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 5ed401ff79e3..fc014a1fb0e0 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -279,6 +279,7 @@ 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, @@ -3088,6 +3089,15 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .capability = ARM64_HAS_GICV5_LEGACY, .matches = test_has_gicv5_legacy, }, +#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 1b32c1232d28..9a15784829f8 100644 --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -45,6 +45,7 @@ HAS_HCX HAS_LDAPR HAS_LPA2 HAS_LSE_ATOMICS +HAS_LSUI HAS_MOPS HAS_NESTED_VIRT HAS_BBML2_NOABORT