104 lines
2.7 KiB
C
104 lines
2.7 KiB
C
/*
|
|
* Copyright (C) 2010 Michael Neuling IBM Corporation
|
|
*
|
|
* Driver for the pseries hardware RNG for POWER7+ and above
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/hw_random.h>
|
|
#include <asm/vio.h>
|
|
|
|
|
|
static int pseries_rng_data_read(struct hwrng *rng, u32 *data)
|
|
{
|
|
int rc;
|
|
|
|
rc = plpar_hcall(H_RANDOM, (unsigned long *)data);
|
|
if (rc != H_SUCCESS) {
|
|
pr_err_ratelimited("H_RANDOM call failed %d\n", rc);
|
|
return -EIO;
|
|
}
|
|
|
|
/* The hypervisor interface returns 64 bits */
|
|
return 8;
|
|
}
|
|
|
|
/**
|
|
* pseries_rng_get_desired_dma - Return desired DMA allocate for CMO operations
|
|
*
|
|
* This is a required function for a driver to operate in a CMO environment
|
|
* but this device does not make use of DMA allocations, return 0.
|
|
*
|
|
* Return value:
|
|
* Number of bytes of IO data the driver will need to perform well -> 0
|
|
*/
|
|
static unsigned long pseries_rng_get_desired_dma(struct vio_dev *vdev)
|
|
{
|
|
return 0;
|
|
};
|
|
|
|
static struct hwrng pseries_rng = {
|
|
.name = KBUILD_MODNAME,
|
|
.data_read = pseries_rng_data_read,
|
|
};
|
|
|
|
static int __init pseries_rng_probe(struct vio_dev *dev,
|
|
const struct vio_device_id *id)
|
|
{
|
|
return hwrng_register(&pseries_rng);
|
|
}
|
|
|
|
static int __exit pseries_rng_remove(struct vio_dev *dev)
|
|
{
|
|
hwrng_unregister(&pseries_rng);
|
|
return 0;
|
|
}
|
|
|
|
static struct vio_device_id pseries_rng_driver_ids[] = {
|
|
{ "ibm,random-v1", "ibm,random"},
|
|
{ "", "" }
|
|
};
|
|
MODULE_DEVICE_TABLE(vio, pseries_rng_driver_ids);
|
|
|
|
static struct vio_driver pseries_rng_driver = {
|
|
.name = KBUILD_MODNAME,
|
|
.probe = pseries_rng_probe,
|
|
.remove = pseries_rng_remove,
|
|
.get_desired_dma = pseries_rng_get_desired_dma,
|
|
.id_table = pseries_rng_driver_ids
|
|
};
|
|
|
|
static int __init rng_init(void)
|
|
{
|
|
pr_info("Registering IBM pSeries RNG driver\n");
|
|
return vio_register_driver(&pseries_rng_driver);
|
|
}
|
|
|
|
module_init(rng_init);
|
|
|
|
static void __exit rng_exit(void)
|
|
{
|
|
vio_unregister_driver(&pseries_rng_driver);
|
|
}
|
|
module_exit(rng_exit);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Michael Neuling <mikey@neuling.org>");
|
|
MODULE_DESCRIPTION("H/W RNG driver for IBM pSeries processors");
|