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         "fphp",
  63         "asimdhp",
  64         NULL
  65 };
  66
  67 #ifdef CONFIG_COMPAT
  68 static const char *const compat_hwcap_str[] = {
  69         "swp",
  70         "half",
  71         "thumb",
  72         "26bit",
  73         "fastmult",
  74         "fpa",
  75         "vfp",
  76         "edsp",
  77         "java",
  78         "iwmmxt",
  79         "crunch",
  80         "thumbee",
  81         "neon",
  82         "vfpv3",
  83         "vfpv3d16",
  84         "tls",
  85         "vfpv4",
  86         "idiva",
  87         "idivt",
  88         "vfpd32",
  89         "lpae",
  90         "evtstrm",
  91         NULL
  92 };
  93
  94 static const char *const compat_hwcap2_str[] = {
  95         "aes",
  96         "pmull",
  97         "sha1",
  98         "sha2",
  99         "crc32",
 100         NULL
 101 };
 102 #endif /* CONFIG_COMPAT */
 103
 104 static int c_show(struct seq_file *m, void *v)
 105 {
 106         int i, j;
 107
 108         for_each_online_cpu(i) {
 109                 struct cpuinfo_arm64 *cpuinfo = &per_cpu(cpu_data, i);
 110                 u32 midr = cpuinfo->reg_midr;
 111
 112                 /*
 113                  * glibc reads /proc/cpuinfo to determine the number of
 114                  * online processors, looking for lines beginning with
 115                  * "processor".  Give glibc what it expects.
 116                  */
 117                 seq_printf(m, "processor\t: %d\n", i);
 118
 119                 seq_printf(m, "BogoMIPS\t: %lu.%02lu\n",
 120                            loops_per_jiffy / (500000UL/HZ),
 121                            loops_per_jiffy / (5000UL/HZ) % 100);
 122
 123                 /*
 124                  * Dump out the common processor features in a single line.
 125                  * Userspace should read the hwcaps with getauxval(AT_HWCAP)
 126                  * rather than attempting to parse this, but there's a body of
 127                  * software which does already (at least for 32-bit).
 128                  */
 129                 seq_puts(m, "Features\t:");
 130                 if (personality(current->personality) == PER_LINUX32) {
 131 #ifdef CONFIG_COMPAT
 132                         for (j = 0; compat_hwcap_str[j]; j++)
 133                                 if (compat_elf_hwcap & (1 << j))
 134                                         seq_printf(m, " %s", compat_hwcap_str[j]);
 135
 136                         for (j = 0; compat_hwcap2_str[j]; j++)
 137                                 if (compat_elf_hwcap2 & (1 << j))
 138                                         seq_printf(m, " %s", compat_hwcap2_str[j]);
 139 #endif /* CONFIG_COMPAT */
 140                 } else {
 141                         for (j = 0; hwcap_str[j]; j++)
 142                                 if (elf_hwcap & (1 << j))
 143                                         seq_printf(m, " %s", hwcap_str[j]);
 144                 }
 145                 seq_puts(m, "\n");
 146
 147                 seq_printf(m, "CPU implementer\t: 0x%02x\n",
 148                            MIDR_IMPLEMENTOR(midr));
 149                 seq_printf(m, "CPU architecture: 8\n");
 150                 seq_printf(m, "CPU variant\t: 0x%x\n", MIDR_VARIANT(midr));
 151                 seq_printf(m, "CPU part\t: 0x%03x\n", MIDR_PARTNUM(midr));
 152                 seq_printf(m, "CPU revision\t: %d\n\n", MIDR_REVISION(midr));
 153         }
 154
 155         return 0;
 156 }
 157
 158 static void *c_start(struct seq_file *m, loff_t *pos)
 159 {
 160         return *pos < 1 ? (void *)1 : NULL;
 161 }
 162
 163 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 164 {
 165         ++*pos;
 166         return NULL;
 167 }
 168
 169 static void c_stop(struct seq_file *m, void *v)
 170 {
 171 }
 172
 173 const struct seq_operations cpuinfo_op = {
 174         .start  = c_start,
 175         .next   = c_next,
 176         .stop   = c_stop,
 177         .show   = c_show
 178 };
 179
 180 static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info)
 181 {
 182         unsigned int cpu = smp_processor_id();
 183         u32 l1ip = CTR_L1IP(info->reg_ctr);
 184
 185         if (l1ip != ICACHE_POLICY_PIPT) {
 186                 /*
 187                  * VIPT caches are non-aliasing if the VA always equals the PA
 188                  * in all bit positions that are covered by the index. This is
 189                  * the case if the size of a way (# of sets * line size) does
 190                  * not exceed PAGE_SIZE.
 191                  */
 192                 u32 waysize = icache_get_numsets() * icache_get_linesize();
 193
 194                 if (l1ip != ICACHE_POLICY_VIPT || waysize > PAGE_SIZE)
 195                         set_bit(ICACHEF_ALIASING, &__icache_flags);
 196         }
 197         if (l1ip == ICACHE_POLICY_AIVIVT)
 198                 set_bit(ICACHEF_AIVIVT, &__icache_flags);
 199
 200         pr_info("Detected %s I-cache on CPU%d\n", icache_policy_str[l1ip], cpu);
 201 }
 202
 203 static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
 204 {
 205         info->reg_cntfrq = arch_timer_get_cntfrq();
 206         info->reg_ctr = read_cpuid_cachetype();
 207         info->reg_dczid = read_cpuid(DCZID_EL0);
 208         info->reg_midr = read_cpuid_id();
 209
 210         info->reg_id_aa64dfr0 = read_cpuid(ID_AA64DFR0_EL1);
 211         info->reg_id_aa64dfr1 = read_cpuid(ID_AA64DFR1_EL1);
 212         info->reg_id_aa64isar0 = read_cpuid(ID_AA64ISAR0_EL1);
 213         info->reg_id_aa64isar1 = read_cpuid(ID_AA64ISAR1_EL1);
 214         info->reg_id_aa64mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
 215         info->reg_id_aa64mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
 216         info->reg_id_aa64mmfr2 = read_cpuid(ID_AA64MMFR2_EL1);
 217         info->reg_id_aa64pfr0 = read_cpuid(ID_AA64PFR0_EL1);
 218         info->reg_id_aa64pfr1 = read_cpuid(ID_AA64PFR1_EL1);
 219
 220         /* Update the 32bit ID registers only if AArch32 is implemented */
 221         if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0)) {
 222                 info->reg_id_dfr0 = read_cpuid(ID_DFR0_EL1);
 223                 info->reg_id_isar0 = read_cpuid(ID_ISAR0_EL1);
 224                 info->reg_id_isar1 = read_cpuid(ID_ISAR1_EL1);
 225                 info->reg_id_isar2 = read_cpuid(ID_ISAR2_EL1);
 226                 info->reg_id_isar3 = read_cpuid(ID_ISAR3_EL1);
 227                 info->reg_id_isar4 = read_cpuid(ID_ISAR4_EL1);
 228                 info->reg_id_isar5 = read_cpuid(ID_ISAR5_EL1);
 229                 info->reg_id_mmfr0 = read_cpuid(ID_MMFR0_EL1);
 230                 info->reg_id_mmfr1 = read_cpuid(ID_MMFR1_EL1);
 231                 info->reg_id_mmfr2 = read_cpuid(ID_MMFR2_EL1);
 232                 info->reg_id_mmfr3 = read_cpuid(ID_MMFR3_EL1);
 233                 info->reg_id_pfr0 = read_cpuid(ID_PFR0_EL1);
 234                 info->reg_id_pfr1 = read_cpuid(ID_PFR1_EL1);
 235
 236                 info->reg_mvfr0 = read_cpuid(MVFR0_EL1);
 237                 info->reg_mvfr1 = read_cpuid(MVFR1_EL1);
 238                 info->reg_mvfr2 = read_cpuid(MVFR2_EL1);
 239         }
 240
 241         cpuinfo_detect_icache_policy(info);
 242
 243         check_local_cpu_errata();
 244 }
 245
 246 void cpuinfo_store_cpu(void)
 247 {
 248         struct cpuinfo_arm64 *info = this_cpu_ptr(&cpu_data);
 249         __cpuinfo_store_cpu(info);
 250         update_cpu_features(smp_processor_id(), info, &boot_cpu_data);
 251 }
 252
 253 void __init cpuinfo_store_boot_cpu(void)
 254 {
 255         struct cpuinfo_arm64 *info = &per_cpu(cpu_data, 0);
 256         __cpuinfo_store_cpu(info);
 257
 258         boot_cpu_data = *info;
 259         init_cpu_features(&boot_cpu_data);
 260 }