Commit | Line | Data |
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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 | |
c743f0a5 PZ |
10 | /** |
11 | * cpumask_next_wrap - helper to implement for_each_cpu_wrap | |
12 | * @n: the cpu prior to the place to search | |
13 | * @mask: the cpumask pointer | |
14 | * @start: the start point of the iteration | |
15 | * @wrap: assume @n crossing @start terminates the iteration | |
16 | * | |
17 | * Returns >= nr_cpu_ids on completion | |
18 | * | |
19 | * Note: the @wrap argument is required for the start condition when | |
20 | * we cannot assume @start is set in @mask. | |
21 | */ | |
8b6b795d | 22 | unsigned int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap) |
c743f0a5 | 23 | { |
8b6b795d | 24 | unsigned int next; |
c743f0a5 PZ |
25 | |
26 | again: | |
27 | next = cpumask_next(n, mask); | |
28 | ||
29 | if (wrap && n < start && next >= start) { | |
30 | return nr_cpumask_bits; | |
31 | ||
32 | } else if (next >= nr_cpumask_bits) { | |
33 | wrap = true; | |
34 | n = -1; | |
35 | goto again; | |
36 | } | |
37 | ||
38 | return next; | |
39 | } | |
40 | EXPORT_SYMBOL(cpumask_next_wrap); | |
41 | ||
2d3854a3 RR |
42 | /* These are not inline because of header tangles. */ |
43 | #ifdef CONFIG_CPUMASK_OFFSTACK | |
ec26b805 MT |
44 | /** |
45 | * alloc_cpumask_var_node - allocate a struct cpumask on a given node | |
46 | * @mask: pointer to cpumask_var_t where the cpumask is returned | |
47 | * @flags: GFP_ flags | |
48 | * | |
49 | * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is | |
50 | * a nop returning a constant 1 (in <linux/cpumask.h>) | |
51 | * Returns TRUE if memory allocation succeeded, FALSE otherwise. | |
52 | * | |
53 | * In addition, mask will be NULL if this fails. Note that gcc is | |
54 | * usually smart enough to know that mask can never be NULL if | |
55 | * CONFIG_CPUMASK_OFFSTACK=n, so does code elimination in that case | |
56 | * too. | |
57 | */ | |
7b4967c5 | 58 | bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node) |
2d3854a3 | 59 | { |
38c7fed2 YL |
60 | *mask = kmalloc_node(cpumask_size(), flags, node); |
61 | ||
2d3854a3 RR |
62 | #ifdef CONFIG_DEBUG_PER_CPU_MAPS |
63 | if (!*mask) { | |
64 | printk(KERN_ERR "=> alloc_cpumask_var: failed!\n"); | |
65 | dump_stack(); | |
66 | } | |
67 | #endif | |
2a530080 | 68 | |
2d3854a3 RR |
69 | return *mask != NULL; |
70 | } | |
7b4967c5 MT |
71 | EXPORT_SYMBOL(alloc_cpumask_var_node); |
72 | ||
0281b5dc YL |
73 | bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node) |
74 | { | |
75 | return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node); | |
76 | } | |
77 | EXPORT_SYMBOL(zalloc_cpumask_var_node); | |
78 | ||
ec26b805 MT |
79 | /** |
80 | * alloc_cpumask_var - allocate a struct cpumask | |
81 | * @mask: pointer to cpumask_var_t where the cpumask is returned | |
82 | * @flags: GFP_ flags | |
83 | * | |
84 | * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is | |
85 | * a nop returning a constant 1 (in <linux/cpumask.h>). | |
86 | * | |
87 | * See alloc_cpumask_var_node. | |
88 | */ | |
7b4967c5 MT |
89 | bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) |
90 | { | |
37e7b5f1 | 91 | return alloc_cpumask_var_node(mask, flags, NUMA_NO_NODE); |
7b4967c5 | 92 | } |
2d3854a3 RR |
93 | EXPORT_SYMBOL(alloc_cpumask_var); |
94 | ||
0281b5dc YL |
95 | bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) |
96 | { | |
97 | return alloc_cpumask_var(mask, flags | __GFP_ZERO); | |
98 | } | |
99 | EXPORT_SYMBOL(zalloc_cpumask_var); | |
100 | ||
ec26b805 MT |
101 | /** |
102 | * alloc_bootmem_cpumask_var - allocate a struct cpumask from the bootmem arena. | |
103 | * @mask: pointer to cpumask_var_t where the cpumask is returned | |
104 | * | |
105 | * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is | |
e9690a6e | 106 | * a nop (in <linux/cpumask.h>). |
ec26b805 MT |
107 | * Either returns an allocated (zero-filled) cpumask, or causes the |
108 | * system to panic. | |
109 | */ | |
2d3854a3 RR |
110 | void __init alloc_bootmem_cpumask_var(cpumask_var_t *mask) |
111 | { | |
7e1c4e27 | 112 | *mask = memblock_alloc(cpumask_size(), SMP_CACHE_BYTES); |
8a7f97b9 MR |
113 | if (!*mask) |
114 | panic("%s: Failed to allocate %u bytes\n", __func__, | |
115 | cpumask_size()); | |
2d3854a3 RR |
116 | } |
117 | ||
ec26b805 MT |
118 | /** |
119 | * free_cpumask_var - frees memory allocated for a struct cpumask. | |
120 | * @mask: cpumask to free | |
121 | * | |
122 | * This is safe on a NULL mask. | |
123 | */ | |
2d3854a3 RR |
124 | void free_cpumask_var(cpumask_var_t mask) |
125 | { | |
126 | kfree(mask); | |
127 | } | |
128 | EXPORT_SYMBOL(free_cpumask_var); | |
cd83e42c | 129 | |
ec26b805 MT |
130 | /** |
131 | * free_bootmem_cpumask_var - frees result of alloc_bootmem_cpumask_var | |
132 | * @mask: cpumask to free | |
133 | */ | |
984f2f37 | 134 | void __init free_bootmem_cpumask_var(cpumask_var_t mask) |
cd83e42c | 135 | { |
4421cca0 | 136 | memblock_free(mask, cpumask_size()); |
cd83e42c | 137 | } |
2d3854a3 | 138 | #endif |
da91309e AV |
139 | |
140 | /** | |
f36963c9 | 141 | * cpumask_local_spread - select the i'th cpu with local numa cpu's first |
da91309e | 142 | * @i: index number |
f36963c9 | 143 | * @node: local numa_node |
da91309e | 144 | * |
f36963c9 RR |
145 | * This function selects an online CPU according to a numa aware policy; |
146 | * local cpus are returned first, followed by non-local ones, then it | |
147 | * wraps around. | |
da91309e | 148 | * |
f36963c9 | 149 | * It's not very efficient, but useful for setup. |
da91309e | 150 | */ |
f36963c9 | 151 | unsigned int cpumask_local_spread(unsigned int i, int node) |
da91309e | 152 | { |
8b6b795d | 153 | unsigned int cpu; |
da91309e | 154 | |
f36963c9 | 155 | /* Wrap: we always want a cpu. */ |
2452483d | 156 | i %= num_online_cpus(); |
da91309e | 157 | |
98fa15f3 | 158 | if (node == NUMA_NO_NODE) { |
2452483d | 159 | for_each_cpu(cpu, cpu_online_mask) |
f36963c9 RR |
160 | if (i-- == 0) |
161 | return cpu; | |
da91309e | 162 | } else { |
f36963c9 | 163 | /* NUMA first. */ |
2452483d | 164 | for_each_cpu_and(cpu, cpumask_of_node(node), cpu_online_mask) |
f36963c9 RR |
165 | if (i-- == 0) |
166 | return cpu; | |
167 | ||
2452483d | 168 | for_each_cpu(cpu, cpu_online_mask) { |
f36963c9 RR |
169 | /* Skip NUMA nodes, done above. */ |
170 | if (cpumask_test_cpu(cpu, cpumask_of_node(node))) | |
171 | continue; | |
172 | ||
173 | if (i-- == 0) | |
174 | return cpu; | |
da91309e AV |
175 | } |
176 | } | |
f36963c9 | 177 | BUG(); |
da91309e | 178 | } |
f36963c9 | 179 | EXPORT_SYMBOL(cpumask_local_spread); |
46a87b38 PT |
180 | |
181 | static DEFINE_PER_CPU(int, distribute_cpu_mask_prev); | |
182 | ||
183 | /** | |
184 | * Returns an arbitrary cpu within srcp1 & srcp2. | |
185 | * | |
186 | * Iterated calls using the same srcp1 and srcp2 will be distributed within | |
187 | * their intersection. | |
188 | * | |
189 | * Returns >= nr_cpu_ids if the intersection is empty. | |
190 | */ | |
8b6b795d | 191 | unsigned int cpumask_any_and_distribute(const struct cpumask *src1p, |
46a87b38 PT |
192 | const struct cpumask *src2p) |
193 | { | |
8b6b795d | 194 | unsigned int next, prev; |
46a87b38 PT |
195 | |
196 | /* NOTE: our first selection will skip 0. */ | |
197 | prev = __this_cpu_read(distribute_cpu_mask_prev); | |
198 | ||
199 | next = cpumask_next_and(prev, src1p, src2p); | |
200 | if (next >= nr_cpu_ids) | |
201 | next = cpumask_first_and(src1p, src2p); | |
202 | ||
203 | if (next < nr_cpu_ids) | |
204 | __this_cpu_write(distribute_cpu_mask_prev, next); | |
205 | ||
206 | return next; | |
207 | } | |
208 | EXPORT_SYMBOL(cpumask_any_and_distribute); | |
14e292f8 | 209 | |
8b6b795d | 210 | unsigned int cpumask_any_distribute(const struct cpumask *srcp) |
14e292f8 | 211 | { |
8b6b795d | 212 | unsigned int next, prev; |
14e292f8 PZ |
213 | |
214 | /* NOTE: our first selection will skip 0. */ | |
215 | prev = __this_cpu_read(distribute_cpu_mask_prev); | |
216 | ||
217 | next = cpumask_next(prev, srcp); | |
218 | if (next >= nr_cpu_ids) | |
219 | next = cpumask_first(srcp); | |
220 | ||
221 | if (next < nr_cpu_ids) | |
222 | __this_cpu_write(distribute_cpu_mask_prev, next); | |
223 | ||
224 | return next; | |
225 | } | |
226 | EXPORT_SYMBOL(cpumask_any_distribute); |