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 14 int alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *locks_mask, 15 size_t max_size, unsigned int cpu_mult, gfp_t gfp) 16 { 17 spinlock_t *tlocks = NULL; 18 unsigned int i, size; 19 #if defined(CONFIG_PROVE_LOCKING) 20 unsigned int nr_pcpus = 2; 21 #else 22 unsigned int nr_pcpus = num_possible_cpus(); 23 #endif 24 25 if (cpu_mult) { 26 nr_pcpus = min_t(unsigned int, nr_pcpus, 64UL); 27 size = min_t(unsigned int, nr_pcpus * cpu_mult, max_size); 28 } else { 29 size = max_size; 30 } 31 32 if (sizeof(spinlock_t) != 0) { 33 tlocks = kvmalloc_array(size, sizeof(spinlock_t), gfp); 34 if (!tlocks) 35 return -ENOMEM; 36 for (i = 0; i < size; i++) 37 spin_lock_init(&tlocks[i]); 38 } 39 40 *locks = tlocks; 41 *locks_mask = size - 1; 42 43 return 0; 44 } 45 EXPORT_SYMBOL(alloc_bucket_spinlocks); 46 47 void free_bucket_spinlocks(spinlock_t *locks) 48 { 49 kvfree(locks); 50 } 51 EXPORT_SYMBOL(free_bucket_spinlocks); 52