linux/mm/memblock.c
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   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
  20struct memblock memblock;
  21
  22static int memblock_debug;
  23
  24static int __init early_memblock(char *p)
  25{
  26        if (p && strstr(p, "debug"))
  27                memblock_debug = 1;
  28        return 0;
  29}
  30early_param("memblock", early_memblock);
  31
  32static 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
  48void 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
  61static 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
  67static 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
  77static 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
  88static 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 */
 100static 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
 107void __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
 122void __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
 132static 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
 196long 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
 208static 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
 256long memblock_remove(u64 base, u64 size)
 257{
 258        return __memblock_remove(&memblock.memory, base, size);
 259}
 260
 261long __init memblock_free(u64 base, u64 size)
 262{
 263        return __memblock_remove(&memblock.reserved, base, size);
 264}
 265
 266long __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
 275long 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
 289static u64 memblock_align_down(u64 addr, u64 size)
 290{
 291        return addr & ~(size - 1);
 292}
 293
 294static u64 memblock_align_up(u64 addr, u64 size)
 295{
 296        return (addr + (size - 1)) & ~(size - 1);
 297}
 298
 299static 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
 323static 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
 350u64 __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
 371u64 __init memblock_alloc(u64 size, u64 align)
 372{
 373        return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ANYWHERE);
 374}
 375
 376u64 __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
 389u64 __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. */
 436u64 __init memblock_phys_mem_size(void)
 437{
 438        return memblock.memory.size;
 439}
 440
 441u64 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. */
 449void __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
 492int __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
 505int 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 */
 514int 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}
 542
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