[PATCH v2 13/20] drm/amdgpu: use multiple entities in amdgpu_move_blit

Pierre-Eric Pelloux-Prayer
2025-11-13T16:10:54Z

Thanks to "drm/ttm: rework pipelined eviction fence handling", ttm
can deal correctly with moves and evictions being executed from
different contexts.

Create several entities and use them in a round-robin fashion.

Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 13 ++++++++++---
drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h | 1 +
2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 486c701d0d5b..6c333dba7a35 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -401,6 +401,7 @@ static int amdgpu_move_blit(struct ttm_buffer_object *bo,
{
struct amdgpu_device *adev = amdgpu_ttm_adev(bo->bdev);
struct amdgpu_bo *abo = ttm_to_amdgpu_bo(bo);
+ struct amdgpu_ttm_buffer_entity *entity;
struct amdgpu_copy_mem src, dst;
struct dma_fence *fence = NULL;
int r;
@@ -412,8 +413,12 @@ static int amdgpu_move_blit(struct ttm_buffer_object *bo,
src.offset = 0;
dst.offset = 0;

+ int e = atomic_inc_return(&adev->mman.next_move_entity) %
+ adev->mman.num_move_entities;
+ entity = &adev->mman.move_entities[e];
+
r = amdgpu_ttm_copy_mem_to_mem(adev,
- &adev->mman.move_entities[0],
+ entity,
&src, &dst,
new_mem->size,
amdgpu_bo_encrypted(abo),
@@ -426,7 +431,7 @@ static int amdgpu_move_blit(struct ttm_buffer_object *bo,
(abo->flags & AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE)) {
struct dma_fence *wipe_fence = NULL;

- r = amdgpu_fill_buffer(&adev->mman.move_entities[0],
+ r = amdgpu_fill_buffer(entity,
abo, 0, NULL, &wipe_fence, fence,
AMDGPU_KERNEL_JOB_ID_MOVE_BLIT);
if (r) {
@@ -2179,7 +2184,8 @@ u32 amdgpu_ttm_set_buffer_funcs_status(struct amdgpu_device *adev, bool enable)
struct ttm_resource_manager *man = ttm_manager_type(&adev->mman.bdev, TTM_PL_VRAM);
uint64_t size;
int r, i, j;
- u32 num_clear_entities, num_move_entities, windows, w;
+ u32 num_clear_entities, num_move_entities;
+ u32 windows, w;

num_clear_entities = adev->sdma.num_instances;
num_move_entities = MIN(adev->sdma.num_instances, TTM_NUM_MOVE_FENCES);
@@ -2205,6 +2211,7 @@ u32 amdgpu_ttm_set_buffer_funcs_status(struct amdgpu_device *adev, bool enable)
}

adev->mman.num_move_entities = num_move_entities;
+ atomic_set(&adev->mman.next_move_entity, 0);
for (i = 0; i < num_move_entities; i++) {
r = drm_sched_entity_init(&adev->mman.move_entities[i].base,
DRM_SCHED_PRIORITY_NORMAL, &sched,
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
index 781b0bdca56c..4844f001f590 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
@@ -76,6 +76,7 @@ struct amdgpu_mman {
atomic_t next_clear_entity;
u32 num_clear_entities;
struct amdgpu_ttm_buffer_entity move_entities[TTM_NUM_MOVE_FENCES];
+ atomic_t next_move_entity;
u32 num_move_entities;

struct amdgpu_vram_mgr vram_mgr;
--
2.43.0