[PATCH v2 1/5] arm64: Add capability denoting FEAT_RASv1p1

[Marc Zyngier <maz@kernel.org>]

Detecting FEAT_RASv1p1 is rather complicated, as there are two
ways for the architecture to advertise the same thing (always a
delight...).

Add a capability that will advertise this in a synthetic way to
the rest of the kernel.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kernel/cpufeature.c | 24 ++++++++++++++++++++++++
 arch/arm64/tools/cpucaps       |  1 +
 2 files changed, 25 insertions(+)

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 4dece9ca68bc6..22a94e548362d 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2235,6 +2235,24 @@ static void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused)
 	/* Firmware may have left a deferred SError in this register. */
 	write_sysreg_s(0, SYS_DISR_EL1);
 }
+static bool has_rasv1p1(const struct arm64_cpu_capabilities *__unused, int scope)
+{
+	const struct arm64_cpu_capabilities rasv1p1_caps[] = {
+		{
+			ARM64_CPUID_FIELDS(ID_AA64PFR0_EL1, RAS, V1P1)
+		},
+		{
+			ARM64_CPUID_FIELDS(ID_AA64PFR0_EL1, RAS, IMP)
+		},
+		{
+			ARM64_CPUID_FIELDS(ID_AA64PFR1_EL1, RAS_frac, RASv1p1)
+		},
+	};
+
+	return (has_cpuid_feature(&rasv1p1_caps[0], scope) ||
+		(has_cpuid_feature(&rasv1p1_caps[1], scope) &&
+		 has_cpuid_feature(&rasv1p1_caps[2], scope)));
+}
 #endif /* CONFIG_ARM64_RAS_EXTN */
 
 #ifdef CONFIG_ARM64_PTR_AUTH
@@ -2653,6 +2671,12 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
 		.cpu_enable = cpu_clear_disr,
 		ARM64_CPUID_FIELDS(ID_AA64PFR0_EL1, RAS, IMP)
 	},
+	{
+		.desc = "RASv1p1 Extension Support",
+		.capability = ARM64_HAS_RASV1P1_EXTN,
+		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
+		.matches = has_rasv1p1,
+	},
 #endif /* CONFIG_ARM64_RAS_EXTN */
 #ifdef CONFIG_ARM64_AMU_EXTN
 	{
diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps
index 115161dd9a24d..eb7f1f5622a8f 100644
--- a/arch/arm64/tools/cpucaps
+++ b/arch/arm64/tools/cpucaps
@@ -52,6 +52,7 @@ HAS_S1PIE
 HAS_S1POE
 HAS_SCTLR2
 HAS_RAS_EXTN
+HAS_RASV1P1_EXTN
 HAS_RNG
 HAS_SB
 HAS_STAGE2_FWB
-- 
2.39.2