diff options
author | James Morse <james.morse@arm.com> | 2015-07-21 13:23:26 +0100 |
---|---|---|
committer | Will Deacon <will.deacon@arm.com> | 2015-07-27 11:08:40 +0100 |
commit | 79b0e09a3c9bd74ee54582efdb351179d7c00351 (patch) | |
tree | f3b5bf111e01a35c09d0444cdc53bfe7da49ce18 | |
parent | ae2fb7ece973f0b285f41985f5de85c57df9bf5a (diff) |
arm64: kernel: Add cpuid_feature_extract_field() for 4bit sign extension
Based on arch/arm/include/asm/cputype.h, this function does the
shifting and sign extension necessary when accessing cpu feature fields.
Signed-off-by: James Morse <james.morse@arm.com>
Suggested-by: Russell King <linux@arm.linux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
-rw-r--r-- | arch/arm64/include/asm/cpufeature.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index c1044218a63a..9fafa7537997 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -70,6 +70,13 @@ static inline void cpus_set_cap(unsigned int num) __set_bit(num, cpu_hwcaps); } +static inline int __attribute_const__ cpuid_feature_extract_field(u64 features, + int field) +{ + return (s64)(features << (64 - 4 - field)) >> (64 - 4); +} + + void check_cpu_capabilities(const struct arm64_cpu_capabilities *caps, const char *info); void check_local_cpu_errata(void); |