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