drm/amdgpu: fix VM sync with always valid BOs v2

All users of a VM must always wait for updates with always
valid BOs to be completed.

v2: remove debugging leftovers, rename struct member
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Roger He <Hongbo.He@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -761,10 +761,6 @@ static int amdgpu_bo_vm_update_pte(struct amdgpu_cs_parser *p)
 	if (r)
 		return r;
 
-	r = amdgpu_sync_fence(adev, &p->job->sync, vm->last_dir_update);
-	if (r)
-		return r;
-
 	r = amdgpu_vm_clear_freed(adev, vm, NULL);
 	if (r)
 		return r;
@@ -819,6 +815,12 @@ static int amdgpu_bo_vm_update_pte(struct amdgpu_cs_parser *p)
 	}
 
 	r = amdgpu_vm_handle_moved(adev, vm, &p->job->sync);
+	if (r)
+		return r;
+
+	r = amdgpu_sync_fence(adev, &p->job->sync, vm->last_update);
+	if (r)
+		return r;
 
 	if (amdgpu_vm_debug && p->bo_list) {
 		/* Invalidate all BOs to test for userspace bugs */

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

@@ -1141,9 +1141,8 @@ static int amdgpu_vm_update_level(struct amdgpu_device *adev,
 				goto error_free;
 
 			amdgpu_bo_fence(parent->base.bo, fence, true);
-			dma_fence_put(vm->last_dir_update);
-			vm->last_dir_update = dma_fence_get(fence);
-			dma_fence_put(fence);
+			dma_fence_put(vm->last_update);
+			vm->last_update = fence;
 		}
 	}
 
@@ -1804,6 +1803,12 @@ int amdgpu_vm_bo_update(struct amdgpu_device *adev,
 			trace_amdgpu_vm_bo_mapping(mapping);
 	}
 
+	if (bo_va->base.bo &&
+	    bo_va->base.bo->tbo.resv == vm->root.base.bo->tbo.resv) {
+		dma_fence_put(vm->last_update);
+		vm->last_update = dma_fence_get(bo_va->last_pt_update);
+	}
+
 	return 0;
 }
 
@@ -2587,7 +2592,7 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
 			 vm->use_cpu_for_update ? "CPU" : "SDMA");
 	WARN_ONCE((vm->use_cpu_for_update & !amdgpu_vm_is_large_bar(adev)),
 		  "CPU update of VM recommended only for large BAR system\n");
-	vm->last_dir_update = NULL;
+	vm->last_update = NULL;
 
 	flags = AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS |
 			AMDGPU_GEM_CREATE_VRAM_CLEARED;
@@ -2693,7 +2698,7 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
 	}
 
 	amdgpu_vm_free_levels(&vm->root);
-	dma_fence_put(vm->last_dir_update);
+	dma_fence_put(vm->last_update);
 	for (i = 0; i < AMDGPU_MAX_VMHUBS; i++)
 		amdgpu_vm_free_reserved_vmid(adev, vm, i);
 }

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

@@ -140,7 +140,7 @@ struct amdgpu_vm {
 
 	/* contains the page directory */
 	struct amdgpu_vm_pt     root;
-	struct dma_fence	*last_dir_update;
+	struct dma_fence	*last_update;
 
 	/* protecting freed */
 	spinlock_t		freed_lock;