diff options
| author | Paul Moore <pmoore@redhat.com> | 2014-06-17 17:30:23 -0400 |
|---|---|---|
| committer | Paul Moore <pmoore@redhat.com> | 2014-06-17 17:30:23 -0400 |
| commit | 170b5910d9fbea79de1bb40df22eda5f98250c0c (patch) | |
| tree | ca9560e878d2842d45c6f99077d0d8b8f8b0f9ba /arch/x86/include/asm/archrandom.h | |
| parent | 47dd0b76ace953bd2c0479076db0d3e3b9594003 (diff) | |
| parent | 1860e379875dfe7271c649058aeddffe5afd9d0d (diff) | |
Merge tag 'v3.15' into next
Linux 3.15
Diffstat (limited to 'arch/x86/include/asm/archrandom.h')
| -rw-r--r-- | arch/x86/include/asm/archrandom.h | 42 |
1 files changed, 41 insertions, 1 deletions
diff --git a/arch/x86/include/asm/archrandom.h b/arch/x86/include/asm/archrandom.h index e6a92455740..69f1366f1aa 100644 --- a/arch/x86/include/asm/archrandom.h +++ b/arch/x86/include/asm/archrandom.h @@ -1,7 +1,7 @@ /* * This file is part of the Linux kernel. * - * Copyright (c) 2011, Intel Corporation + * Copyright (c) 2011-2014, Intel Corporation * Authors: Fenghua Yu <fenghua.yu@intel.com>, * H. Peter Anvin <hpa@linux.intel.com> * @@ -31,10 +31,13 @@ #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 #ifdef CONFIG_ARCH_RANDOM @@ -53,6 +56,16 @@ static inline int rdrand_long(unsigned long *v) return ok; } +/* A single attempt at RDSEED */ +static inline bool rdseed_long(unsigned long *v) +{ + unsigned char ok; + asm volatile(RDSEED_LONG "\n\t" + "setc %0" + : "=qm" (ok), "=a" (*v)); + return ok; +} + #define GET_RANDOM(name, type, rdrand, nop) \ static inline int name(type *v) \ { \ @@ -70,18 +83,40 @@ static inline int name(type *v) \ return ok; \ } +#define GET_SEED(name, type, rdseed, nop) \ +static inline int name(type *v) \ +{ \ + unsigned char ok; \ + alternative_io("movb $0, %0\n\t" \ + nop, \ + rdseed "\n\t" \ + "setc %0", \ + X86_FEATURE_RDSEED, \ + ASM_OUTPUT2("=q" (ok), "=a" (*v))); \ + return ok; \ +} + #ifdef CONFIG_X86_64 GET_RANDOM(arch_get_random_long, unsigned long, RDRAND_LONG, ASM_NOP5); GET_RANDOM(arch_get_random_int, unsigned int, RDRAND_INT, ASM_NOP4); +GET_SEED(arch_get_random_seed_long, unsigned long, RDSEED_LONG, ASM_NOP5); +GET_SEED(arch_get_random_seed_int, unsigned int, RDSEED_INT, ASM_NOP4); + #else GET_RANDOM(arch_get_random_long, unsigned long, RDRAND_LONG, ASM_NOP3); GET_RANDOM(arch_get_random_int, unsigned int, RDRAND_INT, ASM_NOP3); +GET_SEED(arch_get_random_seed_long, unsigned long, RDSEED_LONG, ASM_NOP4); +GET_SEED(arch_get_random_seed_int, unsigned int, RDSEED_INT, ASM_NOP4); + #endif /* CONFIG_X86_64 */ +#define arch_has_random() static_cpu_has(X86_FEATURE_RDRAND) +#define arch_has_random_seed() static_cpu_has(X86_FEATURE_RDSEED) + #else static inline int rdrand_long(unsigned long *v) @@ -89,6 +124,11 @@ static inline int rdrand_long(unsigned long *v) return 0; } +static inline bool rdseed_long(unsigned long *v) +{ + return 0; +} + #endif /* CONFIG_ARCH_RANDOM */ extern void x86_init_rdrand(struct cpuinfo_x86 *c); |