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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 | */ | |
3e347261 | 16 | #ifdef CONFIG_SPARSEMEM_EXTREME |
802f192e BP |
17 | struct mem_section *mem_section[NR_SECTION_ROOTS] |
18 | ____cacheline_maxaligned_in_smp; | |
3e347261 BP |
19 | #else |
20 | struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT] | |
21 | ____cacheline_maxaligned_in_smp; | |
22 | #endif | |
23 | EXPORT_SYMBOL(mem_section); | |
24 | ||
25 | static void sparse_alloc_root(unsigned long root, int nid) | |
26 | { | |
27 | #ifdef CONFIG_SPARSEMEM_EXTREME | |
28 | mem_section[root] = alloc_bootmem_node(NODE_DATA(nid), PAGE_SIZE); | |
29 | #endif | |
30 | } | |
802f192e BP |
31 | |
32 | static void sparse_index_init(unsigned long section, int nid) | |
33 | { | |
3e347261 | 34 | unsigned long root = SECTION_NR_TO_ROOT(section); |
802f192e BP |
35 | |
36 | if (mem_section[root]) | |
37 | return; | |
3e347261 BP |
38 | |
39 | sparse_alloc_root(root, nid); | |
40 | ||
802f192e BP |
41 | if (mem_section[root]) |
42 | memset(mem_section[root], 0, PAGE_SIZE); | |
43 | else | |
44 | panic("memory_present: NO MEMORY\n"); | |
45 | } | |
d41dee36 AW |
46 | /* Record a memory area against a node. */ |
47 | void memory_present(int nid, unsigned long start, unsigned long end) | |
48 | { | |
49 | unsigned long pfn; | |
50 | ||
51 | start &= PAGE_SECTION_MASK; | |
52 | for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) { | |
53 | unsigned long section = pfn_to_section_nr(pfn); | |
802f192e BP |
54 | struct mem_section *ms; |
55 | ||
56 | sparse_index_init(section, nid); | |
57 | ||
58 | ms = __nr_to_section(section); | |
59 | if (!ms->section_mem_map) | |
60 | ms->section_mem_map = SECTION_MARKED_PRESENT; | |
d41dee36 AW |
61 | } |
62 | } | |
63 | ||
64 | /* | |
65 | * Only used by the i386 NUMA architecures, but relatively | |
66 | * generic code. | |
67 | */ | |
68 | unsigned long __init node_memmap_size_bytes(int nid, unsigned long start_pfn, | |
69 | unsigned long end_pfn) | |
70 | { | |
71 | unsigned long pfn; | |
72 | unsigned long nr_pages = 0; | |
73 | ||
74 | for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { | |
75 | if (nid != early_pfn_to_nid(pfn)) | |
76 | continue; | |
77 | ||
78 | if (pfn_valid(pfn)) | |
79 | nr_pages += PAGES_PER_SECTION; | |
80 | } | |
81 | ||
82 | return nr_pages * sizeof(struct page); | |
83 | } | |
84 | ||
29751f69 AW |
85 | /* |
86 | * Subtle, we encode the real pfn into the mem_map such that | |
87 | * the identity pfn - section_mem_map will return the actual | |
88 | * physical page frame number. | |
89 | */ | |
90 | static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum) | |
91 | { | |
92 | return (unsigned long)(mem_map - (section_nr_to_pfn(pnum))); | |
93 | } | |
94 | ||
95 | /* | |
96 | * We need this if we ever free the mem_maps. While not implemented yet, | |
97 | * this function is included for parity with its sibling. | |
98 | */ | |
99 | static __attribute((unused)) | |
100 | struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum) | |
101 | { | |
102 | return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum); | |
103 | } | |
104 | ||
105 | static int sparse_init_one_section(struct mem_section *ms, | |
106 | unsigned long pnum, struct page *mem_map) | |
107 | { | |
108 | if (!valid_section(ms)) | |
109 | return -EINVAL; | |
110 | ||
111 | ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum); | |
112 | ||
113 | return 1; | |
114 | } | |
115 | ||
116 | static struct page *sparse_early_mem_map_alloc(unsigned long pnum) | |
117 | { | |
118 | struct page *map; | |
119 | int nid = early_pfn_to_nid(section_nr_to_pfn(pnum)); | |
802f192e | 120 | struct mem_section *ms = __nr_to_section(pnum); |
29751f69 AW |
121 | |
122 | map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION); | |
123 | if (map) | |
124 | return map; | |
125 | ||
126 | map = alloc_bootmem_node(NODE_DATA(nid), | |
127 | sizeof(struct page) * PAGES_PER_SECTION); | |
128 | if (map) | |
129 | return map; | |
130 | ||
131 | printk(KERN_WARNING "%s: allocation failed\n", __FUNCTION__); | |
802f192e | 132 | ms->section_mem_map = 0; |
29751f69 AW |
133 | return NULL; |
134 | } | |
135 | ||
d41dee36 AW |
136 | /* |
137 | * Allocate the accumulated non-linear sections, allocate a mem_map | |
138 | * for each and record the physical to section mapping. | |
139 | */ | |
140 | void sparse_init(void) | |
141 | { | |
142 | unsigned long pnum; | |
143 | struct page *map; | |
d41dee36 AW |
144 | |
145 | for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) { | |
29751f69 | 146 | if (!valid_section_nr(pnum)) |
d41dee36 AW |
147 | continue; |
148 | ||
29751f69 | 149 | map = sparse_early_mem_map_alloc(pnum); |
802f192e BP |
150 | if (!map) |
151 | continue; | |
152 | sparse_init_one_section(__nr_to_section(pnum), pnum, map); | |
d41dee36 AW |
153 | } |
154 | } | |
29751f69 AW |
155 | |
156 | /* | |
157 | * returns the number of sections whose mem_maps were properly | |
158 | * set. If this is <=0, then that means that the passed-in | |
159 | * map was not consumed and must be freed. | |
160 | */ | |
161 | int sparse_add_one_section(unsigned long start_pfn, int nr_pages, struct page *map) | |
162 | { | |
163 | struct mem_section *ms = __pfn_to_section(start_pfn); | |
164 | ||
165 | if (ms->section_mem_map & SECTION_MARKED_PRESENT) | |
166 | return -EEXIST; | |
167 | ||
168 | ms->section_mem_map |= SECTION_MARKED_PRESENT; | |
169 | ||
170 | return sparse_init_one_section(ms, pfn_to_section_nr(start_pfn), map); | |
171 | } |