LXR linux/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
   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
  20DECLARE_STATIC_KEY_FALSE(s390_arch_random_available);
  21extern atomic64_t s390_arch_random_counter;
  22
  23static void s390_arch_random_generate(u8 *buf, unsigned int nbytes)
  24{
  25        cpacf_trng(NULL, 0, buf, nbytes);
  26        atomic64_add(nbytes, &s390_arch_random_counter);
  27}
  28
  29static inline bool arch_has_random(void)
  30{
  31        if (static_branch_likely(&s390_arch_random_available))
  32                return true;
  33        return false;
  34}
  35
  36static inline bool arch_has_random_seed(void)
  37{
  38        return arch_has_random();
  39}
  40
  41static inline bool arch_get_random_long(unsigned long *v)
  42{
  43        if (static_branch_likely(&s390_arch_random_available)) {
  44                s390_arch_random_generate((u8 *)v, sizeof(*v));
  45                return true;
  46        }
  47        return false;
  48}
  49
  50static inline bool arch_get_random_int(unsigned int *v)
  51{
  52        if (static_branch_likely(&s390_arch_random_available)) {
  53                s390_arch_random_generate((u8 *)v, sizeof(*v));
  54                return true;
  55        }
  56        return false;
  57}
  58
  59static inline bool arch_get_random_seed_long(unsigned long *v)
  60{
  61        return arch_get_random_long(v);
  62}
  63
  64static inline bool arch_get_random_seed_int(unsigned int *v)
  65{
  66        return arch_get_random_int(v);
  67}
  68
  69#endif /* CONFIG_ARCH_RANDOM */
  70#endif /* _ASM_S390_ARCHRANDOM_H */
  71