/*
   * 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)));
  }

  static 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 !
  ",
  		       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;
  }

  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.
  ",
  		      (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;

  }

  /* lowest address */
  phys_addr_t __init_memblock memblock_start_of_DRAM(void)
  {
  	return memblock.memory.regions[0].base;
  }

  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
  ", 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
  ",

  		    name, i, base, base + size - 1, size);
  	}
  }

  void __init_memblock memblock_dump_all(void)

  {
  	if (!memblock_debug)
  		return;
  
  	pr_info("MEMBLOCK configuration:
  ");
  	pr_info(" memory size = 0x%llx
  ", (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

  		!= MEMBLOCK_INACTIVE);

  	WARN_ON(memblock_reserved_init_regions[INIT_MEMBLOCK_REGIONS].base

  		!= MEMBLOCK_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 = MEMBLOCK_INACTIVE;
  	memblock.reserved.regions[INIT_MEMBLOCK_REGIONS].base = MEMBLOCK_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
  ",
  				   (unsigned long)reg->base,
  				   (unsigned long)(reg->base + reg->size - 1));
  		else
  			seq_printf(m, "0x%016llx..0x%016llx
  ",
  				   (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 */