[RFC 4/5] drm/amdgpu: Use preferred placement for VRAM+GTT

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin at igalia.com>

Now that TTM has the preferred placement flag, extend the current
workaround which assumes the GTT placement as fallback in the presence of
the additional VRAM placement.

By marking the VRAM placement as preferred we will make the buffer re-
validation phase actually attempt to migrate them back to VRAM.

Without it, TTM core logic is happy to leave them in GTT placement
"forever".

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at igalia.com>
Cc: Christian König <christian.koenig at amd.com>
Cc: Friedrich Vock <friedrich.vock at gmx.de>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index 50b7e7c0ce50..9be767357e86 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -128,8 +128,8 @@ void amdgpu_bo_placement_from_domain(struct amdgpu_bo *abo, u32 domain)
 	struct amdgpu_device *adev = amdgpu_ttm_adev(abo->tbo.bdev);
 	struct ttm_placement *placement = &abo->placement;
 	struct ttm_place *places = abo->placements;
+	int c = 0, vram_index = -1;
 	u64 flags = abo->flags;
-	u32 c = 0;
 
 	if (domain & AMDGPU_GEM_DOMAIN_VRAM) {
 		unsigned int visible_pfn = adev->gmc.visible_vram_size >> PAGE_SHIFT;
@@ -158,7 +158,7 @@ void amdgpu_bo_placement_from_domain(struct amdgpu_bo *abo, u32 domain)
 		    flags & AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS)
 			places[c].flags |= TTM_PL_FLAG_CONTIGUOUS;
 
-		c++;
+		vram_index = c++;
 	}
 
 	if (domain & AMDGPU_GEM_DOMAIN_DOORBELL) {
@@ -180,8 +180,10 @@ void amdgpu_bo_placement_from_domain(struct amdgpu_bo *abo, u32 domain)
 		 * When GTT is just an alternative to VRAM make sure that we
 		 * only use it as fallback and still try to fill up VRAM first.
 		 */
-		if (domain & abo->preferred_domains & AMDGPU_GEM_DOMAIN_VRAM)
+		if (vram_index >= 0) {
 			places[c].flags |= TTM_PL_FLAG_FALLBACK;
+			places[vram_index].flags |= TTM_PL_FLAG_PREFERRED;
+		}
 		c++;
 	}
 
-- 
2.44.0