From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [Xen-devel] [RFC PATCH V3 16/16] netfront: split event channels support. Date: Mon, 30 Jan 2012 16:25:15 -0500 Message-ID: <20120130212515.GA16261@phenom.dumpdata.com> References: <1327934734-8908-1-git-send-email-wei.liu2@citrix.com> <1327934734-8908-17-git-send-email-wei.liu2@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, xen-devel@lists.xensource.com, ian.campbell@citrix.com To: Wei Liu Return-path: Received: from rcsinet15.oracle.com ([148.87.113.117]:32952 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752852Ab2A3V1u (ORCPT ); Mon, 30 Jan 2012 16:27:50 -0500 Content-Disposition: inline In-Reply-To: <1327934734-8908-17-git-send-email-wei.liu2@citrix.com> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, Jan 30, 2012 at 02:45:34PM +0000, Wei Liu wrote: > If this feature is not activated, rx_irq = tx_irq. See corresponding > netback change log for details. > > Signed-off-by: Wei Liu > --- > drivers/net/xen-netfront.c | 147 ++++++++++++++++++++++++++++++++++---------- > 1 files changed, 115 insertions(+), 32 deletions(-) > > diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c > index 32ec212..72c0429 100644 > --- a/drivers/net/xen-netfront.c > +++ b/drivers/net/xen-netfront.c > @@ -98,7 +98,9 @@ struct netfront_info { > > unsigned long rx_gso_checksum_fixup; > > - unsigned int evtchn; > + unsigned int split_evtchn; bool? > + unsigned int tx_evtchn, rx_evtchn; > + unsigned int tx_irq, rx_irq; > struct xenbus_device *xbdev; > > spinlock_t tx_lock; > @@ -344,7 +346,7 @@ no_skb: > push: > RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->rx, notify); > if (notify) > - notify_remote_via_irq(np->netdev->irq); > + notify_remote_via_irq(np->rx_irq); > } > > static int xennet_open(struct net_device *dev) > @@ -577,7 +579,7 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) > > RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->tx, notify); > if (notify) > - notify_remote_via_irq(np->netdev->irq); > + notify_remote_via_irq(np->tx_irq); > > u64_stats_update_begin(&stats->syncp); > stats->tx_bytes += skb->len; > @@ -1242,22 +1244,35 @@ static int xennet_set_features(struct net_device *dev, u32 features) > return 0; > } > > -static irqreturn_t xennet_interrupt(int irq, void *dev_id) > +static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id) > { > - struct net_device *dev = dev_id; > - struct netfront_info *np = netdev_priv(dev); > + struct netfront_info *np = dev_id; > + struct net_device *dev = np->netdev; > unsigned long flags; > > spin_lock_irqsave(&np->tx_lock, flags); > + xennet_tx_buf_gc(dev); > + spin_unlock_irqrestore(&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); > - } > + return IRQ_HANDLED; > +} > > - spin_unlock_irqrestore(&np->tx_lock, flags); > +static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id) > +{ > + struct netfront_info *np = dev_id; > + struct net_device *dev = np->netdev; > + > + if (likely(netif_carrier_ok(dev)) && > + RING_HAS_UNCONSUMED_RESPONSES(&np->rx)) > + napi_schedule(&np->napi); > + > + return IRQ_HANDLED; > +} > +static irqreturn_t xennet_interrupt(int irq, void *dev_id) > +{ > + xennet_tx_interrupt(0, dev_id); > + > + xennet_rx_interrupt(0, dev_id); > > return IRQ_HANDLED; > } > @@ -1436,9 +1451,14 @@ static void xennet_disconnect_backend(struct netfront_info *info) > spin_unlock_irq(&info->tx_lock); > spin_unlock_bh(&info->rx_lock); > > - if (info->netdev->irq) > - unbind_from_irqhandler(info->netdev->irq, info->netdev); > - info->evtchn = info->netdev->irq = 0; > + if (info->tx_irq && (info->tx_irq == info->rx_irq)) > + unbind_from_irqhandler(info->tx_irq, info); > + if (info->tx_irq && (info->tx_irq != info->rx_irq)) { > + unbind_from_irqhandler(info->tx_irq, info); > + unbind_from_irqhandler(info->rx_irq, info); > + } > + info->tx_evtchn = info->tx_irq = 0; > + info->rx_evtchn = info->rx_irq = 0; > > for (i = 0; i < info->tx_ring_pages; i++) { > int ref = info->tx_ring_ref[i]; > @@ -1507,6 +1527,7 @@ static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info) > int err; > struct net_device *netdev = info->netdev; > unsigned int max_tx_ring_page_order, max_rx_ring_page_order; > + unsigned int split_evtchn; > int i, j; > > for (i = 0; i < XENNET_MAX_RING_PAGES; i++) { > @@ -1515,7 +1536,6 @@ static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info) > } > info->rx.sring = NULL; > info->tx.sring = NULL; > - netdev->irq = 0; > > err = xen_net_read_mac(dev, netdev->dev_addr); > if (err) { > @@ -1524,6 +1544,12 @@ static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info) > } > > err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, > + "split-event-channels", "%u", We don't want to call them 'feature-split-event-channels' ? > + &split_evtchn); > + if (err < 0) > + split_evtchn = 0; > + > + err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, > "max-tx-ring-page-order", "%u", > &max_tx_ring_page_order); > if (err < 0) { > @@ -1589,20 +1615,59 @@ static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info) > info->rx_ring_ref[j] = err; > } > > - err = xenbus_alloc_evtchn(dev, &info->evtchn); > - if (err) > - goto alloc_evtchn_fail; > + if (!split_evtchn) { Why not just move most of the code that deals with this allocation in two seperate functions: setup_netfront_split and setup_netfront_generic ? > + err = xenbus_alloc_evtchn(dev, &info->tx_evtchn); > + if (err) > + goto alloc_evtchn_fail; > > - err = bind_evtchn_to_irqhandler(info->evtchn, xennet_interrupt, > - 0, netdev->name, netdev); > - if (err < 0) > - goto bind_fail; > - netdev->irq = err; > + err = bind_evtchn_to_irqhandler(info->tx_evtchn, > + xennet_interrupt, > + 0, netdev->name, info); > + if (err < 0) > + goto bind_fail; > + info->rx_evtchn = info->tx_evtchn; > + info->tx_irq = info->rx_irq = err; > + info->split_evtchn = 0; > + dev_info(&dev->dev, "single event channel, irq = %d\n", > + info->tx_irq); > + } else { > + err = xenbus_alloc_evtchn(dev, &info->tx_evtchn); > + if (err) > + goto alloc_evtchn_fail; > + err = xenbus_alloc_evtchn(dev, &info->rx_evtchn); > + if (err) { > + xenbus_free_evtchn(dev, info->tx_evtchn); > + goto alloc_evtchn_fail; > + } > + err = bind_evtchn_to_irqhandler(info->tx_evtchn, > + xennet_tx_interrupt, > + 0, netdev->name, info); > + if (err < 0) > + goto bind_fail; > + info->tx_irq = err; > + err = bind_evtchn_to_irqhandler(info->rx_evtchn, > + xennet_rx_interrupt, > + 0, netdev->name, info); > + if (err < 0) { > + unbind_from_irqhandler(info->tx_irq, info); > + goto bind_fail; > + } > + info->rx_irq = err; > + info->split_evtchn = 1; > + dev_info(&dev->dev, "split event channels," > + " tx_irq = %d, rx_irq = %d\n", > + info->tx_irq, info->rx_irq); > + } > > return 0; > > bind_fail: > - xenbus_free_evtchn(dev, info->evtchn); > + if (!split_evtchn) > + xenbus_free_evtchn(dev, info->tx_evtchn); > + else { > + xenbus_free_evtchn(dev, info->tx_evtchn); > + xenbus_free_evtchn(dev, info->rx_evtchn); > + } > alloc_evtchn_fail: > for (; j >= 0; j--) { > int ref = info->rx_ring_ref[j]; > @@ -1690,11 +1755,27 @@ again: > } > } > > - err = xenbus_printf(xbt, dev->nodename, > - "event-channel", "%u", info->evtchn); > - if (err) { > - message = "writing event-channel"; > - goto abort_transaction; > + > + if (!info->split_evtchn) { > + err = xenbus_printf(xbt, dev->nodename, > + "event-channel", "%u", info->tx_evtchn); > + if (err) { > + message = "writing event-channel"; > + goto abort_transaction; > + } > + } else { > + err = xenbus_printf(xbt, dev->nodename, > + "event-channel-tx", "%u", info->tx_evtchn); > + if (err) { > + message = "writing event-channel-tx"; > + goto abort_transaction; > + } > + err = xenbus_printf(xbt, dev->nodename, > + "event-channel-rx", "%u", info->rx_evtchn); > + if (err) { > + message = "writing event-channel-rx"; > + goto abort_transaction; > + } > } > > err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u", > @@ -1808,7 +1889,9 @@ static int xennet_connect(struct net_device *dev) > * packets. > */ > netif_carrier_on(np->netdev); > - notify_remote_via_irq(np->netdev->irq); > + notify_remote_via_irq(np->tx_irq); > + if (np->split_evtchn) > + notify_remote_via_irq(np->rx_irq); > xennet_tx_buf_gc(dev); > xennet_alloc_rx_buffers(dev); > > -- > 1.7.2.5 > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel