arch/mips/kernel/cpu-probe.c

   1 /*
   2  * Processor capabilities determination functions.
   3  *
   4  * Copyright (C) xxxx  the Anonymous
   5  * Copyright (C) 1994 - 2006 Ralf Baechle
   6  * Copyright (C) 2003, 2004  Maciej W. Rozycki
   7  * Copyright (C) 2001, 2004  MIPS Inc.
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License
  11  * as published by the Free Software Foundation; either version
  12  * 2 of the License, or (at your option) any later version.
  13  */
  14 #include <linux/init.h>
  15 #include <linux/kernel.h>
  16 #include <linux/ptrace.h>
  17 #include <linux/stddef.h>
  18
  19 #include <asm/cpu.h>
  20 #include <asm/fpu.h>
  21 #include <asm/mipsregs.h>
  22 #include <asm/system.h>
  23
  24 /*
  25  * Not all of the MIPS CPUs have the "wait" instruction available. Moreover,
  26  * the implementation of the "wait" feature differs between CPU families. This
  27  * points to the function that implements CPU specific wait.
  28  * The wait instruction stops the pipeline and reduces the power consumption of
  29  * the CPU very much.
  30  */
  31 void (*cpu_wait)(void) = NULL;
  32
  33 static void r3081_wait(void)
  34 {
  35         unsigned long cfg = read_c0_conf();
  36         write_c0_conf(cfg | R30XX_CONF_HALT);
  37 }
  38
  39 static void r39xx_wait(void)
  40 {
  41         unsigned long cfg = read_c0_conf();
  42         write_c0_conf(cfg | TX39_CONF_HALT);
  43 }
  44
  45 static void r4k_wait(void)
  46 {
  47         __asm__(".set\tmips3\n\t"
  48                 "wait\n\t"
  49                 ".set\tmips0");
  50 }
  51
  52 /* The Au1xxx wait is available only if using 32khz counter or
  53  * external timer source, but specifically not CP0 Counter. */
  54 int allow_au1k_wait;
  55
  56 static void au1k_wait(void)
  57 {
  58         /* using the wait instruction makes CP0 counter unusable */
  59         __asm__(".set mips3\n\t"
  60                 "cache 0x14, 0(%0)\n\t"
  61                 "cache 0x14, 32(%0)\n\t"
  62                 "sync\n\t"
  63                 "nop\n\t"
  64                 "wait\n\t"
  65                 "nop\n\t"
  66                 "nop\n\t"
  67                 "nop\n\t"
  68                 "nop\n\t"
  69                 ".set mips0\n\t"
  70                 : : "r" (au1k_wait));
  71 }
  72
  73 static int __initdata nowait = 0;
  74
  75 int __init wait_disable(char *s)
  76 {
  77         nowait = 1;
  78
  79         return 1;
  80 }
  81
  82 __setup("nowait", wait_disable);
  83
  84 static inline void check_wait(void)
  85 {
  86         struct cpuinfo_mips *c = &current_cpu_data;
  87
  88         printk("Checking for 'wait' instruction... ");
  89         if (nowait) {
  90                 printk (" disabled.\n");
  91                 return;
  92         }
  93
  94         switch (c->cputype) {
  95         case CPU_R3081:
  96         case CPU_R3081E:
  97                 cpu_wait = r3081_wait;
  98                 printk(" available.\n");
  99                 break;
 100         case CPU_TX3927:
 101                 cpu_wait = r39xx_wait;
 102                 printk(" available.\n");
 103                 break;
 104         case CPU_R4200:
 105 /*      case CPU_R4300: */
 106         case CPU_R4600:
 107         case CPU_R4640:
 108         case CPU_R4650:
 109         case CPU_R4700:
 110         case CPU_R5000:
 111         case CPU_NEVADA:
 112         case CPU_RM7000:
 113         case CPU_RM9000:
 114         case CPU_TX49XX:
 115         case CPU_4KC:
 116         case CPU_4KEC:
 117         case CPU_4KSC:
 118         case CPU_5KC:
 119 /*      case CPU_20KC:*/
 120         case CPU_24K:
 121         case CPU_25KF:
 122         case CPU_34K:
 123         case CPU_74K:
 124         case CPU_PR4450:
 125                 cpu_wait = r4k_wait;
 126                 printk(" available.\n");
 127                 break;
 128         case CPU_AU1000:
 129         case CPU_AU1100:
 130         case CPU_AU1500:
 131         case CPU_AU1550:
 132         case CPU_AU1200:
 133                 if (allow_au1k_wait) {
 134                         cpu_wait = au1k_wait;
 135                         printk(" available.\n");
 136                 } else
 137                         printk(" unavailable.\n");
 138                 break;
 139         default:
 140                 printk(" unavailable.\n");
 141                 break;
 142         }
 143 }
 144
 145 void __init check_bugs32(void)
 146 {
 147         check_wait();
 148 }
 149
 150 /*
 151  * Probe whether cpu has config register by trying to play with
 152  * alternate cache bit and see whether it matters.
 153  * It's used by cpu_probe to distinguish between R3000A and R3081.
 154  */
 155 static inline int cpu_has_confreg(void)
 156 {
 157 #ifdef CONFIG_CPU_R3000
 158         extern unsigned long r3k_cache_size(unsigned long);
 159         unsigned long size1, size2;
 160         unsigned long cfg = read_c0_conf();
 161
 162         size1 = r3k_cache_size(ST0_ISC);
 163         write_c0_conf(cfg ^ R30XX_CONF_AC);
 164         size2 = r3k_cache_size(ST0_ISC);
 165         write_c0_conf(cfg);
 166         return size1 != size2;
 167 #else
 168         return 0;
 169 #endif
 170 }
 171
 172 /*
 173  * Get the FPU Implementation/Revision.
 174  */
 175 static inline unsigned long cpu_get_fpu_id(void)
 176 {
 177         unsigned long tmp, fpu_id;
 178
 179         tmp = read_c0_status();
 180         __enable_fpu();
 181         fpu_id = read_32bit_cp1_register(CP1_REVISION);
 182         write_c0_status(tmp);
 183         return fpu_id;
 184 }
 185
 186 /*
 187  * Check the CPU has an FPU the official way.
 188  */
 189 static inline int __cpu_has_fpu(void)
 190 {
 191         return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
 192 }
 193
 194 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
 195                 | MIPS_CPU_COUNTER)
 196
 197 static inline void cpu_probe_legacy(struct cpuinfo_mips *c)
 198 {
 199         switch (c->processor_id & 0xff00) {
 200         case PRID_IMP_R2000:
 201                 c->cputype = CPU_R2000;
 202                 c->isa_level = MIPS_CPU_ISA_I;
 203                 c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
 204                              MIPS_CPU_NOFPUEX;
 205                 if (__cpu_has_fpu())
 206                         c->options |= MIPS_CPU_FPU;
 207                 c->tlbsize = 64;
 208                 break;
 209         case PRID_IMP_R3000:
 210                 if ((c->processor_id & 0xff) == PRID_REV_R3000A)
 211                         if (cpu_has_confreg())
 212                                 c->cputype = CPU_R3081E;
 213                         else
 214                                 c->cputype = CPU_R3000A;
 215                 else
 216                         c->cputype = CPU_R3000;
 217                 c->isa_level = MIPS_CPU_ISA_I;
 218                 c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
 219                              MIPS_CPU_NOFPUEX;
 220                 if (__cpu_has_fpu())
 221                         c->options |= MIPS_CPU_FPU;
 222                 c->tlbsize = 64;
 223                 break;
 224         case PRID_IMP_R4000:
 225                 if (read_c0_config() & CONF_SC) {
 226                         if ((c->processor_id & 0xff) >= PRID_REV_R4400)
 227                                 c->cputype = CPU_R4400PC;
 228                         else
 229                                 c->cputype = CPU_R4000PC;
 230                 } else {
 231                         if ((c->processor_id & 0xff) >= PRID_REV_R4400)
 232                                 c->cputype = CPU_R4400SC;
 233                         else
 234                                 c->cputype = CPU_R4000SC;
 235                 }
 236
 237                 c->isa_level = MIPS_CPU_ISA_III;
 238                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 239                              MIPS_CPU_WATCH | MIPS_CPU_VCE |
 240                              MIPS_CPU_LLSC;
 241                 c->tlbsize = 48;
 242                 break;
 243         case PRID_IMP_VR41XX:
 244                 switch (c->processor_id & 0xf0) {
 245                 case PRID_REV_VR4111:
 246                         c->cputype = CPU_VR4111;
 247                         break;
 248                 case PRID_REV_VR4121:
 249                         c->cputype = CPU_VR4121;
 250                         break;
 251                 case PRID_REV_VR4122:
 252                         if ((c->processor_id & 0xf) < 0x3)
 253                                 c->cputype = CPU_VR4122;
 254                         else
 255                                 c->cputype = CPU_VR4181A;
 256                         break;
 257                 case PRID_REV_VR4130:
 258                         if ((c->processor_id & 0xf) < 0x4)
 259                                 c->cputype = CPU_VR4131;
 260                         else
 261                                 c->cputype = CPU_VR4133;
 262                         break;
 263                 default:
 264                         printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
 265                         c->cputype = CPU_VR41XX;
 266                         break;
 267                 }
 268                 c->isa_level = MIPS_CPU_ISA_III;
 269                 c->options = R4K_OPTS;
 270                 c->tlbsize = 32;
 271                 break;
 272         case PRID_IMP_R4300:
 273                 c->cputype = CPU_R4300;
 274                 c->isa_level = MIPS_CPU_ISA_III;
 275                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 276                              MIPS_CPU_LLSC;
 277                 c->tlbsize = 32;
 278                 break;
 279         case PRID_IMP_R4600:
 280                 c->cputype = CPU_R4600;
 281                 c->isa_level = MIPS_CPU_ISA_III;
 282                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 283                              MIPS_CPU_LLSC;
 284                 c->tlbsize = 48;
 285                 break;
 286         #if 0
 287         case PRID_IMP_R4650:
 288                 /*
 289                  * This processor doesn't have an MMU, so it's not
 290                  * "real easy" to run Linux on it. It is left purely
 291                  * for documentation.  Commented out because it shares
 292                  * it's c0_prid id number with the TX3900.
 293                  */
 294                 c->cputype = CPU_R4650;
 295                 c->isa_level = MIPS_CPU_ISA_III;
 296                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
 297                 c->tlbsize = 48;
 298                 break;
 299         #endif
 300         case PRID_IMP_TX39:
 301                 c->isa_level = MIPS_CPU_ISA_I;
 302                 c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
 303
 304                 if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
 305                         c->cputype = CPU_TX3927;
 306                         c->tlbsize = 64;
 307                 } else {
 308                         switch (c->processor_id & 0xff) {
 309                         case PRID_REV_TX3912:
 310                                 c->cputype = CPU_TX3912;
 311                                 c->tlbsize = 32;
 312                                 break;
 313                         case PRID_REV_TX3922:
 314                                 c->cputype = CPU_TX3922;
 315                                 c->tlbsize = 64;
 316                                 break;
 317                         default:
 318                                 c->cputype = CPU_UNKNOWN;
 319                                 break;
 320                         }
 321                 }
 322                 break;
 323         case PRID_IMP_R4700:
 324                 c->cputype = CPU_R4700;
 325                 c->isa_level = MIPS_CPU_ISA_III;
 326                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 327                              MIPS_CPU_LLSC;
 328                 c->tlbsize = 48;
 329                 break;
 330         case PRID_IMP_TX49:
 331                 c->cputype = CPU_TX49XX;
 332                 c->isa_level = MIPS_CPU_ISA_III;
 333                 c->options = R4K_OPTS | MIPS_CPU_LLSC;
 334                 if (!(c->processor_id & 0x08))
 335                         c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
 336                 c->tlbsize = 48;
 337                 break;
 338         case PRID_IMP_R5000:
 339                 c->cputype = CPU_R5000;
 340                 c->isa_level = MIPS_CPU_ISA_IV;
 341                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 342                              MIPS_CPU_LLSC;
 343                 c->tlbsize = 48;
 344                 break;
 345         case PRID_IMP_R5432:
 346                 c->cputype = CPU_R5432;
 347                 c->isa_level = MIPS_CPU_ISA_IV;
 348                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 349                              MIPS_CPU_WATCH | MIPS_CPU_LLSC;
 350                 c->tlbsize = 48;
 351                 break;
 352         case PRID_IMP_R5500:
 353                 c->cputype = CPU_R5500;
 354                 c->isa_level = MIPS_CPU_ISA_IV;
 355                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 356                              MIPS_CPU_WATCH | MIPS_CPU_LLSC;
 357                 c->tlbsize = 48;
 358                 break;
 359         case PRID_IMP_NEVADA:
 360                 c->cputype = CPU_NEVADA;
 361                 c->isa_level = MIPS_CPU_ISA_IV;
 362                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 363                              MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
 364                 c->tlbsize = 48;
 365                 break;
 366         case PRID_IMP_R6000:
 367                 c->cputype = CPU_R6000;
 368                 c->isa_level = MIPS_CPU_ISA_II;
 369                 c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
 370                              MIPS_CPU_LLSC;
 371                 c->tlbsize = 32;
 372                 break;
 373         case PRID_IMP_R6000A:
 374                 c->cputype = CPU_R6000A;
 375                 c->isa_level = MIPS_CPU_ISA_II;
 376                 c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
 377                              MIPS_CPU_LLSC;
 378                 c->tlbsize = 32;
 379                 break;
 380         case PRID_IMP_RM7000:
 381                 c->cputype = CPU_RM7000;
 382                 c->isa_level = MIPS_CPU_ISA_IV;
 383                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 384                              MIPS_CPU_LLSC;
 385                 /*
 386                  * Undocumented RM7000:  Bit 29 in the info register of
 387                  * the RM7000 v2.0 indicates if the TLB has 48 or 64
 388                  * entries.
 389                  *
 390                  * 29      1 =>    64 entry JTLB
 391                  *         0 =>    48 entry JTLB
 392                  */
 393                 c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
 394                 break;
 395         case PRID_IMP_RM9000:
 396                 c->cputype = CPU_RM9000;
 397                 c->isa_level = MIPS_CPU_ISA_IV;
 398                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 399                              MIPS_CPU_LLSC;
 400                 /*
 401                  * Bit 29 in the info register of the RM9000
 402                  * indicates if the TLB has 48 or 64 entries.
 403                  *
 404                  * 29      1 =>    64 entry JTLB
 405                  *         0 =>    48 entry JTLB
 406                  */
 407                 c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
 408                 break;
 409         case PRID_IMP_R8000:
 410                 c->cputype = CPU_R8000;
 411                 c->isa_level = MIPS_CPU_ISA_IV;
 412                 c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
 413                              MIPS_CPU_FPU | MIPS_CPU_32FPR |
 414                              MIPS_CPU_LLSC;
 415                 c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
 416                 break;
 417         case PRID_IMP_R10000:
 418                 c->cputype = CPU_R10000;
 419                 c->isa_level = MIPS_CPU_ISA_IV;
 420                 c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
 421                              MIPS_CPU_FPU | MIPS_CPU_32FPR |
 422                              MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
 423                              MIPS_CPU_LLSC;
 424                 c->tlbsize = 64;
 425                 break;
 426         case PRID_IMP_R12000:
 427                 c->cputype = CPU_R12000;
 428                 c->isa_level = MIPS_CPU_ISA_IV;
 429                 c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
 430                              MIPS_CPU_FPU | MIPS_CPU_32FPR |
 431                              MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
 432                              MIPS_CPU_LLSC;
 433                 c->tlbsize = 64;
 434                 break;
 435         case PRID_IMP_R14000:
 436                 c->cputype = CPU_R14000;
 437                 c->isa_level = MIPS_CPU_ISA_IV;
 438                 c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
 439                              MIPS_CPU_FPU | MIPS_CPU_32FPR |
 440                              MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
 441                              MIPS_CPU_LLSC;
 442                 c->tlbsize = 64;
 443                 break;
 444         }
 445 }
 446
 447 static char unknown_isa[] __initdata = KERN_ERR \
 448         "Unsupported ISA type, c0.config0: %d.";
 449
 450 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
 451 {
 452         unsigned int config0;
 453         int isa;
 454
 455         config0 = read_c0_config();
 456
 457         if (((config0 & MIPS_CONF_MT) >> 7) == 1)
 458                 c->options |= MIPS_CPU_TLB;
 459         isa = (config0 & MIPS_CONF_AT) >> 13;
 460         switch (isa) {
 461         case 0:
 462                 switch ((config0 & MIPS_CONF_AR) >> 10) {
 463                 case 0:
 464                         c->isa_level = MIPS_CPU_ISA_M32R1;
 465                         break;
 466                 case 1:
 467                         c->isa_level = MIPS_CPU_ISA_M32R2;
 468                         break;
 469                 default:
 470                         goto unknown;
 471                 }
 472                 break;
 473         case 2:
 474                 switch ((config0 & MIPS_CONF_AR) >> 10) {
 475                 case 0:
 476                         c->isa_level = MIPS_CPU_ISA_M64R1;
 477                         break;
 478                 case 1:
 479                         c->isa_level = MIPS_CPU_ISA_M64R2;
 480                         break;
 481                 default:
 482                         goto unknown;
 483                 }
 484                 break;
 485         default:
 486                 goto unknown;
 487         }
 488
 489         return config0 & MIPS_CONF_M;
 490
 491 unknown:
 492         panic(unknown_isa, config0);
 493 }
 494
 495 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
 496 {
 497         unsigned int config1;
 498
 499         config1 = read_c0_config1();
 500
 501         if (config1 & MIPS_CONF1_MD)
 502                 c->ases |= MIPS_ASE_MDMX;
 503         if (config1 & MIPS_CONF1_WR)
 504                 c->options |= MIPS_CPU_WATCH;
 505         if (config1 & MIPS_CONF1_CA)
 506                 c->ases |= MIPS_ASE_MIPS16;
 507         if (config1 & MIPS_CONF1_EP)
 508                 c->options |= MIPS_CPU_EJTAG;
 509         if (config1 & MIPS_CONF1_FP) {
 510                 c->options |= MIPS_CPU_FPU;
 511                 c->options |= MIPS_CPU_32FPR;
 512         }
 513         if (cpu_has_tlb)
 514                 c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
 515
 516         return config1 & MIPS_CONF_M;
 517 }
 518
 519 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
 520 {
 521         unsigned int config2;
 522
 523         config2 = read_c0_config2();
 524
 525         if (config2 & MIPS_CONF2_SL)
 526                 c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
 527
 528         return config2 & MIPS_CONF_M;
 529 }
 530
 531 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
 532 {
 533         unsigned int config3;
 534
 535         config3 = read_c0_config3();
 536
 537         if (config3 & MIPS_CONF3_SM)
 538                 c->ases |= MIPS_ASE_SMARTMIPS;
 539         if (config3 & MIPS_CONF3_DSP)
 540                 c->ases |= MIPS_ASE_DSP;
 541         if (config3 & MIPS_CONF3_VINT)
 542                 c->options |= MIPS_CPU_VINT;
 543         if (config3 & MIPS_CONF3_VEIC)
 544                 c->options |= MIPS_CPU_VEIC;
 545         if (config3 & MIPS_CONF3_MT)
 546                 c->ases |= MIPS_ASE_MIPSMT;
 547
 548         return config3 & MIPS_CONF_M;
 549 }
 550
 551 static void __init decode_configs(struct cpuinfo_mips *c)
 552 {
 553         /* MIPS32 or MIPS64 compliant CPU.  */
 554         c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
 555                      MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
 556
 557         c->scache.flags = MIPS_CACHE_NOT_PRESENT;
 558
 559         /* Read Config registers.  */
 560         if (!decode_config0(c))
 561                 return;                 /* actually worth a panic() */
 562         if (!decode_config1(c))
 563                 return;
 564         if (!decode_config2(c))
 565                 return;
 566         if (!decode_config3(c))
 567                 return;
 568 }
 569
 570 static inline void cpu_probe_mips(struct cpuinfo_mips *c)
 571 {
 572         decode_configs(c);
 573         switch (c->processor_id & 0xff00) {
 574         case PRID_IMP_4KC:
 575                 c->cputype = CPU_4KC;
 576                 break;
 577         case PRID_IMP_4KEC:
 578                 c->cputype = CPU_4KEC;
 579                 break;
 580         case PRID_IMP_4KECR2:
 581                 c->cputype = CPU_4KEC;
 582                 break;
 583         case PRID_IMP_4KSC:
 584         case PRID_IMP_4KSD:
 585                 c->cputype = CPU_4KSC;
 586                 break;
 587         case PRID_IMP_5KC:
 588                 c->cputype = CPU_5KC;
 589                 break;
 590         case PRID_IMP_20KC:
 591                 c->cputype = CPU_20KC;
 592                 break;
 593         case PRID_IMP_24K:
 594         case PRID_IMP_24KE:
 595                 c->cputype = CPU_24K;
 596                 break;
 597         case PRID_IMP_25KF:
 598                 c->cputype = CPU_25KF;
 599                 break;
 600         case PRID_IMP_34K:
 601                 c->cputype = CPU_34K;
 602                 break;
 603         case PRID_IMP_74K:
 604                 c->cputype = CPU_74K;
 605                 break;
 606         }
 607 }
 608
 609 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c)
 610 {
 611         decode_configs(c);
 612         switch (c->processor_id & 0xff00) {
 613         case PRID_IMP_AU1_REV1:
 614         case PRID_IMP_AU1_REV2:
 615                 switch ((c->processor_id >> 24) & 0xff) {
 616                 case 0:
 617                         c->cputype = CPU_AU1000;
 618                         break;
 619                 case 1:
 620                         c->cputype = CPU_AU1500;
 621                         break;
 622                 case 2:
 623                         c->cputype = CPU_AU1100;
 624                         break;
 625                 case 3:
 626                         c->cputype = CPU_AU1550;
 627                         break;
 628                 case 4:
 629                         c->cputype = CPU_AU1200;
 630                         break;
 631                 default:
 632                         panic("Unknown Au Core!");
 633                         break;
 634                 }
 635                 break;
 636         }
 637 }
 638
 639 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c)
 640 {
 641         decode_configs(c);
 642
 643         /*
 644          * For historical reasons the SB1 comes with it's own variant of
 645          * cache code which eventually will be folded into c-r4k.c.  Until
 646          * then we pretend it's got it's own cache architecture.
 647          */
 648         c->options &= ~MIPS_CPU_4K_CACHE;
 649         c->options |= MIPS_CPU_SB1_CACHE;
 650
 651         switch (c->processor_id & 0xff00) {
 652         case PRID_IMP_SB1:
 653                 c->cputype = CPU_SB1;
 654                 /* FPU in pass1 is known to have issues. */
 655                 if ((c->processor_id & 0xff) < 0x02)
 656                         c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
 657                 break;
 658         case PRID_IMP_SB1A:
 659                 c->cputype = CPU_SB1A;
 660                 break;
 661         }
 662 }
 663
 664 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c)
 665 {
 666         decode_configs(c);
 667         switch (c->processor_id & 0xff00) {
 668         case PRID_IMP_SR71000:
 669                 c->cputype = CPU_SR71000;
 670                 c->scache.ways = 8;
 671                 c->tlbsize = 64;
 672                 break;
 673         }
 674 }
 675
 676 static inline void cpu_probe_philips(struct cpuinfo_mips *c)
 677 {
 678         decode_configs(c);
 679         switch (c->processor_id & 0xff00) {
 680         case PRID_IMP_PR4450:
 681                 c->cputype = CPU_PR4450;
 682                 c->isa_level = MIPS_CPU_ISA_M32R1;
 683                 break;
 684         default:
 685                 panic("Unknown Philips Core!"); /* REVISIT: die? */
 686                 break;
 687         }
 688 }
 689
 690
 691 __init void cpu_probe(void)
 692 {
 693         struct cpuinfo_mips *c = &current_cpu_data;
 694
 695         c->processor_id = PRID_IMP_UNKNOWN;
 696         c->fpu_id       = FPIR_IMP_NONE;
 697         c->cputype      = CPU_UNKNOWN;
 698
 699         c->processor_id = read_c0_prid();
 700         switch (c->processor_id & 0xff0000) {
 701         case PRID_COMP_LEGACY:
 702                 cpu_probe_legacy(c);
 703                 break;
 704         case PRID_COMP_MIPS:
 705                 cpu_probe_mips(c);
 706                 break;
 707         case PRID_COMP_ALCHEMY:
 708                 cpu_probe_alchemy(c);
 709                 break;
 710         case PRID_COMP_SIBYTE:
 711                 cpu_probe_sibyte(c);
 712                 break;
 713         case PRID_COMP_SANDCRAFT:
 714                 cpu_probe_sandcraft(c);
 715                 break;
 716         case PRID_COMP_PHILIPS:
 717                 cpu_probe_philips(c);
 718                 break;
 719         default:
 720                 c->cputype = CPU_UNKNOWN;
 721         }
 722         if (c->options & MIPS_CPU_FPU) {
 723                 c->fpu_id = cpu_get_fpu_id();
 724
 725                 if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
 726                     c->isa_level == MIPS_CPU_ISA_M32R2 ||
 727                     c->isa_level == MIPS_CPU_ISA_M64R1 ||
 728                     c->isa_level == MIPS_CPU_ISA_M64R2) {
 729                         if (c->fpu_id & MIPS_FPIR_3D)
 730                                 c->ases |= MIPS_ASE_MIPS3D;
 731                 }
 732         }
 733 }
 734
 735 __init void cpu_report(void)
 736 {
 737         struct cpuinfo_mips *c = &current_cpu_data;
 738
 739         printk("CPU revision is: %08x\n", c->processor_id);
 740         if (c->options & MIPS_CPU_FPU)
 741                 printk("FPU revision is: %08x\n", c->fpu_id);
 742 }