| /* SPDX-License-Identifier: GPL-2.0 */ |
| /* |
| * Kernel interface for the s390 arch_random_* functions |
| * |
| * Copyright IBM Corp. 2017, 2022 |
| * |
| * Author: Harald Freudenberger <freude@de.ibm.com> |
| * |
| */ |
| |
| #ifndef _ASM_S390_ARCHRANDOM_H |
| #define _ASM_S390_ARCHRANDOM_H |
| |
| #include <linux/static_key.h> |
| #include <linux/preempt.h> |
| #include <linux/atomic.h> |
| #include <asm/cpacf.h> |
| |
| DECLARE_STATIC_KEY_FALSE(s390_arch_random_available); |
| extern atomic64_t s390_arch_random_counter; |
| |
| static inline size_t __must_check arch_get_random_longs(unsigned long *v, size_t max_longs) |
| { |
| return 0; |
| } |
| |
| static inline size_t __must_check arch_get_random_seed_longs(unsigned long *v, size_t max_longs) |
| { |
| if (static_branch_likely(&s390_arch_random_available) && |
| in_task()) { |
| cpacf_trng(NULL, 0, (u8 *)v, max_longs * sizeof(*v)); |
| atomic64_add(max_longs * sizeof(*v), &s390_arch_random_counter); |
| return max_longs; |
| } |
| return 0; |
| } |
| |
| #endif /* _ASM_S390_ARCHRANDOM_H */ |
