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_TX49XX:
 104         case CPU_4KC:
 105         case CPU_4KEC:
 106         case CPU_4KSC:
 107         case CPU_5KC:
 108 /*      case CPU_20KC:*/
 109         case CPU_24K:
 110         case CPU_25KF:
 111                 cpu_wait = r4k_wait;
 112                 printk(" available.\n");
 113                 break;
 114 #ifdef CONFIG_PM
 115         case CPU_AU1000:
 116         case CPU_AU1100:
 117         case CPU_AU1500:
 118                 if (au1k_wait_ptr != NULL) {
 119                         cpu_wait = au1k_wait_ptr;
 120                         printk(" available.\n");
 121                 }
 122                 else {
 123                         printk(" unavailable.\n");
 124                 }
 125                 break;
 126 #endif
 127         default:
 128                 printk(" unavailable.\n");
 129                 break;
 130         }
 131 }
 132
 133 void __init check_bugs32(void)
 134 {
 135         check_wait();
 136 }
 137
 138 /*
 139  * Probe whether cpu has config register by trying to play with
 140  * alternate cache bit and see whether it matters.
 141  * It's used by cpu_probe to distinguish between R3000A and R3081.
 142  */
 143 static inline int cpu_has_confreg(void)
 144 {
 145 #ifdef CONFIG_CPU_R3000
 146         extern unsigned long r3k_cache_size(unsigned long);
 147         unsigned long size1, size2;
 148         unsigned long cfg = read_c0_conf();
 149
 150         size1 = r3k_cache_size(ST0_ISC);
 151         write_c0_conf(cfg ^ R30XX_CONF_AC);
 152         size2 = r3k_cache_size(ST0_ISC);
 153         write_c0_conf(cfg);
 154         return size1 != size2;
 155 #else
 156         return 0;
 157 #endif
 158 }
 159
 160 /*
 161  * Get the FPU Implementation/Revision.
 162  */
 163 static inline unsigned long cpu_get_fpu_id(void)
 164 {
 165         unsigned long tmp, fpu_id;
 166
 167         tmp = read_c0_status();
 168         __enable_fpu();
 169         fpu_id = read_32bit_cp1_register(CP1_REVISION);
 170         write_c0_status(tmp);
 171         return fpu_id;
 172 }
 173
 174 /*
 175  * Check the CPU has an FPU the official way.
 176  */
 177 static inline int __cpu_has_fpu(void)
 178 {
 179         return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
 180 }
 181
 182 #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4KTLB \
 183                 | MIPS_CPU_COUNTER)
 184
 185 static inline void cpu_probe_legacy(struct cpuinfo_mips *c)
 186 {
 187         switch (c->processor_id & 0xff00) {
 188         case PRID_IMP_R2000:
 189                 c->cputype = CPU_R2000;
 190                 c->isa_level = MIPS_CPU_ISA_I;
 191                 c->options = MIPS_CPU_TLB | MIPS_CPU_NOFPUEX;
 192                 if (__cpu_has_fpu())
 193                         c->options |= MIPS_CPU_FPU;
 194                 c->tlbsize = 64;
 195                 break;
 196         case PRID_IMP_R3000:
 197                 if ((c->processor_id & 0xff) == PRID_REV_R3000A)
 198                         if (cpu_has_confreg())
 199                                 c->cputype = CPU_R3081E;
 200                         else
 201                                 c->cputype = CPU_R3000A;
 202                 else
 203                         c->cputype = CPU_R3000;
 204                 c->isa_level = MIPS_CPU_ISA_I;
 205                 c->options = MIPS_CPU_TLB | MIPS_CPU_NOFPUEX;
 206                 if (__cpu_has_fpu())
 207                         c->options |= MIPS_CPU_FPU;
 208                 c->tlbsize = 64;
 209                 break;
 210         case PRID_IMP_R4000:
 211                 if (read_c0_config() & CONF_SC) {
 212                         if ((c->processor_id & 0xff) >= PRID_REV_R4400)
 213                                 c->cputype = CPU_R4400PC;
 214                         else
 215                                 c->cputype = CPU_R4000PC;
 216                 } else {
 217                         if ((c->processor_id & 0xff) >= PRID_REV_R4400)
 218                                 c->cputype = CPU_R4400SC;
 219                         else
 220                                 c->cputype = CPU_R4000SC;
 221                 }
 222
 223                 c->isa_level = MIPS_CPU_ISA_III;
 224                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 225                              MIPS_CPU_WATCH | MIPS_CPU_VCE |
 226                              MIPS_CPU_LLSC;
 227                 c->tlbsize = 48;
 228                 break;
 229         case PRID_IMP_VR41XX:
 230                 switch (c->processor_id & 0xf0) {
 231 #ifndef CONFIG_VR4181
 232                 case PRID_REV_VR4111:
 233                         c->cputype = CPU_VR4111;
 234                         break;
 235 #else
 236                 case PRID_REV_VR4181:
 237                         c->cputype = CPU_VR4181;
 238                         break;
 239 #endif
 240                 case PRID_REV_VR4121:
 241                         c->cputype = CPU_VR4121;
 242                         break;
 243                 case PRID_REV_VR4122:
 244                         if ((c->processor_id & 0xf) < 0x3)
 245                                 c->cputype = CPU_VR4122;
 246                         else
 247                                 c->cputype = CPU_VR4181A;
 248                         break;
 249                 case PRID_REV_VR4130:
 250                         if ((c->processor_id & 0xf) < 0x4)
 251                                 c->cputype = CPU_VR4131;
 252                         else
 253                                 c->cputype = CPU_VR4133;
 254                         break;
 255                 default:
 256                         printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
 257                         c->cputype = CPU_VR41XX;
 258                         break;
 259                 }
 260                 c->isa_level = MIPS_CPU_ISA_III;
 261                 c->options = R4K_OPTS;
 262                 c->tlbsize = 32;
 263                 break;
 264         case PRID_IMP_R4300:
 265                 c->cputype = CPU_R4300;
 266                 c->isa_level = MIPS_CPU_ISA_III;
 267                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 268                              MIPS_CPU_LLSC;
 269                 c->tlbsize = 32;
 270                 break;
 271         case PRID_IMP_R4600:
 272                 c->cputype = CPU_R4600;
 273                 c->isa_level = MIPS_CPU_ISA_III;
 274                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
 275                 c->tlbsize = 48;
 276                 break;
 277         #if 0
 278         case PRID_IMP_R4650:
 279                 /*
 280                  * This processor doesn't have an MMU, so it's not
 281                  * "real easy" to run Linux on it. It is left purely
 282                  * for documentation.  Commented out because it shares
 283                  * it's c0_prid id number with the TX3900.
 284                  */
 285                 c->cputype = CPU_R4650;
 286                 c->isa_level = MIPS_CPU_ISA_III;
 287                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
 288                 c->tlbsize = 48;
 289                 break;
 290         #endif
 291         case PRID_IMP_TX39:
 292                 c->isa_level = MIPS_CPU_ISA_I;
 293                 c->options = MIPS_CPU_TLB;
 294
 295                 if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
 296                         c->cputype = CPU_TX3927;
 297                         c->tlbsize = 64;
 298                 } else {
 299                         switch (c->processor_id & 0xff) {
 300                         case PRID_REV_TX3912:
 301                                 c->cputype = CPU_TX3912;
 302                                 c->tlbsize = 32;
 303                                 break;
 304                         case PRID_REV_TX3922:
 305                                 c->cputype = CPU_TX3922;
 306                                 c->tlbsize = 64;
 307                                 break;
 308                         default:
 309                                 c->cputype = CPU_UNKNOWN;
 310                                 break;
 311                         }
 312                 }
 313                 break;
 314         case PRID_IMP_R4700:
 315                 c->cputype = CPU_R4700;
 316                 c->isa_level = MIPS_CPU_ISA_III;
 317                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 318                              MIPS_CPU_LLSC;
 319                 c->tlbsize = 48;
 320                 break;
 321         case PRID_IMP_TX49:
 322                 c->cputype = CPU_TX49XX;
 323                 c->isa_level = MIPS_CPU_ISA_III;
 324                 c->options = R4K_OPTS | MIPS_CPU_LLSC;
 325                 if (!(c->processor_id & 0x08))
 326                         c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
 327                 c->tlbsize = 48;
 328                 break;
 329         case PRID_IMP_R5000:
 330                 c->cputype = CPU_R5000;
 331                 c->isa_level = MIPS_CPU_ISA_IV;
 332                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 333                              MIPS_CPU_LLSC;
 334                 c->tlbsize = 48;
 335                 break;
 336         case PRID_IMP_R5432:
 337                 c->cputype = CPU_R5432;
 338                 c->isa_level = MIPS_CPU_ISA_IV;
 339                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 340                              MIPS_CPU_WATCH | MIPS_CPU_LLSC;
 341                 c->tlbsize = 48;
 342                 break;
 343         case PRID_IMP_R5500:
 344                 c->cputype = CPU_R5500;
 345                 c->isa_level = MIPS_CPU_ISA_IV;
 346                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 347                              MIPS_CPU_WATCH | MIPS_CPU_LLSC;
 348                 c->tlbsize = 48;
 349                 break;
 350         case PRID_IMP_NEVADA:
 351                 c->cputype = CPU_NEVADA;
 352                 c->isa_level = MIPS_CPU_ISA_IV;
 353                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 354                              MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
 355                 c->tlbsize = 48;
 356                 break;
 357         case PRID_IMP_R6000:
 358                 c->cputype = CPU_R6000;
 359                 c->isa_level = MIPS_CPU_ISA_II;
 360                 c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
 361                              MIPS_CPU_LLSC;
 362                 c->tlbsize = 32;
 363                 break;
 364         case PRID_IMP_R6000A:
 365                 c->cputype = CPU_R6000A;
 366                 c->isa_level = MIPS_CPU_ISA_II;
 367                 c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
 368                              MIPS_CPU_LLSC;
 369                 c->tlbsize = 32;
 370                 break;
 371         case PRID_IMP_RM7000:
 372                 c->cputype = CPU_RM7000;
 373                 c->isa_level = MIPS_CPU_ISA_IV;
 374                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 375                              MIPS_CPU_LLSC;
 376                 /*
 377                  * Undocumented RM7000:  Bit 29 in the info register of
 378                  * the RM7000 v2.0 indicates if the TLB has 48 or 64
 379                  * entries.
 380                  *
 381                  * 29      1 =>    64 entry JTLB
 382                  *         0 =>    48 entry JTLB
 383                  */
 384                 c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
 385                 break;
 386         case PRID_IMP_RM9000:
 387                 c->cputype = CPU_RM9000;
 388                 c->isa_level = MIPS_CPU_ISA_IV;
 389                 c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
 390                              MIPS_CPU_LLSC;
 391                 /*
 392                  * Bit 29 in the info register of the RM9000
 393                  * indicates if the TLB has 48 or 64 entries.
 394                  *
 395                  * 29      1 =>    64 entry JTLB
 396                  *         0 =>    48 entry JTLB
 397                  */
 398                 c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
 399                 break;
 400         case PRID_IMP_R8000:
 401                 c->cputype = CPU_R8000;
 402                 c->isa_level = MIPS_CPU_ISA_IV;
 403                 c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
 404                              MIPS_CPU_FPU | MIPS_CPU_32FPR |
 405                              MIPS_CPU_LLSC;
 406                 c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
 407                 break;
 408         case PRID_IMP_R10000:
 409                 c->cputype = CPU_R10000;
 410                 c->isa_level = MIPS_CPU_ISA_IV;
 411                 c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
 412                              MIPS_CPU_FPU | MIPS_CPU_32FPR |
 413                              MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
 414                              MIPS_CPU_LLSC;
 415                 c->tlbsize = 64;
 416                 break;
 417         case PRID_IMP_R12000:
 418                 c->cputype = CPU_R12000;
 419                 c->isa_level = MIPS_CPU_ISA_IV;
 420                 c->options = MIPS_CPU_TLB | 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         }
 427 }
 428
 429 static inline void decode_config1(struct cpuinfo_mips *c)
 430 {
 431         unsigned long config0 = read_c0_config();
 432         unsigned long config1;
 433
 434         if ((config0 & (1 << 31)) == 0)
 435                 return;                 /* actually wort a panic() */
 436
 437         /* MIPS32 or MIPS64 compliant CPU. Read Config 1 register. */
 438         c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
 439                 MIPS_CPU_4KTLB | MIPS_CPU_COUNTER | MIPS_CPU_DIVEC |
 440                 MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
 441         config1 = read_c0_config1();
 442         if (config1 & (1 << 3))
 443                 c->options |= MIPS_CPU_WATCH;
 444         if (config1 & (1 << 2))
 445                 c->options |= MIPS_CPU_MIPS16;
 446         if (config1 & (1 << 1))
 447                 c->options |= MIPS_CPU_EJTAG;
 448         if (config1 & 1) {
 449                 c->options |= MIPS_CPU_FPU;
 450                 c->options |= MIPS_CPU_32FPR;
 451         }
 452         c->scache.flags = MIPS_CACHE_NOT_PRESENT;
 453
 454         c->tlbsize = ((config1 >> 25) & 0x3f) + 1;
 455 }
 456
 457 static inline void cpu_probe_mips(struct cpuinfo_mips *c)
 458 {
 459         decode_config1(c);
 460         switch (c->processor_id & 0xff00) {
 461         case PRID_IMP_4KC:
 462                 c->cputype = CPU_4KC;
 463                 c->isa_level = MIPS_CPU_ISA_M32;
 464                 break;
 465         case PRID_IMP_4KEC:
 466                 c->cputype = CPU_4KEC;
 467                 c->isa_level = MIPS_CPU_ISA_M32;
 468                 break;
 469         case PRID_IMP_4KSC:
 470                 c->cputype = CPU_4KSC;
 471                 c->isa_level = MIPS_CPU_ISA_M32;
 472                 break;
 473         case PRID_IMP_5KC:
 474                 c->cputype = CPU_5KC;
 475                 c->isa_level = MIPS_CPU_ISA_M64;
 476                 break;
 477         case PRID_IMP_20KC:
 478                 c->cputype = CPU_20KC;
 479                 c->isa_level = MIPS_CPU_ISA_M64;
 480                 break;
 481         case PRID_IMP_24K:
 482                 c->cputype = CPU_24K;
 483                 c->isa_level = MIPS_CPU_ISA_M32;
 484                 break;
 485         case PRID_IMP_25KF:
 486                 c->cputype = CPU_25KF;
 487                 c->isa_level = MIPS_CPU_ISA_M64;
 488                 /* Probe for L2 cache */
 489                 c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
 490                 break;
 491         }
 492 }
 493
 494 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c)
 495 {
 496         decode_config1(c);
 497         switch (c->processor_id & 0xff00) {
 498         case PRID_IMP_AU1_REV1:
 499         case PRID_IMP_AU1_REV2:
 500                 switch ((c->processor_id >> 24) & 0xff) {
 501                 case 0:
 502                         c->cputype = CPU_AU1000;
 503                         break;
 504                 case 1:
 505                         c->cputype = CPU_AU1500;
 506                         break;
 507                 case 2:
 508                         c->cputype = CPU_AU1100;
 509                         break;
 510                 case 3:
 511                         c->cputype = CPU_AU1550;
 512                         break;
 513                 default:
 514                         panic("Unknown Au Core!");
 515                         break;
 516                 }
 517                 c->isa_level = MIPS_CPU_ISA_M32;
 518                 break;
 519         }
 520 }
 521
 522 static inline void cpu_probe_sibyte(struct cpuinfo_mips *c)
 523 {
 524         decode_config1(c);
 525         switch (c->processor_id & 0xff00) {
 526         case PRID_IMP_SB1:
 527                 c->cputype = CPU_SB1;
 528                 c->isa_level = MIPS_CPU_ISA_M64;
 529                 c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
 530                              MIPS_CPU_COUNTER | MIPS_CPU_DIVEC |
 531                              MIPS_CPU_MCHECK | MIPS_CPU_EJTAG |
 532                              MIPS_CPU_WATCH | MIPS_CPU_LLSC;
 533 #ifndef CONFIG_SB1_PASS_1_WORKAROUNDS
 534                 /* FPU in pass1 is known to have issues. */
 535                 c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
 536 #endif
 537                 break;
 538         }
 539 }
 540
 541 static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c)
 542 {
 543         decode_config1(c);
 544         switch (c->processor_id & 0xff00) {
 545         case PRID_IMP_SR71000:
 546                 c->cputype = CPU_SR71000;
 547                 c->isa_level = MIPS_CPU_ISA_M64;
 548                 c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
 549                              MIPS_CPU_4KTLB | MIPS_CPU_FPU |
 550                              MIPS_CPU_COUNTER | MIPS_CPU_MCHECK;
 551                 c->scache.ways = 8;
 552                 c->tlbsize = 64;
 553                 break;
 554         }
 555 }
 556
 557 __init void cpu_probe(void)
 558 {
 559         struct cpuinfo_mips *c = &current_cpu_data;
 560
 561         c->processor_id = PRID_IMP_UNKNOWN;
 562         c->fpu_id       = FPIR_IMP_NONE;
 563         c->cputype      = CPU_UNKNOWN;
 564
 565         c->processor_id = read_c0_prid();
 566         switch (c->processor_id & 0xff0000) {
 567         case PRID_COMP_LEGACY:
 568                 cpu_probe_legacy(c);
 569                 break;
 570         case PRID_COMP_MIPS:
 571                 cpu_probe_mips(c);
 572                 break;
 573         case PRID_COMP_ALCHEMY:
 574                 cpu_probe_alchemy(c);
 575                 break;
 576         case PRID_COMP_SIBYTE:
 577                 cpu_probe_sibyte(c);
 578                 break;
 579
 580         case PRID_COMP_SANDCRAFT:
 581                 cpu_probe_sandcraft(c);
 582                 break;
 583         default:
 584                 c->cputype = CPU_UNKNOWN;
 585         }
 586         if (c->options & MIPS_CPU_FPU)
 587                 c->fpu_id = cpu_get_fpu_id();
 588 }
 589
 590 __init void cpu_report(void)
 591 {
 592         struct cpuinfo_mips *c = &current_cpu_data;
 593
 594         printk("CPU revision is: %08x\n", c->processor_id);
 595         if (c->options & MIPS_CPU_FPU)
 596                 printk("FPU revision is: %08x\n", c->fpu_id);
 597 }