From patchwork Wed Nov 14 11:50:20 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Dooks X-Patchwork-Id: 10682381 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 383E514BA for ; Wed, 14 Nov 2018 11:50:47 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2A3F72B0E6 for ; Wed, 14 Nov 2018 11:50:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1E9542B142; Wed, 14 Nov 2018 11:50:47 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BA6082B0E6 for ; Wed, 14 Nov 2018 11:50:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732811AbeKNVxc (ORCPT ); Wed, 14 Nov 2018 16:53:32 -0500 Received: from imap1.codethink.co.uk ([176.9.8.82]:60564 "EHLO imap1.codethink.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728133AbeKNVxZ (ORCPT ); Wed, 14 Nov 2018 16:53:25 -0500 Received: from [148.252.241.226] (helo=rainbowdash) by imap1.codethink.co.uk with esmtpsa (Exim 4.84_2 #1 (Debian)) id 1gMtge-000203-Ez; Wed, 14 Nov 2018 11:50:24 +0000 Received: from ben by rainbowdash with local (Exim 4.91) (envelope-from ) id 1gMtge-0002XP-5X; Wed, 14 Nov 2018 11:50:24 +0000 From: Ben Dooks To: netdev@vger.kernel.org Cc: oneukum@suse.com, davem@davemloft.net, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, steve.glendinning@shawell.net, linux-kernel@lists.codethink.co.uk, Ben Dooks Subject: [PATCH 2/4] usbnet: smsc95xx: simplify tx_fixup code Date: Wed, 14 Nov 2018 11:50:20 +0000 Message-Id: <20181114115022.9584-3-ben.dooks@codethink.co.uk> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181114115022.9584-1-ben.dooks@codethink.co.uk> References: <20181114115022.9584-1-ben.dooks@codethink.co.uk> MIME-Version: 1.0 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The smsc95xx_tx_fixup is doing multiple calls to skb_push() to put an 8-byte command header onto the packet. It would be easier to do one skb_push() and then copy the data in once the push is done. We also make the code smaller by using proper unaligned puts for the header. This merges in the CPU to LE32 conversion as well and makes the whole sequence easier to understand hopefully. Signed-off-by: Ben Dooks --- Since v1: - Add alignment changes using put_unaligned_le32() --- drivers/net/usb/smsc95xx.c | 28 +++++++++++++--------------- 1 file changed, 13 insertions(+), 15 deletions(-) diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c index 401ec9feb495..50e97a159500 100644 --- a/drivers/net/usb/smsc95xx.c +++ b/drivers/net/usb/smsc95xx.c @@ -2006,6 +2006,7 @@ static struct sk_buff *smsc95xx_tx_fixup(struct usbnet *dev, bool csum = skb->ip_summed == CHECKSUM_PARTIAL; int overhead = csum ? SMSC95XX_TX_OVERHEAD_CSUM : SMSC95XX_TX_OVERHEAD; u32 tx_cmd_a, tx_cmd_b; + void *ptr; /* We do not advertise SG, so skbs should be already linearized */ BUG_ON(skb_shinfo(skb)->nr_frags); @@ -2019,6 +2020,9 @@ static struct sk_buff *smsc95xx_tx_fixup(struct usbnet *dev, return NULL; } + tx_cmd_b = (u32)skb->len; + tx_cmd_a = tx_cmd_b | TX_CMD_A_FIRST_SEG_ | TX_CMD_A_LAST_SEG_; + if (csum) { if (skb->len <= 45) { /* workaround - hardware tx checksum does not work @@ -2032,24 +2036,18 @@ static struct sk_buff *smsc95xx_tx_fixup(struct usbnet *dev, csum = false; } else { u32 csum_preamble = smsc95xx_calc_csum_preamble(skb); - skb_push(skb, 4); - cpu_to_le32s(&csum_preamble); - memcpy(skb->data, &csum_preamble, 4); + ptr = skb_push(skb, 4); + put_unaligned_le32(csum_preamble, ptr); + + tx_cmd_a += 4; + tx_cmd_b += 4; + tx_cmd_b |= TX_CMD_B_CSUM_ENABLE; } } - skb_push(skb, 4); - tx_cmd_b = (u32)(skb->len - 4); - if (csum) - tx_cmd_b |= TX_CMD_B_CSUM_ENABLE; - cpu_to_le32s(&tx_cmd_b); - memcpy(skb->data, &tx_cmd_b, 4); - - skb_push(skb, 4); - tx_cmd_a = (u32)(skb->len - 8) | TX_CMD_A_FIRST_SEG_ | - TX_CMD_A_LAST_SEG_; - cpu_to_le32s(&tx_cmd_a); - memcpy(skb->data, &tx_cmd_a, 4); + ptr = skb_push(skb, 8); + put_unaligned_le32(tx_cmd_a, ptr); + put_unaligned_le32(tx_cmd_b, ptr+4); return skb; }