|  | /* | 
|  | * 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 const 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); |