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 0B6F1C433EF for ; Wed, 6 Jul 2022 03:00:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231415AbiGFDAA (ORCPT ); Tue, 5 Jul 2022 23:00:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51394 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231386AbiGFC75 (ORCPT ); Tue, 5 Jul 2022 22:59:57 -0400 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 849511ADA8 for ; Tue, 5 Jul 2022 19:59:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1657076396; x=1688612396; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=hkGm7YDPu5xil+VGf8bn6+rNMEI6Bw40A3ib6a6DFDY=; b=WiK35u5weMHc1cTY1s6U9peoIsqMY1oNvwRd6eu7bwMR8CiHn0McM8K8 0QiHJW2hKwQbtoOJ46hdVKwyzeYZXHEicLQ/Tuxk49ZEuGqLcilDQaQuY sZ/okp3CmDd9dsp0HBbcSwT3ejwCPsPLEXMUfpgdbJ21n5ceiZ0Y4ZKAK fr3AfNG6T1FzJHrctLKs2/3aYHpimt50DXoNw+u4qDT8S/0rLX+GkK3iq t3p3iDnVEQ6/S2hGV57YY7HRyh0nyuDeJo5qX24VjEVhxF3hWehpHnx/6 3huoxA7sU5syVkSH/045cpCr4kL24TWMgGA3KM6UfnnZyNr1VKG+oPiqQ g==; X-IronPort-AV: E=McAfee;i="6400,9594,10399"; a="272409532" X-IronPort-AV: E=Sophos;i="5.92,248,1650956400"; d="scan'208";a="272409532" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jul 2022 19:59:56 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.92,248,1650956400"; d="scan'208";a="567874772" Received: from allen-box.sh.intel.com ([10.239.159.48]) by orsmga006.jf.intel.com with ESMTP; 05 Jul 2022 19:59:54 -0700 From: Lu Baolu To: iommu@lists.linux-foundation.org, iommu@lists.linux.dev Cc: Kevin Tian , Ashok Raj , Liu Yi L , Jacob jun Pan , linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH v4 02/11] iommu/vt-d: Remove clearing translation data in disable_dmar_iommu() Date: Wed, 6 Jul 2022 10:55:15 +0800 Message-Id: <20220706025524.2904370-3-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220706025524.2904370-1-baolu.lu@linux.intel.com> References: <20220706025524.2904370-1-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 bf5b937848b4..20c54e50f533 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 3b6571681bdd..43aaec5bdd84 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -1716,23 +1716,16 @@ 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