Broadcasting the Linux kernel, one source file at a time!

mm/memblock.c

mm/memblock.c (863 lines, 23222 bytes)
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/*
 * Procedures for maintaining information about logical memory blocks.
 *
 * Peter Bergner, IBM Corp.  June 2001.
 * Copyright (C) 2001 Peter Bergner.
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/poison.h>
#include <linux/pfn.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/memblock.h>

struct memblock memblock __initdata_memblock;

int memblock_debug __initdata_memblock;
int memblock_can_resize __initdata_memblock;
static struct memblock_region memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS + 1] __initdata_memblock;
static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_REGIONS + 1] __initdata_memblock;

/* inline so we don't get a warning when pr_debug is compiled out */
static inline const char *memblock_type_name(struct memblock_type *type)
{
  if (type == &memblock.memory)
      return "memory";
  else if (type == &memblock.reserved)
      return "reserved";
  else
      return "unknown";
}

/*
 * Address comparison utilities
 */

static phys_addr_t __init_memblock memblock_align_down(phys_addr_t addr, phys_addr_t size)
{
  return addr & ~(size - 1);
}

static phys_addr_t __init_memblock memblock_align_up(phys_addr_t addr, phys_addr_t size)
{
  return (addr + (size - 1)) & ~(size - 1);
}

static unsigned long __init_memblock memblock_addrs_overlap(phys_addr_t base1, phys_addr_t size1,
                     phys_addr_t base2, phys_addr_t size2)
{
  return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
}

long __init_memblock memblock_overlaps_region(struct memblock_type *type, phys_addr_t base, phys_addr_t size)
{
  unsigned long i;

  for (i = 0; i < type->cnt; i++) {
      phys_addr_t rgnbase = type->regions[i].base;
      phys_addr_t rgnsize = type->regions[i].size;
      if (memblock_addrs_overlap(base, size, rgnbase, rgnsize))
          break;
  }

  return (i < type->cnt) ? i : -1;
}

/*
 * Find, allocate, deallocate or reserve unreserved regions. All allocations
 * are top-down.
 */

static phys_addr_t __init_memblock memblock_find_region(phys_addr_t start, phys_addr_t end,
                    phys_addr_t size, phys_addr_t align)
{
  phys_addr_t base, res_base;
  long j;

  /* In case, huge size is requested */
  if (end < size)
      return MEMBLOCK_ERROR;

  base = memblock_align_down((end - size), align);

  /* Prevent allocations returning 0 as it's also used to
  * indicate an allocation failure
  */
  if (start == 0)
      start = PAGE_SIZE;

  while (start <= base) {
      j = memblock_overlaps_region(&memblock.reserved, base, size);
      if (j < 0)
          return base;
      res_base = memblock.reserved.regions[j].base;
      if (res_base < size)
          break;
      base = memblock_align_down(res_base - size, align);
  }

  return MEMBLOCK_ERROR;
}

static phys_addr_t __init_memblock memblock_find_base(phys_addr_t size,
          phys_addr_t align, phys_addr_t start, phys_addr_t end)
{
  long i;

  BUG_ON(0 == size);

  /* Pump up max_addr */
  if (end == MEMBLOCK_ALLOC_ACCESSIBLE)
      end = memblock.current_limit;

  /* We do a top-down search, this tends to limit memory
  * fragmentation by keeping early boot allocs near the
  * top of memory
  */
  for (i = memblock.memory.cnt - 1; i >= 0; i--) {
      phys_addr_t memblockbase = memblock.memory.regions[i].base;
      phys_addr_t memblocksize = memblock.memory.regions[i].size;
      phys_addr_t bottom, top, found;

      if (memblocksize < size)
          continue;
      if ((memblockbase + memblocksize) <= start)
          break;
      bottom = max(memblockbase, start);
      top = min(memblockbase + memblocksize, end);
      if (bottom >= top)
          continue;
      found = memblock_find_region(bottom, top, size, align);
      if (found != MEMBLOCK_ERROR)
          return found;
  }
  return MEMBLOCK_ERROR;
}

/*
 * Find a free area with specified alignment in a specific range.
 */
u64 __init_memblock memblock_find_in_range(u64 start, u64 end, u64 size, u64 align)
{
  return memblock_find_base(size, align, start, end);
}

/*
 * Free memblock.reserved.regions
 */
int __init_memblock memblock_free_reserved_regions(void)
{
  if (memblock.reserved.regions == memblock_reserved_init_regions)
      return 0;

  return memblock_free(__pa(memblock.reserved.regions),
       sizeof(struct memblock_region) * memblock.reserved.max);
}

/*
 * Reserve memblock.reserved.regions
 */
int __init_memblock memblock_reserve_reserved_regions(void)
{
  if (memblock.reserved.regions == memblock_reserved_init_regions)
      return 0;

  return memblock_reserve(__pa(memblock.reserved.regions),
       sizeof(struct memblock_region) * memblock.reserved.max);
}

static void __init_memblock memblock_remove_region(struct memblock_type *type, unsigned long r)
{
  unsigned long i;

  for (i = r; i < type->cnt - 1; i++) {
      type->regions[i].base = type->regions[i + 1].base;
      type->regions[i].size = type->regions[i + 1].size;
  }
  type->cnt--;

  /* Special case for empty arrays */
  if (type->cnt == 0) {
      type->cnt = 1;
      type->regions[0].base = 0;
      type->regions[0].size = 0;
  }
}

/* Defined below but needed now */
static long memblock_add_region(struct memblock_type *type, phys_addr_t base, phys_addr_t size);

static int __init_memblock memblock_double_array(struct memblock_type *type)
{
  struct memblock_region *new_array, *old_array;
  phys_addr_t old_size, new_size, addr;
  int use_slab = slab_is_available();

  /* We don't allow resizing until we know about the reserved regions
  * of memory that aren't suitable for allocation
  */
  if (!memblock_can_resize)
      return -1;

  /* Calculate new doubled size */
  old_size = type->max * sizeof(struct memblock_region);
  new_size = old_size << 1;

  /* Try to find some space for it.
  *
  * WARNING: We assume that either slab_is_available() and we use it or
  * we use MEMBLOCK for allocations. That means that this is unsafe to use
  * when bootmem is currently active (unless bootmem itself is implemented
  * on top of MEMBLOCK which isn't the case yet)
  *
  * This should however not be an issue for now, as we currently only
  * call into MEMBLOCK while it's still active, or much later when slab is
  * active for memory hotplug operations
  */
  if (use_slab) {
      new_array = kmalloc(new_size, GFP_KERNEL);
      addr = new_array == NULL ? MEMBLOCK_ERROR : __pa(new_array);
  } else
      addr = memblock_find_base(new_size, sizeof(phys_addr_t), 0, MEMBLOCK_ALLOC_ACCESSIBLE);
  if (addr == MEMBLOCK_ERROR) {
      pr_err("memblock: Failed to double %s array from %ld to %ld entries !\n",
             memblock_type_name(type), type->max, type->max * 2);
      return -1;
  }
  new_array = __va(addr);

  memblock_dbg("memblock: %s array is doubled to %ld at [%#010llx-%#010llx]",
       memblock_type_name(type), type->max * 2, (u64)addr, (u64)addr + new_size - 1);

  /* Found space, we now need to move the array over before
  * we add the reserved region since it may be our reserved
  * array itself that is full.
  */
  memcpy(new_array, type->regions, old_size);
  memset(new_array + type->max, 0, old_size);
  old_array = type->regions;
  type->regions = new_array;
  type->max <<= 1;

  /* If we use SLAB that's it, we are done */
  if (use_slab)
      return 0;

  /* Add the new reserved region now. Should not fail ! */
  BUG_ON(memblock_add_region(&memblock.reserved, addr, new_size));

  /* If the array wasn't our static init one, then free it. We only do
  * that before SLAB is available as later on, we don't know whether
  * to use kfree or free_bootmem_pages(). Shouldn't be a big deal
  * anyways
  */
  if (old_array != memblock_memory_init_regions &&
      old_array != memblock_reserved_init_regions)
      memblock_free(__pa(old_array), old_size);

  return 0;
}

extern int __init_memblock __weak memblock_memory_can_coalesce(phys_addr_t addr1, phys_addr_t size1,
                    phys_addr_t addr2, phys_addr_t size2)
{
  return 1;
}

static long __init_memblock memblock_add_region(struct memblock_type *type,
                      phys_addr_t base, phys_addr_t size)
{
  phys_addr_t end = base + size;
  int i, slot = -1;

  /* First try and coalesce this MEMBLOCK with others */
  for (i = 0; i < type->cnt; i++) {
      struct memblock_region *rgn = &type->regions[i];
      phys_addr_t rend = rgn->base + rgn->size;

      /* Exit if there's no possible hits */
      if (rgn->base > end || rgn->size == 0)
          break;

      /* Check if we are fully enclosed within an existing
      * block
      */
      if (rgn->base <= base && rend >= end)
          return 0;

      /* Check if we overlap or are adjacent with the bottom
      * of a block.
      */
      if (base < rgn->base && end >= rgn->base) {
          /* If we can't coalesce, create a new block */
          if (!memblock_memory_can_coalesce(base, size,
                            rgn->base,
                            rgn->size)) {
              /* Overlap & can't coalesce are mutually
              * exclusive, if you do that, be prepared
              * for trouble
              */
              WARN_ON(end != rgn->base);
              goto new_block;
          }
          /* We extend the bottom of the block down to our
          * base
          */
          rgn->base = base;
          rgn->size = rend - base;

          /* Return if we have nothing else to allocate
          * (fully coalesced)
          */
          if (rend >= end)
              return 0;

          /* We continue processing from the end of the
          * coalesced block.
          */
          base = rend;
          size = end - base;
      }

      /* Now check if we overlap or are adjacent with the
      * top of a block
      */
      if (base <= rend && end >= rend) {
          /* If we can't coalesce, create a new block */
          if (!memblock_memory_can_coalesce(rgn->base,
                            rgn->size,
                            base, size)) {
              /* Overlap & can't coalesce are mutually
              * exclusive, if you do that, be prepared
              * for trouble
              */
              WARN_ON(rend != base);
              goto new_block;
          }
          /* We adjust our base down to enclose the
          * original block and destroy it. It will be
          * part of our new allocation. Since we've
          * freed an entry, we know we won't fail
          * to allocate one later, so we won't risk
          * losing the original block allocation.
          */
          size += (base - rgn->base);
          base = rgn->base;
          memblock_remove_region(type, i--);
      }
  }

  /* If the array is empty, special case, replace the fake
  * filler region and return
  */
  if ((type->cnt == 1) && (type->regions[0].size == 0)) {
      type->regions[0].base = base;
      type->regions[0].size = size;
      return 0;
  }

 new_block:
  /* If we are out of space, we fail. It's too late to resize the array
  * but then this shouldn't have happened in the first place.
  */
  if (WARN_ON(type->cnt >= type->max))
      return -1;

  /* Couldn't coalesce the MEMBLOCK, so add it to the sorted table. */
  for (i = type->cnt - 1; i >= 0; i--) {
      if (base < type->regions[i].base) {
          type->regions[i+1].base = type->regions[i].base;
          type->regions[i+1].size = type->regions[i].size;
      } else {
          type->regions[i+1].base = base;
          type->regions[i+1].size = size;
          slot = i + 1;
          break;
      }
  }
  if (base < type->regions[0].base) {
      type->regions[0].base = base;
      type->regions[0].size = size;
      slot = 0;
  }
  type->cnt++;

  /* The array is full ? Try to resize it. If that fails, we undo
  * our allocation and return an error
  */
  if (type->cnt == type->max && memblock_double_array(type)) {
      BUG_ON(slot < 0);
      memblock_remove_region(type, slot);
      return -1;
  }

  return 0;
}

long __init_memblock memblock_add(phys_addr_t base, phys_addr_t size)
{
  return memblock_add_region(&memblock.memory, base, size);

}

static long __init_memblock __memblock_remove(struct memblock_type *type,
                        phys_addr_t base, phys_addr_t size)
{
  phys_addr_t end = base + size;
  int i;

  /* Walk through the array for collisions */
  for (i = 0; i < type->cnt; i++) {
      struct memblock_region *rgn = &type->regions[i];
      phys_addr_t rend = rgn->base + rgn->size;

      /* Nothing more to do, exit */
      if (rgn->base > end || rgn->size == 0)
          break;

      /* If we fully enclose the block, drop it */
      if (base <= rgn->base && end >= rend) {
          memblock_remove_region(type, i--);
          continue;
      }

      /* If we are fully enclosed within a block
      * then we need to split it and we are done
      */
      if (base > rgn->base && end < rend) {
          rgn->size = base - rgn->base;
          if (!memblock_add_region(type, end, rend - end))
              return 0;
          /* Failure to split is bad, we at least
          * restore the block before erroring
          */
          rgn->size = rend - rgn->base;
          WARN_ON(1);
          return -1;
      }

      /* Check if we need to trim the bottom of a block */
      if (rgn->base < end && rend > end) {
          rgn->size -= end - rgn->base;
          rgn->base = end;
          break;
      }

      /* And check if we need to trim the top of a block */
      if (base < rend)
          rgn->size -= rend - base;

  }
  return 0;
}

long __init_memblock memblock_remove(phys_addr_t base, phys_addr_t size)
{
  return __memblock_remove(&memblock.memory, base, size);
}

long __init_memblock memblock_free(phys_addr_t base, phys_addr_t size)
{
  return __memblock_remove(&memblock.reserved, base, size);
}

long __init_memblock memblock_reserve(phys_addr_t base, phys_addr_t size)
{
  struct memblock_type *_rgn = &memblock.reserved;

  BUG_ON(0 == size);

  return memblock_add_region(_rgn, base, size);
}

phys_addr_t __init __memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
{
  phys_addr_t found;

  /* We align the size to limit fragmentation. Without this, a lot of
  * small allocs quickly eat up the whole reserve array on sparc
  */
  size = memblock_align_up(size, align);

  found = memblock_find_base(size, align, 0, max_addr);
  if (found != MEMBLOCK_ERROR &&
      !memblock_add_region(&memblock.reserved, found, size))
      return found;

  return 0;
}

phys_addr_t __init memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
{
  phys_addr_t alloc;

  alloc = __memblock_alloc_base(size, align, max_addr);

  if (alloc == 0)
      panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
            (unsigned long long) size, (unsigned long long) max_addr);

  return alloc;
}

phys_addr_t __init memblock_alloc(phys_addr_t size, phys_addr_t align)
{
  return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
}


/*
 * Additional node-local allocators. Search for node memory is bottom up
 * and walks memblock regions within that node bottom-up as well, but allocation
 * within an memblock region is top-down. XXX I plan to fix that at some stage
 *
 * WARNING: Only available after early_node_map[] has been populated,
 * on some architectures, that is after all the calls to add_active_range()
 * have been done to populate it.
 */

phys_addr_t __weak __init memblock_nid_range(phys_addr_t start, phys_addr_t end, int *nid)
{
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
  /*
  * This code originates from sparc which really wants use to walk by addresses
  * and returns the nid. This is not very convenient for early_pfn_map[] users
  * as the map isn't sorted yet, and it really wants to be walked by nid.
  *
  * For now, I implement the inefficient method below which walks the early
  * map multiple times. Eventually we may want to use an ARCH config option
  * to implement a completely different method for both case.
  */
  unsigned long start_pfn, end_pfn;
  int i;

  for (i = 0; i < MAX_NUMNODES; i++) {
      get_pfn_range_for_nid(i, &start_pfn, &end_pfn);
      if (start < PFN_PHYS(start_pfn) || start >= PFN_PHYS(end_pfn))
          continue;
      *nid = i;
      return min(end, PFN_PHYS(end_pfn));
  }
#endif
  *nid = 0;

  return end;
}

static phys_addr_t __init memblock_alloc_nid_region(struct memblock_region *mp,
                         phys_addr_t size,
                         phys_addr_t align, int nid)
{
  phys_addr_t start, end;

  start = mp->base;
  end = start + mp->size;

  start = memblock_align_up(start, align);
  while (start < end) {
      phys_addr_t this_end;
      int this_nid;

      this_end = memblock_nid_range(start, end, &this_nid);
      if (this_nid == nid) {
          phys_addr_t ret = memblock_find_region(start, this_end, size, align);
          if (ret != MEMBLOCK_ERROR &&
              !memblock_add_region(&memblock.reserved, ret, size))
              return ret;
      }
      start = this_end;
  }

  return MEMBLOCK_ERROR;
}

phys_addr_t __init memblock_alloc_nid(phys_addr_t size, phys_addr_t align, int nid)
{
  struct memblock_type *mem = &memblock.memory;
  int i;

  BUG_ON(0 == size);

  /* We align the size to limit fragmentation. Without this, a lot of
  * small allocs quickly eat up the whole reserve array on sparc
  */
  size = memblock_align_up(size, align);

  /* We do a bottom-up search for a region with the right
  * nid since that's easier considering how memblock_nid_range()
  * works
  */
  for (i = 0; i < mem->cnt; i++) {
      phys_addr_t ret = memblock_alloc_nid_region(&mem->regions[i],
                         size, align, nid);
      if (ret != MEMBLOCK_ERROR)
          return ret;
  }

  return 0;
}

phys_addr_t __init memblock_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid)
{
  phys_addr_t res = memblock_alloc_nid(size, align, nid);

  if (res)
      return res;
  return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ANYWHERE);
}


/*
 * Remaining API functions
 */

/* You must call memblock_analyze() before this. */
phys_addr_t __init memblock_phys_mem_size(void)
{
  return memblock.memory_size;
}

phys_addr_t __init_memblock memblock_end_of_DRAM(void)
{
  int idx = memblock.memory.cnt - 1;

  return (memblock.memory.regions[idx].base + memblock.memory.regions[idx].size);
}

/* You must call memblock_analyze() after this. */
void __init memblock_enforce_memory_limit(phys_addr_t memory_limit)
{
  unsigned long i;
  phys_addr_t limit;
  struct memblock_region *p;

  if (!memory_limit)
      return;

  /* Truncate the memblock regions to satisfy the memory limit. */
  limit = memory_limit;
  for (i = 0; i < memblock.memory.cnt; i++) {
      if (limit > memblock.memory.regions[i].size) {
          limit -= memblock.memory.regions[i].size;
          continue;
      }

      memblock.memory.regions[i].size = limit;
      memblock.memory.cnt = i + 1;
      break;
  }

  memory_limit = memblock_end_of_DRAM();

  /* And truncate any reserves above the limit also. */
  for (i = 0; i < memblock.reserved.cnt; i++) {
      p = &memblock.reserved.regions[i];

      if (p->base > memory_limit)
          p->size = 0;
      else if ((p->base + p->size) > memory_limit)
          p->size = memory_limit - p->base;

      if (p->size == 0) {
          memblock_remove_region(&memblock.reserved, i);
          i--;
      }
  }
}

static int __init_memblock memblock_search(struct memblock_type *type, phys_addr_t addr)
{
  unsigned int left = 0, right = type->cnt;

  do {
      unsigned int mid = (right + left) / 2;

      if (addr < type->regions[mid].base)
          right = mid;
      else if (addr >= (type->regions[mid].base +
                type->regions[mid].size))
          left = mid + 1;
      else
          return mid;
  } while (left < right);
  return -1;
}

int __init memblock_is_reserved(phys_addr_t addr)
{
  return memblock_search(&memblock.reserved, addr) != -1;
}

int __init_memblock memblock_is_memory(phys_addr_t addr)
{
  return memblock_search(&memblock.memory, addr) != -1;
}

int __init_memblock memblock_is_region_memory(phys_addr_t base, phys_addr_t size)
{
  int idx = memblock_search(&memblock.memory, base);

  if (idx == -1)
      return 0;
  return memblock.memory.regions[idx].base <= base &&
      (memblock.memory.regions[idx].base +
       memblock.memory.regions[idx].size) >= (base + size);
}

int __init_memblock memblock_is_region_reserved(phys_addr_t base, phys_addr_t size)
{
  return memblock_overlaps_region(&memblock.reserved, base, size) >= 0;
}


void __init_memblock memblock_set_current_limit(phys_addr_t limit)
{
  memblock.current_limit = limit;
}

static void __init_memblock memblock_dump(struct memblock_type *region, char *name)
{
  unsigned long long base, size;
  int i;

  pr_info(" %s.cnt  = 0x%lx\n", name, region->cnt);

  for (i = 0; i < region->cnt; i++) {
      base = region->regions[i].base;
      size = region->regions[i].size;

      pr_info(" %s[%#x]\t[%#016llx-%#016llx], %#llx bytes\n",
          name, i, base, base + size - 1, size);
  }
}

void __init_memblock memblock_dump_all(void)
{
  if (!memblock_debug)
      return;

  pr_info("MEMBLOCK configuration:\n");
  pr_info(" memory size = 0x%llx\n", (unsigned long long)memblock.memory_size);

  memblock_dump(&memblock.memory, "memory");
  memblock_dump(&memblock.reserved, "reserved");
}

void __init memblock_analyze(void)
{
  int i;

  /* Check marker in the unused last array entry */
  WARN_ON(memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS].base
      != (phys_addr_t)RED_INACTIVE);
  WARN_ON(memblock_reserved_init_regions[INIT_MEMBLOCK_REGIONS].base
      != (phys_addr_t)RED_INACTIVE);

  memblock.memory_size = 0;

  for (i = 0; i < memblock.memory.cnt; i++)
      memblock.memory_size += memblock.memory.regions[i].size;

  /* We allow resizing from there */
  memblock_can_resize = 1;
}

void __init memblock_init(void)
{
  static int init_done __initdata = 0;

  if (init_done)
      return;
  init_done = 1;

  /* Hookup the initial arrays */
  memblock.memory.regions  = memblock_memory_init_regions;
  memblock.memory.max      = INIT_MEMBLOCK_REGIONS;
  memblock.reserved.regions    = memblock_reserved_init_regions;
  memblock.reserved.max    = INIT_MEMBLOCK_REGIONS;

  /* Write a marker in the unused last array entry */
  memblock.memory.regions[INIT_MEMBLOCK_REGIONS].base = (phys_addr_t)RED_INACTIVE;
  memblock.reserved.regions[INIT_MEMBLOCK_REGIONS].base = (phys_addr_t)RED_INACTIVE;

  /* Create a dummy zero size MEMBLOCK which will get coalesced away later.
  * This simplifies the memblock_add() code below...
  */
  memblock.memory.regions[0].base = 0;
  memblock.memory.regions[0].size = 0;
  memblock.memory.cnt = 1;

  /* Ditto. */
  memblock.reserved.regions[0].base = 0;
  memblock.reserved.regions[0].size = 0;
  memblock.reserved.cnt = 1;

  memblock.current_limit = MEMBLOCK_ALLOC_ANYWHERE;
}

static int __init early_memblock(char *p)
{
  if (p && strstr(p, "debug"))
      memblock_debug = 1;
  return 0;
}
early_param("memblock", early_memblock);

#if defined(CONFIG_DEBUG_FS) && !defined(ARCH_DISCARD_MEMBLOCK)

static int memblock_debug_show(struct seq_file *m, void *private)
{
  struct memblock_type *type = m->private;
  struct memblock_region *reg;
  int i;

  for (i = 0; i < type->cnt; i++) {
      reg = &type->regions[i];
      seq_printf(m, "%4d: ", i);
      if (sizeof(phys_addr_t) == 4)
          seq_printf(m, "0x%08lx..0x%08lx\n",
                 (unsigned long)reg->base,
                 (unsigned long)(reg->base + reg->size - 1));
      else
          seq_printf(m, "0x%016llx..0x%016llx\n",
                 (unsigned long long)reg->base,
                 (unsigned long long)(reg->base + reg->size - 1));

  }
  return 0;
}

static int memblock_debug_open(struct inode *inode, struct file *file)
{
  return single_open(file, memblock_debug_show, inode->i_private);
}

static const struct file_operations memblock_debug_fops = {
  .open = memblock_debug_open,
  .read = seq_read,
  .llseek = seq_lseek,
  .release = single_release,
};

static int __init memblock_init_debugfs(void)
{
  struct dentry *root = debugfs_create_dir("memblock", NULL);
  if (!root)
      return -ENXIO;
  debugfs_create_file("memory", S_IRUGO, root, &memblock.memory, &memblock_debug_fops);
  debugfs_create_file("reserved", S_IRUGO, root, &memblock.reserved, &memblock_debug_fops);

  return 0;
}
__initcall(memblock_init_debugfs);

#endif /* CONFIG_DEBUG_FS */