diff options
Diffstat (limited to 'arch/arm64/kernel/cpuinfo.c')
| -rw-r--r-- | arch/arm64/kernel/cpuinfo.c | 389 |
1 files changed, 389 insertions, 0 deletions
diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c new file mode 100644 index 000000000..36bd58d8c --- /dev/null +++ b/arch/arm64/kernel/cpuinfo.c @@ -0,0 +1,389 @@ +/* + * 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 <asm/fpsimd.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", + "dcpop", + "sha3", + "sm3", + "sm4", + "asimddp", + "sha512", + "sve", + "asimdfhm", + "dit", + "uscat", + "ilrcpc", + "flagm", + "ssbs", + 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_aa64isar2 = read_cpuid(ID_AA64ISAR2_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); + info->reg_id_aa64zfr0 = read_cpuid(ID_AA64ZFR0_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); + } + + if (IS_ENABLED(CONFIG_ARM64_SVE) && + id_aa64pfr0_sve(info->reg_id_aa64pfr0)) + info->reg_zcr = read_zcr_features(); + + 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); |