xref: /openbmc/linux/arch/x86/kernel/cpu/intel.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
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 
15 #include "cpu.h"
16 
17 #ifdef CONFIG_X86_LOCAL_APIC
18 #include <asm/mpspec.h>
19 #include <asm/apic.h>
20 #include <mach_apic.h>
21 #endif
22 
23 #ifdef CONFIG_X86_INTEL_USERCOPY
24 /*
25  * Alignment at which movsl is preferred for bulk memory copies.
26  */
27 struct movsl_mask movsl_mask __read_mostly;
28 #endif
29 
30 void __cpuinit early_intel_workaround(struct cpuinfo_x86 *c)
31 {
32 	if (c->x86_vendor != X86_VENDOR_INTEL)
33 		return;
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 }
38 
39 /*
40  *	Early probe support logic for ppro memory erratum #50
41  *
42  *	This is called before we do cpu ident work
43  */
44 
45 int __cpuinit ppro_with_ram_bug(void)
46 {
47 	/* Uses data from early_cpu_detect now */
48 	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
49 	    boot_cpu_data.x86 == 6 &&
50 	    boot_cpu_data.x86_model == 1 &&
51 	    boot_cpu_data.x86_mask < 8) {
52 		printk(KERN_INFO "Pentium Pro with Errata#50 detected. Taking evasive action.\n");
53 		return 1;
54 	}
55 	return 0;
56 }
57 
58 
59 /*
60  * P4 Xeon errata 037 workaround.
61  * Hardware prefetcher may cause stale data to be loaded into the cache.
62  */
63 static void __cpuinit Intel_errata_workarounds(struct cpuinfo_x86 *c)
64 {
65 	unsigned long lo, hi;
66 
67 	if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
68 		rdmsr (MSR_IA32_MISC_ENABLE, lo, hi);
69 		if ((lo & (1<<9)) == 0) {
70 			printk (KERN_INFO "CPU: C0 stepping P4 Xeon detected.\n");
71 			printk (KERN_INFO "CPU: Disabling hardware prefetching (Errata 037)\n");
72 			lo |= (1<<9);	/* Disable hw prefetching */
73 			wrmsr (MSR_IA32_MISC_ENABLE, lo, hi);
74 		}
75 	}
76 }
77 
78 
79 /*
80  * find out the number of processor cores on the die
81  */
82 static int __cpuinit num_cpu_cores(struct cpuinfo_x86 *c)
83 {
84 	unsigned int eax, ebx, ecx, edx;
85 
86 	if (c->cpuid_level < 4)
87 		return 1;
88 
89 	/* Intel has a non-standard dependency on %ecx for this CPUID level. */
90 	cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
91 	if (eax & 0x1f)
92 		return ((eax >> 26) + 1);
93 	else
94 		return 1;
95 }
96 
97 #ifdef CONFIG_X86_F00F_BUG
98 static void __cpuinit trap_init_f00f_bug(void)
99 {
100 	__set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);
101 
102 	/*
103 	 * Update the IDT descriptor and reload the IDT so that
104 	 * it uses the read-only mapped virtual address.
105 	 */
106 	idt_descr.address = fix_to_virt(FIX_F00F_IDT);
107 	load_idt(&idt_descr);
108 }
109 #endif
110 
111 static void __cpuinit init_intel(struct cpuinfo_x86 *c)
112 {
113 	unsigned int l2 = 0;
114 	char *p = NULL;
115 
116 #ifdef CONFIG_X86_F00F_BUG
117 	/*
118 	 * All current models of Pentium and Pentium with MMX technology CPUs
119 	 * have the F0 0F bug, which lets nonprivileged users lock up the system.
120 	 * Note that the workaround only should be initialized once...
121 	 */
122 	c->f00f_bug = 0;
123 	if (!paravirt_enabled() && c->x86 == 5) {
124 		static int f00f_workaround_enabled = 0;
125 
126 		c->f00f_bug = 1;
127 		if ( !f00f_workaround_enabled ) {
128 			trap_init_f00f_bug();
129 			printk(KERN_NOTICE "Intel Pentium with F0 0F bug - workaround enabled.\n");
130 			f00f_workaround_enabled = 1;
131 		}
132 	}
133 #endif
134 
135 	select_idle_routine(c);
136 	l2 = init_intel_cacheinfo(c);
137 	if (c->cpuid_level > 9 ) {
138 		unsigned eax = cpuid_eax(10);
139 		/* Check for version and the number of counters */
140 		if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
141 			set_bit(X86_FEATURE_ARCH_PERFMON, c->x86_capability);
142 	}
143 
144 	/* SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until model 3 mask 3 */
145 	if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633)
146 		clear_bit(X86_FEATURE_SEP, c->x86_capability);
147 
148 	/* Names for the Pentium II/Celeron processors
149 	   detectable only by also checking the cache size.
150 	   Dixon is NOT a Celeron. */
151 	if (c->x86 == 6) {
152 		switch (c->x86_model) {
153 		case 5:
154 			if (c->x86_mask == 0) {
155 				if (l2 == 0)
156 					p = "Celeron (Covington)";
157 				else if (l2 == 256)
158 					p = "Mobile Pentium II (Dixon)";
159 			}
160 			break;
161 
162 		case 6:
163 			if (l2 == 128)
164 				p = "Celeron (Mendocino)";
165 			else if (c->x86_mask == 0 || c->x86_mask == 5)
166 				p = "Celeron-A";
167 			break;
168 
169 		case 8:
170 			if (l2 == 128)
171 				p = "Celeron (Coppermine)";
172 			break;
173 		}
174 	}
175 
176 	if ( p )
177 		strcpy(c->x86_model_id, p);
178 
179 	c->x86_max_cores = num_cpu_cores(c);
180 
181 	detect_ht(c);
182 
183 	/* Work around errata */
184 	Intel_errata_workarounds(c);
185 
186 #ifdef CONFIG_X86_INTEL_USERCOPY
187 	/*
188 	 * Set up the preferred alignment for movsl bulk memory moves
189 	 */
190 	switch (c->x86) {
191 	case 4:		/* 486: untested */
192 		break;
193 	case 5:		/* Old Pentia: untested */
194 		break;
195 	case 6:		/* PII/PIII only like movsl with 8-byte alignment */
196 		movsl_mask.mask = 7;
197 		break;
198 	case 15:	/* P4 is OK down to 8-byte alignment */
199 		movsl_mask.mask = 7;
200 		break;
201 	}
202 #endif
203 
204 	if (c->x86 == 15) {
205 		set_bit(X86_FEATURE_P4, c->x86_capability);
206 		set_bit(X86_FEATURE_SYNC_RDTSC, c->x86_capability);
207 	}
208 	if (c->x86 == 6)
209 		set_bit(X86_FEATURE_P3, c->x86_capability);
210 	if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
211 		(c->x86 == 0x6 && c->x86_model >= 0x0e))
212 		set_bit(X86_FEATURE_CONSTANT_TSC, c->x86_capability);
213 
214 	if (cpu_has_ds) {
215 		unsigned int l1;
216 		rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
217 		if (!(l1 & (1<<11)))
218 			set_bit(X86_FEATURE_BTS, c->x86_capability);
219 		if (!(l1 & (1<<12)))
220 			set_bit(X86_FEATURE_PEBS, c->x86_capability);
221 	}
222 }
223 
224 static unsigned int __cpuinit intel_size_cache(struct cpuinfo_x86 * c, unsigned int size)
225 {
226 	/* Intel PIII Tualatin. This comes in two flavours.
227 	 * One has 256kb of cache, the other 512. We have no way
228 	 * to determine which, so we use a boottime override
229 	 * for the 512kb model, and assume 256 otherwise.
230 	 */
231 	if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
232 		size = 256;
233 	return size;
234 }
235 
236 static struct cpu_dev intel_cpu_dev __cpuinitdata = {
237 	.c_vendor	= "Intel",
238 	.c_ident 	= { "GenuineIntel" },
239 	.c_models = {
240 		{ .vendor = X86_VENDOR_INTEL, .family = 4, .model_names =
241 		  {
242 			  [0] = "486 DX-25/33",
243 			  [1] = "486 DX-50",
244 			  [2] = "486 SX",
245 			  [3] = "486 DX/2",
246 			  [4] = "486 SL",
247 			  [5] = "486 SX/2",
248 			  [7] = "486 DX/2-WB",
249 			  [8] = "486 DX/4",
250 			  [9] = "486 DX/4-WB"
251 		  }
252 		},
253 		{ .vendor = X86_VENDOR_INTEL, .family = 5, .model_names =
254 		  {
255 			  [0] = "Pentium 60/66 A-step",
256 			  [1] = "Pentium 60/66",
257 			  [2] = "Pentium 75 - 200",
258 			  [3] = "OverDrive PODP5V83",
259 			  [4] = "Pentium MMX",
260 			  [7] = "Mobile Pentium 75 - 200",
261 			  [8] = "Mobile Pentium MMX"
262 		  }
263 		},
264 		{ .vendor = X86_VENDOR_INTEL, .family = 6, .model_names =
265 		  {
266 			  [0] = "Pentium Pro A-step",
267 			  [1] = "Pentium Pro",
268 			  [3] = "Pentium II (Klamath)",
269 			  [4] = "Pentium II (Deschutes)",
270 			  [5] = "Pentium II (Deschutes)",
271 			  [6] = "Mobile Pentium II",
272 			  [7] = "Pentium III (Katmai)",
273 			  [8] = "Pentium III (Coppermine)",
274 			  [10] = "Pentium III (Cascades)",
275 			  [11] = "Pentium III (Tualatin)",
276 		  }
277 		},
278 		{ .vendor = X86_VENDOR_INTEL, .family = 15, .model_names =
279 		  {
280 			  [0] = "Pentium 4 (Unknown)",
281 			  [1] = "Pentium 4 (Willamette)",
282 			  [2] = "Pentium 4 (Northwood)",
283 			  [4] = "Pentium 4 (Foster)",
284 			  [5] = "Pentium 4 (Foster)",
285 		  }
286 		},
287 	},
288 	.c_init		= init_intel,
289 	.c_size_cache	= intel_size_cache,
290 };
291 
292 __init int intel_cpu_init(void)
293 {
294 	cpu_devs[X86_VENDOR_INTEL] = &intel_cpu_dev;
295 	return 0;
296 }
297 
298 #ifndef CONFIG_X86_CMPXCHG
299 unsigned long cmpxchg_386_u8(volatile void *ptr, u8 old, u8 new)
300 {
301 	u8 prev;
302 	unsigned long flags;
303 
304 	/* Poor man's cmpxchg for 386. Unsuitable for SMP */
305 	local_irq_save(flags);
306 	prev = *(u8 *)ptr;
307 	if (prev == old)
308 		*(u8 *)ptr = new;
309 	local_irq_restore(flags);
310 	return prev;
311 }
312 EXPORT_SYMBOL(cmpxchg_386_u8);
313 
314 unsigned long cmpxchg_386_u16(volatile void *ptr, u16 old, u16 new)
315 {
316 	u16 prev;
317 	unsigned long flags;
318 
319 	/* Poor man's cmpxchg for 386. Unsuitable for SMP */
320 	local_irq_save(flags);
321 	prev = *(u16 *)ptr;
322 	if (prev == old)
323 		*(u16 *)ptr = new;
324 	local_irq_restore(flags);
325 	return prev;
326 }
327 EXPORT_SYMBOL(cmpxchg_386_u16);
328 
329 unsigned long cmpxchg_386_u32(volatile void *ptr, u32 old, u32 new)
330 {
331 	u32 prev;
332 	unsigned long flags;
333 
334 	/* Poor man's cmpxchg for 386. Unsuitable for SMP */
335 	local_irq_save(flags);
336 	prev = *(u32 *)ptr;
337 	if (prev == old)
338 		*(u32 *)ptr = new;
339 	local_irq_restore(flags);
340 	return prev;
341 }
342 EXPORT_SYMBOL(cmpxchg_386_u32);
343 #endif
344 
345 // arch_initcall(intel_cpu_init);
346 
347