diff options
| author | H. Peter Anvin <hpa@linux.intel.com> | 2014-03-17 16:36:30 -0700 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2014-03-19 22:24:08 -0400 |
| commit | 7b878d4b48c4e04b936918bb83836a107ba453b3 (patch) | |
| tree | 83df1d702e0162dc7785730356d934b8d59c45e2 | |
| parent | 331c6490c7f10dcf263712e313b7c0bc7fb6d77a (diff) | |
random: Add arch_has_random[_seed]()
Add predicate functions for having arch_get_random[_seed]*(). The
only current use is to avoid the loop in arch_random_refill() when
arch_get_random_seed_long() is unavailable.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| -rw-r--r-- | arch/powerpc/include/asm/archrandom.h | 9 | ||||
| -rw-r--r-- | arch/x86/include/asm/archrandom.h | 3 | ||||
| -rw-r--r-- | drivers/char/random.c | 3 | ||||
| -rw-r--r-- | include/linux/random.h | 8 |
4 files changed, 23 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/archrandom.h b/arch/powerpc/include/asm/archrandom.h index 801beba4e64..bde53110363 100644 --- a/arch/powerpc/include/asm/archrandom.h +++ b/arch/powerpc/include/asm/archrandom.h @@ -25,6 +25,11 @@ static inline int arch_get_random_int(unsigned int *v) return rc; } +static inline int arch_has_random(void) +{ + return !!ppc_md.get_random_long; +} + int powernv_get_random_long(unsigned long *v); static inline int arch_get_random_seed_long(unsigned long *v) @@ -35,6 +40,10 @@ static inline int arch_get_random_seed_int(unsigned int *v) { return 0; } +static inline int arch_has_random_seed(void) +{ + return 0; +} #endif /* CONFIG_ARCH_RANDOM */ diff --git a/arch/x86/include/asm/archrandom.h b/arch/x86/include/asm/archrandom.h index 6ad7f6d3f97..69f1366f1aa 100644 --- a/arch/x86/include/asm/archrandom.h +++ b/arch/x86/include/asm/archrandom.h @@ -114,6 +114,9 @@ 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) diff --git a/drivers/char/random.c b/drivers/char/random.c index c35cee268e1..6b75713d953 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1307,6 +1307,9 @@ static int arch_random_refill(void) unsigned int i; unsigned long buf[nlongs]; + if (!arch_has_random_seed()) + return 0; + for (i = 0; i < nlongs; i++) { if (arch_get_random_seed_long(&buf[n])) n++; diff --git a/include/linux/random.h b/include/linux/random.h index c2f08131050..57fbbffd77a 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -88,6 +88,10 @@ static inline int arch_get_random_int(unsigned int *v) { return 0; } +static inline int arch_has_random(void) +{ + return 0; +} static inline int arch_get_random_seed_long(unsigned long *v) { return 0; @@ -96,6 +100,10 @@ static inline int arch_get_random_seed_int(unsigned int *v) { return 0; } +static inline int arch_has_random_seed(void) +{ + return 0; +} #endif /* Pseudo random number generator from numerical recipes. */ |