diff options
Diffstat (limited to 'arch/s390/include/asm/archrandom.h')
| -rw-r--r-- | arch/s390/include/asm/archrandom.h | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/arch/s390/include/asm/archrandom.h b/arch/s390/include/asm/archrandom.h new file mode 100644 index 000000000..159404989 --- /dev/null +++ b/arch/s390/include/asm/archrandom.h @@ -0,0 +1,38 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Kernel interface for the s390 arch_random_* functions + * + * Copyright IBM Corp. 2017, 2022 + * + * Author: Harald Freudenberger <freude@de.ibm.com> + * + */ + +#ifndef _ASM_S390_ARCHRANDOM_H +#define _ASM_S390_ARCHRANDOM_H + +#include <linux/static_key.h> +#include <linux/preempt.h> +#include <linux/atomic.h> +#include <asm/cpacf.h> + +DECLARE_STATIC_KEY_FALSE(s390_arch_random_available); +extern atomic64_t s390_arch_random_counter; + +static inline size_t __must_check arch_get_random_longs(unsigned long *v, size_t max_longs) +{ + return 0; +} + +static inline size_t __must_check arch_get_random_seed_longs(unsigned long *v, size_t max_longs) +{ + if (static_branch_likely(&s390_arch_random_available) && + in_task()) { + cpacf_trng(NULL, 0, (u8 *)v, max_longs * sizeof(*v)); + atomic64_add(max_longs * sizeof(*v), &s390_arch_random_counter); + return max_longs; + } + return 0; +} + +#endif /* _ASM_S390_ARCHRANDOM_H */ |