]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - arch/x86/kernel/cpu/amd.c
x86, amd: Normalize compute unit IDs on multi-node processors
[mirror_ubuntu-artful-kernel.git] / arch / x86 / kernel / cpu / amd.c
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)
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 * (2) AMD processors supporting compute units
260 */
261 #ifdef CONFIG_X86_HT
262 static void __cpuinit amd_get_topology(struct cpuinfo_x86 *c)
263 {
264 u32 nodes, cores_per_cu;
265 u8 node_id;
266 int cpu = smp_processor_id();
267
268 /* get information required for multi-node processors */
269 if (cpu_has(c, X86_FEATURE_TOPOEXT)) {
270 u32 eax, ebx, ecx, edx;
271
272 cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
273 nodes = ((ecx >> 8) & 7) + 1;
274 node_id = ecx & 7;
275
276 /* get compute unit information */
277 smp_num_siblings = ((ebx >> 8) & 3) + 1;
278 c->compute_unit_id = ebx & 0xff;
279 cores_per_cu = ((ebx >> 8) & 3) + 1;
280 } else if (cpu_has(c, X86_FEATURE_NODEID_MSR)) {
281 u64 value;
282
283 rdmsrl(MSR_FAM10H_NODE_ID, value);
284 nodes = ((value >> 3) & 7) + 1;
285 node_id = value & 7;
286 } else
287 return;
288
289 /* fixup multi-node processor information */
290 if (nodes > 1) {
291 u32 cores_per_node;
292 u32 cus_per_node;
293
294 set_cpu_cap(c, X86_FEATURE_AMD_DCM);
295 cores_per_node = c->x86_max_cores / nodes;
296 cus_per_node = cores_per_node / cores_per_cu;
297
298 /* store NodeID, use llc_shared_map to store sibling info */
299 per_cpu(cpu_llc_id, cpu) = node_id;
300
301 /* core id to be in range from 0 to (cores_per_node - 1) */
302 c->cpu_core_id %= cores_per_node;
303 c->compute_unit_id %= cus_per_node;
304 }
305 }
306 #endif
307
308 /*
309 * On a AMD dual core setup the lower bits of the APIC id distingush the cores.
310 * Assumes number of cores is a power of two.
311 */
312 static void __cpuinit amd_detect_cmp(struct cpuinfo_x86 *c)
313 {
314 #ifdef CONFIG_X86_HT
315 unsigned bits;
316 int cpu = smp_processor_id();
317
318 bits = c->x86_coreid_bits;
319 /* Low order bits define the core id (index of core in socket) */
320 c->cpu_core_id = c->initial_apicid & ((1 << bits)-1);
321 /* Convert the initial APIC ID into the socket ID */
322 c->phys_proc_id = c->initial_apicid >> bits;
323 /* use socket ID also for last level cache */
324 per_cpu(cpu_llc_id, cpu) = c->phys_proc_id;
325 amd_get_topology(c);
326 #endif
327 }
328
329 int amd_get_nb_id(int cpu)
330 {
331 int id = 0;
332 #ifdef CONFIG_SMP
333 id = per_cpu(cpu_llc_id, cpu);
334 #endif
335 return id;
336 }
337 EXPORT_SYMBOL_GPL(amd_get_nb_id);
338
339 static void __cpuinit srat_detect_node(struct cpuinfo_x86 *c)
340 {
341 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
342 int cpu = smp_processor_id();
343 int node;
344 unsigned apicid = c->apicid;
345
346 node = per_cpu(cpu_llc_id, cpu);
347
348 if (apicid_to_node[apicid] != NUMA_NO_NODE)
349 node = apicid_to_node[apicid];
350 if (!node_online(node)) {
351 /* Two possibilities here:
352 - The CPU is missing memory and no node was created.
353 In that case try picking one from a nearby CPU
354 - The APIC IDs differ from the HyperTransport node IDs
355 which the K8 northbridge parsing fills in.
356 Assume they are all increased by a constant offset,
357 but in the same order as the HT nodeids.
358 If that doesn't result in a usable node fall back to the
359 path for the previous case. */
360
361 int ht_nodeid = c->initial_apicid;
362
363 if (ht_nodeid >= 0 &&
364 apicid_to_node[ht_nodeid] != NUMA_NO_NODE)
365 node = apicid_to_node[ht_nodeid];
366 /* Pick a nearby node */
367 if (!node_online(node))
368 node = nearby_node(apicid);
369 }
370 numa_set_node(cpu, node);
371 #endif
372 }
373
374 static void __cpuinit early_init_amd_mc(struct cpuinfo_x86 *c)
375 {
376 #ifdef CONFIG_X86_HT
377 unsigned bits, ecx;
378
379 /* Multi core CPU? */
380 if (c->extended_cpuid_level < 0x80000008)
381 return;
382
383 ecx = cpuid_ecx(0x80000008);
384
385 c->x86_max_cores = (ecx & 0xff) + 1;
386
387 /* CPU telling us the core id bits shift? */
388 bits = (ecx >> 12) & 0xF;
389
390 /* Otherwise recompute */
391 if (bits == 0) {
392 while ((1 << bits) < c->x86_max_cores)
393 bits++;
394 }
395
396 c->x86_coreid_bits = bits;
397 #endif
398 }
399
400 static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
401 {
402 early_init_amd_mc(c);
403
404 /*
405 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
406 * with P/T states and does not stop in deep C-states
407 */
408 if (c->x86_power & (1 << 8)) {
409 set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
410 set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
411 }
412
413 #ifdef CONFIG_X86_64
414 set_cpu_cap(c, X86_FEATURE_SYSCALL32);
415 #else
416 /* Set MTRR capability flag if appropriate */
417 if (c->x86 == 5)
418 if (c->x86_model == 13 || c->x86_model == 9 ||
419 (c->x86_model == 8 && c->x86_mask >= 8))
420 set_cpu_cap(c, X86_FEATURE_K6_MTRR);
421 #endif
422 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_PCI)
423 /* check CPU config space for extended APIC ID */
424 if (cpu_has_apic && c->x86 >= 0xf) {
425 unsigned int val;
426 val = read_pci_config(0, 24, 0, 0x68);
427 if ((val & ((1 << 17) | (1 << 18))) == ((1 << 17) | (1 << 18)))
428 set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
429 }
430 #endif
431
432 /* We need to do the following only once */
433 if (c != &boot_cpu_data)
434 return;
435
436 if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {
437
438 if (c->x86 > 0x10 ||
439 (c->x86 == 0x10 && c->x86_model >= 0x2)) {
440 u64 val;
441
442 rdmsrl(MSR_K7_HWCR, val);
443 if (!(val & BIT(24)))
444 printk(KERN_WARNING FW_BUG "TSC doesn't count "
445 "with P0 frequency!\n");
446 }
447 }
448 }
449
450 static void __cpuinit init_amd(struct cpuinfo_x86 *c)
451 {
452 #ifdef CONFIG_SMP
453 unsigned long long value;
454
455 /*
456 * Disable TLB flush filter by setting HWCR.FFDIS on K8
457 * bit 6 of msr C001_0015
458 *
459 * Errata 63 for SH-B3 steppings
460 * Errata 122 for all steppings (F+ have it disabled by default)
461 */
462 if (c->x86 == 0xf) {
463 rdmsrl(MSR_K7_HWCR, value);
464 value |= 1 << 6;
465 wrmsrl(MSR_K7_HWCR, value);
466 }
467 #endif
468
469 early_init_amd(c);
470
471 /*
472 * Bit 31 in normal CPUID used for nonstandard 3DNow ID;
473 * 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway
474 */
475 clear_cpu_cap(c, 0*32+31);
476
477 #ifdef CONFIG_X86_64
478 /* On C+ stepping K8 rep microcode works well for copy/memset */
479 if (c->x86 == 0xf) {
480 u32 level;
481
482 level = cpuid_eax(1);
483 if ((level >= 0x0f48 && level < 0x0f50) || level >= 0x0f58)
484 set_cpu_cap(c, X86_FEATURE_REP_GOOD);
485
486 /*
487 * Some BIOSes incorrectly force this feature, but only K8
488 * revision D (model = 0x14) and later actually support it.
489 * (AMD Erratum #110, docId: 25759).
490 */
491 if (c->x86_model < 0x14 && cpu_has(c, X86_FEATURE_LAHF_LM)) {
492 u64 val;
493
494 clear_cpu_cap(c, X86_FEATURE_LAHF_LM);
495 if (!rdmsrl_amd_safe(0xc001100d, &val)) {
496 val &= ~(1ULL << 32);
497 wrmsrl_amd_safe(0xc001100d, val);
498 }
499 }
500
501 }
502 if (c->x86 >= 0x10)
503 set_cpu_cap(c, X86_FEATURE_REP_GOOD);
504
505 /* get apicid instead of initial apic id from cpuid */
506 c->apicid = hard_smp_processor_id();
507 #else
508
509 /*
510 * FIXME: We should handle the K5 here. Set up the write
511 * range and also turn on MSR 83 bits 4 and 31 (write alloc,
512 * no bus pipeline)
513 */
514
515 switch (c->x86) {
516 case 4:
517 init_amd_k5(c);
518 break;
519 case 5:
520 init_amd_k6(c);
521 break;
522 case 6: /* An Athlon/Duron */
523 init_amd_k7(c);
524 break;
525 }
526
527 /* K6s reports MCEs but don't actually have all the MSRs */
528 if (c->x86 < 6)
529 clear_cpu_cap(c, X86_FEATURE_MCE);
530 #endif
531
532 /* Enable workaround for FXSAVE leak */
533 if (c->x86 >= 6)
534 set_cpu_cap(c, X86_FEATURE_FXSAVE_LEAK);
535
536 if (!c->x86_model_id[0]) {
537 switch (c->x86) {
538 case 0xf:
539 /* Should distinguish Models here, but this is only
540 a fallback anyways. */
541 strcpy(c->x86_model_id, "Hammer");
542 break;
543 }
544 }
545
546 cpu_detect_cache_sizes(c);
547
548 /* Multi core CPU? */
549 if (c->extended_cpuid_level >= 0x80000008) {
550 amd_detect_cmp(c);
551 srat_detect_node(c);
552 }
553
554 #ifdef CONFIG_X86_32
555 detect_ht(c);
556 #endif
557
558 if (c->extended_cpuid_level >= 0x80000006) {
559 if (cpuid_edx(0x80000006) & 0xf000)
560 num_cache_leaves = 4;
561 else
562 num_cache_leaves = 3;
563 }
564
565 if (c->x86 >= 0xf)
566 set_cpu_cap(c, X86_FEATURE_K8);
567
568 if (cpu_has_xmm2) {
569 /* MFENCE stops RDTSC speculation */
570 set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC);
571 }
572
573 #ifdef CONFIG_X86_64
574 if (c->x86 == 0x10) {
575 /* do this for boot cpu */
576 if (c == &boot_cpu_data)
577 check_enable_amd_mmconf_dmi();
578
579 fam10h_check_enable_mmcfg();
580 }
581
582 if (c == &boot_cpu_data && c->x86 >= 0xf) {
583 unsigned long long tseg;
584
585 /*
586 * Split up direct mapping around the TSEG SMM area.
587 * Don't do it for gbpages because there seems very little
588 * benefit in doing so.
589 */
590 if (!rdmsrl_safe(MSR_K8_TSEG_ADDR, &tseg)) {
591 printk(KERN_DEBUG "tseg: %010llx\n", tseg);
592 if ((tseg>>PMD_SHIFT) <
593 (max_low_pfn_mapped>>(PMD_SHIFT-PAGE_SHIFT)) ||
594 ((tseg>>PMD_SHIFT) <
595 (max_pfn_mapped>>(PMD_SHIFT-PAGE_SHIFT)) &&
596 (tseg>>PMD_SHIFT) >= (1ULL<<(32 - PMD_SHIFT))))
597 set_memory_4k((unsigned long)__va(tseg), 1);
598 }
599 }
600 #endif
601 }
602
603 #ifdef CONFIG_X86_32
604 static unsigned int __cpuinit amd_size_cache(struct cpuinfo_x86 *c,
605 unsigned int size)
606 {
607 /* AMD errata T13 (order #21922) */
608 if ((c->x86 == 6)) {
609 /* Duron Rev A0 */
610 if (c->x86_model == 3 && c->x86_mask == 0)
611 size = 64;
612 /* Tbird rev A1/A2 */
613 if (c->x86_model == 4 &&
614 (c->x86_mask == 0 || c->x86_mask == 1))
615 size = 256;
616 }
617 return size;
618 }
619 #endif
620
621 static const struct cpu_dev __cpuinitconst amd_cpu_dev = {
622 .c_vendor = "AMD",
623 .c_ident = { "AuthenticAMD" },
624 #ifdef CONFIG_X86_32
625 .c_models = {
626 { .vendor = X86_VENDOR_AMD, .family = 4, .model_names =
627 {
628 [3] = "486 DX/2",
629 [7] = "486 DX/2-WB",
630 [8] = "486 DX/4",
631 [9] = "486 DX/4-WB",
632 [14] = "Am5x86-WT",
633 [15] = "Am5x86-WB"
634 }
635 },
636 },
637 .c_size_cache = amd_size_cache,
638 #endif
639 .c_early_init = early_init_amd,
640 .c_init = init_amd,
641 .c_x86_vendor = X86_VENDOR_AMD,
642 };
643
644 cpu_dev_register(amd_cpu_dev);
645
646 /*
647 * AMD errata checking
648 *
649 * Errata are defined as arrays of ints using the AMD_LEGACY_ERRATUM() or
650 * AMD_OSVW_ERRATUM() macros. The latter is intended for newer errata that
651 * have an OSVW id assigned, which it takes as first argument. Both take a
652 * variable number of family-specific model-stepping ranges created by
653 * AMD_MODEL_RANGE(). Each erratum also has to be declared as extern const
654 * int[] in arch/x86/include/asm/processor.h.
655 *
656 * Example:
657 *
658 * const int amd_erratum_319[] =
659 * AMD_LEGACY_ERRATUM(AMD_MODEL_RANGE(0x10, 0x2, 0x1, 0x4, 0x2),
660 * AMD_MODEL_RANGE(0x10, 0x8, 0x0, 0x8, 0x0),
661 * AMD_MODEL_RANGE(0x10, 0x9, 0x0, 0x9, 0x0));
662 */
663
664 const int amd_erratum_400[] =
665 AMD_OSVW_ERRATUM(1, AMD_MODEL_RANGE(0xf, 0x41, 0x2, 0xff, 0xf),
666 AMD_MODEL_RANGE(0x10, 0x2, 0x1, 0xff, 0xf));
667 EXPORT_SYMBOL_GPL(amd_erratum_400);
668
669 const int amd_erratum_383[] =
670 AMD_OSVW_ERRATUM(3, AMD_MODEL_RANGE(0x10, 0, 0, 0xff, 0xf));
671 EXPORT_SYMBOL_GPL(amd_erratum_383);
672
673 bool cpu_has_amd_erratum(const int *erratum)
674 {
675 struct cpuinfo_x86 *cpu = __this_cpu_ptr(&cpu_info);
676 int osvw_id = *erratum++;
677 u32 range;
678 u32 ms;
679
680 /*
681 * If called early enough that current_cpu_data hasn't been initialized
682 * yet, fall back to boot_cpu_data.
683 */
684 if (cpu->x86 == 0)
685 cpu = &boot_cpu_data;
686
687 if (cpu->x86_vendor != X86_VENDOR_AMD)
688 return false;
689
690 if (osvw_id >= 0 && osvw_id < 65536 &&
691 cpu_has(cpu, X86_FEATURE_OSVW)) {
692 u64 osvw_len;
693
694 rdmsrl(MSR_AMD64_OSVW_ID_LENGTH, osvw_len);
695 if (osvw_id < osvw_len) {
696 u64 osvw_bits;
697
698 rdmsrl(MSR_AMD64_OSVW_STATUS + (osvw_id >> 6),
699 osvw_bits);
700 return osvw_bits & (1ULL << (osvw_id & 0x3f));
701 }
702 }
703
704 /* OSVW unavailable or ID unknown, match family-model-stepping range */
705 ms = (cpu->x86_model << 4) | cpu->x86_mask;
706 while ((range = *erratum++))
707 if ((cpu->x86 == AMD_MODEL_RANGE_FAMILY(range)) &&
708 (ms >= AMD_MODEL_RANGE_START(range)) &&
709 (ms <= AMD_MODEL_RANGE_END(range)))
710 return true;
711
712 return false;
713 }
714
715 EXPORT_SYMBOL_GPL(cpu_has_amd_erratum);