| Message ID | 20190920022132.149467-2-justin.he@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fix double page fault on arm64 | expand |
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index c96ffa4722d3..46caf934ba4e 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -667,6 +667,16 @@ static inline u32 id_aa64mmfr0_parange_to_phys_shift(int parange) default: return CONFIG_ARM64_PA_BITS; } } + +/* Decouple AF from AFDBM. */ +static inline bool cpu_has_hw_af(void) +{ + if (IS_ENABLED(CONFIG_ARM64_HW_AFDBM)) + return read_cpuid(ID_AA64MMFR1_EL1) & 0xf; + + return false; +} + #endif /* __ASSEMBLY__ */ #endif
We unconditionally set the HW_AFDBM capability and only enable it on CPUs which really have the feature. But sometimes we need to know whether this cpu has the capability of HW AF. So decouple AF from DBM by new helper cpu_has_hw_af(). Reported-by: kbuild test robot <lkp@intel.com> Suggested-by: Suzuki Poulose <Suzuki.Poulose@arm.com> Signed-off-by: Jia He <justin.he@arm.com> --- arch/arm64/include/asm/cpufeature.h | 10 ++++++++++ 1 file changed, 10 insertions(+)