From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bruce Richardson Subject: Re: [PATCH 04/12] mbuf: add help about TX checksum flags Date: Mon, 10 Nov 2014 17:10:59 +0000 Message-ID: <20141110171059.GD10776@bricha3-MOBL3> References: <1415635166-1364-1-git-send-email-olivier.matz@6wind.com> <1415635166-1364-5-git-send-email-olivier.matz@6wind.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: jigsaw-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, dev-VfR2kkLFssw@public.gmane.org To: Olivier Matz Return-path: Content-Disposition: inline In-Reply-To: <1415635166-1364-5-git-send-email-olivier.matz-pdR9zngts4EAvxtiuMwx3w@public.gmane.org> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces-VfR2kkLFssw@public.gmane.org Sender: "dev" On Mon, Nov 10, 2014 at 04:59:18PM +0100, Olivier Matz wrote: > Describe how to use hardware checksum API. > > Signed-off-by: Olivier Matz Acked-by: Bruce Richardson > --- > lib/librte_mbuf/rte_mbuf.h | 25 +++++++++++++++++-------- > 1 file changed, 17 insertions(+), 8 deletions(-) > > diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h > index be15168..96e322b 100644 > --- a/lib/librte_mbuf/rte_mbuf.h > +++ b/lib/librte_mbuf/rte_mbuf.h > @@ -95,19 +95,28 @@ extern "C" { > #define PKT_RX_TUNNEL_IPV6_HDR (1ULL << 12) /**< RX tunnel packet with IPv6 header. */ > > #define PKT_TX_VLAN_PKT (1ULL << 55) /**< TX packet is a 802.1q VLAN packet. */ > -#define PKT_TX_IP_CKSUM (1ULL << 54) /**< IP cksum of TX pkt. computed by NIC. */ > + > +/** > + * Enable hardware computation of IP cksum. To use it: > + * - fill l2_len and l3_len in mbuf > + * - set the flags PKT_TX_IP_CKSUM > + * - set the ip checksum to 0 in IP header > + */ > +#define PKT_TX_IP_CKSUM (1ULL << 54) > #define PKT_TX_IPV4_CSUM PKT_TX_IP_CKSUM /**< Alias of PKT_TX_IP_CKSUM. */ > #define PKT_TX_IPV4 PKT_RX_IPV4_HDR /**< IPv4 with no IP checksum offload. */ > #define PKT_TX_IPV6 PKT_RX_IPV6_HDR /**< IPv6 packet */ > > -/* > - * Bits 52+53 used for L4 packet type with checksum enabled. > - * 00: Reserved > - * 01: TCP checksum > - * 10: SCTP checksum > - * 11: UDP checksum > +/** > + * Bits 52+53 used for L4 packet type with checksum enabled: 00: Reserved, > + * 01: TCP checksum, 10: SCTP checksum, 11: UDP checksum. To use hardware > + * L4 checksum offload, the user needs to: > + * - fill l2_len and l3_len in mbuf > + * - set the flags PKT_TX_TCP_CKSUM, PKT_TX_SCTP_CKSUM or PKT_TX_UDP_CKSUM > + * - calculate the pseudo header checksum and set it in the L4 header (only > + * for TCP or UDP). For SCTP, set the crc field to 0. > */ > -#define PKT_TX_L4_NO_CKSUM (0ULL << 52) /**< Disable L4 cksum of TX pkt. */ > +#define PKT_TX_L4_NO_CKSUM (0ULL << 52) /* Disable L4 cksum of TX pkt. */ > #define PKT_TX_TCP_CKSUM (1ULL << 52) /**< TCP cksum of TX pkt. computed by NIC. */ > #define PKT_TX_SCTP_CKSUM (2ULL << 52) /**< SCTP cksum of TX pkt. computed by NIC. */ > #define PKT_TX_UDP_CKSUM (3ULL << 52) /**< UDP cksum of TX pkt. computed by NIC. */ > -- > 2.1.0 >