1 files changed, 48 insertions, 21 deletions

diff --git a/drivers/gpu/drm/drm_gpuvm.c b/drivers/gpu/drm/drm_gpuvm.c
index 8a06d296561d..0de47e83d84d 100644
--- a/drivers/gpu/drm/drm_gpuvm.c
+++ b/drivers/gpu/drm/drm_gpuvm.c
@@ -1602,14 +1602,48 @@ drm_gpuvm_bo_create(struct drm_gpuvm *gpuvm,
 }
 EXPORT_SYMBOL_GPL(drm_gpuvm_bo_create);
 
+/*
+ * drm_gpuvm_bo_destroy_not_in_lists() - final part of drm_gpuvm_bo cleanup
+ * @vm_bo: the &drm_gpuvm_bo to destroy
+ *
+ * It is illegal to call this method if the @vm_bo is present in the GEMs gpuva
+ * list, the extobj list, or the evicted list.
+ *
+ * Note that this puts a refcount on the GEM object, which may destroy the GEM
+ * object if the refcount reaches zero. It's illegal for this to happen if the
+ * caller holds the GEMs gpuva mutex because it would free the mutex.
+ */
+static void
+drm_gpuvm_bo_destroy_not_in_lists(struct drm_gpuvm_bo *vm_bo)
+{
+	struct drm_gpuvm *gpuvm = vm_bo->vm;
+	const struct drm_gpuvm_ops *ops = gpuvm->ops;
+	struct drm_gem_object *obj = vm_bo->obj;
+
+	if (ops && ops->vm_bo_free)
+		ops->vm_bo_free(vm_bo);
+	else
+		kfree(vm_bo);
+
+	drm_gpuvm_put(gpuvm);
+	drm_gem_object_put(obj);
+}
+
+static void
+drm_gpuvm_bo_destroy_not_in_lists_kref(struct kref *kref)
+{
+	struct drm_gpuvm_bo *vm_bo = container_of(kref, struct drm_gpuvm_bo,
+						  kref);
+
+	drm_gpuvm_bo_destroy_not_in_lists(vm_bo);
+}
+
 static void
 drm_gpuvm_bo_destroy(struct kref *kref)
 {
 	struct drm_gpuvm_bo *vm_bo = container_of(kref, struct drm_gpuvm_bo,
 						  kref);
 	struct drm_gpuvm *gpuvm = vm_bo->vm;
-	const struct drm_gpuvm_ops *ops = gpuvm->ops;
-	struct drm_gem_object *obj = vm_bo->obj;
 	bool lock = !drm_gpuvm_resv_protected(gpuvm);
 
 	if (!lock)
@@ -1618,16 +1652,10 @@ drm_gpuvm_bo_destroy(struct kref *kref)
 	drm_gpuvm_bo_list_del(vm_bo, extobj, lock);
 	drm_gpuvm_bo_list_del(vm_bo, evict, lock);
 
-	drm_gem_gpuva_assert_lock_held(gpuvm, obj);
+	drm_gem_gpuva_assert_lock_held(gpuvm, vm_bo->obj);
 	list_del(&vm_bo->list.entry.gem);
 
-	if (ops && ops->vm_bo_free)
-		ops->vm_bo_free(vm_bo);
-	else
-		kfree(vm_bo);
-
-	drm_gpuvm_put(gpuvm);
-	drm_gem_object_put(obj);
+	drm_gpuvm_bo_destroy_not_in_lists(vm_bo);
 }
 
 /**
@@ -1745,9 +1773,7 @@ EXPORT_SYMBOL_GPL(drm_gpuvm_bo_put_deferred);
 void
 drm_gpuvm_bo_deferred_cleanup(struct drm_gpuvm *gpuvm)
 {
-	const struct drm_gpuvm_ops *ops = gpuvm->ops;
 	struct drm_gpuvm_bo *vm_bo;
-	struct drm_gem_object *obj;
 	struct llist_node *bo_defer;
 
 	bo_defer = llist_del_all(&gpuvm->bo_defer);
@@ -1766,14 +1792,7 @@ drm_gpuvm_bo_deferred_cleanup(struct drm_gpuvm *gpuvm)
 	while (bo_defer) {
 		vm_bo = llist_entry(bo_defer, struct drm_gpuvm_bo, list.entry.bo_defer);
 		bo_defer = bo_defer->next;
-		obj = vm_bo->obj;
-		if (ops && ops->vm_bo_free)
-			ops->vm_bo_free(vm_bo);
-		else
-			kfree(vm_bo);
-
-		drm_gpuvm_put(gpuvm);
-		drm_gem_object_put(obj);
+		drm_gpuvm_bo_destroy_not_in_lists(vm_bo);
 	}
 }
 EXPORT_SYMBOL_GPL(drm_gpuvm_bo_deferred_cleanup);
@@ -1861,6 +1880,9 @@ EXPORT_SYMBOL_GPL(drm_gpuvm_bo_obtain);
  * count is decreased. If not found @__vm_bo is returned without further
  * increase of the reference count.
  *
+ * The provided @__vm_bo must not already be in the gpuva, evict, or extobj
+ * lists prior to calling this method.
+ *
  * A new &drm_gpuvm_bo is added to the GEMs gpuva list.
  *
  * Returns: a pointer to the found &drm_gpuvm_bo or @__vm_bo if no existing
@@ -1873,14 +1895,19 @@ drm_gpuvm_bo_obtain_prealloc(struct drm_gpuvm_bo *__vm_bo)
 	struct drm_gem_object *obj = __vm_bo->obj;
 	struct drm_gpuvm_bo *vm_bo;
 
+	drm_WARN_ON(gpuvm->drm, !drm_gpuvm_immediate_mode(gpuvm));
+
+	mutex_lock(&obj->gpuva.lock);
 	vm_bo = drm_gpuvm_bo_find(gpuvm, obj);
 	if (vm_bo) {
-		drm_gpuvm_bo_put(__vm_bo);
+		mutex_unlock(&obj->gpuva.lock);
+		kref_put(&__vm_bo->kref, drm_gpuvm_bo_destroy_not_in_lists_kref);
 		return vm_bo;
 	}
 
 	drm_gem_gpuva_assert_lock_held(gpuvm, obj);
 	list_add_tail(&__vm_bo->list.entry.gem, &obj->gpuva.list);
+	mutex_unlock(&obj->gpuva.lock);
 
 	return __vm_bo;
 }