arch/s390/kernel/processor.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Copyright IBM Corp. 2008
   4  *  Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
   5  */
   6
   7 #define KMSG_COMPONENT "cpu"
   8 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
   9
  10 #include <linux/cpufeature.h>
  11 #include <linux/bitops.h>
  12 #include <linux/kernel.h>
  13 #include <linux/sched/mm.h>
  14 #include <linux/init.h>
  15 #include <linux/seq_file.h>
  16 #include <linux/mm_types.h>
  17 #include <linux/delay.h>
  18 #include <linux/cpu.h>
  19
  20 #include <asm/diag.h>
  21 #include <asm/facility.h>
  22 #include <asm/elf.h>
  23 #include <asm/lowcore.h>
  24 #include <asm/param.h>
  25 #include <asm/smp.h>
  26
  27 struct cpu_info {
  28         unsigned int cpu_mhz_dynamic;
  29         unsigned int cpu_mhz_static;
  30         struct cpuid cpu_id;
  31 };
  32
  33 static DEFINE_PER_CPU(struct cpu_info, cpu_info);
  34
  35 static bool machine_has_cpu_mhz;
  36
  37 void __init cpu_detect_mhz_feature(void)
  38 {
  39         if (test_facility(34) && __ecag(ECAG_CPU_ATTRIBUTE, 0) != -1UL)
  40                 machine_has_cpu_mhz = true;
  41 }
  42
  43 static void update_cpu_mhz(void *arg)
  44 {
  45         unsigned long mhz;
  46         struct cpu_info *c;
  47
  48         mhz = __ecag(ECAG_CPU_ATTRIBUTE, 0);
  49         c = this_cpu_ptr(&cpu_info);
  50         c->cpu_mhz_dynamic = mhz >> 32;
  51         c->cpu_mhz_static = mhz & 0xffffffff;
  52 }
  53
  54 void s390_update_cpu_mhz(void)
  55 {
  56         s390_adjust_jiffies();
  57         if (machine_has_cpu_mhz)
  58                 on_each_cpu(update_cpu_mhz, NULL, 0);
  59 }
  60
  61 void notrace cpu_relax_yield(void)
  62 {
  63         if (!smp_cpu_mtid && MACHINE_HAS_DIAG44) {
  64                 diag_stat_inc(DIAG_STAT_X044);
  65                 asm volatile("diag 0,0,0x44");
  66         }
  67         barrier();
  68 }
  69 EXPORT_SYMBOL(cpu_relax_yield);
  70
  71 /*
  72  * cpu_init - initializes state that is per-CPU.
  73  */
  74 void cpu_init(void)
  75 {
  76         struct cpuid *id = this_cpu_ptr(&cpu_info.cpu_id);
  77
  78         get_cpu_id(id);
  79         if (machine_has_cpu_mhz)
  80                 update_cpu_mhz(NULL);
  81         mmgrab(&init_mm);
  82         current->active_mm = &init_mm;
  83         BUG_ON(current->mm);
  84         enter_lazy_tlb(&init_mm, current);
  85 }
  86
  87 /*
  88  * cpu_have_feature - Test CPU features on module initialization
  89  */
  90 int cpu_have_feature(unsigned int num)
  91 {
  92         return elf_hwcap & (1UL << num);
  93 }
  94 EXPORT_SYMBOL(cpu_have_feature);
  95
  96 static void show_facilities(struct seq_file *m)
  97 {
  98         unsigned int bit;
  99         long *facilities;
 100
 101         facilities = (long *)&S390_lowcore.stfle_fac_list;
 102         seq_puts(m, "facilities      :");
 103         for_each_set_bit_inv(bit, facilities, MAX_FACILITY_BIT)
 104                 seq_printf(m, " %d", bit);
 105         seq_putc(m, '\n');
 106 }
 107
 108 static void show_cpu_summary(struct seq_file *m, void *v)
 109 {
 110         static const char *hwcap_str[] = {
 111                 "esan3", "zarch", "stfle", "msa", "ldisp", "eimm", "dfp",
 112                 "edat", "etf3eh", "highgprs", "te", "vx", "vxd", "vxe", "gs",
 113                 "vxe2", "vxp", "sort", "dflt"
 114         };
 115         static const char * const int_hwcap_str[] = {
 116                 "sie"
 117         };
 118         int i, cpu;
 119
 120         seq_printf(m, "vendor_id       : IBM/S390\n"
 121                    "# processors    : %i\n"
 122                    "bogomips per cpu: %lu.%02lu\n",
 123                    num_online_cpus(), loops_per_jiffy/(500000/HZ),
 124                    (loops_per_jiffy/(5000/HZ))%100);
 125         seq_printf(m, "max thread id   : %d\n", smp_cpu_mtid);
 126         seq_puts(m, "features\t: ");
 127         for (i = 0; i < ARRAY_SIZE(hwcap_str); i++)
 128                 if (hwcap_str[i] && (elf_hwcap & (1UL << i)))
 129                         seq_printf(m, "%s ", hwcap_str[i]);
 130         for (i = 0; i < ARRAY_SIZE(int_hwcap_str); i++)
 131                 if (int_hwcap_str[i] && (int_hwcap & (1UL << i)))
 132                         seq_printf(m, "%s ", int_hwcap_str[i]);
 133         seq_puts(m, "\n");
 134         show_facilities(m);
 135         show_cacheinfo(m);
 136         for_each_online_cpu(cpu) {
 137                 struct cpuid *id = &per_cpu(cpu_info.cpu_id, cpu);
 138
 139                 seq_printf(m, "processor %d: "
 140                            "version = %02X,  "
 141                            "identification = %06X,  "
 142                            "machine = %04X\n",
 143                            cpu, id->version, id->ident, id->machine);
 144         }
 145 }
 146
 147 static void show_cpu_mhz(struct seq_file *m, unsigned long n)
 148 {
 149         struct cpu_info *c = per_cpu_ptr(&cpu_info, n);
 150
 151         seq_printf(m, "cpu MHz dynamic : %d\n", c->cpu_mhz_dynamic);
 152         seq_printf(m, "cpu MHz static  : %d\n", c->cpu_mhz_static);
 153 }
 154
 155 /*
 156  * show_cpuinfo - Get information on one CPU for use by procfs.
 157  */
 158 static int show_cpuinfo(struct seq_file *m, void *v)
 159 {
 160         unsigned long n = (unsigned long) v - 1;
 161
 162         if (!n)
 163                 show_cpu_summary(m, v);
 164         if (!machine_has_cpu_mhz)
 165                 return 0;
 166         seq_printf(m, "\ncpu number      : %ld\n", n);
 167         show_cpu_mhz(m, n);
 168         return 0;
 169 }
 170
 171 static inline void *c_update(loff_t *pos)
 172 {
 173         if (*pos)
 174                 *pos = cpumask_next(*pos - 1, cpu_online_mask);
 175         return *pos < nr_cpu_ids ? (void *)*pos + 1 : NULL;
 176 }
 177
 178 static void *c_start(struct seq_file *m, loff_t *pos)
 179 {
 180         get_online_cpus();
 181         return c_update(pos);
 182 }
 183
 184 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 185 {
 186         ++*pos;
 187         return c_update(pos);
 188 }
 189
 190 static void c_stop(struct seq_file *m, void *v)
 191 {
 192         put_online_cpus();
 193 }
 194
 195 const struct seq_operations cpuinfo_op = {
 196         .start  = c_start,
 197         .next   = c_next,
 198         .stop   = c_stop,
 199         .show   = show_cpuinfo,
 200 };
 201
 202 int s390_isolate_bp(void)
 203 {
 204         if (!test_facility(82))
 205                 return -EOPNOTSUPP;
 206         set_thread_flag(TIF_ISOLATE_BP);
 207         return 0;
 208 }
 209 EXPORT_SYMBOL(s390_isolate_bp);
 210
 211 int s390_isolate_bp_guest(void)
 212 {
 213         if (!test_facility(82))
 214                 return -EOPNOTSUPP;
 215         set_thread_flag(TIF_ISOLATE_BP_GUEST);
 216         return 0;
 217 }
 218 EXPORT_SYMBOL(s390_isolate_bp_guest);