From patchwork Tue Jan 4 01:56:36 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolu Lu X-Patchwork-Id: 12702913 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 5F120C433F5 for ; Tue, 4 Jan 2022 01:58:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230447AbiADB6N (ORCPT ); Mon, 3 Jan 2022 20:58:13 -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 S230481AbiADB6N (ORCPT ); Mon, 3 Jan 2022 20:58:13 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1641261493; x=1672797493; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=nfsc1wnBIJ3PlGkbBCL1BGTH9CgBawUsNa+Z9Z5uOzU=; b=iqBiMZqVozcWKbeiW0w/Rz3prNWj+UfJEewQSBjoMKIu55jXXoV7s9EF cARkV5vyAo2zagFTEXdglsUa4MWql1IQ3JLDhxiOpsSsO7bg6TmfE8xr/ l0aceQHHAHxdk9zW20RtiGGOvjvUfmgUx1F3bhlqOT/hSRE0O7GgJZbCu fzoOVFFLG4RLOMQOSvry3t965ET5V8x9geDst+sUqz62P4/cHLkSoZAtn 9jquXvfkLvpO/C1nSmUvYHD8kVw1iw8CUVpst4bQFnT+NcFPhdD3aoBeP fmkATQXE9HMKKAYyMUnchJyHyUvJJcM4XHtHDZajoDCuuwbKMoWXtKeRD w==; X-IronPort-AV: E=McAfee;i="6200,9189,10216"; a="305494264" X-IronPort-AV: E=Sophos;i="5.88,258,1635231600"; d="scan'208";a="305494264" 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 17:58:10 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,258,1635231600"; d="scan'208";a="667573270" Received: from allen-box.sh.intel.com ([10.239.159.118]) by fmsmga001.fm.intel.com with ESMTP; 03 Jan 2022 17:58:02 -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 06/14] bus: fsl-mc: Add driver dma ownership management Date: Tue, 4 Jan 2022 09:56:36 +0800 Message-Id: <20220104015644.2294354-7-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 fsl-mc 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/fsl/mc.h | 5 +++++ drivers/bus/fsl-mc/fsl-mc-bus.c | 26 ++++++++++++++++++++++++-- 2 files changed, 29 insertions(+), 2 deletions(-) diff --git a/include/linux/fsl/mc.h b/include/linux/fsl/mc.h index e026f6c48b49..e85a5f18104d 100644 --- a/include/linux/fsl/mc.h +++ b/include/linux/fsl/mc.h @@ -32,6 +32,10 @@ struct fsl_mc_io; * @shutdown: Function called at shutdown time to quiesce the device * @suspend: Function called when a device is stopped * @resume: Function called when a device is resumed + * @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. * * Generic DPAA device driver object for device drivers that are registered * with a DPRC bus. This structure is to be embedded in each device-specific @@ -45,6 +49,7 @@ struct fsl_mc_driver { void (*shutdown)(struct fsl_mc_device *dev); int (*suspend)(struct fsl_mc_device *dev, pm_message_t state); int (*resume)(struct fsl_mc_device *dev); + bool no_kernel_api_dma; }; #define to_fsl_mc_driver(_drv) \ diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c index 8fd4a356a86e..9ee85f43822a 100644 --- a/drivers/bus/fsl-mc/fsl-mc-bus.c +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c @@ -140,15 +140,36 @@ static int fsl_mc_dma_configure(struct device *dev) { struct device *dma_dev = dev; struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev); + struct fsl_mc_driver *mc_drv = to_fsl_mc_driver(dev->driver); u32 input_id = mc_dev->icid; + int ret; + + if (!mc_drv->no_kernel_api_dma) { + ret = iommu_device_use_dma_api(dev); + if (ret) + return ret; + } while (dev_is_fsl_mc(dma_dev)) dma_dev = dma_dev->parent; if (dev_of_node(dma_dev)) - return of_dma_configure_id(dev, dma_dev->of_node, 0, &input_id); + ret = of_dma_configure_id(dev, dma_dev->of_node, 0, &input_id); + else + ret = acpi_dma_configure_id(dev, DEV_DMA_COHERENT, &input_id); + + if (ret && !mc_drv->no_kernel_api_dma) + iommu_device_unuse_dma_api(dev); + + return ret; +} + +static void fsl_mc_dma_cleanup(struct device *dev) +{ + struct fsl_mc_driver *mc_drv = to_fsl_mc_driver(dev->driver); - return acpi_dma_configure_id(dev, DEV_DMA_COHERENT, &input_id); + if (!mc_drv->no_kernel_api_dma) + iommu_device_unuse_dma_api(dev); } static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, @@ -312,6 +333,7 @@ struct bus_type fsl_mc_bus_type = { .match = fsl_mc_bus_match, .uevent = fsl_mc_bus_uevent, .dma_configure = fsl_mc_dma_configure, + .dma_cleanup = fsl_mc_dma_cleanup, .dev_groups = fsl_mc_dev_groups, .bus_groups = fsl_mc_bus_groups, };