From patchwork Tue Sep 29 08:54:31 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: 11805313 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 2568A6CB for ; Tue, 29 Sep 2020 08:57:24 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 E0E5F206B5 for ; Tue, 29 Sep 2020 08:57:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="fAPZ0FFB" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E0E5F206B5 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=merlin.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=zGQKfZz40jjqd31HqpKeMW4qLOjldEIXWNKzl9xdf1o=; b=fAPZ0FFBkLuXENN9SbLU/6uBKY fbn7vl4G1wZM4jbg0NCt+bO0jJozJg9XcW55S7snshdJvfRSL5xrKzQSFBVN3n859sMCaDT0Zmgua zfgGTidIa/c0OpuCn2aWhW59/jROsmom5lSWJcNyI2j5pjKer6zfBYm1c1YLj6BAOvPoiraApJoCj snrzKjbZ4tfDytAPIAWveYj9DimRHE3injYvGxJp6VgagoZhJIKbLQ0wIIGD6JHWTf7wo2m6MvukJ bF/cPVizq2v5OqCDf5HZWuZu0ytgq/ZAycxIQZaR6FufP6BraYAjj0SrTbItSPSRj5sGEY48XamfS aBTarkXA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kNBPv-0003JP-PR; Tue, 29 Sep 2020 08:55:23 +0000 Received: from inva020.nxp.com ([92.121.34.13]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kNBPe-0003Ay-RM for linux-arm-kernel@lists.infradead.org; Tue, 29 Sep 2020 08:55:10 +0000 Received: from inva020.nxp.com (localhost [127.0.0.1]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 0F7301A122F; Tue, 29 Sep 2020 10:55:06 +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 F03EE1A1212; Tue, 29 Sep 2020 10:55:05 +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 951482032C; Tue, 29 Sep 2020 10:55:05 +0200 (CEST) From: Diana Craciun To: linux-kernel@vger.kernel.org, laurentiu.tudor@nxp.com Subject: [PATCH v5 03/13] bus/fsl-mc: add support for 'driver_override' in the mc-bus Date: Tue, 29 Sep 2020 11:54:31 +0300 Message-Id: <20200929085441.17448-4-diana.craciun@oss.nxp.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200929085441.17448-1-diana.craciun@oss.nxp.com> References: <20200929085441.17448-1-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-20200929_045507_109169_0CB19073 X-CRM114-Status: GOOD ( 21.55 ) X-Spam-Score: -0.7 (/) X-Spam-Report: SpamAssassin version 3.4.4 on merlin.infradead.org summary: Content analysis details: (-0.7 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at https://www.dnswl.org/, low 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 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 --- The patch does not address the comment regarding moving driver_override in the core code. I prefer not to tie these patches on that change and address that separately. 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 b69794e7364d..9a884936e53e 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 * */ @@ -78,6 +79,12 @@ 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; @@ -147,8 +154,52 @@ 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, }; @@ -748,6 +799,9 @@ 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 a428c61ead6e..3b5f0c98636d 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) \