[PATCH v7 4/7] arm64: cpufeature: Enumerate support for FEAT_ECV >= 0x2

[Oliver Upton]

Introduce a new cpucap to indicate if the system supports full enhanced
counter virtualization (i.e. ID_AA64MMFR0_EL1.ECV>=0x2).

Signed-off-by: Oliver Upton <oupton at google.com>
---
 arch/arm64/include/asm/sysreg.h |  1 +
 arch/arm64/kernel/cpufeature.c  | 10 ++++++++++
 arch/arm64/tools/cpucaps        |  1 +
 3 files changed, 12 insertions(+)

diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 943d31d92b5b..c7ddf9a71134 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -847,6 +847,7 @@
 #define ID_AA64MMFR0_ASID_SHIFT		4
 #define ID_AA64MMFR0_PARANGE_SHIFT	0
 
+#define ID_AA64MMFR0_ECV_PHYS		0x2
 #define ID_AA64MMFR0_TGRAN4_NI		0xf
 #define ID_AA64MMFR0_TGRAN4_SUPPORTED	0x0
 #define ID_AA64MMFR0_TGRAN64_NI		0xf
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 0ead8bfedf20..b44cef8deacc 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2301,6 +2301,16 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
 		.matches = has_cpuid_feature,
 		.min_field_value = 1,
 	},
+	{
+		.desc = "Enhanced Counter Virtualization (Physical)",
+		.capability = ARM64_HAS_ECV2,
+		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
+		.sys_reg = SYS_ID_AA64MMFR0_EL1,
+		.sign = FTR_UNSIGNED,
+		.field_pos = ID_AA64MMFR0_ECV_SHIFT,
+		.matches = has_cpuid_feature,
+		.min_field_value = ID_AA64MMFR0_ECV_PHYS,
+	},
 	{},
 };
 
diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps
index 49305c2e6dfd..f73a30d5fb1c 100644
--- a/arch/arm64/tools/cpucaps
+++ b/arch/arm64/tools/cpucaps
@@ -18,6 +18,7 @@ HAS_CRC32
 HAS_DCPODP
 HAS_DCPOP
 HAS_E0PD
+HAS_ECV2
 HAS_EPAN
 HAS_GENERIC_AUTH
 HAS_GENERIC_AUTH_ARCH
-- 
2.33.0.rc1.237.g0d66db33f3-goog