From patchwork Tue Jan 4 01:56:37 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolu Lu X-Patchwork-Id: 12702914 X-Patchwork-Delegate: bhelgaas@google.com 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 1C839C433F5 for ; Tue, 4 Jan 2022 01:58:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232100AbiADB6W (ORCPT ); Mon, 3 Jan 2022 20:58:22 -0500 Received: from mga07.intel.com ([134.134.136.100]:62142 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232095AbiADB6S (ORCPT ); Mon, 3 Jan 2022 20:58:18 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1641261498; x=1672797498; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=UG84GF4gMsRM2TIANUAZ/Eq7BI+0yTChxDMnJO7QbYw=; b=ej/ZbQqe2d1uQ8wGMRSk1BaIR3T7LjBBcmqJPmufoSYURRdQ/Uo388gi BOH5FZO3IHQDIMH1peNwLn8mUCK8LcHCL9X/iAJcC6y4dCTR0XjF3gowa sRYcqALnX/ucMwPbUPnGoLsqWM8tqjtAeyUeEI0n4k4ossLbFUK+PN1eC 1C/5qotepaAcZs8PXlYWFzE/HuPOUf9X9BizxyZE9u57MgMsjs5vu3WFA 7crstkuv47hVBRaOwj8R583euFkfg1LY865fXXRKjJxIIw9qfGyeIe+Wj SU+b3K6mIySy7DSqLEZs0pspOKTH5VnhHL6TrVvAzW6S2mZfEjO2A6vQ2 A==; X-IronPort-AV: E=McAfee;i="6200,9189,10216"; a="305494270" X-IronPort-AV: E=Sophos;i="5.88,258,1635231600"; d="scan'208";a="305494270" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Jan 2022 17:58:15 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,258,1635231600"; d="scan'208";a="667573278" Received: from allen-box.sh.intel.com ([10.239.159.118]) by fmsmga001.fm.intel.com with ESMTP; 03 Jan 2022 17:58:08 -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 , Dmitry Osipenko , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH v5 07/14] PCI: Add driver dma ownership management Date: Tue, 4 Jan 2022 09:56:37 +0800 Message-Id: <20220104015644.2294354-8-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220104015644.2294354-1-baolu.lu@linux.intel.com> References: <20220104015644.2294354-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Multiple PCI 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. The device driver may set a new flag (no_kernel_api_dma) to skip calling iommu_device_use_dma_api() during the binding process. For instance, the userspace framework drivers (vfio etc.) which need to manually claim their own dma ownership when assigning the device to userspace. Signed-off-by: Lu Baolu --- include/linux/pci.h | 5 +++++ drivers/pci/pci-driver.c | 21 +++++++++++++++++++++ 2 files changed, 26 insertions(+) diff --git a/include/linux/pci.h b/include/linux/pci.h index 18a75c8e615c..d29a990e3f02 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -882,6 +882,10 @@ struct module; * created once it is bound to the driver. * @driver: Driver model structure. * @dynids: List of dynamically added device IDs. + * @no_kernel_api_dma: Device driver doesn't use kernel DMA API for DMA. + * Drivers which don't require DMA or want to manually claim the + * owner type (e.g. userspace driver frameworks) could set this + * flag. */ struct pci_driver { struct list_head node; @@ -900,6 +904,7 @@ struct pci_driver { const struct attribute_group **dev_groups; struct device_driver driver; struct pci_dynids dynids; + bool no_kernel_api_dma; }; static inline struct pci_driver *to_pci_driver(struct device_driver *drv) diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 588588cfda48..4e003ea12718 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -20,6 +20,7 @@ #include #include #include +#include #include "pci.h" #include "pcie/portdrv.h" @@ -1590,9 +1591,16 @@ static int pci_bus_num_vf(struct device *dev) */ static int pci_dma_configure(struct device *dev) { + struct pci_driver *driver = to_pci_driver(dev->driver); struct device *bridge; int ret = 0; + if (!driver->no_kernel_api_dma) { + ret = iommu_device_use_dma_api(dev); + if (ret) + return ret; + } + bridge = pci_get_host_bridge_device(to_pci_dev(dev)); if (IS_ENABLED(CONFIG_OF) && bridge->parent && @@ -1605,9 +1613,21 @@ static int pci_dma_configure(struct device *dev) } pci_put_host_bridge_device(bridge); + + if (ret && !driver->no_kernel_api_dma) + iommu_device_unuse_dma_api(dev); + return ret; } +static void pci_dma_cleanup(struct device *dev) +{ + struct pci_driver *driver = to_pci_driver(dev->driver); + + if (!driver->no_kernel_api_dma) + iommu_device_unuse_dma_api(dev); +} + struct bus_type pci_bus_type = { .name = "pci", .match = pci_bus_match, @@ -1621,6 +1641,7 @@ struct bus_type pci_bus_type = { .pm = PCI_PM_OPS_PTR, .num_vf = pci_bus_num_vf, .dma_configure = pci_dma_configure, + .dma_cleanup = pci_dma_cleanup, }; EXPORT_SYMBOL(pci_bus_type);