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author | Bharat Bhushan <Bharat.Bhushan@nxp.com> | 2020-09-29 10:54:31 +0200 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-10-02 16:05:01 +0200 |
commit | 1f86a00c1159fd77e66b1bd6ff1a183f4d46f34d (patch) | |
tree | 4453896a77a54ce6e71d61ecbefdf74c7924760c /drivers/bus | |
parent | bus/fsl-mc: Add a new parameter to dprc_scan_objects function (diff) | |
download | linux-1f86a00c1159fd77e66b1bd6ff1a183f4d46f34d.tar.xz linux-1f86a00c1159fd77e66b1bd6ff1a183f4d46f34d.zip |
bus/fsl-mc: add support for 'driver_override' in the mc-bus
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
Reviewed-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Acked-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
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>
Link: https://lore.kernel.org/r/20200929085441.17448-4-diana.craciun@oss.nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/bus')
-rw-r--r-- | drivers/bus/fsl-mc/fsl-mc-bus.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c index 7345ecef93f8..ef2878bfafd2 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> * */ @@ -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() */ |