arch/microblaze/kernel/cpu/cache.c

   1 /*
   2  * Cache control for MicroBlaze cache memories
   3  *
   4  * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
   5  * Copyright (C) 2007-2009 PetaLogix
   6  * Copyright (C) 2007-2009 John Williams <john.williams@petalogix.com>
   7  *
   8  * This file is subject to the terms and conditions of the GNU General
   9  * Public License. See the file COPYING in the main directory of this
  10  * archive for more details.
  11  */
  12
  13 #include <asm/cacheflush.h>
  14 #include <linux/cache.h>
  15 #include <asm/cpuinfo.h>
  16 #include <asm/pvr.h>
  17
  18 static inline void __enable_icache_msr(void)
  19 {
  20         __asm__ __volatile__ ("  msrset r0, %0;"        \
  21                                 "nop;"                  \
  22                         : : "i" (MSR_ICE) : "memory");
  23 }
  24
  25 static inline void __disable_icache_msr(void)
  26 {
  27         __asm__ __volatile__ ("  msrclr r0, %0;"        \
  28                                 "nop;"                  \
  29                         : : "i" (MSR_ICE) : "memory");
  30 }
  31
  32 static inline void __enable_dcache_msr(void)
  33 {
  34         __asm__ __volatile__ ("  msrset r0, %0;"        \
  35                                 "nop;"                  \
  36                         : : "i" (MSR_DCE) : "memory");
  37 }
  38
  39 static inline void __disable_dcache_msr(void)
  40 {
  41         __asm__ __volatile__ ("  msrclr r0, %0;"        \
  42                                 "nop; "                 \
  43                         : : "i" (MSR_DCE) : "memory");
  44 }
  45
  46 static inline void __enable_icache_nomsr(void)
  47 {
  48         __asm__ __volatile__ ("  mfs    r12, rmsr;"     \
  49                                 "nop;"                  \
  50                                 "ori    r12, r12, %0;"  \
  51                                 "mts    rmsr, r12;"     \
  52                                 "nop;"                  \
  53                         : : "i" (MSR_ICE) : "memory", "r12");
  54 }
  55
  56 static inline void __disable_icache_nomsr(void)
  57 {
  58         __asm__ __volatile__ ("  mfs    r12, rmsr;"     \
  59                                 "nop;"                  \
  60                                 "andi   r12, r12, ~%0;" \
  61                                 "mts    rmsr, r12;"     \
  62                                 "nop;"                  \
  63                         : : "i" (MSR_ICE) : "memory", "r12");
  64 }
  65
  66 static inline void __enable_dcache_nomsr(void)
  67 {
  68         __asm__ __volatile__ ("  mfs    r12, rmsr;"     \
  69                                 "nop;"                  \
  70                                 "ori    r12, r12, %0;"  \
  71                                 "mts    rmsr, r12;"     \
  72                                 "nop;"                  \
  73                         : : "i" (MSR_DCE) : "memory", "r12");
  74 }
  75
  76 static inline void __disable_dcache_nomsr(void)
  77 {
  78         __asm__ __volatile__ ("  mfs    r12, rmsr;"     \
  79                                 "nop;"                  \
  80                                 "andi   r12, r12, ~%0;" \
  81                                 "mts    rmsr, r12;"     \
  82                                 "nop;"                  \
  83                         : : "i" (MSR_DCE) : "memory", "r12");
  84 }
  85
  86
  87 /* Helper macro for computing the limits of cache range loops
  88  *
  89  * End address can be unaligned which is OK for C implementation.
  90  * ASM implementation align it in ASM macros
  91  */
  92 #define CACHE_LOOP_LIMITS(start, end, cache_line_length, cache_size)    \
  93 do {                                                                    \
  94         int align = ~(cache_line_length - 1);                           \
  95         end = min(start + cache_size, end);                             \
  96         start &= align;                                                 \
  97 } while (0)
  98
  99 /*
 100  * Helper macro to loop over the specified cache_size/line_length and
 101  * execute 'op' on that cacheline
 102  */
 103 #define CACHE_ALL_LOOP(cache_size, line_length, op)                     \
 104 do {                                                                    \
 105         unsigned int len = cache_size - line_length;                    \
 106         int step = -line_length;                                        \
 107         WARN_ON(step >= 0);                                             \
 108                                                                         \
 109         __asm__ __volatile__ (" 1:      " #op " %0, r0;"                \
 110                                         "bgtid   %0, 1b;"               \
 111                                         "addk    %0, %0, %1;"           \
 112                                         : : "r" (len), "r" (step)       \
 113                                         : "memory");                    \
 114 } while (0)
 115
 116 /* Used for wdc.flush/clear which can use rB for offset which is not possible
 117  * to use for simple wdc or wic.
 118  *
 119  * start address is cache aligned
 120  * end address is not aligned, if end is aligned then I have to subtract
 121  * cacheline length because I can't flush/invalidate the next cacheline.
 122  * If is not, I align it because I will flush/invalidate whole line.
 123  */
 124 #define CACHE_RANGE_LOOP_2(start, end, line_length, op)                 \
 125 do {                                                                    \
 126         int step = -line_length;                                        \
 127         int align = ~(line_length - 1);                                 \
 128         int count;                                                      \
 129         end = ((end & align) == end) ? end - line_length : end & align; \
 130         count = end - start;                                            \
 131         WARN_ON(count < 0);                                             \
 132                                                                         \
 133         __asm__ __volatile__ (" 1:      " #op " %0, %1;"                \
 134                                         "bgtid  %1, 1b;"                \
 135                                         "addk   %1, %1, %2;"            \
 136                                         : : "r" (start), "r" (count),   \
 137                                         "r" (step) : "memory");         \
 138 } while (0)
 139
 140 /* It is used only first parameter for OP - for wic, wdc */
 141 #define CACHE_RANGE_LOOP_1(start, end, line_length, op)                 \
 142 do {                                                                    \
 143         unsigned int volatile temp = 0;                                         \
 144         unsigned int align = ~(line_length - 1);                                        \
 145         end = ((end & align) == end) ? end - line_length : end & align; \
 146         WARN_ON(end < start);                                   \
 147                                                                         \
 148         __asm__ __volatile__ (" 1:      " #op " %1, r0;"                \
 149                                         "cmpu   %0, %1, %2;"            \
 150                                         "bgtid  %0, 1b;"                \
 151                                         "addk   %1, %1, %3;"            \
 152                                 : : "r" (temp), "r" (start), "r" (end), \
 153                                         "r" (line_length) : "memory");  \
 154 } while (0)
 155
 156 #define ASM_LOOP
 157
 158 static void __flush_icache_range_msr_irq(unsigned long start, unsigned long end)
 159 {
 160         unsigned long flags;
 161 #ifndef ASM_LOOP
 162         int i;
 163 #endif
 164         pr_debug("%s: start 0x%x, end 0x%x\n", __func__,
 165                                 (unsigned int)start, (unsigned int) end);
 166
 167         CACHE_LOOP_LIMITS(start, end,
 168                         cpuinfo.icache_line_length, cpuinfo.icache_size);
 169
 170         local_irq_save(flags);
 171         __disable_icache_msr();
 172
 173 #ifdef ASM_LOOP
 174         CACHE_RANGE_LOOP_1(start, end, cpuinfo.icache_line_length, wic);
 175 #else
 176         for (i = start; i < end; i += cpuinfo.icache_line_length)
 177                 __asm__ __volatile__ ("wic      %0, r0;"        \
 178                                 : : "r" (i));
 179 #endif
 180         __enable_icache_msr();
 181         local_irq_restore(flags);
 182 }
 183
 184 static void __flush_icache_range_nomsr_irq(unsigned long start,
 185                                 unsigned long end)
 186 {
 187         unsigned long flags;
 188 #ifndef ASM_LOOP
 189         int i;
 190 #endif
 191         pr_debug("%s: start 0x%x, end 0x%x\n", __func__,
 192                                 (unsigned int)start, (unsigned int) end);
 193
 194         CACHE_LOOP_LIMITS(start, end,
 195                         cpuinfo.icache_line_length, cpuinfo.icache_size);
 196
 197         local_irq_save(flags);
 198         __disable_icache_nomsr();
 199
 200 #ifdef ASM_LOOP
 201         CACHE_RANGE_LOOP_1(start, end, cpuinfo.icache_line_length, wic);
 202 #else
 203         for (i = start; i < end; i += cpuinfo.icache_line_length)
 204                 __asm__ __volatile__ ("wic      %0, r0;"        \
 205                                 : : "r" (i));
 206 #endif
 207
 208         __enable_icache_nomsr();
 209         local_irq_restore(flags);
 210 }
 211
 212 static void __flush_icache_range_noirq(unsigned long start,
 213                                 unsigned long end)
 214 {
 215 #ifndef ASM_LOOP
 216         int i;
 217 #endif
 218         pr_debug("%s: start 0x%x, end 0x%x\n", __func__,
 219                                 (unsigned int)start, (unsigned int) end);
 220
 221         CACHE_LOOP_LIMITS(start, end,
 222                         cpuinfo.icache_line_length, cpuinfo.icache_size);
 223 #ifdef ASM_LOOP
 224         CACHE_RANGE_LOOP_1(start, end, cpuinfo.icache_line_length, wic);
 225 #else
 226         for (i = start; i < end; i += cpuinfo.icache_line_length)
 227                 __asm__ __volatile__ ("wic      %0, r0;"        \
 228                                 : : "r" (i));
 229 #endif
 230 }
 231
 232 static void __flush_icache_all_msr_irq(void)
 233 {
 234         unsigned long flags;
 235 #ifndef ASM_LOOP
 236         int i;
 237 #endif
 238         pr_debug("%s\n", __func__);
 239
 240         local_irq_save(flags);
 241         __disable_icache_msr();
 242 #ifdef ASM_LOOP
 243         CACHE_ALL_LOOP(cpuinfo.icache_size, cpuinfo.icache_line_length, wic);
 244 #else
 245         for (i = 0; i < cpuinfo.icache_size;
 246                  i += cpuinfo.icache_line_length)
 247                         __asm__ __volatile__ ("wic      %0, r0;" \
 248                                         : : "r" (i));
 249 #endif
 250         __enable_icache_msr();
 251         local_irq_restore(flags);
 252 }
 253
 254 static void __flush_icache_all_nomsr_irq(void)
 255 {
 256         unsigned long flags;
 257 #ifndef ASM_LOOP
 258         int i;
 259 #endif
 260         pr_debug("%s\n", __func__);
 261
 262         local_irq_save(flags);
 263         __disable_icache_nomsr();
 264 #ifdef ASM_LOOP
 265         CACHE_ALL_LOOP(cpuinfo.icache_size, cpuinfo.icache_line_length, wic);
 266 #else
 267         for (i = 0; i < cpuinfo.icache_size;
 268                  i += cpuinfo.icache_line_length)
 269                         __asm__ __volatile__ ("wic      %0, r0;" \
 270                                         : : "r" (i));
 271 #endif
 272         __enable_icache_nomsr();
 273         local_irq_restore(flags);
 274 }
 275
 276 static void __flush_icache_all_noirq(void)
 277 {
 278 #ifndef ASM_LOOP
 279         int i;
 280 #endif
 281         pr_debug("%s\n", __func__);
 282 #ifdef ASM_LOOP
 283         CACHE_ALL_LOOP(cpuinfo.icache_size, cpuinfo.icache_line_length, wic);
 284 #else
 285         for (i = 0; i < cpuinfo.icache_size;
 286                  i += cpuinfo.icache_line_length)
 287                         __asm__ __volatile__ ("wic      %0, r0;" \
 288                                         : : "r" (i));
 289 #endif
 290 }
 291
 292 static void __invalidate_dcache_all_msr_irq(void)
 293 {
 294         unsigned long flags;
 295 #ifndef ASM_LOOP
 296         int i;
 297 #endif
 298         pr_debug("%s\n", __func__);
 299
 300         local_irq_save(flags);
 301         __disable_dcache_msr();
 302 #ifdef ASM_LOOP
 303         CACHE_ALL_LOOP(cpuinfo.dcache_size, cpuinfo.dcache_line_length, wdc);
 304 #else
 305         for (i = 0; i < cpuinfo.dcache_size;
 306                  i += cpuinfo.dcache_line_length)
 307                         __asm__ __volatile__ ("wdc      %0, r0;" \
 308                                         : : "r" (i));
 309 #endif
 310         __enable_dcache_msr();
 311         local_irq_restore(flags);
 312 }
 313
 314 static void __invalidate_dcache_all_nomsr_irq(void)
 315 {
 316         unsigned long flags;
 317 #ifndef ASM_LOOP
 318         int i;
 319 #endif
 320         pr_debug("%s\n", __func__);
 321
 322         local_irq_save(flags);
 323         __disable_dcache_nomsr();
 324 #ifdef ASM_LOOP
 325         CACHE_ALL_LOOP(cpuinfo.dcache_size, cpuinfo.dcache_line_length, wdc);
 326 #else
 327         for (i = 0; i < cpuinfo.dcache_size;
 328                  i += cpuinfo.dcache_line_length)
 329                         __asm__ __volatile__ ("wdc      %0, r0;" \
 330                                         : : "r" (i));
 331 #endif
 332         __enable_dcache_nomsr();
 333         local_irq_restore(flags);
 334 }
 335
 336 static void __invalidate_dcache_all_noirq_wt(void)
 337 {
 338 #ifndef ASM_LOOP
 339         int i;
 340 #endif
 341         pr_debug("%s\n", __func__);
 342 #ifdef ASM_LOOP
 343         CACHE_ALL_LOOP(cpuinfo.dcache_size, cpuinfo.dcache_line_length, wdc);
 344 #else
 345         for (i = 0; i < cpuinfo.dcache_size;
 346                  i += cpuinfo.dcache_line_length)
 347                         __asm__ __volatile__ ("wdc      %0, r0;" \
 348                                         : : "r" (i));
 349 #endif
 350 }
 351
 352 /*
 353  * FIXME It is blindly invalidation as is expected
 354  * but can't be called on noMMU in microblaze_cache_init below
 355  *
 356  * MS: noMMU kernel won't boot if simple wdc is used
 357  * The reason should be that there are discared data which kernel needs
 358  */
 359 static void __invalidate_dcache_all_wb(void)
 360 {
 361 #ifndef ASM_LOOP
 362         int i;
 363 #endif
 364         pr_debug("%s\n", __func__);
 365 #ifdef ASM_LOOP
 366         CACHE_ALL_LOOP(cpuinfo.dcache_size, cpuinfo.dcache_line_length,
 367                                         wdc);
 368 #else
 369         for (i = 0; i < cpuinfo.dcache_size;
 370                  i += cpuinfo.dcache_line_length)
 371                         __asm__ __volatile__ ("wdc      %0, r0;" \
 372                                         : : "r" (i));
 373 #endif
 374 }
 375
 376 static void __invalidate_dcache_range_wb(unsigned long start,
 377                                                 unsigned long end)
 378 {
 379 #ifndef ASM_LOOP
 380         int i;
 381 #endif
 382         pr_debug("%s: start 0x%x, end 0x%x\n", __func__,
 383                                 (unsigned int)start, (unsigned int) end);
 384
 385         CACHE_LOOP_LIMITS(start, end,
 386                         cpuinfo.dcache_line_length, cpuinfo.dcache_size);
 387 #ifdef ASM_LOOP
 388         CACHE_RANGE_LOOP_2(start, end, cpuinfo.dcache_line_length, wdc.clear);
 389 #else
 390         for (i = start; i < end; i += cpuinfo.dcache_line_length)
 391                 __asm__ __volatile__ ("wdc.clear        %0, r0;"        \
 392                                 : : "r" (i));
 393 #endif
 394 }
 395
 396 static void __invalidate_dcache_range_nomsr_wt(unsigned long start,
 397                                                         unsigned long end)
 398 {
 399 #ifndef ASM_LOOP
 400         int i;
 401 #endif
 402         pr_debug("%s: start 0x%x, end 0x%x\n", __func__,
 403                                 (unsigned int)start, (unsigned int) end);
 404         CACHE_LOOP_LIMITS(start, end,
 405                         cpuinfo.dcache_line_length, cpuinfo.dcache_size);
 406
 407 #ifdef ASM_LOOP
 408         CACHE_RANGE_LOOP_1(start, end, cpuinfo.dcache_line_length, wdc);
 409 #else
 410         for (i = start; i < end; i += cpuinfo.dcache_line_length)
 411                 __asm__ __volatile__ ("wdc      %0, r0;"        \
 412                                 : : "r" (i));
 413 #endif
 414 }
 415
 416 static void __invalidate_dcache_range_msr_irq_wt(unsigned long start,
 417                                                         unsigned long end)
 418 {
 419         unsigned long flags;
 420 #ifndef ASM_LOOP
 421         int i;
 422 #endif
 423         pr_debug("%s: start 0x%x, end 0x%x\n", __func__,
 424                                 (unsigned int)start, (unsigned int) end);
 425         CACHE_LOOP_LIMITS(start, end,
 426                         cpuinfo.dcache_line_length, cpuinfo.dcache_size);
 427
 428         local_irq_save(flags);
 429         __disable_dcache_msr();
 430
 431 #ifdef ASM_LOOP
 432         CACHE_RANGE_LOOP_1(start, end, cpuinfo.dcache_line_length, wdc);
 433 #else
 434         for (i = start; i < end; i += cpuinfo.dcache_line_length)
 435                 __asm__ __volatile__ ("wdc      %0, r0;"        \
 436                                 : : "r" (i));
 437 #endif
 438
 439         __enable_dcache_msr();
 440         local_irq_restore(flags);
 441 }
 442
 443 static void __invalidate_dcache_range_nomsr_irq(unsigned long start,
 444                                                         unsigned long end)
 445 {
 446         unsigned long flags;
 447 #ifndef ASM_LOOP
 448         int i;
 449 #endif
 450         pr_debug("%s: start 0x%x, end 0x%x\n", __func__,
 451                                 (unsigned int)start, (unsigned int) end);
 452
 453         CACHE_LOOP_LIMITS(start, end,
 454                         cpuinfo.dcache_line_length, cpuinfo.dcache_size);
 455
 456         local_irq_save(flags);
 457         __disable_dcache_nomsr();
 458
 459 #ifdef ASM_LOOP
 460         CACHE_RANGE_LOOP_1(start, end, cpuinfo.dcache_line_length, wdc);
 461 #else
 462         for (i = start; i < end; i += cpuinfo.dcache_line_length)
 463                 __asm__ __volatile__ ("wdc      %0, r0;"        \
 464                                 : : "r" (i));
 465 #endif
 466
 467         __enable_dcache_nomsr();
 468         local_irq_restore(flags);
 469 }
 470
 471 static void __flush_dcache_all_wb(void)
 472 {
 473 #ifndef ASM_LOOP
 474         int i;
 475 #endif
 476         pr_debug("%s\n", __func__);
 477 #ifdef ASM_LOOP
 478         CACHE_ALL_LOOP(cpuinfo.dcache_size, cpuinfo.dcache_line_length,
 479                                 wdc.flush);
 480 #else
 481         for (i = 0; i < cpuinfo.dcache_size;
 482                  i += cpuinfo.dcache_line_length)
 483                         __asm__ __volatile__ ("wdc.flush        %0, r0;" \
 484                                         : : "r" (i));
 485 #endif
 486 }
 487
 488 static void __flush_dcache_range_wb(unsigned long start, unsigned long end)
 489 {
 490 #ifndef ASM_LOOP
 491         int i;
 492 #endif
 493         pr_debug("%s: start 0x%x, end 0x%x\n", __func__,
 494                                 (unsigned int)start, (unsigned int) end);
 495
 496         CACHE_LOOP_LIMITS(start, end,
 497                         cpuinfo.dcache_line_length, cpuinfo.dcache_size);
 498 #ifdef ASM_LOOP
 499         CACHE_RANGE_LOOP_2(start, end, cpuinfo.dcache_line_length, wdc.flush);
 500 #else
 501         for (i = start; i < end; i += cpuinfo.dcache_line_length)
 502                 __asm__ __volatile__ ("wdc.flush        %0, r0;"        \
 503                                 : : "r" (i));
 504 #endif
 505 }
 506
 507 /* struct for wb caches and for wt caches */
 508 struct scache *mbc;
 509
 510 /* new wb cache model */
 511 static const struct scache wb_msr = {
 512         .ie = __enable_icache_msr,
 513         .id = __disable_icache_msr,
 514         .ifl = __flush_icache_all_noirq,
 515         .iflr = __flush_icache_range_noirq,
 516         .iin = __flush_icache_all_noirq,
 517         .iinr = __flush_icache_range_noirq,
 518         .de = __enable_dcache_msr,
 519         .dd = __disable_dcache_msr,
 520         .dfl = __flush_dcache_all_wb,
 521         .dflr = __flush_dcache_range_wb,
 522         .din = __invalidate_dcache_all_wb,
 523         .dinr = __invalidate_dcache_range_wb,
 524 };
 525
 526 /* There is only difference in ie, id, de, dd functions */
 527 static const struct scache wb_nomsr = {
 528         .ie = __enable_icache_nomsr,
 529         .id = __disable_icache_nomsr,
 530         .ifl = __flush_icache_all_noirq,
 531         .iflr = __flush_icache_range_noirq,
 532         .iin = __flush_icache_all_noirq,
 533         .iinr = __flush_icache_range_noirq,
 534         .de = __enable_dcache_nomsr,
 535         .dd = __disable_dcache_nomsr,
 536         .dfl = __flush_dcache_all_wb,
 537         .dflr = __flush_dcache_range_wb,
 538         .din = __invalidate_dcache_all_wb,
 539         .dinr = __invalidate_dcache_range_wb,
 540 };
 541
 542 /* Old wt cache model with disabling irq and turn off cache */
 543 static const struct scache wt_msr = {
 544         .ie = __enable_icache_msr,
 545         .id = __disable_icache_msr,
 546         .ifl = __flush_icache_all_msr_irq,
 547         .iflr = __flush_icache_range_msr_irq,
 548         .iin = __flush_icache_all_msr_irq,
 549         .iinr = __flush_icache_range_msr_irq,
 550         .de = __enable_dcache_msr,
 551         .dd = __disable_dcache_msr,
 552         .dfl = __invalidate_dcache_all_msr_irq,
 553         .dflr = __invalidate_dcache_range_msr_irq_wt,
 554         .din = __invalidate_dcache_all_msr_irq,
 555         .dinr = __invalidate_dcache_range_msr_irq_wt,
 556 };
 557
 558 static const struct scache wt_nomsr = {
 559         .ie = __enable_icache_nomsr,
 560         .id = __disable_icache_nomsr,
 561         .ifl = __flush_icache_all_nomsr_irq,
 562         .iflr = __flush_icache_range_nomsr_irq,
 563         .iin = __flush_icache_all_nomsr_irq,
 564         .iinr = __flush_icache_range_nomsr_irq,
 565         .de = __enable_dcache_nomsr,
 566         .dd = __disable_dcache_nomsr,
 567         .dfl = __invalidate_dcache_all_nomsr_irq,
 568         .dflr = __invalidate_dcache_range_nomsr_irq,
 569         .din = __invalidate_dcache_all_nomsr_irq,
 570         .dinr = __invalidate_dcache_range_nomsr_irq,
 571 };
 572
 573 /* New wt cache model for newer Microblaze versions */
 574 static const struct scache wt_msr_noirq = {
 575         .ie = __enable_icache_msr,
 576         .id = __disable_icache_msr,
 577         .ifl = __flush_icache_all_noirq,
 578         .iflr = __flush_icache_range_noirq,
 579         .iin = __flush_icache_all_noirq,
 580         .iinr = __flush_icache_range_noirq,
 581         .de = __enable_dcache_msr,
 582         .dd = __disable_dcache_msr,
 583         .dfl = __invalidate_dcache_all_noirq_wt,
 584         .dflr = __invalidate_dcache_range_nomsr_wt,
 585         .din = __invalidate_dcache_all_noirq_wt,
 586         .dinr = __invalidate_dcache_range_nomsr_wt,
 587 };
 588
 589 static const struct scache wt_nomsr_noirq = {
 590         .ie = __enable_icache_nomsr,
 591         .id = __disable_icache_nomsr,
 592         .ifl = __flush_icache_all_noirq,
 593         .iflr = __flush_icache_range_noirq,
 594         .iin = __flush_icache_all_noirq,
 595         .iinr = __flush_icache_range_noirq,
 596         .de = __enable_dcache_nomsr,
 597         .dd = __disable_dcache_nomsr,
 598         .dfl = __invalidate_dcache_all_noirq_wt,
 599         .dflr = __invalidate_dcache_range_nomsr_wt,
 600         .din = __invalidate_dcache_all_noirq_wt,
 601         .dinr = __invalidate_dcache_range_nomsr_wt,
 602 };
 603
 604 /* CPU version code for 7.20.c - see arch/microblaze/kernel/cpu/cpuinfo.c */
 605 #define CPUVER_7_20_A   0x0c
 606 #define CPUVER_7_20_D   0x0f
 607
 608 void microblaze_cache_init(void)
 609 {
 610         if (cpuinfo.use_instr & PVR2_USE_MSR_INSTR) {
 611                 if (cpuinfo.dcache_wb) {
 612                         pr_info("wb_msr\n");
 613                         mbc = (struct scache *)&wb_msr;
 614                         if (cpuinfo.ver_code <= CPUVER_7_20_D) {
 615                                 /* MS: problem with signal handling - hw bug */
 616                                 pr_info("WB won't work properly\n");
 617                         }
 618                 } else {
 619                         if (cpuinfo.ver_code >= CPUVER_7_20_A) {
 620                                 pr_info("wt_msr_noirq\n");
 621                                 mbc = (struct scache *)&wt_msr_noirq;
 622                         } else {
 623                                 pr_info("wt_msr\n");
 624                                 mbc = (struct scache *)&wt_msr;
 625                         }
 626                 }
 627         } else {
 628                 if (cpuinfo.dcache_wb) {
 629                         pr_info("wb_nomsr\n");
 630                         mbc = (struct scache *)&wb_nomsr;
 631                         if (cpuinfo.ver_code <= CPUVER_7_20_D) {
 632                                 /* MS: problem with signal handling - hw bug */
 633                                 pr_info("WB won't work properly\n");
 634                         }
 635                 } else {
 636                         if (cpuinfo.ver_code >= CPUVER_7_20_A) {
 637                                 pr_info("wt_nomsr_noirq\n");
 638                                 mbc = (struct scache *)&wt_nomsr_noirq;
 639                         } else {
 640                                 pr_info("wt_nomsr\n");
 641                                 mbc = (struct scache *)&wt_nomsr;
 642                         }
 643                 }
 644         }
 645         /*
 646          * FIXME Invalidation is done in U-BOOT
 647          * WT cache: Data is already written to main memory
 648          * WB cache: Discard data on noMMU which caused that kernel doesn't boot
 649          */
 650         /* invalidate_dcache(); */
 651         enable_dcache();
 652
 653         invalidate_icache();
 654         enable_icache();
 655 }