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 #ifndef CONFIG_VR4181
 233                 case PRID_REV_VR4111:
 234                         c->cputype = CPU_VR4111;
 235                         break;
 236 #else
 237                 case PRID_REV_VR4181:
 238                         c->cputype = CPU_VR4181;
 239                         break;
 240 #endif
 241                 case PRID_REV_VR4121:
 242                         c->cputype = CPU_VR4121;
 243                         break;
 244                 case PRID_REV_VR4122:
 245                         if ((c->processor_id & 0xf) < 0x3)
 246                                 c->cputype = CPU_VR4122;
 247                         else
 248                                 c->cputype = CPU_VR4181A;
 249                         break;
 250                 case PRID_REV_VR4130:
 251                         if ((c->processor_id & 0xf) < 0x4)
 252                                 c->cputype = CPU_VR4131;
 253                         else
 254                                 c->cputype = CPU_VR4133;
 255                         break;
 256                 default:
 257                         printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
 258                         c->cputype = CPU_VR41XX;
 259                         break;
 260                 }
 261                 c->isa_level = MIPS_CPU_ISA_III;
 262                 c->options = R4K_OPTS;
 263                 c->tlbsize = 32;
 264                 break;
 265         case PRID_IMP_R4300:
 266                 c->cputype = CPU_R4300;
 267                 c->isa_level = MIPS_CPU_ISA_III;
 268                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 269                              MIPS_CPU_LLSC;
 270                 c->tlbsize = 32;
 271                 break;
 272         case PRID_IMP_R4600:
 273                 c->cputype = CPU_R4600;
 274                 c->isa_level = MIPS_CPU_ISA_III;
 275                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
 276                 c->tlbsize = 48;
 277                 break;
 278         #if 0
 279         case PRID_IMP_R4650:
 280                 /*
 281                  * This processor doesn't have an MMU, so it's not
 282                  * "real easy" to run Linux on it. It is left purely
 283                  * for documentation.  Commented out because it shares
 284                  * it's c0_prid id number with the TX3900.
 285                  */
 286                 c->cputype = CPU_R4650;
 287                 c->isa_level = MIPS_CPU_ISA_III;
 288                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
 289                 c->tlbsize = 48;
 290                 break;
 291         #endif
 292         case PRID_IMP_TX39:
 293                 c->isa_level = MIPS_CPU_ISA_I;
 294                 c->options = MIPS_CPU_TLB;
 295
 296                 if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
 297                         c->cputype = CPU_TX3927;
 298                         c->tlbsize = 64;
 299                 } else {
 300                         switch (c->processor_id & 0xff) {
 301                         case PRID_REV_TX3912:
 302                                 c->cputype = CPU_TX3912;
 303                                 c->tlbsize = 32;
 304                                 break;
 305                         case PRID_REV_TX3922:
 306                                 c->cputype = CPU_TX3922;
 307                                 c->tlbsize = 64;
 308                                 break;
 309                         default:
 310                                 c->cputype = CPU_UNKNOWN;
 311                                 break;
 312                         }
 313                 }
 314                 break;
 315         case PRID_IMP_R4700:
 316                 c->cputype = CPU_R4700;
 317                 c->isa_level = MIPS_CPU_ISA_III;
 318                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 319                              MIPS_CPU_LLSC;
 320                 c->tlbsize = 48;
 321                 break;
 322         case PRID_IMP_TX49:
 323                 c->cputype = CPU_TX49XX;
 324                 c->isa_level = MIPS_CPU_ISA_III;
 325                 c->options = R4K_OPTS | MIPS_CPU_LLSC;
 326                 if (!(c->processor_id & 0x08))
 327                         c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
 328                 c->tlbsize = 48;
 329                 break;
 330         case PRID_IMP_R5000:
 331                 c->cputype = CPU_R5000;
 332                 c->isa_level = MIPS_CPU_ISA_IV;
 333                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 334                              MIPS_CPU_LLSC;
 335                 c->tlbsize = 48;
 336                 break;
 337         case PRID_IMP_R5432:
 338                 c->cputype = CPU_R5432;
 339                 c->isa_level = MIPS_CPU_ISA_IV;
 340                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 341                              MIPS_CPU_WATCH | MIPS_CPU_LLSC;
 342                 c->tlbsize = 48;
 343                 break;
 344         case PRID_IMP_R5500:
 345                 c->cputype = CPU_R5500;
 346                 c->isa_level = MIPS_CPU_ISA_IV;
 347                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 348                              MIPS_CPU_WATCH | MIPS_CPU_LLSC;
 349                 c->tlbsize = 48;
 350                 break;
 351         case PRID_IMP_NEVADA:
 352                 c->cputype = CPU_NEVADA;
 353                 c->isa_level = MIPS_CPU_ISA_IV;
 354                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 355                              MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
 356                 c->tlbsize = 48;
 357                 break;
 358         case PRID_IMP_R6000:
 359                 c->cputype = CPU_R6000;
 360                 c->isa_level = MIPS_CPU_ISA_II;
 361                 c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
 362                              MIPS_CPU_LLSC;
 363                 c->tlbsize = 32;
 364                 break;
 365         case PRID_IMP_R6000A:
 366                 c->cputype = CPU_R6000A;
 367                 c->isa_level = MIPS_CPU_ISA_II;
 368                 c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
 369                              MIPS_CPU_LLSC;
 370                 c->tlbsize = 32;
 371                 break;
 372         case PRID_IMP_RM7000:
 373                 c->cputype = CPU_RM7000;
 374                 c->isa_level = MIPS_CPU_ISA_IV;
 375                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 376                              MIPS_CPU_LLSC;
 377                 /*
 378                  * Undocumented RM7000:  Bit 29 in the info register of
 379                  * the RM7000 v2.0 indicates if the TLB has 48 or 64
 380                  * entries.
 381                  *
 382                  * 29      1 =>    64 entry JTLB
 383                  *         0 =>    48 entry JTLB
 384                  */
 385                 c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
 386                 break;
 387         case PRID_IMP_RM9000:
 388                 c->cputype = CPU_RM9000;
 389                 c->isa_level = MIPS_CPU_ISA_IV;
 390                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 391                              MIPS_CPU_LLSC;
 392                 /*
 393                  * Bit 29 in the info register of the RM9000
 394                  * indicates if the TLB has 48 or 64 entries.
 395                  *
 396                  * 29      1 =>    64 entry JTLB
 397                  *         0 =>    48 entry JTLB
 398                  */
 399                 c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
 400                 break;
 401         case PRID_IMP_R8000:
 402                 c->cputype = CPU_R8000;
 403                 c->isa_level = MIPS_CPU_ISA_IV;
 404                 c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
 405                              MIPS_CPU_FPU | MIPS_CPU_32FPR |
 406                              MIPS_CPU_LLSC;
 407                 c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
 408                 break;
 409         case PRID_IMP_R10000:
 410                 c->cputype = CPU_R10000;
 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_COUNTER | MIPS_CPU_WATCH |
 415                              MIPS_CPU_LLSC;
 416                 c->tlbsize = 64;
 417                 break;
 418         case PRID_IMP_R12000:
 419                 c->cputype = CPU_R12000;
 420                 c->isa_level = MIPS_CPU_ISA_IV;
 421                 c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
 422                              MIPS_CPU_FPU | MIPS_CPU_32FPR |
 423                              MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
 424                              MIPS_CPU_LLSC;
 425                 c->tlbsize = 64;
 426                 break;
 427         }
 428 }
 429
 430 static inline void decode_config1(struct cpuinfo_mips *c)
 431 {
 432         unsigned long config0 = read_c0_config();
 433         unsigned long config1;
 434
 435         if ((config0 & (1 << 31)) == 0)
 436                 return;                 /* actually wort a panic() */
 437
 438         /* MIPS32 or MIPS64 compliant CPU. Read Config 1 register. */
 439         c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
 440                 MIPS_CPU_4KTLB | MIPS_CPU_COUNTER | MIPS_CPU_DIVEC |
 441                 MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
 442         config1 = read_c0_config1();
 443         if (config1 & (1 << 3))
 444                 c->options |= MIPS_CPU_WATCH;
 445         if (config1 & (1 << 2))
 446                 c->options |= MIPS_CPU_MIPS16;
 447         if (config1 & (1 << 1))
 448                 c->options |= MIPS_CPU_EJTAG;
 449         if (config1 & 1) {
 450                 c->options |= MIPS_CPU_FPU;
 451                 c->options |= MIPS_CPU_32FPR;
 452         }
 453         c->scache.flags = MIPS_CACHE_NOT_PRESENT;
 454
 455         c->tlbsize = ((config1 >> 25) & 0x3f) + 1;
 456 }
 457
 458 static inline void cpu_probe_mips(struct cpuinfo_mips *c)
 459 {
 460         decode_config1(c);
 461         switch (c->processor_id & 0xff00) {
 462         case PRID_IMP_4KC:
 463                 c->cputype = CPU_4KC;
 464                 c->isa_level = MIPS_CPU_ISA_M32;
 465                 break;
 466         case PRID_IMP_4KEC:
 467                 c->cputype = CPU_4KEC;
 468                 c->isa_level = MIPS_CPU_ISA_M32;
 469                 break;
 470         case PRID_IMP_4KSC:
 471                 c->cputype = CPU_4KSC;
 472                 c->isa_level = MIPS_CPU_ISA_M32;
 473                 break;
 474         case PRID_IMP_5KC:
 475                 c->cputype = CPU_5KC;
 476                 c->isa_level = MIPS_CPU_ISA_M64;
 477                 break;
 478         case PRID_IMP_20KC:
 479                 c->cputype = CPU_20KC;
 480                 c->isa_level = MIPS_CPU_ISA_M64;
 481                 break;
 482         case PRID_IMP_24K:
 483                 c->cputype = CPU_24K;
 484                 c->isa_level = MIPS_CPU_ISA_M32;
 485                 break;
 486         case PRID_IMP_25KF:
 487                 c->cputype = CPU_25KF;
 488                 c->isa_level = MIPS_CPU_ISA_M64;
 489                 /* Probe for L2 cache */
 490                 c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
 491                 break;
 492         }
 493 }
 494
 495 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c)
 496 {
 497         decode_config1(c);
 498         switch (c->processor_id & 0xff00) {
 499         case PRID_IMP_AU1_REV1:
 500         case PRID_IMP_AU1_REV2:
 501                 switch ((c->processor_id >> 24) & 0xff) {
 502                 case 0:
 503                         c->cputype = CPU_AU1000;
 504                         break;
 505                 case 1:
 506                         c->cputype = CPU_AU1500;
 507                         break;
 508                 case 2:
 509                         c->cputype = CPU_AU1100;
 510                         break;
 511                 case 3:
 512                         c->cputype = CPU_AU1550;
 513                         break;
 514                 default:
 515                         panic("Unknown Au Core!");
 516                         break;
 517                 }
 518                 c->isa_level = MIPS_CPU_ISA_M32;
 519                 break;
 520         }
 521 }
 522
 523 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c)
 524 {
 525         decode_config1(c);
 526         switch (c->processor_id & 0xff00) {
 527         case PRID_IMP_SB1:
 528                 c->cputype = CPU_SB1;
 529                 c->isa_level = MIPS_CPU_ISA_M64;
 530                 c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
 531                              MIPS_CPU_COUNTER | MIPS_CPU_DIVEC |
 532                              MIPS_CPU_MCHECK | MIPS_CPU_EJTAG |
 533                              MIPS_CPU_WATCH | MIPS_CPU_LLSC;
 534 #ifndef CONFIG_SB1_PASS_1_WORKAROUNDS
 535                 /* FPU in pass1 is known to have issues. */
 536                 c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
 537 #endif
 538                 break;
 539         }
 540 }
 541
 542 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c)
 543 {
 544         decode_config1(c);
 545         switch (c->processor_id & 0xff00) {
 546         case PRID_IMP_SR71000:
 547                 c->cputype = CPU_SR71000;
 548                 c->isa_level = MIPS_CPU_ISA_M64;
 549                 c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
 550                              MIPS_CPU_4KTLB | MIPS_CPU_FPU |
 551                              MIPS_CPU_COUNTER | MIPS_CPU_MCHECK;
 552                 c->scache.ways = 8;
 553                 c->tlbsize = 64;
 554                 break;
 555         }
 556 }
 557
 558 __init void cpu_probe(void)
 559 {
 560         struct cpuinfo_mips *c = &current_cpu_data;
 561
 562         c->processor_id = PRID_IMP_UNKNOWN;
 563         c->fpu_id       = FPIR_IMP_NONE;
 564         c->cputype      = CPU_UNKNOWN;
 565
 566         c->processor_id = read_c0_prid();
 567         switch (c->processor_id & 0xff0000) {
 568         case PRID_COMP_LEGACY:
 569                 cpu_probe_legacy(c);
 570                 break;
 571         case PRID_COMP_MIPS:
 572                 cpu_probe_mips(c);
 573                 break;
 574         case PRID_COMP_ALCHEMY:
 575                 cpu_probe_alchemy(c);
 576                 break;
 577         case PRID_COMP_SIBYTE:
 578                 cpu_probe_sibyte(c);
 579                 break;
 580
 581         case PRID_COMP_SANDCRAFT:
 582                 cpu_probe_sandcraft(c);
 583                 break;
 584         default:
 585                 c->cputype = CPU_UNKNOWN;
 586         }
 587         if (c->options & MIPS_CPU_FPU)
 588                 c->fpu_id = cpu_get_fpu_id();
 589 }
 590
 591 __init void cpu_report(void)
 592 {
 593         struct cpuinfo_mips *c = &current_cpu_data;
 594
 595         printk("CPU revision is: %08x\n", c->processor_id);
 596         if (c->options & MIPS_CPU_FPU)
 597                 printk("FPU revision is: %08x\n", c->fpu_id);
 598 }