 1158 cmi_mca_init(); 1159 1160 if (boothowto & RB_DEBUG) 1161 kdi_dvec_cpu_init(cp); 1162 1163 /* 1164 * Setting the bit in cpu_ready_set must be the last operation in 1165 * processor initialization; the boot CPU will continue to boot once 1166 * it sees this bit set for all active CPUs. 1167 */ 1168 CPUSET_ATOMIC_ADD(cpu_ready_set, cp->cpu_id); 1169 1170 /* 1171 * Because mp_startup() gets fired off after init() starts, we 1172 * can't use the '?' trick to do 'boot -v' printing - so we 1173 * always direct the 'cpu .. online' messages to the log. 1174 */ 1175 cmn_err(CE_CONT, "!cpu%d initialization complete - online\n", 1176 cp->cpu_id); 1177 1178 /* 1179 * Now we are done with the startup thread, so free it up. 1180 */ 1181 thread_exit(); 1182 panic("mp_startup: cannot return"); 1183 /*NOTREACHED*/ 1184 } 1185 1186 1187 /* 1188 * Start CPU on user request. 1189 */ 1190 /* ARGSUSED */ 1191 int 1192 mp_cpu_start(struct cpu *cp) 1193 { 1194 ASSERT(MUTEX_HELD(&cpu_lock)); 1195 return (0); 1196 } 1197 1198 /* 1199 * Stop CPU on user request. 1200 */ 1201 /* ARGSUSED */ 1202 int 1203 mp_cpu_stop(struct cpu *cp) 1204 { 1205 extern int cbe_psm_timer_mode; 1206 ASSERT(MUTEX_HELD(&cpu_lock)); 1207 1208 /* 1209 * If TIMER_PERIODIC mode is used, CPU0 is the one running it; 1210 * can't stop it. (This is true only for machines with no TSC.) 1211 */ 1212 1213 if ((cbe_psm_timer_mode == TIMER_PERIODIC) && (cp->cpu_id == 0)) 1214 return (1); 1215 1216 return (0); 1217 } 1218 1219 /* 1220 * Power on CPU. 1221 */ 1222 /* ARGSUSED */ 1223 int 1224 mp_cpu_poweron(struct cpu *cp) 1225 { 1226 ASSERT(MUTEX_HELD(&cpu_lock)); 1227 return (ENOTSUP); /* not supported */ 1228 } 1229 1230 /* 1231 * Power off CPU. 1232 */ 1233 /* ARGSUSED */ 1234 int 1235 mp_cpu_poweroff(struct cpu *cp) 1236 { 1237 ASSERT(MUTEX_HELD(&cpu_lock)); 1238 return (ENOTSUP); /* not supported */ 1239 } 1240 1241 1242 /* 1243 * Take the specified CPU out of participation in interrupts. 1244 */ 1245 int 1246 cpu_disable_intr(struct cpu *cp) 1247 { 1248 if (psm_disable_intr(cp->cpu_id) != DDI_SUCCESS) 1249 return (EBUSY); 1250 1251 cp->cpu_flags &= ~CPU_ENABLE; 1252 return (0); 1253 } 1254 1255 /* 1256 * Allow the specified CPU to participate in interrupts. 1257 */ 1258 void 1259 cpu_enable_intr(struct cpu *cp) 1260 { 1261 ASSERT(MUTEX_HELD(&cpu_lock)); 1262 cp->cpu_flags |= CPU_ENABLE; 1263 psm_enable_intr(cp->cpu_id); 1264 } 1265 1266 1267 1268 static ushort_t * 1269 mp_map_warm_reset_vector() 1270 { 1271 ushort_t *warm_reset_vector; 1272 1273 if (!(warm_reset_vector = (ushort_t *)psm_map_phys(WARM_RESET_VECTOR, 1274 sizeof (ushort_t *), PROT_READ|PROT_WRITE))) 1275 return (NULL); 1276 1277 /* 1278 * setup secondary cpu bios boot up vector 1279 */ 1280 *warm_reset_vector = (ushort_t)((caddr_t) 1281 ((struct rm_platter *)rm_platter_va)->rm_code - rm_platter_va 1282 + ((ulong_t)rm_platter_va & 0xf)); 1283 warm_reset_vector++; 1284 *warm_reset_vector = (ushort_t)(rm_platter_pa >> 4); 1285 1286 --warm_reset_vector; 1287 return (warm_reset_vector); 1288 } 1289 1290 static void 1291 mp_unmap_warm_reset_vector(ushort_t *warm_reset_vector) 1292 { 1293 psm_unmap_phys((caddr_t)warm_reset_vector, sizeof (ushort_t *)); 1294 } 1295 1296 void 1297 mp_cpu_faulted_enter(struct cpu *cp) 1298 { 1299 cmi_faulted_enter(cp); 1300 } 1301 1302 void 1303 mp_cpu_faulted_exit(struct cpu *cp) 1304 { 1305 cmi_faulted_exit(cp); 1306 } 1307 1308 /* 1309 * The following two routines are used as context operators on threads belonging 1310 * to processes with a private LDT (see sysi86). Due to the rarity of such 1311 * processes, these routines are currently written for best code readability and 1312 * organization rather than speed. We could avoid checking x86_feature at every 1313 * context switch by installing different context ops, depending on the 1314 * x86_feature flags, at LDT creation time -- one for each combination of fast 1315 * syscall feature flags. 1316 */ 1317 1318 /*ARGSUSED*/ 1319 void 1320 cpu_fast_syscall_disable(void *arg) 1321 { 1322 if (x86_feature & X86_SEP) 1323 cpu_sep_disable(); 1324 if (x86_feature & X86_ASYSC) 1325 cpu_asysc_disable(); 1326 } 1327 1328 /*ARGSUSED*/ 1329 void 1330 cpu_fast_syscall_enable(void *arg) 1331 { 1332 if (x86_feature & X86_SEP) 1333 cpu_sep_enable(); 1334 if (x86_feature & X86_ASYSC) 1335 cpu_asysc_enable(); 1336 } 1337 1338 static void 1339 cpu_sep_enable(void) 1340 { 1341 ASSERT(x86_feature & X86_SEP); 1342 ASSERT(curthread->t_preempt || getpil() >= LOCK_LEVEL); 1343 1344 wrmsr(MSR_INTC_SEP_CS, (uint64_t)(uintptr_t)KCS_SEL); 1345 } 1346 1347 static void 1348 cpu_sep_disable(void) 1349 { 1350 ASSERT(x86_feature & X86_SEP); 1351 ASSERT(curthread->t_preempt || getpil() >= LOCK_LEVEL); 1352 1353 /* 1354 * Setting the SYSENTER_CS_MSR register to 0 causes software executing 1355 * the sysenter or sysexit instruction to trigger a #gp fault. 1356 */ 1357 wrmsr(MSR_INTC_SEP_CS, 0ULL); 1358 } 1359 1360 static void 1361 cpu_asysc_enable(void) 1362 { 1363 ASSERT(x86_feature & X86_ASYSC); 1364 ASSERT(curthread->t_preempt || getpil() >= LOCK_LEVEL); 1365 1366 wrmsr(MSR_AMD_EFER, rdmsr(MSR_AMD_EFER) | 1367 (uint64_t)(uintptr_t)AMD_EFER_SCE); 1368 } 1369 1370 static void 1371 cpu_asysc_disable(void) 1372 { 1373 ASSERT(x86_feature & X86_ASYSC); 1374 ASSERT(curthread->t_preempt || getpil() >= LOCK_LEVEL); 1375 1376 /* 1377 * Turn off the SCE (syscall enable) bit in the EFER register. Software 1378 * executing syscall or sysret with this bit off will incur a #ud trap. 1379 */ 1380 wrmsr(MSR_AMD_EFER, rdmsr(MSR_AMD_EFER) & 1381 ~((uint64_t)(uintptr_t)AMD_EFER_SCE)); 1382 } 1383