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