projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 628c6246 PA |
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 | ||
| 49d859d7 PA |
73 | extern void x86_init_rdrand(struct cpuinfo_x86 *c); |
| 74 | ||
| 628c6246 | 75 | #endif /* ASM_X86_ARCHRANDOM_H */ |