arch/arm64/kernel/cpuinfo.c

   1 /*
   2  * Record and handle CPU attributes.
   3  *
   4  * Copyright (C) 2014 ARM Ltd.
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17 #include <asm/arch_timer.h>
  18 #include <asm/cachetype.h>
  19 #include <asm/cpu.h>
  20 #include <asm/cputype.h>
  21 #include <asm/cpufeature.h>
  22
  23 #include <linux/bitops.h>
  24 #include <linux/bug.h>
  25 #include <linux/init.h>
  26 #include <linux/kernel.h>
  27 #include <linux/personality.h>
  28 #include <linux/preempt.h>
  29 #include <linux/printk.h>
  30 #include <linux/seq_file.h>
  31 #include <linux/sched.h>
  32 #include <linux/smp.h>
  33 #include <linux/delay.h>
  34
  35 /*
  36  * In case the boot CPU is hotpluggable, we record its initial state and
  37  * current state separately. Certain system registers may contain different
  38  * values depending on configuration at or after reset.
  39  */
  40 DEFINE_PER_CPU(struct cpuinfo_arm64, cpu_data);
  41 static struct cpuinfo_arm64 boot_cpu_data;
  42
  43 static char *icache_policy_str[] = {
  44         [ICACHE_POLICY_RESERVED] = "RESERVED/UNKNOWN",
  45         [ICACHE_POLICY_AIVIVT] = "AIVIVT",
  46         [ICACHE_POLICY_VIPT] = "VIPT",
  47         [ICACHE_POLICY_PIPT] = "PIPT",
  48 };
  49
  50 unsigned long __icache_flags;
  51
  52 static const char *const hwcap_str[] = {
  53         "fp",
  54         "asimd",
  55         "evtstrm",
  56         "aes",
  57         "pmull",
  58         "sha1",
  59         "sha2",
  60         "crc32",
  61         "atomics",
  62         NULL
  63 };
  64
  65 #ifdef CONFIG_COMPAT
  66 static const char *const compat_hwcap_str[] = {
  67         "swp",
  68         "half",
  69         "thumb",
  70         "26bit",
  71         "fastmult",
  72         "fpa",
  73         "vfp",
  74         "edsp",
  75         "java",
  76         "iwmmxt",
  77         "crunch",
  78         "thumbee",
  79         "neon",
  80         "vfpv3",
  81         "vfpv3d16",
  82         "tls",
  83         "vfpv4",
  84         "idiva",
  85         "idivt",
  86         "vfpd32",
  87         "lpae",
  88         "evtstrm"
  89 };
  90
  91 static const char *const compat_hwcap2_str[] = {
  92         "aes",
  93         "pmull",
  94         "sha1",
  95         "sha2",
  96         "crc32",
  97         NULL
  98 };
  99 #endif /* CONFIG_COMPAT */
 100
 101 static int c_show(struct seq_file *m, void *v)
 102 {
 103         int i, j;
 104
 105         for_each_online_cpu(i) {
 106                 struct cpuinfo_arm64 *cpuinfo = &per_cpu(cpu_data, i);
 107                 u32 midr = cpuinfo->reg_midr;
 108
 109                 /*
 110                  * glibc reads /proc/cpuinfo to determine the number of
 111                  * online processors, looking for lines beginning with
 112                  * "processor".  Give glibc what it expects.
 113                  */
 114                 seq_printf(m, "processor\t: %d\n", i);
 115
 116                 seq_printf(m, "BogoMIPS\t: %lu.%02lu\n",
 117                            loops_per_jiffy / (500000UL/HZ),
 118                            loops_per_jiffy / (5000UL/HZ) % 100);
 119
 120                 /*
 121                  * Dump out the common processor features in a single line.
 122                  * Userspace should read the hwcaps with getauxval(AT_HWCAP)
 123                  * rather than attempting to parse this, but there's a body of
 124                  * software which does already (at least for 32-bit).
 125                  */
 126                 seq_puts(m, "Features\t:");
 127                 if (personality(current->personality) == PER_LINUX32) {
 128 #ifdef CONFIG_COMPAT
 129                         for (j = 0; compat_hwcap_str[j]; j++)
 130                                 if (compat_elf_hwcap & (1 << j))
 131                                         seq_printf(m, " %s", compat_hwcap_str[j]);
 132
 133                         for (j = 0; compat_hwcap2_str[j]; j++)
 134                                 if (compat_elf_hwcap2 & (1 << j))
 135                                         seq_printf(m, " %s", compat_hwcap2_str[j]);
 136 #endif /* CONFIG_COMPAT */
 137                 } else {
 138                         for (j = 0; hwcap_str[j]; j++)
 139                                 if (elf_hwcap & (1 << j))
 140                                         seq_printf(m, " %s", hwcap_str[j]);
 141                 }
 142                 seq_puts(m, "\n");
 143
 144                 seq_printf(m, "CPU implementer\t: 0x%02x\n",
 145                            MIDR_IMPLEMENTOR(midr));
 146                 seq_printf(m, "CPU architecture: 8\n");
 147                 seq_printf(m, "CPU variant\t: 0x%x\n", MIDR_VARIANT(midr));
 148                 seq_printf(m, "CPU part\t: 0x%03x\n", MIDR_PARTNUM(midr));
 149                 seq_printf(m, "CPU revision\t: %d\n\n", MIDR_REVISION(midr));
 150         }
 151
 152         return 0;
 153 }
 154
 155 static void *c_start(struct seq_file *m, loff_t *pos)
 156 {
 157         return *pos < 1 ? (void *)1 : NULL;
 158 }
 159
 160 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 161 {
 162         ++*pos;
 163         return NULL;
 164 }
 165
 166 static void c_stop(struct seq_file *m, void *v)
 167 {
 168 }
 169
 170 const struct seq_operations cpuinfo_op = {
 171         .start  = c_start,
 172         .next   = c_next,
 173         .stop   = c_stop,
 174         .show   = c_show
 175 };
 176
 177 static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info)
 178 {
 179         unsigned int cpu = smp_processor_id();
 180         u32 l1ip = CTR_L1IP(info->reg_ctr);
 181
 182         if (l1ip != ICACHE_POLICY_PIPT) {
 183                 /*
 184                  * VIPT caches are non-aliasing if the VA always equals the PA
 185                  * in all bit positions that are covered by the index. This is
 186                  * the case if the size of a way (# of sets * line size) does
 187                  * not exceed PAGE_SIZE.
 188                  */
 189                 u32 waysize = icache_get_numsets() * icache_get_linesize();
 190
 191                 if (l1ip != ICACHE_POLICY_VIPT || waysize > PAGE_SIZE)
 192                         set_bit(ICACHEF_ALIASING, &__icache_flags);
 193         }
 194         if (l1ip == ICACHE_POLICY_AIVIVT)
 195                 set_bit(ICACHEF_AIVIVT, &__icache_flags);
 196
 197         pr_info("Detected %s I-cache on CPU%d\n", icache_policy_str[l1ip], cpu);
 198 }
 199
 200 static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
 201 {
 202         info->reg_cntfrq = arch_timer_get_cntfrq();
 203         info->reg_ctr = read_cpuid_cachetype();
 204         info->reg_dczid = read_cpuid(SYS_DCZID_EL0);
 205         info->reg_midr = read_cpuid_id();
 206
 207         info->reg_id_aa64dfr0 = read_cpuid(SYS_ID_AA64DFR0_EL1);
 208         info->reg_id_aa64dfr1 = read_cpuid(SYS_ID_AA64DFR1_EL1);
 209         info->reg_id_aa64isar0 = read_cpuid(SYS_ID_AA64ISAR0_EL1);
 210         info->reg_id_aa64isar1 = read_cpuid(SYS_ID_AA64ISAR1_EL1);
 211         info->reg_id_aa64mmfr0 = read_cpuid(SYS_ID_AA64MMFR0_EL1);
 212         info->reg_id_aa64mmfr1 = read_cpuid(SYS_ID_AA64MMFR1_EL1);
 213         info->reg_id_aa64mmfr2 = read_cpuid(SYS_ID_AA64MMFR2_EL1);
 214         info->reg_id_aa64pfr0 = read_cpuid(SYS_ID_AA64PFR0_EL1);
 215         info->reg_id_aa64pfr1 = read_cpuid(SYS_ID_AA64PFR1_EL1);
 216
 217         info->reg_id_dfr0 = read_cpuid(SYS_ID_DFR0_EL1);
 218         info->reg_id_isar0 = read_cpuid(SYS_ID_ISAR0_EL1);
 219         info->reg_id_isar1 = read_cpuid(SYS_ID_ISAR1_EL1);
 220         info->reg_id_isar2 = read_cpuid(SYS_ID_ISAR2_EL1);
 221         info->reg_id_isar3 = read_cpuid(SYS_ID_ISAR3_EL1);
 222         info->reg_id_isar4 = read_cpuid(SYS_ID_ISAR4_EL1);
 223         info->reg_id_isar5 = read_cpuid(SYS_ID_ISAR5_EL1);
 224         info->reg_id_mmfr0 = read_cpuid(SYS_ID_MMFR0_EL1);
 225         info->reg_id_mmfr1 = read_cpuid(SYS_ID_MMFR1_EL1);
 226         info->reg_id_mmfr2 = read_cpuid(SYS_ID_MMFR2_EL1);
 227         info->reg_id_mmfr3 = read_cpuid(SYS_ID_MMFR3_EL1);
 228         info->reg_id_pfr0 = read_cpuid(SYS_ID_PFR0_EL1);
 229         info->reg_id_pfr1 = read_cpuid(SYS_ID_PFR1_EL1);
 230
 231         info->reg_mvfr0 = read_cpuid(SYS_MVFR0_EL1);
 232         info->reg_mvfr1 = read_cpuid(SYS_MVFR1_EL1);
 233         info->reg_mvfr2 = read_cpuid(SYS_MVFR2_EL1);
 234
 235         cpuinfo_detect_icache_policy(info);
 236
 237         check_local_cpu_errata();
 238 }
 239
 240 void cpuinfo_store_cpu(void)
 241 {
 242         struct cpuinfo_arm64 *info = this_cpu_ptr(&cpu_data);
 243         __cpuinfo_store_cpu(info);
 244         update_cpu_features(smp_processor_id(), info, &boot_cpu_data);
 245 }
 246
 247 void __init cpuinfo_store_boot_cpu(void)
 248 {
 249         struct cpuinfo_arm64 *info = &per_cpu(cpu_data, 0);
 250         __cpuinfo_store_cpu(info);
 251
 252         boot_cpu_data = *info;
 253         init_cpu_features(&boot_cpu_data);
 254 }