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 B1777C4332F for ; Sun, 28 Nov 2021 08:12:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356927AbhK1IPi (ORCPT ); Sun, 28 Nov 2021 03:15:38 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:42918 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244052AbhK1INh (ORCPT ); Sun, 28 Nov 2021 03:13:37 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id B2252B80B58; Sun, 28 Nov 2021 08:10:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 87FC9C004E1; Sun, 28 Nov 2021 08:10:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1638087019; bh=Jh73NsijwFN5QPrga4uDXyFTpW6yedRJeVQ94xz/BvE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=r8dqk03D2jeiNpbJLBgCBKZqW0HDJ5Tm6QLq+9y6d6qfyxcrdfgUx428Ks8OXlp00 DFMNAg0jGMqvpHaytnxROgOKNdVnYWbWHi7Cvni3o9RcgZZbTFm+1iRq/chyaLAgqQ Fug0KlfEBeP61C9AXRDp1L1G0lUVzzX8IelrbImA= Date: Sun, 28 Nov 2021 09:10:14 +0100 From: Greg Kroah-Hartman To: Lu Baolu Cc: Joerg Roedel , Alex Williamson , Bjorn Helgaas , Jason Gunthorpe , Christoph Hellwig , Kevin Tian , Ashok Raj , Will Deacon , Robin Murphy , Dan Williams , rafael@kernel.org, Diana Craciun , Cornelia Huck , Eric Auger , Liu Yi L , Jacob jun Pan , Chaitanya Kulkarni , Stuart Yoder , Laurentiu Tudor , Thierry Reding , David Airlie , Daniel Vetter , Jonathan Hunter , Li Yang , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 04/17] driver core: platform: Add driver dma ownership management Message-ID: References: <20211128025051.355578-1-baolu.lu@linux.intel.com> <20211128025051.355578-5-baolu.lu@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211128025051.355578-5-baolu.lu@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Nov 28, 2021 at 10:50:38AM +0800, Lu Baolu wrote: > Multiple platform devices may be placed in the same IOMMU group because > they cannot be isolated from each other. These devices must either be > entirely under kernel control or userspace control, never a mixture. This > checks and sets DMA ownership during driver binding, and release the > ownership during driver unbinding. > > Driver may set a new flag (suppress_auto_claim_dma_owner) to disable auto > claiming DMA_OWNER_DMA_API ownership in the binding process. For instance, > the userspace framework drivers (vfio etc.) which need to manually claim > DMA_OWNER_PRIVATE_DOMAIN_USER when assigning a device to userspace. Why would any vfio driver be a platform driver? That should never be the case as they obviously are not platform drivers, they are virtual ones. > > Signed-off-by: Lu Baolu > --- > include/linux/platform_device.h | 1 + > drivers/base/platform.c | 30 +++++++++++++++++++++++++++++- > 2 files changed, 30 insertions(+), 1 deletion(-) > > diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h > index 7c96f169d274..779bcf2a851c 100644 > --- a/include/linux/platform_device.h > +++ b/include/linux/platform_device.h > @@ -210,6 +210,7 @@ struct platform_driver { > struct device_driver driver; > const struct platform_device_id *id_table; > bool prevent_deferred_probe; > + bool suppress_auto_claim_dma_owner; What platform driver needs this change? > }; > > #define to_platform_driver(drv) (container_of((drv), struct platform_driver, \ > diff --git a/drivers/base/platform.c b/drivers/base/platform.c > index 598acf93a360..df4b385c8a52 100644 > --- a/drivers/base/platform.c > +++ b/drivers/base/platform.c > @@ -30,6 +30,7 @@ > #include > #include > #include > +#include > > #include "base.h" > #include "power/power.h" > @@ -1465,6 +1466,32 @@ int platform_dma_configure(struct device *dev) > return ret; > } > > +static int _platform_dma_configure(struct device *dev) > +{ > + struct platform_driver *drv = to_platform_driver(dev->driver); > + int ret; > + > + if (!drv->suppress_auto_claim_dma_owner) { > + ret = iommu_device_set_dma_owner(dev, DMA_OWNER_DMA_API, NULL); > + if (ret) > + return ret; > + } > + > + ret = platform_dma_configure(dev); > + if (ret && !drv->suppress_auto_claim_dma_owner) > + iommu_device_release_dma_owner(dev, DMA_OWNER_DMA_API); > + > + return ret; > +} > + > +static void _platform_dma_unconfigure(struct device *dev) > +{ > + struct platform_driver *drv = to_platform_driver(dev->driver); > + > + if (!drv->suppress_auto_claim_dma_owner) > + iommu_device_release_dma_owner(dev, DMA_OWNER_DMA_API); > +} > + > static const struct dev_pm_ops platform_dev_pm_ops = { > SET_RUNTIME_PM_OPS(pm_generic_runtime_suspend, pm_generic_runtime_resume, NULL) > USE_PLATFORM_PM_SLEEP_OPS > @@ -1478,7 +1505,8 @@ struct bus_type platform_bus_type = { > .probe = platform_probe, > .remove = platform_remove, > .shutdown = platform_shutdown, > - .dma_configure = platform_dma_configure, > + .dma_configure = _platform_dma_configure, What happened to the original platform_dma_configure() function? And single "_" prefixes are odd, please just spell out what the difference is in the function name, "_" gives us no hint at all. thnaks, greg k-h