diff options
| author | James Morse <james.morse@arm.com> | 2015-07-21 13:23:26 +0100 |
|---|---|---|
| committer | David Brown <david.brown@linaro.org> | 2015-12-03 16:53:52 -0800 |
| commit | 9d4409c25dabf13d86e7bf48cc45e7edfc8c89dd (patch) | |
| tree | 7f81fef1a888db6251a9d55b3e1b87624f8eb351 | |
| parent | 32bb76ad58ad061526a57d10f99912acd67aa894 (diff) | |
arm64: kernel: Add cpuid_feature_extract_field() for 4bit sign extension
commit 79b0e09a3c9bd74ee54582efdb351179d7c00351 upstream.
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>
Signed-off-by: David Brown <david.brown@linaro.org>
| -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 ad54dbf6b5ea..674cadd2e77c 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); |