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/*
* sparse memory mappings.
*/
#include <linux/config.h>
#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/bootmem.h>
#include <linux/module.h>
#include <asm/dma.h>
/*
* Permanent SPARSEMEM data:
*
* 1) mem_section - memory sections, mem_map's for valid memory
*/
struct mem_section mem_section[NR_MEM_SECTIONS];
EXPORT_SYMBOL(mem_section);
/* Record a memory area against a node. */
void memory_present(int nid, unsigned long start, unsigned long end)
{
unsigned long pfn;
start &= PAGE_SECTION_MASK;
for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
unsigned long section = pfn_to_section_nr(pfn);
if (!mem_section[section].section_mem_map)
mem_section[section].section_mem_map = 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_valid(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)));
}
/*
* We need this if we ever free the mem_maps. While not implemented yet,
* this function is included for parity with its sibling.
*/
static __attribute((unused))
struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum)
{
return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum);
}
static int sparse_init_one_section(struct mem_section *ms,
unsigned long pnum, struct page *mem_map)
{
if (!valid_section(ms))
return -EINVAL;
ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum);
return 1;
}
static struct page *sparse_early_mem_map_alloc(unsigned long pnum)
{
struct page *map;
int nid = early_pfn_to_nid(section_nr_to_pfn(pnum));
map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION);
if (map)
return map;
map = alloc_bootmem_node(NODE_DATA(nid),
sizeof(struct page) * PAGES_PER_SECTION);
if (map)
return map;
printk(KERN_WARNING "%s: allocation failed\n", __FUNCTION__);
mem_section[pnum].section_mem_map = 0;
return NULL;
}
/*
* Allocate the accumulated non-linear sections, allocate a mem_map
* for each and record the physical to section mapping.
*/
void sparse_init(void)
{
unsigned long pnum;
struct page *map;
for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
if (!valid_section_nr(pnum))
continue;
map = sparse_early_mem_map_alloc(pnum);
if (map)
sparse_init_one_section(&mem_section[pnum], pnum, map);
}
}
/*
* 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(unsigned long start_pfn, int nr_pages, struct page *map)
{
struct mem_section *ms = __pfn_to_section(start_pfn);
if (ms->section_mem_map & SECTION_MARKED_PRESENT)
return -EEXIST;
ms->section_mem_map |= SECTION_MARKED_PRESENT;
return sparse_init_one_section(ms, pfn_to_section_nr(start_pfn), map);
}
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