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 685A8C433EF for ; Wed, 29 Jun 2022 07:52:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232487AbiF2HwC (ORCPT ); Wed, 29 Jun 2022 03:52:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36308 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230514AbiF2Hv5 (ORCPT ); Wed, 29 Jun 2022 03:51:57 -0400 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 80AD625C46 for ; Wed, 29 Jun 2022 00:51:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1656489116; x=1688025116; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=hkGm7YDPu5xil+VGf8bn6+rNMEI6Bw40A3ib6a6DFDY=; b=Ijr7Jg3BrD3Sb0WiVl9c2J+tp40WyAJD3zFc7OUh8e5FEzneSVVzNSgB vVXtmLZEJxwji5D46FgFY4rot3AOzm6sVfjICD5SCwpOCf4MXgFqwK3ft K/wHVuwPNQaBb+L2ebpyLPI2NIV52Z6PPsBEQPUMT94N2IuJvj0wICuwc XtslxF0BouNO8DlZ6rE2n46m51MBXXMSL8gvVciepvetUD34neEEFfmEB 2pwrB+9tjeTYD3L7LdSy9bHrlaZMLcH9lQOz7CvtQrDn11+AISh2lejXR r5xd1vxzIV0m5+kx5Q3yMUjvZJb5e+8n9BvA9oB9Hc16PHlthEDzZ95x5 g==; X-IronPort-AV: E=McAfee;i="6400,9594,10392"; a="270719369" X-IronPort-AV: E=Sophos;i="5.92,230,1650956400"; d="scan'208";a="270719369" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Jun 2022 00:51:56 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.92,230,1650956400"; d="scan'208";a="588209588" Received: from allen-box.sh.intel.com ([10.239.159.48]) by orsmga007.jf.intel.com with ESMTP; 29 Jun 2022 00:51:54 -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 v3 02/11] iommu/vt-d: Remove clearing translation data in disable_dmar_iommu() Date: Wed, 29 Jun 2022 15:47:16 +0800 Message-Id: <20220629074725.2331441-3-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220629074725.2331441-1-baolu.lu@linux.intel.com> References: <20220629074725.2331441-1-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