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)
42 if (cpumask_and(&tmp, src1p, src2p))
43 return cpumask_next(n, &tmp);
46 EXPORT_SYMBOL(cpumask_next_and);
49 * cpumask_any_but - return a "random" in a cpumask, but not this one.
50 * @mask: the cpumask to search
51 * @cpu: the cpu to ignore.
53 * Often used to find any cpu but smp_processor_id() in a mask.
54 * Returns >= nr_cpu_ids if no cpus set.
56 int cpumask_any_but(const struct cpumask *mask, unsigned int cpu)
67 /* These are not inline because of header tangles. */
68 #ifdef CONFIG_CPUMASK_OFFSTACK
70 * alloc_cpumask_var_node - allocate a struct cpumask on a given node
71 * @mask: pointer to cpumask_var_t where the cpumask is returned
74 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
75 * a nop returning a constant 1 (in <linux/cpumask.h>)
76 * Returns TRUE if memory allocation succeeded, FALSE otherwise.
78 * In addition, mask will be NULL if this fails. Note that gcc is
79 * usually smart enough to know that mask can never be NULL if
80 * CONFIG_CPUMASK_OFFSTACK=n, so does code elimination in that case
83 bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
85 *mask = kmalloc_node(cpumask_size(), flags, node);
87 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
89 printk(KERN_ERR "=> alloc_cpumask_var: failed!\n");
93 /* FIXME: Bandaid to save us from old primitives which go to NR_CPUS. */
95 unsigned char *ptr = (unsigned char *)cpumask_bits(*mask);
97 tail = BITS_TO_LONGS(NR_CPUS - nr_cpumask_bits) * sizeof(long);
98 memset(ptr + cpumask_size() - tail, 0, tail);
101 return *mask != NULL;
103 EXPORT_SYMBOL(alloc_cpumask_var_node);
105 bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
107 return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node);
109 EXPORT_SYMBOL(zalloc_cpumask_var_node);
112 * alloc_cpumask_var - allocate a struct cpumask
113 * @mask: pointer to cpumask_var_t where the cpumask is returned
116 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
117 * a nop returning a constant 1 (in <linux/cpumask.h>).
119 * See alloc_cpumask_var_node.
121 bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
123 return alloc_cpumask_var_node(mask, flags, NUMA_NO_NODE);
125 EXPORT_SYMBOL(alloc_cpumask_var);
127 bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
129 return alloc_cpumask_var(mask, flags | __GFP_ZERO);
131 EXPORT_SYMBOL(zalloc_cpumask_var);
134 * alloc_bootmem_cpumask_var - allocate a struct cpumask from the bootmem arena.
135 * @mask: pointer to cpumask_var_t where the cpumask is returned
137 * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
138 * a nop (in <linux/cpumask.h>).
139 * Either returns an allocated (zero-filled) cpumask, or causes the
142 void __init alloc_bootmem_cpumask_var(cpumask_var_t *mask)
144 *mask = memblock_virt_alloc(cpumask_size(), 0);
148 * free_cpumask_var - frees memory allocated for a struct cpumask.
149 * @mask: cpumask to free
151 * This is safe on a NULL mask.
153 void free_cpumask_var(cpumask_var_t mask)
157 EXPORT_SYMBOL(free_cpumask_var);
160 * free_bootmem_cpumask_var - frees result of alloc_bootmem_cpumask_var
161 * @mask: cpumask to free
163 void __init free_bootmem_cpumask_var(cpumask_var_t mask)
165 memblock_free_early(__pa(mask), cpumask_size());
170 * cpumask_set_cpu_local_first - set i'th cpu with local numa cpu's first
173 * @numa_node: local numa_node
174 * @dstp: cpumask with the relevant cpu bit set according to the policy
176 * This function sets the cpumask according to a numa aware policy.
177 * cpumask could be used as an affinity hint for the IRQ related to a
178 * queue. When the policy is to spread queues across cores - local cores
181 * Returns 0 on success, -ENOMEM for no memory, and -EAGAIN when failed to set
182 * the cpu bit and need to re-call the function.
184 int cpumask_set_cpu_local_first(int i, int numa_node, cpumask_t *dstp)
190 if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
193 i %= num_online_cpus();
195 if (numa_node == -1 || !cpumask_of_node(numa_node)) {
196 /* Use all online cpu's for non numa aware system */
197 cpumask_copy(mask, cpu_online_mask);
202 cpumask_of_node(numa_node), cpu_online_mask);
204 n = cpumask_weight(mask);
208 /* If index > number of local cpu's, mask out local
211 cpumask_andnot(mask, cpu_online_mask, mask);
215 for_each_cpu(cpu, mask) {
223 free_cpumask_var(mask);
226 cpumask_set_cpu(cpu, dstp);
230 EXPORT_SYMBOL(cpumask_set_cpu_local_first);