Tom Herbert | 92f36cc | 2017-12-04 10:31:44 -0800 | [diff] [blame] | 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 | if (gfpflags_allow_blocking(gfp)) |
| 34 | tlocks = kvmalloc(size * sizeof(spinlock_t), gfp); |
| 35 | else |
| 36 | tlocks = kmalloc_array(size, sizeof(spinlock_t), gfp); |
| 37 | if (!tlocks) |
| 38 | return -ENOMEM; |
| 39 | for (i = 0; i < size; i++) |
| 40 | spin_lock_init(&tlocks[i]); |
| 41 | } |
| 42 | |
| 43 | *locks = tlocks; |
| 44 | *locks_mask = size - 1; |
| 45 | |
| 46 | return 0; |
| 47 | } |
| 48 | EXPORT_SYMBOL(alloc_bucket_spinlocks); |
| 49 | |
| 50 | void free_bucket_spinlocks(spinlock_t *locks) |
| 51 | { |
| 52 | kvfree(locks); |
| 53 | } |
| 54 | EXPORT_SYMBOL(free_bucket_spinlocks); |