tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 */
16int 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}
24EXPORT_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 */
34int 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}
44EXPORT_SYMBOL(cpumask_any_but);
45
46/* These are not inline because of header tangles. */
47#ifdef CONFIG_CPUMASK_OFFSTACK
48/**
49 * alloc_cpumask_var_node - allocate a struct cpumask on a given node
50 * @mask: pointer to cpumask_var_t where the cpumask is returned
51 * @flags: GFP_ flags
52 *
53 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
54 * a nop returning a constant 1 (in <linux/cpumask.h>)
55 * Returns TRUE if memory allocation succeeded, FALSE otherwise.
56 *
57 * In addition, mask will be NULL if this fails. Note that gcc is
58 * usually smart enough to know that mask can never be NULL if
59 * CONFIG_CPUMASK_OFFSTACK=n, so does code elimination in that case
60 * too.
61 */
62bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
63{
64 *mask = kmalloc_node(cpumask_size(), flags, node);
65
66#ifdef CONFIG_DEBUG_PER_CPU_MAPS
67 if (!*mask) {
68 printk(KERN_ERR "=> alloc_cpumask_var: failed!\n");
69 dump_stack();
70 }
71#endif
72
73 return *mask != NULL;
74}
75EXPORT_SYMBOL(alloc_cpumask_var_node);
76
77bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
78{
79 return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node);
80}
81EXPORT_SYMBOL(zalloc_cpumask_var_node);
82
83/**
84 * alloc_cpumask_var - allocate a struct cpumask
85 * @mask: pointer to cpumask_var_t where the cpumask is returned
86 * @flags: GFP_ flags
87 *
88 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
89 * a nop returning a constant 1 (in <linux/cpumask.h>).
90 *
91 * See alloc_cpumask_var_node.
92 */
93bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
94{
95 return alloc_cpumask_var_node(mask, flags, NUMA_NO_NODE);
96}
97EXPORT_SYMBOL(alloc_cpumask_var);
98
99bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
100{
101 return alloc_cpumask_var(mask, flags | __GFP_ZERO);
102}
103EXPORT_SYMBOL(zalloc_cpumask_var);
104
105/**
106 * alloc_bootmem_cpumask_var - allocate a struct cpumask from the bootmem arena.
107 * @mask: pointer to cpumask_var_t where the cpumask is returned
108 *
109 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
110 * a nop (in <linux/cpumask.h>).
111 * Either returns an allocated (zero-filled) cpumask, or causes the
112 * system to panic.
113 */
114void __init alloc_bootmem_cpumask_var(cpumask_var_t *mask)
115{
116 *mask = memblock_virt_alloc(cpumask_size(), 0);
117}
118
119/**
120 * free_cpumask_var - frees memory allocated for a struct cpumask.
121 * @mask: cpumask to free
122 *
123 * This is safe on a NULL mask.
124 */
125void free_cpumask_var(cpumask_var_t mask)
126{
127 kfree(mask);
128}
129EXPORT_SYMBOL(free_cpumask_var);
130
131/**
132 * free_bootmem_cpumask_var - frees result of alloc_bootmem_cpumask_var
133 * @mask: cpumask to free
134 */
135void __init free_bootmem_cpumask_var(cpumask_var_t mask)
136{
137 memblock_free_early(__pa(mask), cpumask_size());
138}
139#endif
140
141/**
142 * cpumask_local_spread - select the i'th cpu with local numa cpu's first
143 * @i: index number
144 * @node: local numa_node
145 *
146 * This function selects an online CPU according to a numa aware policy;
147 * local cpus are returned first, followed by non-local ones, then it
148 * wraps around.
149 *
150 * It's not very efficient, but useful for setup.
151 */
152unsigned int cpumask_local_spread(unsigned int i, int node)
153{
154 int cpu;
155
156 /* Wrap: we always want a cpu. */
157 i %= num_online_cpus();
158
159 if (node == -1) {
160 for_each_cpu(cpu, cpu_online_mask)
161 if (i-- == 0)
162 return cpu;
163 } else {
164 /* NUMA first. */
165 for_each_cpu_and(cpu, cpumask_of_node(node), cpu_online_mask)
166 if (i-- == 0)
167 return cpu;
168
169 for_each_cpu(cpu, cpu_online_mask) {
170 /* Skip NUMA nodes, done above. */
171 if (cpumask_test_cpu(cpu, cpumask_of_node(node)))
172 continue;
173
174 if (i-- == 0)
175 return cpu;
176 }
177 }
178 BUG();
179}
180EXPORT_SYMBOL(cpumask_local_spread);