blob: 8720e9203ecfb07beac7c878aedfc925e2b0db1b [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* s390 arch random implementation.
*
* Copyright IBM Corp. 2017
* Author(s): Harald Freudenberger <freude@de.ibm.com>
*/
#include <linux/kernel.h>
#include <linux/atomic.h>
#include <linux/random.h>
#include <linux/static_key.h>
#include <asm/cpacf.h>
DEFINE_STATIC_KEY_FALSE(s390_arch_random_available);
atomic64_t s390_arch_random_counter = ATOMIC64_INIT(0);
EXPORT_SYMBOL(s390_arch_random_counter);
static int __init s390_arch_random_init(void)
{
/* check if subfunction CPACF_PRNO_TRNG is available */
if (cpacf_query_func(CPACF_PRNO, CPACF_PRNO_TRNG))
static_branch_enable(&s390_arch_random_available);
return 0;
}
arch_initcall(s390_arch_random_init);