drm/amdgpu: use separate status for buffer funcs availability v2

The ring status can change during GPU reset, but we still need to be
able to schedule TTM buffer moves in the meantime.

Otherwise we can ran into problems because of aborted move/fill
operations during GPU resets.

v2: still check if ring is available during direct submit.

Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Chunming zhou <david1.zhou@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c

@@ -213,9 +213,7 @@ static void amdgpu_evict_flags(struct ttm_buffer_object *bo,
 	abo = ttm_to_amdgpu_bo(bo);
 	switch (bo->mem.mem_type) {
 	case TTM_PL_VRAM:
-		if (adev->mman.buffer_funcs &&
-		    adev->mman.buffer_funcs_ring &&
-		    adev->mman.buffer_funcs_ring->ready == false) {
+		if (!adev->mman.buffer_funcs_enabled) {
 			amdgpu_ttm_placement_from_domain(abo, AMDGPU_GEM_DOMAIN_CPU);
 		} else if (adev->gmc.visible_vram_size < adev->gmc.real_vram_size &&
 			   !(abo->flags & AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED)) {
@@ -331,7 +329,7 @@ int amdgpu_ttm_copy_mem_to_mem(struct amdgpu_device *adev,
 	const uint64_t GTT_MAX_BYTES = (AMDGPU_GTT_MAX_TRANSFER_SIZE *
 					AMDGPU_GPU_PAGE_SIZE);
 
-	if (!ring->ready) {
+	if (!adev->mman.buffer_funcs_enabled) {
 		DRM_ERROR("Trying to move memory with ring turned off.\n");
 		return -EINVAL;
 	}
@@ -577,12 +575,9 @@ static int amdgpu_bo_move(struct ttm_buffer_object *bo, bool evict,
 		amdgpu_move_null(bo, new_mem);
 		return 0;
 	}
-	if (adev->mman.buffer_funcs == NULL ||
-	    adev->mman.buffer_funcs_ring == NULL ||
-	    !adev->mman.buffer_funcs_ring->ready) {
-		/* use memcpy */
+
+	if (!adev->mman.buffer_funcs_enabled)
 		goto memcpy;
-	}
 
 	if (old_mem->mem_type == TTM_PL_VRAM &&
 	    new_mem->mem_type == TTM_PL_SYSTEM) {
@@ -1549,6 +1544,7 @@ void amdgpu_ttm_set_buffer_funcs_status(struct amdgpu_device *adev, bool enable)
 	else
 		size = adev->gmc.visible_vram_size;
 	man->size = size >> PAGE_SHIFT;
+	adev->mman.buffer_funcs_enabled = enable;
 }
 
 int amdgpu_mmap(struct file *filp, struct vm_area_struct *vma)
@@ -1647,6 +1643,11 @@ int amdgpu_copy_buffer(struct amdgpu_ring *ring, uint64_t src_offset,
 	unsigned i;
 	int r;
 
+	if (direct_submit && !ring->ready) {
+		DRM_ERROR("Trying to move memory with ring turned off.\n");
+		return -EINVAL;
+	}
+
 	max_bytes = adev->mman.buffer_funcs->copy_max_bytes;
 	num_loops = DIV_ROUND_UP(byte_count, max_bytes);
 	num_dw = num_loops * adev->mman.buffer_funcs->copy_num_dw;
@@ -1720,7 +1721,7 @@ int amdgpu_fill_buffer(struct amdgpu_bo *bo,
 	struct amdgpu_job *job;
 	int r;
 
-	if (!ring->ready) {
+	if (!adev->mman.buffer_funcs_enabled) {
 		DRM_ERROR("Trying to clear memory with ring turned off.\n");
 		return -EINVAL;
 	}

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h

@@ -53,6 +53,7 @@ struct amdgpu_mman {
 	/* buffer handling */
 	const struct amdgpu_buffer_funcs	*buffer_funcs;
 	struct amdgpu_ring			*buffer_funcs_ring;
+	bool					buffer_funcs_enabled;
 
 	struct mutex				gtt_window_lock;
 	/* Scheduler entity for buffer moves */