mm/bootmem.c

   1 /*
   2  *  bootmem - A boot-time physical memory allocator and configurator
   3  *
   4  *  Copyright (C) 1999 Ingo Molnar
   5  *                1999 Kanoj Sarcar, SGI
   6  *                2008 Johannes Weiner
   7  *
   8  * Access to this subsystem has to be serialized externally (which is true
   9  * for the boot process anyway).
  10  */
  11 #include <linux/init.h>
  12 #include <linux/pfn.h>
  13 #include <linux/slab.h>
  14 #include <linux/bootmem.h>
  15 #include <linux/export.h>
  16 #include <linux/kmemleak.h>
  17 #include <linux/range.h>
  18 #include <linux/memblock.h>
  19
  20 #include <asm/bug.h>
  21 #include <asm/io.h>
  22 #include <asm/processor.h>
  23
  24 #include "internal.h"
  25
  26 #ifndef CONFIG_NEED_MULTIPLE_NODES
  27 struct pglist_data __refdata contig_page_data = {
  28         .bdata = &bootmem_node_data[0]
  29 };
  30 EXPORT_SYMBOL(contig_page_data);
  31 #endif
  32
  33 unsigned long max_low_pfn;
  34 unsigned long min_low_pfn;
  35 unsigned long max_pfn;
  36
  37 bootmem_data_t bootmem_node_data[MAX_NUMNODES] __initdata;
  38
  39 static struct list_head bdata_list __initdata = LIST_HEAD_INIT(bdata_list);
  40
  41 static int bootmem_debug;
  42
  43 static int __init bootmem_debug_setup(char *buf)
  44 {
  45         bootmem_debug = 1;
  46         return 0;
  47 }
  48 early_param("bootmem_debug", bootmem_debug_setup);
  49
  50 #define bdebug(fmt, args...) ({                         \
  51         if (unlikely(bootmem_debug))                    \
  52                 printk(KERN_INFO                        \
  53                         "bootmem::%s " fmt,             \
  54                         __func__, ## args);             \
  55 })
  56
  57 static unsigned long __init bootmap_bytes(unsigned long pages)
  58 {
  59         unsigned long bytes = DIV_ROUND_UP(pages, 8);
  60
  61         return ALIGN(bytes, sizeof(long));
  62 }
  63
  64 /**
  65  * bootmem_bootmap_pages - calculate bitmap size in pages
  66  * @pages: number of pages the bitmap has to represent
  67  */
  68 unsigned long __init bootmem_bootmap_pages(unsigned long pages)
  69 {
  70         unsigned long bytes = bootmap_bytes(pages);
  71
  72         return PAGE_ALIGN(bytes) >> PAGE_SHIFT;
  73 }
  74
  75 /*
  76  * link bdata in order
  77  */
  78 static void __init link_bootmem(bootmem_data_t *bdata)
  79 {
  80         struct list_head *iter;
  81
  82         list_for_each(iter, &bdata_list) {
  83                 bootmem_data_t *ent;
  84
  85                 ent = list_entry(iter, bootmem_data_t, list);
  86                 if (bdata->node_min_pfn < ent->node_min_pfn)
  87                         break;
  88         }
  89         list_add_tail(&bdata->list, iter);
  90 }
  91
  92 /*
  93  * Called once to set up the allocator itself.
  94  */
  95 static unsigned long __init init_bootmem_core(bootmem_data_t *bdata,
  96         unsigned long mapstart, unsigned long start, unsigned long end)
  97 {
  98         unsigned long mapsize;
  99
 100         mminit_validate_memmodel_limits(&start, &end);
 101         bdata->node_bootmem_map = phys_to_virt(PFN_PHYS(mapstart));
 102         bdata->node_min_pfn = start;
 103         bdata->node_low_pfn = end;
 104         link_bootmem(bdata);
 105
 106         /*
 107          * Initially all pages are reserved - setup_arch() has to
 108          * register free RAM areas explicitly.
 109          */
 110         mapsize = bootmap_bytes(end - start);
 111         memset(bdata->node_bootmem_map, 0xff, mapsize);
 112
 113         bdebug("nid=%td start=%lx map=%lx end=%lx mapsize=%lx\n",
 114                 bdata - bootmem_node_data, start, mapstart, end, mapsize);
 115
 116         return mapsize;
 117 }
 118
 119 /**
 120  * init_bootmem_node - register a node as boot memory
 121  * @pgdat: node to register
 122  * @freepfn: pfn where the bitmap for this node is to be placed
 123  * @startpfn: first pfn on the node
 124  * @endpfn: first pfn after the node
 125  *
 126  * Returns the number of bytes needed to hold the bitmap for this node.
 127  */
 128 unsigned long __init init_bootmem_node(pg_data_t *pgdat, unsigned long freepfn,
 129                                 unsigned long startpfn, unsigned long endpfn)
 130 {
 131         return init_bootmem_core(pgdat->bdata, freepfn, startpfn, endpfn);
 132 }
 133
 134 /**
 135  * init_bootmem - register boot memory
 136  * @start: pfn where the bitmap is to be placed
 137  * @pages: number of available physical pages
 138  *
 139  * Returns the number of bytes needed to hold the bitmap.
 140  */
 141 unsigned long __init init_bootmem(unsigned long start, unsigned long pages)
 142 {
 143         max_low_pfn = pages;
 144         min_low_pfn = start;
 145         return init_bootmem_core(NODE_DATA(0)->bdata, start, 0, pages);
 146 }
 147
 148 /*
 149  * free_bootmem_late - free bootmem pages directly to page allocator
 150  * @addr: starting address of the range
 151  * @size: size of the range in bytes
 152  *
 153  * This is only useful when the bootmem allocator has already been torn
 154  * down, but we are still initializing the system.  Pages are given directly
 155  * to the page allocator, no bootmem metadata is updated because it is gone.
 156  */
 157 void __init free_bootmem_late(unsigned long addr, unsigned long size)
 158 {
 159         unsigned long cursor, end;
 160
 161         kmemleak_free_part(__va(addr), size);
 162
 163         cursor = PFN_UP(addr);
 164         end = PFN_DOWN(addr + size);
 165
 166         for (; cursor < end; cursor++) {
 167                 __free_pages_bootmem(pfn_to_page(cursor), 0);
 168                 totalram_pages++;
 169         }
 170 }
 171
 172 static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata)
 173 {
 174         struct page *page;
 175         unsigned long start, end, pages, count = 0;
 176
 177         if (!bdata->node_bootmem_map)
 178                 return 0;
 179
 180         start = bdata->node_min_pfn;
 181         end = bdata->node_low_pfn;
 182
 183         bdebug("nid=%td start=%lx end=%lx\n",
 184                 bdata - bootmem_node_data, start, end);
 185
 186         while (start < end) {
 187                 unsigned long *map, idx, vec;
 188
 189                 map = bdata->node_bootmem_map;
 190                 idx = start - bdata->node_min_pfn;
 191                 vec = ~map[idx / BITS_PER_LONG];
 192                 /*
 193                  * If we have a properly aligned and fully unreserved
 194                  * BITS_PER_LONG block of pages in front of us, free
 195                  * it in one go.
 196                  */
 197                 if (IS_ALIGNED(start, BITS_PER_LONG) && vec == ~0UL) {
 198                         int order = ilog2(BITS_PER_LONG);
 199
 200                         __free_pages_bootmem(pfn_to_page(start), order);
 201                         count += BITS_PER_LONG;
 202                         start += BITS_PER_LONG;
 203                 } else {
 204                         unsigned long off = 0;
 205
 206                         while (vec && off < BITS_PER_LONG) {
 207                                 if (vec & 1) {
 208                                         page = pfn_to_page(start + off);
 209                                         __free_pages_bootmem(page, 0);
 210                                         count++;
 211                                 }
 212                                 vec >>= 1;
 213                                 off++;
 214                         }
 215                         start = ALIGN(start + 1, BITS_PER_LONG);
 216                 }
 217         }
 218
 219         page = virt_to_page(bdata->node_bootmem_map);
 220         pages = bdata->node_low_pfn - bdata->node_min_pfn;
 221         pages = bootmem_bootmap_pages(pages);
 222         count += pages;
 223         while (pages--)
 224                 __free_pages_bootmem(page++, 0);
 225
 226         bdebug("nid=%td released=%lx\n", bdata - bootmem_node_data, count);
 227
 228         return count;
 229 }
 230
 231 /**
 232  * free_all_bootmem_node - release a node's free pages to the buddy allocator
 233  * @pgdat: node to be released
 234  *
 235  * Returns the number of pages actually released.
 236  */
 237 unsigned long __init free_all_bootmem_node(pg_data_t *pgdat)
 238 {
 239         register_page_bootmem_info_node(pgdat);
 240         return free_all_bootmem_core(pgdat->bdata);
 241 }
 242
 243 /**
 244  * free_all_bootmem - release free pages to the buddy allocator
 245  *
 246  * Returns the number of pages actually released.
 247  */
 248 unsigned long __init free_all_bootmem(void)
 249 {
 250         unsigned long total_pages = 0;
 251         bootmem_data_t *bdata;
 252
 253         list_for_each_entry(bdata, &bdata_list, list)
 254                 total_pages += free_all_bootmem_core(bdata);
 255
 256         return total_pages;
 257 }
 258
 259 static void __init __free(bootmem_data_t *bdata,
 260                         unsigned long sidx, unsigned long eidx)
 261 {
 262         unsigned long idx;
 263
 264         bdebug("nid=%td start=%lx end=%lx\n", bdata - bootmem_node_data,
 265                 sidx + bdata->node_min_pfn,
 266                 eidx + bdata->node_min_pfn);
 267
 268         if (bdata->hint_idx > sidx)
 269                 bdata->hint_idx = sidx;
 270
 271         for (idx = sidx; idx < eidx; idx++)
 272                 if (!test_and_clear_bit(idx, bdata->node_bootmem_map))
 273                         BUG();
 274 }
 275
 276 static int __init __reserve(bootmem_data_t *bdata, unsigned long sidx,
 277                         unsigned long eidx, int flags)
 278 {
 279         unsigned long idx;
 280         int exclusive = flags & BOOTMEM_EXCLUSIVE;
 281
 282         bdebug("nid=%td start=%lx end=%lx flags=%x\n",
 283                 bdata - bootmem_node_data,
 284                 sidx + bdata->node_min_pfn,
 285                 eidx + bdata->node_min_pfn,
 286                 flags);
 287
 288         for (idx = sidx; idx < eidx; idx++)
 289                 if (test_and_set_bit(idx, bdata->node_bootmem_map)) {
 290                         if (exclusive) {
 291                                 __free(bdata, sidx, idx);
 292                                 return -EBUSY;
 293                         }
 294                         bdebug("silent double reserve of PFN %lx\n",
 295                                 idx + bdata->node_min_pfn);
 296                 }
 297         return 0;
 298 }
 299
 300 static int __init mark_bootmem_node(bootmem_data_t *bdata,
 301                                 unsigned long start, unsigned long end,
 302                                 int reserve, int flags)
 303 {
 304         unsigned long sidx, eidx;
 305
 306         bdebug("nid=%td start=%lx end=%lx reserve=%d flags=%x\n",
 307                 bdata - bootmem_node_data, start, end, reserve, flags);
 308
 309         BUG_ON(start < bdata->node_min_pfn);
 310         BUG_ON(end > bdata->node_low_pfn);
 311
 312         sidx = start - bdata->node_min_pfn;
 313         eidx = end - bdata->node_min_pfn;
 314
 315         if (reserve)
 316                 return __reserve(bdata, sidx, eidx, flags);
 317         else
 318                 __free(bdata, sidx, eidx);
 319         return 0;
 320 }
 321
 322 static int __init mark_bootmem(unsigned long start, unsigned long end,
 323                                 int reserve, int flags)
 324 {
 325         unsigned long pos;
 326         bootmem_data_t *bdata;
 327
 328         pos = start;
 329         list_for_each_entry(bdata, &bdata_list, list) {
 330                 int err;
 331                 unsigned long max;
 332
 333                 if (pos < bdata->node_min_pfn ||
 334                     pos >= bdata->node_low_pfn) {
 335                         BUG_ON(pos != start);
 336                         continue;
 337                 }
 338
 339                 max = min(bdata->node_low_pfn, end);
 340
 341                 err = mark_bootmem_node(bdata, pos, max, reserve, flags);
 342                 if (reserve && err) {
 343                         mark_bootmem(start, pos, 0, 0);
 344                         return err;
 345                 }
 346
 347                 if (max == end)
 348                         return 0;
 349                 pos = bdata->node_low_pfn;
 350         }
 351         BUG();
 352 }
 353
 354 /**
 355  * free_bootmem_node - mark a page range as usable
 356  * @pgdat: node the range resides on
 357  * @physaddr: starting address of the range
 358  * @size: size of the range in bytes
 359  *
 360  * Partial pages will be considered reserved and left as they are.
 361  *
 362  * The range must reside completely on the specified node.
 363  */
 364 void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
 365                               unsigned long size)
 366 {
 367         unsigned long start, end;
 368
 369         kmemleak_free_part(__va(physaddr), size);
 370
 371         start = PFN_UP(physaddr);
 372         end = PFN_DOWN(physaddr + size);
 373
 374         mark_bootmem_node(pgdat->bdata, start, end, 0, 0);
 375 }
 376
 377 /**
 378  * free_bootmem - mark a page range as usable
 379  * @addr: starting address of the range
 380  * @size: size of the range in bytes
 381  *
 382  * Partial pages will be considered reserved and left as they are.
 383  *
 384  * The range must be contiguous but may span node boundaries.
 385  */
 386 void __init free_bootmem(unsigned long addr, unsigned long size)
 387 {
 388         unsigned long start, end;
 389
 390         kmemleak_free_part(__va(addr), size);
 391
 392         start = PFN_UP(addr);
 393         end = PFN_DOWN(addr + size);
 394
 395         mark_bootmem(start, end, 0, 0);
 396 }
 397
 398 /**
 399  * reserve_bootmem_node - mark a page range as reserved
 400  * @pgdat: node the range resides on
 401  * @physaddr: starting address of the range
 402  * @size: size of the range in bytes
 403  * @flags: reservation flags (see linux/bootmem.h)
 404  *
 405  * Partial pages will be reserved.
 406  *
 407  * The range must reside completely on the specified node.
 408  */
 409 int __init reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
 410                                  unsigned long size, int flags)
 411 {
 412         unsigned long start, end;
 413
 414         start = PFN_DOWN(physaddr);
 415         end = PFN_UP(physaddr + size);
 416
 417         return mark_bootmem_node(pgdat->bdata, start, end, 1, flags);
 418 }
 419
 420 /**
 421  * reserve_bootmem - mark a page range as usable
 422  * @addr: starting address of the range
 423  * @size: size of the range in bytes
 424  * @flags: reservation flags (see linux/bootmem.h)
 425  *
 426  * Partial pages will be reserved.
 427  *
 428  * The range must be contiguous but may span node boundaries.
 429  */
 430 int __init reserve_bootmem(unsigned long addr, unsigned long size,
 431                             int flags)
 432 {
 433         unsigned long start, end;
 434
 435         start = PFN_DOWN(addr);
 436         end = PFN_UP(addr + size);
 437
 438         return mark_bootmem(start, end, 1, flags);
 439 }
 440
 441 int __weak __init reserve_bootmem_generic(unsigned long phys, unsigned long len,
 442                                    int flags)
 443 {
 444         return reserve_bootmem(phys, len, flags);
 445 }
 446
 447 static unsigned long __init align_idx(struct bootmem_data *bdata,
 448                                       unsigned long idx, unsigned long step)
 449 {
 450         unsigned long base = bdata->node_min_pfn;
 451
 452         /*
 453          * Align the index with respect to the node start so that the
 454          * combination of both satisfies the requested alignment.
 455          */
 456
 457         return ALIGN(base + idx, step) - base;
 458 }
 459
 460 static unsigned long __init align_off(struct bootmem_data *bdata,
 461                                       unsigned long off, unsigned long align)
 462 {
 463         unsigned long base = PFN_PHYS(bdata->node_min_pfn);
 464
 465         /* Same as align_idx for byte offsets */
 466
 467         return ALIGN(base + off, align) - base;
 468 }
 469
 470 static void * __init alloc_bootmem_core(struct bootmem_data *bdata,
 471                                         unsigned long size, unsigned long align,
 472                                         unsigned long goal, unsigned long limit)
 473 {
 474         unsigned long fallback = 0;
 475         unsigned long min, max, start, sidx, midx, step;
 476
 477         bdebug("nid=%td size=%lx [%lu pages] align=%lx goal=%lx limit=%lx\n",
 478                 bdata - bootmem_node_data, size, PAGE_ALIGN(size) >> PAGE_SHIFT,
 479                 align, goal, limit);
 480
 481         BUG_ON(!size);
 482         BUG_ON(align & (align - 1));
 483         BUG_ON(limit && goal + size > limit);
 484
 485         if (!bdata->node_bootmem_map)
 486                 return NULL;
 487
 488         min = bdata->node_min_pfn;
 489         max = bdata->node_low_pfn;
 490
 491         goal >>= PAGE_SHIFT;
 492         limit >>= PAGE_SHIFT;
 493
 494         if (limit && max > limit)
 495                 max = limit;
 496         if (max <= min)
 497                 return NULL;
 498
 499         step = max(align >> PAGE_SHIFT, 1UL);
 500
 501         if (goal && min < goal && goal < max)
 502                 start = ALIGN(goal, step);
 503         else
 504                 start = ALIGN(min, step);
 505
 506         sidx = start - bdata->node_min_pfn;
 507         midx = max - bdata->node_min_pfn;
 508
 509         if (bdata->hint_idx > sidx) {
 510                 /*
 511                  * Handle the valid case of sidx being zero and still
 512                  * catch the fallback below.
 513                  */
 514                 fallback = sidx + 1;
 515                 sidx = align_idx(bdata, bdata->hint_idx, step);
 516         }
 517
 518         while (1) {
 519                 int merge;
 520                 void *region;
 521                 unsigned long eidx, i, start_off, end_off;
 522 find_block:
 523                 sidx = find_next_zero_bit(bdata->node_bootmem_map, midx, sidx);
 524                 sidx = align_idx(bdata, sidx, step);
 525                 eidx = sidx + PFN_UP(size);
 526
 527                 if (sidx >= midx || eidx > midx)
 528                         break;
 529
 530                 for (i = sidx; i < eidx; i++)
 531                         if (test_bit(i, bdata->node_bootmem_map)) {
 532                                 sidx = align_idx(bdata, i, step);
 533                                 if (sidx == i)
 534                                         sidx += step;
 535                                 goto find_block;
 536                         }
 537
 538                 if (bdata->last_end_off & (PAGE_SIZE - 1) &&
 539                                 PFN_DOWN(bdata->last_end_off) + 1 == sidx)
 540                         start_off = align_off(bdata, bdata->last_end_off, align);
 541                 else
 542                         start_off = PFN_PHYS(sidx);
 543
 544                 merge = PFN_DOWN(start_off) < sidx;
 545                 end_off = start_off + size;
 546
 547                 bdata->last_end_off = end_off;
 548                 bdata->hint_idx = PFN_UP(end_off);
 549
 550                 /*
 551                  * Reserve the area now:
 552                  */
 553                 if (__reserve(bdata, PFN_DOWN(start_off) + merge,
 554                                 PFN_UP(end_off), BOOTMEM_EXCLUSIVE))
 555                         BUG();
 556
 557                 region = phys_to_virt(PFN_PHYS(bdata->node_min_pfn) +
 558                                 start_off);
 559                 memset(region, 0, size);
 560                 /*
 561                  * The min_count is set to 0 so that bootmem allocated blocks
 562                  * are never reported as leaks.
 563                  */
 564                 kmemleak_alloc(region, size, 0, 0);
 565                 return region;
 566         }
 567
 568         if (fallback) {
 569                 sidx = align_idx(bdata, fallback - 1, step);
 570                 fallback = 0;
 571                 goto find_block;
 572         }
 573
 574         return NULL;
 575 }
 576
 577 static void * __init alloc_arch_preferred_bootmem(bootmem_data_t *bdata,
 578                                         unsigned long size, unsigned long align,
 579                                         unsigned long goal, unsigned long limit)
 580 {
 581         if (WARN_ON_ONCE(slab_is_available()))
 582                 return kzalloc(size, GFP_NOWAIT);
 583
 584 #ifdef CONFIG_HAVE_ARCH_BOOTMEM
 585         {
 586                 bootmem_data_t *p_bdata;
 587
 588                 p_bdata = bootmem_arch_preferred_node(bdata, size, align,
 589                                                         goal, limit);
 590                 if (p_bdata)
 591                         return alloc_bootmem_core(p_bdata, size, align,
 592                                                         goal, limit);
 593         }
 594 #endif
 595         return NULL;
 596 }
 597
 598 static void * __init ___alloc_bootmem_nopanic(unsigned long size,
 599                                         unsigned long align,
 600                                         unsigned long goal,
 601                                         unsigned long limit)
 602 {
 603         bootmem_data_t *bdata;
 604         void *region;
 605
 606 restart:
 607         region = alloc_arch_preferred_bootmem(NULL, size, align, goal, limit);
 608         if (region)
 609                 return region;
 610
 611         list_for_each_entry(bdata, &bdata_list, list) {
 612                 if (goal && bdata->node_low_pfn <= PFN_DOWN(goal))
 613                         continue;
 614                 if (limit && bdata->node_min_pfn >= PFN_DOWN(limit))
 615                         break;
 616
 617                 region = alloc_bootmem_core(bdata, size, align, goal, limit);
 618                 if (region)
 619                         return region;
 620         }
 621
 622         if (goal) {
 623                 goal = 0;
 624                 goto restart;
 625         }
 626
 627         return NULL;
 628 }
 629
 630 /**
 631  * __alloc_bootmem_nopanic - allocate boot memory without panicking
 632  * @size: size of the request in bytes
 633  * @align: alignment of the region
 634  * @goal: preferred starting address of the region
 635  *
 636  * The goal is dropped if it can not be satisfied and the allocation will
 637  * fall back to memory below @goal.
 638  *
 639  * Allocation may happen on any node in the system.
 640  *
 641  * Returns NULL on failure.
 642  */
 643 void * __init __alloc_bootmem_nopanic(unsigned long size, unsigned long align,
 644                                         unsigned long goal)
 645 {
 646         unsigned long limit = 0;
 647
 648         return ___alloc_bootmem_nopanic(size, align, goal, limit);
 649 }
 650
 651 static void * __init ___alloc_bootmem(unsigned long size, unsigned long align,
 652                                         unsigned long goal, unsigned long limit)
 653 {
 654         void *mem = ___alloc_bootmem_nopanic(size, align, goal, limit);
 655
 656         if (mem)
 657                 return mem;
 658         /*
 659          * Whoops, we cannot satisfy the allocation request.
 660          */
 661         printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size);
 662         panic("Out of memory");
 663         return NULL;
 664 }
 665
 666 /**
 667  * __alloc_bootmem - allocate boot memory
 668  * @size: size of the request in bytes
 669  * @align: alignment of the region
 670  * @goal: preferred starting address of the region
 671  *
 672  * The goal is dropped if it can not be satisfied and the allocation will
 673  * fall back to memory below @goal.
 674  *
 675  * Allocation may happen on any node in the system.
 676  *
 677  * The function panics if the request can not be satisfied.
 678  */
 679 void * __init __alloc_bootmem(unsigned long size, unsigned long align,
 680                               unsigned long goal)
 681 {
 682         unsigned long limit = 0;
 683
 684         return ___alloc_bootmem(size, align, goal, limit);
 685 }
 686
 687 static void * __init ___alloc_bootmem_node(bootmem_data_t *bdata,
 688                                 unsigned long size, unsigned long align,
 689                                 unsigned long goal, unsigned long limit)
 690 {
 691         void *ptr;
 692
 693         ptr = alloc_arch_preferred_bootmem(bdata, size, align, goal, limit);
 694         if (ptr)
 695                 return ptr;
 696
 697         ptr = alloc_bootmem_core(bdata, size, align, goal, limit);
 698         if (ptr)
 699                 return ptr;
 700
 701         return ___alloc_bootmem(size, align, goal, limit);
 702 }
 703
 704 /**
 705  * __alloc_bootmem_node - allocate boot memory from a specific node
 706  * @pgdat: node to allocate from
 707  * @size: size of the request in bytes
 708  * @align: alignment of the region
 709  * @goal: preferred starting address of the region
 710  *
 711  * The goal is dropped if it can not be satisfied and the allocation will
 712  * fall back to memory below @goal.
 713  *
 714  * Allocation may fall back to any node in the system if the specified node
 715  * can not hold the requested memory.
 716  *
 717  * The function panics if the request can not be satisfied.
 718  */
 719 void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
 720                                    unsigned long align, unsigned long goal)
 721 {
 722         if (WARN_ON_ONCE(slab_is_available()))
 723                 return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
 724
 725         return  ___alloc_bootmem_node(pgdat->bdata, size, align, goal, 0);
 726 }
 727
 728 void * __init __alloc_bootmem_node_high(pg_data_t *pgdat, unsigned long size,
 729                                    unsigned long align, unsigned long goal)
 730 {
 731 #ifdef MAX_DMA32_PFN
 732         unsigned long end_pfn;
 733
 734         if (WARN_ON_ONCE(slab_is_available()))
 735                 return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
 736
 737         /* update goal according ...MAX_DMA32_PFN */
 738         end_pfn = pgdat->node_start_pfn + pgdat->node_spanned_pages;
 739
 740         if (end_pfn > MAX_DMA32_PFN + (128 >> (20 - PAGE_SHIFT)) &&
 741             (goal >> PAGE_SHIFT) < MAX_DMA32_PFN) {
 742                 void *ptr;
 743                 unsigned long new_goal;
 744
 745                 new_goal = MAX_DMA32_PFN << PAGE_SHIFT;
 746                 ptr = alloc_bootmem_core(pgdat->bdata, size, align,
 747                                                  new_goal, 0);
 748                 if (ptr)
 749                         return ptr;
 750         }
 751 #endif
 752
 753         return __alloc_bootmem_node(pgdat, size, align, goal);
 754
 755 }
 756
 757 #ifdef CONFIG_SPARSEMEM
 758 /**
 759  * alloc_bootmem_section - allocate boot memory from a specific section
 760  * @size: size of the request in bytes
 761  * @section_nr: sparse map section to allocate from
 762  *
 763  * Return NULL on failure.
 764  */
 765 void * __init alloc_bootmem_section(unsigned long size,
 766                                     unsigned long section_nr)
 767 {
 768         bootmem_data_t *bdata;
 769         unsigned long pfn, goal, limit;
 770
 771         pfn = section_nr_to_pfn(section_nr);
 772         goal = pfn << PAGE_SHIFT;
 773         limit = section_nr_to_pfn(section_nr + 1) << PAGE_SHIFT;
 774         bdata = &bootmem_node_data[early_pfn_to_nid(pfn)];
 775
 776         return alloc_bootmem_core(bdata, size, SMP_CACHE_BYTES, goal, limit);
 777 }
 778 #endif
 779
 780 void * __init __alloc_bootmem_node_nopanic(pg_data_t *pgdat, unsigned long size,
 781                                    unsigned long align, unsigned long goal)
 782 {
 783         void *ptr;
 784
 785         if (WARN_ON_ONCE(slab_is_available()))
 786                 return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
 787
 788         ptr = alloc_arch_preferred_bootmem(pgdat->bdata, size, align, goal, 0);
 789         if (ptr)
 790                 return ptr;
 791
 792         ptr = alloc_bootmem_core(pgdat->bdata, size, align, goal, 0);
 793         if (ptr)
 794                 return ptr;
 795
 796         return __alloc_bootmem_nopanic(size, align, goal);
 797 }
 798
 799 #ifndef ARCH_LOW_ADDRESS_LIMIT
 800 #define ARCH_LOW_ADDRESS_LIMIT  0xffffffffUL
 801 #endif
 802
 803 /**
 804  * __alloc_bootmem_low - allocate low boot memory
 805  * @size: size of the request in bytes
 806  * @align: alignment of the region
 807  * @goal: preferred starting address of the region
 808  *
 809  * The goal is dropped if it can not be satisfied and the allocation will
 810  * fall back to memory below @goal.
 811  *
 812  * Allocation may happen on any node in the system.
 813  *
 814  * The function panics if the request can not be satisfied.
 815  */
 816 void * __init __alloc_bootmem_low(unsigned long size, unsigned long align,
 817                                   unsigned long goal)
 818 {
 819         return ___alloc_bootmem(size, align, goal, ARCH_LOW_ADDRESS_LIMIT);
 820 }
 821
 822 /**
 823  * __alloc_bootmem_low_node - allocate low boot memory from a specific node
 824  * @pgdat: node to allocate from
 825  * @size: size of the request in bytes
 826  * @align: alignment of the region
 827  * @goal: preferred starting address of the region
 828  *
 829  * The goal is dropped if it can not be satisfied and the allocation will
 830  * fall back to memory below @goal.
 831  *
 832  * Allocation may fall back to any node in the system if the specified node
 833  * can not hold the requested memory.
 834  *
 835  * The function panics if the request can not be satisfied.
 836  */
 837 void * __init __alloc_bootmem_low_node(pg_data_t *pgdat, unsigned long size,
 838                                        unsigned long align, unsigned long goal)
 839 {
 840         if (WARN_ON_ONCE(slab_is_available()))
 841                 return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
 842
 843         return ___alloc_bootmem_node(pgdat->bdata, size, align,
 844                                 goal, ARCH_LOW_ADDRESS_LIMIT);
 845 }