[PATCH v2 12/20] drm/amdgpu: use TTM_NUM_MOVE_FENCES when reserving fences

Pierre-Eric Pelloux-Prayer
2025-11-13T16:10:44Z

Use TTM_NUM_MOVE_FENCES as an upperbound of how many fences
ttm might need to deal with moves/evictions.

---
v2: removed drm_err calls
---

Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 5 ++---
drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 2 +-
drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c | 6 ++----
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 3 ++-
drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 3 +--
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c | 6 ++----
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c | 6 ++----
7 files changed, 12 insertions(+), 19 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index ecdfe6cb36cc..0338522761bc 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -916,9 +916,8 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,
goto out_free_user_pages;

amdgpu_bo_list_for_each_entry(e, p->bo_list) {
- /* One fence for TTM and one for each CS job */
r = drm_exec_prepare_obj(&p->exec, &e->bo->tbo.base,
- 1 + p->gang_size);
+ TTM_NUM_MOVE_FENCES + p->gang_size);
drm_exec_retry_on_contention(&p->exec);
if (unlikely(r))
goto out_free_user_pages;
@@ -928,7 +927,7 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,

if (p->uf_bo) {
r = drm_exec_prepare_obj(&p->exec, &p->uf_bo->tbo.base,
- 1 + p->gang_size);
+ TTM_NUM_MOVE_FENCES + p->gang_size);
drm_exec_retry_on_contention(&p->exec);
if (unlikely(r))
goto out_free_user_pages;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
index ce073e894584..2fe6899f6344 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
@@ -353,7 +353,7 @@ static void amdgpu_gem_object_close(struct drm_gem_object *obj,

drm_exec_init(&exec, DRM_EXEC_IGNORE_DUPLICATES, 0);
drm_exec_until_all_locked(&exec) {
- r = drm_exec_prepare_obj(&exec, &bo->tbo.base, 1);
+ r = drm_exec_prepare_obj(&exec, &bo->tbo.base, TTM_NUM_MOVE_FENCES);
drm_exec_retry_on_contention(&exec);
if (unlikely(r))
goto out_unlock;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
index 79bad9cbe2ab..b92561eea3da 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
@@ -326,11 +326,9 @@ static int amdgpu_vkms_prepare_fb(struct drm_plane *plane,
return r;
}

- r = dma_resv_reserve_fences(rbo->tbo.base.resv, 1);
- if (r) {
- dev_err(adev->dev, "allocating fence slot failed (%d)\n", r);
+ r = dma_resv_reserve_fences(rbo->tbo.base.resv, TTM_NUM_MOVE_FENCES);
+ if (r)
goto error_unlock;
- }

if (plane->type != DRM_PLANE_TYPE_CURSOR)
domain = amdgpu_display_supported_domains(adev, rbo->flags);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 2f8e83f840a8..aaa44199e9f4 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -2630,7 +2630,8 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
}

amdgpu_vm_bo_base_init(&vm->root, vm, root_bo);
- r = dma_resv_reserve_fences(root_bo->tbo.base.resv, 1);
+ r = dma_resv_reserve_fences(root_bo->tbo.base.resv,
+ TTM_NUM_MOVE_FENCES);
if (r)
goto error_free_root;

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index ffb7b36e577c..968cef1cbea6 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -627,9 +627,8 @@ svm_range_vram_node_new(struct kfd_node *node, struct svm_range *prange,
}
}

- r = dma_resv_reserve_fences(bo->tbo.base.resv, 1);
+ r = dma_resv_reserve_fences(bo->tbo.base.resv, TTM_NUM_MOVE_FENCES);
if (r) {
- pr_debug("failed %d to reserve bo\n", r);
amdgpu_bo_unreserve(bo);
goto reserve_bo_failed;
}
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
index 56cb866ac6f8..ceb55dd183ed 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
@@ -952,11 +952,9 @@ static int amdgpu_dm_plane_helper_prepare_fb(struct drm_plane *plane,
return r;
}

- r = dma_resv_reserve_fences(rbo->tbo.base.resv, 1);
- if (r) {
- drm_err(adev_to_drm(adev), "reserving fence slot failed (%d)\n", r);
+ r = dma_resv_reserve_fences(rbo->tbo.base.resv, TTM_NUM_MOVE_FENCES);
+ if (r)
goto error_unlock;
- }

if (plane->type != DRM_PLANE_TYPE_CURSOR)
domain = amdgpu_display_supported_domains(adev, rbo->flags);
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c
index d9527c05fc87..110f0173eee6 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c
@@ -106,11 +106,9 @@ static int amdgpu_dm_wb_prepare_job(struct drm_writeback_connector *wb_connector
return r;
}

- r = dma_resv_reserve_fences(rbo->tbo.base.resv, 1);
- if (r) {
- drm_err(adev_to_drm(adev), "reserving fence slot failed (%d)\n", r);
+ r = dma_resv_reserve_fences(rbo->tbo.base.resv, TTM_NUM_MOVE_FENCES);
+ if (r)
goto error_unlock;
- }

domain = amdgpu_display_supported_domains(adev, rbo->flags);

--
2.43.0