drm/amdgpu: Set/clear CPU_ACCESS flag on page fault and move to VRAM

When a BO is moved to VRAM, clear AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED.
This allows it to potentially later move to invisible VRAM if the CPU
does not access it again.

Setting the CPU_ACCESS flag in amdgpu_bo_fault_reserve_notify() also means
that we can remove the loop to restrict lpfn to the end of visible VRAM,
because amdgpu_ttm_placement_init() will do it for us.

v3 [Michel Dänzer]
* Use AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED instead of a new flag
  (Christian König)
* Clear flag in amdgpu_bo_move instead of amdgpu_move_ram_vram
  (Christian)
* Explicitly mention amdgpu_bo_fault_reserve_notify in amdgpu_bo_move
* Also clear flag in amdgpu_bo_create_restricted

Suggested-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: John Brooks <john@fastquake.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index e429829..93601fb 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -432,6 +432,10 @@ int amdgpu_bo_create_restricted(struct amdgpu_device *adev,
 
        trace_amdgpu_bo_create(bo);
 
+       /* Treat CPU_ACCESS_REQUIRED only as a hint if given by UMD */
+       if (type == ttm_bo_type_device)
+               bo->flags &= ~AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED;
+
        return 0;
 
 fail_unreserve:
@@ -945,13 +949,17 @@ int amdgpu_bo_fault_reserve_notify(struct ttm_buffer_object *bo)
 {
        struct amdgpu_device *adev = amdgpu_ttm_adev(bo->bdev);
        struct amdgpu_bo *abo;
-       unsigned long offset, size, lpfn;
-       int i, r;
+       unsigned long offset, size;
+       int r;
 
        if (!amdgpu_ttm_bo_is_amdgpu_bo(bo))
                return 0;
 
        abo = container_of(bo, struct amdgpu_bo, tbo);
+
+       /* Remember that this BO was accessed by the CPU */
+       abo->flags |= AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED;
+
        if (bo->mem.mem_type != TTM_PL_VRAM)
                return 0;
 
@@ -967,14 +975,6 @@ int amdgpu_bo_fault_reserve_notify(struct ttm_buffer_object *bo)
        /* hurrah the memory is not visible ! */
        atomic64_inc(&adev->num_vram_cpu_page_faults);
        amdgpu_ttm_placement_from_domain(abo, AMDGPU_GEM_DOMAIN_VRAM);
-       lpfn =  adev->mc.visible_vram_size >> PAGE_SHIFT;
-       for (i = 0; i < abo->placement.num_placement; i++) {
-               /* Force into visible VRAM */
-               if ((abo->placements[i].flags & TTM_PL_FLAG_VRAM) &&
-                   (!abo->placements[i].lpfn ||
-                    abo->placements[i].lpfn > lpfn))
-                       abo->placements[i].lpfn = lpfn;
-       }
        r = ttm_bo_validate(bo, &abo->placement, false, false);
        if (unlikely(r == -ENOMEM)) {
                amdgpu_ttm_placement_from_domain(abo, AMDGPU_GEM_DOMAIN_GTT);

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index e238084..9bbaffb 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -499,6 +499,15 @@ memcpy:
                }
        }
 
+       if (bo->type == ttm_bo_type_device &&
+           new_mem->mem_type == TTM_PL_VRAM &&
+           old_mem->mem_type != TTM_PL_VRAM) {
+               /* amdgpu_bo_fault_reserve_notify will re-set this if the CPU
+                * accesses the BO after it's moved.
+                */
+               abo->flags &= ~AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED;
+       }
+
        /* update statistics */
        atomic64_add((u64)bo->num_pages << PAGE_SHIFT, &adev->num_bytes_moved);
        return 0;