LXR linux/arch/s390/include/asm/archrandom.h

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