linux_dsm_epyc7002/arch/x86/include/asm/archrandom.h
Uros Bizjak 3d81b3d1e5 x86/cpu: Use RDRAND and RDSEED mnemonics in archrandom.h
Current minimum required version of binutils is 2.23,
which supports RDRAND and RDSEED instruction mnemonics.

Replace the byte-wise specification of RDRAND and
RDSEED with these proper mnemonics.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200508105817.207887-1-ubizjak@gmail.com
2020-05-18 19:50:47 +02:00

102 lines
2.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* This file is part of the Linux kernel.
*
* Copyright (c) 2011-2014, Intel Corporation
* Authors: Fenghua Yu <fenghua.yu@intel.com>,
* H. Peter Anvin <hpa@linux.intel.com>
*/
#ifndef ASM_X86_ARCHRANDOM_H
#define ASM_X86_ARCHRANDOM_H
#include <asm/processor.h>
#include <asm/cpufeature.h>
#define RDRAND_RETRY_LOOPS 10
/* Unconditional execution of RDRAND and RDSEED */
static inline bool __must_check rdrand_long(unsigned long *v)
{
bool ok;
unsigned int retry = RDRAND_RETRY_LOOPS;
do {
asm volatile("rdrand %[out]"
CC_SET(c)
: CC_OUT(c) (ok), [out] "=r" (*v));
if (ok)
return true;
} while (--retry);
return false;
}
static inline bool __must_check rdrand_int(unsigned int *v)
{
bool ok;
unsigned int retry = RDRAND_RETRY_LOOPS;
do {
asm volatile("rdrand %[out]"
CC_SET(c)
: CC_OUT(c) (ok), [out] "=r" (*v));
if (ok)
return true;
} while (--retry);
return false;
}
static inline bool __must_check rdseed_long(unsigned long *v)
{
bool ok;
asm volatile("rdseed %[out]"
CC_SET(c)
: CC_OUT(c) (ok), [out] "=r" (*v));
return ok;
}
static inline bool __must_check rdseed_int(unsigned int *v)
{
bool ok;
asm volatile("rdseed %[out]"
CC_SET(c)
: CC_OUT(c) (ok), [out] "=r" (*v));
return ok;
}
/*
* These are the generic interfaces; they must not be declared if the
* stubs in <linux/random.h> are to be invoked,
* i.e. CONFIG_ARCH_RANDOM is not defined.
*/
#ifdef CONFIG_ARCH_RANDOM
static inline bool __must_check arch_get_random_long(unsigned long *v)
{
return static_cpu_has(X86_FEATURE_RDRAND) ? rdrand_long(v) : false;
}
static inline bool __must_check arch_get_random_int(unsigned int *v)
{
return static_cpu_has(X86_FEATURE_RDRAND) ? rdrand_int(v) : false;
}
static inline bool __must_check arch_get_random_seed_long(unsigned long *v)
{
return static_cpu_has(X86_FEATURE_RDSEED) ? rdseed_long(v) : false;
}
static inline bool __must_check arch_get_random_seed_int(unsigned int *v)
{
return static_cpu_has(X86_FEATURE_RDSEED) ? rdseed_int(v) : false;
}
extern void x86_init_rdrand(struct cpuinfo_x86 *c);
#else /* !CONFIG_ARCH_RANDOM */
static inline void x86_init_rdrand(struct cpuinfo_x86 *c) { }
#endif /* !CONFIG_ARCH_RANDOM */
#endif /* ASM_X86_ARCHRANDOM_H */