]>
Commit | Line | Data |
---|---|---|
b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
5a0e3ad6 | 2 | #include <linux/slab.h> |
ccb46000 AM |
3 | #include <linux/kernel.h> |
4 | #include <linux/bitops.h> | |
5 | #include <linux/cpumask.h> | |
8bc3bcc9 | 6 | #include <linux/export.h> |
57c8a661 | 7 | #include <linux/memblock.h> |
98fa15f3 | 8 | #include <linux/numa.h> |
ccb46000 | 9 | |
f22ef333 AD |
10 | /** |
11 | * cpumask_next - get the next cpu in a cpumask | |
12 | * @n: the cpu prior to the place to search (ie. return will be > @n) | |
13 | * @srcp: the cpumask pointer | |
14 | * | |
15 | * Returns >= nr_cpu_ids if no further cpus set. | |
16 | */ | |
17 | unsigned int cpumask_next(int n, const struct cpumask *srcp) | |
18 | { | |
19 | /* -1 is a legal arg here. */ | |
20 | if (n != -1) | |
21 | cpumask_check(n); | |
22 | return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n + 1); | |
23 | } | |
24 | EXPORT_SYMBOL(cpumask_next); | |
25 | ||
2d3854a3 RR |
26 | /** |
27 | * cpumask_next_and - get the next cpu in *src1p & *src2p | |
28 | * @n: the cpu prior to the place to search (ie. return will be > @n) | |
29 | * @src1p: the first cpumask pointer | |
30 | * @src2p: the second cpumask pointer | |
31 | * | |
32 | * Returns >= nr_cpu_ids if no further cpus set in both. | |
33 | */ | |
34 | int cpumask_next_and(int n, const struct cpumask *src1p, | |
35 | const struct cpumask *src2p) | |
36 | { | |
0ade34c3 CC |
37 | /* -1 is a legal arg here. */ |
38 | if (n != -1) | |
39 | cpumask_check(n); | |
40 | return find_next_and_bit(cpumask_bits(src1p), cpumask_bits(src2p), | |
41 | nr_cpumask_bits, n + 1); | |
2d3854a3 RR |
42 | } |
43 | EXPORT_SYMBOL(cpumask_next_and); | |
44 | ||
45 | /** | |
46 | * cpumask_any_but - return a "random" in a cpumask, but not this one. | |
47 | * @mask: the cpumask to search | |
48 | * @cpu: the cpu to ignore. | |
49 | * | |
50 | * Often used to find any cpu but smp_processor_id() in a mask. | |
51 | * Returns >= nr_cpu_ids if no cpus set. | |
52 | */ | |
53 | int cpumask_any_but(const struct cpumask *mask, unsigned int cpu) | |
54 | { | |
55 | unsigned int i; | |
56 | ||
984f2f37 | 57 | cpumask_check(cpu); |
2d3854a3 RR |
58 | for_each_cpu(i, mask) |
59 | if (i != cpu) | |
60 | break; | |
61 | return i; | |
62 | } | |
3712bba1 | 63 | EXPORT_SYMBOL(cpumask_any_but); |
2d3854a3 | 64 | |
c743f0a5 PZ |
65 | /** |
66 | * cpumask_next_wrap - helper to implement for_each_cpu_wrap | |
67 | * @n: the cpu prior to the place to search | |
68 | * @mask: the cpumask pointer | |
69 | * @start: the start point of the iteration | |
70 | * @wrap: assume @n crossing @start terminates the iteration | |
71 | * | |
72 | * Returns >= nr_cpu_ids on completion | |
73 | * | |
74 | * Note: the @wrap argument is required for the start condition when | |
75 | * we cannot assume @start is set in @mask. | |
76 | */ | |
77 | int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap) | |
78 | { | |
79 | int next; | |
80 | ||
81 | again: | |
82 | next = cpumask_next(n, mask); | |
83 | ||
84 | if (wrap && n < start && next >= start) { | |
85 | return nr_cpumask_bits; | |
86 | ||
87 | } else if (next >= nr_cpumask_bits) { | |
88 | wrap = true; | |
89 | n = -1; | |
90 | goto again; | |
91 | } | |
92 | ||
93 | return next; | |
94 | } | |
95 | EXPORT_SYMBOL(cpumask_next_wrap); | |
96 | ||
2d3854a3 RR |
97 | /* These are not inline because of header tangles. */ |
98 | #ifdef CONFIG_CPUMASK_OFFSTACK | |
ec26b805 MT |
99 | /** |
100 | * alloc_cpumask_var_node - allocate a struct cpumask on a given node | |
101 | * @mask: pointer to cpumask_var_t where the cpumask is returned | |
102 | * @flags: GFP_ flags | |
103 | * | |
104 | * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is | |
105 | * a nop returning a constant 1 (in <linux/cpumask.h>) | |
106 | * Returns TRUE if memory allocation succeeded, FALSE otherwise. | |
107 | * | |
108 | * In addition, mask will be NULL if this fails. Note that gcc is | |
109 | * usually smart enough to know that mask can never be NULL if | |
110 | * CONFIG_CPUMASK_OFFSTACK=n, so does code elimination in that case | |
111 | * too. | |
112 | */ | |
7b4967c5 | 113 | bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node) |
2d3854a3 | 114 | { |
38c7fed2 YL |
115 | *mask = kmalloc_node(cpumask_size(), flags, node); |
116 | ||
2d3854a3 RR |
117 | #ifdef CONFIG_DEBUG_PER_CPU_MAPS |
118 | if (!*mask) { | |
119 | printk(KERN_ERR "=> alloc_cpumask_var: failed!\n"); | |
120 | dump_stack(); | |
121 | } | |
122 | #endif | |
2a530080 | 123 | |
2d3854a3 RR |
124 | return *mask != NULL; |
125 | } | |
7b4967c5 MT |
126 | EXPORT_SYMBOL(alloc_cpumask_var_node); |
127 | ||
0281b5dc YL |
128 | bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node) |
129 | { | |
130 | return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node); | |
131 | } | |
132 | EXPORT_SYMBOL(zalloc_cpumask_var_node); | |
133 | ||
ec26b805 MT |
134 | /** |
135 | * alloc_cpumask_var - allocate a struct cpumask | |
136 | * @mask: pointer to cpumask_var_t where the cpumask is returned | |
137 | * @flags: GFP_ flags | |
138 | * | |
139 | * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is | |
140 | * a nop returning a constant 1 (in <linux/cpumask.h>). | |
141 | * | |
142 | * See alloc_cpumask_var_node. | |
143 | */ | |
7b4967c5 MT |
144 | bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) |
145 | { | |
37e7b5f1 | 146 | return alloc_cpumask_var_node(mask, flags, NUMA_NO_NODE); |
7b4967c5 | 147 | } |
2d3854a3 RR |
148 | EXPORT_SYMBOL(alloc_cpumask_var); |
149 | ||
0281b5dc YL |
150 | bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) |
151 | { | |
152 | return alloc_cpumask_var(mask, flags | __GFP_ZERO); | |
153 | } | |
154 | EXPORT_SYMBOL(zalloc_cpumask_var); | |
155 | ||
ec26b805 MT |
156 | /** |
157 | * alloc_bootmem_cpumask_var - allocate a struct cpumask from the bootmem arena. | |
158 | * @mask: pointer to cpumask_var_t where the cpumask is returned | |
159 | * | |
160 | * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is | |
e9690a6e | 161 | * a nop (in <linux/cpumask.h>). |
ec26b805 MT |
162 | * Either returns an allocated (zero-filled) cpumask, or causes the |
163 | * system to panic. | |
164 | */ | |
2d3854a3 RR |
165 | void __init alloc_bootmem_cpumask_var(cpumask_var_t *mask) |
166 | { | |
7e1c4e27 | 167 | *mask = memblock_alloc(cpumask_size(), SMP_CACHE_BYTES); |
8a7f97b9 MR |
168 | if (!*mask) |
169 | panic("%s: Failed to allocate %u bytes\n", __func__, | |
170 | cpumask_size()); | |
2d3854a3 RR |
171 | } |
172 | ||
ec26b805 MT |
173 | /** |
174 | * free_cpumask_var - frees memory allocated for a struct cpumask. | |
175 | * @mask: cpumask to free | |
176 | * | |
177 | * This is safe on a NULL mask. | |
178 | */ | |
2d3854a3 RR |
179 | void free_cpumask_var(cpumask_var_t mask) |
180 | { | |
181 | kfree(mask); | |
182 | } | |
183 | EXPORT_SYMBOL(free_cpumask_var); | |
cd83e42c | 184 | |
ec26b805 MT |
185 | /** |
186 | * free_bootmem_cpumask_var - frees result of alloc_bootmem_cpumask_var | |
187 | * @mask: cpumask to free | |
188 | */ | |
984f2f37 | 189 | void __init free_bootmem_cpumask_var(cpumask_var_t mask) |
cd83e42c | 190 | { |
c1529500 | 191 | memblock_free_early(__pa(mask), cpumask_size()); |
cd83e42c | 192 | } |
2d3854a3 | 193 | #endif |
da91309e AV |
194 | |
195 | /** | |
f36963c9 | 196 | * cpumask_local_spread - select the i'th cpu with local numa cpu's first |
da91309e | 197 | * @i: index number |
f36963c9 | 198 | * @node: local numa_node |
da91309e | 199 | * |
f36963c9 RR |
200 | * This function selects an online CPU according to a numa aware policy; |
201 | * local cpus are returned first, followed by non-local ones, then it | |
202 | * wraps around. | |
da91309e | 203 | * |
f36963c9 | 204 | * It's not very efficient, but useful for setup. |
da91309e | 205 | */ |
f36963c9 | 206 | unsigned int cpumask_local_spread(unsigned int i, int node) |
da91309e | 207 | { |
da91309e | 208 | int cpu; |
da91309e | 209 | |
f36963c9 | 210 | /* Wrap: we always want a cpu. */ |
da91309e AV |
211 | i %= num_online_cpus(); |
212 | ||
98fa15f3 | 213 | if (node == NUMA_NO_NODE) { |
f36963c9 RR |
214 | for_each_cpu(cpu, cpu_online_mask) |
215 | if (i-- == 0) | |
216 | return cpu; | |
da91309e | 217 | } else { |
f36963c9 RR |
218 | /* NUMA first. */ |
219 | for_each_cpu_and(cpu, cpumask_of_node(node), cpu_online_mask) | |
220 | if (i-- == 0) | |
221 | return cpu; | |
222 | ||
223 | for_each_cpu(cpu, cpu_online_mask) { | |
224 | /* Skip NUMA nodes, done above. */ | |
225 | if (cpumask_test_cpu(cpu, cpumask_of_node(node))) | |
226 | continue; | |
227 | ||
228 | if (i-- == 0) | |
229 | return cpu; | |
da91309e AV |
230 | } |
231 | } | |
f36963c9 | 232 | BUG(); |
da91309e | 233 | } |
f36963c9 | 234 | EXPORT_SYMBOL(cpumask_local_spread); |