1// SPDX-License-Identifier: GPL-2.0-or-later
 2/*
 3 * Copyright 2013 Michael Ellerman, Guo Chao, IBM Corp.
 
 
 
 
 
 4 */
 5
 6#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
 7
 8#include <linux/module.h>
 9#include <linux/mod_devicetable.h>
10#include <linux/kernel.h>
11#include <linux/platform_device.h>
12#include <linux/random.h>
13#include <linux/hw_random.h>
14#include <asm/archrandom.h>
15
16static int powernv_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
17{
18	unsigned long *buf;
19	int i, len;
20
21	/* We rely on rng_buffer_size() being >= sizeof(unsigned long) */
22	len = max / sizeof(unsigned long);
23
24	buf = (unsigned long *)data;
25
26	for (i = 0; i < len; i++)
27		pnv_get_random_long(buf++);
28
29	return len * sizeof(unsigned long);
30}
31
32static struct hwrng powernv_hwrng = {
33	.name = "powernv-rng",
34	.read = powernv_rng_read,
35};
36
 
 
 
 
 
 
 
37static int powernv_rng_probe(struct platform_device *pdev)
38{
39	int rc;
40
41	rc = devm_hwrng_register(&pdev->dev, &powernv_hwrng);
42	if (rc) {
43		/* We only register one device, ignore any others */
44		if (rc == -EEXIST)
45			rc = -ENODEV;
46
47		return rc;
48	}
49
50	pr_info("Registered powernv hwrng.\n");
51
52	return 0;
53}
54
55static const struct of_device_id powernv_rng_match[] = {
56	{ .compatible	= "ibm,power-rng",},
57	{},
58};
59MODULE_DEVICE_TABLE(of, powernv_rng_match);
60
61static struct platform_driver powernv_rng_driver = {
62	.driver = {
63		.name = "powernv_rng",
64		.of_match_table = powernv_rng_match,
65	},
66	.probe	= powernv_rng_probe,
 
67};
68module_platform_driver(powernv_rng_driver);
69
70MODULE_LICENSE("GPL");
71MODULE_DESCRIPTION("Bare metal HWRNG driver for POWER7+ and above");

 
 1/*
 2 * Copyright 2013 Michael Ellerman, Guo Chao, IBM Corp.
 3 *
 4 * This program is free software; you can redistribute it and/or
 5 * modify it under the terms of the GNU General Public License
 6 * as published by the Free Software Foundation; either version
 7 * 2 of the License, or (at your option) any later version.
 8 */
 9
10#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
11
12#include <linux/module.h>
 
13#include <linux/kernel.h>
14#include <linux/platform_device.h>
15#include <linux/random.h>
16#include <linux/hw_random.h>
 
17
18static int powernv_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
19{
20	unsigned long *buf;
21	int i, len;
22
23	/* We rely on rng_buffer_size() being >= sizeof(unsigned long) */
24	len = max / sizeof(unsigned long);
25
26	buf = (unsigned long *)data;
27
28	for (i = 0; i < len; i++)
29		powernv_get_random_long(buf++);
30
31	return len * sizeof(unsigned long);
32}
33
34static struct hwrng powernv_hwrng = {
35	.name = "powernv-rng",
36	.read = powernv_rng_read,
37};
38
39static int powernv_rng_remove(struct platform_device *pdev)
40{
41	hwrng_unregister(&powernv_hwrng);
42
43	return 0;
44}
45
46static int powernv_rng_probe(struct platform_device *pdev)
47{
48	int rc;
49
50	rc = hwrng_register(&powernv_hwrng);
51	if (rc) {
52		/* We only register one device, ignore any others */
53		if (rc == -EEXIST)
54			rc = -ENODEV;
55
56		return rc;
57	}
58
59	pr_info("Registered powernv hwrng.\n");
60
61	return 0;
62}
63
64static const struct of_device_id powernv_rng_match[] = {
65	{ .compatible	= "ibm,power-rng",},
66	{},
67};
68MODULE_DEVICE_TABLE(of, powernv_rng_match);
69
70static struct platform_driver powernv_rng_driver = {
71	.driver = {
72		.name = "powernv_rng",
73		.of_match_table = powernv_rng_match,
74	},
75	.probe	= powernv_rng_probe,
76	.remove = powernv_rng_remove,
77};
78module_platform_driver(powernv_rng_driver);
79
80MODULE_LICENSE("GPL");
81MODULE_DESCRIPTION("Bare metal HWRNG driver for POWER7+ and above");