Staging: Octeon: Run phy bus accesses on a workqueue.

When directly accessing a phy, we must acquire the mdio bus lock.  To
do that we cannot be in interrupt context, so we need to move these
operations to a workqueue.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
To: netdev@vger.kernel.org
To: gregkh@suse.de
Patchwork: http://patchwork.linux-mips.org/patch/965/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 63 insertions, 50 deletions

diff --git a/drivers/staging/octeon/ethernet.c b/drivers/staging/octeon/ethernet.c
index 5afece0216ca..1771c1035a3c 100644
--- a/drivers/staging/octeon/ethernet.c
+++ b/drivers/staging/octeon/ethernet.c
@@ -123,9 +123,16 @@ MODULE_PARM_DESC(rx_napi_weight, "The NAPI WEIGHT parameter.");
 static unsigned int cvm_oct_mac_addr_offset;
 
 /**
- * Periodic timer to check auto negotiation
+ * cvm_oct_poll_queue - Workqueue for polling operations.
  */
-static struct timer_list cvm_oct_poll_timer;
+struct workqueue_struct *cvm_oct_poll_queue;
+
+/**
+ * cvm_oct_poll_queue_stopping - flag to indicate polling should stop.
+ *
+ * Set to one right before cvm_oct_poll_queue is destroyed.
+ */
+atomic_t cvm_oct_poll_queue_stopping = ATOMIC_INIT(0);
 
 /**
  * Array of every ethernet device owned by this driver indexed by
@@ -133,47 +140,39 @@ static struct timer_list cvm_oct_poll_timer;
  */
 struct net_device *cvm_oct_device[TOTAL_NUMBER_OF_PORTS];
 
-/**
- * Periodic timer tick for slow management operations
- *
- * @arg:    Device to check
- */
-static void cvm_do_timer(unsigned long arg)
+static void cvm_oct_rx_refill_worker(struct work_struct *work);
+static DECLARE_DELAYED_WORK(cvm_oct_rx_refill_work, cvm_oct_rx_refill_worker);
+
+static void cvm_oct_rx_refill_worker(struct work_struct *work)
 {
-	static int port;
-	if (port < CVMX_PIP_NUM_INPUT_PORTS) {
-		if (cvm_oct_device[port]) {
-			struct octeon_ethernet *priv = netdev_priv(cvm_oct_device[port]);
-			if (priv->poll)
-				priv->poll(cvm_oct_device[port]);
-			cvm_oct_free_tx_skbs(priv);
-			cvm_oct_device[port]->netdev_ops->ndo_get_stats(cvm_oct_device[port]);
-		}
-		port++;
-		/*
-		 * Poll the next port in a 50th of a second.  This
-		 * spreads the polling of ports out a little bit.
-		 */
-		mod_timer(&cvm_oct_poll_timer, jiffies + HZ/50);
-	} else {
-		port = 0;
-		/*
-		 * FPA 0 may have been drained, try to refill it if we
-		 * need more than num_packet_buffers / 2, otherwise
-		 * normal receive processing will refill it.  If it
-		 * were drained, no packets could be received so
-		 * cvm_oct_napi_poll would never be invoked to do the
-		 * refill.
-		 */
-		cvm_oct_rx_refill_pool(num_packet_buffers / 2);
-		/*
-		 * All ports have been polled. Start the next iteration through
-		 * the ports in one second.
-		 */
-		mod_timer(&cvm_oct_poll_timer, jiffies + HZ);
-	}
+	/*
+	 * FPA 0 may have been drained, try to refill it if we need
+	 * more than num_packet_buffers / 2, otherwise normal receive
+	 * processing will refill it.  If it were drained, no packets
+	 * could be received so cvm_oct_napi_poll would never be
+	 * invoked to do the refill.
+	 */
+	cvm_oct_rx_refill_pool(num_packet_buffers / 2);
+
+	if (!atomic_read(&cvm_oct_poll_queue_stopping))
+		queue_delayed_work(cvm_oct_poll_queue,
+				   &cvm_oct_rx_refill_work, HZ);
 }
 
+static void cvm_oct_tx_clean_worker(struct work_struct *work)
+{
+	struct octeon_ethernet *priv = container_of(work,
+						    struct octeon_ethernet,
+						    tx_clean_work.work);
+
+	if (priv->poll)
+		priv->poll(cvm_oct_device[priv->port]);
+	cvm_oct_free_tx_skbs(priv);
+	cvm_oct_device[priv->port]->netdev_ops->ndo_get_stats(cvm_oct_device[priv->port]);
+	if (!atomic_read(&cvm_oct_poll_queue_stopping))
+		queue_delayed_work(cvm_oct_poll_queue, &priv->tx_clean_work, HZ);
+ }
+
 /**
  * Configure common hardware for all interfaces
  */
@@ -624,6 +623,12 @@ static int __init cvm_oct_init_module(void)
 	else
 		cvm_oct_mac_addr_offset = 0;
 
+	cvm_oct_poll_queue = create_singlethread_workqueue("octeon-ethernet");
+	if (cvm_oct_poll_queue == NULL) {
+		pr_err("octeon-ethernet: Cannot create workqueue");
+		return -ENOMEM;
+	}
+
 	cvm_oct_proc_initialize();
 	cvm_oct_configure_common_hw();
 
@@ -719,7 +724,9 @@ static int __init cvm_oct_init_module(void)
 
 			/* Initialize the device private structure. */
 			priv = netdev_priv(dev);
-			memset(priv, 0, sizeof(struct octeon_ethernet));
+
+			INIT_DELAYED_WORK(&priv->tx_clean_work,
+					  cvm_oct_tx_clean_worker);
 
 			priv->imode = imode;
 			priv->port = port;
@@ -785,17 +792,15 @@ static int __init cvm_oct_init_module(void)
 				fau -=
 				    cvmx_pko_get_num_queues(priv->port) *
 				    sizeof(uint32_t);
+				queue_delayed_work(cvm_oct_poll_queue,
+						   &priv->tx_clean_work, HZ);
 			}
 		}
 	}
 
 	cvm_oct_rx_initialize();
 
-	/* Enable the poll timer for checking RGMII status */
-	init_timer(&cvm_oct_poll_timer);
-	cvm_oct_poll_timer.data = 0;
-	cvm_oct_poll_timer.function = cvm_do_timer;
-	mod_timer(&cvm_oct_poll_timer, jiffies + HZ);
+	queue_delayed_work(cvm_oct_poll_queue, &cvm_oct_rx_refill_work, HZ);
 
 	return 0;
 }
@@ -817,20 +822,28 @@ static void __exit cvm_oct_cleanup_module(void)
 	/* Free the interrupt handler */
 	free_irq(OCTEON_IRQ_WORKQ0 + pow_receive_group, cvm_oct_device);
 
-	del_timer(&cvm_oct_poll_timer);
+	atomic_inc_return(&cvm_oct_poll_queue_stopping);
+	cancel_delayed_work_sync(&cvm_oct_rx_refill_work);
+
 	cvm_oct_rx_shutdown();
 	cvmx_pko_disable();
 
 	/* Free the ethernet devices */
 	for (port = 0; port < TOTAL_NUMBER_OF_PORTS; port++) {
 		if (cvm_oct_device[port]) {
-			cvm_oct_tx_shutdown(cvm_oct_device[port]);
-			unregister_netdev(cvm_oct_device[port]);
-			kfree(cvm_oct_device[port]);
+			struct net_device *dev = cvm_oct_device[port];
+			struct octeon_ethernet *priv = netdev_priv(dev);
+			cancel_delayed_work_sync(&priv->tx_clean_work);
+
+			cvm_oct_tx_shutdown(dev);
+			unregister_netdev(dev);
+			kfree(dev);
 			cvm_oct_device[port] = NULL;
 		}
 	}
 
+	destroy_workqueue(cvm_oct_poll_queue);
+
 	cvmx_pko_shutdown();
 	cvm_oct_proc_shutdown();