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OpenCloudOS-Kernel
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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>
This commit is contained in:
Sowmini Varadhan 2014-10-25 15:12:31 -04:00 committed by David S. Miller
parent 2a968dd8f7
commit 13b13dd97c
1 changed files with 5 additions and 25 deletions
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30
drivers/net/ethernet/sun/sunvnet.c
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@ -842,18 +842,6 @@ struct vnet_port *__tx_port_find(struct vnet *vp, struct sk_buff *skb)
return NULL; 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, static struct sk_buff *vnet_clean_tx_ring(struct vnet_port *port,
unsigned *pending) unsigned *pending)
{ {
@ -914,11 +902,10 @@ static void vnet_clean_timer_expire(unsigned long port0)
struct vnet_port *port = (struct vnet_port *)port0; struct vnet_port *port = (struct vnet_port *)port0;
struct sk_buff *freeskbs; struct sk_buff *freeskbs;
unsigned pending; 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); freeskbs = vnet_clean_tx_ring(port, &pending);
spin_unlock_irqrestore(&port->vio.lock, flags); netif_tx_unlock(port->vp->dev);
vnet_free_skbs(freeskbs); 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 vnet_port *port = NULL;
struct vio_dring_state *dr; struct vio_dring_state *dr;
struct vio_net_desc *d; struct vio_net_desc *d;
unsigned long flags;
unsigned int len; unsigned int len;
struct sk_buff *freeskbs = NULL; struct sk_buff *freeskbs = NULL;
int i, err, txi; int i, err, txi;
@ -984,7 +970,7 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
goto out_dropped; goto out_dropped;
rcu_read_lock(); rcu_read_lock();
port = tx_port_find(vp, skb); port = __tx_port_find(vp, skb);
if (unlikely(!port)) if (unlikely(!port))
goto out_dropped; goto out_dropped;
@ -1020,8 +1006,6 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
goto out_dropped; goto out_dropped;
} }
spin_lock_irqsave(&port->vio.lock, flags);
dr = &port->vio.drings[VIO_DRIVER_TX_RING]; dr = &port->vio.drings[VIO_DRIVER_TX_RING];
if (unlikely(vnet_tx_dring_avail(dr) < 1)) { if (unlikely(vnet_tx_dring_avail(dr) < 1)) {
if (!netif_queue_stopped(dev)) { 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)); (LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_RW));
if (err < 0) { if (err < 0) {
netdev_info(dev, "tx buffer map error %d\n", err); netdev_info(dev, "tx buffer map error %d\n", err);
goto out_dropped_unlock; goto out_dropped;
} }
port->tx_bufs[txi].ncookies = err; 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); netdev_info(dev, "TX trigger error %d\n", err);
d->hdr.state = VIO_DESC_FREE; d->hdr.state = VIO_DESC_FREE;
dev->stats.tx_carrier_errors++; dev->stats.tx_carrier_errors++;
goto out_dropped_unlock; goto out_dropped;
} }
ldc_start_done: ldc_start_done:
@ -1124,7 +1108,6 @@ ldc_start_done:
netif_wake_queue(dev); netif_wake_queue(dev);
} }
spin_unlock_irqrestore(&port->vio.lock, flags);
(void)mod_timer(&port->clean_timer, jiffies + VNET_CLEAN_TIMEOUT); (void)mod_timer(&port->clean_timer, jiffies + VNET_CLEAN_TIMEOUT);
rcu_read_unlock(); rcu_read_unlock();
@ -1132,9 +1115,6 @@ ldc_start_done:
return NETDEV_TX_OK; return NETDEV_TX_OK;
out_dropped_unlock:
spin_unlock_irqrestore(&port->vio.lock, flags);
out_dropped: out_dropped:
if (pending) if (pending)
(void)mod_timer(&port->clean_timer, (void)mod_timer(&port->clean_timer,