From patchwork Wed Mar 22 06:27:42 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Leizhen \(ThunderTown\)" X-Patchwork-Id: 95694 Delivered-To: patch@linaro.org Received: by 10.140.89.233 with SMTP id v96csp86304qgd; Tue, 21 Mar 2017 23:30:01 -0700 (PDT) X-Received: by 10.99.231.83 with SMTP id j19mr41570289pgk.50.1490164201235; Tue, 21 Mar 2017 23:30:01 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id r5si423551pfl.34.2017.03.21.23.30.00; Tue, 21 Mar 2017 23:30:01 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758811AbdCVG3o (ORCPT + 16 others); Wed, 22 Mar 2017 02:29:44 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:4348 "EHLO dggrg02-dlp.huawei.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1757351AbdCVG32 (ORCPT ); Wed, 22 Mar 2017 02:29:28 -0400 Received: from 172.30.72.54 (EHLO DGGEML404-HUB.china.huawei.com) ([172.30.72.54]) by dggrg02-dlp.huawei.com (MOS 4.4.6-GA FastPath queued) with ESMTP id AKH60775; Wed, 22 Mar 2017 14:29:21 +0800 (CST) Received: from localhost (10.177.23.164) by DGGEML404-HUB.china.huawei.com (10.3.17.39) with Microsoft SMTP Server id 14.3.301.0; Wed, 22 Mar 2017 14:29:10 +0800 From: Zhen Lei To: Joerg Roedel , iommu , Robin Murphy , David Woodhouse , Sudeep Dutt , Ashutosh Dixit , linux-kernel CC: Zefan Li , Xinwei Hu , "Tianhong Ding" , Hanjun Guo , Zhen Lei Subject: [PATCH 2/7] iommu/iova: cut down judgement times Date: Wed, 22 Mar 2017 14:27:42 +0800 Message-ID: <1490164067-12552-3-git-send-email-thunder.leizhen@huawei.com> X-Mailer: git-send-email 1.9.5.msysgit.0 In-Reply-To: <1490164067-12552-1-git-send-email-thunder.leizhen@huawei.com> References: <1490164067-12552-1-git-send-email-thunder.leizhen@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.177.23.164] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A0B0203.58D219C3.04A4, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0, ip=0.0.0.0, so=2014-11-16 11:51:01, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: ce6238b6d6c8f75336f7b9148b5e8178 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Below judgement can only be satisfied at the last time, which produced 2N judgements(suppose N times failed, 0 or 1 time successed) in vain. if ((pfn >= iova->pfn_lo) && (pfn <= iova->pfn_hi)) { return iova; } Signed-off-by: Zhen Lei --- drivers/iommu/iova.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) -- 2.5.0 Reviewed-by: Robin Murphy diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c index 8ba8b496..1c49969 100644 --- a/drivers/iommu/iova.c +++ b/drivers/iommu/iova.c @@ -312,15 +312,12 @@ private_find_iova(struct iova_domain *iovad, unsigned long pfn) while (node) { struct iova *iova = rb_entry(node, struct iova, node); - /* If pfn falls within iova's range, return iova */ - if ((pfn >= iova->pfn_lo) && (pfn <= iova->pfn_hi)) { - return iova; - } - if (pfn < iova->pfn_lo) node = node->rb_left; - else if (pfn > iova->pfn_lo) + else if (pfn > iova->pfn_hi) node = node->rb_right; + else + return iova; /* pfn falls within iova's range */ } return NULL;