From patchwork Sun Nov 28 02:50:38 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolu Lu X-Patchwork-Id: 12642629 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 4E611C433F5 for ; Sun, 28 Nov 2021 02:53:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346876AbhK1C4r (ORCPT ); Sat, 27 Nov 2021 21:56:47 -0500 Received: from mga05.intel.com ([192.55.52.43]:4483 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233520AbhK1Cyq (ORCPT ); Sat, 27 Nov 2021 21:54:46 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10181"; a="322035363" X-IronPort-AV: E=Sophos;i="5.87,270,1631602800"; d="scan'208";a="322035363" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Nov 2021 18:51:31 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,270,1631602800"; d="scan'208";a="652488980" Received: from allen-box.sh.intel.com ([10.239.159.118]) by fmsmga001.fm.intel.com with ESMTP; 27 Nov 2021 18:51:24 -0800 From: Lu Baolu To: Greg Kroah-Hartman , Joerg Roedel , Alex Williamson , Bjorn Helgaas , Jason Gunthorpe , Christoph Hellwig , Kevin Tian , Ashok Raj Cc: 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, Lu Baolu Subject: [PATCH v2 04/17] driver core: platform: Add driver dma ownership management Date: Sun, 28 Nov 2021 10:50:38 +0800 Message-Id: <20211128025051.355578-5-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211128025051.355578-1-baolu.lu@linux.intel.com> References: <20211128025051.355578-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org 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. 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; }; #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, + .dma_unconfigure = _platform_dma_unconfigure, .pm = &platform_dev_pm_ops, }; EXPORT_SYMBOL_GPL(platform_bus_type);