1 files changed, 46 insertions, 7 deletions

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 5ad86ceac..3c9aed32f 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -21,24 +21,57 @@
 #include <linux/types.h>
 #include <asm/cpu.h>
 #include <asm/cpufeature.h>
+#include <asm/processor.h>
 
 static bool
-has_id_aa64pfr0_feature(const struct arm64_cpu_capabilities *entry)
+feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry)
 {
-	u64 val;
+	int val = cpuid_feature_extract_field(reg, entry->field_pos);
 
-	val = read_cpuid(id_aa64pfr0_el1);
-	return (val & entry->register_mask) == entry->register_value;
+	return val >= entry->min_field_value;
 }
 
+#define __ID_FEAT_CHK(reg)						\
+static bool __maybe_unused						\
+has_##reg##_feature(const struct arm64_cpu_capabilities *entry)		\
+{									\
+	u64 val;							\
+									\
+	val = read_cpuid(reg##_el1);					\
+	return feature_matches(val, entry);				\
+}
+
+__ID_FEAT_CHK(id_aa64pfr0);
+__ID_FEAT_CHK(id_aa64mmfr1);
+__ID_FEAT_CHK(id_aa64isar0);
+
 static const struct arm64_cpu_capabilities arm64_features[] = {
 	{
 		.desc = "GIC system register CPU interface",
 		.capability = ARM64_HAS_SYSREG_GIC_CPUIF,
 		.matches = has_id_aa64pfr0_feature,
-		.register_mask = (0xf << 24),
-		.register_value = (1 << 24),
+		.field_pos = 24,
+		.min_field_value = 1,
+	},
+#ifdef CONFIG_ARM64_PAN
+	{
+		.desc = "Privileged Access Never",
+		.capability = ARM64_HAS_PAN,
+		.matches = has_id_aa64mmfr1_feature,
+		.field_pos = 20,
+		.min_field_value = 1,
+		.enable = cpu_enable_pan,
 	},
+#endif /* CONFIG_ARM64_PAN */
+#if defined(CONFIG_AS_LSE) && defined(CONFIG_ARM64_LSE_ATOMICS)
+	{
+		.desc = "LSE atomic instructions",
+		.capability = ARM64_HAS_LSE_ATOMICS,
+		.matches = has_id_aa64isar0_feature,
+		.field_pos = 20,
+		.min_field_value = 2,
+	},
+#endif /* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */
 	{},
 };
 
@@ -55,9 +88,15 @@ void check_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
 			pr_info("%s %s\n", info, caps[i].desc);
 		cpus_set_cap(caps[i].capability);
 	}
+
+	/* second pass allows enable() to consider interacting capabilities */
+	for (i = 0; caps[i].desc; i++) {
+		if (cpus_have_cap(caps[i].capability) && caps[i].enable)
+			caps[i].enable();
+	}
 }
 
 void check_local_cpu_features(void)
 {
-	check_cpu_capabilities(arm64_features, "detected feature");
+	check_cpu_capabilities(arm64_features, "detected feature:");
 }