Re: [patch 25/29] xen: Add the Xen virtual network device driver.

Jeremy Fitzhardinge
2007-05-07T21:10:36Z

Herbert Xu wrote:
> On Sat, May 05, 2007 at 03:05:07AM -0700, Jeremy Fitzhardinge wrote:
>
>> Sorry, I forgot about it. I was waiting to hear back from network
>> people about what this is actually for, and whether we really need it.
>>
>
> We should just change this to use netif_device_attach and
> netif_device_detach.
>

Like this?

---
drivers/net/xen-netfront.c | 28 +++++++++-------------------
1 file changed, 9 insertions(+), 19 deletions(-)

===================================================================
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -95,7 +95,6 @@ struct netfront_info {

unsigned int evtchn;
unsigned int copying_receiver;
- unsigned int carrier;

/* Receive-ring batched refills. */
#define RX_MIN_TARGET 8
@@ -142,15 +141,6 @@ struct netfront_rx_info {
};

/*
- * Implement our own carrier flag: the network stack's version causes delays
- * when the carrier is re-enabled (in particular, dev_activate() may not
- * immediately be called, which can cause packet loss).
- */
-#define netfront_carrier_on(netif) ((netif)->carrier = 1)
-#define netfront_carrier_off(netif) ((netif)->carrier = 0)
-#define netfront_carrier_ok(netif) ((netif)->carrier)
-
-/*
* Access macros for acquiring freeing slots in tx_skbs[].
*/

@@ -241,7 +231,7 @@ static void xennet_alloc_rx_buffers(stru
int nr_flips;
struct xen_netif_rx_request *req;

- if (unlikely(!netfront_carrier_ok(np)))
+ if (unlikely(!netif_device_present(dev)))
return;

/*
@@ -380,7 +370,7 @@ static int xennet_open(struct net_device
memset(&np->stats, 0, sizeof(np->stats));

spin_lock_bh(&np->rx_lock);
- if (netfront_carrier_ok(np)) {
+ if (netif_device_present(dev)) {
xennet_alloc_rx_buffers(dev);
np->rx.sring->rsp_event = np->rx.rsp_cons + 1;
if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx))
@@ -400,7 +390,7 @@ static void xennet_tx_buf_gc(struct net_
struct netfront_info *np = netdev_priv(dev);
struct sk_buff *skb;

- BUG_ON(!netfront_carrier_ok(np));
+ BUG_ON(!netif_device_present(dev));

do {
prod = np->tx.sring->rsp_prod;
@@ -540,7 +530,7 @@ static int xennet_start_xmit(struct sk_b

spin_lock_irq(&np->tx_lock);

- if (unlikely(!netfront_carrier_ok(np) ||
+ if (unlikely(!netif_device_present(dev) ||
(frags > 1 && !xennet_can_sg(dev)) ||
netif_needs_gso(dev, skb))) {
spin_unlock_irq(&np->tx_lock);
@@ -973,7 +963,7 @@ static int xennet_poll(struct net_device

spin_lock(&np->rx_lock);

- if (unlikely(!netfront_carrier_ok(np))) {
+ if (unlikely(!netif_device_present(dev))) {
spin_unlock(&np->rx_lock);
return 0;
}
@@ -1308,7 +1298,7 @@ static struct net_device * __devinit xen

np->netdev = netdev;

- netfront_carrier_off(np);
+ netif_device_detach(netdev);

return netdev;

@@ -1376,7 +1366,7 @@ static void xennet_disconnect_backend(st
/* Stop old i/f to prevent errors whilst we rebuild the state. */
spin_lock_bh(&info->rx_lock);
spin_lock_irq(&info->tx_lock);
- netfront_carrier_off(info);
+ netif_device_detach(info->netdev);
spin_unlock_irq(&info->tx_lock);
spin_unlock_bh(&info->rx_lock);

@@ -1440,7 +1430,7 @@ static irqreturn_t xennet_interrupt(int

spin_lock_irqsave(&np->tx_lock, flags);

- if (likely(netfront_carrier_ok(np))) {
+ if (likely(netif_device_present(dev))) {
xennet_tx_buf_gc(dev);
/* Under tx_lock: protects access to rx shared-ring indexes. */
if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx))
@@ -1728,7 +1718,7 @@ static int xennet_connect(struct net_dev
* domain a kick because we've probably just requeued some
* packets.
*/
- netfront_carrier_on(np);
+ netif_device_attach(np->netdev);
notify_remote_via_irq(np->netdev->irq);
xennet_tx_buf_gc(dev);
xennet_alloc_rx_buffers(dev);