From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 5 Aug 2001 20:33:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 5 Aug 2001 20:32:55 -0400 Received: from zero.aec.at ([195.3.98.22]:5386 "HELO zero.aec.at") by vger.kernel.org with SMTP id ; Sun, 5 Aug 2001 20:32:42 -0400 To: "" cc: linux-kernel@vger.kernel.org Subject: Re: TCP zero-copy In-Reply-To: <663CE32D.1D4A9213.0F45C3B8@netscape.net> <15210.4821.318434.454971@pizda.ninka.net> <3B6A7B96.1591.241743@localhost> From: Andi Kleen Date: 06 Aug 2001 02:32:36 +0200 In-Reply-To: ""'s message of "Fri, 03 Aug 2001 11:30:11 +0200" Message-ID: User-Agent: Gnus/5.0700000000000003 (Pterodactyl Gnus v0.83) Emacs/20.2 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org In article <3B6A7B96.1591.241743@localhost>, "" writes: > I have written a driver for an Intel ixf1002 chip, which has some > surrounding HW, and is capable of checksumming and processing > dma in fragments. Is there any information on what changes I > would have to make to the driver to support zerocopy/checksum ? The driver has to set dev->features to its checksum capabilities (see skbuff.h for more details) and implement them. It should also be able to process skbs with multiple skb fragments in hard_start_xmit for true zero copy; in this case set NETIF_F_SG and also NETIF_F_HIGHDMA if it supports 64bit addresses. When NETIF_F_SG and NETIF_F_IP_CSUM or NETIFI_F_HW_CSUM are set the stack will do zero copy IO on TX with sendfile. -Andi -Andi