aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/kernel/cpu/intel.c
blob: 3260ab04499610d603ca5809758844c025dfaa19 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
#include <linux/init.h>
#include <linux/kernel.h>

#include <linux/string.h>
#include <linux/bitops.h>
#include <linux/smp.h>
#include <linux/sched.h>
#include <linux/thread_info.h>
#include <linux/module.h>

#include <asm/processor.h>
#include <asm/pgtable.h>
#include <asm/msr.h>
#include <asm/uaccess.h>
#include <asm/ds.h>
#include <asm/bugs.h>
#include <asm/cpu.h>

#ifdef CONFIG_X86_64
#include <asm/topology.h>
#include <asm/numa_64.h>
#endif

#include "cpu.h"

#ifdef CONFIG_X86_LOCAL_APIC
#include <asm/mpspec.h>
#include <asm/apic.h>
#endif

static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
{
	/* Unmask CPUID levels if masked: */
	if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
		u64 misc_enable;

		rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);

		if (misc_enable & MSR_IA32_MISC_ENABLE_LIMIT_CPUID) {
			misc_enable &= ~MSR_IA32_MISC_ENABLE_LIMIT_CPUID;
			wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
			c->cpuid_level = cpuid_eax(0);
		}
	}

	if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
		(c->x86 == 0x6 && c->x86_model >= 0x0e))
		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);

#ifdef CONFIG_X86_64
	set_cpu_cap(c, X86_FEATURE_SYSENTER32);
#else
	/* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
	if (c->x86 == 15 && c->x86_cache_alignment == 64)
		c->x86_cache_alignment = 128;
#endif

	/* CPUID workaround for 0F33/0F34 CPU */
	if (c->x86 == 0xF && c->x86_model == 0x3
	    && (c->x86_mask == 0x3 || c->x86_mask == 0x4))
		c->x86_phys_bits = 36;

	/*
	 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
	 * with P/T states and does not stop in deep C-states.
	 *
	 * It is also reliable across cores and sockets. (but not across
	 * cabinets - we turn it off in that case explicitly.)
	 */
	if (c->x86_power & (1 << 8)) {
		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
		set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
		set_cpu_cap(c, X86_FEATURE_TSC_RELIABLE);
		sched_clock_stable = 1;
	}

	/*
	 * There is a known erratum on Pentium III and Core Solo
	 * and Core Duo CPUs.
	 * " Page with PAT set to WC while associated MTRR is UC
	 *   may consolidate to UC "
	 * Because of this erratum, it is better to stick with
	 * setting WC in MTRR rather than using PAT on these CPUs.
	 *
	 * Enable PAT WC only on P4, Core 2 or later CPUs.
	 */
	if (c->x86 == 6 && c->x86_model < 15)
		clear_cpu_cap(c, X86_FEATURE_PAT);

#ifdef CONFIG_KMEMCHECK
	/*
	 * P4s have a "fast strings" feature which causes single-
	 * stepping REP instructions to only generate a #DB on
	 * cache-line boundaries.
	 *
	 * Ingo Molnar reported a Pentium D (model 6) and a Xeon
	 * (model 2) with the same problem.
	 */
	if (c->x86 == 15) {
		u64 misc_enable;

		rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);

		if (misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING) {
			printk(KERN_INFO "kmemcheck: Disabling fast string operations\n");

			misc_enable &= ~MSR_IA32_MISC_ENABLE_FAST_STRING;
			wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
		}
	}
#endif
}

#ifdef CONFIG_X86_32
/*
 *	Early probe support logic for ppro memory erratum #50
 *
 *	This is called before we do cpu ident work
 */

int __cpuinit ppro_with_ram_bug(void)
{
	/* Uses data from early_cpu_detect now */
	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
	    boot_cpu_data.x86 == 6 &&
	    boot_cpu_data.x86_model == 1 &&
	    boot_cpu_data.x86_mask < 8) {
		printk(KERN_INFO "Pentium Pro with Errata#50 detected. Taking evasive action.\n");
		return 1;
	}
	return 0;
}

#ifdef CONFIG_X86_F00F_BUG
static void __cpuinit trap_init_f00f_bug(void)
{
	__set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);

	/*
	 * Update the IDT descriptor and reload the IDT so that
	 * it uses the read-only mapped virtual address.
	 */
	idt_descr.address = fix_to_virt(FIX_F00F_IDT);
	load_idt(&idt_descr);
}
#endif

static void __cpuinit intel_smp_check(struct cpuinfo_x86 *c)
{
#ifdef CONFIG_SMP
	/* calling is from identify_secondary_cpu() ? */
	if (c->cpu_index == boot_cpu_id)
		return;

	/*
	 * Mask B, Pentium, but not Pentium MMX
	 */
	if (c->x86 == 5 &&
	    c->x86_mask >= 1 && c->x86_mask <= 4 &&
	    c->x86_model <= 3) {
		/*
		 * Remember we have B step Pentia with bugs
		 */
		WARN_ONCE(1, "WARNING: SMP operation may be unreliable"
				    "with B stepping processors.\n");
	}
#endif
}

static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
{
	unsigned long lo, hi;

#ifdef CONFIG_X86_F00F_BUG
	/*
	 * All current models of Pentium and Pentium with MMX technology CPUs
	 * have the F0 0F bug, which lets nonprivileged users lock up the system.
	 * Note that the workaround only should be initialized once...
	 */
	c->f00f_bug = 0;
	if (!paravirt_enabled() && c->x86 == 5) {
		static int f00f_workaround_enabled;

		c->f00f_bug = 1;
		if (!f00f_workaround_enabled) {
			trap_init_f00f_bug();
			printk(KERN_NOTICE "Intel Pentium with F0 0F bug - workaround enabled.\n");
			f00f_workaround_enabled = 1;
		}
	}
#endif

	/*
	 * SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until
	 * model 3 mask 3
	 */
	if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633)
		clear_cpu_cap(c, X86_FEATURE_SEP);

	/*
	 * P4 Xeon errata 037 workaround.
	 * Hardware prefetcher may cause stale data to be loaded into the cache.
	 */
	if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
		rdmsr(MSR_IA32_MISC_ENABLE, lo, hi);
		if ((lo & MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE) == 0) {
			printk (KERN_INFO "CPU: C0 stepping P4 Xeon detected.\n");
			printk (KERN_INFO "CPU: Disabling hardware prefetching (Errata 037)\n");
			lo |= MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE;
			wrmsr (MSR_IA32_MISC_ENABLE, lo, hi);
		}
	}

	/*
	 * See if we have a good local APIC by checking for buggy Pentia,
	 * i.e. all B steppings and the C2 stepping of P54C when using their
	 * integrated APIC (see 11AP erratum in "Pentium Processor
	 * Specification Update").
	 */
	if (cpu_has_apic && (c->x86<<8 | c->x86_model<<4) == 0x520 &&
	    (c->x86_mask < 0x6 || c->x86_mask == 0xb))
		set_cpu_cap(c, X86_FEATURE_11AP);


#ifdef CONFIG_X86_INTEL_USERCOPY
	/*
	 * Set up the preferred alignment for movsl bulk memory moves
	 */
	switch (c->x86) {
	case 4:		/* 486: untested */
		break;
	case 5:		/* Old Pentia: untested */
		break;
	case 6:		/* PII/PIII only like movsl with 8-byte alignment */
		movsl_mask.mask = 7;
		break;
	case 15:	/* P4 is OK down to 8-byte alignment */
		movsl_mask.mask = 7;
		break;
	}
#endif

#ifdef CONFIG_X86_NUMAQ
	numaq_tsc_disable();
#endif

	intel_smp_check(c);
}
#else
static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
{
}
#endif

static void __cpuinit srat_detect_node(struct cpuinfo_x86 *c)
{
#if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
	unsigned node;
	int cpu = smp_processor_id();
	int apicid = cpu_has_apic ? hard_smp_processor_id() : c->apicid;

	/* Don't do the funky fallback heuristics the AMD version employs
	   for now. */
	node = apicid_to_node[apicid];
	if (node == NUMA_NO_NODE || !node_online(node))
		node = first_node(node_online_map);
	numa_set_node(cpu, node);

	printk(KERN_INFO "CPU %d/0x%x -> Node %d\n", cpu, apicid, node);
#endif
}

/*
 * find out the number of processor cores on the die
 */
static int __cpuinit intel_num_cpu_cores(struct cpuinfo_x86 *c)
{
	unsigned int eax, ebx, ecx, edx;

	if (c->cpuid_level < 4)
		return 1;

	/* Intel has a non-standard dependency on %ecx for this CPUID level. */
	cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
	if (eax & 0x1f)
		return ((eax >> 26) + 1);
	else
		return 1;
}

static void __cpuinit detect_vmx_virtcap(struct cpuinfo_x86 *c)
{
	/* Intel VMX MSR indicated features */
#define X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW	0x00200000
#define X86_VMX_FEATURE_PROC_CTLS_VNMI		0x00400000
#define X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS	0x80000000
#define X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC	0x00000001
#define X86_VMX_FEATURE_PROC_CTLS2_EPT		0x00000002
#define X86_VMX_FEATURE_PROC_CTLS2_VPID		0x00000020

	u32 vmx_msr_low, vmx_msr_high, msr_ctl, msr_ctl2;

	clear_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
	clear_cpu_cap(c, X86_FEATURE_VNMI);
	clear_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
	clear_cpu_cap(c, X86_FEATURE_EPT);
	clear_cpu_cap(c, X86_FEATURE_VPID);

	rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, vmx_msr_low, vmx_msr_high);
	msr_ctl = vmx_msr_high | vmx_msr_low;
	if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW)
		set_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
	if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_VNMI)
		set_cpu_cap(c, X86_FEATURE_VNMI);
	if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS) {
		rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2,
		      vmx_msr_low, vmx_msr_high);
		msr_ctl2 = vmx_msr_high | vmx_msr_low;
		if ((msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC) &&
		    (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW))
			set_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
		if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_EPT)
			set_cpu_cap(c, X86_FEATURE_EPT);
		if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VPID)
			set_cpu_cap(c, X86_FEATURE_VPID);
	}
}

static void __cpuinit init_intel(struct cpuinfo_x86 *c)
{
	unsigned int l2 = 0;

	early_init_intel(c);

	intel_workarounds(c);

	/*
	 * Detect the extended topology information if available. This
	 * will reinitialise the initial_apicid which will be used
	 * in init_intel_cacheinfo()
	 */
	detect_extended_topology(c);

	l2 = init_intel_cacheinfo(c);
	if (c->cpuid_level > 9) {
		unsigned eax = cpuid_eax(10);
		/* Check for version and the number of counters */
		if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
			set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON);
	}

	if (cpu_has_xmm2)
		set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
	if (cpu_has_ds) {
		unsigned int l1;
		rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
		if (!(l1 & (1<<11)))
			set_cpu_cap(c, X86_FEATURE_BTS);
		if (!(l1 & (1<<12)))
			set_cpu_cap(c, X86_FEATURE_PEBS);
		ds_init_intel(c);
	}

	if (c->x86 == 6 && c->x86_model == 29 && cpu_has_clflush)
		set_cpu_cap(c, X86_FEATURE_CLFLUSH_MONITOR);

#ifdef CONFIG_X86_64
	if (c->x86 == 15)
		c->x86_cache_alignment = c->x86_clflush_size * 2;
	if (c->x86 == 6)
		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
#else
	/*
	 * Names for the Pentium II/Celeron processors
	 * detectable only by also checking the cache size.
	 * Dixon is NOT a Celeron.
	 */
	if (c->x86 == 6) {
		char *p = NULL;

		switch (c->x86_model) {
		case 5:
			if (c->x86_mask == 0) {
				if (l2 == 0)
					p = "Celeron (Covington)";
				else if (l2 == 256)
					p = "Mobile Pentium II (Dixon)";
			}
			break;

		case 6:
			if (l2 == 128)
				p = "Celeron (Mendocino)";
			else if (c->x86_mask == 0 || c->x86_mask == 5)
				p = "Celeron-A";
			break;

		case 8:
			if (l2 == 128)
				p = "Celeron (Coppermine)";
			break;
		}

		if (p)
			strcpy(c->x86_model_id, p);
	}

	if (c->x86 == 15)
		set_cpu_cap(c, X86_FEATURE_P4);
	if (c->x86 == 6)
		set_cpu_cap(c, X86_FEATURE_P3);
#endif

	if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) {
		/*
		 * let's use the legacy cpuid vector 0x1 and 0x4 for topology
		 * detection.
		 */
		c->x86_max_cores = intel_num_cpu_cores(c);
#ifdef CONFIG_X86_32
		detect_ht(c);
#endif
	}

	/* Work around errata */
	srat_detect_node(c);

	if (cpu_has(c, X86_FEATURE_VMX))
		detect_vmx_virtcap(c);
}

#ifdef CONFIG_X86_32
static unsigned int __cpuinit intel_size_cache(struct cpuinfo_x86 *c, unsigned int size)
{
	/*
	 * Intel PIII Tualatin. This comes in two flavours.
	 * One has 256kb of cache, the other 512. We have no way
	 * to determine which, so we use a boottime override
	 * for the 512kb model, and assume 256 otherwise.
	 */
	if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
		size = 256;
	return size;
}
#endif

static const struct cpu_dev __cpuinitconst intel_cpu_dev = {
	.c_vendor	= "Intel",
	.c_ident	= { "GenuineIntel" },
#ifdef CONFIG_X86_32
	.c_models = {
		{ .vendor = X86_VENDOR_INTEL, .family = 4, .model_names =
		  {
			  [0] = "486 DX-25/33",
			  [1] = "486 DX-50",
			  [2] = "486 SX",
			  [3] = "486 DX/2",
			  [4] = "486 SL",
			  [5] = "486 SX/2",
			  [7] = "486 DX/2-WB",
			  [8] = "486 DX/4",
			  [9] = "486 DX/4-WB"
		  }
		},
		{ .vendor = X86_VENDOR_INTEL, .family = 5, .model_names =
		  {
			  [0] = "Pentium 60/66 A-step",
			  [1] = "Pentium 60/66",
			  [2] = "Pentium 75 - 200",
			  [3] = "OverDrive PODP5V83",
			  [4] = "Pentium MMX",
			  [7] = "Mobile Pentium 75 - 200",
			  [8] = "Mobile Pentium MMX"
		  }
		},
		{ .vendor = X86_VENDOR_INTEL, .family = 6, .model_names =
		  {
			  [0] = "Pentium Pro A-step",
			  [1] = "Pentium Pro",
			  [3] = "Pentium II (Klamath)",
			  [4] = "Pentium II (Deschutes)",
			  [5] = "Pentium II (Deschutes)",
			  [6] = "Mobile Pentium II",
			  [7] = "Pentium III (Katmai)",
			  [8] = "Pentium III (Coppermine)",
			  [10] = "Pentium III (Cascades)",
			  [11] = "Pentium III (Tualatin)",
		  }
		},
		{ .vendor = X86_VENDOR_INTEL, .family = 15, .model_names =
		  {
			  [0] = "Pentium 4 (Unknown)",
			  [1] = "Pentium 4 (Willamette)",
			  [2] = "Pentium 4 (Northwood)",
			  [4] = "Pentium 4 (Foster)",
			  [5] = "Pentium 4 (Foster)",
		  }
		},
	},
	.c_size_cache	= intel_size_cache,
#endif
	.c_early_init   = early_init_intel,
	.c_init		= init_intel,
	.c_x86_vendor	= X86_VENDOR_INTEL,
};

cpu_dev_register(intel_cpu_dev);