arch/arm/cpu/armv8/cache_v8.c

   1 /*
   2  * (C) Copyright 2013
   3  * David Feng <fenghua@phytium.com.cn>
   4  *
   5  * (C) Copyright 2016
   6  * Alexander Graf <agraf@suse.de>
   7  *
   8  * SPDX-License-Identifier:     GPL-2.0+
   9  */
  10
  11 #include <common.h>
  12 #include <asm/system.h>
  13 #include <asm/armv8/mmu.h>
  14
  15 DECLARE_GLOBAL_DATA_PTR;
  16
  17 #ifndef CONFIG_SYS_DCACHE_OFF
  18
  19 /*
  20  *  With 4k page granule, a virtual address is split into 4 lookup parts
  21  *  spanning 9 bits each:
  22  *
  23  *    _______________________________________________
  24  *   |       |       |       |       |       |       |
  25  *   |   0   |  Lv0  |  Lv1  |  Lv2  |  Lv3  |  off  |
  26  *   |_______|_______|_______|_______|_______|_______|
  27  *     63-48   47-39   38-30   29-21   20-12   11-00
  28  *
  29  *             mask        page size
  30  *
  31  *    Lv0: FF8000000000       --
  32  *    Lv1:   7FC0000000       1G
  33  *    Lv2:     3FE00000       2M
  34  *    Lv3:       1FF000       4K
  35  *    off:          FFF
  36  */
  37
  38 u64 get_tcr(int el, u64 *pips, u64 *pva_bits)
  39 {
  40         u64 max_addr = 0;
  41         u64 ips, va_bits;
  42         u64 tcr;
  43         int i;
  44
  45         /* Find the largest address we need to support */
  46         for (i = 0; mem_map[i].size || mem_map[i].attrs; i++)
  47                 max_addr = max(max_addr, mem_map[i].virt + mem_map[i].size);
  48
  49         /* Calculate the maximum physical (and thus virtual) address */
  50         if (max_addr > (1ULL << 44)) {
  51                 ips = 5;
  52                 va_bits = 48;
  53         } else  if (max_addr > (1ULL << 42)) {
  54                 ips = 4;
  55                 va_bits = 44;
  56         } else  if (max_addr > (1ULL << 40)) {
  57                 ips = 3;
  58                 va_bits = 42;
  59         } else  if (max_addr > (1ULL << 36)) {
  60                 ips = 2;
  61                 va_bits = 40;
  62         } else  if (max_addr > (1ULL << 32)) {
  63                 ips = 1;
  64                 va_bits = 36;
  65         } else {
  66                 ips = 0;
  67                 va_bits = 32;
  68         }
  69
  70         if (el == 1) {
  71                 tcr = TCR_EL1_RSVD | (ips << 32) | TCR_EPD1_DISABLE;
  72         } else if (el == 2) {
  73                 tcr = TCR_EL2_RSVD | (ips << 16);
  74         } else {
  75                 tcr = TCR_EL3_RSVD | (ips << 16);
  76         }
  77
  78         /* PTWs cacheable, inner/outer WBWA and inner shareable */
  79         tcr |= TCR_TG0_4K | TCR_SHARED_INNER | TCR_ORGN_WBWA | TCR_IRGN_WBWA;
  80         tcr |= TCR_T0SZ(va_bits);
  81
  82         if (pips)
  83                 *pips = ips;
  84         if (pva_bits)
  85                 *pva_bits = va_bits;
  86
  87         return tcr;
  88 }
  89
  90 #define MAX_PTE_ENTRIES 512
  91
  92 static int pte_type(u64 *pte)
  93 {
  94         return *pte & PTE_TYPE_MASK;
  95 }
  96
  97 /* Returns the LSB number for a PTE on level <level> */
  98 static int level2shift(int level)
  99 {
 100         /* Page is 12 bits wide, every level translates 9 bits */
 101         return (12 + 9 * (3 - level));
 102 }
 103
 104 static u64 *find_pte(u64 addr, int level)
 105 {
 106         int start_level = 0;
 107         u64 *pte;
 108         u64 idx;
 109         u64 va_bits;
 110         int i;
 111
 112         debug("addr=%llx level=%d\n", addr, level);
 113
 114         get_tcr(0, NULL, &va_bits);
 115         if (va_bits < 39)
 116                 start_level = 1;
 117
 118         if (level < start_level)
 119                 return NULL;
 120
 121         /* Walk through all page table levels to find our PTE */
 122         pte = (u64*)gd->arch.tlb_addr;
 123         for (i = start_level; i < 4; i++) {
 124                 idx = (addr >> level2shift(i)) & 0x1FF;
 125                 pte += idx;
 126                 debug("idx=%llx PTE %p at level %d: %llx\n", idx, pte, i, *pte);
 127
 128                 /* Found it */
 129                 if (i == level)
 130                         return pte;
 131                 /* PTE is no table (either invalid or block), can't traverse */
 132                 if (pte_type(pte) != PTE_TYPE_TABLE)
 133                         return NULL;
 134                 /* Off to the next level */
 135                 pte = (u64*)(*pte & 0x0000fffffffff000ULL);
 136         }
 137
 138         /* Should never reach here */
 139         return NULL;
 140 }
 141
 142 /* Returns and creates a new full table (512 entries) */
 143 static u64 *create_table(void)
 144 {
 145         u64 *new_table = (u64*)gd->arch.tlb_fillptr;
 146         u64 pt_len = MAX_PTE_ENTRIES * sizeof(u64);
 147
 148         /* Allocate MAX_PTE_ENTRIES pte entries */
 149         gd->arch.tlb_fillptr += pt_len;
 150
 151         if (gd->arch.tlb_fillptr - gd->arch.tlb_addr > gd->arch.tlb_size)
 152                 panic("Insufficient RAM for page table: 0x%lx > 0x%lx. "
 153                       "Please increase the size in get_page_table_size()",
 154                         gd->arch.tlb_fillptr - gd->arch.tlb_addr,
 155                         gd->arch.tlb_size);
 156
 157         /* Mark all entries as invalid */
 158         memset(new_table, 0, pt_len);
 159
 160         return new_table;
 161 }
 162
 163 static void set_pte_table(u64 *pte, u64 *table)
 164 {
 165         /* Point *pte to the new table */
 166         debug("Setting %p to addr=%p\n", pte, table);
 167         *pte = PTE_TYPE_TABLE | (ulong)table;
 168 }
 169
 170 /* Splits a block PTE into table with subpages spanning the old block */
 171 static void split_block(u64 *pte, int level)
 172 {
 173         u64 old_pte = *pte;
 174         u64 *new_table;
 175         u64 i = 0;
 176         /* level describes the parent level, we need the child ones */
 177         int levelshift = level2shift(level + 1);
 178
 179         if (pte_type(pte) != PTE_TYPE_BLOCK)
 180                 panic("PTE %p (%llx) is not a block. Some driver code wants to "
 181                       "modify dcache settings for an range not covered in "
 182                       "mem_map.", pte, old_pte);
 183
 184         new_table = create_table();
 185         debug("Splitting pte %p (%llx) into %p\n", pte, old_pte, new_table);
 186
 187         for (i = 0; i < MAX_PTE_ENTRIES; i++) {
 188                 new_table[i] = old_pte | (i << levelshift);
 189
 190                 /* Level 3 block PTEs have the table type */
 191                 if ((level + 1) == 3)
 192                         new_table[i] |= PTE_TYPE_TABLE;
 193
 194                 debug("Setting new_table[%lld] = %llx\n", i, new_table[i]);
 195         }
 196
 197         /* Set the new table into effect */
 198         set_pte_table(pte, new_table);
 199 }
 200
 201 /* Add one mm_region map entry to the page tables */
 202 static void add_map(struct mm_region *map)
 203 {
 204         u64 *pte;
 205         u64 virt = map->virt;
 206         u64 phys = map->phys;
 207         u64 size = map->size;
 208         u64 attrs = map->attrs | PTE_TYPE_BLOCK | PTE_BLOCK_AF;
 209         u64 blocksize;
 210         int level;
 211         u64 *new_table;
 212
 213         while (size) {
 214                 pte = find_pte(virt, 0);
 215                 if (pte && (pte_type(pte) == PTE_TYPE_FAULT)) {
 216                         debug("Creating table for virt 0x%llx\n", virt);
 217                         new_table = create_table();
 218                         set_pte_table(pte, new_table);
 219                 }
 220
 221                 for (level = 1; level < 4; level++) {
 222                         pte = find_pte(virt, level);
 223                         if (!pte)
 224                                 panic("pte not found\n");
 225
 226                         blocksize = 1ULL << level2shift(level);
 227                         debug("Checking if pte fits for virt=%llx size=%llx blocksize=%llx\n",
 228                               virt, size, blocksize);
 229                         if (size >= blocksize && !(virt & (blocksize - 1))) {
 230                                 /* Page fits, create block PTE */
 231                                 debug("Setting PTE %p to block virt=%llx\n",
 232                                       pte, virt);
 233                                 if (level == 3)
 234                                         *pte = phys | attrs | PTE_TYPE_PAGE;
 235                                 else
 236                                         *pte = phys | attrs;
 237                                 virt += blocksize;
 238                                 phys += blocksize;
 239                                 size -= blocksize;
 240                                 break;
 241                         } else if (pte_type(pte) == PTE_TYPE_FAULT) {
 242                                 /* Page doesn't fit, create subpages */
 243                                 debug("Creating subtable for virt 0x%llx blksize=%llx\n",
 244                                       virt, blocksize);
 245                                 new_table = create_table();
 246                                 set_pte_table(pte, new_table);
 247                         } else if (pte_type(pte) == PTE_TYPE_BLOCK) {
 248                                 debug("Split block into subtable for virt 0x%llx blksize=0x%llx\n",
 249                                       virt, blocksize);
 250                                 split_block(pte, level);
 251                         }
 252                 }
 253         }
 254 }
 255
 256 enum pte_type {
 257         PTE_INVAL,
 258         PTE_BLOCK,
 259         PTE_LEVEL,
 260 };
 261
 262 /*
 263  * This is a recursively called function to count the number of
 264  * page tables we need to cover a particular PTE range. If you
 265  * call this with level = -1 you basically get the full 48 bit
 266  * coverage.
 267  */
 268 static int count_required_pts(u64 addr, int level, u64 maxaddr)
 269 {
 270         int levelshift = level2shift(level);
 271         u64 levelsize = 1ULL << levelshift;
 272         u64 levelmask = levelsize - 1;
 273         u64 levelend = addr + levelsize;
 274         int r = 0;
 275         int i;
 276         enum pte_type pte_type = PTE_INVAL;
 277
 278         for (i = 0; mem_map[i].size || mem_map[i].attrs; i++) {
 279                 struct mm_region *map = &mem_map[i];
 280                 u64 start = map->virt;
 281                 u64 end = start + map->size;
 282
 283                 /* Check if the PTE would overlap with the map */
 284                 if (max(addr, start) <= min(levelend, end)) {
 285                         start = max(addr, start);
 286                         end = min(levelend, end);
 287
 288                         /* We need a sub-pt for this level */
 289                         if ((start & levelmask) || (end & levelmask)) {
 290                                 pte_type = PTE_LEVEL;
 291                                 break;
 292                         }
 293
 294                         /* Lv0 can not do block PTEs, so do levels here too */
 295                         if (level <= 0) {
 296                                 pte_type = PTE_LEVEL;
 297                                 break;
 298                         }
 299
 300                         /* PTE is active, but fits into a block */
 301                         pte_type = PTE_BLOCK;
 302                 }
 303         }
 304
 305         /*
 306          * Block PTEs at this level are already covered by the parent page
 307          * table, so we only need to count sub page tables.
 308          */
 309         if (pte_type == PTE_LEVEL) {
 310                 int sublevel = level + 1;
 311                 u64 sublevelsize = 1ULL << level2shift(sublevel);
 312
 313                 /* Account for the new sub page table ... */
 314                 r = 1;
 315
 316                 /* ... and for all child page tables that one might have */
 317                 for (i = 0; i < MAX_PTE_ENTRIES; i++) {
 318                         r += count_required_pts(addr, sublevel, maxaddr);
 319                         addr += sublevelsize;
 320
 321                         if (addr >= maxaddr) {
 322                                 /*
 323                                  * We reached the end of address space, no need
 324                                  * to look any further.
 325                                  */
 326                                 break;
 327                         }
 328                 }
 329         }
 330
 331         return r;
 332 }
 333
 334 /* Returns the estimated required size of all page tables */
 335 __weak u64 get_page_table_size(void)
 336 {
 337         u64 one_pt = MAX_PTE_ENTRIES * sizeof(u64);
 338         u64 size = 0;
 339         u64 va_bits;
 340         int start_level = 0;
 341
 342         get_tcr(0, NULL, &va_bits);
 343         if (va_bits < 39)
 344                 start_level = 1;
 345
 346         /* Account for all page tables we would need to cover our memory map */
 347         size = one_pt * count_required_pts(0, start_level - 1, 1ULL << va_bits);
 348
 349         /*
 350          * We need to duplicate our page table once to have an emergency pt to
 351          * resort to when splitting page tables later on
 352          */
 353         size *= 2;
 354
 355         /*
 356          * We may need to split page tables later on if dcache settings change,
 357          * so reserve up to 4 (random pick) page tables for that.
 358          */
 359         size += one_pt * 4;
 360
 361         return size;
 362 }
 363
 364 void setup_pgtables(void)
 365 {
 366         int i;
 367
 368         if (!gd->arch.tlb_fillptr || !gd->arch.tlb_addr)
 369                 panic("Page table pointer not setup.");
 370
 371         /*
 372          * Allocate the first level we're on with invalidate entries.
 373          * If the starting level is 0 (va_bits >= 39), then this is our
 374          * Lv0 page table, otherwise it's the entry Lv1 page table.
 375          */
 376         create_table();
 377
 378         /* Now add all MMU table entries one after another to the table */
 379         for (i = 0; mem_map[i].size || mem_map[i].attrs; i++)
 380                 add_map(&mem_map[i]);
 381 }
 382
 383 static void setup_all_pgtables(void)
 384 {
 385         u64 tlb_addr = gd->arch.tlb_addr;
 386         u64 tlb_size = gd->arch.tlb_size;
 387
 388         /* Reset the fill ptr */
 389         gd->arch.tlb_fillptr = tlb_addr;
 390
 391         /* Create normal system page tables */
 392         setup_pgtables();
 393
 394         /* Create emergency page tables */
 395         gd->arch.tlb_size -= (uintptr_t)gd->arch.tlb_fillptr -
 396                              (uintptr_t)gd->arch.tlb_addr;
 397         gd->arch.tlb_addr = gd->arch.tlb_fillptr;
 398         setup_pgtables();
 399         gd->arch.tlb_emerg = gd->arch.tlb_addr;
 400         gd->arch.tlb_addr = tlb_addr;
 401         gd->arch.tlb_size = tlb_size;
 402 }
 403
 404 /* to activate the MMU we need to set up virtual memory */
 405 __weak void mmu_setup(void)
 406 {
 407         int el;
 408
 409         /* Set up page tables only once */
 410         if (!gd->arch.tlb_fillptr)
 411                 setup_all_pgtables();
 412
 413         el = current_el();
 414         set_ttbr_tcr_mair(el, gd->arch.tlb_addr, get_tcr(el, NULL, NULL),
 415                           MEMORY_ATTRIBUTES);
 416
 417         /* enable the mmu */
 418         set_sctlr(get_sctlr() | CR_M);
 419 }
 420
 421 /*
 422  * Performs a invalidation of the entire data cache at all levels
 423  */
 424 void invalidate_dcache_all(void)
 425 {
 426         __asm_invalidate_dcache_all();
 427         __asm_invalidate_l3_dcache();
 428 }
 429
 430 /*
 431  * Performs a clean & invalidation of the entire data cache at all levels.
 432  * This function needs to be inline to avoid using stack.
 433  * __asm_flush_l3_dcache return status of timeout
 434  */
 435 inline void flush_dcache_all(void)
 436 {
 437         int ret;
 438
 439         __asm_flush_dcache_all();
 440         ret = __asm_flush_l3_dcache();
 441         if (ret)
 442                 debug("flushing dcache returns 0x%x\n", ret);
 443         else
 444                 debug("flushing dcache successfully.\n");
 445 }
 446
 447 /*
 448  * Invalidates range in all levels of D-cache/unified cache
 449  */
 450 void invalidate_dcache_range(unsigned long start, unsigned long stop)
 451 {
 452         __asm_invalidate_dcache_range(start, stop);
 453 }
 454
 455 /*
 456  * Flush range(clean & invalidate) from all levels of D-cache/unified cache
 457  */
 458 void flush_dcache_range(unsigned long start, unsigned long stop)
 459 {
 460         __asm_flush_dcache_range(start, stop);
 461 }
 462
 463 void dcache_enable(void)
 464 {
 465         /* The data cache is not active unless the mmu is enabled */
 466         if (!(get_sctlr() & CR_M)) {
 467                 invalidate_dcache_all();
 468                 __asm_invalidate_tlb_all();
 469                 mmu_setup();
 470         }
 471
 472         set_sctlr(get_sctlr() | CR_C);
 473 }
 474
 475 void dcache_disable(void)
 476 {
 477         uint32_t sctlr;
 478
 479         sctlr = get_sctlr();
 480
 481         /* if cache isn't enabled no need to disable */
 482         if (!(sctlr & CR_C))
 483                 return;
 484
 485         set_sctlr(sctlr & ~(CR_C|CR_M));
 486
 487         flush_dcache_all();
 488         __asm_invalidate_tlb_all();
 489 }
 490
 491 int dcache_status(void)
 492 {
 493         return (get_sctlr() & CR_C) != 0;
 494 }
 495
 496 u64 *__weak arch_get_page_table(void) {
 497         puts("No page table offset defined\n");
 498
 499         return NULL;
 500 }
 501
 502 static bool is_aligned(u64 addr, u64 size, u64 align)
 503 {
 504         return !(addr & (align - 1)) && !(size & (align - 1));
 505 }
 506
 507 /* Use flag to indicate if attrs has more than d-cache attributes */
 508 static u64 set_one_region(u64 start, u64 size, u64 attrs, bool flag, int level)
 509 {
 510         int levelshift = level2shift(level);
 511         u64 levelsize = 1ULL << levelshift;
 512         u64 *pte = find_pte(start, level);
 513
 514         /* Can we can just modify the current level block PTE? */
 515         if (is_aligned(start, size, levelsize)) {
 516                 if (flag) {
 517                         *pte &= ~PMD_ATTRMASK;
 518                         *pte |= attrs & PMD_ATTRMASK;
 519                 } else {
 520                         *pte &= ~PMD_ATTRINDX_MASK;
 521                         *pte |= attrs & PMD_ATTRINDX_MASK;
 522                 }
 523                 debug("Set attrs=%llx pte=%p level=%d\n", attrs, pte, level);
 524
 525                 return levelsize;
 526         }
 527
 528         /* Unaligned or doesn't fit, maybe split block into table */
 529         debug("addr=%llx level=%d pte=%p (%llx)\n", start, level, pte, *pte);
 530
 531         /* Maybe we need to split the block into a table */
 532         if (pte_type(pte) == PTE_TYPE_BLOCK)
 533                 split_block(pte, level);
 534
 535         /* And then double-check it became a table or already is one */
 536         if (pte_type(pte) != PTE_TYPE_TABLE)
 537                 panic("PTE %p (%llx) for addr=%llx should be a table",
 538                       pte, *pte, start);
 539
 540         /* Roll on to the next page table level */
 541         return 0;
 542 }
 543
 544 void mmu_set_region_dcache_behaviour(phys_addr_t start, size_t size,
 545                                      enum dcache_option option)
 546 {
 547         u64 attrs = PMD_ATTRINDX(option);
 548         u64 real_start = start;
 549         u64 real_size = size;
 550
 551         debug("start=%lx size=%lx\n", (ulong)start, (ulong)size);
 552
 553         if (!gd->arch.tlb_emerg)
 554                 panic("Emergency page table not setup.");
 555
 556         /*
 557          * We can not modify page tables that we're currently running on,
 558          * so we first need to switch to the "emergency" page tables where
 559          * we can safely modify our primary page tables and then switch back
 560          */
 561         __asm_switch_ttbr(gd->arch.tlb_emerg);
 562
 563         /*
 564          * Loop through the address range until we find a page granule that fits
 565          * our alignment constraints, then set it to the new cache attributes
 566          */
 567         while (size > 0) {
 568                 int level;
 569                 u64 r;
 570
 571                 for (level = 1; level < 4; level++) {
 572                         /* Set d-cache attributes only */
 573                         r = set_one_region(start, size, attrs, false, level);
 574                         if (r) {
 575                                 /* PTE successfully replaced */
 576                                 size -= r;
 577                                 start += r;
 578                                 break;
 579                         }
 580                 }
 581
 582         }
 583
 584         /* We're done modifying page tables, switch back to our primary ones */
 585         __asm_switch_ttbr(gd->arch.tlb_addr);
 586
 587         /*
 588          * Make sure there's nothing stale in dcache for a region that might
 589          * have caches off now
 590          */
 591         flush_dcache_range(real_start, real_start + real_size);
 592 }
 593
 594 /*
 595  * Modify MMU table for a region with updated PXN/UXN/Memory type/valid bits.
 596  * The procecess is break-before-make. The target region will be marked as
 597  * invalid during the process of changing.
 598  */
 599 void mmu_change_region_attr(phys_addr_t addr, size_t siz, u64 attrs)
 600 {
 601         int level;
 602         u64 r, size, start;
 603
 604         start = addr;
 605         size = siz;
 606         /*
 607          * Loop through the address range until we find a page granule that fits
 608          * our alignment constraints, then set it to "invalid".
 609          */
 610         while (size > 0) {
 611                 for (level = 1; level < 4; level++) {
 612                         /* Set PTE to fault */
 613                         r = set_one_region(start, size, PTE_TYPE_FAULT, true,
 614                                            level);
 615                         if (r) {
 616                                 /* PTE successfully invalidated */
 617                                 size -= r;
 618                                 start += r;
 619                                 break;
 620                         }
 621                 }
 622         }
 623
 624         flush_dcache_range(gd->arch.tlb_addr,
 625                            gd->arch.tlb_addr + gd->arch.tlb_size);
 626         __asm_invalidate_tlb_all();
 627
 628         /*
 629          * Loop through the address range until we find a page granule that fits
 630          * our alignment constraints, then set it to the new cache attributes
 631          */
 632         start = addr;
 633         size = siz;
 634         while (size > 0) {
 635                 for (level = 1; level < 4; level++) {
 636                         /* Set PTE to new attributes */
 637                         r = set_one_region(start, size, attrs, true, level);
 638                         if (r) {
 639                                 /* PTE successfully updated */
 640                                 size -= r;
 641                                 start += r;
 642                                 break;
 643                         }
 644                 }
 645         }
 646         flush_dcache_range(gd->arch.tlb_addr,
 647                            gd->arch.tlb_addr + gd->arch.tlb_size);
 648         __asm_invalidate_tlb_all();
 649 }
 650
 651 #else   /* CONFIG_SYS_DCACHE_OFF */
 652
 653 /*
 654  * For SPL builds, we may want to not have dcache enabled. Any real U-Boot
 655  * running however really wants to have dcache and the MMU active. Check that
 656  * everything is sane and give the developer a hint if it isn't.
 657  */
 658 #ifndef CONFIG_SPL_BUILD
 659 #error Please describe your MMU layout in CONFIG_SYS_MEM_MAP and enable dcache.
 660 #endif
 661
 662 void invalidate_dcache_all(void)
 663 {
 664 }
 665
 666 void flush_dcache_all(void)
 667 {
 668 }
 669
 670 void dcache_enable(void)
 671 {
 672 }
 673
 674 void dcache_disable(void)
 675 {
 676 }
 677
 678 int dcache_status(void)
 679 {
 680         return 0;
 681 }
 682
 683 void mmu_set_region_dcache_behaviour(phys_addr_t start, size_t size,
 684                                      enum dcache_option option)
 685 {
 686 }
 687
 688 #endif  /* CONFIG_SYS_DCACHE_OFF */
 689
 690 #ifndef CONFIG_SYS_ICACHE_OFF
 691
 692 void icache_enable(void)
 693 {
 694         invalidate_icache_all();
 695         set_sctlr(get_sctlr() | CR_I);
 696 }
 697
 698 void icache_disable(void)
 699 {
 700         set_sctlr(get_sctlr() & ~CR_I);
 701 }
 702
 703 int icache_status(void)
 704 {
 705         return (get_sctlr() & CR_I) != 0;
 706 }
 707
 708 void invalidate_icache_all(void)
 709 {
 710         __asm_invalidate_icache_all();
 711         __asm_invalidate_l3_icache();
 712 }
 713
 714 #else   /* CONFIG_SYS_ICACHE_OFF */
 715
 716 void icache_enable(void)
 717 {
 718 }
 719
 720 void icache_disable(void)
 721 {
 722 }
 723
 724 int icache_status(void)
 725 {
 726         return 0;
 727 }
 728
 729 void invalidate_icache_all(void)
 730 {
 731 }
 732
 733 #endif  /* CONFIG_SYS_ICACHE_OFF */
 734
 735 /*
 736  * Enable dCache & iCache, whether cache is actually enabled
 737  * depend on CONFIG_SYS_DCACHE_OFF and CONFIG_SYS_ICACHE_OFF
 738  */
 739 void __weak enable_caches(void)
 740 {
 741         icache_enable();
 742         dcache_enable();
 743 }