arch/s390/kernel/processor.c

   1 /*
   2  *  Copyright IBM Corp. 2008
   3  *  Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
   4  */
   5
   6 #define KMSG_COMPONENT "cpu"
   7 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
   8
   9 #include <linux/cpufeature.h>
  10 #include <linux/kernel.h>
  11 #include <linux/sched/mm.h>
  12 #include <linux/init.h>
  13 #include <linux/seq_file.h>
  14 #include <linux/mm_types.h>
  15 #include <linux/delay.h>
  16 #include <linux/cpu.h>
  17
  18 #include <asm/diag.h>
  19 #include <asm/facility.h>
  20 #include <asm/elf.h>
  21 #include <asm/lowcore.h>
  22 #include <asm/param.h>
  23 #include <asm/smp.h>
  24
  25 struct cpu_info {
  26         unsigned int cpu_mhz_dynamic;
  27         unsigned int cpu_mhz_static;
  28         struct cpuid cpu_id;
  29 };
  30
  31 static DEFINE_PER_CPU(struct cpu_info, cpu_info);
  32
  33 static bool machine_has_cpu_mhz;
  34
  35 void __init cpu_detect_mhz_feature(void)
  36 {
  37         if (test_facility(34) && __ecag(ECAG_CPU_ATTRIBUTE, 0) != -1UL)
  38                 machine_has_cpu_mhz = true;
  39 }
  40
  41 static void update_cpu_mhz(void *arg)
  42 {
  43         unsigned long mhz;
  44         struct cpu_info *c;
  45
  46         mhz = __ecag(ECAG_CPU_ATTRIBUTE, 0);
  47         c = this_cpu_ptr(&cpu_info);
  48         c->cpu_mhz_dynamic = mhz >> 32;
  49         c->cpu_mhz_static = mhz & 0xffffffff;
  50 }
  51
  52 void s390_update_cpu_mhz(void)
  53 {
  54         s390_adjust_jiffies();
  55         if (machine_has_cpu_mhz)
  56                 on_each_cpu(update_cpu_mhz, NULL, 0);
  57 }
  58
  59 void notrace cpu_relax_yield(void)
  60 {
  61         if (!smp_cpu_mtid && MACHINE_HAS_DIAG44) {
  62                 diag_stat_inc(DIAG_STAT_X044);
  63                 asm volatile("diag 0,0,0x44");
  64         }
  65         barrier();
  66 }
  67 EXPORT_SYMBOL(cpu_relax_yield);
  68
  69 /*
  70  * cpu_init - initializes state that is per-CPU.
  71  */
  72 void cpu_init(void)
  73 {
  74         struct cpuid *id = this_cpu_ptr(&cpu_info.cpu_id);
  75
  76         get_cpu_id(id);
  77         if (machine_has_cpu_mhz)
  78                 update_cpu_mhz(NULL);
  79         mmgrab(&init_mm);
  80         current->active_mm = &init_mm;
  81         BUG_ON(current->mm);
  82         enter_lazy_tlb(&init_mm, current);
  83 }
  84
  85 /*
  86  * cpu_have_feature - Test CPU features on module initialization
  87  */
  88 int cpu_have_feature(unsigned int num)
  89 {
  90         return elf_hwcap & (1UL << num);
  91 }
  92 EXPORT_SYMBOL(cpu_have_feature);
  93
  94 static void show_cpu_summary(struct seq_file *m, void *v)
  95 {
  96         static const char *hwcap_str[] = {
  97                 "esan3", "zarch", "stfle", "msa", "ldisp", "eimm", "dfp",
  98                 "edat", "etf3eh", "highgprs", "te", "vx", "vxd", "vxe"
  99         };
 100         static const char * const int_hwcap_str[] = {
 101                 "sie"
 102         };
 103         int i, cpu;
 104
 105         seq_printf(m, "vendor_id       : IBM/S390\n"
 106                    "# processors    : %i\n"
 107                    "bogomips per cpu: %lu.%02lu\n",
 108                    num_online_cpus(), loops_per_jiffy/(500000/HZ),
 109                    (loops_per_jiffy/(5000/HZ))%100);
 110         seq_printf(m, "max thread id   : %d\n", smp_cpu_mtid);
 111         seq_puts(m, "features\t: ");
 112         for (i = 0; i < ARRAY_SIZE(hwcap_str); i++)
 113                 if (hwcap_str[i] && (elf_hwcap & (1UL << i)))
 114                         seq_printf(m, "%s ", hwcap_str[i]);
 115         for (i = 0; i < ARRAY_SIZE(int_hwcap_str); i++)
 116                 if (int_hwcap_str[i] && (int_hwcap & (1UL << i)))
 117                         seq_printf(m, "%s ", int_hwcap_str[i]);
 118         seq_puts(m, "\n");
 119         show_cacheinfo(m);
 120         for_each_online_cpu(cpu) {
 121                 struct cpuid *id = &per_cpu(cpu_info.cpu_id, cpu);
 122
 123                 seq_printf(m, "processor %d: "
 124                            "version = %02X,  "
 125                            "identification = %06X,  "
 126                            "machine = %04X\n",
 127                            cpu, id->version, id->ident, id->machine);
 128         }
 129 }
 130
 131 static void show_cpu_mhz(struct seq_file *m, unsigned long n)
 132 {
 133         struct cpu_info *c = per_cpu_ptr(&cpu_info, n);
 134
 135         seq_printf(m, "cpu MHz dynamic : %d\n", c->cpu_mhz_dynamic);
 136         seq_printf(m, "cpu MHz static  : %d\n", c->cpu_mhz_static);
 137 }
 138
 139 /*
 140  * show_cpuinfo - Get information on one CPU for use by procfs.
 141  */
 142 static int show_cpuinfo(struct seq_file *m, void *v)
 143 {
 144         unsigned long n = (unsigned long) v - 1;
 145
 146         if (!n)
 147                 show_cpu_summary(m, v);
 148         if (!machine_has_cpu_mhz)
 149                 return 0;
 150         seq_printf(m, "\ncpu number      : %ld\n", n);
 151         show_cpu_mhz(m, n);
 152         return 0;
 153 }
 154
 155 static inline void *c_update(loff_t *pos)
 156 {
 157         if (*pos)
 158                 *pos = cpumask_next(*pos - 1, cpu_online_mask);
 159         return *pos < nr_cpu_ids ? (void *)*pos + 1 : NULL;
 160 }
 161
 162 static void *c_start(struct seq_file *m, loff_t *pos)
 163 {
 164         get_online_cpus();
 165         return c_update(pos);
 166 }
 167
 168 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 169 {
 170         ++*pos;
 171         return c_update(pos);
 172 }
 173
 174 static void c_stop(struct seq_file *m, void *v)
 175 {
 176         put_online_cpus();
 177 }
 178
 179 const struct seq_operations cpuinfo_op = {
 180         .start  = c_start,
 181         .next   = c_next,
 182         .stop   = c_stop,
 183         .show   = show_cpuinfo,
 184 };