Add the probing code for the FEAT_ECV variant that implements CNTPOFF_EL2.
Why it is optional is a mystery, but let's try and detect it.
Reviewed-by: Reiji Watanabe <reijiw@xxxxxxxxxx>
Reviewed-by: Colton Lewis <coltonlewis@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
arch/arm64/kernel/cpufeature.c | 11 +++++++++++
arch/arm64/tools/cpucaps | 1 +
2 files changed, 12 insertions(+)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 2e3e55139777..c331c49a7d19 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2223,6 +2223,17 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
.sign = FTR_UNSIGNED,
.min_field_value = 1,
},
+ {
+ .desc = "Enhanced Counter Virtualization (CNTPOFF)",
+ .capability = ARM64_HAS_ECV_CNTPOFF,
+ .type = ARM64_CPUCAP_SYSTEM_FEATURE,
+ .matches = has_cpuid_feature,
+ .sys_reg = SYS_ID_AA64MMFR0_EL1,
+ .field_pos = ID_AA64MMFR0_EL1_ECV_SHIFT,
+ .field_width = 4,
+ .sign = FTR_UNSIGNED,
+ .min_field_value = ID_AA64MMFR0_EL1_ECV_CNTPOFF,
+ },
#ifdef CONFIG_ARM64_PAN
{
.desc = "Privileged Access Never",
diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps
index 37b1340e9646..40ba95472594 100644
--- a/arch/arm64/tools/cpucaps
+++ b/arch/arm64/tools/cpucaps
@@ -23,6 +23,7 @@ HAS_DCPOP
HAS_DIT
HAS_E0PD
HAS_ECV
+HAS_ECV_CNTPOFF
HAS_EPAN
HAS_GENERIC_AUTH
HAS_GENERIC_AUTH_ARCH_QARMA3
--
2.34.1
