[PATCH v9 01/10] arm64/cpufeature: add FEAT_MTE_TAGGED_FAR feature
From: Yeoreum Yun <hidden>
Date: 2025-06-18 08:45:20
Also in:
linux-doc, lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
Add FEAT_MTE_TAGGED_FAR cpucap which makes FAR_ELx report all non-address bits on a synchronous MTE tag check fault since Armv8.9 Signed-off-by: Yeoreum Yun <redacted> Acked-by: Yury Khrustalev <redacted> --- arch/arm64/kernel/cpufeature.c | 8 ++++++++ arch/arm64/tools/cpucaps | 1 + 2 files changed, 9 insertions(+)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index b34044e20128..af6a6924a3e8 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c@@ -320,6 +320,7 @@ static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = { static const struct arm64_ftr_bits ftr_id_aa64pfr2[] = { ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR2_EL1_FPMR_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR2_EL1_MTEFAR_SHIFT, 4, ID_AA64PFR2_EL1_MTEFAR_NI), ARM64_FTR_END, };
@@ -2874,6 +2875,13 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .matches = has_cpuid_feature, ARM64_CPUID_FIELDS(ID_AA64PFR1_EL1, MTE, MTE3) }, + { + .desc = "FAR on MTE Tag Check Fault", + .capability = ARM64_MTE_FAR, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = has_cpuid_feature, + ARM64_CPUID_FIELDS(ID_AA64PFR2_EL1, MTEFAR, IMP) + }, #endif /* CONFIG_ARM64_MTE */ { .desc = "RCpc load-acquire (LDAPR)",
diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps
index 10effd4cff6b..fe8f4f8ce95c 100644
--- a/arch/arm64/tools/cpucaps
+++ b/arch/arm64/tools/cpucaps@@ -68,6 +68,7 @@ MPAM MPAM_HCR MTE MTE_ASYMM +MTE_FAR SME SME_FA64 SME2
--
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}