bootmem.c

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/*
 *  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 = {
    .bdata = &bootmem_node_data[0]
};
EXPORT_SYMBOL(contig_page_data);
#endif

unsigned long max_low_pfn;
unsigned long min_low_pfn;
unsigned long max_pfn;

bootmem_data_t bootmem_node_data[MAX_NUMNODES] __initdata;

static struct list_head bdata_list __initdata = LIST_HEAD_INIT(bdata_list);

static int bootmem_debug;

static int __init bootmem_debug_setup(char *buf)
{
    bootmem_debug = 1;
    return 0;
}
early_param("bootmem_debug", bootmem_debug_setup);

#define bdebug(fmt, args...) ({             \
    if (unlikely(bootmem_debug))            \
        printk(KERN_INFO            \
            "bootmem::%s " fmt,     \
            __func__, ## args);     \
})

static unsigned long __init bootmap_bytes(unsigned long pages)
{
    unsigned long bytes = DIV_ROUND_UP(pages, 8);

    return ALIGN(bytes, sizeof(long));
}

unsigned long __init bootmem_bootmap_pages(unsigned long pages)
{
    unsigned long bytes = bootmap_bytes(pages);

    return PAGE_ALIGN(bytes) >> PAGE_SHIFT;
}

/*
 * link bdata in order
 */
static void __init link_bootmem(bootmem_data_t *bdata)
{
    bootmem_data_t *ent;

    list_for_each_entry(ent, &bdata_list, list) {
        if (bdata->node_min_pfn < ent->node_min_pfn) {
            list_add_tail(&bdata->list, &ent->list);
            return;
        }
    }

    list_add_tail(&bdata->list, &bdata_list);
}

/*
 * Called once to set up the allocator itself.
 */
static unsigned long __init init_bootmem_core(bootmem_data_t *bdata,
    unsigned long mapstart, unsigned long start, unsigned long end)
{
    unsigned long mapsize;

    mminit_validate_memmodel_limits(&start, &end);
    bdata->node_bootmem_map = phys_to_virt(PFN_PHYS(mapstart));
    bdata->node_min_pfn = start;
    bdata->node_low_pfn = end;
    link_bootmem(bdata);

    /*
     * Initially all pages are reserved - setup_arch() has to
     * register free RAM areas explicitly.
     */
    mapsize = bootmap_bytes(end - start);
    memset(bdata->node_bootmem_map, 0xff, mapsize);

    bdebug("nid=%td start=%lx map=%lx end=%lx mapsize=%lx\n",
        bdata - bootmem_node_data, start, mapstart, end, mapsize);

    return mapsize;
}

unsigned long __init init_bootmem_node(pg_data_t *pgdat, unsigned long freepfn,
                unsigned long startpfn, unsigned long endpfn)
{
    return init_bootmem_core(pgdat->bdata, freepfn, startpfn, endpfn);
}

unsigned long __init init_bootmem(unsigned long start, unsigned long pages)
{
    max_low_pfn = pages;
    min_low_pfn = start;
    return init_bootmem_core(NODE_DATA(0)->bdata, start, 0, pages);
}

/*
 * 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 unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata)
{
    struct page *page;
    unsigned long start, end, pages, count = 0;

    if (!bdata->node_bootmem_map)
        return 0;

    start = bdata->node_min_pfn;
    end = bdata->node_low_pfn;

    bdebug("nid=%td start=%lx end=%lx\n",
        bdata - bootmem_node_data, start, end);

    while (start < end) {
        unsigned long *map, idx, vec;

        map = bdata->node_bootmem_map;
        idx = start - bdata->node_min_pfn;
        vec = ~map[idx / BITS_PER_LONG];
        /*
         * If we have a properly aligned and fully unreserved
         * BITS_PER_LONG block of pages in front of us, free
         * it in one go.
         */
        if (IS_ALIGNED(start, BITS_PER_LONG) && vec == ~0UL) {
            int order = ilog2(BITS_PER_LONG);

            __free_pages_bootmem(pfn_to_page(start), order);
            count += BITS_PER_LONG;
            start += BITS_PER_LONG;
        } else {
            unsigned long off = 0;

            vec >>= start & (BITS_PER_LONG - 1);
            while (vec) {
                if (vec & 1) {
                    page = pfn_to_page(start + off);
                    __free_pages_bootmem(page, 0);
                    count++;
                }
                vec >>= 1;
                off++;
            }
            start = ALIGN(start + 1, BITS_PER_LONG);
        }
    }

    page = virt_to_page(bdata->node_bootmem_map);
    pages = bdata->node_low_pfn - bdata->node_min_pfn;
    pages = bootmem_bootmap_pages(pages);
    count += pages;
    while (pages--)
        __free_pages_bootmem(page++, 0);

    bdebug("nid=%td released=%lx\n", bdata - bootmem_node_data, count);

    return count;
}

unsigned long __init free_all_bootmem_node(pg_data_t *pgdat)
{
    register_page_bootmem_info_node(pgdat);
    return free_all_bootmem_core(pgdat->bdata);
}

unsigned long __init free_all_bootmem(void)
{
    unsigned long total_pages = 0;
    bootmem_data_t *bdata;

    list_for_each_entry(bdata, &bdata_list, list)
        total_pages += free_all_bootmem_core(bdata);

    return total_pages;
}

static void __init __free(bootmem_data_t *bdata,
            unsigned long sidx, unsigned long eidx)
{
    unsigned long idx;

    bdebug("nid=%td start=%lx end=%lx\n", bdata - bootmem_node_data,
        sidx + bdata->node_min_pfn,
        eidx + bdata->node_min_pfn);

    if (bdata->hint_idx > sidx)
        bdata->hint_idx = sidx;

    for (idx = sidx; idx < eidx; idx++)
        if (!test_and_clear_bit(idx, bdata->node_bootmem_map))
            BUG();
}

static int __init __reserve(bootmem_data_t *bdata, unsigned long sidx,
            unsigned long eidx, int flags)
{
    unsigned long idx;
    int exclusive = flags & BOOTMEM_EXCLUSIVE;

    bdebug("nid=%td start=%lx end=%lx flags=%x\n",
        bdata - bootmem_node_data,
        sidx + bdata->node_min_pfn,
        eidx + bdata->node_min_pfn,
        flags);

    for (idx = sidx; idx < eidx; idx++)
        if (test_and_set_bit(idx, bdata->node_bootmem_map)) {
            if (exclusive) {
                __free(bdata, sidx, idx);
                return -EBUSY;
            }
            bdebug("silent double reserve of PFN %lx\n",
                idx + bdata->node_min_pfn);
        }
    return 0;
}

static int __init mark_bootmem_node(bootmem_data_t *bdata,
                unsigned long start, unsigned long end,
                int reserve, int flags)
{
    unsigned long sidx, eidx;

    bdebug("nid=%td start=%lx end=%lx reserve=%d flags=%x\n",
        bdata - bootmem_node_data, start, end, reserve, flags);

    BUG_ON(start < bdata->node_min_pfn);
    BUG_ON(end > bdata->node_low_pfn);

    sidx = start - bdata->node_min_pfn;
    eidx = end - bdata->node_min_pfn;

    if (reserve)
        return __reserve(bdata, sidx, eidx, flags);
    else
        __free(bdata, sidx, eidx);
    return 0;
}

static int __init mark_bootmem(unsigned long start, unsigned long end,
                int reserve, int flags)
{
    unsigned long pos;
    bootmem_data_t *bdata;

    pos = start;
    list_for_each_entry(bdata, &bdata_list, list) {
        int err;
        unsigned long max;

        if (pos < bdata->node_min_pfn ||
            pos >= bdata->node_low_pfn) {
            BUG_ON(pos != start);
            continue;
        }

        max = min(bdata->node_low_pfn, end);

        err = mark_bootmem_node(bdata, pos, max, reserve, flags);
        if (reserve && err) {
            mark_bootmem(start, pos, 0, 0);
            return err;
        }

        if (max == end)
            return 0;
        pos = bdata->node_low_pfn;
    }
    BUG();
}

void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
                  unsigned long size)
{
    unsigned long start, end;

    kmemleak_free_part(__va(physaddr), size);

    start = PFN_UP(physaddr);
    end = PFN_DOWN(physaddr + size);

    mark_bootmem_node(pgdat->bdata, start, end, 0, 0);
}

void __init free_bootmem(unsigned long addr, unsigned long size)
{
    unsigned long start, end;

    kmemleak_free_part(__va(addr), size);

    start = PFN_UP(addr);
    end = PFN_DOWN(addr + size);

    mark_bootmem(start, end, 0, 0);
}

int __init reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
                 unsigned long size, int flags)
{
    unsigned long start, end;

    start = PFN_DOWN(physaddr);
    end = PFN_UP(physaddr + size);

    return mark_bootmem_node(pgdat->bdata, start, end, 1, flags);
}

int __init reserve_bootmem(unsigned long addr, unsigned long size,
                int flags)
{
    unsigned long start, end;

    start = PFN_DOWN(addr);
    end = PFN_UP(addr + size);

    return mark_bootmem(start, end, 1, flags);
}

int __weak __init reserve_bootmem_generic(unsigned long phys, unsigned long len,
                   int flags)
{
    return reserve_bootmem(phys, len, flags);
}

static unsigned long __init align_idx(struct bootmem_data *bdata,
                      unsigned long idx, unsigned long step)
{
    unsigned long base = bdata->node_min_pfn;

    /*
     * Align the index with respect to the node start so that the
     * combination of both satisfies the requested alignment.
     */

    return ALIGN(base + idx, step) - base;
}

static unsigned long __init align_off(struct bootmem_data *bdata,
                      unsigned long off, unsigned long align)
{
    unsigned long base = PFN_PHYS(bdata->node_min_pfn);

    /* Same as align_idx for byte offsets */

    return ALIGN(base + off, align) - base;
}

static void * __init alloc_bootmem_bdata(struct bootmem_data *bdata,
                    unsigned long size, unsigned long align,
                    unsigned long goal, unsigned long limit)
{
    unsigned long fallback = 0;
    unsigned long min, max, start, sidx, midx, step;

    bdebug("nid=%td size=%lx [%lu pages] align=%lx goal=%lx limit=%lx\n",
        bdata - bootmem_node_data, size, PAGE_ALIGN(size) >> PAGE_SHIFT,
        align, goal, limit);

    BUG_ON(!size);
    BUG_ON(align & (align - 1));
    BUG_ON(limit && goal + size > limit);

    if (!bdata->node_bootmem_map)
        return NULL;

    min = bdata->node_min_pfn;
    max = bdata->node_low_pfn;

    goal >>= PAGE_SHIFT;
    limit >>= PAGE_SHIFT;

    if (limit && max > limit)
        max = limit;
    if (max <= min)
        return NULL;

    step = max(align >> PAGE_SHIFT, 1UL);

    if (goal && min < goal && goal < max)
        start = ALIGN(goal, step);
    else
        start = ALIGN(min, step);

    sidx = start - bdata->node_min_pfn;
    midx = max - bdata->node_min_pfn;

    if (bdata->hint_idx > sidx) {
        /*
         * Handle the valid case of sidx being zero and still
         * catch the fallback below.
         */
        fallback = sidx + 1;
        sidx = align_idx(bdata, bdata->hint_idx, step);
    }

    while (1) {
        int merge;
        void *region;
        unsigned long eidx, i, start_off, end_off;
find_block:
        sidx = find_next_zero_bit(bdata->node_bootmem_map, midx, sidx);
        sidx = align_idx(bdata, sidx, step);
        eidx = sidx + PFN_UP(size);

        if (sidx >= midx || eidx > midx)
            break;

        for (i = sidx; i < eidx; i++)
            if (test_bit(i, bdata->node_bootmem_map)) {
                sidx = align_idx(bdata, i, step);
                if (sidx == i)
                    sidx += step;
                goto find_block;
            }

        if (bdata->last_end_off & (PAGE_SIZE - 1) &&
                PFN_DOWN(bdata->last_end_off) + 1 == sidx)
            start_off = align_off(bdata, bdata->last_end_off, align);
        else
            start_off = PFN_PHYS(sidx);

        merge = PFN_DOWN(start_off) < sidx;
        end_off = start_off + size;

        bdata->last_end_off = end_off;
        bdata->hint_idx = PFN_UP(end_off);

        /*
         * Reserve the area now:
         */
        if (__reserve(bdata, PFN_DOWN(start_off) + merge,
                PFN_UP(end_off), BOOTMEM_EXCLUSIVE))
            BUG();

        region = phys_to_virt(PFN_PHYS(bdata->node_min_pfn) +
                start_off);
        memset(region, 0, size);
        /*
         * The min_count is set to 0 so that bootmem allocated blocks
         * are never reported as leaks.
         */
        kmemleak_alloc(region, size, 0, 0);
        return region;
    }

    if (fallback) {
        sidx = align_idx(bdata, fallback - 1, step);
        fallback = 0;
        goto find_block;
    }

    return NULL;
}

static void * __init alloc_arch_preferred_bootmem(bootmem_data_t *bdata,
                    unsigned long size, unsigned long align,
                    unsigned long goal, unsigned long limit)
{
    if (WARN_ON_ONCE(slab_is_available()))
        return kzalloc(size, GFP_NOWAIT);

#ifdef CONFIG_HAVE_ARCH_BOOTMEM
    {
        bootmem_data_t *p_bdata;

        p_bdata = bootmem_arch_preferred_node(bdata, size, align,
                            goal, limit);
        if (p_bdata)
            return alloc_bootmem_bdata(p_bdata, size, align,
                            goal, limit);
    }
#endif
    return NULL;
}

static void * __init alloc_bootmem_core(unsigned long size,
                    unsigned long align,
                    unsigned long goal,
                    unsigned long limit)
{
    bootmem_data_t *bdata;
    void *region;

    region = alloc_arch_preferred_bootmem(NULL, size, align, goal, limit);
    if (region)
        return region;

    list_for_each_entry(bdata, &bdata_list, list) {
        if (goal && bdata->node_low_pfn <= PFN_DOWN(goal))
            continue;
        if (limit && bdata->node_min_pfn >= PFN_DOWN(limit))
            break;

        region = alloc_bootmem_bdata(bdata, size, align, goal, limit);
        if (region)
            return region;
    }

    return NULL;
}

static void * __init ___alloc_bootmem_nopanic(unsigned long size,
                          unsigned long align,
                          unsigned long goal,
                          unsigned long limit)
{
    void *ptr;

restart:
    ptr = alloc_bootmem_core(size, align, goal, limit);
    if (ptr)
        return ptr;
    if (goal) {
        goal = 0;
        goto restart;
    }

    return NULL;
}

void * __init __alloc_bootmem_nopanic(unsigned long size, unsigned long align,
                    unsigned long goal)
{
    unsigned long limit = 0;

    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;
}

void * __init __alloc_bootmem(unsigned long size, unsigned long align,
                  unsigned long goal)
{
    unsigned long limit = 0;

    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_arch_preferred_bootmem(pgdat->bdata, size,
                       align, goal, limit);
    if (ptr)
        return ptr;

    /* do not panic in alloc_bootmem_bdata() */
    if (limit && goal + size > limit)
        limit = 0;

    ptr = alloc_bootmem_bdata(pgdat->bdata, size, align, goal, limit);
    if (ptr)
        return ptr;

    ptr = alloc_bootmem_core(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);
}

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, 0);
    if (ptr)
        return ptr;

    printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size);
    panic("Out of memory");
    return NULL;
}

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)
{
#ifdef MAX_DMA32_PFN
    unsigned long end_pfn;

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

    /* update goal according ...MAX_DMA32_PFN */
    end_pfn = pgdat->node_start_pfn + pgdat->node_spanned_pages;

    if (end_pfn > MAX_DMA32_PFN + (128 >> (20 - PAGE_SHIFT)) &&
        (goal >> PAGE_SHIFT) < MAX_DMA32_PFN) {
        void *ptr;
        unsigned long new_goal;

        new_goal = MAX_DMA32_PFN << PAGE_SHIFT;
        ptr = alloc_bootmem_bdata(pgdat->bdata, size, align,
                         new_goal, 0);
        if (ptr)
            return ptr;
    }
#endif

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

}

#ifndef ARCH_LOW_ADDRESS_LIMIT
#define ARCH_LOW_ADDRESS_LIMIT  0xffffffffUL
#endif

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_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);
}