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x86, amd: Add support for CPUID topology extension of AMD CPUs
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1 #include <linux/init.h>
2 #include <linux/bitops.h>
3 #include <linux/mm.h>
4
5 #include <linux/io.h>
6 #include <asm/processor.h>
7 #include <asm/apic.h>
8 #include <asm/cpu.h>
9 #include <asm/pci-direct.h>
10
11 #ifdef CONFIG_X86_64
12 # include <asm/numa_64.h>
13 # include <asm/mmconfig.h>
14 # include <asm/cacheflush.h>
15 #endif
16
17 #include "cpu.h"
18
19 #ifdef CONFIG_X86_32
20 /*
21 * B step AMD K6 before B 9730xxxx have hardware bugs that can cause
22 * misexecution of code under Linux. Owners of such processors should
23 * contact AMD for precise details and a CPU swap.
24 *
25 * See http://www.multimania.com/poulot/k6bug.html
26 * http://www.amd.com/K6/k6docs/revgd.html
27 *
28 * The following test is erm.. interesting. AMD neglected to up
29 * the chip setting when fixing the bug but they also tweaked some
30 * performance at the same time..
31 */
32
33 extern void vide(void);
34 __asm__(".align 4\nvide: ret");
35
36 static void __cpuinit init_amd_k5(struct cpuinfo_x86 *c)
37 {
38 /*
39 * General Systems BIOSen alias the cpu frequency registers
40 * of the Elan at 0x000df000. Unfortuantly, one of the Linux
41 * drivers subsequently pokes it, and changes the CPU speed.
42 * Workaround : Remove the unneeded alias.
43 */
44 #define CBAR (0xfffc) /* Configuration Base Address (32-bit) */
45 #define CBAR_ENB (0x80000000)
46 #define CBAR_KEY (0X000000CB)
47 if (c->x86_model == 9 || c->x86_model == 10) {
48 if (inl(CBAR) & CBAR_ENB)
49 outl(0 | CBAR_KEY, CBAR);
50 }
51 }
52
53
54 static void __cpuinit init_amd_k6(struct cpuinfo_x86 *c)
55 {
56 u32 l, h;
57 int mbytes = num_physpages >> (20-PAGE_SHIFT);
58
59 if (c->x86_model < 6) {
60 /* Based on AMD doc 20734R - June 2000 */
61 if (c->x86_model == 0) {
62 clear_cpu_cap(c, X86_FEATURE_APIC);
63 set_cpu_cap(c, X86_FEATURE_PGE);
64 }
65 return;
66 }
67
68 if (c->x86_model == 6 && c->x86_mask == 1) {
69 const int K6_BUG_LOOP = 1000000;
70 int n;
71 void (*f_vide)(void);
72 unsigned long d, d2;
73
74 printk(KERN_INFO "AMD K6 stepping B detected - ");
75
76 /*
77 * It looks like AMD fixed the 2.6.2 bug and improved indirect
78 * calls at the same time.
79 */
80
81 n = K6_BUG_LOOP;
82 f_vide = vide;
83 rdtscl(d);
84 while (n--)
85 f_vide();
86 rdtscl(d2);
87 d = d2-d;
88
89 if (d > 20*K6_BUG_LOOP)
90 printk(KERN_CONT
91 "system stability may be impaired when more than 32 MB are used.\n");
92 else
93 printk(KERN_CONT "probably OK (after B9730xxxx).\n");
94 printk(KERN_INFO "Please see http://membres.lycos.fr/poulot/k6bug.html\n");
95 }
96
97 /* K6 with old style WHCR */
98 if (c->x86_model < 8 ||
99 (c->x86_model == 8 && c->x86_mask < 8)) {
100 /* We can only write allocate on the low 508Mb */
101 if (mbytes > 508)
102 mbytes = 508;
103
104 rdmsr(MSR_K6_WHCR, l, h);
105 if ((l&0x0000FFFF) == 0) {
106 unsigned long flags;
107 l = (1<<0)|((mbytes/4)<<1);
108 local_irq_save(flags);
109 wbinvd();
110 wrmsr(MSR_K6_WHCR, l, h);
111 local_irq_restore(flags);
112 printk(KERN_INFO "Enabling old style K6 write allocation for %d Mb\n",
113 mbytes);
114 }
115 return;
116 }
117
118 if ((c->x86_model == 8 && c->x86_mask > 7) ||
119 c->x86_model == 9 || c->x86_model == 13) {
120 /* The more serious chips .. */
121
122 if (mbytes > 4092)
123 mbytes = 4092;
124
125 rdmsr(MSR_K6_WHCR, l, h);
126 if ((l&0xFFFF0000) == 0) {
127 unsigned long flags;
128 l = ((mbytes>>2)<<22)|(1<<16);
129 local_irq_save(flags);
130 wbinvd();
131 wrmsr(MSR_K6_WHCR, l, h);
132 local_irq_restore(flags);
133 printk(KERN_INFO "Enabling new style K6 write allocation for %d Mb\n",
134 mbytes);
135 }
136
137 return;
138 }
139
140 if (c->x86_model == 10) {
141 /* AMD Geode LX is model 10 */
142 /* placeholder for any needed mods */
143 return;
144 }
145 }
146
147 static void __cpuinit amd_k7_smp_check(struct cpuinfo_x86 *c)
148 {
149 #ifdef CONFIG_SMP
150 /* calling is from identify_secondary_cpu() ? */
151 if (c->cpu_index == boot_cpu_id)
152 return;
153
154 /*
155 * Certain Athlons might work (for various values of 'work') in SMP
156 * but they are not certified as MP capable.
157 */
158 /* Athlon 660/661 is valid. */
159 if ((c->x86_model == 6) && ((c->x86_mask == 0) ||
160 (c->x86_mask == 1)))
161 goto valid_k7;
162
163 /* Duron 670 is valid */
164 if ((c->x86_model == 7) && (c->x86_mask == 0))
165 goto valid_k7;
166
167 /*
168 * Athlon 662, Duron 671, and Athlon >model 7 have capability
169 * bit. It's worth noting that the A5 stepping (662) of some
170 * Athlon XP's have the MP bit set.
171 * See http://www.heise.de/newsticker/data/jow-18.10.01-000 for
172 * more.
173 */
174 if (((c->x86_model == 6) && (c->x86_mask >= 2)) ||
175 ((c->x86_model == 7) && (c->x86_mask >= 1)) ||
176 (c->x86_model > 7))
177 if (cpu_has_mp)
178 goto valid_k7;
179
180 /* If we get here, not a certified SMP capable AMD system. */
181
182 /*
183 * Don't taint if we are running SMP kernel on a single non-MP
184 * approved Athlon
185 */
186 WARN_ONCE(1, "WARNING: This combination of AMD"
187 " processors is not suitable for SMP.\n");
188 if (!test_taint(TAINT_UNSAFE_SMP))
189 add_taint(TAINT_UNSAFE_SMP);
190
191 valid_k7:
192 ;
193 #endif
194 }
195
196 static void __cpuinit init_amd_k7(struct cpuinfo_x86 *c)
197 {
198 u32 l, h;
199
200 /*
201 * Bit 15 of Athlon specific MSR 15, needs to be 0
202 * to enable SSE on Palomino/Morgan/Barton CPU's.
203 * If the BIOS didn't enable it already, enable it here.
204 */
205 if (c->x86_model >= 6 && c->x86_model <= 10) {
206 if (!cpu_has(c, X86_FEATURE_XMM)) {
207 printk(KERN_INFO "Enabling disabled K7/SSE Support.\n");
208 rdmsr(MSR_K7_HWCR, l, h);
209 l &= ~0x00008000;
210 wrmsr(MSR_K7_HWCR, l, h);
211 set_cpu_cap(c, X86_FEATURE_XMM);
212 }
213 }
214
215 /*
216 * It's been determined by AMD that Athlons since model 8 stepping 1
217 * are more robust with CLK_CTL set to 200xxxxx instead of 600xxxxx
218 * As per AMD technical note 27212 0.2
219 */
220 if ((c->x86_model == 8 && c->x86_mask >= 1) || (c->x86_model > 8)) {
221 rdmsr(MSR_K7_CLK_CTL, l, h);
222 if ((l & 0xfff00000) != 0x20000000) {
223 printk(KERN_INFO
224 "CPU: CLK_CTL MSR was %x. Reprogramming to %x\n",
225 l, ((l & 0x000fffff)|0x20000000));
226 wrmsr(MSR_K7_CLK_CTL, (l & 0x000fffff)|0x20000000, h);
227 }
228 }
229
230 set_cpu_cap(c, X86_FEATURE_K7);
231
232 amd_k7_smp_check(c);
233 }
234 #endif
235
236 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
237 static int __cpuinit nearby_node(int apicid)
238 {
239 int i, node;
240
241 for (i = apicid - 1; i >= 0; i--) {
242 node = apicid_to_node[i];
243 if (node != NUMA_NO_NODE && node_online(node))
244 return node;
245 }
246 for (i = apicid + 1; i < MAX_LOCAL_APIC; i++) {
247 node = apicid_to_node[i];
248 if (node != NUMA_NO_NODE && node_online(node))
249 return node;
250 }
251 return first_node(node_online_map); /* Shouldn't happen */
252 }
253 #endif
254
255 /*
256 * Fixup core topology information for
257 * (1) AMD multi-node processors
258 * Assumption: Number of cores in each internal node is the same.
259 */
260 #ifdef CONFIG_X86_HT
261 static void __cpuinit amd_get_topology(struct cpuinfo_x86 *c)
262 {
263 u32 nodes, cores_per_node;
264 u8 node_id;
265 unsigned long long value;
266 int cpu = smp_processor_id();
267
268 /* get information required for multi-node processors */
269 if (cpu_has(c, X86_FEATURE_TOPOEXT)) {
270 value = cpuid_ecx(0x8000001e);
271 nodes = ((value >> 8) & 7) + 1;
272 node_id = value & 7;
273 } else if (cpu_has(c, X86_FEATURE_NODEID_MSR)) {
274 rdmsrl(MSR_FAM10H_NODE_ID, value);
275 nodes = ((value >> 3) & 7) + 1;
276 node_id = value & 7;
277 } else
278 return;
279
280 /* fixup multi-node processor information */
281 if (nodes > 1) {
282 set_cpu_cap(c, X86_FEATURE_AMD_DCM);
283 cores_per_node = c->x86_max_cores / nodes;
284
285 /* store NodeID, use llc_shared_map to store sibling info */
286 per_cpu(cpu_llc_id, cpu) = node_id;
287
288 /* core id to be in range from 0 to (cores_per_node - 1) */
289 c->cpu_core_id = c->cpu_core_id % cores_per_node;
290 }
291 }
292 #endif
293
294 /*
295 * On a AMD dual core setup the lower bits of the APIC id distingush the cores.
296 * Assumes number of cores is a power of two.
297 */
298 static void __cpuinit amd_detect_cmp(struct cpuinfo_x86 *c)
299 {
300 #ifdef CONFIG_X86_HT
301 unsigned bits;
302 int cpu = smp_processor_id();
303
304 bits = c->x86_coreid_bits;
305 /* Low order bits define the core id (index of core in socket) */
306 c->cpu_core_id = c->initial_apicid & ((1 << bits)-1);
307 /* Convert the initial APIC ID into the socket ID */
308 c->phys_proc_id = c->initial_apicid >> bits;
309 /* use socket ID also for last level cache */
310 per_cpu(cpu_llc_id, cpu) = c->phys_proc_id;
311 amd_get_topology(c);
312 #endif
313 }
314
315 int amd_get_nb_id(int cpu)
316 {
317 int id = 0;
318 #ifdef CONFIG_SMP
319 id = per_cpu(cpu_llc_id, cpu);
320 #endif
321 return id;
322 }
323 EXPORT_SYMBOL_GPL(amd_get_nb_id);
324
325 static void __cpuinit srat_detect_node(struct cpuinfo_x86 *c)
326 {
327 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
328 int cpu = smp_processor_id();
329 int node;
330 unsigned apicid = c->apicid;
331
332 node = per_cpu(cpu_llc_id, cpu);
333
334 if (apicid_to_node[apicid] != NUMA_NO_NODE)
335 node = apicid_to_node[apicid];
336 if (!node_online(node)) {
337 /* Two possibilities here:
338 - The CPU is missing memory and no node was created.
339 In that case try picking one from a nearby CPU
340 - The APIC IDs differ from the HyperTransport node IDs
341 which the K8 northbridge parsing fills in.
342 Assume they are all increased by a constant offset,
343 but in the same order as the HT nodeids.
344 If that doesn't result in a usable node fall back to the
345 path for the previous case. */
346
347 int ht_nodeid = c->initial_apicid;
348
349 if (ht_nodeid >= 0 &&
350 apicid_to_node[ht_nodeid] != NUMA_NO_NODE)
351 node = apicid_to_node[ht_nodeid];
352 /* Pick a nearby node */
353 if (!node_online(node))
354 node = nearby_node(apicid);
355 }
356 numa_set_node(cpu, node);
357 #endif
358 }
359
360 static void __cpuinit early_init_amd_mc(struct cpuinfo_x86 *c)
361 {
362 #ifdef CONFIG_X86_HT
363 unsigned bits, ecx;
364
365 /* Multi core CPU? */
366 if (c->extended_cpuid_level < 0x80000008)
367 return;
368
369 ecx = cpuid_ecx(0x80000008);
370
371 c->x86_max_cores = (ecx & 0xff) + 1;
372
373 /* CPU telling us the core id bits shift? */
374 bits = (ecx >> 12) & 0xF;
375
376 /* Otherwise recompute */
377 if (bits == 0) {
378 while ((1 << bits) < c->x86_max_cores)
379 bits++;
380 }
381
382 c->x86_coreid_bits = bits;
383 #endif
384 }
385
386 static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
387 {
388 early_init_amd_mc(c);
389
390 /*
391 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
392 * with P/T states and does not stop in deep C-states
393 */
394 if (c->x86_power & (1 << 8)) {
395 set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
396 set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
397 }
398
399 #ifdef CONFIG_X86_64
400 set_cpu_cap(c, X86_FEATURE_SYSCALL32);
401 #else
402 /* Set MTRR capability flag if appropriate */
403 if (c->x86 == 5)
404 if (c->x86_model == 13 || c->x86_model == 9 ||
405 (c->x86_model == 8 && c->x86_mask >= 8))
406 set_cpu_cap(c, X86_FEATURE_K6_MTRR);
407 #endif
408 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_PCI)
409 /* check CPU config space for extended APIC ID */
410 if (cpu_has_apic && c->x86 >= 0xf) {
411 unsigned int val;
412 val = read_pci_config(0, 24, 0, 0x68);
413 if ((val & ((1 << 17) | (1 << 18))) == ((1 << 17) | (1 << 18)))
414 set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
415 }
416 #endif
417
418 /* We need to do the following only once */
419 if (c != &boot_cpu_data)
420 return;
421
422 if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {
423
424 if (c->x86 > 0x10 ||
425 (c->x86 == 0x10 && c->x86_model >= 0x2)) {
426 u64 val;
427
428 rdmsrl(MSR_K7_HWCR, val);
429 if (!(val & BIT(24)))
430 printk(KERN_WARNING FW_BUG "TSC doesn't count "
431 "with P0 frequency!\n");
432 }
433 }
434 }
435
436 static void __cpuinit init_amd(struct cpuinfo_x86 *c)
437 {
438 #ifdef CONFIG_SMP
439 unsigned long long value;
440
441 /*
442 * Disable TLB flush filter by setting HWCR.FFDIS on K8
443 * bit 6 of msr C001_0015
444 *
445 * Errata 63 for SH-B3 steppings
446 * Errata 122 for all steppings (F+ have it disabled by default)
447 */
448 if (c->x86 == 0xf) {
449 rdmsrl(MSR_K7_HWCR, value);
450 value |= 1 << 6;
451 wrmsrl(MSR_K7_HWCR, value);
452 }
453 #endif
454
455 early_init_amd(c);
456
457 /*
458 * Bit 31 in normal CPUID used for nonstandard 3DNow ID;
459 * 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway
460 */
461 clear_cpu_cap(c, 0*32+31);
462
463 #ifdef CONFIG_X86_64
464 /* On C+ stepping K8 rep microcode works well for copy/memset */
465 if (c->x86 == 0xf) {
466 u32 level;
467
468 level = cpuid_eax(1);
469 if ((level >= 0x0f48 && level < 0x0f50) || level >= 0x0f58)
470 set_cpu_cap(c, X86_FEATURE_REP_GOOD);
471
472 /*
473 * Some BIOSes incorrectly force this feature, but only K8
474 * revision D (model = 0x14) and later actually support it.
475 * (AMD Erratum #110, docId: 25759).
476 */
477 if (c->x86_model < 0x14 && cpu_has(c, X86_FEATURE_LAHF_LM)) {
478 u64 val;
479
480 clear_cpu_cap(c, X86_FEATURE_LAHF_LM);
481 if (!rdmsrl_amd_safe(0xc001100d, &val)) {
482 val &= ~(1ULL << 32);
483 wrmsrl_amd_safe(0xc001100d, val);
484 }
485 }
486
487 }
488 if (c->x86 >= 0x10)
489 set_cpu_cap(c, X86_FEATURE_REP_GOOD);
490
491 /* get apicid instead of initial apic id from cpuid */
492 c->apicid = hard_smp_processor_id();
493 #else
494
495 /*
496 * FIXME: We should handle the K5 here. Set up the write
497 * range and also turn on MSR 83 bits 4 and 31 (write alloc,
498 * no bus pipeline)
499 */
500
501 switch (c->x86) {
502 case 4:
503 init_amd_k5(c);
504 break;
505 case 5:
506 init_amd_k6(c);
507 break;
508 case 6: /* An Athlon/Duron */
509 init_amd_k7(c);
510 break;
511 }
512
513 /* K6s reports MCEs but don't actually have all the MSRs */
514 if (c->x86 < 6)
515 clear_cpu_cap(c, X86_FEATURE_MCE);
516 #endif
517
518 /* Enable workaround for FXSAVE leak */
519 if (c->x86 >= 6)
520 set_cpu_cap(c, X86_FEATURE_FXSAVE_LEAK);
521
522 if (!c->x86_model_id[0]) {
523 switch (c->x86) {
524 case 0xf:
525 /* Should distinguish Models here, but this is only
526 a fallback anyways. */
527 strcpy(c->x86_model_id, "Hammer");
528 break;
529 }
530 }
531
532 cpu_detect_cache_sizes(c);
533
534 /* Multi core CPU? */
535 if (c->extended_cpuid_level >= 0x80000008) {
536 amd_detect_cmp(c);
537 srat_detect_node(c);
538 }
539
540 #ifdef CONFIG_X86_32
541 detect_ht(c);
542 #endif
543
544 if (c->extended_cpuid_level >= 0x80000006) {
545 if (cpuid_edx(0x80000006) & 0xf000)
546 num_cache_leaves = 4;
547 else
548 num_cache_leaves = 3;
549 }
550
551 if (c->x86 >= 0xf)
552 set_cpu_cap(c, X86_FEATURE_K8);
553
554 if (cpu_has_xmm2) {
555 /* MFENCE stops RDTSC speculation */
556 set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC);
557 }
558
559 #ifdef CONFIG_X86_64
560 if (c->x86 == 0x10) {
561 /* do this for boot cpu */
562 if (c == &boot_cpu_data)
563 check_enable_amd_mmconf_dmi();
564
565 fam10h_check_enable_mmcfg();
566 }
567
568 if (c == &boot_cpu_data && c->x86 >= 0xf) {
569 unsigned long long tseg;
570
571 /*
572 * Split up direct mapping around the TSEG SMM area.
573 * Don't do it for gbpages because there seems very little
574 * benefit in doing so.
575 */
576 if (!rdmsrl_safe(MSR_K8_TSEG_ADDR, &tseg)) {
577 printk(KERN_DEBUG "tseg: %010llx\n", tseg);
578 if ((tseg>>PMD_SHIFT) <
579 (max_low_pfn_mapped>>(PMD_SHIFT-PAGE_SHIFT)) ||
580 ((tseg>>PMD_SHIFT) <
581 (max_pfn_mapped>>(PMD_SHIFT-PAGE_SHIFT)) &&
582 (tseg>>PMD_SHIFT) >= (1ULL<<(32 - PMD_SHIFT))))
583 set_memory_4k((unsigned long)__va(tseg), 1);
584 }
585 }
586 #endif
587 }
588
589 #ifdef CONFIG_X86_32
590 static unsigned int __cpuinit amd_size_cache(struct cpuinfo_x86 *c,
591 unsigned int size)
592 {
593 /* AMD errata T13 (order #21922) */
594 if ((c->x86 == 6)) {
595 /* Duron Rev A0 */
596 if (c->x86_model == 3 && c->x86_mask == 0)
597 size = 64;
598 /* Tbird rev A1/A2 */
599 if (c->x86_model == 4 &&
600 (c->x86_mask == 0 || c->x86_mask == 1))
601 size = 256;
602 }
603 return size;
604 }
605 #endif
606
607 static const struct cpu_dev __cpuinitconst amd_cpu_dev = {
608 .c_vendor = "AMD",
609 .c_ident = { "AuthenticAMD" },
610 #ifdef CONFIG_X86_32
611 .c_models = {
612 { .vendor = X86_VENDOR_AMD, .family = 4, .model_names =
613 {
614 [3] = "486 DX/2",
615 [7] = "486 DX/2-WB",
616 [8] = "486 DX/4",
617 [9] = "486 DX/4-WB",
618 [14] = "Am5x86-WT",
619 [15] = "Am5x86-WB"
620 }
621 },
622 },
623 .c_size_cache = amd_size_cache,
624 #endif
625 .c_early_init = early_init_amd,
626 .c_init = init_amd,
627 .c_x86_vendor = X86_VENDOR_AMD,
628 };
629
630 cpu_dev_register(amd_cpu_dev);
631
632 /*
633 * AMD errata checking
634 *
635 * Errata are defined as arrays of ints using the AMD_LEGACY_ERRATUM() or
636 * AMD_OSVW_ERRATUM() macros. The latter is intended for newer errata that
637 * have an OSVW id assigned, which it takes as first argument. Both take a
638 * variable number of family-specific model-stepping ranges created by
639 * AMD_MODEL_RANGE(). Each erratum also has to be declared as extern const
640 * int[] in arch/x86/include/asm/processor.h.
641 *
642 * Example:
643 *
644 * const int amd_erratum_319[] =
645 * AMD_LEGACY_ERRATUM(AMD_MODEL_RANGE(0x10, 0x2, 0x1, 0x4, 0x2),
646 * AMD_MODEL_RANGE(0x10, 0x8, 0x0, 0x8, 0x0),
647 * AMD_MODEL_RANGE(0x10, 0x9, 0x0, 0x9, 0x0));
648 */
649
650 const int amd_erratum_400[] =
651 AMD_OSVW_ERRATUM(1, AMD_MODEL_RANGE(0xf, 0x41, 0x2, 0xff, 0xf),
652 AMD_MODEL_RANGE(0x10, 0x2, 0x1, 0xff, 0xf));
653 EXPORT_SYMBOL_GPL(amd_erratum_400);
654
655 const int amd_erratum_383[] =
656 AMD_OSVW_ERRATUM(3, AMD_MODEL_RANGE(0x10, 0, 0, 0xff, 0xf));
657 EXPORT_SYMBOL_GPL(amd_erratum_383);
658
659 bool cpu_has_amd_erratum(const int *erratum)
660 {
661 struct cpuinfo_x86 *cpu = &current_cpu_data;
662 int osvw_id = *erratum++;
663 u32 range;
664 u32 ms;
665
666 /*
667 * If called early enough that current_cpu_data hasn't been initialized
668 * yet, fall back to boot_cpu_data.
669 */
670 if (cpu->x86 == 0)
671 cpu = &boot_cpu_data;
672
673 if (cpu->x86_vendor != X86_VENDOR_AMD)
674 return false;
675
676 if (osvw_id >= 0 && osvw_id < 65536 &&
677 cpu_has(cpu, X86_FEATURE_OSVW)) {
678 u64 osvw_len;
679
680 rdmsrl(MSR_AMD64_OSVW_ID_LENGTH, osvw_len);
681 if (osvw_id < osvw_len) {
682 u64 osvw_bits;
683
684 rdmsrl(MSR_AMD64_OSVW_STATUS + (osvw_id >> 6),
685 osvw_bits);
686 return osvw_bits & (1ULL << (osvw_id & 0x3f));
687 }
688 }
689
690 /* OSVW unavailable or ID unknown, match family-model-stepping range */
691 ms = (cpu->x86_model << 4) | cpu->x86_mask;
692 while ((range = *erratum++))
693 if ((cpu->x86 == AMD_MODEL_RANGE_FAMILY(range)) &&
694 (ms >= AMD_MODEL_RANGE_START(range)) &&
695 (ms <= AMD_MODEL_RANGE_END(range)))
696 return true;
697
698 return false;
699 }
700
701 EXPORT_SYMBOL_GPL(cpu_has_amd_erratum);