bucket_locks.c (1437B)
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 arguments 8 * indicate the number of elements to allocate in the array. max_size 9 * gives the maximum number of elements to allocate. cpu_mult gives 10 * the number of locks per CPU to allocate. The size is rounded up 11 * 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#else 23 unsigned int nr_pcpus = num_possible_cpus(); 24#endif 25 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);