From 2890ea5c13321d26732c4520649681965480ee1c Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Mon, 31 Oct 2016 14:58:41 +0100 Subject: [PATCH] xen: make use of xenbus_read_unsigned() in xen-netfront Use xenbus_read_unsigned() instead of xenbus_scanf() when possible. This requires to change the type of some reads from int to unsigned, but these cases have been wrong before: negative values are not allowed for the modified cases. Cc: netdev@vger.kernel.org Signed-off-by: Juergen Gross Acked-by: David Vrabel --- drivers/net/xen-netfront.c | 67 ++++++++++---------------------------- 1 file changed, 18 insertions(+), 49 deletions(-) diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index e17879dd5d5a..95d664e3d09c 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -1169,43 +1169,23 @@ static netdev_features_t xennet_fix_features(struct net_device *dev, netdev_features_t features) { struct netfront_info *np = netdev_priv(dev); - int val; - if (features & NETIF_F_SG) { - if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg", - "%d", &val) < 0) - val = 0; + if (features & NETIF_F_SG && + !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0)) + features &= ~NETIF_F_SG; - if (!val) - features &= ~NETIF_F_SG; - } - - if (features & NETIF_F_IPV6_CSUM) { - if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, - "feature-ipv6-csum-offload", "%d", &val) < 0) - val = 0; - - if (!val) - features &= ~NETIF_F_IPV6_CSUM; - } - - if (features & NETIF_F_TSO) { - if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, - "feature-gso-tcpv4", "%d", &val) < 0) - val = 0; + if (features & NETIF_F_IPV6_CSUM && + !xenbus_read_unsigned(np->xbdev->otherend, + "feature-ipv6-csum-offload", 0)) + features &= ~NETIF_F_IPV6_CSUM; - if (!val) - features &= ~NETIF_F_TSO; - } + if (features & NETIF_F_TSO && + !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0)) + features &= ~NETIF_F_TSO; - if (features & NETIF_F_TSO6) { - if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, - "feature-gso-tcpv6", "%d", &val) < 0) - val = 0; - - if (!val) - features &= ~NETIF_F_TSO6; - } + if (features & NETIF_F_TSO6 && + !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0)) + features &= ~NETIF_F_TSO6; return features; } @@ -1821,18 +1801,13 @@ static int talk_to_netback(struct xenbus_device *dev, info->netdev->irq = 0; /* Check if backend supports multiple queues */ - err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, - "multi-queue-max-queues", "%u", &max_queues); - if (err < 0) - max_queues = 1; + max_queues = xenbus_read_unsigned(info->xbdev->otherend, + "multi-queue-max-queues", 1); num_queues = min(max_queues, xennet_max_queues); /* Check feature-split-event-channels */ - err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, - "feature-split-event-channels", "%u", - &feature_split_evtchn); - if (err < 0) - feature_split_evtchn = 0; + feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend, + "feature-split-event-channels", 0); /* Read mac addr. */ err = xen_net_read_mac(dev, info->netdev->dev_addr); @@ -1966,16 +1941,10 @@ static int xennet_connect(struct net_device *dev) struct netfront_info *np = netdev_priv(dev); unsigned int num_queues = 0; int err; - unsigned int feature_rx_copy; unsigned int j = 0; struct netfront_queue *queue = NULL; - err = xenbus_scanf(XBT_NIL, np->xbdev->otherend, - "feature-rx-copy", "%u", &feature_rx_copy); - if (err != 1) - feature_rx_copy = 0; - - if (!feature_rx_copy) { + if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) { dev_info(&dev->dev, "backend does not support copying receive path\n"); return -ENODEV; -- GitLab