#include <linux/slab.h> #include <linux/kernel.h> #include <linux/bitops.h> #include <linux/cpumask.h> #include <linux/export.h> #include <linux/bootmem.h> int __first_cpu(const cpumask_t *srcp) { return min_t(int, NR_CPUS, find_first_bit(srcp->bits, NR_CPUS)); } EXPORT_SYMBOL(__first_cpu); int __next_cpu(int n, const cpumask_t *srcp) { return min_t(int, NR_CPUS, find_next_bit(srcp->bits, NR_CPUS, n+1)); } EXPORT_SYMBOL(__next_cpu); #if NR_CPUS > 64 int __next_cpu_nr(int n, const cpumask_t *srcp) { return min_t(int, nr_cpu_ids, find_next_bit(srcp->bits, nr_cpu_ids, n+1)); } EXPORT_SYMBOL(__next_cpu_nr); #endif /** * 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) { struct cpumask tmp; if (cpumask_and(&tmp, src1p, src2p)) return cpumask_next(n, &tmp); return nr_cpu_ids; } 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 /* FIXME: Bandaid to save us from old primitives which go to NR_CPUS. */ if (*mask) { unsigned char *ptr = (unsigned char *)cpumask_bits(*mask); unsigned int tail; tail = BITS_TO_LONGS(NR_CPUS - nr_cpumask_bits) * sizeof(long); memset(ptr + cpumask_size() - tail, 0, tail); } 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_set_cpu_local_first - set i'th cpu with local numa cpu's first * * @i: index number * @numa_node: local numa_node * @dstp: cpumask with the relevant cpu bit set according to the policy * * This function sets the cpumask according to a numa aware policy. * cpumask could be used as an affinity hint for the IRQ related to a * queue. When the policy is to spread queues across cores - local cores * first. * * Returns 0 on success, -ENOMEM for no memory, and -EAGAIN when failed to set * the cpu bit and need to re-call the function. */ int cpumask_set_cpu_local_first(int i, int numa_node, cpumask_t *dstp) { cpumask_var_t mask; int cpu; int ret = 0; if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) return -ENOMEM; i %= num_online_cpus(); if (numa_node == -1 || !cpumask_of_node(numa_node)) { /* Use all online cpu's for non numa aware system */ cpumask_copy(mask, cpu_online_mask); } else { int n; cpumask_and(mask, cpumask_of_node(numa_node), cpu_online_mask); n = cpumask_weight(mask); if (i >= n) { i -= n; /* If index > number of local cpu's, mask out local * cpu's */ cpumask_andnot(mask, cpu_online_mask, mask); } } for_each_cpu(cpu, mask) { if (--i < 0) goto out; } ret = -EAGAIN; out: free_cpumask_var(mask); if (!ret) cpumask_set_cpu(cpu, dstp); return ret; } EXPORT_SYMBOL(cpumask_set_cpu_local_first);