1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/bitops.h> 3 #include <linux/export.h> 4 #include <linux/kernel.h> 5 #include <linux/random.h> 6 #include <linux/slab.h> 7 #include <linux/types.h> 8 9 #include "gpu_random.h" 10 11 u32 gpu_prandom_u32_max_state(u32 ep_ro, struct rnd_state *state) 12 { 13 return upper_32_bits((u64)prandom_u32_state(state) * ep_ro); 14 } 15 EXPORT_SYMBOL(gpu_prandom_u32_max_state); 16 17 void gpu_random_reorder(unsigned int *order, unsigned int count, 18 struct rnd_state *state) 19 { 20 unsigned int i, j; 21 22 for (i = 0; i < count; ++i) { 23 BUILD_BUG_ON(sizeof(unsigned int) > sizeof(u32)); 24 j = gpu_prandom_u32_max_state(count, state); 25 swap(order[i], order[j]); 26 } 27 } 28 EXPORT_SYMBOL(gpu_random_reorder); 29 30 unsigned int *gpu_random_order(unsigned int count, struct rnd_state *state) 31 { 32 unsigned int *order, i; 33 34 order = kmalloc_array(count, sizeof(*order), GFP_KERNEL); 35 if (!order) 36 return order; 37 38 for (i = 0; i < count; i++) 39 order[i] = i; 40 41 gpu_random_reorder(order, count, state); 42 return order; 43 } 44 EXPORT_SYMBOL(gpu_random_order); 45