xref: /openbmc/linux/arch/x86/kernel/cpu/amd.c (revision a06c488d)
1 #include <linux/export.h>
2 #include <linux/bitops.h>
3 #include <linux/elf.h>
4 #include <linux/mm.h>
5 
6 #include <linux/io.h>
7 #include <linux/sched.h>
8 #include <linux/random.h>
9 #include <asm/processor.h>
10 #include <asm/apic.h>
11 #include <asm/cpu.h>
12 #include <asm/smp.h>
13 #include <asm/pci-direct.h>
14 #include <asm/delay.h>
15 
16 #ifdef CONFIG_X86_64
17 # include <asm/mmconfig.h>
18 # include <asm/cacheflush.h>
19 #endif
20 
21 #include "cpu.h"
22 
23 /*
24  * nodes_per_socket: Stores the number of nodes per socket.
25  * Refer to Fam15h Models 00-0fh BKDG - CPUID Fn8000_001E_ECX
26  * Node Identifiers[10:8]
27  */
28 static u32 nodes_per_socket = 1;
29 
30 static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p)
31 {
32 	u32 gprs[8] = { 0 };
33 	int err;
34 
35 	WARN_ONCE((boot_cpu_data.x86 != 0xf),
36 		  "%s should only be used on K8!\n", __func__);
37 
38 	gprs[1] = msr;
39 	gprs[7] = 0x9c5a203a;
40 
41 	err = rdmsr_safe_regs(gprs);
42 
43 	*p = gprs[0] | ((u64)gprs[2] << 32);
44 
45 	return err;
46 }
47 
48 static inline int wrmsrl_amd_safe(unsigned msr, unsigned long long val)
49 {
50 	u32 gprs[8] = { 0 };
51 
52 	WARN_ONCE((boot_cpu_data.x86 != 0xf),
53 		  "%s should only be used on K8!\n", __func__);
54 
55 	gprs[0] = (u32)val;
56 	gprs[1] = msr;
57 	gprs[2] = val >> 32;
58 	gprs[7] = 0x9c5a203a;
59 
60 	return wrmsr_safe_regs(gprs);
61 }
62 
63 /*
64  *	B step AMD K6 before B 9730xxxx have hardware bugs that can cause
65  *	misexecution of code under Linux. Owners of such processors should
66  *	contact AMD for precise details and a CPU swap.
67  *
68  *	See	http://www.multimania.com/poulot/k6bug.html
69  *	and	section 2.6.2 of "AMD-K6 Processor Revision Guide - Model 6"
70  *		(Publication # 21266  Issue Date: August 1998)
71  *
72  *	The following test is erm.. interesting. AMD neglected to up
73  *	the chip setting when fixing the bug but they also tweaked some
74  *	performance at the same time..
75  */
76 
77 extern __visible void vide(void);
78 __asm__(".globl vide\n\t.align 4\nvide: ret");
79 
80 static void init_amd_k5(struct cpuinfo_x86 *c)
81 {
82 #ifdef CONFIG_X86_32
83 /*
84  * General Systems BIOSen alias the cpu frequency registers
85  * of the Elan at 0x000df000. Unfortuantly, one of the Linux
86  * drivers subsequently pokes it, and changes the CPU speed.
87  * Workaround : Remove the unneeded alias.
88  */
89 #define CBAR		(0xfffc) /* Configuration Base Address  (32-bit) */
90 #define CBAR_ENB	(0x80000000)
91 #define CBAR_KEY	(0X000000CB)
92 	if (c->x86_model == 9 || c->x86_model == 10) {
93 		if (inl(CBAR) & CBAR_ENB)
94 			outl(0 | CBAR_KEY, CBAR);
95 	}
96 #endif
97 }
98 
99 static void init_amd_k6(struct cpuinfo_x86 *c)
100 {
101 #ifdef CONFIG_X86_32
102 	u32 l, h;
103 	int mbytes = get_num_physpages() >> (20-PAGE_SHIFT);
104 
105 	if (c->x86_model < 6) {
106 		/* Based on AMD doc 20734R - June 2000 */
107 		if (c->x86_model == 0) {
108 			clear_cpu_cap(c, X86_FEATURE_APIC);
109 			set_cpu_cap(c, X86_FEATURE_PGE);
110 		}
111 		return;
112 	}
113 
114 	if (c->x86_model == 6 && c->x86_mask == 1) {
115 		const int K6_BUG_LOOP = 1000000;
116 		int n;
117 		void (*f_vide)(void);
118 		u64 d, d2;
119 
120 		printk(KERN_INFO "AMD K6 stepping B detected - ");
121 
122 		/*
123 		 * It looks like AMD fixed the 2.6.2 bug and improved indirect
124 		 * calls at the same time.
125 		 */
126 
127 		n = K6_BUG_LOOP;
128 		f_vide = vide;
129 		d = rdtsc();
130 		while (n--)
131 			f_vide();
132 		d2 = rdtsc();
133 		d = d2-d;
134 
135 		if (d > 20*K6_BUG_LOOP)
136 			printk(KERN_CONT
137 				"system stability may be impaired when more than 32 MB are used.\n");
138 		else
139 			printk(KERN_CONT "probably OK (after B9730xxxx).\n");
140 	}
141 
142 	/* K6 with old style WHCR */
143 	if (c->x86_model < 8 ||
144 	   (c->x86_model == 8 && c->x86_mask < 8)) {
145 		/* We can only write allocate on the low 508Mb */
146 		if (mbytes > 508)
147 			mbytes = 508;
148 
149 		rdmsr(MSR_K6_WHCR, l, h);
150 		if ((l&0x0000FFFF) == 0) {
151 			unsigned long flags;
152 			l = (1<<0)|((mbytes/4)<<1);
153 			local_irq_save(flags);
154 			wbinvd();
155 			wrmsr(MSR_K6_WHCR, l, h);
156 			local_irq_restore(flags);
157 			printk(KERN_INFO "Enabling old style K6 write allocation for %d Mb\n",
158 				mbytes);
159 		}
160 		return;
161 	}
162 
163 	if ((c->x86_model == 8 && c->x86_mask > 7) ||
164 	     c->x86_model == 9 || c->x86_model == 13) {
165 		/* The more serious chips .. */
166 
167 		if (mbytes > 4092)
168 			mbytes = 4092;
169 
170 		rdmsr(MSR_K6_WHCR, l, h);
171 		if ((l&0xFFFF0000) == 0) {
172 			unsigned long flags;
173 			l = ((mbytes>>2)<<22)|(1<<16);
174 			local_irq_save(flags);
175 			wbinvd();
176 			wrmsr(MSR_K6_WHCR, l, h);
177 			local_irq_restore(flags);
178 			printk(KERN_INFO "Enabling new style K6 write allocation for %d Mb\n",
179 				mbytes);
180 		}
181 
182 		return;
183 	}
184 
185 	if (c->x86_model == 10) {
186 		/* AMD Geode LX is model 10 */
187 		/* placeholder for any needed mods */
188 		return;
189 	}
190 #endif
191 }
192 
193 static void init_amd_k7(struct cpuinfo_x86 *c)
194 {
195 #ifdef CONFIG_X86_32
196 	u32 l, h;
197 
198 	/*
199 	 * Bit 15 of Athlon specific MSR 15, needs to be 0
200 	 * to enable SSE on Palomino/Morgan/Barton CPU's.
201 	 * If the BIOS didn't enable it already, enable it here.
202 	 */
203 	if (c->x86_model >= 6 && c->x86_model <= 10) {
204 		if (!cpu_has(c, X86_FEATURE_XMM)) {
205 			printk(KERN_INFO "Enabling disabled K7/SSE Support.\n");
206 			msr_clear_bit(MSR_K7_HWCR, 15);
207 			set_cpu_cap(c, X86_FEATURE_XMM);
208 		}
209 	}
210 
211 	/*
212 	 * It's been determined by AMD that Athlons since model 8 stepping 1
213 	 * are more robust with CLK_CTL set to 200xxxxx instead of 600xxxxx
214 	 * As per AMD technical note 27212 0.2
215 	 */
216 	if ((c->x86_model == 8 && c->x86_mask >= 1) || (c->x86_model > 8)) {
217 		rdmsr(MSR_K7_CLK_CTL, l, h);
218 		if ((l & 0xfff00000) != 0x20000000) {
219 			printk(KERN_INFO
220 			    "CPU: CLK_CTL MSR was %x. Reprogramming to %x\n",
221 					l, ((l & 0x000fffff)|0x20000000));
222 			wrmsr(MSR_K7_CLK_CTL, (l & 0x000fffff)|0x20000000, h);
223 		}
224 	}
225 
226 	set_cpu_cap(c, X86_FEATURE_K7);
227 
228 	/* calling is from identify_secondary_cpu() ? */
229 	if (!c->cpu_index)
230 		return;
231 
232 	/*
233 	 * Certain Athlons might work (for various values of 'work') in SMP
234 	 * but they are not certified as MP capable.
235 	 */
236 	/* Athlon 660/661 is valid. */
237 	if ((c->x86_model == 6) && ((c->x86_mask == 0) ||
238 	    (c->x86_mask == 1)))
239 		return;
240 
241 	/* Duron 670 is valid */
242 	if ((c->x86_model == 7) && (c->x86_mask == 0))
243 		return;
244 
245 	/*
246 	 * Athlon 662, Duron 671, and Athlon >model 7 have capability
247 	 * bit. It's worth noting that the A5 stepping (662) of some
248 	 * Athlon XP's have the MP bit set.
249 	 * See http://www.heise.de/newsticker/data/jow-18.10.01-000 for
250 	 * more.
251 	 */
252 	if (((c->x86_model == 6) && (c->x86_mask >= 2)) ||
253 	    ((c->x86_model == 7) && (c->x86_mask >= 1)) ||
254 	     (c->x86_model > 7))
255 		if (cpu_has(c, X86_FEATURE_MP))
256 			return;
257 
258 	/* If we get here, not a certified SMP capable AMD system. */
259 
260 	/*
261 	 * Don't taint if we are running SMP kernel on a single non-MP
262 	 * approved Athlon
263 	 */
264 	WARN_ONCE(1, "WARNING: This combination of AMD"
265 		" processors is not suitable for SMP.\n");
266 	add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_NOW_UNRELIABLE);
267 #endif
268 }
269 
270 #ifdef CONFIG_NUMA
271 /*
272  * To workaround broken NUMA config.  Read the comment in
273  * srat_detect_node().
274  */
275 static int nearby_node(int apicid)
276 {
277 	int i, node;
278 
279 	for (i = apicid - 1; i >= 0; i--) {
280 		node = __apicid_to_node[i];
281 		if (node != NUMA_NO_NODE && node_online(node))
282 			return node;
283 	}
284 	for (i = apicid + 1; i < MAX_LOCAL_APIC; i++) {
285 		node = __apicid_to_node[i];
286 		if (node != NUMA_NO_NODE && node_online(node))
287 			return node;
288 	}
289 	return first_node(node_online_map); /* Shouldn't happen */
290 }
291 #endif
292 
293 /*
294  * Fixup core topology information for
295  * (1) AMD multi-node processors
296  *     Assumption: Number of cores in each internal node is the same.
297  * (2) AMD processors supporting compute units
298  */
299 #ifdef CONFIG_SMP
300 static void amd_get_topology(struct cpuinfo_x86 *c)
301 {
302 	u32 cores_per_cu = 1;
303 	u8 node_id;
304 	int cpu = smp_processor_id();
305 
306 	/* get information required for multi-node processors */
307 	if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
308 		u32 eax, ebx, ecx, edx;
309 
310 		cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
311 		nodes_per_socket = ((ecx >> 8) & 7) + 1;
312 		node_id = ecx & 7;
313 
314 		/* get compute unit information */
315 		smp_num_siblings = ((ebx >> 8) & 3) + 1;
316 		c->compute_unit_id = ebx & 0xff;
317 		cores_per_cu += ((ebx >> 8) & 3);
318 	} else if (cpu_has(c, X86_FEATURE_NODEID_MSR)) {
319 		u64 value;
320 
321 		rdmsrl(MSR_FAM10H_NODE_ID, value);
322 		nodes_per_socket = ((value >> 3) & 7) + 1;
323 		node_id = value & 7;
324 	} else
325 		return;
326 
327 	/* fixup multi-node processor information */
328 	if (nodes_per_socket > 1) {
329 		u32 cores_per_node;
330 		u32 cus_per_node;
331 
332 		set_cpu_cap(c, X86_FEATURE_AMD_DCM);
333 		cores_per_node = c->x86_max_cores / nodes_per_socket;
334 		cus_per_node = cores_per_node / cores_per_cu;
335 
336 		/* store NodeID, use llc_shared_map to store sibling info */
337 		per_cpu(cpu_llc_id, cpu) = node_id;
338 
339 		/* core id has to be in the [0 .. cores_per_node - 1] range */
340 		c->cpu_core_id %= cores_per_node;
341 		c->compute_unit_id %= cus_per_node;
342 	}
343 }
344 #endif
345 
346 /*
347  * On a AMD dual core setup the lower bits of the APIC id distinguish the cores.
348  * Assumes number of cores is a power of two.
349  */
350 static void amd_detect_cmp(struct cpuinfo_x86 *c)
351 {
352 #ifdef CONFIG_SMP
353 	unsigned bits;
354 	int cpu = smp_processor_id();
355 	unsigned int socket_id, core_complex_id;
356 
357 	bits = c->x86_coreid_bits;
358 	/* Low order bits define the core id (index of core in socket) */
359 	c->cpu_core_id = c->initial_apicid & ((1 << bits)-1);
360 	/* Convert the initial APIC ID into the socket ID */
361 	c->phys_proc_id = c->initial_apicid >> bits;
362 	/* use socket ID also for last level cache */
363 	per_cpu(cpu_llc_id, cpu) = c->phys_proc_id;
364 	amd_get_topology(c);
365 
366 	/*
367 	 * Fix percpu cpu_llc_id here as LLC topology is different
368 	 * for Fam17h systems.
369 	 */
370 	 if (c->x86 != 0x17 || !cpuid_edx(0x80000006))
371 		return;
372 
373 	socket_id	= (c->apicid >> bits) - 1;
374 	core_complex_id	= (c->apicid & ((1 << bits) - 1)) >> 3;
375 
376 	per_cpu(cpu_llc_id, cpu) = (socket_id << 3) | core_complex_id;
377 #endif
378 }
379 
380 u16 amd_get_nb_id(int cpu)
381 {
382 	u16 id = 0;
383 #ifdef CONFIG_SMP
384 	id = per_cpu(cpu_llc_id, cpu);
385 #endif
386 	return id;
387 }
388 EXPORT_SYMBOL_GPL(amd_get_nb_id);
389 
390 u32 amd_get_nodes_per_socket(void)
391 {
392 	return nodes_per_socket;
393 }
394 EXPORT_SYMBOL_GPL(amd_get_nodes_per_socket);
395 
396 static void srat_detect_node(struct cpuinfo_x86 *c)
397 {
398 #ifdef CONFIG_NUMA
399 	int cpu = smp_processor_id();
400 	int node;
401 	unsigned apicid = c->apicid;
402 
403 	node = numa_cpu_node(cpu);
404 	if (node == NUMA_NO_NODE)
405 		node = per_cpu(cpu_llc_id, cpu);
406 
407 	/*
408 	 * On multi-fabric platform (e.g. Numascale NumaChip) a
409 	 * platform-specific handler needs to be called to fixup some
410 	 * IDs of the CPU.
411 	 */
412 	if (x86_cpuinit.fixup_cpu_id)
413 		x86_cpuinit.fixup_cpu_id(c, node);
414 
415 	if (!node_online(node)) {
416 		/*
417 		 * Two possibilities here:
418 		 *
419 		 * - The CPU is missing memory and no node was created.  In
420 		 *   that case try picking one from a nearby CPU.
421 		 *
422 		 * - The APIC IDs differ from the HyperTransport node IDs
423 		 *   which the K8 northbridge parsing fills in.  Assume
424 		 *   they are all increased by a constant offset, but in
425 		 *   the same order as the HT nodeids.  If that doesn't
426 		 *   result in a usable node fall back to the path for the
427 		 *   previous case.
428 		 *
429 		 * This workaround operates directly on the mapping between
430 		 * APIC ID and NUMA node, assuming certain relationship
431 		 * between APIC ID, HT node ID and NUMA topology.  As going
432 		 * through CPU mapping may alter the outcome, directly
433 		 * access __apicid_to_node[].
434 		 */
435 		int ht_nodeid = c->initial_apicid;
436 
437 		if (__apicid_to_node[ht_nodeid] != NUMA_NO_NODE)
438 			node = __apicid_to_node[ht_nodeid];
439 		/* Pick a nearby node */
440 		if (!node_online(node))
441 			node = nearby_node(apicid);
442 	}
443 	numa_set_node(cpu, node);
444 #endif
445 }
446 
447 static void early_init_amd_mc(struct cpuinfo_x86 *c)
448 {
449 #ifdef CONFIG_SMP
450 	unsigned bits, ecx;
451 
452 	/* Multi core CPU? */
453 	if (c->extended_cpuid_level < 0x80000008)
454 		return;
455 
456 	ecx = cpuid_ecx(0x80000008);
457 
458 	c->x86_max_cores = (ecx & 0xff) + 1;
459 
460 	/* CPU telling us the core id bits shift? */
461 	bits = (ecx >> 12) & 0xF;
462 
463 	/* Otherwise recompute */
464 	if (bits == 0) {
465 		while ((1 << bits) < c->x86_max_cores)
466 			bits++;
467 	}
468 
469 	c->x86_coreid_bits = bits;
470 #endif
471 }
472 
473 static void bsp_init_amd(struct cpuinfo_x86 *c)
474 {
475 
476 #ifdef CONFIG_X86_64
477 	if (c->x86 >= 0xf) {
478 		unsigned long long tseg;
479 
480 		/*
481 		 * Split up direct mapping around the TSEG SMM area.
482 		 * Don't do it for gbpages because there seems very little
483 		 * benefit in doing so.
484 		 */
485 		if (!rdmsrl_safe(MSR_K8_TSEG_ADDR, &tseg)) {
486 			unsigned long pfn = tseg >> PAGE_SHIFT;
487 
488 			printk(KERN_DEBUG "tseg: %010llx\n", tseg);
489 			if (pfn_range_is_mapped(pfn, pfn + 1))
490 				set_memory_4k((unsigned long)__va(tseg), 1);
491 		}
492 	}
493 #endif
494 
495 	if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {
496 
497 		if (c->x86 > 0x10 ||
498 		    (c->x86 == 0x10 && c->x86_model >= 0x2)) {
499 			u64 val;
500 
501 			rdmsrl(MSR_K7_HWCR, val);
502 			if (!(val & BIT(24)))
503 				printk(KERN_WARNING FW_BUG "TSC doesn't count "
504 					"with P0 frequency!\n");
505 		}
506 	}
507 
508 	if (c->x86 == 0x15) {
509 		unsigned long upperbit;
510 		u32 cpuid, assoc;
511 
512 		cpuid	 = cpuid_edx(0x80000005);
513 		assoc	 = cpuid >> 16 & 0xff;
514 		upperbit = ((cpuid >> 24) << 10) / assoc;
515 
516 		va_align.mask	  = (upperbit - 1) & PAGE_MASK;
517 		va_align.flags    = ALIGN_VA_32 | ALIGN_VA_64;
518 
519 		/* A random value per boot for bit slice [12:upper_bit) */
520 		va_align.bits = get_random_int() & va_align.mask;
521 	}
522 
523 	if (cpu_has(c, X86_FEATURE_MWAITX))
524 		use_mwaitx_delay();
525 }
526 
527 static void early_init_amd(struct cpuinfo_x86 *c)
528 {
529 	early_init_amd_mc(c);
530 
531 	/*
532 	 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
533 	 * with P/T states and does not stop in deep C-states
534 	 */
535 	if (c->x86_power & (1 << 8)) {
536 		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
537 		set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
538 		if (!check_tsc_unstable())
539 			set_sched_clock_stable();
540 	}
541 
542 #ifdef CONFIG_X86_64
543 	set_cpu_cap(c, X86_FEATURE_SYSCALL32);
544 #else
545 	/*  Set MTRR capability flag if appropriate */
546 	if (c->x86 == 5)
547 		if (c->x86_model == 13 || c->x86_model == 9 ||
548 		    (c->x86_model == 8 && c->x86_mask >= 8))
549 			set_cpu_cap(c, X86_FEATURE_K6_MTRR);
550 #endif
551 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_PCI)
552 	/*
553 	 * ApicID can always be treated as an 8-bit value for AMD APIC versions
554 	 * >= 0x10, but even old K8s came out of reset with version 0x10. So, we
555 	 * can safely set X86_FEATURE_EXTD_APICID unconditionally for families
556 	 * after 16h.
557 	 */
558 	if (cpu_has_apic && c->x86 > 0x16) {
559 		set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
560 	} else if (cpu_has_apic && c->x86 >= 0xf) {
561 		/* check CPU config space for extended APIC ID */
562 		unsigned int val;
563 		val = read_pci_config(0, 24, 0, 0x68);
564 		if ((val & ((1 << 17) | (1 << 18))) == ((1 << 17) | (1 << 18)))
565 			set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
566 	}
567 #endif
568 
569 	/*
570 	 * This is only needed to tell the kernel whether to use VMCALL
571 	 * and VMMCALL.  VMMCALL is never executed except under virt, so
572 	 * we can set it unconditionally.
573 	 */
574 	set_cpu_cap(c, X86_FEATURE_VMMCALL);
575 
576 	/* F16h erratum 793, CVE-2013-6885 */
577 	if (c->x86 == 0x16 && c->x86_model <= 0xf)
578 		msr_set_bit(MSR_AMD64_LS_CFG, 15);
579 }
580 
581 static const int amd_erratum_383[];
582 static const int amd_erratum_400[];
583 static bool cpu_has_amd_erratum(struct cpuinfo_x86 *cpu, const int *erratum);
584 
585 static void init_amd_k8(struct cpuinfo_x86 *c)
586 {
587 	u32 level;
588 	u64 value;
589 
590 	/* On C+ stepping K8 rep microcode works well for copy/memset */
591 	level = cpuid_eax(1);
592 	if ((level >= 0x0f48 && level < 0x0f50) || level >= 0x0f58)
593 		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
594 
595 	/*
596 	 * Some BIOSes incorrectly force this feature, but only K8 revision D
597 	 * (model = 0x14) and later actually support it.
598 	 * (AMD Erratum #110, docId: 25759).
599 	 */
600 	if (c->x86_model < 0x14 && cpu_has(c, X86_FEATURE_LAHF_LM)) {
601 		clear_cpu_cap(c, X86_FEATURE_LAHF_LM);
602 		if (!rdmsrl_amd_safe(0xc001100d, &value)) {
603 			value &= ~BIT_64(32);
604 			wrmsrl_amd_safe(0xc001100d, value);
605 		}
606 	}
607 
608 	if (!c->x86_model_id[0])
609 		strcpy(c->x86_model_id, "Hammer");
610 
611 #ifdef CONFIG_SMP
612 	/*
613 	 * Disable TLB flush filter by setting HWCR.FFDIS on K8
614 	 * bit 6 of msr C001_0015
615 	 *
616 	 * Errata 63 for SH-B3 steppings
617 	 * Errata 122 for all steppings (F+ have it disabled by default)
618 	 */
619 	msr_set_bit(MSR_K7_HWCR, 6);
620 #endif
621 }
622 
623 static void init_amd_gh(struct cpuinfo_x86 *c)
624 {
625 #ifdef CONFIG_X86_64
626 	/* do this for boot cpu */
627 	if (c == &boot_cpu_data)
628 		check_enable_amd_mmconf_dmi();
629 
630 	fam10h_check_enable_mmcfg();
631 #endif
632 
633 	/*
634 	 * Disable GART TLB Walk Errors on Fam10h. We do this here because this
635 	 * is always needed when GART is enabled, even in a kernel which has no
636 	 * MCE support built in. BIOS should disable GartTlbWlk Errors already.
637 	 * If it doesn't, we do it here as suggested by the BKDG.
638 	 *
639 	 * Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=33012
640 	 */
641 	msr_set_bit(MSR_AMD64_MCx_MASK(4), 10);
642 
643 	/*
644 	 * On family 10h BIOS may not have properly enabled WC+ support, causing
645 	 * it to be converted to CD memtype. This may result in performance
646 	 * degradation for certain nested-paging guests. Prevent this conversion
647 	 * by clearing bit 24 in MSR_AMD64_BU_CFG2.
648 	 *
649 	 * NOTE: we want to use the _safe accessors so as not to #GP kvm
650 	 * guests on older kvm hosts.
651 	 */
652 	msr_clear_bit(MSR_AMD64_BU_CFG2, 24);
653 
654 	if (cpu_has_amd_erratum(c, amd_erratum_383))
655 		set_cpu_bug(c, X86_BUG_AMD_TLB_MMATCH);
656 }
657 
658 static void init_amd_bd(struct cpuinfo_x86 *c)
659 {
660 	u64 value;
661 
662 	/* re-enable TopologyExtensions if switched off by BIOS */
663 	if ((c->x86_model >= 0x10) && (c->x86_model <= 0x1f) &&
664 	    !cpu_has(c, X86_FEATURE_TOPOEXT)) {
665 
666 		if (msr_set_bit(0xc0011005, 54) > 0) {
667 			rdmsrl(0xc0011005, value);
668 			if (value & BIT_64(54)) {
669 				set_cpu_cap(c, X86_FEATURE_TOPOEXT);
670 				pr_info(FW_INFO "CPU: Re-enabling disabled Topology Extensions Support.\n");
671 			}
672 		}
673 	}
674 
675 	/*
676 	 * The way access filter has a performance penalty on some workloads.
677 	 * Disable it on the affected CPUs.
678 	 */
679 	if ((c->x86_model >= 0x02) && (c->x86_model < 0x20)) {
680 		if (!rdmsrl_safe(MSR_F15H_IC_CFG, &value) && !(value & 0x1E)) {
681 			value |= 0x1E;
682 			wrmsrl_safe(MSR_F15H_IC_CFG, value);
683 		}
684 	}
685 }
686 
687 static void init_amd(struct cpuinfo_x86 *c)
688 {
689 	u32 dummy;
690 
691 	early_init_amd(c);
692 
693 	/*
694 	 * Bit 31 in normal CPUID used for nonstandard 3DNow ID;
695 	 * 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway
696 	 */
697 	clear_cpu_cap(c, 0*32+31);
698 
699 	if (c->x86 >= 0x10)
700 		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
701 
702 	/* get apicid instead of initial apic id from cpuid */
703 	c->apicid = hard_smp_processor_id();
704 
705 	/* K6s reports MCEs but don't actually have all the MSRs */
706 	if (c->x86 < 6)
707 		clear_cpu_cap(c, X86_FEATURE_MCE);
708 
709 	switch (c->x86) {
710 	case 4:    init_amd_k5(c); break;
711 	case 5:    init_amd_k6(c); break;
712 	case 6:	   init_amd_k7(c); break;
713 	case 0xf:  init_amd_k8(c); break;
714 	case 0x10: init_amd_gh(c); break;
715 	case 0x15: init_amd_bd(c); break;
716 	}
717 
718 	/* Enable workaround for FXSAVE leak */
719 	if (c->x86 >= 6)
720 		set_cpu_bug(c, X86_BUG_FXSAVE_LEAK);
721 
722 	cpu_detect_cache_sizes(c);
723 
724 	/* Multi core CPU? */
725 	if (c->extended_cpuid_level >= 0x80000008) {
726 		amd_detect_cmp(c);
727 		srat_detect_node(c);
728 	}
729 
730 #ifdef CONFIG_X86_32
731 	detect_ht(c);
732 #endif
733 
734 	init_amd_cacheinfo(c);
735 
736 	if (c->x86 >= 0xf)
737 		set_cpu_cap(c, X86_FEATURE_K8);
738 
739 	if (cpu_has_xmm2) {
740 		/* MFENCE stops RDTSC speculation */
741 		set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC);
742 	}
743 
744 	/*
745 	 * Family 0x12 and above processors have APIC timer
746 	 * running in deep C states.
747 	 */
748 	if (c->x86 > 0x11)
749 		set_cpu_cap(c, X86_FEATURE_ARAT);
750 
751 	if (cpu_has_amd_erratum(c, amd_erratum_400))
752 		set_cpu_bug(c, X86_BUG_AMD_APIC_C1E);
753 
754 	rdmsr_safe(MSR_AMD64_PATCH_LEVEL, &c->microcode, &dummy);
755 
756 	/* 3DNow or LM implies PREFETCHW */
757 	if (!cpu_has(c, X86_FEATURE_3DNOWPREFETCH))
758 		if (cpu_has(c, X86_FEATURE_3DNOW) || cpu_has(c, X86_FEATURE_LM))
759 			set_cpu_cap(c, X86_FEATURE_3DNOWPREFETCH);
760 
761 	/* AMD CPUs don't reset SS attributes on SYSRET */
762 	set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
763 }
764 
765 #ifdef CONFIG_X86_32
766 static unsigned int amd_size_cache(struct cpuinfo_x86 *c, unsigned int size)
767 {
768 	/* AMD errata T13 (order #21922) */
769 	if ((c->x86 == 6)) {
770 		/* Duron Rev A0 */
771 		if (c->x86_model == 3 && c->x86_mask == 0)
772 			size = 64;
773 		/* Tbird rev A1/A2 */
774 		if (c->x86_model == 4 &&
775 			(c->x86_mask == 0 || c->x86_mask == 1))
776 			size = 256;
777 	}
778 	return size;
779 }
780 #endif
781 
782 static void cpu_detect_tlb_amd(struct cpuinfo_x86 *c)
783 {
784 	u32 ebx, eax, ecx, edx;
785 	u16 mask = 0xfff;
786 
787 	if (c->x86 < 0xf)
788 		return;
789 
790 	if (c->extended_cpuid_level < 0x80000006)
791 		return;
792 
793 	cpuid(0x80000006, &eax, &ebx, &ecx, &edx);
794 
795 	tlb_lld_4k[ENTRIES] = (ebx >> 16) & mask;
796 	tlb_lli_4k[ENTRIES] = ebx & mask;
797 
798 	/*
799 	 * K8 doesn't have 2M/4M entries in the L2 TLB so read out the L1 TLB
800 	 * characteristics from the CPUID function 0x80000005 instead.
801 	 */
802 	if (c->x86 == 0xf) {
803 		cpuid(0x80000005, &eax, &ebx, &ecx, &edx);
804 		mask = 0xff;
805 	}
806 
807 	/* Handle DTLB 2M and 4M sizes, fall back to L1 if L2 is disabled */
808 	if (!((eax >> 16) & mask))
809 		tlb_lld_2m[ENTRIES] = (cpuid_eax(0x80000005) >> 16) & 0xff;
810 	else
811 		tlb_lld_2m[ENTRIES] = (eax >> 16) & mask;
812 
813 	/* a 4M entry uses two 2M entries */
814 	tlb_lld_4m[ENTRIES] = tlb_lld_2m[ENTRIES] >> 1;
815 
816 	/* Handle ITLB 2M and 4M sizes, fall back to L1 if L2 is disabled */
817 	if (!(eax & mask)) {
818 		/* Erratum 658 */
819 		if (c->x86 == 0x15 && c->x86_model <= 0x1f) {
820 			tlb_lli_2m[ENTRIES] = 1024;
821 		} else {
822 			cpuid(0x80000005, &eax, &ebx, &ecx, &edx);
823 			tlb_lli_2m[ENTRIES] = eax & 0xff;
824 		}
825 	} else
826 		tlb_lli_2m[ENTRIES] = eax & mask;
827 
828 	tlb_lli_4m[ENTRIES] = tlb_lli_2m[ENTRIES] >> 1;
829 }
830 
831 static const struct cpu_dev amd_cpu_dev = {
832 	.c_vendor	= "AMD",
833 	.c_ident	= { "AuthenticAMD" },
834 #ifdef CONFIG_X86_32
835 	.legacy_models = {
836 		{ .family = 4, .model_names =
837 		  {
838 			  [3] = "486 DX/2",
839 			  [7] = "486 DX/2-WB",
840 			  [8] = "486 DX/4",
841 			  [9] = "486 DX/4-WB",
842 			  [14] = "Am5x86-WT",
843 			  [15] = "Am5x86-WB"
844 		  }
845 		},
846 	},
847 	.legacy_cache_size = amd_size_cache,
848 #endif
849 	.c_early_init   = early_init_amd,
850 	.c_detect_tlb	= cpu_detect_tlb_amd,
851 	.c_bsp_init	= bsp_init_amd,
852 	.c_init		= init_amd,
853 	.c_x86_vendor	= X86_VENDOR_AMD,
854 };
855 
856 cpu_dev_register(amd_cpu_dev);
857 
858 /*
859  * AMD errata checking
860  *
861  * Errata are defined as arrays of ints using the AMD_LEGACY_ERRATUM() or
862  * AMD_OSVW_ERRATUM() macros. The latter is intended for newer errata that
863  * have an OSVW id assigned, which it takes as first argument. Both take a
864  * variable number of family-specific model-stepping ranges created by
865  * AMD_MODEL_RANGE().
866  *
867  * Example:
868  *
869  * const int amd_erratum_319[] =
870  *	AMD_LEGACY_ERRATUM(AMD_MODEL_RANGE(0x10, 0x2, 0x1, 0x4, 0x2),
871  *			   AMD_MODEL_RANGE(0x10, 0x8, 0x0, 0x8, 0x0),
872  *			   AMD_MODEL_RANGE(0x10, 0x9, 0x0, 0x9, 0x0));
873  */
874 
875 #define AMD_LEGACY_ERRATUM(...)		{ -1, __VA_ARGS__, 0 }
876 #define AMD_OSVW_ERRATUM(osvw_id, ...)	{ osvw_id, __VA_ARGS__, 0 }
877 #define AMD_MODEL_RANGE(f, m_start, s_start, m_end, s_end) \
878 	((f << 24) | (m_start << 16) | (s_start << 12) | (m_end << 4) | (s_end))
879 #define AMD_MODEL_RANGE_FAMILY(range)	(((range) >> 24) & 0xff)
880 #define AMD_MODEL_RANGE_START(range)	(((range) >> 12) & 0xfff)
881 #define AMD_MODEL_RANGE_END(range)	((range) & 0xfff)
882 
883 static const int amd_erratum_400[] =
884 	AMD_OSVW_ERRATUM(1, AMD_MODEL_RANGE(0xf, 0x41, 0x2, 0xff, 0xf),
885 			    AMD_MODEL_RANGE(0x10, 0x2, 0x1, 0xff, 0xf));
886 
887 static const int amd_erratum_383[] =
888 	AMD_OSVW_ERRATUM(3, AMD_MODEL_RANGE(0x10, 0, 0, 0xff, 0xf));
889 
890 
891 static bool cpu_has_amd_erratum(struct cpuinfo_x86 *cpu, const int *erratum)
892 {
893 	int osvw_id = *erratum++;
894 	u32 range;
895 	u32 ms;
896 
897 	if (osvw_id >= 0 && osvw_id < 65536 &&
898 	    cpu_has(cpu, X86_FEATURE_OSVW)) {
899 		u64 osvw_len;
900 
901 		rdmsrl(MSR_AMD64_OSVW_ID_LENGTH, osvw_len);
902 		if (osvw_id < osvw_len) {
903 			u64 osvw_bits;
904 
905 			rdmsrl(MSR_AMD64_OSVW_STATUS + (osvw_id >> 6),
906 			    osvw_bits);
907 			return osvw_bits & (1ULL << (osvw_id & 0x3f));
908 		}
909 	}
910 
911 	/* OSVW unavailable or ID unknown, match family-model-stepping range */
912 	ms = (cpu->x86_model << 4) | cpu->x86_mask;
913 	while ((range = *erratum++))
914 		if ((cpu->x86 == AMD_MODEL_RANGE_FAMILY(range)) &&
915 		    (ms >= AMD_MODEL_RANGE_START(range)) &&
916 		    (ms <= AMD_MODEL_RANGE_END(range)))
917 			return true;
918 
919 	return false;
920 }
921 
922 void set_dr_addr_mask(unsigned long mask, int dr)
923 {
924 	if (!boot_cpu_has(X86_FEATURE_BPEXT))
925 		return;
926 
927 	switch (dr) {
928 	case 0:
929 		wrmsr(MSR_F16H_DR0_ADDR_MASK, mask, 0);
930 		break;
931 	case 1:
932 	case 2:
933 	case 3:
934 		wrmsr(MSR_F16H_DR1_ADDR_MASK - 1 + dr, mask, 0);
935 		break;
936 	default:
937 		break;
938 	}
939 }
940