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.go...@arm.com>
Cc: Catalin Marinas <catalin.mari...@arm.com>
Cc: Will Deacon <w...@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 b10515c0200b..1f1a12e28c3f 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -2060,6 +2060,22 @@ 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 444a73c2e638..f1c1f348a31d 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2719,6 +2719,15 @@ 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 c3f06fdef609..b8348e40f6d9 100644
--- a/arch/arm64/tools/cpucaps
+++ b/arch/arm64/tools/cpucaps
@@ -43,6 +43,7 @@ HAS_NO_FPSIMD
HAS_NO_HW_PREFETCH
HAS_PAN
HAS_S1PIE
+HAS_S1POE
HAS_RAS_EXTN
HAS_RNG
HAS_SB
--
2.25.1
