net/mlx5: Add async garbage collector for DEK bulk

After invalidation, the idle bulk with all DEKs available for use, is
destroyed, to free keys and mem.

To get better performance, the firmware destruction operation is done
asynchronously. So idle bulks are enqueued in destroy_list first, then
destroyed in system workqueue. This will improve performance, as the
destruction doesn't need to hold pool's mutex.
Signed-off-by: Jianbo Liu <jianbol@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/lib/crypto.c

@@ -46,6 +46,10 @@ struct mlx5_crypto_dek_pool {
 	bool syncing;
 	struct list_head wait_for_free;
 	struct work_struct sync_work;
+
+	spinlock_t destroy_lock; /* protect destroy_list */
+	struct list_head destroy_list;
+	struct work_struct destroy_work;
 };
 
 struct mlx5_crypto_dek_bulk {
@@ -351,13 +355,15 @@ static void mlx5_crypto_dek_bulk_free(struct mlx5_crypto_dek_bulk *bulk)
 }
 
 static void mlx5_crypto_dek_pool_remove_bulk(struct mlx5_crypto_dek_pool *pool,
-					     struct mlx5_crypto_dek_bulk *bulk)
+					     struct mlx5_crypto_dek_bulk *bulk,
+					     bool delay)
 {
 	pool->num_deks -= bulk->num_deks;
 	pool->avail_deks -= bulk->avail_deks;
 	pool->in_use_deks -= bulk->in_use_deks;
 	list_del(&bulk->entry);
-	mlx5_crypto_dek_bulk_free(bulk);
+	if (!delay)
+		mlx5_crypto_dek_bulk_free(bulk);
 }
 
 static struct mlx5_crypto_dek_bulk *
@@ -500,6 +506,23 @@ static void mlx5_crypto_dek_bulk_reset_synced(struct mlx5_crypto_dek_pool *pool,
 	}
 }
 
+static void mlx5_crypto_dek_bulk_handle_avail(struct mlx5_crypto_dek_pool *pool,
+					      struct mlx5_crypto_dek_bulk *bulk,
+					      struct list_head *destroy_list)
+{
+	mlx5_crypto_dek_pool_remove_bulk(pool, bulk, true);
+	list_add(&bulk->entry, destroy_list);
+}
+
+static void mlx5_crypto_dek_pool_splice_destroy_list(struct mlx5_crypto_dek_pool *pool,
+						     struct list_head *list,
+						     struct list_head *head)
+{
+	spin_lock(&pool->destroy_lock);
+	list_splice_init(list, head);
+	spin_unlock(&pool->destroy_lock);
+}
+
 static void mlx5_crypto_dek_pool_free_wait_keys(struct mlx5_crypto_dek_pool *pool)
 {
 	struct mlx5_crypto_dek *dek, *next;
@@ -512,16 +535,18 @@ static void mlx5_crypto_dek_pool_free_wait_keys(struct mlx5_crypto_dek_pool *poo
 
 /* For all the bulks in each list, reset the bits while sync.
  * Move them to different lists according to the number of available DEKs.
+ * Destrory all the idle bulks for now.
  * And free DEKs in the waiting list at the end of this func.
  */
 static void mlx5_crypto_dek_pool_reset_synced(struct mlx5_crypto_dek_pool *pool)
 {
 	struct mlx5_crypto_dek_bulk *bulk, *tmp;
+	LIST_HEAD(destroy_list);
 
 	list_for_each_entry_safe(bulk, tmp, &pool->partial_list, entry) {
 		mlx5_crypto_dek_bulk_reset_synced(pool, bulk);
 		if (MLX5_CRYPTO_DEK_BULK_IDLE(bulk))
-			list_move(&bulk->entry, &pool->avail_list);
+			mlx5_crypto_dek_bulk_handle_avail(pool, bulk, &destroy_list);
 	}
 
 	list_for_each_entry_safe(bulk, tmp, &pool->full_list, entry) {
@@ -531,7 +556,7 @@ static void mlx5_crypto_dek_pool_reset_synced(struct mlx5_crypto_dek_pool *pool)
 			continue;
 
 		if (MLX5_CRYPTO_DEK_BULK_IDLE(bulk))
-			list_move(&bulk->entry, &pool->avail_list);
+			mlx5_crypto_dek_bulk_handle_avail(pool, bulk, &destroy_list);
 		else
 			list_move(&bulk->entry, &pool->partial_list);
 	}
@@ -541,10 +566,16 @@ static void mlx5_crypto_dek_pool_reset_synced(struct mlx5_crypto_dek_pool *pool)
 		bulk->avail_start = 0;
 		bulk->avail_deks = bulk->num_deks;
 		pool->avail_deks += bulk->num_deks;
+		mlx5_crypto_dek_bulk_handle_avail(pool, bulk, &destroy_list);
 	}
-	list_splice_init(&pool->sync_list, &pool->avail_list);
 
 	mlx5_crypto_dek_pool_free_wait_keys(pool);
+
+	if (!list_empty(&destroy_list)) {
+		mlx5_crypto_dek_pool_splice_destroy_list(pool, &destroy_list,
+							 &pool->destroy_list);
+		schedule_work(&pool->destroy_work);
+	}
 }
 
 static void mlx5_crypto_dek_sync_work_fn(struct work_struct *work)
@@ -620,6 +651,25 @@ void mlx5_crypto_dek_destroy(struct mlx5_crypto_dek_pool *dek_pool,
 	}
 }
 
+static void mlx5_crypto_dek_free_destroy_list(struct list_head *destroy_list)
+{
+	struct mlx5_crypto_dek_bulk *bulk, *tmp;
+
+	list_for_each_entry_safe(bulk, tmp, destroy_list, entry)
+		mlx5_crypto_dek_bulk_free(bulk);
+}
+
+static void mlx5_crypto_dek_destroy_work_fn(struct work_struct *work)
+{
+	struct mlx5_crypto_dek_pool *pool =
+		container_of(work, struct mlx5_crypto_dek_pool, destroy_work);
+	LIST_HEAD(destroy_list);
+
+	mlx5_crypto_dek_pool_splice_destroy_list(pool, &pool->destroy_list,
+						 &destroy_list);
+	mlx5_crypto_dek_free_destroy_list(&destroy_list);
+}
+
 struct mlx5_crypto_dek_pool *
 mlx5_crypto_dek_pool_create(struct mlx5_core_dev *mdev, int key_purpose)
 {
@@ -639,6 +689,9 @@ mlx5_crypto_dek_pool_create(struct mlx5_core_dev *mdev, int key_purpose)
 	INIT_LIST_HEAD(&pool->sync_list);
 	INIT_LIST_HEAD(&pool->wait_for_free);
 	INIT_WORK(&pool->sync_work, mlx5_crypto_dek_sync_work_fn);
+	spin_lock_init(&pool->destroy_lock);
+	INIT_LIST_HEAD(&pool->destroy_list);
+	INIT_WORK(&pool->destroy_work, mlx5_crypto_dek_destroy_work_fn);
 
 	return pool;
 }
@@ -648,20 +701,23 @@ void mlx5_crypto_dek_pool_destroy(struct mlx5_crypto_dek_pool *pool)
 	struct mlx5_crypto_dek_bulk *bulk, *tmp;
 
 	cancel_work_sync(&pool->sync_work);
+	cancel_work_sync(&pool->destroy_work);
 
 	mlx5_crypto_dek_pool_free_wait_keys(pool);
 
 	list_for_each_entry_safe(bulk, tmp, &pool->avail_list, entry)
-		mlx5_crypto_dek_pool_remove_bulk(pool, bulk);
+		mlx5_crypto_dek_pool_remove_bulk(pool, bulk, false);
 
 	list_for_each_entry_safe(bulk, tmp, &pool->full_list, entry)
-		mlx5_crypto_dek_pool_remove_bulk(pool, bulk);
+		mlx5_crypto_dek_pool_remove_bulk(pool, bulk, false);
 
 	list_for_each_entry_safe(bulk, tmp, &pool->sync_list, entry)
-		mlx5_crypto_dek_pool_remove_bulk(pool, bulk);
+		mlx5_crypto_dek_pool_remove_bulk(pool, bulk, false);
 
 	list_for_each_entry_safe(bulk, tmp, &pool->partial_list, entry)
-		mlx5_crypto_dek_pool_remove_bulk(pool, bulk);
+		mlx5_crypto_dek_pool_remove_bulk(pool, bulk, false);
+
+	mlx5_crypto_dek_free_destroy_list(&pool->destroy_list);
 
 	mutex_destroy(&pool->lock);