From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755957AbYIQQyk (ORCPT ); Wed, 17 Sep 2008 12:54:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754545AbYIQQxP (ORCPT ); Wed, 17 Sep 2008 12:53:15 -0400 Received: from outbound-sin.frontbridge.com ([207.46.51.80]:52820 "EHLO SG2EHSOBE005.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754330AbYIQQxM (ORCPT ); Wed, 17 Sep 2008 12:53:12 -0400 X-BigFish: VPS4(zzzz10d3izzz32i43j65h) X-Spam-TCS-SCL: 4:0 X-WSS-ID: 0K7CMW5-03-U8T-01 From: Joerg Roedel To: linux-kernel@vger.kernel.org CC: iommu@lists.linux-foundation.org, Joerg Roedel Subject: [PATCH 04/23] AMD IOMMU: add branch hints to completion wait checks Date: Wed, 17 Sep 2008 18:52:38 +0200 Message-ID: <1221670377-19295-5-git-send-email-joerg.roedel@amd.com> X-Mailer: git-send-email 1.5.6.4 In-Reply-To: <1221670377-19295-1-git-send-email-joerg.roedel@amd.com> References: <1221670377-19295-1-git-send-email-joerg.roedel@amd.com> X-OriginalArrivalTime: 17 Sep 2008 16:52:57.0923 (UTC) FILETIME=[D654D130:01C918E5] 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 patch adds branch hints to the cecks if a completion_wait is necessary. The completion_waits in the mapping paths are unlikly because they will only happen on software implementations of AMD IOMMU which don't exists today or with lazy IO/TLB flushing when the allocator wraps around the address space. With lazy IO/TLB flushing the completion_wait in the unmapping path is unlikely too. Signed-off-by: Joerg Roedel --- arch/x86/kernel/amd_iommu.c | 12 ++++++------ 1 files changed, 6 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c index 0569098..7e9e4e7 100644 --- a/arch/x86/kernel/amd_iommu.c +++ b/arch/x86/kernel/amd_iommu.c @@ -876,7 +876,7 @@ static dma_addr_t map_single(struct device *dev, phys_addr_t paddr, if (addr == bad_dma_address) goto out; - if (iommu->need_sync) + if (unlikely(iommu->need_sync)) iommu_completion_wait(iommu); out: @@ -905,7 +905,7 @@ static void unmap_single(struct device *dev, dma_addr_t dma_addr, __unmap_single(iommu, domain->priv, dma_addr, size, dir); - if (iommu->need_sync) + if (unlikely(iommu->need_sync)) iommu_completion_wait(iommu); spin_unlock_irqrestore(&domain->lock, flags); @@ -968,7 +968,7 @@ static int map_sg(struct device *dev, struct scatterlist *sglist, goto unmap; } - if (iommu->need_sync) + if (unlikely(iommu->need_sync)) iommu_completion_wait(iommu); out: @@ -1014,7 +1014,7 @@ static void unmap_sg(struct device *dev, struct scatterlist *sglist, s->dma_address = s->dma_length = 0; } - if (iommu->need_sync) + if (unlikely(iommu->need_sync)) iommu_completion_wait(iommu); spin_unlock_irqrestore(&domain->lock, flags); @@ -1061,7 +1061,7 @@ static void *alloc_coherent(struct device *dev, size_t size, goto out; } - if (iommu->need_sync) + if (unlikely(iommu->need_sync)) iommu_completion_wait(iommu); out: @@ -1093,7 +1093,7 @@ static void free_coherent(struct device *dev, size_t size, __unmap_single(iommu, domain->priv, dma_addr, size, DMA_BIDIRECTIONAL); - if (iommu->need_sync) + if (unlikely(iommu->need_sync)) iommu_completion_wait(iommu); spin_unlock_irqrestore(&domain->lock, flags); -- 1.5.6.4