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Subject[PATCH 04/17] hwrng: pseries - PFO-based hwrng driver
From
Date
From: Michael Neuling <mikey@neuling.org>

Adds support for the Platform Facilities Option (PFO)-based hardware
random number generator for POWER hardware.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>
---
drivers/char/hw_random/Kconfig | 13 +++++
drivers/char/hw_random/Makefile | 1 +
drivers/char/hw_random/pseries-rng.c | 99 ++++++++++++++++++++++++++++++++++
3 files changed, 113 insertions(+), 0 deletions(-)
create mode 100644 drivers/char/hw_random/pseries-rng.c

diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 0689bf6..9355347 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -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.
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index b2ff526..d901dfa 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -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
diff --git a/drivers/char/hw_random/pseries-rng.c b/drivers/char/hw_random/pseries-rng.c
new file mode 100644
index 0000000..6ee70ca
--- /dev/null
+++ b/drivers/char/hw_random/pseries-rng.c
@@ -0,0 +1,99 @@
+/*
+ * 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 = {
+ .driver = {
+ .name = MODULE_NAME,
+ .owner = THIS_MODULE,
+ },
+ .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");
--
1.7.1



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