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2012-08-14 Initial commit
1 #include <linux/slab.h>
2 #include <linux/kernel.h>
3 #include <linux/bitops.h>
4 #include <linux/cpumask.h>
5 #include <linux/module.h>
6 #include <linux/bootmem.h>
7
8 int __first_cpu(const cpumask_t *srcp)
9 {
10 return min_t(int, NR_CPUS, find_first_bit(srcp->bits, NR_CPUS));
11 }
12 EXPORT_SYMBOL(__first_cpu);
13
14 int __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 }
18 EXPORT_SYMBOL(__next_cpu);
19
20 #if NR_CPUS > 64
21 int __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 }
26 EXPORT_SYMBOL(__next_cpu_nr);
27 #endif
28
29 int __any_online_cpu(const cpumask_t *mask)
30 {
31 int cpu;
32
33 for_each_cpu_mask(cpu, *mask) {
34 if (cpu_online(cpu))
35 break;
36 }
37 return cpu;
38 }
39 EXPORT_SYMBOL(__any_online_cpu);
40
41 /**
42 * cpumask_next_and - get the next cpu in *src1p & *src2p
43 * @n: the cpu prior to the place to search (ie. return will be > @n)
44 * @src1p: the first cpumask pointer
45 * @src2p: the second cpumask pointer
46 *
47 * Returns >= nr_cpu_ids if no further cpus set in both.
48 */
49 int cpumask_next_and(int n, const struct cpumask *src1p,
50 const struct cpumask *src2p)
51 {
52 while ((n = cpumask_next(n, src1p)) < nr_cpu_ids)
53 if (cpumask_test_cpu(n, src2p))
54 break;
55 return n;
56 }
57 EXPORT_SYMBOL(cpumask_next_and);
58
59 /**
60 * cpumask_any_but - return a "random" in a cpumask, but not this one.
61 * @mask: the cpumask to search
62 * @cpu: the cpu to ignore.
63 *
64 * Often used to find any cpu but smp_processor_id() in a mask.
65 * Returns >= nr_cpu_ids if no cpus set.
66 */
67 int cpumask_any_but(const struct cpumask *mask, unsigned int cpu)
68 {
69 unsigned int i;
70
71 cpumask_check(cpu);
72 for_each_cpu(i, mask)
73 if (i != cpu)
74 break;
75 return i;
76 }
77
78 /* These are not inline because of header tangles. */
79 #ifdef CONFIG_CPUMASK_OFFSTACK
80 /**
81 * alloc_cpumask_var_node - allocate a struct cpumask on a given node
82 * @mask: pointer to cpumask_var_t where the cpumask is returned
83 * @flags: GFP_ flags
84 *
85 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
86 * a nop returning a constant 1 (in <linux/cpumask.h>)
87 * Returns TRUE if memory allocation succeeded, FALSE otherwise.
88 *
89 * In addition, mask will be NULL if this fails. Note that gcc is
90 * usually smart enough to know that mask can never be NULL if
91 * CONFIG_CPUMASK_OFFSTACK=n, so does code elimination in that case
92 * too.
93 */
94 bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
95 {
96 *mask = kmalloc_node(cpumask_size(), flags, node);
97
98 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
99 if (!*mask) {
100 printk(KERN_ERR "=> alloc_cpumask_var: failed!\n");
101 dump_stack();
102 }
103 #endif
104 /* FIXME: Bandaid to save us from old primitives which go to NR_CPUS. */
105 if (*mask) {
106 unsigned char *ptr = (unsigned char *)cpumask_bits(*mask);
107 unsigned int tail;
108 tail = BITS_TO_LONGS(NR_CPUS - nr_cpumask_bits) * sizeof(long);
109 memset(ptr + cpumask_size() - tail, 0, tail);
110 }
111
112 return *mask != NULL;
113 }
114 EXPORT_SYMBOL(alloc_cpumask_var_node);
115
116 bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
117 {
118 return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node);
119 }
120 EXPORT_SYMBOL(zalloc_cpumask_var_node);
121
122 /**
123 * alloc_cpumask_var - allocate a struct cpumask
124 * @mask: pointer to cpumask_var_t where the cpumask is returned
125 * @flags: GFP_ flags
126 *
127 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
128 * a nop returning a constant 1 (in <linux/cpumask.h>).
129 *
130 * See alloc_cpumask_var_node.
131 */
132 bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
133 {
134 return alloc_cpumask_var_node(mask, flags, numa_node_id());
135 }
136 EXPORT_SYMBOL(alloc_cpumask_var);
137
138 bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
139 {
140 return alloc_cpumask_var(mask, flags | __GFP_ZERO);
141 }
142 EXPORT_SYMBOL(zalloc_cpumask_var);
143
144 /**
145 * alloc_bootmem_cpumask_var - allocate a struct cpumask from the bootmem arena.
146 * @mask: pointer to cpumask_var_t where the cpumask is returned
147 *
148 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
149 * a nop (in <linux/cpumask.h>).
150 * Either returns an allocated (zero-filled) cpumask, or causes the
151 * system to panic.
152 */
153 void __init alloc_bootmem_cpumask_var(cpumask_var_t *mask)
154 {
155 *mask = alloc_bootmem(cpumask_size());
156 }
157
158 /**
159 * free_cpumask_var - frees memory allocated for a struct cpumask.
160 * @mask: cpumask to free
161 *
162 * This is safe on a NULL mask.
163 */
164 void free_cpumask_var(cpumask_var_t mask)
165 {
166 kfree(mask);
167 }
168 EXPORT_SYMBOL(free_cpumask_var);
169
170 /**
171 * free_bootmem_cpumask_var - frees result of alloc_bootmem_cpumask_var
172 * @mask: cpumask to free
173 */
174 void __init free_bootmem_cpumask_var(cpumask_var_t mask)
175 {
176 free_bootmem((unsigned long)mask, cpumask_size());
177 }
178 #endif
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