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 C8C00C001E0 for ; Tue, 15 Aug 2023 01:19:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233798AbjHOBT0 (ORCPT ); Mon, 14 Aug 2023 21:19:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59306 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233817AbjHOBTN (ORCPT ); Mon, 14 Aug 2023 21:19:13 -0400 Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EC50EB2; Mon, 14 Aug 2023 18:19:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1692062352; x=1723598352; h=message-id:date:mime-version:cc:subject:to:references: from:in-reply-to:content-transfer-encoding; bh=QvD+OczAXQfY3EnI/faV3RaAbFUkc5kfqnTaF1n9e4M=; b=KfE+LdogsKCuQU3lSwOttxtxK/1FgbUC0TiTqWxL3UF2k1oAbJyp8DX/ N386jiPwbd17Ed7aO7t7UNO63wNa96/6u7cH/+kisuBHaiDyUgkxzktZS J1mdRuHwaCZYXU39pLpABoU7G8yI80eg0aYTKt2cBB6Ra4jZMb4Uiqwzd b11lOsEOrROT859dAWnLKeKFEJRenQclPdbtcetIEQ89+fy7i1eFsQYqn t9UkFnWrzc8BwNyXywNEAgqqg0I7Udgm2vU6Y8MUFd1Yg4itE2bFNKN/U +iXhFYEIxvYacxXgbAl2Vek7GMLXBSU3Hdm+CRAXYc3lwBAXcTlDIETE0 g==; X-IronPort-AV: E=McAfee;i="6600,9927,10802"; a="438516171" X-IronPort-AV: E=Sophos;i="6.01,173,1684825200"; d="scan'208";a="438516171" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Aug 2023 18:19:12 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10802"; a="823667919" X-IronPort-AV: E=Sophos;i="6.01,173,1684825200"; d="scan'208";a="823667919" Received: from blu2-mobl.ccr.corp.intel.com (HELO [10.254.215.149]) ([10.254.215.149]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Aug 2023 18:19:01 -0700 Message-ID: Date: Tue, 15 Aug 2023 09:18:59 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.14.0 Cc: baolu.lu@linux.intel.com, Andy Gross , Alim Akhtar , Bjorn Andersson , AngeloGioacchino Del Regno , Baolin Wang , Christophe Leroy , Gerald Schaefer , Heiko Stuebner , iommu@lists.linux.dev, Jernej Skrabec , Jonathan Hunter , Joerg Roedel , Kevin Tian , Konrad Dybcio , Krzysztof Kozlowski , linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-s390@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-sunxi@lists.linux.dev, linux-tegra@vger.kernel.org, Russell King , linuxppc-dev@lists.ozlabs.org, Matthias Brugger , Matthew Rosato , Michael Ellerman , Nicholas Piggin , Orson Zhai , Rob Clark , Robin Murphy , Samuel Holland , Thierry Reding , Krishna Reddy , Chen-Yu Tsai , Will Deacon , Yong Wu , Chunyan Zhang , Dmitry Osipenko , Marek Szyprowski , Nicolin Chen , Niklas Schnelle , Steven Price , Thierry Reding Subject: Re: [PATCH v6 08/25] iommu: Reorganize iommu_get_default_domain_type() to respect def_domain_type() Content-Language: en-US To: Jason Gunthorpe References: <8-v6-e8114faedade+425-iommu_all_defdom_jgg@nvidia.com> From: Baolu Lu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On 2023/8/15 1:25, Jason Gunthorpe wrote: > Ah, I went over all this again and decided to try again, it is too > complicated. This patch can do what the commit message says and the > following patches are even simpler: Yes. This method is more concise. Some nits below. > > /* > * Combine the driver's choosen def_domain_type across all the devices in a > * group. Drivers must give a consistent result. > */ > static int iommu_get_def_domain_type(struct iommu_group *group, > struct device *dev, int cur_type) > { > const struct iommu_ops *ops = group_iommu_ops(group); > int type; > > if (!ops->def_domain_type) > return cur_type; > > type = ops->def_domain_type(dev); > if (!type || cur_type == type) > return cur_type; > if (!cur_type) > return type; > > dev_err_ratelimited( > dev, > "IOMMU driver error, requesting conflicting def_domain_type, %s and %s, for devices in group %u.\n", > iommu_domain_type_str(cur_type), iommu_domain_type_str(type), > group->id); > > /* > * Try to recover, drivers are allowed to force IDENITY or DMA, IDENTITY > * takes precedence. > */ > if (cur_type || type == IOMMU_DOMAIN_IDENTITY) > return IOMMU_DOMAIN_IDENTITY; No need to check cur_type. It already returned if cur_type is 0. > return cur_type; > } > > /* > * A target_type of 0 will select the best domain type. 0 can be returned in > * this case meaning the global default should be used. > */ > static int iommu_get_default_domain_type(struct iommu_group *group, > int target_type) > { > struct device *untrusted = NULL; > struct group_device *gdev; > int driver_type = 0; > > lockdep_assert_held(&group->mutex); > > /* > * ARM32 drivers supporting CONFIG_ARM_DMA_USE_IOMMU can declare an > * identity_domain and it will automatically become their default > * domain. Later on ARM_DMA_USE_IOMMU will install its UNMANAGED domain. > * Override the selection to IDENTITY. > */ > if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)) { > static_assert(!(IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU) && > IS_ENABLED(CONFIG_IOMMU_DMA))); IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU) is duplicate with the condition in the if statement. So only static_assert(!IS_ENABLED(CONFIG_IOMMU_DMA)); ? > driver_type = IOMMU_DOMAIN_IDENTITY; > } > > for_each_group_device(group, gdev) { > driver_type = iommu_get_def_domain_type(group, gdev->dev, > driver_type); No need to call this in the loop body? > > if (dev_is_pci(gdev->dev) && to_pci_dev(gdev->dev)->untrusted) { > /* > * No ARM32 using systems will set untrusted, it cannot > * work. > */ > if (WARN_ON(IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU))) > return -1; > untrusted = gdev->dev; > } > } > > if (untrusted) { > if (driver_type && driver_type != IOMMU_DOMAIN_DMA) { > dev_err_ratelimited( > untrusted, > "Device is not trusted, but driver is overriding group %u to %s, refusing to probe.\n", > group->id, iommu_domain_type_str(driver_type)); > return -1; > } > driver_type = IOMMU_DOMAIN_DMA; > } > > if (target_type) { > if (driver_type && target_type != driver_type) > return -1; > return target_type; > } > return driver_type; > } Best regards, baolu