From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robert Jennings Subject: [PATCH 2/3] ibmveth: Enable IPv6 checksum offload Date: Wed, 18 Aug 2010 11:07:38 -0500 Message-ID: <20100818160738.GB29528@linux.vnet.ibm.com> References: <20100818160515.GA29528@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: David Miller , netdev@vger.kernel.org, Santiago Leon , Brian King Return-path: Received: from e34.co.us.ibm.com ([32.97.110.152]:42653 "EHLO e34.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753783Ab0HRQHk (ORCPT ); Wed, 18 Aug 2010 12:07:40 -0400 Received: from d03relay02.boulder.ibm.com (d03relay02.boulder.ibm.com [9.17.195.227]) by e34.co.us.ibm.com (8.14.4/8.13.1) with ESMTP id o7IFwoTx023360 for ; Wed, 18 Aug 2010 09:58:50 -0600 Received: from d03av05.boulder.ibm.com (d03av05.boulder.ibm.com [9.17.195.85]) by d03relay02.boulder.ibm.com (8.13.8/8.13.8/NCO v9.1) with ESMTP id o7IG7eVi219402 for ; Wed, 18 Aug 2010 10:07:40 -0600 Received: from d03av05.boulder.ibm.com (loopback [127.0.0.1]) by d03av05.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id o7IG7dNH022091 for ; Wed, 18 Aug 2010 10:07:39 -0600 Content-Disposition: inline In-Reply-To: <20100818160515.GA29528@linux.vnet.ibm.com> Sender: netdev-owner@vger.kernel.org List-ID: 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 --- drivers/net/ibmveth.c | 59 +++++++++++++++++++++++++++++++++++++++++--------- drivers/net/ibmveth.h | 2 ++ 2 files changed, 50 insertions(+), 11 deletions(-) Index: b/drivers/net/ibmveth.c =================================================================== --- a/drivers/net/ibmveth.c +++ b/drivers/net/ibmveth.c @@ -50,6 +50,7 @@ #include #include #include +#include #include #include #include @@ -134,6 +135,8 @@ 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 */ @@ -739,6 +742,7 @@ static void ibmveth_set_rx_csum_flags(st */ adapter->rx_csum = 0; dev->features &= ~NETIF_F_IP_CSUM; + dev->features &= ~NETIF_F_IPV6_CSUM; } } @@ -747,10 +751,15 @@ static void ibmveth_set_tx_csum_flags(st 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, @@ -758,7 +767,8 @@ static int ibmveth_set_csum_offload(stru { 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; @@ -772,10 +782,13 @@ static int ibmveth_set_csum_offload(stru 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); @@ -786,14 +799,33 @@ static int ibmveth_set_csum_offload(stru 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." @@ -821,9 +853,9 @@ static int ibmveth_set_tx_csum(struct ne 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) @@ -910,7 +942,12 @@ static netdev_tx_t ibmveth_start_xmit(st desc.fields.flags_len = IBMVETH_BUF_VALID | skb->len; 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"); tx_dropped++; goto out; Index: b/drivers/net/ibmveth.h =================================================================== --- a/drivers/net/ibmveth.h +++ b/drivers/net/ibmveth.h @@ -149,6 +149,8 @@ struct ibmveth_adapter { void *bounce_buffer; dma_addr_t bounce_buffer_dma; + u64 fw_ipv6_csum_support; + u64 fw_ipv4_csum_support; /* adapter specific stats */ u64 replenish_task_cycles; u64 replenish_no_mem;