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 <pajay@xxxxxxxxxxxxxxxx>
Signed-off-by: Prasad Sodagudi <psodagud@xxxxxxxxxxxxxx>
Signed-off-by: Srinivas Ramana <sramana@xxxxxxxxxxxxxx>
---
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 \
{ \
--
2.7.4
