| #include <linux/bitops.h> |
| #include <linux/kernel.h> |
| #include <linux/random.h> |
| #include <linux/slab.h> |
| #include <linux/types.h> |
| |
| #include "drm_random.h" |
| |
| static inline u32 drm_prandom_u32_max_state(u32 ep_ro, struct rnd_state *state) |
| { |
| return upper_32_bits((u64)prandom_u32_state(state) * ep_ro); |
| } |
| |
| void drm_random_reorder(unsigned int *order, unsigned int count, |
| struct rnd_state *state) |
| { |
| unsigned int i, j; |
| |
| for (i = 0; i < count; ++i) { |
| BUILD_BUG_ON(sizeof(unsigned int) > sizeof(u32)); |
| j = drm_prandom_u32_max_state(count, state); |
| swap(order[i], order[j]); |
| } |
| } |
| EXPORT_SYMBOL(drm_random_reorder); |
| |
| unsigned int *drm_random_order(unsigned int count, struct rnd_state *state) |
| { |
| unsigned int *order, i; |
| |
| order = kmalloc_array(count, sizeof(*order), GFP_KERNEL); |
| if (!order) |
| return order; |
| |
| for (i = 0; i < count; i++) |
| order[i] = i; |
| |
| drm_random_reorder(order, count, state); |
| return order; |
| } |
| EXPORT_SYMBOL(drm_random_order); |