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/kernel.h>
  14 #include <linux/sched.h>
  15 #include <linux/init.h>
  16 #include <linux/delay.h>
  17 #include <linux/cpu.h>
  18 #include <linux/smp.h>
  19 #include <linux/mm.h>
  20 #include <asm/sysinfo.h>
  21
  22 #define PTF_HORIZONTAL  (0UL)
  23 #define PTF_VERTICAL    (1UL)
  24 #define PTF_CHECK       (2UL)
  25
  26 struct mask_info {
  27         struct mask_info *next;
  28         unsigned char id;
  29         cpumask_t mask;
  30 };
  31
  32 static int topology_enabled = 1;
  33 static void topology_work_fn(struct work_struct *work);
  34 static struct sysinfo_15_1_x *tl_info;
  35 static void set_topology_timer(void);
  36 static DECLARE_WORK(topology_work, topology_work_fn);
  37 /* topology_lock protects the core linked list */
  38 static DEFINE_SPINLOCK(topology_lock);
  39
  40 static struct mask_info core_info;
  41 cpumask_t cpu_core_map[NR_CPUS];
  42 unsigned char cpu_core_id[NR_CPUS];
  43 unsigned char cpu_socket_id[NR_CPUS];
  44
  45 static struct mask_info book_info;
  46 cpumask_t cpu_book_map[NR_CPUS];
  47 unsigned char cpu_book_id[NR_CPUS];
  48
  49 static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
  50 {
  51         cpumask_t mask;
  52
  53         cpumask_clear(&mask);
  54         if (!topology_enabled || !MACHINE_HAS_TOPOLOGY) {
  55                 cpumask_copy(&mask, cpumask_of(cpu));
  56                 return mask;
  57         }
  58         while (info) {
  59                 if (cpumask_test_cpu(cpu, &info->mask)) {
  60                         mask = info->mask;
  61                         break;
  62                 }
  63                 info = info->next;
  64         }
  65         if (cpumask_empty(&mask))
  66                 cpumask_copy(&mask, cpumask_of(cpu));
  67         return mask;
  68 }
  69
  70 static struct mask_info *add_cpus_to_mask(struct topology_cpu *tl_cpu,
  71                                           struct mask_info *book,
  72                                           struct mask_info *core,
  73                                           int one_core_per_cpu)
  74 {
  75         unsigned int cpu;
  76
  77         for_each_set_bit(cpu, &tl_cpu->mask[0], TOPOLOGY_CPU_BITS) {
  78                 unsigned int rcpu;
  79                 int lcpu;
  80
  81                 rcpu = TOPOLOGY_CPU_BITS - 1 - cpu + tl_cpu->origin;
  82                 lcpu = smp_find_processor_id(rcpu);
  83                 if (lcpu >= 0) {
  84                         cpumask_set_cpu(lcpu, &book->mask);
  85                         cpu_book_id[lcpu] = book->id;
  86                         cpumask_set_cpu(lcpu, &core->mask);
  87                         cpu_core_id[lcpu] = rcpu;
  88                         if (one_core_per_cpu) {
  89                                 cpu_socket_id[lcpu] = rcpu;
  90                                 core = core->next;
  91                         } else {
  92                                 cpu_socket_id[lcpu] = core->id;
  93                         }
  94                         smp_cpu_set_polarization(lcpu, tl_cpu->pp);
  95                 }
  96         }
  97         return core;
  98 }
  99
 100 static void clear_masks(void)
 101 {
 102         struct mask_info *info;
 103
 104         info = &core_info;
 105         while (info) {
 106                 cpumask_clear(&info->mask);
 107                 info = info->next;
 108         }
 109         info = &book_info;
 110         while (info) {
 111                 cpumask_clear(&info->mask);
 112                 info = info->next;
 113         }
 114 }
 115
 116 static union topology_entry *next_tle(union topology_entry *tle)
 117 {
 118         if (!tle->nl)
 119                 return (union topology_entry *)((struct topology_cpu *)tle + 1);
 120         return (union topology_entry *)((struct topology_container *)tle + 1);
 121 }
 122
 123 static void __tl_to_cores_generic(struct sysinfo_15_1_x *info)
 124 {
 125         struct mask_info *core = &core_info;
 126         struct mask_info *book = &book_info;
 127         union topology_entry *tle, *end;
 128
 129         tle = info->tle;
 130         end = (union topology_entry *)((unsigned long)info + info->length);
 131         while (tle < end) {
 132                 switch (tle->nl) {
 133                 case 2:
 134                         book = book->next;
 135                         book->id = tle->container.id;
 136                         break;
 137                 case 1:
 138                         core = core->next;
 139                         core->id = tle->container.id;
 140                         break;
 141                 case 0:
 142                         add_cpus_to_mask(&tle->cpu, book, core, 0);
 143                         break;
 144                 default:
 145                         clear_masks();
 146                         return;
 147                 }
 148                 tle = next_tle(tle);
 149         }
 150 }
 151
 152 static void __tl_to_cores_z10(struct sysinfo_15_1_x *info)
 153 {
 154         struct mask_info *core = &core_info;
 155         struct mask_info *book = &book_info;
 156         union topology_entry *tle, *end;
 157
 158         tle = info->tle;
 159         end = (union topology_entry *)((unsigned long)info + info->length);
 160         while (tle < end) {
 161                 switch (tle->nl) {
 162                 case 1:
 163                         book = book->next;
 164                         book->id = tle->container.id;
 165                         break;
 166                 case 0:
 167                         core = add_cpus_to_mask(&tle->cpu, book, core, 1);
 168                         break;
 169                 default:
 170                         clear_masks();
 171                         return;
 172                 }
 173                 tle = next_tle(tle);
 174         }
 175 }
 176
 177 static void tl_to_cores(struct sysinfo_15_1_x *info)
 178 {
 179         struct cpuid cpu_id;
 180
 181         get_cpu_id(&cpu_id);
 182         spin_lock_irq(&topology_lock);
 183         clear_masks();
 184         switch (cpu_id.machine) {
 185         case 0x2097:
 186         case 0x2098:
 187                 __tl_to_cores_z10(info);
 188                 break;
 189         default:
 190                 __tl_to_cores_generic(info);
 191         }
 192         spin_unlock_irq(&topology_lock);
 193 }
 194
 195 static void topology_update_polarization_simple(void)
 196 {
 197         int cpu;
 198
 199         mutex_lock(&smp_cpu_state_mutex);
 200         for_each_possible_cpu(cpu)
 201                 smp_cpu_set_polarization(cpu, POLARIZATION_HRZ);
 202         mutex_unlock(&smp_cpu_state_mutex);
 203 }
 204
 205 static int ptf(unsigned long fc)
 206 {
 207         int rc;
 208
 209         asm volatile(
 210                 "       .insn   rre,0xb9a20000,%1,%1\n"
 211                 "       ipm     %0\n"
 212                 "       srl     %0,28\n"
 213                 : "=d" (rc)
 214                 : "d" (fc)  : "cc");
 215         return rc;
 216 }
 217
 218 int topology_set_cpu_management(int fc)
 219 {
 220         int cpu, rc;
 221
 222         if (!MACHINE_HAS_TOPOLOGY)
 223                 return -EOPNOTSUPP;
 224         if (fc)
 225                 rc = ptf(PTF_VERTICAL);
 226         else
 227                 rc = ptf(PTF_HORIZONTAL);
 228         if (rc)
 229                 return -EBUSY;
 230         for_each_possible_cpu(cpu)
 231                 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
 232         return rc;
 233 }
 234
 235 static void update_cpu_core_map(void)
 236 {
 237         unsigned long flags;
 238         int cpu;
 239
 240         spin_lock_irqsave(&topology_lock, flags);
 241         for_each_possible_cpu(cpu) {
 242                 cpu_core_map[cpu] = cpu_group_map(&core_info, cpu);
 243                 cpu_book_map[cpu] = cpu_group_map(&book_info, cpu);
 244         }
 245         spin_unlock_irqrestore(&topology_lock, flags);
 246 }
 247
 248 void store_topology(struct sysinfo_15_1_x *info)
 249 {
 250         if (topology_max_mnest >= 3)
 251                 stsi(info, 15, 1, 3);
 252         else
 253                 stsi(info, 15, 1, 2);
 254 }
 255
 256 int arch_update_cpu_topology(void)
 257 {
 258         struct sysinfo_15_1_x *info = tl_info;
 259         struct device *dev;
 260         int cpu;
 261
 262         if (!MACHINE_HAS_TOPOLOGY) {
 263                 update_cpu_core_map();
 264                 topology_update_polarization_simple();
 265                 return 0;
 266         }
 267         store_topology(info);
 268         tl_to_cores(info);
 269         update_cpu_core_map();
 270         for_each_online_cpu(cpu) {
 271                 dev = get_cpu_device(cpu);
 272                 kobject_uevent(&dev->kobj, KOBJ_CHANGE);
 273         }
 274         return 1;
 275 }
 276
 277 static void topology_work_fn(struct work_struct *work)
 278 {
 279         rebuild_sched_domains();
 280 }
 281
 282 void topology_schedule_update(void)
 283 {
 284         schedule_work(&topology_work);
 285 }
 286
 287 static void topology_timer_fn(unsigned long ignored)
 288 {
 289         if (ptf(PTF_CHECK))
 290                 topology_schedule_update();
 291         set_topology_timer();
 292 }
 293
 294 static struct timer_list topology_timer =
 295         TIMER_DEFERRED_INITIALIZER(topology_timer_fn, 0, 0);
 296
 297 static atomic_t topology_poll = ATOMIC_INIT(0);
 298
 299 static void set_topology_timer(void)
 300 {
 301         if (atomic_add_unless(&topology_poll, -1, 0))
 302                 mod_timer(&topology_timer, jiffies + HZ / 10);
 303         else
 304                 mod_timer(&topology_timer, jiffies + HZ * 60);
 305 }
 306
 307 void topology_expect_change(void)
 308 {
 309         if (!MACHINE_HAS_TOPOLOGY)
 310                 return;
 311         /* This is racy, but it doesn't matter since it is just a heuristic.
 312          * Worst case is that we poll in a higher frequency for a bit longer.
 313          */
 314         if (atomic_read(&topology_poll) > 60)
 315                 return;
 316         atomic_add(60, &topology_poll);
 317         set_topology_timer();
 318 }
 319
 320 static int __init early_parse_topology(char *p)
 321 {
 322         if (strncmp(p, "off", 3))
 323                 return 0;
 324         topology_enabled = 0;
 325         return 0;
 326 }
 327 early_param("topology", early_parse_topology);
 328
 329 static void __init alloc_masks(struct sysinfo_15_1_x *info,
 330                                struct mask_info *mask, int offset)
 331 {
 332         int i, nr_masks;
 333
 334         nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
 335         for (i = 0; i < info->mnest - offset; i++)
 336                 nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
 337         nr_masks = max(nr_masks, 1);
 338         for (i = 0; i < nr_masks; i++) {
 339                 mask->next = alloc_bootmem(sizeof(struct mask_info));
 340                 mask = mask->next;
 341         }
 342 }
 343
 344 void __init s390_init_cpu_topology(void)
 345 {
 346         struct sysinfo_15_1_x *info;
 347         int i;
 348
 349         if (!MACHINE_HAS_TOPOLOGY)
 350                 return;
 351         tl_info = alloc_bootmem_pages(PAGE_SIZE);
 352         info = tl_info;
 353         store_topology(info);
 354         pr_info("The CPU configuration topology of the machine is:");
 355         for (i = 0; i < TOPOLOGY_NR_MAG; i++)
 356                 printk(KERN_CONT " %d", info->mag[i]);
 357         printk(KERN_CONT " / %d\n", info->mnest);
 358         alloc_masks(info, &core_info, 1);
 359         alloc_masks(info, &book_info, 2);
 360 }
 361
 362 static int cpu_management;
 363
 364 static ssize_t dispatching_show(struct device *dev,
 365                                 struct device_attribute *attr,
 366                                 char *buf)
 367 {
 368         ssize_t count;
 369
 370         mutex_lock(&smp_cpu_state_mutex);
 371         count = sprintf(buf, "%d\n", cpu_management);
 372         mutex_unlock(&smp_cpu_state_mutex);
 373         return count;
 374 }
 375
 376 static ssize_t dispatching_store(struct device *dev,
 377                                  struct device_attribute *attr,
 378                                  const char *buf,
 379                                  size_t count)
 380 {
 381         int val, rc;
 382         char delim;
 383
 384         if (sscanf(buf, "%d %c", &val, &delim) != 1)
 385                 return -EINVAL;
 386         if (val != 0 && val != 1)
 387                 return -EINVAL;
 388         rc = 0;
 389         get_online_cpus();
 390         mutex_lock(&smp_cpu_state_mutex);
 391         if (cpu_management == val)
 392                 goto out;
 393         rc = topology_set_cpu_management(val);
 394         if (rc)
 395                 goto out;
 396         cpu_management = val;
 397         topology_expect_change();
 398 out:
 399         mutex_unlock(&smp_cpu_state_mutex);
 400         put_online_cpus();
 401         return rc ? rc : count;
 402 }
 403 static DEVICE_ATTR(dispatching, 0644, dispatching_show,
 404                          dispatching_store);
 405
 406 static ssize_t cpu_polarization_show(struct device *dev,
 407                                      struct device_attribute *attr, char *buf)
 408 {
 409         int cpu = dev->id;
 410         ssize_t count;
 411
 412         mutex_lock(&smp_cpu_state_mutex);
 413         switch (smp_cpu_get_polarization(cpu)) {
 414         case POLARIZATION_HRZ:
 415                 count = sprintf(buf, "horizontal\n");
 416                 break;
 417         case POLARIZATION_VL:
 418                 count = sprintf(buf, "vertical:low\n");
 419                 break;
 420         case POLARIZATION_VM:
 421                 count = sprintf(buf, "vertical:medium\n");
 422                 break;
 423         case POLARIZATION_VH:
 424                 count = sprintf(buf, "vertical:high\n");
 425                 break;
 426         default:
 427                 count = sprintf(buf, "unknown\n");
 428                 break;
 429         }
 430         mutex_unlock(&smp_cpu_state_mutex);
 431         return count;
 432 }
 433 static DEVICE_ATTR(polarization, 0444, cpu_polarization_show, NULL);
 434
 435 static struct attribute *topology_cpu_attrs[] = {
 436         &dev_attr_polarization.attr,
 437         NULL,
 438 };
 439
 440 static struct attribute_group topology_cpu_attr_group = {
 441         .attrs = topology_cpu_attrs,
 442 };
 443
 444 int topology_cpu_init(struct cpu *cpu)
 445 {
 446         return sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
 447 }
 448
 449 static int __init topology_init(void)
 450 {
 451         if (!MACHINE_HAS_TOPOLOGY) {
 452                 topology_update_polarization_simple();
 453                 goto out;
 454         }
 455         set_topology_timer();
 456 out:
 457         update_cpu_core_map();
 458         return device_create_file(cpu_subsys.dev_root, &dev_attr_dispatching);
 459 }
 460 device_initcall(topology_init);