blob: 35fe142ebb5e2fefe6803445804b7481a52dded3 [file] [log] [blame]
Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001// SPDX-License-Identifier: GPL-2.0
Tejun Heo5a0e3ad2010-03-24 17:04:11 +09002#include <linux/slab.h>
Andrew Mortonccb46002006-03-25 03:08:08 -08003#include <linux/kernel.h>
4#include <linux/bitops.h>
5#include <linux/cpumask.h>
Paul Gortmaker8bc3bcc2011-11-16 21:29:17 -05006#include <linux/export.h>
Rusty Russell2d3854a2008-11-05 13:39:10 +11007#include <linux/bootmem.h>
Andrew Mortonccb46002006-03-25 03:08:08 -08008
Rusty Russell2d3854a2008-11-05 13:39:10 +11009/**
Alexey Dobriyanf22ef332017-09-08 16:17:15 -070010 * cpumask_next - get the next cpu in a cpumask
11 * @n: the cpu prior to the place to search (ie. return will be > @n)
12 * @srcp: the cpumask pointer
13 *
14 * Returns >= nr_cpu_ids if no further cpus set.
15 */
16unsigned int cpumask_next(int n, const struct cpumask *srcp)
17{
18 /* -1 is a legal arg here. */
19 if (n != -1)
20 cpumask_check(n);
21 return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n + 1);
22}
23EXPORT_SYMBOL(cpumask_next);
24
25/**
Rusty Russell2d3854a2008-11-05 13:39:10 +110026 * cpumask_next_and - get the next cpu in *src1p & *src2p
27 * @n: the cpu prior to the place to search (ie. return will be > @n)
28 * @src1p: the first cpumask pointer
29 * @src2p: the second cpumask pointer
30 *
31 * Returns >= nr_cpu_ids if no further cpus set in both.
32 */
33int cpumask_next_and(int n, const struct cpumask *src1p,
34 const struct cpumask *src2p)
35{
Andrew Morton5ca62d62015-06-18 11:01:11 -070036 while ((n = cpumask_next(n, src1p)) < nr_cpu_ids)
37 if (cpumask_test_cpu(n, src2p))
38 break;
39 return n;
Rusty Russell2d3854a2008-11-05 13:39:10 +110040}
41EXPORT_SYMBOL(cpumask_next_and);
42
43/**
44 * cpumask_any_but - return a "random" in a cpumask, but not this one.
45 * @mask: the cpumask to search
46 * @cpu: the cpu to ignore.
47 *
48 * Often used to find any cpu but smp_processor_id() in a mask.
49 * Returns >= nr_cpu_ids if no cpus set.
50 */
51int cpumask_any_but(const struct cpumask *mask, unsigned int cpu)
52{
53 unsigned int i;
54
Rusty Russell984f2f32008-11-08 20:24:19 +110055 cpumask_check(cpu);
Rusty Russell2d3854a2008-11-05 13:39:10 +110056 for_each_cpu(i, mask)
57 if (i != cpu)
58 break;
59 return i;
60}
Thomas Gleixner3712bba2016-02-22 22:19:18 +000061EXPORT_SYMBOL(cpumask_any_but);
Rusty Russell2d3854a2008-11-05 13:39:10 +110062
Peter Zijlstrac743f0a2017-04-14 14:20:05 +020063/**
64 * cpumask_next_wrap - helper to implement for_each_cpu_wrap
65 * @n: the cpu prior to the place to search
66 * @mask: the cpumask pointer
67 * @start: the start point of the iteration
68 * @wrap: assume @n crossing @start terminates the iteration
69 *
70 * Returns >= nr_cpu_ids on completion
71 *
72 * Note: the @wrap argument is required for the start condition when
73 * we cannot assume @start is set in @mask.
74 */
75int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap)
76{
77 int next;
78
79again:
80 next = cpumask_next(n, mask);
81
82 if (wrap && n < start && next >= start) {
83 return nr_cpumask_bits;
84
85 } else if (next >= nr_cpumask_bits) {
86 wrap = true;
87 n = -1;
88 goto again;
89 }
90
91 return next;
92}
93EXPORT_SYMBOL(cpumask_next_wrap);
94
Rusty Russell2d3854a2008-11-05 13:39:10 +110095/* These are not inline because of header tangles. */
96#ifdef CONFIG_CPUMASK_OFFSTACK
Mike Travisec26b802008-12-19 16:56:52 +103097/**
98 * alloc_cpumask_var_node - allocate a struct cpumask on a given node
99 * @mask: pointer to cpumask_var_t where the cpumask is returned
100 * @flags: GFP_ flags
101 *
102 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
103 * a nop returning a constant 1 (in <linux/cpumask.h>)
104 * Returns TRUE if memory allocation succeeded, FALSE otherwise.
105 *
106 * In addition, mask will be NULL if this fails. Note that gcc is
107 * usually smart enough to know that mask can never be NULL if
108 * CONFIG_CPUMASK_OFFSTACK=n, so does code elimination in that case
109 * too.
110 */
Mike Travis7b4967c2008-12-19 16:56:37 +1030111bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
Rusty Russell2d3854a2008-11-05 13:39:10 +1100112{
Yinghai Lu38c7fed2009-05-25 15:10:58 +0300113 *mask = kmalloc_node(cpumask_size(), flags, node);
114
Rusty Russell2d3854a2008-11-05 13:39:10 +1100115#ifdef CONFIG_DEBUG_PER_CPU_MAPS
116 if (!*mask) {
117 printk(KERN_ERR "=> alloc_cpumask_var: failed!\n");
118 dump_stack();
119 }
120#endif
Rusty Russell2a530082009-01-01 10:12:30 +1030121
Rusty Russell2d3854a2008-11-05 13:39:10 +1100122 return *mask != NULL;
123}
Mike Travis7b4967c2008-12-19 16:56:37 +1030124EXPORT_SYMBOL(alloc_cpumask_var_node);
125
Yinghai Lu0281b5d2009-06-06 14:50:36 -0700126bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
127{
128 return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node);
129}
130EXPORT_SYMBOL(zalloc_cpumask_var_node);
131
Mike Travisec26b802008-12-19 16:56:52 +1030132/**
133 * alloc_cpumask_var - allocate a struct cpumask
134 * @mask: pointer to cpumask_var_t where the cpumask is returned
135 * @flags: GFP_ flags
136 *
137 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
138 * a nop returning a constant 1 (in <linux/cpumask.h>).
139 *
140 * See alloc_cpumask_var_node.
141 */
Mike Travis7b4967c2008-12-19 16:56:37 +1030142bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
143{
KOSAKI Motohiro37e7b5f2011-07-26 16:08:44 -0700144 return alloc_cpumask_var_node(mask, flags, NUMA_NO_NODE);
Mike Travis7b4967c2008-12-19 16:56:37 +1030145}
Rusty Russell2d3854a2008-11-05 13:39:10 +1100146EXPORT_SYMBOL(alloc_cpumask_var);
147
Yinghai Lu0281b5d2009-06-06 14:50:36 -0700148bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
149{
150 return alloc_cpumask_var(mask, flags | __GFP_ZERO);
151}
152EXPORT_SYMBOL(zalloc_cpumask_var);
153
Mike Travisec26b802008-12-19 16:56:52 +1030154/**
155 * alloc_bootmem_cpumask_var - allocate a struct cpumask from the bootmem arena.
156 * @mask: pointer to cpumask_var_t where the cpumask is returned
157 *
158 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
Li Zefane9690a62008-12-31 16:45:50 +0800159 * a nop (in <linux/cpumask.h>).
Mike Travisec26b802008-12-19 16:56:52 +1030160 * Either returns an allocated (zero-filled) cpumask, or causes the
161 * system to panic.
162 */
Rusty Russell2d3854a2008-11-05 13:39:10 +1100163void __init alloc_bootmem_cpumask_var(cpumask_var_t *mask)
164{
Santosh Shilimkarc1529502014-01-21 15:50:32 -0800165 *mask = memblock_virt_alloc(cpumask_size(), 0);
Rusty Russell2d3854a2008-11-05 13:39:10 +1100166}
167
Mike Travisec26b802008-12-19 16:56:52 +1030168/**
169 * free_cpumask_var - frees memory allocated for a struct cpumask.
170 * @mask: cpumask to free
171 *
172 * This is safe on a NULL mask.
173 */
Rusty Russell2d3854a2008-11-05 13:39:10 +1100174void free_cpumask_var(cpumask_var_t mask)
175{
176 kfree(mask);
177}
178EXPORT_SYMBOL(free_cpumask_var);
Rusty Russellcd83e422008-11-07 11:12:29 +1100179
Mike Travisec26b802008-12-19 16:56:52 +1030180/**
181 * free_bootmem_cpumask_var - frees result of alloc_bootmem_cpumask_var
182 * @mask: cpumask to free
183 */
Rusty Russell984f2f32008-11-08 20:24:19 +1100184void __init free_bootmem_cpumask_var(cpumask_var_t mask)
Rusty Russellcd83e422008-11-07 11:12:29 +1100185{
Santosh Shilimkarc1529502014-01-21 15:50:32 -0800186 memblock_free_early(__pa(mask), cpumask_size());
Rusty Russellcd83e422008-11-07 11:12:29 +1100187}
Rusty Russell2d3854a2008-11-05 13:39:10 +1100188#endif
Amir Vadaida913092014-06-09 10:24:38 +0300189
190/**
Rusty Russellf36963c2015-05-09 03:14:13 +0930191 * cpumask_local_spread - select the i'th cpu with local numa cpu's first
Amir Vadaida913092014-06-09 10:24:38 +0300192 * @i: index number
Rusty Russellf36963c2015-05-09 03:14:13 +0930193 * @node: local numa_node
Amir Vadaida913092014-06-09 10:24:38 +0300194 *
Rusty Russellf36963c2015-05-09 03:14:13 +0930195 * This function selects an online CPU according to a numa aware policy;
196 * local cpus are returned first, followed by non-local ones, then it
197 * wraps around.
Amir Vadaida913092014-06-09 10:24:38 +0300198 *
Rusty Russellf36963c2015-05-09 03:14:13 +0930199 * It's not very efficient, but useful for setup.
Amir Vadaida913092014-06-09 10:24:38 +0300200 */
Rusty Russellf36963c2015-05-09 03:14:13 +0930201unsigned int cpumask_local_spread(unsigned int i, int node)
Amir Vadaida913092014-06-09 10:24:38 +0300202{
Amir Vadaida913092014-06-09 10:24:38 +0300203 int cpu;
Amir Vadaida913092014-06-09 10:24:38 +0300204
Rusty Russellf36963c2015-05-09 03:14:13 +0930205 /* Wrap: we always want a cpu. */
Amir Vadaida913092014-06-09 10:24:38 +0300206 i %= num_online_cpus();
207
Rusty Russellf36963c2015-05-09 03:14:13 +0930208 if (node == -1) {
209 for_each_cpu(cpu, cpu_online_mask)
210 if (i-- == 0)
211 return cpu;
Amir Vadaida913092014-06-09 10:24:38 +0300212 } else {
Rusty Russellf36963c2015-05-09 03:14:13 +0930213 /* NUMA first. */
214 for_each_cpu_and(cpu, cpumask_of_node(node), cpu_online_mask)
215 if (i-- == 0)
216 return cpu;
Amir Vadaida913092014-06-09 10:24:38 +0300217
Rusty Russellf36963c2015-05-09 03:14:13 +0930218 for_each_cpu(cpu, cpu_online_mask) {
219 /* Skip NUMA nodes, done above. */
220 if (cpumask_test_cpu(cpu, cpumask_of_node(node)))
221 continue;
Amir Vadaida913092014-06-09 10:24:38 +0300222
Rusty Russellf36963c2015-05-09 03:14:13 +0930223 if (i-- == 0)
224 return cpu;
Amir Vadaida913092014-06-09 10:24:38 +0300225 }
226 }
Rusty Russellf36963c2015-05-09 03:14:13 +0930227 BUG();
Amir Vadaida913092014-06-09 10:24:38 +0300228}
Rusty Russellf36963c2015-05-09 03:14:13 +0930229EXPORT_SYMBOL(cpumask_local_spread);