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 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         if (test_facility(0))
 176                 elf_hwcap |= HWCAP_ESAN3;
 177
 178         /* z/Architecture mode active */
 179         elf_hwcap |= HWCAP_ZARCH;
 180
 181         /* store-facility-list-extended */
 182         if (test_facility(7))
 183                 elf_hwcap |= HWCAP_STFLE;
 184
 185         /* message-security assist */
 186         if (test_facility(17))
 187                 elf_hwcap |= HWCAP_MSA;
 188
 189         /* long-displacement */
 190         if (test_facility(19))
 191                 elf_hwcap |= HWCAP_LDISP;
 192
 193         /* extended-immediate */
 194         if (test_facility(21))
 195                 elf_hwcap |= HWCAP_EIMM;
 196
 197         /* extended-translation facility 3 enhancement */
 198         if (test_facility(22) && test_facility(30))
 199                 elf_hwcap |= HWCAP_ETF3EH;
 200
 201         /* decimal floating point & perform floating point operation */
 202         if (test_facility(42) && test_facility(44))
 203                 elf_hwcap |= HWCAP_DFP;
 204
 205         /* huge page support */
 206         if (MACHINE_HAS_EDAT1)
 207                 elf_hwcap |= HWCAP_HPAGE;
 208
 209         /* 64-bit register support for 31-bit processes */
 210         elf_hwcap |= HWCAP_HIGH_GPRS;
 211
 212         /* transactional execution */
 213         if (MACHINE_HAS_TE)
 214                 elf_hwcap |= HWCAP_TE;
 215
 216         /*
 217          * Vector extension can be disabled with the "novx" parameter.
 218          * Use MACHINE_HAS_VX instead of facility bit 129.
 219          */
 220         if (MACHINE_HAS_VX) {
 221                 elf_hwcap |= HWCAP_VXRS;
 222                 if (test_facility(134))
 223                         elf_hwcap |= HWCAP_VXRS_BCD;
 224                 if (test_facility(135))
 225                         elf_hwcap |= HWCAP_VXRS_EXT;
 226                 if (test_facility(148))
 227                         elf_hwcap |= HWCAP_VXRS_EXT2;
 228                 if (test_facility(152))
 229                         elf_hwcap |= HWCAP_VXRS_PDE;
 230                 if (test_facility(192))
 231                         elf_hwcap |= HWCAP_VXRS_PDE2;
 232         }
 233
 234         if (test_facility(150))
 235                 elf_hwcap |= HWCAP_SORT;
 236
 237         if (test_facility(151))
 238                 elf_hwcap |= HWCAP_DFLT;
 239
 240         if (test_facility(165))
 241                 elf_hwcap |= HWCAP_NNPA;
 242
 243         /* guarded storage */
 244         if (MACHINE_HAS_GS)
 245                 elf_hwcap |= HWCAP_GS;
 246
 247         if (MACHINE_HAS_PCI_MIO)
 248                 elf_hwcap |= HWCAP_PCI_MIO;
 249
 250         /* virtualization support */
 251         if (sclp.has_sief2)
 252                 elf_hwcap |= HWCAP_SIE;
 253
 254         return 0;
 255 }
 256 arch_initcall(setup_hwcaps);
 257
 258 static int __init setup_elf_platform(void)
 259 {
 260         struct cpuid cpu_id;
 261
 262         get_cpu_id(&cpu_id);
 263         add_device_randomness(&cpu_id, sizeof(cpu_id));
 264         switch (cpu_id.machine) {
 265         case 0x2064:
 266         case 0x2066:
 267         default:        /* Use "z900" as default for 64 bit kernels. */
 268                 strcpy(elf_platform, "z900");
 269                 break;
 270         case 0x2084:
 271         case 0x2086:
 272                 strcpy(elf_platform, "z990");
 273                 break;
 274         case 0x2094:
 275         case 0x2096:
 276                 strcpy(elf_platform, "z9-109");
 277                 break;
 278         case 0x2097:
 279         case 0x2098:
 280                 strcpy(elf_platform, "z10");
 281                 break;
 282         case 0x2817:
 283         case 0x2818:
 284                 strcpy(elf_platform, "z196");
 285                 break;
 286         case 0x2827:
 287         case 0x2828:
 288                 strcpy(elf_platform, "zEC12");
 289                 break;
 290         case 0x2964:
 291         case 0x2965:
 292                 strcpy(elf_platform, "z13");
 293                 break;
 294         case 0x3906:
 295         case 0x3907:
 296                 strcpy(elf_platform, "z14");
 297                 break;
 298         case 0x8561:
 299         case 0x8562:
 300                 strcpy(elf_platform, "z15");
 301                 break;
 302         }
 303         return 0;
 304 }
 305 arch_initcall(setup_elf_platform);
 306
 307 static void show_cpu_topology(struct seq_file *m, unsigned long n)
 308 {
 309 #ifdef CONFIG_SCHED_TOPOLOGY
 310         seq_printf(m, "physical id     : %d\n", topology_physical_package_id(n));
 311         seq_printf(m, "core id         : %d\n", topology_core_id(n));
 312         seq_printf(m, "book id         : %d\n", topology_book_id(n));
 313         seq_printf(m, "drawer id       : %d\n", topology_drawer_id(n));
 314         seq_printf(m, "dedicated       : %d\n", topology_cpu_dedicated(n));
 315         seq_printf(m, "address         : %d\n", smp_cpu_get_cpu_address(n));
 316         seq_printf(m, "siblings        : %d\n", cpumask_weight(topology_core_cpumask(n)));
 317         seq_printf(m, "cpu cores       : %d\n", topology_booted_cores(n));
 318 #endif /* CONFIG_SCHED_TOPOLOGY */
 319 }
 320
 321 static void show_cpu_ids(struct seq_file *m, unsigned long n)
 322 {
 323         struct cpuid *id = &per_cpu(cpu_info.cpu_id, n);
 324
 325         seq_printf(m, "version         : %02X\n", id->version);
 326         seq_printf(m, "identification  : %06X\n", id->ident);
 327         seq_printf(m, "machine         : %04X\n", id->machine);
 328 }
 329
 330 static void show_cpu_mhz(struct seq_file *m, unsigned long n)
 331 {
 332         struct cpu_info *c = per_cpu_ptr(&cpu_info, n);
 333
 334         if (!machine_has_cpu_mhz)
 335                 return;
 336         seq_printf(m, "cpu MHz dynamic : %d\n", c->cpu_mhz_dynamic);
 337         seq_printf(m, "cpu MHz static  : %d\n", c->cpu_mhz_static);
 338 }
 339
 340 /*
 341  * show_cpuinfo - Get information on one CPU for use by procfs.
 342  */
 343 static int show_cpuinfo(struct seq_file *m, void *v)
 344 {
 345         unsigned long n = (unsigned long) v - 1;
 346         unsigned long first = cpumask_first(cpu_online_mask);
 347
 348         if (n == first)
 349                 show_cpu_summary(m, v);
 350         seq_printf(m, "\ncpu number      : %ld\n", n);
 351         show_cpu_topology(m, n);
 352         show_cpu_ids(m, n);
 353         show_cpu_mhz(m, n);
 354         return 0;
 355 }
 356
 357 static inline void *c_update(loff_t *pos)
 358 {
 359         if (*pos)
 360                 *pos = cpumask_next(*pos - 1, cpu_online_mask);
 361         else
 362                 *pos = cpumask_first(cpu_online_mask);
 363         return *pos < nr_cpu_ids ? (void *)*pos + 1 : NULL;
 364 }
 365
 366 static void *c_start(struct seq_file *m, loff_t *pos)
 367 {
 368         cpus_read_lock();
 369         return c_update(pos);
 370 }
 371
 372 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 373 {
 374         ++*pos;
 375         return c_update(pos);
 376 }
 377
 378 static void c_stop(struct seq_file *m, void *v)
 379 {
 380         cpus_read_unlock();
 381 }
 382
 383 const struct seq_operations cpuinfo_op = {
 384         .start  = c_start,
 385         .next   = c_next,
 386         .stop   = c_stop,
 387         .show   = show_cpuinfo,
 388 };
 389
 390 int s390_isolate_bp(void)
 391 {
 392         if (!test_facility(82))
 393                 return -EOPNOTSUPP;
 394         set_thread_flag(TIF_ISOLATE_BP);
 395         return 0;
 396 }
 397 EXPORT_SYMBOL(s390_isolate_bp);
 398
 399 int s390_isolate_bp_guest(void)
 400 {
 401         if (!test_facility(82))
 402                 return -EOPNOTSUPP;
 403         set_thread_flag(TIF_ISOLATE_BP_GUEST);
 404         return 0;
 405 }
 406 EXPORT_SYMBOL(s390_isolate_bp_guest);