Since Armv9.6, FEAT_LSUI provides load/store instructions
that allow privileged code to access user memory without
clearing the PSTATE.PAN bit.
Add CPU feature detection for FEAT_LSUI.
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
---
arch/arm64/kernel/cpufeature.c | 10 ++++++++++
arch/arm64/tools/cpucaps | 1 +
2 files changed, 11 insertions(+)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index c840a93b9ef9..4c75220e53a1 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -280,6 +280,7 @@ static const struct arm64_ftr_bits ftr_id_aa64isar2[] = {
static const struct arm64_ftr_bits ftr_id_aa64isar3[] = {
ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR3_EL1_FPRCVT_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR3_EL1_LSUI_SHIFT, 4, ID_AA64ISAR3_EL1_LSUI_NI),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR3_EL1_LSFE_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR3_EL1_FAMINMAX_SHIFT, 4, 0),
ARM64_FTR_END,
@@ -3148,6 +3149,15 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
.matches = has_cpuid_feature,
ARM64_CPUID_FIELDS(ID_AA64MMFR1_EL1, XNX, IMP)
},
+#ifdef CONFIG_AS_HAS_LSUI
+ {
+ .desc = "Unprivileged Load Store Instructions (LSUI)",
+ .capability = ARM64_HAS_LSUI,
+ .type = ARM64_CPUCAP_SYSTEM_FEATURE,
+ .matches = has_cpuid_feature,
+ ARM64_CPUID_FIELDS(ID_AA64ISAR3_EL1, LSUI, IMP)
+ },
+#endif
{},
};
diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps
index 0fac75f01534..4b2f7f3f2b80 100644
--- a/arch/arm64/tools/cpucaps
+++ b/arch/arm64/tools/cpucaps
@@ -46,6 +46,7 @@ HAS_HCX
HAS_LDAPR
HAS_LPA2
HAS_LSE_ATOMICS
+HAS_LSUI
HAS_MOPS
HAS_NESTED_VIRT
HAS_BBML2_NOABORT
--
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}