[PATCH 04/10] bus/fsl-mc: Propagate driver_override for a child DPRC's children

From: Diana Craciun
Date: Thu Mar 19 2020 - 11:41:14 EST


From: Bharat Bhushan <Bharat.Bhushan@xxxxxxx>

When a child DPRC is bound to the vfio_fsl_mc driver via
driver_override, its own children should not be bound to corresponding
host kernel drivers, but instead should be bound to the vfio_fsl_mc
driver as well.

Currently, when a child container is scanned by the vfio_fsl_mc
driver, child devices found are automatically bound to corresponding
host kernel drivers (e.g., DPMCP and DPBP objects are bound to the
fsl_mc_allocator driver, DPNI objects are bound to the ldpaa_eth
driver, etc), Then, the user has to manually unbind these child
devices from their drivers, set the driver_override sysfs attribute
to vfio_fsl_mc driver, for each of them and rebind them.

Signed-off-by: J. German Rivera <German.Rivera@xxxxxxxxxxxxx>
Signed-off-by: Stuart Yoder <stuart.yoder@xxxxxxx>
Signed-off-by: Bharat Bhushan <Bharat.Bhushan@xxxxxxx>
Signed-off-by: Laurentiu Tudor <laurentiu.tudor@xxxxxxx>
Signed-off-by: Diana Craciun <diana.craciun@xxxxxxxxxxx>
---
drivers/bus/fsl-mc/dprc-driver.c | 12 ++++++++----
drivers/bus/fsl-mc/fsl-mc-bus.c | 18 +++++++++++++++++-
drivers/bus/fsl-mc/fsl-mc-private.h | 2 ++
include/linux/fsl/mc.h | 2 ++
4 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/drivers/bus/fsl-mc/dprc-driver.c b/drivers/bus/fsl-mc/dprc-driver.c
index d373b28abe2d..7eaf78900dfc 100644
--- a/drivers/bus/fsl-mc/dprc-driver.c
+++ b/drivers/bus/fsl-mc/dprc-driver.c
@@ -155,6 +155,8 @@ static void check_plugged_state_change(struct fsl_mc_device *mc_dev,
* dprc_add_new_devices - Adds devices to the logical bus for a DPRC
*
* @mc_bus_dev: pointer to the fsl-mc device that represents a DPRC object
+ * @driver_override: driver override to apply to new objects found in the
+ * DPRC, or NULL, if none.
* @obj_desc_array: array of device descriptors for child devices currently
* present in the physical DPRC.
* @num_child_objects_in_mc: number of entries in obj_desc_array
@@ -164,6 +166,7 @@ static void check_plugged_state_change(struct fsl_mc_device *mc_dev,
* in the physical DPRC.
*/
static void dprc_add_new_devices(struct fsl_mc_device *mc_bus_dev,
+ const char *driver_override,
struct fsl_mc_obj_desc *obj_desc_array,
int num_child_objects_in_mc)
{
@@ -188,7 +191,7 @@ static void dprc_add_new_devices(struct fsl_mc_device *mc_bus_dev,
}

error = fsl_mc_device_add(obj_desc, NULL, &mc_bus_dev->dev,
- &child_dev);
+ driver_override, &child_dev);
if (error < 0)
continue;
}
@@ -214,6 +217,7 @@ static void dprc_add_new_devices(struct fsl_mc_device *mc_bus_dev,
* of the device drivers for the non-allocatable devices.
*/
static int dprc_scan_objects(struct fsl_mc_device *mc_bus_dev,
+ const char *driver_override,
bool alloc_interrupts)
{
int num_child_objects;
@@ -313,7 +317,7 @@ static int dprc_scan_objects(struct fsl_mc_device *mc_bus_dev,
dprc_remove_devices(mc_bus_dev, child_obj_desc_array,
num_child_objects);

- dprc_add_new_devices(mc_bus_dev, child_obj_desc_array,
+ dprc_add_new_devices(mc_bus_dev, driver_override, child_obj_desc_array,
num_child_objects);

if (child_obj_desc_array)
@@ -342,7 +346,7 @@ static int dprc_scan_container(struct fsl_mc_device *mc_bus_dev)
* Discover objects in the DPRC:
*/
mutex_lock(&mc_bus->scan_mutex);
- error = dprc_scan_objects(mc_bus_dev, true);
+ error = dprc_scan_objects(mc_bus_dev, NULL, true);
mutex_unlock(&mc_bus->scan_mutex);
if (error < 0) {
fsl_mc_cleanup_all_resource_pools(mc_bus_dev);
@@ -412,7 +416,7 @@ static irqreturn_t dprc_irq0_handler_thread(int irq_num, void *arg)
DPRC_IRQ_EVENT_OBJ_DESTROYED |
DPRC_IRQ_EVENT_OBJ_CREATED)) {

- error = dprc_scan_objects(mc_dev, true);
+ error = dprc_scan_objects(mc_dev, NULL, true);
if (error < 0) {
/*
* If the error is -ENXIO, we ignore it, as it indicates
diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c
index baf8259262a9..b9ccac9862b7 100644
--- a/drivers/bus/fsl-mc/fsl-mc-bus.c
+++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
@@ -617,6 +617,7 @@ static void fsl_mc_device_release(struct device *dev)
int fsl_mc_device_add(struct fsl_mc_obj_desc *obj_desc,
struct fsl_mc_io *mc_io,
struct device *parent_dev,
+ const char *driver_override,
struct fsl_mc_device **new_mc_dev)
{
int error;
@@ -649,6 +650,19 @@ int fsl_mc_device_add(struct fsl_mc_obj_desc *obj_desc,

mc_dev->obj_desc = *obj_desc;
mc_dev->mc_io = mc_io;
+
+ if (driver_override) {
+ /*
+ * We trust driver_override, so we don't need to use
+ * kstrndup() here
+ */
+ mc_dev->driver_override = kstrdup(driver_override, GFP_KERNEL);
+ if (!mc_dev->driver_override) {
+ error = -ENOMEM;
+ goto error_cleanup_dev;
+ }
+ }
+
device_initialize(&mc_dev->dev);
mc_dev->dev.parent = parent_dev;
mc_dev->dev.bus = &fsl_mc_bus_type;
@@ -740,6 +754,7 @@ int fsl_mc_device_add(struct fsl_mc_obj_desc *obj_desc,

error_cleanup_dev:
kfree(mc_dev->regions);
+ kfree(mc_dev->driver_override);
kfree(mc_bus);
kfree(mc_dev);

@@ -980,7 +995,8 @@ static int fsl_mc_bus_probe(struct platform_device *pdev)
obj_desc.irq_count = 1;
obj_desc.region_count = 0;

- error = fsl_mc_device_add(&obj_desc, mc_io, &pdev->dev, &mc_bus_dev);
+ error = fsl_mc_device_add(&obj_desc, mc_io, &pdev->dev, NULL,
+ &mc_bus_dev);
if (error < 0)
goto error_cleanup_mc_io;

diff --git a/drivers/bus/fsl-mc/fsl-mc-private.h b/drivers/bus/fsl-mc/fsl-mc-private.h
index 21ca8c756ee7..be6bb0fb4603 100644
--- a/drivers/bus/fsl-mc/fsl-mc-private.h
+++ b/drivers/bus/fsl-mc/fsl-mc-private.h
@@ -3,6 +3,7 @@
* Freescale Management Complex (MC) bus private declarations
*
* Copyright (C) 2016 Freescale Semiconductor, Inc.
+ * Copyright 2019-2020 NXP
*
*/
#ifndef _FSL_MC_PRIVATE_H_
@@ -567,6 +568,7 @@ struct fsl_mc_bus {
int __must_check fsl_mc_device_add(struct fsl_mc_obj_desc *obj_desc,
struct fsl_mc_io *mc_io,
struct device *parent_dev,
+ const char *driver_override,
struct fsl_mc_device **new_mc_dev);

void fsl_mc_device_remove(struct fsl_mc_device *mc_dev);
diff --git a/include/linux/fsl/mc.h b/include/linux/fsl/mc.h
index 88095fd30c80..f997f8091408 100644
--- a/include/linux/fsl/mc.h
+++ b/include/linux/fsl/mc.h
@@ -3,6 +3,7 @@
* Freescale Management Complex (MC) bus public interface
*
* Copyright (C) 2014-2016 Freescale Semiconductor, Inc.
+ * Copyright 2019-2020 NXP
* Author: German Rivera <German.Rivera@xxxxxxxxxxxxx>
*
*/
@@ -161,6 +162,7 @@ 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.
--
2.17.1