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/kernel.h>
  10 #include <linux/init.h>
  11 #include <linux/seq_file.h>
  12 #include <linux/delay.h>
  13 #include <linux/cpu.h>
  14 #include <asm/diag.h>
  15 #include <asm/elf.h>
  16 #include <asm/lowcore.h>
  17 #include <asm/param.h>
  18 #include <asm/smp.h>
  19
  20 static DEFINE_PER_CPU(struct cpuid, cpu_id);
  21
  22 void notrace cpu_relax(void)
  23 {
  24         if (!smp_cpu_mtid && MACHINE_HAS_DIAG44) {
  25                 diag_stat_inc(DIAG_STAT_X044);
  26                 asm volatile("diag 0,0,0x44");
  27         }
  28         barrier();
  29 }
  30 EXPORT_SYMBOL(cpu_relax);
  31
  32 /*
  33  * cpu_init - initializes state that is per-CPU.
  34  */
  35 void cpu_init(void)
  36 {
  37         struct cpuid *id = this_cpu_ptr(&cpu_id);
  38
  39         get_cpu_id(id);
  40         atomic_inc(&init_mm.mm_count);
  41         current->active_mm = &init_mm;
  42         BUG_ON(current->mm);
  43         enter_lazy_tlb(&init_mm, current);
  44 }
  45
  46 /*
  47  * cpu_have_feature - Test CPU features on module initialization
  48  */
  49 int cpu_have_feature(unsigned int num)
  50 {
  51         return elf_hwcap & (1UL << num);
  52 }
  53 EXPORT_SYMBOL(cpu_have_feature);
  54
  55 /*
  56  * show_cpuinfo - Get information on one CPU for use by procfs.
  57  */
  58 static int show_cpuinfo(struct seq_file *m, void *v)
  59 {
  60         static const char *hwcap_str[] = {
  61                 "esan3", "zarch", "stfle", "msa", "ldisp", "eimm", "dfp",
  62                 "edat", "etf3eh", "highgprs", "te", "vx"
  63         };
  64         unsigned long n = (unsigned long) v - 1;
  65         int i;
  66
  67         if (!n) {
  68                 s390_adjust_jiffies();
  69                 seq_printf(m, "vendor_id       : IBM/S390\n"
  70                            "# processors    : %i\n"
  71                            "bogomips per cpu: %lu.%02lu\n",
  72                            num_online_cpus(), loops_per_jiffy/(500000/HZ),
  73                            (loops_per_jiffy/(5000/HZ))%100);
  74                 seq_puts(m, "features\t: ");
  75                 for (i = 0; i < ARRAY_SIZE(hwcap_str); i++)
  76                         if (hwcap_str[i] && (elf_hwcap & (1UL << i)))
  77                                 seq_printf(m, "%s ", hwcap_str[i]);
  78                 seq_puts(m, "\n");
  79                 show_cacheinfo(m);
  80         }
  81         get_online_cpus();
  82         if (cpu_online(n)) {
  83                 struct cpuid *id = &per_cpu(cpu_id, n);
  84                 seq_printf(m, "processor %li: "
  85                            "version = %02X,  "
  86                            "identification = %06X,  "
  87                            "machine = %04X\n",
  88                            n, id->version, id->ident, id->machine);
  89         }
  90         put_online_cpus();
  91         return 0;
  92 }
  93
  94 static void *c_start(struct seq_file *m, loff_t *pos)
  95 {
  96         return *pos < nr_cpu_ids ? (void *)((unsigned long) *pos + 1) : NULL;
  97 }
  98
  99 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 100 {
 101         ++*pos;
 102         return c_start(m, pos);
 103 }
 104
 105 static void c_stop(struct seq_file *m, void *v)
 106 {
 107 }
 108
 109 const struct seq_operations cpuinfo_op = {
 110         .start  = c_start,
 111         .next   = c_next,
 112         .stop   = c_stop,
 113         .show   = show_cpuinfo,
 114 };
 115