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/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 unsigned long int_hwcap;
  34
  35 struct cpu_info {
  36         unsigned int cpu_mhz_dynamic;
  37         unsigned int cpu_mhz_static;
  38         struct cpuid cpu_id;
  39 };
  40
  41 static DEFINE_PER_CPU(struct cpu_info, cpu_info);
  42 static DEFINE_PER_CPU(int, cpu_relax_retry);
  43
  44 static bool machine_has_cpu_mhz;
  45
  46 void __init cpu_detect_mhz_feature(void)
  47 {
  48         if (test_facility(34) && __ecag(ECAG_CPU_ATTRIBUTE, 0) != -1UL)
  49                 machine_has_cpu_mhz = true;
  50 }
  51
  52 static void update_cpu_mhz(void *arg)
  53 {
  54         unsigned long mhz;
  55         struct cpu_info *c;
  56
  57         mhz = __ecag(ECAG_CPU_ATTRIBUTE, 0);
  58         c = this_cpu_ptr(&cpu_info);
  59         c->cpu_mhz_dynamic = mhz >> 32;
  60         c->cpu_mhz_static = mhz & 0xffffffff;
  61 }
  62
  63 void s390_update_cpu_mhz(void)
  64 {
  65         s390_adjust_jiffies();
  66         if (machine_has_cpu_mhz)
  67                 on_each_cpu(update_cpu_mhz, NULL, 0);
  68 }
  69
  70 void notrace stop_machine_yield(const struct cpumask *cpumask)
  71 {
  72         int cpu, this_cpu;
  73
  74         this_cpu = smp_processor_id();
  75         if (__this_cpu_inc_return(cpu_relax_retry) >= spin_retry) {
  76                 __this_cpu_write(cpu_relax_retry, 0);
  77                 cpu = cpumask_next_wrap(this_cpu, cpumask, this_cpu, false);
  78                 if (cpu >= nr_cpu_ids)
  79                         return;
  80                 if (arch_vcpu_is_preempted(cpu))
  81                         smp_yield_cpu(cpu);
  82         }
  83 }
  84
  85 /*
  86  * cpu_init - initializes state that is per-CPU.
  87  */
  88 void cpu_init(void)
  89 {
  90         struct cpuid *id = this_cpu_ptr(&cpu_info.cpu_id);
  91
  92         get_cpu_id(id);
  93         if (machine_has_cpu_mhz)
  94                 update_cpu_mhz(NULL);
  95         mmgrab(&init_mm);
  96         current->active_mm = &init_mm;
  97         BUG_ON(current->mm);
  98         enter_lazy_tlb(&init_mm, current);
  99 }
 100
 101 /*
 102  * cpu_have_feature - Test CPU features on module initialization
 103  */
 104 int cpu_have_feature(unsigned int num)
 105 {
 106         return elf_hwcap & (1UL << num);
 107 }
 108 EXPORT_SYMBOL(cpu_have_feature);
 109
 110 static void show_facilities(struct seq_file *m)
 111 {
 112         unsigned int bit;
 113
 114         seq_puts(m, "facilities      :");
 115         for_each_set_bit_inv(bit, (long *)&stfle_fac_list, MAX_FACILITY_BIT)
 116                 seq_printf(m, " %d", bit);
 117         seq_putc(m, '\n');
 118 }
 119
 120 static void show_cpu_summary(struct seq_file *m, void *v)
 121 {
 122         static const char *hwcap_str[] = {
 123                 [HWCAP_NR_ESAN3]        = "esan3",
 124                 [HWCAP_NR_ZARCH]        = "zarch",
 125                 [HWCAP_NR_STFLE]        = "stfle",
 126                 [HWCAP_NR_MSA]          = "msa",
 127                 [HWCAP_NR_LDISP]        = "ldisp",
 128                 [HWCAP_NR_EIMM]         = "eimm",
 129                 [HWCAP_NR_DFP]          = "dfp",
 130                 [HWCAP_NR_HPAGE]        = "edat",
 131                 [HWCAP_NR_ETF3EH]       = "etf3eh",
 132                 [HWCAP_NR_HIGH_GPRS]    = "highgprs",
 133                 [HWCAP_NR_TE]           = "te",
 134                 [HWCAP_NR_VXRS]         = "vx",
 135                 [HWCAP_NR_VXRS_BCD]     = "vxd",
 136                 [HWCAP_NR_VXRS_EXT]     = "vxe",
 137                 [HWCAP_NR_GS]           = "gs",
 138                 [HWCAP_NR_VXRS_EXT2]    = "vxe2",
 139                 [HWCAP_NR_VXRS_PDE]     = "vxp",
 140                 [HWCAP_NR_SORT]         = "sort",
 141                 [HWCAP_NR_DFLT]         = "dflt",
 142                 [HWCAP_NR_VXRS_PDE2]    = "vxp2",
 143                 [HWCAP_NR_NNPA]         = "nnpa",
 144                 [HWCAP_NR_PCI_MIO]      = "pcimio",
 145         };
 146         static const char * const int_hwcap_str[] = {
 147                 [HWCAP_INT_NR_SIE]      = "sie",
 148         };
 149         int i, cpu;
 150
 151         BUILD_BUG_ON(ARRAY_SIZE(hwcap_str) != HWCAP_NR_MAX);
 152         BUILD_BUG_ON(ARRAY_SIZE(int_hwcap_str) != HWCAP_INT_NR_MAX);
 153         seq_printf(m, "vendor_id       : IBM/S390\n"
 154                    "# processors    : %i\n"
 155                    "bogomips per cpu: %lu.%02lu\n",
 156                    num_online_cpus(), loops_per_jiffy/(500000/HZ),
 157                    (loops_per_jiffy/(5000/HZ))%100);
 158         seq_printf(m, "max thread id   : %d\n", smp_cpu_mtid);
 159         seq_puts(m, "features\t: ");
 160         for (i = 0; i < ARRAY_SIZE(hwcap_str); i++)
 161                 if (hwcap_str[i] && (elf_hwcap & (1UL << i)))
 162                         seq_printf(m, "%s ", hwcap_str[i]);
 163         for (i = 0; i < ARRAY_SIZE(int_hwcap_str); i++)
 164                 if (int_hwcap_str[i] && (int_hwcap & (1UL << i)))
 165                         seq_printf(m, "%s ", int_hwcap_str[i]);
 166         seq_puts(m, "\n");
 167         show_facilities(m);
 168         show_cacheinfo(m);
 169         for_each_online_cpu(cpu) {
 170                 struct cpuid *id = &per_cpu(cpu_info.cpu_id, cpu);
 171
 172                 seq_printf(m, "processor %d: "
 173                            "version = %02X,  "
 174                            "identification = %06X,  "
 175                            "machine = %04X\n",
 176                            cpu, id->version, id->ident, id->machine);
 177         }
 178 }
 179
 180 static int __init setup_hwcaps(void)
 181 {
 182         /* instructions named N3, "backported" to esa-mode */
 183         if (test_facility(0))
 184                 elf_hwcap |= HWCAP_ESAN3;
 185
 186         /* z/Architecture mode active */
 187         elf_hwcap |= HWCAP_ZARCH;
 188
 189         /* store-facility-list-extended */
 190         if (test_facility(7))
 191                 elf_hwcap |= HWCAP_STFLE;
 192
 193         /* message-security assist */
 194         if (test_facility(17))
 195                 elf_hwcap |= HWCAP_MSA;
 196
 197         /* long-displacement */
 198         if (test_facility(19))
 199                 elf_hwcap |= HWCAP_LDISP;
 200
 201         /* extended-immediate */
 202         if (test_facility(21))
 203                 elf_hwcap |= HWCAP_EIMM;
 204
 205         /* extended-translation facility 3 enhancement */
 206         if (test_facility(22) && test_facility(30))
 207                 elf_hwcap |= HWCAP_ETF3EH;
 208
 209         /* decimal floating point & perform floating point operation */
 210         if (test_facility(42) && test_facility(44))
 211                 elf_hwcap |= HWCAP_DFP;
 212
 213         /* huge page support */
 214         if (MACHINE_HAS_EDAT1)
 215                 elf_hwcap |= HWCAP_HPAGE;
 216
 217         /* 64-bit register support for 31-bit processes */
 218         elf_hwcap |= HWCAP_HIGH_GPRS;
 219
 220         /* transactional execution */
 221         if (MACHINE_HAS_TE)
 222                 elf_hwcap |= HWCAP_TE;
 223
 224         /*
 225          * Vector extension can be disabled with the "novx" parameter.
 226          * Use MACHINE_HAS_VX instead of facility bit 129.
 227          */
 228         if (MACHINE_HAS_VX) {
 229                 elf_hwcap |= HWCAP_VXRS;
 230                 if (test_facility(134))
 231                         elf_hwcap |= HWCAP_VXRS_BCD;
 232                 if (test_facility(135))
 233                         elf_hwcap |= HWCAP_VXRS_EXT;
 234                 if (test_facility(148))
 235                         elf_hwcap |= HWCAP_VXRS_EXT2;
 236                 if (test_facility(152))
 237                         elf_hwcap |= HWCAP_VXRS_PDE;
 238                 if (test_facility(192))
 239                         elf_hwcap |= HWCAP_VXRS_PDE2;
 240         }
 241
 242         if (test_facility(150))
 243                 elf_hwcap |= HWCAP_SORT;
 244
 245         if (test_facility(151))
 246                 elf_hwcap |= HWCAP_DFLT;
 247
 248         if (test_facility(165))
 249                 elf_hwcap |= HWCAP_NNPA;
 250
 251         /* guarded storage */
 252         if (MACHINE_HAS_GS)
 253                 elf_hwcap |= HWCAP_GS;
 254
 255         if (MACHINE_HAS_PCI_MIO)
 256                 elf_hwcap |= HWCAP_PCI_MIO;
 257
 258         /* virtualization support */
 259         if (sclp.has_sief2)
 260                 int_hwcap |= HWCAP_INT_SIE;
 261
 262         return 0;
 263 }
 264 arch_initcall(setup_hwcaps);
 265
 266 static int __init setup_elf_platform(void)
 267 {
 268         struct cpuid cpu_id;
 269
 270         get_cpu_id(&cpu_id);
 271         add_device_randomness(&cpu_id, sizeof(cpu_id));
 272         switch (cpu_id.machine) {
 273         case 0x2064:
 274         case 0x2066:
 275         default:        /* Use "z900" as default for 64 bit kernels. */
 276                 strcpy(elf_platform, "z900");
 277                 break;
 278         case 0x2084:
 279         case 0x2086:
 280                 strcpy(elf_platform, "z990");
 281                 break;
 282         case 0x2094:
 283         case 0x2096:
 284                 strcpy(elf_platform, "z9-109");
 285                 break;
 286         case 0x2097:
 287         case 0x2098:
 288                 strcpy(elf_platform, "z10");
 289                 break;
 290         case 0x2817:
 291         case 0x2818:
 292                 strcpy(elf_platform, "z196");
 293                 break;
 294         case 0x2827:
 295         case 0x2828:
 296                 strcpy(elf_platform, "zEC12");
 297                 break;
 298         case 0x2964:
 299         case 0x2965:
 300                 strcpy(elf_platform, "z13");
 301                 break;
 302         case 0x3906:
 303         case 0x3907:
 304                 strcpy(elf_platform, "z14");
 305                 break;
 306         case 0x8561:
 307         case 0x8562:
 308                 strcpy(elf_platform, "z15");
 309                 break;
 310         }
 311         return 0;
 312 }
 313 arch_initcall(setup_elf_platform);
 314
 315 static void show_cpu_topology(struct seq_file *m, unsigned long n)
 316 {
 317 #ifdef CONFIG_SCHED_TOPOLOGY
 318         seq_printf(m, "physical id     : %d\n", topology_physical_package_id(n));
 319         seq_printf(m, "core id         : %d\n", topology_core_id(n));
 320         seq_printf(m, "book id         : %d\n", topology_book_id(n));
 321         seq_printf(m, "drawer id       : %d\n", topology_drawer_id(n));
 322         seq_printf(m, "dedicated       : %d\n", topology_cpu_dedicated(n));
 323         seq_printf(m, "address         : %d\n", smp_cpu_get_cpu_address(n));
 324         seq_printf(m, "siblings        : %d\n", cpumask_weight(topology_core_cpumask(n)));
 325         seq_printf(m, "cpu cores       : %d\n", topology_booted_cores(n));
 326 #endif /* CONFIG_SCHED_TOPOLOGY */
 327 }
 328
 329 static void show_cpu_ids(struct seq_file *m, unsigned long n)
 330 {
 331         struct cpuid *id = &per_cpu(cpu_info.cpu_id, n);
 332
 333         seq_printf(m, "version         : %02X\n", id->version);
 334         seq_printf(m, "identification  : %06X\n", id->ident);
 335         seq_printf(m, "machine         : %04X\n", id->machine);
 336 }
 337
 338 static void show_cpu_mhz(struct seq_file *m, unsigned long n)
 339 {
 340         struct cpu_info *c = per_cpu_ptr(&cpu_info, n);
 341
 342         if (!machine_has_cpu_mhz)
 343                 return;
 344         seq_printf(m, "cpu MHz dynamic : %d\n", c->cpu_mhz_dynamic);
 345         seq_printf(m, "cpu MHz static  : %d\n", c->cpu_mhz_static);
 346 }
 347
 348 /*
 349  * show_cpuinfo - Get information on one CPU for use by procfs.
 350  */
 351 static int show_cpuinfo(struct seq_file *m, void *v)
 352 {
 353         unsigned long n = (unsigned long) v - 1;
 354         unsigned long first = cpumask_first(cpu_online_mask);
 355
 356         if (n == first)
 357                 show_cpu_summary(m, v);
 358         seq_printf(m, "\ncpu number      : %ld\n", n);
 359         show_cpu_topology(m, n);
 360         show_cpu_ids(m, n);
 361         show_cpu_mhz(m, n);
 362         return 0;
 363 }
 364
 365 static inline void *c_update(loff_t *pos)
 366 {
 367         if (*pos)
 368                 *pos = cpumask_next(*pos - 1, cpu_online_mask);
 369         else
 370                 *pos = cpumask_first(cpu_online_mask);
 371         return *pos < nr_cpu_ids ? (void *)*pos + 1 : NULL;
 372 }
 373
 374 static void *c_start(struct seq_file *m, loff_t *pos)
 375 {
 376         get_online_cpus();
 377         return c_update(pos);
 378 }
 379
 380 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 381 {
 382         ++*pos;
 383         return c_update(pos);
 384 }
 385
 386 static void c_stop(struct seq_file *m, void *v)
 387 {
 388         put_online_cpus();
 389 }
 390
 391 const struct seq_operations cpuinfo_op = {
 392         .start  = c_start,
 393         .next   = c_next,
 394         .stop   = c_stop,
 395         .show   = show_cpuinfo,
 396 };
 397
 398 int s390_isolate_bp(void)
 399 {
 400         if (!test_facility(82))
 401                 return -EOPNOTSUPP;
 402         set_thread_flag(TIF_ISOLATE_BP);
 403         return 0;
 404 }
 405 EXPORT_SYMBOL(s390_isolate_bp);
 406
 407 int s390_isolate_bp_guest(void)
 408 {
 409         if (!test_facility(82))
 410                 return -EOPNOTSUPP;
 411         set_thread_flag(TIF_ISOLATE_BP_GUEST);
 412         return 0;
 413 }
 414 EXPORT_SYMBOL(s390_isolate_bp_guest);