diff options
Diffstat (limited to 'arch/s390/crypto/arch_random.c')
| -rw-r--r-- | arch/s390/crypto/arch_random.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/arch/s390/crypto/arch_random.c b/arch/s390/crypto/arch_random.c new file mode 100644 index 000000000000..9317b3e645e2 --- /dev/null +++ b/arch/s390/crypto/arch_random.c @@ -0,0 +1,31 @@ +/* + * 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/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); |