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