diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/Kconfig | 9 | ||||
| -rw-r--r-- | arch/x86/include/asm/archrandom.h | 73 |
2 files changed, 82 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 37357a599dca..a0e9bda72fda 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig | |||
| @@ -1451,6 +1451,15 @@ config ARCH_USES_PG_UNCACHED | |||
| 1451 | def_bool y | 1451 | def_bool y |
| 1452 | depends on X86_PAT | 1452 | depends on X86_PAT |
| 1453 | 1453 | ||
| 1454 | config ARCH_RANDOM | ||
| 1455 | def_bool y | ||
| 1456 | prompt "x86 architectural random number generator" if EXPERT | ||
| 1457 | ---help--- | ||
| 1458 | Enable the x86 architectural RDRAND instruction | ||
| 1459 | (Intel Bull Mountain technology) to generate random numbers. | ||
| 1460 | If supported, this is a high bandwidth, cryptographically | ||
| 1461 | secure hardware random number generator. | ||
| 1462 | |||
| 1454 | config EFI | 1463 | config EFI |
| 1455 | bool "EFI runtime service support" | 1464 | bool "EFI runtime service support" |
| 1456 | depends on ACPI | 1465 | depends on ACPI |
diff --git a/arch/x86/include/asm/archrandom.h b/arch/x86/include/asm/archrandom.h new file mode 100644 index 000000000000..b7b5bc02e361 --- /dev/null +++ b/arch/x86/include/asm/archrandom.h | |||
| @@ -0,0 +1,73 @@ | |||
| 1 | /* | ||
| 2 | * This file is part of the Linux kernel. | ||
| 3 | * | ||
| 4 | * Copyright (c) 2011, Intel Corporation | ||
| 5 | * Authors: Fenghua Yu <fenghua.yu@intel.com>, | ||
| 6 | * H. Peter Anvin <hpa@linux.intel.com> | ||
| 7 | * | ||
| 8 | * This program is free software; you can redistribute it and/or modify it | ||
| 9 | * under the terms and conditions of the GNU General Public License, | ||
| 10 | * version 2, as published by the Free Software Foundation. | ||
| 11 | * | ||
| 12 | * This program is distributed in the hope it will be useful, but WITHOUT | ||
| 13 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | ||
| 14 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | ||
| 15 | * more details. | ||
| 16 | * | ||
| 17 | * You should have received a copy of the GNU General Public License along with | ||
| 18 | * this program; if not, write to the Free Software Foundation, Inc., | ||
| 19 | * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. | ||
| 20 | * | ||
| 21 | */ | ||
| 22 | |||
| 23 | #ifndef ASM_X86_ARCHRANDOM_H | ||
| 24 | #define ASM_X86_ARCHRANDOM_H | ||
| 25 | |||
| 26 | #include <asm/processor.h> | ||
| 27 | #include <asm/cpufeature.h> | ||
| 28 | #include <asm/alternative.h> | ||
| 29 | #include <asm/nops.h> | ||
| 30 | |||
| 31 | #define RDRAND_RETRY_LOOPS 10 | ||
| 32 | |||
| 33 | #define RDRAND_INT ".byte 0x0f,0xc7,0xf0" | ||
| 34 | #ifdef CONFIG_X86_64 | ||
| 35 | # define RDRAND_LONG ".byte 0x48,0x0f,0xc7,0xf0" | ||
| 36 | #else | ||
| 37 | # define RDRAND_LONG RDRAND_INT | ||
| 38 | #endif | ||
| 39 | |||
| 40 | #ifdef CONFIG_ARCH_RANDOM | ||
| 41 | |||
| 42 | #define GET_RANDOM(name, type, rdrand, nop) \ | ||
| 43 | static inline int name(type *v) \ | ||
| 44 | { \ | ||
| 45 | int ok; \ | ||
| 46 | alternative_io("movl $0, %0\n\t" \ | ||
| 47 | nop, \ | ||
| 48 | "\n1: " rdrand "\n\t" \ | ||
| 49 | "jc 2f\n\t" \ | ||
| 50 | "decl %0\n\t" \ | ||
| 51 | "jnz 1b\n\t" \ | ||
| 52 | "2:", \ | ||
| 53 | X86_FEATURE_RDRAND, \ | ||
| 54 | ASM_OUTPUT2("=r" (ok), "=a" (*v)), \ | ||
| 55 | "0" (RDRAND_RETRY_LOOPS)); \ | ||
| 56 | return ok; \ | ||
| 57 | } | ||
| 58 | |||
| 59 | #ifdef CONFIG_X86_64 | ||
| 60 | |||
| 61 | GET_RANDOM(arch_get_random_long, unsigned long, RDRAND_LONG, ASM_NOP5); | ||
| 62 | GET_RANDOM(arch_get_random_int, unsigned int, RDRAND_INT, ASM_NOP4); | ||
| 63 | |||
| 64 | #else | ||
| 65 | |||
| 66 | GET_RANDOM(arch_get_random_long, unsigned long, RDRAND_LONG, ASM_NOP3); | ||
| 67 | GET_RANDOM(arch_get_random_int, unsigned int, RDRAND_INT, ASM_NOP3); | ||
| 68 | |||
| 69 | #endif /* CONFIG_X86_64 */ | ||
| 70 | |||
| 71 | #endif /* CONFIG_ARCH_RANDOM */ | ||
| 72 | |||
| 73 | #endif /* ASM_X86_ARCHRANDOM_H */ | ||