From: kfraser@localhost.localdomain <kfraser@localhost.localdomain>
Date: Tue, 1 Aug 2006 10:54:45 +0000 (+0100)
Subject: [NET] Enable TCPv4 segmentation offload in front/back drivers.
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~15754^2~30
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks://%22Dat/%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22Dat?a=commitdiff_plain;h=0434f44fcd71e71ab93df1a90109357d5d6c6e65;p=xen.git

[NET] Enable TCPv4 segmentation offload in front/back drivers.
Signed-off-by: Keir Fraser <keir@xensource.com>
---

diff --git a/linux-2.6-xen-sparse/drivers/xen/netback/netback.c b/linux-2.6-xen-sparse/drivers/xen/netback/netback.c
index 82832368b9..4de5a9cb0b 100644
--- a/linux-2.6-xen-sparse/drivers/xen/netback/netback.c
+++ b/linux-2.6-xen-sparse/drivers/xen/netback/netback.c
@@ -221,13 +221,20 @@ static struct sk_buff *netbk_copy_skb(struct sk_buff *skb)
 	return NULL;
 }
 
+static inline int netbk_max_required_rx_slots(netif_t *netif)
+{
+	if (netif->features & (NETIF_F_SG|NETIF_F_TSO))
+		return MAX_SKB_FRAGS + 2; /* header + extra_info + frags */
+	return 1; /* all in one */
+}
+
 static inline int netbk_queue_full(netif_t *netif)
 {
-	RING_IDX peek = netif->rx_req_cons_peek;
+	RING_IDX peek   = netif->rx_req_cons_peek;
+	RING_IDX needed = netbk_max_required_rx_slots(netif);
 
-	return ((netif->rx.sring->req_prod - peek) <= (MAX_SKB_FRAGS + 1)) ||
-	       ((netif->rx.rsp_prod_pvt + NET_RX_RING_SIZE - peek) <=
-		(MAX_SKB_FRAGS + 1));
+	return ((netif->rx.sring->req_prod - peek) < needed) ||
+	       ((netif->rx.rsp_prod_pvt + NET_RX_RING_SIZE - peek) < needed);
 }
 
 int netif_be_start_xmit(struct sk_buff *skb, struct net_device *dev)
@@ -271,7 +278,7 @@ int netif_be_start_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	if (netbk_can_queue(dev) && netbk_queue_full(netif)) {
 		netif->rx.sring->req_event = netif->rx_req_cons_peek +
-			MAX_SKB_FRAGS + 2;
+			netbk_max_required_rx_slots(netif);
 		mb(); /* request notification /then/ check & stop the queue */
 		if (netbk_queue_full(netif))
 			netif_stop_queue(dev);
diff --git a/linux-2.6-xen-sparse/drivers/xen/netback/xenbus.c b/linux-2.6-xen-sparse/drivers/xen/netback/xenbus.c
index eb51533942..0d34bc8511 100644
--- a/linux-2.6-xen-sparse/drivers/xen/netback/xenbus.c
+++ b/linux-2.6-xen-sparse/drivers/xen/netback/xenbus.c
@@ -101,14 +101,12 @@ static int netback_probe(struct xenbus_device *dev,
 			goto abort_transaction;
 		}
 
-#if 0 /* KAF: After the protocol is finalised. */
 		err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4",
 				    "%d", 1);
 		if (err) {
 			message = "writing feature-gso-tcpv4";
 			goto abort_transaction;
 		}
-#endif
 
 		err = xenbus_transaction_end(xbt, 0);
 	} while (err == -EAGAIN);
@@ -384,7 +382,6 @@ static int connect_rings(struct backend_info *be)
 		be->netif->dev->features |= NETIF_F_SG;
 	}
 
-#if 0 /* KAF: After the protocol is finalised. */
 	if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4", "%d",
 			 &val) < 0)
 		val = 0;
@@ -392,7 +389,6 @@ static int connect_rings(struct backend_info *be)
 		be->netif->features |= NETIF_F_TSO;
 		be->netif->dev->features |= NETIF_F_TSO;
 	}
-#endif
 
 	/* Map the shared frame, irq etc. */
 	err = netif_map(be->netif, tx_ring_ref, rx_ring_ref, evtchn);
diff --git a/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c b/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
index 9ab89571de..3be2e87a7c 100644
--- a/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
+++ b/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
@@ -338,13 +338,11 @@ again:
 		goto abort_transaction;
 	}
 
-#if 0 /* KAF: After the protocol is finalised. */
 	err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
 	if (err) {
 		message = "writing feature-gso-tcpv4";
 		goto abort_transaction;
 	}
-#endif
 
 	err = xenbus_transaction_end(xbt, 0);
 	if (err) {
@@ -1327,9 +1325,7 @@ static int xennet_set_tso(struct net_device *dev, u32 data)
 		if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
 				 "feature-gso-tcpv4", "%d", &val) < 0)
 			val = 0;
-#if 0 /* KAF: After the protocol is finalised. */
 		if (!val)
-#endif
 			return -ENOSYS;
 	}