linux/drivers/s390/crypto/vfio_ap_drv.c
Pierre Morel 36360658eb s390: vfio_ap: link the vfio_ap devices to the vfio_ap bus subsystem
Libudev relies on having a subsystem link for non-root devices. To
avoid libudev (and potentially other userspace tools) choking on the
matrix device let us introduce a matrix bus and with it the matrix
bus subsytem. Also make the matrix device reside within the matrix
bus.

Doing this we remove the forced link from the matrix device to the
vfio_ap driver and the device_type we do not need anymore.

Since the associated matrix driver is not the vfio_ap driver any more,
we have to change the search for the devices on the vfio_ap driver in
the function vfio_ap_verify_queue_reserved.
Fixes: 1fde573413 ("s390: vfio-ap: base implementation of VFIO AP device driver")
Cc: stable@vger.kernel.org

Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-02-22 09:20:01 +01:00

185 lines
4.0 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* VFIO based AP device driver
*
* Copyright IBM Corp. 2018
*
* Author(s): Tony Krowiak <akrowiak@linux.ibm.com>
*/
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <asm/facility.h>
#include "vfio_ap_private.h"
#define VFIO_AP_ROOT_NAME "vfio_ap"
#define VFIO_AP_DEV_NAME "matrix"
MODULE_AUTHOR("IBM Corporation");
MODULE_DESCRIPTION("VFIO AP device driver, Copyright IBM Corp. 2018");
MODULE_LICENSE("GPL v2");
static struct ap_driver vfio_ap_drv;
struct ap_matrix_dev *matrix_dev;
/* Only type 10 adapters (CEX4 and later) are supported
* by the AP matrix device driver
*/
static struct ap_device_id ap_queue_ids[] = {
{ .dev_type = AP_DEVICE_TYPE_CEX4,
.match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
{ .dev_type = AP_DEVICE_TYPE_CEX5,
.match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
{ .dev_type = AP_DEVICE_TYPE_CEX6,
.match_flags = AP_DEVICE_ID_MATCH_QUEUE_TYPE },
{ /* end of sibling */ },
};
MODULE_DEVICE_TABLE(vfio_ap, ap_queue_ids);
static int vfio_ap_queue_dev_probe(struct ap_device *apdev)
{
return 0;
}
static void vfio_ap_queue_dev_remove(struct ap_device *apdev)
{
/* Nothing to do yet */
}
static void vfio_ap_matrix_dev_release(struct device *dev)
{
struct ap_matrix_dev *matrix_dev = dev_get_drvdata(dev);
kfree(matrix_dev);
}
static int matrix_bus_match(struct device *dev, struct device_driver *drv)
{
return 1;
}
static struct bus_type matrix_bus = {
.name = "matrix",
.match = &matrix_bus_match,
};
static struct device_driver matrix_driver = {
.name = "vfio_ap",
.bus = &matrix_bus,
.suppress_bind_attrs = true,
};
static int vfio_ap_matrix_dev_create(void)
{
int ret;
struct device *root_device;
root_device = root_device_register(VFIO_AP_ROOT_NAME);
if (IS_ERR(root_device))
return PTR_ERR(root_device);
ret = bus_register(&matrix_bus);
if (ret)
goto bus_register_err;
matrix_dev = kzalloc(sizeof(*matrix_dev), GFP_KERNEL);
if (!matrix_dev) {
ret = -ENOMEM;
goto matrix_alloc_err;
}
/* Fill in config info via PQAP(QCI), if available */
if (test_facility(12)) {
ret = ap_qci(&matrix_dev->info);
if (ret)
goto matrix_alloc_err;
}
mutex_init(&matrix_dev->lock);
INIT_LIST_HEAD(&matrix_dev->mdev_list);
dev_set_name(&matrix_dev->device, "%s", VFIO_AP_DEV_NAME);
matrix_dev->device.parent = root_device;
matrix_dev->device.bus = &matrix_bus;
matrix_dev->device.release = vfio_ap_matrix_dev_release;
matrix_dev->vfio_ap_drv = &vfio_ap_drv;
ret = device_register(&matrix_dev->device);
if (ret)
goto matrix_reg_err;
ret = driver_register(&matrix_driver);
if (ret)
goto matrix_drv_err;
return 0;
matrix_drv_err:
device_unregister(&matrix_dev->device);
matrix_reg_err:
put_device(&matrix_dev->device);
matrix_alloc_err:
bus_unregister(&matrix_bus);
bus_register_err:
root_device_unregister(root_device);
return ret;
}
static void vfio_ap_matrix_dev_destroy(void)
{
struct device *root_device = matrix_dev->device.parent;
driver_unregister(&matrix_driver);
device_unregister(&matrix_dev->device);
bus_unregister(&matrix_bus);
root_device_unregister(root_device);
}
static int __init vfio_ap_init(void)
{
int ret;
/* If there are no AP instructions, there is nothing to pass through. */
if (!ap_instructions_available())
return -ENODEV;
ret = vfio_ap_matrix_dev_create();
if (ret)
return ret;
memset(&vfio_ap_drv, 0, sizeof(vfio_ap_drv));
vfio_ap_drv.probe = vfio_ap_queue_dev_probe;
vfio_ap_drv.remove = vfio_ap_queue_dev_remove;
vfio_ap_drv.ids = ap_queue_ids;
ret = ap_driver_register(&vfio_ap_drv, THIS_MODULE, VFIO_AP_DRV_NAME);
if (ret) {
vfio_ap_matrix_dev_destroy();
return ret;
}
ret = vfio_ap_mdev_register();
if (ret) {
ap_driver_unregister(&vfio_ap_drv);
vfio_ap_matrix_dev_destroy();
return ret;
}
return 0;
}
static void __exit vfio_ap_exit(void)
{
vfio_ap_mdev_unregister();
ap_driver_unregister(&vfio_ap_drv);
vfio_ap_matrix_dev_destroy();
}
module_init(vfio_ap_init);
module_exit(vfio_ap_exit);