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>
8 int __first_cpu(const cpumask_t *srcp)
10 return min_t(int, NR_CPUS, find_first_bit(srcp->bits, NR_CPUS));
12 EXPORT_SYMBOL(__first_cpu);
14 int __next_cpu(int n, const cpumask_t *srcp)
16 return min_t(int, NR_CPUS, find_next_bit(srcp->bits, NR_CPUS, n+1));
18 EXPORT_SYMBOL(__next_cpu);
21 int __next_cpu_nr(int n, const cpumask_t *srcp)
23 return min_t(int, nr_cpu_ids,
24 find_next_bit(srcp->bits, nr_cpu_ids, n+1));
26 EXPORT_SYMBOL(__next_cpu_nr);
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
35 * Returns >= nr_cpu_ids if no further cpus set in both.
37 int cpumask_next_and(int n, const struct cpumask *src1p,
38 const struct cpumask *src2p)
40 while ((n = cpumask_next(n, src1p)) < nr_cpu_ids)
41 if (cpumask_test_cpu(n, src2p))
45 EXPORT_SYMBOL(cpumask_next_and);
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.
52 * Often used to find any cpu but smp_processor_id() in a mask.
53 * Returns >= nr_cpu_ids if no cpus set.
55 int cpumask_any_but(const struct cpumask *mask, unsigned int cpu)
66 /* These are not inline because of header tangles. */
67 #ifdef CONFIG_CPUMASK_OFFSTACK
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
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.
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
82 bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
84 *mask = kmalloc_node(cpumask_size(), flags, node);
86 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
88 printk(KERN_ERR "=> alloc_cpumask_var: failed!\n");
95 EXPORT_SYMBOL(alloc_cpumask_var_node);
97 bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
99 return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node);
101 EXPORT_SYMBOL(zalloc_cpumask_var_node);
104 * alloc_cpumask_var - allocate a struct cpumask
105 * @mask: pointer to cpumask_var_t where the cpumask is returned
108 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
109 * a nop returning a constant 1 (in <linux/cpumask.h>).
111 * See alloc_cpumask_var_node.
113 bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
115 return alloc_cpumask_var_node(mask, flags, NUMA_NO_NODE);
117 EXPORT_SYMBOL(alloc_cpumask_var);
119 bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
121 return alloc_cpumask_var(mask, flags | __GFP_ZERO);
123 EXPORT_SYMBOL(zalloc_cpumask_var);
126 * alloc_bootmem_cpumask_var - allocate a struct cpumask from the bootmem arena.
127 * @mask: pointer to cpumask_var_t where the cpumask is returned
129 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
130 * a nop (in <linux/cpumask.h>).
131 * Either returns an allocated (zero-filled) cpumask, or causes the
134 void __init alloc_bootmem_cpumask_var(cpumask_var_t *mask)
136 *mask = memblock_virt_alloc(cpumask_size(), 0);
140 * free_cpumask_var - frees memory allocated for a struct cpumask.
141 * @mask: cpumask to free
143 * This is safe on a NULL mask.
145 void free_cpumask_var(cpumask_var_t mask)
149 EXPORT_SYMBOL(free_cpumask_var);
152 * free_bootmem_cpumask_var - frees result of alloc_bootmem_cpumask_var
153 * @mask: cpumask to free
155 void __init free_bootmem_cpumask_var(cpumask_var_t mask)
157 memblock_free_early(__pa(mask), cpumask_size());
162 * cpumask_set_cpu_local_first - set i'th cpu with local numa cpu's first
165 * @numa_node: local numa_node
166 * @dstp: cpumask with the relevant cpu bit set according to the policy
168 * This function sets the cpumask according to a numa aware policy.
169 * cpumask could be used as an affinity hint for the IRQ related to a
170 * queue. When the policy is to spread queues across cores - local cores
173 * Returns 0 on success, -ENOMEM for no memory, and -EAGAIN when failed to set
174 * the cpu bit and need to re-call the function.
176 int cpumask_set_cpu_local_first(int i, int numa_node, cpumask_t *dstp)
182 if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
185 i %= num_online_cpus();
187 if (numa_node == -1 || !cpumask_of_node(numa_node)) {
188 /* Use all online cpu's for non numa aware system */
189 cpumask_copy(mask, cpu_online_mask);
194 cpumask_of_node(numa_node), cpu_online_mask);
196 n = cpumask_weight(mask);
200 /* If index > number of local cpu's, mask out local
203 cpumask_andnot(mask, cpu_online_mask, mask);
207 for_each_cpu(cpu, mask) {
215 free_cpumask_var(mask);
218 cpumask_set_cpu(cpu, dstp);
222 EXPORT_SYMBOL(cpumask_set_cpu_local_first);