kernel/arch/s390/kernel/topology.c

   1 /*
   2  *    Copyright IBM Corp. 2007, 2011
   3  *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
   4  */
   5
   6 #define KMSG_COMPONENT "cpu"
   7 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
   8
   9 #include <linux/workqueue.h>
  10 #include <linux/cpuset.h>
  11 #include <linux/device.h>
  12 #include <linux/export.h>
  13 #include <linux/kernel.h>
  14 #include <linux/sched.h>
  15 #include <linux/delay.h>
  16 #include <linux/init.h>
  17 #include <linux/slab.h>
  18 #include <linux/cpu.h>
  19 #include <linux/smp.h>
  20 #include <linux/mm.h>
  21 #include <asm/sysinfo.h>
  22
  23 #define PTF_HORIZONTAL  (0UL)
  24 #define PTF_VERTICAL    (1UL)
  25 #define PTF_CHECK       (2UL)
  26
  27 struct mask_info {
  28         struct mask_info *next;
  29         unsigned char id;
  30         cpumask_t mask;
  31 };
  32
  33 static void set_topology_timer(void);
  34 static void topology_work_fn(struct work_struct *work);
  35 static struct sysinfo_15_1_x *tl_info;
  36
  37 static int topology_enabled = 1;
  38 static DECLARE_WORK(topology_work, topology_work_fn);
  39
  40 /* topology_lock protects the socket and book linked lists */
  41 static DEFINE_SPINLOCK(topology_lock);
  42 static struct mask_info socket_info;
  43 static struct mask_info book_info;
  44
  45 DEFINE_PER_CPU(struct cpu_topology_s390, cpu_topology);
  46 EXPORT_PER_CPU_SYMBOL_GPL(cpu_topology);
  47
  48 static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
  49 {
  50         cpumask_t mask;
  51
  52         cpumask_copy(&mask, cpumask_of(cpu));
  53         if (!topology_enabled || !MACHINE_HAS_TOPOLOGY)
  54                 return mask;
  55         for (; info; info = info->next) {
  56                 if (cpumask_test_cpu(cpu, &info->mask))
  57                         return info->mask;
  58         }
  59         return mask;
  60 }
  61
  62 static cpumask_t cpu_thread_map(unsigned int cpu)
  63 {
  64         cpumask_t mask;
  65         int i;
  66
  67         cpumask_copy(&mask, cpumask_of(cpu));
  68         if (!topology_enabled || !MACHINE_HAS_TOPOLOGY)
  69                 return mask;
  70         cpu -= cpu % (smp_cpu_mtid + 1);
  71         for (i = 0; i <= smp_cpu_mtid; i++)
  72                 if (cpu_present(cpu + i))
  73                         cpumask_set_cpu(cpu + i, &mask);
  74         return mask;
  75 }
  76
  77 static struct mask_info *add_cpus_to_mask(struct topology_core *tl_core,
  78                                           struct mask_info *book,
  79                                           struct mask_info *socket,
  80                                           int one_socket_per_cpu)
  81 {
  82         unsigned int core;
  83
  84         for_each_set_bit(core, &tl_core->mask[0], TOPOLOGY_CORE_BITS) {
  85                 unsigned int rcore;
  86                 int lcpu, i;
  87
  88                 rcore = TOPOLOGY_CORE_BITS - 1 - core + tl_core->origin;
  89                 lcpu = smp_find_processor_id(rcore << smp_cpu_mt_shift);
  90                 if (lcpu < 0)
  91                         continue;
  92                 for (i = 0; i <= smp_cpu_mtid; i++) {
  93                         per_cpu(cpu_topology, lcpu + i).book_id = book->id;
  94                         per_cpu(cpu_topology, lcpu + i).core_id = rcore;
  95                         per_cpu(cpu_topology, lcpu + i).thread_id = lcpu + i;
  96                         cpumask_set_cpu(lcpu + i, &book->mask);
  97                         cpumask_set_cpu(lcpu + i, &socket->mask);
  98                         if (one_socket_per_cpu)
  99                                 per_cpu(cpu_topology, lcpu + i).socket_id = rcore;
 100                         else
 101                                 per_cpu(cpu_topology, lcpu + i).socket_id = socket->id;
 102                         smp_cpu_set_polarization(lcpu + i, tl_core->pp);
 103                 }
 104                 if (one_socket_per_cpu)
 105                         socket = socket->next;
 106         }
 107         return socket;
 108 }
 109
 110 static void clear_masks(void)
 111 {
 112         struct mask_info *info;
 113
 114         info = &socket_info;
 115         while (info) {
 116                 cpumask_clear(&info->mask);
 117                 info = info->next;
 118         }
 119         info = &book_info;
 120         while (info) {
 121                 cpumask_clear(&info->mask);
 122                 info = info->next;
 123         }
 124 }
 125
 126 static union topology_entry *next_tle(union topology_entry *tle)
 127 {
 128         if (!tle->nl)
 129                 return (union topology_entry *)((struct topology_core *)tle + 1);
 130         return (union topology_entry *)((struct topology_container *)tle + 1);
 131 }
 132
 133 static void __tl_to_masks_generic(struct sysinfo_15_1_x *info)
 134 {
 135         struct mask_info *socket = &socket_info;
 136         struct mask_info *book = &book_info;
 137         union topology_entry *tle, *end;
 138
 139         tle = info->tle;
 140         end = (union topology_entry *)((unsigned long)info + info->length);
 141         while (tle < end) {
 142                 switch (tle->nl) {
 143                 case 2:
 144                         book = book->next;
 145                         book->id = tle->container.id;
 146                         break;
 147                 case 1:
 148                         socket = socket->next;
 149                         socket->id = tle->container.id;
 150                         break;
 151                 case 0:
 152                         add_cpus_to_mask(&tle->cpu, book, socket, 0);
 153                         break;
 154                 default:
 155                         clear_masks();
 156                         return;
 157                 }
 158                 tle = next_tle(tle);
 159         }
 160 }
 161
 162 static void __tl_to_masks_z10(struct sysinfo_15_1_x *info)
 163 {
 164         struct mask_info *socket = &socket_info;
 165         struct mask_info *book = &book_info;
 166         union topology_entry *tle, *end;
 167
 168         tle = info->tle;
 169         end = (union topology_entry *)((unsigned long)info + info->length);
 170         while (tle < end) {
 171                 switch (tle->nl) {
 172                 case 1:
 173                         book = book->next;
 174                         book->id = tle->container.id;
 175                         break;
 176                 case 0:
 177                         socket = add_cpus_to_mask(&tle->cpu, book, socket, 1);
 178                         break;
 179                 default:
 180                         clear_masks();
 181                         return;
 182                 }
 183                 tle = next_tle(tle);
 184         }
 185 }
 186
 187 static void tl_to_masks(struct sysinfo_15_1_x *info)
 188 {
 189         struct cpuid cpu_id;
 190
 191         spin_lock_irq(&topology_lock);
 192         get_cpu_id(&cpu_id);
 193         clear_masks();
 194         switch (cpu_id.machine) {
 195         case 0x2097:
 196         case 0x2098:
 197                 __tl_to_masks_z10(info);
 198                 break;
 199         default:
 200                 __tl_to_masks_generic(info);
 201         }
 202         spin_unlock_irq(&topology_lock);
 203 }
 204
 205 static void topology_update_polarization_simple(void)
 206 {
 207         int cpu;
 208
 209         mutex_lock(&smp_cpu_state_mutex);
 210         for_each_possible_cpu(cpu)
 211                 smp_cpu_set_polarization(cpu, POLARIZATION_HRZ);
 212         mutex_unlock(&smp_cpu_state_mutex);
 213 }
 214
 215 static int ptf(unsigned long fc)
 216 {
 217         int rc;
 218
 219         asm volatile(
 220                 "       .insn   rre,0xb9a20000,%1,%1\n"
 221                 "       ipm     %0\n"
 222                 "       srl     %0,28\n"
 223                 : "=d" (rc)
 224                 : "d" (fc)  : "cc");
 225         return rc;
 226 }
 227
 228 int topology_set_cpu_management(int fc)
 229 {
 230         int cpu, rc;
 231
 232         if (!MACHINE_HAS_TOPOLOGY)
 233                 return -EOPNOTSUPP;
 234         if (fc)
 235                 rc = ptf(PTF_VERTICAL);
 236         else
 237                 rc = ptf(PTF_HORIZONTAL);
 238         if (rc)
 239                 return -EBUSY;
 240         for_each_possible_cpu(cpu)
 241                 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
 242         return rc;
 243 }
 244
 245 static void update_cpu_masks(void)
 246 {
 247         unsigned long flags;
 248         int cpu;
 249
 250         spin_lock_irqsave(&topology_lock, flags);
 251         for_each_possible_cpu(cpu) {
 252                 per_cpu(cpu_topology, cpu).thread_mask = cpu_thread_map(cpu);
 253                 per_cpu(cpu_topology, cpu).core_mask = cpu_group_map(&socket_info, cpu);
 254                 per_cpu(cpu_topology, cpu).book_mask = cpu_group_map(&book_info, cpu);
 255                 if (!MACHINE_HAS_TOPOLOGY) {
 256                         per_cpu(cpu_topology, cpu).thread_id = cpu;
 257                         per_cpu(cpu_topology, cpu).core_id = cpu;
 258                         per_cpu(cpu_topology, cpu).socket_id = cpu;
 259                         per_cpu(cpu_topology, cpu).book_id = cpu;
 260                 }
 261         }
 262         spin_unlock_irqrestore(&topology_lock, flags);
 263 }
 264
 265 void store_topology(struct sysinfo_15_1_x *info)
 266 {
 267         if (topology_max_mnest >= 3)
 268                 stsi(info, 15, 1, 3);
 269         else
 270                 stsi(info, 15, 1, 2);
 271 }
 272
 273 int arch_update_cpu_topology(void)
 274 {
 275         struct sysinfo_15_1_x *info = tl_info;
 276         struct device *dev;
 277         int cpu;
 278
 279         if (!MACHINE_HAS_TOPOLOGY) {
 280                 update_cpu_masks();
 281                 topology_update_polarization_simple();
 282                 return 0;
 283         }
 284         store_topology(info);
 285         tl_to_masks(info);
 286         update_cpu_masks();
 287         for_each_online_cpu(cpu) {
 288                 dev = get_cpu_device(cpu);
 289                 kobject_uevent(&dev->kobj, KOBJ_CHANGE);
 290         }
 291         return 1;
 292 }
 293
 294 static void topology_work_fn(struct work_struct *work)
 295 {
 296         rebuild_sched_domains();
 297 }
 298
 299 void topology_schedule_update(void)
 300 {
 301         schedule_work(&topology_work);
 302 }
 303
 304 static void topology_timer_fn(unsigned long ignored)
 305 {
 306         if (ptf(PTF_CHECK))
 307                 topology_schedule_update();
 308         set_topology_timer();
 309 }
 310
 311 static struct timer_list topology_timer =
 312         TIMER_DEFERRED_INITIALIZER(topology_timer_fn, 0, 0);
 313
 314 static atomic_t topology_poll = ATOMIC_INIT(0);
 315
 316 static void set_topology_timer(void)
 317 {
 318         if (atomic_add_unless(&topology_poll, -1, 0))
 319                 mod_timer(&topology_timer, jiffies + HZ / 10);
 320         else
 321                 mod_timer(&topology_timer, jiffies + HZ * 60);
 322 }
 323
 324 void topology_expect_change(void)
 325 {
 326         if (!MACHINE_HAS_TOPOLOGY)
 327                 return;
 328         /* This is racy, but it doesn't matter since it is just a heuristic.
 329          * Worst case is that we poll in a higher frequency for a bit longer.
 330          */
 331         if (atomic_read(&topology_poll) > 60)
 332                 return;
 333         atomic_add(60, &topology_poll);
 334         set_topology_timer();
 335 }
 336
 337 static int cpu_management;
 338
 339 static ssize_t dispatching_show(struct device *dev,
 340                                 struct device_attribute *attr,
 341                                 char *buf)
 342 {
 343         ssize_t count;
 344
 345         mutex_lock(&smp_cpu_state_mutex);
 346         count = sprintf(buf, "%d\n", cpu_management);
 347         mutex_unlock(&smp_cpu_state_mutex);
 348         return count;
 349 }
 350
 351 static ssize_t dispatching_store(struct device *dev,
 352                                  struct device_attribute *attr,
 353                                  const char *buf,
 354                                  size_t count)
 355 {
 356         int val, rc;
 357         char delim;
 358
 359         if (sscanf(buf, "%d %c", &val, &delim) != 1)
 360                 return -EINVAL;
 361         if (val != 0 && val != 1)
 362                 return -EINVAL;
 363         rc = 0;
 364         get_online_cpus();
 365         mutex_lock(&smp_cpu_state_mutex);
 366         if (cpu_management == val)
 367                 goto out;
 368         rc = topology_set_cpu_management(val);
 369         if (rc)
 370                 goto out;
 371         cpu_management = val;
 372         topology_expect_change();
 373 out:
 374         mutex_unlock(&smp_cpu_state_mutex);
 375         put_online_cpus();
 376         return rc ? rc : count;
 377 }
 378 static DEVICE_ATTR(dispatching, 0644, dispatching_show,
 379                          dispatching_store);
 380
 381 static ssize_t cpu_polarization_show(struct device *dev,
 382                                      struct device_attribute *attr, char *buf)
 383 {
 384         int cpu = dev->id;
 385         ssize_t count;
 386
 387         mutex_lock(&smp_cpu_state_mutex);
 388         switch (smp_cpu_get_polarization(cpu)) {
 389         case POLARIZATION_HRZ:
 390                 count = sprintf(buf, "horizontal\n");
 391                 break;
 392         case POLARIZATION_VL:
 393                 count = sprintf(buf, "vertical:low\n");
 394                 break;
 395         case POLARIZATION_VM:
 396                 count = sprintf(buf, "vertical:medium\n");
 397                 break;
 398         case POLARIZATION_VH:
 399                 count = sprintf(buf, "vertical:high\n");
 400                 break;
 401         default:
 402                 count = sprintf(buf, "unknown\n");
 403                 break;
 404         }
 405         mutex_unlock(&smp_cpu_state_mutex);
 406         return count;
 407 }
 408 static DEVICE_ATTR(polarization, 0444, cpu_polarization_show, NULL);
 409
 410 static struct attribute *topology_cpu_attrs[] = {
 411         &dev_attr_polarization.attr,
 412         NULL,
 413 };
 414
 415 static struct attribute_group topology_cpu_attr_group = {
 416         .attrs = topology_cpu_attrs,
 417 };
 418
 419 int topology_cpu_init(struct cpu *cpu)
 420 {
 421         return sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
 422 }
 423
 424 static const struct cpumask *cpu_thread_mask(int cpu)
 425 {
 426         return &per_cpu(cpu_topology, cpu).thread_mask;
 427 }
 428
 429
 430 const struct cpumask *cpu_coregroup_mask(int cpu)
 431 {
 432         return &per_cpu(cpu_topology, cpu).core_mask;
 433 }
 434
 435 static const struct cpumask *cpu_book_mask(int cpu)
 436 {
 437         return &per_cpu(cpu_topology, cpu).book_mask;
 438 }
 439
 440 static int __init early_parse_topology(char *p)
 441 {
 442         if (strncmp(p, "off", 3))
 443                 return 0;
 444         topology_enabled = 0;
 445         return 0;
 446 }
 447 early_param("topology", early_parse_topology);
 448
 449 static struct sched_domain_topology_level s390_topology[] = {
 450         { cpu_thread_mask, cpu_smt_flags, SD_INIT_NAME(SMT) },
 451         { cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) },
 452         { cpu_book_mask, SD_INIT_NAME(BOOK) },
 453         { cpu_cpu_mask, SD_INIT_NAME(DIE) },
 454         { NULL, },
 455 };
 456
 457 static void __init alloc_masks(struct sysinfo_15_1_x *info,
 458                                struct mask_info *mask, int offset)
 459 {
 460         int i, nr_masks;
 461
 462         nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
 463         for (i = 0; i < info->mnest - offset; i++)
 464                 nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
 465         nr_masks = max(nr_masks, 1);
 466         for (i = 0; i < nr_masks; i++) {
 467                 mask->next = kzalloc(sizeof(*mask->next), GFP_KERNEL);
 468                 mask = mask->next;
 469         }
 470 }
 471
 472 static int __init s390_topology_init(void)
 473 {
 474         struct sysinfo_15_1_x *info;
 475         int i;
 476
 477         if (!MACHINE_HAS_TOPOLOGY)
 478                 return 0;
 479         tl_info = (struct sysinfo_15_1_x *)__get_free_page(GFP_KERNEL);
 480         info = tl_info;
 481         store_topology(info);
 482         pr_info("The CPU configuration topology of the machine is:");
 483         for (i = 0; i < TOPOLOGY_NR_MAG; i++)
 484                 printk(KERN_CONT " %d", info->mag[i]);
 485         printk(KERN_CONT " / %d\n", info->mnest);
 486         alloc_masks(info, &socket_info, 1);
 487         alloc_masks(info, &book_info, 2);
 488         set_sched_topology(s390_topology);
 489         return 0;
 490 }
 491 early_initcall(s390_topology_init);
 492
 493 static int __init topology_init(void)
 494 {
 495         if (MACHINE_HAS_TOPOLOGY)
 496                 set_topology_timer();
 497         else
 498                 topology_update_polarization_simple();
 499         return device_create_file(cpu_subsys.dev_root, &dev_attr_dispatching);
 500 }
 501 device_initcall(topology_init);