This indicates if the system supports POE. This is a CPUCAP_BOOT_CPU_FEATURE as the boot CPU will enable POE if it has it, so secondary CPUs must also have this feature.
Add a new config option: ARM64_POE
Signed-off-by: Joey Gouly joey.gouly@arm.com Cc: Catalin Marinas catalin.marinas@arm.com Cc: Will Deacon will@kernel.org --- arch/arm64/Kconfig | 16 ++++++++++++++++ arch/arm64/kernel/cpufeature.c | 9 +++++++++ arch/arm64/tools/cpucaps | 1 + 3 files changed, 26 insertions(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 7b071a00425d..d7df6c603190 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -2078,6 +2078,22 @@ config ARM64_EPAN if the cpu does not implement the feature. endmenu # "ARMv8.7 architectural features"
+menu "ARMv8.9 architectural features" +config ARM64_POE + prompt "Permission Overlay Extension" + def_bool y + help + The Permission Overlay Extension is used to implement Memory + Protection Keys. Memory Protection Keys provides a mechanism for + enforcing page-based protections, but without requiring modification + of the page tables when an application changes protection domains. + + For details, see Documentation/core-api/protection-keys.rst + + If unsure, say y. + +endmenu # "ARMv8.9 architectural features" + config ARM64_SVE bool "ARM Scalable Vector Extension support" default y diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 646591c67e7a..00b6d516ed3f 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -2731,6 +2731,15 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .matches = has_cpuid_feature, ARM64_CPUID_FIELDS(ID_AA64MMFR2_EL1, EVT, IMP) }, +#ifdef CONFIG_ARM64_POE + { + .desc = "Stage-1 Permission Overlay Extension (S1POE)", + .capability = ARM64_HAS_S1POE, + .type = ARM64_CPUCAP_BOOT_CPU_FEATURE, + .matches = has_cpuid_feature, + ARM64_CPUID_FIELDS(ID_AA64MMFR3_EL1, S1POE, IMP) + }, +#endif {}, };
diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps index b98c38288a9d..bbd2fac9345a 100644 --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -43,6 +43,7 @@ HAS_NESTED_VIRT HAS_NO_HW_PREFETCH HAS_PAN HAS_S1PIE +HAS_S1POE HAS_RAS_EXTN HAS_RNG HAS_SB