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
);