arch/s390/kernel/topology.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *    Copyright IBM Corp. 2007, 2011
   4  *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
   5  */
   6
   7 #define KMSG_COMPONENT "cpu"
   8 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
   9
  10 #include <linux/workqueue.h>
  11 #include <linux/memblock.h>
  12 #include <linux/uaccess.h>
  13 #include <linux/sysctl.h>
  14 #include <linux/cpuset.h>
  15 #include <linux/device.h>
  16 #include <linux/export.h>
  17 #include <linux/kernel.h>
  18 #include <linux/sched.h>
  19 #include <linux/sched/topology.h>
  20 #include <linux/delay.h>
  21 #include <linux/init.h>
  22 #include <linux/slab.h>
  23 #include <linux/cpu.h>
  24 #include <linux/smp.h>
  25 #include <linux/mm.h>
  26 #include <linux/nodemask.h>
  27 #include <linux/node.h>
  28 #include <asm/sysinfo.h>
  29
  30 #define PTF_HORIZONTAL  (0UL)
  31 #define PTF_VERTICAL    (1UL)
  32 #define PTF_CHECK       (2UL)
  33
  34 enum {
  35         TOPOLOGY_MODE_HW,
  36         TOPOLOGY_MODE_SINGLE,
  37         TOPOLOGY_MODE_PACKAGE,
  38         TOPOLOGY_MODE_UNINITIALIZED
  39 };
  40
  41 struct mask_info {
  42         struct mask_info *next;
  43         unsigned char id;
  44         cpumask_t mask;
  45 };
  46
  47 static int topology_mode = TOPOLOGY_MODE_UNINITIALIZED;
  48 static void set_topology_timer(void);
  49 static void topology_work_fn(struct work_struct *work);
  50 static struct sysinfo_15_1_x *tl_info;
  51
  52 static DECLARE_WORK(topology_work, topology_work_fn);
  53
  54 /*
  55  * Socket/Book linked lists and cpu_topology updates are
  56  * protected by "sched_domains_mutex".
  57  */
  58 static struct mask_info socket_info;
  59 static struct mask_info book_info;
  60 static struct mask_info drawer_info;
  61
  62 struct cpu_topology_s390 cpu_topology[NR_CPUS];
  63 EXPORT_SYMBOL_GPL(cpu_topology);
  64
  65 static void cpu_group_map(cpumask_t *dst, struct mask_info *info, unsigned int cpu)
  66 {
  67         static cpumask_t mask;
  68
  69         cpumask_copy(&mask, cpumask_of(cpu));
  70         switch (topology_mode) {
  71         case TOPOLOGY_MODE_HW:
  72                 while (info) {
  73                         if (cpumask_test_cpu(cpu, &info->mask)) {
  74                                 cpumask_copy(&mask, &info->mask);
  75                                 break;
  76                         }
  77                         info = info->next;
  78                 }
  79                 if (cpumask_empty(&mask))
  80                         cpumask_copy(&mask, cpumask_of(cpu));
  81                 break;
  82         case TOPOLOGY_MODE_PACKAGE:
  83                 cpumask_copy(&mask, cpu_present_mask);
  84                 break;
  85         default:
  86                 fallthrough;
  87         case TOPOLOGY_MODE_SINGLE:
  88                 cpumask_copy(&mask, cpumask_of(cpu));
  89                 break;
  90         }
  91         cpumask_and(&mask, &mask, cpu_online_mask);
  92         cpumask_copy(dst, &mask);
  93 }
  94
  95 static void cpu_thread_map(cpumask_t *dst, unsigned int cpu)
  96 {
  97         static cpumask_t mask;
  98         int i;
  99
 100         cpumask_copy(&mask, cpumask_of(cpu));
 101         if (topology_mode != TOPOLOGY_MODE_HW)
 102                 goto out;
 103         cpu -= cpu % (smp_cpu_mtid + 1);
 104         for (i = 0; i <= smp_cpu_mtid; i++)
 105                 if (cpu_present(cpu + i))
 106                         cpumask_set_cpu(cpu + i, &mask);
 107         cpumask_and(&mask, &mask, cpu_online_mask);
 108 out:
 109         cpumask_copy(dst, &mask);
 110 }
 111
 112 #define TOPOLOGY_CORE_BITS      64
 113
 114 static void add_cpus_to_mask(struct topology_core *tl_core,
 115                              struct mask_info *drawer,
 116                              struct mask_info *book,
 117                              struct mask_info *socket)
 118 {
 119         struct cpu_topology_s390 *topo;
 120         unsigned int core;
 121
 122         for_each_set_bit(core, &tl_core->mask, TOPOLOGY_CORE_BITS) {
 123                 unsigned int rcore;
 124                 int lcpu, i;
 125
 126                 rcore = TOPOLOGY_CORE_BITS - 1 - core + tl_core->origin;
 127                 lcpu = smp_find_processor_id(rcore << smp_cpu_mt_shift);
 128                 if (lcpu < 0)
 129                         continue;
 130                 for (i = 0; i <= smp_cpu_mtid; i++) {
 131                         topo = &cpu_topology[lcpu + i];
 132                         topo->drawer_id = drawer->id;
 133                         topo->book_id = book->id;
 134                         topo->socket_id = socket->id;
 135                         topo->core_id = rcore;
 136                         topo->thread_id = lcpu + i;
 137                         topo->dedicated = tl_core->d;
 138                         cpumask_set_cpu(lcpu + i, &drawer->mask);
 139                         cpumask_set_cpu(lcpu + i, &book->mask);
 140                         cpumask_set_cpu(lcpu + i, &socket->mask);
 141                         smp_cpu_set_polarization(lcpu + i, tl_core->pp);
 142                 }
 143         }
 144 }
 145
 146 static void clear_masks(void)
 147 {
 148         struct mask_info *info;
 149
 150         info = &socket_info;
 151         while (info) {
 152                 cpumask_clear(&info->mask);
 153                 info = info->next;
 154         }
 155         info = &book_info;
 156         while (info) {
 157                 cpumask_clear(&info->mask);
 158                 info = info->next;
 159         }
 160         info = &drawer_info;
 161         while (info) {
 162                 cpumask_clear(&info->mask);
 163                 info = info->next;
 164         }
 165 }
 166
 167 static union topology_entry *next_tle(union topology_entry *tle)
 168 {
 169         if (!tle->nl)
 170                 return (union topology_entry *)((struct topology_core *)tle + 1);
 171         return (union topology_entry *)((struct topology_container *)tle + 1);
 172 }
 173
 174 static void tl_to_masks(struct sysinfo_15_1_x *info)
 175 {
 176         struct mask_info *socket = &socket_info;
 177         struct mask_info *book = &book_info;
 178         struct mask_info *drawer = &drawer_info;
 179         union topology_entry *tle, *end;
 180
 181         clear_masks();
 182         tle = info->tle;
 183         end = (union topology_entry *)((unsigned long)info + info->length);
 184         while (tle < end) {
 185                 switch (tle->nl) {
 186                 case 3:
 187                         drawer = drawer->next;
 188                         drawer->id = tle->container.id;
 189                         break;
 190                 case 2:
 191                         book = book->next;
 192                         book->id = tle->container.id;
 193                         break;
 194                 case 1:
 195                         socket = socket->next;
 196                         socket->id = tle->container.id;
 197                         break;
 198                 case 0:
 199                         add_cpus_to_mask(&tle->cpu, drawer, book, socket);
 200                         break;
 201                 default:
 202                         clear_masks();
 203                         return;
 204                 }
 205                 tle = next_tle(tle);
 206         }
 207 }
 208
 209 static void topology_update_polarization_simple(void)
 210 {
 211         int cpu;
 212
 213         for_each_possible_cpu(cpu)
 214                 smp_cpu_set_polarization(cpu, POLARIZATION_HRZ);
 215 }
 216
 217 static int ptf(unsigned long fc)
 218 {
 219         int rc;
 220
 221         asm volatile(
 222                 "       .insn   rre,0xb9a20000,%1,%1\n"
 223                 "       ipm     %0\n"
 224                 "       srl     %0,28\n"
 225                 : "=d" (rc)
 226                 : "d" (fc)  : "cc");
 227         return rc;
 228 }
 229
 230 int topology_set_cpu_management(int fc)
 231 {
 232         int cpu, rc;
 233
 234         if (!MACHINE_HAS_TOPOLOGY)
 235                 return -EOPNOTSUPP;
 236         if (fc)
 237                 rc = ptf(PTF_VERTICAL);
 238         else
 239                 rc = ptf(PTF_HORIZONTAL);
 240         if (rc)
 241                 return -EBUSY;
 242         for_each_possible_cpu(cpu)
 243                 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
 244         return rc;
 245 }
 246
 247 void update_cpu_masks(void)
 248 {
 249         struct cpu_topology_s390 *topo, *topo_package, *topo_sibling;
 250         int cpu, sibling, pkg_first, smt_first, id;
 251
 252         for_each_possible_cpu(cpu) {
 253                 topo = &cpu_topology[cpu];
 254                 cpu_thread_map(&topo->thread_mask, cpu);
 255                 cpu_group_map(&topo->core_mask, &socket_info, cpu);
 256                 cpu_group_map(&topo->book_mask, &book_info, cpu);
 257                 cpu_group_map(&topo->drawer_mask, &drawer_info, cpu);
 258                 topo->booted_cores = 0;
 259                 if (topology_mode != TOPOLOGY_MODE_HW) {
 260                         id = topology_mode == TOPOLOGY_MODE_PACKAGE ? 0 : cpu;
 261                         topo->thread_id = cpu;
 262                         topo->core_id = cpu;
 263                         topo->socket_id = id;
 264                         topo->book_id = id;
 265                         topo->drawer_id = id;
 266                 }
 267         }
 268         for_each_online_cpu(cpu) {
 269                 topo = &cpu_topology[cpu];
 270                 pkg_first = cpumask_first(&topo->core_mask);
 271                 topo_package = &cpu_topology[pkg_first];
 272                 if (cpu == pkg_first) {
 273                         for_each_cpu(sibling, &topo->core_mask) {
 274                                 topo_sibling = &cpu_topology[sibling];
 275                                 smt_first = cpumask_first(&topo_sibling->thread_mask);
 276                                 if (sibling == smt_first)
 277                                         topo_package->booted_cores++;
 278                         }
 279                 } else {
 280                         topo->booted_cores = topo_package->booted_cores;
 281                 }
 282         }
 283 }
 284
 285 void store_topology(struct sysinfo_15_1_x *info)
 286 {
 287         stsi(info, 15, 1, topology_mnest_limit());
 288 }
 289
 290 static void __arch_update_dedicated_flag(void *arg)
 291 {
 292         if (topology_cpu_dedicated(smp_processor_id()))
 293                 set_cpu_flag(CIF_DEDICATED_CPU);
 294         else
 295                 clear_cpu_flag(CIF_DEDICATED_CPU);
 296 }
 297
 298 static int __arch_update_cpu_topology(void)
 299 {
 300         struct sysinfo_15_1_x *info = tl_info;
 301         int rc = 0;
 302
 303         mutex_lock(&smp_cpu_state_mutex);
 304         if (MACHINE_HAS_TOPOLOGY) {
 305                 rc = 1;
 306                 store_topology(info);
 307                 tl_to_masks(info);
 308         }
 309         update_cpu_masks();
 310         if (!MACHINE_HAS_TOPOLOGY)
 311                 topology_update_polarization_simple();
 312         mutex_unlock(&smp_cpu_state_mutex);
 313         return rc;
 314 }
 315
 316 int arch_update_cpu_topology(void)
 317 {
 318         struct device *dev;
 319         int cpu, rc;
 320
 321         rc = __arch_update_cpu_topology();
 322         on_each_cpu(__arch_update_dedicated_flag, NULL, 0);
 323         for_each_online_cpu(cpu) {
 324                 dev = get_cpu_device(cpu);
 325                 if (dev)
 326                         kobject_uevent(&dev->kobj, KOBJ_CHANGE);
 327         }
 328         return rc;
 329 }
 330
 331 static void topology_work_fn(struct work_struct *work)
 332 {
 333         rebuild_sched_domains();
 334 }
 335
 336 void topology_schedule_update(void)
 337 {
 338         schedule_work(&topology_work);
 339 }
 340
 341 static void topology_flush_work(void)
 342 {
 343         flush_work(&topology_work);
 344 }
 345
 346 static void topology_timer_fn(struct timer_list *unused)
 347 {
 348         if (ptf(PTF_CHECK))
 349                 topology_schedule_update();
 350         set_topology_timer();
 351 }
 352
 353 static struct timer_list topology_timer;
 354
 355 static atomic_t topology_poll = ATOMIC_INIT(0);
 356
 357 static void set_topology_timer(void)
 358 {
 359         if (atomic_add_unless(&topology_poll, -1, 0))
 360                 mod_timer(&topology_timer, jiffies + msecs_to_jiffies(100));
 361         else
 362                 mod_timer(&topology_timer, jiffies + msecs_to_jiffies(60 * MSEC_PER_SEC));
 363 }
 364
 365 void topology_expect_change(void)
 366 {
 367         if (!MACHINE_HAS_TOPOLOGY)
 368                 return;
 369         /* This is racy, but it doesn't matter since it is just a heuristic.
 370          * Worst case is that we poll in a higher frequency for a bit longer.
 371          */
 372         if (atomic_read(&topology_poll) > 60)
 373                 return;
 374         atomic_add(60, &topology_poll);
 375         set_topology_timer();
 376 }
 377
 378 static int cpu_management;
 379
 380 static ssize_t dispatching_show(struct device *dev,
 381                                 struct device_attribute *attr,
 382                                 char *buf)
 383 {
 384         ssize_t count;
 385
 386         mutex_lock(&smp_cpu_state_mutex);
 387         count = sprintf(buf, "%d\n", cpu_management);
 388         mutex_unlock(&smp_cpu_state_mutex);
 389         return count;
 390 }
 391
 392 static ssize_t dispatching_store(struct device *dev,
 393                                  struct device_attribute *attr,
 394                                  const char *buf,
 395                                  size_t count)
 396 {
 397         int val, rc;
 398         char delim;
 399
 400         if (sscanf(buf, "%d %c", &val, &delim) != 1)
 401                 return -EINVAL;
 402         if (val != 0 && val != 1)
 403                 return -EINVAL;
 404         rc = 0;
 405         get_online_cpus();
 406         mutex_lock(&smp_cpu_state_mutex);
 407         if (cpu_management == val)
 408                 goto out;
 409         rc = topology_set_cpu_management(val);
 410         if (rc)
 411                 goto out;
 412         cpu_management = val;
 413         topology_expect_change();
 414 out:
 415         mutex_unlock(&smp_cpu_state_mutex);
 416         put_online_cpus();
 417         return rc ? rc : count;
 418 }
 419 static DEVICE_ATTR_RW(dispatching);
 420
 421 static ssize_t cpu_polarization_show(struct device *dev,
 422                                      struct device_attribute *attr, char *buf)
 423 {
 424         int cpu = dev->id;
 425         ssize_t count;
 426
 427         mutex_lock(&smp_cpu_state_mutex);
 428         switch (smp_cpu_get_polarization(cpu)) {
 429         case POLARIZATION_HRZ:
 430                 count = sprintf(buf, "horizontal\n");
 431                 break;
 432         case POLARIZATION_VL:
 433                 count = sprintf(buf, "vertical:low\n");
 434                 break;
 435         case POLARIZATION_VM:
 436                 count = sprintf(buf, "vertical:medium\n");
 437                 break;
 438         case POLARIZATION_VH:
 439                 count = sprintf(buf, "vertical:high\n");
 440                 break;
 441         default:
 442                 count = sprintf(buf, "unknown\n");
 443                 break;
 444         }
 445         mutex_unlock(&smp_cpu_state_mutex);
 446         return count;
 447 }
 448 static DEVICE_ATTR(polarization, 0444, cpu_polarization_show, NULL);
 449
 450 static struct attribute *topology_cpu_attrs[] = {
 451         &dev_attr_polarization.attr,
 452         NULL,
 453 };
 454
 455 static struct attribute_group topology_cpu_attr_group = {
 456         .attrs = topology_cpu_attrs,
 457 };
 458
 459 static ssize_t cpu_dedicated_show(struct device *dev,
 460                                   struct device_attribute *attr, char *buf)
 461 {
 462         int cpu = dev->id;
 463         ssize_t count;
 464
 465         mutex_lock(&smp_cpu_state_mutex);
 466         count = sprintf(buf, "%d\n", topology_cpu_dedicated(cpu));
 467         mutex_unlock(&smp_cpu_state_mutex);
 468         return count;
 469 }
 470 static DEVICE_ATTR(dedicated, 0444, cpu_dedicated_show, NULL);
 471
 472 static struct attribute *topology_extra_cpu_attrs[] = {
 473         &dev_attr_dedicated.attr,
 474         NULL,
 475 };
 476
 477 static struct attribute_group topology_extra_cpu_attr_group = {
 478         .attrs = topology_extra_cpu_attrs,
 479 };
 480
 481 int topology_cpu_init(struct cpu *cpu)
 482 {
 483         int rc;
 484
 485         rc = sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
 486         if (rc || !MACHINE_HAS_TOPOLOGY)
 487                 return rc;
 488         rc = sysfs_create_group(&cpu->dev.kobj, &topology_extra_cpu_attr_group);
 489         if (rc)
 490                 sysfs_remove_group(&cpu->dev.kobj, &topology_cpu_attr_group);
 491         return rc;
 492 }
 493
 494 static const struct cpumask *cpu_thread_mask(int cpu)
 495 {
 496         return &cpu_topology[cpu].thread_mask;
 497 }
 498
 499
 500 const struct cpumask *cpu_coregroup_mask(int cpu)
 501 {
 502         return &cpu_topology[cpu].core_mask;
 503 }
 504
 505 static const struct cpumask *cpu_book_mask(int cpu)
 506 {
 507         return &cpu_topology[cpu].book_mask;
 508 }
 509
 510 static const struct cpumask *cpu_drawer_mask(int cpu)
 511 {
 512         return &cpu_topology[cpu].drawer_mask;
 513 }
 514
 515 static struct sched_domain_topology_level s390_topology[] = {
 516         { cpu_thread_mask, cpu_smt_flags, SD_INIT_NAME(SMT) },
 517         { cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) },
 518         { cpu_book_mask, SD_INIT_NAME(BOOK) },
 519         { cpu_drawer_mask, SD_INIT_NAME(DRAWER) },
 520         { cpu_cpu_mask, SD_INIT_NAME(DIE) },
 521         { NULL, },
 522 };
 523
 524 static void __init alloc_masks(struct sysinfo_15_1_x *info,
 525                                struct mask_info *mask, int offset)
 526 {
 527         int i, nr_masks;
 528
 529         nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
 530         for (i = 0; i < info->mnest - offset; i++)
 531                 nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
 532         nr_masks = max(nr_masks, 1);
 533         for (i = 0; i < nr_masks; i++) {
 534                 mask->next = memblock_alloc(sizeof(*mask->next), 8);
 535                 if (!mask->next)
 536                         panic("%s: Failed to allocate %zu bytes align=0x%x\n",
 537                               __func__, sizeof(*mask->next), 8);
 538                 mask = mask->next;
 539         }
 540 }
 541
 542 void __init topology_init_early(void)
 543 {
 544         struct sysinfo_15_1_x *info;
 545
 546         set_sched_topology(s390_topology);
 547         if (topology_mode == TOPOLOGY_MODE_UNINITIALIZED) {
 548                 if (MACHINE_HAS_TOPOLOGY)
 549                         topology_mode = TOPOLOGY_MODE_HW;
 550                 else
 551                         topology_mode = TOPOLOGY_MODE_SINGLE;
 552         }
 553         if (!MACHINE_HAS_TOPOLOGY)
 554                 goto out;
 555         tl_info = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 556         if (!tl_info)
 557                 panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
 558                       __func__, PAGE_SIZE, PAGE_SIZE);
 559         info = tl_info;
 560         store_topology(info);
 561         pr_info("The CPU configuration topology of the machine is: %d %d %d %d %d %d / %d\n",
 562                 info->mag[0], info->mag[1], info->mag[2], info->mag[3],
 563                 info->mag[4], info->mag[5], info->mnest);
 564         alloc_masks(info, &socket_info, 1);
 565         alloc_masks(info, &book_info, 2);
 566         alloc_masks(info, &drawer_info, 3);
 567 out:
 568         __arch_update_cpu_topology();
 569         __arch_update_dedicated_flag(NULL);
 570 }
 571
 572 static inline int topology_get_mode(int enabled)
 573 {
 574         if (!enabled)
 575                 return TOPOLOGY_MODE_SINGLE;
 576         return MACHINE_HAS_TOPOLOGY ? TOPOLOGY_MODE_HW : TOPOLOGY_MODE_PACKAGE;
 577 }
 578
 579 static inline int topology_is_enabled(void)
 580 {
 581         return topology_mode != TOPOLOGY_MODE_SINGLE;
 582 }
 583
 584 static int __init topology_setup(char *str)
 585 {
 586         bool enabled;
 587         int rc;
 588
 589         rc = kstrtobool(str, &enabled);
 590         if (rc)
 591                 return rc;
 592         topology_mode = topology_get_mode(enabled);
 593         return 0;
 594 }
 595 early_param("topology", topology_setup);
 596
 597 static int topology_ctl_handler(struct ctl_table *ctl, int write,
 598                                 void *buffer, size_t *lenp, loff_t *ppos)
 599 {
 600         int enabled = topology_is_enabled();
 601         int new_mode;
 602         int rc;
 603         struct ctl_table ctl_entry = {
 604                 .procname       = ctl->procname,
 605                 .data           = &enabled,
 606                 .maxlen         = sizeof(int),
 607                 .extra1         = SYSCTL_ZERO,
 608                 .extra2         = SYSCTL_ONE,
 609         };
 610
 611         rc = proc_douintvec_minmax(&ctl_entry, write, buffer, lenp, ppos);
 612         if (rc < 0 || !write)
 613                 return rc;
 614
 615         mutex_lock(&smp_cpu_state_mutex);
 616         new_mode = topology_get_mode(enabled);
 617         if (topology_mode != new_mode) {
 618                 topology_mode = new_mode;
 619                 topology_schedule_update();
 620         }
 621         mutex_unlock(&smp_cpu_state_mutex);
 622         topology_flush_work();
 623
 624         return rc;
 625 }
 626
 627 static struct ctl_table topology_ctl_table[] = {
 628         {
 629                 .procname       = "topology",
 630                 .mode           = 0644,
 631                 .proc_handler   = topology_ctl_handler,
 632         },
 633         { },
 634 };
 635
 636 static struct ctl_table topology_dir_table[] = {
 637         {
 638                 .procname       = "s390",
 639                 .maxlen         = 0,
 640                 .mode           = 0555,
 641                 .child          = topology_ctl_table,
 642         },
 643         { },
 644 };
 645
 646 static int __init topology_init(void)
 647 {
 648         timer_setup(&topology_timer, topology_timer_fn, TIMER_DEFERRABLE);
 649         if (MACHINE_HAS_TOPOLOGY)
 650                 set_topology_timer();
 651         else
 652                 topology_update_polarization_simple();
 653         register_sysctl_table(topology_dir_table);
 654         return device_create_file(cpu_subsys.dev_root, &dev_attr_dispatching);
 655 }
 656 device_initcall(topology_init);