From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [PATCH] add netconsole support for xen-netfront Date: Thu, 12 Jan 2012 06:17:45 -0800 (PST) Message-ID: <20120112141745.GA7685@phenom.dumpdata.com> References: <1326271956-25565-1-git-send-email-zhenzhong.duan@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: xen-devel@lists.xensource.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, gurudas.pai@oracle.com, "Tina.Yang" , Jeremy Fitzhardinge To: Zhenzhong Duan , Ian Campbell Return-path: In-Reply-To: <1326271956-25565-1-git-send-email-zhenzhong.duan@oracle.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Wed, Jan 11, 2012 at 04:52:36PM +0800, Zhenzhong Duan wrote: > add polling interface to xen-netfront device to support netconsole > Ian, any thoughts on the spinlock changes? > Signed-off-by: Tina.Yang > Cc: Konrad Rzeszutek Wilk > Cc: Jeremy Fitzhardinge > Signed-off-by: Zhenzhong.Duan > Tested-by: gurudas.pai > --- > drivers/net/xen-netfront.c | 57 ++++++++++++++++++++++++++----------------- > 1 files changed, 34 insertions(+), 23 deletions(-) > > diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c > index fa67905..db638b4 100644 > --- a/drivers/net/xen-netfront.c > +++ b/drivers/net/xen-netfront.c > @@ -489,6 +489,7 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) > int frags = skb_shinfo(skb)->nr_frags; > unsigned int offset = offset_in_page(data); > unsigned int len = skb_headlen(skb); > + unsigned long flags; > > frags += DIV_ROUND_UP(offset + len, PAGE_SIZE); > if (unlikely(frags > MAX_SKB_FRAGS + 1)) { > @@ -498,12 +499,12 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) > goto drop; > } > > - spin_lock_irq(&np->tx_lock); > + spin_lock_irqsave(&np->tx_lock, flags); > > if (unlikely(!netif_carrier_ok(dev) || > (frags > 1 && !xennet_can_sg(dev)) || > netif_needs_gso(skb, netif_skb_features(skb)))) { > - spin_unlock_irq(&np->tx_lock); > + spin_unlock_irqrestore(&np->tx_lock, flags); > goto drop; > } > > @@ -574,7 +575,7 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) > if (!netfront_tx_slot_available(np)) > netif_stop_queue(dev); > > - spin_unlock_irq(&np->tx_lock); > + spin_unlock_irqrestore(&np->tx_lock, flags); > > return NETDEV_TX_OK; > > @@ -1228,6 +1229,33 @@ static int xennet_set_features(struct net_device *dev, > return 0; > } > > +static irqreturn_t xennet_interrupt(int irq, void *dev_id) > +{ > + struct net_device *dev = dev_id; > + struct netfront_info *np = netdev_priv(dev); > + unsigned long flags; > + > + spin_lock_irqsave(&np->tx_lock, flags); > + > + if (likely(netif_carrier_ok(dev))) { > + xennet_tx_buf_gc(dev); > + /* Under tx_lock: protects access to rx shared-ring indexes. */ > + if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx)) > + napi_schedule(&np->napi); > + } > + > + spin_unlock_irqrestore(&np->tx_lock, flags); > + > + return IRQ_HANDLED; > +} > + > +#ifdef CONFIG_NET_POLL_CONTROLLER > +static void xennet_poll_controller(struct net_device *dev) > +{ > + xennet_interrupt(0, dev); > +} > +#endif > + > static const struct net_device_ops xennet_netdev_ops = { > .ndo_open = xennet_open, > .ndo_uninit = xennet_uninit, > @@ -1239,6 +1267,9 @@ static const struct net_device_ops xennet_netdev_ops = { > .ndo_validate_addr = eth_validate_addr, > .ndo_fix_features = xennet_fix_features, > .ndo_set_features = xennet_set_features, > +#ifdef CONFIG_NET_POLL_CONTROLLER > + .ndo_poll_controller = xennet_poll_controller, > +#endif > }; > > static struct net_device * __devinit xennet_create_dev(struct xenbus_device *dev) > @@ -1448,26 +1479,6 @@ static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[]) > return 0; > } > > -static irqreturn_t xennet_interrupt(int irq, void *dev_id) > -{ > - struct net_device *dev = dev_id; > - struct netfront_info *np = netdev_priv(dev); > - unsigned long flags; > - > - spin_lock_irqsave(&np->tx_lock, flags); > - > - if (likely(netif_carrier_ok(dev))) { > - xennet_tx_buf_gc(dev); > - /* Under tx_lock: protects access to rx shared-ring indexes. */ > - if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx)) > - napi_schedule(&np->napi); > - } > - > - spin_unlock_irqrestore(&np->tx_lock, flags); > - > - return IRQ_HANDLED; > -} > - > static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info) > { > struct xen_netif_tx_sring *txs; > -- > 1.7.3