1*4a9671a0SJoel Fernandes // SPDX-License-Identifier: GPL-2.0 2*4a9671a0SJoel Fernandes #include <linux/bitops.h> 3*4a9671a0SJoel Fernandes #include <linux/export.h> 4*4a9671a0SJoel Fernandes #include <linux/kernel.h> 5*4a9671a0SJoel Fernandes #include <linux/random.h> 6*4a9671a0SJoel Fernandes #include <linux/slab.h> 7*4a9671a0SJoel Fernandes #include <linux/types.h> 8*4a9671a0SJoel Fernandes 9*4a9671a0SJoel Fernandes #include "gpu_random.h" 10*4a9671a0SJoel Fernandes 11*4a9671a0SJoel Fernandes u32 drm_prandom_u32_max_state(u32 ep_ro, struct rnd_state *state) 12*4a9671a0SJoel Fernandes { 13*4a9671a0SJoel Fernandes return upper_32_bits((u64)prandom_u32_state(state) * ep_ro); 14*4a9671a0SJoel Fernandes } 15*4a9671a0SJoel Fernandes EXPORT_SYMBOL(drm_prandom_u32_max_state); 16*4a9671a0SJoel Fernandes 17*4a9671a0SJoel Fernandes void drm_random_reorder(unsigned int *order, unsigned int count, 18*4a9671a0SJoel Fernandes struct rnd_state *state) 19*4a9671a0SJoel Fernandes { 20*4a9671a0SJoel Fernandes unsigned int i, j; 21*4a9671a0SJoel Fernandes 22*4a9671a0SJoel Fernandes for (i = 0; i < count; ++i) { 23*4a9671a0SJoel Fernandes BUILD_BUG_ON(sizeof(unsigned int) > sizeof(u32)); 24*4a9671a0SJoel Fernandes j = drm_prandom_u32_max_state(count, state); 25*4a9671a0SJoel Fernandes swap(order[i], order[j]); 26*4a9671a0SJoel Fernandes } 27*4a9671a0SJoel Fernandes } 28*4a9671a0SJoel Fernandes EXPORT_SYMBOL(drm_random_reorder); 29*4a9671a0SJoel Fernandes 30*4a9671a0SJoel Fernandes unsigned int *drm_random_order(unsigned int count, struct rnd_state *state) 31*4a9671a0SJoel Fernandes { 32*4a9671a0SJoel Fernandes unsigned int *order, i; 33*4a9671a0SJoel Fernandes 34*4a9671a0SJoel Fernandes order = kmalloc_array(count, sizeof(*order), GFP_KERNEL); 35*4a9671a0SJoel Fernandes if (!order) 36*4a9671a0SJoel Fernandes return order; 37*4a9671a0SJoel Fernandes 38*4a9671a0SJoel Fernandes for (i = 0; i < count; i++) 39*4a9671a0SJoel Fernandes order[i] = i; 40*4a9671a0SJoel Fernandes 41*4a9671a0SJoel Fernandes drm_random_reorder(order, count, state); 42*4a9671a0SJoel Fernandes return order; 43*4a9671a0SJoel Fernandes } 44*4a9671a0SJoel Fernandes EXPORT_SYMBOL(drm_random_order); 45