mm/memblock.c

   1 /*
   2  * Procedures for maintaining information about logical memory blocks.
   3  *
   4  * Peter Bergner, IBM Corp.     June 2001.
   5  * Copyright (C) 2001 Peter Bergner.
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License
   9  *      as published by the Free Software Foundation; either version
  10  *      2 of the License, or (at your option) any later version.
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/init.h>
  15 #include <linux/bitops.h>
  16 #include <linux/poison.h>
  17 #include <linux/memblock.h>
  18
  19 struct memblock memblock;
  20
  21 static int memblock_debug;
  22 static struct memblock_region memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS + 1];
  23 static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_REGIONS + 1];
  24
  25 #define MEMBLOCK_ERROR  (~(phys_addr_t)0)
  26
  27 static int __init early_memblock(char *p)
  28 {
  29         if (p && strstr(p, "debug"))
  30                 memblock_debug = 1;
  31         return 0;
  32 }
  33 early_param("memblock", early_memblock);
  34
  35 static void memblock_dump(struct memblock_type *region, char *name)
  36 {
  37         unsigned long long base, size;
  38         int i;
  39
  40         pr_info(" %s.cnt  = 0x%lx\n", name, region->cnt);
  41
  42         for (i = 0; i < region->cnt; i++) {
  43                 base = region->regions[i].base;
  44                 size = region->regions[i].size;
  45
  46                 pr_info(" %s[0x%x]\t0x%016llx - 0x%016llx, 0x%llx bytes\n",
  47                     name, i, base, base + size - 1, size);
  48         }
  49 }
  50
  51 void memblock_dump_all(void)
  52 {
  53         if (!memblock_debug)
  54                 return;
  55
  56         pr_info("MEMBLOCK configuration:\n");
  57         pr_info(" memory size = 0x%llx\n", (unsigned long long)memblock.memory_size);
  58
  59         memblock_dump(&memblock.memory, "memory");
  60         memblock_dump(&memblock.reserved, "reserved");
  61 }
  62
  63 static unsigned long memblock_addrs_overlap(phys_addr_t base1, phys_addr_t size1,
  64                                        phys_addr_t base2, phys_addr_t size2)
  65 {
  66         return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
  67 }
  68
  69 static long memblock_addrs_adjacent(phys_addr_t base1, phys_addr_t size1,
  70                                phys_addr_t base2, phys_addr_t size2)
  71 {
  72         if (base2 == base1 + size1)
  73                 return 1;
  74         else if (base1 == base2 + size2)
  75                 return -1;
  76
  77         return 0;
  78 }
  79
  80 static long memblock_regions_adjacent(struct memblock_type *type,
  81                                  unsigned long r1, unsigned long r2)
  82 {
  83         phys_addr_t base1 = type->regions[r1].base;
  84         phys_addr_t size1 = type->regions[r1].size;
  85         phys_addr_t base2 = type->regions[r2].base;
  86         phys_addr_t size2 = type->regions[r2].size;
  87
  88         return memblock_addrs_adjacent(base1, size1, base2, size2);
  89 }
  90
  91 static void memblock_remove_region(struct memblock_type *type, unsigned long r)
  92 {
  93         unsigned long i;
  94
  95         for (i = r; i < type->cnt - 1; i++) {
  96                 type->regions[i].base = type->regions[i + 1].base;
  97                 type->regions[i].size = type->regions[i + 1].size;
  98         }
  99         type->cnt--;
 100 }
 101
 102 /* Assumption: base addr of region 1 < base addr of region 2 */
 103 static void memblock_coalesce_regions(struct memblock_type *type,
 104                 unsigned long r1, unsigned long r2)
 105 {
 106         type->regions[r1].size += type->regions[r2].size;
 107         memblock_remove_region(type, r2);
 108 }
 109
 110 void __init memblock_init(void)
 111 {
 112         /* Hookup the initial arrays */
 113         memblock.memory.regions = memblock_memory_init_regions;
 114         memblock.memory.max             = INIT_MEMBLOCK_REGIONS;
 115         memblock.reserved.regions       = memblock_reserved_init_regions;
 116         memblock.reserved.max   = INIT_MEMBLOCK_REGIONS;
 117
 118         /* Write a marker in the unused last array entry */
 119         memblock.memory.regions[INIT_MEMBLOCK_REGIONS].base = (phys_addr_t)RED_INACTIVE;
 120         memblock.reserved.regions[INIT_MEMBLOCK_REGIONS].base = (phys_addr_t)RED_INACTIVE;
 121
 122         /* Create a dummy zero size MEMBLOCK which will get coalesced away later.
 123          * This simplifies the memblock_add() code below...
 124          */
 125         memblock.memory.regions[0].base = 0;
 126         memblock.memory.regions[0].size = 0;
 127         memblock.memory.cnt = 1;
 128
 129         /* Ditto. */
 130         memblock.reserved.regions[0].base = 0;
 131         memblock.reserved.regions[0].size = 0;
 132         memblock.reserved.cnt = 1;
 133
 134         memblock.current_limit = MEMBLOCK_ALLOC_ANYWHERE;
 135 }
 136
 137 void __init memblock_analyze(void)
 138 {
 139         int i;
 140
 141         /* Check marker in the unused last array entry */
 142         WARN_ON(memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS].base
 143                 != (phys_addr_t)RED_INACTIVE);
 144         WARN_ON(memblock_reserved_init_regions[INIT_MEMBLOCK_REGIONS].base
 145                 != (phys_addr_t)RED_INACTIVE);
 146
 147         memblock.memory_size = 0;
 148
 149         for (i = 0; i < memblock.memory.cnt; i++)
 150                 memblock.memory_size += memblock.memory.regions[i].size;
 151 }
 152
 153 static long memblock_add_region(struct memblock_type *type, phys_addr_t base, phys_addr_t size)
 154 {
 155         unsigned long coalesced = 0;
 156         long adjacent, i;
 157
 158         if ((type->cnt == 1) && (type->regions[0].size == 0)) {
 159                 type->regions[0].base = base;
 160                 type->regions[0].size = size;
 161                 return 0;
 162         }
 163
 164         /* First try and coalesce this MEMBLOCK with another. */
 165         for (i = 0; i < type->cnt; i++) {
 166                 phys_addr_t rgnbase = type->regions[i].base;
 167                 phys_addr_t rgnsize = type->regions[i].size;
 168
 169                 if ((rgnbase == base) && (rgnsize == size))
 170                         /* Already have this region, so we're done */
 171                         return 0;
 172
 173                 adjacent = memblock_addrs_adjacent(base, size, rgnbase, rgnsize);
 174                 if (adjacent > 0) {
 175                         type->regions[i].base -= size;
 176                         type->regions[i].size += size;
 177                         coalesced++;
 178                         break;
 179                 } else if (adjacent < 0) {
 180                         type->regions[i].size += size;
 181                         coalesced++;
 182                         break;
 183                 }
 184         }
 185
 186         if ((i < type->cnt - 1) && memblock_regions_adjacent(type, i, i+1)) {
 187                 memblock_coalesce_regions(type, i, i+1);
 188                 coalesced++;
 189         }
 190
 191         if (coalesced)
 192                 return coalesced;
 193         if (type->cnt >= type->max)
 194                 return -1;
 195
 196         /* Couldn't coalesce the MEMBLOCK, so add it to the sorted table. */
 197         for (i = type->cnt - 1; i >= 0; i--) {
 198                 if (base < type->regions[i].base) {
 199                         type->regions[i+1].base = type->regions[i].base;
 200                         type->regions[i+1].size = type->regions[i].size;
 201                 } else {
 202                         type->regions[i+1].base = base;
 203                         type->regions[i+1].size = size;
 204                         break;
 205                 }
 206         }
 207
 208         if (base < type->regions[0].base) {
 209                 type->regions[0].base = base;
 210                 type->regions[0].size = size;
 211         }
 212         type->cnt++;
 213
 214         return 0;
 215 }
 216
 217 long memblock_add(phys_addr_t base, phys_addr_t size)
 218 {
 219         return memblock_add_region(&memblock.memory, base, size);
 220
 221 }
 222
 223 static long __memblock_remove(struct memblock_type *type, phys_addr_t base, phys_addr_t size)
 224 {
 225         phys_addr_t rgnbegin, rgnend;
 226         phys_addr_t end = base + size;
 227         int i;
 228
 229         rgnbegin = rgnend = 0; /* supress gcc warnings */
 230
 231         /* Find the region where (base, size) belongs to */
 232         for (i=0; i < type->cnt; i++) {
 233                 rgnbegin = type->regions[i].base;
 234                 rgnend = rgnbegin + type->regions[i].size;
 235
 236                 if ((rgnbegin <= base) && (end <= rgnend))
 237                         break;
 238         }
 239
 240         /* Didn't find the region */
 241         if (i == type->cnt)
 242                 return -1;
 243
 244         /* Check to see if we are removing entire region */
 245         if ((rgnbegin == base) && (rgnend == end)) {
 246                 memblock_remove_region(type, i);
 247                 return 0;
 248         }
 249
 250         /* Check to see if region is matching at the front */
 251         if (rgnbegin == base) {
 252                 type->regions[i].base = end;
 253                 type->regions[i].size -= size;
 254                 return 0;
 255         }
 256
 257         /* Check to see if the region is matching at the end */
 258         if (rgnend == end) {
 259                 type->regions[i].size -= size;
 260                 return 0;
 261         }
 262
 263         /*
 264          * We need to split the entry -  adjust the current one to the
 265          * beginging of the hole and add the region after hole.
 266          */
 267         type->regions[i].size = base - type->regions[i].base;
 268         return memblock_add_region(type, end, rgnend - end);
 269 }
 270
 271 long memblock_remove(phys_addr_t base, phys_addr_t size)
 272 {
 273         return __memblock_remove(&memblock.memory, base, size);
 274 }
 275
 276 long __init memblock_free(phys_addr_t base, phys_addr_t size)
 277 {
 278         return __memblock_remove(&memblock.reserved, base, size);
 279 }
 280
 281 long __init memblock_reserve(phys_addr_t base, phys_addr_t size)
 282 {
 283         struct memblock_type *_rgn = &memblock.reserved;
 284
 285         BUG_ON(0 == size);
 286
 287         return memblock_add_region(_rgn, base, size);
 288 }
 289
 290 long memblock_overlaps_region(struct memblock_type *type, phys_addr_t base, phys_addr_t size)
 291 {
 292         unsigned long i;
 293
 294         for (i = 0; i < type->cnt; i++) {
 295                 phys_addr_t rgnbase = type->regions[i].base;
 296                 phys_addr_t rgnsize = type->regions[i].size;
 297                 if (memblock_addrs_overlap(base, size, rgnbase, rgnsize))
 298                         break;
 299         }
 300
 301         return (i < type->cnt) ? i : -1;
 302 }
 303
 304 static phys_addr_t memblock_align_down(phys_addr_t addr, phys_addr_t size)
 305 {
 306         return addr & ~(size - 1);
 307 }
 308
 309 static phys_addr_t memblock_align_up(phys_addr_t addr, phys_addr_t size)
 310 {
 311         return (addr + (size - 1)) & ~(size - 1);
 312 }
 313
 314 static phys_addr_t __init memblock_find_region(phys_addr_t start, phys_addr_t end,
 315                                           phys_addr_t size, phys_addr_t align)
 316 {
 317         phys_addr_t base, res_base;
 318         long j;
 319
 320         base = memblock_align_down((end - size), align);
 321         while (start <= base) {
 322                 j = memblock_overlaps_region(&memblock.reserved, base, size);
 323                 if (j < 0)
 324                         return base;
 325                 res_base = memblock.reserved.regions[j].base;
 326                 if (res_base < size)
 327                         break;
 328                 base = memblock_align_down(res_base - size, align);
 329         }
 330
 331         return MEMBLOCK_ERROR;
 332 }
 333
 334 phys_addr_t __weak __init memblock_nid_range(phys_addr_t start, phys_addr_t end, int *nid)
 335 {
 336         *nid = 0;
 337
 338         return end;
 339 }
 340
 341 static phys_addr_t __init memblock_alloc_nid_region(struct memblock_region *mp,
 342                                                phys_addr_t size,
 343                                                phys_addr_t align, int nid)
 344 {
 345         phys_addr_t start, end;
 346
 347         start = mp->base;
 348         end = start + mp->size;
 349
 350         start = memblock_align_up(start, align);
 351         while (start < end) {
 352                 phys_addr_t this_end;
 353                 int this_nid;
 354
 355                 this_end = memblock_nid_range(start, end, &this_nid);
 356                 if (this_nid == nid) {
 357                         phys_addr_t ret = memblock_find_region(start, this_end, size, align);
 358                         if (ret != MEMBLOCK_ERROR &&
 359                             memblock_add_region(&memblock.reserved, ret, size) >= 0)
 360                                 return ret;
 361                 }
 362                 start = this_end;
 363         }
 364
 365         return MEMBLOCK_ERROR;
 366 }
 367
 368 phys_addr_t __init memblock_alloc_nid(phys_addr_t size, phys_addr_t align, int nid)
 369 {
 370         struct memblock_type *mem = &memblock.memory;
 371         int i;
 372
 373         BUG_ON(0 == size);
 374
 375         /* We do a bottom-up search for a region with the right
 376          * nid since that's easier considering how memblock_nid_range()
 377          * works
 378          */
 379         size = memblock_align_up(size, align);
 380
 381         for (i = 0; i < mem->cnt; i++) {
 382                 phys_addr_t ret = memblock_alloc_nid_region(&mem->regions[i],
 383                                                size, align, nid);
 384                 if (ret != MEMBLOCK_ERROR)
 385                         return ret;
 386         }
 387
 388         return memblock_alloc(size, align);
 389 }
 390
 391 phys_addr_t __init memblock_alloc(phys_addr_t size, phys_addr_t align)
 392 {
 393         return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
 394 }
 395
 396 phys_addr_t __init memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
 397 {
 398         phys_addr_t alloc;
 399
 400         alloc = __memblock_alloc_base(size, align, max_addr);
 401
 402         if (alloc == 0)
 403                 panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
 404                       (unsigned long long) size, (unsigned long long) max_addr);
 405
 406         return alloc;
 407 }
 408
 409 phys_addr_t __init __memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
 410 {
 411         long i;
 412         phys_addr_t base = 0;
 413         phys_addr_t res_base;
 414
 415         BUG_ON(0 == size);
 416
 417         size = memblock_align_up(size, align);
 418
 419         /* Pump up max_addr */
 420         if (max_addr == MEMBLOCK_ALLOC_ACCESSIBLE)
 421                 max_addr = memblock.current_limit;
 422
 423         /* We do a top-down search, this tends to limit memory
 424          * fragmentation by keeping early boot allocs near the
 425          * top of memory
 426          */
 427         for (i = memblock.memory.cnt - 1; i >= 0; i--) {
 428                 phys_addr_t memblockbase = memblock.memory.regions[i].base;
 429                 phys_addr_t memblocksize = memblock.memory.regions[i].size;
 430
 431                 if (memblocksize < size)
 432                         continue;
 433                 base = min(memblockbase + memblocksize, max_addr);
 434                 res_base = memblock_find_region(memblockbase, base, size, align);
 435                 if (res_base != MEMBLOCK_ERROR &&
 436                     memblock_add_region(&memblock.reserved, res_base, size) >= 0)
 437                         return res_base;
 438         }
 439         return 0;
 440 }
 441
 442 /* You must call memblock_analyze() before this. */
 443 phys_addr_t __init memblock_phys_mem_size(void)
 444 {
 445         return memblock.memory_size;
 446 }
 447
 448 phys_addr_t memblock_end_of_DRAM(void)
 449 {
 450         int idx = memblock.memory.cnt - 1;
 451
 452         return (memblock.memory.regions[idx].base + memblock.memory.regions[idx].size);
 453 }
 454
 455 /* You must call memblock_analyze() after this. */
 456 void __init memblock_enforce_memory_limit(phys_addr_t memory_limit)
 457 {
 458         unsigned long i;
 459         phys_addr_t limit;
 460         struct memblock_region *p;
 461
 462         if (!memory_limit)
 463                 return;
 464
 465         /* Truncate the memblock regions to satisfy the memory limit. */
 466         limit = memory_limit;
 467         for (i = 0; i < memblock.memory.cnt; i++) {
 468                 if (limit > memblock.memory.regions[i].size) {
 469                         limit -= memblock.memory.regions[i].size;
 470                         continue;
 471                 }
 472
 473                 memblock.memory.regions[i].size = limit;
 474                 memblock.memory.cnt = i + 1;
 475                 break;
 476         }
 477
 478         memory_limit = memblock_end_of_DRAM();
 479
 480         /* And truncate any reserves above the limit also. */
 481         for (i = 0; i < memblock.reserved.cnt; i++) {
 482                 p = &memblock.reserved.regions[i];
 483
 484                 if (p->base > memory_limit)
 485                         p->size = 0;
 486                 else if ((p->base + p->size) > memory_limit)
 487                         p->size = memory_limit - p->base;
 488
 489                 if (p->size == 0) {
 490                         memblock_remove_region(&memblock.reserved, i);
 491                         i--;
 492                 }
 493         }
 494 }
 495
 496 static int memblock_search(struct memblock_type *type, phys_addr_t addr)
 497 {
 498         unsigned int left = 0, right = type->cnt;
 499
 500         do {
 501                 unsigned int mid = (right + left) / 2;
 502
 503                 if (addr < type->regions[mid].base)
 504                         right = mid;
 505                 else if (addr >= (type->regions[mid].base +
 506                                   type->regions[mid].size))
 507                         left = mid + 1;
 508                 else
 509                         return mid;
 510         } while (left < right);
 511         return -1;
 512 }
 513
 514 int __init memblock_is_reserved(phys_addr_t addr)
 515 {
 516         return memblock_search(&memblock.reserved, addr) != -1;
 517 }
 518
 519 int memblock_is_memory(phys_addr_t addr)
 520 {
 521         return memblock_search(&memblock.memory, addr) != -1;
 522 }
 523
 524 int memblock_is_region_memory(phys_addr_t base, phys_addr_t size)
 525 {
 526         int idx = memblock_search(&memblock.reserved, base);
 527
 528         if (idx == -1)
 529                 return 0;
 530         return memblock.reserved.regions[idx].base <= base &&
 531                 (memblock.reserved.regions[idx].base +
 532                  memblock.reserved.regions[idx].size) >= (base + size);
 533 }
 534
 535 int memblock_is_region_reserved(phys_addr_t base, phys_addr_t size)
 536 {
 537         return memblock_overlaps_region(&memblock.reserved, base, size) >= 0;
 538 }
 539
 540
 541 void __init memblock_set_current_limit(phys_addr_t limit)
 542 {
 543         memblock.current_limit = limit;
 544 }
 545