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
__alloc_bucket_spinlocks(spinlock_t ** locks,unsigned int * locks_mask,size_t max_size,unsigned int cpu_mult,gfp_t gfp,const char * name,struct lock_class_key * key)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 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 }
48 EXPORT_SYMBOL(__alloc_bucket_spinlocks);
49
free_bucket_spinlocks(spinlock_t * locks)50 void free_bucket_spinlocks(spinlock_t *locks)
51 {
52 kvfree(locks);
53 }
54 EXPORT_SYMBOL(free_bucket_spinlocks);
55