drm/radeon: fence virtual address and free it once idle v4

Virtual address need to be fenced to know when we can safely remove it.
This patch also properly clear the pagetable. Previously it was
serouisly broken.

Kernel 3.5/3.4 need a similar patch but adapted for difference in mutex locking.

v2: For to update pagetable when unbinding bo (don't bailout if
    bo_va->valid is true).
v3: Add kernel 3.5/3.4 comment.
v4: Fix compilation warnings.

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 22 insertions, 2 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_gart.c b/drivers/gpu/drm/radeon/radeon_gart.c
index b3720054614d..9912182682ec 100644
--- a/drivers/gpu/drm/radeon/radeon_gart.c
+++ b/drivers/gpu/drm/radeon/radeon_gart.c
@@ -814,7 +814,7 @@ int radeon_vm_bo_update_pte(struct radeon_device *rdev,
 		return -EINVAL;
 	}
 
-	if (bo_va->valid)
+	if (bo_va->valid && mem)
 		return 0;
 
 	ngpu_pages = radeon_bo_ngpu_pages(bo);
@@ -859,11 +859,27 @@ int radeon_vm_bo_rmv(struct radeon_device *rdev,
 		     struct radeon_bo *bo)
 {
 	struct radeon_bo_va *bo_va;
+	int r;
 
 	bo_va = radeon_bo_va(bo, vm);
 	if (bo_va == NULL)
 		return 0;
 
+	/* wait for va use to end */
+	while (bo_va->fence) {
+		r = radeon_fence_wait(bo_va->fence, false);
+		if (r) {
+			DRM_ERROR("error while waiting for fence: %d\n", r);
+		}
+		if (r == -EDEADLK) {
+			r = radeon_gpu_reset(rdev);
+			if (!r)
+				continue;
+		}
+		break;
+	}
+	radeon_fence_unref(&bo_va->fence);
+
 	mutex_lock(&rdev->vm_manager.lock);
 	mutex_lock(&vm->mutex);
 	radeon_vm_bo_update_pte(rdev, vm, bo, NULL);
@@ -952,12 +968,15 @@ void radeon_vm_fini(struct radeon_device *rdev, struct radeon_vm *vm)
 	radeon_vm_unbind_locked(rdev, vm);
 	mutex_unlock(&rdev->vm_manager.lock);
 
-	/* remove all bo */
+	/* remove all bo at this point non are busy any more because unbind
+	 * waited for the last vm fence to signal
+	 */
 	r = radeon_bo_reserve(rdev->ring_tmp_bo.bo, false);
 	if (!r) {
 		bo_va = radeon_bo_va(rdev->ring_tmp_bo.bo, vm);
 		list_del_init(&bo_va->bo_list);
 		list_del_init(&bo_va->vm_list);
+		radeon_fence_unref(&bo_va->fence);
 		radeon_bo_unreserve(rdev->ring_tmp_bo.bo);
 		kfree(bo_va);
 	}
@@ -969,6 +988,7 @@ void radeon_vm_fini(struct radeon_device *rdev, struct radeon_vm *vm)
 		r = radeon_bo_reserve(bo_va->bo, false);
 		if (!r) {
 			list_del_init(&bo_va->bo_list);
+			radeon_fence_unref(&bo_va->fence);
 			radeon_bo_unreserve(bo_va->bo);
 			kfree(bo_va);
 		}