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