From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932737AbZIDGpr (ORCPT ); Fri, 4 Sep 2009 02:45:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932700AbZIDGpo (ORCPT ); Fri, 4 Sep 2009 02:45:44 -0400 Received: from mga02.intel.com ([134.134.136.20]:36135 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756678AbZIDGpd (ORCPT ); Fri, 4 Sep 2009 02:45:33 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.44,330,1249282800"; d="scan'208";a="445599562" Subject: [PATCH 09/18] ioat3: enable dca for completion writes To: linux-kernel@vger.kernel.org From: Dan Williams Cc: linux-raid@vger.kernel.org, maciej.sosnowski@intel.com Date: Thu, 03 Sep 2009 23:45:20 -0700 Message-ID: <20090904064520.7141.62811.stgit@dwillia2-linux.ch.intel.com> In-Reply-To: <20090904064308.7141.30576.stgit@dwillia2-linux.ch.intel.com> References: <20090904064308.7141.30576.stgit@dwillia2-linux.ch.intel.com> User-Agent: StGit/0.14.3.289.g7daff MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Tag completion writes for direct cache access to reduce the latency of checking for descriptor completions. Signed-off-by: Dan Williams --- drivers/dma/ioat/dma_v3.c | 3 ++- drivers/dma/ioat/registers.h | 1 + 2 files changed, 3 insertions(+), 1 deletions(-) diff --git a/drivers/dma/ioat/dma_v3.c b/drivers/dma/ioat/dma_v3.c index 22af78e..0913d11 100644 --- a/drivers/dma/ioat/dma_v3.c +++ b/drivers/dma/ioat/dma_v3.c @@ -167,7 +167,8 @@ static void ioat3_cleanup_tasklet(unsigned long data) struct ioat2_dma_chan *ioat = (void *) data; ioat3_cleanup(ioat); - writew(IOAT_CHANCTRL_RUN, ioat->base.reg_base + IOAT_CHANCTRL_OFFSET); + writew(IOAT_CHANCTRL_RUN | IOAT3_CHANCTRL_COMPL_DCA_EN, + ioat->base.reg_base + IOAT_CHANCTRL_OFFSET); } static void ioat3_restart_channel(struct ioat2_dma_chan *ioat) diff --git a/drivers/dma/ioat/registers.h b/drivers/dma/ioat/registers.h index 85d04b8..97d26ea 100644 --- a/drivers/dma/ioat/registers.h +++ b/drivers/dma/ioat/registers.h @@ -84,6 +84,7 @@ /* DMA Channel Registers */ #define IOAT_CHANCTRL_OFFSET 0x00 /* 16-bit Channel Control Register */ #define IOAT_CHANCTRL_CHANNEL_PRIORITY_MASK 0xF000 +#define IOAT3_CHANCTRL_COMPL_DCA_EN 0x0200 #define IOAT_CHANCTRL_CHANNEL_IN_USE 0x0100 #define IOAT_CHANCTRL_DESCRIPTOR_ADDR_SNOOP_CONTROL 0x0020 #define IOAT_CHANCTRL_ERR_INT_EN 0x0010