From: Marc Zyngier <[email protected]> Now that the capabilities are only available once all the CPUs have booted, we're unable to check for a particular feature in any subsystem that gets initialized before then.
In order to support this, introduce a local_cpu_has_cap() function that tests for the presence of a given capability independently of the whole framework. Signed-off-by: Marc Zyngier <[email protected]> Signed-off-by: Suzuki K Poulose <[email protected]> --- arch/arm64/include/asm/cpufeature.h | 2 ++ arch/arm64/kernel/cpufeature.c | 11 +++++++++++ 2 files changed, 13 insertions(+) diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 5f10344..733b016 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -108,6 +108,8 @@ struct arm64_cpu_capabilities { extern DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS); +bool this_cpu_has_cap(unsigned int cap); + static inline bool cpu_have_feature(unsigned int num) { return elf_hwcap & (1UL << num); diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index d3ee1df..3ace45f 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -995,6 +995,17 @@ static void __init setup_feature_capabilities(void) enable_cpu_capabilities(arm64_features); } +bool this_cpu_has_cap(unsigned int cap) +{ + const struct arm64_cpu_capabilities *caps = arm64_features; + + for (caps = arm64_features; caps->desc; caps++) + if (caps->capability == cap && caps->matches) + return caps->matches(caps, SCOPE_CPU); + + return false; +} + void __init setup_cpu_features(void) { u32 cwg; -- 1.7.9.5
