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  * cpu_have_feature - Test CPU features on module initialization
  45  */
  46 int cpu_have_feature(unsigned int num)
  47 {
  48         return elf_hwcap & (1UL << num);
  49 }
  50 EXPORT_SYMBOL(cpu_have_feature);
  51
  52 /*
  53  * show_cpuinfo - Get information on one CPU for use by procfs.
  54  */
  55 static int show_cpuinfo(struct seq_file *m, void *v)
  56 {
  57         static const char *hwcap_str[] = {
  58                 "esan3", "zarch", "stfle", "msa", "ldisp", "eimm", "dfp",
  59                 "edat", "etf3eh", "highgprs", "te", "vx"
  60         };
  61         unsigned long n = (unsigned long) v - 1;
  62         int i;
  63
  64         if (!n) {
  65                 s390_adjust_jiffies();
  66                 seq_printf(m, "vendor_id       : IBM/S390\n"
  67                            "# processors    : %i\n"
  68                            "bogomips per cpu: %lu.%02lu\n",
  69                            num_online_cpus(), loops_per_jiffy/(500000/HZ),
  70                            (loops_per_jiffy/(5000/HZ))%100);
  71                 seq_puts(m, "features\t: ");
  72                 for (i = 0; i < ARRAY_SIZE(hwcap_str); i++)
  73                         if (hwcap_str[i] && (elf_hwcap & (1UL << i)))
  74                                 seq_printf(m, "%s ", hwcap_str[i]);
  75                 seq_puts(m, "\n");
  76                 show_cacheinfo(m);
  77         }
  78         get_online_cpus();
  79         if (cpu_online(n)) {
  80                 struct cpuid *id = &per_cpu(cpu_id, n);
  81                 seq_printf(m, "processor %li: "
  82                            "version = %02X,  "
  83                            "identification = %06X,  "
  84                            "machine = %04X\n",
  85                            n, id->version, id->ident, id->machine);
  86         }
  87         put_online_cpus();
  88         return 0;
  89 }
  90
  91 static void *c_start(struct seq_file *m, loff_t *pos)
  92 {
  93         return *pos < nr_cpu_ids ? (void *)((unsigned long) *pos + 1) : NULL;
  94 }
  95
  96 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
  97 {
  98         ++*pos;
  99         return c_start(m, pos);
 100 }
 101
 102 static void c_stop(struct seq_file *m, void *v)
 103 {
 104 }
 105
 106 const struct seq_operations cpuinfo_op = {
 107         .start  = c_start,
 108         .next   = c_next,
 109         .stop   = c_stop,
 110         .show   = show_cpuinfo,
 111 };
 112