From patchwork Tue Oct 2 09:26:43 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Dooks X-Patchwork-Id: 977690 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 42PYhW01kbz9sj0 for ; Tue, 2 Oct 2018 19:27:23 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727353AbeJBQJM (ORCPT ); Tue, 2 Oct 2018 12:09:12 -0400 Received: from imap1.codethink.co.uk ([176.9.8.82]:50405 "EHLO imap1.codethink.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727164AbeJBQJM (ORCPT ); Tue, 2 Oct 2018 12:09:12 -0400 Received: from [148.252.241.226] (helo=rainbowdash) by imap1.codethink.co.uk with esmtpsa (Exim 4.84_2 #1 (Debian)) id 1g7Gx6-0002za-CP; Tue, 02 Oct 2018 10:26:48 +0100 Received: from ben by rainbowdash with local (Exim 4.91) (envelope-from ) id 1g7Gx6-0000Jd-4b; Tue, 02 Oct 2018 10:26:48 +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 2/4] usbnet: smsc95xx: align tx-buffer to word Date: Tue, 2 Oct 2018 10:26:43 +0100 Message-Id: <20181002092645.1115-3-ben.dooks@codethink.co.uk> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20181002092645.1115-1-ben.dooks@codethink.co.uk> References: <20181002092645.1115-1-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 tegra driver requires alignment of the buffer, so try and make this better by pushing the buffer start back to an word aligned address. At the worst this makes memcpy() easier as it is word aligned, at best it makes sure the usb can directly map the buffer. Signed-off-by: Ben Dooks [todo - make this configurable] --- drivers/net/usb/Kconfig | 12 ++++++++++++ drivers/net/usb/smsc95xx.c | 22 ++++++++++++++++++++-- 2 files changed, 32 insertions(+), 2 deletions(-) diff --git a/drivers/net/usb/Kconfig b/drivers/net/usb/Kconfig index a32f1a446ce9..35bad8bd2e2a 100644 --- a/drivers/net/usb/Kconfig +++ b/drivers/net/usb/Kconfig @@ -360,6 +360,18 @@ config USB_NET_SMSC95XX_TURBO driver's receive path. These can also be altered by the turbo_mode module parameter. +config USB_NET_SMSC95XX_TXALIGN + bool "Add bytes to align transmit buffers" + depends on USB_NET_SMSC95XX + default n + help + This option makes the tx buffers 32 bit aligned which might + help with systems that want tx data aligned to a 32 bit + boundary. + + Using this option will mean there may be up to 3 bytes of + data per packet sent. + config USB_NET_GL620A tristate "GeneSys GL620USB-A based cables" depends on USB_USBNET diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c index fe13bef9579e..d244357bf1ad 100644 --- a/drivers/net/usb/smsc95xx.c +++ b/drivers/net/usb/smsc95xx.c @@ -78,6 +78,10 @@ struct smsc95xx_priv { struct usbnet *dev; }; +static bool align_tx = IS_ENABLED(CONFIG_USB_NET_SMSC95XX_TXALIGN); +module_param(align_tx, bool, 0644); +MODULE_PARM_DESC(align_tx, "Align TX buffers to word boundaries"); + static bool turbo_mode = IS_ENABLED(CONFIG_USB_NET_SMSC95XX_TURBO); module_param(turbo_mode, bool, 0644); MODULE_PARM_DESC(turbo_mode, "Enable multiple frames per Rx transaction"); @@ -2005,10 +2009,18 @@ 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; + u32 data_len; + uintptr_t align = 0; /* We do not advertise SG, so skbs should be already linearized */ BUG_ON(skb_shinfo(skb)->nr_frags); + if (IS_ENABLED(CONFIG_USB_NET_SMSC95XX_TXALIGN) && align_tx) { + align = (uintptr_t)skb->data & 3; + if (align) + overhead += 4 - align; + } + /* Make writable and expand header space by overhead if required */ if (skb_cow_head(skb, overhead)) { /* Must deallocate here as returning NULL to indicate error @@ -2037,16 +2049,22 @@ static struct sk_buff *smsc95xx_tx_fixup(struct usbnet *dev, } } + data_len = skb->len; + if (align) + skb_push(skb, 4 - align); + skb_push(skb, 4); - tx_cmd_b = (u32)(skb->len - 4); + tx_cmd_b = (u32)(data_len); 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 = (u32)(data_len) | TX_CMD_A_FIRST_SEG_ | TX_CMD_A_LAST_SEG_; + if (align) + tx_cmd_a |= (4 - align) << 16; cpu_to_le32s(&tx_cmd_a); memcpy(skb->data, &tx_cmd_a, 4);