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