From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 99849C25B48 for ; Thu, 26 Oct 2023 08:54:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344839AbjJZIyL (ORCPT ); Thu, 26 Oct 2023 04:54:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56234 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344743AbjJZIxh (ORCPT ); Thu, 26 Oct 2023 04:53:37 -0400 Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 21C191B9 for ; Thu, 26 Oct 2023 01:53:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1698310415; x=1729846415; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=SGBMlTmr6toh8djYlkspv5ApDTa9BRAdKaaxwXIo8zw=; b=SKf8lRq2c+q3PQ8l7PQqWnP71ipUV/m695uvAS1XADhI04uR6LsXJELL wGKr6NprCmiXwFn1fZ8tHDL2CVuYrhjAIUySiOdLEFT5ypctsRFM3OKD2 tHVClW7LacFCDqsI3KWV6q5egsn6TbQg0Lj+JxMTkTvcvLP3fKLVj0cA+ 3BtYrAyL7n/eYF6THSdnSaL2wWQGHYFAGBTb32S2+XbQ3SfUUyRcEqJoz 4zAb4O2vFfjTj/sVhc+Cie/jk4itjqX/2FifeAJHN6OK/w4QUeD8p/6/n MQGFBYgQGd3KnJg7BtH+7Wkr0t2TOoNr3VKGPnW2u851/l6gLkWMEtGz7 g==; X-IronPort-AV: E=McAfee;i="6600,9927,10874"; a="391361929" X-IronPort-AV: E=Sophos;i="6.03,253,1694761200"; d="scan'208";a="391361929" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Oct 2023 01:53:34 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10874"; a="708996342" X-IronPort-AV: E=Sophos;i="6.03,253,1694761200"; d="scan'208";a="708996342" Received: from allen-box.sh.intel.com ([10.239.159.127]) by orsmga003.jf.intel.com with ESMTP; 26 Oct 2023 01:53:32 -0700 From: Lu Baolu To: Joerg Roedel Cc: Will Deacon , Robin Murphy , Jason Gunthorpe , Kevin Tian , iommu@lists.linux.dev, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH 1/1] iommu: Avoid unnecessary cache invalidations Date: Thu, 26 Oct 2023 16:49:42 +0800 Message-Id: <20231026084942.17387-1-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The iommu_create_device_direct_mappings() only needs to flush the caches when the mappings are changed in the affected domain. This is not true for non-DMA domains, or for devices attached to the domain that have no reserved regions. To avoid unnecessary cache invalidations, add a check before iommu_flush_iotlb_all(). Fixes: a48ce36e2786 ("iommu: Prevent RESV_DIRECT devices from blocking domains") Signed-off-by: Lu Baolu --- drivers/iommu/iommu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 00d0a2b5d7dc..0cb676590bfa 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -1114,7 +1114,8 @@ static int iommu_create_device_direct_mappings(struct iommu_domain *domain, } - iommu_flush_iotlb_all(domain); + if (!list_empty(&mappings) && iommu_is_dma_domain(domain)) + iommu_flush_iotlb_all(domain); out: iommu_put_resv_regions(dev, &mappings); -- 2.34.1