mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-11-01 08:58:07 +00:00
3d81b3d1e5
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
101 lines
2.3 KiB
C
101 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 */
|