Re: [dpdk-dev] [PATCH 1/3] pmd: add new flag to indicate TX TSO operation on the packet

["Liu, Jijiang" <jijiang.liu@intel.com>]

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of
> miroslaw.walukiewicz@intel.com
> Sent: Monday, October 13, 2014 10:39 PM
> To: dev@dpdk.org
> Subject: [dpdk-dev] [PATCH 1/3] pmd: add new flag to indicate TX TSO operation
> on the packet
> 
> From: Miroslaw Walukiewicz <miroslaw.walukiewicz@intel.com>
> 
> Transmission of TCP packets could be accelerated by HW Transmit Segmentation
> Offload. With TSO packets up to 64K could be transmismitted.
> 
> When this flag is set the PMD drived will enable TCP segmentation.
> 
> The new field tso_segsz is added to indicate how long is TCP TSO segment.
> 
> Signed-off-by: Mirek Walukiewicz <miroslaw.walukiewicz@intel.com>
> ---
>  lib/librte_mbuf/rte_mbuf.h |    5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h index
> ddadc21..63cbc36 100644
> --- a/lib/librte_mbuf/rte_mbuf.h
> +++ b/lib/librte_mbuf/rte_mbuf.h
> @@ -117,6 +117,9 @@ extern "C" {
>  /* Use final bit of flags to indicate a control mbuf */
>  #define CTRL_MBUF_FLAG       (1ULL << 63) /**< Mbuf contains control data */
> 
> +/* Bit 50 - TSO (TCP Transmit Segmenation Offload) */
> +#define PKT_TX_TCP_TSO       (1ULL << 50) /**< Mbuf needs TSO enabling */


In VxLAN patch set  [PATCH v5 7/8]i40e:support VxLAN Tx checksum offload, the  bit (1ULL << 50)   in offload flag have already been used.
+#define PKT_TX_VXLAN_CKSUM   (1ULL << 50) /**< TX checksum of VxLAN computed by NIC */

>  /**
>   * Bit Mask to indicate what bits required for building TX context
>   */
> @@ -196,6 +199,8 @@ struct rte_mbuf {
>  			uint16_t l2_len:7;      /**< L2 (MAC) Header Length. */
>  		};
>  	};
> +	/* field to support TSO segment size */
> +	uint32_t tso_segsz;
>  } __rte_cache_aligned;
> 
>  /**