arch/i386/kernel/cpu/intel.c

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