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 <linux/nodemask.h>
  22 #include <linux/node.h>
  23 #include <asm/sysinfo.h>
  24 #include <asm/numa.h>
  25
  26 #define PTF_HORIZONTAL  (0UL)
  27 #define PTF_VERTICAL    (1UL)
  28 #define PTF_CHECK       (2UL)
  29
  30 struct mask_info {
  31         struct mask_info *next;
  32         unsigned char id;
  33         cpumask_t mask;
  34 };
  35
  36 static void set_topology_timer(void);
  37 static void topology_work_fn(struct work_struct *work);
  38 static struct sysinfo_15_1_x *tl_info;
  39
  40 static int topology_enabled = 1;
  41 static DECLARE_WORK(topology_work, topology_work_fn);
  42
  43 /*
  44  * Socket/Book linked lists and per_cpu(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
  50 DEFINE_PER_CPU(struct cpu_topology_s390, cpu_topology);
  51 EXPORT_PER_CPU_SYMBOL_GPL(cpu_topology);
  52
  53 static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
  54 {
  55         cpumask_t mask;
  56
  57         cpumask_copy(&mask, cpumask_of(cpu));
  58         if (!topology_enabled || !MACHINE_HAS_TOPOLOGY)
  59                 return mask;
  60         for (; info; info = info->next) {
  61                 if (cpumask_test_cpu(cpu, &info->mask))
  62                         return info->mask;
  63         }
  64         return mask;
  65 }
  66
  67 static cpumask_t cpu_thread_map(unsigned int cpu)
  68 {
  69         cpumask_t mask;
  70         int i;
  71
  72         cpumask_copy(&mask, cpumask_of(cpu));
  73         if (!topology_enabled || !MACHINE_HAS_TOPOLOGY)
  74                 return mask;
  75         cpu -= cpu % (smp_cpu_mtid + 1);
  76         for (i = 0; i <= smp_cpu_mtid; i++)
  77                 if (cpu_present(cpu + i))
  78                         cpumask_set_cpu(cpu + i, &mask);
  79         return mask;
  80 }
  81
  82 static struct mask_info *add_cpus_to_mask(struct topology_core *tl_core,
  83                                           struct mask_info *book,
  84                                           struct mask_info *socket,
  85                                           int one_socket_per_cpu)
  86 {
  87         struct cpu_topology_s390 *topo;
  88         unsigned int core;
  89
  90         for_each_set_bit(core, &tl_core->mask[0], TOPOLOGY_CORE_BITS) {
  91                 unsigned int rcore;
  92                 int lcpu, i;
  93
  94                 rcore = TOPOLOGY_CORE_BITS - 1 - core + tl_core->origin;
  95                 lcpu = smp_find_processor_id(rcore << smp_cpu_mt_shift);
  96                 if (lcpu < 0)
  97                         continue;
  98                 for (i = 0; i <= smp_cpu_mtid; i++) {
  99                         topo = &per_cpu(cpu_topology, lcpu + i);
 100                         topo->book_id = book->id;
 101                         topo->core_id = rcore;
 102                         topo->thread_id = lcpu + i;
 103                         cpumask_set_cpu(lcpu + i, &book->mask);
 104                         cpumask_set_cpu(lcpu + i, &socket->mask);
 105                         if (one_socket_per_cpu)
 106                                 topo->socket_id = rcore;
 107                         else
 108                                 topo->socket_id = socket->id;
 109                         smp_cpu_set_polarization(lcpu + i, tl_core->pp);
 110                 }
 111                 if (one_socket_per_cpu)
 112                         socket = socket->next;
 113         }
 114         return socket;
 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 }
 132
 133 static union topology_entry *next_tle(union topology_entry *tle)
 134 {
 135         if (!tle->nl)
 136                 return (union topology_entry *)((struct topology_core *)tle + 1);
 137         return (union topology_entry *)((struct topology_container *)tle + 1);
 138 }
 139
 140 static void __tl_to_masks_generic(struct sysinfo_15_1_x *info)
 141 {
 142         struct mask_info *socket = &socket_info;
 143         struct mask_info *book = &book_info;
 144         union topology_entry *tle, *end;
 145
 146         tle = info->tle;
 147         end = (union topology_entry *)((unsigned long)info + info->length);
 148         while (tle < end) {
 149                 switch (tle->nl) {
 150                 case 2:
 151                         book = book->next;
 152                         book->id = tle->container.id;
 153                         break;
 154                 case 1:
 155                         socket = socket->next;
 156                         socket->id = tle->container.id;
 157                         break;
 158                 case 0:
 159                         add_cpus_to_mask(&tle->cpu, book, socket, 0);
 160                         break;
 161                 default:
 162                         clear_masks();
 163                         return;
 164                 }
 165                 tle = next_tle(tle);
 166         }
 167 }
 168
 169 static void __tl_to_masks_z10(struct sysinfo_15_1_x *info)
 170 {
 171         struct mask_info *socket = &socket_info;
 172         struct mask_info *book = &book_info;
 173         union topology_entry *tle, *end;
 174
 175         tle = info->tle;
 176         end = (union topology_entry *)((unsigned long)info + info->length);
 177         while (tle < end) {
 178                 switch (tle->nl) {
 179                 case 1:
 180                         book = book->next;
 181                         book->id = tle->container.id;
 182                         break;
 183                 case 0:
 184                         socket = add_cpus_to_mask(&tle->cpu, book, socket, 1);
 185                         break;
 186                 default:
 187                         clear_masks();
 188                         return;
 189                 }
 190                 tle = next_tle(tle);
 191         }
 192 }
 193
 194 static void tl_to_masks(struct sysinfo_15_1_x *info)
 195 {
 196         struct cpuid cpu_id;
 197
 198         get_cpu_id(&cpu_id);
 199         clear_masks();
 200         switch (cpu_id.machine) {
 201         case 0x2097:
 202         case 0x2098:
 203                 __tl_to_masks_z10(info);
 204                 break;
 205         default:
 206                 __tl_to_masks_generic(info);
 207         }
 208 }
 209
 210 static void topology_update_polarization_simple(void)
 211 {
 212         int cpu;
 213
 214         mutex_lock(&smp_cpu_state_mutex);
 215         for_each_possible_cpu(cpu)
 216                 smp_cpu_set_polarization(cpu, POLARIZATION_HRZ);
 217         mutex_unlock(&smp_cpu_state_mutex);
 218 }
 219
 220 static int ptf(unsigned long fc)
 221 {
 222         int rc;
 223
 224         asm volatile(
 225                 "       .insn   rre,0xb9a20000,%1,%1\n"
 226                 "       ipm     %0\n"
 227                 "       srl     %0,28\n"
 228                 : "=d" (rc)
 229                 : "d" (fc)  : "cc");
 230         return rc;
 231 }
 232
 233 int topology_set_cpu_management(int fc)
 234 {
 235         int cpu, rc;
 236
 237         if (!MACHINE_HAS_TOPOLOGY)
 238                 return -EOPNOTSUPP;
 239         if (fc)
 240                 rc = ptf(PTF_VERTICAL);
 241         else
 242                 rc = ptf(PTF_HORIZONTAL);
 243         if (rc)
 244                 return -EBUSY;
 245         for_each_possible_cpu(cpu)
 246                 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
 247         return rc;
 248 }
 249
 250 static void update_cpu_masks(void)
 251 {
 252         struct cpu_topology_s390 *topo;
 253         int cpu;
 254
 255         for_each_possible_cpu(cpu) {
 256                 topo = &per_cpu(cpu_topology, cpu);
 257                 topo->thread_mask = cpu_thread_map(cpu);
 258                 topo->core_mask = cpu_group_map(&socket_info, cpu);
 259                 topo->book_mask = cpu_group_map(&book_info, cpu);
 260                 if (!MACHINE_HAS_TOPOLOGY) {
 261                         topo->thread_id = cpu;
 262                         topo->core_id = cpu;
 263                         topo->socket_id = cpu;
 264                         topo->book_id = cpu;
 265                 }
 266         }
 267         numa_update_cpu_topology();
 268 }
 269
 270 void store_topology(struct sysinfo_15_1_x *info)
 271 {
 272         if (topology_max_mnest >= 3)
 273                 stsi(info, 15, 1, 3);
 274         else
 275                 stsi(info, 15, 1, 2);
 276 }
 277
 278 int arch_update_cpu_topology(void)
 279 {
 280         struct sysinfo_15_1_x *info = tl_info;
 281         struct device *dev;
 282         int cpu, rc = 0;
 283
 284         if (MACHINE_HAS_TOPOLOGY) {
 285                 rc = 1;
 286                 store_topology(info);
 287                 tl_to_masks(info);
 288         }
 289         update_cpu_masks();
 290         if (!MACHINE_HAS_TOPOLOGY)
 291                 topology_update_polarization_simple();
 292         for_each_online_cpu(cpu) {
 293                 dev = get_cpu_device(cpu);
 294                 kobject_uevent(&dev->kobj, KOBJ_CHANGE);
 295         }
 296         return rc;
 297 }
 298
 299 static void topology_work_fn(struct work_struct *work)
 300 {
 301         rebuild_sched_domains();
 302 }
 303
 304 void topology_schedule_update(void)
 305 {
 306         schedule_work(&topology_work);
 307 }
 308
 309 static void topology_timer_fn(unsigned long ignored)
 310 {
 311         if (ptf(PTF_CHECK))
 312                 topology_schedule_update();
 313         set_topology_timer();
 314 }
 315
 316 static struct timer_list topology_timer =
 317         TIMER_DEFERRED_INITIALIZER(topology_timer_fn, 0, 0);
 318
 319 static atomic_t topology_poll = ATOMIC_INIT(0);
 320
 321 static void set_topology_timer(void)
 322 {
 323         if (atomic_add_unless(&topology_poll, -1, 0))
 324                 mod_timer(&topology_timer, jiffies + HZ / 10);
 325         else
 326                 mod_timer(&topology_timer, jiffies + HZ * 60);
 327 }
 328
 329 void topology_expect_change(void)
 330 {
 331         if (!MACHINE_HAS_TOPOLOGY)
 332                 return;
 333         /* This is racy, but it doesn't matter since it is just a heuristic.
 334          * Worst case is that we poll in a higher frequency for a bit longer.
 335          */
 336         if (atomic_read(&topology_poll) > 60)
 337                 return;
 338         atomic_add(60, &topology_poll);
 339         set_topology_timer();
 340 }
 341
 342 static int cpu_management;
 343
 344 static ssize_t dispatching_show(struct device *dev,
 345                                 struct device_attribute *attr,
 346                                 char *buf)
 347 {
 348         ssize_t count;
 349
 350         mutex_lock(&smp_cpu_state_mutex);
 351         count = sprintf(buf, "%d\n", cpu_management);
 352         mutex_unlock(&smp_cpu_state_mutex);
 353         return count;
 354 }
 355
 356 static ssize_t dispatching_store(struct device *dev,
 357                                  struct device_attribute *attr,
 358                                  const char *buf,
 359                                  size_t count)
 360 {
 361         int val, rc;
 362         char delim;
 363
 364         if (sscanf(buf, "%d %c", &val, &delim) != 1)
 365                 return -EINVAL;
 366         if (val != 0 && val != 1)
 367                 return -EINVAL;
 368         rc = 0;
 369         get_online_cpus();
 370         mutex_lock(&smp_cpu_state_mutex);
 371         if (cpu_management == val)
 372                 goto out;
 373         rc = topology_set_cpu_management(val);
 374         if (rc)
 375                 goto out;
 376         cpu_management = val;
 377         topology_expect_change();
 378 out:
 379         mutex_unlock(&smp_cpu_state_mutex);
 380         put_online_cpus();
 381         return rc ? rc : count;
 382 }
 383 static DEVICE_ATTR(dispatching, 0644, dispatching_show,
 384                          dispatching_store);
 385
 386 static ssize_t cpu_polarization_show(struct device *dev,
 387                                      struct device_attribute *attr, char *buf)
 388 {
 389         int cpu = dev->id;
 390         ssize_t count;
 391
 392         mutex_lock(&smp_cpu_state_mutex);
 393         switch (smp_cpu_get_polarization(cpu)) {
 394         case POLARIZATION_HRZ:
 395                 count = sprintf(buf, "horizontal\n");
 396                 break;
 397         case POLARIZATION_VL:
 398                 count = sprintf(buf, "vertical:low\n");
 399                 break;
 400         case POLARIZATION_VM:
 401                 count = sprintf(buf, "vertical:medium\n");
 402                 break;
 403         case POLARIZATION_VH:
 404                 count = sprintf(buf, "vertical:high\n");
 405                 break;
 406         default:
 407                 count = sprintf(buf, "unknown\n");
 408                 break;
 409         }
 410         mutex_unlock(&smp_cpu_state_mutex);
 411         return count;
 412 }
 413 static DEVICE_ATTR(polarization, 0444, cpu_polarization_show, NULL);
 414
 415 static struct attribute *topology_cpu_attrs[] = {
 416         &dev_attr_polarization.attr,
 417         NULL,
 418 };
 419
 420 static struct attribute_group topology_cpu_attr_group = {
 421         .attrs = topology_cpu_attrs,
 422 };
 423
 424 int topology_cpu_init(struct cpu *cpu)
 425 {
 426         return sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
 427 }
 428
 429 static const struct cpumask *cpu_thread_mask(int cpu)
 430 {
 431         return &per_cpu(cpu_topology, cpu).thread_mask;
 432 }
 433
 434
 435 const struct cpumask *cpu_coregroup_mask(int cpu)
 436 {
 437         return &per_cpu(cpu_topology, cpu).core_mask;
 438 }
 439
 440 static const struct cpumask *cpu_book_mask(int cpu)
 441 {
 442         return &per_cpu(cpu_topology, cpu).book_mask;
 443 }
 444
 445 static int __init early_parse_topology(char *p)
 446 {
 447         if (strncmp(p, "off", 3))
 448                 return 0;
 449         topology_enabled = 0;
 450         return 0;
 451 }
 452 early_param("topology", early_parse_topology);
 453
 454 static struct sched_domain_topology_level s390_topology[] = {
 455         { cpu_thread_mask, cpu_smt_flags, SD_INIT_NAME(SMT) },
 456         { cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) },
 457         { cpu_book_mask, SD_INIT_NAME(BOOK) },
 458         { cpu_cpu_mask, SD_INIT_NAME(DIE) },
 459         { NULL, },
 460 };
 461
 462 static void __init alloc_masks(struct sysinfo_15_1_x *info,
 463                                struct mask_info *mask, int offset)
 464 {
 465         int i, nr_masks;
 466
 467         nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
 468         for (i = 0; i < info->mnest - offset; i++)
 469                 nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
 470         nr_masks = max(nr_masks, 1);
 471         for (i = 0; i < nr_masks; i++) {
 472                 mask->next = kzalloc(sizeof(*mask->next), GFP_KERNEL);
 473                 mask = mask->next;
 474         }
 475 }
 476
 477 static int __init s390_topology_init(void)
 478 {
 479         struct sysinfo_15_1_x *info;
 480         int i;
 481
 482         if (!MACHINE_HAS_TOPOLOGY)
 483                 return 0;
 484         tl_info = (struct sysinfo_15_1_x *)__get_free_page(GFP_KERNEL);
 485         info = tl_info;
 486         store_topology(info);
 487         pr_info("The CPU configuration topology of the machine is:");
 488         for (i = 0; i < TOPOLOGY_NR_MAG; i++)
 489                 printk(KERN_CONT " %d", info->mag[i]);
 490         printk(KERN_CONT " / %d\n", info->mnest);
 491         alloc_masks(info, &socket_info, 1);
 492         alloc_masks(info, &book_info, 2);
 493         set_sched_topology(s390_topology);
 494         return 0;
 495 }
 496 early_initcall(s390_topology_init);
 497
 498 static int __init topology_init(void)
 499 {
 500         if (MACHINE_HAS_TOPOLOGY)
 501                 set_topology_timer();
 502         else
 503                 topology_update_polarization_simple();
 504         return device_create_file(cpu_subsys.dev_root, &dev_attr_dispatching);
 505 }
 506 device_initcall(topology_init);