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1/*
2 * Kernel interface for the s390 arch_random_* functions
3 *
4 * Copyright IBM Corp. 2017
5 *
6 * Author: Harald Freudenberger <freude@de.ibm.com>
7 *
8 */
9
10#ifndef _ASM_S390_ARCHRANDOM_H
11#define _ASM_S390_ARCHRANDOM_H
12
13#ifdef CONFIG_ARCH_RANDOM
14
15#include <linux/static_key.h>
16#include <linux/atomic.h>
17#include <asm/cpacf.h>
18
19DECLARE_STATIC_KEY_FALSE(s390_arch_random_available);
20extern atomic64_t s390_arch_random_counter;
21
22static void s390_arch_random_generate(u8 *buf, unsigned int nbytes)
23{
24 cpacf_trng(NULL, 0, buf, nbytes);
25 atomic64_add(nbytes, &s390_arch_random_counter);
26}
27
28static inline bool arch_has_random(void)
29{
30 if (static_branch_likely(&s390_arch_random_available))
31 return true;
32 return false;
33}
34
35static inline bool arch_has_random_seed(void)
36{
37 return arch_has_random();
38}
39
40static inline bool arch_get_random_long(unsigned long *v)
41{
42 if (static_branch_likely(&s390_arch_random_available)) {
43 s390_arch_random_generate((u8 *)v, sizeof(*v));
44 return true;
45 }
46 return false;
47}
48
49static inline bool arch_get_random_int(unsigned int *v)
50{
51 if (static_branch_likely(&s390_arch_random_available)) {
52 s390_arch_random_generate((u8 *)v, sizeof(*v));
53 return true;
54 }
55 return false;
56}
57
58static inline bool arch_get_random_seed_long(unsigned long *v)
59{
60 return arch_get_random_long(v);
61}
62
63static inline bool arch_get_random_seed_int(unsigned int *v)
64{
65 return arch_get_random_int(v);
66}
67
68#endif /* CONFIG_ARCH_RANDOM */
69#endif /* _ASM_S390_ARCHRANDOM_H */