Brooklyn/arch/s390/include/asm/archrandom.h

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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Kernel interface for the s390 arch_random_* functions
*
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* Copyright IBM Corp. 2017, 2022
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*
* Author: Harald Freudenberger <freude@de.ibm.com>
*
*/
#ifndef _ASM_S390_ARCHRANDOM_H
#define _ASM_S390_ARCHRANDOM_H
#include <linux/static_key.h>
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#include <linux/preempt.h>
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#include <linux/atomic.h>
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#include <asm/cpacf.h>
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DECLARE_STATIC_KEY_FALSE(s390_arch_random_available);
extern atomic64_t s390_arch_random_counter;
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static inline size_t __must_check arch_get_random_longs(unsigned long *v, size_t max_longs)
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{
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return 0;
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}
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static inline size_t __must_check arch_get_random_seed_longs(unsigned long *v, size_t max_longs)
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{
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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;
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}
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return 0;
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}
#endif /* _ASM_S390_ARCHRANDOM_H */