xref: /openbmc/linux/arch/x86/kernel/cpu/intel.c (revision d3964221)
1 // SPDX-License-Identifier: GPL-2.0
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/sched/clock.h>
9 #include <linux/thread_info.h>
10 #include <linux/init.h>
11 #include <linux/uaccess.h>
12 
13 #include <asm/cpufeature.h>
14 #include <asm/pgtable.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 
23 #ifdef CONFIG_X86_64
24 #include <linux/topology.h>
25 #endif
26 
27 #include "cpu.h"
28 
29 #ifdef CONFIG_X86_LOCAL_APIC
30 #include <asm/mpspec.h>
31 #include <asm/apic.h>
32 #endif
33 
34 /*
35  * Just in case our CPU detection goes bad, or you have a weird system,
36  * allow a way to override the automatic disabling of MPX.
37  */
38 static int forcempx;
39 
40 static int __init forcempx_setup(char *__unused)
41 {
42 	forcempx = 1;
43 
44 	return 1;
45 }
46 __setup("intel-skd-046-workaround=disable", forcempx_setup);
47 
48 void check_mpx_erratum(struct cpuinfo_x86 *c)
49 {
50 	if (forcempx)
51 		return;
52 	/*
53 	 * Turn off the MPX feature on CPUs where SMEP is not
54 	 * available or disabled.
55 	 *
56 	 * Works around Intel Erratum SKD046: "Branch Instructions
57 	 * May Initialize MPX Bound Registers Incorrectly".
58 	 *
59 	 * This might falsely disable MPX on systems without
60 	 * SMEP, like Atom processors without SMEP.  But there
61 	 * is no such hardware known at the moment.
62 	 */
63 	if (cpu_has(c, X86_FEATURE_MPX) && !cpu_has(c, X86_FEATURE_SMEP)) {
64 		setup_clear_cpu_cap(X86_FEATURE_MPX);
65 		pr_warn("x86/mpx: Disabling MPX since SMEP not present\n");
66 	}
67 }
68 
69 static bool ring3mwait_disabled __read_mostly;
70 
71 static int __init ring3mwait_disable(char *__unused)
72 {
73 	ring3mwait_disabled = true;
74 	return 0;
75 }
76 __setup("ring3mwait=disable", ring3mwait_disable);
77 
78 static void probe_xeon_phi_r3mwait(struct cpuinfo_x86 *c)
79 {
80 	/*
81 	 * Ring 3 MONITOR/MWAIT feature cannot be detected without
82 	 * cpu model and family comparison.
83 	 */
84 	if (c->x86 != 6)
85 		return;
86 	switch (c->x86_model) {
87 	case INTEL_FAM6_XEON_PHI_KNL:
88 	case INTEL_FAM6_XEON_PHI_KNM:
89 		break;
90 	default:
91 		return;
92 	}
93 
94 	if (ring3mwait_disabled)
95 		return;
96 
97 	set_cpu_cap(c, X86_FEATURE_RING3MWAIT);
98 	this_cpu_or(msr_misc_features_shadow,
99 		    1UL << MSR_MISC_FEATURES_ENABLES_RING3MWAIT_BIT);
100 
101 	if (c == &boot_cpu_data)
102 		ELF_HWCAP2 |= HWCAP2_RING3MWAIT;
103 }
104 
105 static void early_init_intel(struct cpuinfo_x86 *c)
106 {
107 	u64 misc_enable;
108 
109 	/* Unmask CPUID levels if masked: */
110 	if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
111 		if (msr_clear_bit(MSR_IA32_MISC_ENABLE,
112 				  MSR_IA32_MISC_ENABLE_LIMIT_CPUID_BIT) > 0) {
113 			c->cpuid_level = cpuid_eax(0);
114 			get_cpu_cap(c);
115 		}
116 	}
117 
118 	if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
119 		(c->x86 == 0x6 && c->x86_model >= 0x0e))
120 		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
121 
122 	if (c->x86 >= 6 && !cpu_has(c, X86_FEATURE_IA64))
123 		c->microcode = intel_get_microcode_revision();
124 
125 	/*
126 	 * Atom erratum AAE44/AAF40/AAG38/AAH41:
127 	 *
128 	 * A race condition between speculative fetches and invalidating
129 	 * a large page.  This is worked around in microcode, but we
130 	 * need the microcode to have already been loaded... so if it is
131 	 * not, recommend a BIOS update and disable large pages.
132 	 */
133 	if (c->x86 == 6 && c->x86_model == 0x1c && c->x86_mask <= 2 &&
134 	    c->microcode < 0x20e) {
135 		pr_warn("Atom PSE erratum detected, BIOS microcode update recommended\n");
136 		clear_cpu_cap(c, X86_FEATURE_PSE);
137 	}
138 
139 #ifdef CONFIG_X86_64
140 	set_cpu_cap(c, X86_FEATURE_SYSENTER32);
141 #else
142 	/* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
143 	if (c->x86 == 15 && c->x86_cache_alignment == 64)
144 		c->x86_cache_alignment = 128;
145 #endif
146 
147 	/* CPUID workaround for 0F33/0F34 CPU */
148 	if (c->x86 == 0xF && c->x86_model == 0x3
149 	    && (c->x86_mask == 0x3 || c->x86_mask == 0x4))
150 		c->x86_phys_bits = 36;
151 
152 	/*
153 	 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
154 	 * with P/T states and does not stop in deep C-states.
155 	 *
156 	 * It is also reliable across cores and sockets. (but not across
157 	 * cabinets - we turn it off in that case explicitly.)
158 	 */
159 	if (c->x86_power & (1 << 8)) {
160 		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
161 		set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
162 	}
163 
164 	/* Penwell and Cloverview have the TSC which doesn't sleep on S3 */
165 	if (c->x86 == 6) {
166 		switch (c->x86_model) {
167 		case 0x27:	/* Penwell */
168 		case 0x35:	/* Cloverview */
169 		case 0x4a:	/* Merrifield */
170 			set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC_S3);
171 			break;
172 		default:
173 			break;
174 		}
175 	}
176 
177 	/*
178 	 * There is a known erratum on Pentium III and Core Solo
179 	 * and Core Duo CPUs.
180 	 * " Page with PAT set to WC while associated MTRR is UC
181 	 *   may consolidate to UC "
182 	 * Because of this erratum, it is better to stick with
183 	 * setting WC in MTRR rather than using PAT on these CPUs.
184 	 *
185 	 * Enable PAT WC only on P4, Core 2 or later CPUs.
186 	 */
187 	if (c->x86 == 6 && c->x86_model < 15)
188 		clear_cpu_cap(c, X86_FEATURE_PAT);
189 
190 #ifdef CONFIG_KMEMCHECK
191 	/*
192 	 * P4s have a "fast strings" feature which causes single-
193 	 * stepping REP instructions to only generate a #DB on
194 	 * cache-line boundaries.
195 	 *
196 	 * Ingo Molnar reported a Pentium D (model 6) and a Xeon
197 	 * (model 2) with the same problem.
198 	 */
199 	if (c->x86 == 15)
200 		if (msr_clear_bit(MSR_IA32_MISC_ENABLE,
201 				  MSR_IA32_MISC_ENABLE_FAST_STRING_BIT) > 0)
202 			pr_info("kmemcheck: Disabling fast string operations\n");
203 #endif
204 
205 	/*
206 	 * If fast string is not enabled in IA32_MISC_ENABLE for any reason,
207 	 * clear the fast string and enhanced fast string CPU capabilities.
208 	 */
209 	if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
210 		rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
211 		if (!(misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING)) {
212 			pr_info("Disabled fast string operations\n");
213 			setup_clear_cpu_cap(X86_FEATURE_REP_GOOD);
214 			setup_clear_cpu_cap(X86_FEATURE_ERMS);
215 		}
216 	}
217 
218 	/*
219 	 * Intel Quark Core DevMan_001.pdf section 6.4.11
220 	 * "The operating system also is required to invalidate (i.e., flush)
221 	 *  the TLB when any changes are made to any of the page table entries.
222 	 *  The operating system must reload CR3 to cause the TLB to be flushed"
223 	 *
224 	 * As a result, boot_cpu_has(X86_FEATURE_PGE) in arch/x86/include/asm/tlbflush.h
225 	 * should be false so that __flush_tlb_all() causes CR3 insted of CR4.PGE
226 	 * to be modified.
227 	 */
228 	if (c->x86 == 5 && c->x86_model == 9) {
229 		pr_info("Disabling PGE capability bit\n");
230 		setup_clear_cpu_cap(X86_FEATURE_PGE);
231 	}
232 
233 	if (c->cpuid_level >= 0x00000001) {
234 		u32 eax, ebx, ecx, edx;
235 
236 		cpuid(0x00000001, &eax, &ebx, &ecx, &edx);
237 		/*
238 		 * If HTT (EDX[28]) is set EBX[16:23] contain the number of
239 		 * apicids which are reserved per package. Store the resulting
240 		 * shift value for the package management code.
241 		 */
242 		if (edx & (1U << 28))
243 			c->x86_coreid_bits = get_count_order((ebx >> 16) & 0xff);
244 	}
245 
246 	check_mpx_erratum(c);
247 }
248 
249 #ifdef CONFIG_X86_32
250 /*
251  *	Early probe support logic for ppro memory erratum #50
252  *
253  *	This is called before we do cpu ident work
254  */
255 
256 int ppro_with_ram_bug(void)
257 {
258 	/* Uses data from early_cpu_detect now */
259 	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
260 	    boot_cpu_data.x86 == 6 &&
261 	    boot_cpu_data.x86_model == 1 &&
262 	    boot_cpu_data.x86_mask < 8) {
263 		pr_info("Pentium Pro with Errata#50 detected. Taking evasive action.\n");
264 		return 1;
265 	}
266 	return 0;
267 }
268 
269 static void intel_smp_check(struct cpuinfo_x86 *c)
270 {
271 	/* calling is from identify_secondary_cpu() ? */
272 	if (!c->cpu_index)
273 		return;
274 
275 	/*
276 	 * Mask B, Pentium, but not Pentium MMX
277 	 */
278 	if (c->x86 == 5 &&
279 	    c->x86_mask >= 1 && c->x86_mask <= 4 &&
280 	    c->x86_model <= 3) {
281 		/*
282 		 * Remember we have B step Pentia with bugs
283 		 */
284 		WARN_ONCE(1, "WARNING: SMP operation may be unreliable"
285 				    "with B stepping processors.\n");
286 	}
287 }
288 
289 static int forcepae;
290 static int __init forcepae_setup(char *__unused)
291 {
292 	forcepae = 1;
293 	return 1;
294 }
295 __setup("forcepae", forcepae_setup);
296 
297 static void intel_workarounds(struct cpuinfo_x86 *c)
298 {
299 #ifdef CONFIG_X86_F00F_BUG
300 	/*
301 	 * All models of Pentium and Pentium with MMX technology CPUs
302 	 * have the F0 0F bug, which lets nonprivileged users lock up the
303 	 * system. Announce that the fault handler will be checking for it.
304 	 * The Quark is also family 5, but does not have the same bug.
305 	 */
306 	clear_cpu_bug(c, X86_BUG_F00F);
307 	if (c->x86 == 5 && c->x86_model < 9) {
308 		static int f00f_workaround_enabled;
309 
310 		set_cpu_bug(c, X86_BUG_F00F);
311 		if (!f00f_workaround_enabled) {
312 			pr_notice("Intel Pentium with F0 0F bug - workaround enabled.\n");
313 			f00f_workaround_enabled = 1;
314 		}
315 	}
316 #endif
317 
318 	/*
319 	 * SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until
320 	 * model 3 mask 3
321 	 */
322 	if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633)
323 		clear_cpu_cap(c, X86_FEATURE_SEP);
324 
325 	/*
326 	 * PAE CPUID issue: many Pentium M report no PAE but may have a
327 	 * functionally usable PAE implementation.
328 	 * Forcefully enable PAE if kernel parameter "forcepae" is present.
329 	 */
330 	if (forcepae) {
331 		pr_warn("PAE forced!\n");
332 		set_cpu_cap(c, X86_FEATURE_PAE);
333 		add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_NOW_UNRELIABLE);
334 	}
335 
336 	/*
337 	 * P4 Xeon erratum 037 workaround.
338 	 * Hardware prefetcher may cause stale data to be loaded into the cache.
339 	 */
340 	if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
341 		if (msr_set_bit(MSR_IA32_MISC_ENABLE,
342 				MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE_BIT) > 0) {
343 			pr_info("CPU: C0 stepping P4 Xeon detected.\n");
344 			pr_info("CPU: Disabling hardware prefetching (Erratum 037)\n");
345 		}
346 	}
347 
348 	/*
349 	 * See if we have a good local APIC by checking for buggy Pentia,
350 	 * i.e. all B steppings and the C2 stepping of P54C when using their
351 	 * integrated APIC (see 11AP erratum in "Pentium Processor
352 	 * Specification Update").
353 	 */
354 	if (boot_cpu_has(X86_FEATURE_APIC) && (c->x86<<8 | c->x86_model<<4) == 0x520 &&
355 	    (c->x86_mask < 0x6 || c->x86_mask == 0xb))
356 		set_cpu_bug(c, X86_BUG_11AP);
357 
358 
359 #ifdef CONFIG_X86_INTEL_USERCOPY
360 	/*
361 	 * Set up the preferred alignment for movsl bulk memory moves
362 	 */
363 	switch (c->x86) {
364 	case 4:		/* 486: untested */
365 		break;
366 	case 5:		/* Old Pentia: untested */
367 		break;
368 	case 6:		/* PII/PIII only like movsl with 8-byte alignment */
369 		movsl_mask.mask = 7;
370 		break;
371 	case 15:	/* P4 is OK down to 8-byte alignment */
372 		movsl_mask.mask = 7;
373 		break;
374 	}
375 #endif
376 
377 	intel_smp_check(c);
378 }
379 #else
380 static void intel_workarounds(struct cpuinfo_x86 *c)
381 {
382 }
383 #endif
384 
385 static void srat_detect_node(struct cpuinfo_x86 *c)
386 {
387 #ifdef CONFIG_NUMA
388 	unsigned node;
389 	int cpu = smp_processor_id();
390 
391 	/* Don't do the funky fallback heuristics the AMD version employs
392 	   for now. */
393 	node = numa_cpu_node(cpu);
394 	if (node == NUMA_NO_NODE || !node_online(node)) {
395 		/* reuse the value from init_cpu_to_node() */
396 		node = cpu_to_node(cpu);
397 	}
398 	numa_set_node(cpu, node);
399 #endif
400 }
401 
402 /*
403  * find out the number of processor cores on the die
404  */
405 static int intel_num_cpu_cores(struct cpuinfo_x86 *c)
406 {
407 	unsigned int eax, ebx, ecx, edx;
408 
409 	if (!IS_ENABLED(CONFIG_SMP) || c->cpuid_level < 4)
410 		return 1;
411 
412 	/* Intel has a non-standard dependency on %ecx for this CPUID level. */
413 	cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
414 	if (eax & 0x1f)
415 		return (eax >> 26) + 1;
416 	else
417 		return 1;
418 }
419 
420 static void detect_vmx_virtcap(struct cpuinfo_x86 *c)
421 {
422 	/* Intel VMX MSR indicated features */
423 #define X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW	0x00200000
424 #define X86_VMX_FEATURE_PROC_CTLS_VNMI		0x00400000
425 #define X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS	0x80000000
426 #define X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC	0x00000001
427 #define X86_VMX_FEATURE_PROC_CTLS2_EPT		0x00000002
428 #define X86_VMX_FEATURE_PROC_CTLS2_VPID		0x00000020
429 
430 	u32 vmx_msr_low, vmx_msr_high, msr_ctl, msr_ctl2;
431 
432 	clear_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
433 	clear_cpu_cap(c, X86_FEATURE_VNMI);
434 	clear_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
435 	clear_cpu_cap(c, X86_FEATURE_EPT);
436 	clear_cpu_cap(c, X86_FEATURE_VPID);
437 
438 	rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, vmx_msr_low, vmx_msr_high);
439 	msr_ctl = vmx_msr_high | vmx_msr_low;
440 	if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW)
441 		set_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
442 	if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_VNMI)
443 		set_cpu_cap(c, X86_FEATURE_VNMI);
444 	if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS) {
445 		rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2,
446 		      vmx_msr_low, vmx_msr_high);
447 		msr_ctl2 = vmx_msr_high | vmx_msr_low;
448 		if ((msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC) &&
449 		    (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW))
450 			set_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
451 		if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_EPT)
452 			set_cpu_cap(c, X86_FEATURE_EPT);
453 		if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VPID)
454 			set_cpu_cap(c, X86_FEATURE_VPID);
455 	}
456 }
457 
458 static void init_intel_energy_perf(struct cpuinfo_x86 *c)
459 {
460 	u64 epb;
461 
462 	/*
463 	 * Initialize MSR_IA32_ENERGY_PERF_BIAS if not already initialized.
464 	 * (x86_energy_perf_policy(8) is available to change it at run-time.)
465 	 */
466 	if (!cpu_has(c, X86_FEATURE_EPB))
467 		return;
468 
469 	rdmsrl(MSR_IA32_ENERGY_PERF_BIAS, epb);
470 	if ((epb & 0xF) != ENERGY_PERF_BIAS_PERFORMANCE)
471 		return;
472 
473 	pr_warn_once("ENERGY_PERF_BIAS: Set to 'normal', was 'performance'\n");
474 	pr_warn_once("ENERGY_PERF_BIAS: View and update with x86_energy_perf_policy(8)\n");
475 	epb = (epb & ~0xF) | ENERGY_PERF_BIAS_NORMAL;
476 	wrmsrl(MSR_IA32_ENERGY_PERF_BIAS, epb);
477 }
478 
479 static void intel_bsp_resume(struct cpuinfo_x86 *c)
480 {
481 	/*
482 	 * MSR_IA32_ENERGY_PERF_BIAS is lost across suspend/resume,
483 	 * so reinitialize it properly like during bootup:
484 	 */
485 	init_intel_energy_perf(c);
486 }
487 
488 static void init_cpuid_fault(struct cpuinfo_x86 *c)
489 {
490 	u64 msr;
491 
492 	if (!rdmsrl_safe(MSR_PLATFORM_INFO, &msr)) {
493 		if (msr & MSR_PLATFORM_INFO_CPUID_FAULT)
494 			set_cpu_cap(c, X86_FEATURE_CPUID_FAULT);
495 	}
496 }
497 
498 static void init_intel_misc_features(struct cpuinfo_x86 *c)
499 {
500 	u64 msr;
501 
502 	if (rdmsrl_safe(MSR_MISC_FEATURES_ENABLES, &msr))
503 		return;
504 
505 	/* Clear all MISC features */
506 	this_cpu_write(msr_misc_features_shadow, 0);
507 
508 	/* Check features and update capabilities and shadow control bits */
509 	init_cpuid_fault(c);
510 	probe_xeon_phi_r3mwait(c);
511 
512 	msr = this_cpu_read(msr_misc_features_shadow);
513 	wrmsrl(MSR_MISC_FEATURES_ENABLES, msr);
514 }
515 
516 static void init_intel(struct cpuinfo_x86 *c)
517 {
518 	unsigned int l2 = 0;
519 
520 	early_init_intel(c);
521 
522 	intel_workarounds(c);
523 
524 	/*
525 	 * Detect the extended topology information if available. This
526 	 * will reinitialise the initial_apicid which will be used
527 	 * in init_intel_cacheinfo()
528 	 */
529 	detect_extended_topology(c);
530 
531 	if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) {
532 		/*
533 		 * let's use the legacy cpuid vector 0x1 and 0x4 for topology
534 		 * detection.
535 		 */
536 		c->x86_max_cores = intel_num_cpu_cores(c);
537 #ifdef CONFIG_X86_32
538 		detect_ht(c);
539 #endif
540 	}
541 
542 	l2 = init_intel_cacheinfo(c);
543 
544 	/* Detect legacy cache sizes if init_intel_cacheinfo did not */
545 	if (l2 == 0) {
546 		cpu_detect_cache_sizes(c);
547 		l2 = c->x86_cache_size;
548 	}
549 
550 	if (c->cpuid_level > 9) {
551 		unsigned eax = cpuid_eax(10);
552 		/* Check for version and the number of counters */
553 		if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
554 			set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON);
555 	}
556 
557 	if (cpu_has(c, X86_FEATURE_XMM2))
558 		set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
559 
560 	if (boot_cpu_has(X86_FEATURE_DS)) {
561 		unsigned int l1;
562 		rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
563 		if (!(l1 & (1<<11)))
564 			set_cpu_cap(c, X86_FEATURE_BTS);
565 		if (!(l1 & (1<<12)))
566 			set_cpu_cap(c, X86_FEATURE_PEBS);
567 	}
568 
569 	if (c->x86 == 6 && boot_cpu_has(X86_FEATURE_CLFLUSH) &&
570 	    (c->x86_model == 29 || c->x86_model == 46 || c->x86_model == 47))
571 		set_cpu_bug(c, X86_BUG_CLFLUSH_MONITOR);
572 
573 	if (c->x86 == 6 && boot_cpu_has(X86_FEATURE_MWAIT) &&
574 		((c->x86_model == INTEL_FAM6_ATOM_GOLDMONT)))
575 		set_cpu_bug(c, X86_BUG_MONITOR);
576 
577 #ifdef CONFIG_X86_64
578 	if (c->x86 == 15)
579 		c->x86_cache_alignment = c->x86_clflush_size * 2;
580 	if (c->x86 == 6)
581 		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
582 #else
583 	/*
584 	 * Names for the Pentium II/Celeron processors
585 	 * detectable only by also checking the cache size.
586 	 * Dixon is NOT a Celeron.
587 	 */
588 	if (c->x86 == 6) {
589 		char *p = NULL;
590 
591 		switch (c->x86_model) {
592 		case 5:
593 			if (l2 == 0)
594 				p = "Celeron (Covington)";
595 			else if (l2 == 256)
596 				p = "Mobile Pentium II (Dixon)";
597 			break;
598 
599 		case 6:
600 			if (l2 == 128)
601 				p = "Celeron (Mendocino)";
602 			else if (c->x86_mask == 0 || c->x86_mask == 5)
603 				p = "Celeron-A";
604 			break;
605 
606 		case 8:
607 			if (l2 == 128)
608 				p = "Celeron (Coppermine)";
609 			break;
610 		}
611 
612 		if (p)
613 			strcpy(c->x86_model_id, p);
614 	}
615 
616 	if (c->x86 == 15)
617 		set_cpu_cap(c, X86_FEATURE_P4);
618 	if (c->x86 == 6)
619 		set_cpu_cap(c, X86_FEATURE_P3);
620 #endif
621 
622 	/* Work around errata */
623 	srat_detect_node(c);
624 
625 	if (cpu_has(c, X86_FEATURE_VMX))
626 		detect_vmx_virtcap(c);
627 
628 	init_intel_energy_perf(c);
629 
630 	init_intel_misc_features(c);
631 }
632 
633 #ifdef CONFIG_X86_32
634 static unsigned int intel_size_cache(struct cpuinfo_x86 *c, unsigned int size)
635 {
636 	/*
637 	 * Intel PIII Tualatin. This comes in two flavours.
638 	 * One has 256kb of cache, the other 512. We have no way
639 	 * to determine which, so we use a boottime override
640 	 * for the 512kb model, and assume 256 otherwise.
641 	 */
642 	if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
643 		size = 256;
644 
645 	/*
646 	 * Intel Quark SoC X1000 contains a 4-way set associative
647 	 * 16K cache with a 16 byte cache line and 256 lines per tag
648 	 */
649 	if ((c->x86 == 5) && (c->x86_model == 9))
650 		size = 16;
651 	return size;
652 }
653 #endif
654 
655 #define TLB_INST_4K	0x01
656 #define TLB_INST_4M	0x02
657 #define TLB_INST_2M_4M	0x03
658 
659 #define TLB_INST_ALL	0x05
660 #define TLB_INST_1G	0x06
661 
662 #define TLB_DATA_4K	0x11
663 #define TLB_DATA_4M	0x12
664 #define TLB_DATA_2M_4M	0x13
665 #define TLB_DATA_4K_4M	0x14
666 
667 #define TLB_DATA_1G	0x16
668 
669 #define TLB_DATA0_4K	0x21
670 #define TLB_DATA0_4M	0x22
671 #define TLB_DATA0_2M_4M	0x23
672 
673 #define STLB_4K		0x41
674 #define STLB_4K_2M	0x42
675 
676 static const struct _tlb_table intel_tlb_table[] = {
677 	{ 0x01, TLB_INST_4K,		32,	" TLB_INST 4 KByte pages, 4-way set associative" },
678 	{ 0x02, TLB_INST_4M,		2,	" TLB_INST 4 MByte pages, full associative" },
679 	{ 0x03, TLB_DATA_4K,		64,	" TLB_DATA 4 KByte pages, 4-way set associative" },
680 	{ 0x04, TLB_DATA_4M,		8,	" TLB_DATA 4 MByte pages, 4-way set associative" },
681 	{ 0x05, TLB_DATA_4M,		32,	" TLB_DATA 4 MByte pages, 4-way set associative" },
682 	{ 0x0b, TLB_INST_4M,		4,	" TLB_INST 4 MByte pages, 4-way set associative" },
683 	{ 0x4f, TLB_INST_4K,		32,	" TLB_INST 4 KByte pages */" },
684 	{ 0x50, TLB_INST_ALL,		64,	" TLB_INST 4 KByte and 2-MByte or 4-MByte pages" },
685 	{ 0x51, TLB_INST_ALL,		128,	" TLB_INST 4 KByte and 2-MByte or 4-MByte pages" },
686 	{ 0x52, TLB_INST_ALL,		256,	" TLB_INST 4 KByte and 2-MByte or 4-MByte pages" },
687 	{ 0x55, TLB_INST_2M_4M,		7,	" TLB_INST 2-MByte or 4-MByte pages, fully associative" },
688 	{ 0x56, TLB_DATA0_4M,		16,	" TLB_DATA0 4 MByte pages, 4-way set associative" },
689 	{ 0x57, TLB_DATA0_4K,		16,	" TLB_DATA0 4 KByte pages, 4-way associative" },
690 	{ 0x59, TLB_DATA0_4K,		16,	" TLB_DATA0 4 KByte pages, fully associative" },
691 	{ 0x5a, TLB_DATA0_2M_4M,	32,	" TLB_DATA0 2-MByte or 4 MByte pages, 4-way set associative" },
692 	{ 0x5b, TLB_DATA_4K_4M,		64,	" TLB_DATA 4 KByte and 4 MByte pages" },
693 	{ 0x5c, TLB_DATA_4K_4M,		128,	" TLB_DATA 4 KByte and 4 MByte pages" },
694 	{ 0x5d, TLB_DATA_4K_4M,		256,	" TLB_DATA 4 KByte and 4 MByte pages" },
695 	{ 0x61, TLB_INST_4K,		48,	" TLB_INST 4 KByte pages, full associative" },
696 	{ 0x63, TLB_DATA_1G,		4,	" TLB_DATA 1 GByte pages, 4-way set associative" },
697 	{ 0x76, TLB_INST_2M_4M,		8,	" TLB_INST 2-MByte or 4-MByte pages, fully associative" },
698 	{ 0xb0, TLB_INST_4K,		128,	" TLB_INST 4 KByte pages, 4-way set associative" },
699 	{ 0xb1, TLB_INST_2M_4M,		4,	" TLB_INST 2M pages, 4-way, 8 entries or 4M pages, 4-way entries" },
700 	{ 0xb2, TLB_INST_4K,		64,	" TLB_INST 4KByte pages, 4-way set associative" },
701 	{ 0xb3, TLB_DATA_4K,		128,	" TLB_DATA 4 KByte pages, 4-way set associative" },
702 	{ 0xb4, TLB_DATA_4K,		256,	" TLB_DATA 4 KByte pages, 4-way associative" },
703 	{ 0xb5, TLB_INST_4K,		64,	" TLB_INST 4 KByte pages, 8-way set associative" },
704 	{ 0xb6, TLB_INST_4K,		128,	" TLB_INST 4 KByte pages, 8-way set associative" },
705 	{ 0xba, TLB_DATA_4K,		64,	" TLB_DATA 4 KByte pages, 4-way associative" },
706 	{ 0xc0, TLB_DATA_4K_4M,		8,	" TLB_DATA 4 KByte and 4 MByte pages, 4-way associative" },
707 	{ 0xc1, STLB_4K_2M,		1024,	" STLB 4 KByte and 2 MByte pages, 8-way associative" },
708 	{ 0xc2, TLB_DATA_2M_4M,		16,	" DTLB 2 MByte/4MByte pages, 4-way associative" },
709 	{ 0xca, STLB_4K,		512,	" STLB 4 KByte pages, 4-way associative" },
710 	{ 0x00, 0, 0 }
711 };
712 
713 static void intel_tlb_lookup(const unsigned char desc)
714 {
715 	unsigned char k;
716 	if (desc == 0)
717 		return;
718 
719 	/* look up this descriptor in the table */
720 	for (k = 0; intel_tlb_table[k].descriptor != desc && \
721 			intel_tlb_table[k].descriptor != 0; k++)
722 		;
723 
724 	if (intel_tlb_table[k].tlb_type == 0)
725 		return;
726 
727 	switch (intel_tlb_table[k].tlb_type) {
728 	case STLB_4K:
729 		if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
730 			tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
731 		if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
732 			tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
733 		break;
734 	case STLB_4K_2M:
735 		if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
736 			tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
737 		if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
738 			tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
739 		if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries)
740 			tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries;
741 		if (tlb_lld_2m[ENTRIES] < intel_tlb_table[k].entries)
742 			tlb_lld_2m[ENTRIES] = intel_tlb_table[k].entries;
743 		if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
744 			tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
745 		if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
746 			tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
747 		break;
748 	case TLB_INST_ALL:
749 		if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
750 			tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
751 		if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries)
752 			tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries;
753 		if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
754 			tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
755 		break;
756 	case TLB_INST_4K:
757 		if (tlb_lli_4k[ENTRIES] < intel_tlb_table[k].entries)
758 			tlb_lli_4k[ENTRIES] = intel_tlb_table[k].entries;
759 		break;
760 	case TLB_INST_4M:
761 		if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
762 			tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
763 		break;
764 	case TLB_INST_2M_4M:
765 		if (tlb_lli_2m[ENTRIES] < intel_tlb_table[k].entries)
766 			tlb_lli_2m[ENTRIES] = intel_tlb_table[k].entries;
767 		if (tlb_lli_4m[ENTRIES] < intel_tlb_table[k].entries)
768 			tlb_lli_4m[ENTRIES] = intel_tlb_table[k].entries;
769 		break;
770 	case TLB_DATA_4K:
771 	case TLB_DATA0_4K:
772 		if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
773 			tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
774 		break;
775 	case TLB_DATA_4M:
776 	case TLB_DATA0_4M:
777 		if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
778 			tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
779 		break;
780 	case TLB_DATA_2M_4M:
781 	case TLB_DATA0_2M_4M:
782 		if (tlb_lld_2m[ENTRIES] < intel_tlb_table[k].entries)
783 			tlb_lld_2m[ENTRIES] = intel_tlb_table[k].entries;
784 		if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
785 			tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
786 		break;
787 	case TLB_DATA_4K_4M:
788 		if (tlb_lld_4k[ENTRIES] < intel_tlb_table[k].entries)
789 			tlb_lld_4k[ENTRIES] = intel_tlb_table[k].entries;
790 		if (tlb_lld_4m[ENTRIES] < intel_tlb_table[k].entries)
791 			tlb_lld_4m[ENTRIES] = intel_tlb_table[k].entries;
792 		break;
793 	case TLB_DATA_1G:
794 		if (tlb_lld_1g[ENTRIES] < intel_tlb_table[k].entries)
795 			tlb_lld_1g[ENTRIES] = intel_tlb_table[k].entries;
796 		break;
797 	}
798 }
799 
800 static void intel_detect_tlb(struct cpuinfo_x86 *c)
801 {
802 	int i, j, n;
803 	unsigned int regs[4];
804 	unsigned char *desc = (unsigned char *)regs;
805 
806 	if (c->cpuid_level < 2)
807 		return;
808 
809 	/* Number of times to iterate */
810 	n = cpuid_eax(2) & 0xFF;
811 
812 	for (i = 0 ; i < n ; i++) {
813 		cpuid(2, &regs[0], &regs[1], &regs[2], &regs[3]);
814 
815 		/* If bit 31 is set, this is an unknown format */
816 		for (j = 0 ; j < 3 ; j++)
817 			if (regs[j] & (1 << 31))
818 				regs[j] = 0;
819 
820 		/* Byte 0 is level count, not a descriptor */
821 		for (j = 1 ; j < 16 ; j++)
822 			intel_tlb_lookup(desc[j]);
823 	}
824 }
825 
826 static const struct cpu_dev intel_cpu_dev = {
827 	.c_vendor	= "Intel",
828 	.c_ident	= { "GenuineIntel" },
829 #ifdef CONFIG_X86_32
830 	.legacy_models = {
831 		{ .family = 4, .model_names =
832 		  {
833 			  [0] = "486 DX-25/33",
834 			  [1] = "486 DX-50",
835 			  [2] = "486 SX",
836 			  [3] = "486 DX/2",
837 			  [4] = "486 SL",
838 			  [5] = "486 SX/2",
839 			  [7] = "486 DX/2-WB",
840 			  [8] = "486 DX/4",
841 			  [9] = "486 DX/4-WB"
842 		  }
843 		},
844 		{ .family = 5, .model_names =
845 		  {
846 			  [0] = "Pentium 60/66 A-step",
847 			  [1] = "Pentium 60/66",
848 			  [2] = "Pentium 75 - 200",
849 			  [3] = "OverDrive PODP5V83",
850 			  [4] = "Pentium MMX",
851 			  [7] = "Mobile Pentium 75 - 200",
852 			  [8] = "Mobile Pentium MMX",
853 			  [9] = "Quark SoC X1000",
854 		  }
855 		},
856 		{ .family = 6, .model_names =
857 		  {
858 			  [0] = "Pentium Pro A-step",
859 			  [1] = "Pentium Pro",
860 			  [3] = "Pentium II (Klamath)",
861 			  [4] = "Pentium II (Deschutes)",
862 			  [5] = "Pentium II (Deschutes)",
863 			  [6] = "Mobile Pentium II",
864 			  [7] = "Pentium III (Katmai)",
865 			  [8] = "Pentium III (Coppermine)",
866 			  [10] = "Pentium III (Cascades)",
867 			  [11] = "Pentium III (Tualatin)",
868 		  }
869 		},
870 		{ .family = 15, .model_names =
871 		  {
872 			  [0] = "Pentium 4 (Unknown)",
873 			  [1] = "Pentium 4 (Willamette)",
874 			  [2] = "Pentium 4 (Northwood)",
875 			  [4] = "Pentium 4 (Foster)",
876 			  [5] = "Pentium 4 (Foster)",
877 		  }
878 		},
879 	},
880 	.legacy_cache_size = intel_size_cache,
881 #endif
882 	.c_detect_tlb	= intel_detect_tlb,
883 	.c_early_init   = early_init_intel,
884 	.c_init		= init_intel,
885 	.c_bsp_resume	= intel_bsp_resume,
886 	.c_x86_vendor	= X86_VENDOR_INTEL,
887 };
888 
889 cpu_dev_register(intel_cpu_dev);
890 
891