Files
Joel Fernandes ba110db8e1 gpu: Move DRM buddy allocator one level up (part two)
Move the DRM buddy allocator one level up so that it can be used by GPU
drivers (example, nova-core) that have usecases other than DRM (such as
VFIO vGPU support). Modify the API, structures and Kconfigs to use
"gpu_buddy" terminology. Adapt the drivers and tests to use the new API.

The commit cannot be split due to bisectability, however no functional
change is intended. Verified by running K-UNIT tests and build tested
various configurations.

Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
[airlied: I've split this into two so git can find copies easier.
I've also just nuked drm_random library, that stuff needs to be done
elsewhere and only the buddy tests seem to be using it].
Signed-off-by: Dave Airlie <airlied@redhat.com>
2026-02-06 11:38:35 +10:00

45 lines
1.0 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/bitops.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/types.h>
#include "gpu_random.h"
u32 gpu_prandom_u32_max_state(u32 ep_ro, struct rnd_state *state)
{
return upper_32_bits((u64)prandom_u32_state(state) * ep_ro);
}
EXPORT_SYMBOL(gpu_prandom_u32_max_state);
void gpu_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 = gpu_prandom_u32_max_state(count, state);
swap(order[i], order[j]);
}
}
EXPORT_SYMBOL(gpu_random_reorder);
unsigned int *gpu_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;
gpu_random_reorder(order, count, state);
return order;
}
EXPORT_SYMBOL(gpu_random_order);