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 19 DECLARE_STATIC_KEY_FALSE(s390_arch_random_available); 20 extern atomic64_t s390_arch_random_counter; 21 22 static 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 28 static inline bool arch_has_random(void) 29 { 30 if (static_branch_likely(&s390_arch_random_available)) 31 return true; 32 return false; 33 } 34 35 static inline bool arch_has_random_seed(void) 36 { 37 return arch_has_random(); 38 } 39 40 static 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 49 static 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 58 static inline bool arch_get_random_seed_long(unsigned long *v) 59 { 60 return arch_get_random_long(v); 61 } 62 63 static 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 */ 70