// SPDX-License-Identifier: GPL-2.0
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#include <linux/bitops.h>
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#include <linux/kernel.h>
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#include <linux/random.h>
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#include <linux/slab.h>
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#include <linux/types.h>
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#include "drm_random.h"
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static inline u32 drm_prandom_u32_max_state(u32 ep_ro, struct rnd_state *state)
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{
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return upper_32_bits((u64)prandom_u32_state(state) * ep_ro);
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}
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void drm_random_reorder(unsigned int *order, unsigned int count,
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struct rnd_state *state)
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{
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unsigned int i, j;
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for (i = 0; i < count; ++i) {
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BUILD_BUG_ON(sizeof(unsigned int) > sizeof(u32));
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j = drm_prandom_u32_max_state(count, state);
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swap(order[i], order[j]);
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}
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}
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EXPORT_SYMBOL(drm_random_reorder);
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unsigned int *drm_random_order(unsigned int count, struct rnd_state *state)
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{
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unsigned int *order, i;
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order = kmalloc_array(count, sizeof(*order), GFP_KERNEL);
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if (!order)
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return order;
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for (i = 0; i < count; i++)
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order[i] = i;
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drm_random_reorder(order, count, state);
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return order;
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}
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EXPORT_SYMBOL(drm_random_order);
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