arch/i386/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 "cpu.h"
   9
  10 /*
  11  *      B step AMD K6 before B 9730xxxx have hardware bugs that can cause
  12  *      misexecution of code under Linux. Owners of such processors should
  13  *      contact AMD for precise details and a CPU swap.
  14  *
  15  *      See     http://www.multimania.com/poulot/k6bug.html
  16  *              http://www.amd.com/K6/k6docs/revgd.html
  17  *
  18  *      The following test is erm.. interesting. AMD neglected to up
  19  *      the chip setting when fixing the bug but they also tweaked some
  20  *      performance at the same time..
  21  */
  22
  23 extern void vide(void);
  24 __asm__(".align 4\nvide: ret");
  25
  26 #ifdef CONFIG_X86_LOCAL_APIC
  27 #define ENABLE_C1E_MASK         0x18000000
  28 #define CPUID_PROCESSOR_SIGNATURE       1
  29 #define CPUID_XFAM              0x0ff00000
  30 #define CPUID_XFAM_K8           0x00000000
  31 #define CPUID_XFAM_10H          0x00100000
  32 #define CPUID_XFAM_11H          0x00200000
  33 #define CPUID_XMOD              0x000f0000
  34 #define CPUID_XMOD_REV_F        0x00040000
  35
  36 /* AMD systems with C1E don't have a working lAPIC timer. Check for that. */
  37 static __cpuinit int amd_apic_timer_broken(void)
  38 {
  39         u32 lo, hi;
  40         u32 eax = cpuid_eax(CPUID_PROCESSOR_SIGNATURE);
  41         switch (eax & CPUID_XFAM) {
  42         case CPUID_XFAM_K8:
  43                 if ((eax & CPUID_XMOD) < CPUID_XMOD_REV_F)
  44                         break;
  45         case CPUID_XFAM_10H:
  46         case CPUID_XFAM_11H:
  47                 rdmsr(MSR_K8_ENABLE_C1E, lo, hi);
  48                 if (lo & ENABLE_C1E_MASK)
  49                         return 1;
  50                 break;
  51         default:
  52                 /* err on the side of caution */
  53                 return 1;
  54         }
  55         return 0;
  56 }
  57 #endif
  58
  59 int force_mwait __cpuinitdata;
  60
  61 static void __cpuinit init_amd(struct cpuinfo_x86 *c)
  62 {
  63         u32 l, h;
  64         int mbytes = num_physpages >> (20-PAGE_SHIFT);
  65         int r;
  66
  67 #ifdef CONFIG_SMP
  68         unsigned long long value;
  69
  70         /* Disable TLB flush filter by setting HWCR.FFDIS on K8
  71          * bit 6 of msr C001_0015
  72          *
  73          * Errata 63 for SH-B3 steppings
  74          * Errata 122 for all steppings (F+ have it disabled by default)
  75          */
  76         if (c->x86 == 15) {
  77                 rdmsrl(MSR_K7_HWCR, value);
  78                 value |= 1 << 6;
  79                 wrmsrl(MSR_K7_HWCR, value);
  80         }
  81 #endif
  82
  83         /*
  84          *      FIXME: We should handle the K5 here. Set up the write
  85          *      range and also turn on MSR 83 bits 4 and 31 (write alloc,
  86          *      no bus pipeline)
  87          */
  88
  89         /* Bit 31 in normal CPUID used for nonstandard 3DNow ID;
  90            3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway */
  91         clear_bit(0*32+31, c->x86_capability);
  92
  93         r = get_model_name(c);
  94
  95         switch(c->x86)
  96         {
  97                 case 4:
  98                 /*
  99                  * General Systems BIOSen alias the cpu frequency registers
 100                  * of the Elan at 0x000df000. Unfortuantly, one of the Linux
 101                  * drivers subsequently pokes it, and changes the CPU speed.
 102                  * Workaround : Remove the unneeded alias.
 103                  */
 104 #define CBAR            (0xfffc) /* Configuration Base Address  (32-bit) */
 105 #define CBAR_ENB        (0x80000000)
 106 #define CBAR_KEY        (0X000000CB)
 107                         if (c->x86_model==9 || c->x86_model == 10) {
 108                                 if (inl (CBAR) & CBAR_ENB)
 109                                         outl (0 | CBAR_KEY, CBAR);
 110                         }
 111                         break;
 112                 case 5:
 113                         if( c->x86_model < 6 )
 114                         {
 115                                 /* Based on AMD doc 20734R - June 2000 */
 116                                 if ( c->x86_model == 0 ) {
 117                                         clear_bit(X86_FEATURE_APIC, c->x86_capability);
 118                                         set_bit(X86_FEATURE_PGE, c->x86_capability);
 119                                 }
 120                                 break;
 121                         }
 122
 123                         if ( c->x86_model == 6 && c->x86_mask == 1 ) {
 124                                 const int K6_BUG_LOOP = 1000000;
 125                                 int n;
 126                                 void (*f_vide)(void);
 127                                 unsigned long d, d2;
 128
 129                                 printk(KERN_INFO "AMD K6 stepping B detected - ");
 130
 131                                 /*
 132                                  * It looks like AMD fixed the 2.6.2 bug and improved indirect
 133                                  * calls at the same time.
 134                                  */
 135
 136                                 n = K6_BUG_LOOP;
 137                                 f_vide = vide;
 138                                 rdtscl(d);
 139                                 while (n--)
 140                                         f_vide();
 141                                 rdtscl(d2);
 142                                 d = d2-d;
 143
 144                                 if (d > 20*K6_BUG_LOOP)
 145                                         printk("system stability may be impaired when more than 32 MB are used.\n");
 146                                 else
 147                                         printk("probably OK (after B9730xxxx).\n");
 148                                 printk(KERN_INFO "Please see http://membres.lycos.fr/poulot/k6bug.html\n");
 149                         }
 150
 151                         /* K6 with old style WHCR */
 152                         if (c->x86_model < 8 ||
 153                            (c->x86_model== 8 && c->x86_mask < 8)) {
 154                                 /* We can only write allocate on the low 508Mb */
 155                                 if(mbytes>508)
 156                                         mbytes=508;
 157
 158                                 rdmsr(MSR_K6_WHCR, l, h);
 159                                 if ((l&0x0000FFFF)==0) {
 160                                         unsigned long flags;
 161                                         l=(1<<0)|((mbytes/4)<<1);
 162                                         local_irq_save(flags);
 163                                         wbinvd();
 164                                         wrmsr(MSR_K6_WHCR, l, h);
 165                                         local_irq_restore(flags);
 166                                         printk(KERN_INFO "Enabling old style K6 write allocation for %d Mb\n",
 167                                                 mbytes);
 168                                 }
 169                                 break;
 170                         }
 171
 172                         if ((c->x86_model == 8 && c->x86_mask >7) ||
 173                              c->x86_model == 9 || c->x86_model == 13) {
 174                                 /* The more serious chips .. */
 175
 176                                 if(mbytes>4092)
 177                                         mbytes=4092;
 178
 179                                 rdmsr(MSR_K6_WHCR, l, h);
 180                                 if ((l&0xFFFF0000)==0) {
 181                                         unsigned long flags;
 182                                         l=((mbytes>>2)<<22)|(1<<16);
 183                                         local_irq_save(flags);
 184                                         wbinvd();
 185                                         wrmsr(MSR_K6_WHCR, l, h);
 186                                         local_irq_restore(flags);
 187                                         printk(KERN_INFO "Enabling new style K6 write allocation for %d Mb\n",
 188                                                 mbytes);
 189                                 }
 190
 191                                 /*  Set MTRR capability flag if appropriate */
 192                                 if (c->x86_model == 13 || c->x86_model == 9 ||
 193                                    (c->x86_model == 8 && c->x86_mask >= 8))
 194                                         set_bit(X86_FEATURE_K6_MTRR, c->x86_capability);
 195                                 break;
 196                         }
 197
 198                         if (c->x86_model == 10) {
 199                                 /* AMD Geode LX is model 10 */
 200                                 /* placeholder for any needed mods */
 201                                 break;
 202                         }
 203                         break;
 204                 case 6: /* An Athlon/Duron */
 205
 206                         /* Bit 15 of Athlon specific MSR 15, needs to be 0
 207                          * to enable SSE on Palomino/Morgan/Barton CPU's.
 208                          * If the BIOS didn't enable it already, enable it here.
 209                          */
 210                         if (c->x86_model >= 6 && c->x86_model <= 10) {
 211                                 if (!cpu_has(c, X86_FEATURE_XMM)) {
 212                                         printk(KERN_INFO "Enabling disabled K7/SSE Support.\n");
 213                                         rdmsr(MSR_K7_HWCR, l, h);
 214                                         l &= ~0x00008000;
 215                                         wrmsr(MSR_K7_HWCR, l, h);
 216                                         set_bit(X86_FEATURE_XMM, c->x86_capability);
 217                                 }
 218                         }
 219
 220                         /* It's been determined by AMD that Athlons since model 8 stepping 1
 221                          * are more robust with CLK_CTL set to 200xxxxx instead of 600xxxxx
 222                          * As per AMD technical note 27212 0.2
 223                          */
 224                         if ((c->x86_model == 8 && c->x86_mask>=1) || (c->x86_model > 8)) {
 225                                 rdmsr(MSR_K7_CLK_CTL, l, h);
 226                                 if ((l & 0xfff00000) != 0x20000000) {
 227                                         printk ("CPU: CLK_CTL MSR was %x. Reprogramming to %x\n", l,
 228                                                 ((l & 0x000fffff)|0x20000000));
 229                                         wrmsr(MSR_K7_CLK_CTL, (l & 0x000fffff)|0x20000000, h);
 230                                 }
 231                         }
 232                         break;
 233         }
 234
 235         switch (c->x86) {
 236         case 15:
 237         /* Use K8 tuning for Fam10h and Fam11h */
 238         case 0x10:
 239         case 0x11:
 240                 set_bit(X86_FEATURE_K8, c->x86_capability);
 241                 break;
 242         case 6:
 243                 set_bit(X86_FEATURE_K7, c->x86_capability);
 244                 break;
 245         }
 246         if (c->x86 >= 6)
 247                 set_bit(X86_FEATURE_FXSAVE_LEAK, c->x86_capability);
 248
 249         display_cacheinfo(c);
 250
 251         if (cpuid_eax(0x80000000) >= 0x80000008) {
 252                 c->x86_max_cores = (cpuid_ecx(0x80000008) & 0xff) + 1;
 253         }
 254
 255         if (cpuid_eax(0x80000000) >= 0x80000007) {
 256                 c->x86_power = cpuid_edx(0x80000007);
 257                 if (c->x86_power & (1<<8))
 258                         set_bit(X86_FEATURE_CONSTANT_TSC, c->x86_capability);
 259         }
 260
 261 #ifdef CONFIG_X86_HT
 262         /*
 263          * On a AMD multi core setup the lower bits of the APIC id
 264          * distingush the cores.
 265          */
 266         if (c->x86_max_cores > 1) {
 267                 int cpu = smp_processor_id();
 268                 unsigned bits = (cpuid_ecx(0x80000008) >> 12) & 0xf;
 269
 270                 if (bits == 0) {
 271                         while ((1 << bits) < c->x86_max_cores)
 272                                 bits++;
 273                 }
 274                 c->cpu_core_id = c->phys_proc_id & ((1<<bits)-1);
 275                 c->phys_proc_id >>= bits;
 276                 printk(KERN_INFO "CPU %d(%d) -> Core %d\n",
 277                        cpu, c->x86_max_cores, c->cpu_core_id);
 278         }
 279 #endif
 280
 281         if (cpuid_eax(0x80000000) >= 0x80000006) {
 282                 if ((c->x86 == 0x10) && (cpuid_edx(0x80000006) & 0xf000))
 283                         num_cache_leaves = 4;
 284                 else
 285                         num_cache_leaves = 3;
 286         }
 287
 288 #ifdef CONFIG_X86_LOCAL_APIC
 289         if (amd_apic_timer_broken())
 290                 local_apic_timer_disabled = 1;
 291 #endif
 292
 293         if (c->x86 == 0x10 && !force_mwait)
 294                 clear_bit(X86_FEATURE_MWAIT, c->x86_capability);
 295
 296         /* K6s reports MCEs but don't actually have all the MSRs */
 297         if (c->x86 < 6)
 298                 clear_bit(X86_FEATURE_MCE, c->x86_capability);
 299 }
 300
 301 static unsigned int __cpuinit amd_size_cache(struct cpuinfo_x86 * c, unsigned int size)
 302 {
 303         /* AMD errata T13 (order #21922) */
 304         if ((c->x86 == 6)) {
 305                 if (c->x86_model == 3 && c->x86_mask == 0)      /* Duron Rev A0 */
 306                         size = 64;
 307                 if (c->x86_model == 4 &&
 308                     (c->x86_mask==0 || c->x86_mask==1)) /* Tbird rev A1/A2 */
 309                         size = 256;
 310         }
 311         return size;
 312 }
 313
 314 static struct cpu_dev amd_cpu_dev __cpuinitdata = {
 315         .c_vendor       = "AMD",
 316         .c_ident        = { "AuthenticAMD" },
 317         .c_models = {
 318                 { .vendor = X86_VENDOR_AMD, .family = 4, .model_names =
 319                   {
 320                           [3] = "486 DX/2",
 321                           [7] = "486 DX/2-WB",
 322                           [8] = "486 DX/4",
 323                           [9] = "486 DX/4-WB",
 324                           [14] = "Am5x86-WT",
 325                           [15] = "Am5x86-WB"
 326                   }
 327                 },
 328         },
 329         .c_init         = init_amd,
 330         .c_size_cache   = amd_size_cache,
 331 };
 332
 333 int __init amd_init_cpu(void)
 334 {
 335         cpu_devs[X86_VENDOR_AMD] = &amd_cpu_dev;
 336         return 0;
 337 }