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 21 #define PTF_HORIZONTAL (0UL) 22 #define PTF_VERTICAL (1UL) 23 #define PTF_CHECK (2UL) 24 25 struct mask_info { 26 struct mask_info *next; 27 unsigned char id; 28 cpumask_t mask; 29 }; 30 31 static int topology_enabled = 1; 32 static void topology_work_fn(struct work_struct *work); 33 static struct sysinfo_15_1_x *tl_info; 34 static void set_topology_timer(void); 35 static DECLARE_WORK(topology_work, topology_work_fn); 36 /* topology_lock protects the core linked list */ 37 static DEFINE_SPINLOCK(topology_lock); 38 39 static struct mask_info core_info; 40 cpumask_t cpu_core_map[NR_CPUS]; 41 unsigned char cpu_core_id[NR_CPUS]; 42 43 static struct mask_info book_info; 44 cpumask_t cpu_book_map[NR_CPUS]; 45 unsigned char cpu_book_id[NR_CPUS]; 46 47 /* smp_cpu_state_mutex must be held when accessing this array */ 48 int cpu_polarization[NR_CPUS]; 49 50 static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu) 51 { 52 cpumask_t mask; 53 54 cpumask_clear(&mask); 55 if (!topology_enabled || !MACHINE_HAS_TOPOLOGY) { 56 cpumask_copy(&mask, cpumask_of(cpu)); 57 return mask; 58 } 59 while (info) { 60 if (cpumask_test_cpu(cpu, &info->mask)) { 61 mask = info->mask; 62 break; 63 } 64 info = info->next; 65 } 66 if (cpumask_empty(&mask)) 67 cpumask_copy(&mask, cpumask_of(cpu)); 68 return mask; 69 } 70 71 static struct mask_info *add_cpus_to_mask(struct topology_cpu *tl_cpu, 72 struct mask_info *book, 73 struct mask_info *core, 74 int one_core_per_cpu) 75 { 76 unsigned int cpu; 77 78 for (cpu = find_first_bit(&tl_cpu->mask[0], TOPOLOGY_CPU_BITS); 79 cpu < TOPOLOGY_CPU_BITS; 80 cpu = find_next_bit(&tl_cpu->mask[0], TOPOLOGY_CPU_BITS, cpu + 1)) 81 { 82 unsigned int rcpu; 83 int lcpu; 84 85 rcpu = TOPOLOGY_CPU_BITS - 1 - cpu + tl_cpu->origin; 86 lcpu = smp_find_processor_id(rcpu); 87 if (lcpu >= 0) { 88 cpumask_set_cpu(lcpu, &book->mask); 89 cpu_book_id[lcpu] = book->id; 90 cpumask_set_cpu(lcpu, &core->mask); 91 if (one_core_per_cpu) { 92 cpu_core_id[lcpu] = rcpu; 93 core = core->next; 94 } else { 95 cpu_core_id[lcpu] = core->id; 96 } 97 cpu_set_polarization(lcpu, tl_cpu->pp); 98 } 99 } 100 return core; 101 } 102 103 static void clear_masks(void) 104 { 105 struct mask_info *info; 106 107 info = &core_info; 108 while (info) { 109 cpumask_clear(&info->mask); 110 info = info->next; 111 } 112 info = &book_info; 113 while (info) { 114 cpumask_clear(&info->mask); 115 info = info->next; 116 } 117 } 118 119 static union topology_entry *next_tle(union topology_entry *tle) 120 { 121 if (!tle->nl) 122 return (union topology_entry *)((struct topology_cpu *)tle + 1); 123 return (union topology_entry *)((struct topology_container *)tle + 1); 124 } 125 126 static void __tl_to_cores_generic(struct sysinfo_15_1_x *info) 127 { 128 struct mask_info *core = &core_info; 129 struct mask_info *book = &book_info; 130 union topology_entry *tle, *end; 131 132 tle = info->tle; 133 end = (union topology_entry *)((unsigned long)info + info->length); 134 while (tle < end) { 135 switch (tle->nl) { 136 case 2: 137 book = book->next; 138 book->id = tle->container.id; 139 break; 140 case 1: 141 core = core->next; 142 core->id = tle->container.id; 143 break; 144 case 0: 145 add_cpus_to_mask(&tle->cpu, book, core, 0); 146 break; 147 default: 148 clear_masks(); 149 return; 150 } 151 tle = next_tle(tle); 152 } 153 } 154 155 static void __tl_to_cores_z10(struct sysinfo_15_1_x *info) 156 { 157 struct mask_info *core = &core_info; 158 struct mask_info *book = &book_info; 159 union topology_entry *tle, *end; 160 161 tle = info->tle; 162 end = (union topology_entry *)((unsigned long)info + info->length); 163 while (tle < end) { 164 switch (tle->nl) { 165 case 1: 166 book = book->next; 167 book->id = tle->container.id; 168 break; 169 case 0: 170 core = add_cpus_to_mask(&tle->cpu, book, core, 1); 171 break; 172 default: 173 clear_masks(); 174 return; 175 } 176 tle = next_tle(tle); 177 } 178 } 179 180 static void tl_to_cores(struct sysinfo_15_1_x *info) 181 { 182 struct cpuid cpu_id; 183 184 get_cpu_id(&cpu_id); 185 spin_lock_irq(&topology_lock); 186 clear_masks(); 187 switch (cpu_id.machine) { 188 case 0x2097: 189 case 0x2098: 190 __tl_to_cores_z10(info); 191 break; 192 default: 193 __tl_to_cores_generic(info); 194 } 195 spin_unlock_irq(&topology_lock); 196 } 197 198 static void topology_update_polarization_simple(void) 199 { 200 int cpu; 201 202 mutex_lock(&smp_cpu_state_mutex); 203 for_each_possible_cpu(cpu) 204 cpu_set_polarization(cpu, POLARIZATION_HRZ); 205 mutex_unlock(&smp_cpu_state_mutex); 206 } 207 208 static int ptf(unsigned long fc) 209 { 210 int rc; 211 212 asm volatile( 213 " .insn rre,0xb9a20000,%1,%1\n" 214 " ipm %0\n" 215 " srl %0,28\n" 216 : "=d" (rc) 217 : "d" (fc) : "cc"); 218 return rc; 219 } 220 221 int topology_set_cpu_management(int fc) 222 { 223 int cpu, rc; 224 225 if (!MACHINE_HAS_TOPOLOGY) 226 return -EOPNOTSUPP; 227 if (fc) 228 rc = ptf(PTF_VERTICAL); 229 else 230 rc = ptf(PTF_HORIZONTAL); 231 if (rc) 232 return -EBUSY; 233 for_each_possible_cpu(cpu) 234 cpu_set_polarization(cpu, POLARIZATION_UNKNOWN); 235 return rc; 236 } 237 238 static void update_cpu_core_map(void) 239 { 240 unsigned long flags; 241 int cpu; 242 243 spin_lock_irqsave(&topology_lock, flags); 244 for_each_possible_cpu(cpu) { 245 cpu_core_map[cpu] = cpu_group_map(&core_info, cpu); 246 cpu_book_map[cpu] = cpu_group_map(&book_info, cpu); 247 } 248 spin_unlock_irqrestore(&topology_lock, flags); 249 } 250 251 void store_topology(struct sysinfo_15_1_x *info) 252 { 253 int rc; 254 255 rc = stsi(info, 15, 1, 3); 256 if (rc != -ENOSYS) 257 return; 258 stsi(info, 15, 1, 2); 259 } 260 261 int arch_update_cpu_topology(void) 262 { 263 struct sysinfo_15_1_x *info = tl_info; 264 struct device *dev; 265 int cpu; 266 267 if (!MACHINE_HAS_TOPOLOGY) { 268 update_cpu_core_map(); 269 topology_update_polarization_simple(); 270 return 0; 271 } 272 store_topology(info); 273 tl_to_cores(info); 274 update_cpu_core_map(); 275 for_each_online_cpu(cpu) { 276 dev = get_cpu_device(cpu); 277 kobject_uevent(&dev->kobj, KOBJ_CHANGE); 278 } 279 return 1; 280 } 281 282 static void topology_work_fn(struct work_struct *work) 283 { 284 rebuild_sched_domains(); 285 } 286 287 void topology_schedule_update(void) 288 { 289 schedule_work(&topology_work); 290 } 291 292 static void topology_timer_fn(unsigned long ignored) 293 { 294 if (ptf(PTF_CHECK)) 295 topology_schedule_update(); 296 set_topology_timer(); 297 } 298 299 static struct timer_list topology_timer = 300 TIMER_DEFERRED_INITIALIZER(topology_timer_fn, 0, 0); 301 302 static atomic_t topology_poll = ATOMIC_INIT(0); 303 304 static void set_topology_timer(void) 305 { 306 if (atomic_add_unless(&topology_poll, -1, 0)) 307 mod_timer(&topology_timer, jiffies + HZ / 10); 308 else 309 mod_timer(&topology_timer, jiffies + HZ * 60); 310 } 311 312 void topology_expect_change(void) 313 { 314 if (!MACHINE_HAS_TOPOLOGY) 315 return; 316 /* This is racy, but it doesn't matter since it is just a heuristic. 317 * Worst case is that we poll in a higher frequency for a bit longer. 318 */ 319 if (atomic_read(&topology_poll) > 60) 320 return; 321 atomic_add(60, &topology_poll); 322 set_topology_timer(); 323 } 324 325 static int __init early_parse_topology(char *p) 326 { 327 if (strncmp(p, "off", 3)) 328 return 0; 329 topology_enabled = 0; 330 return 0; 331 } 332 early_param("topology", early_parse_topology); 333 334 static void __init alloc_masks(struct sysinfo_15_1_x *info, 335 struct mask_info *mask, int offset) 336 { 337 int i, nr_masks; 338 339 nr_masks = info->mag[TOPOLOGY_NR_MAG - offset]; 340 for (i = 0; i < info->mnest - offset; i++) 341 nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i]; 342 nr_masks = max(nr_masks, 1); 343 for (i = 0; i < nr_masks; i++) { 344 mask->next = alloc_bootmem(sizeof(struct mask_info)); 345 mask = mask->next; 346 } 347 } 348 349 void __init s390_init_cpu_topology(void) 350 { 351 struct sysinfo_15_1_x *info; 352 int i; 353 354 if (!MACHINE_HAS_TOPOLOGY) 355 return; 356 tl_info = alloc_bootmem_pages(PAGE_SIZE); 357 info = tl_info; 358 store_topology(info); 359 pr_info("The CPU configuration topology of the machine is:"); 360 for (i = 0; i < TOPOLOGY_NR_MAG; i++) 361 printk(KERN_CONT " %d", info->mag[i]); 362 printk(KERN_CONT " / %d\n", info->mnest); 363 alloc_masks(info, &core_info, 1); 364 alloc_masks(info, &book_info, 2); 365 } 366 367 static int cpu_management; 368 369 static ssize_t dispatching_show(struct device *dev, 370 struct device_attribute *attr, 371 char *buf) 372 { 373 ssize_t count; 374 375 mutex_lock(&smp_cpu_state_mutex); 376 count = sprintf(buf, "%d\n", cpu_management); 377 mutex_unlock(&smp_cpu_state_mutex); 378 return count; 379 } 380 381 static ssize_t dispatching_store(struct device *dev, 382 struct device_attribute *attr, 383 const char *buf, 384 size_t count) 385 { 386 int val, rc; 387 char delim; 388 389 if (sscanf(buf, "%d %c", &val, &delim) != 1) 390 return -EINVAL; 391 if (val != 0 && val != 1) 392 return -EINVAL; 393 rc = 0; 394 get_online_cpus(); 395 mutex_lock(&smp_cpu_state_mutex); 396 if (cpu_management == val) 397 goto out; 398 rc = topology_set_cpu_management(val); 399 if (rc) 400 goto out; 401 cpu_management = val; 402 topology_expect_change(); 403 out: 404 mutex_unlock(&smp_cpu_state_mutex); 405 put_online_cpus(); 406 return rc ? rc : count; 407 } 408 static DEVICE_ATTR(dispatching, 0644, dispatching_show, 409 dispatching_store); 410 411 static ssize_t cpu_polarization_show(struct device *dev, 412 struct device_attribute *attr, char *buf) 413 { 414 int cpu = dev->id; 415 ssize_t count; 416 417 mutex_lock(&smp_cpu_state_mutex); 418 switch (cpu_read_polarization(cpu)) { 419 case POLARIZATION_HRZ: 420 count = sprintf(buf, "horizontal\n"); 421 break; 422 case POLARIZATION_VL: 423 count = sprintf(buf, "vertical:low\n"); 424 break; 425 case POLARIZATION_VM: 426 count = sprintf(buf, "vertical:medium\n"); 427 break; 428 case POLARIZATION_VH: 429 count = sprintf(buf, "vertical:high\n"); 430 break; 431 default: 432 count = sprintf(buf, "unknown\n"); 433 break; 434 } 435 mutex_unlock(&smp_cpu_state_mutex); 436 return count; 437 } 438 static DEVICE_ATTR(polarization, 0444, cpu_polarization_show, NULL); 439 440 static struct attribute *topology_cpu_attrs[] = { 441 &dev_attr_polarization.attr, 442 NULL, 443 }; 444 445 static struct attribute_group topology_cpu_attr_group = { 446 .attrs = topology_cpu_attrs, 447 }; 448 449 int topology_cpu_init(struct cpu *cpu) 450 { 451 return sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group); 452 } 453 454 static int __init topology_init(void) 455 { 456 if (!MACHINE_HAS_TOPOLOGY) { 457 topology_update_polarization_simple(); 458 goto out; 459 } 460 set_topology_timer(); 461 out: 462 update_cpu_core_map(); 463 return device_create_file(cpu_subsys.dev_root, &dev_attr_dispatching); 464 } 465 device_initcall(topology_init); 466