arch/mips/kernel/cpu-probe.c

   1 /*
   2  * Processor capabilities determination functions.
   3  *
   4  * Copyright (C) xxxx  the Anonymous
   5  * Copyright (C) 2003  Maciej W. Rozycki
   6  * Copyright (C) 1994 - 2003 Ralf Baechle
   7  * Copyright (C) 2001 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/config.h>
  15 #include <linux/init.h>
  16 #include <linux/kernel.h>
  17 #include <linux/ptrace.h>
  18 #include <linux/stddef.h>
  19
  20 #include <asm/bugs.h>
  21 #include <asm/cpu.h>
  22 #include <asm/fpu.h>
  23 #include <asm/mipsregs.h>
  24 #include <asm/system.h>
  25
  26 /*
  27  * Not all of the MIPS CPUs have the "wait" instruction available. Moreover,
  28  * the implementation of the "wait" feature differs between CPU families. This
  29  * points to the function that implements CPU specific wait.
  30  * The wait instruction stops the pipeline and reduces the power consumption of
  31  * the CPU very much.
  32  */
  33 void (*cpu_wait)(void) = NULL;
  34
  35 static void r3081_wait(void)
  36 {
  37         unsigned long cfg = read_c0_conf();
  38         write_c0_conf(cfg | R30XX_CONF_HALT);
  39 }
  40
  41 static void r39xx_wait(void)
  42 {
  43         unsigned long cfg = read_c0_conf();
  44         write_c0_conf(cfg | TX39_CONF_HALT);
  45 }
  46
  47 static void r4k_wait(void)
  48 {
  49         __asm__(".set\tmips3\n\t"
  50                 "wait\n\t"
  51                 ".set\tmips0");
  52 }
  53
  54 /*
  55  * The Au1xxx wait is available only if we run CONFIG_PM and
  56  * the timer setup found we had a 32KHz counter available.
  57  * There are still problems with functions that may call au1k_wait
  58  * directly, but that will be discovered pretty quickly.
  59  */
  60 extern void (*au1k_wait_ptr)(void);
  61
  62 void au1k_wait(void)
  63 {
  64 #ifdef CONFIG_PM
  65         /* using the wait instruction makes CP0 counter unusable */
  66         __asm__(".set\tmips3\n\t"
  67                 "wait\n\t"
  68                 "nop\n\t"
  69                 "nop\n\t"
  70                 "nop\n\t"
  71                 "nop\n\t"
  72                 ".set\tmips0");
  73 #else
  74         __asm__("nop\n\t"
  75                 "nop");
  76 #endif
  77 }
  78
  79 static inline void check_wait(void)
  80 {
  81         struct cpuinfo_mips *c = &current_cpu_data;
  82
  83         printk("Checking for 'wait' instruction... ");
  84         switch (c->cputype) {
  85         case CPU_R3081:
  86         case CPU_R3081E:
  87                 cpu_wait = r3081_wait;
  88                 printk(" available.\n");
  89                 break;
  90         case CPU_TX3927:
  91                 cpu_wait = r39xx_wait;
  92                 printk(" available.\n");
  93                 break;
  94         case CPU_R4200:
  95 /*      case CPU_R4300: */
  96         case CPU_R4600:
  97         case CPU_R4640:
  98         case CPU_R4650:
  99         case CPU_R4700:
 100         case CPU_R5000:
 101         case CPU_NEVADA:
 102         case CPU_RM7000:
 103         case CPU_RM9000:
 104         case CPU_TX49XX:
 105         case CPU_4KC:
 106         case CPU_4KEC:
 107         case CPU_4KSC:
 108         case CPU_5KC:
 109 /*      case CPU_20KC:*/
 110         case CPU_24K:
 111         case CPU_25KF:
 112                 cpu_wait = r4k_wait;
 113                 printk(" available.\n");
 114                 break;
 115 #ifdef CONFIG_PM
 116         case CPU_AU1000:
 117         case CPU_AU1100:
 118         case CPU_AU1500:
 119                 if (au1k_wait_ptr != NULL) {
 120                         cpu_wait = au1k_wait_ptr;
 121                         printk(" available.\n");
 122                 }
 123                 else {
 124                         printk(" unavailable.\n");
 125                 }
 126                 break;
 127 #endif
 128         default:
 129                 printk(" unavailable.\n");
 130                 break;
 131         }
 132 }
 133
 134 void __init check_bugs32(void)
 135 {
 136         check_wait();
 137 }
 138
 139 /*
 140  * Probe whether cpu has config register by trying to play with
 141  * alternate cache bit and see whether it matters.
 142  * It's used by cpu_probe to distinguish between R3000A and R3081.
 143  */
 144 static inline int cpu_has_confreg(void)
 145 {
 146 #ifdef CONFIG_CPU_R3000
 147         extern unsigned long r3k_cache_size(unsigned long);
 148         unsigned long size1, size2;
 149         unsigned long cfg = read_c0_conf();
 150
 151         size1 = r3k_cache_size(ST0_ISC);
 152         write_c0_conf(cfg ^ R30XX_CONF_AC);
 153         size2 = r3k_cache_size(ST0_ISC);
 154         write_c0_conf(cfg);
 155         return size1 != size2;
 156 #else
 157         return 0;
 158 #endif
 159 }
 160
 161 /*
 162  * Get the FPU Implementation/Revision.
 163  */
 164 static inline unsigned long cpu_get_fpu_id(void)
 165 {
 166         unsigned long tmp, fpu_id;
 167
 168         tmp = read_c0_status();
 169         __enable_fpu();
 170         fpu_id = read_32bit_cp1_register(CP1_REVISION);
 171         write_c0_status(tmp);
 172         return fpu_id;
 173 }
 174
 175 /*
 176  * Check the CPU has an FPU the official way.
 177  */
 178 static inline int __cpu_has_fpu(void)
 179 {
 180         return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
 181 }
 182
 183 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4KTLB \
 184                 | MIPS_CPU_COUNTER)
 185
 186 static inline void cpu_probe_legacy(struct cpuinfo_mips *c)
 187 {
 188         switch (c->processor_id & 0xff00) {
 189         case PRID_IMP_R2000:
 190                 c->cputype = CPU_R2000;
 191                 c->isa_level = MIPS_CPU_ISA_I;
 192                 c->options = MIPS_CPU_TLB | MIPS_CPU_NOFPUEX;
 193                 if (__cpu_has_fpu())
 194                         c->options |= MIPS_CPU_FPU;
 195                 c->tlbsize = 64;
 196                 break;
 197         case PRID_IMP_R3000:
 198                 if ((c->processor_id & 0xff) == PRID_REV_R3000A)
 199                         if (cpu_has_confreg())
 200                                 c->cputype = CPU_R3081E;
 201                         else
 202                                 c->cputype = CPU_R3000A;
 203                 else
 204                         c->cputype = CPU_R3000;
 205                 c->isa_level = MIPS_CPU_ISA_I;
 206                 c->options = MIPS_CPU_TLB | MIPS_CPU_NOFPUEX;
 207                 if (__cpu_has_fpu())
 208                         c->options |= MIPS_CPU_FPU;
 209                 c->tlbsize = 64;
 210                 break;
 211         case PRID_IMP_R4000:
 212                 if (read_c0_config() & CONF_SC) {
 213                         if ((c->processor_id & 0xff) >= PRID_REV_R4400)
 214                                 c->cputype = CPU_R4400PC;
 215                         else
 216                                 c->cputype = CPU_R4000PC;
 217                 } else {
 218                         if ((c->processor_id & 0xff) >= PRID_REV_R4400)
 219                                 c->cputype = CPU_R4400SC;
 220                         else
 221                                 c->cputype = CPU_R4000SC;
 222                 }
 223
 224                 c->isa_level = MIPS_CPU_ISA_III;
 225                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 226                              MIPS_CPU_WATCH | MIPS_CPU_VCE |
 227                              MIPS_CPU_LLSC;
 228                 c->tlbsize = 48;
 229                 break;
 230         case PRID_IMP_VR41XX:
 231                 switch (c->processor_id & 0xf0) {
 232                 case PRID_REV_VR4111:
 233                         c->cputype = CPU_VR4111;
 234                         break;
 235                 case PRID_REV_VR4121:
 236                         c->cputype = CPU_VR4121;
 237                         break;
 238                 case PRID_REV_VR4122:
 239                         if ((c->processor_id & 0xf) < 0x3)
 240                                 c->cputype = CPU_VR4122;
 241                         else
 242                                 c->cputype = CPU_VR4181A;
 243                         break;
 244                 case PRID_REV_VR4130:
 245                         if ((c->processor_id & 0xf) < 0x4)
 246                                 c->cputype = CPU_VR4131;
 247                         else
 248                                 c->cputype = CPU_VR4133;
 249                         break;
 250                 default:
 251                         printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
 252                         c->cputype = CPU_VR41XX;
 253                         break;
 254                 }
 255                 c->isa_level = MIPS_CPU_ISA_III;
 256                 c->options = R4K_OPTS;
 257                 c->tlbsize = 32;
 258                 break;
 259         case PRID_IMP_R4300:
 260                 c->cputype = CPU_R4300;
 261                 c->isa_level = MIPS_CPU_ISA_III;
 262                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 263                              MIPS_CPU_LLSC;
 264                 c->tlbsize = 32;
 265                 break;
 266         case PRID_IMP_R4600:
 267                 c->cputype = CPU_R4600;
 268                 c->isa_level = MIPS_CPU_ISA_III;
 269                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
 270                 c->tlbsize = 48;
 271                 break;
 272         #if 0
 273         case PRID_IMP_R4650:
 274                 /*
 275                  * This processor doesn't have an MMU, so it's not
 276                  * "real easy" to run Linux on it. It is left purely
 277                  * for documentation.  Commented out because it shares
 278                  * it's c0_prid id number with the TX3900.
 279                  */
 280                 c->cputype = CPU_R4650;
 281                 c->isa_level = MIPS_CPU_ISA_III;
 282                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
 283                 c->tlbsize = 48;
 284                 break;
 285         #endif
 286         case PRID_IMP_TX39:
 287                 c->isa_level = MIPS_CPU_ISA_I;
 288                 c->options = MIPS_CPU_TLB;
 289
 290                 if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
 291                         c->cputype = CPU_TX3927;
 292                         c->tlbsize = 64;
 293                 } else {
 294                         switch (c->processor_id & 0xff) {
 295                         case PRID_REV_TX3912:
 296                                 c->cputype = CPU_TX3912;
 297                                 c->tlbsize = 32;
 298                                 break;
 299                         case PRID_REV_TX3922:
 300                                 c->cputype = CPU_TX3922;
 301                                 c->tlbsize = 64;
 302                                 break;
 303                         default:
 304                                 c->cputype = CPU_UNKNOWN;
 305                                 break;
 306                         }
 307                 }
 308                 break;
 309         case PRID_IMP_R4700:
 310                 c->cputype = CPU_R4700;
 311                 c->isa_level = MIPS_CPU_ISA_III;
 312                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 313                              MIPS_CPU_LLSC;
 314                 c->tlbsize = 48;
 315                 break;
 316         case PRID_IMP_TX49:
 317                 c->cputype = CPU_TX49XX;
 318                 c->isa_level = MIPS_CPU_ISA_III;
 319                 c->options = R4K_OPTS | MIPS_CPU_LLSC;
 320                 if (!(c->processor_id & 0x08))
 321                         c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
 322                 c->tlbsize = 48;
 323                 break;
 324         case PRID_IMP_R5000:
 325                 c->cputype = CPU_R5000;
 326                 c->isa_level = MIPS_CPU_ISA_IV;
 327                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 328                              MIPS_CPU_LLSC;
 329                 c->tlbsize = 48;
 330                 break;
 331         case PRID_IMP_R5432:
 332                 c->cputype = CPU_R5432;
 333                 c->isa_level = MIPS_CPU_ISA_IV;
 334                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 335                              MIPS_CPU_WATCH | MIPS_CPU_LLSC;
 336                 c->tlbsize = 48;
 337                 break;
 338         case PRID_IMP_R5500:
 339                 c->cputype = CPU_R5500;
 340                 c->isa_level = MIPS_CPU_ISA_IV;
 341                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 342                              MIPS_CPU_WATCH | MIPS_CPU_LLSC;
 343                 c->tlbsize = 48;
 344                 break;
 345         case PRID_IMP_NEVADA:
 346                 c->cputype = CPU_NEVADA;
 347                 c->isa_level = MIPS_CPU_ISA_IV;
 348                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 349                              MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
 350                 c->tlbsize = 48;
 351                 break;
 352         case PRID_IMP_R6000:
 353                 c->cputype = CPU_R6000;
 354                 c->isa_level = MIPS_CPU_ISA_II;
 355                 c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
 356                              MIPS_CPU_LLSC;
 357                 c->tlbsize = 32;
 358                 break;
 359         case PRID_IMP_R6000A:
 360                 c->cputype = CPU_R6000A;
 361                 c->isa_level = MIPS_CPU_ISA_II;
 362                 c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
 363                              MIPS_CPU_LLSC;
 364                 c->tlbsize = 32;
 365                 break;
 366         case PRID_IMP_RM7000:
 367                 c->cputype = CPU_RM7000;
 368                 c->isa_level = MIPS_CPU_ISA_IV;
 369                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 370                              MIPS_CPU_LLSC;
 371                 /*
 372                  * Undocumented RM7000:  Bit 29 in the info register of
 373                  * the RM7000 v2.0 indicates if the TLB has 48 or 64
 374                  * entries.
 375                  *
 376                  * 29      1 =>    64 entry JTLB
 377                  *         0 =>    48 entry JTLB
 378                  */
 379                 c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
 380                 break;
 381         case PRID_IMP_RM9000:
 382                 c->cputype = CPU_RM9000;
 383                 c->isa_level = MIPS_CPU_ISA_IV;
 384                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 385                              MIPS_CPU_LLSC;
 386                 /*
 387                  * Bit 29 in the info register of the RM9000
 388                  * indicates if the TLB has 48 or 64 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_R8000:
 396                 c->cputype = CPU_R8000;
 397                 c->isa_level = MIPS_CPU_ISA_IV;
 398                 c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
 399                              MIPS_CPU_FPU | MIPS_CPU_32FPR |
 400                              MIPS_CPU_LLSC;
 401                 c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
 402                 break;
 403         case PRID_IMP_R10000:
 404                 c->cputype = CPU_R10000;
 405                 c->isa_level = MIPS_CPU_ISA_IV;
 406                 c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
 407                              MIPS_CPU_FPU | MIPS_CPU_32FPR |
 408                              MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
 409                              MIPS_CPU_LLSC;
 410                 c->tlbsize = 64;
 411                 break;
 412         case PRID_IMP_R12000:
 413                 c->cputype = CPU_R12000;
 414                 c->isa_level = MIPS_CPU_ISA_IV;
 415                 c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
 416                              MIPS_CPU_FPU | MIPS_CPU_32FPR |
 417                              MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
 418                              MIPS_CPU_LLSC;
 419                 c->tlbsize = 64;
 420                 break;
 421         }
 422 }
 423
 424 static inline void decode_config1(struct cpuinfo_mips *c)
 425 {
 426         unsigned long config0 = read_c0_config();
 427         unsigned long config1;
 428
 429         if ((config0 & (1 << 31)) == 0)
 430                 return;                 /* actually wort a panic() */
 431
 432         /* MIPS32 or MIPS64 compliant CPU. Read Config 1 register. */
 433         c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
 434                 MIPS_CPU_4KTLB | MIPS_CPU_COUNTER | MIPS_CPU_DIVEC |
 435                 MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
 436         config1 = read_c0_config1();
 437         if (config1 & (1 << 3))
 438                 c->options |= MIPS_CPU_WATCH;
 439         if (config1 & (1 << 2))
 440                 c->options |= MIPS_CPU_MIPS16;
 441         if (config1 & (1 << 1))
 442                 c->options |= MIPS_CPU_EJTAG;
 443         if (config1 & 1) {
 444                 c->options |= MIPS_CPU_FPU;
 445                 c->options |= MIPS_CPU_32FPR;
 446         }
 447         c->scache.flags = MIPS_CACHE_NOT_PRESENT;
 448
 449         c->tlbsize = ((config1 >> 25) & 0x3f) + 1;
 450 }
 451
 452 static inline void cpu_probe_mips(struct cpuinfo_mips *c)
 453 {
 454         decode_config1(c);
 455         switch (c->processor_id & 0xff00) {
 456         case PRID_IMP_4KC:
 457                 c->cputype = CPU_4KC;
 458                 c->isa_level = MIPS_CPU_ISA_M32;
 459                 break;
 460         case PRID_IMP_4KEC:
 461                 c->cputype = CPU_4KEC;
 462                 c->isa_level = MIPS_CPU_ISA_M32;
 463                 break;
 464         case PRID_IMP_4KSC:
 465                 c->cputype = CPU_4KSC;
 466                 c->isa_level = MIPS_CPU_ISA_M32;
 467                 break;
 468         case PRID_IMP_5KC:
 469                 c->cputype = CPU_5KC;
 470                 c->isa_level = MIPS_CPU_ISA_M64;
 471                 break;
 472         case PRID_IMP_20KC:
 473                 c->cputype = CPU_20KC;
 474                 c->isa_level = MIPS_CPU_ISA_M64;
 475                 break;
 476         case PRID_IMP_24K:
 477                 c->cputype = CPU_24K;
 478                 c->isa_level = MIPS_CPU_ISA_M32;
 479                 break;
 480         case PRID_IMP_25KF:
 481                 c->cputype = CPU_25KF;
 482                 c->isa_level = MIPS_CPU_ISA_M64;
 483                 /* Probe for L2 cache */
 484                 c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
 485                 break;
 486         }
 487 }
 488
 489 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c)
 490 {
 491         decode_config1(c);
 492         switch (c->processor_id & 0xff00) {
 493         case PRID_IMP_AU1_REV1:
 494         case PRID_IMP_AU1_REV2:
 495                 switch ((c->processor_id >> 24) & 0xff) {
 496                 case 0:
 497                         c->cputype = CPU_AU1000;
 498                         break;
 499                 case 1:
 500                         c->cputype = CPU_AU1500;
 501                         break;
 502                 case 2:
 503                         c->cputype = CPU_AU1100;
 504                         break;
 505                 case 3:
 506                         c->cputype = CPU_AU1550;
 507                         break;
 508                 default:
 509                         panic("Unknown Au Core!");
 510                         break;
 511                 }
 512                 c->isa_level = MIPS_CPU_ISA_M32;
 513                 break;
 514         }
 515 }
 516
 517 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c)
 518 {
 519         decode_config1(c);
 520         switch (c->processor_id & 0xff00) {
 521         case PRID_IMP_SB1:
 522                 c->cputype = CPU_SB1;
 523                 c->isa_level = MIPS_CPU_ISA_M64;
 524                 c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
 525                              MIPS_CPU_COUNTER | MIPS_CPU_DIVEC |
 526                              MIPS_CPU_MCHECK | MIPS_CPU_EJTAG |
 527                              MIPS_CPU_WATCH | MIPS_CPU_LLSC;
 528 #ifndef CONFIG_SB1_PASS_1_WORKAROUNDS
 529                 /* FPU in pass1 is known to have issues. */
 530                 c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
 531 #endif
 532                 break;
 533         }
 534 }
 535
 536 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c)
 537 {
 538         decode_config1(c);
 539         switch (c->processor_id & 0xff00) {
 540         case PRID_IMP_SR71000:
 541                 c->cputype = CPU_SR71000;
 542                 c->isa_level = MIPS_CPU_ISA_M64;
 543                 c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
 544                              MIPS_CPU_4KTLB | MIPS_CPU_FPU |
 545                              MIPS_CPU_COUNTER | MIPS_CPU_MCHECK;
 546                 c->scache.ways = 8;
 547                 c->tlbsize = 64;
 548                 break;
 549         }
 550 }
 551
 552 __init void cpu_probe(void)
 553 {
 554         struct cpuinfo_mips *c = &current_cpu_data;
 555
 556         c->processor_id = PRID_IMP_UNKNOWN;
 557         c->fpu_id       = FPIR_IMP_NONE;
 558         c->cputype      = CPU_UNKNOWN;
 559
 560         c->processor_id = read_c0_prid();
 561         switch (c->processor_id & 0xff0000) {
 562         case PRID_COMP_LEGACY:
 563                 cpu_probe_legacy(c);
 564                 break;
 565         case PRID_COMP_MIPS:
 566                 cpu_probe_mips(c);
 567                 break;
 568         case PRID_COMP_ALCHEMY:
 569                 cpu_probe_alchemy(c);
 570                 break;
 571         case PRID_COMP_SIBYTE:
 572                 cpu_probe_sibyte(c);
 573                 break;
 574
 575         case PRID_COMP_SANDCRAFT:
 576                 cpu_probe_sandcraft(c);
 577                 break;
 578         default:
 579                 c->cputype = CPU_UNKNOWN;
 580         }
 581         if (c->options & MIPS_CPU_FPU)
 582                 c->fpu_id = cpu_get_fpu_id();
 583 }
 584
 585 __init void cpu_report(void)
 586 {
 587         struct cpuinfo_mips *c = &current_cpu_data;
 588
 589         printk("CPU revision is: %08x\n", c->processor_id);
 590         if (c->options & MIPS_CPU_FPU)
 591                 printk("FPU revision is: %08x\n", c->fpu_id);
 592 }