tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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{
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}
45EXPORT_SYMBOL(alloc_bucket_spinlocks);
46
47void free_bucket_spinlocks(spinlock_t *locks)
48{
49 kvfree(locks);
50}
51EXPORT_SYMBOL(free_bucket_spinlocks);