commit 567b3c127a79277bac31a9609734b355d30e7905
author Mintz, Yuval <Yuval.Mintz@cavium.com> Tue Nov 29 16:47:05 2016 +0200
committer David S. Miller <davem@davemloft.net> Wed Nov 30 14:32:04 2016 -0500
tree ceb94723ae2d5527ab2b5ff46158012678289b16
parent f4fad34c0e45b3e30d2b5312d545e2d416778c7b

qede: Revise state locking scheme

As qede utilizes an internal-reload sequence as result of various
configuration changes, the netif state wouldn't always accurately describe
the status of the configuration.
To compensate, we're storing an internal state of the device, which should
only be accessed under the qede_lock.

This patch fixes and improves several state/lock interactions:
  - The internal state should only be checked while locked.
  - While holding lock, it's preferable to check state rather than
    the netdevice's state.
  - The reload sequence is not 'atomic' - unload and subsequent load
    are not in the same critical section.

This also add the 'locked' variant for the reload, which would later be
used by XDP - useful in the case where the correct sequence is 'lock,
check state and re-configure if good', instead of allowing the reload
itself to make the decision regarding the configurability of the device.

Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/qlogic/qede/qede_ethtool.c

diff --git a/drivers/net/ethernet/qlogic/qede/qede_ethtool.c b/drivers/net/ethernet/qlogic/qede/qede_ethtool.c
index d2c23d1..ef8c327 100644
--- a/drivers/net/ethernet/qlogic/qede/qede_ethtool.c
+++ b/drivers/net/ethernet/qlogic/qede/qede_ethtool.c
@@ -258,7 +258,9 @@ static void qede_get_ethtool_stats(struct net_device *dev,
 
 	qede_fill_by_demand_stats(edev);
 
-	mutex_lock(&edev->qede_lock);
+	/* Need to protect the access to the fastpath array */
+	__qede_lock(edev);
+
 	for (i = 0; i < QEDE_QUEUE_CNT(edev); i++) {
 		fp = &edev->fp_array[i];
 
@@ -278,7 +280,7 @@ static void qede_get_ethtool_stats(struct net_device *dev,
 		buf++;
 	}
 
-	mutex_unlock(&edev->qede_lock);
+	__qede_unlock(edev);
 }
 
 static int qede_get_sset_count(struct net_device *dev, int stringset)
@@ -374,6 +376,8 @@ static int qede_get_link_ksettings(struct net_device *dev,
 	struct qede_dev *edev = netdev_priv(dev);
 	struct qed_link_output current_link;
 
+	__qede_lock(edev);
+
 	memset(&current_link, 0, sizeof(current_link));
 	edev->ops->common->get_link(edev->cdev, &current_link);
 
@@ -393,6 +397,9 @@ static int qede_get_link_ksettings(struct net_device *dev,
 		base->speed = SPEED_UNKNOWN;
 		base->duplex = DUPLEX_UNKNOWN;
 	}
+
+	__qede_unlock(edev);
+
 	base->port = current_link.port;
 	base->autoneg = (current_link.autoneg) ? AUTONEG_ENABLE :
 			AUTONEG_DISABLE;
@@ -701,8 +708,7 @@ static int qede_set_ringparam(struct net_device *dev,
 	edev->q_num_rx_buffers = ering->rx_pending;
 	edev->q_num_tx_buffers = ering->tx_pending;
 
-	if (netif_running(edev->ndev))
-		qede_reload(edev, NULL, NULL);
+	qede_reload(edev, NULL, false);
 
 	return 0;
 }
@@ -787,29 +793,27 @@ static int qede_get_regs_len(struct net_device *ndev)
 		return -EINVAL;
 }
 
-static void qede_update_mtu(struct qede_dev *edev, union qede_reload_args *args)
+static void qede_update_mtu(struct qede_dev *edev,
+			    struct qede_reload_args *args)
 {
-	edev->ndev->mtu = args->mtu;
+	edev->ndev->mtu = args->u.mtu;
 }
 
 /* Netdevice NDOs */
 int qede_change_mtu(struct net_device *ndev, int new_mtu)
 {
 	struct qede_dev *edev = netdev_priv(ndev);
-	union qede_reload_args args;
+	struct qede_reload_args args;
 
 	DP_VERBOSE(edev, (NETIF_MSG_IFUP | NETIF_MSG_IFDOWN),
 		   "Configuring MTU size of %d\n", new_mtu);
 
-	/* Set the mtu field and re-start the interface if needed*/
-	args.mtu = new_mtu;
+	/* Set the mtu field and re-start the interface if needed */
+	args.u.mtu = new_mtu;
+	args.func = &qede_update_mtu;
+	qede_reload(edev, &args, false);
 
-	if (netif_running(edev->ndev))
-		qede_reload(edev, &qede_update_mtu, &args);
-
-	qede_update_mtu(edev, &args);
-
-	edev->ops->common->update_mtu(edev->cdev, args.mtu);
+	edev->ops->common->update_mtu(edev->cdev, new_mtu);
 
 	return 0;
 }
@@ -893,8 +897,7 @@ static int qede_set_channels(struct net_device *dev,
 		       sizeof(edev->rss_params.rss_ind_table));
 	}
 
-	if (netif_running(dev))
-		qede_reload(edev, NULL, NULL);
+	qede_reload(edev, NULL, false);
 
 	return 0;
 }