- 根目录:
- mm
- memblock.c
/*
* Procedures for maintaining information about logical memory blocks.
*
* Peter Bergner, IBM Corp. June 2001.
* Copyright (C) 2001 Peter Bergner.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/poison.h>
#include <linux/pfn.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/memblock.h>
struct memblock memblock __initdata_memblock;
int memblock_debug __initdata_memblock;
int memblock_can_resize __initdata_memblock;
static struct memblock_region memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS + 1] __initdata_memblock;
static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_REGIONS + 1] __initdata_memblock;
/* inline so we don't get a warning when pr_debug is compiled out */
static inline const char *memblock_type_name(struct memblock_type *type)
{
if (type == &memblock.memory)
return "memory";
else if (type == &memblock.reserved)
return "reserved";
else
return "unknown";
}
/*
* Address comparison utilities
*/
static phys_addr_t __init_memblock memblock_align_down(phys_addr_t addr, phys_addr_t size)
{
return addr & ~(size - 1);
}
static phys_addr_t __init_memblock memblock_align_up(phys_addr_t addr, phys_addr_t size)
{
return (addr + (size - 1)) & ~(size - 1);
}
static unsigned long __init_memblock memblock_addrs_overlap(phys_addr_t base1, phys_addr_t size1,
phys_addr_t base2, phys_addr_t size2)
{
return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
}
long __init_memblock memblock_overlaps_region(struct memblock_type *type, phys_addr_t base, phys_addr_t size)
{
unsigned long i;
for (i = 0; i < type->cnt; i++) {
phys_addr_t rgnbase = type->regions[i].base;
phys_addr_t rgnsize = type->regions[i].size;
if (memblock_addrs_overlap(base, size, rgnbase, rgnsize))
break;
}
return (i < type->cnt) ? i : -1;
}
/*
* Find, allocate, deallocate or reserve unreserved regions. All allocations
* are top-down.
*/
static phys_addr_t __init_memblock memblock_find_region(phys_addr_t start, phys_addr_t end,
phys_addr_t size, phys_addr_t align)
{
phys_addr_t base, res_base;
long j;
/* In case, huge size is requested */
if (end < size)
return MEMBLOCK_ERROR;
base = memblock_align_down((end - size), align);
/* Prevent allocations returning 0 as it's also used to
* indicate an allocation failure
*/
if (start == 0)
start = PAGE_SIZE;
while (start <= base) {
j = memblock_overlaps_region(&memblock.reserved, base, size);
if (j < 0)
return base;
res_base = memblock.reserved.regions[j].base;
if (res_base < size)
break;
base = memblock_align_down(res_base - size, align);
}
return MEMBLOCK_ERROR;
}
static phys_addr_t __init_memblock memblock_find_base(phys_addr_t size,
phys_addr_t align, phys_addr_t start, phys_addr_t end)
{
long i;
BUG_ON(0 == size);
/* Pump up max_addr */
if (end == MEMBLOCK_ALLOC_ACCESSIBLE)
end = memblock.current_limit;
/* We do a top-down search, this tends to limit memory
* fragmentation by keeping early boot allocs near the
* top of memory
*/
for (i = memblock.memory.cnt - 1; i >= 0; i--) {
phys_addr_t memblockbase = memblock.memory.regions[i].base;
phys_addr_t memblocksize = memblock.memory.regions[i].size;
phys_addr_t bottom, top, found;
if (memblocksize < size)
continue;
if ((memblockbase + memblocksize) <= start)
break;
bottom = max(memblockbase, start);
top = min(memblockbase + memblocksize, end);
if (bottom >= top)
continue;
found = memblock_find_region(bottom, top, size, align);
if (found != MEMBLOCK_ERROR)
return found;
}
return MEMBLOCK_ERROR;
}
/*
* Find a free area with specified alignment in a specific range.
*/
u64 __init_memblock memblock_find_in_range(u64 start, u64 end, u64 size, u64 align)
{
return memblock_find_base(size, align, start, end);
}
/*
* Free memblock.reserved.regions
*/
int __init_memblock memblock_free_reserved_regions(void)
{
if (memblock.reserved.regions == memblock_reserved_init_regions)
return 0;
return memblock_free(__pa(memblock.reserved.regions),
sizeof(struct memblock_region) * memblock.reserved.max);
}
/*
* Reserve memblock.reserved.regions
*/
int __init_memblock memblock_reserve_reserved_regions(void)
{
if (memblock.reserved.regions == memblock_reserved_init_regions)
return 0;
return memblock_reserve(__pa(memblock.reserved.regions),
sizeof(struct memblock_region) * memblock.reserved.max);
}
static void __init_memblock memblock_remove_region(struct memblock_type *type, unsigned long r)
{
unsigned long i;
for (i = r; i < type->cnt - 1; i++) {
type->regions[i].base = type->regions[i + 1].base;
type->regions[i].size = type->regions[i + 1].size;
}
type->cnt--;
/* Special case for empty arrays */
if (type->cnt == 0) {
type->cnt = 1;
type->regions[0].base = 0;
type->regions[0].size = 0;
}
}
/* Defined below but needed now */
static long memblock_add_region(struct memblock_type *type, phys_addr_t base, phys_addr_t size);
static int __init_memblock memblock_double_array(struct memblock_type *type)
{
struct memblock_region *new_array, *old_array;
phys_addr_t old_size, new_size, addr;
int use_slab = slab_is_available();
/* We don't allow resizing until we know about the reserved regions
* of memory that aren't suitable for allocation
*/
if (!memblock_can_resize)
return -1;
/* Calculate new doubled size */
old_size = type->max * sizeof(struct memblock_region);
new_size = old_size << 1;
/* Try to find some space for it.
*
* WARNING: We assume that either slab_is_available() and we use it or
* we use MEMBLOCK for allocations. That means that this is unsafe to use
* when bootmem is currently active (unless bootmem itself is implemented
* on top of MEMBLOCK which isn't the case yet)
*
* This should however not be an issue for now, as we currently only
* call into MEMBLOCK while it's still active, or much later when slab is
* active for memory hotplug operations
*/
if (use_slab) {
new_array = kmalloc(new_size, GFP_KERNEL);
addr = new_array == NULL ? MEMBLOCK_ERROR : __pa(new_array);
} else
addr = memblock_find_base(new_size, sizeof(phys_addr_t), 0, MEMBLOCK_ALLOC_ACCESSIBLE);
if (addr == MEMBLOCK_ERROR) {
pr_err("memblock: Failed to double %s array from %ld to %ld entries !\n",
memblock_type_name(type), type->max, type->max * 2);
return -1;
}
new_array = __va(addr);
memblock_dbg("memblock: %s array is doubled to %ld at [%#010llx-%#010llx]",
memblock_type_name(type), type->max * 2, (u64)addr, (u64)addr + new_size - 1);
/* Found space, we now need to move the array over before
* we add the reserved region since it may be our reserved
* array itself that is full.
*/
memcpy(new_array, type->regions, old_size);
memset(new_array + type->max, 0, old_size);
old_array = type->regions;
type->regions = new_array;
type->max <<= 1;
/* If we use SLAB that's it, we are done */
if (use_slab)
return 0;
/* Add the new reserved region now. Should not fail ! */
BUG_ON(memblock_add_region(&memblock.reserved, addr, new_size));
/* If the array wasn't our static init one, then free it. We only do
* that before SLAB is available as later on, we don't know whether
* to use kfree or free_bootmem_pages(). Shouldn't be a big deal
* anyways
*/
if (old_array != memblock_memory_init_regions &&
old_array != memblock_reserved_init_regions)
memblock_free(__pa(old_array), old_size);
return 0;
}
extern int __init_memblock __weak memblock_memory_can_coalesce(phys_addr_t addr1, phys_addr_t size1,
phys_addr_t addr2, phys_addr_t size2)
{
return 1;
}
static long __init_memblock memblock_add_region(struct memblock_type *type,
phys_addr_t base, phys_addr_t size)
{
phys_addr_t end = base + size;
int i, slot = -1;
/* First try and coalesce this MEMBLOCK with others */
for (i = 0; i < type->cnt; i++) {
struct memblock_region *rgn = &type->regions[i];
phys_addr_t rend = rgn->base + rgn->size;
/* Exit if there's no possible hits */
if (rgn->base > end || rgn->size == 0)
break;
/* Check if we are fully enclosed within an existing
* block
*/
if (rgn->base <= base && rend >= end)
return 0;
/* Check if we overlap or are adjacent with the bottom
* of a block.
*/
if (base < rgn->base && end >= rgn->base) {
/* If we can't coalesce, create a new block */
if (!memblock_memory_can_coalesce(base, size,
rgn->base,
rgn->size)) {
/* Overlap & can't coalesce are mutually
* exclusive, if you do that, be prepared
* for trouble
*/
WARN_ON(end != rgn->base);
goto new_block;
}
/* We extend the bottom of the block down to our
* base
*/
rgn->base = base;
rgn->size = rend - base;
/* Return if we have nothing else to allocate
* (fully coalesced)
*/
if (rend >= end)
return 0;
/* We continue processing from the end of the
* coalesced block.
*/
base = rend;
size = end - base;
}
/* Now check if we overlap or are adjacent with the
* top of a block
*/
if (base <= rend && end >= rend) {
/* If we can't coalesce, create a new block */
if (!memblock_memory_can_coalesce(rgn->base,
rgn->size,
base, size)) {
/* Overlap & can't coalesce are mutually
* exclusive, if you do that, be prepared
* for trouble
*/
WARN_ON(rend != base);
goto new_block;
}
/* We adjust our base down to enclose the
* original block and destroy it. It will be
* part of our new allocation. Since we've
* freed an entry, we know we won't fail
* to allocate one later, so we won't risk
* losing the original block allocation.
*/
size += (base - rgn->base);
base = rgn->base;
memblock_remove_region(type, i--);
}
}
/* If the array is empty, special case, replace the fake
* filler region and return
*/
if ((type->cnt == 1) && (type->regions[0].size == 0)) {
type->regions[0].base = base;
type->regions[0].size = size;
return 0;
}
new_block:
/* If we are out of space, we fail. It's too late to resize the array
* but then this shouldn't have happened in the first place.
*/
if (WARN_ON(type->cnt >= type->max))
return -1;
/* Couldn't coalesce the MEMBLOCK, so add it to the sorted table. */
for (i = type->cnt - 1; i >= 0; i--) {
if (base < type->regions[i].base) {
type->regions[i+1].base = type->regions[i].base;
type->regions[i+1].size = type->regions[i].size;
} else {
type->regions[i+1].base = base;
type->regions[i+1].size = size;
slot = i + 1;
break;
}
}
if (base < type->regions[0].base) {
type->regions[0].base = base;
type->regions[0].size = size;
slot = 0;
}
type->cnt++;
/* The array is full ? Try to resize it. If that fails, we undo
* our allocation and return an error
*/
if (type->cnt == type->max && memblock_double_array(type)) {
BUG_ON(slot < 0);
memblock_remove_region(type, slot);
return -1;
}
return 0;
}
long __init_memblock memblock_add(phys_addr_t base, phys_addr_t size)
{
return memblock_add_region(&memblock.memory, base, size);
}
static long __init_memblock __memblock_remove(struct memblock_type *type,
phys_addr_t base, phys_addr_t size)
{
phys_addr_t end = base + size;
int i;
/* Walk through the array for collisions */
for (i = 0; i < type->cnt; i++) {
struct memblock_region *rgn = &type->regions[i];
phys_addr_t rend = rgn->base + rgn->size;
/* Nothing more to do, exit */
if (rgn->base > end || rgn->size == 0)
break;
/* If we fully enclose the block, drop it */
if (base <= rgn->base && end >= rend) {
memblock_remove_region(type, i--);
continue;
}
/* If we are fully enclosed within a block
* then we need to split it and we are done
*/
if (base > rgn->base && end < rend) {
rgn->size = base - rgn->base;
if (!memblock_add_region(type, end, rend - end))
return 0;
/* Failure to split is bad, we at least
* restore the block before erroring
*/
rgn->size = rend - rgn->base;
WARN_ON(1);
return -1;
}
/* Check if we need to trim the bottom of a block */
if (rgn->base < end && rend > end) {
rgn->size -= end - rgn->base;
rgn->base = end;
break;
}
/* And check if we need to trim the top of a block */
if (base < rend)
rgn->size -= rend - base;
}
return 0;
}
long __init_memblock memblock_remove(phys_addr_t base, phys_addr_t size)
{
return __memblock_remove(&memblock.memory, base, size);
}
long __init_memblock memblock_free(phys_addr_t base, phys_addr_t size)
{
return __memblock_remove(&memblock.reserved, base, size);
}
long __init_memblock memblock_reserve(phys_addr_t base, phys_addr_t size)
{
struct memblock_type *_rgn = &memblock.reserved;
BUG_ON(0 == size);
return memblock_add_region(_rgn, base, size);
}
phys_addr_t __init __memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
{
phys_addr_t found;
/* We align the size to limit fragmentation. Without this, a lot of
* small allocs quickly eat up the whole reserve array on sparc
*/
size = memblock_align_up(size, align);
found = memblock_find_base(size, align, 0, max_addr);
if (found != MEMBLOCK_ERROR &&
!memblock_add_region(&memblock.reserved, found, size))
return found;
return 0;
}
phys_addr_t __init memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
{
phys_addr_t alloc;
alloc = __memblock_alloc_base(size, align, max_addr);
if (alloc == 0)
panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
(unsigned long long) size, (unsigned long long) max_addr);
return alloc;
}
phys_addr_t __init memblock_alloc(phys_addr_t size, phys_addr_t align)
{
return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
}
/*
* Additional node-local allocators. Search for node memory is bottom up
* and walks memblock regions within that node bottom-up as well, but allocation
* within an memblock region is top-down. XXX I plan to fix that at some stage
*
* WARNING: Only available after early_node_map[] has been populated,
* on some architectures, that is after all the calls to add_active_range()
* have been done to populate it.
*/
phys_addr_t __weak __init memblock_nid_range(phys_addr_t start, phys_addr_t end, int *nid)
{
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
/*
* This code originates from sparc which really wants use to walk by addresses
* and returns the nid. This is not very convenient for early_pfn_map[] users
* as the map isn't sorted yet, and it really wants to be walked by nid.
*
* For now, I implement the inefficient method below which walks the early
* map multiple times. Eventually we may want to use an ARCH config option
* to implement a completely different method for both case.
*/
unsigned long start_pfn, end_pfn;
int i;
for (i = 0; i < MAX_NUMNODES; i++) {
get_pfn_range_for_nid(i, &start_pfn, &end_pfn);
if (start < PFN_PHYS(start_pfn) || start >= PFN_PHYS(end_pfn))
continue;
*nid = i;
return min(end, PFN_PHYS(end_pfn));
}
#endif
*nid = 0;
return end;
}
static phys_addr_t __init memblock_alloc_nid_region(struct memblock_region *mp,
phys_addr_t size,
phys_addr_t align, int nid)
{
phys_addr_t start, end;
start = mp->base;
end = start + mp->size;
start = memblock_align_up(start, align);
while (start < end) {
phys_addr_t this_end;
int this_nid;
this_end = memblock_nid_range(start, end, &this_nid);
if (this_nid == nid) {
phys_addr_t ret = memblock_find_region(start, this_end, size, align);
if (ret != MEMBLOCK_ERROR &&
!memblock_add_region(&memblock.reserved, ret, size))
return ret;
}
start = this_end;
}
return MEMBLOCK_ERROR;
}
phys_addr_t __init memblock_alloc_nid(phys_addr_t size, phys_addr_t align, int nid)
{
struct memblock_type *mem = &memblock.memory;
int i;
BUG_ON(0 == size);
/* We align the size to limit fragmentation. Without this, a lot of
* small allocs quickly eat up the whole reserve array on sparc
*/
size = memblock_align_up(size, align);
/* We do a bottom-up search for a region with the right
* nid since that's easier considering how memblock_nid_range()
* works
*/
for (i = 0; i < mem->cnt; i++) {
phys_addr_t ret = memblock_alloc_nid_region(&mem->regions[i],
size, align, nid);
if (ret != MEMBLOCK_ERROR)
return ret;
}
return 0;
}
phys_addr_t __init memblock_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid)
{
phys_addr_t res = memblock_alloc_nid(size, align, nid);
if (res)
return res;
return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ANYWHERE);
}
/*
* Remaining API functions
*/
/* You must call memblock_analyze() before this. */
phys_addr_t __init memblock_phys_mem_size(void)
{
return memblock.memory_size;
}
phys_addr_t __init_memblock memblock_end_of_DRAM(void)
{
int idx = memblock.memory.cnt - 1;
return (memblock.memory.regions[idx].base + memblock.memory.regions[idx].size);
}
/* You must call memblock_analyze() after this. */
void __init memblock_enforce_memory_limit(phys_addr_t memory_limit)
{
unsigned long i;
phys_addr_t limit;
struct memblock_region *p;
if (!memory_limit)
return;
/* Truncate the memblock regions to satisfy the memory limit. */
limit = memory_limit;
for (i = 0; i < memblock.memory.cnt; i++) {
if (limit > memblock.memory.regions[i].size) {
limit -= memblock.memory.regions[i].size;
continue;
}
memblock.memory.regions[i].size = limit;
memblock.memory.cnt = i + 1;
break;
}
memory_limit = memblock_end_of_DRAM();
/* And truncate any reserves above the limit also. */
for (i = 0; i < memblock.reserved.cnt; i++) {
p = &memblock.reserved.regions[i];
if (p->base > memory_limit)
p->size = 0;
else if ((p->base + p->size) > memory_limit)
p->size = memory_limit - p->base;
if (p->size == 0) {
memblock_remove_region(&memblock.reserved, i);
i--;
}
}
}
static int __init_memblock memblock_search(struct memblock_type *type, phys_addr_t addr)
{
unsigned int left = 0, right = type->cnt;
do {
unsigned int mid = (right + left) / 2;
if (addr < type->regions[mid].base)
right = mid;
else if (addr >= (type->regions[mid].base +
type->regions[mid].size))
left = mid + 1;
else
return mid;
} while (left < right);
return -1;
}
int __init memblock_is_reserved(phys_addr_t addr)
{
return memblock_search(&memblock.reserved, addr) != -1;
}
int __init_memblock memblock_is_memory(phys_addr_t addr)
{
return memblock_search(&memblock.memory, addr) != -1;
}
int __init_memblock memblock_is_region_memory(phys_addr_t base, phys_addr_t size)
{
int idx = memblock_search(&memblock.memory, base);
if (idx == -1)
return 0;
return memblock.memory.regions[idx].base <= base &&
(memblock.memory.regions[idx].base +
memblock.memory.regions[idx].size) >= (base + size);
}
int __init_memblock memblock_is_region_reserved(phys_addr_t base, phys_addr_t size)
{
return memblock_overlaps_region(&memblock.reserved, base, size) >= 0;
}
void __init_memblock memblock_set_current_limit(phys_addr_t limit)
{
memblock.current_limit = limit;
}
static void __init_memblock memblock_dump(struct memblock_type *region, char *name)
{
unsigned long long base, size;
int i;
pr_info(" %s.cnt = 0x%lx\n", name, region->cnt);
for (i = 0; i < region->cnt; i++) {
base = region->regions[i].base;
size = region->regions[i].size;
pr_info(" %s[%#x]\t[%#016llx-%#016llx], %#llx bytes\n",
name, i, base, base + size - 1, size);
}
}
void __init_memblock memblock_dump_all(void)
{
if (!memblock_debug)
return;
pr_info("MEMBLOCK configuration:\n");
pr_info(" memory size = 0x%llx\n", (unsigned long long)memblock.memory_size);
memblock_dump(&memblock.memory, "memory");
memblock_dump(&memblock.reserved, "reserved");
}
void __init memblock_analyze(void)
{
int i;
/* Check marker in the unused last array entry */
WARN_ON(memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS].base
!= (phys_addr_t)RED_INACTIVE);
WARN_ON(memblock_reserved_init_regions[INIT_MEMBLOCK_REGIONS].base
!= (phys_addr_t)RED_INACTIVE);
memblock.memory_size = 0;
for (i = 0; i < memblock.memory.cnt; i++)
memblock.memory_size += memblock.memory.regions[i].size;
/* We allow resizing from there */
memblock_can_resize = 1;
}
void __init memblock_init(void)
{
static int init_done __initdata = 0;
if (init_done)
return;
init_done = 1;
/* Hookup the initial arrays */
memblock.memory.regions = memblock_memory_init_regions;
memblock.memory.max = INIT_MEMBLOCK_REGIONS;
memblock.reserved.regions = memblock_reserved_init_regions;
memblock.reserved.max = INIT_MEMBLOCK_REGIONS;
/* Write a marker in the unused last array entry */
memblock.memory.regions[INIT_MEMBLOCK_REGIONS].base = (phys_addr_t)RED_INACTIVE;
memblock.reserved.regions[INIT_MEMBLOCK_REGIONS].base = (phys_addr_t)RED_INACTIVE;
/* Create a dummy zero size MEMBLOCK which will get coalesced away later.
* This simplifies the memblock_add() code below...
*/
memblock.memory.regions[0].base = 0;
memblock.memory.regions[0].size = 0;
memblock.memory.cnt = 1;
/* Ditto. */
memblock.reserved.regions[0].base = 0;
memblock.reserved.regions[0].size = 0;
memblock.reserved.cnt = 1;
memblock.current_limit = MEMBLOCK_ALLOC_ANYWHERE;
}
static int __init early_memblock(char *p)
{
if (p && strstr(p, "debug"))
memblock_debug = 1;
return 0;
}
early_param("memblock", early_memblock);
#if defined(CONFIG_DEBUG_FS) && !defined(ARCH_DISCARD_MEMBLOCK)
static int memblock_debug_show(struct seq_file *m, void *private)
{
struct memblock_type *type = m->private;
struct memblock_region *reg;
int i;
for (i = 0; i < type->cnt; i++) {
reg = &type->regions[i];
seq_printf(m, "%4d: ", i);
if (sizeof(phys_addr_t) == 4)
seq_printf(m, "0x%08lx..0x%08lx\n",
(unsigned long)reg->base,
(unsigned long)(reg->base + reg->size - 1));
else
seq_printf(m, "0x%016llx..0x%016llx\n",
(unsigned long long)reg->base,
(unsigned long long)(reg->base + reg->size - 1));
}
return 0;
}
static int memblock_debug_open(struct inode *inode, struct file *file)
{
return single_open(file, memblock_debug_show, inode->i_private);
}
static const struct file_operations memblock_debug_fops = {
.open = memblock_debug_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static int __init memblock_init_debugfs(void)
{
struct dentry *root = debugfs_create_dir("memblock", NULL);
if (!root)
return -ENXIO;
debugfs_create_file("memory", S_IRUGO, root, &memblock.memory, &memblock_debug_fops);
debugfs_create_file("reserved", S_IRUGO, root, &memblock.reserved, &memblock_debug_fops);
return 0;
}
__initcall(memblock_init_debugfs);
#endif /* CONFIG_DEBUG_FS */