blob: c101230658ebc9af1f7daf35252e293e0ce8d3f0 [file] [log] [blame]
Tejun Heo5a0e3ad2010-03-24 17:04:11 +09001#include <linux/slab.h>
Andrew Mortonccb46002006-03-25 03:08:08 -08002#include <linux/kernel.h>
3#include <linux/bitops.h>
4#include <linux/cpumask.h>
Paul Gortmaker8bc3bcc2011-11-16 21:29:17 -05005#include <linux/export.h>
Rusty Russell2d3854a2008-11-05 13:39:10 +11006#include <linux/bootmem.h>
Andrew Mortonccb46002006-03-25 03:08:08 -08007
8int __first_cpu(const cpumask_t *srcp)
9{
10 return min_t(int, NR_CPUS, find_first_bit(srcp->bits, NR_CPUS));
11}
12EXPORT_SYMBOL(__first_cpu);
13
Andrew Morton3d18bd72006-03-25 03:08:09 -080014int __next_cpu(int n, const cpumask_t *srcp)
15{
16 return min_t(int, NR_CPUS, find_next_bit(srcp->bits, NR_CPUS, n+1));
17}
18EXPORT_SYMBOL(__next_cpu);
Andrew Morton86302822006-03-25 03:08:09 -080019
Mike Travis41df0d612008-05-12 21:21:13 +020020#if NR_CPUS > 64
21int __next_cpu_nr(int n, const cpumask_t *srcp)
22{
23 return min_t(int, nr_cpu_ids,
24 find_next_bit(srcp->bits, nr_cpu_ids, n+1));
25}
26EXPORT_SYMBOL(__next_cpu_nr);
27#endif
28
Rusty Russell2d3854a2008-11-05 13:39:10 +110029/**
30 * cpumask_next_and - get the next cpu in *src1p & *src2p
31 * @n: the cpu prior to the place to search (ie. return will be > @n)
32 * @src1p: the first cpumask pointer
33 * @src2p: the second cpumask pointer
34 *
35 * Returns >= nr_cpu_ids if no further cpus set in both.
36 */
37int cpumask_next_and(int n, const struct cpumask *src1p,
38 const struct cpumask *src2p)
39{
40 while ((n = cpumask_next(n, src1p)) < nr_cpu_ids)
41 if (cpumask_test_cpu(n, src2p))
42 break;
43 return n;
44}
45EXPORT_SYMBOL(cpumask_next_and);
46
47/**
48 * cpumask_any_but - return a "random" in a cpumask, but not this one.
49 * @mask: the cpumask to search
50 * @cpu: the cpu to ignore.
51 *
52 * Often used to find any cpu but smp_processor_id() in a mask.
53 * Returns >= nr_cpu_ids if no cpus set.
54 */
55int cpumask_any_but(const struct cpumask *mask, unsigned int cpu)
56{
57 unsigned int i;
58
Rusty Russell984f2f32008-11-08 20:24:19 +110059 cpumask_check(cpu);
Rusty Russell2d3854a2008-11-05 13:39:10 +110060 for_each_cpu(i, mask)
61 if (i != cpu)
62 break;
63 return i;
64}
65
66/* These are not inline because of header tangles. */
67#ifdef CONFIG_CPUMASK_OFFSTACK
Mike Travisec26b802008-12-19 16:56:52 +103068/**
69 * alloc_cpumask_var_node - allocate a struct cpumask on a given node
70 * @mask: pointer to cpumask_var_t where the cpumask is returned
71 * @flags: GFP_ flags
72 *
73 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
74 * a nop returning a constant 1 (in <linux/cpumask.h>)
75 * Returns TRUE if memory allocation succeeded, FALSE otherwise.
76 *
77 * In addition, mask will be NULL if this fails. Note that gcc is
78 * usually smart enough to know that mask can never be NULL if
79 * CONFIG_CPUMASK_OFFSTACK=n, so does code elimination in that case
80 * too.
81 */
Mike Travis7b4967c2008-12-19 16:56:37 +103082bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
Rusty Russell2d3854a2008-11-05 13:39:10 +110083{
Yinghai Lu38c7fed2009-05-25 15:10:58 +030084 *mask = kmalloc_node(cpumask_size(), flags, node);
85
Rusty Russell2d3854a2008-11-05 13:39:10 +110086#ifdef CONFIG_DEBUG_PER_CPU_MAPS
87 if (!*mask) {
88 printk(KERN_ERR "=> alloc_cpumask_var: failed!\n");
89 dump_stack();
90 }
91#endif
Rusty Russell2a530082009-01-01 10:12:30 +103092 /* FIXME: Bandaid to save us from old primitives which go to NR_CPUS. */
93 if (*mask) {
Jack Steiner4f032ac2009-04-02 16:59:48 -070094 unsigned char *ptr = (unsigned char *)cpumask_bits(*mask);
Rusty Russell2a530082009-01-01 10:12:30 +103095 unsigned int tail;
96 tail = BITS_TO_LONGS(NR_CPUS - nr_cpumask_bits) * sizeof(long);
Jack Steiner4f032ac2009-04-02 16:59:48 -070097 memset(ptr + cpumask_size() - tail, 0, tail);
Rusty Russell2a530082009-01-01 10:12:30 +103098 }
99
Rusty Russell2d3854a2008-11-05 13:39:10 +1100100 return *mask != NULL;
101}
Mike Travis7b4967c2008-12-19 16:56:37 +1030102EXPORT_SYMBOL(alloc_cpumask_var_node);
103
Yinghai Lu0281b5d2009-06-06 14:50:36 -0700104bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
105{
106 return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node);
107}
108EXPORT_SYMBOL(zalloc_cpumask_var_node);
109
Mike Travisec26b802008-12-19 16:56:52 +1030110/**
111 * alloc_cpumask_var - allocate a struct cpumask
112 * @mask: pointer to cpumask_var_t where the cpumask is returned
113 * @flags: GFP_ flags
114 *
115 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
116 * a nop returning a constant 1 (in <linux/cpumask.h>).
117 *
118 * See alloc_cpumask_var_node.
119 */
Mike Travis7b4967c2008-12-19 16:56:37 +1030120bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
121{
KOSAKI Motohiro37e7b5f2011-07-26 16:08:44 -0700122 return alloc_cpumask_var_node(mask, flags, NUMA_NO_NODE);
Mike Travis7b4967c2008-12-19 16:56:37 +1030123}
Rusty Russell2d3854a2008-11-05 13:39:10 +1100124EXPORT_SYMBOL(alloc_cpumask_var);
125
Yinghai Lu0281b5d2009-06-06 14:50:36 -0700126bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
127{
128 return alloc_cpumask_var(mask, flags | __GFP_ZERO);
129}
130EXPORT_SYMBOL(zalloc_cpumask_var);
131
Mike Travisec26b802008-12-19 16:56:52 +1030132/**
133 * alloc_bootmem_cpumask_var - allocate a struct cpumask from the bootmem arena.
134 * @mask: pointer to cpumask_var_t where the cpumask is returned
135 *
136 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
Li Zefane9690a62008-12-31 16:45:50 +0800137 * a nop (in <linux/cpumask.h>).
Mike Travisec26b802008-12-19 16:56:52 +1030138 * Either returns an allocated (zero-filled) cpumask, or causes the
139 * system to panic.
140 */
Rusty Russell2d3854a2008-11-05 13:39:10 +1100141void __init alloc_bootmem_cpumask_var(cpumask_var_t *mask)
142{
Santosh Shilimkarc1529502014-01-21 15:50:32 -0800143 *mask = memblock_virt_alloc(cpumask_size(), 0);
Rusty Russell2d3854a2008-11-05 13:39:10 +1100144}
145
Mike Travisec26b802008-12-19 16:56:52 +1030146/**
147 * free_cpumask_var - frees memory allocated for a struct cpumask.
148 * @mask: cpumask to free
149 *
150 * This is safe on a NULL mask.
151 */
Rusty Russell2d3854a2008-11-05 13:39:10 +1100152void free_cpumask_var(cpumask_var_t mask)
153{
154 kfree(mask);
155}
156EXPORT_SYMBOL(free_cpumask_var);
Rusty Russellcd83e422008-11-07 11:12:29 +1100157
Mike Travisec26b802008-12-19 16:56:52 +1030158/**
159 * free_bootmem_cpumask_var - frees result of alloc_bootmem_cpumask_var
160 * @mask: cpumask to free
161 */
Rusty Russell984f2f32008-11-08 20:24:19 +1100162void __init free_bootmem_cpumask_var(cpumask_var_t mask)
Rusty Russellcd83e422008-11-07 11:12:29 +1100163{
Santosh Shilimkarc1529502014-01-21 15:50:32 -0800164 memblock_free_early(__pa(mask), cpumask_size());
Rusty Russellcd83e422008-11-07 11:12:29 +1100165}
Rusty Russell2d3854a2008-11-05 13:39:10 +1100166#endif
Amir Vadaida913092014-06-09 10:24:38 +0300167
168/**
169 * cpumask_set_cpu_local_first - set i'th cpu with local numa cpu's first
170 *
171 * @i: index number
172 * @numa_node: local numa_node
173 * @dstp: cpumask with the relevant cpu bit set according to the policy
174 *
175 * This function sets the cpumask according to a numa aware policy.
176 * cpumask could be used as an affinity hint for the IRQ related to a
177 * queue. When the policy is to spread queues across cores - local cores
178 * first.
179 *
180 * Returns 0 on success, -ENOMEM for no memory, and -EAGAIN when failed to set
181 * the cpu bit and need to re-call the function.
182 */
183int cpumask_set_cpu_local_first(int i, int numa_node, cpumask_t *dstp)
184{
185 cpumask_var_t mask;
186 int cpu;
187 int ret = 0;
188
189 if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
190 return -ENOMEM;
191
192 i %= num_online_cpus();
193
194 if (!cpumask_of_node(numa_node)) {
195 /* Use all online cpu's for non numa aware system */
196 cpumask_copy(mask, cpu_online_mask);
197 } else {
198 int n;
199
200 cpumask_and(mask,
201 cpumask_of_node(numa_node), cpu_online_mask);
202
203 n = cpumask_weight(mask);
204 if (i >= n) {
205 i -= n;
206
207 /* If index > number of local cpu's, mask out local
208 * cpu's
209 */
210 cpumask_andnot(mask, cpu_online_mask, mask);
211 }
212 }
213
214 for_each_cpu(cpu, mask) {
215 if (--i < 0)
216 goto out;
217 }
218
219 ret = -EAGAIN;
220
221out:
222 free_cpumask_var(mask);
223
224 if (!ret)
225 cpumask_set_cpu(cpu, dstp);
226
227 return ret;
228}
229EXPORT_SYMBOL(cpumask_set_cpu_local_first);