[PATCH v8 02/38] arm64: Add feature detection for fine grained traps

[Mark Brown]

Some of the traps for nVHE SME support are provided as fine grained traps
so add detection of fine grained traps in order to allow us to guard usage.

Signed-off-by: Mark Brown <broonie at kernel.org>
---
 arch/arm64/kernel/cpufeature.c | 11 +++++++++++
 arch/arm64/tools/cpucaps       |  1 +
 2 files changed, 12 insertions(+)

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index d9f09e40aaf6..ec060db1dcf0 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2400,6 +2400,17 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
 		.matches = has_cpuid_feature,
 		.min_field_value = 1,
 	},
+	{
+		.desc = "Fine Grained Traps",
+		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
+		.capability = ARM64_HAS_FGT,
+		.sys_reg = SYS_ID_AA64MMFR0_EL1,
+		.sign = FTR_UNSIGNED,
+		.field_pos = ID_AA64MMFR0_FGT_SHIFT,
+		.field_width = 4,
+		.min_field_value = 1,
+		.matches = has_cpuid_feature,
+	},
 	{},
 };
 
diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps
index 870c39537dd0..b3ada80aa48d 100644
--- a/arch/arm64/tools/cpucaps
+++ b/arch/arm64/tools/cpucaps
@@ -20,6 +20,7 @@ HAS_DCPOP
 HAS_E0PD
 HAS_ECV
 HAS_EPAN
+HAS_FGT
 HAS_GENERIC_AUTH
 HAS_GENERIC_AUTH_ARCH
 HAS_GENERIC_AUTH_IMP_DEF
-- 
2.30.2