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Subject[RFC 4/9] arm64/cpufeature: detect pointer authentication
Date
So that we can dynamically handle the presence of pointer authentication
functionality, wire up probing code in cpufeature.c.

Currently, this only detects the presence of an architected algorithm.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
arch/arm64/include/asm/cpucaps.h | 4 +++-
arch/arm64/kernel/cpufeature.c | 22 ++++++++++++++++++++++
2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
index fb78a5d..15dd6d6 100644
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/arch/arm64/include/asm/cpucaps.h
@@ -37,7 +37,9 @@
#define ARM64_HAS_NO_FPSIMD 16
#define ARM64_WORKAROUND_REPEAT_TLBI 17
#define ARM64_WORKAROUND_QCOM_FALKOR_E1003 18
+#define ARM64_HAS_ADDRESS_AUTH 19
+#define ARM64_HAS_GENERIC_AUTH 20

-#define ARM64_NCAPS 19
+#define ARM64_NCAPS 21

#endif /* __ASM_CPUCAPS_H */
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 30255b2..172c80e 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -871,6 +871,28 @@ static bool has_no_fpsimd(const struct arm64_cpu_capabilities *entry, int __unus
.min_field_value = 0,
.matches = has_no_fpsimd,
},
+#ifdef CONFIG_ARM64_POINTER_AUTHENTICATION
+ {
+ .desc = "Address authentication (architected algorithm)",
+ .capability = ARM64_HAS_ADDRESS_AUTH,
+ .def_scope = SCOPE_SYSTEM,
+ .sys_reg = SYS_ID_AA64ISAR1_EL1,
+ .sign = FTR_UNSIGNED,
+ .field_pos = ID_AA64ISAR1_APA_SHIFT,
+ .min_field_value = ID_AA64ISAR1_APA_ARCHITECTED,
+ .matches = has_cpuid_feature,
+ },
+ {
+ .desc = "Generic authentication (architected algorithm)",
+ .capability = ARM64_HAS_GENERIC_AUTH,
+ .def_scope = SCOPE_SYSTEM,
+ .sys_reg = SYS_ID_AA64ISAR1_EL1,
+ .sign = FTR_UNSIGNED,
+ .field_pos = ID_AA64ISAR1_GPA_SHIFT,
+ .min_field_value = ID_AA64ISAR1_GPA_ARCHITECTED,
+ .matches = has_cpuid_feature
+ },
+#endif /* CONFIG_ARM64_POINTER_AUTHENTICATION */
{},
};

--
1.9.1
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