// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   * Procedures for maintaining information about logical memory blocks.
   *
   * Peter Bergner, IBM Corp.	June 2001.
   * Copyright (C) 2001 Peter Bergner.

   */
  
  #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/kmemleak.h>

  #include <linux/seq_file.h>

  #include <linux/memblock.h>

  #include <asm/sections.h>

  #include <linux/io.h>
  
  #include "internal.h"

  #define INIT_MEMBLOCK_REGIONS			128
  #define INIT_PHYSMEM_REGIONS			4
  
  #ifndef INIT_MEMBLOCK_RESERVED_REGIONS
  # define INIT_MEMBLOCK_RESERVED_REGIONS		INIT_MEMBLOCK_REGIONS
  #endif

  /**
   * DOC: memblock overview
   *
   * Memblock is a method of managing memory regions during the early
   * boot period when the usual kernel memory allocators are not up and
   * running.
   *
   * Memblock views the system memory as collections of contiguous
   * regions. There are several types of these collections:
   *
   * * ``memory`` - describes the physical memory available to the
   *   kernel; this may differ from the actual physical memory installed
   *   in the system, for instance when the memory is restricted with
   *   ``mem=`` command line parameter
   * * ``reserved`` - describes the regions that were allocated
   * * ``physmap`` - describes the actual physical memory regardless of
   *   the possible restrictions; the ``physmap`` type is only available
   *   on some architectures.
   *
   * Each region is represented by :c:type:`struct memblock_region` that
   * defines the region extents, its attributes and NUMA node id on NUMA
   * systems. Every memory type is described by the :c:type:`struct
   * memblock_type` which contains an array of memory regions along with
   * the allocator metadata. The memory types are nicely wrapped with
   * :c:type:`struct memblock`. This structure is statically initialzed
   * at build time. The region arrays for the "memory" and "reserved"
   * types are initially sized to %INIT_MEMBLOCK_REGIONS and for the
   * "physmap" type to %INIT_PHYSMEM_REGIONS.
   * The :c:func:`memblock_allow_resize` enables automatic resizing of
   * the region arrays during addition of new regions. This feature
   * should be used with care so that memory allocated for the region
   * array will not overlap with areas that should be reserved, for
   * example initrd.
   *
   * The early architecture setup should tell memblock what the physical
   * memory layout is by using :c:func:`memblock_add` or
   * :c:func:`memblock_add_node` functions. The first function does not
   * assign the region to a NUMA node and it is appropriate for UMA
   * systems. Yet, it is possible to use it on NUMA systems as well and
   * assign the region to a NUMA node later in the setup process using
   * :c:func:`memblock_set_node`. The :c:func:`memblock_add_node`
   * performs such an assignment directly.
   *

   * Once memblock is setup the memory can be allocated using one of the
   * API variants:
   *
   * * :c:func:`memblock_phys_alloc*` - these functions return the
   *   **physical** address of the allocated memory
   * * :c:func:`memblock_alloc*` - these functions return the **virtual**
   *   address of the allocated memory.
   *
   * Note, that both API variants use implict assumptions about allowed
   * memory ranges and the fallback methods. Consult the documentation
   * of :c:func:`memblock_alloc_internal` and
   * :c:func:`memblock_alloc_range_nid` functions for more elaboarte
   * description.

   *
   * As the system boot progresses, the architecture specific
   * :c:func:`mem_init` function frees all the memory to the buddy page
   * allocator.
   *

   * Unless an architecure enables %CONFIG_ARCH_KEEP_MEMBLOCK, the

   * memblock data structures will be discarded after the system
   * initialization compltes.
   */

  #ifndef CONFIG_NEED_MULTIPLE_NODES
  struct pglist_data __refdata contig_page_data;
  EXPORT_SYMBOL(contig_page_data);
  #endif
  
  unsigned long max_low_pfn;
  unsigned long min_low_pfn;
  unsigned long max_pfn;
  unsigned long long max_possible_pfn;

  static struct memblock_region memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock;

  static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_RESERVED_REGIONS] __initdata_memblock;

  #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP
  static struct memblock_region memblock_physmem_init_regions[INIT_PHYSMEM_REGIONS] __initdata_memblock;
  #endif

  
  struct memblock memblock __initdata_memblock = {
  	.memory.regions		= memblock_memory_init_regions,
  	.memory.cnt		= 1,	/* empty dummy entry */
  	.memory.max		= INIT_MEMBLOCK_REGIONS,

  	.memory.name		= "memory",

  
  	.reserved.regions	= memblock_reserved_init_regions,
  	.reserved.cnt		= 1,	/* empty dummy entry */

  	.reserved.max		= INIT_MEMBLOCK_RESERVED_REGIONS,

  	.reserved.name		= "reserved",

  #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP
  	.physmem.regions	= memblock_physmem_init_regions,
  	.physmem.cnt		= 1,	/* empty dummy entry */
  	.physmem.max		= INIT_PHYSMEM_REGIONS,

  	.physmem.name		= "physmem",

  #endif

  	.bottom_up		= false,

  	.current_limit		= MEMBLOCK_ALLOC_ANYWHERE,
  };

  int memblock_debug __initdata_memblock;

  static bool system_has_some_mirror __initdata_memblock = false;

  static int memblock_can_resize __initdata_memblock;

  static int memblock_memory_in_slab __initdata_memblock = 0;
  static int memblock_reserved_in_slab __initdata_memblock = 0;

  static enum memblock_flags __init_memblock choose_memblock_flags(void)

  {
  	return system_has_some_mirror ? MEMBLOCK_MIRROR : MEMBLOCK_NONE;
  }

  /* adjust *@size so that (@base + *@size) doesn't overflow, return new size */
  static inline phys_addr_t memblock_cap_size(phys_addr_t base, phys_addr_t *size)
  {

  	return *size = min(*size, PHYS_ADDR_MAX - base);

  }

  /*
   * Address comparison utilities
   */

  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)));
  }

  bool __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++)
  		if (memblock_addrs_overlap(base, size, type->regions[i].base,
  					   type->regions[i].size))

  			break;

  	return i < type->cnt;

  }

  /**

   * __memblock_find_range_bottom_up - find free area utility in bottom-up
   * @start: start of candidate range

   * @end: end of candidate range, can be %MEMBLOCK_ALLOC_ANYWHERE or
   *       %MEMBLOCK_ALLOC_ACCESSIBLE

   * @size: size of free area to find
   * @align: alignment of free area to find

   * @nid: nid of the free area to find, %NUMA_NO_NODE for any node

   * @flags: pick from blocks based on memory attributes

   *
   * Utility called from memblock_find_in_range_node(), find free area bottom-up.
   *

   * Return:

   * Found address on success, 0 on failure.
   */
  static phys_addr_t __init_memblock
  __memblock_find_range_bottom_up(phys_addr_t start, phys_addr_t end,

  				phys_addr_t size, phys_addr_t align, int nid,

  				enum memblock_flags flags)

  {
  	phys_addr_t this_start, this_end, cand;
  	u64 i;

  	for_each_free_mem_range(i, nid, flags, &this_start, &this_end, NULL) {

  		this_start = clamp(this_start, start, end);
  		this_end = clamp(this_end, start, end);
  
  		cand = round_up(this_start, align);
  		if (cand < this_end && this_end - cand >= size)
  			return cand;
  	}
  
  	return 0;
  }

  /**

   * __memblock_find_range_top_down - find free area utility, in top-down

   * @start: start of candidate range

   * @end: end of candidate range, can be %MEMBLOCK_ALLOC_ANYWHERE or
   *       %MEMBLOCK_ALLOC_ACCESSIBLE

   * @size: size of free area to find
   * @align: alignment of free area to find

   * @nid: nid of the free area to find, %NUMA_NO_NODE for any node

   * @flags: pick from blocks based on memory attributes

   *

   * Utility called from memblock_find_in_range_node(), find free area top-down.

   *

   * Return:

   * Found address on success, 0 on failure.

   */

  static phys_addr_t __init_memblock
  __memblock_find_range_top_down(phys_addr_t start, phys_addr_t end,

  			       phys_addr_t size, phys_addr_t align, int nid,

  			       enum memblock_flags flags)

  {
  	phys_addr_t this_start, this_end, cand;
  	u64 i;

  	for_each_free_mem_range_reverse(i, nid, flags, &this_start, &this_end,
  					NULL) {

  		this_start = clamp(this_start, start, end);
  		this_end = clamp(this_end, start, end);
  
  		if (this_end < size)
  			continue;
  
  		cand = round_down(this_end - size, align);
  		if (cand >= this_start)
  			return cand;
  	}

  	return 0;
  }

  /**

   * memblock_find_in_range_node - find free area in given range and node

   * @size: size of free area to find
   * @align: alignment of free area to find

   * @start: start of candidate range

   * @end: end of candidate range, can be %MEMBLOCK_ALLOC_ANYWHERE or
   *       %MEMBLOCK_ALLOC_ACCESSIBLE

   * @nid: nid of the free area to find, %NUMA_NO_NODE for any node

   * @flags: pick from blocks based on memory attributes

   *
   * Find @size free area aligned to @align in the specified range and node.
   *

   * When allocation direction is bottom-up, the @start should be greater
   * than the end of the kernel image. Otherwise, it will be trimmed. The
   * reason is that we want the bottom-up allocation just near the kernel
   * image so it is highly likely that the allocated memory and the kernel
   * will reside in the same node.
   *
   * If bottom-up allocation failed, will try to allocate memory top-down.
   *

   * Return:

   * Found address on success, 0 on failure.

   */

  static phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t size,

  					phys_addr_t align, phys_addr_t start,

  					phys_addr_t end, int nid,
  					enum memblock_flags flags)

  {

  	phys_addr_t kernel_end, ret;

  	/* pump up @end */

  	if (end == MEMBLOCK_ALLOC_ACCESSIBLE ||
  	    end == MEMBLOCK_ALLOC_KASAN)

  		end = memblock.current_limit;
  
  	/* avoid allocating the first page */
  	start = max_t(phys_addr_t, start, PAGE_SIZE);
  	end = max(start, end);

  	kernel_end = __pa_symbol(_end);
  
  	/*
  	 * try bottom-up allocation only when bottom-up mode
  	 * is set and @end is above the kernel image.
  	 */
  	if (memblock_bottom_up() && end > kernel_end) {
  		phys_addr_t bottom_up_start;
  
  		/* make sure we will allocate above the kernel */
  		bottom_up_start = max(start, kernel_end);
  
  		/* ok, try bottom-up allocation first */
  		ret = __memblock_find_range_bottom_up(bottom_up_start, end,

  						      size, align, nid, flags);

  		if (ret)
  			return ret;
  
  		/*
  		 * we always limit bottom-up allocation above the kernel,
  		 * but top-down allocation doesn't have the limit, so
  		 * retrying top-down allocation may succeed when bottom-up
  		 * allocation failed.
  		 *
  		 * bottom-up allocation is expected to be fail very rarely,
  		 * so we use WARN_ONCE() here to see the stack trace if
  		 * fail happens.
  		 */

  		WARN_ONCE(IS_ENABLED(CONFIG_MEMORY_HOTREMOVE),
  			  "memblock: bottom-up allocation failed, memory hotremove may be affected
  ");

  	}

  	return __memblock_find_range_top_down(start, end, size, align, nid,
  					      flags);

  }
  
  /**

   * memblock_find_in_range - find free area in given range
   * @start: start of candidate range

   * @end: end of candidate range, can be %MEMBLOCK_ALLOC_ANYWHERE or
   *       %MEMBLOCK_ALLOC_ACCESSIBLE

   * @size: size of free area to find
   * @align: alignment of free area to find
   *
   * Find @size free area aligned to @align in the specified range.
   *

   * Return:

   * Found address on success, 0 on failure.

   */

  phys_addr_t __init_memblock memblock_find_in_range(phys_addr_t start,
  					phys_addr_t end, phys_addr_t size,
  					phys_addr_t align)

  {

  	phys_addr_t ret;

  	enum memblock_flags flags = choose_memblock_flags();

  
  again:
  	ret = memblock_find_in_range_node(size, align, start, end,
  					    NUMA_NO_NODE, flags);
  
  	if (!ret && (flags & MEMBLOCK_MIRROR)) {
  		pr_warn("Could not allocate %pap bytes of mirrored memory
  ",
  			&size);
  		flags &= ~MEMBLOCK_MIRROR;
  		goto again;
  	}
  
  	return ret;

  }

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

  {

  	type->total_size -= type->regions[r].size;

  	memmove(&type->regions[r], &type->regions[r + 1],
  		(type->cnt - (r + 1)) * sizeof(type->regions[r]));

  	type->cnt--;

  	/* Special case for empty arrays */
  	if (type->cnt == 0) {

  		WARN_ON(type->total_size != 0);

  		type->cnt = 1;
  		type->regions[0].base = 0;
  		type->regions[0].size = 0;

  		type->regions[0].flags = 0;

  		memblock_set_region_node(&type->regions[0], MAX_NUMNODES);

  	}

  }

  #ifndef CONFIG_ARCH_KEEP_MEMBLOCK

  /**

   * memblock_discard - discard memory and reserved arrays if they were allocated

   */
  void __init memblock_discard(void)

  {

  	phys_addr_t addr, size;

  	if (memblock.reserved.regions != memblock_reserved_init_regions) {
  		addr = __pa(memblock.reserved.regions);
  		size = PAGE_ALIGN(sizeof(struct memblock_region) *
  				  memblock.reserved.max);
  		__memblock_free_late(addr, size);
  	}

  	if (memblock.memory.regions != memblock_memory_init_regions) {

  		addr = __pa(memblock.memory.regions);
  		size = PAGE_ALIGN(sizeof(struct memblock_region) *
  				  memblock.memory.max);
  		__memblock_free_late(addr, size);
  	}

  }

  #endif

  /**
   * memblock_double_array - double the size of the memblock regions array
   * @type: memblock type of the regions array being doubled
   * @new_area_start: starting address of memory range to avoid overlap with
   * @new_area_size: size of memory range to avoid overlap with
   *
   * Double the size of the @type regions array. If memblock is being used to
   * allocate memory for a new reserved regions array and there is a previously

   * allocated memory range [@new_area_start, @new_area_start + @new_area_size]

   * waiting to be reserved, ensure the memory used by the new array does
   * not overlap.
   *

   * Return:

   * 0 on success, -1 on failure.
   */
  static int __init_memblock memblock_double_array(struct memblock_type *type,
  						phys_addr_t new_area_start,
  						phys_addr_t new_area_size)

  {
  	struct memblock_region *new_array, *old_array;

  	phys_addr_t old_alloc_size, new_alloc_size;

  	phys_addr_t old_size, new_size, addr, new_end;

  	int use_slab = slab_is_available();

  	int *in_slab;

  
  	/* 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;

  	/*
  	 * We need to allocated new one align to PAGE_SIZE,
  	 *   so we can free them completely later.
  	 */
  	old_alloc_size = PAGE_ALIGN(old_size);
  	new_alloc_size = PAGE_ALIGN(new_size);

  	/* Retrieve the slab flag */
  	if (type == &memblock.memory)
  		in_slab = &memblock_memory_in_slab;
  	else
  		in_slab = &memblock_reserved_in_slab;

  	/* Try to find some space for it */

  	if (use_slab) {
  		new_array = kmalloc(new_size, GFP_KERNEL);

  		addr = new_array ? __pa(new_array) : 0;

  	} else {

  		/* only exclude range when trying to double reserved.regions */
  		if (type != &memblock.reserved)
  			new_area_start = new_area_size = 0;
  
  		addr = memblock_find_in_range(new_area_start + new_area_size,
  						memblock.current_limit,

  						new_alloc_size, PAGE_SIZE);

  		if (!addr && new_area_size)
  			addr = memblock_find_in_range(0,

  				min(new_area_start, memblock.current_limit),
  				new_alloc_size, PAGE_SIZE);

  		new_array = addr ? __va(addr) : NULL;

  	}

  	if (!addr) {

  		pr_err("memblock: Failed to double %s array from %ld to %ld entries !
  ",

  		       type->name, type->max, type->max * 2);

  		return -1;
  	}

  	new_end = addr + new_size - 1;
  	memblock_dbg("memblock: %s is doubled to %ld at [%pa-%pa]",
  			type->name, type->max * 2, &addr, &new_end);

  	/*
  	 * 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;

  	/* Free old array. We needn't free it if the array is the static one */

  	if (*in_slab)
  		kfree(old_array);
  	else if (old_array != memblock_memory_init_regions &&
  		 old_array != memblock_reserved_init_regions)

  		memblock_free(__pa(old_array), old_alloc_size);

  	/*
  	 * Reserve the new array if that comes from the memblock.  Otherwise, we
  	 * needn't do it

  	 */
  	if (!use_slab)

  		BUG_ON(memblock_reserve(addr, new_alloc_size));

  
  	/* Update slab flag */
  	*in_slab = use_slab;

  	return 0;
  }

  /**
   * memblock_merge_regions - merge neighboring compatible regions
   * @type: memblock type to scan
   *
   * Scan @type and merge neighboring compatible regions.
   */
  static void __init_memblock memblock_merge_regions(struct memblock_type *type)

  {

  	int i = 0;

  	/* cnt never goes below 1 */
  	while (i < type->cnt - 1) {
  		struct memblock_region *this = &type->regions[i];
  		struct memblock_region *next = &type->regions[i + 1];

  		if (this->base + this->size != next->base ||
  		    memblock_get_region_node(this) !=

  		    memblock_get_region_node(next) ||
  		    this->flags != next->flags) {

  			BUG_ON(this->base + this->size > next->base);
  			i++;
  			continue;

  		}

  		this->size += next->size;

  		/* move forward from next + 1, index of which is i + 2 */
  		memmove(next, next + 1, (type->cnt - (i + 2)) * sizeof(*next));

  		type->cnt--;

  	}

  }

  /**
   * memblock_insert_region - insert new memblock region

   * @type:	memblock type to insert into
   * @idx:	index for the insertion point
   * @base:	base address of the new region
   * @size:	size of the new region
   * @nid:	node id of the new region

   * @flags:	flags of the new region

   *

   * Insert new memblock region [@base, @base + @size) into @type at @idx.

   * @type must already have extra room to accommodate the new region.

   */
  static void __init_memblock memblock_insert_region(struct memblock_type *type,
  						   int idx, phys_addr_t base,

  						   phys_addr_t size,

  						   int nid,
  						   enum memblock_flags flags)

  {
  	struct memblock_region *rgn = &type->regions[idx];
  
  	BUG_ON(type->cnt >= type->max);
  	memmove(rgn + 1, rgn, (type->cnt - idx) * sizeof(*rgn));
  	rgn->base = base;
  	rgn->size = size;

  	rgn->flags = flags;

  	memblock_set_region_node(rgn, nid);

  	type->cnt++;

  	type->total_size += size;

  }
  
  /**

   * memblock_add_range - add new memblock region

   * @type: memblock type to add new region into
   * @base: base address of the new region
   * @size: size of the new region

   * @nid: nid of the new region

   * @flags: flags of the new region

   *

   * Add new memblock region [@base, @base + @size) into @type.  The new region

   * is allowed to overlap with existing ones - overlaps don't affect already
   * existing regions.  @type is guaranteed to be minimal (all neighbouring
   * compatible regions are merged) after the addition.
   *

   * Return:

   * 0 on success, -errno on failure.
   */

  int __init_memblock memblock_add_range(struct memblock_type *type,

  				phys_addr_t base, phys_addr_t size,

  				int nid, enum memblock_flags flags)

  {
  	bool insert = false;

  	phys_addr_t obase = base;
  	phys_addr_t end = base + memblock_cap_size(base, &size);

  	int idx, nr_new;
  	struct memblock_region *rgn;

  	if (!size)
  		return 0;

  	/* special case for empty array */
  	if (type->regions[0].size == 0) {

  		WARN_ON(type->cnt != 1 || type->total_size);

  		type->regions[0].base = base;
  		type->regions[0].size = size;

  		type->regions[0].flags = flags;

  		memblock_set_region_node(&type->regions[0], nid);

  		type->total_size = size;

  		return 0;

  	}

  repeat:
  	/*
  	 * The following is executed twice.  Once with %false @insert and
  	 * then with %true.  The first counts the number of regions needed

  	 * to accommodate the new area.  The second actually inserts them.

  	 */

  	base = obase;
  	nr_new = 0;

  	for_each_memblock_type(idx, type, rgn) {

  		phys_addr_t rbase = rgn->base;
  		phys_addr_t rend = rbase + rgn->size;
  
  		if (rbase >= end)

  			break;

  		if (rend <= base)
  			continue;
  		/*
  		 * @rgn overlaps.  If it separates the lower part of new
  		 * area, insert that portion.
  		 */
  		if (rbase > base) {

  #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
  			WARN_ON(nid != memblock_get_region_node(rgn));
  #endif

  			WARN_ON(flags != rgn->flags);

  			nr_new++;
  			if (insert)

  				memblock_insert_region(type, idx++, base,

  						       rbase - base, nid,
  						       flags);

  		}

  		/* area below @rend is dealt with, forget about it */
  		base = min(rend, end);

  	}

  
  	/* insert the remaining portion */
  	if (base < end) {
  		nr_new++;
  		if (insert)

  			memblock_insert_region(type, idx, base, end - base,

  					       nid, flags);

  	}

  	if (!nr_new)
  		return 0;

  	/*
  	 * If this was the first round, resize array and repeat for actual
  	 * insertions; otherwise, merge and return.

  	 */

  	if (!insert) {
  		while (type->cnt + nr_new > type->max)

  			if (memblock_double_array(type, obase, size) < 0)

  				return -ENOMEM;
  		insert = true;
  		goto repeat;
  	} else {
  		memblock_merge_regions(type);
  		return 0;

  	}

  }

  /**
   * memblock_add_node - add new memblock region within a NUMA node
   * @base: base address of the new region
   * @size: size of the new region
   * @nid: nid of the new region
   *
   * Add new memblock region [@base, @base + @size) to the "memory"
   * type. See memblock_add_range() description for mode details
   *
   * Return:
   * 0 on success, -errno on failure.
   */

  int __init_memblock memblock_add_node(phys_addr_t base, phys_addr_t size,
  				       int nid)
  {

  	return memblock_add_range(&memblock.memory, base, size, nid, 0);

  }

  /**
   * memblock_add - add new memblock region
   * @base: base address of the new region
   * @size: size of the new region
   *
   * Add new memblock region [@base, @base + @size) to the "memory"
   * type. See memblock_add_range() description for mode details
   *
   * Return:
   * 0 on success, -errno on failure.
   */

  int __init_memblock memblock_add(phys_addr_t base, phys_addr_t size)

  {

  	phys_addr_t end = base + size - 1;

  	memblock_dbg("memblock_add: [%pa-%pa] %pS
  ",

  		     &base, &end, (void *)_RET_IP_);

  	return memblock_add_range(&memblock.memory, base, size, MAX_NUMNODES, 0);

  }

  /**
   * memblock_isolate_range - isolate given range into disjoint memblocks
   * @type: memblock type to isolate range for
   * @base: base of range to isolate
   * @size: size of range to isolate
   * @start_rgn: out parameter for the start of isolated region
   * @end_rgn: out parameter for the end of isolated region
   *
   * Walk @type and ensure that regions don't cross the boundaries defined by

   * [@base, @base + @size).  Crossing regions are split at the boundaries,

   * which may create at most two more regions.  The index of the first
   * region inside the range is returned in *@start_rgn and end in *@end_rgn.
   *

   * Return:

   * 0 on success, -errno on failure.
   */
  static int __init_memblock memblock_isolate_range(struct memblock_type *type,
  					phys_addr_t base, phys_addr_t size,
  					int *start_rgn, int *end_rgn)
  {

  	phys_addr_t end = base + memblock_cap_size(base, &size);

  	int idx;
  	struct memblock_region *rgn;

  
  	*start_rgn = *end_rgn = 0;

  	if (!size)
  		return 0;

  	/* we'll create at most two more regions */
  	while (type->cnt + 2 > type->max)

  		if (memblock_double_array(type, base, size) < 0)

  			return -ENOMEM;

  	for_each_memblock_type(idx, type, rgn) {

  		phys_addr_t rbase = rgn->base;
  		phys_addr_t rend = rbase + rgn->size;
  
  		if (rbase >= end)
  			break;
  		if (rend <= base)
  			continue;
  
  		if (rbase < base) {
  			/*
  			 * @rgn intersects from below.  Split and continue
  			 * to process the next region - the new top half.
  			 */
  			rgn->base = base;

  			rgn->size -= base - rbase;
  			type->total_size -= base - rbase;

  			memblock_insert_region(type, idx, rbase, base - rbase,

  					       memblock_get_region_node(rgn),
  					       rgn->flags);

  		} else if (rend > end) {
  			/*
  			 * @rgn intersects from above.  Split and redo the
  			 * current region - the new bottom half.
  			 */
  			rgn->base = end;

  			rgn->size -= end - rbase;
  			type->total_size -= end - rbase;

  			memblock_insert_region(type, idx--, rbase, end - rbase,

  					       memblock_get_region_node(rgn),
  					       rgn->flags);

  		} else {
  			/* @rgn is fully contained, record it */
  			if (!*end_rgn)

  				*start_rgn = idx;
  			*end_rgn = idx + 1;

  		}
  	}
  
  	return 0;
  }

  static int __init_memblock memblock_remove_range(struct memblock_type *type,

  					  phys_addr_t base, phys_addr_t size)

  {

  	int start_rgn, end_rgn;
  	int i, ret;

  	ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
  	if (ret)
  		return ret;

  	for (i = end_rgn - 1; i >= start_rgn; i--)
  		memblock_remove_region(type, i);

  	return 0;

  }

  int __init_memblock memblock_remove(phys_addr_t base, phys_addr_t size)

  {

  	phys_addr_t end = base + size - 1;
  
  	memblock_dbg("memblock_remove: [%pa-%pa] %pS
  ",
  		     &base, &end, (void *)_RET_IP_);

  	return memblock_remove_range(&memblock.memory, base, size);

  }

  /**
   * memblock_free - free boot memory block
   * @base: phys starting address of the  boot memory block
   * @size: size of the boot memory block in bytes
   *
   * Free boot memory block previously allocated by memblock_alloc_xx() API.
   * The freeing memory will not be released to the buddy allocator.
   */

  int __init_memblock memblock_free(phys_addr_t base, phys_addr_t size)

  {

  	phys_addr_t end = base + size - 1;

  	memblock_dbg("   memblock_free: [%pa-%pa] %pS
  ",

  		     &base, &end, (void *)_RET_IP_);

  	kmemleak_free_part_phys(base, size);

  	return memblock_remove_range(&memblock.reserved, base, size);

  }

  int __init_memblock memblock_reserve(phys_addr_t base, phys_addr_t size)

  {

  	phys_addr_t end = base + size - 1;

  	memblock_dbg("memblock_reserve: [%pa-%pa] %pS
  ",

  		     &base, &end, (void *)_RET_IP_);

  	return memblock_add_range(&memblock.reserved, base, size, MAX_NUMNODES, 0);

  }

  /**

   * memblock_setclr_flag - set or clear flag for a memory region
   * @base: base address of the region
   * @size: size of the region
   * @set: set or clear the flag
   * @flag: the flag to udpate

   *

   * This function isolates region [@base, @base + @size), and sets/clears flag

   *

   * Return: 0 on success, -errno on failure.

   */

  static int __init_memblock memblock_setclr_flag(phys_addr_t base,
  				phys_addr_t size, int set, int flag)

  {
  	struct memblock_type *type = &memblock.memory;
  	int i, ret, start_rgn, end_rgn;
  
  	ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
  	if (ret)
  		return ret;

  	for (i = start_rgn; i < end_rgn; i++) {
  		struct memblock_region *r = &type->regions[i];

  		if (set)

  			r->flags |= flag;

  		else

  			r->flags &= ~flag;
  	}

  
  	memblock_merge_regions(type);
  	return 0;
  }
  
  /**

   * memblock_mark_hotplug - Mark hotpluggable memory with flag MEMBLOCK_HOTPLUG.

   * @base: the base phys addr of the region
   * @size: the size of the region
   *

   * Return: 0 on success, -errno on failure.

   */
  int __init_memblock memblock_mark_hotplug(phys_addr_t base, phys_addr_t size)
  {
  	return memblock_setclr_flag(base, size, 1, MEMBLOCK_HOTPLUG);
  }
  
  /**
   * memblock_clear_hotplug - Clear flag MEMBLOCK_HOTPLUG for a specified region.
   * @base: the base phys addr of the region
   * @size: the size of the region

   *

   * Return: 0 on success, -errno on failure.

   */
  int __init_memblock memblock_clear_hotplug(phys_addr_t base, phys_addr_t size)
  {

  	return memblock_setclr_flag(base, size, 0, MEMBLOCK_HOTPLUG);

  }
  
  /**

   * memblock_mark_mirror - Mark mirrored memory with flag MEMBLOCK_MIRROR.
   * @base: the base phys addr of the region
   * @size: the size of the region
   *

   * Return: 0 on success, -errno on failure.

   */
  int __init_memblock memblock_mark_mirror(phys_addr_t base, phys_addr_t size)
  {
  	system_has_some_mirror = true;
  
  	return memblock_setclr_flag(base, size, 1, MEMBLOCK_MIRROR);
  }

  /**
   * memblock_mark_nomap - Mark a memory region with flag MEMBLOCK_NOMAP.
   * @base: the base phys addr of the region
   * @size: the size of the region
   *

   * Return: 0 on success, -errno on failure.

   */
  int __init_memblock memblock_mark_nomap(phys_addr_t base, phys_addr_t size)
  {
  	return memblock_setclr_flag(base, size, 1, MEMBLOCK_NOMAP);
  }

  
  /**

   * memblock_clear_nomap - Clear flag MEMBLOCK_NOMAP for a specified region.
   * @base: the base phys addr of the region
   * @size: the size of the region
   *

   * Return: 0 on success, -errno on failure.

   */
  int __init_memblock memblock_clear_nomap(phys_addr_t base, phys_addr_t size)
  {
  	return memblock_setclr_flag(base, size, 0, MEMBLOCK_NOMAP);
  }
  
  /**

   * __next_reserved_mem_region - next function for for_each_reserved_region()
   * @idx: pointer to u64 loop variable
   * @out_start: ptr to phys_addr_t for start address of the region, can be %NULL
   * @out_end: ptr to phys_addr_t for end address of the region, can be %NULL
   *
   * Iterate over all reserved memory regions.
   */
  void __init_memblock __next_reserved_mem_region(u64 *idx,
  					   phys_addr_t *out_start,
  					   phys_addr_t *out_end)
  {

  	struct memblock_type *type = &memblock.reserved;

  	if (*idx < type->cnt) {

  		struct memblock_region *r = &type->regions[*idx];

  		phys_addr_t base = r->base;
  		phys_addr_t size = r->size;
  
  		if (out_start)
  			*out_start = base;
  		if (out_end)
  			*out_end = base + size - 1;
  
  		*idx += 1;
  		return;
  	}
  
  	/* signal end of iteration */
  	*idx = ULLONG_MAX;
  }

  static bool should_skip_region(struct memblock_region *m, int nid, int flags)
  {
  	int m_nid = memblock_get_region_node(m);
  
  	/* only memory regions are associated with nodes, check it */
  	if (nid != NUMA_NO_NODE && nid != m_nid)
  		return true;
  
  	/* skip hotpluggable memory regions if needed */
  	if (movable_node_is_enabled() && memblock_is_hotpluggable(m))
  		return true;
  
  	/* if we want mirror memory skip non-mirror memory regions */
  	if ((flags & MEMBLOCK_MIRROR) && !memblock_is_mirror(m))
  		return true;
  
  	/* skip nomap memory unless we were asked for it explicitly */
  	if (!(flags & MEMBLOCK_NOMAP) && memblock_is_nomap(m))
  		return true;
  
  	return false;
  }

  /**

   * __next_mem_range - next function for for_each_free_mem_range() etc.

   * @idx: pointer to u64 loop variable

   * @nid: node selector, %NUMA_NO_NODE for all nodes

   * @flags: pick from blocks based on memory attributes

   * @type_a: pointer to memblock_type from where the range is taken
   * @type_b: pointer to memblock_type which excludes memory from being taken

   * @out_start: ptr to phys_addr_t for start address of the range, can be %NULL
   * @out_end: ptr to phys_addr_t for end address of the range, can be %NULL
   * @out_nid: ptr to int for nid of the range, can be %NULL

   *

   * Find the first area from *@idx which matches @nid, fill the out

   * parameters, and update *@idx for the next iteration.  The lower 32bit of

   * *@idx contains index into type_a and the upper 32bit indexes the
   * areas before each region in type_b.	For example, if type_b regions

   * look like the following,
   *
   *	0:[0-16), 1:[32-48), 2:[128-130)
   *
   * The upper 32bit indexes the following regions.
   *
   *	0:[0-0), 1:[16-32), 2:[48-128), 3:[130-MAX)
   *
   * As both region arrays are sorted, the function advances the two indices
   * in lockstep and returns each intersection.
   */

  void __init_memblock __next_mem_range(u64 *idx, int nid,
  				      enum memblock_flags flags,

  				      struct memblock_type *type_a,
  				      struct memblock_type *type_b,
  				      phys_addr_t *out_start,
  				      phys_addr_t *out_end, int *out_nid)

  {

  	int idx_a = *idx & 0xffffffff;
  	int idx_b = *idx >> 32;

  	if (WARN_ONCE(nid == MAX_NUMNODES,
  	"Usage of MAX_NUMNODES is deprecated. Use NUMA_NO_NODE instead
  "))

  		nid = NUMA_NO_NODE;

  	for (; idx_a < type_a->cnt; idx_a++) {
  		struct memblock_region *m = &type_a->regions[idx_a];

  		phys_addr_t m_start = m->base;
  		phys_addr_t m_end = m->base + m->size;

  		int	    m_nid = memblock_get_region_node(m);

  		if (should_skip_region(m, nid, flags))

  			continue;

  		if (!type_b) {
  			if (out_start)
  				*out_start = m_start;
  			if (out_end)
  				*out_end = m_end;
  			if (out_nid)
  				*out_nid = m_nid;
  			idx_a++;
  			*idx = (u32)idx_a | (u64)idx_b << 32;
  			return;
  		}
  
  		/* scan areas before each reservation */
  		for (; idx_b < type_b->cnt + 1; idx_b++) {
  			struct memblock_region *r;
  			phys_addr_t r_start;
  			phys_addr_t r_end;
  
  			r = &type_b->regions[idx_b];
  			r_start = idx_b ? r[-1].base + r[-1].size : 0;
  			r_end = idx_b < type_b->cnt ?

  				r->base : PHYS_ADDR_MAX;

  			/*
  			 * if idx_b advanced past idx_a,
  			 * break out to advance idx_a
  			 */

  			if (r_start >= m_end)
  				break;
  			/* if the two regions intersect, we're done */
  			if (m_start < r_end) {
  				if (out_start)

  					*out_start =
  						max(m_start, r_start);

  				if (out_end)
  					*out_end = min(m_end, r_end);
  				if (out_nid)

  					*out_nid = m_nid;

  				/*

  				 * The region which ends first is
  				 * advanced for the next iteration.

  				 */
  				if (m_end <= r_end)

  					idx_a++;

  				else

  					idx_b++;
  				*idx = (u32)idx_a | (u64)idx_b << 32;

  				return;
  			}
  		}
  	}
  
  	/* signal end of iteration */
  	*idx = ULLONG_MAX;
  }

  /**

   * __next_mem_range_rev - generic next function for for_each_*_range_rev()
   *

   * @idx: pointer to u64 loop variable

   * @nid: node selector, %NUMA_NO_NODE for all nodes

   * @flags: pick from blocks based on memory attributes

   * @type_a: pointer to memblock_type from where the range is taken
   * @type_b: pointer to memblock_type which excludes memory from being taken

   * @out_start: ptr to phys_addr_t for start address of the range, can be %NULL
   * @out_end: ptr to phys_addr_t for end address of the range, can be %NULL
   * @out_nid: ptr to int for nid of the range, can be %NULL

   *

   * Finds the next range from type_a which is not marked as unsuitable
   * in type_b.
   *

   * Reverse of __next_mem_range().

   */

  void __init_memblock __next_mem_range_rev(u64 *idx, int nid,
  					  enum memblock_flags flags,

  					  struct memblock_type *type_a,
  					  struct memblock_type *type_b,
  					  phys_addr_t *out_start,
  					  phys_addr_t *out_end, int *out_nid)

  {

  	int idx_a = *idx & 0xffffffff;
  	int idx_b = *idx >> 32;

  	if (WARN_ONCE(nid == MAX_NUMNODES, "Usage of MAX_NUMNODES is deprecated. Use NUMA_NO_NODE instead
  "))
  		nid = NUMA_NO_NODE;

  
  	if (*idx == (u64)ULLONG_MAX) {

  		idx_a = type_a->cnt - 1;

  		if (type_b != NULL)
  			idx_b = type_b->cnt;
  		else
  			idx_b = 0;

  	}

  	for (; idx_a >= 0; idx_a--) {
  		struct memblock_region *m = &type_a->regions[idx_a];

  		phys_addr_t m_start = m->base;
  		phys_addr_t m_end = m->base + m->size;

  		int m_nid = memblock_get_region_node(m);

  		if (should_skip_region(m, nid, flags))

  			continue;

  		if (!type_b) {
  			if (out_start)
  				*out_start = m_start;
  			if (out_end)
  				*out_end = m_end;
  			if (out_nid)
  				*out_nid = m_nid;

  			idx_a--;

  			*idx = (u32)idx_a | (u64)idx_b << 32;
  			return;
  		}
  
  		/* scan areas before each reservation */
  		for (; idx_b >= 0; idx_b--) {
  			struct memblock_region *r;
  			phys_addr_t r_start;
  			phys_addr_t r_end;
  
  			r = &type_b->regions[idx_b];
  			r_start = idx_b ? r[-1].base + r[-1].size : 0;
  			r_end = idx_b < type_b->cnt ?

  				r->base : PHYS_ADDR_MAX;

  			/*
  			 * if idx_b advanced past idx_a,
  			 * break out to advance idx_a
  			 */

  			if (r_end <= m_start)
  				break;
  			/* if the two regions intersect, we're done */
  			if (m_end > r_start) {
  				if (out_start)
  					*out_start = max(m_start, r_start);
  				if (out_end)
  					*out_end = min(m_end, r_end);
  				if (out_nid)

  					*out_nid = m_nid;

  				if (m_start >= r_start)

  					idx_a--;

  				else

  					idx_b--;
  				*idx = (u32)idx_a | (u64)idx_b << 32;

  				return;
  			}
  		}
  	}

  	/* signal end of iteration */

  	*idx = ULLONG_MAX;
  }

  #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
  /*

   * Common iterator interface used to define for_each_mem_pfn_range().

   */
  void __init_memblock __next_mem_pfn_range(int *idx, int nid,
  				unsigned long *out_start_pfn,
  				unsigned long *out_end_pfn, int *out_nid)
  {
  	struct memblock_type *type = &memblock.memory;
  	struct memblock_region *r;
  
  	while (++*idx < type->cnt) {
  		r = &type->regions[*idx];
  
  		if (PFN_UP(r->base) >= PFN_DOWN(r->base + r->size))
  			continue;
  		if (nid == MAX_NUMNODES || nid == r->nid)
  			break;
  	}
  	if (*idx >= type->cnt) {
  		*idx = -1;
  		return;
  	}
  
  	if (out_start_pfn)
  		*out_start_pfn = PFN_UP(r->base);
  	if (out_end_pfn)
  		*out_end_pfn = PFN_DOWN(r->base + r->size);
  	if (out_nid)
  		*out_nid = r->nid;
  }
  
  /**
   * memblock_set_node - set node ID on memblock regions
   * @base: base of area to set node ID for
   * @size: size of area to set node ID for

   * @type: memblock type to set node ID for

   * @nid: node ID to set
   *

   * Set the nid of memblock @type regions in [@base, @base + @size) to @nid.

   * Regions which cross the area boundaries are split as necessary.
   *

   * Return:

   * 0 on success, -errno on failure.
   */
  int __init_memblock memblock_set_node(phys_addr_t base, phys_addr_t size,

  				      struct memblock_type *type, int nid)

  {

  	int start_rgn, end_rgn;
  	int i, ret;

  	ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
  	if (ret)
  		return ret;

  	for (i = start_rgn; i < end_rgn; i++)

  		memblock_set_region_node(&type->regions[i], nid);

  
  	memblock_merge_regions(type);
  	return 0;
  }
  #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */

  #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
  /**
   * __next_mem_pfn_range_in_zone - iterator for for_each_*_range_in_zone()
   *
   * @idx: pointer to u64 loop variable
   * @zone: zone in which all of the memory blocks reside
   * @out_spfn: ptr to ulong for start pfn of the range, can be %NULL
   * @out_epfn: ptr to ulong for end pfn of the range, can be %NULL
   *
   * This function is meant to be a zone/pfn specific wrapper for the
   * for_each_mem_range type iterators. Specifically they are used in the
   * deferred memory init routines and as such we were duplicating much of
   * this logic throughout the code. So instead of having it in multiple
   * locations it seemed like it would make more sense to centralize this to
   * one new iterator that does everything they need.
   */
  void __init_memblock
  __next_mem_pfn_range_in_zone(u64 *idx, struct zone *zone,
  			     unsigned long *out_spfn, unsigned long *out_epfn)
  {
  	int zone_nid = zone_to_nid(zone);
  	phys_addr_t spa, epa;
  	int nid;
  
  	__next_mem_range(idx, zone_nid, MEMBLOCK_NONE,
  			 &memblock.memory, &memblock.reserved,
  			 &spa, &epa, &nid);
  
  	while (*idx != U64_MAX) {
  		unsigned long epfn = PFN_DOWN(epa);
  		unsigned long spfn = PFN_UP(spa);
  
  		/*
  		 * Verify the end is at least past the start of the zone and
  		 * that we have at least one PFN to initialize.
  		 */
  		if (zone->zone_start_pfn < epfn && spfn < epfn) {
  			/* if we went too far just stop searching */
  			if (zone_end_pfn(zone) <= spfn) {
  				*idx = U64_MAX;
  				break;
  			}
  
  			if (out_spfn)
  				*out_spfn = max(zone->zone_start_pfn, spfn);
  			if (out_epfn)
  				*out_epfn = min(zone_end_pfn(zone), epfn);
  
  			return;
  		}
  
  		__next_mem_range(idx, zone_nid, MEMBLOCK_NONE,
  				 &memblock.memory, &memblock.reserved,
  				 &spa, &epa, &nid);
  	}
  
  	/* signal end of iteration */
  	if (out_spfn)
  		*out_spfn = ULONG_MAX;
  	if (out_epfn)
  		*out_epfn = 0;
  }
  
  #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */

  /**
   * memblock_alloc_range_nid - allocate boot memory block
   * @size: size of memory block to be allocated in bytes
   * @align: alignment of the region and block's size
   * @start: the lower bound of the memory region to allocate (phys address)
   * @end: the upper bound of the memory region to allocate (phys address)
   * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
   *
   * The allocation is performed from memory region limited by
   * memblock.current_limit if @max_addr == %MEMBLOCK_ALLOC_ACCESSIBLE.
   *
   * If the specified node can not hold the requested memory the
   * allocation falls back to any node in the system
   *
   * For systems with memory mirroring, the allocation is attempted first
   * from the regions with mirroring enabled and then retried from any
   * memory region.
   *
   * In addition, function sets the min_count to 0 using kmemleak_alloc_phys for
   * allocated boot memory block, so that it is never reported as leaks.
   *
   * Return:
   * Physical address of allocated memory block on success, %0 on failure.
   */

  static phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size,
  					phys_addr_t align, phys_addr_t start,

  					phys_addr_t end, int nid)

  {

  	enum memblock_flags flags = choose_memblock_flags();

  	phys_addr_t found;

  	if (WARN_ONCE(nid == MAX_NUMNODES, "Usage of MAX_NUMNODES is deprecated. Use NUMA_NO_NODE instead
  "))
  		nid = NUMA_NO_NODE;

  	if (!align) {
  		/* Can't use WARNs this early in boot on powerpc */
  		dump_stack();
  		align = SMP_CACHE_BYTES;
  	}

  again:

  	found = memblock_find_in_range_node(size, align, start, end, nid,
  					    flags);

  	if (found && !memblock_reserve(found, size))
  		goto done;
  
  	if (nid != NUMA_NO_NODE) {
  		found = memblock_find_in_range_node(size, align, start,
  						    end, NUMA_NO_NODE,
  						    flags);
  		if (found && !memblock_reserve(found, size))
  			goto done;
  	}
  
  	if (flags & MEMBLOCK_MIRROR) {
  		flags &= ~MEMBLOCK_MIRROR;
  		pr_warn("Could not allocate %pap bytes of mirrored memory
  ",
  			&size);
  		goto again;
  	}
  
  	return 0;
  
  done:
  	/* Skip kmemleak for kasan_init() due to high volume. */
  	if (end != MEMBLOCK_ALLOC_KASAN)

  		/*

  		 * The min_count is set to 0 so that memblock allocated
  		 * blocks are never reported as leaks. This is because many
  		 * of these blocks are only referred via the physical
  		 * address which is not looked up by kmemleak.

  		 */

  		kmemleak_alloc_phys(found, size, 0, 0);

  
  	return found;

  }

  /**
   * memblock_phys_alloc_range - allocate a memory block inside specified range
   * @size: size of memory block to be allocated in bytes
   * @align: alignment of the region and block's size
   * @start: the lower bound of the memory region to allocate (physical address)
   * @end: the upper bound of the memory region to allocate (physical address)
   *
   * Allocate @size bytes in the between @start and @end.
   *
   * Return: physical address of the allocated memory block on success,
   * %0 on failure.
   */

  phys_addr_t __init memblock_phys_alloc_range(phys_addr_t size,
  					     phys_addr_t align,
  					     phys_addr_t start,
  					     phys_addr_t end)

  {

  	return memblock_alloc_range_nid(size, align, start, end, NUMA_NO_NODE);

  }

  /**
   * memblock_phys_alloc_try_nid - allocate a memory block from specified MUMA node
   * @size: size of memory block to be allocated in bytes
   * @align: alignment of the region and block's size
   * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
   *
   * Allocates memory block from the specified NUMA node. If the node
   * has no available memory, attempts to allocated from any node in the
   * system.
   *
   * Return: physical address of the allocated memory block on success,
   * %0 on failure.
   */

  phys_addr_t __init memblock_phys_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid)

  {

  	return memblock_alloc_range_nid(size, align, 0,

  					MEMBLOCK_ALLOC_ACCESSIBLE, nid);

  }

  /**

   * memblock_alloc_internal - allocate boot memory block

   * @size: size of memory block to be allocated in bytes
   * @align: alignment of the region and block's size
   * @min_addr: the lower bound of the memory region to allocate (phys address)
   * @max_addr: the upper bound of the memory region to allocate (phys address)
   * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
   *

   * Allocates memory block using memblock_alloc_range_nid() and
   * converts the returned physical address to virtual.

   *

   * The @min_addr limit is dropped if it can not be satisfied and the allocation
   * will fall back to memory below @min_addr. Other constraints, such
   * as node and mirrored memory will be handled again in
   * memblock_alloc_range_nid().

   *

   * Return:

   * Virtual address of allocated memory block on success, NULL on failure.
   */

  static void * __init memblock_alloc_internal(

  				phys_addr_t size, phys_addr_t align,
  				phys_addr_t min_addr, phys_addr_t max_addr,
  				int nid)
  {
  	phys_addr_t alloc;

  
  	/*
  	 * Detect any accidental use of these APIs after slab is ready, as at
  	 * this moment memblock may be deinitialized already and its

  	 * internal data may be destroyed (after execution of memblock_free_all)

  	 */
  	if (WARN_ON_ONCE(slab_is_available()))
  		return kzalloc_node(size, GFP_NOWAIT, nid);

  	if (max_addr > memblock.current_limit)
  		max_addr = memblock.current_limit;

  	alloc = memblock_alloc_range_nid(size, align, min_addr, max_addr, nid);

  	/* retry allocation without lower limit */
  	if (!alloc && min_addr)
  		alloc = memblock_alloc_range_nid(size, align, 0, max_addr, nid);

  	if (!alloc)
  		return NULL;

  	return phys_to_virt(alloc);

  }
  
  /**

   * memblock_alloc_try_nid_raw - allocate boot memory block without zeroing

   * memory and without panicking
   * @size: size of memory block to be allocated in bytes
   * @align: alignment of the region and block's size
   * @min_addr: the lower bound of the memory region from where the allocation
   *	  is preferred (phys address)
   * @max_addr: the upper bound of the memory region from where the allocation

   *	      is preferred (phys address), or %MEMBLOCK_ALLOC_ACCESSIBLE to

   *	      allocate only from memory limited by memblock.current_limit value
   * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
   *
   * Public function, provides additional debug information (including caller
   * info), if enabled. Does not zero allocated memory, does not panic if request
   * cannot be satisfied.
   *

   * Return:

   * Virtual address of allocated memory block on success, NULL on failure.
   */

  void * __init memblock_alloc_try_nid_raw(

  			phys_addr_t size, phys_addr_t align,
  			phys_addr_t min_addr, phys_addr_t max_addr,
  			int nid)
  {
  	void *ptr;

  	memblock_dbg("%s: %llu bytes align=0x%llx nid=%d from=%pa max_addr=%pa %pS
  ",

  		     __func__, (u64)size, (u64)align, nid, &min_addr,
  		     &max_addr, (void *)_RET_IP_);

  	ptr = memblock_alloc_internal(size, align,

  					   min_addr, max_addr, nid);

  	if (ptr && size > 0)

  		page_init_poison(ptr, size);

  	return ptr;
  }
  
  /**

   * memblock_alloc_try_nid - allocate boot memory block

   * @size: size of memory block to be allocated in bytes
   * @align: alignment of the region and block's size
   * @min_addr: the lower bound of the memory region from where the allocation
   *	  is preferred (phys address)
   * @max_addr: the upper bound of the memory region from where the allocation

   *	      is preferred (phys address), or %MEMBLOCK_ALLOC_ACCESSIBLE to

   *	      allocate only from memory limited by memblock.current_limit value
   * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
   *

   * Public function, provides additional debug information (including caller
   * info), if enabled. This function zeroes the allocated memory.

   *

   * Return:

   * Virtual address of allocated memory block on success, NULL on failure.
   */

  void * __init memblock_alloc_try_nid(

  			phys_addr_t size, phys_addr_t align,
  			phys_addr_t min_addr, phys_addr_t max_addr,
  			int nid)
  {
  	void *ptr;

  	memblock_dbg("%s: %llu bytes align=0x%llx nid=%d from=%pa max_addr=%pa %pS
  ",

  		     __func__, (u64)size, (u64)align, nid, &min_addr,
  		     &max_addr, (void *)_RET_IP_);

  	ptr = memblock_alloc_internal(size, align,

  					   min_addr, max_addr, nid);

  	if (ptr)

  		memset(ptr, 0, size);

  	return ptr;

  }
  
  /**

   * __memblock_free_late - free pages directly to buddy allocator

   * @base: phys starting address of the  boot memory block

   * @size: size of the boot memory block in bytes
   *

   * This is only useful when the memblock allocator has already been torn

   * down, but we are still initializing the system.  Pages are released directly

   * to the buddy allocator.

   */
  void __init __memblock_free_late(phys_addr_t base, phys_addr_t size)
  {

  	phys_addr_t cursor, end;

  	end = base + size - 1;

  	memblock_dbg("%s: [%pa-%pa] %pS
  ",

  		     __func__, &base, &end, (void *)_RET_IP_);

  	kmemleak_free_part_phys(base, size);

  	cursor = PFN_UP(base);
  	end = PFN_DOWN(base + size);
  
  	for (; cursor < end; cursor++) {

  		memblock_free_pages(pfn_to_page(cursor), cursor, 0);

  		totalram_pages_inc();

  	}
  }

  
  /*
   * Remaining API functions
   */

  phys_addr_t __init_memblock memblock_phys_mem_size(void)

  {

  	return memblock.memory.total_size;

  }

  phys_addr_t __init_memblock memblock_reserved_size(void)
  {
  	return memblock.reserved.total_size;
  }

  phys_addr_t __init memblock_mem_size(unsigned long limit_pfn)
  {
  	unsigned long pages = 0;
  	struct memblock_region *r;
  	unsigned long start_pfn, end_pfn;
  
  	for_each_memblock(memory, r) {
  		start_pfn = memblock_region_memory_base_pfn(r);
  		end_pfn = memblock_region_memory_end_pfn(r);
  		start_pfn = min_t(unsigned long, start_pfn, limit_pfn);
  		end_pfn = min_t(unsigned long, end_pfn, limit_pfn);
  		pages += end_pfn - start_pfn;
  	}

  	return PFN_PHYS(pages);

  }

  /* 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);

  }

  static phys_addr_t __init_memblock __find_max_addr(phys_addr_t limit)

  {

  	phys_addr_t max_addr = PHYS_ADDR_MAX;

  	struct memblock_region *r;

  	/*
  	 * translate the memory @limit size into the max address within one of
  	 * the memory memblock regions, if the @limit exceeds the total size

  	 * of those regions, max_addr will keep original value PHYS_ADDR_MAX

  	 */

  	for_each_memblock(memory, r) {

  		if (limit <= r->size) {
  			max_addr = r->base + limit;
  			break;

  		}

  		limit -= r->size;

  	}

  	return max_addr;
  }
  
  void __init memblock_enforce_memory_limit(phys_addr_t limit)
  {

  	phys_addr_t max_addr = PHYS_ADDR_MAX;

  
  	if (!limit)
  		return;
  
  	max_addr = __find_max_addr(limit);
  
  	/* @limit exceeds the total size of the memory, do nothing */

  	if (max_addr == PHYS_ADDR_MAX)

  		return;

  	/* truncate both memory and reserved regions */

  	memblock_remove_range(&memblock.memory, max_addr,

  			      PHYS_ADDR_MAX);

  	memblock_remove_range(&memblock.reserved, max_addr,

  			      PHYS_ADDR_MAX);

  }

  void __init memblock_cap_memory_range(phys_addr_t base, phys_addr_t size)
  {
  	int start_rgn, end_rgn;
  	int i, ret;
  
  	if (!size)
  		return;
  
  	ret = memblock_isolate_range(&memblock.memory, base, size,
  						&start_rgn, &end_rgn);
  	if (ret)
  		return;
  
  	/* remove all the MAP regions */
  	for (i = memblock.memory.cnt - 1; i >= end_rgn; i--)
  		if (!memblock_is_nomap(&memblock.memory.regions[i]))
  			memblock_remove_region(&memblock.memory, i);
  
  	for (i = start_rgn - 1; i >= 0; i--)
  		if (!memblock_is_nomap(&memblock.memory.regions[i]))
  			memblock_remove_region(&memblock.memory, i);
  
  	/* truncate the reserved regions */
  	memblock_remove_range(&memblock.reserved, 0, base);
  	memblock_remove_range(&memblock.reserved,

  			base + size, PHYS_ADDR_MAX);

  }

  void __init memblock_mem_limit_remove_map(phys_addr_t limit)
  {

  	phys_addr_t max_addr;

  
  	if (!limit)
  		return;
  
  	max_addr = __find_max_addr(limit);
  
  	/* @limit exceeds the total size of the memory, do nothing */

  	if (max_addr == PHYS_ADDR_MAX)

  		return;

  	memblock_cap_memory_range(0, max_addr);

  }

  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;
  }

  bool __init_memblock memblock_is_reserved(phys_addr_t addr)

  {

  	return memblock_search(&memblock.reserved, addr) != -1;
  }