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