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1#include <linux/init.h>
2#include <linux/kernel.h>
3
4#include <linux/string.h>
5#include <linux/bitops.h>
6#include <linux/smp.h>
7#include <linux/sched.h>
8#include <linux/thread_info.h>
9#include <linux/module.h>
10#include <linux/uaccess.h>
11
12#include <asm/processor.h>
13#include <asm/pgtable.h>
14#include <asm/msr.h>
15#include <asm/bugs.h>
16#include <asm/cpu.h>
17
18#ifdef CONFIG_X86_64
19#include <linux/topology.h>
20#include <asm/numa_64.h>
21#endif
22
23#include "cpu.h"
24
25#ifdef CONFIG_X86_LOCAL_APIC
26#include <asm/mpspec.h>
27#include <asm/apic.h>
28#endif
29
30static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
31{
32 u64 misc_enable;
33
34 /* Unmask CPUID levels if masked: */
35 if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
36 rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
37
38 if (misc_enable & MSR_IA32_MISC_ENABLE_LIMIT_CPUID) {
39 misc_enable &= ~MSR_IA32_MISC_ENABLE_LIMIT_CPUID;
40 wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
41 c->cpuid_level = cpuid_eax(0);
42 get_cpu_cap(c);
43 }
44 }
45
46 if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
47 (c->x86 == 0x6 && c->x86_model >= 0x0e))
48 set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
49
50 if (c->x86 >= 6 && !cpu_has(c, X86_FEATURE_IA64)) {
51 unsigned lower_word;
52
53 wrmsr(MSR_IA32_UCODE_REV, 0, 0);
54 /* Required by the SDM */
55 sync_core();
56 rdmsr(MSR_IA32_UCODE_REV, lower_word, c->microcode);
57 }
58
59 /*
60 * Atom erratum AAE44/AAF40/AAG38/AAH41:
61 *
62 * A race condition between speculative fetches and invalidating
63 * a large page. This is worked around in microcode, but we
64 * need the microcode to have already been loaded... so if it is
65 * not, recommend a BIOS update and disable large pages.
66 */
67 if (c->x86 == 6 && c->x86_model == 0x1c && c->x86_mask <= 2 &&
68 c->microcode < 0x20e) {
69 printk(KERN_WARNING "Atom PSE erratum detected, BIOS microcode update recommended\n");
70 clear_cpu_cap(c, X86_FEATURE_PSE);
71 }
72
73#ifdef CONFIG_X86_64
74 set_cpu_cap(c, X86_FEATURE_SYSENTER32);
75#else
76 /* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
77 if (c->x86 == 15 && c->x86_cache_alignment == 64)
78 c->x86_cache_alignment = 128;
79#endif
80
81 /* CPUID workaround for 0F33/0F34 CPU */
82 if (c->x86 == 0xF && c->x86_model == 0x3
83 && (c->x86_mask == 0x3 || c->x86_mask == 0x4))
84 c->x86_phys_bits = 36;
85
86 /*
87 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
88 * with P/T states and does not stop in deep C-states.
89 *
90 * It is also reliable across cores and sockets. (but not across
91 * cabinets - we turn it off in that case explicitly.)
92 */
93 if (c->x86_power & (1 << 8)) {
94 set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
95 set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
96 if (!check_tsc_unstable())
97 sched_clock_stable = 1;
98 }
99
100 /*
101 * There is a known erratum on Pentium III and Core Solo
102 * and Core Duo CPUs.
103 * " Page with PAT set to WC while associated MTRR is UC
104 * may consolidate to UC "
105 * Because of this erratum, it is better to stick with
106 * setting WC in MTRR rather than using PAT on these CPUs.
107 *
108 * Enable PAT WC only on P4, Core 2 or later CPUs.
109 */
110 if (c->x86 == 6 && c->x86_model < 15)
111 clear_cpu_cap(c, X86_FEATURE_PAT);
112
113#ifdef CONFIG_KMEMCHECK
114 /*
115 * P4s have a "fast strings" feature which causes single-
116 * stepping REP instructions to only generate a #DB on
117 * cache-line boundaries.
118 *
119 * Ingo Molnar reported a Pentium D (model 6) and a Xeon
120 * (model 2) with the same problem.
121 */
122 if (c->x86 == 15) {
123 rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
124
125 if (misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING) {
126 printk(KERN_INFO "kmemcheck: Disabling fast string operations\n");
127
128 misc_enable &= ~MSR_IA32_MISC_ENABLE_FAST_STRING;
129 wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
130 }
131 }
132#endif
133
134 /*
135 * If fast string is not enabled in IA32_MISC_ENABLE for any reason,
136 * clear the fast string and enhanced fast string CPU capabilities.
137 */
138 if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
139 rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
140 if (!(misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING)) {
141 printk(KERN_INFO "Disabled fast string operations\n");
142 setup_clear_cpu_cap(X86_FEATURE_REP_GOOD);
143 setup_clear_cpu_cap(X86_FEATURE_ERMS);
144 }
145 }
146}
147
148#ifdef CONFIG_X86_32
149/*
150 * Early probe support logic for ppro memory erratum #50
151 *
152 * This is called before we do cpu ident work
153 */
154
155int __cpuinit ppro_with_ram_bug(void)
156{
157 /* Uses data from early_cpu_detect now */
158 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
159 boot_cpu_data.x86 == 6 &&
160 boot_cpu_data.x86_model == 1 &&
161 boot_cpu_data.x86_mask < 8) {
162 printk(KERN_INFO "Pentium Pro with Errata#50 detected. Taking evasive action.\n");
163 return 1;
164 }
165 return 0;
166}
167
168#ifdef CONFIG_X86_F00F_BUG
169static void __cpuinit trap_init_f00f_bug(void)
170{
171 __set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);
172
173 /*
174 * Update the IDT descriptor and reload the IDT so that
175 * it uses the read-only mapped virtual address.
176 */
177 idt_descr.address = fix_to_virt(FIX_F00F_IDT);
178 load_idt(&idt_descr);
179}
180#endif
181
182static void __cpuinit intel_smp_check(struct cpuinfo_x86 *c)
183{
184 /* calling is from identify_secondary_cpu() ? */
185 if (!c->cpu_index)
186 return;
187
188 /*
189 * Mask B, Pentium, but not Pentium MMX
190 */
191 if (c->x86 == 5 &&
192 c->x86_mask >= 1 && c->x86_mask <= 4 &&
193 c->x86_model <= 3) {
194 /*
195 * Remember we have B step Pentia with bugs
196 */
197 WARN_ONCE(1, "WARNING: SMP operation may be unreliable"
198 "with B stepping processors.\n");
199 }
200}
201
202static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
203{
204 unsigned long lo, hi;
205
206#ifdef CONFIG_X86_F00F_BUG
207 /*
208 * All current models of Pentium and Pentium with MMX technology CPUs
209 * have the F0 0F bug, which lets nonprivileged users lock up the
210 * system.
211 * Note that the workaround only should be initialized once...
212 */
213 c->f00f_bug = 0;
214 if (!paravirt_enabled() && c->x86 == 5) {
215 static int f00f_workaround_enabled;
216
217 c->f00f_bug = 1;
218 if (!f00f_workaround_enabled) {
219 trap_init_f00f_bug();
220 printk(KERN_NOTICE "Intel Pentium with F0 0F bug - workaround enabled.\n");
221 f00f_workaround_enabled = 1;
222 }
223 }
224#endif
225
226 /*
227 * SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until
228 * model 3 mask 3
229 */
230 if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633)
231 clear_cpu_cap(c, X86_FEATURE_SEP);
232
233 /*
234 * P4 Xeon errata 037 workaround.
235 * Hardware prefetcher may cause stale data to be loaded into the cache.
236 */
237 if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
238 rdmsr(MSR_IA32_MISC_ENABLE, lo, hi);
239 if ((lo & MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE) == 0) {
240 printk (KERN_INFO "CPU: C0 stepping P4 Xeon detected.\n");
241 printk (KERN_INFO "CPU: Disabling hardware prefetching (Errata 037)\n");
242 lo |= MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE;
243 wrmsr(MSR_IA32_MISC_ENABLE, lo, hi);
244 }
245 }
246
247 /*
248 * See if we have a good local APIC by checking for buggy Pentia,
249 * i.e. all B steppings and the C2 stepping of P54C when using their
250 * integrated APIC (see 11AP erratum in "Pentium Processor
251 * Specification Update").
252 */
253 if (cpu_has_apic && (c->x86<<8 | c->x86_model<<4) == 0x520 &&
254 (c->x86_mask < 0x6 || c->x86_mask == 0xb))
255 set_cpu_cap(c, X86_FEATURE_11AP);
256
257
258#ifdef CONFIG_X86_INTEL_USERCOPY
259 /*
260 * Set up the preferred alignment for movsl bulk memory moves
261 */
262 switch (c->x86) {
263 case 4: /* 486: untested */
264 break;
265 case 5: /* Old Pentia: untested */
266 break;
267 case 6: /* PII/PIII only like movsl with 8-byte alignment */
268 movsl_mask.mask = 7;
269 break;
270 case 15: /* P4 is OK down to 8-byte alignment */
271 movsl_mask.mask = 7;
272 break;
273 }
274#endif
275
276#ifdef CONFIG_X86_NUMAQ
277 numaq_tsc_disable();
278#endif
279
280 intel_smp_check(c);
281}
282#else
283static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
284{
285}
286#endif
287
288static void __cpuinit srat_detect_node(struct cpuinfo_x86 *c)
289{
290#ifdef CONFIG_NUMA
291 unsigned node;
292 int cpu = smp_processor_id();
293
294 /* Don't do the funky fallback heuristics the AMD version employs
295 for now. */
296 node = numa_cpu_node(cpu);
297 if (node == NUMA_NO_NODE || !node_online(node)) {
298 /* reuse the value from init_cpu_to_node() */
299 node = cpu_to_node(cpu);
300 }
301 numa_set_node(cpu, node);
302#endif
303}
304
305/*
306 * find out the number of processor cores on the die
307 */
308static int __cpuinit intel_num_cpu_cores(struct cpuinfo_x86 *c)
309{
310 unsigned int eax, ebx, ecx, edx;
311
312 if (c->cpuid_level < 4)
313 return 1;
314
315 /* Intel has a non-standard dependency on %ecx for this CPUID level. */
316 cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
317 if (eax & 0x1f)
318 return (eax >> 26) + 1;
319 else
320 return 1;
321}
322
323static void __cpuinit detect_vmx_virtcap(struct cpuinfo_x86 *c)
324{
325 /* Intel VMX MSR indicated features */
326#define X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW 0x00200000
327#define X86_VMX_FEATURE_PROC_CTLS_VNMI 0x00400000
328#define X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS 0x80000000
329#define X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC 0x00000001
330#define X86_VMX_FEATURE_PROC_CTLS2_EPT 0x00000002
331#define X86_VMX_FEATURE_PROC_CTLS2_VPID 0x00000020
332
333 u32 vmx_msr_low, vmx_msr_high, msr_ctl, msr_ctl2;
334
335 clear_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
336 clear_cpu_cap(c, X86_FEATURE_VNMI);
337 clear_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
338 clear_cpu_cap(c, X86_FEATURE_EPT);
339 clear_cpu_cap(c, X86_FEATURE_VPID);
340
341 rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, vmx_msr_low, vmx_msr_high);
342 msr_ctl = vmx_msr_high | vmx_msr_low;
343 if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW)
344 set_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
345 if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_VNMI)
346 set_cpu_cap(c, X86_FEATURE_VNMI);
347 if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS) {
348 rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2,
349 vmx_msr_low, vmx_msr_high);
350 msr_ctl2 = vmx_msr_high | vmx_msr_low;
351 if ((msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC) &&
352 (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW))
353 set_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
354 if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_EPT)
355 set_cpu_cap(c, X86_FEATURE_EPT);
356 if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VPID)
357 set_cpu_cap(c, X86_FEATURE_VPID);
358 }
359}
360
361static void __cpuinit init_intel(struct cpuinfo_x86 *c)
362{
363 unsigned int l2 = 0;
364
365 early_init_intel(c);
366
367 intel_workarounds(c);
368
369 /*
370 * Detect the extended topology information if available. This
371 * will reinitialise the initial_apicid which will be used
372 * in init_intel_cacheinfo()
373 */
374 detect_extended_topology(c);
375
376 l2 = init_intel_cacheinfo(c);
377 if (c->cpuid_level > 9) {
378 unsigned eax = cpuid_eax(10);
379 /* Check for version and the number of counters */
380 if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
381 set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON);
382 }
383
384 if (cpu_has_xmm2)
385 set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
386 if (cpu_has_ds) {
387 unsigned int l1;
388 rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
389 if (!(l1 & (1<<11)))
390 set_cpu_cap(c, X86_FEATURE_BTS);
391 if (!(l1 & (1<<12)))
392 set_cpu_cap(c, X86_FEATURE_PEBS);
393 }
394
395 if (c->x86 == 6 && c->x86_model == 29 && cpu_has_clflush)
396 set_cpu_cap(c, X86_FEATURE_CLFLUSH_MONITOR);
397
398#ifdef CONFIG_X86_64
399 if (c->x86 == 15)
400 c->x86_cache_alignment = c->x86_clflush_size * 2;
401 if (c->x86 == 6)
402 set_cpu_cap(c, X86_FEATURE_REP_GOOD);
403#else
404 /*
405 * Names for the Pentium II/Celeron processors
406 * detectable only by also checking the cache size.
407 * Dixon is NOT a Celeron.
408 */
409 if (c->x86 == 6) {
410 char *p = NULL;
411
412 switch (c->x86_model) {
413 case 5:
414 if (l2 == 0)
415 p = "Celeron (Covington)";
416 else if (l2 == 256)
417 p = "Mobile Pentium II (Dixon)";
418 break;
419
420 case 6:
421 if (l2 == 128)
422 p = "Celeron (Mendocino)";
423 else if (c->x86_mask == 0 || c->x86_mask == 5)
424 p = "Celeron-A";
425 break;
426
427 case 8:
428 if (l2 == 128)
429 p = "Celeron (Coppermine)";
430 break;
431 }
432
433 if (p)
434 strcpy(c->x86_model_id, p);
435 }
436
437 if (c->x86 == 15)
438 set_cpu_cap(c, X86_FEATURE_P4);
439 if (c->x86 == 6)
440 set_cpu_cap(c, X86_FEATURE_P3);
441#endif
442
443 if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) {
444 /*
445 * let's use the legacy cpuid vector 0x1 and 0x4 for topology
446 * detection.
447 */
448 c->x86_max_cores = intel_num_cpu_cores(c);
449#ifdef CONFIG_X86_32
450 detect_ht(c);
451#endif
452 }
453
454 /* Work around errata */
455 srat_detect_node(c);
456
457 if (cpu_has(c, X86_FEATURE_VMX))
458 detect_vmx_virtcap(c);
459
460 /*
461 * Initialize MSR_IA32_ENERGY_PERF_BIAS if BIOS did not.
462 * x86_energy_perf_policy(8) is available to change it at run-time
463 */
464 if (cpu_has(c, X86_FEATURE_EPB)) {
465 u64 epb;
466
467 rdmsrl(MSR_IA32_ENERGY_PERF_BIAS, epb);
468 if ((epb & 0xF) == ENERGY_PERF_BIAS_PERFORMANCE) {
469 printk_once(KERN_WARNING "ENERGY_PERF_BIAS:"
470 " Set to 'normal', was 'performance'\n"
471 "ENERGY_PERF_BIAS: View and update with"
472 " x86_energy_perf_policy(8)\n");
473 epb = (epb & ~0xF) | ENERGY_PERF_BIAS_NORMAL;
474 wrmsrl(MSR_IA32_ENERGY_PERF_BIAS, epb);
475 }
476 }
477}
478
479#ifdef CONFIG_X86_32
480static unsigned int __cpuinit intel_size_cache(struct cpuinfo_x86 *c, unsigned int size)
481{
482 /*
483 * Intel PIII Tualatin. This comes in two flavours.
484 * One has 256kb of cache, the other 512. We have no way
485 * to determine which, so we use a boottime override
486 * for the 512kb model, and assume 256 otherwise.
487 */
488 if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
489 size = 256;
490 return size;
491}
492#endif
493
494static const struct cpu_dev __cpuinitconst intel_cpu_dev = {
495 .c_vendor = "Intel",
496 .c_ident = { "GenuineIntel" },
497#ifdef CONFIG_X86_32
498 .c_models = {
499 { .vendor = X86_VENDOR_INTEL, .family = 4, .model_names =
500 {
501 [0] = "486 DX-25/33",
502 [1] = "486 DX-50",
503 [2] = "486 SX",
504 [3] = "486 DX/2",
505 [4] = "486 SL",
506 [5] = "486 SX/2",
507 [7] = "486 DX/2-WB",
508 [8] = "486 DX/4",
509 [9] = "486 DX/4-WB"
510 }
511 },
512 { .vendor = X86_VENDOR_INTEL, .family = 5, .model_names =
513 {
514 [0] = "Pentium 60/66 A-step",
515 [1] = "Pentium 60/66",
516 [2] = "Pentium 75 - 200",
517 [3] = "OverDrive PODP5V83",
518 [4] = "Pentium MMX",
519 [7] = "Mobile Pentium 75 - 200",
520 [8] = "Mobile Pentium MMX"
521 }
522 },
523 { .vendor = X86_VENDOR_INTEL, .family = 6, .model_names =
524 {
525 [0] = "Pentium Pro A-step",
526 [1] = "Pentium Pro",
527 [3] = "Pentium II (Klamath)",
528 [4] = "Pentium II (Deschutes)",
529 [5] = "Pentium II (Deschutes)",
530 [6] = "Mobile Pentium II",
531 [7] = "Pentium III (Katmai)",
532 [8] = "Pentium III (Coppermine)",
533 [10] = "Pentium III (Cascades)",
534 [11] = "Pentium III (Tualatin)",
535 }
536 },
537 { .vendor = X86_VENDOR_INTEL, .family = 15, .model_names =
538 {
539 [0] = "Pentium 4 (Unknown)",
540 [1] = "Pentium 4 (Willamette)",
541 [2] = "Pentium 4 (Northwood)",
542 [4] = "Pentium 4 (Foster)",
543 [5] = "Pentium 4 (Foster)",
544 }
545 },
546 },
547 .c_size_cache = intel_size_cache,
548#endif
549 .c_early_init = early_init_intel,
550 .c_init = init_intel,
551 .c_x86_vendor = X86_VENDOR_INTEL,
552};
553
554cpu_dev_register(intel_cpu_dev);
555
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/semaphore.h>
11#include <linux/thread_info.h>
12#include <linux/init.h>
13#include <linux/uaccess.h>
14#include <linux/workqueue.h>
15#include <linux/delay.h>
16#include <linux/cpuhotplug.h>
17
18#include <asm/cpufeature.h>
19#include <asm/msr.h>
20#include <asm/bugs.h>
21#include <asm/cpu.h>
22#include <asm/intel-family.h>
23#include <asm/microcode.h>
24#include <asm/hwcap2.h>
25#include <asm/elf.h>
26#include <asm/cpu_device_id.h>
27#include <asm/cmdline.h>
28#include <asm/traps.h>
29#include <asm/resctrl.h>
30#include <asm/numa.h>
31#include <asm/thermal.h>
32
33#ifdef CONFIG_X86_64
34#include <linux/topology.h>
35#endif
36
37#include "cpu.h"
38
39#ifdef CONFIG_X86_LOCAL_APIC
40#include <asm/mpspec.h>
41#include <asm/apic.h>
42#endif
43
44enum split_lock_detect_state {
45 sld_off = 0,
46 sld_warn,
47 sld_fatal,
48 sld_ratelimit,
49};
50
51/*
52 * Default to sld_off because most systems do not support split lock detection.
53 * sld_state_setup() will switch this to sld_warn on systems that support
54 * split lock/bus lock detect, unless there is a command line override.
55 */
56static enum split_lock_detect_state sld_state __ro_after_init = sld_off;
57static u64 msr_test_ctrl_cache __ro_after_init;
58
59/*
60 * With a name like MSR_TEST_CTL it should go without saying, but don't touch
61 * MSR_TEST_CTL unless the CPU is one of the whitelisted models. Writing it
62 * on CPUs that do not support SLD can cause fireworks, even when writing '0'.
63 */
64static bool cpu_model_supports_sld __ro_after_init;
65
66/*
67 * Processors which have self-snooping capability can handle conflicting
68 * memory type across CPUs by snooping its own cache. However, there exists
69 * CPU models in which having conflicting memory types still leads to
70 * unpredictable behavior, machine check errors, or hangs. Clear this
71 * feature to prevent its use on machines with known erratas.
72 */
73static void check_memory_type_self_snoop_errata(struct cpuinfo_x86 *c)
74{
75 switch (c->x86_model) {
76 case INTEL_FAM6_CORE_YONAH:
77 case INTEL_FAM6_CORE2_MEROM:
78 case INTEL_FAM6_CORE2_MEROM_L:
79 case INTEL_FAM6_CORE2_PENRYN:
80 case INTEL_FAM6_CORE2_DUNNINGTON:
81 case INTEL_FAM6_NEHALEM:
82 case INTEL_FAM6_NEHALEM_G:
83 case INTEL_FAM6_NEHALEM_EP:
84 case INTEL_FAM6_NEHALEM_EX:
85 case INTEL_FAM6_WESTMERE:
86 case INTEL_FAM6_WESTMERE_EP:
87 case INTEL_FAM6_SANDYBRIDGE:
88 setup_clear_cpu_cap(X86_FEATURE_SELFSNOOP);
89 }
90}
91
92static bool ring3mwait_disabled __read_mostly;
93
94static int __init ring3mwait_disable(char *__unused)
95{
96 ring3mwait_disabled = true;
97 return 1;
98}
99__setup("ring3mwait=disable", ring3mwait_disable);
100
101static void probe_xeon_phi_r3mwait(struct cpuinfo_x86 *c)
102{
103 /*
104 * Ring 3 MONITOR/MWAIT feature cannot be detected without
105 * cpu model and family comparison.
106 */
107 if (c->x86 != 6)
108 return;
109 switch (c->x86_model) {
110 case INTEL_FAM6_XEON_PHI_KNL:
111 case INTEL_FAM6_XEON_PHI_KNM:
112 break;
113 default:
114 return;
115 }
116
117 if (ring3mwait_disabled)
118 return;
119
120 set_cpu_cap(c, X86_FEATURE_RING3MWAIT);
121 this_cpu_or(msr_misc_features_shadow,
122 1UL << MSR_MISC_FEATURES_ENABLES_RING3MWAIT_BIT);
123
124 if (c == &boot_cpu_data)
125 ELF_HWCAP2 |= HWCAP2_RING3MWAIT;
126}
127
128/*
129 * Early microcode releases for the Spectre v2 mitigation were broken.
130 * Information taken from;
131 * - https://newsroom.intel.com/wp-content/uploads/sites/11/2018/03/microcode-update-guidance.pdf
132 * - https://kb.vmware.com/s/article/52345
133 * - Microcode revisions observed in the wild
134 * - Release note from 20180108 microcode release
135 */
136struct sku_microcode {
137 u8 model;
138 u8 stepping;
139 u32 microcode;
140};
141static const struct sku_microcode spectre_bad_microcodes[] = {
142 { INTEL_FAM6_KABYLAKE, 0x0B, 0x80 },
143 { INTEL_FAM6_KABYLAKE, 0x0A, 0x80 },
144 { INTEL_FAM6_KABYLAKE, 0x09, 0x80 },
145 { INTEL_FAM6_KABYLAKE_L, 0x0A, 0x80 },
146 { INTEL_FAM6_KABYLAKE_L, 0x09, 0x80 },
147 { INTEL_FAM6_SKYLAKE_X, 0x03, 0x0100013e },
148 { INTEL_FAM6_SKYLAKE_X, 0x04, 0x0200003c },
149 { INTEL_FAM6_BROADWELL, 0x04, 0x28 },
150 { INTEL_FAM6_BROADWELL_G, 0x01, 0x1b },
151 { INTEL_FAM6_BROADWELL_D, 0x02, 0x14 },
152 { INTEL_FAM6_BROADWELL_D, 0x03, 0x07000011 },
153 { INTEL_FAM6_BROADWELL_X, 0x01, 0x0b000025 },
154 { INTEL_FAM6_HASWELL_L, 0x01, 0x21 },
155 { INTEL_FAM6_HASWELL_G, 0x01, 0x18 },
156 { INTEL_FAM6_HASWELL, 0x03, 0x23 },
157 { INTEL_FAM6_HASWELL_X, 0x02, 0x3b },
158 { INTEL_FAM6_HASWELL_X, 0x04, 0x10 },
159 { INTEL_FAM6_IVYBRIDGE_X, 0x04, 0x42a },
160 /* Observed in the wild */
161 { INTEL_FAM6_SANDYBRIDGE_X, 0x06, 0x61b },
162 { INTEL_FAM6_SANDYBRIDGE_X, 0x07, 0x712 },
163};
164
165static bool bad_spectre_microcode(struct cpuinfo_x86 *c)
166{
167 int i;
168
169 /*
170 * We know that the hypervisor lie to us on the microcode version so
171 * we may as well hope that it is running the correct version.
172 */
173 if (cpu_has(c, X86_FEATURE_HYPERVISOR))
174 return false;
175
176 if (c->x86 != 6)
177 return false;
178
179 for (i = 0; i < ARRAY_SIZE(spectre_bad_microcodes); i++) {
180 if (c->x86_model == spectre_bad_microcodes[i].model &&
181 c->x86_stepping == spectre_bad_microcodes[i].stepping)
182 return (c->microcode <= spectre_bad_microcodes[i].microcode);
183 }
184 return false;
185}
186
187#define MSR_IA32_TME_ACTIVATE 0x982
188
189/* Helpers to access TME_ACTIVATE MSR */
190#define TME_ACTIVATE_LOCKED(x) (x & 0x1)
191#define TME_ACTIVATE_ENABLED(x) (x & 0x2)
192
193#define TME_ACTIVATE_POLICY(x) ((x >> 4) & 0xf) /* Bits 7:4 */
194#define TME_ACTIVATE_POLICY_AES_XTS_128 0
195
196#define TME_ACTIVATE_KEYID_BITS(x) ((x >> 32) & 0xf) /* Bits 35:32 */
197
198#define TME_ACTIVATE_CRYPTO_ALGS(x) ((x >> 48) & 0xffff) /* Bits 63:48 */
199#define TME_ACTIVATE_CRYPTO_AES_XTS_128 1
200
201/* Values for mktme_status (SW only construct) */
202#define MKTME_ENABLED 0
203#define MKTME_DISABLED 1
204#define MKTME_UNINITIALIZED 2
205static int mktme_status = MKTME_UNINITIALIZED;
206
207static void detect_tme_early(struct cpuinfo_x86 *c)
208{
209 u64 tme_activate, tme_policy, tme_crypto_algs;
210 int keyid_bits = 0, nr_keyids = 0;
211 static u64 tme_activate_cpu0 = 0;
212
213 rdmsrl(MSR_IA32_TME_ACTIVATE, tme_activate);
214
215 if (mktme_status != MKTME_UNINITIALIZED) {
216 if (tme_activate != tme_activate_cpu0) {
217 /* Broken BIOS? */
218 pr_err_once("x86/tme: configuration is inconsistent between CPUs\n");
219 pr_err_once("x86/tme: MKTME is not usable\n");
220 mktme_status = MKTME_DISABLED;
221
222 /* Proceed. We may need to exclude bits from x86_phys_bits. */
223 }
224 } else {
225 tme_activate_cpu0 = tme_activate;
226 }
227
228 if (!TME_ACTIVATE_LOCKED(tme_activate) || !TME_ACTIVATE_ENABLED(tme_activate)) {
229 pr_info_once("x86/tme: not enabled by BIOS\n");
230 mktme_status = MKTME_DISABLED;
231 return;
232 }
233
234 if (mktme_status != MKTME_UNINITIALIZED)
235 goto detect_keyid_bits;
236
237 pr_info("x86/tme: enabled by BIOS\n");
238
239 tme_policy = TME_ACTIVATE_POLICY(tme_activate);
240 if (tme_policy != TME_ACTIVATE_POLICY_AES_XTS_128)
241 pr_warn("x86/tme: Unknown policy is active: %#llx\n", tme_policy);
242
243 tme_crypto_algs = TME_ACTIVATE_CRYPTO_ALGS(tme_activate);
244 if (!(tme_crypto_algs & TME_ACTIVATE_CRYPTO_AES_XTS_128)) {
245 pr_err("x86/mktme: No known encryption algorithm is supported: %#llx\n",
246 tme_crypto_algs);
247 mktme_status = MKTME_DISABLED;
248 }
249detect_keyid_bits:
250 keyid_bits = TME_ACTIVATE_KEYID_BITS(tme_activate);
251 nr_keyids = (1UL << keyid_bits) - 1;
252 if (nr_keyids) {
253 pr_info_once("x86/mktme: enabled by BIOS\n");
254 pr_info_once("x86/mktme: %d KeyIDs available\n", nr_keyids);
255 } else {
256 pr_info_once("x86/mktme: disabled by BIOS\n");
257 }
258
259 if (mktme_status == MKTME_UNINITIALIZED) {
260 /* MKTME is usable */
261 mktme_status = MKTME_ENABLED;
262 }
263
264 /*
265 * KeyID bits effectively lower the number of physical address
266 * bits. Update cpuinfo_x86::x86_phys_bits accordingly.
267 */
268 c->x86_phys_bits -= keyid_bits;
269}
270
271static void early_init_intel(struct cpuinfo_x86 *c)
272{
273 u64 misc_enable;
274
275 /* Unmask CPUID levels if masked: */
276 if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
277 if (msr_clear_bit(MSR_IA32_MISC_ENABLE,
278 MSR_IA32_MISC_ENABLE_LIMIT_CPUID_BIT) > 0) {
279 c->cpuid_level = cpuid_eax(0);
280 get_cpu_cap(c);
281 }
282 }
283
284 if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
285 (c->x86 == 0x6 && c->x86_model >= 0x0e))
286 set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
287
288 if (c->x86 >= 6 && !cpu_has(c, X86_FEATURE_IA64))
289 c->microcode = intel_get_microcode_revision();
290
291 /* Now if any of them are set, check the blacklist and clear the lot */
292 if ((cpu_has(c, X86_FEATURE_SPEC_CTRL) ||
293 cpu_has(c, X86_FEATURE_INTEL_STIBP) ||
294 cpu_has(c, X86_FEATURE_IBRS) || cpu_has(c, X86_FEATURE_IBPB) ||
295 cpu_has(c, X86_FEATURE_STIBP)) && bad_spectre_microcode(c)) {
296 pr_warn("Intel Spectre v2 broken microcode detected; disabling Speculation Control\n");
297 setup_clear_cpu_cap(X86_FEATURE_IBRS);
298 setup_clear_cpu_cap(X86_FEATURE_IBPB);
299 setup_clear_cpu_cap(X86_FEATURE_STIBP);
300 setup_clear_cpu_cap(X86_FEATURE_SPEC_CTRL);
301 setup_clear_cpu_cap(X86_FEATURE_MSR_SPEC_CTRL);
302 setup_clear_cpu_cap(X86_FEATURE_INTEL_STIBP);
303 setup_clear_cpu_cap(X86_FEATURE_SSBD);
304 setup_clear_cpu_cap(X86_FEATURE_SPEC_CTRL_SSBD);
305 }
306
307 /*
308 * Atom erratum AAE44/AAF40/AAG38/AAH41:
309 *
310 * A race condition between speculative fetches and invalidating
311 * a large page. This is worked around in microcode, but we
312 * need the microcode to have already been loaded... so if it is
313 * not, recommend a BIOS update and disable large pages.
314 */
315 if (c->x86 == 6 && c->x86_model == 0x1c && c->x86_stepping <= 2 &&
316 c->microcode < 0x20e) {
317 pr_warn("Atom PSE erratum detected, BIOS microcode update recommended\n");
318 clear_cpu_cap(c, X86_FEATURE_PSE);
319 }
320
321#ifdef CONFIG_X86_64
322 set_cpu_cap(c, X86_FEATURE_SYSENTER32);
323#else
324 /* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
325 if (c->x86 == 15 && c->x86_cache_alignment == 64)
326 c->x86_cache_alignment = 128;
327#endif
328
329 /* CPUID workaround for 0F33/0F34 CPU */
330 if (c->x86 == 0xF && c->x86_model == 0x3
331 && (c->x86_stepping == 0x3 || c->x86_stepping == 0x4))
332 c->x86_phys_bits = 36;
333
334 /*
335 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
336 * with P/T states and does not stop in deep C-states.
337 *
338 * It is also reliable across cores and sockets. (but not across
339 * cabinets - we turn it off in that case explicitly.)
340 */
341 if (c->x86_power & (1 << 8)) {
342 set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
343 set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
344 }
345
346 /* Penwell and Cloverview have the TSC which doesn't sleep on S3 */
347 if (c->x86 == 6) {
348 switch (c->x86_model) {
349 case INTEL_FAM6_ATOM_SALTWELL_MID:
350 case INTEL_FAM6_ATOM_SALTWELL_TABLET:
351 case INTEL_FAM6_ATOM_SILVERMONT_MID:
352 case INTEL_FAM6_ATOM_AIRMONT_NP:
353 set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC_S3);
354 break;
355 default:
356 break;
357 }
358 }
359
360 /*
361 * There is a known erratum on Pentium III and Core Solo
362 * and Core Duo CPUs.
363 * " Page with PAT set to WC while associated MTRR is UC
364 * may consolidate to UC "
365 * Because of this erratum, it is better to stick with
366 * setting WC in MTRR rather than using PAT on these CPUs.
367 *
368 * Enable PAT WC only on P4, Core 2 or later CPUs.
369 */
370 if (c->x86 == 6 && c->x86_model < 15)
371 clear_cpu_cap(c, X86_FEATURE_PAT);
372
373 /*
374 * If fast string is not enabled in IA32_MISC_ENABLE for any reason,
375 * clear the fast string and enhanced fast string CPU capabilities.
376 */
377 if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
378 rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
379 if (!(misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING)) {
380 pr_info("Disabled fast string operations\n");
381 setup_clear_cpu_cap(X86_FEATURE_REP_GOOD);
382 setup_clear_cpu_cap(X86_FEATURE_ERMS);
383 }
384 }
385
386 /*
387 * Intel Quark Core DevMan_001.pdf section 6.4.11
388 * "The operating system also is required to invalidate (i.e., flush)
389 * the TLB when any changes are made to any of the page table entries.
390 * The operating system must reload CR3 to cause the TLB to be flushed"
391 *
392 * As a result, boot_cpu_has(X86_FEATURE_PGE) in arch/x86/include/asm/tlbflush.h
393 * should be false so that __flush_tlb_all() causes CR3 instead of CR4.PGE
394 * to be modified.
395 */
396 if (c->x86 == 5 && c->x86_model == 9) {
397 pr_info("Disabling PGE capability bit\n");
398 setup_clear_cpu_cap(X86_FEATURE_PGE);
399 }
400
401 check_memory_type_self_snoop_errata(c);
402
403 /*
404 * Get the number of SMT siblings early from the extended topology
405 * leaf, if available. Otherwise try the legacy SMT detection.
406 */
407 if (detect_extended_topology_early(c) < 0)
408 detect_ht_early(c);
409
410 /*
411 * Adjust the number of physical bits early because it affects the
412 * valid bits of the MTRR mask registers.
413 */
414 if (cpu_has(c, X86_FEATURE_TME))
415 detect_tme_early(c);
416}
417
418static void bsp_init_intel(struct cpuinfo_x86 *c)
419{
420 resctrl_cpu_detect(c);
421}
422
423#ifdef CONFIG_X86_32
424/*
425 * Early probe support logic for ppro memory erratum #50
426 *
427 * This is called before we do cpu ident work
428 */
429
430int ppro_with_ram_bug(void)
431{
432 /* Uses data from early_cpu_detect now */
433 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
434 boot_cpu_data.x86 == 6 &&
435 boot_cpu_data.x86_model == 1 &&
436 boot_cpu_data.x86_stepping < 8) {
437 pr_info("Pentium Pro with Errata#50 detected. Taking evasive action.\n");
438 return 1;
439 }
440 return 0;
441}
442
443static void intel_smp_check(struct cpuinfo_x86 *c)
444{
445 /* calling is from identify_secondary_cpu() ? */
446 if (!c->cpu_index)
447 return;
448
449 /*
450 * Mask B, Pentium, but not Pentium MMX
451 */
452 if (c->x86 == 5 &&
453 c->x86_stepping >= 1 && c->x86_stepping <= 4 &&
454 c->x86_model <= 3) {
455 /*
456 * Remember we have B step Pentia with bugs
457 */
458 WARN_ONCE(1, "WARNING: SMP operation may be unreliable"
459 "with B stepping processors.\n");
460 }
461}
462
463static int forcepae;
464static int __init forcepae_setup(char *__unused)
465{
466 forcepae = 1;
467 return 1;
468}
469__setup("forcepae", forcepae_setup);
470
471static void intel_workarounds(struct cpuinfo_x86 *c)
472{
473#ifdef CONFIG_X86_F00F_BUG
474 /*
475 * All models of Pentium and Pentium with MMX technology CPUs
476 * have the F0 0F bug, which lets nonprivileged users lock up the
477 * system. Announce that the fault handler will be checking for it.
478 * The Quark is also family 5, but does not have the same bug.
479 */
480 clear_cpu_bug(c, X86_BUG_F00F);
481 if (c->x86 == 5 && c->x86_model < 9) {
482 static int f00f_workaround_enabled;
483
484 set_cpu_bug(c, X86_BUG_F00F);
485 if (!f00f_workaround_enabled) {
486 pr_notice("Intel Pentium with F0 0F bug - workaround enabled.\n");
487 f00f_workaround_enabled = 1;
488 }
489 }
490#endif
491
492 /*
493 * SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until
494 * model 3 mask 3
495 */
496 if ((c->x86<<8 | c->x86_model<<4 | c->x86_stepping) < 0x633)
497 clear_cpu_cap(c, X86_FEATURE_SEP);
498
499 /*
500 * PAE CPUID issue: many Pentium M report no PAE but may have a
501 * functionally usable PAE implementation.
502 * Forcefully enable PAE if kernel parameter "forcepae" is present.
503 */
504 if (forcepae) {
505 pr_warn("PAE forced!\n");
506 set_cpu_cap(c, X86_FEATURE_PAE);
507 add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_NOW_UNRELIABLE);
508 }
509
510 /*
511 * P4 Xeon erratum 037 workaround.
512 * Hardware prefetcher may cause stale data to be loaded into the cache.
513 */
514 if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_stepping == 1)) {
515 if (msr_set_bit(MSR_IA32_MISC_ENABLE,
516 MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE_BIT) > 0) {
517 pr_info("CPU: C0 stepping P4 Xeon detected.\n");
518 pr_info("CPU: Disabling hardware prefetching (Erratum 037)\n");
519 }
520 }
521
522 /*
523 * See if we have a good local APIC by checking for buggy Pentia,
524 * i.e. all B steppings and the C2 stepping of P54C when using their
525 * integrated APIC (see 11AP erratum in "Pentium Processor
526 * Specification Update").
527 */
528 if (boot_cpu_has(X86_FEATURE_APIC) && (c->x86<<8 | c->x86_model<<4) == 0x520 &&
529 (c->x86_stepping < 0x6 || c->x86_stepping == 0xb))
530 set_cpu_bug(c, X86_BUG_11AP);
531
532
533#ifdef CONFIG_X86_INTEL_USERCOPY
534 /*
535 * Set up the preferred alignment for movsl bulk memory moves
536 */
537 switch (c->x86) {
538 case 4: /* 486: untested */
539 break;
540 case 5: /* Old Pentia: untested */
541 break;
542 case 6: /* PII/PIII only like movsl with 8-byte alignment */
543 movsl_mask.mask = 7;
544 break;
545 case 15: /* P4 is OK down to 8-byte alignment */
546 movsl_mask.mask = 7;
547 break;
548 }
549#endif
550
551 intel_smp_check(c);
552}
553#else
554static void intel_workarounds(struct cpuinfo_x86 *c)
555{
556}
557#endif
558
559static void srat_detect_node(struct cpuinfo_x86 *c)
560{
561#ifdef CONFIG_NUMA
562 unsigned node;
563 int cpu = smp_processor_id();
564
565 /* Don't do the funky fallback heuristics the AMD version employs
566 for now. */
567 node = numa_cpu_node(cpu);
568 if (node == NUMA_NO_NODE || !node_online(node)) {
569 /* reuse the value from init_cpu_to_node() */
570 node = cpu_to_node(cpu);
571 }
572 numa_set_node(cpu, node);
573#endif
574}
575
576static void init_cpuid_fault(struct cpuinfo_x86 *c)
577{
578 u64 msr;
579
580 if (!rdmsrl_safe(MSR_PLATFORM_INFO, &msr)) {
581 if (msr & MSR_PLATFORM_INFO_CPUID_FAULT)
582 set_cpu_cap(c, X86_FEATURE_CPUID_FAULT);
583 }
584}
585
586static void init_intel_misc_features(struct cpuinfo_x86 *c)
587{
588 u64 msr;
589
590 if (rdmsrl_safe(MSR_MISC_FEATURES_ENABLES, &msr))
591 return;
592
593 /* Clear all MISC features */
594 this_cpu_write(msr_misc_features_shadow, 0);
595
596 /* Check features and update capabilities and shadow control bits */
597 init_cpuid_fault(c);
598 probe_xeon_phi_r3mwait(c);
599
600 msr = this_cpu_read(msr_misc_features_shadow);
601 wrmsrl(MSR_MISC_FEATURES_ENABLES, msr);
602}
603
604static void split_lock_init(void);
605static void bus_lock_init(void);
606
607static 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 & MSR_IA32_MISC_ENABLE_BTS_UNAVAIL))
648 set_cpu_cap(c, X86_FEATURE_BTS);
649 if (!(l1 & MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL))
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 init_intel_misc_features(c);
713
714 split_lock_init();
715 bus_lock_init();
716
717 intel_init_thermal(c);
718}
719
720#ifdef CONFIG_X86_32
721static unsigned int intel_size_cache(struct cpuinfo_x86 *c, unsigned int size)
722{
723 /*
724 * Intel PIII Tualatin. This comes in two flavours.
725 * One has 256kb of cache, the other 512. We have no way
726 * to determine which, so we use a boottime override
727 * for the 512kb model, and assume 256 otherwise.
728 */
729 if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
730 size = 256;
731
732 /*
733 * Intel Quark SoC X1000 contains a 4-way set associative
734 * 16K cache with a 16 byte cache line and 256 lines per tag
735 */
736 if ((c->x86 == 5) && (c->x86_model == 9))
737 size = 16;
738 return size;
739}
740#endif
741
742#define TLB_INST_4K 0x01
743#define TLB_INST_4M 0x02
744#define TLB_INST_2M_4M 0x03
745
746#define TLB_INST_ALL 0x05
747#define TLB_INST_1G 0x06
748
749#define TLB_DATA_4K 0x11
750#define TLB_DATA_4M 0x12
751#define TLB_DATA_2M_4M 0x13
752#define TLB_DATA_4K_4M 0x14
753
754#define TLB_DATA_1G 0x16
755
756#define TLB_DATA0_4K 0x21
757#define TLB_DATA0_4M 0x22
758#define TLB_DATA0_2M_4M 0x23
759
760#define STLB_4K 0x41
761#define STLB_4K_2M 0x42
762
763static const struct _tlb_table intel_tlb_table[] = {
764 { 0x01, TLB_INST_4K, 32, " TLB_INST 4 KByte pages, 4-way set associative" },
765 { 0x02, TLB_INST_4M, 2, " TLB_INST 4 MByte pages, full associative" },
766 { 0x03, TLB_DATA_4K, 64, " TLB_DATA 4 KByte pages, 4-way set associative" },
767 { 0x04, TLB_DATA_4M, 8, " TLB_DATA 4 MByte pages, 4-way set associative" },
768 { 0x05, TLB_DATA_4M, 32, " TLB_DATA 4 MByte pages, 4-way set associative" },
769 { 0x0b, TLB_INST_4M, 4, " TLB_INST 4 MByte pages, 4-way set associative" },
770 { 0x4f, TLB_INST_4K, 32, " TLB_INST 4 KByte pages" },
771 { 0x50, TLB_INST_ALL, 64, " TLB_INST 4 KByte and 2-MByte or 4-MByte pages" },
772 { 0x51, TLB_INST_ALL, 128, " TLB_INST 4 KByte and 2-MByte or 4-MByte pages" },
773 { 0x52, TLB_INST_ALL, 256, " TLB_INST 4 KByte and 2-MByte or 4-MByte pages" },
774 { 0x55, TLB_INST_2M_4M, 7, " TLB_INST 2-MByte or 4-MByte pages, fully associative" },
775 { 0x56, TLB_DATA0_4M, 16, " TLB_DATA0 4 MByte pages, 4-way set associative" },
776 { 0x57, TLB_DATA0_4K, 16, " TLB_DATA0 4 KByte pages, 4-way associative" },
777 { 0x59, TLB_DATA0_4K, 16, " TLB_DATA0 4 KByte pages, fully associative" },
778 { 0x5a, TLB_DATA0_2M_4M, 32, " TLB_DATA0 2-MByte or 4 MByte pages, 4-way set associative" },
779 { 0x5b, TLB_DATA_4K_4M, 64, " TLB_DATA 4 KByte and 4 MByte pages" },
780 { 0x5c, TLB_DATA_4K_4M, 128, " TLB_DATA 4 KByte and 4 MByte pages" },
781 { 0x5d, TLB_DATA_4K_4M, 256, " TLB_DATA 4 KByte and 4 MByte pages" },
782 { 0x61, TLB_INST_4K, 48, " TLB_INST 4 KByte pages, full associative" },
783 { 0x63, TLB_DATA_1G, 4, " TLB_DATA 1 GByte pages, 4-way set associative" },
784 { 0x6b, TLB_DATA_4K, 256, " TLB_DATA 4 KByte pages, 8-way associative" },
785 { 0x6c, TLB_DATA_2M_4M, 128, " TLB_DATA 2 MByte or 4 MByte pages, 8-way associative" },
786 { 0x6d, TLB_DATA_1G, 16, " TLB_DATA 1 GByte pages, fully associative" },
787 { 0x76, TLB_INST_2M_4M, 8, " TLB_INST 2-MByte or 4-MByte pages, fully associative" },
788 { 0xb0, TLB_INST_4K, 128, " TLB_INST 4 KByte pages, 4-way set associative" },
789 { 0xb1, TLB_INST_2M_4M, 4, " TLB_INST 2M pages, 4-way, 8 entries or 4M pages, 4-way entries" },
790 { 0xb2, TLB_INST_4K, 64, " TLB_INST 4KByte pages, 4-way set associative" },
791 { 0xb3, TLB_DATA_4K, 128, " TLB_DATA 4 KByte pages, 4-way set associative" },
792 { 0xb4, TLB_DATA_4K, 256, " TLB_DATA 4 KByte pages, 4-way associative" },
793 { 0xb5, TLB_INST_4K, 64, " TLB_INST 4 KByte pages, 8-way set associative" },
794 { 0xb6, TLB_INST_4K, 128, " TLB_INST 4 KByte pages, 8-way set associative" },
795 { 0xba, TLB_DATA_4K, 64, " TLB_DATA 4 KByte pages, 4-way associative" },
796 { 0xc0, TLB_DATA_4K_4M, 8, " TLB_DATA 4 KByte and 4 MByte pages, 4-way associative" },
797 { 0xc1, STLB_4K_2M, 1024, " STLB 4 KByte and 2 MByte pages, 8-way associative" },
798 { 0xc2, TLB_DATA_2M_4M, 16, " TLB_DATA 2 MByte/4MByte pages, 4-way associative" },
799 { 0xca, STLB_4K, 512, " STLB 4 KByte pages, 4-way associative" },
800 { 0x00, 0, 0 }
801};
802
803static void intel_tlb_lookup(const unsigned char desc)
804{
805 unsigned char k;
806 if (desc == 0)
807 return;
808
809 /* look up this descriptor in the table */
810 for (k = 0; intel_tlb_table[k].descriptor != desc &&
811 intel_tlb_table[k].descriptor != 0; k++)
812 ;
813
814 if (intel_tlb_table[k].tlb_type == 0)
815 return;
816
817 switch (intel_tlb_table[k].tlb_type) {
818 case STLB_4K:
819 if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
820 tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
821 if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
822 tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
823 break;
824 case STLB_4K_2M:
825 if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
826 tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
827 if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
828 tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
829 if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries)
830 tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries;
831 if (tlb_lld_2m[ENTRIES] < intel_tlb_table[k].entries)
832 tlb_lld_2m[ENTRIES] = intel_tlb_table[k].entries;
833 if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
834 tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
835 if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
836 tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
837 break;
838 case TLB_INST_ALL:
839 if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
840 tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
841 if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries)
842 tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries;
843 if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
844 tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
845 break;
846 case TLB_INST_4K:
847 if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
848 tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
849 break;
850 case TLB_INST_4M:
851 if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
852 tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
853 break;
854 case TLB_INST_2M_4M:
855 if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries)
856 tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries;
857 if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
858 tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
859 break;
860 case TLB_DATA_4K:
861 case TLB_DATA0_4K:
862 if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
863 tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
864 break;
865 case TLB_DATA_4M:
866 case TLB_DATA0_4M:
867 if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
868 tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
869 break;
870 case TLB_DATA_2M_4M:
871 case TLB_DATA0_2M_4M:
872 if (tlb_lld_2m[ENTRIES] < intel_tlb_table[k].entries)
873 tlb_lld_2m[ENTRIES] = intel_tlb_table[k].entries;
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_4K_4M:
878 if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
879 tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
880 if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
881 tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
882 break;
883 case TLB_DATA_1G:
884 if (tlb_lld_1g[ENTRIES] < intel_tlb_table[k].entries)
885 tlb_lld_1g[ENTRIES] = intel_tlb_table[k].entries;
886 break;
887 }
888}
889
890static void intel_detect_tlb(struct cpuinfo_x86 *c)
891{
892 int i, j, n;
893 unsigned int regs[4];
894 unsigned char *desc = (unsigned char *)regs;
895
896 if (c->cpuid_level < 2)
897 return;
898
899 /* Number of times to iterate */
900 n = cpuid_eax(2) & 0xFF;
901
902 for (i = 0 ; i < n ; i++) {
903 cpuid(2, ®s[0], ®s[1], ®s[2], ®s[3]);
904
905 /* If bit 31 is set, this is an unknown format */
906 for (j = 0 ; j < 3 ; j++)
907 if (regs[j] & (1 << 31))
908 regs[j] = 0;
909
910 /* Byte 0 is level count, not a descriptor */
911 for (j = 1 ; j < 16 ; j++)
912 intel_tlb_lookup(desc[j]);
913 }
914}
915
916static const struct cpu_dev intel_cpu_dev = {
917 .c_vendor = "Intel",
918 .c_ident = { "GenuineIntel" },
919#ifdef CONFIG_X86_32
920 .legacy_models = {
921 { .family = 4, .model_names =
922 {
923 [0] = "486 DX-25/33",
924 [1] = "486 DX-50",
925 [2] = "486 SX",
926 [3] = "486 DX/2",
927 [4] = "486 SL",
928 [5] = "486 SX/2",
929 [7] = "486 DX/2-WB",
930 [8] = "486 DX/4",
931 [9] = "486 DX/4-WB"
932 }
933 },
934 { .family = 5, .model_names =
935 {
936 [0] = "Pentium 60/66 A-step",
937 [1] = "Pentium 60/66",
938 [2] = "Pentium 75 - 200",
939 [3] = "OverDrive PODP5V83",
940 [4] = "Pentium MMX",
941 [7] = "Mobile Pentium 75 - 200",
942 [8] = "Mobile Pentium MMX",
943 [9] = "Quark SoC X1000",
944 }
945 },
946 { .family = 6, .model_names =
947 {
948 [0] = "Pentium Pro A-step",
949 [1] = "Pentium Pro",
950 [3] = "Pentium II (Klamath)",
951 [4] = "Pentium II (Deschutes)",
952 [5] = "Pentium II (Deschutes)",
953 [6] = "Mobile Pentium II",
954 [7] = "Pentium III (Katmai)",
955 [8] = "Pentium III (Coppermine)",
956 [10] = "Pentium III (Cascades)",
957 [11] = "Pentium III (Tualatin)",
958 }
959 },
960 { .family = 15, .model_names =
961 {
962 [0] = "Pentium 4 (Unknown)",
963 [1] = "Pentium 4 (Willamette)",
964 [2] = "Pentium 4 (Northwood)",
965 [4] = "Pentium 4 (Foster)",
966 [5] = "Pentium 4 (Foster)",
967 }
968 },
969 },
970 .legacy_cache_size = intel_size_cache,
971#endif
972 .c_detect_tlb = intel_detect_tlb,
973 .c_early_init = early_init_intel,
974 .c_bsp_init = bsp_init_intel,
975 .c_init = init_intel,
976 .c_x86_vendor = X86_VENDOR_INTEL,
977};
978
979cpu_dev_register(intel_cpu_dev);
980
981#undef pr_fmt
982#define pr_fmt(fmt) "x86/split lock detection: " fmt
983
984static const struct {
985 const char *option;
986 enum split_lock_detect_state state;
987} sld_options[] __initconst = {
988 { "off", sld_off },
989 { "warn", sld_warn },
990 { "fatal", sld_fatal },
991 { "ratelimit:", sld_ratelimit },
992};
993
994static struct ratelimit_state bld_ratelimit;
995
996static unsigned int sysctl_sld_mitigate = 1;
997static DEFINE_SEMAPHORE(buslock_sem, 1);
998
999#ifdef CONFIG_PROC_SYSCTL
1000static struct ctl_table sld_sysctls[] = {
1001 {
1002 .procname = "split_lock_mitigate",
1003 .data = &sysctl_sld_mitigate,
1004 .maxlen = sizeof(unsigned int),
1005 .mode = 0644,
1006 .proc_handler = proc_douintvec_minmax,
1007 .extra1 = SYSCTL_ZERO,
1008 .extra2 = SYSCTL_ONE,
1009 },
1010};
1011
1012static int __init sld_mitigate_sysctl_init(void)
1013{
1014 register_sysctl_init("kernel", sld_sysctls);
1015 return 0;
1016}
1017
1018late_initcall(sld_mitigate_sysctl_init);
1019#endif
1020
1021static inline bool match_option(const char *arg, int arglen, const char *opt)
1022{
1023 int len = strlen(opt), ratelimit;
1024
1025 if (strncmp(arg, opt, len))
1026 return false;
1027
1028 /*
1029 * Min ratelimit is 1 bus lock/sec.
1030 * Max ratelimit is 1000 bus locks/sec.
1031 */
1032 if (sscanf(arg, "ratelimit:%d", &ratelimit) == 1 &&
1033 ratelimit > 0 && ratelimit <= 1000) {
1034 ratelimit_state_init(&bld_ratelimit, HZ, ratelimit);
1035 ratelimit_set_flags(&bld_ratelimit, RATELIMIT_MSG_ON_RELEASE);
1036 return true;
1037 }
1038
1039 return len == arglen;
1040}
1041
1042static bool split_lock_verify_msr(bool on)
1043{
1044 u64 ctrl, tmp;
1045
1046 if (rdmsrl_safe(MSR_TEST_CTRL, &ctrl))
1047 return false;
1048 if (on)
1049 ctrl |= MSR_TEST_CTRL_SPLIT_LOCK_DETECT;
1050 else
1051 ctrl &= ~MSR_TEST_CTRL_SPLIT_LOCK_DETECT;
1052 if (wrmsrl_safe(MSR_TEST_CTRL, ctrl))
1053 return false;
1054 rdmsrl(MSR_TEST_CTRL, tmp);
1055 return ctrl == tmp;
1056}
1057
1058static void __init sld_state_setup(void)
1059{
1060 enum split_lock_detect_state state = sld_warn;
1061 char arg[20];
1062 int i, ret;
1063
1064 if (!boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) &&
1065 !boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT))
1066 return;
1067
1068 ret = cmdline_find_option(boot_command_line, "split_lock_detect",
1069 arg, sizeof(arg));
1070 if (ret >= 0) {
1071 for (i = 0; i < ARRAY_SIZE(sld_options); i++) {
1072 if (match_option(arg, ret, sld_options[i].option)) {
1073 state = sld_options[i].state;
1074 break;
1075 }
1076 }
1077 }
1078 sld_state = state;
1079}
1080
1081static void __init __split_lock_setup(void)
1082{
1083 if (!split_lock_verify_msr(false)) {
1084 pr_info("MSR access failed: Disabled\n");
1085 return;
1086 }
1087
1088 rdmsrl(MSR_TEST_CTRL, msr_test_ctrl_cache);
1089
1090 if (!split_lock_verify_msr(true)) {
1091 pr_info("MSR access failed: Disabled\n");
1092 return;
1093 }
1094
1095 /* Restore the MSR to its cached value. */
1096 wrmsrl(MSR_TEST_CTRL, msr_test_ctrl_cache);
1097
1098 setup_force_cpu_cap(X86_FEATURE_SPLIT_LOCK_DETECT);
1099}
1100
1101/*
1102 * MSR_TEST_CTRL is per core, but we treat it like a per CPU MSR. Locking
1103 * is not implemented as one thread could undo the setting of the other
1104 * thread immediately after dropping the lock anyway.
1105 */
1106static void sld_update_msr(bool on)
1107{
1108 u64 test_ctrl_val = msr_test_ctrl_cache;
1109
1110 if (on)
1111 test_ctrl_val |= MSR_TEST_CTRL_SPLIT_LOCK_DETECT;
1112
1113 wrmsrl(MSR_TEST_CTRL, test_ctrl_val);
1114}
1115
1116static void split_lock_init(void)
1117{
1118 /*
1119 * #DB for bus lock handles ratelimit and #AC for split lock is
1120 * disabled.
1121 */
1122 if (sld_state == sld_ratelimit) {
1123 split_lock_verify_msr(false);
1124 return;
1125 }
1126
1127 if (cpu_model_supports_sld)
1128 split_lock_verify_msr(sld_state != sld_off);
1129}
1130
1131static void __split_lock_reenable_unlock(struct work_struct *work)
1132{
1133 sld_update_msr(true);
1134 up(&buslock_sem);
1135}
1136
1137static DECLARE_DELAYED_WORK(sl_reenable_unlock, __split_lock_reenable_unlock);
1138
1139static void __split_lock_reenable(struct work_struct *work)
1140{
1141 sld_update_msr(true);
1142}
1143static DECLARE_DELAYED_WORK(sl_reenable, __split_lock_reenable);
1144
1145/*
1146 * If a CPU goes offline with pending delayed work to re-enable split lock
1147 * detection then the delayed work will be executed on some other CPU. That
1148 * handles releasing the buslock_sem, but because it executes on a
1149 * different CPU probably won't re-enable split lock detection. This is a
1150 * problem on HT systems since the sibling CPU on the same core may then be
1151 * left running with split lock detection disabled.
1152 *
1153 * Unconditionally re-enable detection here.
1154 */
1155static int splitlock_cpu_offline(unsigned int cpu)
1156{
1157 sld_update_msr(true);
1158
1159 return 0;
1160}
1161
1162static void split_lock_warn(unsigned long ip)
1163{
1164 struct delayed_work *work;
1165 int cpu;
1166
1167 if (!current->reported_split_lock)
1168 pr_warn_ratelimited("#AC: %s/%d took a split_lock trap at address: 0x%lx\n",
1169 current->comm, current->pid, ip);
1170 current->reported_split_lock = 1;
1171
1172 if (sysctl_sld_mitigate) {
1173 /*
1174 * misery factor #1:
1175 * sleep 10ms before trying to execute split lock.
1176 */
1177 if (msleep_interruptible(10) > 0)
1178 return;
1179 /*
1180 * Misery factor #2:
1181 * only allow one buslocked disabled core at a time.
1182 */
1183 if (down_interruptible(&buslock_sem) == -EINTR)
1184 return;
1185 work = &sl_reenable_unlock;
1186 } else {
1187 work = &sl_reenable;
1188 }
1189
1190 cpu = get_cpu();
1191 schedule_delayed_work_on(cpu, work, 2);
1192
1193 /* Disable split lock detection on this CPU to make progress */
1194 sld_update_msr(false);
1195 put_cpu();
1196}
1197
1198bool handle_guest_split_lock(unsigned long ip)
1199{
1200 if (sld_state == sld_warn) {
1201 split_lock_warn(ip);
1202 return true;
1203 }
1204
1205 pr_warn_once("#AC: %s/%d %s split_lock trap at address: 0x%lx\n",
1206 current->comm, current->pid,
1207 sld_state == sld_fatal ? "fatal" : "bogus", ip);
1208
1209 current->thread.error_code = 0;
1210 current->thread.trap_nr = X86_TRAP_AC;
1211 force_sig_fault(SIGBUS, BUS_ADRALN, NULL);
1212 return false;
1213}
1214EXPORT_SYMBOL_GPL(handle_guest_split_lock);
1215
1216static void bus_lock_init(void)
1217{
1218 u64 val;
1219
1220 if (!boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT))
1221 return;
1222
1223 rdmsrl(MSR_IA32_DEBUGCTLMSR, val);
1224
1225 if ((boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) &&
1226 (sld_state == sld_warn || sld_state == sld_fatal)) ||
1227 sld_state == sld_off) {
1228 /*
1229 * Warn and fatal are handled by #AC for split lock if #AC for
1230 * split lock is supported.
1231 */
1232 val &= ~DEBUGCTLMSR_BUS_LOCK_DETECT;
1233 } else {
1234 val |= DEBUGCTLMSR_BUS_LOCK_DETECT;
1235 }
1236
1237 wrmsrl(MSR_IA32_DEBUGCTLMSR, val);
1238}
1239
1240bool handle_user_split_lock(struct pt_regs *regs, long error_code)
1241{
1242 if ((regs->flags & X86_EFLAGS_AC) || sld_state == sld_fatal)
1243 return false;
1244 split_lock_warn(regs->ip);
1245 return true;
1246}
1247
1248void handle_bus_lock(struct pt_regs *regs)
1249{
1250 switch (sld_state) {
1251 case sld_off:
1252 break;
1253 case sld_ratelimit:
1254 /* Enforce no more than bld_ratelimit bus locks/sec. */
1255 while (!__ratelimit(&bld_ratelimit))
1256 msleep(20);
1257 /* Warn on the bus lock. */
1258 fallthrough;
1259 case sld_warn:
1260 pr_warn_ratelimited("#DB: %s/%d took a bus_lock trap at address: 0x%lx\n",
1261 current->comm, current->pid, regs->ip);
1262 break;
1263 case sld_fatal:
1264 force_sig_fault(SIGBUS, BUS_ADRALN, NULL);
1265 break;
1266 }
1267}
1268
1269/*
1270 * CPU models that are known to have the per-core split-lock detection
1271 * feature even though they do not enumerate IA32_CORE_CAPABILITIES.
1272 */
1273static const struct x86_cpu_id split_lock_cpu_ids[] __initconst = {
1274 X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_X, 0),
1275 X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_L, 0),
1276 X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_D, 0),
1277 {}
1278};
1279
1280static void __init split_lock_setup(struct cpuinfo_x86 *c)
1281{
1282 const struct x86_cpu_id *m;
1283 u64 ia32_core_caps;
1284
1285 if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
1286 return;
1287
1288 /* Check for CPUs that have support but do not enumerate it: */
1289 m = x86_match_cpu(split_lock_cpu_ids);
1290 if (m)
1291 goto supported;
1292
1293 if (!cpu_has(c, X86_FEATURE_CORE_CAPABILITIES))
1294 return;
1295
1296 /*
1297 * Not all bits in MSR_IA32_CORE_CAPS are architectural, but
1298 * MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT is. All CPUs that set
1299 * it have split lock detection.
1300 */
1301 rdmsrl(MSR_IA32_CORE_CAPS, ia32_core_caps);
1302 if (ia32_core_caps & MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT)
1303 goto supported;
1304
1305 /* CPU is not in the model list and does not have the MSR bit: */
1306 return;
1307
1308supported:
1309 cpu_model_supports_sld = true;
1310 __split_lock_setup();
1311}
1312
1313static void sld_state_show(void)
1314{
1315 if (!boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT) &&
1316 !boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT))
1317 return;
1318
1319 switch (sld_state) {
1320 case sld_off:
1321 pr_info("disabled\n");
1322 break;
1323 case sld_warn:
1324 if (boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) {
1325 pr_info("#AC: crashing the kernel on kernel split_locks and warning on user-space split_locks\n");
1326 if (cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
1327 "x86/splitlock", NULL, splitlock_cpu_offline) < 0)
1328 pr_warn("No splitlock CPU offline handler\n");
1329 } else if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) {
1330 pr_info("#DB: warning on user-space bus_locks\n");
1331 }
1332 break;
1333 case sld_fatal:
1334 if (boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) {
1335 pr_info("#AC: crashing the kernel on kernel split_locks and sending SIGBUS on user-space split_locks\n");
1336 } else if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) {
1337 pr_info("#DB: sending SIGBUS on user-space bus_locks%s\n",
1338 boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) ?
1339 " from non-WB" : "");
1340 }
1341 break;
1342 case sld_ratelimit:
1343 if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT))
1344 pr_info("#DB: setting system wide bus lock rate limit to %u/sec\n", bld_ratelimit.burst);
1345 break;
1346 }
1347}
1348
1349void __init sld_setup(struct cpuinfo_x86 *c)
1350{
1351 split_lock_setup(c);
1352 sld_state_setup();
1353 sld_state_show();
1354}
1355
1356#define X86_HYBRID_CPU_TYPE_ID_SHIFT 24
1357
1358/**
1359 * get_this_hybrid_cpu_type() - Get the type of this hybrid CPU
1360 *
1361 * Returns the CPU type [31:24] (i.e., Atom or Core) of a CPU in
1362 * a hybrid processor. If the processor is not hybrid, returns 0.
1363 */
1364u8 get_this_hybrid_cpu_type(void)
1365{
1366 if (!cpu_feature_enabled(X86_FEATURE_HYBRID_CPU))
1367 return 0;
1368
1369 return cpuid_eax(0x0000001a) >> X86_HYBRID_CPU_TYPE_ID_SHIFT;
1370}