arch/s390/kernel/processor.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Copyright IBM Corp. 2008
   4  *  Author(s): Martin Schwidefsky ([email protected])
   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/random.h>
  15 #include <linux/sched/mm.h>
  16 #include <linux/init.h>
  17 #include <linux/seq_file.h>
  18 #include <linux/mm_types.h>
  19 #include <linux/delay.h>
  20 #include <linux/cpu.h>
  21
  22 #include <asm/diag.h>
  23 #include <asm/facility.h>
  24 #include <asm/elf.h>
  25 #include <asm/lowcore.h>
  26 #include <asm/param.h>
  27 #include <asm/sclp.h>
  28 #include <asm/smp.h>
  29
  30 unsigned long __read_mostly elf_hwcap;
  31 char elf_platform[ELF_PLATFORM_SIZE];
  32
  33 struct cpu_info {
  34         unsigned int cpu_mhz_dynamic;
  35         unsigned int cpu_mhz_static;
  36         struct cpuid cpu_id;
  37 };
  38
  39 static DEFINE_PER_CPU(struct cpu_info, cpu_info);
  40 static DEFINE_PER_CPU(int, cpu_relax_retry);
  41
  42 static bool machine_has_cpu_mhz;
  43
  44 void __init cpu_detect_mhz_feature(void)
  45 {
  46         if (test_facility(34) && __ecag(ECAG_CPU_ATTRIBUTE, 0) != -1UL)
  47                 machine_has_cpu_mhz = true;
  48 }
  49
  50 static void update_cpu_mhz(void *arg)
  51 {
  52         unsigned long mhz;
  53         struct cpu_info *c;
  54
  55         mhz = __ecag(ECAG_CPU_ATTRIBUTE, 0);
  56         c = this_cpu_ptr(&cpu_info);
  57         c->cpu_mhz_dynamic = mhz >> 32;
  58         c->cpu_mhz_static = mhz & 0xffffffff;
  59 }
  60
  61 void s390_update_cpu_mhz(void)
  62 {
  63         s390_adjust_jiffies();
  64         if (machine_has_cpu_mhz)
  65                 on_each_cpu(update_cpu_mhz, NULL, 0);
  66 }
  67
  68 void notrace stop_machine_yield(const struct cpumask *cpumask)
  69 {
  70         int cpu, this_cpu;
  71
  72         this_cpu = smp_processor_id();
  73         if (__this_cpu_inc_return(cpu_relax_retry) >= spin_retry) {
  74                 __this_cpu_write(cpu_relax_retry, 0);
  75                 cpu = cpumask_next_wrap(this_cpu, cpumask, this_cpu, false);
  76                 if (cpu >= nr_cpu_ids)
  77                         return;
  78                 if (arch_vcpu_is_preempted(cpu))
  79                         smp_yield_cpu(cpu);
  80         }
  81 }
  82
  83 /*
  84  * cpu_init - initializes state that is per-CPU.
  85  */
  86 void cpu_init(void)
  87 {
  88         struct cpuid *id = this_cpu_ptr(&cpu_info.cpu_id);
  89
  90         get_cpu_id(id);
  91         if (machine_has_cpu_mhz)
  92                 update_cpu_mhz(NULL);
  93         mmgrab(&init_mm);
  94         current->active_mm = &init_mm;
  95         BUG_ON(current->mm);
  96         enter_lazy_tlb(&init_mm, current);
  97 }
  98
  99 /*
 100  * cpu_have_feature - Test CPU features on module initialization
 101  */
 102 int cpu_have_feature(unsigned int num)
 103 {
 104         return elf_hwcap & (1UL << num);
 105 }
 106 EXPORT_SYMBOL(cpu_have_feature);
 107
 108 static void show_facilities(struct seq_file *m)
 109 {
 110         unsigned int bit;
 111
 112         seq_puts(m, "facilities      :");
 113         for_each_set_bit_inv(bit, (long *)&stfle_fac_list, MAX_FACILITY_BIT)
 114                 seq_printf(m, " %d", bit);
 115         seq_putc(m, '\n');
 116 }
 117
 118 static void show_cpu_summary(struct seq_file *m, void *v)
 119 {
 120         static const char *hwcap_str[] = {
 121                 [HWCAP_NR_ESAN3]        = "esan3",
 122                 [HWCAP_NR_ZARCH]        = "zarch",
 123                 [HWCAP_NR_STFLE]        = "stfle",
 124                 [HWCAP_NR_MSA]          = "msa",
 125                 [HWCAP_NR_LDISP]        = "ldisp",
 126                 [HWCAP_NR_EIMM]         = "eimm",
 127                 [HWCAP_NR_DFP]          = "dfp",
 128                 [HWCAP_NR_HPAGE]        = "edat",
 129                 [HWCAP_NR_ETF3EH]       = "etf3eh",
 130                 [HWCAP_NR_HIGH_GPRS]    = "highgprs",
 131                 [HWCAP_NR_TE]           = "te",
 132                 [HWCAP_NR_VXRS]         = "vx",
 133                 [HWCAP_NR_VXRS_BCD]     = "vxd",
 134                 [HWCAP_NR_VXRS_EXT]     = "vxe",
 135                 [HWCAP_NR_GS]           = "gs",
 136                 [HWCAP_NR_VXRS_EXT2]    = "vxe2",
 137                 [HWCAP_NR_VXRS_PDE]     = "vxp",
 138                 [HWCAP_NR_SORT]         = "sort",
 139                 [HWCAP_NR_DFLT]         = "dflt",
 140                 [HWCAP_NR_VXRS_PDE2]    = "vxp2",
 141                 [HWCAP_NR_NNPA]         = "nnpa",
 142                 [HWCAP_NR_PCI_MIO]      = "pcimio",
 143                 [HWCAP_NR_SIE]          = "sie",
 144         };
 145         int i, cpu;
 146
 147         BUILD_BUG_ON(ARRAY_SIZE(hwcap_str) != HWCAP_NR_MAX);
 148         seq_printf(m, "vendor_id       : IBM/S390\n"
 149                    "# processors    : %i\n"
 150                    "bogomips per cpu: %lu.%02lu\n",
 151                    num_online_cpus(), loops_per_jiffy/(500000/HZ),
 152                    (loops_per_jiffy/(5000/HZ))%100);
 153         seq_printf(m, "max thread id   : %d\n", smp_cpu_mtid);
 154         seq_puts(m, "features\t: ");
 155         for (i = 0; i < ARRAY_SIZE(hwcap_str); i++)
 156                 if (hwcap_str[i] && (elf_hwcap & (1UL << i)))
 157                         seq_printf(m, "%s ", hwcap_str[i]);
 158         seq_puts(m, "\n");
 159         show_facilities(m);
 160         show_cacheinfo(m);
 161         for_each_online_cpu(cpu) {
 162                 struct cpuid *id = &per_cpu(cpu_info.cpu_id, cpu);
 163
 164                 seq_printf(m, "processor %d: "
 165                            "version = %02X,  "
 166                            "identification = %06X,  "
 167                            "machine = %04X\n",
 168                            cpu, id->version, id->ident, id->machine);
 169         }
 170 }
 171
 172 static int __init setup_hwcaps(void)
 173 {
 174         /* instructions named N3, "backported" to esa-mode */
 175         elf_hwcap |= HWCAP_ESAN3;
 176
 177         /* z/Architecture mode active */
 178         elf_hwcap |= HWCAP_ZARCH;
 179
 180         /* store-facility-list-extended */
 181         if (test_facility(7))
 182                 elf_hwcap |= HWCAP_STFLE;
 183
 184         /* message-security assist */
 185         if (test_facility(17))
 186                 elf_hwcap |= HWCAP_MSA;
 187
 188         /* long-displacement */
 189         if (test_facility(19))
 190                 elf_hwcap |= HWCAP_LDISP;
 191
 192         /* extended-immediate */
 193         elf_hwcap |= HWCAP_EIMM;
 194
 195         /* extended-translation facility 3 enhancement */
 196         if (test_facility(22) && test_facility(30))
 197                 elf_hwcap |= HWCAP_ETF3EH;
 198
 199         /* decimal floating point & perform floating point operation */
 200         if (test_facility(42) && test_facility(44))
 201                 elf_hwcap |= HWCAP_DFP;
 202
 203         /* huge page support */
 204         if (MACHINE_HAS_EDAT1)
 205                 elf_hwcap |= HWCAP_HPAGE;
 206
 207         /* 64-bit register support for 31-bit processes */
 208         elf_hwcap |= HWCAP_HIGH_GPRS;
 209
 210         /* transactional execution */
 211         if (MACHINE_HAS_TE)
 212                 elf_hwcap |= HWCAP_TE;
 213
 214         /*
 215          * Vector extension can be disabled with the "novx" parameter.
 216          * Use MACHINE_HAS_VX instead of facility bit 129.
 217          */
 218         if (MACHINE_HAS_VX) {
 219                 elf_hwcap |= HWCAP_VXRS;
 220                 if (test_facility(134))
 221                         elf_hwcap |= HWCAP_VXRS_BCD;
 222                 if (test_facility(135))
 223                         elf_hwcap |= HWCAP_VXRS_EXT;
 224                 if (test_facility(148))
 225                         elf_hwcap |= HWCAP_VXRS_EXT2;
 226                 if (test_facility(152))
 227                         elf_hwcap |= HWCAP_VXRS_PDE;
 228                 if (test_facility(192))
 229                         elf_hwcap |= HWCAP_VXRS_PDE2;
 230         }
 231
 232         if (test_facility(150))
 233                 elf_hwcap |= HWCAP_SORT;
 234
 235         if (test_facility(151))
 236                 elf_hwcap |= HWCAP_DFLT;
 237
 238         if (test_facility(165))
 239                 elf_hwcap |= HWCAP_NNPA;
 240
 241         /* guarded storage */
 242         if (MACHINE_HAS_GS)
 243                 elf_hwcap |= HWCAP_GS;
 244
 245         if (MACHINE_HAS_PCI_MIO)
 246                 elf_hwcap |= HWCAP_PCI_MIO;
 247
 248         /* virtualization support */
 249         if (sclp.has_sief2)
 250                 elf_hwcap |= HWCAP_SIE;
 251
 252         return 0;
 253 }
 254 arch_initcall(setup_hwcaps);
 255
 256 static int __init setup_elf_platform(void)
 257 {
 258         struct cpuid cpu_id;
 259
 260         get_cpu_id(&cpu_id);
 261         add_device_randomness(&cpu_id, sizeof(cpu_id));
 262         switch (cpu_id.machine) {
 263         default:        /* Use "z10" as default. */
 264                 strcpy(elf_platform, "z10");
 265                 break;
 266         case 0x2817:
 267         case 0x2818:
 268                 strcpy(elf_platform, "z196");
 269                 break;
 270         case 0x2827:
 271         case 0x2828:
 272                 strcpy(elf_platform, "zEC12");
 273                 break;
 274         case 0x2964:
 275         case 0x2965:
 276                 strcpy(elf_platform, "z13");
 277                 break;
 278         case 0x3906:
 279         case 0x3907:
 280                 strcpy(elf_platform, "z14");
 281                 break;
 282         case 0x8561:
 283         case 0x8562:
 284                 strcpy(elf_platform, "z15");
 285                 break;
 286         case 0x3931:
 287         case 0x3932:
 288                 strcpy(elf_platform, "z16");
 289                 break;
 290         }
 291         return 0;
 292 }
 293 arch_initcall(setup_elf_platform);
 294
 295 static void show_cpu_topology(struct seq_file *m, unsigned long n)
 296 {
 297 #ifdef CONFIG_SCHED_TOPOLOGY
 298         seq_printf(m, "physical id     : %d\n", topology_physical_package_id(n));
 299         seq_printf(m, "core id         : %d\n", topology_core_id(n));
 300         seq_printf(m, "book id         : %d\n", topology_book_id(n));
 301         seq_printf(m, "drawer id       : %d\n", topology_drawer_id(n));
 302         seq_printf(m, "dedicated       : %d\n", topology_cpu_dedicated(n));
 303         seq_printf(m, "address         : %d\n", smp_cpu_get_cpu_address(n));
 304         seq_printf(m, "siblings        : %d\n", cpumask_weight(topology_core_cpumask(n)));
 305         seq_printf(m, "cpu cores       : %d\n", topology_booted_cores(n));
 306 #endif /* CONFIG_SCHED_TOPOLOGY */
 307 }
 308
 309 static void show_cpu_ids(struct seq_file *m, unsigned long n)
 310 {
 311         struct cpuid *id = &per_cpu(cpu_info.cpu_id, n);
 312
 313         seq_printf(m, "version         : %02X\n", id->version);
 314         seq_printf(m, "identification  : %06X\n", id->ident);
 315         seq_printf(m, "machine         : %04X\n", id->machine);
 316 }
 317
 318 static void show_cpu_mhz(struct seq_file *m, unsigned long n)
 319 {
 320         struct cpu_info *c = per_cpu_ptr(&cpu_info, n);
 321
 322         if (!machine_has_cpu_mhz)
 323                 return;
 324         seq_printf(m, "cpu MHz dynamic : %d\n", c->cpu_mhz_dynamic);
 325         seq_printf(m, "cpu MHz static  : %d\n", c->cpu_mhz_static);
 326 }
 327
 328 /*
 329  * show_cpuinfo - Get information on one CPU for use by procfs.
 330  */
 331 static int show_cpuinfo(struct seq_file *m, void *v)
 332 {
 333         unsigned long n = (unsigned long) v - 1;
 334         unsigned long first = cpumask_first(cpu_online_mask);
 335
 336         if (n == first)
 337                 show_cpu_summary(m, v);
 338         seq_printf(m, "\ncpu number      : %ld\n", n);
 339         show_cpu_topology(m, n);
 340         show_cpu_ids(m, n);
 341         show_cpu_mhz(m, n);
 342         return 0;
 343 }
 344
 345 static inline void *c_update(loff_t *pos)
 346 {
 347         if (*pos)
 348                 *pos = cpumask_next(*pos - 1, cpu_online_mask);
 349         else
 350                 *pos = cpumask_first(cpu_online_mask);
 351         return *pos < nr_cpu_ids ? (void *)*pos + 1 : NULL;
 352 }
 353
 354 static void *c_start(struct seq_file *m, loff_t *pos)
 355 {
 356         cpus_read_lock();
 357         return c_update(pos);
 358 }
 359
 360 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 361 {
 362         ++*pos;
 363         return c_update(pos);
 364 }
 365
 366 static void c_stop(struct seq_file *m, void *v)
 367 {
 368         cpus_read_unlock();
 369 }
 370
 371 const struct seq_operations cpuinfo_op = {
 372         .start  = c_start,
 373         .next   = c_next,
 374         .stop   = c_stop,
 375         .show   = show_cpuinfo,
 376 };
 377
 378 int s390_isolate_bp(void)
 379 {
 380         if (!test_facility(82))
 381                 return -EOPNOTSUPP;
 382         set_thread_flag(TIF_ISOLATE_BP);
 383         return 0;
 384 }
 385 EXPORT_SYMBOL(s390_isolate_bp);
 386
 387 int s390_isolate_bp_guest(void)
 388 {
 389         if (!test_facility(82))
 390                 return -EOPNOTSUPP;
 391         set_thread_flag(TIF_ISOLATE_BP_GUEST);
 392         return 0;
 393 }
 394 EXPORT_SYMBOL(s390_isolate_bp_guest);