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1// SPDX-License-Identifier: GPL-2.02#include <linux/bitops.h>3#include <linux/kernel.h>4#include <linux/random.h>5#include <linux/slab.h>6#include <linux/types.h>7 8#include "drm_random.h"9 10u32 drm_prandom_u32_max_state(u32 ep_ro, struct rnd_state *state)11{12 return upper_32_bits((u64)prandom_u32_state(state) * ep_ro);13}14EXPORT_SYMBOL(drm_prandom_u32_max_state);15 16void drm_random_reorder(unsigned int *order, unsigned int count,17 struct rnd_state *state)18{19 unsigned int i, j;20 21 for (i = 0; i < count; ++i) {22 BUILD_BUG_ON(sizeof(unsigned int) > sizeof(u32));23 j = drm_prandom_u32_max_state(count, state);24 swap(order[i], order[j]);25 }26}27EXPORT_SYMBOL(drm_random_reorder);28 29unsigned int *drm_random_order(unsigned int count, struct rnd_state *state)30{31 unsigned int *order, i;32 33 order = kmalloc_array(count, sizeof(*order), GFP_KERNEL);34 if (!order)35 return order;36 37 for (i = 0; i < count; i++)38 order[i] = i;39 40 drm_random_reorder(order, count, state);41 return order;42}43EXPORT_SYMBOL(drm_random_order);44