1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Kernel interface for the s390 arch_random_* functions
4 *
5 * Copyright IBM Corp. 2017, 2022
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 #include <linux/static_key.h>
15 #include <linux/preempt.h>
16 #include <linux/atomic.h>
17 #include <asm/cpacf.h>
18
19 DECLARE_STATIC_KEY_FALSE(s390_arch_random_available);
20 extern atomic64_t s390_arch_random_counter;
21
22 static inline size_t __must_check arch_get_random_longs(unsigned long *v, size_t max_longs)
23 {
24 return 0;
25 }
26
27 static inline size_t __must_check arch_get_random_seed_longs(unsigned long *v, size_t max_longs)
28 {
29 if (static_branch_likely(&s390_arch_random_available) &&
30 in_task()) {
31 cpacf_trng(NULL, 0, (u8 *)v, max_longs * sizeof(*v));
32 atomic64_add(max_longs * sizeof(*v), &s390_arch_random_counter);
33 return max_longs;
34 }
35 return 0;
36 }
37
38 #endif /* _ASM_S390_ARCHRANDOM_H */
39
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.