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 __cpuinit 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 __cpuinit 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 __cpuinit 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 __cpuinit 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 __cpuinit 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         if (c->cpuid_level > 9 ) {
 126                 unsigned eax = cpuid_eax(10);
 127                 /* Check for version and the number of counters */
 128                 if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
 129                         set_bit(X86_FEATURE_ARCH_PERFMON, c->x86_capability);
 130         }
 131
 132         /* SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until model 3 mask 3 */
 133         if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633)
 134                 clear_bit(X86_FEATURE_SEP, c->x86_capability);
 135
 136         /* Names for the Pentium II/Celeron processors
 137            detectable only by also checking the cache size.
 138            Dixon is NOT a Celeron. */
 139         if (c->x86 == 6) {
 140                 switch (c->x86_model) {
 141                 case 5:
 142                         if (c->x86_mask == 0) {
 143                                 if (l2 == 0)
 144                                         p = "Celeron (Covington)";
 145                                 else if (l2 == 256)
 146                                         p = "Mobile Pentium II (Dixon)";
 147                         }
 148                         break;
 149
 150                 case 6:
 151                         if (l2 == 128)
 152                                 p = "Celeron (Mendocino)";
 153                         else if (c->x86_mask == 0 || c->x86_mask == 5)
 154                                 p = "Celeron-A";
 155                         break;
 156
 157                 case 8:
 158                         if (l2 == 128)
 159                                 p = "Celeron (Coppermine)";
 160                         break;
 161                 }
 162         }
 163
 164         if ( p )
 165                 strcpy(c->x86_model_id, p);
 166
 167         c->x86_max_cores = num_cpu_cores(c);
 168
 169         detect_ht(c);
 170
 171         /* Work around errata */
 172         Intel_errata_workarounds(c);
 173
 174 #ifdef CONFIG_X86_INTEL_USERCOPY
 175         /*
 176          * Set up the preferred alignment for movsl bulk memory moves
 177          */
 178         switch (c->x86) {
 179         case 4:         /* 486: untested */
 180                 break;
 181         case 5:         /* Old Pentia: untested */
 182                 break;
 183         case 6:         /* PII/PIII only like movsl with 8-byte alignment */
 184                 movsl_mask.mask = 7;
 185                 break;
 186         case 15:        /* P4 is OK down to 8-byte alignment */
 187                 movsl_mask.mask = 7;
 188                 break;
 189         }
 190 #endif
 191
 192         if (c->x86 == 15)
 193                 set_bit(X86_FEATURE_P4, c->x86_capability);
 194         if (c->x86 == 6)
 195                 set_bit(X86_FEATURE_P3, c->x86_capability);
 196         if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
 197                 (c->x86 == 0x6 && c->x86_model >= 0x0e))
 198                 set_bit(X86_FEATURE_CONSTANT_TSC, c->x86_capability);
 199 }
 200
 201
 202 static unsigned int intel_size_cache(struct cpuinfo_x86 * c, unsigned int size)
 203 {
 204         /* Intel PIII Tualatin. This comes in two flavours.
 205          * One has 256kb of cache, the other 512. We have no way
 206          * to determine which, so we use a boottime override
 207          * for the 512kb model, and assume 256 otherwise.
 208          */
 209         if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
 210                 size = 256;
 211         return size;
 212 }
 213
 214 static struct cpu_dev intel_cpu_dev __cpuinitdata = {
 215         .c_vendor       = "Intel",
 216         .c_ident        = { "GenuineIntel" },
 217         .c_models = {
 218                 { .vendor = X86_VENDOR_INTEL, .family = 4, .model_names =
 219                   {
 220                           [0] = "486 DX-25/33",
 221                           [1] = "486 DX-50",
 222                           [2] = "486 SX",
 223                           [3] = "486 DX/2",
 224                           [4] = "486 SL",
 225                           [5] = "486 SX/2",
 226                           [7] = "486 DX/2-WB",
 227                           [8] = "486 DX/4",
 228                           [9] = "486 DX/4-WB"
 229                   }
 230                 },
 231                 { .vendor = X86_VENDOR_INTEL, .family = 5, .model_names =
 232                   {
 233                           [0] = "Pentium 60/66 A-step",
 234                           [1] = "Pentium 60/66",
 235                           [2] = "Pentium 75 - 200",
 236                           [3] = "OverDrive PODP5V83",
 237                           [4] = "Pentium MMX",
 238                           [7] = "Mobile Pentium 75 - 200",
 239                           [8] = "Mobile Pentium MMX"
 240                   }
 241                 },
 242                 { .vendor = X86_VENDOR_INTEL, .family = 6, .model_names =
 243                   {
 244                           [0] = "Pentium Pro A-step",
 245                           [1] = "Pentium Pro",
 246                           [3] = "Pentium II (Klamath)",
 247                           [4] = "Pentium II (Deschutes)",
 248                           [5] = "Pentium II (Deschutes)",
 249                           [6] = "Mobile Pentium II",
 250                           [7] = "Pentium III (Katmai)",
 251                           [8] = "Pentium III (Coppermine)",
 252                           [10] = "Pentium III (Cascades)",
 253                           [11] = "Pentium III (Tualatin)",
 254                   }
 255                 },
 256                 { .vendor = X86_VENDOR_INTEL, .family = 15, .model_names =
 257                   {
 258                           [0] = "Pentium 4 (Unknown)",
 259                           [1] = "Pentium 4 (Willamette)",
 260                           [2] = "Pentium 4 (Northwood)",
 261                           [4] = "Pentium 4 (Foster)",
 262                           [5] = "Pentium 4 (Foster)",
 263                   }
 264                 },
 265         },
 266         .c_init         = init_intel,
 267         .c_identify     = generic_identify,
 268         .c_size_cache   = intel_size_cache,
 269 };
 270
 271 __init int intel_cpu_init(void)
 272 {
 273         cpu_devs[X86_VENDOR_INTEL] = &intel_cpu_dev;
 274         return 0;
 275 }
 276
 277 #ifndef CONFIG_X86_CMPXCHG
 278 unsigned long cmpxchg_386_u8(volatile void *ptr, u8 old, u8 new)
 279 {
 280         u8 prev;
 281         unsigned long flags;
 282
 283         /* Poor man's cmpxchg for 386. Unsuitable for SMP */
 284         local_irq_save(flags);
 285         prev = *(u8 *)ptr;
 286         if (prev == old)
 287                 *(u8 *)ptr = new;
 288         local_irq_restore(flags);
 289         return prev;
 290 }
 291 EXPORT_SYMBOL(cmpxchg_386_u8);
 292
 293 unsigned long cmpxchg_386_u16(volatile void *ptr, u16 old, u16 new)
 294 {
 295         u16 prev;
 296         unsigned long flags;
 297
 298         /* Poor man's cmpxchg for 386. Unsuitable for SMP */
 299         local_irq_save(flags);
 300         prev = *(u16 *)ptr;
 301         if (prev == old)
 302                 *(u16 *)ptr = new;
 303         local_irq_restore(flags);
 304         return prev;
 305 }
 306 EXPORT_SYMBOL(cmpxchg_386_u16);
 307
 308 unsigned long cmpxchg_386_u32(volatile void *ptr, u32 old, u32 new)
 309 {
 310         u32 prev;
 311         unsigned long flags;
 312
 313         /* Poor man's cmpxchg for 386. Unsuitable for SMP */
 314         local_irq_save(flags);
 315         prev = *(u32 *)ptr;
 316         if (prev == old)
 317                 *(u32 *)ptr = new;
 318         local_irq_restore(flags);
 319         return prev;
 320 }
 321 EXPORT_SYMBOL(cmpxchg_386_u32);
 322 #endif
 323
 324 // arch_initcall(intel_cpu_init);
 325