xref: /openbmc/linux/arch/x86/kernel/cpu/intel.c (revision 643d1f7f)
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 
17 #include "cpu.h"
18 
19 #ifdef CONFIG_X86_LOCAL_APIC
20 #include <asm/mpspec.h>
21 #include <asm/apic.h>
22 #include <mach_apic.h>
23 #endif
24 
25 #ifdef CONFIG_X86_INTEL_USERCOPY
26 /*
27  * Alignment at which movsl is preferred for bulk memory copies.
28  */
29 struct movsl_mask movsl_mask __read_mostly;
30 #endif
31 
32 void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
33 {
34 	/* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
35 	if (c->x86 == 15 && c->x86_cache_alignment == 64)
36 		c->x86_cache_alignment = 128;
37 	if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
38 		(c->x86 == 0x6 && c->x86_model >= 0x0e))
39 		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
40 }
41 
42 /*
43  *	Early probe support logic for ppro memory erratum #50
44  *
45  *	This is called before we do cpu ident work
46  */
47 
48 int __cpuinit ppro_with_ram_bug(void)
49 {
50 	/* Uses data from early_cpu_detect now */
51 	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
52 	    boot_cpu_data.x86 == 6 &&
53 	    boot_cpu_data.x86_model == 1 &&
54 	    boot_cpu_data.x86_mask < 8) {
55 		printk(KERN_INFO "Pentium Pro with Errata#50 detected. Taking evasive action.\n");
56 		return 1;
57 	}
58 	return 0;
59 }
60 
61 
62 /*
63  * P4 Xeon errata 037 workaround.
64  * Hardware prefetcher may cause stale data to be loaded into the cache.
65  */
66 static void __cpuinit Intel_errata_workarounds(struct cpuinfo_x86 *c)
67 {
68 	unsigned long lo, hi;
69 
70 	if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
71 		rdmsr (MSR_IA32_MISC_ENABLE, lo, hi);
72 		if ((lo & (1<<9)) == 0) {
73 			printk (KERN_INFO "CPU: C0 stepping P4 Xeon detected.\n");
74 			printk (KERN_INFO "CPU: Disabling hardware prefetching (Errata 037)\n");
75 			lo |= (1<<9);	/* Disable hw prefetching */
76 			wrmsr (MSR_IA32_MISC_ENABLE, lo, hi);
77 		}
78 	}
79 }
80 
81 
82 /*
83  * find out the number of processor cores on the die
84  */
85 static int __cpuinit num_cpu_cores(struct cpuinfo_x86 *c)
86 {
87 	unsigned int eax, ebx, ecx, edx;
88 
89 	if (c->cpuid_level < 4)
90 		return 1;
91 
92 	/* Intel has a non-standard dependency on %ecx for this CPUID level. */
93 	cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
94 	if (eax & 0x1f)
95 		return ((eax >> 26) + 1);
96 	else
97 		return 1;
98 }
99 
100 #ifdef CONFIG_X86_F00F_BUG
101 static void __cpuinit trap_init_f00f_bug(void)
102 {
103 	__set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);
104 
105 	/*
106 	 * Update the IDT descriptor and reload the IDT so that
107 	 * it uses the read-only mapped virtual address.
108 	 */
109 	idt_descr.address = fix_to_virt(FIX_F00F_IDT);
110 	load_idt(&idt_descr);
111 }
112 #endif
113 
114 static void __cpuinit init_intel(struct cpuinfo_x86 *c)
115 {
116 	unsigned int l2 = 0;
117 	char *p = NULL;
118 
119 	early_init_intel(c);
120 
121 #ifdef CONFIG_X86_F00F_BUG
122 	/*
123 	 * All current models of Pentium and Pentium with MMX technology CPUs
124 	 * have the F0 0F bug, which lets nonprivileged users lock up the system.
125 	 * Note that the workaround only should be initialized once...
126 	 */
127 	c->f00f_bug = 0;
128 	if (!paravirt_enabled() && c->x86 == 5) {
129 		static int f00f_workaround_enabled = 0;
130 
131 		c->f00f_bug = 1;
132 		if ( !f00f_workaround_enabled ) {
133 			trap_init_f00f_bug();
134 			printk(KERN_NOTICE "Intel Pentium with F0 0F bug - workaround enabled.\n");
135 			f00f_workaround_enabled = 1;
136 		}
137 	}
138 #endif
139 
140 	l2 = init_intel_cacheinfo(c);
141 	if (c->cpuid_level > 9 ) {
142 		unsigned eax = cpuid_eax(10);
143 		/* Check for version and the number of counters */
144 		if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
145 			set_bit(X86_FEATURE_ARCH_PERFMON, c->x86_capability);
146 	}
147 
148 	/* SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until model 3 mask 3 */
149 	if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633)
150 		clear_bit(X86_FEATURE_SEP, c->x86_capability);
151 
152 	/* Names for the Pentium II/Celeron processors
153 	   detectable only by also checking the cache size.
154 	   Dixon is NOT a Celeron. */
155 	if (c->x86 == 6) {
156 		switch (c->x86_model) {
157 		case 5:
158 			if (c->x86_mask == 0) {
159 				if (l2 == 0)
160 					p = "Celeron (Covington)";
161 				else if (l2 == 256)
162 					p = "Mobile Pentium II (Dixon)";
163 			}
164 			break;
165 
166 		case 6:
167 			if (l2 == 128)
168 				p = "Celeron (Mendocino)";
169 			else if (c->x86_mask == 0 || c->x86_mask == 5)
170 				p = "Celeron-A";
171 			break;
172 
173 		case 8:
174 			if (l2 == 128)
175 				p = "Celeron (Coppermine)";
176 			break;
177 		}
178 	}
179 
180 	if ( p )
181 		strcpy(c->x86_model_id, p);
182 
183 	c->x86_max_cores = num_cpu_cores(c);
184 
185 	detect_ht(c);
186 
187 	/* Work around errata */
188 	Intel_errata_workarounds(c);
189 
190 #ifdef CONFIG_X86_INTEL_USERCOPY
191 	/*
192 	 * Set up the preferred alignment for movsl bulk memory moves
193 	 */
194 	switch (c->x86) {
195 	case 4:		/* 486: untested */
196 		break;
197 	case 5:		/* Old Pentia: untested */
198 		break;
199 	case 6:		/* PII/PIII only like movsl with 8-byte alignment */
200 		movsl_mask.mask = 7;
201 		break;
202 	case 15:	/* P4 is OK down to 8-byte alignment */
203 		movsl_mask.mask = 7;
204 		break;
205 	}
206 #endif
207 
208 	if (cpu_has_xmm2)
209 		set_bit(X86_FEATURE_LFENCE_RDTSC, c->x86_capability);
210 	if (c->x86 == 15) {
211 		set_bit(X86_FEATURE_P4, c->x86_capability);
212 	}
213 	if (c->x86 == 6)
214 		set_bit(X86_FEATURE_P3, c->x86_capability);
215 	if (cpu_has_ds) {
216 		unsigned int l1;
217 		rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
218 		if (!(l1 & (1<<11)))
219 			set_bit(X86_FEATURE_BTS, c->x86_capability);
220 		if (!(l1 & (1<<12)))
221 			set_bit(X86_FEATURE_PEBS, c->x86_capability);
222 	}
223 
224 	if (cpu_has_bts)
225 		ds_init_intel(c);
226 }
227 
228 static unsigned int __cpuinit intel_size_cache(struct cpuinfo_x86 * c, unsigned int size)
229 {
230 	/* Intel PIII Tualatin. This comes in two flavours.
231 	 * One has 256kb of cache, the other 512. We have no way
232 	 * to determine which, so we use a boottime override
233 	 * for the 512kb model, and assume 256 otherwise.
234 	 */
235 	if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
236 		size = 256;
237 	return size;
238 }
239 
240 static struct cpu_dev intel_cpu_dev __cpuinitdata = {
241 	.c_vendor	= "Intel",
242 	.c_ident 	= { "GenuineIntel" },
243 	.c_models = {
244 		{ .vendor = X86_VENDOR_INTEL, .family = 4, .model_names =
245 		  {
246 			  [0] = "486 DX-25/33",
247 			  [1] = "486 DX-50",
248 			  [2] = "486 SX",
249 			  [3] = "486 DX/2",
250 			  [4] = "486 SL",
251 			  [5] = "486 SX/2",
252 			  [7] = "486 DX/2-WB",
253 			  [8] = "486 DX/4",
254 			  [9] = "486 DX/4-WB"
255 		  }
256 		},
257 		{ .vendor = X86_VENDOR_INTEL, .family = 5, .model_names =
258 		  {
259 			  [0] = "Pentium 60/66 A-step",
260 			  [1] = "Pentium 60/66",
261 			  [2] = "Pentium 75 - 200",
262 			  [3] = "OverDrive PODP5V83",
263 			  [4] = "Pentium MMX",
264 			  [7] = "Mobile Pentium 75 - 200",
265 			  [8] = "Mobile Pentium MMX"
266 		  }
267 		},
268 		{ .vendor = X86_VENDOR_INTEL, .family = 6, .model_names =
269 		  {
270 			  [0] = "Pentium Pro A-step",
271 			  [1] = "Pentium Pro",
272 			  [3] = "Pentium II (Klamath)",
273 			  [4] = "Pentium II (Deschutes)",
274 			  [5] = "Pentium II (Deschutes)",
275 			  [6] = "Mobile Pentium II",
276 			  [7] = "Pentium III (Katmai)",
277 			  [8] = "Pentium III (Coppermine)",
278 			  [10] = "Pentium III (Cascades)",
279 			  [11] = "Pentium III (Tualatin)",
280 		  }
281 		},
282 		{ .vendor = X86_VENDOR_INTEL, .family = 15, .model_names =
283 		  {
284 			  [0] = "Pentium 4 (Unknown)",
285 			  [1] = "Pentium 4 (Willamette)",
286 			  [2] = "Pentium 4 (Northwood)",
287 			  [4] = "Pentium 4 (Foster)",
288 			  [5] = "Pentium 4 (Foster)",
289 		  }
290 		},
291 	},
292 	.c_init		= init_intel,
293 	.c_size_cache	= intel_size_cache,
294 };
295 
296 __init int intel_cpu_init(void)
297 {
298 	cpu_devs[X86_VENDOR_INTEL] = &intel_cpu_dev;
299 	return 0;
300 }
301 
302 #ifndef CONFIG_X86_CMPXCHG
303 unsigned long cmpxchg_386_u8(volatile void *ptr, u8 old, u8 new)
304 {
305 	u8 prev;
306 	unsigned long flags;
307 
308 	/* Poor man's cmpxchg for 386. Unsuitable for SMP */
309 	local_irq_save(flags);
310 	prev = *(u8 *)ptr;
311 	if (prev == old)
312 		*(u8 *)ptr = new;
313 	local_irq_restore(flags);
314 	return prev;
315 }
316 EXPORT_SYMBOL(cmpxchg_386_u8);
317 
318 unsigned long cmpxchg_386_u16(volatile void *ptr, u16 old, u16 new)
319 {
320 	u16 prev;
321 	unsigned long flags;
322 
323 	/* Poor man's cmpxchg for 386. Unsuitable for SMP */
324 	local_irq_save(flags);
325 	prev = *(u16 *)ptr;
326 	if (prev == old)
327 		*(u16 *)ptr = new;
328 	local_irq_restore(flags);
329 	return prev;
330 }
331 EXPORT_SYMBOL(cmpxchg_386_u16);
332 
333 unsigned long cmpxchg_386_u32(volatile void *ptr, u32 old, u32 new)
334 {
335 	u32 prev;
336 	unsigned long flags;
337 
338 	/* Poor man's cmpxchg for 386. Unsuitable for SMP */
339 	local_irq_save(flags);
340 	prev = *(u32 *)ptr;
341 	if (prev == old)
342 		*(u32 *)ptr = new;
343 	local_irq_restore(flags);
344 	return prev;
345 }
346 EXPORT_SYMBOL(cmpxchg_386_u32);
347 #endif
348 
349 #ifndef CONFIG_X86_CMPXCHG64
350 unsigned long long cmpxchg_486_u64(volatile void *ptr, u64 old, u64 new)
351 {
352 	u64 prev;
353 	unsigned long flags;
354 
355 	/* Poor man's cmpxchg8b for 386 and 486. Unsuitable for SMP */
356 	local_irq_save(flags);
357 	prev = *(u64 *)ptr;
358 	if (prev == old)
359 		*(u64 *)ptr = new;
360 	local_irq_restore(flags);
361 	return prev;
362 }
363 EXPORT_SYMBOL(cmpxchg_486_u64);
364 #endif
365 
366 // arch_initcall(intel_cpu_init);
367 
368