arch/arm64/kernel/cpuinfo.c - linux - Git at Google

 /*
  * Record and handle CPU attributes.
  *
  * Copyright (C) 2014 ARM Ltd.
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <asm/arch_timer.h>
 #include <asm/cache.h>
 #include <asm/cpu.h>
 #include <asm/cputype.h>
 #include <asm/cpufeature.h>

 #include <linux/bitops.h>
 #include <linux/bug.h>
 #include <linux/compat.h>
 #include <linux/elf.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/personality.h>
 #include <linux/preempt.h>
 #include <linux/printk.h>
 #include <linux/seq_file.h>
 #include <linux/sched.h>
 #include <linux/smp.h>
 #include <linux/delay.h>

 /*
  * In case the boot CPU is hotpluggable, we record its initial state and
  * current state separately. Certain system registers may contain different
  * values depending on configuration at or after reset.
  */
 DEFINE_PER_CPU(struct cpuinfo_arm64, cpu_data);
 static struct cpuinfo_arm64 boot_cpu_data;

 static char *icache_policy_str[] = {
 	[0 ... ICACHE_POLICY_PIPT]	= "RESERVED/UNKNOWN",
 	[ICACHE_POLICY_VIPT]		= "VIPT",
 	[ICACHE_POLICY_PIPT]		= "PIPT",
 	[ICACHE_POLICY_VPIPT]		= "VPIPT",
 };

 unsigned long __icache_flags;

 static const char *const hwcap_str[] = {
 	"fp",
 	"asimd",
 	"evtstrm",
 	"aes",
 	"pmull",
 	"sha1",
 	"sha2",
 	"crc32",
 	"atomics",
 	"fphp",
 	"asimdhp",
 	"cpuid",
 	"asimdrdm",
 	"jscvt",
 	"fcma",
 	"lrcpc",
 	NULL
 };

 #ifdef CONFIG_COMPAT
 static const char *const compat_hwcap_str[] = {
 	"swp",
 	"half",
 	"thumb",
 	"26bit",
 	"fastmult",
 	"fpa",
 	"vfp",
 	"edsp",
 	"java",
 	"iwmmxt",
 	"crunch",
 	"thumbee",
 	"neon",
 	"vfpv3",
 	"vfpv3d16",
 	"tls",
 	"vfpv4",
 	"idiva",
 	"idivt",
 	"vfpd32",
 	"lpae",
 	"evtstrm",
 	NULL
 };

 static const char *const compat_hwcap2_str[] = {
 	"aes",
 	"pmull",
 	"sha1",
 	"sha2",
 	"crc32",
 	NULL
 };
 #endif /* CONFIG_COMPAT */

 static int c_show(struct seq_file *m, void *v)
 {
 	int i, j;
 	bool compat = personality(current->personality) == PER_LINUX32;

 	for_each_online_cpu(i) {
 		struct cpuinfo_arm64 *cpuinfo = &per_cpu(cpu_data, i);
 		u32 midr = cpuinfo->reg_midr;

 		/*
 		 * glibc reads /proc/cpuinfo to determine the number of
 		 * online processors, looking for lines beginning with
 		 * "processor".  Give glibc what it expects.
 		 */
 		seq_printf(m, "processor\t: %d\n", i);
 		if (compat)
 			seq_printf(m, "model name\t: ARMv8 Processor rev %d (%s)\n",
 				   MIDR_REVISION(midr), COMPAT_ELF_PLATFORM);

 		seq_printf(m, "BogoMIPS\t: %lu.%02lu\n",
 			   loops_per_jiffy / (500000UL/HZ),
 			   loops_per_jiffy / (5000UL/HZ) % 100);

 		/*
 		 * Dump out the common processor features in a single line.
 		 * Userspace should read the hwcaps with getauxval(AT_HWCAP)
 		 * rather than attempting to parse this, but there's a body of
 		 * software which does already (at least for 32-bit).
 		 */
 		seq_puts(m, "Features\t:");
 		if (compat) {
 #ifdef CONFIG_COMPAT
 			for (j = 0; compat_hwcap_str[j]; j++)
 				if (compat_elf_hwcap & (1 << j))
 					seq_printf(m, " %s", compat_hwcap_str[j]);

 			for (j = 0; compat_hwcap2_str[j]; j++)
 				if (compat_elf_hwcap2 & (1 << j))
 					seq_printf(m, " %s", compat_hwcap2_str[j]);
 #endif /* CONFIG_COMPAT */
 		} else {
 			for (j = 0; hwcap_str[j]; j++)
 				if (elf_hwcap & (1 << j))
 					seq_printf(m, " %s", hwcap_str[j]);
 		}
 		seq_puts(m, "\n");

 		seq_printf(m, "CPU implementer\t: 0x%02x\n",
 			   MIDR_IMPLEMENTOR(midr));
 		seq_printf(m, "CPU architecture: 8\n");
 		seq_printf(m, "CPU variant\t: 0x%x\n", MIDR_VARIANT(midr));
 		seq_printf(m, "CPU part\t: 0x%03x\n", MIDR_PARTNUM(midr));
 		seq_printf(m, "CPU revision\t: %d\n\n", MIDR_REVISION(midr));
 	}

 	return 0;
 }

 static void *c_start(struct seq_file *m, loff_t *pos)
 {
 	return *pos < 1 ? (void *)1 : NULL;
 }

 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 {
 	++*pos;
 	return NULL;
 }

 static void c_stop(struct seq_file *m, void *v)
 {
 }

 const struct seq_operations cpuinfo_op = {
 	.start	= c_start,
 	.next	= c_next,
 	.stop	= c_stop,
 	.show	= c_show
 };


 static struct kobj_type cpuregs_kobj_type = {
 	.sysfs_ops = &kobj_sysfs_ops,
 };

 /*
  * The ARM ARM uses the phrase "32-bit register" to describe a register
  * whose upper 32 bits are RES0 (per C5.1.1, ARM DDI 0487A.i), however
  * no statement is made as to whether the upper 32 bits will or will not
  * be made use of in future, and between ARM DDI 0487A.c and ARM DDI
  * 0487A.d CLIDR_EL1 was expanded from 32-bit to 64-bit.
  *
  * Thus, while both MIDR_EL1 and REVIDR_EL1 are described as 32-bit
  * registers, we expose them both as 64 bit values to cater for possible
  * future expansion without an ABI break.
  */
 #define kobj_to_cpuinfo(kobj)	container_of(kobj, struct cpuinfo_arm64, kobj)
 #define CPUREGS_ATTR_RO(_name, _field)						\
 	static ssize_t _name##_show(struct kobject *kobj,			\
 			struct kobj_attribute *attr, char *buf)			\
 	{									\
 		struct cpuinfo_arm64 *info = kobj_to_cpuinfo(kobj);		\
 										\
 		if (info->reg_midr)						\
 			return sprintf(buf, "0x%016x\n", info->reg_##_field);	\
 		else								\
 			return 0;						\
 	}									\
 	static struct kobj_attribute cpuregs_attr_##_name = __ATTR_RO(_name)

 CPUREGS_ATTR_RO(midr_el1, midr);
 CPUREGS_ATTR_RO(revidr_el1, revidr);

 static struct attribute *cpuregs_id_attrs[] = {
 	&cpuregs_attr_midr_el1.attr,
 	&cpuregs_attr_revidr_el1.attr,
 	NULL
 };

 static struct attribute_group cpuregs_attr_group = {
 	.attrs = cpuregs_id_attrs,
 	.name = "identification"
 };

 static int cpuid_cpu_online(unsigned int cpu)
 {
 	int rc;
 	struct device *dev;
 	struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);

 	dev = get_cpu_device(cpu);
 	if (!dev) {
 		rc = -ENODEV;
 		goto out;
 	}
 	rc = kobject_add(&info->kobj, &dev->kobj, "regs");
 	if (rc)
 		goto out;
 	rc = sysfs_create_group(&info->kobj, &cpuregs_attr_group);
 	if (rc)
 		kobject_del(&info->kobj);
 out:
 	return rc;
 }

 static int cpuid_cpu_offline(unsigned int cpu)
 {
 	struct device *dev;
 	struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);

 	dev = get_cpu_device(cpu);
 	if (!dev)
 		return -ENODEV;
 	if (info->kobj.parent) {
 		sysfs_remove_group(&info->kobj, &cpuregs_attr_group);
 		kobject_del(&info->kobj);
 	}

 	return 0;
 }

 static int __init cpuinfo_regs_init(void)
 {
 	int cpu, ret;

 	for_each_possible_cpu(cpu) {
 		struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);

 		kobject_init(&info->kobj, &cpuregs_kobj_type);
 	}

 	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "arm64/cpuinfo:online",
 				cpuid_cpu_online, cpuid_cpu_offline);
 	if (ret < 0) {
 		pr_err("cpuinfo: failed to register hotplug callbacks.\n");
 		return ret;
 	}
 	return 0;
 }
 static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info)
 {
 	unsigned int cpu = smp_processor_id();
 	u32 l1ip = CTR_L1IP(info->reg_ctr);

 	switch (l1ip) {
 	case ICACHE_POLICY_PIPT:
 		break;
 	case ICACHE_POLICY_VPIPT:
 		set_bit(ICACHEF_VPIPT, &__icache_flags);
 		break;
 	default:
 		/* Fallthrough */
 	case ICACHE_POLICY_VIPT:
 		/* Assume aliasing */
 		set_bit(ICACHEF_ALIASING, &__icache_flags);
 	}

 	pr_info("Detected %s I-cache on CPU%d\n", icache_policy_str[l1ip], cpu);
 }

 static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
 {
 	info->reg_cntfrq = arch_timer_get_cntfrq();
 	info->reg_ctr = read_cpuid_cachetype();
 	info->reg_dczid = read_cpuid(DCZID_EL0);
 	info->reg_midr = read_cpuid_id();
 	info->reg_revidr = read_cpuid(REVIDR_EL1);

 	info->reg_id_aa64dfr0 = read_cpuid(ID_AA64DFR0_EL1);
 	info->reg_id_aa64dfr1 = read_cpuid(ID_AA64DFR1_EL1);
 	info->reg_id_aa64isar0 = read_cpuid(ID_AA64ISAR0_EL1);
 	info->reg_id_aa64isar1 = read_cpuid(ID_AA64ISAR1_EL1);
 	info->reg_id_aa64mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
 	info->reg_id_aa64mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
 	info->reg_id_aa64mmfr2 = read_cpuid(ID_AA64MMFR2_EL1);
 	info->reg_id_aa64pfr0 = read_cpuid(ID_AA64PFR0_EL1);
 	info->reg_id_aa64pfr1 = read_cpuid(ID_AA64PFR1_EL1);

 	/* Update the 32bit ID registers only if AArch32 is implemented */
 	if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
 		info->reg_id_dfr0 = read_cpuid(ID_DFR0_EL1);
 		info->reg_id_isar0 = read_cpuid(ID_ISAR0_EL1);
 		info->reg_id_isar1 = read_cpuid(ID_ISAR1_EL1);
 		info->reg_id_isar2 = read_cpuid(ID_ISAR2_EL1);
 		info->reg_id_isar3 = read_cpuid(ID_ISAR3_EL1);
 		info->reg_id_isar4 = read_cpuid(ID_ISAR4_EL1);
 		info->reg_id_isar5 = read_cpuid(ID_ISAR5_EL1);
 		info->reg_id_mmfr0 = read_cpuid(ID_MMFR0_EL1);
 		info->reg_id_mmfr1 = read_cpuid(ID_MMFR1_EL1);
 		info->reg_id_mmfr2 = read_cpuid(ID_MMFR2_EL1);
 		info->reg_id_mmfr3 = read_cpuid(ID_MMFR3_EL1);
 		info->reg_id_pfr0 = read_cpuid(ID_PFR0_EL1);
 		info->reg_id_pfr1 = read_cpuid(ID_PFR1_EL1);

 		info->reg_mvfr0 = read_cpuid(MVFR0_EL1);
 		info->reg_mvfr1 = read_cpuid(MVFR1_EL1);
 		info->reg_mvfr2 = read_cpuid(MVFR2_EL1);
 	}

 	cpuinfo_detect_icache_policy(info);
 }

 void cpuinfo_store_cpu(void)
 {
 	struct cpuinfo_arm64 *info = this_cpu_ptr(&cpu_data);
 	__cpuinfo_store_cpu(info);
 	update_cpu_features(smp_processor_id(), info, &boot_cpu_data);
 }

 void __init cpuinfo_store_boot_cpu(void)
 {
 	struct cpuinfo_arm64 *info = &per_cpu(cpu_data, 0);
 	__cpuinfo_store_cpu(info);

 	boot_cpu_data = *info;
 	init_cpu_features(&boot_cpu_data);
 }

 device_initcall(cpuinfo_regs_init);
	/*
	* Record and handle CPU attributes.
	*
	* Copyright (C) 2014 ARM Ltd.
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	*/
	#include <asm/arch_timer.h>
	#include <asm/cache.h>
	#include <asm/cpu.h>
	#include <asm/cputype.h>
	#include <asm/cpufeature.h>

	#include <linux/bitops.h>
	#include <linux/bug.h>
	#include <linux/compat.h>
	#include <linux/elf.h>
	#include <linux/init.h>
	#include <linux/kernel.h>
	#include <linux/personality.h>
	#include <linux/preempt.h>
	#include <linux/printk.h>
	#include <linux/seq_file.h>
	#include <linux/sched.h>
	#include <linux/smp.h>
	#include <linux/delay.h>

	/*
	* In case the boot CPU is hotpluggable, we record its initial state and
	* current state separately. Certain system registers may contain different
	* values depending on configuration at or after reset.
	*/
	DEFINE_PER_CPU(struct cpuinfo_arm64, cpu_data);
	static struct cpuinfo_arm64 boot_cpu_data;

	static char *icache_policy_str[] = {
	[0 ... ICACHE_POLICY_PIPT] = "RESERVED/UNKNOWN",
	[ICACHE_POLICY_VIPT] = "VIPT",
	[ICACHE_POLICY_PIPT] = "PIPT",
	[ICACHE_POLICY_VPIPT] = "VPIPT",
	};

	unsigned long __icache_flags;

	static const char *const hwcap_str[] = {
	"fp",
	"asimd",
	"evtstrm",
	"aes",
	"pmull",
	"sha1",
	"sha2",
	"crc32",
	"atomics",
	"fphp",
	"asimdhp",
	"cpuid",
	"asimdrdm",
	"jscvt",
	"fcma",
	"lrcpc",
	NULL
	};

	#ifdef CONFIG_COMPAT
	static const char *const compat_hwcap_str[] = {
	"swp",
	"half",
	"thumb",
	"26bit",
	"fastmult",
	"fpa",
	"vfp",
	"edsp",
	"java",
	"iwmmxt",
	"crunch",
	"thumbee",
	"neon",
	"vfpv3",
	"vfpv3d16",
	"tls",
	"vfpv4",
	"idiva",
	"idivt",
	"vfpd32",
	"lpae",
	"evtstrm",
	NULL
	};

	static const char *const compat_hwcap2_str[] = {
	"aes",
	"pmull",
	"sha1",
	"sha2",
	"crc32",
	NULL
	};
	#endif /* CONFIG_COMPAT */

	static int c_show(struct seq_file m, void v)
	{
	int i, j;
	bool compat = personality(current->personality) == PER_LINUX32;

	for_each_online_cpu(i) {
	struct cpuinfo_arm64 *cpuinfo = &per_cpu(cpu_data, i);
	u32 midr = cpuinfo->reg_midr;

	/*
	* glibc reads /proc/cpuinfo to determine the number of
	* online processors, looking for lines beginning with
	* "processor". Give glibc what it expects.
	*/
	seq_printf(m, "processor\t: %d\n", i);
	if (compat)
	seq_printf(m, "model name\t: ARMv8 Processor rev %d (%s)\n",
	MIDR_REVISION(midr), COMPAT_ELF_PLATFORM);

	seq_printf(m, "BogoMIPS\t: %lu.%02lu\n",
	loops_per_jiffy / (500000UL/HZ),
	loops_per_jiffy / (5000UL/HZ) % 100);

	/*
	* Dump out the common processor features in a single line.
	* Userspace should read the hwcaps with getauxval(AT_HWCAP)
	* rather than attempting to parse this, but there's a body of
	* software which does already (at least for 32-bit).
	*/
	seq_puts(m, "Features\t:");
	if (compat) {
	#ifdef CONFIG_COMPAT
	for (j = 0; compat_hwcap_str[j]; j++)
	if (compat_elf_hwcap & (1 << j))
	seq_printf(m, " %s", compat_hwcap_str[j]);

	for (j = 0; compat_hwcap2_str[j]; j++)
	if (compat_elf_hwcap2 & (1 << j))
	seq_printf(m, " %s", compat_hwcap2_str[j]);
	#endif /* CONFIG_COMPAT */
	} else {
	for (j = 0; hwcap_str[j]; j++)
	if (elf_hwcap & (1 << j))
	seq_printf(m, " %s", hwcap_str[j]);
	}
	seq_puts(m, "\n");

	seq_printf(m, "CPU implementer\t: 0x%02x\n",
	MIDR_IMPLEMENTOR(midr));
	seq_printf(m, "CPU architecture: 8\n");
	seq_printf(m, "CPU variant\t: 0x%x\n", MIDR_VARIANT(midr));
	seq_printf(m, "CPU part\t: 0x%03x\n", MIDR_PARTNUM(midr));
	seq_printf(m, "CPU revision\t: %d\n\n", MIDR_REVISION(midr));
	}

	return 0;
	}

	static void c_start(struct seq_file m, loff_t *pos)
	{
	return pos < 1 ? (void )1 : NULL;
	}

	static void c_next(struct seq_file m, void v, loff_t pos)
	{
	++*pos;
	return NULL;
	}

	static void c_stop(struct seq_file m, void v)
	{
	}

	const struct seq_operations cpuinfo_op = {
	.start = c_start,
	.next = c_next,
	.stop = c_stop,
	.show = c_show
	};


	static struct kobj_type cpuregs_kobj_type = {
	.sysfs_ops = &kobj_sysfs_ops,
	};

	/*
	* The ARM ARM uses the phrase "32-bit register" to describe a register
	* whose upper 32 bits are RES0 (per C5.1.1, ARM DDI 0487A.i), however
	* no statement is made as to whether the upper 32 bits will or will not
	* be made use of in future, and between ARM DDI 0487A.c and ARM DDI
	* 0487A.d CLIDR_EL1 was expanded from 32-bit to 64-bit.
	*
	* Thus, while both MIDR_EL1 and REVIDR_EL1 are described as 32-bit
	* registers, we expose them both as 64 bit values to cater for possible
	* future expansion without an ABI break.
	*/
	#define kobj_to_cpuinfo(kobj) container_of(kobj, struct cpuinfo_arm64, kobj)
	#define CPUREGS_ATTR_RO(_name, _field) \
	static ssize_t _name##_show(struct kobject *kobj, \
	struct kobj_attribute attr, char buf) \
	{ \
	struct cpuinfo_arm64 *info = kobj_to_cpuinfo(kobj); \
	\
	if (info->reg_midr) \
	return sprintf(buf, "0x%016x\n", info->reg_##_field); \
	else \
	return 0; \
	} \
	static struct kobj_attribute cpuregs_attr_##_name = __ATTR_RO(_name)

	CPUREGS_ATTR_RO(midr_el1, midr);
	CPUREGS_ATTR_RO(revidr_el1, revidr);

	static struct attribute *cpuregs_id_attrs[] = {
	&cpuregs_attr_midr_el1.attr,
	&cpuregs_attr_revidr_el1.attr,
	NULL
	};

	static struct attribute_group cpuregs_attr_group = {
	.attrs = cpuregs_id_attrs,
	.name = "identification"
	};

	static int cpuid_cpu_online(unsigned int cpu)
	{
	int rc;
	struct device *dev;
	struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);

	dev = get_cpu_device(cpu);
	if (!dev) {
	rc = -ENODEV;
	goto out;
	}
	rc = kobject_add(&info->kobj, &dev->kobj, "regs");
	if (rc)
	goto out;
	rc = sysfs_create_group(&info->kobj, &cpuregs_attr_group);
	if (rc)
	kobject_del(&info->kobj);
	out:
	return rc;
	}

	static int cpuid_cpu_offline(unsigned int cpu)
	{
	struct device *dev;
	struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);

	dev = get_cpu_device(cpu);
	if (!dev)
	return -ENODEV;
	if (info->kobj.parent) {
	sysfs_remove_group(&info->kobj, &cpuregs_attr_group);
	kobject_del(&info->kobj);
	}

	return 0;
	}

	static int __init cpuinfo_regs_init(void)
	{
	int cpu, ret;

	for_each_possible_cpu(cpu) {
	struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu);

	kobject_init(&info->kobj, &cpuregs_kobj_type);
	}

	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "arm64/cpuinfo:online",
	cpuid_cpu_online, cpuid_cpu_offline);
	if (ret < 0) {
	pr_err("cpuinfo: failed to register hotplug callbacks.\n");
	return ret;
	}
	return 0;
	}
	static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info)
	{
	unsigned int cpu = smp_processor_id();
	u32 l1ip = CTR_L1IP(info->reg_ctr);

	switch (l1ip) {
	case ICACHE_POLICY_PIPT:
	break;
	case ICACHE_POLICY_VPIPT:
	set_bit(ICACHEF_VPIPT, &__icache_flags);
	break;
	default:
	/* Fallthrough */
	case ICACHE_POLICY_VIPT:
	/* Assume aliasing */
	set_bit(ICACHEF_ALIASING, &__icache_flags);
	}

	pr_info("Detected %s I-cache on CPU%d\n", icache_policy_str[l1ip], cpu);
	}

	static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
	{
	info->reg_cntfrq = arch_timer_get_cntfrq();
	info->reg_ctr = read_cpuid_cachetype();
	info->reg_dczid = read_cpuid(DCZID_EL0);
	info->reg_midr = read_cpuid_id();
	info->reg_revidr = read_cpuid(REVIDR_EL1);

	info->reg_id_aa64dfr0 = read_cpuid(ID_AA64DFR0_EL1);
	info->reg_id_aa64dfr1 = read_cpuid(ID_AA64DFR1_EL1);
	info->reg_id_aa64isar0 = read_cpuid(ID_AA64ISAR0_EL1);
	info->reg_id_aa64isar1 = read_cpuid(ID_AA64ISAR1_EL1);
	info->reg_id_aa64mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
	info->reg_id_aa64mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
	info->reg_id_aa64mmfr2 = read_cpuid(ID_AA64MMFR2_EL1);
	info->reg_id_aa64pfr0 = read_cpuid(ID_AA64PFR0_EL1);
	info->reg_id_aa64pfr1 = read_cpuid(ID_AA64PFR1_EL1);

	/* Update the 32bit ID registers only if AArch32 is implemented */
	if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
	info->reg_id_dfr0 = read_cpuid(ID_DFR0_EL1);
	info->reg_id_isar0 = read_cpuid(ID_ISAR0_EL1);
	info->reg_id_isar1 = read_cpuid(ID_ISAR1_EL1);
	info->reg_id_isar2 = read_cpuid(ID_ISAR2_EL1);
	info->reg_id_isar3 = read_cpuid(ID_ISAR3_EL1);
	info->reg_id_isar4 = read_cpuid(ID_ISAR4_EL1);
	info->reg_id_isar5 = read_cpuid(ID_ISAR5_EL1);
	info->reg_id_mmfr0 = read_cpuid(ID_MMFR0_EL1);
	info->reg_id_mmfr1 = read_cpuid(ID_MMFR1_EL1);
	info->reg_id_mmfr2 = read_cpuid(ID_MMFR2_EL1);
	info->reg_id_mmfr3 = read_cpuid(ID_MMFR3_EL1);
	info->reg_id_pfr0 = read_cpuid(ID_PFR0_EL1);
	info->reg_id_pfr1 = read_cpuid(ID_PFR1_EL1);

	info->reg_mvfr0 = read_cpuid(MVFR0_EL1);
	info->reg_mvfr1 = read_cpuid(MVFR1_EL1);
	info->reg_mvfr2 = read_cpuid(MVFR2_EL1);
	}

	cpuinfo_detect_icache_policy(info);
	}

	void cpuinfo_store_cpu(void)
	{
	struct cpuinfo_arm64 *info = this_cpu_ptr(&cpu_data);
	__cpuinfo_store_cpu(info);
	update_cpu_features(smp_processor_id(), info, &boot_cpu_data);
	}

	void __init cpuinfo_store_boot_cpu(void)
	{
	struct cpuinfo_arm64 *info = &per_cpu(cpu_data, 0);
	__cpuinfo_store_cpu(info);

	boot_cpu_data = *info;
	init_cpu_features(&boot_cpu_data);
	}

	device_initcall(cpuinfo_regs_init);