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
  34 /*
  35  * In case the boot CPU is hotpluggable, we record its initial state and
  36  * current state separately. Certain system registers may contain different
  37  * values depending on configuration at or after reset.
  38  */
  39 DEFINE_PER_CPU(struct cpuinfo_arm64, cpu_data);
  40 static struct cpuinfo_arm64 boot_cpu_data;
  41
  42 static char *icache_policy_str[] = {
  43         [ICACHE_POLICY_RESERVED] = "RESERVED/UNKNOWN",
  44         [ICACHE_POLICY_AIVIVT] = "AIVIVT",
  45         [ICACHE_POLICY_VIPT] = "VIPT",
  46         [ICACHE_POLICY_PIPT] = "PIPT",
  47 };
  48
  49 unsigned long __icache_flags;
  50
  51 static const char *const hwcap_str[] = {
  52         "fp",
  53         "asimd",
  54         "evtstrm",
  55         "aes",
  56         "pmull",
  57         "sha1",
  58         "sha2",
  59         "crc32",
  60         "atomics",
  61         NULL
  62 };
  63
  64 #ifdef CONFIG_COMPAT
  65 static const char *const compat_hwcap_str[] = {
  66         "swp",
  67         "half",
  68         "thumb",
  69         "26bit",
  70         "fastmult",
  71         "fpa",
  72         "vfp",
  73         "edsp",
  74         "java",
  75         "iwmmxt",
  76         "crunch",
  77         "thumbee",
  78         "neon",
  79         "vfpv3",
  80         "vfpv3d16",
  81         "tls",
  82         "vfpv4",
  83         "idiva",
  84         "idivt",
  85         "vfpd32",
  86         "lpae",
  87         "evtstrm"
  88 };
  89
  90 static const char *const compat_hwcap2_str[] = {
  91         "aes",
  92         "pmull",
  93         "sha1",
  94         "sha2",
  95         "crc32",
  96         NULL
  97 };
  98 #endif /* CONFIG_COMPAT */
  99
 100 static int c_show(struct seq_file *m, void *v)
 101 {
 102         int i, j;
 103
 104         for_each_online_cpu(i) {
 105                 struct cpuinfo_arm64 *cpuinfo = &per_cpu(cpu_data, i);
 106                 u32 midr = cpuinfo->reg_midr;
 107
 108                 /*
 109                  * glibc reads /proc/cpuinfo to determine the number of
 110                  * online processors, looking for lines beginning with
 111                  * "processor".  Give glibc what it expects.
 112                  */
 113                 seq_printf(m, "processor\t: %d\n", i);
 114
 115                 /*
 116                  * Dump out the common processor features in a single line.
 117                  * Userspace should read the hwcaps with getauxval(AT_HWCAP)
 118                  * rather than attempting to parse this, but there's a body of
 119                  * software which does already (at least for 32-bit).
 120                  */
 121                 seq_puts(m, "Features\t:");
 122                 if (personality(current->personality) == PER_LINUX32) {
 123 #ifdef CONFIG_COMPAT
 124                         for (j = 0; compat_hwcap_str[j]; j++)
 125                                 if (compat_elf_hwcap & (1 << j))
 126                                         seq_printf(m, " %s", compat_hwcap_str[j]);
 127
 128                         for (j = 0; compat_hwcap2_str[j]; j++)
 129                                 if (compat_elf_hwcap2 & (1 << j))
 130                                         seq_printf(m, " %s", compat_hwcap2_str[j]);
 131 #endif /* CONFIG_COMPAT */
 132                 } else {
 133                         for (j = 0; hwcap_str[j]; j++)
 134                                 if (elf_hwcap & (1 << j))
 135                                         seq_printf(m, " %s", hwcap_str[j]);
 136                 }
 137                 seq_puts(m, "\n");
 138
 139                 seq_printf(m, "CPU implementer\t: 0x%02x\n",
 140                            MIDR_IMPLEMENTOR(midr));
 141                 seq_printf(m, "CPU architecture: 8\n");
 142                 seq_printf(m, "CPU variant\t: 0x%x\n", MIDR_VARIANT(midr));
 143                 seq_printf(m, "CPU part\t: 0x%03x\n", MIDR_PARTNUM(midr));
 144                 seq_printf(m, "CPU revision\t: %d\n\n", MIDR_REVISION(midr));
 145         }
 146
 147         return 0;
 148 }
 149
 150 static void *c_start(struct seq_file *m, loff_t *pos)
 151 {
 152         return *pos < 1 ? (void *)1 : NULL;
 153 }
 154
 155 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 156 {
 157         ++*pos;
 158         return NULL;
 159 }
 160
 161 static void c_stop(struct seq_file *m, void *v)
 162 {
 163 }
 164
 165 const struct seq_operations cpuinfo_op = {
 166         .start  = c_start,
 167         .next   = c_next,
 168         .stop   = c_stop,
 169         .show   = c_show
 170 };
 171
 172 static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info)
 173 {
 174         unsigned int cpu = smp_processor_id();
 175         u32 l1ip = CTR_L1IP(info->reg_ctr);
 176
 177         if (l1ip != ICACHE_POLICY_PIPT) {
 178                 /*
 179                  * VIPT caches are non-aliasing if the VA always equals the PA
 180                  * in all bit positions that are covered by the index. This is
 181                  * the case if the size of a way (# of sets * line size) does
 182                  * not exceed PAGE_SIZE.
 183                  */
 184                 u32 waysize = icache_get_numsets() * icache_get_linesize();
 185
 186                 if (l1ip != ICACHE_POLICY_VIPT || waysize > PAGE_SIZE)
 187                         set_bit(ICACHEF_ALIASING, &__icache_flags);
 188         }
 189         if (l1ip == ICACHE_POLICY_AIVIVT)
 190                 set_bit(ICACHEF_AIVIVT, &__icache_flags);
 191
 192         pr_info("Detected %s I-cache on CPU%d\n", icache_policy_str[l1ip], cpu);
 193 }
 194
 195 static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
 196 {
 197         info->reg_cntfrq = arch_timer_get_cntfrq();
 198         info->reg_ctr = read_cpuid_cachetype();
 199         info->reg_dczid = read_cpuid(DCZID_EL0);
 200         info->reg_midr = read_cpuid_id();
 201
 202         info->reg_id_aa64dfr0 = read_cpuid(ID_AA64DFR0_EL1);
 203         info->reg_id_aa64dfr1 = read_cpuid(ID_AA64DFR1_EL1);
 204         info->reg_id_aa64isar0 = read_cpuid(ID_AA64ISAR0_EL1);
 205         info->reg_id_aa64isar1 = read_cpuid(ID_AA64ISAR1_EL1);
 206         info->reg_id_aa64mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
 207         info->reg_id_aa64mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
 208         info->reg_id_aa64pfr0 = read_cpuid(ID_AA64PFR0_EL1);
 209         info->reg_id_aa64pfr1 = read_cpuid(ID_AA64PFR1_EL1);
 210
 211         info->reg_id_dfr0 = read_cpuid(ID_DFR0_EL1);
 212         info->reg_id_isar0 = read_cpuid(ID_ISAR0_EL1);
 213         info->reg_id_isar1 = read_cpuid(ID_ISAR1_EL1);
 214         info->reg_id_isar2 = read_cpuid(ID_ISAR2_EL1);
 215         info->reg_id_isar3 = read_cpuid(ID_ISAR3_EL1);
 216         info->reg_id_isar4 = read_cpuid(ID_ISAR4_EL1);
 217         info->reg_id_isar5 = read_cpuid(ID_ISAR5_EL1);
 218         info->reg_id_mmfr0 = read_cpuid(ID_MMFR0_EL1);
 219         info->reg_id_mmfr1 = read_cpuid(ID_MMFR1_EL1);
 220         info->reg_id_mmfr2 = read_cpuid(ID_MMFR2_EL1);
 221         info->reg_id_mmfr3 = read_cpuid(ID_MMFR3_EL1);
 222         info->reg_id_pfr0 = read_cpuid(ID_PFR0_EL1);
 223         info->reg_id_pfr1 = read_cpuid(ID_PFR1_EL1);
 224
 225         info->reg_mvfr0 = read_cpuid(MVFR0_EL1);
 226         info->reg_mvfr1 = read_cpuid(MVFR1_EL1);
 227         info->reg_mvfr2 = read_cpuid(MVFR2_EL1);
 228
 229         cpuinfo_detect_icache_policy(info);
 230
 231         check_local_cpu_errata();
 232 }
 233
 234 void cpuinfo_store_cpu(void)
 235 {
 236         struct cpuinfo_arm64 *info = this_cpu_ptr(&cpu_data);
 237         __cpuinfo_store_cpu(info);
 238         update_cpu_features(smp_processor_id(), info, &boot_cpu_data);
 239 }
 240
 241 void __init cpuinfo_store_boot_cpu(void)
 242 {
 243         struct cpuinfo_arm64 *info = &per_cpu(cpu_data, 0);
 244         __cpuinfo_store_cpu(info);
 245
 246         boot_cpu_data = *info;
 247         init_cpu_features(&boot_cpu_data);
 248 }