From patchwork Mon May 20 23:02:11 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wei Liu X-Patchwork-Id: 245130 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 9B7442C0119 for ; Tue, 21 May 2013 09:02:36 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757322Ab3ETXCT (ORCPT ); Mon, 20 May 2013 19:02:19 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:7824 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755872Ab3ETXCO (ORCPT ); Mon, 20 May 2013 19:02:14 -0400 X-IronPort-AV: E=Sophos;i="4.87,711,1363132800"; d="scan'208";a="25093637" Received: from accessns.citrite.net (HELO FTLPEX01CL01.citrite.net) ([10.9.154.239]) by FTLPIPO02.CITRIX.COM with ESMTP/TLS/AES128-SHA; 20 May 2013 23:02:13 +0000 Received: from ukmail1.uk.xensource.com (10.80.16.128) by smtprelay.citrix.com (10.13.107.78) with Microsoft SMTP Server id 14.2.342.3; Mon, 20 May 2013 19:02:12 -0400 Received: from dt47.uk.xensource.com ([10.80.229.47] helo=dt47.uk.xensource.com.) by ukmail1.uk.xensource.com with esmtp (Exim 4.69) (envelope-from ) id 1UeZ5n-0007Vu-JJ; Tue, 21 May 2013 00:02:11 +0100 From: Wei Liu To: , CC: , , Wei Liu Subject: [PATCH net-next 2/2] xen-netfront: split event channels feature support Date: Tue, 21 May 2013 00:02:11 +0100 Message-ID: <1369090931-27306-3-git-send-email-wei.liu2@citrix.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1369090931-27306-1-git-send-email-wei.liu2@citrix.com> References: <1369090931-27306-1-git-send-email-wei.liu2@citrix.com> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This patch adds a new feature called feature-split-event-channels for netfront, enabling it to handle TX and RX events separately. If netback does not support this feature, it falls back to use single event channel. Signed-off-by: Wei Liu Reviewed-by: David Vrabel --- drivers/net/xen-netfront.c | 181 +++++++++++++++++++++++++++++++++++++------- 1 file changed, 152 insertions(+), 29 deletions(-) diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 5770e3b..716b2bd 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -85,7 +85,15 @@ struct netfront_info { struct napi_struct napi; - unsigned int evtchn; + /* Split event channels support, tx_* == rx_* when using + * single event channel. + */ + unsigned int tx_evtchn, rx_evtchn; + unsigned int tx_irq, rx_irq; + /* Only used when split event channels support is enabled */ + char tx_irq_name[IFNAMSIZ+4]; /* DEVNAME-tx */ + char rx_irq_name[IFNAMSIZ+4]; /* DEVNAME-rx */ + struct xenbus_device *xbdev; spinlock_t tx_lock; @@ -330,7 +338,7 @@ 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) @@ -623,7 +631,7 @@ 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; @@ -1254,23 +1262,35 @@ static int xennet_set_features(struct net_device *dev, 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)) + return IRQ_HANDLED; +} + +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); - } - spin_unlock_irqrestore(&np->tx_lock, flags); + return IRQ_HANDLED; +} +static irqreturn_t xennet_interrupt(int irq, void *dev_id) +{ + xennet_tx_interrupt(irq, dev_id); + xennet_rx_interrupt(irq, dev_id); return IRQ_HANDLED; } @@ -1451,9 +1471,14 @@ 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->rx_evtchn = 0; + info->tx_irq = info->rx_irq = 0; /* End access and free the pages */ xennet_end_access(info->tx_ring_ref, info->tx.sring); @@ -1503,12 +1528,90 @@ static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[]) return 0; } +static int setup_netfront_single(struct netfront_info *info) +{ + int err; + + err = xenbus_alloc_evtchn(info->xbdev, &info->tx_evtchn); + if (err < 0) + goto fail; + + err = bind_evtchn_to_irqhandler(info->tx_evtchn, + xennet_interrupt, + 0, info->netdev->name, info); + if (err < 0) + goto bind_fail; + info->rx_evtchn = info->tx_evtchn; + info->rx_irq = info->tx_irq = err; + dev_info(&info->xbdev->dev, + "single event channel, evtchn = %d, irq = %d\n", + info->tx_evtchn, info->tx_irq); + + return 0; + +bind_fail: + xenbus_free_evtchn(info->xbdev, info->tx_evtchn); + info->tx_evtchn = 0; +fail: + return err; +} + +static int setup_netfront_split(struct netfront_info *info) +{ + int err; + + err = xenbus_alloc_evtchn(info->xbdev, &info->tx_evtchn); + if (err < 0) + goto fail; + err = xenbus_alloc_evtchn(info->xbdev, &info->rx_evtchn); + if (err < 0) + goto alloc_rx_evtchn_fail; + + snprintf(info->tx_irq_name, sizeof(info->tx_irq_name), + "%s-tx", info->netdev->name); + err = bind_evtchn_to_irqhandler(info->tx_evtchn, + xennet_tx_interrupt, + 0, info->tx_irq_name, info); + if (err < 0) + goto bind_tx_fail; + info->tx_irq = err; + + snprintf(info->rx_irq_name, sizeof(info->rx_irq_name), + "%s-rx", info->netdev->name); + err = bind_evtchn_to_irqhandler(info->rx_evtchn, + xennet_rx_interrupt, + 0, info->rx_irq_name, info); + if (err < 0) + goto bind_rx_fail; + info->rx_irq = err; + + dev_info(&info->xbdev->dev, + "split event channels, tx_evtchn/irq = %d/%d, rx_evtchn/irq = %d/%d", + info->tx_evtchn, info->tx_irq, + info->rx_evtchn, info->rx_irq); + + return 0; + +bind_rx_fail: + unbind_from_irqhandler(info->tx_irq, info); + info->tx_irq = 0; +bind_tx_fail: + xenbus_free_evtchn(info->xbdev, info->rx_evtchn); + info->rx_evtchn = 0; +alloc_rx_evtchn_fail: + xenbus_free_evtchn(info->xbdev, info->tx_evtchn); + info->tx_evtchn = 0; +fail: + return err; +} + static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info) { struct xen_netif_tx_sring *txs; struct xen_netif_rx_sring *rxs; int err; struct net_device *netdev = info->netdev; + unsigned int feature_split_evtchn; info->tx_ring_ref = GRANT_INVALID_REF; info->rx_ring_ref = GRANT_INVALID_REF; @@ -1516,6 +1619,12 @@ static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info) info->tx.sring = NULL; netdev->irq = 0; + err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, + "feature-split-event-channels", "%u", + &feature_split_evtchn); + if (err < 0) + feature_split_evtchn = 0; + err = xen_net_read_mac(dev, netdev->dev_addr); if (err) { xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename); @@ -1550,22 +1659,18 @@ static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info) goto grant_rx_ring_fail; info->rx_ring_ref = err; - err = xenbus_alloc_evtchn(dev, &info->evtchn); + if (feature_split_evtchn) + err = setup_netfront_split(info); + else + err = setup_netfront_single(info); 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; return 0; /* If we fail to setup netfront, it is safe to just revoke access to * granted pages because backend is not accessing it at this point. */ -bind_fail: - xenbus_free_evtchn(dev, info->evtchn); alloc_evtchn_fail: gnttab_end_foreign_access_ref(info->rx_ring_ref, 0); grant_rx_ring_fail: @@ -1610,11 +1715,27 @@ again: message = "writing rx ring-ref"; goto abort_transaction; } - err = xenbus_printf(xbt, dev->nodename, - "event-channel", "%u", info->evtchn); - if (err) { - message = "writing event-channel"; - goto abort_transaction; + + if (info->tx_evtchn == info->rx_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", @@ -1727,7 +1848,9 @@ 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->tx_irq != np->rx_irq) + notify_remote_via_irq(np->rx_irq); xennet_tx_buf_gc(dev); xennet_alloc_rx_buffers(dev);