From patchwork Sat Aug 3 02:46:36 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 264372 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 529CA2C0097 for ; Sat, 3 Aug 2013 12:48:31 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754849Ab3HCCsQ (ORCPT ); Fri, 2 Aug 2013 22:48:16 -0400 Received: from mail-pd0-f173.google.com ([209.85.192.173]:39373 "EHLO mail-pd0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753512Ab3HCCsN (ORCPT ); Fri, 2 Aug 2013 22:48:13 -0400 Received: by mail-pd0-f173.google.com with SMTP id p11so1276323pdj.32 for ; Fri, 02 Aug 2013 19:48:13 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; bh=lUulvL1xC2o+x9mEMXgAOhJaYO1mTw/XsaNoFmpSrZU=; b=Ihh2AbCPwX+R3ua23OFE6yxSHo/4vZcK0iRNoFLEyrBjQAyEQkEw6ZEdRmDDZUR4aw 1BClf9I+xM7HjO0SGKpCBhGjAsyY1KnPMJufbPA1cEfLGfLU+i8ra4fJFvE1GjqH6G1y c1nIu5EIcQSBLCeUnOZnZNuUqoGsX9ZwIYx7hEE6khcCuy1NM8GVZgvJf+7vECXEv73F Oo1EhVU9mQFX42XrDsp1T1z+rX3y0ZP2yn0D7I/oX8xmZAm9S3FMg534NmR0YfsNB96G G+riF40aeEZI2U4iHUhxD9AZERdf7Go9CfpGgtbNWZxsGiNDy82uVFx6h4cSicbXVwFM yz/Q== X-Received: by 10.66.136.237 with SMTP id qd13mr13707579pab.74.1375498093162; Fri, 02 Aug 2013 19:48:13 -0700 (PDT) Received: from localhost ([183.37.205.90]) by mx.google.com with ESMTPSA id a5sm13348097pbw.4.2013.08.02.19.48.03 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Fri, 02 Aug 2013 19:48:12 -0700 (PDT) From: Ming Lei To: "David S. Miller" , Greg Kroah-Hartman Cc: Oliver Neukum , Sarah Sharp , netdev@vger.kernel.org, linux-usb@vger.kernel.org, Ming Lei , Eric Dumazet , Ben Hutchings , Grant Grundler , Freddy Xin , Alan Stern Subject: [PATCH v1 3/4] USBNET: support DMA SG Date: Sat, 3 Aug 2013 10:46:36 +0800 Message-Id: <1375497998-7424-4-git-send-email-ming.lei@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1375497998-7424-1-git-send-email-ming.lei@canonical.com> References: <1375497998-7424-1-git-send-email-ming.lei@canonical.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This patch introduces support of DMA SG if the USB host controller which usbnet device is attached to is capable of building packet from discontinuous buffers. The patch supports passing the skb fragment buffers to usb stack directly via urb->sg. Cc: Eric Dumazet Cc: Ben Hutchings Cc: Grant Grundler Cc: Freddy Xin Cc: Oliver Neukum Cc: Alan Stern Signed-off-by: Ming Lei --- drivers/net/usb/usbnet.c | 38 ++++++++++++++++++++++++++++++++++++-- include/linux/usb/usbnet.h | 1 + 2 files changed, 37 insertions(+), 2 deletions(-) diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index e4811d7..51753b3 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -1232,6 +1232,37 @@ EXPORT_SYMBOL_GPL(usbnet_tx_timeout); /*-------------------------------------------------------------------------*/ +static int build_dma_sg(const struct sk_buff *skb, struct urb *urb) +{ + unsigned num_sgs, total_len = 0; + int i, s = 0; + + num_sgs = skb_shinfo(skb)->nr_frags + 1; + if (num_sgs == 1) + return 0; + + urb->sg = kmalloc(num_sgs * sizeof(struct scatterlist), GFP_ATOMIC); + if (!urb->sg) + return -ENOMEM; + + urb->num_sgs = num_sgs; + sg_init_table(urb->sg, urb->num_sgs); + + sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb)); + total_len += skb_headlen(skb); + + for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { + struct skb_frag_struct *f = &skb_shinfo(skb)->frags[i]; + + total_len += skb_frag_size(f); + sg_set_page(&urb->sg[i + s], f->page.p, f->size, + f->page_offset); + } + urb->transfer_buffer_length = total_len; + + return 1; +} + netdev_tx_t usbnet_start_xmit (struct sk_buff *skb, struct net_device *net) { @@ -1258,7 +1289,6 @@ netdev_tx_t usbnet_start_xmit (struct sk_buff *skb, goto drop; } } - length = skb->len; if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) { netif_dbg(dev, tx_err, dev->net, "no urb\n"); @@ -1268,10 +1298,14 @@ netdev_tx_t usbnet_start_xmit (struct sk_buff *skb, entry = (struct skb_data *) skb->cb; entry->urb = urb; entry->dev = dev; - entry->length = length; usb_fill_bulk_urb (urb, dev->udev, dev->out, skb->data, skb->len, tx_complete, skb); + if (dev->can_dma_sg) { + if (build_dma_sg(skb, urb) < 0) + goto drop; + } + entry->length = length = urb->transfer_buffer_length; /* don't assume the hardware handles USB_ZERO_PACKET * NOTE: strictly conforming cdc-ether devices should expect diff --git a/include/linux/usb/usbnet.h b/include/linux/usb/usbnet.h index 8fbc008..9cb2fe8 100644 --- a/include/linux/usb/usbnet.h +++ b/include/linux/usb/usbnet.h @@ -35,6 +35,7 @@ struct usbnet { unsigned char suspend_count; unsigned char pkt_cnt, pkt_err; unsigned short rx_qlen, tx_qlen; + unsigned can_dma_sg:1; /* i/o info: pipes etc */ unsigned in, out;