arch/s390/include/asm/archrandom.h

   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
  19 DECLARE_STATIC_KEY_FALSE(s390_arch_random_available);
  20 extern atomic64_t s390_arch_random_counter;
  21
  22 bool s390_arch_get_random_long(unsigned long *v);
  23 bool s390_arch_random_generate(u8 *buf, unsigned int nbytes);
  24
  25 static inline bool __must_check arch_get_random_long(unsigned long *v)
  26 {
  27         if (static_branch_likely(&s390_arch_random_available))
  28                 return s390_arch_get_random_long(v);
  29         return false;
  30 }
  31
  32 static inline bool __must_check arch_get_random_int(unsigned int *v)
  33 {
  34         return false;
  35 }
  36
  37 static inline bool __must_check arch_get_random_seed_long(unsigned long *v)
  38 {
  39         if (static_branch_likely(&s390_arch_random_available)) {
  40                 return s390_arch_random_generate((u8 *)v, sizeof(*v));
  41         }
  42         return false;
  43 }
  44
  45 static inline bool __must_check arch_get_random_seed_int(unsigned int *v)
  46 {
  47         if (static_branch_likely(&s390_arch_random_available)) {
  48                 return s390_arch_random_generate((u8 *)v, sizeof(*v));
  49         }
  50         return false;
  51 }
  52
  53 #endif /* CONFIG_ARCH_RANDOM */
  54 #endif /* _ASM_S390_ARCHRANDOM_H */