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/memblock.h>
  17
  18 #define MEMBLOCK_ALLOC_ANYWHERE 0
  19
  20 struct memblock memblock;
  21
  22 static int memblock_debug;
  23
  24 static int __init early_memblock(char *p)
  25 {
  26         if (p && strstr(p, "debug"))
  27                 memblock_debug = 1;
  28         return 0;
  29 }
  30 early_param("memblock", early_memblock);
  31
  32 static void memblock_dump(struct memblock_region *region, char *name)
  33 {
  34         unsigned long long base, size;
  35         int i;
  36
  37         pr_info(" %s.cnt  = 0x%lx\n", name, region->cnt);
  38
  39         for (i = 0; i < region->cnt; i++) {
  40                 base = region->region[i].base;
  41                 size = region->region[i].size;
  42
  43                 pr_info(" %s[0x%x]\t0x%016llx - 0x%016llx, 0x%llx bytes\n",
  44                     name, i, base, base + size - 1, size);
  45         }
  46 }
  47
  48 void memblock_dump_all(void)
  49 {
  50         if (!memblock_debug)
  51                 return;
  52
  53         pr_info("MEMBLOCK configuration:\n");
  54         pr_info(" rmo_size    = 0x%llx\n", (unsigned long long)memblock.rmo_size);
  55         pr_info(" memory.size = 0x%llx\n", (unsigned long long)memblock.memory.size);
  56
  57         memblock_dump(&memblock.memory, "memory");
  58         memblock_dump(&memblock.reserved, "reserved");
  59 }
  60
  61 static unsigned long memblock_addrs_overlap(u64 base1, u64 size1, u64 base2,
  62                                         u64 size2)
  63 {
  64         return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
  65 }
  66
  67 static long memblock_addrs_adjacent(u64 base1, u64 size1, u64 base2, u64 size2)
  68 {
  69         if (base2 == base1 + size1)
  70                 return 1;
  71         else if (base1 == base2 + size2)
  72                 return -1;
  73
  74         return 0;
  75 }
  76
  77 static long memblock_regions_adjacent(struct memblock_region *rgn,
  78                 unsigned long r1, unsigned long r2)
  79 {
  80         u64 base1 = rgn->region[r1].base;
  81         u64 size1 = rgn->region[r1].size;
  82         u64 base2 = rgn->region[r2].base;
  83         u64 size2 = rgn->region[r2].size;
  84
  85         return memblock_addrs_adjacent(base1, size1, base2, size2);
  86 }
  87
  88 static void memblock_remove_region(struct memblock_region *rgn, unsigned long r)
  89 {
  90         unsigned long i;
  91
  92         for (i = r; i < rgn->cnt - 1; i++) {
  93                 rgn->region[i].base = rgn->region[i + 1].base;
  94                 rgn->region[i].size = rgn->region[i + 1].size;
  95         }
  96         rgn->cnt--;
  97 }
  98
  99 /* Assumption: base addr of region 1 < base addr of region 2 */
 100 static void memblock_coalesce_regions(struct memblock_region *rgn,
 101                 unsigned long r1, unsigned long r2)
 102 {
 103         rgn->region[r1].size += rgn->region[r2].size;
 104         memblock_remove_region(rgn, r2);
 105 }
 106
 107 void __init memblock_init(void)
 108 {
 109         /* Create a dummy zero size MEMBLOCK which will get coalesced away later.
 110          * This simplifies the memblock_add() code below...
 111          */
 112         memblock.memory.region[0].base = 0;
 113         memblock.memory.region[0].size = 0;
 114         memblock.memory.cnt = 1;
 115
 116         /* Ditto. */
 117         memblock.reserved.region[0].base = 0;
 118         memblock.reserved.region[0].size = 0;
 119         memblock.reserved.cnt = 1;
 120 }
 121
 122 void __init memblock_analyze(void)
 123 {
 124         int i;
 125
 126         memblock.memory.size = 0;
 127
 128         for (i = 0; i < memblock.memory.cnt; i++)
 129                 memblock.memory.size += memblock.memory.region[i].size;
 130 }
 131
 132 static long memblock_add_region(struct memblock_region *rgn, u64 base, u64 size)
 133 {
 134         unsigned long coalesced = 0;
 135         long adjacent, i;
 136
 137         if ((rgn->cnt == 1) && (rgn->region[0].size == 0)) {
 138                 rgn->region[0].base = base;
 139                 rgn->region[0].size = size;
 140                 return 0;
 141         }
 142
 143         /* First try and coalesce this MEMBLOCK with another. */
 144         for (i = 0; i < rgn->cnt; i++) {
 145                 u64 rgnbase = rgn->region[i].base;
 146                 u64 rgnsize = rgn->region[i].size;
 147
 148                 if ((rgnbase == base) && (rgnsize == size))
 149                         /* Already have this region, so we're done */
 150                         return 0;
 151
 152                 adjacent = memblock_addrs_adjacent(base, size, rgnbase, rgnsize);
 153                 if (adjacent > 0) {
 154                         rgn->region[i].base -= size;
 155                         rgn->region[i].size += size;
 156                         coalesced++;
 157                         break;
 158                 } else if (adjacent < 0) {
 159                         rgn->region[i].size += size;
 160                         coalesced++;
 161                         break;
 162                 }
 163         }
 164
 165         if ((i < rgn->cnt - 1) && memblock_regions_adjacent(rgn, i, i+1)) {
 166                 memblock_coalesce_regions(rgn, i, i+1);
 167                 coalesced++;
 168         }
 169
 170         if (coalesced)
 171                 return coalesced;
 172         if (rgn->cnt >= MAX_MEMBLOCK_REGIONS)
 173                 return -1;
 174
 175         /* Couldn't coalesce the MEMBLOCK, so add it to the sorted table. */
 176         for (i = rgn->cnt - 1; i >= 0; i--) {
 177                 if (base < rgn->region[i].base) {
 178                         rgn->region[i+1].base = rgn->region[i].base;
 179                         rgn->region[i+1].size = rgn->region[i].size;
 180                 } else {
 181                         rgn->region[i+1].base = base;
 182                         rgn->region[i+1].size = size;
 183                         break;
 184                 }
 185         }
 186
 187         if (base < rgn->region[0].base) {
 188                 rgn->region[0].base = base;
 189                 rgn->region[0].size = size;
 190         }
 191         rgn->cnt++;
 192
 193         return 0;
 194 }
 195
 196 long memblock_add(u64 base, u64 size)
 197 {
 198         struct memblock_region *_rgn = &memblock.memory;
 199
 200         /* On pSeries LPAR systems, the first MEMBLOCK is our RMO region. */
 201         if (base == 0)
 202                 memblock.rmo_size = size;
 203
 204         return memblock_add_region(_rgn, base, size);
 205
 206 }
 207
 208 static long __memblock_remove(struct memblock_region *rgn, u64 base, u64 size)
 209 {
 210         u64 rgnbegin, rgnend;
 211         u64 end = base + size;
 212         int i;
 213
 214         rgnbegin = rgnend = 0; /* supress gcc warnings */
 215
 216         /* Find the region where (base, size) belongs to */
 217         for (i=0; i < rgn->cnt; i++) {
 218                 rgnbegin = rgn->region[i].base;
 219                 rgnend = rgnbegin + rgn->region[i].size;
 220
 221                 if ((rgnbegin <= base) && (end <= rgnend))
 222                         break;
 223         }
 224
 225         /* Didn't find the region */
 226         if (i == rgn->cnt)
 227                 return -1;
 228
 229         /* Check to see if we are removing entire region */
 230         if ((rgnbegin == base) && (rgnend == end)) {
 231                 memblock_remove_region(rgn, i);
 232                 return 0;
 233         }
 234
 235         /* Check to see if region is matching at the front */
 236         if (rgnbegin == base) {
 237                 rgn->region[i].base = end;
 238                 rgn->region[i].size -= size;
 239                 return 0;
 240         }
 241
 242         /* Check to see if the region is matching at the end */
 243         if (rgnend == end) {
 244                 rgn->region[i].size -= size;
 245                 return 0;
 246         }
 247
 248         /*
 249          * We need to split the entry -  adjust the current one to the
 250          * beginging of the hole and add the region after hole.
 251          */
 252         rgn->region[i].size = base - rgn->region[i].base;
 253         return memblock_add_region(rgn, end, rgnend - end);
 254 }
 255
 256 long memblock_remove(u64 base, u64 size)
 257 {
 258         return __memblock_remove(&memblock.memory, base, size);
 259 }
 260
 261 long __init memblock_free(u64 base, u64 size)
 262 {
 263         return __memblock_remove(&memblock.reserved, base, size);
 264 }
 265
 266 long __init memblock_reserve(u64 base, u64 size)
 267 {
 268         struct memblock_region *_rgn = &memblock.reserved;
 269
 270         BUG_ON(0 == size);
 271
 272         return memblock_add_region(_rgn, base, size);
 273 }
 274
 275 long memblock_overlaps_region(struct memblock_region *rgn, u64 base, u64 size)
 276 {
 277         unsigned long i;
 278
 279         for (i = 0; i < rgn->cnt; i++) {
 280                 u64 rgnbase = rgn->region[i].base;
 281                 u64 rgnsize = rgn->region[i].size;
 282                 if (memblock_addrs_overlap(base, size, rgnbase, rgnsize))
 283                         break;
 284         }
 285
 286         return (i < rgn->cnt) ? i : -1;
 287 }
 288
 289 static u64 memblock_align_down(u64 addr, u64 size)
 290 {
 291         return addr & ~(size - 1);
 292 }
 293
 294 static u64 memblock_align_up(u64 addr, u64 size)
 295 {
 296         return (addr + (size - 1)) & ~(size - 1);
 297 }
 298
 299 static u64 __init memblock_alloc_nid_unreserved(u64 start, u64 end,
 300                                            u64 size, u64 align)
 301 {
 302         u64 base, res_base;
 303         long j;
 304
 305         base = memblock_align_down((end - size), align);
 306         while (start <= base) {
 307                 j = memblock_overlaps_region(&memblock.reserved, base, size);
 308                 if (j < 0) {
 309                         /* this area isn't reserved, take it */
 310                         if (memblock_add_region(&memblock.reserved, base, size) < 0)
 311                                 base = ~(u64)0;
 312                         return base;
 313                 }
 314                 res_base = memblock.reserved.region[j].base;
 315                 if (res_base < size)
 316                         break;
 317                 base = memblock_align_down(res_base - size, align);
 318         }
 319
 320         return ~(u64)0;
 321 }
 322
 323 static u64 __init memblock_alloc_nid_region(struct memblock_property *mp,
 324                                        u64 (*nid_range)(u64, u64, int *),
 325                                        u64 size, u64 align, int nid)
 326 {
 327         u64 start, end;
 328
 329         start = mp->base;
 330         end = start + mp->size;
 331
 332         start = memblock_align_up(start, align);
 333         while (start < end) {
 334                 u64 this_end;
 335                 int this_nid;
 336
 337                 this_end = nid_range(start, end, &this_nid);
 338                 if (this_nid == nid) {
 339                         u64 ret = memblock_alloc_nid_unreserved(start, this_end,
 340                                                            size, align);
 341                         if (ret != ~(u64)0)
 342                                 return ret;
 343                 }
 344                 start = this_end;
 345         }
 346
 347         return ~(u64)0;
 348 }
 349
 350 u64 __init memblock_alloc_nid(u64 size, u64 align, int nid,
 351                          u64 (*nid_range)(u64 start, u64 end, int *nid))
 352 {
 353         struct memblock_region *mem = &memblock.memory;
 354         int i;
 355
 356         BUG_ON(0 == size);
 357
 358         size = memblock_align_up(size, align);
 359
 360         for (i = 0; i < mem->cnt; i++) {
 361                 u64 ret = memblock_alloc_nid_region(&mem->region[i],
 362                                                nid_range,
 363                                                size, align, nid);
 364                 if (ret != ~(u64)0)
 365                         return ret;
 366         }
 367
 368         return memblock_alloc(size, align);
 369 }
 370
 371 u64 __init memblock_alloc(u64 size, u64 align)
 372 {
 373         return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ANYWHERE);
 374 }
 375
 376 u64 __init memblock_alloc_base(u64 size, u64 align, u64 max_addr)
 377 {
 378         u64 alloc;
 379
 380         alloc = __memblock_alloc_base(size, align, max_addr);
 381
 382         if (alloc == 0)
 383                 panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
 384                       (unsigned long long) size, (unsigned long long) max_addr);
 385
 386         return alloc;
 387 }
 388
 389 u64 __init __memblock_alloc_base(u64 size, u64 align, u64 max_addr)
 390 {
 391         long i, j;
 392         u64 base = 0;
 393         u64 res_base;
 394
 395         BUG_ON(0 == size);
 396
 397         size = memblock_align_up(size, align);
 398
 399         /* On some platforms, make sure we allocate lowmem */
 400         /* Note that MEMBLOCK_REAL_LIMIT may be MEMBLOCK_ALLOC_ANYWHERE */
 401         if (max_addr == MEMBLOCK_ALLOC_ANYWHERE)
 402                 max_addr = MEMBLOCK_REAL_LIMIT;
 403
 404         for (i = memblock.memory.cnt - 1; i >= 0; i--) {
 405                 u64 memblockbase = memblock.memory.region[i].base;
 406                 u64 memblocksize = memblock.memory.region[i].size;
 407
 408                 if (memblocksize < size)
 409                         continue;
 410                 if (max_addr == MEMBLOCK_ALLOC_ANYWHERE)
 411                         base = memblock_align_down(memblockbase + memblocksize - size, align);
 412                 else if (memblockbase < max_addr) {
 413                         base = min(memblockbase + memblocksize, max_addr);
 414                         base = memblock_align_down(base - size, align);
 415                 } else
 416                         continue;
 417
 418                 while (base && memblockbase <= base) {
 419                         j = memblock_overlaps_region(&memblock.reserved, base, size);
 420                         if (j < 0) {
 421                                 /* this area isn't reserved, take it */
 422                                 if (memblock_add_region(&memblock.reserved, base, size) < 0)
 423                                         return 0;
 424                                 return base;
 425                         }
 426                         res_base = memblock.reserved.region[j].base;
 427                         if (res_base < size)
 428                                 break;
 429                         base = memblock_align_down(res_base - size, align);
 430                 }
 431         }
 432         return 0;
 433 }
 434
 435 /* You must call memblock_analyze() before this. */
 436 u64 __init memblock_phys_mem_size(void)
 437 {
 438         return memblock.memory.size;
 439 }
 440
 441 u64 memblock_end_of_DRAM(void)
 442 {
 443         int idx = memblock.memory.cnt - 1;
 444
 445         return (memblock.memory.region[idx].base + memblock.memory.region[idx].size);
 446 }
 447
 448 /* You must call memblock_analyze() after this. */
 449 void __init memblock_enforce_memory_limit(u64 memory_limit)
 450 {
 451         unsigned long i;
 452         u64 limit;
 453         struct memblock_property *p;
 454
 455         if (!memory_limit)
 456                 return;
 457
 458         /* Truncate the memblock regions to satisfy the memory limit. */
 459         limit = memory_limit;
 460         for (i = 0; i < memblock.memory.cnt; i++) {
 461                 if (limit > memblock.memory.region[i].size) {
 462                         limit -= memblock.memory.region[i].size;
 463                         continue;
 464                 }
 465
 466                 memblock.memory.region[i].size = limit;
 467                 memblock.memory.cnt = i + 1;
 468                 break;
 469         }
 470
 471         if (memblock.memory.region[0].size < memblock.rmo_size)
 472                 memblock.rmo_size = memblock.memory.region[0].size;
 473
 474         memory_limit = memblock_end_of_DRAM();
 475
 476         /* And truncate any reserves above the limit also. */
 477         for (i = 0; i < memblock.reserved.cnt; i++) {
 478                 p = &memblock.reserved.region[i];
 479
 480                 if (p->base > memory_limit)
 481                         p->size = 0;
 482                 else if ((p->base + p->size) > memory_limit)
 483                         p->size = memory_limit - p->base;
 484
 485                 if (p->size == 0) {
 486                         memblock_remove_region(&memblock.reserved, i);
 487                         i--;
 488                 }
 489         }
 490 }
 491
 492 int __init memblock_is_reserved(u64 addr)
 493 {
 494         int i;
 495
 496         for (i = 0; i < memblock.reserved.cnt; i++) {
 497                 u64 upper = memblock.reserved.region[i].base +
 498                         memblock.reserved.region[i].size - 1;
 499                 if ((addr >= memblock.reserved.region[i].base) && (addr <= upper))
 500                         return 1;
 501         }
 502         return 0;
 503 }
 504
 505 int memblock_is_region_reserved(u64 base, u64 size)
 506 {
 507         return memblock_overlaps_region(&memblock.reserved, base, size);
 508 }
 509
 510 /*
 511  * Given a <base, len>, find which memory regions belong to this range.
 512  * Adjust the request and return a contiguous chunk.
 513  */
 514 int memblock_find(struct memblock_property *res)
 515 {
 516         int i;
 517         u64 rstart, rend;
 518
 519         rstart = res->base;
 520         rend = rstart + res->size - 1;
 521
 522         for (i = 0; i < memblock.memory.cnt; i++) {
 523                 u64 start = memblock.memory.region[i].base;
 524                 u64 end = start + memblock.memory.region[i].size - 1;
 525
 526                 if (start > rend)
 527                         return -1;
 528
 529                 if ((end >= rstart) && (start < rend)) {
 530                         /* adjust the request */
 531                         if (rstart < start)
 532                                 rstart = start;
 533                         if (rend > end)
 534                                 rend = end;
 535                         res->base = rstart;
 536                         res->size = rend - rstart + 1;
 537                         return 0;
 538                 }
 539         }
 540         return -1;
 541 }