mwifiex: add rx workqueue support

This patch adds RX work queue support to mwifiex.
Packets received are queued to internal queue which are then
processed by scheduling a work item for RX process.

RX work is enabled only on SMP systems.

Reviewed-by: James Cameron <quozl@laptop.org>
Signed-off-by: Avinash Patil <patila@marvell.com>
Signed-off-by: Marc Yang <yangyang@marvell.com>
Signed-off-by: Cathy Luo <cluo@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 91 insertions, 0 deletions

diff --git a/drivers/net/wireless/mwifiex/main.c b/drivers/net/wireless/mwifiex/main.c
index f1393868d04c..b522f7c36901 100644
--- a/drivers/net/wireless/mwifiex/main.c
+++ b/drivers/net/wireless/mwifiex/main.c
@@ -126,6 +126,42 @@ static int mwifiex_unregister(struct mwifiex_adapter *adapter)
 	return 0;
 }
 
+static int mwifiex_process_rx(struct mwifiex_adapter *adapter)
+{
+	unsigned long flags;
+	struct sk_buff *skb;
+	bool delay_main_work = adapter->delay_main_work;
+
+	spin_lock_irqsave(&adapter->rx_proc_lock, flags);
+	if (adapter->rx_processing || adapter->rx_locked) {
+		spin_unlock_irqrestore(&adapter->rx_proc_lock, flags);
+		goto exit_rx_proc;
+	} else {
+		adapter->rx_processing = true;
+		spin_unlock_irqrestore(&adapter->rx_proc_lock, flags);
+	}
+
+	/* Check for Rx data */
+	while ((skb = skb_dequeue(&adapter->rx_data_q))) {
+		atomic_dec(&adapter->rx_pending);
+		if (adapter->delay_main_work &&
+		    (atomic_dec_return(&adapter->rx_pending) <
+		     LOW_RX_PENDING)) {
+			adapter->delay_main_work = false;
+			queue_work(adapter->rx_workqueue, &adapter->rx_work);
+		}
+		mwifiex_handle_rx_packet(adapter, skb);
+	}
+	spin_lock_irqsave(&adapter->rx_proc_lock, flags);
+	adapter->rx_processing = false;
+	spin_unlock_irqrestore(&adapter->rx_proc_lock, flags);
+
+	if (delay_main_work)
+		queue_work(adapter->workqueue, &adapter->main_work);
+exit_rx_proc:
+	return 0;
+}
+
 /*
  * The main process.
  *
@@ -163,6 +199,19 @@ process_start:
 		    (adapter->hw_status == MWIFIEX_HW_STATUS_NOT_READY))
 			break;
 
+		/* If we process interrupts first, it would increase RX pending
+		 * even further. Avoid this by checking if rx_pending has
+		 * crossed high threshold and schedule rx work queue
+		 * and then process interrupts
+		 */
+		if (atomic_read(&adapter->rx_pending) >= HIGH_RX_PENDING) {
+			adapter->delay_main_work = true;
+			if (!adapter->rx_processing)
+				queue_work(adapter->rx_workqueue,
+					   &adapter->rx_work);
+			break;
+		}
+
 		/* Handle pending interrupt if any */
 		if (adapter->int_status) {
 			if (adapter->hs_activated)
@@ -171,6 +220,9 @@ process_start:
 				adapter->if_ops.process_int_status(adapter);
 		}
 
+		if (adapter->rx_work_enabled && adapter->data_received)
+			queue_work(adapter->rx_workqueue, &adapter->rx_work);
+
 		/* Need to wake up the card ? */
 		if ((adapter->ps_state == PS_STATE_SLEEP) &&
 		    (adapter->pm_wakeup_card_req &&
@@ -183,6 +235,7 @@ process_start:
 		}
 
 		if (IS_CARD_RX_RCVD(adapter)) {
+			adapter->data_received = false;
 			adapter->pm_wakeup_fw_try = false;
 			if (adapter->ps_state == PS_STATE_SLEEP)
 				adapter->ps_state = PS_STATE_AWAKE;
@@ -318,6 +371,12 @@ static void mwifiex_terminate_workqueue(struct mwifiex_adapter *adapter)
 	flush_workqueue(adapter->workqueue);
 	destroy_workqueue(adapter->workqueue);
 	adapter->workqueue = NULL;
+
+	if (adapter->rx_workqueue) {
+		flush_workqueue(adapter->rx_workqueue);
+		destroy_workqueue(adapter->rx_workqueue);
+		adapter->rx_workqueue = NULL;
+	}
 }
 
 /*
@@ -732,6 +791,21 @@ int is_command_pending(struct mwifiex_adapter *adapter)
 }
 
 /*
+ * This is the RX work queue function.
+ *
+ * It handles the RX operations.
+ */
+static void mwifiex_rx_work_queue(struct work_struct *work)
+{
+	struct mwifiex_adapter *adapter =
+		container_of(work, struct mwifiex_adapter, rx_work);
+
+	if (adapter->surprise_removed)
+		return;
+	mwifiex_process_rx(adapter);
+}
+
+/*
  * This is the main work queue function.
  *
  * It handles the main process, which in turn handles the complete
@@ -787,6 +861,11 @@ mwifiex_add_card(void *card, struct semaphore *sem,
 	adapter->cmd_wait_q.status = 0;
 	adapter->scan_wait_q_woken = false;
 
+	if (num_possible_cpus() > 1) {
+		adapter->rx_work_enabled = true;
+		pr_notice("rx work enabled, cpus %d\n", num_possible_cpus());
+	}
+
 	adapter->workqueue =
 		alloc_workqueue("MWIFIEX_WORK_QUEUE",
 				WQ_HIGHPRI | WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
@@ -794,6 +873,18 @@ mwifiex_add_card(void *card, struct semaphore *sem,
 		goto err_kmalloc;
 
 	INIT_WORK(&adapter->main_work, mwifiex_main_work_queue);
+
+	if (adapter->rx_work_enabled) {
+		adapter->rx_workqueue = alloc_workqueue("MWIFIEX_RX_WORK_QUEUE",
+							WQ_HIGHPRI |
+							WQ_MEM_RECLAIM |
+							WQ_UNBOUND, 1);
+		if (!adapter->rx_workqueue)
+			goto err_kmalloc;
+
+		INIT_WORK(&adapter->rx_work, mwifiex_rx_work_queue);
+	}
+
 	if (adapter->if_ops.iface_work)
 		INIT_WORK(&adapter->iface_work, adapter->if_ops.iface_work);