[PATCH v2 2/2] drm/amdgpu: unref the bo after job submit

[xinhui pan]

Otherwise we might free BOs before job has completed.
We add the fence to BO after commit, so free BOs after that.

Cc: Christian König <christian.koenig at amd.com>
Cc: Alex Deucher <alexander.deucher at amd.com>
Cc: Felix Kuehling <Felix.Kuehling at amd.com>
Signed-off-by: xinhui pan <xinhui.pan at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 38 +++++++++++++++++++-------
 1 file changed, 28 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 73398831196f..bd40a7923b67 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -942,13 +942,17 @@ static int amdgpu_vm_alloc_pts(struct amdgpu_device *adev,
  *
  * @entry: PDE to free
  */
-static void amdgpu_vm_free_table(struct amdgpu_vm_pt *entry)
+static void amdgpu_vm_free_table(struct amdgpu_vm_pt *entry,
+					struct list_head *head)
 {
 	if (entry->base.bo) {
 		entry->base.bo->vm_bo = NULL;
 		list_del(&entry->base.vm_status);
-		amdgpu_bo_unref(&entry->base.bo->shadow);
-		amdgpu_bo_unref(&entry->base.bo);
+		if (!head) {
+			amdgpu_bo_unref(&entry->base.bo->shadow);
+			amdgpu_bo_unref(&entry->base.bo);
+		} else
+			list_add(&entry->base.vm_status, head);
 	}
 	kvfree(entry->entries);
 	entry->entries = NULL;
@@ -965,7 +969,8 @@ static void amdgpu_vm_free_table(struct amdgpu_vm_pt *entry)
  */
 static void amdgpu_vm_free_pts(struct amdgpu_device *adev,
 			       struct amdgpu_vm *vm,
-			       struct amdgpu_vm_pt_cursor *start)
+			       struct amdgpu_vm_pt_cursor *start,
+				   struct list_head *head)
 {
 	struct amdgpu_vm_pt_cursor cursor;
 	struct amdgpu_vm_pt *entry;
@@ -973,10 +978,10 @@ static void amdgpu_vm_free_pts(struct amdgpu_device *adev,
 	vm->bulk_moveable = false;
 
 	for_each_amdgpu_vm_pt_dfs_safe(adev, vm, start, cursor, entry)
-		amdgpu_vm_free_table(entry);
+		amdgpu_vm_free_table(entry, head);
 
 	if (start)
-		amdgpu_vm_free_table(start->entry);
+		amdgpu_vm_free_table(start->entry, head);
 }
 
 /**
@@ -1428,7 +1433,8 @@ static void amdgpu_vm_fragment(struct amdgpu_vm_update_params *params,
  */
 static int amdgpu_vm_update_ptes(struct amdgpu_vm_update_params *params,
 				 uint64_t start, uint64_t end,
-				 uint64_t dst, uint64_t flags)
+				 uint64_t dst, uint64_t flags,
+				 struct list_head *head)
 {
 	struct amdgpu_device *adev = params->adev;
 	struct amdgpu_vm_pt_cursor cursor;
@@ -1539,7 +1545,7 @@ static int amdgpu_vm_update_ptes(struct amdgpu_vm_update_params *params,
 			 * completely covered by the range and so potentially still in use.
 			 */
 			while (cursor.pfn < frag_start) {
-				amdgpu_vm_free_pts(adev, params->vm, &cursor);
+				amdgpu_vm_free_pts(adev, params->vm, &cursor, head);
 				amdgpu_vm_pt_next(adev, &cursor);
 			}
 
@@ -1582,6 +1588,7 @@ static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
 	struct amdgpu_vm_update_params params;
 	enum amdgpu_sync_mode sync_mode;
 	int r;
+	struct list_head head;
 
 	memset(&params, 0, sizeof(params));
 	params.adev = adev;
@@ -1589,6 +1596,8 @@ static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
 	params.direct = direct;
 	params.pages_addr = pages_addr;
 
+	INIT_LIST_HEAD(&head);
+
 	/* Implicitly sync to command submissions in the same VM before
 	 * unmapping. Sync to moving fences before mapping.
 	 */
@@ -1617,13 +1626,22 @@ static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
 	if (r)
 		goto error_unlock;
 
-	r = amdgpu_vm_update_ptes(&params, start, last + 1, addr, flags);
+	r = amdgpu_vm_update_ptes(&params, start, last + 1, addr, flags, &head);
 	if (r)
 		goto error_unlock;
 
 	r = vm->update_funcs->commit(&params, fence);
 
 error_unlock:
+	while (!list_empty(&head)) {
+		struct amdgpu_vm_pt *entry = list_first_entry(&head,
+				struct amdgpu_vm_pt, base.vm_status);
+		list_del(&entry->base.vm_status);
+
+		amdgpu_bo_unref(&entry->base.bo->shadow);
+		amdgpu_bo_unref(&entry->base.bo);
+	}
+
 	amdgpu_vm_eviction_unlock(vm);
 	return r;
 }
@@ -3118,7 +3136,7 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
 		amdgpu_vm_free_mapping(adev, vm, mapping, NULL);
 	}
 
-	amdgpu_vm_free_pts(adev, vm, NULL);
+	amdgpu_vm_free_pts(adev, vm, NULL, NULL);
 	amdgpu_bo_unreserve(root);
 	amdgpu_bo_unref(&root);
 	WARN_ON(vm->root.base.bo);
-- 
2.17.1