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 83A63C6FD1D for ; Thu, 30 Mar 2023 15:10:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232790AbjC3PK0 (ORCPT ); Thu, 30 Mar 2023 11:10:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56782 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232705AbjC3PKZ (ORCPT ); Thu, 30 Mar 2023 11:10:25 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id CF862D528 for ; Thu, 30 Mar 2023 08:09:10 -0700 (PDT) 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 989CF2F4; Thu, 30 Mar 2023 08:09:54 -0700 (PDT) Received: from [10.57.54.254] (unknown [10.57.54.254]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 988113F6C4; Thu, 30 Mar 2023 08:09:08 -0700 (PDT) Message-ID: <3356d18f-d1ce-4995-2b95-16938df1b7d6@arm.com> Date: Thu, 30 Mar 2023 16:09:03 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:102.0) Gecko/20100101 Thunderbird/102.9.1 Subject: Re: [PATCH v3] iommu/rockchip: Add missing set_platform_dma_ops callback Content-Language: en-GB To: Steven Price , Heiko Stuebner , Joerg Roedel , Jason Gunthorpe Cc: Will Deacon , iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org, John Keeping , Jason Gunthorpe References: <20230330144604.2431436-1-steven.price@arm.com> From: Robin Murphy In-Reply-To: <20230330144604.2431436-1-steven.price@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023-03-30 15:46, Steven Price wrote: > Similar to exynos, we need a set_platform_dma_ops() callback for proper > operation on ARM 32 bit after recent changes in the IOMMU framework > (detach ops removal). But also the use of a NULL domain is confusing. > > Rework the code to have a singleton rk_identity_domain which is assigned > to domain when using an identity mapping rather than "detaching". This > makes the code easier to reason about. Really this is adding complete support for IOMMU_DOMAIN_IDENTITY in general, which will also be visible on arm64. The part then using it to bodge a pseudo-default-domain for Arm seems more incidental ;) > Signed-off-by: Steven Price > Reviewed-by: Jason Gunthorpe > --- > Changes since v2[1]: > > * Fixed suspend/resume handlers to check against rk_identity_domain > rather than NULL (thanks John). > > [1] https://lore.kernel.org/r/20230324111127.221640-1-steven.price%40arm.com > > drivers/iommu/rockchip-iommu.c | 56 +++++++++++++++++++++++++--------- > 1 file changed, 42 insertions(+), 14 deletions(-) > > diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c > index f30db22ea5d7..4f97af471671 100644 > --- a/drivers/iommu/rockchip-iommu.c > +++ b/drivers/iommu/rockchip-iommu.c > @@ -124,6 +124,7 @@ struct rk_iommudata { > > static struct device *dma_dev; > static const struct rk_iommu_ops *rk_ops; > +static struct iommu_domain rk_identity_domain; > > static inline void rk_table_flush(struct rk_iommu_domain *dom, dma_addr_t dma, > unsigned int count) > @@ -646,7 +647,7 @@ static irqreturn_t rk_iommu_irq(int irq, void *dev_id) > * Ignore the return code, though, since we always zap cache > * and clear the page fault anyway. > */ > - if (iommu->domain) > + if (iommu->domain != &rk_identity_domain) > report_iommu_fault(iommu->domain, iommu->dev, iova, > flags); > else > @@ -980,26 +981,27 @@ static int rk_iommu_enable(struct rk_iommu *iommu) > return ret; > } > > -static void rk_iommu_detach_device(struct iommu_domain *domain, > - struct device *dev) > +static int rk_iommu_identity_attach(struct iommu_domain *identity_domain, > + struct device *dev) > { > struct rk_iommu *iommu; > - struct rk_iommu_domain *rk_domain = to_rk_domain(domain); > + struct rk_iommu_domain *rk_domain; > unsigned long flags; > int ret; > > /* Allow 'virtual devices' (eg drm) to detach from domain */ > iommu = rk_iommu_from_dev(dev); > if (!iommu) > - return; > + return -ENODEV; > + > + rk_domain = to_rk_domain(iommu->domain); > > dev_dbg(dev, "Detaching from iommu domain\n"); > > - /* iommu already detached */ > - if (iommu->domain != domain) > - return; > + if (iommu->domain == identity_domain) > + return 0; > > - iommu->domain = NULL; > + iommu->domain = identity_domain; > > spin_lock_irqsave(&rk_domain->iommus_lock, flags); > list_del_init(&iommu->node); > @@ -1011,7 +1013,25 @@ static void rk_iommu_detach_device(struct iommu_domain *domain, > rk_iommu_disable(iommu); > pm_runtime_put(iommu->dev); > } > + > + return 0; > +} > + > +static struct iommu_domain_ops rk_identity_ops = { > + .attach_dev = rk_iommu_identity_attach, Since it's going to behave like a regular identity domain and be treated as one, it needs to support .free as well. Thanks, Robin. > +}; > + > +static struct iommu_domain rk_identity_domain = { > + .type = IOMMU_DOMAIN_IDENTITY, > + .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) > @@ -1035,8 +1055,9 @@ static int rk_iommu_attach_device(struct iommu_domain *domain, > if (iommu->domain == domain) > return 0; > > - if (iommu->domain) > - rk_iommu_detach_device(iommu->domain, dev); > + ret = rk_iommu_identity_attach(&rk_identity_domain, dev); > + if (ret) > + return ret; > > iommu->domain = domain; > > @@ -1050,7 +1071,7 @@ static int rk_iommu_attach_device(struct iommu_domain *domain, > > ret = rk_iommu_enable(iommu); > if (ret) > - rk_iommu_detach_device(iommu->domain, dev); > + WARN_ON(rk_iommu_identity_attach(&rk_identity_domain, dev)); > > pm_runtime_put(iommu->dev); > > @@ -1061,6 +1082,9 @@ static struct iommu_domain *rk_iommu_domain_alloc(unsigned type) > { > struct rk_iommu_domain *rk_domain; > > + if (type == IOMMU_DOMAIN_IDENTITY) > + return &rk_identity_domain; > + > if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA) > return NULL; > > @@ -1176,6 +1200,7 @@ static int rk_iommu_of_xlate(struct device *dev, > iommu_dev = of_find_device_by_node(args->np); > > data->iommu = platform_get_drvdata(iommu_dev); > + data->iommu->domain = &rk_identity_domain; > dev_iommu_priv_set(dev, data); > > platform_device_put(iommu_dev); > @@ -1188,6 +1213,9 @@ 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) { > @@ -1343,7 +1371,7 @@ static int __maybe_unused rk_iommu_suspend(struct device *dev) > { > struct rk_iommu *iommu = dev_get_drvdata(dev); > > - if (!iommu->domain) > + if (iommu->domain == &rk_identity_domain) > return 0; > > rk_iommu_disable(iommu); > @@ -1354,7 +1382,7 @@ static int __maybe_unused rk_iommu_resume(struct device *dev) > { > struct rk_iommu *iommu = dev_get_drvdata(dev); > > - if (!iommu->domain) > + if (iommu->domain == &rk_identity_domain) > return 0; > > return rk_iommu_enable(iommu);