xref: /linux/arch/x86/kernel/cpu/amd.c (revision 1eb63378354ac37b7e27d256bbf84684751bac32)
1 #include <linux/init.h>
2 #include <linux/bitops.h>
3 #include <linux/elf.h>
4 #include <linux/mm.h>
5 
6 #include <linux/io.h>
7 #include <asm/processor.h>
8 #include <asm/apic.h>
9 #include <asm/cpu.h>
10 #include <asm/pci-direct.h>
11 
12 #ifdef CONFIG_X86_64
13 # include <asm/numa_64.h>
14 # include <asm/mmconfig.h>
15 # include <asm/cacheflush.h>
16 #endif
17 
18 #include "cpu.h"
19 
20 #ifdef CONFIG_X86_32
21 /*
22  *	B step AMD K6 before B 9730xxxx have hardware bugs that can cause
23  *	misexecution of code under Linux. Owners of such processors should
24  *	contact AMD for precise details and a CPU swap.
25  *
26  *	See	http://www.multimania.com/poulot/k6bug.html
27  *		http://www.amd.com/K6/k6docs/revgd.html
28  *
29  *	The following test is erm.. interesting. AMD neglected to up
30  *	the chip setting when fixing the bug but they also tweaked some
31  *	performance at the same time..
32  */
33 
34 extern void vide(void);
35 __asm__(".align 4\nvide: ret");
36 
37 static void __cpuinit init_amd_k5(struct cpuinfo_x86 *c)
38 {
39 /*
40  * General Systems BIOSen alias the cpu frequency registers
41  * of the Elan at 0x000df000. Unfortuantly, one of the Linux
42  * drivers subsequently pokes it, and changes the CPU speed.
43  * Workaround : Remove the unneeded alias.
44  */
45 #define CBAR		(0xfffc) /* Configuration Base Address  (32-bit) */
46 #define CBAR_ENB	(0x80000000)
47 #define CBAR_KEY	(0X000000CB)
48 	if (c->x86_model == 9 || c->x86_model == 10) {
49 		if (inl(CBAR) & CBAR_ENB)
50 			outl(0 | CBAR_KEY, CBAR);
51 	}
52 }
53 
54 
55 static void __cpuinit init_amd_k6(struct cpuinfo_x86 *c)
56 {
57 	u32 l, h;
58 	int mbytes = num_physpages >> (20-PAGE_SHIFT);
59 
60 	if (c->x86_model < 6) {
61 		/* Based on AMD doc 20734R - June 2000 */
62 		if (c->x86_model == 0) {
63 			clear_cpu_cap(c, X86_FEATURE_APIC);
64 			set_cpu_cap(c, X86_FEATURE_PGE);
65 		}
66 		return;
67 	}
68 
69 	if (c->x86_model == 6 && c->x86_mask == 1) {
70 		const int K6_BUG_LOOP = 1000000;
71 		int n;
72 		void (*f_vide)(void);
73 		unsigned long d, d2;
74 
75 		printk(KERN_INFO "AMD K6 stepping B detected - ");
76 
77 		/*
78 		 * It looks like AMD fixed the 2.6.2 bug and improved indirect
79 		 * calls at the same time.
80 		 */
81 
82 		n = K6_BUG_LOOP;
83 		f_vide = vide;
84 		rdtscl(d);
85 		while (n--)
86 			f_vide();
87 		rdtscl(d2);
88 		d = d2-d;
89 
90 		if (d > 20*K6_BUG_LOOP)
91 			printk(KERN_CONT
92 				"system stability may be impaired when more than 32 MB are used.\n");
93 		else
94 			printk(KERN_CONT "probably OK (after B9730xxxx).\n");
95 		printk(KERN_INFO "Please see http://membres.lycos.fr/poulot/k6bug.html\n");
96 	}
97 
98 	/* K6 with old style WHCR */
99 	if (c->x86_model < 8 ||
100 	   (c->x86_model == 8 && c->x86_mask < 8)) {
101 		/* We can only write allocate on the low 508Mb */
102 		if (mbytes > 508)
103 			mbytes = 508;
104 
105 		rdmsr(MSR_K6_WHCR, l, h);
106 		if ((l&0x0000FFFF) == 0) {
107 			unsigned long flags;
108 			l = (1<<0)|((mbytes/4)<<1);
109 			local_irq_save(flags);
110 			wbinvd();
111 			wrmsr(MSR_K6_WHCR, l, h);
112 			local_irq_restore(flags);
113 			printk(KERN_INFO "Enabling old style K6 write allocation for %d Mb\n",
114 				mbytes);
115 		}
116 		return;
117 	}
118 
119 	if ((c->x86_model == 8 && c->x86_mask > 7) ||
120 	     c->x86_model == 9 || c->x86_model == 13) {
121 		/* The more serious chips .. */
122 
123 		if (mbytes > 4092)
124 			mbytes = 4092;
125 
126 		rdmsr(MSR_K6_WHCR, l, h);
127 		if ((l&0xFFFF0000) == 0) {
128 			unsigned long flags;
129 			l = ((mbytes>>2)<<22)|(1<<16);
130 			local_irq_save(flags);
131 			wbinvd();
132 			wrmsr(MSR_K6_WHCR, l, h);
133 			local_irq_restore(flags);
134 			printk(KERN_INFO "Enabling new style K6 write allocation for %d Mb\n",
135 				mbytes);
136 		}
137 
138 		return;
139 	}
140 
141 	if (c->x86_model == 10) {
142 		/* AMD Geode LX is model 10 */
143 		/* placeholder for any needed mods */
144 		return;
145 	}
146 }
147 
148 static void __cpuinit amd_k7_smp_check(struct cpuinfo_x86 *c)
149 {
150 #ifdef CONFIG_SMP
151 	/* calling is from identify_secondary_cpu() ? */
152 	if (!c->cpu_index)
153 		return;
154 
155 	/*
156 	 * Certain Athlons might work (for various values of 'work') in SMP
157 	 * but they are not certified as MP capable.
158 	 */
159 	/* Athlon 660/661 is valid. */
160 	if ((c->x86_model == 6) && ((c->x86_mask == 0) ||
161 	    (c->x86_mask == 1)))
162 		goto valid_k7;
163 
164 	/* Duron 670 is valid */
165 	if ((c->x86_model == 7) && (c->x86_mask == 0))
166 		goto valid_k7;
167 
168 	/*
169 	 * Athlon 662, Duron 671, and Athlon >model 7 have capability
170 	 * bit. It's worth noting that the A5 stepping (662) of some
171 	 * Athlon XP's have the MP bit set.
172 	 * See http://www.heise.de/newsticker/data/jow-18.10.01-000 for
173 	 * more.
174 	 */
175 	if (((c->x86_model == 6) && (c->x86_mask >= 2)) ||
176 	    ((c->x86_model == 7) && (c->x86_mask >= 1)) ||
177 	     (c->x86_model > 7))
178 		if (cpu_has_mp)
179 			goto valid_k7;
180 
181 	/* If we get here, not a certified SMP capable AMD system. */
182 
183 	/*
184 	 * Don't taint if we are running SMP kernel on a single non-MP
185 	 * approved Athlon
186 	 */
187 	WARN_ONCE(1, "WARNING: This combination of AMD"
188 		" processors is not suitable for SMP.\n");
189 	if (!test_taint(TAINT_UNSAFE_SMP))
190 		add_taint(TAINT_UNSAFE_SMP);
191 
192 valid_k7:
193 	;
194 #endif
195 }
196 
197 static void __cpuinit init_amd_k7(struct cpuinfo_x86 *c)
198 {
199 	u32 l, h;
200 
201 	/*
202 	 * Bit 15 of Athlon specific MSR 15, needs to be 0
203 	 * to enable SSE on Palomino/Morgan/Barton CPU's.
204 	 * If the BIOS didn't enable it already, enable it here.
205 	 */
206 	if (c->x86_model >= 6 && c->x86_model <= 10) {
207 		if (!cpu_has(c, X86_FEATURE_XMM)) {
208 			printk(KERN_INFO "Enabling disabled K7/SSE Support.\n");
209 			rdmsr(MSR_K7_HWCR, l, h);
210 			l &= ~0x00008000;
211 			wrmsr(MSR_K7_HWCR, l, h);
212 			set_cpu_cap(c, X86_FEATURE_XMM);
213 		}
214 	}
215 
216 	/*
217 	 * It's been determined by AMD that Athlons since model 8 stepping 1
218 	 * are more robust with CLK_CTL set to 200xxxxx instead of 600xxxxx
219 	 * As per AMD technical note 27212 0.2
220 	 */
221 	if ((c->x86_model == 8 && c->x86_mask >= 1) || (c->x86_model > 8)) {
222 		rdmsr(MSR_K7_CLK_CTL, l, h);
223 		if ((l & 0xfff00000) != 0x20000000) {
224 			printk(KERN_INFO
225 			    "CPU: CLK_CTL MSR was %x. Reprogramming to %x\n",
226 					l, ((l & 0x000fffff)|0x20000000));
227 			wrmsr(MSR_K7_CLK_CTL, (l & 0x000fffff)|0x20000000, h);
228 		}
229 	}
230 
231 	set_cpu_cap(c, X86_FEATURE_K7);
232 
233 	amd_k7_smp_check(c);
234 }
235 #endif
236 
237 #ifdef CONFIG_NUMA
238 /*
239  * To workaround broken NUMA config.  Read the comment in
240  * srat_detect_node().
241  */
242 static int __cpuinit nearby_node(int apicid)
243 {
244 	int i, node;
245 
246 	for (i = apicid - 1; i >= 0; i--) {
247 		node = __apicid_to_node[i];
248 		if (node != NUMA_NO_NODE && node_online(node))
249 			return node;
250 	}
251 	for (i = apicid + 1; i < MAX_LOCAL_APIC; i++) {
252 		node = __apicid_to_node[i];
253 		if (node != NUMA_NO_NODE && node_online(node))
254 			return node;
255 	}
256 	return first_node(node_online_map); /* Shouldn't happen */
257 }
258 #endif
259 
260 /*
261  * Fixup core topology information for
262  * (1) AMD multi-node processors
263  *     Assumption: Number of cores in each internal node is the same.
264  * (2) AMD processors supporting compute units
265  */
266 #ifdef CONFIG_X86_HT
267 static void __cpuinit amd_get_topology(struct cpuinfo_x86 *c)
268 {
269 	u32 nodes, cores_per_cu = 1;
270 	u8 node_id;
271 	int cpu = smp_processor_id();
272 
273 	/* get information required for multi-node processors */
274 	if (cpu_has(c, X86_FEATURE_TOPOEXT)) {
275 		u32 eax, ebx, ecx, edx;
276 
277 		cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
278 		nodes = ((ecx >> 8) & 7) + 1;
279 		node_id = ecx & 7;
280 
281 		/* get compute unit information */
282 		smp_num_siblings = ((ebx >> 8) & 3) + 1;
283 		c->compute_unit_id = ebx & 0xff;
284 		cores_per_cu += ((ebx >> 8) & 3);
285 	} else if (cpu_has(c, X86_FEATURE_NODEID_MSR)) {
286 		u64 value;
287 
288 		rdmsrl(MSR_FAM10H_NODE_ID, value);
289 		nodes = ((value >> 3) & 7) + 1;
290 		node_id = value & 7;
291 	} else
292 		return;
293 
294 	/* fixup multi-node processor information */
295 	if (nodes > 1) {
296 		u32 cores_per_node;
297 		u32 cus_per_node;
298 
299 		set_cpu_cap(c, X86_FEATURE_AMD_DCM);
300 		cores_per_node = c->x86_max_cores / nodes;
301 		cus_per_node = cores_per_node / cores_per_cu;
302 
303 		/* store NodeID, use llc_shared_map to store sibling info */
304 		per_cpu(cpu_llc_id, cpu) = node_id;
305 
306 		/* core id has to be in the [0 .. cores_per_node - 1] range */
307 		c->cpu_core_id %= cores_per_node;
308 		c->compute_unit_id %= cus_per_node;
309 	}
310 }
311 #endif
312 
313 /*
314  * On a AMD dual core setup the lower bits of the APIC id distingush the cores.
315  * Assumes number of cores is a power of two.
316  */
317 static void __cpuinit amd_detect_cmp(struct cpuinfo_x86 *c)
318 {
319 #ifdef CONFIG_X86_HT
320 	unsigned bits;
321 	int cpu = smp_processor_id();
322 
323 	bits = c->x86_coreid_bits;
324 	/* Low order bits define the core id (index of core in socket) */
325 	c->cpu_core_id = c->initial_apicid & ((1 << bits)-1);
326 	/* Convert the initial APIC ID into the socket ID */
327 	c->phys_proc_id = c->initial_apicid >> bits;
328 	/* use socket ID also for last level cache */
329 	per_cpu(cpu_llc_id, cpu) = c->phys_proc_id;
330 	amd_get_topology(c);
331 #endif
332 }
333 
334 int amd_get_nb_id(int cpu)
335 {
336 	int id = 0;
337 #ifdef CONFIG_SMP
338 	id = per_cpu(cpu_llc_id, cpu);
339 #endif
340 	return id;
341 }
342 EXPORT_SYMBOL_GPL(amd_get_nb_id);
343 
344 static void __cpuinit srat_detect_node(struct cpuinfo_x86 *c)
345 {
346 #ifdef CONFIG_NUMA
347 	int cpu = smp_processor_id();
348 	int node;
349 	unsigned apicid = c->apicid;
350 
351 	node = numa_cpu_node(cpu);
352 	if (node == NUMA_NO_NODE)
353 		node = per_cpu(cpu_llc_id, cpu);
354 
355 	if (!node_online(node)) {
356 		/*
357 		 * Two possibilities here:
358 		 *
359 		 * - The CPU is missing memory and no node was created.  In
360 		 *   that case try picking one from a nearby CPU.
361 		 *
362 		 * - The APIC IDs differ from the HyperTransport node IDs
363 		 *   which the K8 northbridge parsing fills in.  Assume
364 		 *   they are all increased by a constant offset, but in
365 		 *   the same order as the HT nodeids.  If that doesn't
366 		 *   result in a usable node fall back to the path for the
367 		 *   previous case.
368 		 *
369 		 * This workaround operates directly on the mapping between
370 		 * APIC ID and NUMA node, assuming certain relationship
371 		 * between APIC ID, HT node ID and NUMA topology.  As going
372 		 * through CPU mapping may alter the outcome, directly
373 		 * access __apicid_to_node[].
374 		 */
375 		int ht_nodeid = c->initial_apicid;
376 
377 		if (ht_nodeid >= 0 &&
378 		    __apicid_to_node[ht_nodeid] != NUMA_NO_NODE)
379 			node = __apicid_to_node[ht_nodeid];
380 		/* Pick a nearby node */
381 		if (!node_online(node))
382 			node = nearby_node(apicid);
383 	}
384 	numa_set_node(cpu, node);
385 #endif
386 }
387 
388 static void __cpuinit early_init_amd_mc(struct cpuinfo_x86 *c)
389 {
390 #ifdef CONFIG_X86_HT
391 	unsigned bits, ecx;
392 
393 	/* Multi core CPU? */
394 	if (c->extended_cpuid_level < 0x80000008)
395 		return;
396 
397 	ecx = cpuid_ecx(0x80000008);
398 
399 	c->x86_max_cores = (ecx & 0xff) + 1;
400 
401 	/* CPU telling us the core id bits shift? */
402 	bits = (ecx >> 12) & 0xF;
403 
404 	/* Otherwise recompute */
405 	if (bits == 0) {
406 		while ((1 << bits) < c->x86_max_cores)
407 			bits++;
408 	}
409 
410 	c->x86_coreid_bits = bits;
411 #endif
412 }
413 
414 static void __cpuinit bsp_init_amd(struct cpuinfo_x86 *c)
415 {
416 	if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {
417 
418 		if (c->x86 > 0x10 ||
419 		    (c->x86 == 0x10 && c->x86_model >= 0x2)) {
420 			u64 val;
421 
422 			rdmsrl(MSR_K7_HWCR, val);
423 			if (!(val & BIT(24)))
424 				printk(KERN_WARNING FW_BUG "TSC doesn't count "
425 					"with P0 frequency!\n");
426 		}
427 	}
428 
429 	if (c->x86 == 0x15) {
430 		unsigned long upperbit;
431 		u32 cpuid, assoc;
432 
433 		cpuid	 = cpuid_edx(0x80000005);
434 		assoc	 = cpuid >> 16 & 0xff;
435 		upperbit = ((cpuid >> 24) << 10) / assoc;
436 
437 		va_align.mask	  = (upperbit - 1) & PAGE_MASK;
438 		va_align.flags    = ALIGN_VA_32 | ALIGN_VA_64;
439 	}
440 }
441 
442 static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
443 {
444 	u32 dummy;
445 
446 	early_init_amd_mc(c);
447 
448 	/*
449 	 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
450 	 * with P/T states and does not stop in deep C-states
451 	 */
452 	if (c->x86_power & (1 << 8)) {
453 		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
454 		set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
455 	}
456 
457 #ifdef CONFIG_X86_64
458 	set_cpu_cap(c, X86_FEATURE_SYSCALL32);
459 #else
460 	/*  Set MTRR capability flag if appropriate */
461 	if (c->x86 == 5)
462 		if (c->x86_model == 13 || c->x86_model == 9 ||
463 		    (c->x86_model == 8 && c->x86_mask >= 8))
464 			set_cpu_cap(c, X86_FEATURE_K6_MTRR);
465 #endif
466 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_PCI)
467 	/* check CPU config space for extended APIC ID */
468 	if (cpu_has_apic && c->x86 >= 0xf) {
469 		unsigned int val;
470 		val = read_pci_config(0, 24, 0, 0x68);
471 		if ((val & ((1 << 17) | (1 << 18))) == ((1 << 17) | (1 << 18)))
472 			set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
473 	}
474 #endif
475 
476 	rdmsr_safe(MSR_AMD64_PATCH_LEVEL, &c->microcode, &dummy);
477 }
478 
479 static void __cpuinit init_amd(struct cpuinfo_x86 *c)
480 {
481 #ifdef CONFIG_SMP
482 	unsigned long long value;
483 
484 	/*
485 	 * Disable TLB flush filter by setting HWCR.FFDIS on K8
486 	 * bit 6 of msr C001_0015
487 	 *
488 	 * Errata 63 for SH-B3 steppings
489 	 * Errata 122 for all steppings (F+ have it disabled by default)
490 	 */
491 	if (c->x86 == 0xf) {
492 		rdmsrl(MSR_K7_HWCR, value);
493 		value |= 1 << 6;
494 		wrmsrl(MSR_K7_HWCR, value);
495 	}
496 #endif
497 
498 	early_init_amd(c);
499 
500 	/*
501 	 * Bit 31 in normal CPUID used for nonstandard 3DNow ID;
502 	 * 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway
503 	 */
504 	clear_cpu_cap(c, 0*32+31);
505 
506 #ifdef CONFIG_X86_64
507 	/* On C+ stepping K8 rep microcode works well for copy/memset */
508 	if (c->x86 == 0xf) {
509 		u32 level;
510 
511 		level = cpuid_eax(1);
512 		if ((level >= 0x0f48 && level < 0x0f50) || level >= 0x0f58)
513 			set_cpu_cap(c, X86_FEATURE_REP_GOOD);
514 
515 		/*
516 		 * Some BIOSes incorrectly force this feature, but only K8
517 		 * revision D (model = 0x14) and later actually support it.
518 		 * (AMD Erratum #110, docId: 25759).
519 		 */
520 		if (c->x86_model < 0x14 && cpu_has(c, X86_FEATURE_LAHF_LM)) {
521 			u64 val;
522 
523 			clear_cpu_cap(c, X86_FEATURE_LAHF_LM);
524 			if (!rdmsrl_amd_safe(0xc001100d, &val)) {
525 				val &= ~(1ULL << 32);
526 				wrmsrl_amd_safe(0xc001100d, val);
527 			}
528 		}
529 
530 	}
531 	if (c->x86 >= 0x10)
532 		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
533 
534 	/* get apicid instead of initial apic id from cpuid */
535 	c->apicid = hard_smp_processor_id();
536 #else
537 
538 	/*
539 	 *	FIXME: We should handle the K5 here. Set up the write
540 	 *	range and also turn on MSR 83 bits 4 and 31 (write alloc,
541 	 *	no bus pipeline)
542 	 */
543 
544 	switch (c->x86) {
545 	case 4:
546 		init_amd_k5(c);
547 		break;
548 	case 5:
549 		init_amd_k6(c);
550 		break;
551 	case 6: /* An Athlon/Duron */
552 		init_amd_k7(c);
553 		break;
554 	}
555 
556 	/* K6s reports MCEs but don't actually have all the MSRs */
557 	if (c->x86 < 6)
558 		clear_cpu_cap(c, X86_FEATURE_MCE);
559 #endif
560 
561 	/* Enable workaround for FXSAVE leak */
562 	if (c->x86 >= 6)
563 		set_cpu_cap(c, X86_FEATURE_FXSAVE_LEAK);
564 
565 	if (!c->x86_model_id[0]) {
566 		switch (c->x86) {
567 		case 0xf:
568 			/* Should distinguish Models here, but this is only
569 			   a fallback anyways. */
570 			strcpy(c->x86_model_id, "Hammer");
571 			break;
572 		}
573 	}
574 
575 	cpu_detect_cache_sizes(c);
576 
577 	/* Multi core CPU? */
578 	if (c->extended_cpuid_level >= 0x80000008) {
579 		amd_detect_cmp(c);
580 		srat_detect_node(c);
581 	}
582 
583 #ifdef CONFIG_X86_32
584 	detect_ht(c);
585 #endif
586 
587 	if (c->extended_cpuid_level >= 0x80000006) {
588 		if (cpuid_edx(0x80000006) & 0xf000)
589 			num_cache_leaves = 4;
590 		else
591 			num_cache_leaves = 3;
592 	}
593 
594 	if (c->x86 >= 0xf)
595 		set_cpu_cap(c, X86_FEATURE_K8);
596 
597 	if (cpu_has_xmm2) {
598 		/* MFENCE stops RDTSC speculation */
599 		set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC);
600 	}
601 
602 #ifdef CONFIG_X86_64
603 	if (c->x86 == 0x10) {
604 		/* do this for boot cpu */
605 		if (c == &boot_cpu_data)
606 			check_enable_amd_mmconf_dmi();
607 
608 		fam10h_check_enable_mmcfg();
609 	}
610 
611 	if (c == &boot_cpu_data && c->x86 >= 0xf) {
612 		unsigned long long tseg;
613 
614 		/*
615 		 * Split up direct mapping around the TSEG SMM area.
616 		 * Don't do it for gbpages because there seems very little
617 		 * benefit in doing so.
618 		 */
619 		if (!rdmsrl_safe(MSR_K8_TSEG_ADDR, &tseg)) {
620 			printk(KERN_DEBUG "tseg: %010llx\n", tseg);
621 			if ((tseg>>PMD_SHIFT) <
622 				(max_low_pfn_mapped>>(PMD_SHIFT-PAGE_SHIFT)) ||
623 				((tseg>>PMD_SHIFT) <
624 				(max_pfn_mapped>>(PMD_SHIFT-PAGE_SHIFT)) &&
625 				(tseg>>PMD_SHIFT) >= (1ULL<<(32 - PMD_SHIFT))))
626 				set_memory_4k((unsigned long)__va(tseg), 1);
627 		}
628 	}
629 #endif
630 
631 	/*
632 	 * Family 0x12 and above processors have APIC timer
633 	 * running in deep C states.
634 	 */
635 	if (c->x86 > 0x11)
636 		set_cpu_cap(c, X86_FEATURE_ARAT);
637 
638 	/*
639 	 * Disable GART TLB Walk Errors on Fam10h. We do this here
640 	 * because this is always needed when GART is enabled, even in a
641 	 * kernel which has no MCE support built in.
642 	 */
643 	if (c->x86 == 0x10) {
644 		/*
645 		 * BIOS should disable GartTlbWlk Errors themself. If
646 		 * it doesn't do it here as suggested by the BKDG.
647 		 *
648 		 * Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=33012
649 		 */
650 		u64 mask;
651 		int err;
652 
653 		err = rdmsrl_safe(MSR_AMD64_MCx_MASK(4), &mask);
654 		if (err == 0) {
655 			mask |= (1 << 10);
656 			checking_wrmsrl(MSR_AMD64_MCx_MASK(4), mask);
657 		}
658 	}
659 }
660 
661 #ifdef CONFIG_X86_32
662 static unsigned int __cpuinit amd_size_cache(struct cpuinfo_x86 *c,
663 							unsigned int size)
664 {
665 	/* AMD errata T13 (order #21922) */
666 	if ((c->x86 == 6)) {
667 		/* Duron Rev A0 */
668 		if (c->x86_model == 3 && c->x86_mask == 0)
669 			size = 64;
670 		/* Tbird rev A1/A2 */
671 		if (c->x86_model == 4 &&
672 			(c->x86_mask == 0 || c->x86_mask == 1))
673 			size = 256;
674 	}
675 	return size;
676 }
677 #endif
678 
679 static const struct cpu_dev __cpuinitconst amd_cpu_dev = {
680 	.c_vendor	= "AMD",
681 	.c_ident	= { "AuthenticAMD" },
682 #ifdef CONFIG_X86_32
683 	.c_models = {
684 		{ .vendor = X86_VENDOR_AMD, .family = 4, .model_names =
685 		  {
686 			  [3] = "486 DX/2",
687 			  [7] = "486 DX/2-WB",
688 			  [8] = "486 DX/4",
689 			  [9] = "486 DX/4-WB",
690 			  [14] = "Am5x86-WT",
691 			  [15] = "Am5x86-WB"
692 		  }
693 		},
694 	},
695 	.c_size_cache	= amd_size_cache,
696 #endif
697 	.c_early_init   = early_init_amd,
698 	.c_bsp_init	= bsp_init_amd,
699 	.c_init		= init_amd,
700 	.c_x86_vendor	= X86_VENDOR_AMD,
701 };
702 
703 cpu_dev_register(amd_cpu_dev);
704 
705 /*
706  * AMD errata checking
707  *
708  * Errata are defined as arrays of ints using the AMD_LEGACY_ERRATUM() or
709  * AMD_OSVW_ERRATUM() macros. The latter is intended for newer errata that
710  * have an OSVW id assigned, which it takes as first argument. Both take a
711  * variable number of family-specific model-stepping ranges created by
712  * AMD_MODEL_RANGE(). Each erratum also has to be declared as extern const
713  * int[] in arch/x86/include/asm/processor.h.
714  *
715  * Example:
716  *
717  * const int amd_erratum_319[] =
718  *	AMD_LEGACY_ERRATUM(AMD_MODEL_RANGE(0x10, 0x2, 0x1, 0x4, 0x2),
719  *			   AMD_MODEL_RANGE(0x10, 0x8, 0x0, 0x8, 0x0),
720  *			   AMD_MODEL_RANGE(0x10, 0x9, 0x0, 0x9, 0x0));
721  */
722 
723 const int amd_erratum_400[] =
724 	AMD_OSVW_ERRATUM(1, AMD_MODEL_RANGE(0xf, 0x41, 0x2, 0xff, 0xf),
725 			    AMD_MODEL_RANGE(0x10, 0x2, 0x1, 0xff, 0xf));
726 EXPORT_SYMBOL_GPL(amd_erratum_400);
727 
728 const int amd_erratum_383[] =
729 	AMD_OSVW_ERRATUM(3, AMD_MODEL_RANGE(0x10, 0, 0, 0xff, 0xf));
730 EXPORT_SYMBOL_GPL(amd_erratum_383);
731 
732 bool cpu_has_amd_erratum(const int *erratum)
733 {
734 	struct cpuinfo_x86 *cpu = __this_cpu_ptr(&cpu_info);
735 	int osvw_id = *erratum++;
736 	u32 range;
737 	u32 ms;
738 
739 	/*
740 	 * If called early enough that current_cpu_data hasn't been initialized
741 	 * yet, fall back to boot_cpu_data.
742 	 */
743 	if (cpu->x86 == 0)
744 		cpu = &boot_cpu_data;
745 
746 	if (cpu->x86_vendor != X86_VENDOR_AMD)
747 		return false;
748 
749 	if (osvw_id >= 0 && osvw_id < 65536 &&
750 	    cpu_has(cpu, X86_FEATURE_OSVW)) {
751 		u64 osvw_len;
752 
753 		rdmsrl(MSR_AMD64_OSVW_ID_LENGTH, osvw_len);
754 		if (osvw_id < osvw_len) {
755 			u64 osvw_bits;
756 
757 			rdmsrl(MSR_AMD64_OSVW_STATUS + (osvw_id >> 6),
758 			    osvw_bits);
759 			return osvw_bits & (1ULL << (osvw_id & 0x3f));
760 		}
761 	}
762 
763 	/* OSVW unavailable or ID unknown, match family-model-stepping range */
764 	ms = (cpu->x86_model << 4) | cpu->x86_mask;
765 	while ((range = *erratum++))
766 		if ((cpu->x86 == AMD_MODEL_RANGE_FAMILY(range)) &&
767 		    (ms >= AMD_MODEL_RANGE_START(range)) &&
768 		    (ms <= AMD_MODEL_RANGE_END(range)))
769 			return true;
770 
771 	return false;
772 }
773 
774 EXPORT_SYMBOL_GPL(cpu_has_amd_erratum);
775