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arm64: mte: CPU feature detection for Asymm MTE

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Add the cpufeature entries to detect the presence of Asymmetric MTE.

Note: The tag checking mode is initialized via cpu_enable_mte() ->
kasan_init_hw_tags() hence to enable it we require asymmetric mode
to be at least on the boot CPU. If the boot CPU does not have it, it is
fine for late CPUs to have it as long as the feature is not enabled
(ARM64_CPUCAP_BOOT_CPU_FEATURE).

Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Suzuki K Poulose <Suzuki.Poulose@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20211006154751.4463-4-vincenzo.frascino@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Vincenzo Frascino 2021-10-06 16:47:49 +01:00 committed by Will Deacon
parent ba1a98e8b1
commit d73c162e07
2 changed files with 11 additions and 0 deletions
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10
arch/arm64/kernel/cpufeature.c
View File

@ -2321,6 +2321,16 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
.sign = FTR_UNSIGNED,
.cpu_enable = cpu_enable_mte,
},
{
.desc = "Asymmetric MTE Tag Check Fault",
.capability = ARM64_MTE_ASYMM,
.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
.matches = has_cpuid_feature,
.sys_reg = SYS_ID_AA64PFR1_EL1,
.field_pos = ID_AA64PFR1_MTE_SHIFT,
.min_field_value = ID_AA64PFR1_MTE_ASYMM,
.sign = FTR_UNSIGNED,
},
#endif /* CONFIG_ARM64_MTE */
{
.desc = "RCpc load-acquire (LDAPR)",

1
arch/arm64/tools/cpucaps
View File

@ -39,6 +39,7 @@ HW_DBM
KVM_PROTECTED_MODE
MISMATCHED_CACHE_TYPE
MTE
MTE_ASYMM
SPECTRE_V2
SPECTRE_V3A
SPECTRE_V4