xref: /linux/arch/x86/kernel/cpu/intel.c (revision ee665ecca6d6775f65b1a4154c34f551f62cec52)
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 
11 #include <asm/processor.h>
12 #include <asm/pgtable.h>
13 #include <asm/msr.h>
14 #include <asm/uaccess.h>
15 #include <asm/ds.h>
16 #include <asm/bugs.h>
17 
18 #ifdef CONFIG_X86_64
19 #include <asm/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 
30 static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
31 {
32 	/* Unmask CPUID levels if masked: */
33 	if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
34 		u64 misc_enable;
35 
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 		}
43 	}
44 
45 	if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
46 		(c->x86 == 0x6 && c->x86_model >= 0x0e))
47 		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
48 
49 #ifdef CONFIG_X86_64
50 	set_cpu_cap(c, X86_FEATURE_SYSENTER32);
51 #else
52 	/* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
53 	if (c->x86 == 15 && c->x86_cache_alignment == 64)
54 		c->x86_cache_alignment = 128;
55 #endif
56 
57 	/*
58 	 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
59 	 * with P/T states and does not stop in deep C-states.
60 	 *
61 	 * It is also reliable across cores and sockets. (but not across
62 	 * cabinets - we turn it off in that case explicitly.)
63 	 */
64 	if (c->x86_power & (1 << 8)) {
65 		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
66 		set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
67 		set_cpu_cap(c, X86_FEATURE_TSC_RELIABLE);
68 		sched_clock_stable = 1;
69 	}
70 
71 	/*
72 	 * There is a known erratum on Pentium III and Core Solo
73 	 * and Core Duo CPUs.
74 	 * " Page with PAT set to WC while associated MTRR is UC
75 	 *   may consolidate to UC "
76 	 * Because of this erratum, it is better to stick with
77 	 * setting WC in MTRR rather than using PAT on these CPUs.
78 	 *
79 	 * Enable PAT WC only on P4, Core 2 or later CPUs.
80 	 */
81 	if (c->x86 == 6 && c->x86_model < 15)
82 		clear_cpu_cap(c, X86_FEATURE_PAT);
83 }
84 
85 #ifdef CONFIG_X86_32
86 /*
87  *	Early probe support logic for ppro memory erratum #50
88  *
89  *	This is called before we do cpu ident work
90  */
91 
92 int __cpuinit ppro_with_ram_bug(void)
93 {
94 	/* Uses data from early_cpu_detect now */
95 	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
96 	    boot_cpu_data.x86 == 6 &&
97 	    boot_cpu_data.x86_model == 1 &&
98 	    boot_cpu_data.x86_mask < 8) {
99 		printk(KERN_INFO "Pentium Pro with Errata#50 detected. Taking evasive action.\n");
100 		return 1;
101 	}
102 	return 0;
103 }
104 
105 #ifdef CONFIG_X86_F00F_BUG
106 static void __cpuinit trap_init_f00f_bug(void)
107 {
108 	__set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);
109 
110 	/*
111 	 * Update the IDT descriptor and reload the IDT so that
112 	 * it uses the read-only mapped virtual address.
113 	 */
114 	idt_descr.address = fix_to_virt(FIX_F00F_IDT);
115 	load_idt(&idt_descr);
116 }
117 #endif
118 
119 static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
120 {
121 	unsigned long lo, hi;
122 
123 #ifdef CONFIG_X86_F00F_BUG
124 	/*
125 	 * All current models of Pentium and Pentium with MMX technology CPUs
126 	 * have the F0 0F bug, which lets nonprivileged users lock up the system.
127 	 * Note that the workaround only should be initialized once...
128 	 */
129 	c->f00f_bug = 0;
130 	if (!paravirt_enabled() && c->x86 == 5) {
131 		static int f00f_workaround_enabled;
132 
133 		c->f00f_bug = 1;
134 		if (!f00f_workaround_enabled) {
135 			trap_init_f00f_bug();
136 			printk(KERN_NOTICE "Intel Pentium with F0 0F bug - workaround enabled.\n");
137 			f00f_workaround_enabled = 1;
138 		}
139 	}
140 #endif
141 
142 	/*
143 	 * SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until
144 	 * model 3 mask 3
145 	 */
146 	if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633)
147 		clear_cpu_cap(c, X86_FEATURE_SEP);
148 
149 	/*
150 	 * P4 Xeon errata 037 workaround.
151 	 * Hardware prefetcher may cause stale data to be loaded into the cache.
152 	 */
153 	if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
154 		rdmsr(MSR_IA32_MISC_ENABLE, lo, hi);
155 		if ((lo & MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE) == 0) {
156 			printk (KERN_INFO "CPU: C0 stepping P4 Xeon detected.\n");
157 			printk (KERN_INFO "CPU: Disabling hardware prefetching (Errata 037)\n");
158 			lo |= MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE;
159 			wrmsr (MSR_IA32_MISC_ENABLE, lo, hi);
160 		}
161 	}
162 
163 	/*
164 	 * See if we have a good local APIC by checking for buggy Pentia,
165 	 * i.e. all B steppings and the C2 stepping of P54C when using their
166 	 * integrated APIC (see 11AP erratum in "Pentium Processor
167 	 * Specification Update").
168 	 */
169 	if (cpu_has_apic && (c->x86<<8 | c->x86_model<<4) == 0x520 &&
170 	    (c->x86_mask < 0x6 || c->x86_mask == 0xb))
171 		set_cpu_cap(c, X86_FEATURE_11AP);
172 
173 
174 #ifdef CONFIG_X86_INTEL_USERCOPY
175 	/*
176 	 * Set up the preferred alignment for movsl bulk memory moves
177 	 */
178 	switch (c->x86) {
179 	case 4:		/* 486: untested */
180 		break;
181 	case 5:		/* Old Pentia: untested */
182 		break;
183 	case 6:		/* PII/PIII only like movsl with 8-byte alignment */
184 		movsl_mask.mask = 7;
185 		break;
186 	case 15:	/* P4 is OK down to 8-byte alignment */
187 		movsl_mask.mask = 7;
188 		break;
189 	}
190 #endif
191 
192 #ifdef CONFIG_X86_NUMAQ
193 	numaq_tsc_disable();
194 #endif
195 }
196 #else
197 static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c)
198 {
199 }
200 #endif
201 
202 static void __cpuinit srat_detect_node(void)
203 {
204 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
205 	unsigned node;
206 	int cpu = smp_processor_id();
207 	int apicid = hard_smp_processor_id();
208 
209 	/* Don't do the funky fallback heuristics the AMD version employs
210 	   for now. */
211 	node = apicid_to_node[apicid];
212 	if (node == NUMA_NO_NODE || !node_online(node))
213 		node = first_node(node_online_map);
214 	numa_set_node(cpu, node);
215 
216 	printk(KERN_INFO "CPU %d/0x%x -> Node %d\n", cpu, apicid, node);
217 #endif
218 }
219 
220 /*
221  * find out the number of processor cores on the die
222  */
223 static int __cpuinit intel_num_cpu_cores(struct cpuinfo_x86 *c)
224 {
225 	unsigned int eax, ebx, ecx, edx;
226 
227 	if (c->cpuid_level < 4)
228 		return 1;
229 
230 	/* Intel has a non-standard dependency on %ecx for this CPUID level. */
231 	cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
232 	if (eax & 0x1f)
233 		return ((eax >> 26) + 1);
234 	else
235 		return 1;
236 }
237 
238 static void __cpuinit detect_vmx_virtcap(struct cpuinfo_x86 *c)
239 {
240 	/* Intel VMX MSR indicated features */
241 #define X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW	0x00200000
242 #define X86_VMX_FEATURE_PROC_CTLS_VNMI		0x00400000
243 #define X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS	0x80000000
244 #define X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC	0x00000001
245 #define X86_VMX_FEATURE_PROC_CTLS2_EPT		0x00000002
246 #define X86_VMX_FEATURE_PROC_CTLS2_VPID		0x00000020
247 
248 	u32 vmx_msr_low, vmx_msr_high, msr_ctl, msr_ctl2;
249 
250 	clear_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
251 	clear_cpu_cap(c, X86_FEATURE_VNMI);
252 	clear_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
253 	clear_cpu_cap(c, X86_FEATURE_EPT);
254 	clear_cpu_cap(c, X86_FEATURE_VPID);
255 
256 	rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, vmx_msr_low, vmx_msr_high);
257 	msr_ctl = vmx_msr_high | vmx_msr_low;
258 	if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW)
259 		set_cpu_cap(c, X86_FEATURE_TPR_SHADOW);
260 	if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_VNMI)
261 		set_cpu_cap(c, X86_FEATURE_VNMI);
262 	if (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_2ND_CTLS) {
263 		rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2,
264 		      vmx_msr_low, vmx_msr_high);
265 		msr_ctl2 = vmx_msr_high | vmx_msr_low;
266 		if ((msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VIRT_APIC) &&
267 		    (msr_ctl & X86_VMX_FEATURE_PROC_CTLS_TPR_SHADOW))
268 			set_cpu_cap(c, X86_FEATURE_FLEXPRIORITY);
269 		if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_EPT)
270 			set_cpu_cap(c, X86_FEATURE_EPT);
271 		if (msr_ctl2 & X86_VMX_FEATURE_PROC_CTLS2_VPID)
272 			set_cpu_cap(c, X86_FEATURE_VPID);
273 	}
274 }
275 
276 static void __cpuinit init_intel(struct cpuinfo_x86 *c)
277 {
278 	unsigned int l2 = 0;
279 
280 	early_init_intel(c);
281 
282 	intel_workarounds(c);
283 
284 	/*
285 	 * Detect the extended topology information if available. This
286 	 * will reinitialise the initial_apicid which will be used
287 	 * in init_intel_cacheinfo()
288 	 */
289 	detect_extended_topology(c);
290 
291 	l2 = init_intel_cacheinfo(c);
292 	if (c->cpuid_level > 9) {
293 		unsigned eax = cpuid_eax(10);
294 		/* Check for version and the number of counters */
295 		if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
296 			set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON);
297 	}
298 
299 	if (cpu_has_xmm2)
300 		set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
301 	if (cpu_has_ds) {
302 		unsigned int l1;
303 		rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
304 		if (!(l1 & (1<<11)))
305 			set_cpu_cap(c, X86_FEATURE_BTS);
306 		if (!(l1 & (1<<12)))
307 			set_cpu_cap(c, X86_FEATURE_PEBS);
308 		ds_init_intel(c);
309 	}
310 
311 	if (c->x86 == 6 && c->x86_model == 29 && cpu_has_clflush)
312 		set_cpu_cap(c, X86_FEATURE_CLFLUSH_MONITOR);
313 
314 #ifdef CONFIG_X86_64
315 	if (c->x86 == 15)
316 		c->x86_cache_alignment = c->x86_clflush_size * 2;
317 	if (c->x86 == 6)
318 		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
319 #else
320 	/*
321 	 * Names for the Pentium II/Celeron processors
322 	 * detectable only by also checking the cache size.
323 	 * Dixon is NOT a Celeron.
324 	 */
325 	if (c->x86 == 6) {
326 		char *p = NULL;
327 
328 		switch (c->x86_model) {
329 		case 5:
330 			if (c->x86_mask == 0) {
331 				if (l2 == 0)
332 					p = "Celeron (Covington)";
333 				else if (l2 == 256)
334 					p = "Mobile Pentium II (Dixon)";
335 			}
336 			break;
337 
338 		case 6:
339 			if (l2 == 128)
340 				p = "Celeron (Mendocino)";
341 			else if (c->x86_mask == 0 || c->x86_mask == 5)
342 				p = "Celeron-A";
343 			break;
344 
345 		case 8:
346 			if (l2 == 128)
347 				p = "Celeron (Coppermine)";
348 			break;
349 		}
350 
351 		if (p)
352 			strcpy(c->x86_model_id, p);
353 	}
354 
355 	if (c->x86 == 15)
356 		set_cpu_cap(c, X86_FEATURE_P4);
357 	if (c->x86 == 6)
358 		set_cpu_cap(c, X86_FEATURE_P3);
359 #endif
360 
361 	if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) {
362 		/*
363 		 * let's use the legacy cpuid vector 0x1 and 0x4 for topology
364 		 * detection.
365 		 */
366 		c->x86_max_cores = intel_num_cpu_cores(c);
367 #ifdef CONFIG_X86_32
368 		detect_ht(c);
369 #endif
370 	}
371 
372 	/* Work around errata */
373 	srat_detect_node();
374 
375 	if (cpu_has(c, X86_FEATURE_VMX))
376 		detect_vmx_virtcap(c);
377 }
378 
379 #ifdef CONFIG_X86_32
380 static unsigned int __cpuinit intel_size_cache(struct cpuinfo_x86 *c, unsigned int size)
381 {
382 	/*
383 	 * Intel PIII Tualatin. This comes in two flavours.
384 	 * One has 256kb of cache, the other 512. We have no way
385 	 * to determine which, so we use a boottime override
386 	 * for the 512kb model, and assume 256 otherwise.
387 	 */
388 	if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
389 		size = 256;
390 	return size;
391 }
392 #endif
393 
394 static struct cpu_dev intel_cpu_dev __cpuinitdata = {
395 	.c_vendor	= "Intel",
396 	.c_ident	= { "GenuineIntel" },
397 #ifdef CONFIG_X86_32
398 	.c_models = {
399 		{ .vendor = X86_VENDOR_INTEL, .family = 4, .model_names =
400 		  {
401 			  [0] = "486 DX-25/33",
402 			  [1] = "486 DX-50",
403 			  [2] = "486 SX",
404 			  [3] = "486 DX/2",
405 			  [4] = "486 SL",
406 			  [5] = "486 SX/2",
407 			  [7] = "486 DX/2-WB",
408 			  [8] = "486 DX/4",
409 			  [9] = "486 DX/4-WB"
410 		  }
411 		},
412 		{ .vendor = X86_VENDOR_INTEL, .family = 5, .model_names =
413 		  {
414 			  [0] = "Pentium 60/66 A-step",
415 			  [1] = "Pentium 60/66",
416 			  [2] = "Pentium 75 - 200",
417 			  [3] = "OverDrive PODP5V83",
418 			  [4] = "Pentium MMX",
419 			  [7] = "Mobile Pentium 75 - 200",
420 			  [8] = "Mobile Pentium MMX"
421 		  }
422 		},
423 		{ .vendor = X86_VENDOR_INTEL, .family = 6, .model_names =
424 		  {
425 			  [0] = "Pentium Pro A-step",
426 			  [1] = "Pentium Pro",
427 			  [3] = "Pentium II (Klamath)",
428 			  [4] = "Pentium II (Deschutes)",
429 			  [5] = "Pentium II (Deschutes)",
430 			  [6] = "Mobile Pentium II",
431 			  [7] = "Pentium III (Katmai)",
432 			  [8] = "Pentium III (Coppermine)",
433 			  [10] = "Pentium III (Cascades)",
434 			  [11] = "Pentium III (Tualatin)",
435 		  }
436 		},
437 		{ .vendor = X86_VENDOR_INTEL, .family = 15, .model_names =
438 		  {
439 			  [0] = "Pentium 4 (Unknown)",
440 			  [1] = "Pentium 4 (Willamette)",
441 			  [2] = "Pentium 4 (Northwood)",
442 			  [4] = "Pentium 4 (Foster)",
443 			  [5] = "Pentium 4 (Foster)",
444 		  }
445 		},
446 	},
447 	.c_size_cache	= intel_size_cache,
448 #endif
449 	.c_early_init   = early_init_intel,
450 	.c_init		= init_intel,
451 	.c_x86_vendor	= X86_VENDOR_INTEL,
452 };
453 
454 cpu_dev_register(intel_cpu_dev);
455 
456