/*
   *  bootmem - A boot-time physical memory allocator and configurator
   *
   *  Copyright (C) 1999 Ingo Molnar
   *                1999 Kanoj Sarcar, SGI
   *                2008 Johannes Weiner
   *
   * Access to this subsystem has to be serialized externally (which is true
   * for the boot process anyway).
   */
  #include <linux/init.h>
  #include <linux/pfn.h>
  #include <linux/slab.h>
  #include <linux/bootmem.h>

  #include <linux/export.h>

  #include <linux/kmemleak.h>
  #include <linux/range.h>
  #include <linux/memblock.h>
  
  #include <asm/bug.h>
  #include <asm/io.h>
  #include <asm/processor.h>
  
  #include "internal.h"

  #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 void * __init __alloc_memory_core_early(int nid, u64 size, u64 align,
  					u64 goal, u64 limit)
  {
  	void *ptr;
  	u64 addr;

  	ulong flags = choose_memblock_flags();

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

  again:

  	addr = memblock_find_in_range_node(size, align, goal, limit, nid,

  					   flags);
  	if (!addr && (flags & MEMBLOCK_MIRROR)) {
  		flags &= ~MEMBLOCK_MIRROR;
  		pr_warn("Could not allocate %pap bytes of mirrored memory
  ",
  			&size);
  		goto again;
  	}

  	if (!addr)

  		return NULL;

  	if (memblock_reserve(addr, size))
  		return NULL;

  	ptr = phys_to_virt(addr);
  	memset(ptr, 0, size);

  	/*
  	 * The min_count is set to 0 so that bootmem allocated blocks
  	 * are never reported as leaks.
  	 */
  	kmemleak_alloc(ptr, size, 0, 0);
  	return ptr;
  }

  /*
   * free_bootmem_late - free bootmem pages directly to page allocator
   * @addr: starting address of the range
   * @size: size of the range in bytes
   *
   * This is only useful when the bootmem allocator has already been torn
   * down, but we are still initializing the system.  Pages are given directly
   * to the page allocator, no bootmem metadata is updated because it is gone.
   */
  void __init free_bootmem_late(unsigned long addr, unsigned long size)
  {
  	unsigned long cursor, end;
  
  	kmemleak_free_part(__va(addr), size);
  
  	cursor = PFN_UP(addr);
  	end = PFN_DOWN(addr + size);
  
  	for (; cursor < end; cursor++) {

  		__free_pages_bootmem(pfn_to_page(cursor), cursor, 0);

  		totalram_pages++;
  	}
  }
  
  static void __init __free_pages_memory(unsigned long start, unsigned long end)
  {

  	int order;

  	while (start < end) {
  		order = min(MAX_ORDER - 1UL, __ffs(start));

  		while (start + (1UL << order) > end)
  			order--;

  		__free_pages_bootmem(pfn_to_page(start), start, order);

  		start += (1UL << order);
  	}

  }

  static unsigned long __init __free_memory_core(phys_addr_t start,
  				 phys_addr_t end)
  {
  	unsigned long start_pfn = PFN_UP(start);
  	unsigned long end_pfn = min_t(unsigned long,
  				      PFN_DOWN(end), max_low_pfn);
  
  	if (start_pfn > end_pfn)
  		return 0;
  
  	__free_pages_memory(start_pfn, end_pfn);
  
  	return end_pfn - start_pfn;
  }

  static unsigned long __init free_low_memory_core_early(void)

  {

  	unsigned long count = 0;

  	phys_addr_t start, end;

  	u64 i;

  	memblock_clear_hotplug(0, -1);

  	for_each_reserved_mem_region(i, &start, &end)
  		reserve_bootmem_region(start, end);

  	for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end,
  				NULL)

  		count += __free_memory_core(start, end);

  #ifdef CONFIG_ARCH_DISCARD_MEMBLOCK

  	{
  		phys_addr_t size;
  
  		/* Free memblock.reserved array if it was allocated */
  		size = get_allocated_memblock_reserved_regions_info(&start);
  		if (size)
  			count += __free_memory_core(start, start + size);
  
  		/* Free memblock.memory array if it was allocated */
  		size = get_allocated_memblock_memory_regions_info(&start);
  		if (size)
  			count += __free_memory_core(start, start + size);
  	}

  #endif

  	return count;
  }

  static int reset_managed_pages_done __initdata;

  void reset_node_managed_pages(pg_data_t *pgdat)

  {
  	struct zone *z;

  	for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)

  		z->managed_pages = 0;
  }
  
  void __init reset_all_zones_managed_pages(void)
  {
  	struct pglist_data *pgdat;

  	if (reset_managed_pages_done)
  		return;

  	for_each_online_pgdat(pgdat)
  		reset_node_managed_pages(pgdat);

  	reset_managed_pages_done = 1;

  }

  /**

   * free_all_bootmem - release free pages to the buddy allocator
   *
   * Returns the number of pages actually released.
   */
  unsigned long __init free_all_bootmem(void)
  {

  	unsigned long pages;

  	reset_all_zones_managed_pages();

  	/*

  	 * We need to use NUMA_NO_NODE instead of NODE_DATA(0)->node_id

  	 *  because in some case like Node0 doesn't have RAM installed

  	 *  low ram will be on Node1

  	 */

  	pages = free_low_memory_core_early();
  	totalram_pages += pages;
  
  	return pages;

  }
  
  /**
   * free_bootmem_node - mark a page range as usable
   * @pgdat: node the range resides on
   * @physaddr: starting address of the range
   * @size: size of the range in bytes
   *
   * Partial pages will be considered reserved and left as they are.
   *
   * The range must reside completely on the specified node.
   */
  void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
  			      unsigned long size)
  {

  	memblock_free(physaddr, size);

  }
  
  /**
   * free_bootmem - mark a page range as usable
   * @addr: starting address of the range
   * @size: size of the range in bytes
   *
   * Partial pages will be considered reserved and left as they are.
   *
   * The range must be contiguous but may span node boundaries.
   */
  void __init free_bootmem(unsigned long addr, unsigned long size)
  {

  	memblock_free(addr, size);

  }
  
  static void * __init ___alloc_bootmem_nopanic(unsigned long size,
  					unsigned long align,
  					unsigned long goal,
  					unsigned long limit)
  {
  	void *ptr;
  
  	if (WARN_ON_ONCE(slab_is_available()))
  		return kzalloc(size, GFP_NOWAIT);
  
  restart:

  	ptr = __alloc_memory_core_early(NUMA_NO_NODE, size, align, goal, limit);

  
  	if (ptr)
  		return ptr;
  
  	if (goal != 0) {
  		goal = 0;
  		goto restart;
  	}
  
  	return NULL;
  }
  
  /**
   * __alloc_bootmem_nopanic - allocate boot memory without panicking
   * @size: size of the request in bytes
   * @align: alignment of the region
   * @goal: preferred starting address of the region
   *
   * The goal is dropped if it can not be satisfied and the allocation will
   * fall back to memory below @goal.
   *
   * Allocation may happen on any node in the system.
   *
   * Returns NULL on failure.
   */
  void * __init __alloc_bootmem_nopanic(unsigned long size, unsigned long align,
  					unsigned long goal)
  {
  	unsigned long limit = -1UL;
  
  	return ___alloc_bootmem_nopanic(size, align, goal, limit);
  }
  
  static void * __init ___alloc_bootmem(unsigned long size, unsigned long align,
  					unsigned long goal, unsigned long limit)
  {
  	void *mem = ___alloc_bootmem_nopanic(size, align, goal, limit);
  
  	if (mem)
  		return mem;
  	/*
  	 * Whoops, we cannot satisfy the allocation request.
  	 */

  	pr_alert("bootmem alloc of %lu bytes failed!
  ", size);

  	panic("Out of memory");
  	return NULL;
  }
  
  /**
   * __alloc_bootmem - allocate boot memory
   * @size: size of the request in bytes
   * @align: alignment of the region
   * @goal: preferred starting address of the region
   *
   * The goal is dropped if it can not be satisfied and the allocation will
   * fall back to memory below @goal.
   *
   * Allocation may happen on any node in the system.
   *
   * The function panics if the request can not be satisfied.
   */
  void * __init __alloc_bootmem(unsigned long size, unsigned long align,
  			      unsigned long goal)
  {
  	unsigned long limit = -1UL;
  
  	return ___alloc_bootmem(size, align, goal, limit);
  }

  void * __init ___alloc_bootmem_node_nopanic(pg_data_t *pgdat,

  						   unsigned long size,
  						   unsigned long align,
  						   unsigned long goal,
  						   unsigned long limit)
  {
  	void *ptr;
  
  again:
  	ptr = __alloc_memory_core_early(pgdat->node_id, size, align,
  					goal, limit);
  	if (ptr)
  		return ptr;

  	ptr = __alloc_memory_core_early(NUMA_NO_NODE, size, align,

  					goal, limit);
  	if (ptr)
  		return ptr;
  
  	if (goal) {
  		goal = 0;
  		goto again;
  	}
  
  	return NULL;
  }
  
  void * __init __alloc_bootmem_node_nopanic(pg_data_t *pgdat, unsigned long size,
  				   unsigned long align, unsigned long goal)
  {
  	if (WARN_ON_ONCE(slab_is_available()))
  		return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
  
  	return ___alloc_bootmem_node_nopanic(pgdat, size, align, goal, 0);
  }

  static void * __init ___alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,

  				    unsigned long align, unsigned long goal,
  				    unsigned long limit)
  {
  	void *ptr;
  
  	ptr = ___alloc_bootmem_node_nopanic(pgdat, size, align, goal, limit);
  	if (ptr)
  		return ptr;

  	pr_alert("bootmem alloc of %lu bytes failed!
  ", size);

  	panic("Out of memory");
  	return NULL;
  }

  /**
   * __alloc_bootmem_node - allocate boot memory from a specific node
   * @pgdat: node to allocate from
   * @size: size of the request in bytes
   * @align: alignment of the region
   * @goal: preferred starting address of the region
   *
   * The goal is dropped if it can not be satisfied and the allocation will
   * fall back to memory below @goal.
   *
   * Allocation may fall back to any node in the system if the specified node
   * can not hold the requested memory.
   *
   * The function panics if the request can not be satisfied.
   */
  void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
  				   unsigned long align, unsigned long goal)
  {

  	if (WARN_ON_ONCE(slab_is_available()))
  		return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);

  	return ___alloc_bootmem_node(pgdat, size, align, goal, 0);

  }
  
  void * __init __alloc_bootmem_node_high(pg_data_t *pgdat, unsigned long size,
  				   unsigned long align, unsigned long goal)
  {

  	return __alloc_bootmem_node(pgdat, size, align, goal);

  }

  #ifndef ARCH_LOW_ADDRESS_LIMIT
  #define ARCH_LOW_ADDRESS_LIMIT	0xffffffffUL
  #endif
  
  /**
   * __alloc_bootmem_low - allocate low boot memory
   * @size: size of the request in bytes
   * @align: alignment of the region
   * @goal: preferred starting address of the region
   *
   * The goal is dropped if it can not be satisfied and the allocation will
   * fall back to memory below @goal.
   *
   * Allocation may happen on any node in the system.
   *
   * The function panics if the request can not be satisfied.
   */
  void * __init __alloc_bootmem_low(unsigned long size, unsigned long align,
  				  unsigned long goal)
  {
  	return ___alloc_bootmem(size, align, goal, ARCH_LOW_ADDRESS_LIMIT);
  }

  void * __init __alloc_bootmem_low_nopanic(unsigned long size,
  					  unsigned long align,
  					  unsigned long goal)
  {
  	return ___alloc_bootmem_nopanic(size, align, goal,
  					ARCH_LOW_ADDRESS_LIMIT);
  }

  /**
   * __alloc_bootmem_low_node - allocate low boot memory from a specific node
   * @pgdat: node to allocate from
   * @size: size of the request in bytes
   * @align: alignment of the region
   * @goal: preferred starting address of the region
   *
   * The goal is dropped if it can not be satisfied and the allocation will
   * fall back to memory below @goal.
   *
   * Allocation may fall back to any node in the system if the specified node
   * can not hold the requested memory.
   *
   * The function panics if the request can not be satisfied.
   */
  void * __init __alloc_bootmem_low_node(pg_data_t *pgdat, unsigned long size,
  				       unsigned long align, unsigned long goal)
  {

  	if (WARN_ON_ONCE(slab_is_available()))
  		return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);

  	return ___alloc_bootmem_node(pgdat, size, align, goal,
  				     ARCH_LOW_ADDRESS_LIMIT);

  }