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// 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);
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