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