From patchwork Tue Aug 6 00:52:48 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 264824 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 6D5DF2C0077 for ; Tue, 6 Aug 2013 10:53:43 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752190Ab3HFAxk (ORCPT ); Mon, 5 Aug 2013 20:53:40 -0400 Received: from mail-pa0-f54.google.com ([209.85.220.54]:62625 "EHLO mail-pa0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752078Ab3HFAxi (ORCPT ); Mon, 5 Aug 2013 20:53:38 -0400 Received: by mail-pa0-f54.google.com with SMTP id kx1so43856pab.41 for ; Mon, 05 Aug 2013 17:53:38 -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:in-reply-to:references; bh=OJtJ8OjoSp0nx0Lwbr5UJ2aWU2L2zWDUzSGJWU1b8yg=; b=W1iuS52q2CML4lLzgDZw2Sz46/rVmzW72AVoJc0g05PL63S7TfOV/Hiiw0YMiRX9HC TrRynFpPpzpJA4anNDNKb2wv4T2vyv9qUUWxkDb7IM01LAYBFQUPCu5rwGbprYXdcfyF 2NDDGFZJoIg85B27bx21TYV8Fadyb/6lwW3zmEQRWIesqSmnvIMvxnStqpKQcQEpRTrz fi+n6HDcsdaePxJp++EUgjuqV0QoR9sWlWe9CFceRHOKsQmVuExuJuFkgQ4Xg1AXYjYS b93vVseDKwszoAYPdoNc9FuoIaU/w6ozqpzXrJGD551EgolVRxpX4APmp6TIErPFUtCG rjkg== X-Received: by 10.66.227.39 with SMTP id rx7mr278873pac.44.1375750418290; Mon, 05 Aug 2013 17:53:38 -0700 (PDT) Received: from localhost ([183.37.198.249]) by mx.google.com with ESMTPSA id ht5sm1673137pbb.29.2013.08.05.17.53.29 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Mon, 05 Aug 2013 17:53:37 -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 v3 3/4] USBNET: support DMA SG Date: Tue, 6 Aug 2013 08:52:48 +0800 Message-Id: <1375750370-18194-4-git-send-email-ming.lei@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1375750370-18194-1-git-send-email-ming.lei@canonical.com> References: <1375750370-18194-1-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 Acked-by: Oliver Neukum --- drivers/net/usb/usbnet.c | 45 +++++++++++++++++++++++++++++++++++++++++--- include/linux/usb/usbnet.h | 1 + 2 files changed, 43 insertions(+), 3 deletions(-) diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index e4811d7..534b60b 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 @@ -1340,7 +1374,10 @@ drop: not_drop: if (skb) dev_kfree_skb_any (skb); - usb_free_urb (urb); + if (urb) { + kfree(urb->sg); + usb_free_urb(urb); + } } else netif_dbg(dev, tx_queued, dev->net, "> tx, len %d, type 0x%x\n", length, skb->protocol); @@ -1391,6 +1428,7 @@ static void usbnet_bh (unsigned long param) rx_process (dev, skb); continue; case tx_done: + kfree(entry->urb->sg); case rx_cleanup: usb_free_urb (entry->urb); dev_kfree_skb (skb); @@ -1727,6 +1765,7 @@ int usbnet_resume (struct usb_interface *intf) retval = usb_submit_urb(res, GFP_ATOMIC); if (retval < 0) { dev_kfree_skb_any(skb); + kfree(res->sg); usb_free_urb(res); usb_autopm_put_interface_async(dev->intf); } else { 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;