xref: /openbmc/linux/arch/s390/include/asm/archrandom.h (revision 4cb760b0)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Kernel interface for the s390 arch_random_* functions
4  *
5  * Copyright IBM Corp. 2017
6  *
7  * Author: Harald Freudenberger <freude@de.ibm.com>
8  *
9  */
10 
11 #ifndef _ASM_S390_ARCHRANDOM_H
12 #define _ASM_S390_ARCHRANDOM_H
13 
14 #ifdef CONFIG_ARCH_RANDOM
15 
16 #include <linux/static_key.h>
17 #include <linux/atomic.h>
18 
19 DECLARE_STATIC_KEY_FALSE(s390_arch_random_available);
20 extern atomic64_t s390_arch_random_counter;
21 
22 bool s390_arch_random_generate(u8 *buf, unsigned int nbytes);
23 
24 static inline bool __must_check arch_get_random_long(unsigned long *v)
25 {
26 	return false;
27 }
28 
29 static inline bool __must_check arch_get_random_int(unsigned int *v)
30 {
31 	return false;
32 }
33 
34 static inline bool __must_check arch_get_random_seed_long(unsigned long *v)
35 {
36 	if (static_branch_likely(&s390_arch_random_available)) {
37 		return s390_arch_random_generate((u8 *)v, sizeof(*v));
38 	}
39 	return false;
40 }
41 
42 static inline bool __must_check arch_get_random_seed_int(unsigned int *v)
43 {
44 	if (static_branch_likely(&s390_arch_random_available)) {
45 		return s390_arch_random_generate((u8 *)v, sizeof(*v));
46 	}
47 	return false;
48 }
49 
50 #endif /* CONFIG_ARCH_RANDOM */
51 #endif /* _ASM_S390_ARCHRANDOM_H */
52