| /* |
| * s390 arch random implementation. |
| * |
| * Copyright IBM Corp. 2017 |
| * Author(s): Harald Freudenberger <freude@de.ibm.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License (version 2 only) |
| * as published by the Free Software Foundation. |
| * |
| */ |
| |
| #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); |
