cpufeature.c

	/*
	 * For reasons that aren't entirely clear, enabling KPTI on Cavium
	 * ThunderX leads to apparent I-cache corruption of kernel text, which
	 * ends as well as you might imagine. Don't even try.
	 */
	if (cpus_have_const_cap(ARM64_WORKAROUND_CAVIUM_27456)) {
		str = "ARM64_WORKAROUND_CAVIUM_27456";
		__kpti_forced = -1;
	}

	/* Useful for KASLR robustness */
	if (kaslr_requires_kpti()) {
		if (!__kpti_forced) {
			str = "KASLR";
			__kpti_forced = 1;
		}
	}

	if (cpu_mitigations_off() && !__kpti_forced) {
		str = "mitigations=off";
		__kpti_forced = -1;
	}

	if (!IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0)) {
		pr_info_once("kernel page table isolation disabled by kernel configuration\n");
		return false;
	}

	/* Forced? */
	if (__kpti_forced) {
		pr_info_once("kernel page table isolation forced %s by %s\n",
			     __kpti_forced > 0 ? "ON" : "OFF", str);
		return __kpti_forced > 0;
	}

	return !meltdown_safe;
}

#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
static void
kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
{
	typedef void (kpti_remap_fn)(int, int, phys_addr_t);
	extern kpti_remap_fn idmap_kpti_install_ng_mappings;
	kpti_remap_fn *remap_fn;

	static bool kpti_applied = false;
	int cpu = smp_processor_id();

	/*
	 * We don't need to rewrite the page-tables if either we've done
	 * it already or we have KASLR enabled and therefore have not
	 * created any global mappings at all.
	 */
	if (kpti_applied || kaslr_offset() > 0)
		return;

	remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings);

	cpu_install_idmap();
	remap_fn(cpu, num_online_cpus(), __pa_symbol(swapper_pg_dir));
	cpu_uninstall_idmap();

	if (!cpu)
		kpti_applied = true;

	return;
}
#else
static void
kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
{
}
#endif	/* CONFIG_UNMAP_KERNEL_AT_EL0 */

static int __init parse_kpti(char *str)
{
	bool enabled;
	int ret = strtobool(str, &enabled);

	if (ret)
		return ret;

	__kpti_forced = enabled ? 1 : -1;
	return 0;
}
early_param("kpti", parse_kpti);

#ifdef CONFIG_ARM64_HW_AFDBM
static inline void __cpu_enable_hw_dbm(void)
{
	u64 tcr = read_sysreg(tcr_el1) | TCR_HD;

	write_sysreg(tcr, tcr_el1);
	isb();
}

static bool cpu_has_broken_dbm(void)
{
	/* List of CPUs which have broken DBM support. */
	static const struct midr_range cpus[] = {
#ifdef CONFIG_ARM64_ERRATUM_1024718
		MIDR_RANGE(MIDR_CORTEX_A55, 0, 0, 1, 0),  // A55 r0p0 -r1p0
#endif
		{},
	};

	return is_midr_in_range_list(read_cpuid_id(), cpus);
}

static bool cpu_can_use_dbm(const struct arm64_cpu_capabilities *cap)
{
	return has_cpuid_feature(cap, SCOPE_LOCAL_CPU) &&
	       !cpu_has_broken_dbm();
}

static void cpu_enable_hw_dbm(struct arm64_cpu_capabilities const *cap)
{
	if (cpu_can_use_dbm(cap))
		__cpu_enable_hw_dbm();
}

static bool has_hw_dbm(const struct arm64_cpu_capabilities *cap,
		       int __unused)
{
	static bool detected = false;
	/*
	 * DBM is a non-conflicting feature. i.e, the kernel can safely
	 * run a mix of CPUs with and without the feature. So, we
	 * unconditionally enable the capability to allow any late CPU
	 * to use the feature. We only enable the control bits on the
	 * CPU, if it actually supports.
	 *
	 * We have to make sure we print the "feature" detection only
	 * when at least one CPU actually uses it. So check if this CPU
	 * can actually use it and print the message exactly once.
	 *
	 * This is safe as all CPUs (including secondary CPUs - due to the
	 * LOCAL_CPU scope - and the hotplugged CPUs - via verification)
	 * goes through the "matches" check exactly once. Also if a CPU
	 * matches the criteria, it is guaranteed that the CPU will turn
	 * the DBM on, as the capability is unconditionally enabled.
	 */
	if (!detected && cpu_can_use_dbm(cap)) {
		detected = true;
		pr_info("detected: Hardware dirty bit management\n");
	}

	return true;
}

#endif

#ifdef CONFIG_ARM64_VHE
static bool runs_at_el2(const struct arm64_cpu_capabilities *entry, int __unused)
{
	return is_kernel_in_hyp_mode();
}

static void cpu_copy_el2regs(const struct arm64_cpu_capabilities *__unused)
{
	/*
	 * Copy register values that aren't redirected by hardware.
	 *
	 * Before code patching, we only set tpidr_el1, all CPUs need to copy
	 * this value to tpidr_el2 before we patch the code. Once we've done
	 * that, freshly-onlined CPUs will set tpidr_el2, so we don't need to
	 * do anything here.
	 */
	if (!alternative_is_applied(ARM64_HAS_VIRT_HOST_EXTN))
		write_sysreg(read_sysreg(tpidr_el1), tpidr_el2);
}
#endif

static void cpu_has_fwb(const struct arm64_cpu_capabilities *__unused)
{
	u64 val = read_sysreg_s(SYS_CLIDR_EL1);

	/* Check that CLIDR_EL1.LOU{U,IS} are both 0 */
	WARN_ON(val & (7 << 27 | 7 << 21));
}

#ifdef CONFIG_ARM64_SSBD
static int ssbs_emulation_handler(struct pt_regs *regs, u32 instr)
{
	if (user_mode(regs))
		return 1;

	if (instr & BIT(PSTATE_Imm_shift))
		regs->pstate |= PSR_SSBS_BIT;
	else
		regs->pstate &= ~PSR_SSBS_BIT;

	arm64_skip_faulting_instruction(regs, 4);
	return 0;
}

static struct undef_hook ssbs_emulation_hook = {
	.instr_mask	= ~(1U << PSTATE_Imm_shift),
	.instr_val	= 0xd500401f | PSTATE_SSBS,
	.fn		= ssbs_emulation_handler,
};

static void cpu_enable_ssbs(const struct arm64_cpu_capabilities *__unused)
{
	static bool undef_hook_registered = false;
	static DEFINE_RAW_SPINLOCK(hook_lock);

	raw_spin_lock(&hook_lock);
	if (!undef_hook_registered) {
		register_undef_hook(&ssbs_emulation_hook);
		undef_hook_registered = true;
	}
	raw_spin_unlock(&hook_lock);

	if (arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE) {
		sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_DSSBS);
		arm64_set_ssbd_mitigation(false);
	} else {
		arm64_set_ssbd_mitigation(true);
	}
}
#endif /* CONFIG_ARM64_SSBD */

#ifdef CONFIG_ARM64_PAN
static void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused)
{
	/*
	 * We modify PSTATE. This won't work from irq context as the PSTATE
	 * is discarded once we return from the exception.
	 */
	WARN_ON_ONCE(in_interrupt());

	sysreg_clear_set(sctlr_el1, SCTLR_EL1_SPAN, 0);
	asm(SET_PSTATE_PAN(1));
}
#endif /* CONFIG_ARM64_PAN */

#ifdef CONFIG_ARM64_RAS_EXTN
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);
}
#endif /* CONFIG_ARM64_RAS_EXTN */

#ifdef CONFIG_ARM64_PTR_AUTH
static void cpu_enable_address_auth(struct arm64_cpu_capabilities const *cap)
{
	sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_ENIA | SCTLR_ELx_ENIB |
				       SCTLR_ELx_ENDA | SCTLR_ELx_ENDB);
}
#endif /* CONFIG_ARM64_PTR_AUTH */

#ifdef CONFIG_ARM64_E0PD
static void cpu_enable_e0pd(struct arm64_cpu_capabilities const *cap)
{
	if (this_cpu_has_cap(ARM64_HAS_E0PD))
		sysreg_clear_set(tcr_el1, 0, TCR_E0PD1);
}
#endif /* CONFIG_ARM64_E0PD */

#ifdef CONFIG_ARM64_PSEUDO_NMI
static bool enable_pseudo_nmi;

static int __init early_enable_pseudo_nmi(char *p)
{
	return strtobool(p, &enable_pseudo_nmi);
}
early_param("irqchip.gicv3_pseudo_nmi", early_enable_pseudo_nmi);

static bool can_use_gic_priorities(const struct arm64_cpu_capabilities *entry,
				   int scope)
{
	return enable_pseudo_nmi && has_useable_gicv3_cpuif(entry, scope);
}
#endif

static const struct arm64_cpu_capabilities arm64_features[] = {
	{
		.desc = "GIC system register CPU interface",
		.capability = ARM64_HAS_SYSREG_GIC_CPUIF,
		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
		.matches = has_useable_gicv3_cpuif,
		.sys_reg = SYS_ID_AA64PFR0_EL1,
		.field_pos = ID_AA64PFR0_GIC_SHIFT,
		.sign = FTR_UNSIGNED,
		.min_field_value = 1,
	},
#ifdef CONFIG_ARM64_PAN
	{
		.desc = "Privileged Access Never",
		.capability = ARM64_HAS_PAN,
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
		.matches = has_cpuid_feature,
		.sys_reg = SYS_ID_AA64MMFR1_EL1,
		.field_pos = ID_AA64MMFR1_PAN_SHIFT,
		.sign = FTR_UNSIGNED,
		.min_field_value = 1,
		.cpu_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,
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
		.matches = has_cpuid_feature,
		.sys_reg = SYS_ID_AA64ISAR0_EL1,
		.field_pos = ID_AA64ISAR0_ATOMICS_SHIFT,
		.sign = FTR_UNSIGNED,
		.min_field_value = 2,
	},
#endif /* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */
	{
		.desc = "Software prefetching using PRFM",
		.capability = ARM64_HAS_NO_HW_PREFETCH,
		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
		.matches = has_no_hw_prefetch,
	},
#ifdef CONFIG_ARM64_UAO
	{
		.desc = "User Access Override",
		.capability = ARM64_HAS_UAO,
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
		.matches = has_cpuid_feature,
		.sys_reg = SYS_ID_AA64MMFR2_EL1,
		.field_pos = ID_AA64MMFR2_UAO_SHIFT,
		.min_field_value = 1,
		/*
		 * We rely on stop_machine() calling uao_thread_switch() to set
		 * UAO immediately after patching.
		 */
	},
#endif /* CONFIG_ARM64_UAO */
#ifdef CONFIG_ARM64_PAN
	{
		.capability = ARM64_ALT_PAN_NOT_UAO,
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
		.matches = cpufeature_pan_not_uao,
	},
#endif /* CONFIG_ARM64_PAN */
#ifdef CONFIG_ARM64_VHE
	{
		.desc = "Virtualization Host Extensions",
		.capability = ARM64_HAS_VIRT_HOST_EXTN,
		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
		.matches = runs_at_el2,
		.cpu_enable = cpu_copy_el2regs,
	},
#endif	/* CONFIG_ARM64_VHE */
	{
		.desc = "32-bit EL0 Support",
		.capability = ARM64_HAS_32BIT_EL0,
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
		.matches = has_cpuid_feature,
		.sys_reg = SYS_ID_AA64PFR0_EL1,
		.sign = FTR_UNSIGNED,
		.field_pos = ID_AA64PFR0_EL0_SHIFT,
		.min_field_value = ID_AA64PFR0_EL0_32BIT_64BIT,
	},
	{
		.desc = "Kernel page table isolation (KPTI)",
		.capability = ARM64_UNMAP_KERNEL_AT_EL0,
		.type = ARM64_CPUCAP_BOOT_RESTRICTED_CPU_LOCAL_FEATURE,
		/*
		 * The ID feature fields below are used to indicate that
		 * the CPU doesn't need KPTI. See unmap_kernel_at_el0 for
		 * more details.
		 */
		.sys_reg = SYS_ID_AA64PFR0_EL1,
		.field_pos = ID_AA64PFR0_CSV3_SHIFT,
		.min_field_value = 1,
		.matches = unmap_kernel_at_el0,
		.cpu_enable = kpti_install_ng_mappings,
	},
	{
		/* FP/SIMD is not implemented */
		.capability = ARM64_HAS_NO_FPSIMD,
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
		.min_field_value = 0,
		.matches = has_no_fpsimd,
	},
#ifdef CONFIG_ARM64_PMEM
	{
		.desc = "Data cache clean to Point of Persistence",
		.capability = ARM64_HAS_DCPOP,
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
		.matches = has_cpuid_feature,
		.sys_reg = SYS_ID_AA64ISAR1_EL1,
		.field_pos = ID_AA64ISAR1_DPB_SHIFT,
		.min_field_value = 1,
	},
	{
		.desc = "Data cache clean to Point of Deep Persistence",
		.capability = ARM64_HAS_DCPODP,
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
		.matches = has_cpuid_feature,
		.sys_reg = SYS_ID_AA64ISAR1_EL1,
		.sign = FTR_UNSIGNED,
		.field_pos = ID_AA64ISAR1_DPB_SHIFT,
		.min_field_value = 2,
	},
#endif
#ifdef CONFIG_ARM64_SVE
	{
		.desc = "Scalable Vector Extension",
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
		.capability = ARM64_SVE,
		.sys_reg = SYS_ID_AA64PFR0_EL1,
		.sign = FTR_UNSIGNED,
		.field_pos = ID_AA64PFR0_SVE_SHIFT,
		.min_field_value = ID_AA64PFR0_SVE,
		.matches = has_cpuid_feature,
		.cpu_enable = sve_kernel_enable,
	},
#endif /* CONFIG_ARM64_SVE */
#ifdef CONFIG_ARM64_RAS_EXTN
	{
		.desc = "RAS Extension Support",
		.capability = ARM64_HAS_RAS_EXTN,
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
		.matches = has_cpuid_feature,
		.sys_reg = SYS_ID_AA64PFR0_EL1,
		.sign = FTR_UNSIGNED,
		.field_pos = ID_AA64PFR0_RAS_SHIFT,
		.min_field_value = ID_AA64PFR0_RAS_V1,
		.cpu_enable = cpu_clear_disr,
	},
#endif /* CONFIG_ARM64_RAS_EXTN */
	{
		.desc = "Data cache clean to the PoU not required for I/D coherence",
		.capability = ARM64_HAS_CACHE_IDC,
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
		.matches = has_cache_idc,
		.cpu_enable = cpu_emulate_effective_ctr,
	},
	{
		.desc = "Instruction cache invalidation not required for I/D coherence",
		.capability = ARM64_HAS_CACHE_DIC,
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
		.matches = has_cache_dic,
	},
	{
		.desc = "Stage-2 Force Write-Back",
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
		.capability = ARM64_HAS_STAGE2_FWB,
		.sys_reg = SYS_ID_AA64MMFR2_EL1,
		.sign = FTR_UNSIGNED,
		.field_pos = ID_AA64MMFR2_FWB_SHIFT,
		.min_field_value = 1,
		.matches = has_cpuid_feature,
		.cpu_enable = cpu_has_fwb,
	},
#ifdef CONFIG_ARM64_HW_AFDBM
	{
		/*
		 * Since we turn this on always, we don't want the user to
		 * think that the feature is available when it may not be.
		 * So hide the description.
		 *
		 * .desc = "Hardware pagetable Dirty Bit Management",
		 *
		 */
		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
		.capability = ARM64_HW_DBM,
		.sys_reg = SYS_ID_AA64MMFR1_EL1,
		.sign = FTR_UNSIGNED,
		.field_pos = ID_AA64MMFR1_HADBS_SHIFT,
		.min_field_value = 2,
		.matches = has_hw_dbm,
		.cpu_enable = cpu_enable_hw_dbm,
	},
#endif
	{
		.desc = "CRC32 instructions",
		.capability = ARM64_HAS_CRC32,
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
		.matches = has_cpuid_feature,
		.sys_reg = SYS_ID_AA64ISAR0_EL1,
		.field_pos = ID_AA64ISAR0_CRC32_SHIFT,
		.min_field_value = 1,
	},
#ifdef CONFIG_ARM64_SSBD
	{
		.desc = "Speculative Store Bypassing Safe (SSBS)",
		.capability = ARM64_SSBS,
		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
		.matches = has_cpuid_feature,
		.sys_reg = SYS_ID_AA64PFR1_EL1,
		.field_pos = ID_AA64PFR1_SSBS_SHIFT,
		.sign = FTR_UNSIGNED,
		.min_field_value = ID_AA64PFR1_SSBS_PSTATE_ONLY,
		.cpu_enable = cpu_enable_ssbs,
	},
#endif
#ifdef CONFIG_ARM64_CNP
	{
		.desc = "Common not Private translations",
		.capability = ARM64_HAS_CNP,
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
		.matches = has_useable_cnp,
		.sys_reg = SYS_ID_AA64MMFR2_EL1,
		.sign = FTR_UNSIGNED,
		.field_pos = ID_AA64MMFR2_CNP_SHIFT,
		.min_field_value = 1,
		.cpu_enable = cpu_enable_cnp,
	},
#endif
	{
		.desc = "Speculation barrier (SB)",
		.capability = ARM64_HAS_SB,
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
		.matches = has_cpuid_feature,
		.sys_reg = SYS_ID_AA64ISAR1_EL1,
		.field_pos = ID_AA64ISAR1_SB_SHIFT,
		.sign = FTR_UNSIGNED,
		.min_field_value = 1,
	},
#ifdef CONFIG_ARM64_PTR_AUTH
	{
		.desc = "Address authentication (architected algorithm)",
		.capability = ARM64_HAS_ADDRESS_AUTH_ARCH,
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
		.sys_reg = SYS_ID_AA64ISAR1_EL1,
		.sign = FTR_UNSIGNED,
		.field_pos = ID_AA64ISAR1_APA_SHIFT,
		.min_field_value = ID_AA64ISAR1_APA_ARCHITECTED,
		.matches = has_cpuid_feature,
		.cpu_enable = cpu_enable_address_auth,
	},
	{
		.desc = "Address authentication (IMP DEF algorithm)",
		.capability = ARM64_HAS_ADDRESS_AUTH_IMP_DEF,
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
		.sys_reg = SYS_ID_AA64ISAR1_EL1,
		.sign = FTR_UNSIGNED,
		.field_pos = ID_AA64ISAR1_API_SHIFT,
		.min_field_value = ID_AA64ISAR1_API_IMP_DEF,
		.matches = has_cpuid_feature,
		.cpu_enable = cpu_enable_address_auth,
	},
	{
		.desc = "Generic authentication (architected algorithm)",
		.capability = ARM64_HAS_GENERIC_AUTH_ARCH,
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
		.sys_reg = SYS_ID_AA64ISAR1_EL1,
		.sign = FTR_UNSIGNED,
		.field_pos = ID_AA64ISAR1_GPA_SHIFT,
		.min_field_value = ID_AA64ISAR1_GPA_ARCHITECTED,
		.matches = has_cpuid_feature,
	},
	{
		.desc = "Generic authentication (IMP DEF algorithm)",
		.capability = ARM64_HAS_GENERIC_AUTH_IMP_DEF,
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
		.sys_reg = SYS_ID_AA64ISAR1_EL1,
		.sign = FTR_UNSIGNED,
		.field_pos = ID_AA64ISAR1_GPI_SHIFT,
		.min_field_value = ID_AA64ISAR1_GPI_IMP_DEF,
		.matches = has_cpuid_feature,
	},
#endif /* CONFIG_ARM64_PTR_AUTH */
#ifdef CONFIG_ARM64_PSEUDO_NMI
	{
		/*
		 * Depends on having GICv3
		 */
		.desc = "IRQ priority masking",
		.capability = ARM64_HAS_IRQ_PRIO_MASKING,
		.type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE,
		.matches = can_use_gic_priorities,
		.sys_reg = SYS_ID_AA64PFR0_EL1,
		.field_pos = ID_AA64PFR0_GIC_SHIFT,
		.sign = FTR_UNSIGNED,
		.min_field_value = 1,
	},
#endif
#ifdef CONFIG_ARM64_E0PD
	{
		.desc = "E0PD",
		.capability = ARM64_HAS_E0PD,
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
		.sys_reg = SYS_ID_AA64MMFR2_EL1,
		.sign = FTR_UNSIGNED,
		.field_pos = ID_AA64MMFR2_E0PD_SHIFT,
		.matches = has_cpuid_feature,
		.min_field_value = 1,
		.cpu_enable = cpu_enable_e0pd,
	},
#endif
	{},
};

#define HWCAP_CPUID_MATCH(reg, field, s, min_value)				\
		.matches = has_cpuid_feature,					\
		.sys_reg = reg,							\
		.field_pos = field,						\
		.sign = s,							\
		.min_field_value = min_value,

#define __HWCAP_CAP(name, cap_type, cap)					\
		.desc = name,							\
		.type = ARM64_CPUCAP_SYSTEM_FEATURE,				\
		.hwcap_type = cap_type,						\
		.hwcap = cap,							\

#define HWCAP_CAP(reg, field, s, min_value, cap_type, cap)			\
	{									\
		__HWCAP_CAP(#cap, cap_type, cap)				\
		HWCAP_CPUID_MATCH(reg, field, s, min_value)			\
	}

#define HWCAP_MULTI_CAP(list, cap_type, cap)					\
	{									\
		__HWCAP_CAP(#cap, cap_type, cap)				\
		.matches = cpucap_multi_entry_cap_matches,			\
		.match_list = list,						\
	}

#ifdef CONFIG_ARM64_PTR_AUTH
static const struct arm64_cpu_capabilities ptr_auth_hwcap_addr_matches[] = {
	{
		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_APA_SHIFT,
				  FTR_UNSIGNED, ID_AA64ISAR1_APA_ARCHITECTED)
	},
	{
		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_API_SHIFT,
				  FTR_UNSIGNED, ID_AA64ISAR1_API_IMP_DEF)
	},
	{},
};

static const struct arm64_cpu_capabilities ptr_auth_hwcap_gen_matches[] = {
	{
		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_GPA_SHIFT,
				  FTR_UNSIGNED, ID_AA64ISAR1_GPA_ARCHITECTED)
	},
	{
		HWCAP_CPUID_MATCH(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_GPI_SHIFT,
				  FTR_UNSIGNED, ID_AA64ISAR1_GPI_IMP_DEF)
	},
	{},
};
#endif

static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_PMULL),
	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_AES),
	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA1_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA1),
	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA2),
	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_SHA512),
	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_CRC32_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_CRC32),
	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_ATOMICS_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_ATOMICS),
	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_RDM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDRDM),
	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA3_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SHA3),
	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SM3_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SM3),
	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SM4_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SM4),
	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_DP_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDDP),
	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_FHM_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDFHM),
	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_TS_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FLAGM),
	HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_TS_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_FLAGM2),
	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_FP),
	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FPHP),
	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 0, CAP_HWCAP, KERNEL_HWCAP_ASIMD),
	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDHP),
	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_DIT_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DIT),
	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DCPOP),
	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_DCPODP),
	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_JSCVT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_JSCVT),
	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FCMA_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FCMA),
	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_LRCPC),
	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_ILRCPC),
	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FRINTTS_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FRINT),
	HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_SB_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SB),
	HWCAP_CAP(SYS_ID_AA64MMFR2_EL1, ID_AA64MMFR2_AT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_USCAT),
#ifdef CONFIG_ARM64_SVE
	HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_SVE_SHIFT, FTR_UNSIGNED, ID_AA64PFR0_SVE, CAP_HWCAP, KERNEL_HWCAP_SVE),
	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SVEVER_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SVEVER_SVE2, CAP_HWCAP, KERNEL_HWCAP_SVE2),
	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_AES_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_AES, CAP_HWCAP, KERNEL_HWCAP_SVEAES),
	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_AES_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_AES_PMULL, CAP_HWCAP, KERNEL_HWCAP_SVEPMULL),
	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_BITPERM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_BITPERM, CAP_HWCAP, KERNEL_HWCAP_SVEBITPERM),
	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SHA3_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SHA3, CAP_HWCAP, KERNEL_HWCAP_SVESHA3),
	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SM4_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SM4, CAP_HWCAP, KERNEL_HWCAP_SVESM4),
#endif
	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_SSBS_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_SSBS_PSTATE_INSNS, CAP_HWCAP, KERNEL_HWCAP_SSBS),
#ifdef CONFIG_ARM64_PTR_AUTH
	HWCAP_MULTI_CAP(ptr_auth_hwcap_addr_matches, CAP_HWCAP, KERNEL_HWCAP_PACA),
	HWCAP_MULTI_CAP(ptr_auth_hwcap_gen_matches, CAP_HWCAP, KERNEL_HWCAP_PACG),
#endif
	{},
};

static const struct arm64_cpu_capabilities compat_elf_hwcaps[] = {
#ifdef CONFIG_COMPAT
	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, FTR_UNSIGNED, 2, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_PMULL),
	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_AES),
	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA1_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA1),
	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA2_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA2),
	HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_CRC32_SHIFT, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_CRC32),
#endif
	{},
};

static void __init cap_set_elf_hwcap(const struct arm64_cpu_capabilities *cap)
{
	switch (cap->hwcap_type) {
	case CAP_HWCAP:
		cpu_set_feature(cap->hwcap);
		break;
#ifdef CONFIG_COMPAT
	case CAP_COMPAT_HWCAP:
		compat_elf_hwcap |= (u32)cap->hwcap;
		break;
	case CAP_COMPAT_HWCAP2:
		compat_elf_hwcap2 |= (u32)cap->hwcap;
		break;
#endif
	default:
		WARN_ON(1);
		break;
	}
}

/* Check if we have a particular HWCAP enabled */
static bool cpus_have_elf_hwcap(const struct arm64_cpu_capabilities *cap)
{
	bool rc;

	switch (cap->hwcap_type) {
	case CAP_HWCAP:
		rc = cpu_have_feature(cap->hwcap);
		break;
#ifdef CONFIG_COMPAT
	case CAP_COMPAT_HWCAP:
		rc = (compat_elf_hwcap & (u32)cap->hwcap) != 0;
		break;
	case CAP_COMPAT_HWCAP2:
		rc = (compat_elf_hwcap2 & (u32)cap->hwcap) != 0;
		break;
#endif
	default:
		WARN_ON(1);
		rc = false;
	}

	return rc;
}

static void __init setup_elf_hwcaps(const struct arm64_cpu_capabilities *hwcaps)
{
	/* We support emulation of accesses to CPU ID feature registers */
	cpu_set_named_feature(CPUID);
	for (; hwcaps->matches; hwcaps++)
		if (hwcaps->matches(hwcaps, cpucap_default_scope(hwcaps)))
			cap_set_elf_hwcap(hwcaps);
}

static void update_cpu_capabilities(u16 scope_mask)
{
	int i;
	const struct arm64_cpu_capabilities *caps;

	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
	for (i = 0; i < ARM64_NCAPS; i++) {
		caps = cpu_hwcaps_ptrs[i];
		if (!caps || !(caps->type & scope_mask) ||
		    cpus_have_cap(caps->capability) ||
		    !caps->matches(caps, cpucap_default_scope(caps)))
			continue;

		if (caps->desc)
			pr_info("detected: %s\n", caps->desc);
		cpus_set_cap(caps->capability);

		if ((scope_mask & SCOPE_BOOT_CPU) && (caps->type & SCOPE_BOOT_CPU))
			set_bit(caps->capability, boot_capabilities);
	}
}

/*
 * Enable all the available capabilities on this CPU. The capabilities
 * with BOOT_CPU scope are handled separately and hence skipped here.
 */
static int cpu_enable_non_boot_scope_capabilities(void *__unused)
{
	int i;
	u16 non_boot_scope = SCOPE_ALL & ~SCOPE_BOOT_CPU;

	for_each_available_cap(i) {
		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[i];

		if (WARN_ON(!cap))
			continue;

		if (!(cap->type & non_boot_scope))
			continue;

		if (cap->cpu_enable)
			cap->cpu_enable(cap);
	}
	return 0;
}

/*
 * Run through the enabled capabilities and enable() it on all active
 * CPUs
 */
static void __init enable_cpu_capabilities(u16 scope_mask)
{
	int i;
	const struct arm64_cpu_capabilities *caps;
	bool boot_scope;

	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;
	boot_scope = !!(scope_mask & SCOPE_BOOT_CPU);

	for (i = 0; i < ARM64_NCAPS; i++) {
		unsigned int num;

		caps = cpu_hwcaps_ptrs[i];
		if (!caps || !(caps->type & scope_mask))
			continue;
		num = caps->capability;
		if (!cpus_have_cap(num))
			continue;

		/* Ensure cpus_have_const_cap(num) works */
		static_branch_enable(&cpu_hwcap_keys[num]);

		if (boot_scope && caps->cpu_enable)
			/*
			 * Capabilities with SCOPE_BOOT_CPU scope are finalised
			 * before any secondary CPU boots. Thus, each secondary
			 * will enable the capability as appropriate via
			 * check_local_cpu_capabilities(). The only exception is
			 * the boot CPU, for which the capability must be
			 * enabled here. This approach avoids costly
			 * stop_machine() calls for this case.
			 */
			caps->cpu_enable(caps);
	}

	/*
	 * For all non-boot scope capabilities, use stop_machine()
	 * as it schedules the work allowing us to modify PSTATE,
	 * instead of on_each_cpu() which uses an IPI, giving us a
	 * PSTATE that disappears when we return.
	 */
	if (!boot_scope)
		stop_machine(cpu_enable_non_boot_scope_capabilities,
			     NULL, cpu_online_mask);
}

/*
 * Run through the list of capabilities to check for conflicts.
 * If the system has already detected a capability, take necessary
 * action on this CPU.
 *
 * Returns "false" on conflicts.
 */
static bool verify_local_cpu_caps(u16 scope_mask)
{
	int i;
	bool cpu_has_cap, system_has_cap;
	const struct arm64_cpu_capabilities *caps;

	scope_mask &= ARM64_CPUCAP_SCOPE_MASK;

	for (i = 0; i < ARM64_NCAPS; i++) {
		caps = cpu_hwcaps_ptrs[i];
		if (!caps || !(caps->type & scope_mask))
			continue;

		cpu_has_cap = caps->matches(caps, SCOPE_LOCAL_CPU);
		system_has_cap = cpus_have_cap(caps->capability);

		if (system_has_cap) {
			/*
			 * Check if the new CPU misses an advertised feature,
			 * which is not safe to miss.
			 */
			if (!cpu_has_cap && !cpucap_late_cpu_optional(caps))
				break;
			/*
			 * We have to issue cpu_enable() irrespective of
			 * whether the CPU has it or not, as it is enabeld
			 * system wide. It is upto the call back to take
			 * appropriate action on this CPU.
			 */
			if (caps->cpu_enable)
				caps->cpu_enable(caps);
		} else {
			/*
			 * Check if the CPU has this capability if it isn't
			 * safe to have when the system doesn't.
			 */
			if (cpu_has_cap && !cpucap_late_cpu_permitted(caps))
				break;
		}
	}

	if (i < ARM64_NCAPS) {
		pr_crit("CPU%d: Detected conflict for capability %d (%s), System: %d, CPU: %d\n",
			smp_processor_id(), caps->capability,
			caps->desc, system_has_cap, cpu_has_cap);
		return false;
	}

	return true;
}

/*
 * Check for CPU features that are used in early boot
 * based on the Boot CPU value.
 */
static void check_early_cpu_features(void)
{
	verify_cpu_asid_bits();
	/*
	 * Early features are used by the kernel already. If there
	 * is a conflict, we cannot proceed further.
	 */
	if (!verify_local_cpu_caps(SCOPE_BOOT_CPU))
		cpu_panic_kernel();
}

static void
verify_local_elf_hwcaps(const struct arm64_cpu_capabilities *caps)
{

	for (; caps->matches; caps++)
		if (cpus_have_elf_hwcap(caps) && !caps->matches(caps, SCOPE_LOCAL_CPU)) {
			pr_crit("CPU%d: missing HWCAP: %s\n",
					smp_processor_id(), caps->desc);
			cpu_die_early();
		}
}

static void verify_sve_features(void)
{
	u64 safe_zcr = read_sanitised_ftr_reg(SYS_ZCR_EL1);
	u64 zcr = read_zcr_features();

	unsigned int safe_len = safe_zcr & ZCR_ELx_LEN_MASK;
	unsigned int len = zcr & ZCR_ELx_LEN_MASK;

	if (len < safe_len || sve_verify_vq_map()) {
		pr_crit("CPU%d: SVE: vector length support mismatch\n",
			smp_processor_id());
		cpu_die_early();
	}

	/* Add checks on other ZCR bits here if necessary */
}


/*
 * Run through the enabled system capabilities and enable() it on this CPU.
 * The capabilities were decided based on the available CPUs at the boot time.
 * Any new CPU should match the system wide status of the capability. If the
 * new CPU doesn't have a capability which the system now has enabled, we
 * cannot do anything to fix it up and could cause unexpected failures. So
 * we park the CPU.
 */
static void verify_local_cpu_capabilities(void)
{
	/*
	 * The capabilities with SCOPE_BOOT_CPU are checked from
	 * check_early_cpu_features(), as they need to be verified
	 * on all secondary CPUs.
	 */
	if (!verify_local_cpu_caps(SCOPE_ALL & ~SCOPE_BOOT_CPU))
		cpu_die_early();

	verify_local_elf_hwcaps(arm64_elf_hwcaps);

	if (system_supports_32bit_el0())
		verify_local_elf_hwcaps(compat_elf_hwcaps);

	if (system_supports_sve())
		verify_sve_features();
}

void check_local_cpu_capabilities(void)
{
	/*
	 * All secondary CPUs should conform to the early CPU features
	 * in use by the kernel based on boot CPU.
	 */
	check_early_cpu_features();

	/*
	 * If we haven't finalised the system capabilities, this CPU gets
	 * a chance to update the errata work arounds and local features.
	 * Otherwise, this CPU should verify that it has all the system
	 * advertised capabilities.
	 */
	if (!sys_caps_initialised)
		update_cpu_capabilities(SCOPE_LOCAL_CPU);