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Commit | Line | Data |
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5a0e3ad6 | 1 | #include <linux/slab.h> |
ccb46000 AM |
2 | #include <linux/kernel.h> |
3 | #include <linux/bitops.h> | |
4 | #include <linux/cpumask.h> | |
8bc3bcc9 | 5 | #include <linux/export.h> |
2d3854a3 | 6 | #include <linux/bootmem.h> |
ccb46000 | 7 | |
f22ef333 AD |
8 | /** |
9 | * cpumask_next - get the next cpu in a cpumask | |
10 | * @n: the cpu prior to the place to search (ie. return will be > @n) | |
11 | * @srcp: the cpumask pointer | |
12 | * | |
13 | * Returns >= nr_cpu_ids if no further cpus set. | |
14 | */ | |
15 | unsigned int cpumask_next(int n, const struct cpumask *srcp) | |
16 | { | |
17 | /* -1 is a legal arg here. */ | |
18 | if (n != -1) | |
19 | cpumask_check(n); | |
20 | return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n + 1); | |
21 | } | |
22 | EXPORT_SYMBOL(cpumask_next); | |
23 | ||
2d3854a3 RR |
24 | /** |
25 | * cpumask_next_and - get the next cpu in *src1p & *src2p | |
26 | * @n: the cpu prior to the place to search (ie. return will be > @n) | |
27 | * @src1p: the first cpumask pointer | |
28 | * @src2p: the second cpumask pointer | |
29 | * | |
30 | * Returns >= nr_cpu_ids if no further cpus set in both. | |
31 | */ | |
32 | int cpumask_next_and(int n, const struct cpumask *src1p, | |
33 | const struct cpumask *src2p) | |
34 | { | |
5ca62d65 AM |
35 | while ((n = cpumask_next(n, src1p)) < nr_cpu_ids) |
36 | if (cpumask_test_cpu(n, src2p)) | |
37 | break; | |
38 | return n; | |
2d3854a3 RR |
39 | } |
40 | EXPORT_SYMBOL(cpumask_next_and); | |
41 | ||
42 | /** | |
43 | * cpumask_any_but - return a "random" in a cpumask, but not this one. | |
44 | * @mask: the cpumask to search | |
45 | * @cpu: the cpu to ignore. | |
46 | * | |
47 | * Often used to find any cpu but smp_processor_id() in a mask. | |
48 | * Returns >= nr_cpu_ids if no cpus set. | |
49 | */ | |
50 | int cpumask_any_but(const struct cpumask *mask, unsigned int cpu) | |
51 | { | |
52 | unsigned int i; | |
53 | ||
984f2f37 | 54 | cpumask_check(cpu); |
2d3854a3 RR |
55 | for_each_cpu(i, mask) |
56 | if (i != cpu) | |
57 | break; | |
58 | return i; | |
59 | } | |
3712bba1 | 60 | EXPORT_SYMBOL(cpumask_any_but); |
2d3854a3 | 61 | |
c743f0a5 PZ |
62 | /** |
63 | * cpumask_next_wrap - helper to implement for_each_cpu_wrap | |
64 | * @n: the cpu prior to the place to search | |
65 | * @mask: the cpumask pointer | |
66 | * @start: the start point of the iteration | |
67 | * @wrap: assume @n crossing @start terminates the iteration | |
68 | * | |
69 | * Returns >= nr_cpu_ids on completion | |
70 | * | |
71 | * Note: the @wrap argument is required for the start condition when | |
72 | * we cannot assume @start is set in @mask. | |
73 | */ | |
74 | int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap) | |
75 | { | |
76 | int next; | |
77 | ||
78 | again: | |
79 | next = cpumask_next(n, mask); | |
80 | ||
81 | if (wrap && n < start && next >= start) { | |
82 | return nr_cpumask_bits; | |
83 | ||
84 | } else if (next >= nr_cpumask_bits) { | |
85 | wrap = true; | |
86 | n = -1; | |
87 | goto again; | |
88 | } | |
89 | ||
90 | return next; | |
91 | } | |
92 | EXPORT_SYMBOL(cpumask_next_wrap); | |
93 | ||
2d3854a3 RR |
94 | /* These are not inline because of header tangles. */ |
95 | #ifdef CONFIG_CPUMASK_OFFSTACK | |
ec26b805 MT |
96 | /** |
97 | * alloc_cpumask_var_node - allocate a struct cpumask on a given node | |
98 | * @mask: pointer to cpumask_var_t where the cpumask is returned | |
99 | * @flags: GFP_ flags | |
100 | * | |
101 | * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is | |
102 | * a nop returning a constant 1 (in <linux/cpumask.h>) | |
103 | * Returns TRUE if memory allocation succeeded, FALSE otherwise. | |
104 | * | |
105 | * In addition, mask will be NULL if this fails. Note that gcc is | |
106 | * usually smart enough to know that mask can never be NULL if | |
107 | * CONFIG_CPUMASK_OFFSTACK=n, so does code elimination in that case | |
108 | * too. | |
109 | */ | |
7b4967c5 | 110 | bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node) |
2d3854a3 | 111 | { |
38c7fed2 YL |
112 | *mask = kmalloc_node(cpumask_size(), flags, node); |
113 | ||
2d3854a3 RR |
114 | #ifdef CONFIG_DEBUG_PER_CPU_MAPS |
115 | if (!*mask) { | |
116 | printk(KERN_ERR "=> alloc_cpumask_var: failed!\n"); | |
117 | dump_stack(); | |
118 | } | |
119 | #endif | |
2a530080 | 120 | |
2d3854a3 RR |
121 | return *mask != NULL; |
122 | } | |
7b4967c5 MT |
123 | EXPORT_SYMBOL(alloc_cpumask_var_node); |
124 | ||
0281b5dc YL |
125 | bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node) |
126 | { | |
127 | return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node); | |
128 | } | |
129 | EXPORT_SYMBOL(zalloc_cpumask_var_node); | |
130 | ||
ec26b805 MT |
131 | /** |
132 | * alloc_cpumask_var - allocate a struct cpumask | |
133 | * @mask: pointer to cpumask_var_t where the cpumask is returned | |
134 | * @flags: GFP_ flags | |
135 | * | |
136 | * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is | |
137 | * a nop returning a constant 1 (in <linux/cpumask.h>). | |
138 | * | |
139 | * See alloc_cpumask_var_node. | |
140 | */ | |
7b4967c5 MT |
141 | bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) |
142 | { | |
37e7b5f1 | 143 | return alloc_cpumask_var_node(mask, flags, NUMA_NO_NODE); |
7b4967c5 | 144 | } |
2d3854a3 RR |
145 | EXPORT_SYMBOL(alloc_cpumask_var); |
146 | ||
0281b5dc YL |
147 | bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) |
148 | { | |
149 | return alloc_cpumask_var(mask, flags | __GFP_ZERO); | |
150 | } | |
151 | EXPORT_SYMBOL(zalloc_cpumask_var); | |
152 | ||
ec26b805 MT |
153 | /** |
154 | * alloc_bootmem_cpumask_var - allocate a struct cpumask from the bootmem arena. | |
155 | * @mask: pointer to cpumask_var_t where the cpumask is returned | |
156 | * | |
157 | * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is | |
e9690a6e | 158 | * a nop (in <linux/cpumask.h>). |
ec26b805 MT |
159 | * Either returns an allocated (zero-filled) cpumask, or causes the |
160 | * system to panic. | |
161 | */ | |
2d3854a3 RR |
162 | void __init alloc_bootmem_cpumask_var(cpumask_var_t *mask) |
163 | { | |
c1529500 | 164 | *mask = memblock_virt_alloc(cpumask_size(), 0); |
2d3854a3 RR |
165 | } |
166 | ||
ec26b805 MT |
167 | /** |
168 | * free_cpumask_var - frees memory allocated for a struct cpumask. | |
169 | * @mask: cpumask to free | |
170 | * | |
171 | * This is safe on a NULL mask. | |
172 | */ | |
2d3854a3 RR |
173 | void free_cpumask_var(cpumask_var_t mask) |
174 | { | |
175 | kfree(mask); | |
176 | } | |
177 | EXPORT_SYMBOL(free_cpumask_var); | |
cd83e42c | 178 | |
ec26b805 MT |
179 | /** |
180 | * free_bootmem_cpumask_var - frees result of alloc_bootmem_cpumask_var | |
181 | * @mask: cpumask to free | |
182 | */ | |
984f2f37 | 183 | void __init free_bootmem_cpumask_var(cpumask_var_t mask) |
cd83e42c | 184 | { |
c1529500 | 185 | memblock_free_early(__pa(mask), cpumask_size()); |
cd83e42c | 186 | } |
2d3854a3 | 187 | #endif |
da91309e AV |
188 | |
189 | /** | |
f36963c9 | 190 | * cpumask_local_spread - select the i'th cpu with local numa cpu's first |
da91309e | 191 | * @i: index number |
f36963c9 | 192 | * @node: local numa_node |
da91309e | 193 | * |
f36963c9 RR |
194 | * This function selects an online CPU according to a numa aware policy; |
195 | * local cpus are returned first, followed by non-local ones, then it | |
196 | * wraps around. | |
da91309e | 197 | * |
f36963c9 | 198 | * It's not very efficient, but useful for setup. |
da91309e | 199 | */ |
f36963c9 | 200 | unsigned int cpumask_local_spread(unsigned int i, int node) |
da91309e | 201 | { |
da91309e | 202 | int cpu; |
da91309e | 203 | |
f36963c9 | 204 | /* Wrap: we always want a cpu. */ |
da91309e AV |
205 | i %= num_online_cpus(); |
206 | ||
f36963c9 RR |
207 | if (node == -1) { |
208 | for_each_cpu(cpu, cpu_online_mask) | |
209 | if (i-- == 0) | |
210 | return cpu; | |
da91309e | 211 | } else { |
f36963c9 RR |
212 | /* NUMA first. */ |
213 | for_each_cpu_and(cpu, cpumask_of_node(node), cpu_online_mask) | |
214 | if (i-- == 0) | |
215 | return cpu; | |
216 | ||
217 | for_each_cpu(cpu, cpu_online_mask) { | |
218 | /* Skip NUMA nodes, done above. */ | |
219 | if (cpumask_test_cpu(cpu, cpumask_of_node(node))) | |
220 | continue; | |
221 | ||
222 | if (i-- == 0) | |
223 | return cpu; | |
da91309e AV |
224 | } |
225 | } | |
f36963c9 | 226 | BUG(); |
da91309e | 227 | } |
f36963c9 | 228 | EXPORT_SYMBOL(cpumask_local_spread); |