43 lines
982 B
C
43 lines
982 B
C
|
// SPDX-License-Identifier: GPL-2.0
|
||
|
|
#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);
|