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 1AAEDC43334 for ; Tue, 12 Jul 2022 00:14:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229606AbiGLAOf (ORCPT ); Mon, 11 Jul 2022 20:14:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50234 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229476AbiGLAOP (ORCPT ); Mon, 11 Jul 2022 20:14:15 -0400 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 033611FCC0 for ; Mon, 11 Jul 2022 17:13:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1657584838; x=1689120838; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=JZxZdCVM9VdvZ5C9SB8NDFeX/+e0lgtKOLXXi+obFWY=; b=DNAcByYZuiehcwD/g6UC9+Snn/PEfITXECKboDU39RsMEXl7F0ibR1nG F5t8w0i4kFeABGQhBIj2LY/lcyB8ayUfgwVQNLtpPDhGuRBhTvqlcYk8M V6fw5RGgWBvH8m4xOFUZy96my/ZpR/RerEILK5pI4MyiNrvVfZoZCKYAZ aaqwBrh6LjdGoMPqRF9ILh4VAeKW2tqQ4XurIkQHwzTEzsM2sFgrAfOas xLzoXpUsA9pqBQl4PB/SuatfrdOo6OBdZToqZlci0Vg2T8nesa+B9kw7l 1uIr9BkTbBVJz1Zd4tVvfeUkHQgLLpXdaMLmVf4cFhRQEoPGUoo86Mgaw g==; X-IronPort-AV: E=McAfee;i="6400,9594,10405"; a="284827958" X-IronPort-AV: E=Sophos;i="5.92,264,1650956400"; d="scan'208";a="284827958" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jul 2022 17:13:56 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.92,264,1650956400"; d="scan'208";a="592445746" Received: from allen-box.sh.intel.com ([10.239.159.48]) by orsmga007.jf.intel.com with ESMTP; 11 Jul 2022 17:13:54 -0700 From: Lu Baolu To: Joerg Roedel Cc: iommu@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH 10/25] iommu/vt-d: Remove clearing translation data in disable_dmar_iommu() Date: Tue, 12 Jul 2022 08:08:53 +0800 Message-Id: <20220712000908.3431936-11-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220712000908.3431936-1-baolu.lu@linux.intel.com> References: <20220712000908.3431936-1-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 Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20220706025524.2904370-3-baolu.lu@linux.intel.com --- 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