Commit | Line | Data |
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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> | |
28ae55c9 | 9 | #include <linux/spinlock.h> |
d41dee36 AW |
10 | #include <asm/dma.h> |
11 | ||
12 | /* | |
13 | * Permanent SPARSEMEM data: | |
14 | * | |
15 | * 1) mem_section - memory sections, mem_map's for valid memory | |
16 | */ | |
3e347261 | 17 | #ifdef CONFIG_SPARSEMEM_EXTREME |
802f192e BP |
18 | struct mem_section *mem_section[NR_SECTION_ROOTS] |
19 | ____cacheline_maxaligned_in_smp; | |
3e347261 BP |
20 | #else |
21 | struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT] | |
22 | ____cacheline_maxaligned_in_smp; | |
23 | #endif | |
24 | EXPORT_SYMBOL(mem_section); | |
25 | ||
3e347261 | 26 | #ifdef CONFIG_SPARSEMEM_EXTREME |
28ae55c9 DH |
27 | static struct mem_section *sparse_index_alloc(int nid) |
28 | { | |
29 | struct mem_section *section = NULL; | |
30 | unsigned long array_size = SECTIONS_PER_ROOT * | |
31 | sizeof(struct mem_section); | |
32 | ||
33 | section = alloc_bootmem_node(NODE_DATA(nid), array_size); | |
34 | ||
35 | if (section) | |
36 | memset(section, 0, array_size); | |
37 | ||
38 | return section; | |
3e347261 | 39 | } |
802f192e | 40 | |
28ae55c9 | 41 | static int sparse_index_init(unsigned long section_nr, int nid) |
802f192e | 42 | { |
28ae55c9 DH |
43 | static spinlock_t index_init_lock = SPIN_LOCK_UNLOCKED; |
44 | unsigned long root = SECTION_NR_TO_ROOT(section_nr); | |
45 | struct mem_section *section; | |
46 | int ret = 0; | |
802f192e BP |
47 | |
48 | if (mem_section[root]) | |
28ae55c9 | 49 | return -EEXIST; |
3e347261 | 50 | |
28ae55c9 DH |
51 | section = sparse_index_alloc(nid); |
52 | /* | |
53 | * This lock keeps two different sections from | |
54 | * reallocating for the same index | |
55 | */ | |
56 | spin_lock(&index_init_lock); | |
3e347261 | 57 | |
28ae55c9 DH |
58 | if (mem_section[root]) { |
59 | ret = -EEXIST; | |
60 | goto out; | |
61 | } | |
62 | ||
63 | mem_section[root] = section; | |
64 | out: | |
65 | spin_unlock(&index_init_lock); | |
66 | return ret; | |
67 | } | |
68 | #else /* !SPARSEMEM_EXTREME */ | |
69 | static inline int sparse_index_init(unsigned long section_nr, int nid) | |
70 | { | |
71 | return 0; | |
802f192e | 72 | } |
28ae55c9 DH |
73 | #endif |
74 | ||
d41dee36 AW |
75 | /* Record a memory area against a node. */ |
76 | void memory_present(int nid, unsigned long start, unsigned long end) | |
77 | { | |
78 | unsigned long pfn; | |
79 | ||
80 | start &= PAGE_SECTION_MASK; | |
81 | for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) { | |
82 | unsigned long section = pfn_to_section_nr(pfn); | |
802f192e BP |
83 | struct mem_section *ms; |
84 | ||
85 | sparse_index_init(section, nid); | |
86 | ||
87 | ms = __nr_to_section(section); | |
88 | if (!ms->section_mem_map) | |
89 | ms->section_mem_map = SECTION_MARKED_PRESENT; | |
d41dee36 AW |
90 | } |
91 | } | |
92 | ||
93 | /* | |
94 | * Only used by the i386 NUMA architecures, but relatively | |
95 | * generic code. | |
96 | */ | |
97 | unsigned long __init node_memmap_size_bytes(int nid, unsigned long start_pfn, | |
98 | unsigned long end_pfn) | |
99 | { | |
100 | unsigned long pfn; | |
101 | unsigned long nr_pages = 0; | |
102 | ||
103 | for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { | |
104 | if (nid != early_pfn_to_nid(pfn)) | |
105 | continue; | |
106 | ||
107 | if (pfn_valid(pfn)) | |
108 | nr_pages += PAGES_PER_SECTION; | |
109 | } | |
110 | ||
111 | return nr_pages * sizeof(struct page); | |
112 | } | |
113 | ||
29751f69 AW |
114 | /* |
115 | * Subtle, we encode the real pfn into the mem_map such that | |
116 | * the identity pfn - section_mem_map will return the actual | |
117 | * physical page frame number. | |
118 | */ | |
119 | static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum) | |
120 | { | |
121 | return (unsigned long)(mem_map - (section_nr_to_pfn(pnum))); | |
122 | } | |
123 | ||
124 | /* | |
125 | * We need this if we ever free the mem_maps. While not implemented yet, | |
126 | * this function is included for parity with its sibling. | |
127 | */ | |
128 | static __attribute((unused)) | |
129 | struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum) | |
130 | { | |
131 | return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum); | |
132 | } | |
133 | ||
134 | static int sparse_init_one_section(struct mem_section *ms, | |
135 | unsigned long pnum, struct page *mem_map) | |
136 | { | |
137 | if (!valid_section(ms)) | |
138 | return -EINVAL; | |
139 | ||
140 | ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum); | |
141 | ||
142 | return 1; | |
143 | } | |
144 | ||
145 | static struct page *sparse_early_mem_map_alloc(unsigned long pnum) | |
146 | { | |
147 | struct page *map; | |
148 | int nid = early_pfn_to_nid(section_nr_to_pfn(pnum)); | |
802f192e | 149 | struct mem_section *ms = __nr_to_section(pnum); |
29751f69 AW |
150 | |
151 | map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION); | |
152 | if (map) | |
153 | return map; | |
154 | ||
155 | map = alloc_bootmem_node(NODE_DATA(nid), | |
156 | sizeof(struct page) * PAGES_PER_SECTION); | |
157 | if (map) | |
158 | return map; | |
159 | ||
160 | printk(KERN_WARNING "%s: allocation failed\n", __FUNCTION__); | |
802f192e | 161 | ms->section_mem_map = 0; |
29751f69 AW |
162 | return NULL; |
163 | } | |
164 | ||
d41dee36 AW |
165 | /* |
166 | * Allocate the accumulated non-linear sections, allocate a mem_map | |
167 | * for each and record the physical to section mapping. | |
168 | */ | |
169 | void sparse_init(void) | |
170 | { | |
171 | unsigned long pnum; | |
172 | struct page *map; | |
d41dee36 AW |
173 | |
174 | for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) { | |
29751f69 | 175 | if (!valid_section_nr(pnum)) |
d41dee36 AW |
176 | continue; |
177 | ||
29751f69 | 178 | map = sparse_early_mem_map_alloc(pnum); |
802f192e BP |
179 | if (!map) |
180 | continue; | |
181 | sparse_init_one_section(__nr_to_section(pnum), pnum, map); | |
d41dee36 AW |
182 | } |
183 | } | |
29751f69 AW |
184 | |
185 | /* | |
186 | * returns the number of sections whose mem_maps were properly | |
187 | * set. If this is <=0, then that means that the passed-in | |
188 | * map was not consumed and must be freed. | |
189 | */ | |
190 | int sparse_add_one_section(unsigned long start_pfn, int nr_pages, struct page *map) | |
191 | { | |
192 | struct mem_section *ms = __pfn_to_section(start_pfn); | |
193 | ||
194 | if (ms->section_mem_map & SECTION_MARKED_PRESENT) | |
195 | return -EEXIST; | |
196 | ||
197 | ms->section_mem_map |= SECTION_MARKED_PRESENT; | |
198 | ||
199 | return sparse_init_one_section(ms, pfn_to_section_nr(start_pfn), map); | |
200 | } |