xref: /linux/arch/x86/kernel/cpu/intel.c (revision 2b8232ce512105e28453f301d1510de8363bccd1)
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/msr.h>
12 #include <asm/uaccess.h>
13 
14 #include "cpu.h"
15 
16 #ifdef CONFIG_X86_LOCAL_APIC
17 #include <asm/mpspec.h>
18 #include <asm/apic.h>
19 #include <mach_apic.h>
20 #endif
21 
22 extern int trap_init_f00f_bug(void);
23 
24 #ifdef CONFIG_X86_INTEL_USERCOPY
25 /*
26  * Alignment at which movsl is preferred for bulk memory copies.
27  */
28 struct movsl_mask movsl_mask __read_mostly;
29 #endif
30 
31 void __cpuinit early_intel_workaround(struct cpuinfo_x86 *c)
32 {
33 	if (c->x86_vendor != X86_VENDOR_INTEL)
34 		return;
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 }
39 
40 /*
41  *	Early probe support logic for ppro memory erratum #50
42  *
43  *	This is called before we do cpu ident work
44  */
45 
46 int __cpuinit ppro_with_ram_bug(void)
47 {
48 	/* Uses data from early_cpu_detect now */
49 	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
50 	    boot_cpu_data.x86 == 6 &&
51 	    boot_cpu_data.x86_model == 1 &&
52 	    boot_cpu_data.x86_mask < 8) {
53 		printk(KERN_INFO "Pentium Pro with Errata#50 detected. Taking evasive action.\n");
54 		return 1;
55 	}
56 	return 0;
57 }
58 
59 
60 /*
61  * P4 Xeon errata 037 workaround.
62  * Hardware prefetcher may cause stale data to be loaded into the cache.
63  */
64 static void __cpuinit Intel_errata_workarounds(struct cpuinfo_x86 *c)
65 {
66 	unsigned long lo, hi;
67 
68 	if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
69 		rdmsr (MSR_IA32_MISC_ENABLE, lo, hi);
70 		if ((lo & (1<<9)) == 0) {
71 			printk (KERN_INFO "CPU: C0 stepping P4 Xeon detected.\n");
72 			printk (KERN_INFO "CPU: Disabling hardware prefetching (Errata 037)\n");
73 			lo |= (1<<9);	/* Disable hw prefetching */
74 			wrmsr (MSR_IA32_MISC_ENABLE, lo, hi);
75 		}
76 	}
77 }
78 
79 
80 /*
81  * find out the number of processor cores on the die
82  */
83 static int __cpuinit num_cpu_cores(struct cpuinfo_x86 *c)
84 {
85 	unsigned int eax, ebx, ecx, edx;
86 
87 	if (c->cpuid_level < 4)
88 		return 1;
89 
90 	/* Intel has a non-standard dependency on %ecx for this CPUID level. */
91 	cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
92 	if (eax & 0x1f)
93 		return ((eax >> 26) + 1);
94 	else
95 		return 1;
96 }
97 
98 static void __cpuinit init_intel(struct cpuinfo_x86 *c)
99 {
100 	unsigned int l2 = 0;
101 	char *p = NULL;
102 
103 #ifdef CONFIG_X86_F00F_BUG
104 	/*
105 	 * All current models of Pentium and Pentium with MMX technology CPUs
106 	 * have the F0 0F bug, which lets nonprivileged users lock up the system.
107 	 * Note that the workaround only should be initialized once...
108 	 */
109 	c->f00f_bug = 0;
110 	if (!paravirt_enabled() && c->x86 == 5) {
111 		static int f00f_workaround_enabled = 0;
112 
113 		c->f00f_bug = 1;
114 		if ( !f00f_workaround_enabled ) {
115 			trap_init_f00f_bug();
116 			printk(KERN_NOTICE "Intel Pentium with F0 0F bug - workaround enabled.\n");
117 			f00f_workaround_enabled = 1;
118 		}
119 	}
120 #endif
121 
122 	select_idle_routine(c);
123 	l2 = init_intel_cacheinfo(c);
124 	if (c->cpuid_level > 9 ) {
125 		unsigned eax = cpuid_eax(10);
126 		/* Check for version and the number of counters */
127 		if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
128 			set_bit(X86_FEATURE_ARCH_PERFMON, c->x86_capability);
129 	}
130 
131 	/* SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until model 3 mask 3 */
132 	if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633)
133 		clear_bit(X86_FEATURE_SEP, c->x86_capability);
134 
135 	/* Names for the Pentium II/Celeron processors
136 	   detectable only by also checking the cache size.
137 	   Dixon is NOT a Celeron. */
138 	if (c->x86 == 6) {
139 		switch (c->x86_model) {
140 		case 5:
141 			if (c->x86_mask == 0) {
142 				if (l2 == 0)
143 					p = "Celeron (Covington)";
144 				else if (l2 == 256)
145 					p = "Mobile Pentium II (Dixon)";
146 			}
147 			break;
148 
149 		case 6:
150 			if (l2 == 128)
151 				p = "Celeron (Mendocino)";
152 			else if (c->x86_mask == 0 || c->x86_mask == 5)
153 				p = "Celeron-A";
154 			break;
155 
156 		case 8:
157 			if (l2 == 128)
158 				p = "Celeron (Coppermine)";
159 			break;
160 		}
161 	}
162 
163 	if ( p )
164 		strcpy(c->x86_model_id, p);
165 
166 	c->x86_max_cores = num_cpu_cores(c);
167 
168 	detect_ht(c);
169 
170 	/* Work around errata */
171 	Intel_errata_workarounds(c);
172 
173 #ifdef CONFIG_X86_INTEL_USERCOPY
174 	/*
175 	 * Set up the preferred alignment for movsl bulk memory moves
176 	 */
177 	switch (c->x86) {
178 	case 4:		/* 486: untested */
179 		break;
180 	case 5:		/* Old Pentia: untested */
181 		break;
182 	case 6:		/* PII/PIII only like movsl with 8-byte alignment */
183 		movsl_mask.mask = 7;
184 		break;
185 	case 15:	/* P4 is OK down to 8-byte alignment */
186 		movsl_mask.mask = 7;
187 		break;
188 	}
189 #endif
190 
191 	if (c->x86 == 15) {
192 		set_bit(X86_FEATURE_P4, c->x86_capability);
193 		set_bit(X86_FEATURE_SYNC_RDTSC, c->x86_capability);
194 	}
195 	if (c->x86 == 6)
196 		set_bit(X86_FEATURE_P3, c->x86_capability);
197 	if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
198 		(c->x86 == 0x6 && c->x86_model >= 0x0e))
199 		set_bit(X86_FEATURE_CONSTANT_TSC, c->x86_capability);
200 
201 	if (cpu_has_ds) {
202 		unsigned int l1;
203 		rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
204 		if (!(l1 & (1<<11)))
205 			set_bit(X86_FEATURE_BTS, c->x86_capability);
206 		if (!(l1 & (1<<12)))
207 			set_bit(X86_FEATURE_PEBS, c->x86_capability);
208 	}
209 }
210 
211 static unsigned int __cpuinit intel_size_cache(struct cpuinfo_x86 * c, unsigned int size)
212 {
213 	/* Intel PIII Tualatin. This comes in two flavours.
214 	 * One has 256kb of cache, the other 512. We have no way
215 	 * to determine which, so we use a boottime override
216 	 * for the 512kb model, and assume 256 otherwise.
217 	 */
218 	if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
219 		size = 256;
220 	return size;
221 }
222 
223 static struct cpu_dev intel_cpu_dev __cpuinitdata = {
224 	.c_vendor	= "Intel",
225 	.c_ident 	= { "GenuineIntel" },
226 	.c_models = {
227 		{ .vendor = X86_VENDOR_INTEL, .family = 4, .model_names =
228 		  {
229 			  [0] = "486 DX-25/33",
230 			  [1] = "486 DX-50",
231 			  [2] = "486 SX",
232 			  [3] = "486 DX/2",
233 			  [4] = "486 SL",
234 			  [5] = "486 SX/2",
235 			  [7] = "486 DX/2-WB",
236 			  [8] = "486 DX/4",
237 			  [9] = "486 DX/4-WB"
238 		  }
239 		},
240 		{ .vendor = X86_VENDOR_INTEL, .family = 5, .model_names =
241 		  {
242 			  [0] = "Pentium 60/66 A-step",
243 			  [1] = "Pentium 60/66",
244 			  [2] = "Pentium 75 - 200",
245 			  [3] = "OverDrive PODP5V83",
246 			  [4] = "Pentium MMX",
247 			  [7] = "Mobile Pentium 75 - 200",
248 			  [8] = "Mobile Pentium MMX"
249 		  }
250 		},
251 		{ .vendor = X86_VENDOR_INTEL, .family = 6, .model_names =
252 		  {
253 			  [0] = "Pentium Pro A-step",
254 			  [1] = "Pentium Pro",
255 			  [3] = "Pentium II (Klamath)",
256 			  [4] = "Pentium II (Deschutes)",
257 			  [5] = "Pentium II (Deschutes)",
258 			  [6] = "Mobile Pentium II",
259 			  [7] = "Pentium III (Katmai)",
260 			  [8] = "Pentium III (Coppermine)",
261 			  [10] = "Pentium III (Cascades)",
262 			  [11] = "Pentium III (Tualatin)",
263 		  }
264 		},
265 		{ .vendor = X86_VENDOR_INTEL, .family = 15, .model_names =
266 		  {
267 			  [0] = "Pentium 4 (Unknown)",
268 			  [1] = "Pentium 4 (Willamette)",
269 			  [2] = "Pentium 4 (Northwood)",
270 			  [4] = "Pentium 4 (Foster)",
271 			  [5] = "Pentium 4 (Foster)",
272 		  }
273 		},
274 	},
275 	.c_init		= init_intel,
276 	.c_size_cache	= intel_size_cache,
277 };
278 
279 __init int intel_cpu_init(void)
280 {
281 	cpu_devs[X86_VENDOR_INTEL] = &intel_cpu_dev;
282 	return 0;
283 }
284 
285 #ifndef CONFIG_X86_CMPXCHG
286 unsigned long cmpxchg_386_u8(volatile void *ptr, u8 old, u8 new)
287 {
288 	u8 prev;
289 	unsigned long flags;
290 
291 	/* Poor man's cmpxchg for 386. Unsuitable for SMP */
292 	local_irq_save(flags);
293 	prev = *(u8 *)ptr;
294 	if (prev == old)
295 		*(u8 *)ptr = new;
296 	local_irq_restore(flags);
297 	return prev;
298 }
299 EXPORT_SYMBOL(cmpxchg_386_u8);
300 
301 unsigned long cmpxchg_386_u16(volatile void *ptr, u16 old, u16 new)
302 {
303 	u16 prev;
304 	unsigned long flags;
305 
306 	/* Poor man's cmpxchg for 386. Unsuitable for SMP */
307 	local_irq_save(flags);
308 	prev = *(u16 *)ptr;
309 	if (prev == old)
310 		*(u16 *)ptr = new;
311 	local_irq_restore(flags);
312 	return prev;
313 }
314 EXPORT_SYMBOL(cmpxchg_386_u16);
315 
316 unsigned long cmpxchg_386_u32(volatile void *ptr, u32 old, u32 new)
317 {
318 	u32 prev;
319 	unsigned long flags;
320 
321 	/* Poor man's cmpxchg for 386. Unsuitable for SMP */
322 	local_irq_save(flags);
323 	prev = *(u32 *)ptr;
324 	if (prev == old)
325 		*(u32 *)ptr = new;
326 	local_irq_restore(flags);
327 	return prev;
328 }
329 EXPORT_SYMBOL(cmpxchg_386_u32);
330 #endif
331 
332 // arch_initcall(intel_cpu_init);
333 
334