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authorSantiago Leon <santil@linux.vnet.ibm.com>2010-09-03 18:28:52 +0000
committerDavid S. Miller <davem@davemloft.net>2010-09-06 18:21:50 -0700
commitab78df75cac4d90b5b5471af795a64141243c02a (patch)
treed645048489a624d90687cb1d90747927150f3f80 /drivers/net/ibmveth.c
parentbc4c6f54e4e9971717d84c630acef0c7c3c75a97 (diff)
ibmveth: Enable IPv6 checksum offload
This patch enables TCP checksum offload support for IPv6 on ibmveth. This completely eliminates the generation and checking of the checksum for IPv6 packets that are completely virtual and never touch a physical network. A basic TCPIPV6_STREAM netperf run showed a ~30% throughput improvement when an MTU of 64000 was used. This featured is enabled by default, as is the case for IPv4 checksum offload. When checksum offload is enabled the driver will negotiate IPv4 and IPv6 offload with the firmware separately and enable what is available. As long as either IPv4 or IPv6 offload is supported and enabled the device will report that checksum offload is enabled. The device stats, available through ethtool, will display which checksum offload features are supported/enabled by firmware. Performance testing against a stock kernel shows no regression for IPv4 or IPv6 in terms of throughput or processor utilization with checksum disabled or enabled. Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> Signed-off-by: Santiago Leon <santil@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ibmveth.c')
-rw-r--r--drivers/net/ibmveth.c59
1 files changed, 48 insertions, 11 deletions
diff --git a/drivers/net/ibmveth.c b/drivers/net/ibmveth.c
index ab80d8fcccb..25cf7e0476d 100644
--- a/drivers/net/ibmveth.c
+++ b/drivers/net/ibmveth.c
@@ -50,6 +50,7 @@
#include <linux/proc_fs.h>
#include <linux/in.h>
#include <linux/ip.h>
+#include <linux/ipv6.h>
#include <linux/slab.h>
#include <net/net_namespace.h>
#include <asm/hvcall.h>
@@ -148,6 +149,8 @@ struct ibmveth_stat ibmveth_stats[] = {
{ "rx_no_buffer", IBMVETH_STAT_OFF(rx_no_buffer) },
{ "tx_map_failed", IBMVETH_STAT_OFF(tx_map_failed) },
{ "tx_send_failed", IBMVETH_STAT_OFF(tx_send_failed) },
+ { "fw_enabled_ipv4_csum", IBMVETH_STAT_OFF(fw_ipv4_csum_support) },
+ { "fw_enabled_ipv6_csum", IBMVETH_STAT_OFF(fw_ipv6_csum_support) },
};
/* simple methods of getting data from the current rxq entry */
@@ -773,6 +776,7 @@ static void ibmveth_set_rx_csum_flags(struct net_device *dev, u32 data)
*/
adapter->rx_csum = 0;
dev->features &= ~NETIF_F_IP_CSUM;
+ dev->features &= ~NETIF_F_IPV6_CSUM;
}
}
@@ -781,10 +785,15 @@ static void ibmveth_set_tx_csum_flags(struct net_device *dev, u32 data)
struct ibmveth_adapter *adapter = netdev_priv(dev);
if (data) {
- dev->features |= NETIF_F_IP_CSUM;
+ if (adapter->fw_ipv4_csum_support)
+ dev->features |= NETIF_F_IP_CSUM;
+ if (adapter->fw_ipv6_csum_support)
+ dev->features |= NETIF_F_IPV6_CSUM;
adapter->rx_csum = 1;
- } else
+ } else {
dev->features &= ~NETIF_F_IP_CSUM;
+ dev->features &= ~NETIF_F_IPV6_CSUM;
+ }
}
static int ibmveth_set_csum_offload(struct net_device *dev, u32 data,
@@ -792,7 +801,8 @@ static int ibmveth_set_csum_offload(struct net_device *dev, u32 data,
{
struct ibmveth_adapter *adapter = netdev_priv(dev);
unsigned long set_attr, clr_attr, ret_attr;
- long ret;
+ unsigned long set_attr6, clr_attr6;
+ long ret, ret6;
int rc1 = 0, rc2 = 0;
int restart = 0;
@@ -806,10 +816,13 @@ static int ibmveth_set_csum_offload(struct net_device *dev, u32 data,
set_attr = 0;
clr_attr = 0;
- if (data)
+ if (data) {
set_attr = IBMVETH_ILLAN_IPV4_TCP_CSUM;
- else
+ set_attr6 = IBMVETH_ILLAN_IPV6_TCP_CSUM;
+ } else {
clr_attr = IBMVETH_ILLAN_IPV4_TCP_CSUM;
+ clr_attr6 = IBMVETH_ILLAN_IPV6_TCP_CSUM;
+ }
ret = h_illan_attributes(adapter->vdev->unit_address, 0, 0, &ret_attr);
@@ -820,14 +833,33 @@ static int ibmveth_set_csum_offload(struct net_device *dev, u32 data,
set_attr, &ret_attr);
if (ret != H_SUCCESS) {
- rc1 = -EIO;
- ibmveth_error_printk("unable to change checksum offload settings."
- " %d rc=%ld\n", data, ret);
+ ibmveth_error_printk("unable to change IPv4 checksum "
+ "offload settings. %d rc=%ld\n",
+ data, ret);
ret = h_illan_attributes(adapter->vdev->unit_address,
set_attr, clr_attr, &ret_attr);
} else
+ adapter->fw_ipv4_csum_support = data;
+
+ ret6 = h_illan_attributes(adapter->vdev->unit_address,
+ clr_attr6, set_attr6, &ret_attr);
+
+ if (ret6 != H_SUCCESS) {
+ ibmveth_error_printk("unable to change IPv6 checksum "
+ "offload settings. %d rc=%ld\n",
+ data, ret);
+
+ ret = h_illan_attributes(adapter->vdev->unit_address,
+ set_attr6, clr_attr6,
+ &ret_attr);
+ } else
+ adapter->fw_ipv6_csum_support = data;
+
+ if (ret == H_SUCCESS || ret6 == H_SUCCESS)
done(dev, data);
+ else
+ rc1 = -EIO;
} else {
rc1 = -EIO;
ibmveth_error_printk("unable to change checksum offload settings."
@@ -855,9 +887,9 @@ static int ibmveth_set_tx_csum(struct net_device *dev, u32 data)
struct ibmveth_adapter *adapter = netdev_priv(dev);
int rc = 0;
- if (data && (dev->features & NETIF_F_IP_CSUM))
+ if (data && (dev->features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)))
return 0;
- if (!data && !(dev->features & NETIF_F_IP_CSUM))
+ if (!data && !(dev->features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)))
return 0;
if (data && !adapter->rx_csum)
@@ -975,7 +1007,12 @@ static netdev_tx_t ibmveth_start_xmit(struct sk_buff *skb,
/* veth can't checksum offload UDP */
if (skb->ip_summed == CHECKSUM_PARTIAL &&
- ip_hdr(skb)->protocol != IPPROTO_TCP && skb_checksum_help(skb)) {
+ ((skb->protocol == htons(ETH_P_IP) &&
+ ip_hdr(skb)->protocol != IPPROTO_TCP) ||
+ (skb->protocol == htons(ETH_P_IPV6) &&
+ ipv6_hdr(skb)->nexthdr != IPPROTO_TCP)) &&
+ skb_checksum_help(skb)) {
+
ibmveth_error_printk("tx: failed to checksum packet\n");
netdev->stats.tx_dropped++;
goto out;