1 files changed, 113 insertions, 0 deletions

diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index bd8d4ca81a48..df62b61ff467 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -17,6 +17,7 @@
 
 #define ARM64_SW_FEATURE_OVERRIDE_NOKASLR	0
 #define ARM64_SW_FEATURE_OVERRIDE_HVHE		4
+#define ARM64_SW_FEATURE_OVERRIDE_RODATA_OFF	8
 
 #ifndef __ASSEMBLY__
 
@@ -768,6 +769,11 @@ static __always_inline bool system_supports_tpidr2(void)
 	return system_supports_sme();
 }
 
+static __always_inline bool system_supports_fpmr(void)
+{
+	return alternative_has_cap_unlikely(ARM64_HAS_FPMR);
+}
+
 static __always_inline bool system_supports_cnp(void)
 {
 	return alternative_has_cap_unlikely(ARM64_HAS_CNP);
@@ -905,7 +911,9 @@ static inline unsigned int get_vmid_bits(u64 mmfr1)
 s64 arm64_ftr_safe_value(const struct arm64_ftr_bits *ftrp, s64 new, s64 cur);
 struct arm64_ftr_reg *get_arm64_ftr_reg(u32 sys_id);
 
+extern struct arm64_ftr_override id_aa64mmfr0_override;
 extern struct arm64_ftr_override id_aa64mmfr1_override;
+extern struct arm64_ftr_override id_aa64mmfr2_override;
 extern struct arm64_ftr_override id_aa64pfr0_override;
 extern struct arm64_ftr_override id_aa64pfr1_override;
 extern struct arm64_ftr_override id_aa64zfr0_override;
@@ -915,9 +923,114 @@ extern struct arm64_ftr_override id_aa64isar2_override;
 
 extern struct arm64_ftr_override arm64_sw_feature_override;
 
+static inline
+u64 arm64_apply_feature_override(u64 val, int feat, int width,
+				 const struct arm64_ftr_override *override)
+{
+	u64 oval = override->val;
+
+	/*
+	 * When it encounters an invalid override (e.g., an override that
+	 * cannot be honoured due to a missing CPU feature), the early idreg
+	 * override code will set the mask to 0x0 and the value to non-zero for
+	 * the field in question. In order to determine whether the override is
+	 * valid or not for the field we are interested in, we first need to
+	 * disregard bits belonging to other fields.
+	 */
+	oval &= GENMASK_ULL(feat + width - 1, feat);
+
+	/*
+	 * The override is valid if all value bits are accounted for in the
+	 * mask. If so, replace the masked bits with the override value.
+	 */
+	if (oval == (oval & override->mask)) {
+		val &= ~override->mask;
+		val |= oval;
+	}
+
+	/* Extract the field from the updated value */
+	return cpuid_feature_extract_unsigned_field(val, feat);
+}
+
+static inline bool arm64_test_sw_feature_override(int feat)
+{
+	/*
+	 * Software features are pseudo CPU features that have no underlying
+	 * CPUID system register value to apply the override to.
+	 */
+	return arm64_apply_feature_override(0, feat, 4,
+					    &arm64_sw_feature_override);
+}
+
+static inline bool kaslr_disabled_cmdline(void)
+{
+	return arm64_test_sw_feature_override(ARM64_SW_FEATURE_OVERRIDE_NOKASLR);
+}
+
 u32 get_kvm_ipa_limit(void);
 void dump_cpu_features(void);
 
+static inline bool cpu_has_bti(void)
+{
+	if (!IS_ENABLED(CONFIG_ARM64_BTI))
+		return false;
+
+	return arm64_apply_feature_override(read_cpuid(ID_AA64PFR1_EL1),
+					    ID_AA64PFR1_EL1_BT_SHIFT, 4,
+					    &id_aa64pfr1_override);
+}
+
+static inline bool cpu_has_pac(void)
+{
+	u64 isar1, isar2;
+
+	if (!IS_ENABLED(CONFIG_ARM64_PTR_AUTH))
+		return false;
+
+	isar1 = read_cpuid(ID_AA64ISAR1_EL1);
+	isar2 = read_cpuid(ID_AA64ISAR2_EL1);
+
+	if (arm64_apply_feature_override(isar1, ID_AA64ISAR1_EL1_APA_SHIFT, 4,
+					 &id_aa64isar1_override))
+		return true;
+
+	if (arm64_apply_feature_override(isar1, ID_AA64ISAR1_EL1_API_SHIFT, 4,
+					 &id_aa64isar1_override))
+		return true;
+
+	return arm64_apply_feature_override(isar2, ID_AA64ISAR2_EL1_APA3_SHIFT, 4,
+					    &id_aa64isar2_override);
+}
+
+static inline bool cpu_has_lva(void)
+{
+	u64 mmfr2;
+
+	mmfr2 = read_sysreg_s(SYS_ID_AA64MMFR2_EL1);
+	mmfr2 &= ~id_aa64mmfr2_override.mask;
+	mmfr2 |= id_aa64mmfr2_override.val;
+	return cpuid_feature_extract_unsigned_field(mmfr2,
+						    ID_AA64MMFR2_EL1_VARange_SHIFT);
+}
+
+static inline bool cpu_has_lpa2(void)
+{
+#ifdef CONFIG_ARM64_LPA2
+	u64 mmfr0;
+	int feat;
+
+	mmfr0 = read_sysreg(id_aa64mmfr0_el1);
+	mmfr0 &= ~id_aa64mmfr0_override.mask;
+	mmfr0 |= id_aa64mmfr0_override.val;
+	feat = cpuid_feature_extract_signed_field(mmfr0,
+						  ID_AA64MMFR0_EL1_TGRAN_SHIFT);
+
+	return feat >= ID_AA64MMFR0_EL1_TGRAN_LPA2;
+#else
+	return false;
+#endif
+}
+
 #endif /* __ASSEMBLY__ */
 
 #endif