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