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/stop_machine.h>
  11 #include <linux/cpufeature.h>
  12 #include <linux/bitops.h>
  13 #include <linux/kernel.h>
  14 #include <linux/sched/mm.h>
  15 #include <linux/init.h>
  16 #include <linux/seq_file.h>
  17 #include <linux/mm_types.h>
  18 #include <linux/delay.h>
  19 #include <linux/cpu.h>
  20
  21 #include <asm/diag.h>
  22 #include <asm/facility.h>
  23 #include <asm/elf.h>
  24 #include <asm/lowcore.h>
  25 #include <asm/param.h>
  26 #include <asm/smp.h>
  27
  28 struct cpu_info {
  29         unsigned int cpu_mhz_dynamic;
  30         unsigned int cpu_mhz_static;
  31         struct cpuid cpu_id;
  32 };
  33
  34 static DEFINE_PER_CPU(struct cpu_info, cpu_info);
  35 static DEFINE_PER_CPU(int, cpu_relax_retry);
  36
  37 static bool machine_has_cpu_mhz;
  38
  39 void __init cpu_detect_mhz_feature(void)
  40 {
  41         if (test_facility(34) && __ecag(ECAG_CPU_ATTRIBUTE, 0) != -1UL)
  42                 machine_has_cpu_mhz = true;
  43 }
  44
  45 static void update_cpu_mhz(void *arg)
  46 {
  47         unsigned long mhz;
  48         struct cpu_info *c;
  49
  50         mhz = __ecag(ECAG_CPU_ATTRIBUTE, 0);
  51         c = this_cpu_ptr(&cpu_info);
  52         c->cpu_mhz_dynamic = mhz >> 32;
  53         c->cpu_mhz_static = mhz & 0xffffffff;
  54 }
  55
  56 void s390_update_cpu_mhz(void)
  57 {
  58         s390_adjust_jiffies();
  59         if (machine_has_cpu_mhz)
  60                 on_each_cpu(update_cpu_mhz, NULL, 0);
  61 }
  62
  63 void notrace stop_machine_yield(const struct cpumask *cpumask)
  64 {
  65         int cpu, this_cpu;
  66
  67         this_cpu = smp_processor_id();
  68         if (__this_cpu_inc_return(cpu_relax_retry) >= spin_retry) {
  69                 __this_cpu_write(cpu_relax_retry, 0);
  70                 cpu = cpumask_next_wrap(this_cpu, cpumask, this_cpu, false);
  71                 if (cpu >= nr_cpu_ids)
  72                         return;
  73                 if (arch_vcpu_is_preempted(cpu))
  74                         smp_yield_cpu(cpu);
  75         }
  76 }
  77
  78 /*
  79  * cpu_init - initializes state that is per-CPU.
  80  */
  81 void cpu_init(void)
  82 {
  83         struct cpuid *id = this_cpu_ptr(&cpu_info.cpu_id);
  84
  85         get_cpu_id(id);
  86         if (machine_has_cpu_mhz)
  87                 update_cpu_mhz(NULL);
  88         mmgrab(&init_mm);
  89         current->active_mm = &init_mm;
  90         BUG_ON(current->mm);
  91         enter_lazy_tlb(&init_mm, current);
  92 }
  93
  94 /*
  95  * cpu_have_feature - Test CPU features on module initialization
  96  */
  97 int cpu_have_feature(unsigned int num)
  98 {
  99         return elf_hwcap & (1UL << num);
 100 }
 101 EXPORT_SYMBOL(cpu_have_feature);
 102
 103 static void show_facilities(struct seq_file *m)
 104 {
 105         unsigned int bit;
 106         long *facilities;
 107
 108         facilities = (long *)&S390_lowcore.stfle_fac_list;
 109         seq_puts(m, "facilities      :");
 110         for_each_set_bit_inv(bit, facilities, MAX_FACILITY_BIT)
 111                 seq_printf(m, " %d", bit);
 112         seq_putc(m, '\n');
 113 }
 114
 115 static void show_cpu_summary(struct seq_file *m, void *v)
 116 {
 117         static const char *hwcap_str[] = {
 118                 "esan3", "zarch", "stfle", "msa", "ldisp", "eimm", "dfp",
 119                 "edat", "etf3eh", "highgprs", "te", "vx", "vxd", "vxe", "gs",
 120                 "vxe2", "vxp", "sort", "dflt"
 121         };
 122         static const char * const int_hwcap_str[] = {
 123                 "sie"
 124         };
 125         int i, cpu;
 126
 127         seq_printf(m, "vendor_id       : IBM/S390\n"
 128                    "# processors    : %i\n"
 129                    "bogomips per cpu: %lu.%02lu\n",
 130                    num_online_cpus(), loops_per_jiffy/(500000/HZ),
 131                    (loops_per_jiffy/(5000/HZ))%100);
 132         seq_printf(m, "max thread id   : %d\n", smp_cpu_mtid);
 133         seq_puts(m, "features\t: ");
 134         for (i = 0; i < ARRAY_SIZE(hwcap_str); i++)
 135                 if (hwcap_str[i] && (elf_hwcap & (1UL << i)))
 136                         seq_printf(m, "%s ", hwcap_str[i]);
 137         for (i = 0; i < ARRAY_SIZE(int_hwcap_str); i++)
 138                 if (int_hwcap_str[i] && (int_hwcap & (1UL << i)))
 139                         seq_printf(m, "%s ", int_hwcap_str[i]);
 140         seq_puts(m, "\n");
 141         show_facilities(m);
 142         show_cacheinfo(m);
 143         for_each_online_cpu(cpu) {
 144                 struct cpuid *id = &per_cpu(cpu_info.cpu_id, cpu);
 145
 146                 seq_printf(m, "processor %d: "
 147                            "version = %02X,  "
 148                            "identification = %06X,  "
 149                            "machine = %04X\n",
 150                            cpu, id->version, id->ident, id->machine);
 151         }
 152 }
 153
 154 static void show_cpu_topology(struct seq_file *m, unsigned long n)
 155 {
 156 #ifdef CONFIG_SCHED_TOPOLOGY
 157         seq_printf(m, "physical id     : %d\n", topology_physical_package_id(n));
 158         seq_printf(m, "core id         : %d\n", topology_core_id(n));
 159         seq_printf(m, "book id         : %d\n", topology_book_id(n));
 160         seq_printf(m, "drawer id       : %d\n", topology_drawer_id(n));
 161         seq_printf(m, "dedicated       : %d\n", topology_cpu_dedicated(n));
 162         seq_printf(m, "address         : %d\n", smp_cpu_get_cpu_address(n));
 163         seq_printf(m, "siblings        : %d\n", cpumask_weight(topology_core_cpumask(n)));
 164         seq_printf(m, "cpu cores       : %d\n", topology_booted_cores(n));
 165 #endif /* CONFIG_SCHED_TOPOLOGY */
 166 }
 167
 168 static void show_cpu_ids(struct seq_file *m, unsigned long n)
 169 {
 170         struct cpuid *id = &per_cpu(cpu_info.cpu_id, n);
 171
 172         seq_printf(m, "version         : %02X\n", id->version);
 173         seq_printf(m, "identification  : %06X\n", id->ident);
 174         seq_printf(m, "machine         : %04X\n", id->machine);
 175 }
 176
 177 static void show_cpu_mhz(struct seq_file *m, unsigned long n)
 178 {
 179         struct cpu_info *c = per_cpu_ptr(&cpu_info, n);
 180
 181         if (!machine_has_cpu_mhz)
 182                 return;
 183         seq_printf(m, "cpu MHz dynamic : %d\n", c->cpu_mhz_dynamic);
 184         seq_printf(m, "cpu MHz static  : %d\n", c->cpu_mhz_static);
 185 }
 186
 187 /*
 188  * show_cpuinfo - Get information on one CPU for use by procfs.
 189  */
 190 static int show_cpuinfo(struct seq_file *m, void *v)
 191 {
 192         unsigned long n = (unsigned long) v - 1;
 193         unsigned long first = cpumask_first(cpu_online_mask);
 194
 195         if (n == first)
 196                 show_cpu_summary(m, v);
 197         seq_printf(m, "\ncpu number      : %ld\n", n);
 198         show_cpu_topology(m, n);
 199         show_cpu_ids(m, n);
 200         show_cpu_mhz(m, n);
 201         return 0;
 202 }
 203
 204 static inline void *c_update(loff_t *pos)
 205 {
 206         if (*pos)
 207                 *pos = cpumask_next(*pos - 1, cpu_online_mask);
 208         else
 209                 *pos = cpumask_first(cpu_online_mask);
 210         return *pos < nr_cpu_ids ? (void *)*pos + 1 : NULL;
 211 }
 212
 213 static void *c_start(struct seq_file *m, loff_t *pos)
 214 {
 215         get_online_cpus();
 216         return c_update(pos);
 217 }
 218
 219 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 220 {
 221         ++*pos;
 222         return c_update(pos);
 223 }
 224
 225 static void c_stop(struct seq_file *m, void *v)
 226 {
 227         put_online_cpus();
 228 }
 229
 230 const struct seq_operations cpuinfo_op = {
 231         .start  = c_start,
 232         .next   = c_next,
 233         .stop   = c_stop,
 234         .show   = show_cpuinfo,
 235 };
 236
 237 int s390_isolate_bp(void)
 238 {
 239         if (!test_facility(82))
 240                 return -EOPNOTSUPP;
 241         set_thread_flag(TIF_ISOLATE_BP);
 242         return 0;
 243 }
 244 EXPORT_SYMBOL(s390_isolate_bp);
 245
 246 int s390_isolate_bp_guest(void)
 247 {
 248         if (!test_facility(82))
 249                 return -EOPNOTSUPP;
 250         set_thread_flag(TIF_ISOLATE_BP_GUEST);
 251         return 0;
 252 }
 253 EXPORT_SYMBOL(s390_isolate_bp_guest);