xref: /linux/arch/x86/kernel/cpu/intel.c (revision f99cb7a43c5cca1813a97312487acf7a0f88ee2a)
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/thread_info.h>
8 #include <linux/module.h>
9 
10 #include <asm/processor.h>
11 #include <asm/pgtable.h>
12 #include <asm/msr.h>
13 #include <asm/uaccess.h>
14 #include <asm/ptrace.h>
15 #include <asm/ds.h>
16 #include <asm/bugs.h>
17 
18 #include "cpu.h"
19 
20 #ifdef CONFIG_X86_LOCAL_APIC
21 #include <asm/mpspec.h>
22 #include <asm/apic.h>
23 #include <mach_apic.h>
24 #endif
25 
26 #ifdef CONFIG_X86_INTEL_USERCOPY
27 /*
28  * Alignment at which movsl is preferred for bulk memory copies.
29  */
30 struct movsl_mask movsl_mask __read_mostly;
31 #endif
32 
33 void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
34 {
35 	/* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
36 	if (c->x86 == 15 && c->x86_cache_alignment == 64)
37 		c->x86_cache_alignment = 128;
38 	if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
39 		(c->x86 == 0x6 && c->x86_model >= 0x0e))
40 		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
41 }
42 
43 /*
44  *	Early probe support logic for ppro memory erratum #50
45  *
46  *	This is called before we do cpu ident work
47  */
48 
49 int __cpuinit ppro_with_ram_bug(void)
50 {
51 	/* Uses data from early_cpu_detect now */
52 	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
53 	    boot_cpu_data.x86 == 6 &&
54 	    boot_cpu_data.x86_model == 1 &&
55 	    boot_cpu_data.x86_mask < 8) {
56 		printk(KERN_INFO "Pentium Pro with Errata#50 detected. Taking evasive action.\n");
57 		return 1;
58 	}
59 	return 0;
60 }
61 
62 
63 /*
64  * P4 Xeon errata 037 workaround.
65  * Hardware prefetcher may cause stale data to be loaded into the cache.
66  */
67 static void __cpuinit Intel_errata_workarounds(struct cpuinfo_x86 *c)
68 {
69 	unsigned long lo, hi;
70 
71 	if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
72 		rdmsr (MSR_IA32_MISC_ENABLE, lo, hi);
73 		if ((lo & (1<<9)) == 0) {
74 			printk (KERN_INFO "CPU: C0 stepping P4 Xeon detected.\n");
75 			printk (KERN_INFO "CPU: Disabling hardware prefetching (Errata 037)\n");
76 			lo |= (1<<9);	/* Disable hw prefetching */
77 			wrmsr (MSR_IA32_MISC_ENABLE, lo, hi);
78 		}
79 	}
80 }
81 
82 
83 /*
84  * find out the number of processor cores on the die
85  */
86 static int __cpuinit num_cpu_cores(struct cpuinfo_x86 *c)
87 {
88 	unsigned int eax, ebx, ecx, edx;
89 
90 	if (c->cpuid_level < 4)
91 		return 1;
92 
93 	/* Intel has a non-standard dependency on %ecx for this CPUID level. */
94 	cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
95 	if (eax & 0x1f)
96 		return ((eax >> 26) + 1);
97 	else
98 		return 1;
99 }
100 
101 #ifdef CONFIG_X86_F00F_BUG
102 static void __cpuinit trap_init_f00f_bug(void)
103 {
104 	__set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);
105 
106 	/*
107 	 * Update the IDT descriptor and reload the IDT so that
108 	 * it uses the read-only mapped virtual address.
109 	 */
110 	idt_descr.address = fix_to_virt(FIX_F00F_IDT);
111 	load_idt(&idt_descr);
112 }
113 #endif
114 
115 static void __cpuinit init_intel(struct cpuinfo_x86 *c)
116 {
117 	unsigned int l2 = 0;
118 	char *p = NULL;
119 
120 	early_init_intel(c);
121 
122 #ifdef CONFIG_X86_F00F_BUG
123 	/*
124 	 * All current models of Pentium and Pentium with MMX technology CPUs
125 	 * have the F0 0F bug, which lets nonprivileged users lock up the system.
126 	 * Note that the workaround only should be initialized once...
127 	 */
128 	c->f00f_bug = 0;
129 	if (!paravirt_enabled() && c->x86 == 5) {
130 		static int f00f_workaround_enabled = 0;
131 
132 		c->f00f_bug = 1;
133 		if ( !f00f_workaround_enabled ) {
134 			trap_init_f00f_bug();
135 			printk(KERN_NOTICE "Intel Pentium with F0 0F bug - workaround enabled.\n");
136 			f00f_workaround_enabled = 1;
137 		}
138 	}
139 #endif
140 
141 	l2 = init_intel_cacheinfo(c);
142 	if (c->cpuid_level > 9 ) {
143 		unsigned eax = cpuid_eax(10);
144 		/* Check for version and the number of counters */
145 		if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
146 			set_bit(X86_FEATURE_ARCH_PERFMON, c->x86_capability);
147 	}
148 
149 	/* SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until model 3 mask 3 */
150 	if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633)
151 		clear_bit(X86_FEATURE_SEP, c->x86_capability);
152 
153 	/* Names for the Pentium II/Celeron processors
154 	   detectable only by also checking the cache size.
155 	   Dixon is NOT a Celeron. */
156 	if (c->x86 == 6) {
157 		switch (c->x86_model) {
158 		case 5:
159 			if (c->x86_mask == 0) {
160 				if (l2 == 0)
161 					p = "Celeron (Covington)";
162 				else if (l2 == 256)
163 					p = "Mobile Pentium II (Dixon)";
164 			}
165 			break;
166 
167 		case 6:
168 			if (l2 == 128)
169 				p = "Celeron (Mendocino)";
170 			else if (c->x86_mask == 0 || c->x86_mask == 5)
171 				p = "Celeron-A";
172 			break;
173 
174 		case 8:
175 			if (l2 == 128)
176 				p = "Celeron (Coppermine)";
177 			break;
178 		}
179 	}
180 
181 	if ( p )
182 		strcpy(c->x86_model_id, p);
183 
184 	c->x86_max_cores = num_cpu_cores(c);
185 
186 	detect_ht(c);
187 
188 	/* Work around errata */
189 	Intel_errata_workarounds(c);
190 
191 #ifdef CONFIG_X86_INTEL_USERCOPY
192 	/*
193 	 * Set up the preferred alignment for movsl bulk memory moves
194 	 */
195 	switch (c->x86) {
196 	case 4:		/* 486: untested */
197 		break;
198 	case 5:		/* Old Pentia: untested */
199 		break;
200 	case 6:		/* PII/PIII only like movsl with 8-byte alignment */
201 		movsl_mask.mask = 7;
202 		break;
203 	case 15:	/* P4 is OK down to 8-byte alignment */
204 		movsl_mask.mask = 7;
205 		break;
206 	}
207 #endif
208 
209 	if (cpu_has_xmm2)
210 		set_bit(X86_FEATURE_LFENCE_RDTSC, c->x86_capability);
211 	if (c->x86 == 15) {
212 		set_bit(X86_FEATURE_P4, c->x86_capability);
213 	}
214 	if (c->x86 == 6)
215 		set_bit(X86_FEATURE_P3, c->x86_capability);
216 	if (cpu_has_ds) {
217 		unsigned int l1;
218 		rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
219 		if (!(l1 & (1<<11)))
220 			set_bit(X86_FEATURE_BTS, c->x86_capability);
221 		if (!(l1 & (1<<12)))
222 			set_bit(X86_FEATURE_PEBS, c->x86_capability);
223 	}
224 
225 	if (cpu_has_bts)
226 		ds_init_intel(c);
227 }
228 
229 static unsigned int __cpuinit intel_size_cache(struct cpuinfo_x86 * c, unsigned int size)
230 {
231 	/* Intel PIII Tualatin. This comes in two flavours.
232 	 * One has 256kb of cache, the other 512. We have no way
233 	 * to determine which, so we use a boottime override
234 	 * for the 512kb model, and assume 256 otherwise.
235 	 */
236 	if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
237 		size = 256;
238 	return size;
239 }
240 
241 static struct cpu_dev intel_cpu_dev __cpuinitdata = {
242 	.c_vendor	= "Intel",
243 	.c_ident 	= { "GenuineIntel" },
244 	.c_models = {
245 		{ .vendor = X86_VENDOR_INTEL, .family = 4, .model_names =
246 		  {
247 			  [0] = "486 DX-25/33",
248 			  [1] = "486 DX-50",
249 			  [2] = "486 SX",
250 			  [3] = "486 DX/2",
251 			  [4] = "486 SL",
252 			  [5] = "486 SX/2",
253 			  [7] = "486 DX/2-WB",
254 			  [8] = "486 DX/4",
255 			  [9] = "486 DX/4-WB"
256 		  }
257 		},
258 		{ .vendor = X86_VENDOR_INTEL, .family = 5, .model_names =
259 		  {
260 			  [0] = "Pentium 60/66 A-step",
261 			  [1] = "Pentium 60/66",
262 			  [2] = "Pentium 75 - 200",
263 			  [3] = "OverDrive PODP5V83",
264 			  [4] = "Pentium MMX",
265 			  [7] = "Mobile Pentium 75 - 200",
266 			  [8] = "Mobile Pentium MMX"
267 		  }
268 		},
269 		{ .vendor = X86_VENDOR_INTEL, .family = 6, .model_names =
270 		  {
271 			  [0] = "Pentium Pro A-step",
272 			  [1] = "Pentium Pro",
273 			  [3] = "Pentium II (Klamath)",
274 			  [4] = "Pentium II (Deschutes)",
275 			  [5] = "Pentium II (Deschutes)",
276 			  [6] = "Mobile Pentium II",
277 			  [7] = "Pentium III (Katmai)",
278 			  [8] = "Pentium III (Coppermine)",
279 			  [10] = "Pentium III (Cascades)",
280 			  [11] = "Pentium III (Tualatin)",
281 		  }
282 		},
283 		{ .vendor = X86_VENDOR_INTEL, .family = 15, .model_names =
284 		  {
285 			  [0] = "Pentium 4 (Unknown)",
286 			  [1] = "Pentium 4 (Willamette)",
287 			  [2] = "Pentium 4 (Northwood)",
288 			  [4] = "Pentium 4 (Foster)",
289 			  [5] = "Pentium 4 (Foster)",
290 		  }
291 		},
292 	},
293 	.c_init		= init_intel,
294 	.c_size_cache	= intel_size_cache,
295 };
296 
297 __init int intel_cpu_init(void)
298 {
299 	cpu_devs[X86_VENDOR_INTEL] = &intel_cpu_dev;
300 	return 0;
301 }
302 
303 #ifndef CONFIG_X86_CMPXCHG
304 unsigned long cmpxchg_386_u8(volatile void *ptr, u8 old, u8 new)
305 {
306 	u8 prev;
307 	unsigned long flags;
308 
309 	/* Poor man's cmpxchg for 386. Unsuitable for SMP */
310 	local_irq_save(flags);
311 	prev = *(u8 *)ptr;
312 	if (prev == old)
313 		*(u8 *)ptr = new;
314 	local_irq_restore(flags);
315 	return prev;
316 }
317 EXPORT_SYMBOL(cmpxchg_386_u8);
318 
319 unsigned long cmpxchg_386_u16(volatile void *ptr, u16 old, u16 new)
320 {
321 	u16 prev;
322 	unsigned long flags;
323 
324 	/* Poor man's cmpxchg for 386. Unsuitable for SMP */
325 	local_irq_save(flags);
326 	prev = *(u16 *)ptr;
327 	if (prev == old)
328 		*(u16 *)ptr = new;
329 	local_irq_restore(flags);
330 	return prev;
331 }
332 EXPORT_SYMBOL(cmpxchg_386_u16);
333 
334 unsigned long cmpxchg_386_u32(volatile void *ptr, u32 old, u32 new)
335 {
336 	u32 prev;
337 	unsigned long flags;
338 
339 	/* Poor man's cmpxchg for 386. Unsuitable for SMP */
340 	local_irq_save(flags);
341 	prev = *(u32 *)ptr;
342 	if (prev == old)
343 		*(u32 *)ptr = new;
344 	local_irq_restore(flags);
345 	return prev;
346 }
347 EXPORT_SYMBOL(cmpxchg_386_u32);
348 #endif
349 
350 #ifndef CONFIG_X86_CMPXCHG64
351 unsigned long long cmpxchg_486_u64(volatile void *ptr, u64 old, u64 new)
352 {
353 	u64 prev;
354 	unsigned long flags;
355 
356 	/* Poor man's cmpxchg8b for 386 and 486. Unsuitable for SMP */
357 	local_irq_save(flags);
358 	prev = *(u64 *)ptr;
359 	if (prev == old)
360 		*(u64 *)ptr = new;
361 	local_irq_restore(flags);
362 	return prev;
363 }
364 EXPORT_SYMBOL(cmpxchg_486_u64);
365 #endif
366 
367 // arch_initcall(intel_cpu_init);
368 
369