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/bugs.h>
  20 #include <asm/cpu.h>
  21 #include <asm/fpu.h>
  22 #include <asm/mipsregs.h>
  23 #include <asm/system.h>
  24
  25 /*
  26  * Not all of the MIPS CPUs have the "wait" instruction available. Moreover,
  27  * the implementation of the "wait" feature differs between CPU families. This
  28  * points to the function that implements CPU specific wait.
  29  * The wait instruction stops the pipeline and reduces the power consumption of
  30  * the CPU very much.
  31  */
  32 void (*cpu_wait)(void) = NULL;
  33
  34 static void r3081_wait(void)
  35 {
  36         unsigned long cfg = read_c0_conf();
  37         write_c0_conf(cfg | R30XX_CONF_HALT);
  38 }
  39
  40 static void r39xx_wait(void)
  41 {
  42         local_irq_disable();
  43         if (!need_resched())
  44                 write_c0_conf(read_c0_conf() | TX39_CONF_HALT);
  45         local_irq_enable();
  46 }
  47
  48 /*
  49  * There is a race when WAIT instruction executed with interrupt
  50  * enabled.
  51  * But it is implementation-dependent wheter the pipelie restarts when
  52  * a non-enabled interrupt is requested.
  53  */
  54 static void r4k_wait(void)
  55 {
  56         __asm__("       .set    mips3                   \n"
  57                 "       wait                            \n"
  58                 "       .set    mips0                   \n");
  59 }
  60
  61 /*
  62  * This variant is preferable as it allows testing need_resched and going to
  63  * sleep depending on the outcome atomically.  Unfortunately the "It is
  64  * implementation-dependent whether the pipeline restarts when a non-enabled
  65  * interrupt is requested" restriction in the MIPS32/MIPS64 architecture makes
  66  * using this version a gamble.
  67  */
  68 static void r4k_wait_irqoff(void)
  69 {
  70         local_irq_disable();
  71         if (!need_resched())
  72                 __asm__("       .set    mips3           \n"
  73                         "       wait                    \n"
  74                         "       .set    mips0           \n");
  75         local_irq_enable();
  76 }
  77
  78 /*
  79  * The RM7000 variant has to handle erratum 38.  The workaround is to not
  80  * have any pending stores when the WAIT instruction is executed.
  81  */
  82 static void rm7k_wait_irqoff(void)
  83 {
  84         local_irq_disable();
  85         if (!need_resched())
  86                 __asm__(
  87                 "       .set    push                                    \n"
  88                 "       .set    mips3                                   \n"
  89                 "       .set    noat                                    \n"
  90                 "       mfc0    $1, $12                                 \n"
  91                 "       sync                                            \n"
  92                 "       mtc0    $1, $12         # stalls until W stage  \n"
  93                 "       wait                                            \n"
  94                 "       mtc0    $1, $12         # stalls until W stage  \n"
  95                 "       .set    pop                                     \n");
  96         local_irq_enable();
  97 }
  98
  99 /* The Au1xxx wait is available only if using 32khz counter or
 100  * external timer source, but specifically not CP0 Counter. */
 101 int allow_au1k_wait;
 102
 103 static void au1k_wait(void)
 104 {
 105         /* using the wait instruction makes CP0 counter unusable */
 106         __asm__("       .set    mips3                   \n"
 107                 "       cache   0x14, 0(%0)             \n"
 108                 "       cache   0x14, 32(%0)            \n"
 109                 "       sync                            \n"
 110                 "       nop                             \n"
 111                 "       wait                            \n"
 112                 "       nop                             \n"
 113                 "       nop                             \n"
 114                 "       nop                             \n"
 115                 "       nop                             \n"
 116                 "       .set    mips0                   \n"
 117                 : : "r" (au1k_wait));
 118 }
 119
 120 static int __initdata nowait = 0;
 121
 122 static int __init wait_disable(char *s)
 123 {
 124         nowait = 1;
 125
 126         return 1;
 127 }
 128
 129 __setup("nowait", wait_disable);
 130
 131 static inline void check_wait(void)
 132 {
 133         struct cpuinfo_mips *c = &current_cpu_data;
 134
 135         if (nowait) {
 136                 printk("Wait instruction disabled.\n");
 137                 return;
 138         }
 139
 140         switch (c->cputype) {
 141         case CPU_R3081:
 142         case CPU_R3081E:
 143                 cpu_wait = r3081_wait;
 144                 break;
 145         case CPU_TX3927:
 146                 cpu_wait = r39xx_wait;
 147                 break;
 148         case CPU_R4200:
 149 /*      case CPU_R4300: */
 150         case CPU_R4600:
 151         case CPU_R4640:
 152         case CPU_R4650:
 153         case CPU_R4700:
 154         case CPU_R5000:
 155         case CPU_NEVADA:
 156         case CPU_4KC:
 157         case CPU_4KEC:
 158         case CPU_4KSC:
 159         case CPU_5KC:
 160         case CPU_25KF:
 161         case CPU_PR4450:
 162                 cpu_wait = r4k_wait;
 163                 break;
 164
 165         case CPU_RM7000:
 166                 cpu_wait = rm7k_wait_irqoff;
 167                 break;
 168
 169         case CPU_24K:
 170         case CPU_34K:
 171                 cpu_wait = r4k_wait;
 172                 if (read_c0_config7() & MIPS_CONF7_WII)
 173                         cpu_wait = r4k_wait_irqoff;
 174                 break;
 175
 176         case CPU_74K:
 177                 cpu_wait = r4k_wait;
 178                 if ((c->processor_id & 0xff) >= PRID_REV_ENCODE_332(2, 1, 0))
 179                         cpu_wait = r4k_wait_irqoff;
 180                 break;
 181
 182         case CPU_TX49XX:
 183                 cpu_wait = r4k_wait_irqoff;
 184                 break;
 185         case CPU_AU1000:
 186         case CPU_AU1100:
 187         case CPU_AU1500:
 188         case CPU_AU1550:
 189         case CPU_AU1200:
 190                 if (allow_au1k_wait)
 191                         cpu_wait = au1k_wait;
 192                 break;
 193         case CPU_20KC:
 194                 /*
 195                  * WAIT on Rev1.0 has E1, E2, E3 and E16.
 196                  * WAIT on Rev2.0 and Rev3.0 has E16.
 197                  * Rev3.1 WAIT is nop, why bother
 198                  */
 199                 if ((c->processor_id & 0xff) <= 0x64)
 200                         break;
 201
 202                 cpu_wait = r4k_wait;
 203                 break;
 204         case CPU_RM9000:
 205                 if ((c->processor_id & 0x00ff) >= 0x40)
 206                         cpu_wait = r4k_wait;
 207                 break;
 208         default:
 209                 break;
 210         }
 211 }
 212
 213 static inline void check_errata(void)
 214 {
 215         struct cpuinfo_mips *c = &current_cpu_data;
 216
 217         switch (c->cputype) {
 218         case CPU_34K:
 219                 /*
 220                  * Erratum "RPS May Cause Incorrect Instruction Execution"
 221                  * This code only handles VPE0, any SMP/SMTC/RTOS code
 222                  * making use of VPE1 will be responsable for that VPE.
 223                  */
 224                 if ((c->processor_id & PRID_REV_MASK) <= PRID_REV_34K_V1_0_2)
 225                         write_c0_config7(read_c0_config7() | MIPS_CONF7_RPS);
 226                 break;
 227         default:
 228                 break;
 229         }
 230 }
 231
 232 void __init check_bugs32(void)
 233 {
 234         check_wait();
 235         check_errata();
 236 }
 237
 238 /*
 239  * Probe whether cpu has config register by trying to play with
 240  * alternate cache bit and see whether it matters.
 241  * It's used by cpu_probe to distinguish between R3000A and R3081.
 242  */
 243 static inline int cpu_has_confreg(void)
 244 {
 245 #ifdef CONFIG_CPU_R3000
 246         extern unsigned long r3k_cache_size(unsigned long);
 247         unsigned long size1, size2;
 248         unsigned long cfg = read_c0_conf();
 249
 250         size1 = r3k_cache_size(ST0_ISC);
 251         write_c0_conf(cfg ^ R30XX_CONF_AC);
 252         size2 = r3k_cache_size(ST0_ISC);
 253         write_c0_conf(cfg);
 254         return size1 != size2;
 255 #else
 256         return 0;
 257 #endif
 258 }
 259
 260 /*
 261  * Get the FPU Implementation/Revision.
 262  */
 263 static inline unsigned long cpu_get_fpu_id(void)
 264 {
 265         unsigned long tmp, fpu_id;
 266
 267         tmp = read_c0_status();
 268         __enable_fpu();
 269         fpu_id = read_32bit_cp1_register(CP1_REVISION);
 270         write_c0_status(tmp);
 271         return fpu_id;
 272 }
 273
 274 /*
 275  * Check the CPU has an FPU the official way.
 276  */
 277 static inline int __cpu_has_fpu(void)
 278 {
 279         return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
 280 }
 281
 282 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
 283                 | MIPS_CPU_COUNTER)
 284
 285 static inline void cpu_probe_legacy(struct cpuinfo_mips *c)
 286 {
 287         switch (c->processor_id & 0xff00) {
 288         case PRID_IMP_R2000:
 289                 c->cputype = CPU_R2000;
 290                 c->isa_level = MIPS_CPU_ISA_I;
 291                 c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
 292                              MIPS_CPU_NOFPUEX;
 293                 if (__cpu_has_fpu())
 294                         c->options |= MIPS_CPU_FPU;
 295                 c->tlbsize = 64;
 296                 break;
 297         case PRID_IMP_R3000:
 298                 if ((c->processor_id & 0xff) == PRID_REV_R3000A)
 299                         if (cpu_has_confreg())
 300                                 c->cputype = CPU_R3081E;
 301                         else
 302                                 c->cputype = CPU_R3000A;
 303                 else
 304                         c->cputype = CPU_R3000;
 305                 c->isa_level = MIPS_CPU_ISA_I;
 306                 c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
 307                              MIPS_CPU_NOFPUEX;
 308                 if (__cpu_has_fpu())
 309                         c->options |= MIPS_CPU_FPU;
 310                 c->tlbsize = 64;
 311                 break;
 312         case PRID_IMP_R4000:
 313                 if (read_c0_config() & CONF_SC) {
 314                         if ((c->processor_id & 0xff) >= PRID_REV_R4400)
 315                                 c->cputype = CPU_R4400PC;
 316                         else
 317                                 c->cputype = CPU_R4000PC;
 318                 } else {
 319                         if ((c->processor_id & 0xff) >= PRID_REV_R4400)
 320                                 c->cputype = CPU_R4400SC;
 321                         else
 322                                 c->cputype = CPU_R4000SC;
 323                 }
 324
 325                 c->isa_level = MIPS_CPU_ISA_III;
 326                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 327                              MIPS_CPU_WATCH | MIPS_CPU_VCE |
 328                              MIPS_CPU_LLSC;
 329                 c->tlbsize = 48;
 330                 break;
 331         case PRID_IMP_VR41XX:
 332                 switch (c->processor_id & 0xf0) {
 333                 case PRID_REV_VR4111:
 334                         c->cputype = CPU_VR4111;
 335                         break;
 336                 case PRID_REV_VR4121:
 337                         c->cputype = CPU_VR4121;
 338                         break;
 339                 case PRID_REV_VR4122:
 340                         if ((c->processor_id & 0xf) < 0x3)
 341                                 c->cputype = CPU_VR4122;
 342                         else
 343                                 c->cputype = CPU_VR4181A;
 344                         break;
 345                 case PRID_REV_VR4130:
 346                         if ((c->processor_id & 0xf) < 0x4)
 347                                 c->cputype = CPU_VR4131;
 348                         else
 349                                 c->cputype = CPU_VR4133;
 350                         break;
 351                 default:
 352                         printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
 353                         c->cputype = CPU_VR41XX;
 354                         break;
 355                 }
 356                 c->isa_level = MIPS_CPU_ISA_III;
 357                 c->options = R4K_OPTS;
 358                 c->tlbsize = 32;
 359                 break;
 360         case PRID_IMP_R4300:
 361                 c->cputype = CPU_R4300;
 362                 c->isa_level = MIPS_CPU_ISA_III;
 363                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 364                              MIPS_CPU_LLSC;
 365                 c->tlbsize = 32;
 366                 break;
 367         case PRID_IMP_R4600:
 368                 c->cputype = CPU_R4600;
 369                 c->isa_level = MIPS_CPU_ISA_III;
 370                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 371                              MIPS_CPU_LLSC;
 372                 c->tlbsize = 48;
 373                 break;
 374         #if 0
 375         case PRID_IMP_R4650:
 376                 /*
 377                  * This processor doesn't have an MMU, so it's not
 378                  * "real easy" to run Linux on it. It is left purely
 379                  * for documentation.  Commented out because it shares
 380                  * it's c0_prid id number with the TX3900.
 381                  */
 382                 c->cputype = CPU_R4650;
 383                 c->isa_level = MIPS_CPU_ISA_III;
 384                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
 385                 c->tlbsize = 48;
 386                 break;
 387         #endif
 388         case PRID_IMP_TX39:
 389                 c->isa_level = MIPS_CPU_ISA_I;
 390                 c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
 391
 392                 if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
 393                         c->cputype = CPU_TX3927;
 394                         c->tlbsize = 64;
 395                 } else {
 396                         switch (c->processor_id & 0xff) {
 397                         case PRID_REV_TX3912:
 398                                 c->cputype = CPU_TX3912;
 399                                 c->tlbsize = 32;
 400                                 break;
 401                         case PRID_REV_TX3922:
 402                                 c->cputype = CPU_TX3922;
 403                                 c->tlbsize = 64;
 404                                 break;
 405                         default:
 406                                 c->cputype = CPU_UNKNOWN;
 407                                 break;
 408                         }
 409                 }
 410                 break;
 411         case PRID_IMP_R4700:
 412                 c->cputype = CPU_R4700;
 413                 c->isa_level = MIPS_CPU_ISA_III;
 414                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 415                              MIPS_CPU_LLSC;
 416                 c->tlbsize = 48;
 417                 break;
 418         case PRID_IMP_TX49:
 419                 c->cputype = CPU_TX49XX;
 420                 c->isa_level = MIPS_CPU_ISA_III;
 421                 c->options = R4K_OPTS | MIPS_CPU_LLSC;
 422                 if (!(c->processor_id & 0x08))
 423                         c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
 424                 c->tlbsize = 48;
 425                 break;
 426         case PRID_IMP_R5000:
 427                 c->cputype = CPU_R5000;
 428                 c->isa_level = MIPS_CPU_ISA_IV;
 429                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 430                              MIPS_CPU_LLSC;
 431                 c->tlbsize = 48;
 432                 break;
 433         case PRID_IMP_R5432:
 434                 c->cputype = CPU_R5432;
 435                 c->isa_level = MIPS_CPU_ISA_IV;
 436                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 437                              MIPS_CPU_WATCH | MIPS_CPU_LLSC;
 438                 c->tlbsize = 48;
 439                 break;
 440         case PRID_IMP_R5500:
 441                 c->cputype = CPU_R5500;
 442                 c->isa_level = MIPS_CPU_ISA_IV;
 443                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 444                              MIPS_CPU_WATCH | MIPS_CPU_LLSC;
 445                 c->tlbsize = 48;
 446                 break;
 447         case PRID_IMP_NEVADA:
 448                 c->cputype = CPU_NEVADA;
 449                 c->isa_level = MIPS_CPU_ISA_IV;
 450                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 451                              MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
 452                 c->tlbsize = 48;
 453                 break;
 454         case PRID_IMP_R6000:
 455                 c->cputype = CPU_R6000;
 456                 c->isa_level = MIPS_CPU_ISA_II;
 457                 c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
 458                              MIPS_CPU_LLSC;
 459                 c->tlbsize = 32;
 460                 break;
 461         case PRID_IMP_R6000A:
 462                 c->cputype = CPU_R6000A;
 463                 c->isa_level = MIPS_CPU_ISA_II;
 464                 c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
 465                              MIPS_CPU_LLSC;
 466                 c->tlbsize = 32;
 467                 break;
 468         case PRID_IMP_RM7000:
 469                 c->cputype = CPU_RM7000;
 470                 c->isa_level = MIPS_CPU_ISA_IV;
 471                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 472                              MIPS_CPU_LLSC;
 473                 /*
 474                  * Undocumented RM7000:  Bit 29 in the info register of
 475                  * the RM7000 v2.0 indicates if the TLB has 48 or 64
 476                  * entries.
 477                  *
 478                  * 29      1 =>    64 entry JTLB
 479                  *         0 =>    48 entry JTLB
 480                  */
 481                 c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
 482                 break;
 483         case PRID_IMP_RM9000:
 484                 c->cputype = CPU_RM9000;
 485                 c->isa_level = MIPS_CPU_ISA_IV;
 486                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 487                              MIPS_CPU_LLSC;
 488                 /*
 489                  * Bit 29 in the info register of the RM9000
 490                  * indicates if the TLB has 48 or 64 entries.
 491                  *
 492                  * 29      1 =>    64 entry JTLB
 493                  *         0 =>    48 entry JTLB
 494                  */
 495                 c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
 496                 break;
 497         case PRID_IMP_R8000:
 498                 c->cputype = CPU_R8000;
 499                 c->isa_level = MIPS_CPU_ISA_IV;
 500                 c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
 501                              MIPS_CPU_FPU | MIPS_CPU_32FPR |
 502                              MIPS_CPU_LLSC;
 503                 c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
 504                 break;
 505         case PRID_IMP_R10000:
 506                 c->cputype = CPU_R10000;
 507                 c->isa_level = MIPS_CPU_ISA_IV;
 508                 c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
 509                              MIPS_CPU_FPU | MIPS_CPU_32FPR |
 510                              MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
 511                              MIPS_CPU_LLSC;
 512                 c->tlbsize = 64;
 513                 break;
 514         case PRID_IMP_R12000:
 515                 c->cputype = CPU_R12000;
 516                 c->isa_level = MIPS_CPU_ISA_IV;
 517                 c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
 518                              MIPS_CPU_FPU | MIPS_CPU_32FPR |
 519                              MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
 520                              MIPS_CPU_LLSC;
 521                 c->tlbsize = 64;
 522                 break;
 523         case PRID_IMP_R14000:
 524                 c->cputype = CPU_R14000;
 525                 c->isa_level = MIPS_CPU_ISA_IV;
 526                 c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
 527                              MIPS_CPU_FPU | MIPS_CPU_32FPR |
 528                              MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
 529                              MIPS_CPU_LLSC;
 530                 c->tlbsize = 64;
 531                 break;
 532         case PRID_IMP_LOONGSON2:
 533                 c->cputype = CPU_LOONGSON2;
 534                 c->isa_level = MIPS_CPU_ISA_III;
 535                 c->options = R4K_OPTS |
 536                              MIPS_CPU_FPU | MIPS_CPU_LLSC |
 537                              MIPS_CPU_32FPR;
 538                 c->tlbsize = 64;
 539                 break;
 540         }
 541 }
 542
 543 static char unknown_isa[] __initdata = KERN_ERR \
 544         "Unsupported ISA type, c0.config0: %d.";
 545
 546 static inline unsigned int decode_config0(struct cpuinfo_mips *c)
 547 {
 548         unsigned int config0;
 549         int isa;
 550
 551         config0 = read_c0_config();
 552
 553         if (((config0 & MIPS_CONF_MT) >> 7) == 1)
 554                 c->options |= MIPS_CPU_TLB;
 555         isa = (config0 & MIPS_CONF_AT) >> 13;
 556         switch (isa) {
 557         case 0:
 558                 switch ((config0 & MIPS_CONF_AR) >> 10) {
 559                 case 0:
 560                         c->isa_level = MIPS_CPU_ISA_M32R1;
 561                         break;
 562                 case 1:
 563                         c->isa_level = MIPS_CPU_ISA_M32R2;
 564                         break;
 565                 default:
 566                         goto unknown;
 567                 }
 568                 break;
 569         case 2:
 570                 switch ((config0 & MIPS_CONF_AR) >> 10) {
 571                 case 0:
 572                         c->isa_level = MIPS_CPU_ISA_M64R1;
 573                         break;
 574                 case 1:
 575                         c->isa_level = MIPS_CPU_ISA_M64R2;
 576                         break;
 577                 default:
 578                         goto unknown;
 579                 }
 580                 break;
 581         default:
 582                 goto unknown;
 583         }
 584
 585         return config0 & MIPS_CONF_M;
 586
 587 unknown:
 588         panic(unknown_isa, config0);
 589 }
 590
 591 static inline unsigned int decode_config1(struct cpuinfo_mips *c)
 592 {
 593         unsigned int config1;
 594
 595         config1 = read_c0_config1();
 596
 597         if (config1 & MIPS_CONF1_MD)
 598                 c->ases |= MIPS_ASE_MDMX;
 599         if (config1 & MIPS_CONF1_WR)
 600                 c->options |= MIPS_CPU_WATCH;
 601         if (config1 & MIPS_CONF1_CA)
 602                 c->ases |= MIPS_ASE_MIPS16;
 603         if (config1 & MIPS_CONF1_EP)
 604                 c->options |= MIPS_CPU_EJTAG;
 605         if (config1 & MIPS_CONF1_FP) {
 606                 c->options |= MIPS_CPU_FPU;
 607                 c->options |= MIPS_CPU_32FPR;
 608         }
 609         if (cpu_has_tlb)
 610                 c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
 611
 612         return config1 & MIPS_CONF_M;
 613 }
 614
 615 static inline unsigned int decode_config2(struct cpuinfo_mips *c)
 616 {
 617         unsigned int config2;
 618
 619         config2 = read_c0_config2();
 620
 621         if (config2 & MIPS_CONF2_SL)
 622                 c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
 623
 624         return config2 & MIPS_CONF_M;
 625 }
 626
 627 static inline unsigned int decode_config3(struct cpuinfo_mips *c)
 628 {
 629         unsigned int config3;
 630
 631         config3 = read_c0_config3();
 632
 633         if (config3 & MIPS_CONF3_SM)
 634                 c->ases |= MIPS_ASE_SMARTMIPS;
 635         if (config3 & MIPS_CONF3_DSP)
 636                 c->ases |= MIPS_ASE_DSP;
 637         if (config3 & MIPS_CONF3_VINT)
 638                 c->options |= MIPS_CPU_VINT;
 639         if (config3 & MIPS_CONF3_VEIC)
 640                 c->options |= MIPS_CPU_VEIC;
 641         if (config3 & MIPS_CONF3_MT)
 642                 c->ases |= MIPS_ASE_MIPSMT;
 643         if (config3 & MIPS_CONF3_ULRI)
 644                 c->options |= MIPS_CPU_ULRI;
 645
 646         return config3 & MIPS_CONF_M;
 647 }
 648
 649 static void __init decode_configs(struct cpuinfo_mips *c)
 650 {
 651         /* MIPS32 or MIPS64 compliant CPU.  */
 652         c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
 653                      MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
 654
 655         c->scache.flags = MIPS_CACHE_NOT_PRESENT;
 656
 657         /* Read Config registers.  */
 658         if (!decode_config0(c))
 659                 return;                 /* actually worth a panic() */
 660         if (!decode_config1(c))
 661                 return;
 662         if (!decode_config2(c))
 663                 return;
 664         if (!decode_config3(c))
 665                 return;
 666 }
 667
 668 static inline void cpu_probe_mips(struct cpuinfo_mips *c)
 669 {
 670         decode_configs(c);
 671         switch (c->processor_id & 0xff00) {
 672         case PRID_IMP_4KC:
 673                 c->cputype = CPU_4KC;
 674                 break;
 675         case PRID_IMP_4KEC:
 676                 c->cputype = CPU_4KEC;
 677                 break;
 678         case PRID_IMP_4KECR2:
 679                 c->cputype = CPU_4KEC;
 680                 break;
 681         case PRID_IMP_4KSC:
 682         case PRID_IMP_4KSD:
 683                 c->cputype = CPU_4KSC;
 684                 break;
 685         case PRID_IMP_5KC:
 686                 c->cputype = CPU_5KC;
 687                 break;
 688         case PRID_IMP_20KC:
 689                 c->cputype = CPU_20KC;
 690                 break;
 691         case PRID_IMP_24K:
 692         case PRID_IMP_24KE:
 693                 c->cputype = CPU_24K;
 694                 break;
 695         case PRID_IMP_25KF:
 696                 c->cputype = CPU_25KF;
 697                 break;
 698         case PRID_IMP_34K:
 699                 c->cputype = CPU_34K;
 700                 break;
 701         case PRID_IMP_74K:
 702                 c->cputype = CPU_74K;
 703                 break;
 704         }
 705 }
 706
 707 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c)
 708 {
 709         decode_configs(c);
 710         switch (c->processor_id & 0xff00) {
 711         case PRID_IMP_AU1_REV1:
 712         case PRID_IMP_AU1_REV2:
 713                 switch ((c->processor_id >> 24) & 0xff) {
 714                 case 0:
 715                         c->cputype = CPU_AU1000;
 716                         break;
 717                 case 1:
 718                         c->cputype = CPU_AU1500;
 719                         break;
 720                 case 2:
 721                         c->cputype = CPU_AU1100;
 722                         break;
 723                 case 3:
 724                         c->cputype = CPU_AU1550;
 725                         break;
 726                 case 4:
 727                         c->cputype = CPU_AU1200;
 728                         break;
 729                 default:
 730                         panic("Unknown Au Core!");
 731                         break;
 732                 }
 733                 break;
 734         }
 735 }
 736
 737 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c)
 738 {
 739         decode_configs(c);
 740
 741         /*
 742          * For historical reasons the SB1 comes with it's own variant of
 743          * cache code which eventually will be folded into c-r4k.c.  Until
 744          * then we pretend it's got it's own cache architecture.
 745          */
 746         c->options &= ~MIPS_CPU_4K_CACHE;
 747         c->options |= MIPS_CPU_SB1_CACHE;
 748
 749         switch (c->processor_id & 0xff00) {
 750         case PRID_IMP_SB1:
 751                 c->cputype = CPU_SB1;
 752                 /* FPU in pass1 is known to have issues. */
 753                 if ((c->processor_id & 0xff) < 0x02)
 754                         c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
 755                 break;
 756         case PRID_IMP_SB1A:
 757                 c->cputype = CPU_SB1A;
 758                 break;
 759         }
 760 }
 761
 762 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c)
 763 {
 764         decode_configs(c);
 765         switch (c->processor_id & 0xff00) {
 766         case PRID_IMP_SR71000:
 767                 c->cputype = CPU_SR71000;
 768                 c->scache.ways = 8;
 769                 c->tlbsize = 64;
 770                 break;
 771         }
 772 }
 773
 774 static inline void cpu_probe_philips(struct cpuinfo_mips *c)
 775 {
 776         decode_configs(c);
 777         switch (c->processor_id & 0xff00) {
 778         case PRID_IMP_PR4450:
 779                 c->cputype = CPU_PR4450;
 780                 c->isa_level = MIPS_CPU_ISA_M32R1;
 781                 break;
 782         default:
 783                 panic("Unknown Philips Core!"); /* REVISIT: die? */
 784                 break;
 785         }
 786 }
 787
 788
 789 __init void cpu_probe(void)
 790 {
 791         struct cpuinfo_mips *c = &current_cpu_data;
 792
 793         c->processor_id = PRID_IMP_UNKNOWN;
 794         c->fpu_id       = FPIR_IMP_NONE;
 795         c->cputype      = CPU_UNKNOWN;
 796
 797         c->processor_id = read_c0_prid();
 798         switch (c->processor_id & 0xff0000) {
 799         case PRID_COMP_LEGACY:
 800                 cpu_probe_legacy(c);
 801                 break;
 802         case PRID_COMP_MIPS:
 803                 cpu_probe_mips(c);
 804                 break;
 805         case PRID_COMP_ALCHEMY:
 806                 cpu_probe_alchemy(c);
 807                 break;
 808         case PRID_COMP_SIBYTE:
 809                 cpu_probe_sibyte(c);
 810                 break;
 811         case PRID_COMP_SANDCRAFT:
 812                 cpu_probe_sandcraft(c);
 813                 break;
 814         case PRID_COMP_PHILIPS:
 815                 cpu_probe_philips(c);
 816                 break;
 817         default:
 818                 c->cputype = CPU_UNKNOWN;
 819         }
 820         if (c->options & MIPS_CPU_FPU) {
 821                 c->fpu_id = cpu_get_fpu_id();
 822
 823                 if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
 824                     c->isa_level == MIPS_CPU_ISA_M32R2 ||
 825                     c->isa_level == MIPS_CPU_ISA_M64R1 ||
 826                     c->isa_level == MIPS_CPU_ISA_M64R2) {
 827                         if (c->fpu_id & MIPS_FPIR_3D)
 828                                 c->ases |= MIPS_ASE_MIPS3D;
 829                 }
 830         }
 831 }
 832
 833 __init void cpu_report(void)
 834 {
 835         struct cpuinfo_mips *c = &current_cpu_data;
 836
 837         printk("CPU revision is: %08x\n", c->processor_id);
 838         if (c->options & MIPS_CPU_FPU)
 839                 printk("FPU revision is: %08x\n", c->fpu_id);
 840 }