xref: /openbmc/linux/arch/x86/kernel/cpu/intel.c (revision 7dd65feb)
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/ds.h>
16 #include <asm/bugs.h>
17 #include <asm/cpu.h>
18 
19 #ifdef CONFIG_X86_64
20 #include <linux/topology.h>
21 #include <asm/numa_64.h>
22 #endif
23 
24 #include "cpu.h"
25 
26 #ifdef CONFIG_X86_LOCAL_APIC
27 #include <asm/mpspec.h>
28 #include <asm/apic.h>
29 #endif
30 
31 static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
32 {
33 	/* Unmask CPUID levels if masked: */
34 	if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
35 		u64 misc_enable;
36 
37 		rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
38 
39 		if (misc_enable & MSR_IA32_MISC_ENABLE_LIMIT_CPUID) {
40 			misc_enable &= ~MSR_IA32_MISC_ENABLE_LIMIT_CPUID;
41 			wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
42 			c->cpuid_level = cpuid_eax(0);
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 #ifdef CONFIG_X86_64
51 	set_cpu_cap(c, X86_FEATURE_SYSENTER32);
52 #else
53 	/* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
54 	if (c->x86 == 15 && c->x86_cache_alignment == 64)
55 		c->x86_cache_alignment = 128;
56 #endif
57 
58 	/* CPUID workaround for 0F33/0F34 CPU */
59 	if (c->x86 == 0xF && c->x86_model == 0x3
60 	    && (c->x86_mask == 0x3 || c->x86_mask == 0x4))
61 		c->x86_phys_bits = 36;
62 
63 	/*
64 	 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
65 	 * with P/T states and does not stop in deep C-states.
66 	 *
67 	 * It is also reliable across cores and sockets. (but not across
68 	 * cabinets - we turn it off in that case explicitly.)
69 	 */
70 	if (c->x86_power & (1 << 8)) {
71 		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
72 		set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
73 		sched_clock_stable = 1;
74 	}
75 
76 	/*
77 	 * There is a known erratum on Pentium III and Core Solo
78 	 * and Core Duo CPUs.
79 	 * " Page with PAT set to WC while associated MTRR is UC
80 	 *   may consolidate to UC "
81 	 * Because of this erratum, it is better to stick with
82 	 * setting WC in MTRR rather than using PAT on these CPUs.
83 	 *
84 	 * Enable PAT WC only on P4, Core 2 or later CPUs.
85 	 */
86 	if (c->x86 == 6 && c->x86_model < 15)
87 		clear_cpu_cap(c, X86_FEATURE_PAT);
88 
89 #ifdef CONFIG_KMEMCHECK
90 	/*
91 	 * P4s have a "fast strings" feature which causes single-
92 	 * stepping REP instructions to only generate a #DB on
93 	 * cache-line boundaries.
94 	 *
95 	 * Ingo Molnar reported a Pentium D (model 6) and a Xeon
96 	 * (model 2) with the same problem.
97 	 */
98 	if (c->x86 == 15) {
99 		u64 misc_enable;
100 
101 		rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
102 
103 		if (misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING) {
104 			printk(KERN_INFO "kmemcheck: Disabling fast string operations\n");
105 
106 			misc_enable &= ~MSR_IA32_MISC_ENABLE_FAST_STRING;
107 			wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
108 		}
109 	}
110 #endif
111 }
112 
113 #ifdef CONFIG_X86_32
114 /*
115  *	Early probe support logic for ppro memory erratum #50
116  *
117  *	This is called before we do cpu ident work
118  */
119 
120 int __cpuinit ppro_with_ram_bug(void)
121 {
122 	/* Uses data from early_cpu_detect now */
123 	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
124 	    boot_cpu_data.x86 == 6 &&
125 	    boot_cpu_data.x86_model == 1 &&
126 	    boot_cpu_data.x86_mask < 8) {
127 		printk(KERN_INFO "Pentium Pro with Errata#50 detected. Taking evasive action.\n");
128 		return 1;
129 	}
130 	return 0;
131 }
132 
133 #ifdef CONFIG_X86_F00F_BUG
134 static void __cpuinit trap_init_f00f_bug(void)
135 {
136 	__set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);
137 
138 	/*
139 	 * Update the IDT descriptor and reload the IDT so that
140 	 * it uses the read-only mapped virtual address.
141 	 */
142 	idt_descr.address = fix_to_virt(FIX_F00F_IDT);
143 	load_idt(&idt_descr);
144 }
145 #endif
146 
147 static void __cpuinit intel_smp_check(struct cpuinfo_x86 *c)
148 {
149 #ifdef CONFIG_SMP
150 	/* calling is from identify_secondary_cpu() ? */
151 	if (c->cpu_index == boot_cpu_id)
152 		return;
153 
154 	/*
155 	 * Mask B, Pentium, but not Pentium MMX
156 	 */
157 	if (c->x86 == 5 &&
158 	    c->x86_mask >= 1 && c->x86_mask <= 4 &&
159 	    c->x86_model <= 3) {
160 		/*
161 		 * Remember we have B step Pentia with bugs
162 		 */
163 		WARN_ONCE(1, "WARNING: SMP operation may be unreliable"
164 				    "with B stepping processors.\n");
165 	}
166 #endif
167 }
168 
169 static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
170 {
171 	unsigned long lo, hi;
172 
173 #ifdef CONFIG_X86_F00F_BUG
174 	/*
175 	 * All current models of Pentium and Pentium with MMX technology CPUs
176 	 * have the F0 0F bug, which lets nonprivileged users lock up the
177 	 * system.
178 	 * Note that the workaround only should be initialized once...
179 	 */
180 	c->f00f_bug = 0;
181 	if (!paravirt_enabled() && c->x86 == 5) {
182 		static int f00f_workaround_enabled;
183 
184 		c->f00f_bug = 1;
185 		if (!f00f_workaround_enabled) {
186 			trap_init_f00f_bug();
187 			printk(KERN_NOTICE "Intel Pentium with F0 0F bug - workaround enabled.\n");
188 			f00f_workaround_enabled = 1;
189 		}
190 	}
191 #endif
192 
193 	/*
194 	 * SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until
195 	 * model 3 mask 3
196 	 */
197 	if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633)
198 		clear_cpu_cap(c, X86_FEATURE_SEP);
199 
200 	/*
201 	 * P4 Xeon errata 037 workaround.
202 	 * Hardware prefetcher may cause stale data to be loaded into the cache.
203 	 */
204 	if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
205 		rdmsr(MSR_IA32_MISC_ENABLE, lo, hi);
206 		if ((lo & MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE) == 0) {
207 			printk (KERN_INFO "CPU: C0 stepping P4 Xeon detected.\n");
208 			printk (KERN_INFO "CPU: Disabling hardware prefetching (Errata 037)\n");
209 			lo |= MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE;
210 			wrmsr(MSR_IA32_MISC_ENABLE, lo, hi);
211 		}
212 	}
213 
214 	/*
215 	 * See if we have a good local APIC by checking for buggy Pentia,
216 	 * i.e. all B steppings and the C2 stepping of P54C when using their
217 	 * integrated APIC (see 11AP erratum in "Pentium Processor
218 	 * Specification Update").
219 	 */
220 	if (cpu_has_apic && (c->x86<<8 | c->x86_model<<4) == 0x520 &&
221 	    (c->x86_mask < 0x6 || c->x86_mask == 0xb))
222 		set_cpu_cap(c, X86_FEATURE_11AP);
223 
224 
225 #ifdef CONFIG_X86_INTEL_USERCOPY
226 	/*
227 	 * Set up the preferred alignment for movsl bulk memory moves
228 	 */
229 	switch (c->x86) {
230 	case 4:		/* 486: untested */
231 		break;
232 	case 5:		/* Old Pentia: untested */
233 		break;
234 	case 6:		/* PII/PIII only like movsl with 8-byte alignment */
235 		movsl_mask.mask = 7;
236 		break;
237 	case 15:	/* P4 is OK down to 8-byte alignment */
238 		movsl_mask.mask = 7;
239 		break;
240 	}
241 #endif
242 
243 #ifdef CONFIG_X86_NUMAQ
244 	numaq_tsc_disable();
245 #endif
246 
247 	intel_smp_check(c);
248 }
249 #else
250 static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
251 {
252 }
253 #endif
254 
255 static void __cpuinit srat_detect_node(struct cpuinfo_x86 *c)
256 {
257 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
258 	unsigned node;
259 	int cpu = smp_processor_id();
260 	int apicid = cpu_has_apic ? hard_smp_processor_id() : c->apicid;
261 
262 	/* Don't do the funky fallback heuristics the AMD version employs
263 	   for now. */
264 	node = apicid_to_node[apicid];
265 	if (node == NUMA_NO_NODE)
266 		node = first_node(node_online_map);
267 	else if (!node_online(node)) {
268 		/* reuse the value from init_cpu_to_node() */
269 		node = cpu_to_node(cpu);
270 	}
271 	numa_set_node(cpu, node);
272 #endif
273 }
274 
275 /*
276  * find out the number of processor cores on the die
277  */
278 static int __cpuinit intel_num_cpu_cores(struct cpuinfo_x86 *c)
279 {
280 	unsigned int eax, ebx, ecx, edx;
281 
282 	if (c->cpuid_level < 4)
283 		return 1;
284 
285 	/* Intel has a non-standard dependency on %ecx for this CPUID level. */
286 	cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
287 	if (eax & 0x1f)
288 		return (eax >> 26) + 1;
289 	else
290 		return 1;
291 }
292 
293 static void __cpuinit detect_vmx_virtcap(struct cpuinfo_x86 *c)
294 {
295 	/* Intel VMX MSR indicated features */
296 #define X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW	0x00200000
297 #define X86_VMX_FEATURE_PROC_CTLS_VNMI		0x00400000
298 #define X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS	0x80000000
299 #define X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC	0x00000001
300 #define X86_VMX_FEATURE_PROC_CTLS2_EPT		0x00000002
301 #define X86_VMX_FEATURE_PROC_CTLS2_VPID		0x00000020
302 
303 	u32 vmx_msr_low, vmx_msr_high, msr_ctl, msr_ctl2;
304 
305 	clear_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
306 	clear_cpu_cap(c, X86_FEATURE_VNMI);
307 	clear_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
308 	clear_cpu_cap(c, X86_FEATURE_EPT);
309 	clear_cpu_cap(c, X86_FEATURE_VPID);
310 
311 	rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, vmx_msr_low, vmx_msr_high);
312 	msr_ctl = vmx_msr_high | vmx_msr_low;
313 	if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW)
314 		set_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
315 	if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_VNMI)
316 		set_cpu_cap(c, X86_FEATURE_VNMI);
317 	if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS) {
318 		rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2,
319 		      vmx_msr_low, vmx_msr_high);
320 		msr_ctl2 = vmx_msr_high | vmx_msr_low;
321 		if ((msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC) &&
322 		    (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW))
323 			set_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
324 		if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_EPT)
325 			set_cpu_cap(c, X86_FEATURE_EPT);
326 		if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VPID)
327 			set_cpu_cap(c, X86_FEATURE_VPID);
328 	}
329 }
330 
331 static void __cpuinit init_intel(struct cpuinfo_x86 *c)
332 {
333 	unsigned int l2 = 0;
334 
335 	early_init_intel(c);
336 
337 	intel_workarounds(c);
338 
339 	/*
340 	 * Detect the extended topology information if available. This
341 	 * will reinitialise the initial_apicid which will be used
342 	 * in init_intel_cacheinfo()
343 	 */
344 	detect_extended_topology(c);
345 
346 	l2 = init_intel_cacheinfo(c);
347 	if (c->cpuid_level > 9) {
348 		unsigned eax = cpuid_eax(10);
349 		/* Check for version and the number of counters */
350 		if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
351 			set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON);
352 	}
353 
354 	if (c->cpuid_level > 6) {
355 		unsigned ecx = cpuid_ecx(6);
356 		if (ecx & 0x01)
357 			set_cpu_cap(c, X86_FEATURE_APERFMPERF);
358 	}
359 
360 	if (cpu_has_xmm2)
361 		set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
362 	if (cpu_has_ds) {
363 		unsigned int l1;
364 		rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
365 		if (!(l1 & (1<<11)))
366 			set_cpu_cap(c, X86_FEATURE_BTS);
367 		if (!(l1 & (1<<12)))
368 			set_cpu_cap(c, X86_FEATURE_PEBS);
369 		ds_init_intel(c);
370 	}
371 
372 	if (c->x86 == 6 && c->x86_model == 29 && cpu_has_clflush)
373 		set_cpu_cap(c, X86_FEATURE_CLFLUSH_MONITOR);
374 
375 #ifdef CONFIG_X86_64
376 	if (c->x86 == 15)
377 		c->x86_cache_alignment = c->x86_clflush_size * 2;
378 	if (c->x86 == 6)
379 		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
380 #else
381 	/*
382 	 * Names for the Pentium II/Celeron processors
383 	 * detectable only by also checking the cache size.
384 	 * Dixon is NOT a Celeron.
385 	 */
386 	if (c->x86 == 6) {
387 		char *p = NULL;
388 
389 		switch (c->x86_model) {
390 		case 5:
391 			if (c->x86_mask == 0) {
392 				if (l2 == 0)
393 					p = "Celeron (Covington)";
394 				else if (l2 == 256)
395 					p = "Mobile Pentium II (Dixon)";
396 			}
397 			break;
398 
399 		case 6:
400 			if (l2 == 128)
401 				p = "Celeron (Mendocino)";
402 			else if (c->x86_mask == 0 || c->x86_mask == 5)
403 				p = "Celeron-A";
404 			break;
405 
406 		case 8:
407 			if (l2 == 128)
408 				p = "Celeron (Coppermine)";
409 			break;
410 		}
411 
412 		if (p)
413 			strcpy(c->x86_model_id, p);
414 	}
415 
416 	if (c->x86 == 15)
417 		set_cpu_cap(c, X86_FEATURE_P4);
418 	if (c->x86 == 6)
419 		set_cpu_cap(c, X86_FEATURE_P3);
420 #endif
421 
422 	if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) {
423 		/*
424 		 * let's use the legacy cpuid vector 0x1 and 0x4 for topology
425 		 * detection.
426 		 */
427 		c->x86_max_cores = intel_num_cpu_cores(c);
428 #ifdef CONFIG_X86_32
429 		detect_ht(c);
430 #endif
431 	}
432 
433 	/* Work around errata */
434 	srat_detect_node(c);
435 
436 	if (cpu_has(c, X86_FEATURE_VMX))
437 		detect_vmx_virtcap(c);
438 }
439 
440 #ifdef CONFIG_X86_32
441 static unsigned int __cpuinit intel_size_cache(struct cpuinfo_x86 *c, unsigned int size)
442 {
443 	/*
444 	 * Intel PIII Tualatin. This comes in two flavours.
445 	 * One has 256kb of cache, the other 512. We have no way
446 	 * to determine which, so we use a boottime override
447 	 * for the 512kb model, and assume 256 otherwise.
448 	 */
449 	if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
450 		size = 256;
451 	return size;
452 }
453 #endif
454 
455 static const struct cpu_dev __cpuinitconst intel_cpu_dev = {
456 	.c_vendor	= "Intel",
457 	.c_ident	= { "GenuineIntel" },
458 #ifdef CONFIG_X86_32
459 	.c_models = {
460 		{ .vendor = X86_VENDOR_INTEL, .family = 4, .model_names =
461 		  {
462 			  [0] = "486 DX-25/33",
463 			  [1] = "486 DX-50",
464 			  [2] = "486 SX",
465 			  [3] = "486 DX/2",
466 			  [4] = "486 SL",
467 			  [5] = "486 SX/2",
468 			  [7] = "486 DX/2-WB",
469 			  [8] = "486 DX/4",
470 			  [9] = "486 DX/4-WB"
471 		  }
472 		},
473 		{ .vendor = X86_VENDOR_INTEL, .family = 5, .model_names =
474 		  {
475 			  [0] = "Pentium 60/66 A-step",
476 			  [1] = "Pentium 60/66",
477 			  [2] = "Pentium 75 - 200",
478 			  [3] = "OverDrive PODP5V83",
479 			  [4] = "Pentium MMX",
480 			  [7] = "Mobile Pentium 75 - 200",
481 			  [8] = "Mobile Pentium MMX"
482 		  }
483 		},
484 		{ .vendor = X86_VENDOR_INTEL, .family = 6, .model_names =
485 		  {
486 			  [0] = "Pentium Pro A-step",
487 			  [1] = "Pentium Pro",
488 			  [3] = "Pentium II (Klamath)",
489 			  [4] = "Pentium II (Deschutes)",
490 			  [5] = "Pentium II (Deschutes)",
491 			  [6] = "Mobile Pentium II",
492 			  [7] = "Pentium III (Katmai)",
493 			  [8] = "Pentium III (Coppermine)",
494 			  [10] = "Pentium III (Cascades)",
495 			  [11] = "Pentium III (Tualatin)",
496 		  }
497 		},
498 		{ .vendor = X86_VENDOR_INTEL, .family = 15, .model_names =
499 		  {
500 			  [0] = "Pentium 4 (Unknown)",
501 			  [1] = "Pentium 4 (Willamette)",
502 			  [2] = "Pentium 4 (Northwood)",
503 			  [4] = "Pentium 4 (Foster)",
504 			  [5] = "Pentium 4 (Foster)",
505 		  }
506 		},
507 	},
508 	.c_size_cache	= intel_size_cache,
509 #endif
510 	.c_early_init   = early_init_intel,
511 	.c_init		= init_intel,
512 	.c_x86_vendor	= X86_VENDOR_INTEL,
513 };
514 
515 cpu_dev_register(intel_cpu_dev);
516 
517