Thread (35 messages) 35 messages, 11 authors, 2017-08-11
STALE3244d

[PATCH 05/11] arm64/cpufeature: detect pointer authentication

From: mark.rutland@arm.com (Mark Rutland)
Date: 2017-07-19 16:03:01
Also in: kvmarm, linux-arch, lkml
Subsystem: arm64 port (aarch64 architecture), the rest · Maintainers: Catalin Marinas, Will Deacon, Linus Torvalds

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 <redacted>
---
 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 8d2272c..903b458 100644
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/arch/arm64/include/asm/cpucaps.h
@@ -39,7 +39,9 @@
 #define ARM64_WORKAROUND_QCOM_FALKOR_E1003	18
 #define ARM64_WORKAROUND_858921			19
 #define ARM64_WORKAROUND_CAVIUM_30115		20
+#define ARM64_HAS_ADDRESS_AUTH			21
+#define ARM64_HAS_GENERIC_AUTH			22
 
-#define ARM64_NCAPS				21
+#define ARM64_NCAPS				23
 
 #endif /* __ASM_CPUCAPS_H */
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index b23ad83..4016b1e7 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -892,6 +892,28 @@ 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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