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