xref: /linux/arch/x86/kernel/cpu/intel.c (revision 163b099146b85d1b05bd2eaa045acbeee25c29e4)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
3 #include <linux/pgtable.h>
4 
5 #include <linux/string.h>
6 #include <linux/bitops.h>
7 #include <linux/smp.h>
8 #include <linux/sched.h>
9 #include <linux/sched/clock.h>
10 #include <linux/thread_info.h>
11 #include <linux/init.h>
12 #include <linux/uaccess.h>
13 
14 #include <asm/cpufeature.h>
15 #include <asm/msr.h>
16 #include <asm/bugs.h>
17 #include <asm/cpu.h>
18 #include <asm/intel-family.h>
19 #include <asm/microcode_intel.h>
20 #include <asm/hwcap2.h>
21 #include <asm/elf.h>
22 #include <asm/cpu_device_id.h>
23 #include <asm/cmdline.h>
24 #include <asm/traps.h>
25 #include <asm/resctrl.h>
26 #include <asm/numa.h>
27 #include <asm/thermal.h>
28 
29 #ifdef CONFIG_X86_64
30 #include <linux/topology.h>
31 #endif
32 
33 #include "cpu.h"
34 
35 #ifdef CONFIG_X86_LOCAL_APIC
36 #include <asm/mpspec.h>
37 #include <asm/apic.h>
38 #endif
39 
40 enum split_lock_detect_state {
41 	sld_off = 0,
42 	sld_warn,
43 	sld_fatal,
44 };
45 
46 /*
47  * Default to sld_off because most systems do not support split lock detection
48  * split_lock_setup() will switch this to sld_warn on systems that support
49  * split lock detect, unless there is a command line override.
50  */
51 static enum split_lock_detect_state sld_state __ro_after_init = sld_off;
52 static u64 msr_test_ctrl_cache __ro_after_init;
53 
54 /*
55  * With a name like MSR_TEST_CTL it should go without saying, but don't touch
56  * MSR_TEST_CTL unless the CPU is one of the whitelisted models.  Writing it
57  * on CPUs that do not support SLD can cause fireworks, even when writing '0'.
58  */
59 static bool cpu_model_supports_sld __ro_after_init;
60 
61 /*
62  * Processors which have self-snooping capability can handle conflicting
63  * memory type across CPUs by snooping its own cache. However, there exists
64  * CPU models in which having conflicting memory types still leads to
65  * unpredictable behavior, machine check errors, or hangs. Clear this
66  * feature to prevent its use on machines with known erratas.
67  */
68 static void check_memory_type_self_snoop_errata(struct cpuinfo_x86 *c)
69 {
70 	switch (c->x86_model) {
71 	case INTEL_FAM6_CORE_YONAH:
72 	case INTEL_FAM6_CORE2_MEROM:
73 	case INTEL_FAM6_CORE2_MEROM_L:
74 	case INTEL_FAM6_CORE2_PENRYN:
75 	case INTEL_FAM6_CORE2_DUNNINGTON:
76 	case INTEL_FAM6_NEHALEM:
77 	case INTEL_FAM6_NEHALEM_G:
78 	case INTEL_FAM6_NEHALEM_EP:
79 	case INTEL_FAM6_NEHALEM_EX:
80 	case INTEL_FAM6_WESTMERE:
81 	case INTEL_FAM6_WESTMERE_EP:
82 	case INTEL_FAM6_SANDYBRIDGE:
83 		setup_clear_cpu_cap(X86_FEATURE_SELFSNOOP);
84 	}
85 }
86 
87 static bool ring3mwait_disabled __read_mostly;
88 
89 static int __init ring3mwait_disable(char *__unused)
90 {
91 	ring3mwait_disabled = true;
92 	return 0;
93 }
94 __setup("ring3mwait=disable", ring3mwait_disable);
95 
96 static void probe_xeon_phi_r3mwait(struct cpuinfo_x86 *c)
97 {
98 	/*
99 	 * Ring 3 MONITOR/MWAIT feature cannot be detected without
100 	 * cpu model and family comparison.
101 	 */
102 	if (c->x86 != 6)
103 		return;
104 	switch (c->x86_model) {
105 	case INTEL_FAM6_XEON_PHI_KNL:
106 	case INTEL_FAM6_XEON_PHI_KNM:
107 		break;
108 	default:
109 		return;
110 	}
111 
112 	if (ring3mwait_disabled)
113 		return;
114 
115 	set_cpu_cap(c, X86_FEATURE_RING3MWAIT);
116 	this_cpu_or(msr_misc_features_shadow,
117 		    1UL << MSR_MISC_FEATURES_ENABLES_RING3MWAIT_BIT);
118 
119 	if (c == &boot_cpu_data)
120 		ELF_HWCAP2 |= HWCAP2_RING3MWAIT;
121 }
122 
123 /*
124  * Early microcode releases for the Spectre v2 mitigation were broken.
125  * Information taken from;
126  * - https://newsroom.intel.com/wp-content/uploads/sites/11/2018/03/microcode-update-guidance.pdf
127  * - https://kb.vmware.com/s/article/52345
128  * - Microcode revisions observed in the wild
129  * - Release note from 20180108 microcode release
130  */
131 struct sku_microcode {
132 	u8 model;
133 	u8 stepping;
134 	u32 microcode;
135 };
136 static const struct sku_microcode spectre_bad_microcodes[] = {
137 	{ INTEL_FAM6_KABYLAKE,		0x0B,	0x80 },
138 	{ INTEL_FAM6_KABYLAKE,		0x0A,	0x80 },
139 	{ INTEL_FAM6_KABYLAKE,		0x09,	0x80 },
140 	{ INTEL_FAM6_KABYLAKE_L,	0x0A,	0x80 },
141 	{ INTEL_FAM6_KABYLAKE_L,	0x09,	0x80 },
142 	{ INTEL_FAM6_SKYLAKE_X,		0x03,	0x0100013e },
143 	{ INTEL_FAM6_SKYLAKE_X,		0x04,	0x0200003c },
144 	{ INTEL_FAM6_BROADWELL,		0x04,	0x28 },
145 	{ INTEL_FAM6_BROADWELL_G,	0x01,	0x1b },
146 	{ INTEL_FAM6_BROADWELL_D,	0x02,	0x14 },
147 	{ INTEL_FAM6_BROADWELL_D,	0x03,	0x07000011 },
148 	{ INTEL_FAM6_BROADWELL_X,	0x01,	0x0b000025 },
149 	{ INTEL_FAM6_HASWELL_L,		0x01,	0x21 },
150 	{ INTEL_FAM6_HASWELL_G,		0x01,	0x18 },
151 	{ INTEL_FAM6_HASWELL,		0x03,	0x23 },
152 	{ INTEL_FAM6_HASWELL_X,		0x02,	0x3b },
153 	{ INTEL_FAM6_HASWELL_X,		0x04,	0x10 },
154 	{ INTEL_FAM6_IVYBRIDGE_X,	0x04,	0x42a },
155 	/* Observed in the wild */
156 	{ INTEL_FAM6_SANDYBRIDGE_X,	0x06,	0x61b },
157 	{ INTEL_FAM6_SANDYBRIDGE_X,	0x07,	0x712 },
158 };
159 
160 static bool bad_spectre_microcode(struct cpuinfo_x86 *c)
161 {
162 	int i;
163 
164 	/*
165 	 * We know that the hypervisor lie to us on the microcode version so
166 	 * we may as well hope that it is running the correct version.
167 	 */
168 	if (cpu_has(c, X86_FEATURE_HYPERVISOR))
169 		return false;
170 
171 	if (c->x86 != 6)
172 		return false;
173 
174 	for (i = 0; i < ARRAY_SIZE(spectre_bad_microcodes); i++) {
175 		if (c->x86_model == spectre_bad_microcodes[i].model &&
176 		    c->x86_stepping == spectre_bad_microcodes[i].stepping)
177 			return (c->microcode <= spectre_bad_microcodes[i].microcode);
178 	}
179 	return false;
180 }
181 
182 static void early_init_intel(struct cpuinfo_x86 *c)
183 {
184 	u64 misc_enable;
185 
186 	/* Unmask CPUID levels if masked: */
187 	if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
188 		if (msr_clear_bit(MSR_IA32_MISC_ENABLE,
189 				  MSR_IA32_MISC_ENABLE_LIMIT_CPUID_BIT) > 0) {
190 			c->cpuid_level = cpuid_eax(0);
191 			get_cpu_cap(c);
192 		}
193 	}
194 
195 	if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
196 		(c->x86 == 0x6 && c->x86_model >= 0x0e))
197 		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
198 
199 	if (c->x86 >= 6 && !cpu_has(c, X86_FEATURE_IA64))
200 		c->microcode = intel_get_microcode_revision();
201 
202 	/* Now if any of them are set, check the blacklist and clear the lot */
203 	if ((cpu_has(c, X86_FEATURE_SPEC_CTRL) ||
204 	     cpu_has(c, X86_FEATURE_INTEL_STIBP) ||
205 	     cpu_has(c, X86_FEATURE_IBRS) || cpu_has(c, X86_FEATURE_IBPB) ||
206 	     cpu_has(c, X86_FEATURE_STIBP)) && bad_spectre_microcode(c)) {
207 		pr_warn("Intel Spectre v2 broken microcode detected; disabling Speculation Control\n");
208 		setup_clear_cpu_cap(X86_FEATURE_IBRS);
209 		setup_clear_cpu_cap(X86_FEATURE_IBPB);
210 		setup_clear_cpu_cap(X86_FEATURE_STIBP);
211 		setup_clear_cpu_cap(X86_FEATURE_SPEC_CTRL);
212 		setup_clear_cpu_cap(X86_FEATURE_MSR_SPEC_CTRL);
213 		setup_clear_cpu_cap(X86_FEATURE_INTEL_STIBP);
214 		setup_clear_cpu_cap(X86_FEATURE_SSBD);
215 		setup_clear_cpu_cap(X86_FEATURE_SPEC_CTRL_SSBD);
216 	}
217 
218 	/*
219 	 * Atom erratum AAE44/AAF40/AAG38/AAH41:
220 	 *
221 	 * A race condition between speculative fetches and invalidating
222 	 * a large page.  This is worked around in microcode, but we
223 	 * need the microcode to have already been loaded... so if it is
224 	 * not, recommend a BIOS update and disable large pages.
225 	 */
226 	if (c->x86 == 6 && c->x86_model == 0x1c && c->x86_stepping <= 2 &&
227 	    c->microcode < 0x20e) {
228 		pr_warn("Atom PSE erratum detected, BIOS microcode update recommended\n");
229 		clear_cpu_cap(c, X86_FEATURE_PSE);
230 	}
231 
232 #ifdef CONFIG_X86_64
233 	set_cpu_cap(c, X86_FEATURE_SYSENTER32);
234 #else
235 	/* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
236 	if (c->x86 == 15 && c->x86_cache_alignment == 64)
237 		c->x86_cache_alignment = 128;
238 #endif
239 
240 	/* CPUID workaround for 0F33/0F34 CPU */
241 	if (c->x86 == 0xF && c->x86_model == 0x3
242 	    && (c->x86_stepping == 0x3 || c->x86_stepping == 0x4))
243 		c->x86_phys_bits = 36;
244 
245 	/*
246 	 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
247 	 * with P/T states and does not stop in deep C-states.
248 	 *
249 	 * It is also reliable across cores and sockets. (but not across
250 	 * cabinets - we turn it off in that case explicitly.)
251 	 */
252 	if (c->x86_power & (1 << 8)) {
253 		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
254 		set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
255 	}
256 
257 	/* Penwell and Cloverview have the TSC which doesn't sleep on S3 */
258 	if (c->x86 == 6) {
259 		switch (c->x86_model) {
260 		case INTEL_FAM6_ATOM_SALTWELL_MID:
261 		case INTEL_FAM6_ATOM_SALTWELL_TABLET:
262 		case INTEL_FAM6_ATOM_SILVERMONT_MID:
263 		case INTEL_FAM6_ATOM_AIRMONT_NP:
264 			set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC_S3);
265 			break;
266 		default:
267 			break;
268 		}
269 	}
270 
271 	/*
272 	 * There is a known erratum on Pentium III and Core Solo
273 	 * and Core Duo CPUs.
274 	 * " Page with PAT set to WC while associated MTRR is UC
275 	 *   may consolidate to UC "
276 	 * Because of this erratum, it is better to stick with
277 	 * setting WC in MTRR rather than using PAT on these CPUs.
278 	 *
279 	 * Enable PAT WC only on P4, Core 2 or later CPUs.
280 	 */
281 	if (c->x86 == 6 && c->x86_model < 15)
282 		clear_cpu_cap(c, X86_FEATURE_PAT);
283 
284 	/*
285 	 * If fast string is not enabled in IA32_MISC_ENABLE for any reason,
286 	 * clear the fast string and enhanced fast string CPU capabilities.
287 	 */
288 	if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
289 		rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
290 		if (!(misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING)) {
291 			pr_info("Disabled fast string operations\n");
292 			setup_clear_cpu_cap(X86_FEATURE_REP_GOOD);
293 			setup_clear_cpu_cap(X86_FEATURE_ERMS);
294 		}
295 	}
296 
297 	/*
298 	 * Intel Quark Core DevMan_001.pdf section 6.4.11
299 	 * "The operating system also is required to invalidate (i.e., flush)
300 	 *  the TLB when any changes are made to any of the page table entries.
301 	 *  The operating system must reload CR3 to cause the TLB to be flushed"
302 	 *
303 	 * As a result, boot_cpu_has(X86_FEATURE_PGE) in arch/x86/include/asm/tlbflush.h
304 	 * should be false so that __flush_tlb_all() causes CR3 instead of CR4.PGE
305 	 * to be modified.
306 	 */
307 	if (c->x86 == 5 && c->x86_model == 9) {
308 		pr_info("Disabling PGE capability bit\n");
309 		setup_clear_cpu_cap(X86_FEATURE_PGE);
310 	}
311 
312 	if (c->cpuid_level >= 0x00000001) {
313 		u32 eax, ebx, ecx, edx;
314 
315 		cpuid(0x00000001, &eax, &ebx, &ecx, &edx);
316 		/*
317 		 * If HTT (EDX[28]) is set EBX[16:23] contain the number of
318 		 * apicids which are reserved per package. Store the resulting
319 		 * shift value for the package management code.
320 		 */
321 		if (edx & (1U << 28))
322 			c->x86_coreid_bits = get_count_order((ebx >> 16) & 0xff);
323 	}
324 
325 	check_memory_type_self_snoop_errata(c);
326 
327 	/*
328 	 * Get the number of SMT siblings early from the extended topology
329 	 * leaf, if available. Otherwise try the legacy SMT detection.
330 	 */
331 	if (detect_extended_topology_early(c) < 0)
332 		detect_ht_early(c);
333 }
334 
335 static void bsp_init_intel(struct cpuinfo_x86 *c)
336 {
337 	resctrl_cpu_detect(c);
338 }
339 
340 #ifdef CONFIG_X86_32
341 /*
342  *	Early probe support logic for ppro memory erratum #50
343  *
344  *	This is called before we do cpu ident work
345  */
346 
347 int ppro_with_ram_bug(void)
348 {
349 	/* Uses data from early_cpu_detect now */
350 	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
351 	    boot_cpu_data.x86 == 6 &&
352 	    boot_cpu_data.x86_model == 1 &&
353 	    boot_cpu_data.x86_stepping < 8) {
354 		pr_info("Pentium Pro with Errata#50 detected. Taking evasive action.\n");
355 		return 1;
356 	}
357 	return 0;
358 }
359 
360 static void intel_smp_check(struct cpuinfo_x86 *c)
361 {
362 	/* calling is from identify_secondary_cpu() ? */
363 	if (!c->cpu_index)
364 		return;
365 
366 	/*
367 	 * Mask B, Pentium, but not Pentium MMX
368 	 */
369 	if (c->x86 == 5 &&
370 	    c->x86_stepping >= 1 && c->x86_stepping <= 4 &&
371 	    c->x86_model <= 3) {
372 		/*
373 		 * Remember we have B step Pentia with bugs
374 		 */
375 		WARN_ONCE(1, "WARNING: SMP operation may be unreliable"
376 				    "with B stepping processors.\n");
377 	}
378 }
379 
380 static int forcepae;
381 static int __init forcepae_setup(char *__unused)
382 {
383 	forcepae = 1;
384 	return 1;
385 }
386 __setup("forcepae", forcepae_setup);
387 
388 static void intel_workarounds(struct cpuinfo_x86 *c)
389 {
390 #ifdef CONFIG_X86_F00F_BUG
391 	/*
392 	 * All models of Pentium and Pentium with MMX technology CPUs
393 	 * have the F0 0F bug, which lets nonprivileged users lock up the
394 	 * system. Announce that the fault handler will be checking for it.
395 	 * The Quark is also family 5, but does not have the same bug.
396 	 */
397 	clear_cpu_bug(c, X86_BUG_F00F);
398 	if (c->x86 == 5 && c->x86_model < 9) {
399 		static int f00f_workaround_enabled;
400 
401 		set_cpu_bug(c, X86_BUG_F00F);
402 		if (!f00f_workaround_enabled) {
403 			pr_notice("Intel Pentium with F0 0F bug - workaround enabled.\n");
404 			f00f_workaround_enabled = 1;
405 		}
406 	}
407 #endif
408 
409 	/*
410 	 * SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until
411 	 * model 3 mask 3
412 	 */
413 	if ((c->x86<<8 | c->x86_model<<4 | c->x86_stepping) < 0x633)
414 		clear_cpu_cap(c, X86_FEATURE_SEP);
415 
416 	/*
417 	 * PAE CPUID issue: many Pentium M report no PAE but may have a
418 	 * functionally usable PAE implementation.
419 	 * Forcefully enable PAE if kernel parameter "forcepae" is present.
420 	 */
421 	if (forcepae) {
422 		pr_warn("PAE forced!\n");
423 		set_cpu_cap(c, X86_FEATURE_PAE);
424 		add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_NOW_UNRELIABLE);
425 	}
426 
427 	/*
428 	 * P4 Xeon erratum 037 workaround.
429 	 * Hardware prefetcher may cause stale data to be loaded into the cache.
430 	 */
431 	if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_stepping == 1)) {
432 		if (msr_set_bit(MSR_IA32_MISC_ENABLE,
433 				MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE_BIT) > 0) {
434 			pr_info("CPU: C0 stepping P4 Xeon detected.\n");
435 			pr_info("CPU: Disabling hardware prefetching (Erratum 037)\n");
436 		}
437 	}
438 
439 	/*
440 	 * See if we have a good local APIC by checking for buggy Pentia,
441 	 * i.e. all B steppings and the C2 stepping of P54C when using their
442 	 * integrated APIC (see 11AP erratum in "Pentium Processor
443 	 * Specification Update").
444 	 */
445 	if (boot_cpu_has(X86_FEATURE_APIC) && (c->x86<<8 | c->x86_model<<4) == 0x520 &&
446 	    (c->x86_stepping < 0x6 || c->x86_stepping == 0xb))
447 		set_cpu_bug(c, X86_BUG_11AP);
448 
449 
450 #ifdef CONFIG_X86_INTEL_USERCOPY
451 	/*
452 	 * Set up the preferred alignment for movsl bulk memory moves
453 	 */
454 	switch (c->x86) {
455 	case 4:		/* 486: untested */
456 		break;
457 	case 5:		/* Old Pentia: untested */
458 		break;
459 	case 6:		/* PII/PIII only like movsl with 8-byte alignment */
460 		movsl_mask.mask = 7;
461 		break;
462 	case 15:	/* P4 is OK down to 8-byte alignment */
463 		movsl_mask.mask = 7;
464 		break;
465 	}
466 #endif
467 
468 	intel_smp_check(c);
469 }
470 #else
471 static void intel_workarounds(struct cpuinfo_x86 *c)
472 {
473 }
474 #endif
475 
476 static void srat_detect_node(struct cpuinfo_x86 *c)
477 {
478 #ifdef CONFIG_NUMA
479 	unsigned node;
480 	int cpu = smp_processor_id();
481 
482 	/* Don't do the funky fallback heuristics the AMD version employs
483 	   for now. */
484 	node = numa_cpu_node(cpu);
485 	if (node == NUMA_NO_NODE || !node_online(node)) {
486 		/* reuse the value from init_cpu_to_node() */
487 		node = cpu_to_node(cpu);
488 	}
489 	numa_set_node(cpu, node);
490 #endif
491 }
492 
493 #define MSR_IA32_TME_ACTIVATE		0x982
494 
495 /* Helpers to access TME_ACTIVATE MSR */
496 #define TME_ACTIVATE_LOCKED(x)		(x & 0x1)
497 #define TME_ACTIVATE_ENABLED(x)		(x & 0x2)
498 
499 #define TME_ACTIVATE_POLICY(x)		((x >> 4) & 0xf)	/* Bits 7:4 */
500 #define TME_ACTIVATE_POLICY_AES_XTS_128	0
501 
502 #define TME_ACTIVATE_KEYID_BITS(x)	((x >> 32) & 0xf)	/* Bits 35:32 */
503 
504 #define TME_ACTIVATE_CRYPTO_ALGS(x)	((x >> 48) & 0xffff)	/* Bits 63:48 */
505 #define TME_ACTIVATE_CRYPTO_AES_XTS_128	1
506 
507 /* Values for mktme_status (SW only construct) */
508 #define MKTME_ENABLED			0
509 #define MKTME_DISABLED			1
510 #define MKTME_UNINITIALIZED		2
511 static int mktme_status = MKTME_UNINITIALIZED;
512 
513 static void detect_tme(struct cpuinfo_x86 *c)
514 {
515 	u64 tme_activate, tme_policy, tme_crypto_algs;
516 	int keyid_bits = 0, nr_keyids = 0;
517 	static u64 tme_activate_cpu0 = 0;
518 
519 	rdmsrl(MSR_IA32_TME_ACTIVATE, tme_activate);
520 
521 	if (mktme_status != MKTME_UNINITIALIZED) {
522 		if (tme_activate != tme_activate_cpu0) {
523 			/* Broken BIOS? */
524 			pr_err_once("x86/tme: configuration is inconsistent between CPUs\n");
525 			pr_err_once("x86/tme: MKTME is not usable\n");
526 			mktme_status = MKTME_DISABLED;
527 
528 			/* Proceed. We may need to exclude bits from x86_phys_bits. */
529 		}
530 	} else {
531 		tme_activate_cpu0 = tme_activate;
532 	}
533 
534 	if (!TME_ACTIVATE_LOCKED(tme_activate) || !TME_ACTIVATE_ENABLED(tme_activate)) {
535 		pr_info_once("x86/tme: not enabled by BIOS\n");
536 		mktme_status = MKTME_DISABLED;
537 		return;
538 	}
539 
540 	if (mktme_status != MKTME_UNINITIALIZED)
541 		goto detect_keyid_bits;
542 
543 	pr_info("x86/tme: enabled by BIOS\n");
544 
545 	tme_policy = TME_ACTIVATE_POLICY(tme_activate);
546 	if (tme_policy != TME_ACTIVATE_POLICY_AES_XTS_128)
547 		pr_warn("x86/tme: Unknown policy is active: %#llx\n", tme_policy);
548 
549 	tme_crypto_algs = TME_ACTIVATE_CRYPTO_ALGS(tme_activate);
550 	if (!(tme_crypto_algs & TME_ACTIVATE_CRYPTO_AES_XTS_128)) {
551 		pr_err("x86/mktme: No known encryption algorithm is supported: %#llx\n",
552 				tme_crypto_algs);
553 		mktme_status = MKTME_DISABLED;
554 	}
555 detect_keyid_bits:
556 	keyid_bits = TME_ACTIVATE_KEYID_BITS(tme_activate);
557 	nr_keyids = (1UL << keyid_bits) - 1;
558 	if (nr_keyids) {
559 		pr_info_once("x86/mktme: enabled by BIOS\n");
560 		pr_info_once("x86/mktme: %d KeyIDs available\n", nr_keyids);
561 	} else {
562 		pr_info_once("x86/mktme: disabled by BIOS\n");
563 	}
564 
565 	if (mktme_status == MKTME_UNINITIALIZED) {
566 		/* MKTME is usable */
567 		mktme_status = MKTME_ENABLED;
568 	}
569 
570 	/*
571 	 * KeyID bits effectively lower the number of physical address
572 	 * bits.  Update cpuinfo_x86::x86_phys_bits accordingly.
573 	 */
574 	c->x86_phys_bits -= keyid_bits;
575 }
576 
577 static void init_cpuid_fault(struct cpuinfo_x86 *c)
578 {
579 	u64 msr;
580 
581 	if (!rdmsrl_safe(MSR_PLATFORM_INFO, &msr)) {
582 		if (msr & MSR_PLATFORM_INFO_CPUID_FAULT)
583 			set_cpu_cap(c, X86_FEATURE_CPUID_FAULT);
584 	}
585 }
586 
587 static void init_intel_misc_features(struct cpuinfo_x86 *c)
588 {
589 	u64 msr;
590 
591 	if (rdmsrl_safe(MSR_MISC_FEATURES_ENABLES, &msr))
592 		return;
593 
594 	/* Clear all MISC features */
595 	this_cpu_write(msr_misc_features_shadow, 0);
596 
597 	/* Check features and update capabilities and shadow control bits */
598 	init_cpuid_fault(c);
599 	probe_xeon_phi_r3mwait(c);
600 
601 	msr = this_cpu_read(msr_misc_features_shadow);
602 	wrmsrl(MSR_MISC_FEATURES_ENABLES, msr);
603 }
604 
605 static void split_lock_init(void);
606 
607 static void init_intel(struct cpuinfo_x86 *c)
608 {
609 	early_init_intel(c);
610 
611 	intel_workarounds(c);
612 
613 	/*
614 	 * Detect the extended topology information if available. This
615 	 * will reinitialise the initial_apicid which will be used
616 	 * in init_intel_cacheinfo()
617 	 */
618 	detect_extended_topology(c);
619 
620 	if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) {
621 		/*
622 		 * let's use the legacy cpuid vector 0x1 and 0x4 for topology
623 		 * detection.
624 		 */
625 		detect_num_cpu_cores(c);
626 #ifdef CONFIG_X86_32
627 		detect_ht(c);
628 #endif
629 	}
630 
631 	init_intel_cacheinfo(c);
632 
633 	if (c->cpuid_level > 9) {
634 		unsigned eax = cpuid_eax(10);
635 		/* Check for version and the number of counters */
636 		if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
637 			set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON);
638 	}
639 
640 	if (cpu_has(c, X86_FEATURE_XMM2))
641 		set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
642 
643 	if (boot_cpu_has(X86_FEATURE_DS)) {
644 		unsigned int l1, l2;
645 
646 		rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
647 		if (!(l1 & (1<<11)))
648 			set_cpu_cap(c, X86_FEATURE_BTS);
649 		if (!(l1 & (1<<12)))
650 			set_cpu_cap(c, X86_FEATURE_PEBS);
651 	}
652 
653 	if (c->x86 == 6 && boot_cpu_has(X86_FEATURE_CLFLUSH) &&
654 	    (c->x86_model == 29 || c->x86_model == 46 || c->x86_model == 47))
655 		set_cpu_bug(c, X86_BUG_CLFLUSH_MONITOR);
656 
657 	if (c->x86 == 6 && boot_cpu_has(X86_FEATURE_MWAIT) &&
658 		((c->x86_model == INTEL_FAM6_ATOM_GOLDMONT)))
659 		set_cpu_bug(c, X86_BUG_MONITOR);
660 
661 #ifdef CONFIG_X86_64
662 	if (c->x86 == 15)
663 		c->x86_cache_alignment = c->x86_clflush_size * 2;
664 	if (c->x86 == 6)
665 		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
666 #else
667 	/*
668 	 * Names for the Pentium II/Celeron processors
669 	 * detectable only by also checking the cache size.
670 	 * Dixon is NOT a Celeron.
671 	 */
672 	if (c->x86 == 6) {
673 		unsigned int l2 = c->x86_cache_size;
674 		char *p = NULL;
675 
676 		switch (c->x86_model) {
677 		case 5:
678 			if (l2 == 0)
679 				p = "Celeron (Covington)";
680 			else if (l2 == 256)
681 				p = "Mobile Pentium II (Dixon)";
682 			break;
683 
684 		case 6:
685 			if (l2 == 128)
686 				p = "Celeron (Mendocino)";
687 			else if (c->x86_stepping == 0 || c->x86_stepping == 5)
688 				p = "Celeron-A";
689 			break;
690 
691 		case 8:
692 			if (l2 == 128)
693 				p = "Celeron (Coppermine)";
694 			break;
695 		}
696 
697 		if (p)
698 			strcpy(c->x86_model_id, p);
699 	}
700 
701 	if (c->x86 == 15)
702 		set_cpu_cap(c, X86_FEATURE_P4);
703 	if (c->x86 == 6)
704 		set_cpu_cap(c, X86_FEATURE_P3);
705 #endif
706 
707 	/* Work around errata */
708 	srat_detect_node(c);
709 
710 	init_ia32_feat_ctl(c);
711 
712 	if (cpu_has(c, X86_FEATURE_TME))
713 		detect_tme(c);
714 
715 	init_intel_misc_features(c);
716 
717 	if (tsx_ctrl_state == TSX_CTRL_ENABLE)
718 		tsx_enable();
719 	if (tsx_ctrl_state == TSX_CTRL_DISABLE)
720 		tsx_disable();
721 
722 	split_lock_init();
723 
724 	intel_init_thermal(c);
725 }
726 
727 #ifdef CONFIG_X86_32
728 static unsigned int intel_size_cache(struct cpuinfo_x86 *c, unsigned int size)
729 {
730 	/*
731 	 * Intel PIII Tualatin. This comes in two flavours.
732 	 * One has 256kb of cache, the other 512. We have no way
733 	 * to determine which, so we use a boottime override
734 	 * for the 512kb model, and assume 256 otherwise.
735 	 */
736 	if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
737 		size = 256;
738 
739 	/*
740 	 * Intel Quark SoC X1000 contains a 4-way set associative
741 	 * 16K cache with a 16 byte cache line and 256 lines per tag
742 	 */
743 	if ((c->x86 == 5) && (c->x86_model == 9))
744 		size = 16;
745 	return size;
746 }
747 #endif
748 
749 #define TLB_INST_4K	0x01
750 #define TLB_INST_4M	0x02
751 #define TLB_INST_2M_4M	0x03
752 
753 #define TLB_INST_ALL	0x05
754 #define TLB_INST_1G	0x06
755 
756 #define TLB_DATA_4K	0x11
757 #define TLB_DATA_4M	0x12
758 #define TLB_DATA_2M_4M	0x13
759 #define TLB_DATA_4K_4M	0x14
760 
761 #define TLB_DATA_1G	0x16
762 
763 #define TLB_DATA0_4K	0x21
764 #define TLB_DATA0_4M	0x22
765 #define TLB_DATA0_2M_4M	0x23
766 
767 #define STLB_4K		0x41
768 #define STLB_4K_2M	0x42
769 
770 static const struct _tlb_table intel_tlb_table[] = {
771 	{ 0x01, TLB_INST_4K,		32,	" TLB_INST 4 KByte pages, 4-way set associative" },
772 	{ 0x02, TLB_INST_4M,		2,	" TLB_INST 4 MByte pages, full associative" },
773 	{ 0x03, TLB_DATA_4K,		64,	" TLB_DATA 4 KByte pages, 4-way set associative" },
774 	{ 0x04, TLB_DATA_4M,		8,	" TLB_DATA 4 MByte pages, 4-way set associative" },
775 	{ 0x05, TLB_DATA_4M,		32,	" TLB_DATA 4 MByte pages, 4-way set associative" },
776 	{ 0x0b, TLB_INST_4M,		4,	" TLB_INST 4 MByte pages, 4-way set associative" },
777 	{ 0x4f, TLB_INST_4K,		32,	" TLB_INST 4 KByte pages" },
778 	{ 0x50, TLB_INST_ALL,		64,	" TLB_INST 4 KByte and 2-MByte or 4-MByte pages" },
779 	{ 0x51, TLB_INST_ALL,		128,	" TLB_INST 4 KByte and 2-MByte or 4-MByte pages" },
780 	{ 0x52, TLB_INST_ALL,		256,	" TLB_INST 4 KByte and 2-MByte or 4-MByte pages" },
781 	{ 0x55, TLB_INST_2M_4M,		7,	" TLB_INST 2-MByte or 4-MByte pages, fully associative" },
782 	{ 0x56, TLB_DATA0_4M,		16,	" TLB_DATA0 4 MByte pages, 4-way set associative" },
783 	{ 0x57, TLB_DATA0_4K,		16,	" TLB_DATA0 4 KByte pages, 4-way associative" },
784 	{ 0x59, TLB_DATA0_4K,		16,	" TLB_DATA0 4 KByte pages, fully associative" },
785 	{ 0x5a, TLB_DATA0_2M_4M,	32,	" TLB_DATA0 2-MByte or 4 MByte pages, 4-way set associative" },
786 	{ 0x5b, TLB_DATA_4K_4M,		64,	" TLB_DATA 4 KByte and 4 MByte pages" },
787 	{ 0x5c, TLB_DATA_4K_4M,		128,	" TLB_DATA 4 KByte and 4 MByte pages" },
788 	{ 0x5d, TLB_DATA_4K_4M,		256,	" TLB_DATA 4 KByte and 4 MByte pages" },
789 	{ 0x61, TLB_INST_4K,		48,	" TLB_INST 4 KByte pages, full associative" },
790 	{ 0x63, TLB_DATA_1G,		4,	" TLB_DATA 1 GByte pages, 4-way set associative" },
791 	{ 0x6b, TLB_DATA_4K,		256,	" TLB_DATA 4 KByte pages, 8-way associative" },
792 	{ 0x6c, TLB_DATA_2M_4M,		128,	" TLB_DATA 2 MByte or 4 MByte pages, 8-way associative" },
793 	{ 0x6d, TLB_DATA_1G,		16,	" TLB_DATA 1 GByte pages, fully associative" },
794 	{ 0x76, TLB_INST_2M_4M,		8,	" TLB_INST 2-MByte or 4-MByte pages, fully associative" },
795 	{ 0xb0, TLB_INST_4K,		128,	" TLB_INST 4 KByte pages, 4-way set associative" },
796 	{ 0xb1, TLB_INST_2M_4M,		4,	" TLB_INST 2M pages, 4-way, 8 entries or 4M pages, 4-way entries" },
797 	{ 0xb2, TLB_INST_4K,		64,	" TLB_INST 4KByte pages, 4-way set associative" },
798 	{ 0xb3, TLB_DATA_4K,		128,	" TLB_DATA 4 KByte pages, 4-way set associative" },
799 	{ 0xb4, TLB_DATA_4K,		256,	" TLB_DATA 4 KByte pages, 4-way associative" },
800 	{ 0xb5, TLB_INST_4K,		64,	" TLB_INST 4 KByte pages, 8-way set associative" },
801 	{ 0xb6, TLB_INST_4K,		128,	" TLB_INST 4 KByte pages, 8-way set associative" },
802 	{ 0xba, TLB_DATA_4K,		64,	" TLB_DATA 4 KByte pages, 4-way associative" },
803 	{ 0xc0, TLB_DATA_4K_4M,		8,	" TLB_DATA 4 KByte and 4 MByte pages, 4-way associative" },
804 	{ 0xc1, STLB_4K_2M,		1024,	" STLB 4 KByte and 2 MByte pages, 8-way associative" },
805 	{ 0xc2, TLB_DATA_2M_4M,		16,	" TLB_DATA 2 MByte/4MByte pages, 4-way associative" },
806 	{ 0xca, STLB_4K,		512,	" STLB 4 KByte pages, 4-way associative" },
807 	{ 0x00, 0, 0 }
808 };
809 
810 static void intel_tlb_lookup(const unsigned char desc)
811 {
812 	unsigned char k;
813 	if (desc == 0)
814 		return;
815 
816 	/* look up this descriptor in the table */
817 	for (k = 0; intel_tlb_table[k].descriptor != desc &&
818 	     intel_tlb_table[k].descriptor != 0; k++)
819 		;
820 
821 	if (intel_tlb_table[k].tlb_type == 0)
822 		return;
823 
824 	switch (intel_tlb_table[k].tlb_type) {
825 	case STLB_4K:
826 		if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
827 			tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
828 		if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
829 			tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
830 		break;
831 	case STLB_4K_2M:
832 		if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
833 			tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
834 		if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
835 			tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
836 		if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries)
837 			tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries;
838 		if (tlb_lld_2m[ENTRIES] < intel_tlb_table[k].entries)
839 			tlb_lld_2m[ENTRIES] = intel_tlb_table[k].entries;
840 		if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
841 			tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
842 		if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
843 			tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
844 		break;
845 	case TLB_INST_ALL:
846 		if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
847 			tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
848 		if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries)
849 			tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries;
850 		if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
851 			tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
852 		break;
853 	case TLB_INST_4K:
854 		if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
855 			tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
856 		break;
857 	case TLB_INST_4M:
858 		if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
859 			tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
860 		break;
861 	case TLB_INST_2M_4M:
862 		if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries)
863 			tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries;
864 		if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
865 			tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
866 		break;
867 	case TLB_DATA_4K:
868 	case TLB_DATA0_4K:
869 		if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
870 			tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
871 		break;
872 	case TLB_DATA_4M:
873 	case TLB_DATA0_4M:
874 		if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
875 			tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
876 		break;
877 	case TLB_DATA_2M_4M:
878 	case TLB_DATA0_2M_4M:
879 		if (tlb_lld_2m[ENTRIES] < intel_tlb_table[k].entries)
880 			tlb_lld_2m[ENTRIES] = intel_tlb_table[k].entries;
881 		if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
882 			tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
883 		break;
884 	case TLB_DATA_4K_4M:
885 		if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
886 			tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
887 		if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
888 			tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
889 		break;
890 	case TLB_DATA_1G:
891 		if (tlb_lld_1g[ENTRIES] < intel_tlb_table[k].entries)
892 			tlb_lld_1g[ENTRIES] = intel_tlb_table[k].entries;
893 		break;
894 	}
895 }
896 
897 static void intel_detect_tlb(struct cpuinfo_x86 *c)
898 {
899 	int i, j, n;
900 	unsigned int regs[4];
901 	unsigned char *desc = (unsigned char *)regs;
902 
903 	if (c->cpuid_level < 2)
904 		return;
905 
906 	/* Number of times to iterate */
907 	n = cpuid_eax(2) & 0xFF;
908 
909 	for (i = 0 ; i < n ; i++) {
910 		cpuid(2, &regs[0], &regs[1], &regs[2], &regs[3]);
911 
912 		/* If bit 31 is set, this is an unknown format */
913 		for (j = 0 ; j < 3 ; j++)
914 			if (regs[j] & (1 << 31))
915 				regs[j] = 0;
916 
917 		/* Byte 0 is level count, not a descriptor */
918 		for (j = 1 ; j < 16 ; j++)
919 			intel_tlb_lookup(desc[j]);
920 	}
921 }
922 
923 static const struct cpu_dev intel_cpu_dev = {
924 	.c_vendor	= "Intel",
925 	.c_ident	= { "GenuineIntel" },
926 #ifdef CONFIG_X86_32
927 	.legacy_models = {
928 		{ .family = 4, .model_names =
929 		  {
930 			  [0] = "486 DX-25/33",
931 			  [1] = "486 DX-50",
932 			  [2] = "486 SX",
933 			  [3] = "486 DX/2",
934 			  [4] = "486 SL",
935 			  [5] = "486 SX/2",
936 			  [7] = "486 DX/2-WB",
937 			  [8] = "486 DX/4",
938 			  [9] = "486 DX/4-WB"
939 		  }
940 		},
941 		{ .family = 5, .model_names =
942 		  {
943 			  [0] = "Pentium 60/66 A-step",
944 			  [1] = "Pentium 60/66",
945 			  [2] = "Pentium 75 - 200",
946 			  [3] = "OverDrive PODP5V83",
947 			  [4] = "Pentium MMX",
948 			  [7] = "Mobile Pentium 75 - 200",
949 			  [8] = "Mobile Pentium MMX",
950 			  [9] = "Quark SoC X1000",
951 		  }
952 		},
953 		{ .family = 6, .model_names =
954 		  {
955 			  [0] = "Pentium Pro A-step",
956 			  [1] = "Pentium Pro",
957 			  [3] = "Pentium II (Klamath)",
958 			  [4] = "Pentium II (Deschutes)",
959 			  [5] = "Pentium II (Deschutes)",
960 			  [6] = "Mobile Pentium II",
961 			  [7] = "Pentium III (Katmai)",
962 			  [8] = "Pentium III (Coppermine)",
963 			  [10] = "Pentium III (Cascades)",
964 			  [11] = "Pentium III (Tualatin)",
965 		  }
966 		},
967 		{ .family = 15, .model_names =
968 		  {
969 			  [0] = "Pentium 4 (Unknown)",
970 			  [1] = "Pentium 4 (Willamette)",
971 			  [2] = "Pentium 4 (Northwood)",
972 			  [4] = "Pentium 4 (Foster)",
973 			  [5] = "Pentium 4 (Foster)",
974 		  }
975 		},
976 	},
977 	.legacy_cache_size = intel_size_cache,
978 #endif
979 	.c_detect_tlb	= intel_detect_tlb,
980 	.c_early_init   = early_init_intel,
981 	.c_bsp_init	= bsp_init_intel,
982 	.c_init		= init_intel,
983 	.c_x86_vendor	= X86_VENDOR_INTEL,
984 };
985 
986 cpu_dev_register(intel_cpu_dev);
987 
988 #undef pr_fmt
989 #define pr_fmt(fmt) "x86/split lock detection: " fmt
990 
991 static const struct {
992 	const char			*option;
993 	enum split_lock_detect_state	state;
994 } sld_options[] __initconst = {
995 	{ "off",	sld_off   },
996 	{ "warn",	sld_warn  },
997 	{ "fatal",	sld_fatal },
998 };
999 
1000 static inline bool match_option(const char *arg, int arglen, const char *opt)
1001 {
1002 	int len = strlen(opt);
1003 
1004 	return len == arglen && !strncmp(arg, opt, len);
1005 }
1006 
1007 static bool split_lock_verify_msr(bool on)
1008 {
1009 	u64 ctrl, tmp;
1010 
1011 	if (rdmsrl_safe(MSR_TEST_CTRL, &ctrl))
1012 		return false;
1013 	if (on)
1014 		ctrl |= MSR_TEST_CTRL_SPLIT_LOCK_DETECT;
1015 	else
1016 		ctrl &= ~MSR_TEST_CTRL_SPLIT_LOCK_DETECT;
1017 	if (wrmsrl_safe(MSR_TEST_CTRL, ctrl))
1018 		return false;
1019 	rdmsrl(MSR_TEST_CTRL, tmp);
1020 	return ctrl == tmp;
1021 }
1022 
1023 static void __init split_lock_setup(void)
1024 {
1025 	enum split_lock_detect_state state = sld_warn;
1026 	char arg[20];
1027 	int i, ret;
1028 
1029 	if (!split_lock_verify_msr(false)) {
1030 		pr_info("MSR access failed: Disabled\n");
1031 		return;
1032 	}
1033 
1034 	ret = cmdline_find_option(boot_command_line, "split_lock_detect",
1035 				  arg, sizeof(arg));
1036 	if (ret >= 0) {
1037 		for (i = 0; i < ARRAY_SIZE(sld_options); i++) {
1038 			if (match_option(arg, ret, sld_options[i].option)) {
1039 				state = sld_options[i].state;
1040 				break;
1041 			}
1042 		}
1043 	}
1044 
1045 	switch (state) {
1046 	case sld_off:
1047 		pr_info("disabled\n");
1048 		return;
1049 	case sld_warn:
1050 		pr_info("warning about user-space split_locks\n");
1051 		break;
1052 	case sld_fatal:
1053 		pr_info("sending SIGBUS on user-space split_locks\n");
1054 		break;
1055 	}
1056 
1057 	rdmsrl(MSR_TEST_CTRL, msr_test_ctrl_cache);
1058 
1059 	if (!split_lock_verify_msr(true)) {
1060 		pr_info("MSR access failed: Disabled\n");
1061 		return;
1062 	}
1063 
1064 	sld_state = state;
1065 	setup_force_cpu_cap(X86_FEATURE_SPLIT_LOCK_DETECT);
1066 }
1067 
1068 /*
1069  * MSR_TEST_CTRL is per core, but we treat it like a per CPU MSR. Locking
1070  * is not implemented as one thread could undo the setting of the other
1071  * thread immediately after dropping the lock anyway.
1072  */
1073 static void sld_update_msr(bool on)
1074 {
1075 	u64 test_ctrl_val = msr_test_ctrl_cache;
1076 
1077 	if (on)
1078 		test_ctrl_val |= MSR_TEST_CTRL_SPLIT_LOCK_DETECT;
1079 
1080 	wrmsrl(MSR_TEST_CTRL, test_ctrl_val);
1081 }
1082 
1083 static void split_lock_init(void)
1084 {
1085 	if (cpu_model_supports_sld)
1086 		split_lock_verify_msr(sld_state != sld_off);
1087 }
1088 
1089 static void split_lock_warn(unsigned long ip)
1090 {
1091 	pr_warn_ratelimited("#AC: %s/%d took a split_lock trap at address: 0x%lx\n",
1092 			    current->comm, current->pid, ip);
1093 
1094 	/*
1095 	 * Disable the split lock detection for this task so it can make
1096 	 * progress and set TIF_SLD so the detection is re-enabled via
1097 	 * switch_to_sld() when the task is scheduled out.
1098 	 */
1099 	sld_update_msr(false);
1100 	set_tsk_thread_flag(current, TIF_SLD);
1101 }
1102 
1103 bool handle_guest_split_lock(unsigned long ip)
1104 {
1105 	if (sld_state == sld_warn) {
1106 		split_lock_warn(ip);
1107 		return true;
1108 	}
1109 
1110 	pr_warn_once("#AC: %s/%d %s split_lock trap at address: 0x%lx\n",
1111 		     current->comm, current->pid,
1112 		     sld_state == sld_fatal ? "fatal" : "bogus", ip);
1113 
1114 	current->thread.error_code = 0;
1115 	current->thread.trap_nr = X86_TRAP_AC;
1116 	force_sig_fault(SIGBUS, BUS_ADRALN, NULL);
1117 	return false;
1118 }
1119 EXPORT_SYMBOL_GPL(handle_guest_split_lock);
1120 
1121 bool handle_user_split_lock(struct pt_regs *regs, long error_code)
1122 {
1123 	if ((regs->flags & X86_EFLAGS_AC) || sld_state == sld_fatal)
1124 		return false;
1125 	split_lock_warn(regs->ip);
1126 	return true;
1127 }
1128 
1129 /*
1130  * This function is called only when switching between tasks with
1131  * different split-lock detection modes. It sets the MSR for the
1132  * mode of the new task. This is right most of the time, but since
1133  * the MSR is shared by hyperthreads on a physical core there can
1134  * be glitches when the two threads need different modes.
1135  */
1136 void switch_to_sld(unsigned long tifn)
1137 {
1138 	sld_update_msr(!(tifn & _TIF_SLD));
1139 }
1140 
1141 /*
1142  * Bits in the IA32_CORE_CAPABILITIES are not architectural, so they should
1143  * only be trusted if it is confirmed that a CPU model implements a
1144  * specific feature at a particular bit position.
1145  *
1146  * The possible driver data field values:
1147  *
1148  * - 0: CPU models that are known to have the per-core split-lock detection
1149  *	feature even though they do not enumerate IA32_CORE_CAPABILITIES.
1150  *
1151  * - 1: CPU models which may enumerate IA32_CORE_CAPABILITIES and if so use
1152  *      bit 5 to enumerate the per-core split-lock detection feature.
1153  */
1154 static const struct x86_cpu_id split_lock_cpu_ids[] __initconst = {
1155 	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_X,		0),
1156 	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_L,		0),
1157 	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_D,		0),
1158 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT,	1),
1159 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT_D,	1),
1160 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT_L,	1),
1161 	X86_MATCH_INTEL_FAM6_MODEL(TIGERLAKE_L,		1),
1162 	X86_MATCH_INTEL_FAM6_MODEL(TIGERLAKE,		1),
1163 	X86_MATCH_INTEL_FAM6_MODEL(SAPPHIRERAPIDS_X,	1),
1164 	X86_MATCH_INTEL_FAM6_MODEL(ALDERLAKE,		1),
1165 	X86_MATCH_INTEL_FAM6_MODEL(ALDERLAKE_L,		1),
1166 	{}
1167 };
1168 
1169 void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c)
1170 {
1171 	const struct x86_cpu_id *m;
1172 	u64 ia32_core_caps;
1173 
1174 	if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
1175 		return;
1176 
1177 	m = x86_match_cpu(split_lock_cpu_ids);
1178 	if (!m)
1179 		return;
1180 
1181 	switch (m->driver_data) {
1182 	case 0:
1183 		break;
1184 	case 1:
1185 		if (!cpu_has(c, X86_FEATURE_CORE_CAPABILITIES))
1186 			return;
1187 		rdmsrl(MSR_IA32_CORE_CAPS, ia32_core_caps);
1188 		if (!(ia32_core_caps & MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT))
1189 			return;
1190 		break;
1191 	default:
1192 		return;
1193 	}
1194 
1195 	cpu_model_supports_sld = true;
1196 	split_lock_setup();
1197 }
1198