1 files changed, 83 insertions, 8 deletions

diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index dbc78d2b8cc6..11d5bb0fdd54 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -10,6 +10,7 @@
 #define __ASM_CPUFEATURE_H
 
 #include <asm/hwcap.h>
+#include <asm/sysreg.h>
 
 /*
  * In the arm64 world (as in the ARM world), elf_hwcap is used both internally
@@ -35,11 +36,42 @@
 
 #include <linux/kernel.h>
 
+/* CPU feature register tracking */
+enum ftr_type {
+	FTR_EXACT,	/* Use a predefined safe value */
+	FTR_LOWER_SAFE,	/* Smaller value is safe */
+	FTR_HIGHER_SAFE,/* Bigger value is safe */
+};
+
+#define FTR_STRICT	true	/* SANITY check strict matching required */
+#define FTR_NONSTRICT	false	/* SANITY check ignored */
+
+struct arm64_ftr_bits {
+	bool		strict;	  /* CPU Sanity check: strict matching required ? */
+	enum ftr_type	type;
+	u8		shift;
+	u8		width;
+	s64		safe_val; /* safe value for discrete features */
+};
+
+/*
+ * @arm64_ftr_reg - Feature register
+ * @strict_mask		Bits which should match across all CPUs for sanity.
+ * @sys_val		Safe value across the CPUs (system view)
+ */
+struct arm64_ftr_reg {
+	u32			sys_id;
+	const char		*name;
+	u64			strict_mask;
+	u64			sys_val;
+	struct arm64_ftr_bits	*ftr_bits;
+};
+
 struct arm64_cpu_capabilities {
 	const char *desc;
 	u16 capability;
 	bool (*matches)(const struct arm64_cpu_capabilities *);
-	void (*enable)(void);
+	void (*enable)(void *);		/* Called on all active CPUs */
 	union {
 		struct {	/* To be used for erratum handling only */
 			u32 midr_model;
@@ -47,8 +79,11 @@ struct arm64_cpu_capabilities {
 		};
 
 		struct {	/* Feature register checking */
+			u32 sys_reg;
 			int field_pos;
 			int min_field_value;
+			int hwcap_type;
+			unsigned long hwcap;
 		};
 	};
 };
@@ -76,19 +111,59 @@ static inline void cpus_set_cap(unsigned int num)
 		__set_bit(num, cpu_hwcaps);
 }
 
-static inline int __attribute_const__ cpuid_feature_extract_field(u64 features,
-								  int field)
+static inline int __attribute_const__
+cpuid_feature_extract_field_width(u64 features, int field, int width)
+{
+	return (s64)(features << (64 - width - field)) >> (64 - width);
+}
+
+static inline int __attribute_const__
+cpuid_feature_extract_field(u64 features, int field)
+{
+	return cpuid_feature_extract_field_width(features, field, 4);
+}
+
+static inline u64 arm64_ftr_mask(struct arm64_ftr_bits *ftrp)
+{
+	return (u64)GENMASK(ftrp->shift + ftrp->width - 1, ftrp->shift);
+}
+
+static inline s64 arm64_ftr_value(struct arm64_ftr_bits *ftrp, u64 val)
+{
+	return cpuid_feature_extract_field_width(val, ftrp->shift, ftrp->width);
+}
+
+static inline bool id_aa64mmfr0_mixed_endian_el0(u64 mmfr0)
 {
-	return (s64)(features << (64 - 4 - field)) >> (64 - 4);
+	return cpuid_feature_extract_field(mmfr0, ID_AA64MMFR0_BIGENDEL_SHIFT) == 0x1 ||
+		cpuid_feature_extract_field(mmfr0, ID_AA64MMFR0_BIGENDEL0_SHIFT) == 0x1;
 }
 
+void __init setup_cpu_features(void);
 
-void check_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
+void update_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
 			    const char *info);
 void check_local_cpu_errata(void);
-void check_local_cpu_features(void);
-bool cpu_supports_mixed_endian_el0(void);
-bool system_supports_mixed_endian_el0(void);
+
+#ifdef CONFIG_HOTPLUG_CPU
+void verify_local_cpu_capabilities(void);
+#else
+static inline void verify_local_cpu_capabilities(void)
+{
+}
+#endif
+
+u64 read_system_reg(u32 id);
+
+static inline bool cpu_supports_mixed_endian_el0(void)
+{
+	return id_aa64mmfr0_mixed_endian_el0(read_cpuid(ID_AA64MMFR0_EL1));
+}
+
+static inline bool system_supports_mixed_endian_el0(void)
+{
+	return id_aa64mmfr0_mixed_endian_el0(read_system_reg(SYS_ID_AA64MMFR0_EL1));
+}
 
 #endif /* __ASSEMBLY__ */