arch/x86/kernel/cpu/amd.c

   1 #include <linux/init.h>
   2 #include <linux/bitops.h>
   3 #include <linux/mm.h>
   4 #include <asm/io.h>
   5 #include <asm/processor.h>
   6 #include <asm/apic.h>
   7 #include <asm/mach_apic.h>
   8
   9 #include "cpu.h"
  10
  11 /*
  12  *      B step AMD K6 before B 9730xxxx have hardware bugs that can cause
  13  *      misexecution of code under Linux. Owners of such processors should
  14  *      contact AMD for precise details and a CPU swap.
  15  *
  16  *      See     http://www.multimania.com/poulot/k6bug.html
  17  *              http://www.amd.com/K6/k6docs/revgd.html
  18  *
  19  *      The following test is erm.. interesting. AMD neglected to up
  20  *      the chip setting when fixing the bug but they also tweaked some
  21  *      performance at the same time..
  22  */
  23
  24 extern void vide(void);
  25 __asm__(".align 4\nvide: ret");
  26
  27 #ifdef CONFIG_X86_LOCAL_APIC
  28 #define ENABLE_C1E_MASK         0x18000000
  29 #define CPUID_PROCESSOR_SIGNATURE       1
  30 #define CPUID_XFAM              0x0ff00000
  31 #define CPUID_XFAM_K8           0x00000000
  32 #define CPUID_XFAM_10H          0x00100000
  33 #define CPUID_XFAM_11H          0x00200000
  34 #define CPUID_XMOD              0x000f0000
  35 #define CPUID_XMOD_REV_F        0x00040000
  36
  37 /* AMD systems with C1E don't have a working lAPIC timer. Check for that. */
  38 static __cpuinit int amd_apic_timer_broken(void)
  39 {
  40         u32 lo, hi;
  41         u32 eax = cpuid_eax(CPUID_PROCESSOR_SIGNATURE);
  42         switch (eax & CPUID_XFAM) {
  43         case CPUID_XFAM_K8:
  44                 if ((eax & CPUID_XMOD) < CPUID_XMOD_REV_F)
  45                         break;
  46         case CPUID_XFAM_10H:
  47         case CPUID_XFAM_11H:
  48                 rdmsr(MSR_K8_ENABLE_C1E, lo, hi);
  49                 if (lo & ENABLE_C1E_MASK) {
  50                         if (smp_processor_id() != boot_cpu_physical_apicid)
  51                                 printk(KERN_INFO "AMD C1E detected late. "
  52                                        "        Force timer broadcast.\n");
  53                         return 1;
  54                 }
  55                 break;
  56         default:
  57                 /* err on the side of caution */
  58                 return 1;
  59         }
  60         return 0;
  61 }
  62 #endif
  63
  64 int force_mwait __cpuinitdata;
  65
  66 void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
  67 {
  68         if (cpuid_eax(0x80000000) >= 0x80000007) {
  69                 c->x86_power = cpuid_edx(0x80000007);
  70                 if (c->x86_power & (1<<8))
  71                         set_bit(X86_FEATURE_CONSTANT_TSC, c->x86_capability);
  72         }
  73 }
  74
  75 static void __cpuinit init_amd(struct cpuinfo_x86 *c)
  76 {
  77         u32 l, h;
  78         int mbytes = num_physpages >> (20-PAGE_SHIFT);
  79         int r;
  80
  81 #ifdef CONFIG_SMP
  82         unsigned long long value;
  83
  84         /* Disable TLB flush filter by setting HWCR.FFDIS on K8
  85          * bit 6 of msr C001_0015
  86          *
  87          * Errata 63 for SH-B3 steppings
  88          * Errata 122 for all steppings (F+ have it disabled by default)
  89          */
  90         if (c->x86 == 15) {
  91                 rdmsrl(MSR_K7_HWCR, value);
  92                 value |= 1 << 6;
  93                 wrmsrl(MSR_K7_HWCR, value);
  94         }
  95 #endif
  96
  97         early_init_amd(c);
  98
  99         /*
 100          *      FIXME: We should handle the K5 here. Set up the write
 101          *      range and also turn on MSR 83 bits 4 and 31 (write alloc,
 102          *      no bus pipeline)
 103          */
 104
 105         /* Bit 31 in normal CPUID used for nonstandard 3DNow ID;
 106            3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway */
 107         clear_bit(0*32+31, c->x86_capability);
 108
 109         r = get_model_name(c);
 110
 111         switch(c->x86)
 112         {
 113                 case 4:
 114                 /*
 115                  * General Systems BIOSen alias the cpu frequency registers
 116                  * of the Elan at 0x000df000. Unfortuantly, one of the Linux
 117                  * drivers subsequently pokes it, and changes the CPU speed.
 118                  * Workaround : Remove the unneeded alias.
 119                  */
 120 #define CBAR            (0xfffc) /* Configuration Base Address  (32-bit) */
 121 #define CBAR_ENB        (0x80000000)
 122 #define CBAR_KEY        (0X000000CB)
 123                         if (c->x86_model==9 || c->x86_model == 10) {
 124                                 if (inl (CBAR) & CBAR_ENB)
 125                                         outl (0 | CBAR_KEY, CBAR);
 126                         }
 127                         break;
 128                 case 5:
 129                         if( c->x86_model < 6 )
 130                         {
 131                                 /* Based on AMD doc 20734R - June 2000 */
 132                                 if ( c->x86_model == 0 ) {
 133                                         clear_bit(X86_FEATURE_APIC, c->x86_capability);
 134                                         set_bit(X86_FEATURE_PGE, c->x86_capability);
 135                                 }
 136                                 break;
 137                         }
 138
 139                         if ( c->x86_model == 6 && c->x86_mask == 1 ) {
 140                                 const int K6_BUG_LOOP = 1000000;
 141                                 int n;
 142                                 void (*f_vide)(void);
 143                                 unsigned long d, d2;
 144
 145                                 printk(KERN_INFO "AMD K6 stepping B detected - ");
 146
 147                                 /*
 148                                  * It looks like AMD fixed the 2.6.2 bug and improved indirect
 149                                  * calls at the same time.
 150                                  */
 151
 152                                 n = K6_BUG_LOOP;
 153                                 f_vide = vide;
 154                                 rdtscl(d);
 155                                 while (n--)
 156                                         f_vide();
 157                                 rdtscl(d2);
 158                                 d = d2-d;
 159
 160                                 if (d > 20*K6_BUG_LOOP)
 161                                         printk("system stability may be impaired when more than 32 MB are used.\n");
 162                                 else
 163                                         printk("probably OK (after B9730xxxx).\n");
 164                                 printk(KERN_INFO "Please see http://membres.lycos.fr/poulot/k6bug.html\n");
 165                         }
 166
 167                         /* K6 with old style WHCR */
 168                         if (c->x86_model < 8 ||
 169                            (c->x86_model== 8 && c->x86_mask < 8)) {
 170                                 /* We can only write allocate on the low 508Mb */
 171                                 if(mbytes>508)
 172                                         mbytes=508;
 173
 174                                 rdmsr(MSR_K6_WHCR, l, h);
 175                                 if ((l&0x0000FFFF)==0) {
 176                                         unsigned long flags;
 177                                         l=(1<<0)|((mbytes/4)<<1);
 178                                         local_irq_save(flags);
 179                                         wbinvd();
 180                                         wrmsr(MSR_K6_WHCR, l, h);
 181                                         local_irq_restore(flags);
 182                                         printk(KERN_INFO "Enabling old style K6 write allocation for %d Mb\n",
 183                                                 mbytes);
 184                                 }
 185                                 break;
 186                         }
 187
 188                         if ((c->x86_model == 8 && c->x86_mask >7) ||
 189                              c->x86_model == 9 || c->x86_model == 13) {
 190                                 /* The more serious chips .. */
 191
 192                                 if(mbytes>4092)
 193                                         mbytes=4092;
 194
 195                                 rdmsr(MSR_K6_WHCR, l, h);
 196                                 if ((l&0xFFFF0000)==0) {
 197                                         unsigned long flags;
 198                                         l=((mbytes>>2)<<22)|(1<<16);
 199                                         local_irq_save(flags);
 200                                         wbinvd();
 201                                         wrmsr(MSR_K6_WHCR, l, h);
 202                                         local_irq_restore(flags);
 203                                         printk(KERN_INFO "Enabling new style K6 write allocation for %d Mb\n",
 204                                                 mbytes);
 205                                 }
 206
 207                                 /*  Set MTRR capability flag if appropriate */
 208                                 if (c->x86_model == 13 || c->x86_model == 9 ||
 209                                    (c->x86_model == 8 && c->x86_mask >= 8))
 210                                         set_bit(X86_FEATURE_K6_MTRR, c->x86_capability);
 211                                 break;
 212                         }
 213
 214                         if (c->x86_model == 10) {
 215                                 /* AMD Geode LX is model 10 */
 216                                 /* placeholder for any needed mods */
 217                                 break;
 218                         }
 219                         break;
 220                 case 6: /* An Athlon/Duron */
 221
 222                         /* Bit 15 of Athlon specific MSR 15, needs to be 0
 223                          * to enable SSE on Palomino/Morgan/Barton CPU's.
 224                          * If the BIOS didn't enable it already, enable it here.
 225                          */
 226                         if (c->x86_model >= 6 && c->x86_model <= 10) {
 227                                 if (!cpu_has(c, X86_FEATURE_XMM)) {
 228                                         printk(KERN_INFO "Enabling disabled K7/SSE Support.\n");
 229                                         rdmsr(MSR_K7_HWCR, l, h);
 230                                         l &= ~0x00008000;
 231                                         wrmsr(MSR_K7_HWCR, l, h);
 232                                         set_bit(X86_FEATURE_XMM, c->x86_capability);
 233                                 }
 234                         }
 235
 236                         /* It's been determined by AMD that Athlons since model 8 stepping 1
 237                          * are more robust with CLK_CTL set to 200xxxxx instead of 600xxxxx
 238                          * As per AMD technical note 27212 0.2
 239                          */
 240                         if ((c->x86_model == 8 && c->x86_mask>=1) || (c->x86_model > 8)) {
 241                                 rdmsr(MSR_K7_CLK_CTL, l, h);
 242                                 if ((l & 0xfff00000) != 0x20000000) {
 243                                         printk ("CPU: CLK_CTL MSR was %x. Reprogramming to %x\n", l,
 244                                                 ((l & 0x000fffff)|0x20000000));
 245                                         wrmsr(MSR_K7_CLK_CTL, (l & 0x000fffff)|0x20000000, h);
 246                                 }
 247                         }
 248                         break;
 249         }
 250
 251         switch (c->x86) {
 252         case 15:
 253         /* Use K8 tuning for Fam10h and Fam11h */
 254         case 0x10:
 255         case 0x11:
 256                 set_bit(X86_FEATURE_K8, c->x86_capability);
 257                 break;
 258         case 6:
 259                 set_bit(X86_FEATURE_K7, c->x86_capability);
 260                 break;
 261         }
 262         if (c->x86 >= 6)
 263                 set_bit(X86_FEATURE_FXSAVE_LEAK, c->x86_capability);
 264
 265         display_cacheinfo(c);
 266
 267         if (cpuid_eax(0x80000000) >= 0x80000008) {
 268                 c->x86_max_cores = (cpuid_ecx(0x80000008) & 0xff) + 1;
 269         }
 270
 271 #ifdef CONFIG_X86_HT
 272         /*
 273          * On a AMD multi core setup the lower bits of the APIC id
 274          * distinguish the cores.
 275          */
 276         if (c->x86_max_cores > 1) {
 277                 int cpu = smp_processor_id();
 278                 unsigned bits = (cpuid_ecx(0x80000008) >> 12) & 0xf;
 279
 280                 if (bits == 0) {
 281                         while ((1 << bits) < c->x86_max_cores)
 282                                 bits++;
 283                 }
 284                 c->cpu_core_id = c->phys_proc_id & ((1<<bits)-1);
 285                 c->phys_proc_id >>= bits;
 286                 printk(KERN_INFO "CPU %d(%d) -> Core %d\n",
 287                        cpu, c->x86_max_cores, c->cpu_core_id);
 288         }
 289 #endif
 290
 291         if (cpuid_eax(0x80000000) >= 0x80000006) {
 292                 if ((c->x86 == 0x10) && (cpuid_edx(0x80000006) & 0xf000))
 293                         num_cache_leaves = 4;
 294                 else
 295                         num_cache_leaves = 3;
 296         }
 297
 298 #ifdef CONFIG_X86_LOCAL_APIC
 299         if (amd_apic_timer_broken())
 300                 local_apic_timer_disabled = 1;
 301 #endif
 302
 303         /* K6s reports MCEs but don't actually have all the MSRs */
 304         if (c->x86 < 6)
 305                 clear_bit(X86_FEATURE_MCE, c->x86_capability);
 306
 307         if (cpu_has_xmm2)
 308                 set_bit(X86_FEATURE_MFENCE_RDTSC, c->x86_capability);
 309 }
 310
 311 static unsigned int __cpuinit amd_size_cache(struct cpuinfo_x86 * c, unsigned int size)
 312 {
 313         /* AMD errata T13 (order #21922) */
 314         if ((c->x86 == 6)) {
 315                 if (c->x86_model == 3 && c->x86_mask == 0)      /* Duron Rev A0 */
 316                         size = 64;
 317                 if (c->x86_model == 4 &&
 318                     (c->x86_mask==0 || c->x86_mask==1)) /* Tbird rev A1/A2 */
 319                         size = 256;
 320         }
 321         return size;
 322 }
 323
 324 static struct cpu_dev amd_cpu_dev __cpuinitdata = {
 325         .c_vendor       = "AMD",
 326         .c_ident        = { "AuthenticAMD" },
 327         .c_models = {
 328                 { .vendor = X86_VENDOR_AMD, .family = 4, .model_names =
 329                   {
 330                           [3] = "486 DX/2",
 331                           [7] = "486 DX/2-WB",
 332                           [8] = "486 DX/4",
 333                           [9] = "486 DX/4-WB",
 334                           [14] = "Am5x86-WT",
 335                           [15] = "Am5x86-WB"
 336                   }
 337                 },
 338         },
 339         .c_init         = init_amd,
 340         .c_size_cache   = amd_size_cache,
 341 };
 342
 343 int __init amd_init_cpu(void)
 344 {
 345         cpu_devs[X86_VENDOR_AMD] = &amd_cpu_dev;
 346         return 0;
 347 }