Andy Whitcroft | d41dee3 | 2005-06-23 00:07:54 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * sparse memory mappings. |
| 3 | */ |
| 4 | #include <linux/config.h> |
| 5 | #include <linux/mm.h> |
| 6 | #include <linux/mmzone.h> |
| 7 | #include <linux/bootmem.h> |
| 8 | #include <linux/module.h> |
| 9 | #include <asm/dma.h> |
| 10 | |
| 11 | /* |
| 12 | * Permanent SPARSEMEM data: |
| 13 | * |
| 14 | * 1) mem_section - memory sections, mem_map's for valid memory |
| 15 | */ |
| 16 | struct mem_section mem_section[NR_MEM_SECTIONS]; |
| 17 | EXPORT_SYMBOL(mem_section); |
| 18 | |
| 19 | /* Record a memory area against a node. */ |
| 20 | void memory_present(int nid, unsigned long start, unsigned long end) |
| 21 | { |
| 22 | unsigned long pfn; |
| 23 | |
| 24 | start &= PAGE_SECTION_MASK; |
| 25 | for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) { |
| 26 | unsigned long section = pfn_to_section_nr(pfn); |
| 27 | if (!mem_section[section].section_mem_map) |
| 28 | mem_section[section].section_mem_map = (void *) -1; |
| 29 | } |
| 30 | } |
| 31 | |
| 32 | /* |
| 33 | * Only used by the i386 NUMA architecures, but relatively |
| 34 | * generic code. |
| 35 | */ |
| 36 | unsigned long __init node_memmap_size_bytes(int nid, unsigned long start_pfn, |
| 37 | unsigned long end_pfn) |
| 38 | { |
| 39 | unsigned long pfn; |
| 40 | unsigned long nr_pages = 0; |
| 41 | |
| 42 | for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { |
| 43 | if (nid != early_pfn_to_nid(pfn)) |
| 44 | continue; |
| 45 | |
| 46 | if (pfn_valid(pfn)) |
| 47 | nr_pages += PAGES_PER_SECTION; |
| 48 | } |
| 49 | |
| 50 | return nr_pages * sizeof(struct page); |
| 51 | } |
| 52 | |
| 53 | /* |
| 54 | * Allocate the accumulated non-linear sections, allocate a mem_map |
| 55 | * for each and record the physical to section mapping. |
| 56 | */ |
| 57 | void sparse_init(void) |
| 58 | { |
| 59 | unsigned long pnum; |
| 60 | struct page *map; |
| 61 | int nid; |
| 62 | |
| 63 | for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) { |
| 64 | if (!mem_section[pnum].section_mem_map) |
| 65 | continue; |
| 66 | |
| 67 | nid = early_pfn_to_nid(section_nr_to_pfn(pnum)); |
| 68 | map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION); |
| 69 | if (!map) |
| 70 | map = alloc_bootmem_node(NODE_DATA(nid), |
| 71 | sizeof(struct page) * PAGES_PER_SECTION); |
| 72 | if (!map) { |
| 73 | mem_section[pnum].section_mem_map = 0; |
| 74 | continue; |
| 75 | } |
| 76 | |
| 77 | /* |
| 78 | * Subtle, we encode the real pfn into the mem_map such that |
| 79 | * the identity pfn - section_mem_map will return the actual |
| 80 | * physical page frame number. |
| 81 | */ |
| 82 | mem_section[pnum].section_mem_map = map - |
| 83 | section_nr_to_pfn(pnum); |
| 84 | } |
| 85 | } |