From 649e9ea0ab611ab54d4ff606475812d52b6e34fc Mon Sep 17 00:00:00 2001 From: Kent Yoder Date: Thu, 12 Apr 2012 05:08:53 +0000 Subject: powerpc/pseries/hwrng: PFO-based hwrng driver Adds support for the Platform Facilities Option (PFO)-based hardware random number generator for POWER hardware. Signed-off-by: Michael Neuling Signed-off-by: Robert Jennings Signed-off-by: Kent Yoder Signed-off-by: Benjamin Herrenschmidt --- drivers/char/hw_random/pseries-rng.c | 96 ++++++++++++++++++++++++++++++++++++ 1 file changed, 96 insertions(+) create mode 100644 drivers/char/hw_random/pseries-rng.c (limited to 'drivers/char/hw_random/pseries-rng.c') diff --git a/drivers/char/hw_random/pseries-rng.c b/drivers/char/hw_random/pseries-rng.c new file mode 100644 index 000000000000..5f1197929f0c --- /dev/null +++ b/drivers/char/hw_random/pseries-rng.c @@ -0,0 +1,96 @@ +/* + * 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 + */ + +#include +#include +#include + +#define MODULE_NAME "pseries-rng" + +static int pseries_rng_data_read(struct hwrng *rng, u32 *data) +{ + if (plpar_hcall(H_RANDOM, (unsigned long *)data) != H_SUCCESS) { + printk(KERN_ERR "pseries rng hcall error\n"); + return 0; + } + 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 = MODULE_NAME, + .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 = MODULE_NAME, + .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) +{ + printk(KERN_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 "); +MODULE_DESCRIPTION("H/W RNG driver for IBM pSeries processors"); -- cgit v1.2.3-59-g8ed1b