From patchwork Fri Dec 10 17:38:17 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Hutchings X-Patchwork-Id: 75116 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 611C0B70A5 for ; Sat, 11 Dec 2010 04:38:25 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753547Ab0LJRiU (ORCPT ); Fri, 10 Dec 2010 12:38:20 -0500 Received: from exchange.solarflare.com ([216.237.3.220]:26836 "EHLO exchange.solarflare.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751420Ab0LJRiU (ORCPT ); Fri, 10 Dec 2010 12:38:20 -0500 Received: from [10.17.20.137] ([10.17.20.137]) by exchange.solarflare.com over TLS secured channel with Microsoft SMTPSVC(6.0.3790.4675); Fri, 10 Dec 2010 09:38:19 -0800 Subject: [PATCH net-next-2.6 02/10] sfc: Use ACCESS_ONCE when copying efx_tx_queue::read_count From: Ben Hutchings To: David Miller Cc: netdev@vger.kernel.org, linux-net-drivers@solarflare.com In-Reply-To: <1292002527.11673.14.camel@bwh-desktop> References: <1292002527.11673.14.camel@bwh-desktop> Organization: Solarflare Communications Date: Fri, 10 Dec 2010 17:38:17 +0000 Message-ID: <1292002697.11673.16.camel@bwh-desktop> Mime-Version: 1.0 X-Mailer: Evolution 2.32.0 (2.32.0-2.fc14) X-OriginalArrivalTime: 10 Dec 2010 17:38:19.0761 (UTC) FILETIME=[08ECD610:01CB9891] X-TM-AS-Product-Ver: SMEX-8.0.0.1181-6.500.1024-17820.005 X-TM-AS-Result: No--9.715800-0.000000-31 X-TM-AS-User-Approved-Sender: Yes X-TM-AS-User-Blocked-Sender: No Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Signed-off-by: Ben Hutchings --- drivers/net/sfc/tx.c | 5 ++--- 1 files changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/net/sfc/tx.c b/drivers/net/sfc/tx.c index 03194f7..fef2235 100644 --- a/drivers/net/sfc/tx.c +++ b/drivers/net/sfc/tx.c @@ -240,8 +240,7 @@ netdev_tx_t efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb) * of read_count. */ smp_mb(); tx_queue->old_read_count = - *(volatile unsigned *) - &tx_queue->read_count; + ACCESS_ONCE(tx_queue->read_count); fill_level = (tx_queue->insert_count - tx_queue->old_read_count); q_space = efx->txq_entries - 1 - fill_level; @@ -764,7 +763,7 @@ static int efx_tx_queue_insert(struct efx_tx_queue *tx_queue, * stopped from the access of read_count. */ smp_mb(); tx_queue->old_read_count = - *(volatile unsigned *)&tx_queue->read_count; + ACCESS_ONCE(tx_queue->read_count); fill_level = (tx_queue->insert_count - tx_queue->old_read_count); q_space = efx->txq_entries - 1 - fill_level;