diff options
author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
---|---|---|
committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
commit | 57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch) | |
tree | 5e910f0e82173f4ef4f51111366a3f1299037a7b /lib/cpumask.c |
Initial import
Diffstat (limited to 'lib/cpumask.c')
-rw-r--r-- | lib/cpumask.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/lib/cpumask.c b/lib/cpumask.c new file mode 100644 index 000000000..5a70f6196 --- /dev/null +++ b/lib/cpumask.c @@ -0,0 +1,179 @@ +#include <linux/slab.h> +#include <linux/kernel.h> +#include <linux/bitops.h> +#include <linux/cpumask.h> +#include <linux/export.h> +#include <linux/bootmem.h> + +/** + * cpumask_next_and - get the next cpu in *src1p & *src2p + * @n: the cpu prior to the place to search (ie. return will be > @n) + * @src1p: the first cpumask pointer + * @src2p: the second cpumask pointer + * + * Returns >= nr_cpu_ids if no further cpus set in both. + */ +int cpumask_next_and(int n, const struct cpumask *src1p, + const struct cpumask *src2p) +{ + while ((n = cpumask_next(n, src1p)) < nr_cpu_ids) + if (cpumask_test_cpu(n, src2p)) + break; + return n; +} +EXPORT_SYMBOL(cpumask_next_and); + +/** + * cpumask_any_but - return a "random" in a cpumask, but not this one. + * @mask: the cpumask to search + * @cpu: the cpu to ignore. + * + * Often used to find any cpu but smp_processor_id() in a mask. + * Returns >= nr_cpu_ids if no cpus set. + */ +int cpumask_any_but(const struct cpumask *mask, unsigned int cpu) +{ + unsigned int i; + + cpumask_check(cpu); + for_each_cpu(i, mask) + if (i != cpu) + break; + return i; +} + +/* These are not inline because of header tangles. */ +#ifdef CONFIG_CPUMASK_OFFSTACK +/** + * alloc_cpumask_var_node - allocate a struct cpumask on a given node + * @mask: pointer to cpumask_var_t where the cpumask is returned + * @flags: GFP_ flags + * + * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is + * a nop returning a constant 1 (in <linux/cpumask.h>) + * Returns TRUE if memory allocation succeeded, FALSE otherwise. + * + * In addition, mask will be NULL if this fails. Note that gcc is + * usually smart enough to know that mask can never be NULL if + * CONFIG_CPUMASK_OFFSTACK=n, so does code elimination in that case + * too. + */ +bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node) +{ + *mask = kmalloc_node(cpumask_size(), flags, node); + +#ifdef CONFIG_DEBUG_PER_CPU_MAPS + if (!*mask) { + printk(KERN_ERR "=> alloc_cpumask_var: failed!\n"); + dump_stack(); + } +#endif + + return *mask != NULL; +} +EXPORT_SYMBOL(alloc_cpumask_var_node); + +bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node) +{ + return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node); +} +EXPORT_SYMBOL(zalloc_cpumask_var_node); + +/** + * alloc_cpumask_var - allocate a struct cpumask + * @mask: pointer to cpumask_var_t where the cpumask is returned + * @flags: GFP_ flags + * + * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is + * a nop returning a constant 1 (in <linux/cpumask.h>). + * + * See alloc_cpumask_var_node. + */ +bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) +{ + return alloc_cpumask_var_node(mask, flags, NUMA_NO_NODE); +} +EXPORT_SYMBOL(alloc_cpumask_var); + +bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) +{ + return alloc_cpumask_var(mask, flags | __GFP_ZERO); +} +EXPORT_SYMBOL(zalloc_cpumask_var); + +/** + * alloc_bootmem_cpumask_var - allocate a struct cpumask from the bootmem arena. + * @mask: pointer to cpumask_var_t where the cpumask is returned + * + * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is + * a nop (in <linux/cpumask.h>). + * Either returns an allocated (zero-filled) cpumask, or causes the + * system to panic. + */ +void __init alloc_bootmem_cpumask_var(cpumask_var_t *mask) +{ + *mask = memblock_virt_alloc(cpumask_size(), 0); +} + +/** + * free_cpumask_var - frees memory allocated for a struct cpumask. + * @mask: cpumask to free + * + * This is safe on a NULL mask. + */ +void free_cpumask_var(cpumask_var_t mask) +{ + kfree(mask); +} +EXPORT_SYMBOL(free_cpumask_var); + +/** + * free_bootmem_cpumask_var - frees result of alloc_bootmem_cpumask_var + * @mask: cpumask to free + */ +void __init free_bootmem_cpumask_var(cpumask_var_t mask) +{ + memblock_free_early(__pa(mask), cpumask_size()); +} +#endif + +/** + * cpumask_local_spread - select the i'th cpu with local numa cpu's first + * @i: index number + * @node: local numa_node + * + * This function selects an online CPU according to a numa aware policy; + * local cpus are returned first, followed by non-local ones, then it + * wraps around. + * + * It's not very efficient, but useful for setup. + */ +unsigned int cpumask_local_spread(unsigned int i, int node) +{ + int cpu; + + /* Wrap: we always want a cpu. */ + i %= num_online_cpus(); + + if (node == -1) { + for_each_cpu(cpu, cpu_online_mask) + if (i-- == 0) + return cpu; + } else { + /* NUMA first. */ + for_each_cpu_and(cpu, cpumask_of_node(node), cpu_online_mask) + if (i-- == 0) + return cpu; + + for_each_cpu(cpu, cpu_online_mask) { + /* Skip NUMA nodes, done above. */ + if (cpumask_test_cpu(cpu, cpumask_of_node(node))) + continue; + + if (i-- == 0) + return cpu; + } + } + BUG(); +} +EXPORT_SYMBOL(cpumask_local_spread); |