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d41dee36 AW |
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) | |
29751f69 | 28 | mem_section[section].section_mem_map = SECTION_MARKED_PRESENT; |
d41dee36 AW |
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 | ||
29751f69 AW |
53 | /* |
54 | * Subtle, we encode the real pfn into the mem_map such that | |
55 | * the identity pfn - section_mem_map will return the actual | |
56 | * physical page frame number. | |
57 | */ | |
58 | static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum) | |
59 | { | |
60 | return (unsigned long)(mem_map - (section_nr_to_pfn(pnum))); | |
61 | } | |
62 | ||
63 | /* | |
64 | * We need this if we ever free the mem_maps. While not implemented yet, | |
65 | * this function is included for parity with its sibling. | |
66 | */ | |
67 | static __attribute((unused)) | |
68 | struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum) | |
69 | { | |
70 | return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum); | |
71 | } | |
72 | ||
73 | static int sparse_init_one_section(struct mem_section *ms, | |
74 | unsigned long pnum, struct page *mem_map) | |
75 | { | |
76 | if (!valid_section(ms)) | |
77 | return -EINVAL; | |
78 | ||
79 | ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum); | |
80 | ||
81 | return 1; | |
82 | } | |
83 | ||
84 | static struct page *sparse_early_mem_map_alloc(unsigned long pnum) | |
85 | { | |
86 | struct page *map; | |
87 | int nid = early_pfn_to_nid(section_nr_to_pfn(pnum)); | |
88 | ||
89 | map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION); | |
90 | if (map) | |
91 | return map; | |
92 | ||
93 | map = alloc_bootmem_node(NODE_DATA(nid), | |
94 | sizeof(struct page) * PAGES_PER_SECTION); | |
95 | if (map) | |
96 | return map; | |
97 | ||
98 | printk(KERN_WARNING "%s: allocation failed\n", __FUNCTION__); | |
99 | mem_section[pnum].section_mem_map = 0; | |
100 | return NULL; | |
101 | } | |
102 | ||
d41dee36 AW |
103 | /* |
104 | * Allocate the accumulated non-linear sections, allocate a mem_map | |
105 | * for each and record the physical to section mapping. | |
106 | */ | |
107 | void sparse_init(void) | |
108 | { | |
109 | unsigned long pnum; | |
110 | struct page *map; | |
d41dee36 AW |
111 | |
112 | for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) { | |
29751f69 | 113 | if (!valid_section_nr(pnum)) |
d41dee36 AW |
114 | continue; |
115 | ||
29751f69 AW |
116 | map = sparse_early_mem_map_alloc(pnum); |
117 | if (map) | |
118 | sparse_init_one_section(&mem_section[pnum], pnum, map); | |
d41dee36 AW |
119 | } |
120 | } | |
29751f69 AW |
121 | |
122 | /* | |
123 | * returns the number of sections whose mem_maps were properly | |
124 | * set. If this is <=0, then that means that the passed-in | |
125 | * map was not consumed and must be freed. | |
126 | */ | |
127 | int sparse_add_one_section(unsigned long start_pfn, int nr_pages, struct page *map) | |
128 | { | |
129 | struct mem_section *ms = __pfn_to_section(start_pfn); | |
130 | ||
131 | if (ms->section_mem_map & SECTION_MARKED_PRESENT) | |
132 | return -EEXIST; | |
133 | ||
134 | ms->section_mem_map |= SECTION_MARKED_PRESENT; | |
135 | ||
136 | return sparse_init_one_section(ms, pfn_to_section_nr(start_pfn), map); | |
137 | } |