From patchwork Fri Oct 15 09:12:05 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Xin, Xiaohui" X-Patchwork-Id: 67909 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id DE390B70E8 for ; Fri, 15 Oct 2010 19:57:56 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754927Ab0JOI5M (ORCPT ); Fri, 15 Oct 2010 04:57:12 -0400 Received: from mga01.intel.com ([192.55.52.88]:56852 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753649Ab0JOIwy (ORCPT ); Fri, 15 Oct 2010 04:52:54 -0400 Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga101.fm.intel.com with ESMTP; 15 Oct 2010 01:52:51 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.57,335,1283756400"; d="scan'208";a="616995379" Received: from unknown (HELO localhost.localdomain.sh.intel.com) ([10.239.36.73]) by fmsmga002.fm.intel.com with ESMTP; 15 Oct 2010 01:52:49 -0700 From: xiaohui.xin@intel.com To: netdev@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, mst@redhat.com, mingo@elte.hu, davem@davemloft.net, herbert@gondor.apana.org.au, jdike@linux.intel.com Cc: Xin Xiaohui Subject: [PATCH v13 04/16] Add a function make external buffer owner to query capability. Date: Fri, 15 Oct 2010 17:12:05 +0800 Message-Id: X-Mailer: git-send-email 1.7.3 In-Reply-To: <1287133937-5538-1-git-send-email-xiaohui.xin@intel.com> References: <1287133937-5538-1-git-send-email-xiaohui.xin@intel.com> In-Reply-To: References: Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Xin Xiaohui The external buffer owner can use the functions to get the capability of the underlying NIC driver. Signed-off-by: Xin Xiaohui Signed-off-by: Zhao Yu Reviewed-by: Jeff Dike --- include/linux/netdevice.h | 2 + net/core/dev.c | 49 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 51 insertions(+), 0 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 575777f..8dcf6de 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1736,6 +1736,8 @@ extern gro_result_t napi_frags_finish(struct napi_struct *napi, gro_result_t ret); extern struct sk_buff * napi_frags_skb(struct napi_struct *napi); extern gro_result_t napi_gro_frags(struct napi_struct *napi); +extern int netdev_mp_port_prep(struct net_device *dev, + struct mp_port *port); static inline void napi_free_frags(struct napi_struct *napi) { diff --git a/net/core/dev.c b/net/core/dev.c index 660dd41..e48639d 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2942,6 +2942,55 @@ out: return ret; } +/* To support meidate passthru(zero-copy) with NIC driver, + * we'd better query NIC driver for the capability it can + * provide, especially for packet split mode, now we only + * query for the header size, and the payload a descriptor + * may carry. If a driver does not use the API to export, + * then we may try to use a default value, currently, + * we use the default value from an IGB driver. Now, + * it's only called by mpassthru device. + */ +#if defined(CONFIG_MEDIATE_PASSTHRU) || defined(CONFIG_MEDIATE_PASSTHRU_MODULE) +int netdev_mp_port_prep(struct net_device *dev, + struct mp_port *port) +{ + int rc; + int npages, data_len; + const struct net_device_ops *ops = dev->netdev_ops; + + if (ops->ndo_mp_port_prep) { + rc = ops->ndo_mp_port_prep(dev, port); + if (rc) + return rc; + } else { + /* If the NIC driver did not report this, + * then we try to use default value. + */ + port->hdr_len = 128; + port->data_len = 2048; + port->npages = 1; + } + + if (port->hdr_len <= 0) + goto err; + + npages = port->npages; + data_len = port->data_len; + if (npages <= 0 || npages > MAX_SKB_FRAGS || + (data_len < PAGE_SIZE * (npages - 1) || + data_len > PAGE_SIZE * npages)) + goto err; + + return 0; +err: + dev_warn(&dev->dev, "invalid page constructor parameters\n"); + + return -EINVAL; +} +EXPORT_SYMBOL(netdev_mp_port_prep); +#endif + /** * netif_receive_skb - process receive buffer from network * @skb: buffer to process