[PATCH 2/3] arm64: cpufeature: Add a filter function to cpufeature
From: Srinivas Ramana <hidden>
Date: 2021-01-09 00:31:02
Also in:
linux-arm-msm, lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
Add a filter function to cpufeature so that it can be used when dynamic control of the feature is required. Signed-off-by: Ajay Patil <redacted> Signed-off-by: Prasad Sodagudi <redacted> Signed-off-by: Srinivas Ramana <redacted> --- arch/arm64/include/asm/cpufeature.h | 8 +++++++- arch/arm64/kernel/cpufeature.c | 15 ++++++++++----- 2 files changed, 17 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index 9a555809b89c..81a5c97d647d 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h@@ -61,6 +61,7 @@ struct arm64_ftr_bits { u8 shift; u8 width; s64 safe_val; /* safe value for FTR_EXACT features */ + s64 (*filter)(const struct arm64_ftr_bits *ftrp, s64 fval); }; /*
@@ -566,7 +567,12 @@ cpuid_feature_extract_field(u64 features, int field, bool sign) static inline s64 arm64_ftr_value(const struct arm64_ftr_bits *ftrp, u64 val) { - return (s64)cpuid_feature_extract_field_width(val, ftrp->shift, ftrp->width, ftrp->sign); + s64 fval = (s64)cpuid_feature_extract_field_width(val, ftrp->shift, + ftrp->width, ftrp->sign); + + if (ftrp->filter) + fval = ftrp->filter(ftrp, fval); + return fval; } static inline bool id_aa64mmfr0_mixed_endian_el0(u64 mmfr0)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 7ffb5f1d8b68..b2ffa9eaaaff 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c@@ -132,23 +132,28 @@ DEFINE_STATIC_KEY_ARRAY_FALSE(cpu_hwcap_keys, ARM64_NCAPS); EXPORT_SYMBOL(cpu_hwcap_keys); #define __ARM64_FTR_BITS(SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \ - { \ .sign = SIGNED, \ .visible = VISIBLE, \ .strict = STRICT, \ .type = TYPE, \ .shift = SHIFT, \ .width = WIDTH, \ - .safe_val = SAFE_VAL, \ - } + .safe_val = SAFE_VAL /* Define a feature with unsigned values */ #define ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \ - __ARM64_FTR_BITS(FTR_UNSIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) + {__ARM64_FTR_BITS(FTR_UNSIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL), } /* Define a feature with a signed value */ #define S_ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \ - __ARM64_FTR_BITS(FTR_SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) + {__ARM64_FTR_BITS(FTR_SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL), } + +/* Define a feature with a filter function to process the field value */ +#define FILTERED_ARM64_FTR_BITS(SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL, filter_fn) \ + { \ + __ARM64_FTR_BITS(SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL), \ + .filter = filter_fn, \ + } #define ARM64_FTR_END \ { \
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2.7.4