| #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; |
| } |
| EXPORT_SYMBOL(cpumask_any_but); |
| |
| /** |
| * cpumask_next_wrap - helper to implement for_each_cpu_wrap |
| * @n: the cpu prior to the place to search |
| * @mask: the cpumask pointer |
| * @start: the start point of the iteration |
| * @wrap: assume @n crossing @start terminates the iteration |
| * |
| * Returns >= nr_cpu_ids on completion |
| * |
| * Note: the @wrap argument is required for the start condition when |
| * we cannot assume @start is set in @mask. |
| */ |
| int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap) |
| { |
| int next; |
| |
| again: |
| next = cpumask_next(n, mask); |
| |
| if (wrap && n < start && next >= start) { |
| return nr_cpumask_bits; |
| |
| } else if (next >= nr_cpumask_bits) { |
| wrap = true; |
| n = -1; |
| goto again; |
| } |
| |
| return next; |
| } |
| EXPORT_SYMBOL(cpumask_next_wrap); |
| |
| /* 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); |