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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DD36FC77B7E for ; Thu, 1 Jun 2023 18:58:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=mKjASkMfCrXXpN9jXbps012SDjEq7MmlGxFX2821i2w=; b=aMr21OWbR+94h1 ndy6uQFW2eheGNsndrKO9LbnQgNVBRIhmIogTmJgcw018568H2N4VtSoVDnKkVXwUa+h6NPDCHCQj i9Ov9jnPaUbId0rgG51KXxTY1IWAjK8xQ9Z3DKOQuIkyflEfFsjPJ9SyolwKcVa11mPp+jLpYaDW8 fOJu8Bt3btEqFNSAAtvfbNOLkE4WFbhgCIqWrowlcV0P8wNxgX4DFiNfZmJCd+4N/Lb1vxVbljvqt R8XkOEQv3lj53loAYHe0jWxGDBVRSNZPDhRJEvMXNOeyVmMwZvy5pqtq8ldMnVttAuipBLS7ftRje 0dAEkfVadnhFoZUNm8Cg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1q4nUY-004f7e-0A; Thu, 01 Jun 2023 18:57:46 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1q4nUT-004f6j-24; Thu, 01 Jun 2023 18:57:44 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 69B4A1063; Thu, 1 Jun 2023 11:58:24 -0700 (PDT) Received: from [10.57.84.85] (unknown [10.57.84.85]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id F213C3F7BD; Thu, 1 Jun 2023 11:57:30 -0700 (PDT) Message-ID: Date: Thu, 1 Jun 2023 19:57:25 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:102.0) Gecko/20100101 Thunderbird/102.11.2 Subject: Re: [PATCH v2 08/25] iommu: Allow an IDENTITY domain as the default_domain in ARM32 Content-Language: en-GB To: Jason Gunthorpe , 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, Marek Szyprowski , Matthias Brugger , Matthew Rosato , Michael Ellerman , Nicholas Piggin , Orson Zhai , Rob Clark , Samuel Holland , Thierry Reding , Krishna Reddy , Chen-Yu Tsai , Will Deacon , Yong Wu , Chunyan Zhang Cc: Lu Baolu , Dmitry Osipenko , Nicolin Chen , Niklas Schnelle , Steven Price , Thierry Reding References: <8-v2-8d1dc464eac9+10f-iommu_all_defdom_jgg@nvidia.com> From: Robin Murphy In-Reply-To: <8-v2-8d1dc464eac9+10f-iommu_all_defdom_jgg@nvidia.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230601_115742_196153_0F55FCF0 X-CRM114-Status: GOOD ( 43.67 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2023-05-16 01:00, Jason Gunthorpe wrote: > Even though dma-iommu.c and CONFIG_ARM_DMA_USE_IOMMU do approximately the > same stuff, the way they relate to the IOMMU core is quiet different. > > dma-iommu.c expects the core code to setup an UNMANAGED domain (of type > IOMMU_DOMAIN_DMA) and then configures itself to use that domain. This > becomes the default_domain for the group. > > ARM_DMA_USE_IOMMU does not use the default_domain, instead it directly > allocates an UNMANAGED domain and operates it just like an external > driver. In this case group->default_domain is NULL. > > If the driver provides a global static identity_domain then automatically > use it as the default_domain when in ARM_DMA_USE_IOMMU mode. > > This allows drivers that implemented default_domain == NULL as an IDENTITY > translation to trivially get a properly labeled non-NULL default_domain on > ARM32 configs. > > With this arrangment when ARM_DMA_USE_IOMMU wants to disconnect from the > device the normal detach_domain flow will restore the IDENTITY domain as > the default domain. Overall this makes attach_dev() of the IDENTITY domain > called in the same places as detach_dev(). > > This effectively migrates these drivers to default_domain mode. For > drivers that support ARM64 they will gain support for the IDENTITY > translation mode for the dma_api and behave in a uniform way. > > Drivers use this by setting ops->identity_domain to a static singleton > iommu_domain that implements the identity attach. If the core detects > ARM_DMA_USE_IOMMU mode then it automatically attaches the IDENTITY domain > during probe. > > Drivers can continue to prevent the use of DMA translation by returning > IOMMU_DOMAIN_IDENTITY from def_domain_type, this will completely prevent > IOMMU_DMA from running but will not impact ARM_DMA_USE_IOMMU. > > This allows removing the set_platform_dma_ops() from every remaining > driver. > > Remove the set_platform_dma_ops from rockchip and mkt_v1 as all it does > is set an existing global static identity domain. mkt_v1 does not support > IOMMU_DOMAIN_DMA and it does not compile on ARM64 so this transformation > is safe. > > Signed-off-by: Jason Gunthorpe > --- > drivers/iommu/iommu.c | 40 +++++++++++++++++++++++++++++----- > drivers/iommu/mtk_iommu_v1.c | 12 ---------- > drivers/iommu/rockchip-iommu.c | 10 --------- > 3 files changed, 35 insertions(+), 27 deletions(-) > > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > index 8ba90571449cec..bed7cb6e5ee65b 100644 > --- a/drivers/iommu/iommu.c > +++ b/drivers/iommu/iommu.c > @@ -1757,18 +1757,48 @@ static int iommu_get_default_domain_type(struct iommu_group *group, > int type; > > 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 we are sure the driver supports > + * it. > + */ > + if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU) && ops->identity_domain) { If I cared about arm-smmu on 32-bit, I'd bring that up again, but honestly I'm not sure that I do... I think it might end up working after patch #21, and it's currently still broken for lack of .set_platform_dma anyway, so meh. > + type = IOMMU_DOMAIN_IDENTITY; > + if (best_type && type && best_type != type) > + goto err; > + best_type = target_type = IOMMU_DOMAIN_IDENTITY; > + } > + > for_each_group_device(group, gdev) { > type = best_type; > if (ops->def_domain_type) { > type = ops->def_domain_type(gdev->dev); > - if (best_type && type && best_type != type) > + if (best_type && type && best_type != type) { > + /* Stick with the last driver override we saw */ > + best_type = type; > goto err; > + } > } > > if (dev_is_pci(gdev->dev) && to_pci_dev(gdev->dev)->untrusted) { > - type = IOMMU_DOMAIN_DMA; > - if (best_type && type && best_type != type) > - goto err; > + /* > + * We don't have any way for the iommu core code to > + * force arm_iommu to activate so we can't enforce > + * trusted. Log it and keep going with the IDENTITY > + * default domain. > + */ > + if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)) { > + dev_warn( > + gdev->dev, > + "PCI device is untrusted but ARM32 does not support secure IOMMU operation, continuing anyway.\n"); To within experimental error, this is dead code. The ARM DMA ops don't even understand groups, so already have the much bigger problem of being broken for any non-trivial PCI setup anyway. That's if you could even find a 32-bit SoC with both PCI(e) and a relevant IOMMU. None of those will have Thunderbolt, and I expect even fewer would be using the "external-facing" DT property (which is likely newer than they are) for any other reason. Thanks, Robin. > + } else { > + type = IOMMU_DOMAIN_DMA; > + if (best_type && type && best_type != type) > + goto err; > + } > } > best_type = type; > last_dev = gdev->dev; > @@ -1790,7 +1820,7 @@ static int iommu_get_default_domain_type(struct iommu_group *group, > "Device needs domain type %s, but device %s in the same iommu group requires type %s - using default\n", > iommu_domain_type_str(type), dev_name(last_dev), > iommu_domain_type_str(best_type)); > - return 0; > + return best_type; > } > > static void iommu_group_do_probe_finalize(struct device *dev) > diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c > index cc3e7d53d33ad9..7c0c1d50df5f75 100644 > --- a/drivers/iommu/mtk_iommu_v1.c > +++ b/drivers/iommu/mtk_iommu_v1.c > @@ -337,11 +337,6 @@ static struct iommu_domain mtk_iommu_v1_identity_domain = { > .ops = &mtk_iommu_v1_identity_ops, > }; > > -static void mtk_iommu_v1_set_platform_dma(struct device *dev) > -{ > - mtk_iommu_v1_identity_attach(&mtk_iommu_v1_identity_domain, dev); > -} > - > static int mtk_iommu_v1_map(struct iommu_domain *domain, unsigned long iova, > phys_addr_t paddr, size_t pgsize, size_t pgcount, > int prot, gfp_t gfp, size_t *mapped) > @@ -457,11 +452,6 @@ static int mtk_iommu_v1_create_mapping(struct device *dev, struct of_phandle_arg > return 0; > } > > -static int mtk_iommu_v1_def_domain_type(struct device *dev) > -{ > - return IOMMU_DOMAIN_IDENTITY; > -} > - > static struct iommu_device *mtk_iommu_v1_probe_device(struct device *dev) > { > struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); > @@ -599,10 +589,8 @@ static const struct iommu_ops mtk_iommu_v1_ops = { > .probe_device = mtk_iommu_v1_probe_device, > .probe_finalize = mtk_iommu_v1_probe_finalize, > .release_device = mtk_iommu_v1_release_device, > - .def_domain_type = mtk_iommu_v1_def_domain_type, > .device_group = generic_device_group, > .pgsize_bitmap = MT2701_IOMMU_PAGE_SIZE, > - .set_platform_dma_ops = mtk_iommu_v1_set_platform_dma, > .owner = THIS_MODULE, > .default_domain_ops = &(const struct iommu_domain_ops) { > .attach_dev = mtk_iommu_v1_attach_device, > diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c > index ebce56d6e9c634..9e1296a856ac4c 100644 > --- a/drivers/iommu/rockchip-iommu.c > +++ b/drivers/iommu/rockchip-iommu.c > @@ -1026,13 +1026,6 @@ static struct iommu_domain rk_identity_domain = { > .ops = &rk_identity_ops, > }; > > -#ifdef CONFIG_ARM > -static void rk_iommu_set_platform_dma(struct device *dev) > -{ > - WARN_ON(rk_iommu_identity_attach(&rk_identity_domain, dev)); > -} > -#endif > - > static int rk_iommu_attach_device(struct iommu_domain *domain, > struct device *dev) > { > @@ -1211,9 +1204,6 @@ static const struct iommu_ops rk_iommu_ops = { > .probe_device = rk_iommu_probe_device, > .release_device = rk_iommu_release_device, > .device_group = rk_iommu_device_group, > -#ifdef CONFIG_ARM > - .set_platform_dma_ops = rk_iommu_set_platform_dma, > -#endif > .pgsize_bitmap = RK_IOMMU_PGSIZE_BITMAP, > .of_xlate = rk_iommu_of_xlate, > .default_domain_ops = &(const struct iommu_domain_ops) { _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel