powerpc/pseries/hwrng: PFO-based hwrng driver (649e9ea0) · Commits · e / devices / android_kernel_fairphone_FP5

drivers/char/hw_random/Kconfig

+13 −0

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		@@ -250,3 +250,16 @@ config UML_RANDOM
		(check your distro, or download from
		http://sourceforge.net/projects/gkernel/). rngd periodically reads
		/dev/hwrng and injects the entropy into /dev/random.

		config HW_RANDOM_PSERIES
		tristate "pSeries HW Random Number Generator support"
		depends on HW_RANDOM && PPC64 && IBMVIO
		default HW_RANDOM
		---help---
		This driver provides kernel-side support for the Random Number
		Generator hardware found on POWER7+ machines and above

		To compile this driver as a module, choose M here: the
		module will be called pseries-rng.

		If unsure, say Y.

drivers/char/hw_random/Makefile

+1 −0

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		@@ -22,3 +22,4 @@ obj-$(CONFIG_HW_RANDOM_OCTEON) += octeon-rng.o
		obj-$(CONFIG_HW_RANDOM_NOMADIK) += nomadik-rng.o
		obj-$(CONFIG_HW_RANDOM_PICOXCELL) += picoxcell-rng.o
		obj-$(CONFIG_HW_RANDOM_PPC4XX) += ppc4xx-rng.o
		obj-$(CONFIG_HW_RANDOM_PSERIES) += pseries-rng.o

drivers/char/hw_random/pseries-rng.c

0 → 100644

+96 −0

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		/*
		* 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 <linux/module.h>
		#include <linux/hw_random.h>
		#include <asm/vio.h>

		#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 <mikey@neuling.org>");
		MODULE_DESCRIPTION("H/W RNG driver for IBM pSeries processors");