55 lines · c
1#include <linux/export.h>2#include <linux/kernel.h>3#include <linux/mm.h>4#include <linux/slab.h>5#include <linux/vmalloc.h>6 7/* Allocate an array of spinlocks to be accessed by a hash. Two arguments8 * indicate the number of elements to allocate in the array. max_size9 * gives the maximum number of elements to allocate. cpu_mult gives10 * the number of locks per CPU to allocate. The size is rounded up11 * to a power of 2 to be suitable as a hash table.12 */13 14int __alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *locks_mask,15 size_t max_size, unsigned int cpu_mult, gfp_t gfp,16 const char *name, struct lock_class_key *key)17{18 spinlock_t *tlocks = NULL;19 unsigned int i, size;20#if defined(CONFIG_PROVE_LOCKING)21 unsigned int nr_pcpus = 2;22#else23 unsigned int nr_pcpus = num_possible_cpus();24#endif25 26 if (cpu_mult) {27 nr_pcpus = min_t(unsigned int, nr_pcpus, 64UL);28 size = min_t(unsigned int, nr_pcpus * cpu_mult, max_size);29 } else {30 size = max_size;31 }32 33 if (sizeof(spinlock_t) != 0) {34 tlocks = kvmalloc_array(size, sizeof(spinlock_t), gfp);35 if (!tlocks)36 return -ENOMEM;37 for (i = 0; i < size; i++) {38 spin_lock_init(&tlocks[i]);39 lockdep_init_map(&tlocks[i].dep_map, name, key, 0);40 }41 }42 43 *locks = tlocks;44 *locks_mask = size - 1;45 46 return 0;47}48EXPORT_SYMBOL(__alloc_bucket_spinlocks);49 50void free_bucket_spinlocks(spinlock_t *locks)51{52 kvfree(locks);53}54EXPORT_SYMBOL(free_bucket_spinlocks);55