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