From: Diana Craciun <diana.craciun@nxp.com>
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 <Bharat.Bhushan@nxp.com>,
Diana Craciun <diana.craciun@oss.nxp.com>
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 [thread overview]
Message-ID: <20200706124243.10697-4-diana.craciun@nxp.com> (raw)
In-Reply-To: <20200706124243.10697-1-diana.craciun@nxp.com>
From: Bharat Bhushan <Bharat.Bhushan@nxp.com>
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 <Bharat.Bhushan@nxp.com>
Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: Diana Craciun <diana.craciun@oss.nxp.com>
---
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 <German.Rivera@freescale.com>
*
*/
@@ -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
next prev parent reply other threads:[~2020-07-06 12:43 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-06 12:42 [PATCH v3 00/13] bus/fsl-mc: Extend mc-bus driver functionalities in preparation for mc-bus VFIO support Diana Craciun
2020-07-06 12:42 ` [PATCH v3 01/13] bus/fsl-mc: Do no longer export the total number of irqs outside dprc_scan_objects Diana Craciun
2020-07-06 12:42 ` [PATCH v3 02/13] bus/fsl-mc: Add a new parameter to dprc_scan_objects function Diana Craciun
2020-07-06 12:42 ` Diana Craciun [this message]
2020-07-06 13:57 ` [PATCH v3 03/13] bus/fsl-mc: add support for 'driver_override' in the mc-bus Andrew Lunn
2020-07-06 16:35 ` Diana Craciun OSS
2020-07-06 12:42 ` [PATCH v3 04/13] bus/fsl-mc: Set the QMAN/BMAN region flags Diana Craciun
2020-07-06 12:42 ` [PATCH v3 05/13] bus/fsl-mc: Cache the DPRC API version Diana Craciun
2020-07-06 12:42 ` [PATCH v3 06/13] bus/fsl-mc: Add dprc-reset-container support Diana Craciun
2020-07-06 12:42 ` [PATCH v3 07/13] bus/fsl-mc: Export a dprc scan function to be used by multiple entities Diana Craciun
2020-07-06 12:42 ` [PATCH v3 08/13] bus/fsl-mc: Export a cleanup function for DPRC Diana Craciun
2020-07-06 12:42 ` [PATCH v3 09/13] bus/fsl-mc: Add a container setup function Diana Craciun
2020-07-06 12:42 ` [PATCH v3 10/13] bus/fsl_mc: Do not rely on caller to provide non NULL mc_io Diana Craciun
2020-07-06 12:42 ` [PATCH v3 11/13] bus/fsl-mc: Export IRQ pool handling functions to be used by VFIO Diana Craciun
2020-07-06 12:42 ` [PATCH v3 12/13] bus/fsl-mc: Extend ICID size from 16bit to 32bit Diana Craciun
2020-07-06 12:42 ` [PATCH v3 13/13] bus/fsl-mc: Add a new version for dprc_get_obj_region command Diana Craciun
2020-07-06 13:14 ` Laurentiu Tudor
2020-07-06 15:49 ` Diana Craciun OSS
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