NFC: Use system_nrt_wq instead of custom ones

NFC is using a number of custom ordered workqueues w/ WQ_MEM_RECLAIM.
WQ_MEM_RECLAIM is unnecessary unless NFC is gonna be used as transport
for storage device, and all use cases match one work item to one
ordered workqueue - IOW, there's no actual ordering going on at all
and using system_nrt_wq gives the same behavior.

There's nothing to be gained by using custom workqueues.  Use
system_nrt_wq instead and drop all the custom ones.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

2 files changed, 8 insertions, 52 deletions

diff --git a/net/nfc/llcp/llcp.c b/net/nfc/llcp/llcp.c
index 82f0f7588b4..6f368412ffd 100644
--- a/net/nfc/llcp/llcp.c
+++ b/net/nfc/llcp/llcp.c
@@ -114,9 +114,9 @@ static void local_release(struct kref *ref)
 	nfc_llcp_socket_release(local, false);
 	del_timer_sync(&local->link_timer);
 	skb_queue_purge(&local->tx_queue);
-	destroy_workqueue(local->tx_wq);
-	destroy_workqueue(local->rx_wq);
-	destroy_workqueue(local->timeout_wq);
+	cancel_work_sync(&local->tx_work);
+	cancel_work_sync(&local->rx_work);
+	cancel_work_sync(&local->timeout_work);
 	kfree_skb(local->rx_pending);
 	kfree(local);
 }
@@ -181,7 +181,7 @@ static void nfc_llcp_symm_timer(unsigned long data)
 
 	pr_err("SYMM timeout\n");
 
-	queue_work(local->timeout_wq, &local->timeout_work);
+	queue_work(system_nrt_wq, &local->timeout_work);
 }
 
 struct nfc_llcp_local *nfc_llcp_find_local(struct nfc_dev *dev)
@@ -1052,7 +1052,7 @@ static void nfc_llcp_rx_work(struct work_struct *work)
 
 	}
 
-	queue_work(local->tx_wq, &local->tx_work);
+	queue_work(system_nrt_wq, &local->tx_work);
 	kfree_skb(local->rx_pending);
 	local->rx_pending = NULL;
 
@@ -1071,7 +1071,7 @@ void nfc_llcp_recv(void *data, struct sk_buff *skb, int err)
 
 	local->rx_pending = skb_get(skb);
 	del_timer(&local->link_timer);
-	queue_work(local->rx_wq, &local->rx_work);
+	queue_work(system_nrt_wq, &local->rx_work);
 
 	return;
 }
@@ -1086,7 +1086,7 @@ int nfc_llcp_data_received(struct nfc_dev *dev, struct sk_buff *skb)
 
 	local->rx_pending = skb_get(skb);
 	del_timer(&local->link_timer);
-	queue_work(local->rx_wq, &local->rx_work);
+	queue_work(system_nrt_wq, &local->rx_work);
 
 	return 0;
 }
@@ -1121,7 +1121,7 @@ void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
 	if (rf_mode == NFC_RF_INITIATOR) {
 		pr_debug("Queueing Tx work\n");
 
-		queue_work(local->tx_wq, &local->tx_work);
+		queue_work(system_nrt_wq, &local->tx_work);
 	} else {
 		mod_timer(&local->link_timer,
 			  jiffies + msecs_to_jiffies(local->remote_lto));
@@ -1130,10 +1130,7 @@ void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
 
 int nfc_llcp_register_device(struct nfc_dev *ndev)
 {
-	struct device *dev = &ndev->dev;
 	struct nfc_llcp_local *local;
-	char name[32];
-	int err;
 
 	local = kzalloc(sizeof(struct nfc_llcp_local), GFP_KERNEL);
 	if (local == NULL)
@@ -1149,38 +1146,11 @@ int nfc_llcp_register_device(struct nfc_dev *ndev)
 
 	skb_queue_head_init(&local->tx_queue);
 	INIT_WORK(&local->tx_work, nfc_llcp_tx_work);
-	snprintf(name, sizeof(name), "%s_llcp_tx_wq", dev_name(dev));
-	local->tx_wq =
-		alloc_workqueue(name,
-				WQ_NON_REENTRANT | WQ_UNBOUND | WQ_MEM_RECLAIM,
-				1);
-	if (local->tx_wq == NULL) {
-		err = -ENOMEM;
-		goto err_local;
-	}
 
 	local->rx_pending = NULL;
 	INIT_WORK(&local->rx_work, nfc_llcp_rx_work);
-	snprintf(name, sizeof(name), "%s_llcp_rx_wq", dev_name(dev));
-	local->rx_wq =
-		alloc_workqueue(name,
-				WQ_NON_REENTRANT | WQ_UNBOUND | WQ_MEM_RECLAIM,
-				1);
-	if (local->rx_wq == NULL) {
-		err = -ENOMEM;
-		goto err_tx_wq;
-	}
 
 	INIT_WORK(&local->timeout_work, nfc_llcp_timeout_work);
-	snprintf(name, sizeof(name), "%s_llcp_timeout_wq", dev_name(dev));
-	local->timeout_wq =
-		alloc_workqueue(name,
-				WQ_NON_REENTRANT | WQ_UNBOUND | WQ_MEM_RECLAIM,
-				1);
-	if (local->timeout_wq == NULL) {
-		err = -ENOMEM;
-		goto err_rx_wq;
-	}
 
 	local->sockets.lock = __RW_LOCK_UNLOCKED(local->sockets.lock);
 	local->connecting_sockets.lock = __RW_LOCK_UNLOCKED(local->connecting_sockets.lock);
@@ -1193,17 +1163,6 @@ int nfc_llcp_register_device(struct nfc_dev *ndev)
 	list_add(&llcp_devices, &local->list);
 
 	return 0;
-
-err_rx_wq:
-	destroy_workqueue(local->rx_wq);
-
-err_tx_wq:
-	destroy_workqueue(local->tx_wq);
-
-err_local:
-	kfree(local);
-
-	return 0;
 }
 
 void nfc_llcp_unregister_device(struct nfc_dev *dev)
diff --git a/net/nfc/llcp/llcp.h b/net/nfc/llcp/llcp.h
index 83b8bba5a28..af395c9ceb0 100644
--- a/net/nfc/llcp/llcp.h
+++ b/net/nfc/llcp/llcp.h
@@ -56,12 +56,9 @@ struct nfc_llcp_local {
 
 	struct timer_list link_timer;
 	struct sk_buff_head tx_queue;
-	struct workqueue_struct	*tx_wq;
 	struct work_struct	 tx_work;
-	struct workqueue_struct	*rx_wq;
 	struct work_struct	 rx_work;
 	struct sk_buff *rx_pending;
-	struct workqueue_struct	*timeout_wq;
 	struct work_struct	 timeout_work;
 
 	u32 target_idx;