sunvnet: Remove irqsave/irqrestore on vio.lock

After the  NAPIfication of sunvnet, we no longer need to
synchronize by doing irqsave/restore on vio.lock in the
I/O fastpath.

NAPI ->poll() is non-reentrant, so all RX processing occurs
strictly in a serialized environment. TX reclaim is done in NAPI
context, so the netif_tx_lock can be used to serialize
critical sections between Tx and Rx paths.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/sun/sunvnet.c b/drivers/net/ethernet/sun/sunvnet.c
index 966c252c3ca9b4b1e7019063ef68c62e5a12b6f5..c390a2784546545536833a18de19bf414b6aebd5 100644 (file)
--- a/drivers/net/ethernet/sun/sunvnet.c
+++ b/drivers/net/ethernet/sun/sunvnet.c
@@ -842,18 +842,6 @@ struct vnet_port *__tx_port_find(struct vnet *vp, struct sk_buff *skb)
        return NULL;
 }
 
-struct vnet_port *tx_port_find(struct vnet *vp, struct sk_buff *skb)
-{
-       struct vnet_port *ret;
-       unsigned long flags;
-
-       spin_lock_irqsave(&vp->lock, flags);
-       ret = __tx_port_find(vp, skb);
-       spin_unlock_irqrestore(&vp->lock, flags);
-
-       return ret;
-}
-
 static struct sk_buff *vnet_clean_tx_ring(struct vnet_port *port,
                                          unsigned *pending)
 {
@@ -914,11 +902,10 @@ static void vnet_clean_timer_expire(unsigned long port0)
        struct vnet_port *port = (struct vnet_port *)port0;
        struct sk_buff *freeskbs;
        unsigned pending;
-       unsigned long flags;
 
-       spin_lock_irqsave(&port->vio.lock, flags);
+       netif_tx_lock(port->vp->dev);
        freeskbs = vnet_clean_tx_ring(port, &pending);
-       spin_unlock_irqrestore(&port->vio.lock, flags);
+       netif_tx_unlock(port->vp->dev);
 
        vnet_free_skbs(freeskbs);
 
@@ -971,7 +958,6 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
        struct vnet_port *port = NULL;
        struct vio_dring_state *dr;
        struct vio_net_desc *d;
-       unsigned long flags;
        unsigned int len;
        struct sk_buff *freeskbs = NULL;
        int i, err, txi;
@@ -984,7 +970,7 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
                goto out_dropped;
 
        rcu_read_lock();
-       port = tx_port_find(vp, skb);
+       port = __tx_port_find(vp, skb);
        if (unlikely(!port))
                goto out_dropped;
 
@@ -1020,8 +1006,6 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
                goto out_dropped;
        }
 
-       spin_lock_irqsave(&port->vio.lock, flags);
-
        dr = &port->vio.drings[VIO_DRIVER_TX_RING];
        if (unlikely(vnet_tx_dring_avail(dr) < 1)) {
                if (!netif_queue_stopped(dev)) {
@@ -1055,7 +1039,7 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
                             (LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_RW));
        if (err < 0) {
                netdev_info(dev, "tx buffer map error %d\n", err);
-               goto out_dropped_unlock;
+               goto out_dropped;
        }
        port->tx_bufs[txi].ncookies = err;
 
@@ -1108,7 +1092,7 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
                netdev_info(dev, "TX trigger error %d\n", err);
                d->hdr.state = VIO_DESC_FREE;
                dev->stats.tx_carrier_errors++;
-               goto out_dropped_unlock;
+               goto out_dropped;
        }
 
 ldc_start_done:
@@ -1124,7 +1108,6 @@ ldc_start_done:
                        netif_wake_queue(dev);
        }
 
-       spin_unlock_irqrestore(&port->vio.lock, flags);
        (void)mod_timer(&port->clean_timer, jiffies + VNET_CLEAN_TIMEOUT);
        rcu_read_unlock();
 
@@ -1132,9 +1115,6 @@ ldc_start_done:
 
        return NETDEV_TX_OK;
 
-out_dropped_unlock:
-       spin_unlock_irqrestore(&port->vio.lock, flags);
-
 out_dropped:
        if (pending)
                (void)mod_timer(&port->clean_timer,