[PATCH v3 08/24] arm64: Handle width of a cpuid feature

From: Suzuki K. Poulose
Date: Tue Oct 13 2015 - 13:30:36 EST


Introduce a helper to extract cpuid feature for any given
width.

Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@xxxxxxx>
---
arch/arm64/include/asm/cpufeature.h | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index b5f313d..85507fe 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -76,10 +76,16 @@ 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)
+static inline int __attribute_const__
+cpuid_feature_extract_field_width(u64 features, int field, int width)
{
- return (s64)(features << (64 - 4 - field)) >> (64 - 4);
+ return (s64)(features << (64 - width - field)) >> (64 - width);
+}
+
+static inline int __attribute_const__
+cpuid_feature_extract_field(u64 features, int field)
+{
+ return cpuid_feature_extract_field_width(features, field, 4);
}

static inline bool id_aa64mmfr0_mixed_endian_el0(u64 mmfr0)
--
1.7.9.5

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