From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joseph Gasparakis Subject: Re: [PATCH v3 1/4] net: Add support for hardware-offloaded encapsulation Date: Fri, 7 Dec 2012 11:41:46 -0800 (PST) Message-ID: References: <50C21D21.5040101@intel.com> <1354900385.2707.42.camel@bwh-desktop.uk.solarflarecom.com> <20121207.142845.1145515122357569641.davem@davemloft.net> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: joseph.gasparakis@intel.com, bhutchings@solarflare.com, alexander.h.duyck@intel.com, shemminger@vyatta.com, chrisw@sous-sol.org, gospo@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, dmitry@broadcom.com, saeed.bishara@gmail.com, peter.p.waskiewicz.jr@intel.com To: David Miller Return-path: In-Reply-To: <20121207.142845.1145515122357569641.davem@davemloft.net> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Fri, 7 Dec 2012, David Miller wrote: > From: Joseph Gasparakis > Date: Fri, 7 Dec 2012 10:24:17 -0800 (PST) > > > So the idea here is that the driver will use the headers for checksumming > > if the skb->encapsulation bit is on. The bit should be set in the protocol > > driver. > > > > To answer the second comment, the flags that we use in this series of > > patches is NETIF_F_IP_CSUM, NETIF_F_IPV6_CSUM and NETIF_F_SG. These are > > the bits that we propose will be used for checksumming of encapsulation. > > As per a previous comment in v2, the hw_enc_features field should be used > > also in the future when NICs have more encap offloads, so one could > > indicate these features there from the driver. > > > > Furthermore, I submitted a patch for Rx checksumming, where NETIF_F_RXCSUM > > is used, again in conjunction with skb->encapsulation flag. As I mention > > in my logs, the driver is expected to set the ip_summed to UNNECESSARY and > > turn the skb->encapsulation on, to indicate that the inner headers are > > already HW checksummed. > > > > This is the kind of language that belongs in the commit message and > code comments. > Sure. I'll wait to gather some more feedback if there is any and I will re-spin this off adding more code comments and clarify this in the logs.