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