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