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