android_kernel_samsung_msm8976/mm/sparse.c
Yasunori Goto 0c0a4a517a memory hotplug: free memmaps allocated by bootmem
This patch is to free memmaps which is allocated by bootmem.

Freeing usemap is not necessary.  The pages of usemap may be necessary for
other sections.

If removing section is last section on the node, its section is the final user
of usemap page.  (usemaps are allocated on its section by previous patch.) But
it shouldn't be freed too, because the section must be logical offline state
which all pages are isolated against page allocater.  If it is freed, page
alloctor may use it which will be removed physically soon.  It will be
disaster.  So, this patch keeps it as it is.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:26 -07:00

551 lines
14 KiB
C

/*
* sparse memory mappings.
*/
#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/bootmem.h>
#include <linux/highmem.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/vmalloc.h>
#include "internal.h"
#include <asm/dma.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
/*
* Permanent SPARSEMEM data:
*
* 1) mem_section - memory sections, mem_map's for valid memory
*/
#ifdef CONFIG_SPARSEMEM_EXTREME
struct mem_section *mem_section[NR_SECTION_ROOTS]
____cacheline_internodealigned_in_smp;
#else
struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]
____cacheline_internodealigned_in_smp;
#endif
EXPORT_SYMBOL(mem_section);
#ifdef NODE_NOT_IN_PAGE_FLAGS
/*
* If we did not store the node number in the page then we have to
* do a lookup in the section_to_node_table in order to find which
* node the page belongs to.
*/
#if MAX_NUMNODES <= 256
static u8 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
#else
static u16 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
#endif
int page_to_nid(struct page *page)
{
return section_to_node_table[page_to_section(page)];
}
EXPORT_SYMBOL(page_to_nid);
static void set_section_nid(unsigned long section_nr, int nid)
{
section_to_node_table[section_nr] = nid;
}
#else /* !NODE_NOT_IN_PAGE_FLAGS */
static inline void set_section_nid(unsigned long section_nr, int nid)
{
}
#endif
#ifdef CONFIG_SPARSEMEM_EXTREME
static struct mem_section noinline __init_refok *sparse_index_alloc(int nid)
{
struct mem_section *section = NULL;
unsigned long array_size = SECTIONS_PER_ROOT *
sizeof(struct mem_section);
if (slab_is_available())
section = kmalloc_node(array_size, GFP_KERNEL, nid);
else
section = alloc_bootmem_node(NODE_DATA(nid), array_size);
if (section)
memset(section, 0, array_size);
return section;
}
static int __meminit sparse_index_init(unsigned long section_nr, int nid)
{
static DEFINE_SPINLOCK(index_init_lock);
unsigned long root = SECTION_NR_TO_ROOT(section_nr);
struct mem_section *section;
int ret = 0;
if (mem_section[root])
return -EEXIST;
section = sparse_index_alloc(nid);
if (!section)
return -ENOMEM;
/*
* This lock keeps two different sections from
* reallocating for the same index
*/
spin_lock(&index_init_lock);
if (mem_section[root]) {
ret = -EEXIST;
goto out;
}
mem_section[root] = section;
out:
spin_unlock(&index_init_lock);
return ret;
}
#else /* !SPARSEMEM_EXTREME */
static inline int sparse_index_init(unsigned long section_nr, int nid)
{
return 0;
}
#endif
/*
* Although written for the SPARSEMEM_EXTREME case, this happens
* to also work for the flat array case because
* NR_SECTION_ROOTS==NR_MEM_SECTIONS.
*/
int __section_nr(struct mem_section* ms)
{
unsigned long root_nr;
struct mem_section* root;
for (root_nr = 0; root_nr < NR_SECTION_ROOTS; root_nr++) {
root = __nr_to_section(root_nr * SECTIONS_PER_ROOT);
if (!root)
continue;
if ((ms >= root) && (ms < (root + SECTIONS_PER_ROOT)))
break;
}
return (root_nr * SECTIONS_PER_ROOT) + (ms - root);
}
/*
* During early boot, before section_mem_map is used for an actual
* mem_map, we use section_mem_map to store the section's NUMA
* node. This keeps us from having to use another data structure. The
* node information is cleared just before we store the real mem_map.
*/
static inline unsigned long sparse_encode_early_nid(int nid)
{
return (nid << SECTION_NID_SHIFT);
}
static inline int sparse_early_nid(struct mem_section *section)
{
return (section->section_mem_map >> SECTION_NID_SHIFT);
}
/* Record a memory area against a node. */
void __init memory_present(int nid, unsigned long start, unsigned long end)
{
unsigned long max_arch_pfn = 1UL << (MAX_PHYSMEM_BITS-PAGE_SHIFT);
unsigned long pfn;
/*
* Sanity checks - do not allow an architecture to pass
* in larger pfns than the maximum scope of sparsemem:
*/
if (start >= max_arch_pfn)
return;
if (end >= max_arch_pfn)
end = max_arch_pfn;
start &= PAGE_SECTION_MASK;
for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
unsigned long section = pfn_to_section_nr(pfn);
struct mem_section *ms;
sparse_index_init(section, nid);
set_section_nid(section, nid);
ms = __nr_to_section(section);
if (!ms->section_mem_map)
ms->section_mem_map = sparse_encode_early_nid(nid) |
SECTION_MARKED_PRESENT;
}
}
/*
* Only used by the i386 NUMA architecures, but relatively
* generic code.
*/
unsigned long __init node_memmap_size_bytes(int nid, unsigned long start_pfn,
unsigned long end_pfn)
{
unsigned long pfn;
unsigned long nr_pages = 0;
for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
if (nid != early_pfn_to_nid(pfn))
continue;
if (pfn_present(pfn))
nr_pages += PAGES_PER_SECTION;
}
return nr_pages * sizeof(struct page);
}
/*
* Subtle, we encode the real pfn into the mem_map such that
* the identity pfn - section_mem_map will return the actual
* physical page frame number.
*/
static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum)
{
return (unsigned long)(mem_map - (section_nr_to_pfn(pnum)));
}
/*
* Decode mem_map from the coded memmap
*/
struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum)
{
/* mask off the extra low bits of information */
coded_mem_map &= SECTION_MAP_MASK;
return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum);
}
static int __meminit sparse_init_one_section(struct mem_section *ms,
unsigned long pnum, struct page *mem_map,
unsigned long *pageblock_bitmap)
{
if (!present_section(ms))
return -EINVAL;
ms->section_mem_map &= ~SECTION_MAP_MASK;
ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) |
SECTION_HAS_MEM_MAP;
ms->pageblock_flags = pageblock_bitmap;
return 1;
}
unsigned long usemap_size(void)
{
unsigned long size_bytes;
size_bytes = roundup(SECTION_BLOCKFLAGS_BITS, 8) / 8;
size_bytes = roundup(size_bytes, sizeof(unsigned long));
return size_bytes;
}
#ifdef CONFIG_MEMORY_HOTPLUG
static unsigned long *__kmalloc_section_usemap(void)
{
return kmalloc(usemap_size(), GFP_KERNEL);
}
#endif /* CONFIG_MEMORY_HOTPLUG */
static unsigned long *__init sparse_early_usemap_alloc(unsigned long pnum)
{
unsigned long *usemap, section_nr;
struct mem_section *ms = __nr_to_section(pnum);
int nid = sparse_early_nid(ms);
struct pglist_data *pgdat = NODE_DATA(nid);
/*
* Usemap's page can't be freed until freeing other sections
* which use it. And, Pgdat has same feature.
* If section A has pgdat and section B has usemap for other
* sections (includes section A), both sections can't be removed,
* because there is the dependency each other.
* To solve above issue, this collects all usemap on the same section
* which has pgdat.
*/
section_nr = pfn_to_section_nr(__pa(pgdat) >> PAGE_SHIFT);
usemap = alloc_bootmem_section(usemap_size(), section_nr);
if (usemap)
return usemap;
/* Stupid: suppress gcc warning for SPARSEMEM && !NUMA */
nid = 0;
printk(KERN_WARNING "%s: allocation failed\n", __FUNCTION__);
return NULL;
}
#ifndef CONFIG_SPARSEMEM_VMEMMAP
struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid)
{
struct page *map;
map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION);
if (map)
return map;
map = alloc_bootmem_pages_node(NODE_DATA(nid),
PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION));
return map;
}
#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
struct page __init *sparse_early_mem_map_alloc(unsigned long pnum)
{
struct page *map;
struct mem_section *ms = __nr_to_section(pnum);
int nid = sparse_early_nid(ms);
map = sparse_mem_map_populate(pnum, nid);
if (map)
return map;
printk(KERN_ERR "%s: sparsemem memory map backing failed "
"some memory will not be available.\n", __FUNCTION__);
ms->section_mem_map = 0;
return NULL;
}
void __attribute__((weak)) __meminit vmemmap_populate_print_last(void)
{
}
/*
* Allocate the accumulated non-linear sections, allocate a mem_map
* for each and record the physical to section mapping.
*/
void __init sparse_init(void)
{
unsigned long pnum;
struct page *map;
unsigned long *usemap;
unsigned long **usemap_map;
int size;
/*
* map is using big page (aka 2M in x86 64 bit)
* usemap is less one page (aka 24 bytes)
* so alloc 2M (with 2M align) and 24 bytes in turn will
* make next 2M slip to one more 2M later.
* then in big system, the memory will have a lot of holes...
* here try to allocate 2M pages continously.
*
* powerpc need to call sparse_init_one_section right after each
* sparse_early_mem_map_alloc, so allocate usemap_map at first.
*/
size = sizeof(unsigned long *) * NR_MEM_SECTIONS;
usemap_map = alloc_bootmem(size);
if (!usemap_map)
panic("can not allocate usemap_map\n");
for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
if (!present_section_nr(pnum))
continue;
usemap_map[pnum] = sparse_early_usemap_alloc(pnum);
}
for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
if (!present_section_nr(pnum))
continue;
usemap = usemap_map[pnum];
if (!usemap)
continue;
map = sparse_early_mem_map_alloc(pnum);
if (!map)
continue;
sparse_init_one_section(__nr_to_section(pnum), pnum, map,
usemap);
}
vmemmap_populate_print_last();
free_bootmem(__pa(usemap_map), size);
}
#ifdef CONFIG_MEMORY_HOTPLUG
#ifdef CONFIG_SPARSEMEM_VMEMMAP
static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
unsigned long nr_pages)
{
/* This will make the necessary allocations eventually. */
return sparse_mem_map_populate(pnum, nid);
}
static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
{
return; /* XXX: Not implemented yet */
}
static void free_map_bootmem(struct page *page, unsigned long nr_pages)
{
}
#else
static struct page *__kmalloc_section_memmap(unsigned long nr_pages)
{
struct page *page, *ret;
unsigned long memmap_size = sizeof(struct page) * nr_pages;
page = alloc_pages(GFP_KERNEL|__GFP_NOWARN, get_order(memmap_size));
if (page)
goto got_map_page;
ret = vmalloc(memmap_size);
if (ret)
goto got_map_ptr;
return NULL;
got_map_page:
ret = (struct page *)pfn_to_kaddr(page_to_pfn(page));
got_map_ptr:
memset(ret, 0, memmap_size);
return ret;
}
static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
unsigned long nr_pages)
{
return __kmalloc_section_memmap(nr_pages);
}
static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
{
if (is_vmalloc_addr(memmap))
vfree(memmap);
else
free_pages((unsigned long)memmap,
get_order(sizeof(struct page) * nr_pages));
}
static void free_map_bootmem(struct page *page, unsigned long nr_pages)
{
unsigned long maps_section_nr, removing_section_nr, i;
int magic;
for (i = 0; i < nr_pages; i++, page++) {
magic = atomic_read(&page->_mapcount);
BUG_ON(magic == NODE_INFO);
maps_section_nr = pfn_to_section_nr(page_to_pfn(page));
removing_section_nr = page->private;
/*
* When this function is called, the removing section is
* logical offlined state. This means all pages are isolated
* from page allocator. If removing section's memmap is placed
* on the same section, it must not be freed.
* If it is freed, page allocator may allocate it which will
* be removed physically soon.
*/
if (maps_section_nr != removing_section_nr)
put_page_bootmem(page);
}
}
#endif /* CONFIG_SPARSEMEM_VMEMMAP */
static void free_section_usemap(struct page *memmap, unsigned long *usemap)
{
struct page *usemap_page;
unsigned long nr_pages;
if (!usemap)
return;
usemap_page = virt_to_page(usemap);
/*
* Check to see if allocation came from hot-plug-add
*/
if (PageSlab(usemap_page)) {
kfree(usemap);
if (memmap)
__kfree_section_memmap(memmap, PAGES_PER_SECTION);
return;
}
/*
* The usemap came from bootmem. This is packed with other usemaps
* on the section which has pgdat at boot time. Just keep it as is now.
*/
if (memmap) {
struct page *memmap_page;
memmap_page = virt_to_page(memmap);
nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
>> PAGE_SHIFT;
free_map_bootmem(memmap_page, nr_pages);
}
}
/*
* returns the number of sections whose mem_maps were properly
* set. If this is <=0, then that means that the passed-in
* map was not consumed and must be freed.
*/
int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
int nr_pages)
{
unsigned long section_nr = pfn_to_section_nr(start_pfn);
struct pglist_data *pgdat = zone->zone_pgdat;
struct mem_section *ms;
struct page *memmap;
unsigned long *usemap;
unsigned long flags;
int ret;
/*
* no locking for this, because it does its own
* plus, it does a kmalloc
*/
ret = sparse_index_init(section_nr, pgdat->node_id);
if (ret < 0 && ret != -EEXIST)
return ret;
memmap = kmalloc_section_memmap(section_nr, pgdat->node_id, nr_pages);
if (!memmap)
return -ENOMEM;
usemap = __kmalloc_section_usemap();
if (!usemap) {
__kfree_section_memmap(memmap, nr_pages);
return -ENOMEM;
}
pgdat_resize_lock(pgdat, &flags);
ms = __pfn_to_section(start_pfn);
if (ms->section_mem_map & SECTION_MARKED_PRESENT) {
ret = -EEXIST;
goto out;
}
ms->section_mem_map |= SECTION_MARKED_PRESENT;
ret = sparse_init_one_section(ms, section_nr, memmap, usemap);
out:
pgdat_resize_unlock(pgdat, &flags);
if (ret <= 0) {
kfree(usemap);
__kfree_section_memmap(memmap, nr_pages);
}
return ret;
}
void sparse_remove_one_section(struct zone *zone, struct mem_section *ms)
{
struct page *memmap = NULL;
unsigned long *usemap = NULL;
if (ms->section_mem_map) {
usemap = ms->pageblock_flags;
memmap = sparse_decode_mem_map(ms->section_mem_map,
__section_nr(ms));
ms->section_mem_map = 0;
ms->pageblock_flags = NULL;
}
free_section_usemap(memmap, usemap);
}
#endif