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/facility.h>
  17 #include <asm/lowcore.h>
  18 #include <asm/param.h>
  19 #include <asm/smp.h>
  20
  21 static DEFINE_PER_CPU(struct cpuid, cpu_id);
  22
  23 void notrace cpu_relax(void)
  24 {
  25         if (!smp_cpu_mtid && MACHINE_HAS_DIAG44) {
  26                 diag_stat_inc(DIAG_STAT_X044);
  27                 asm volatile("diag 0,0,0x44");
  28         }
  29         barrier();
  30 }
  31 EXPORT_SYMBOL(cpu_relax);
  32
  33 /*
  34  * cpu_init - initializes state that is per-CPU.
  35  */
  36 void cpu_init(void)
  37 {
  38         struct cpuid *id = this_cpu_ptr(&cpu_id);
  39
  40         get_cpu_id(id);
  41         atomic_inc(&init_mm.mm_count);
  42         current->active_mm = &init_mm;
  43         BUG_ON(current->mm);
  44         enter_lazy_tlb(&init_mm, current);
  45 }
  46
  47 /*
  48  * cpu_have_feature - Test CPU features on module initialization
  49  */
  50 int cpu_have_feature(unsigned int num)
  51 {
  52         return elf_hwcap & (1UL << num);
  53 }
  54 EXPORT_SYMBOL(cpu_have_feature);
  55
  56 /*
  57  * show_cpuinfo - Get information on one CPU for use by procfs.
  58  */
  59 static int show_cpuinfo(struct seq_file *m, void *v)
  60 {
  61         static const char *hwcap_str[] = {
  62                 "esan3", "zarch", "stfle", "msa", "ldisp", "eimm", "dfp",
  63                 "edat", "etf3eh", "highgprs", "te", "vx"
  64         };
  65         unsigned long n = (unsigned long) v - 1;
  66         int i;
  67
  68         if (!n) {
  69                 s390_adjust_jiffies();
  70                 seq_printf(m, "vendor_id       : IBM/S390\n"
  71                            "# processors    : %i\n"
  72                            "bogomips per cpu: %lu.%02lu\n",
  73                            num_online_cpus(), loops_per_jiffy/(500000/HZ),
  74                            (loops_per_jiffy/(5000/HZ))%100);
  75                 seq_puts(m, "features\t: ");
  76                 for (i = 0; i < ARRAY_SIZE(hwcap_str); i++)
  77                         if (hwcap_str[i] && (elf_hwcap & (1UL << i)))
  78                                 seq_printf(m, "%s ", hwcap_str[i]);
  79                 seq_puts(m, "\n");
  80                 show_cacheinfo(m);
  81         }
  82         get_online_cpus();
  83         if (cpu_online(n)) {
  84                 struct cpuid *id = &per_cpu(cpu_id, n);
  85                 seq_printf(m, "processor %li: "
  86                            "version = %02X,  "
  87                            "identification = %06X,  "
  88                            "machine = %04X\n",
  89                            n, id->version, id->ident, id->machine);
  90         }
  91         put_online_cpus();
  92         return 0;
  93 }
  94
  95 static void *c_start(struct seq_file *m, loff_t *pos)
  96 {
  97         return *pos < nr_cpu_ids ? (void *)((unsigned long) *pos + 1) : NULL;
  98 }
  99
 100 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 101 {
 102         ++*pos;
 103         return c_start(m, pos);
 104 }
 105
 106 static void c_stop(struct seq_file *m, void *v)
 107 {
 108 }
 109
 110 const struct seq_operations cpuinfo_op = {
 111         .start  = c_start,
 112         .next   = c_next,
 113         .stop   = c_stop,
 114         .show   = show_cpuinfo,
 115 };
 116
 117 int s390_isolate_bp(void)
 118 {
 119         if (!test_facility(82))
 120                 return -EOPNOTSUPP;
 121         set_thread_flag(TIF_ISOLATE_BP);
 122         return 0;
 123 }
 124 EXPORT_SYMBOL(s390_isolate_bp);
 125
 126 int s390_isolate_bp_guest(void)
 127 {
 128         if (!test_facility(82))
 129                 return -EOPNOTSUPP;
 130         set_thread_flag(TIF_ISOLATE_BP_GUEST);
 131         return 0;
 132 }
 133 EXPORT_SYMBOL(s390_isolate_bp_guest);