/*
   *  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;

  static void * __init __alloc_memory_core_early(int nid, u64 size, u64 align,
  					u64 goal, u64 limit)
  {
  	void *ptr;
  	u64 addr;
  
  	if (limit > memblock.current_limit)
  		limit = memblock.current_limit;

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

  	if (!addr)

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

  	memblock_reserve(addr, 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), 0);
  		totalram_pages++;
  	}
  }
  
  static void __init __free_pages_memory(unsigned long start, unsigned long end)
  {
  	int i;
  	unsigned long start_aligned, end_aligned;
  	int order = ilog2(BITS_PER_LONG);
  
  	start_aligned = (start + (BITS_PER_LONG - 1)) & ~(BITS_PER_LONG - 1);
  	end_aligned = end & ~(BITS_PER_LONG - 1);
  
  	if (end_aligned <= start_aligned) {
  		for (i = start; i < end; i++)
  			__free_pages_bootmem(pfn_to_page(i), 0);
  
  		return;
  	}
  
  	for (i = start; i < start_aligned; i++)
  		__free_pages_bootmem(pfn_to_page(i), 0);
  
  	for (i = start_aligned; i < end_aligned; i += BITS_PER_LONG)
  		__free_pages_bootmem(pfn_to_page(i), order);
  
  	for (i = end_aligned; i < end; i++)
  		__free_pages_bootmem(pfn_to_page(i), 0);
  }

  unsigned long __init free_low_memory_core_early(int nodeid)

  {

  	unsigned long count = 0;

  	phys_addr_t start, end;
  	u64 i;
  
  	/* free reserved array temporarily so that it's treated as free area */
  	memblock_free_reserved_regions();
  
  	for_each_free_mem_range(i, MAX_NUMNODES, &start, &end, NULL) {
  		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) {
  			__free_pages_memory(start_pfn, end_pfn);
  			count += end_pfn - start_pfn;
  		}

  	}

  	/* put region array back? */
  	memblock_reserve_reserved_regions();

  	return count;
  }
  
  /**
   * free_all_bootmem_node - release a node's free pages to the buddy allocator
   * @pgdat: node to be released
   *
   * Returns the number of pages actually released.
   */
  unsigned long __init free_all_bootmem_node(pg_data_t *pgdat)
  {
  	register_page_bootmem_info_node(pgdat);

  	/* free_low_memory_core_early(MAX_NUMNODES) will be called later */

  	return 0;
  }
  
  /**
   * free_all_bootmem - release free pages to the buddy allocator
   *
   * Returns the number of pages actually released.
   */
  unsigned long __init free_all_bootmem(void)
  {
  	/*
  	 * We need to use MAX_NUMNODES instead of NODE_DATA(0)->node_id

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

  	 *  low ram will be on Node1
  	 * Use MAX_NUMNODES will make sure all ranges in early_node_map[]
  	 *  will be used instead of only Node0 related
  	 */

  	return free_low_memory_core_early(MAX_NUMNODES);

  }
  
  /**
   * 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)
  {
  	kmemleak_free_part(__va(physaddr), 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)
  {
  	kmemleak_free_part(__va(addr), 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(MAX_NUMNODES, 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.
  	 */
  	printk(KERN_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);
  }
  
  /**
   * __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)
  {
  	void *ptr;
  
  	if (WARN_ON_ONCE(slab_is_available()))
  		return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
  
  	ptr = __alloc_memory_core_early(pgdat->node_id, size, align,
  					 goal, -1ULL);
  	if (ptr)
  		return ptr;
  
  	return __alloc_memory_core_early(MAX_NUMNODES, size, align,
  					 goal, -1ULL);
  }
  
  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);

  }
  
  #ifdef CONFIG_SPARSEMEM
  /**
   * alloc_bootmem_section - allocate boot memory from a specific section
   * @size: size of the request in bytes
   * @section_nr: sparse map section to allocate from
   *
   * Return NULL on failure.
   */
  void * __init alloc_bootmem_section(unsigned long size,
  				    unsigned long section_nr)
  {
  	unsigned long pfn, goal, limit;
  
  	pfn = section_nr_to_pfn(section_nr);
  	goal = pfn << PAGE_SHIFT;
  	limit = section_nr_to_pfn(section_nr + 1) << PAGE_SHIFT;
  
  	return __alloc_memory_core_early(early_pfn_to_nid(pfn), size,
  					 SMP_CACHE_BYTES, goal, limit);
  }
  #endif
  
  void * __init __alloc_bootmem_node_nopanic(pg_data_t *pgdat, unsigned long size,
  				   unsigned long align, unsigned long goal)
  {
  	void *ptr;
  
  	if (WARN_ON_ONCE(slab_is_available()))
  		return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
  
  	ptr =  __alloc_memory_core_early(pgdat->node_id, size, align,
  						 goal, -1ULL);
  	if (ptr)
  		return ptr;
  
  	return __alloc_bootmem_nopanic(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);
  }
  
  /**
   * __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)
  {
  	void *ptr;
  
  	if (WARN_ON_ONCE(slab_is_available()))
  		return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
  
  	ptr = __alloc_memory_core_early(pgdat->node_id, size, align,
  				goal, ARCH_LOW_ADDRESS_LIMIT);
  	if (ptr)
  		return ptr;
  
  	return  __alloc_memory_core_early(MAX_NUMNODES, size, align,
  				goal, ARCH_LOW_ADDRESS_LIMIT);
  }