From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933453AbZIDJjn (ORCPT ); Fri, 4 Sep 2009 05:39:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933366AbZIDJi2 (ORCPT ); Fri, 4 Sep 2009 05:38:28 -0400 Received: from va3ehsobe003.messaging.microsoft.com ([216.32.180.13]:1826 "EHLO VA3EHSOBE003.bigfish.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933352AbZIDJiZ (ORCPT ); Fri, 4 Sep 2009 05:38:25 -0400 X-SpamScore: 3 X-BigFish: VPS3(zzzz1202hzzz32i203h43j65h) X-Spam-TCS-SCL: 4:0 X-FB-SS: 5, X-WSS-ID: 0KPFXFU-01-4M2-02 X-M-MSG: From: Joerg Roedel To: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org CC: Joerg Roedel Subject: [PATCH 1/8] x86/dma: Mark iommu_pass_through as __read_mostly Date: Fri, 4 Sep 2009 11:36:27 +0200 Message-ID: <1252056994-31980-2-git-send-email-joerg.roedel@amd.com> X-Mailer: git-send-email 1.6.3.3 In-Reply-To: <1252056994-31980-1-git-send-email-joerg.roedel@amd.com> References: <1252056994-31980-1-git-send-email-joerg.roedel@amd.com> X-OriginalArrivalTime: 04 Sep 2009 09:36:43.0279 (UTC) FILETIME=[366F19F0:01CA2D43] MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This variable is read most of the time. This patch marks it as such. It also documents the meaning the this variable while at it. Signed-off-by: Joerg Roedel --- arch/x86/kernel/pci-dma.c | 9 ++++++++- 1 files changed, 8 insertions(+), 1 deletions(-) diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c index 1a041bc..873aa07 100644 --- a/arch/x86/kernel/pci-dma.c +++ b/arch/x86/kernel/pci-dma.c @@ -32,7 +32,14 @@ int no_iommu __read_mostly; /* Set this to 1 if there is a HW IOMMU in the system */ int iommu_detected __read_mostly = 0; -int iommu_pass_through; +/* + * This variable becomes 1 if iommu=pt is passed on the kernel command line. + * If this variable is 1, IOMMU implementations do no DMA ranslation for + * devices and allow every device to access to whole physical memory. This is + * useful if a user want to use an IOMMU only for KVM device assignment to + * guests and not for driver dma translation. + */ +int iommu_pass_through __read_mostly; dma_addr_t bad_dma_address __read_mostly = 0; EXPORT_SYMBOL(bad_dma_address); -- 1.6.3.3