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 7250AC433EF for ; Tue, 14 Jun 2022 02:59:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350370AbiFNC7Z (ORCPT ); Mon, 13 Jun 2022 22:59:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56264 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355539AbiFNC6x (ORCPT ); Mon, 13 Jun 2022 22:58:53 -0400 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 504E32725 for ; Mon, 13 Jun 2022 19:55:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1655175344; x=1686711344; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=JgUJCM9giMMlxrrl4/MFeIqwQoPEmE59CZySUaxICSM=; b=TBisvL0qAE8ibKUgiigKFVdB0S29oOjaGyUF9NeJo2yWrfyLmPB6KKfT CiBBFFdvpx7WFAvUPUCuRgyusNgI8H9WGGe8T6BYalH7UyT9W4e4ty0bN 2ugwWxQHHXsq8hOaTAE1bPdMVKVX/9cCC1RIZ4QJOOHL8l8guxiLrTwhG YI9By6aQm8US5eTlbtvuWSInzUNPp/biJqW2KPr+LtwFbJ5Nq3sHM3uWv /bHgOAiVvS+JOtfOGtV89tKKLp21vEXRZKnugKDLF/b/FUtFcWIetrb9b hKYtIrK/Gldwd8oRBHV8BOiwMTd/TWIYy5z9aV05q3K9U6EF3BV/NI6ak Q==; X-IronPort-AV: E=McAfee;i="6400,9594,10377"; a="258930299" X-IronPort-AV: E=Sophos;i="5.91,298,1647327600"; d="scan'208";a="258930299" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jun 2022 19:55:44 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.91,298,1647327600"; d="scan'208";a="588166453" Received: from allen-box.sh.intel.com ([10.239.159.48]) by fmsmga007.fm.intel.com with ESMTP; 13 Jun 2022 19:55:41 -0700 From: Lu Baolu To: Joerg Roedel , Kevin Tian , Ashok Raj , Christoph Hellwig , Jason Gunthorpe Cc: Will Deacon , Robin Murphy , Liu Yi L , Jacob jun Pan , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH v2 03/12] iommu/vt-d: Remove clearing translation data in disable_dmar_iommu() Date: Tue, 14 Jun 2022 10:51:28 +0800 Message-Id: <20220614025137.1632762-4-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220614025137.1632762-1-baolu.lu@linux.intel.com> References: <20220614025137.1632762-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The disable_dmar_iommu() is called when IOMMU initialization fails or the IOMMU is hot-removed from the system. In both cases, there is no need to clear the IOMMU translation data structures for devices. On the initialization path, the device probing only happens after the IOMMU is initialized successfully, hence there're no translation data structures. On the hot-remove path, there is no real use case where the IOMMU is hot-removed, but the devices that it manages are still alive in the system. The translation data structures were torn down during device release, hence there's no need to repeat it in IOMMU hot-remove path either. This removes the unnecessary code and only leaves a check. Signed-off-by: Lu Baolu --- drivers/iommu/intel/pasid.h | 1 + drivers/iommu/intel/iommu.c | 21 +++++++-------------- 2 files changed, 8 insertions(+), 14 deletions(-) diff --git a/drivers/iommu/intel/pasid.h b/drivers/iommu/intel/pasid.h index 583ea67fc783..2afbb2afe8cc 100644 --- a/drivers/iommu/intel/pasid.h +++ b/drivers/iommu/intel/pasid.h @@ -39,6 +39,7 @@ * only and pass-through transfer modes. */ #define FLPT_DEFAULT_DID 1 +#define NUM_RESERVED_DID 2 /* * The SUPERVISOR_MODE flag indicates a first level translation which diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index ff6018f746e0..695aed474e5d 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -1715,23 +1715,16 @@ static int iommu_init_domains(struct intel_iommu *iommu) static void disable_dmar_iommu(struct intel_iommu *iommu) { - struct device_domain_info *info, *tmp; - unsigned long flags; - if (!iommu->domain_ids) return; - spin_lock_irqsave(&device_domain_lock, flags); - list_for_each_entry_safe(info, tmp, &device_domain_list, global) { - if (info->iommu != iommu) - continue; - - if (!info->dev || !info->domain) - continue; - - __dmar_remove_one_dev_info(info); - } - spin_unlock_irqrestore(&device_domain_lock, flags); + /* + * All iommu domains must have been detached from the devices, + * hence there should be no domain IDs in use. + */ + if (WARN_ON(bitmap_weight(iommu->domain_ids, cap_ndoms(iommu->cap)) + != NUM_RESERVED_DID)) + return; if (iommu->gcmd & DMA_GCMD_TE) iommu_disable_translation(iommu); -- 2.25.1