From patchwork Thu May 7 07:34:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Diana Madalina Craciun X-Patchwork-Id: 11532689 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 12003139A for ; Thu, 7 May 2020 07:37:39 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D04D72078C for ; Thu, 7 May 2020 07:37:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="k/Wh5SNF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D04D72078C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=oss.nxp.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=nZtOIV8FtojD5pj/AZcaUS8kSnZ99gJaDmPiz9TdPyc=; b=k/Wh5SNF0VRKLIzKsrjTDEEtfW 5+hBmnESB7swbqHZrAjtVVORFL+AUl65ijllm1+jNPzD4eWseOk1D+E54bMWBv1KYf2c8Y08bpGw/ jZqtQRZRVDl0o7NseNrpNKP437Y2kffmwkFLJvPdDqKZknMxIpmo+DKMCkIM1zOuiDU63L5T620jt 4250kdW9dHSxjXPXPYL5EQ2VTUcQDRfXONcfUZNf244JG6DrBtFwdZwqj/gfGWRI49nZ88qI+Yh2P dYiYoaHTyAohT/kxrBlyyAAJDcF1iygaqE+CLpT46dqEaI2HwbNJt5MKzF42Trv8UlZHkjikCLf7P CSJSthhg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jWb67-0003DJ-SN; Thu, 07 May 2020 07:37:35 +0000 Received: from inva020.nxp.com ([92.121.34.13]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jWb4N-0001Y2-N5 for linux-arm-kernel@lists.infradead.org; Thu, 07 May 2020 07:35:51 +0000 Received: from inva020.nxp.com (localhost [127.0.0.1]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 876A51A0FC0; Thu, 7 May 2020 09:35:44 +0200 (CEST) Received: from inva024.eu-rdc02.nxp.com (inva024.eu-rdc02.nxp.com [134.27.226.22]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 7A6441A0FB0; Thu, 7 May 2020 09:35:44 +0200 (CEST) Received: from fsr-ub1864-111.ea.freescale.net (fsr-ub1864-111.ea.freescale.net [10.171.82.141]) by inva024.eu-rdc02.nxp.com (Postfix) with ESMTP id 231FB203C5; Thu, 7 May 2020 09:35:44 +0200 (CEST) From: Diana Craciun To: linux-kernel@vger.kernel.org Subject: [PATCH v2 03/12] bus/fsl-mc: add support for 'driver_override' in the mc-bus Date: Thu, 7 May 2020 10:34:22 +0300 Message-Id: <20200507073431.2710-4-diana.craciun@oss.nxp.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200507073431.2710-1-diana.craciun@oss.nxp.com> References: <20200507073431.2710-1-diana.craciun@oss.nxp.com> X-Virus-Scanned: ClamAV using ClamSMTP X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200507_003548_033649_04921EFE X-CRM114-Status: GOOD ( 13.70 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.4 on bombadil.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [92.121.34.13 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: stuyoder@gmail.com, gregkh@linuxfoundation.org, leoyang.li@nxp.com, Diana Craciun , Bharat Bhushan , linux-arm-kernel@lists.infradead.org, laurentiu.tudor@nxp.com MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org From: Bharat Bhushan This patch is required for vfio-fsl-mc meta driver to successfully bind layerscape container devices for device passthrough. This patch adds a mechanism to allow a layerscape device to specify a driver rather than a layerscape driver provide a device match. Example to allow a device (dprc.1) to specifically bind with driver (vfio-fsl-mc): - echo vfio-fsl-mc > /sys/bus/fsl-mc/devices/dprc.1/driver_override - echo dprc.1 > /sys/bus/fsl-mc/drivers/fsl_mc_dprc/unbind - echo dprc.1 > /sys/bus/fsl-mc/drivers/vfio-fsl-mc/bind Signed-off-by: Bharat Bhushan Signed-off-by: Laurentiu Tudor Signed-off-by: Diana Craciun --- drivers/bus/fsl-mc/fsl-mc-bus.c | 54 +++++++++++++++++++++++++++++++++ include/linux/fsl/mc.h | 2 ++ 2 files changed, 56 insertions(+) diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c index 40526da5c6a6..3a86f5087717 100644 --- a/drivers/bus/fsl-mc/fsl-mc-bus.c +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c @@ -3,6 +3,7 @@ * Freescale Management Complex (MC) bus driver * * Copyright (C) 2014-2016 Freescale Semiconductor, Inc. + * Copyright 2019-2020 NXP * Author: German Rivera * */ @@ -71,6 +72,12 @@ static int fsl_mc_bus_match(struct device *dev, struct device_driver *drv) struct fsl_mc_driver *mc_drv = to_fsl_mc_driver(drv); bool found = false; + /* When driver_override is set, only bind to the matching driver */ + if (mc_dev->driver_override) { + found = !strcmp(mc_dev->driver_override, mc_drv->driver.name); + goto out; + } + if (!mc_drv->match_id_table) goto out; @@ -135,8 +142,52 @@ static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR_RO(modalias); +static ssize_t driver_override_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev); + char *driver_override, *old = mc_dev->driver_override; + char *cp; + + if (WARN_ON(dev->bus != &fsl_mc_bus_type)) + return -EINVAL; + + if (count >= (PAGE_SIZE - 1)) + return -EINVAL; + + driver_override = kstrndup(buf, count, GFP_KERNEL); + if (!driver_override) + return -ENOMEM; + + cp = strchr(driver_override, '\n'); + if (cp) + *cp = '\0'; + + if (strlen(driver_override)) { + mc_dev->driver_override = driver_override; + } else { + kfree(driver_override); + mc_dev->driver_override = NULL; + } + + kfree(old); + + return count; +} + +static ssize_t driver_override_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev); + + return snprintf(buf, PAGE_SIZE, "%s\n", mc_dev->driver_override); +} +static DEVICE_ATTR_RW(driver_override); + static struct attribute *fsl_mc_dev_attrs[] = { &dev_attr_modalias.attr, + &dev_attr_driver_override.attr, NULL, }; @@ -706,6 +757,9 @@ EXPORT_SYMBOL_GPL(fsl_mc_device_add); */ void fsl_mc_device_remove(struct fsl_mc_device *mc_dev) { + kfree(mc_dev->driver_override); + mc_dev->driver_override = NULL; + /* * The device-specific remove callback will get invoked by device_del() */ diff --git a/include/linux/fsl/mc.h b/include/linux/fsl/mc.h index 2b5f8366dbe1..4e9b570a1845 100644 --- a/include/linux/fsl/mc.h +++ b/include/linux/fsl/mc.h @@ -161,6 +161,7 @@ struct fsl_mc_obj_desc { * @regions: pointer to array of MMIO region entries * @irqs: pointer to array of pointers to interrupts allocated to this device * @resource: generic resource associated with this MC object device, if any. + * @driver_override: driver name to force a match * * Generic device object for MC object devices that are "attached" to a * MC bus. @@ -194,6 +195,7 @@ struct fsl_mc_device { struct fsl_mc_device_irq **irqs; struct fsl_mc_resource *resource; struct device_link *consumer_link; + char *driver_override; }; #define to_fsl_mc_device(_dev) \