1 #include <linux/export.h>
2 #include <linux/bitops.h>
7 #include <linux/sched.h>
8 #include <asm/processor.h>
12 #include <asm/pci-direct.h>
15 # include <asm/mmconfig.h>
16 # include <asm/cacheflush.h>
21 static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
26 WARN_ONCE((boot_cpu_data.x86 != 0xf),
27 "%s should only be used on K8!\n", __func__);
32 err = rdmsr_safe_regs(gprs);
34 *p = gprs[0] | ((u64)gprs[2] << 32);
39 static inline int wrmsrl_amd_safe(unsigned msr, unsigned long long val)
43 WARN_ONCE((boot_cpu_data.x86 != 0xf),
44 "%s should only be used on K8!\n", __func__);
51 return wrmsr_safe_regs(gprs);
55 * B step AMD K6 before B 9730xxxx have hardware bugs that can cause
56 * misexecution of code under Linux. Owners of such processors should
57 * contact AMD for precise details and a CPU swap.
59 * See http://www.multimania.com/poulot/k6bug.html
60 * and section 2.6.2 of "AMD-K6 Processor Revision Guide - Model 6"
61 * (Publication # 21266 Issue Date: August 1998)
63 * The following test is erm.. interesting. AMD neglected to up
64 * the chip setting when fixing the bug but they also tweaked some
65 * performance at the same time..
68 extern __visible void vide(void);
69 __asm__(".globl vide\n\t.align 4\nvide: ret");
71 static void init_amd_k5(struct cpuinfo_x86 *c)
75 * General Systems BIOSen alias the cpu frequency registers
76 * of the Elan at 0x000df000. Unfortuantly, one of the Linux
77 * drivers subsequently pokes it, and changes the CPU speed.
78 * Workaround : Remove the unneeded alias.
80 #define CBAR (0xfffc) /* Configuration Base Address (32-bit) */
81 #define CBAR_ENB (0x80000000)
82 #define CBAR_KEY (0X000000CB)
83 if (c->x86_model == 9 || c->x86_model == 10) {
84 if (inl(CBAR) & CBAR_ENB)
85 outl(0 | CBAR_KEY, CBAR);
90 static void init_amd_k6(struct cpuinfo_x86 *c)
94 int mbytes = get_num_physpages() >> (20-PAGE_SHIFT);
96 if (c->x86_model < 6) {
97 /* Based on AMD doc 20734R - June 2000 */
98 if (c->x86_model == 0) {
99 clear_cpu_cap(c, X86_FEATURE_APIC);
100 set_cpu_cap(c, X86_FEATURE_PGE);
105 if (c->x86_model == 6 && c->x86_mask == 1) {
106 const int K6_BUG_LOOP = 1000000;
108 void (*f_vide)(void);
111 printk(KERN_INFO "AMD K6 stepping B detected - ");
114 * It looks like AMD fixed the 2.6.2 bug and improved indirect
115 * calls at the same time.
126 if (d > 20*K6_BUG_LOOP)
128 "system stability may be impaired when more than 32 MB are used.\n");
130 printk(KERN_CONT "probably OK (after B9730xxxx).\n");
133 /* K6 with old style WHCR */
134 if (c->x86_model < 8 ||
135 (c->x86_model == 8 && c->x86_mask < 8)) {
136 /* We can only write allocate on the low 508Mb */
140 rdmsr(MSR_K6_WHCR, l, h);
141 if ((l&0x0000FFFF) == 0) {
143 l = (1<<0)|((mbytes/4)<<1);
144 local_irq_save(flags);
146 wrmsr(MSR_K6_WHCR, l, h);
147 local_irq_restore(flags);
148 printk(KERN_INFO "Enabling old style K6 write allocation for %d Mb\n",
154 if ((c->x86_model == 8 && c->x86_mask > 7) ||
155 c->x86_model == 9 || c->x86_model == 13) {
156 /* The more serious chips .. */
161 rdmsr(MSR_K6_WHCR, l, h);
162 if ((l&0xFFFF0000) == 0) {
164 l = ((mbytes>>2)<<22)|(1<<16);
165 local_irq_save(flags);
167 wrmsr(MSR_K6_WHCR, l, h);
168 local_irq_restore(flags);
169 printk(KERN_INFO "Enabling new style K6 write allocation for %d Mb\n",
176 if (c->x86_model == 10) {
177 /* AMD Geode LX is model 10 */
178 /* placeholder for any needed mods */
184 static void init_amd_k7(struct cpuinfo_x86 *c)
190 * Bit 15 of Athlon specific MSR 15, needs to be 0
191 * to enable SSE on Palomino/Morgan/Barton CPU's.
192 * If the BIOS didn't enable it already, enable it here.
194 if (c->x86_model >= 6 && c->x86_model <= 10) {
195 if (!cpu_has(c, X86_FEATURE_XMM)) {
196 printk(KERN_INFO "Enabling disabled K7/SSE Support.\n");
197 msr_clear_bit(MSR_K7_HWCR, 15);
198 set_cpu_cap(c, X86_FEATURE_XMM);
203 * It's been determined by AMD that Athlons since model 8 stepping 1
204 * are more robust with CLK_CTL set to 200xxxxx instead of 600xxxxx
205 * As per AMD technical note 27212 0.2
207 if ((c->x86_model == 8 && c->x86_mask >= 1) || (c->x86_model > 8)) {
208 rdmsr(MSR_K7_CLK_CTL, l, h);
209 if ((l & 0xfff00000) != 0x20000000) {
211 "CPU: CLK_CTL MSR was %x. Reprogramming to %x\n",
212 l, ((l & 0x000fffff)|0x20000000));
213 wrmsr(MSR_K7_CLK_CTL, (l & 0x000fffff)|0x20000000, h);
217 set_cpu_cap(c, X86_FEATURE_K7);
219 /* calling is from identify_secondary_cpu() ? */
224 * Certain Athlons might work (for various values of 'work') in SMP
225 * but they are not certified as MP capable.
227 /* Athlon 660/661 is valid. */
228 if ((c->x86_model == 6) && ((c->x86_mask == 0) ||
232 /* Duron 670 is valid */
233 if ((c->x86_model == 7) && (c->x86_mask == 0))
237 * Athlon 662, Duron 671, and Athlon >model 7 have capability
238 * bit. It's worth noting that the A5 stepping (662) of some
239 * Athlon XP's have the MP bit set.
240 * See http://www.heise.de/newsticker/data/jow-18.10.01-000 for
243 if (((c->x86_model == 6) && (c->x86_mask >= 2)) ||
244 ((c->x86_model == 7) && (c->x86_mask >= 1)) ||
246 if (cpu_has(c, X86_FEATURE_MP))
249 /* If we get here, not a certified SMP capable AMD system. */
252 * Don't taint if we are running SMP kernel on a single non-MP
255 WARN_ONCE(1, "WARNING: This combination of AMD"
256 " processors is not suitable for SMP.\n");
257 add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_NOW_UNRELIABLE);
263 * To workaround broken NUMA config. Read the comment in
264 * srat_detect_node().
266 static int nearby_node(int apicid)
270 for (i = apicid - 1; i >= 0; i--) {
271 node = __apicid_to_node[i];
272 if (node != NUMA_NO_NODE && node_online(node))
275 for (i = apicid + 1; i < MAX_LOCAL_APIC; i++) {
276 node = __apicid_to_node[i];
277 if (node != NUMA_NO_NODE && node_online(node))
280 return first_node(node_online_map); /* Shouldn't happen */
285 * Fixup core topology information for
286 * (1) AMD multi-node processors
287 * Assumption: Number of cores in each internal node is the same.
288 * (2) AMD processors supporting compute units
291 static void amd_get_topology(struct cpuinfo_x86 *c)
293 u32 nodes, cores_per_cu = 1;
295 int cpu = smp_processor_id();
297 /* get information required for multi-node processors */
298 if (cpu_has_topoext) {
299 u32 eax, ebx, ecx, edx;
301 cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
302 nodes = ((ecx >> 8) & 7) + 1;
305 /* get compute unit information */
306 smp_num_siblings = ((ebx >> 8) & 3) + 1;
307 c->compute_unit_id = ebx & 0xff;
308 cores_per_cu += ((ebx >> 8) & 3);
309 } else if (cpu_has(c, X86_FEATURE_NODEID_MSR)) {
312 rdmsrl(MSR_FAM10H_NODE_ID, value);
313 nodes = ((value >> 3) & 7) + 1;
318 /* fixup multi-node processor information */
323 set_cpu_cap(c, X86_FEATURE_AMD_DCM);
324 cores_per_node = c->x86_max_cores / nodes;
325 cus_per_node = cores_per_node / cores_per_cu;
327 /* store NodeID, use llc_shared_map to store sibling info */
328 per_cpu(cpu_llc_id, cpu) = node_id;
330 /* core id has to be in the [0 .. cores_per_node - 1] range */
331 c->cpu_core_id %= cores_per_node;
332 c->compute_unit_id %= cus_per_node;
338 * On a AMD dual core setup the lower bits of the APIC id distinguish the cores.
339 * Assumes number of cores is a power of two.
341 static void amd_detect_cmp(struct cpuinfo_x86 *c)
345 int cpu = smp_processor_id();
347 bits = c->x86_coreid_bits;
348 /* Low order bits define the core id (index of core in socket) */
349 c->cpu_core_id = c->initial_apicid & ((1 << bits)-1);
350 /* Convert the initial APIC ID into the socket ID */
351 c->phys_proc_id = c->initial_apicid >> bits;
352 /* use socket ID also for last level cache */
353 per_cpu(cpu_llc_id, cpu) = c->phys_proc_id;
358 u16 amd_get_nb_id(int cpu)
362 id = per_cpu(cpu_llc_id, cpu);
366 EXPORT_SYMBOL_GPL(amd_get_nb_id);
368 static void srat_detect_node(struct cpuinfo_x86 *c)
371 int cpu = smp_processor_id();
373 unsigned apicid = c->apicid;
375 node = numa_cpu_node(cpu);
376 if (node == NUMA_NO_NODE)
377 node = per_cpu(cpu_llc_id, cpu);
380 * On multi-fabric platform (e.g. Numascale NumaChip) a
381 * platform-specific handler needs to be called to fixup some
384 if (x86_cpuinit.fixup_cpu_id)
385 x86_cpuinit.fixup_cpu_id(c, node);
387 if (!node_online(node)) {
389 * Two possibilities here:
391 * - The CPU is missing memory and no node was created. In
392 * that case try picking one from a nearby CPU.
394 * - The APIC IDs differ from the HyperTransport node IDs
395 * which the K8 northbridge parsing fills in. Assume
396 * they are all increased by a constant offset, but in
397 * the same order as the HT nodeids. If that doesn't
398 * result in a usable node fall back to the path for the
401 * This workaround operates directly on the mapping between
402 * APIC ID and NUMA node, assuming certain relationship
403 * between APIC ID, HT node ID and NUMA topology. As going
404 * through CPU mapping may alter the outcome, directly
405 * access __apicid_to_node[].
407 int ht_nodeid = c->initial_apicid;
409 if (ht_nodeid >= 0 &&
410 __apicid_to_node[ht_nodeid] != NUMA_NO_NODE)
411 node = __apicid_to_node[ht_nodeid];
412 /* Pick a nearby node */
413 if (!node_online(node))
414 node = nearby_node(apicid);
416 numa_set_node(cpu, node);
420 static void early_init_amd_mc(struct cpuinfo_x86 *c)
425 /* Multi core CPU? */
426 if (c->extended_cpuid_level < 0x80000008)
429 ecx = cpuid_ecx(0x80000008);
431 c->x86_max_cores = (ecx & 0xff) + 1;
433 /* CPU telling us the core id bits shift? */
434 bits = (ecx >> 12) & 0xF;
436 /* Otherwise recompute */
438 while ((1 << bits) < c->x86_max_cores)
442 c->x86_coreid_bits = bits;
446 static void bsp_init_amd(struct cpuinfo_x86 *c)
451 unsigned long long tseg;
454 * Split up direct mapping around the TSEG SMM area.
455 * Don't do it for gbpages because there seems very little
456 * benefit in doing so.
458 if (!rdmsrl_safe(MSR_K8_TSEG_ADDR, &tseg)) {
459 unsigned long pfn = tseg >> PAGE_SHIFT;
461 printk(KERN_DEBUG "tseg: %010llx\n", tseg);
462 if (pfn_range_is_mapped(pfn, pfn + 1))
463 set_memory_4k((unsigned long)__va(tseg), 1);
468 if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {
471 (c->x86 == 0x10 && c->x86_model >= 0x2)) {
474 rdmsrl(MSR_K7_HWCR, val);
475 if (!(val & BIT(24)))
476 printk(KERN_WARNING FW_BUG "TSC doesn't count "
477 "with P0 frequency!\n");
481 if (c->x86 == 0x15) {
482 unsigned long upperbit;
485 cpuid = cpuid_edx(0x80000005);
486 assoc = cpuid >> 16 & 0xff;
487 upperbit = ((cpuid >> 24) << 10) / assoc;
489 va_align.mask = (upperbit - 1) & PAGE_MASK;
490 va_align.flags = ALIGN_VA_32 | ALIGN_VA_64;
494 static void early_init_amd(struct cpuinfo_x86 *c)
496 early_init_amd_mc(c);
499 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
500 * with P/T states and does not stop in deep C-states
502 if (c->x86_power & (1 << 8)) {
503 set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
504 set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
505 if (!check_tsc_unstable())
506 set_sched_clock_stable();
510 set_cpu_cap(c, X86_FEATURE_SYSCALL32);
512 /* Set MTRR capability flag if appropriate */
514 if (c->x86_model == 13 || c->x86_model == 9 ||
515 (c->x86_model == 8 && c->x86_mask >= 8))
516 set_cpu_cap(c, X86_FEATURE_K6_MTRR);
518 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_PCI)
519 /* check CPU config space for extended APIC ID */
520 if (cpu_has_apic && c->x86 >= 0xf) {
522 val = read_pci_config(0, 24, 0, 0x68);
523 if ((val & ((1 << 17) | (1 << 18))) == ((1 << 17) | (1 << 18)))
524 set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
528 /* F16h erratum 793, CVE-2013-6885 */
529 if (c->x86 == 0x16 && c->x86_model <= 0xf)
530 msr_set_bit(MSR_AMD64_LS_CFG, 15);
533 static const int amd_erratum_383[];
534 static const int amd_erratum_400[];
535 static bool cpu_has_amd_erratum(struct cpuinfo_x86 *cpu, const int *erratum);
537 static void init_amd_k8(struct cpuinfo_x86 *c)
542 /* On C+ stepping K8 rep microcode works well for copy/memset */
543 level = cpuid_eax(1);
544 if ((level >= 0x0f48 && level < 0x0f50) || level >= 0x0f58)
545 set_cpu_cap(c, X86_FEATURE_REP_GOOD);
548 * Some BIOSes incorrectly force this feature, but only K8 revision D
549 * (model = 0x14) and later actually support it.
550 * (AMD Erratum #110, docId: 25759).
552 if (c->x86_model < 0x14 && cpu_has(c, X86_FEATURE_LAHF_LM)) {
553 clear_cpu_cap(c, X86_FEATURE_LAHF_LM);
554 if (!rdmsrl_amd_safe(0xc001100d, &value)) {
555 value &= ~BIT_64(32);
556 wrmsrl_amd_safe(0xc001100d, value);
560 if (!c->x86_model_id[0])
561 strcpy(c->x86_model_id, "Hammer");
564 static void init_amd_gh(struct cpuinfo_x86 *c)
567 /* do this for boot cpu */
568 if (c == &boot_cpu_data)
569 check_enable_amd_mmconf_dmi();
571 fam10h_check_enable_mmcfg();
575 * Disable GART TLB Walk Errors on Fam10h. We do this here because this
576 * is always needed when GART is enabled, even in a kernel which has no
577 * MCE support built in. BIOS should disable GartTlbWlk Errors already.
578 * If it doesn't, we do it here as suggested by the BKDG.
580 * Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=33012
582 msr_set_bit(MSR_AMD64_MCx_MASK(4), 10);
585 * On family 10h BIOS may not have properly enabled WC+ support, causing
586 * it to be converted to CD memtype. This may result in performance
587 * degradation for certain nested-paging guests. Prevent this conversion
588 * by clearing bit 24 in MSR_AMD64_BU_CFG2.
590 * NOTE: we want to use the _safe accessors so as not to #GP kvm
591 * guests on older kvm hosts.
593 msr_clear_bit(MSR_AMD64_BU_CFG2, 24);
595 if (cpu_has_amd_erratum(c, amd_erratum_383))
596 set_cpu_bug(c, X86_BUG_AMD_TLB_MMATCH);
599 static void init_amd_bd(struct cpuinfo_x86 *c)
603 /* re-enable TopologyExtensions if switched off by BIOS */
604 if ((c->x86_model >= 0x10) && (c->x86_model <= 0x1f) &&
605 !cpu_has(c, X86_FEATURE_TOPOEXT)) {
607 if (msr_set_bit(0xc0011005, 54) > 0) {
608 rdmsrl(0xc0011005, value);
609 if (value & BIT_64(54)) {
610 set_cpu_cap(c, X86_FEATURE_TOPOEXT);
611 pr_info(FW_INFO "CPU: Re-enabling disabled Topology Extensions Support.\n");
617 * The way access filter has a performance penalty on some workloads.
618 * Disable it on the affected CPUs.
620 if ((c->x86_model >= 0x02) && (c->x86_model < 0x20)) {
621 if (!rdmsrl_safe(0xc0011021, &value) && !(value & 0x1E)) {
623 wrmsrl_safe(0xc0011021, value);
628 static void init_amd(struct cpuinfo_x86 *c)
634 * Disable TLB flush filter by setting HWCR.FFDIS on K8
635 * bit 6 of msr C001_0015
637 * Errata 63 for SH-B3 steppings
638 * Errata 122 for all steppings (F+ have it disabled by default)
641 msr_set_bit(MSR_K7_HWCR, 6);
647 * Bit 31 in normal CPUID used for nonstandard 3DNow ID;
648 * 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway
650 clear_cpu_cap(c, 0*32+31);
653 set_cpu_cap(c, X86_FEATURE_REP_GOOD);
655 /* get apicid instead of initial apic id from cpuid */
656 c->apicid = hard_smp_processor_id();
658 /* K6s reports MCEs but don't actually have all the MSRs */
660 clear_cpu_cap(c, X86_FEATURE_MCE);
663 case 4: init_amd_k5(c); break;
664 case 5: init_amd_k6(c); break;
665 case 6: init_amd_k7(c); break;
666 case 0xf: init_amd_k8(c); break;
667 case 0x10: init_amd_gh(c); break;
668 case 0x15: init_amd_bd(c); break;
671 /* Enable workaround for FXSAVE leak */
673 set_cpu_bug(c, X86_BUG_FXSAVE_LEAK);
675 cpu_detect_cache_sizes(c);
677 /* Multi core CPU? */
678 if (c->extended_cpuid_level >= 0x80000008) {
687 init_amd_cacheinfo(c);
690 set_cpu_cap(c, X86_FEATURE_K8);
693 /* MFENCE stops RDTSC speculation */
694 set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC);
698 * Family 0x12 and above processors have APIC timer
699 * running in deep C states.
702 set_cpu_cap(c, X86_FEATURE_ARAT);
704 if (cpu_has_amd_erratum(c, amd_erratum_400))
705 set_cpu_bug(c, X86_BUG_AMD_APIC_C1E);
707 rdmsr_safe(MSR_AMD64_PATCH_LEVEL, &c->microcode, &dummy);
711 static unsigned int amd_size_cache(struct cpuinfo_x86 *c, unsigned int size)
713 /* AMD errata T13 (order #21922) */
716 if (c->x86_model == 3 && c->x86_mask == 0)
718 /* Tbird rev A1/A2 */
719 if (c->x86_model == 4 &&
720 (c->x86_mask == 0 || c->x86_mask == 1))
727 static void cpu_detect_tlb_amd(struct cpuinfo_x86 *c)
729 u32 ebx, eax, ecx, edx;
735 if (c->extended_cpuid_level < 0x80000006)
738 cpuid(0x80000006, &eax, &ebx, &ecx, &edx);
740 tlb_lld_4k[ENTRIES] = (ebx >> 16) & mask;
741 tlb_lli_4k[ENTRIES] = ebx & mask;
744 * K8 doesn't have 2M/4M entries in the L2 TLB so read out the L1 TLB
745 * characteristics from the CPUID function 0x80000005 instead.
748 cpuid(0x80000005, &eax, &ebx, &ecx, &edx);
752 /* Handle DTLB 2M and 4M sizes, fall back to L1 if L2 is disabled */
753 if (!((eax >> 16) & mask))
754 tlb_lld_2m[ENTRIES] = (cpuid_eax(0x80000005) >> 16) & 0xff;
756 tlb_lld_2m[ENTRIES] = (eax >> 16) & mask;
758 /* a 4M entry uses two 2M entries */
759 tlb_lld_4m[ENTRIES] = tlb_lld_2m[ENTRIES] >> 1;
761 /* Handle ITLB 2M and 4M sizes, fall back to L1 if L2 is disabled */
764 if (c->x86 == 0x15 && c->x86_model <= 0x1f) {
765 tlb_lli_2m[ENTRIES] = 1024;
767 cpuid(0x80000005, &eax, &ebx, &ecx, &edx);
768 tlb_lli_2m[ENTRIES] = eax & 0xff;
771 tlb_lli_2m[ENTRIES] = eax & mask;
773 tlb_lli_4m[ENTRIES] = tlb_lli_2m[ENTRIES] >> 1;
776 static const struct cpu_dev amd_cpu_dev = {
778 .c_ident = { "AuthenticAMD" },
781 { .family = 4, .model_names =
792 .legacy_cache_size = amd_size_cache,
794 .c_early_init = early_init_amd,
795 .c_detect_tlb = cpu_detect_tlb_amd,
796 .c_bsp_init = bsp_init_amd,
798 .c_x86_vendor = X86_VENDOR_AMD,
801 cpu_dev_register(amd_cpu_dev);
804 * AMD errata checking
806 * Errata are defined as arrays of ints using the AMD_LEGACY_ERRATUM() or
807 * AMD_OSVW_ERRATUM() macros. The latter is intended for newer errata that
808 * have an OSVW id assigned, which it takes as first argument. Both take a
809 * variable number of family-specific model-stepping ranges created by
814 * const int amd_erratum_319[] =
815 * AMD_LEGACY_ERRATUM(AMD_MODEL_RANGE(0x10, 0x2, 0x1, 0x4, 0x2),
816 * AMD_MODEL_RANGE(0x10, 0x8, 0x0, 0x8, 0x0),
817 * AMD_MODEL_RANGE(0x10, 0x9, 0x0, 0x9, 0x0));
820 #define AMD_LEGACY_ERRATUM(...) { -1, __VA_ARGS__, 0 }
821 #define AMD_OSVW_ERRATUM(osvw_id, ...) { osvw_id, __VA_ARGS__, 0 }
822 #define AMD_MODEL_RANGE(f, m_start, s_start, m_end, s_end) \
823 ((f << 24) | (m_start << 16) | (s_start << 12) | (m_end << 4) | (s_end))
824 #define AMD_MODEL_RANGE_FAMILY(range) (((range) >> 24) & 0xff)
825 #define AMD_MODEL_RANGE_START(range) (((range) >> 12) & 0xfff)
826 #define AMD_MODEL_RANGE_END(range) ((range) & 0xfff)
828 static const int amd_erratum_400[] =
829 AMD_OSVW_ERRATUM(1, AMD_MODEL_RANGE(0xf, 0x41, 0x2, 0xff, 0xf),
830 AMD_MODEL_RANGE(0x10, 0x2, 0x1, 0xff, 0xf));
832 static const int amd_erratum_383[] =
833 AMD_OSVW_ERRATUM(3, AMD_MODEL_RANGE(0x10, 0, 0, 0xff, 0xf));
836 static bool cpu_has_amd_erratum(struct cpuinfo_x86 *cpu, const int *erratum)
838 int osvw_id = *erratum++;
842 if (osvw_id >= 0 && osvw_id < 65536 &&
843 cpu_has(cpu, X86_FEATURE_OSVW)) {
846 rdmsrl(MSR_AMD64_OSVW_ID_LENGTH, osvw_len);
847 if (osvw_id < osvw_len) {
850 rdmsrl(MSR_AMD64_OSVW_STATUS + (osvw_id >> 6),
852 return osvw_bits & (1ULL << (osvw_id & 0x3f));
856 /* OSVW unavailable or ID unknown, match family-model-stepping range */
857 ms = (cpu->x86_model << 4) | cpu->x86_mask;
858 while ((range = *erratum++))
859 if ((cpu->x86 == AMD_MODEL_RANGE_FAMILY(range)) &&
860 (ms >= AMD_MODEL_RANGE_START(range)) &&
861 (ms <= AMD_MODEL_RANGE_END(range)))