diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-10-28 08:29:07 -0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-10-28 08:29:07 -0400 |
commit | 8e6d539e0fd0c2124a20a207da70f2af7a9ae52c (patch) | |
tree | 73016c1bdb5005125cdb5d60d48f73ab4300be64 /arch/x86/include | |
parent | 8237eb946a1a23c600fb289cf8dd3b399b10604e (diff) | |
parent | 49d859d78c5aeb998b6936fcb5f288f78d713489 (diff) |
Merge branch 'x86-rdrand-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'x86-rdrand-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, random: Verify RDRAND functionality and allow it to be disabled
x86, random: Architectural inlines to get random integers with RDRAND
random: Add support for architectural random hooks
Fix up trivial conflicts in drivers/char/random.c: the architectural
random hooks touched "get_random_int()" that was simplified to use MD5
and not do the keyptr thing any more (see commit 6e5714eaf77d: "net:
Compute protocol sequence numbers and fragment IDs using MD5").
Diffstat (limited to 'arch/x86/include')
-rw-r--r-- | arch/x86/include/asm/archrandom.h | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/arch/x86/include/asm/archrandom.h b/arch/x86/include/asm/archrandom.h new file mode 100644 index 000000000000..0d9ec770f2f8 --- /dev/null +++ b/arch/x86/include/asm/archrandom.h | |||
@@ -0,0 +1,75 @@ | |||
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 | extern void x86_init_rdrand(struct cpuinfo_x86 *c); | ||
74 | |||
75 | #endif /* ASM_X86_ARCHRANDOM_H */ | ||