/*
 *  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!\n", 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);
}