From patchwork Fri Oct 12 08:34:00 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Dooks X-Patchwork-Id: 982909 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=codethink.co.uk Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 42Wh3n0P4jz9s1c for ; Fri, 12 Oct 2018 19:35:17 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728164AbeJLQGY (ORCPT ); Fri, 12 Oct 2018 12:06:24 -0400 Received: from imap1.codethink.co.uk ([176.9.8.82]:48204 "EHLO imap1.codethink.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727658AbeJLQFd (ORCPT ); Fri, 12 Oct 2018 12:05:33 -0400 Received: from [148.252.241.226] (helo=rainbowdash) by imap1.codethink.co.uk with esmtpsa (Exim 4.84_2 #1 (Debian)) id 1gAstc-0005TZ-Lz; Fri, 12 Oct 2018 09:34:08 +0100 Received: from ben by rainbowdash with local (Exim 4.91) (envelope-from ) id 1gAstc-00052b-5Z; Fri, 12 Oct 2018 09:34:08 +0100 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, linux-kernel@lists.codethink.co.uk, Ben Dooks Subject: [PATCH 3/8] usbnet: smsc95xx: simplify tx_fixup code Date: Fri, 12 Oct 2018 09:34:00 +0100 Message-Id: <20181012083405.19246-4-ben.dooks@codethink.co.uk> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181012083405.19246-1-ben.dooks@codethink.co.uk> References: <20181012083405.19246-1-ben.dooks@codethink.co.uk> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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 cb19aea139d3..0c083d1b7f34 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; }