blob: 4731a0895760e70cab07d59a0cff45c2590da450
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); |
213 |