drm/amdgpu: Enable clear page functionality

Add clear page support in vram memory region.

v1(Christian):
  - Dont handle clear page as TTM flag since when moving the BO back
    in from GTT again we don't need that.
  - Make a specialized version of amdgpu_fill_buffer() which only
    clears the VRAM areas which are not already cleared
  - Drop the TTM_PL_FLAG_WIPE_ON_RELEASE check in
    amdgpu_object.c

v2:
  - Modify the function name amdgpu_ttm_* (Alex)
  - Drop the delayed parameter (Christian)
  - handle amdgpu_res_cleared(&cursor) just above the size
    calculation (Christian)
  - Use AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE for clearing the buffers
    in the free path to properly wait for fences etc.. (Christian)

v3(Christian):
  - Remove buffer clear code in VRAM manager instead change the
    AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE handling to set
    the DRM_BUDDY_CLEARED flag.
  - Remove ! from amdgpu_res_cleared(&cursor) check.

v4(Christian):
  - vres flag setting move to vram manager file
  - use dma_fence_get_stub in amdgpu_ttm_clear_buffer function
  - make fence a mandatory parameter and drop the if and the get/put dance

Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Suggested-by: Christian König <christian.koenig@amd.com>
Acked-by: Felix Kuehling <felix.kuehling@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240419063538.11957-2-Arunpravin.PaneerSelvam@amd.com
Signed-off-by: Christian König <christian.koenig@amd.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
index c0c851409241..e494f5bf136a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -450,6 +450,7 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
 {
 	struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);
 	struct amdgpu_device *adev = to_amdgpu_device(mgr);
+	struct amdgpu_bo *bo = ttm_to_amdgpu_bo(tbo);
 	u64 vis_usage = 0, max_bytes, min_block_size;
 	struct amdgpu_vram_mgr_resource *vres;
 	u64 size, remaining_size, lpfn, fpfn;
@@ -501,6 +502,9 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
 	if (place->flags & TTM_PL_FLAG_CONTIGUOUS)
 		vres->flags |= DRM_BUDDY_CONTIGUOUS_ALLOCATION;
 
+	if (bo->flags & AMDGPU_GEM_CREATE_VRAM_CLEARED)
+		vres->flags |= DRM_BUDDY_CLEAR_ALLOCATION;
+
 	if (fpfn || lpfn != mgr->mm.size)
 		/* Allocate blocks in desired range */
 		vres->flags |= DRM_BUDDY_RANGE_ALLOCATION;
@@ -604,7 +608,7 @@ static void amdgpu_vram_mgr_del(struct ttm_resource_manager *man,
 
 	amdgpu_vram_mgr_do_reserve(man);
 
-	drm_buddy_free_list(mm, &vres->blocks, 0);
+	drm_buddy_free_list(mm, &vres->blocks, vres->flags);
 	mutex_unlock(&mgr->lock);
 
 	atomic64_sub(vis_usage, &mgr->vis_usage);