1/*
2 * Copyright 2013, Michael Ellerman, IBM Corporation.
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)	"pseries-rng: " fmt
11
12#include <linux/kernel.h>
13#include <linux/of.h>
14#include <asm/archrandom.h>
15#include <asm/machdep.h>
16#include <asm/plpar_wrappers.h>
17
18
19static int pseries_get_random_long(unsigned long *v)
20{
21	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
22
23	if (plpar_hcall(H_RANDOM, retbuf) == H_SUCCESS) {
24		*v = retbuf[0];
25		return 1;
26	}
27
28	return 0;
29}
30
31static __init int rng_init(void)
32{
33	struct device_node *dn;
34
35	dn = of_find_compatible_node(NULL, NULL, "ibm,random");
36	if (!dn)
37		return -ENODEV;
38
39	pr_info("Registering arch random hook.\n");
40
41	ppc_md.get_random_long = pseries_get_random_long;
42
43	return 0;
44}
45machine_subsys_initcall(pseries, rng_init);
46