/*
 *  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/export.h>
#include <linux/kmemleak.h>
#include <linux/range.h>
#include <linux/memblock.h>
#include <linux/bootmem.h>

#include <asm/bug.h>
#include <asm/io.h>

#include "internal.h"

#ifndef CONFIG_HAVE_MEMBLOCK
#error CONFIG_HAVE_MEMBLOCK not defined
#endif

#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\n",
                        &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_phys(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);

        /*
         * 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
         */
        for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end,
                                NULL)
                count += __free_memory_core(start, end);

        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();

        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!\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);
}

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!\n", 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);
}


/**
 * __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);
}