xref: /OK3568_Linux_fs/kernel/arch/powerpc/platforms/pseries/rng.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * Copyright 2013, Michael Ellerman, IBM Corporation.
4*4882a593Smuzhiyun  */
5*4882a593Smuzhiyun 
6*4882a593Smuzhiyun #define pr_fmt(fmt)	"pseries-rng: " fmt
7*4882a593Smuzhiyun 
8*4882a593Smuzhiyun #include <linux/kernel.h>
9*4882a593Smuzhiyun #include <linux/of.h>
10*4882a593Smuzhiyun #include <asm/archrandom.h>
11*4882a593Smuzhiyun #include <asm/machdep.h>
12*4882a593Smuzhiyun #include <asm/plpar_wrappers.h>
13*4882a593Smuzhiyun #include "pseries.h"
14*4882a593Smuzhiyun 
15*4882a593Smuzhiyun 
pseries_get_random_long(unsigned long * v)16*4882a593Smuzhiyun static int pseries_get_random_long(unsigned long *v)
17*4882a593Smuzhiyun {
18*4882a593Smuzhiyun 	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
19*4882a593Smuzhiyun 
20*4882a593Smuzhiyun 	if (plpar_hcall(H_RANDOM, retbuf) == H_SUCCESS) {
21*4882a593Smuzhiyun 		*v = retbuf[0];
22*4882a593Smuzhiyun 		return 1;
23*4882a593Smuzhiyun 	}
24*4882a593Smuzhiyun 
25*4882a593Smuzhiyun 	return 0;
26*4882a593Smuzhiyun }
27*4882a593Smuzhiyun 
pseries_rng_init(void)28*4882a593Smuzhiyun void __init pseries_rng_init(void)
29*4882a593Smuzhiyun {
30*4882a593Smuzhiyun 	struct device_node *dn;
31*4882a593Smuzhiyun 
32*4882a593Smuzhiyun 	dn = of_find_compatible_node(NULL, NULL, "ibm,random");
33*4882a593Smuzhiyun 	if (!dn)
34*4882a593Smuzhiyun 		return;
35*4882a593Smuzhiyun 	ppc_md.get_random_seed = pseries_get_random_long;
36*4882a593Smuzhiyun 	of_node_put(dn);
37*4882a593Smuzhiyun }
38