1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Kernel interface for the s390 arch_random_* functions 4 * 5 * Copyright IBM Corp. 2017, 2020 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 #include <asm/cpacf.h> 19 20 DECLARE_STATIC_KEY_FALSE(s390_arch_random_available); 21 extern atomic64_t s390_arch_random_counter; 22 23 static inline bool __must_check arch_get_random_long(unsigned long *v) 24 { 25 return false; 26 } 27 28 static inline bool __must_check arch_get_random_int(unsigned int *v) 29 { 30 return false; 31 } 32 33 static inline bool __must_check arch_get_random_seed_long(unsigned long *v) 34 { 35 if (static_branch_likely(&s390_arch_random_available)) { 36 cpacf_trng(NULL, 0, (u8 *)v, sizeof(*v)); 37 atomic64_add(sizeof(*v), &s390_arch_random_counter); 38 return true; 39 } 40 return false; 41 } 42 43 static inline bool __must_check arch_get_random_seed_int(unsigned int *v) 44 { 45 if (static_branch_likely(&s390_arch_random_available)) { 46 cpacf_trng(NULL, 0, (u8 *)v, sizeof(*v)); 47 atomic64_add(sizeof(*v), &s390_arch_random_counter); 48 return true; 49 } 50 return false; 51 } 52 53 #endif /* CONFIG_ARCH_RANDOM */ 54 #endif /* _ASM_S390_ARCHRANDOM_H */ 55