From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EDC4EC433E1 for ; Mon, 6 Jul 2020 12:43:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D5D7E20715 for ; Mon, 6 Jul 2020 12:43:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729177AbgGFMnJ (ORCPT ); Mon, 6 Jul 2020 08:43:09 -0400 Received: from inva020.nxp.com ([92.121.34.13]:42682 "EHLO inva020.nxp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729013AbgGFMnI (ORCPT ); Mon, 6 Jul 2020 08:43:08 -0400 Received: from inva020.nxp.com (localhost [127.0.0.1]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 257131A06A9; Mon, 6 Jul 2020 14:43:06 +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 18A091A0650; Mon, 6 Jul 2020 14:43:06 +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 ADE4C203C3; Mon, 6 Jul 2020 14:43:05 +0200 (CEST) From: Diana Craciun To: linux-kernel@vger.kernel.org, laurentiu.tudor@nxp.com, gregkh@linuxfoundation.org Cc: stuyoder@gmail.com, leoyang.li@nxp.com, linux-arm-kernel@lists.infradead.org, bharatb.linux@gmail.com, Bharat Bhushan , Diana Craciun Subject: [PATCH v3 03/13] bus/fsl-mc: add support for 'driver_override' in the mc-bus Date: Mon, 6 Jul 2020 15:42:33 +0300 Message-Id: <20200706124243.10697-4-diana.craciun@nxp.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200706124243.10697-1-diana.craciun@nxp.com> References: <20200706124243.10697-1-diana.craciun@nxp.com> X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.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) \ -- 2.17.1