505 lines
12 KiB
C
505 lines
12 KiB
C
/*
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* linux/mm/bootmem.c
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*
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* Copyright (C) 1999 Ingo Molnar
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* Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
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*
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* simple boot-time physical memory area allocator and
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* free memory collector. It's used to deal with reserved
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* system memory and memory holes as well.
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*/
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#include <linux/init.h>
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#include <linux/pfn.h>
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#include <linux/bootmem.h>
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#include <linux/module.h>
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#include <asm/bug.h>
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#include <asm/io.h>
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#include <asm/processor.h>
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#include "internal.h"
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/*
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* Access to this subsystem has to be serialized externally. (this is
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* true for the boot process anyway)
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*/
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unsigned long max_low_pfn;
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unsigned long min_low_pfn;
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unsigned long max_pfn;
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static LIST_HEAD(bdata_list);
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#ifdef CONFIG_CRASH_DUMP
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/*
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* If we have booted due to a crash, max_pfn will be a very low value. We need
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* to know the amount of memory that the previous kernel used.
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*/
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unsigned long saved_max_pfn;
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#endif
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/* return the number of _pages_ that will be allocated for the boot bitmap */
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unsigned long __init bootmem_bootmap_pages(unsigned long pages)
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{
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unsigned long mapsize;
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mapsize = (pages+7)/8;
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mapsize = (mapsize + ~PAGE_MASK) & PAGE_MASK;
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mapsize >>= PAGE_SHIFT;
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return mapsize;
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}
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/*
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* link bdata in order
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*/
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static void __init link_bootmem(bootmem_data_t *bdata)
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{
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bootmem_data_t *ent;
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if (list_empty(&bdata_list)) {
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list_add(&bdata->list, &bdata_list);
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return;
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}
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/* insert in order */
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list_for_each_entry(ent, &bdata_list, list) {
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if (bdata->node_boot_start < ent->node_boot_start) {
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list_add_tail(&bdata->list, &ent->list);
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return;
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}
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}
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list_add_tail(&bdata->list, &bdata_list);
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}
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/*
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* Given an initialised bdata, it returns the size of the boot bitmap
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*/
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static unsigned long __init get_mapsize(bootmem_data_t *bdata)
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{
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unsigned long mapsize;
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unsigned long start = PFN_DOWN(bdata->node_boot_start);
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unsigned long end = bdata->node_low_pfn;
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mapsize = ((end - start) + 7) / 8;
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return ALIGN(mapsize, sizeof(long));
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}
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/*
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* Called once to set up the allocator itself.
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*/
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static unsigned long __init init_bootmem_core(pg_data_t *pgdat,
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unsigned long mapstart, unsigned long start, unsigned long end)
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{
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bootmem_data_t *bdata = pgdat->bdata;
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unsigned long mapsize;
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bdata->node_bootmem_map = phys_to_virt(PFN_PHYS(mapstart));
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bdata->node_boot_start = PFN_PHYS(start);
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bdata->node_low_pfn = end;
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link_bootmem(bdata);
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/*
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* Initially all pages are reserved - setup_arch() has to
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* register free RAM areas explicitly.
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*/
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mapsize = get_mapsize(bdata);
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memset(bdata->node_bootmem_map, 0xff, mapsize);
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return mapsize;
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}
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/*
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* Marks a particular physical memory range as unallocatable. Usable RAM
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* might be used for boot-time allocations - or it might get added
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* to the free page pool later on.
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*/
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static int __init reserve_bootmem_core(bootmem_data_t *bdata,
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unsigned long addr, unsigned long size, int flags)
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{
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unsigned long sidx, eidx;
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unsigned long i;
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int ret;
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/*
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* round up, partially reserved pages are considered
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* fully reserved.
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*/
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BUG_ON(!size);
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BUG_ON(PFN_DOWN(addr) >= bdata->node_low_pfn);
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BUG_ON(PFN_UP(addr + size) > bdata->node_low_pfn);
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sidx = PFN_DOWN(addr - bdata->node_boot_start);
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eidx = PFN_UP(addr + size - bdata->node_boot_start);
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for (i = sidx; i < eidx; i++)
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if (test_and_set_bit(i, bdata->node_bootmem_map)) {
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#ifdef CONFIG_DEBUG_BOOTMEM
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printk("hm, page %08lx reserved twice.\n", i*PAGE_SIZE);
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#endif
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if (flags & BOOTMEM_EXCLUSIVE) {
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ret = -EBUSY;
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goto err;
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}
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}
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return 0;
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err:
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/* unreserve memory we accidentally reserved */
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for (i--; i >= sidx; i--)
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clear_bit(i, bdata->node_bootmem_map);
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return ret;
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}
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static void __init free_bootmem_core(bootmem_data_t *bdata, unsigned long addr,
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unsigned long size)
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{
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unsigned long sidx, eidx;
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unsigned long i;
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/*
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* round down end of usable mem, partially free pages are
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* considered reserved.
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*/
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BUG_ON(!size);
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BUG_ON(PFN_DOWN(addr + size) > bdata->node_low_pfn);
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if (addr < bdata->last_success)
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bdata->last_success = addr;
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/*
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* Round up the beginning of the address.
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*/
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sidx = PFN_UP(addr) - PFN_DOWN(bdata->node_boot_start);
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eidx = PFN_DOWN(addr + size - bdata->node_boot_start);
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for (i = sidx; i < eidx; i++) {
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if (unlikely(!test_and_clear_bit(i, bdata->node_bootmem_map)))
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BUG();
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}
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}
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/*
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* We 'merge' subsequent allocations to save space. We might 'lose'
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* some fraction of a page if allocations cannot be satisfied due to
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* size constraints on boxes where there is physical RAM space
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* fragmentation - in these cases (mostly large memory boxes) this
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* is not a problem.
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*
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* On low memory boxes we get it right in 100% of the cases.
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*
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* alignment has to be a power of 2 value.
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*
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* NOTE: This function is _not_ reentrant.
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*/
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void * __init
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__alloc_bootmem_core(struct bootmem_data *bdata, unsigned long size,
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unsigned long align, unsigned long goal, unsigned long limit)
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{
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unsigned long offset, remaining_size, areasize, preferred;
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unsigned long i, start = 0, incr, eidx, end_pfn;
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void *ret;
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if (!size) {
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printk("__alloc_bootmem_core(): zero-sized request\n");
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BUG();
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}
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BUG_ON(align & (align-1));
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if (limit && bdata->node_boot_start >= limit)
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return NULL;
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/* on nodes without memory - bootmem_map is NULL */
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if (!bdata->node_bootmem_map)
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return NULL;
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end_pfn = bdata->node_low_pfn;
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limit = PFN_DOWN(limit);
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if (limit && end_pfn > limit)
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end_pfn = limit;
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eidx = end_pfn - PFN_DOWN(bdata->node_boot_start);
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offset = 0;
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if (align && (bdata->node_boot_start & (align - 1UL)) != 0)
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offset = align - (bdata->node_boot_start & (align - 1UL));
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offset = PFN_DOWN(offset);
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/*
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* We try to allocate bootmem pages above 'goal'
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* first, then we try to allocate lower pages.
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*/
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if (goal && goal >= bdata->node_boot_start && PFN_DOWN(goal) < end_pfn) {
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preferred = goal - bdata->node_boot_start;
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if (bdata->last_success >= preferred)
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if (!limit || (limit && limit > bdata->last_success))
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preferred = bdata->last_success;
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} else
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preferred = 0;
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preferred = PFN_DOWN(ALIGN(preferred, align)) + offset;
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areasize = (size + PAGE_SIZE-1) / PAGE_SIZE;
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incr = align >> PAGE_SHIFT ? : 1;
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restart_scan:
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for (i = preferred; i < eidx; i += incr) {
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unsigned long j;
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i = find_next_zero_bit(bdata->node_bootmem_map, eidx, i);
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i = ALIGN(i, incr);
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if (i >= eidx)
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break;
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if (test_bit(i, bdata->node_bootmem_map))
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continue;
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for (j = i + 1; j < i + areasize; ++j) {
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if (j >= eidx)
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goto fail_block;
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if (test_bit(j, bdata->node_bootmem_map))
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goto fail_block;
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}
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start = i;
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goto found;
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fail_block:
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i = ALIGN(j, incr);
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}
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if (preferred > offset) {
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preferred = offset;
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goto restart_scan;
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}
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return NULL;
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found:
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bdata->last_success = PFN_PHYS(start);
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BUG_ON(start >= eidx);
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/*
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* Is the next page of the previous allocation-end the start
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* of this allocation's buffer? If yes then we can 'merge'
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* the previous partial page with this allocation.
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*/
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if (align < PAGE_SIZE &&
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bdata->last_offset && bdata->last_pos+1 == start) {
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offset = ALIGN(bdata->last_offset, align);
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BUG_ON(offset > PAGE_SIZE);
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remaining_size = PAGE_SIZE - offset;
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if (size < remaining_size) {
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areasize = 0;
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/* last_pos unchanged */
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bdata->last_offset = offset + size;
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ret = phys_to_virt(bdata->last_pos * PAGE_SIZE +
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offset +
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bdata->node_boot_start);
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} else {
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remaining_size = size - remaining_size;
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areasize = (remaining_size + PAGE_SIZE-1) / PAGE_SIZE;
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ret = phys_to_virt(bdata->last_pos * PAGE_SIZE +
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offset +
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bdata->node_boot_start);
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bdata->last_pos = start + areasize - 1;
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bdata->last_offset = remaining_size;
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}
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bdata->last_offset &= ~PAGE_MASK;
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} else {
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bdata->last_pos = start + areasize - 1;
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bdata->last_offset = size & ~PAGE_MASK;
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ret = phys_to_virt(start * PAGE_SIZE + bdata->node_boot_start);
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}
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/*
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* Reserve the area now:
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*/
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for (i = start; i < start + areasize; i++)
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if (unlikely(test_and_set_bit(i, bdata->node_bootmem_map)))
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BUG();
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memset(ret, 0, size);
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return ret;
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}
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static unsigned long __init free_all_bootmem_core(pg_data_t *pgdat)
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{
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struct page *page;
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unsigned long pfn;
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bootmem_data_t *bdata = pgdat->bdata;
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unsigned long i, count, total = 0;
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unsigned long idx;
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unsigned long *map;
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int gofast = 0;
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BUG_ON(!bdata->node_bootmem_map);
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count = 0;
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/* first extant page of the node */
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pfn = PFN_DOWN(bdata->node_boot_start);
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idx = bdata->node_low_pfn - pfn;
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map = bdata->node_bootmem_map;
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/* Check physaddr is O(LOG2(BITS_PER_LONG)) page aligned */
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if (bdata->node_boot_start == 0 ||
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ffs(bdata->node_boot_start) - PAGE_SHIFT > ffs(BITS_PER_LONG))
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gofast = 1;
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for (i = 0; i < idx; ) {
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unsigned long v = ~map[i / BITS_PER_LONG];
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if (gofast && v == ~0UL) {
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int order;
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page = pfn_to_page(pfn);
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count += BITS_PER_LONG;
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order = ffs(BITS_PER_LONG) - 1;
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__free_pages_bootmem(page, order);
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i += BITS_PER_LONG;
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page += BITS_PER_LONG;
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} else if (v) {
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unsigned long m;
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page = pfn_to_page(pfn);
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for (m = 1; m && i < idx; m<<=1, page++, i++) {
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if (v & m) {
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count++;
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__free_pages_bootmem(page, 0);
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}
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}
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} else {
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i += BITS_PER_LONG;
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}
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pfn += BITS_PER_LONG;
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}
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total += count;
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/*
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* Now free the allocator bitmap itself, it's not
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* needed anymore:
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*/
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page = virt_to_page(bdata->node_bootmem_map);
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count = 0;
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idx = (get_mapsize(bdata) + PAGE_SIZE-1) >> PAGE_SHIFT;
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for (i = 0; i < idx; i++, page++) {
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__free_pages_bootmem(page, 0);
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count++;
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}
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total += count;
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bdata->node_bootmem_map = NULL;
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return total;
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}
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unsigned long __init init_bootmem_node(pg_data_t *pgdat, unsigned long freepfn,
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unsigned long startpfn, unsigned long endpfn)
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{
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return init_bootmem_core(pgdat, freepfn, startpfn, endpfn);
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}
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void __init reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
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unsigned long size, int flags)
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{
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reserve_bootmem_core(pgdat->bdata, physaddr, size, flags);
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}
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void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
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unsigned long size)
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{
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free_bootmem_core(pgdat->bdata, physaddr, size);
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}
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unsigned long __init free_all_bootmem_node(pg_data_t *pgdat)
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{
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return free_all_bootmem_core(pgdat);
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}
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unsigned long __init init_bootmem(unsigned long start, unsigned long pages)
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{
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max_low_pfn = pages;
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min_low_pfn = start;
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return init_bootmem_core(NODE_DATA(0), start, 0, pages);
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}
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#ifndef CONFIG_HAVE_ARCH_BOOTMEM_NODE
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int __init reserve_bootmem(unsigned long addr, unsigned long size,
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int flags)
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{
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return reserve_bootmem_core(NODE_DATA(0)->bdata, addr, size, flags);
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}
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#endif /* !CONFIG_HAVE_ARCH_BOOTMEM_NODE */
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void __init free_bootmem(unsigned long addr, unsigned long size)
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{
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free_bootmem_core(NODE_DATA(0)->bdata, addr, size);
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}
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unsigned long __init free_all_bootmem(void)
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{
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return free_all_bootmem_core(NODE_DATA(0));
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}
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void * __init __alloc_bootmem_nopanic(unsigned long size, unsigned long align,
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unsigned long goal)
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{
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bootmem_data_t *bdata;
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void *ptr;
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list_for_each_entry(bdata, &bdata_list, list) {
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ptr = __alloc_bootmem_core(bdata, size, align, goal, 0);
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if (ptr)
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return ptr;
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}
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return NULL;
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}
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void * __init __alloc_bootmem(unsigned long size, unsigned long align,
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unsigned long goal)
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{
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void *mem = __alloc_bootmem_nopanic(size,align,goal);
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if (mem)
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return mem;
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/*
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* Whoops, we cannot satisfy the allocation request.
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*/
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printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size);
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panic("Out of memory");
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return NULL;
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}
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void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
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unsigned long align, unsigned long goal)
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{
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void *ptr;
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ptr = __alloc_bootmem_core(pgdat->bdata, size, align, goal, 0);
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if (ptr)
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return ptr;
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return __alloc_bootmem(size, align, goal);
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}
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#ifndef ARCH_LOW_ADDRESS_LIMIT
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#define ARCH_LOW_ADDRESS_LIMIT 0xffffffffUL
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#endif
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void * __init __alloc_bootmem_low(unsigned long size, unsigned long align,
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unsigned long goal)
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{
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bootmem_data_t *bdata;
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void *ptr;
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list_for_each_entry(bdata, &bdata_list, list) {
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ptr = __alloc_bootmem_core(bdata, size, align, goal,
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ARCH_LOW_ADDRESS_LIMIT);
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if (ptr)
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return ptr;
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}
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/*
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* Whoops, we cannot satisfy the allocation request.
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*/
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printk(KERN_ALERT "low bootmem alloc of %lu bytes failed!\n", size);
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panic("Out of low memory");
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return NULL;
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}
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void * __init __alloc_bootmem_low_node(pg_data_t *pgdat, unsigned long size,
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unsigned long align, unsigned long goal)
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{
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return __alloc_bootmem_core(pgdat->bdata, size, align, goal,
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ARCH_LOW_ADDRESS_LIMIT);
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}
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