diff options
Diffstat (limited to 'arch/x86/include/asm/archrandom.h')
| -rw-r--r-- | arch/x86/include/asm/archrandom.h | 98 |
1 files changed, 15 insertions, 83 deletions
diff --git a/arch/x86/include/asm/archrandom.h b/arch/x86/include/asm/archrandom.h index 3ac991d81e74..4c305305871b 100644 --- a/arch/x86/include/asm/archrandom.h +++ b/arch/x86/include/asm/archrandom.h @@ -1,23 +1,10 @@ +/* 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> - * - * This program is free software; you can redistribute it and/or modify it - * under the terms and conditions of the GNU General Public License, - * version 2, as published by the Free Software Foundation. - * - * This program is distributed in the hope it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for - * more details. - * - * You should have received a copy of the GNU General Public License along with - * this program; if not, write to the Free Software Foundation, Inc., - * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. - * */ #ifndef ASM_X86_ARCHRANDOM_H @@ -28,101 +15,46 @@ #define RDRAND_RETRY_LOOPS 10 -#define RDRAND_INT ".byte 0x0f,0xc7,0xf0" -#define RDSEED_INT ".byte 0x0f,0xc7,0xf8" -#ifdef CONFIG_X86_64 -# define RDRAND_LONG ".byte 0x48,0x0f,0xc7,0xf0" -# define RDSEED_LONG ".byte 0x48,0x0f,0xc7,0xf8" -#else -# define RDRAND_LONG RDRAND_INT -# define RDSEED_LONG RDSEED_INT -#endif - /* Unconditional execution of RDRAND and RDSEED */ -static inline bool rdrand_long(unsigned long *v) -{ - bool ok; - unsigned int retry = RDRAND_RETRY_LOOPS; - do { - asm volatile(RDRAND_LONG - CC_SET(c) - : CC_OUT(c) (ok), "=a" (*v)); - if (ok) - return true; - } while (--retry); - return false; -} - -static inline bool rdrand_int(unsigned int *v) +static inline bool __must_check rdrand_long(unsigned long *v) { bool ok; unsigned int retry = RDRAND_RETRY_LOOPS; do { - asm volatile(RDRAND_INT - CC_SET(c) - : CC_OUT(c) (ok), "=a" (*v)); + asm volatile("rdrand %[out]" + : "=@ccc" (ok), [out] "=r" (*v)); if (ok) return true; } while (--retry); return false; } -static inline bool rdseed_long(unsigned long *v) +static inline bool __must_check rdseed_long(unsigned long *v) { bool ok; - asm volatile(RDSEED_LONG - CC_SET(c) - : CC_OUT(c) (ok), "=a" (*v)); + asm volatile("rdseed %[out]" + : "=@ccc" (ok), [out] "=r" (*v)); return ok; } -static inline bool rdseed_int(unsigned int *v) -{ - bool ok; - asm volatile(RDSEED_INT - CC_SET(c) - : CC_OUT(c) (ok), "=a" (*v)); - return ok; -} - -/* Conditional execution based on CPU type */ -#define arch_has_random() static_cpu_has(X86_FEATURE_RDRAND) -#define arch_has_random_seed() static_cpu_has(X86_FEATURE_RDSEED) - /* * 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. + * stubs in <linux/random.h> are to be invoked. */ -#ifdef CONFIG_ARCH_RANDOM - -static inline bool arch_get_random_long(unsigned long *v) -{ - return arch_has_random() ? rdrand_long(v) : false; -} - -static inline bool arch_get_random_int(unsigned int *v) -{ - return arch_has_random() ? rdrand_int(v) : false; -} -static inline bool arch_get_random_seed_long(unsigned long *v) +static inline size_t __must_check arch_get_random_longs(unsigned long *v, size_t max_longs) { - return arch_has_random_seed() ? rdseed_long(v) : false; + return max_longs && static_cpu_has(X86_FEATURE_RDRAND) && rdrand_long(v) ? 1 : 0; } -static inline bool arch_get_random_seed_int(unsigned int *v) +static inline size_t __must_check arch_get_random_seed_longs(unsigned long *v, size_t max_longs) { - return arch_has_random_seed() ? rdseed_int(v) : false; + return max_longs && static_cpu_has(X86_FEATURE_RDSEED) && rdseed_long(v) ? 1 : 0; } -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 */ +#ifndef CONFIG_UML +void x86_init_rdrand(struct cpuinfo_x86 *c); +#endif #endif /* ASM_X86_ARCHRANDOM_H */ |