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