1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright IBM Corp. 2007, 2011
4 */
5
6 #define KMSG_COMPONENT "cpu"
7 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
8
9 #include <linux/workqueue.h>
10 #include <linux/memblock.h>
11 #include <linux/uaccess.h>
12 #include <linux/sysctl.h>
13 #include <linux/cpuset.h>
14 #include <linux/device.h>
15 #include <linux/export.h>
16 #include <linux/kernel.h>
17 #include <linux/sched.h>
18 #include <linux/sched/topology.h>
19 #include <linux/delay.h>
20 #include <linux/init.h>
21 #include <linux/slab.h>
22 #include <linux/cpu.h>
23 #include <linux/smp.h>
24 #include <linux/mm.h>
25 #include <linux/nodemask.h>
26 #include <linux/node.h>
27 #include <asm/sysinfo.h>
28
29 #define PTF_HORIZONTAL (0UL)
30 #define PTF_VERTICAL (1UL)
31 #define PTF_CHECK (2UL)
32
33 enum {
34 TOPOLOGY_MODE_HW,
35 TOPOLOGY_MODE_SINGLE,
36 TOPOLOGY_MODE_PACKAGE,
37 TOPOLOGY_MODE_UNINITIALIZED
38 };
39
40 struct mask_info {
41 struct mask_info *next;
42 unsigned char id;
43 cpumask_t mask;
44 };
45
46 static int topology_mode = TOPOLOGY_MODE_UNINITIALIZED;
47 static void set_topology_timer(void);
48 static void topology_work_fn(struct work_struct *work);
49 static struct sysinfo_15_1_x *tl_info;
50
51 static DECLARE_WORK(topology_work, topology_work_fn);
52
53 /*
54 * Socket/Book linked lists and cpu_topology updates are
55 * protected by "sched_domains_mutex".
56 */
57 static struct mask_info socket_info;
58 static struct mask_info book_info;
59 static struct mask_info drawer_info;
60
61 struct cpu_topology_s390 cpu_topology[NR_CPUS];
62 EXPORT_SYMBOL_GPL(cpu_topology);
63
64 static void cpu_group_map(cpumask_t *dst, struct mask_info *info, unsigned int cpu)
65 {
66 static cpumask_t mask;
67
68 cpumask_clear(&mask);
69 if (!cpumask_test_cpu(cpu, &cpu_setup_mask))
70 goto out;
71 cpumask_set_cpu(cpu, &mask);
72 switch (topology_mode) {
73 case TOPOLOGY_MODE_HW:
74 while (info) {
75 if (cpumask_test_cpu(cpu, &info->mask)) {
76 cpumask_copy(&mask, &info->mask);
77 break;
78 }
79 info = info->next;
80 }
81 break;
82 case TOPOLOGY_MODE_PACKAGE:
83 cpumask_copy(&mask, cpu_present_mask);
84 break;
85 default:
86 fallthrough;
87 case TOPOLOGY_MODE_SINGLE:
88 break;
89 }
90 cpumask_and(&mask, &mask, &cpu_setup_mask);
91 out:
92 cpumask_copy(dst, &mask);
93 }
94
95 static void cpu_thread_map(cpumask_t *dst, unsigned int cpu)
96 {
97 static cpumask_t mask;
98 unsigned int max_cpu;
99
100 cpumask_clear(&mask);
101 if (!cpumask_test_cpu(cpu, &cpu_setup_mask))
102 goto out;
103 cpumask_set_cpu(cpu, &mask);
104 if (topology_mode != TOPOLOGY_MODE_HW)
105 goto out;
106 cpu -= cpu % (smp_cpu_mtid + 1);
107 max_cpu = min(cpu + smp_cpu_mtid, nr_cpu_ids - 1);
108 for (; cpu <= max_cpu; cpu++) {
109 if (cpumask_test_cpu(cpu, &cpu_setup_mask))
110 cpumask_set_cpu(cpu, &mask);
111 }
112 out:
113 cpumask_copy(dst, &mask);
114 }
115
116 #define TOPOLOGY_CORE_BITS 64
117
118 static void add_cpus_to_mask(struct topology_core *tl_core,
119 struct mask_info *drawer,
120 struct mask_info *book,
121 struct mask_info *socket)
122 {
123 struct cpu_topology_s390 *topo;
124 unsigned int core;
125
126 for_each_set_bit(core, &tl_core->mask, TOPOLOGY_CORE_BITS) {
127 unsigned int max_cpu, rcore;
128 int cpu;
129
130 rcore = TOPOLOGY_CORE_BITS - 1 - core + tl_core->origin;
131 cpu = smp_find_processor_id(rcore << smp_cpu_mt_shift);
132 if (cpu < 0)
133 continue;
134 max_cpu = min(cpu + smp_cpu_mtid, nr_cpu_ids - 1);
135 for (; cpu <= max_cpu; cpu++) {
136 topo = &cpu_topology[cpu];
137 topo->drawer_id = drawer->id;
138 topo->book_id = book->id;
139 topo->socket_id = socket->id;
140 topo->core_id = rcore;
141 topo->thread_id = cpu;
142 topo->dedicated = tl_core->d;
143 cpumask_set_cpu(cpu, &drawer->mask);
144 cpumask_set_cpu(cpu, &book->mask);
145 cpumask_set_cpu(cpu, &socket->mask);
146 smp_cpu_set_polarization(cpu, tl_core->pp);
147 }
148 }
149 }
150
151 static void clear_masks(void)
152 {
153 struct mask_info *info;
154
155 info = &socket_info;
156 while (info) {
157 cpumask_clear(&info->mask);
158 info = info->next;
159 }
160 info = &book_info;
161 while (info) {
162 cpumask_clear(&info->mask);
163 info = info->next;
164 }
165 info = &drawer_info;
166 while (info) {
167 cpumask_clear(&info->mask);
168 info = info->next;
169 }
170 }
171
172 static union topology_entry *next_tle(union topology_entry *tle)
173 {
174 if (!tle->nl)
175 return (union topology_entry *)((struct topology_core *)tle + 1);
176 return (union topology_entry *)((struct topology_container *)tle + 1);
177 }
178
179 static void tl_to_masks(struct sysinfo_15_1_x *info)
180 {
181 struct mask_info *socket = &socket_info;
182 struct mask_info *book = &book_info;
183 struct mask_info *drawer = &drawer_info;
184 union topology_entry *tle, *end;
185
186 clear_masks();
187 tle = info->tle;
188 end = (union topology_entry *)((unsigned long)info + info->length);
189 while (tle < end) {
190 switch (tle->nl) {
191 case 3:
192 drawer = drawer->next;
193 drawer->id = tle->container.id;
194 break;
195 case 2:
196 book = book->next;
197 book->id = tle->container.id;
198 break;
199 case 1:
200 socket = socket->next;
201 socket->id = tle->container.id;
202 break;
203 case 0:
204 add_cpus_to_mask(&tle->cpu, drawer, book, socket);
205 break;
206 default:
207 clear_masks();
208 return;
209 }
210 tle = next_tle(tle);
211 }
212 }
213
214 static void topology_update_polarization_simple(void)
215 {
216 int cpu;
217
218 for_each_possible_cpu(cpu)
219 smp_cpu_set_polarization(cpu, POLARIZATION_HRZ);
220 }
221
222 static int ptf(unsigned long fc)
223 {
224 int rc;
225
226 asm volatile(
227 " .insn rre,0xb9a20000,%1,%1\n"
228 " ipm %0\n"
229 " srl %0,28\n"
230 : "=d" (rc)
231 : "d" (fc) : "cc");
232 return rc;
233 }
234
235 int topology_set_cpu_management(int fc)
236 {
237 int cpu, rc;
238
239 if (!MACHINE_HAS_TOPOLOGY)
240 return -EOPNOTSUPP;
241 if (fc)
242 rc = ptf(PTF_VERTICAL);
243 else
244 rc = ptf(PTF_HORIZONTAL);
245 if (rc)
246 return -EBUSY;
247 for_each_possible_cpu(cpu)
248 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
249 return rc;
250 }
251
252 void update_cpu_masks(void)
253 {
254 struct cpu_topology_s390 *topo, *topo_package, *topo_sibling;
255 int cpu, sibling, pkg_first, smt_first, id;
256
257 for_each_possible_cpu(cpu) {
258 topo = &cpu_topology[cpu];
259 cpu_thread_map(&topo->thread_mask, cpu);
260 cpu_group_map(&topo->core_mask, &socket_info, cpu);
261 cpu_group_map(&topo->book_mask, &book_info, cpu);
262 cpu_group_map(&topo->drawer_mask, &drawer_info, cpu);
263 topo->booted_cores = 0;
264 if (topology_mode != TOPOLOGY_MODE_HW) {
265 id = topology_mode == TOPOLOGY_MODE_PACKAGE ? 0 : cpu;
266 topo->thread_id = cpu;
267 topo->core_id = cpu;
268 topo->socket_id = id;
269 topo->book_id = id;
270 topo->drawer_id = id;
271 }
272 }
273 for_each_online_cpu(cpu) {
274 topo = &cpu_topology[cpu];
275 pkg_first = cpumask_first(&topo->core_mask);
276 topo_package = &cpu_topology[pkg_first];
277 if (cpu == pkg_first) {
278 for_each_cpu(sibling, &topo->core_mask) {
279 topo_sibling = &cpu_topology[sibling];
280 smt_first = cpumask_first(&topo_sibling->thread_mask);
281 if (sibling == smt_first)
282 topo_package->booted_cores++;
283 }
284 } else {
285 topo->booted_cores = topo_package->booted_cores;
286 }
287 }
288 }
289
290 void store_topology(struct sysinfo_15_1_x *info)
291 {
292 stsi(info, 15, 1, topology_mnest_limit());
293 }
294
295 static void __arch_update_dedicated_flag(void *arg)
296 {
297 if (topology_cpu_dedicated(smp_processor_id()))
298 set_cpu_flag(CIF_DEDICATED_CPU);
299 else
300 clear_cpu_flag(CIF_DEDICATED_CPU);
301 }
302
303 static int __arch_update_cpu_topology(void)
304 {
305 struct sysinfo_15_1_x *info = tl_info;
306 int rc = 0;
307
308 mutex_lock(&smp_cpu_state_mutex);
309 if (MACHINE_HAS_TOPOLOGY) {
310 rc = 1;
311 store_topology(info);
312 tl_to_masks(info);
313 }
314 update_cpu_masks();
315 if (!MACHINE_HAS_TOPOLOGY)
316 topology_update_polarization_simple();
317 mutex_unlock(&smp_cpu_state_mutex);
318 return rc;
319 }
320
321 int arch_update_cpu_topology(void)
322 {
323 int rc;
324
325 rc = __arch_update_cpu_topology();
326 on_each_cpu(__arch_update_dedicated_flag, NULL, 0);
327 return rc;
328 }
329
330 static void topology_work_fn(struct work_struct *work)
331 {
332 rebuild_sched_domains();
333 }
334
335 void topology_schedule_update(void)
336 {
337 schedule_work(&topology_work);
338 }
339
340 static void topology_flush_work(void)
341 {
342 flush_work(&topology_work);
343 }
344
345 static void topology_timer_fn(struct timer_list *unused)
346 {
347 if (ptf(PTF_CHECK))
348 topology_schedule_update();
349 set_topology_timer();
350 }
351
352 static struct timer_list topology_timer;
353
354 static atomic_t topology_poll = ATOMIC_INIT(0);
355
356 static void set_topology_timer(void)
357 {
358 if (atomic_add_unless(&topology_poll, -1, 0))
359 mod_timer(&topology_timer, jiffies + msecs_to_jiffies(100));
360 else
361 mod_timer(&topology_timer, jiffies + msecs_to_jiffies(60 * MSEC_PER_SEC));
362 }
363
364 void topology_expect_change(void)
365 {
366 if (!MACHINE_HAS_TOPOLOGY)
367 return;
368 /* This is racy, but it doesn't matter since it is just a heuristic.
369 * Worst case is that we poll in a higher frequency for a bit longer.
370 */
371 if (atomic_read(&topology_poll) > 60)
372 return;
373 atomic_add(60, &topology_poll);
374 set_topology_timer();
375 }
376
377 static int cpu_management;
378
379 static ssize_t dispatching_show(struct device *dev,
380 struct device_attribute *attr,
381 char *buf)
382 {
383 ssize_t count;
384
385 mutex_lock(&smp_cpu_state_mutex);
386 count = sprintf(buf, "%d\n", cpu_management);
387 mutex_unlock(&smp_cpu_state_mutex);
388 return count;
389 }
390
391 static ssize_t dispatching_store(struct device *dev,
392 struct device_attribute *attr,
393 const char *buf,
394 size_t count)
395 {
396 int val, rc;
397 char delim;
398
399 if (sscanf(buf, "%d %c", &val, &delim) != 1)
400 return -EINVAL;
401 if (val != 0 && val != 1)
402 return -EINVAL;
403 rc = 0;
404 cpus_read_lock();
405 mutex_lock(&smp_cpu_state_mutex);
406 if (cpu_management == val)
407 goto out;
408 rc = topology_set_cpu_management(val);
409 if (rc)
410 goto out;
411 cpu_management = val;
412 topology_expect_change();
413 out:
414 mutex_unlock(&smp_cpu_state_mutex);
415 cpus_read_unlock();
416 return rc ? rc : count;
417 }
418 static DEVICE_ATTR_RW(dispatching);
419
420 static ssize_t cpu_polarization_show(struct device *dev,
421 struct device_attribute *attr, char *buf)
422 {
423 int cpu = dev->id;
424 ssize_t count;
425
426 mutex_lock(&smp_cpu_state_mutex);
427 switch (smp_cpu_get_polarization(cpu)) {
428 case POLARIZATION_HRZ:
429 count = sprintf(buf, "horizontal\n");
430 break;
431 case POLARIZATION_VL:
432 count = sprintf(buf, "vertical:low\n");
433 break;
434 case POLARIZATION_VM:
435 count = sprintf(buf, "vertical:medium\n");
436 break;
437 case POLARIZATION_VH:
438 count = sprintf(buf, "vertical:high\n");
439 break;
440 default:
441 count = sprintf(buf, "unknown\n");
442 break;
443 }
444 mutex_unlock(&smp_cpu_state_mutex);
445 return count;
446 }
447 static DEVICE_ATTR(polarization, 0444, cpu_polarization_show, NULL);
448
449 static struct attribute *topology_cpu_attrs[] = {
450 &dev_attr_polarization.attr,
451 NULL,
452 };
453
454 static struct attribute_group topology_cpu_attr_group = {
455 .attrs = topology_cpu_attrs,
456 };
457
458 static ssize_t cpu_dedicated_show(struct device *dev,
459 struct device_attribute *attr, char *buf)
460 {
461 int cpu = dev->id;
462 ssize_t count;
463
464 mutex_lock(&smp_cpu_state_mutex);
465 count = sprintf(buf, "%d\n", topology_cpu_dedicated(cpu));
466 mutex_unlock(&smp_cpu_state_mutex);
467 return count;
468 }
469 static DEVICE_ATTR(dedicated, 0444, cpu_dedicated_show, NULL);
470
471 static struct attribute *topology_extra_cpu_attrs[] = {
472 &dev_attr_dedicated.attr,
473 NULL,
474 };
475
476 static struct attribute_group topology_extra_cpu_attr_group = {
477 .attrs = topology_extra_cpu_attrs,
478 };
479
480 int topology_cpu_init(struct cpu *cpu)
481 {
482 int rc;
483
484 rc = sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
485 if (rc || !MACHINE_HAS_TOPOLOGY)
486 return rc;
487 rc = sysfs_create_group(&cpu->dev.kobj, &topology_extra_cpu_attr_group);
488 if (rc)
489 sysfs_remove_group(&cpu->dev.kobj, &topology_cpu_attr_group);
490 return rc;
491 }
492
493 static const struct cpumask *cpu_thread_mask(int cpu)
494 {
495 return &cpu_topology[cpu].thread_mask;
496 }
497
498
499 const struct cpumask *cpu_coregroup_mask(int cpu)
500 {
501 return &cpu_topology[cpu].core_mask;
502 }
503
504 static const struct cpumask *cpu_book_mask(int cpu)
505 {
506 return &cpu_topology[cpu].book_mask;
507 }
508
509 static const struct cpumask *cpu_drawer_mask(int cpu)
510 {
511 return &cpu_topology[cpu].drawer_mask;
512 }
513
514 static struct sched_domain_topology_level s390_topology[] = {
515 { cpu_thread_mask, cpu_smt_flags, SD_INIT_NAME(SMT) },
516 { cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) },
517 { cpu_book_mask, SD_INIT_NAME(BOOK) },
518 { cpu_drawer_mask, SD_INIT_NAME(DRAWER) },
519 { cpu_cpu_mask, SD_INIT_NAME(PKG) },
520 { NULL, },
521 };
522
523 static void __init alloc_masks(struct sysinfo_15_1_x *info,
524 struct mask_info *mask, int offset)
525 {
526 int i, nr_masks;
527
528 nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
529 for (i = 0; i < info->mnest - offset; i++)
530 nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
531 nr_masks = max(nr_masks, 1);
532 for (i = 0; i < nr_masks; i++) {
533 mask->next = memblock_alloc(sizeof(*mask->next), 8);
534 if (!mask->next)
535 panic("%s: Failed to allocate %zu bytes align=0x%x\n",
536 __func__, sizeof(*mask->next), 8);
537 mask = mask->next;
538 }
539 }
540
541 void __init topology_init_early(void)
542 {
543 struct sysinfo_15_1_x *info;
544
545 set_sched_topology(s390_topology);
546 if (topology_mode == TOPOLOGY_MODE_UNINITIALIZED) {
547 if (MACHINE_HAS_TOPOLOGY)
548 topology_mode = TOPOLOGY_MODE_HW;
549 else
550 topology_mode = TOPOLOGY_MODE_SINGLE;
551 }
552 if (!MACHINE_HAS_TOPOLOGY)
553 goto out;
554 tl_info = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
555 if (!tl_info)
556 panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
557 __func__, PAGE_SIZE, PAGE_SIZE);
558 info = tl_info;
559 store_topology(info);
560 pr_info("The CPU configuration topology of the machine is: %d %d %d %d %d %d / %d\n",
561 info->mag[0], info->mag[1], info->mag[2], info->mag[3],
562 info->mag[4], info->mag[5], info->mnest);
563 alloc_masks(info, &socket_info, 1);
564 alloc_masks(info, &book_info, 2);
565 alloc_masks(info, &drawer_info, 3);
566 out:
567 cpumask_set_cpu(0, &cpu_setup_mask);
568 __arch_update_cpu_topology();
569 __arch_update_dedicated_flag(NULL);
570 }
571
572 static inline int topology_get_mode(int enabled)
573 {
574 if (!enabled)
575 return TOPOLOGY_MODE_SINGLE;
576 return MACHINE_HAS_TOPOLOGY ? TOPOLOGY_MODE_HW : TOPOLOGY_MODE_PACKAGE;
577 }
578
579 static inline int topology_is_enabled(void)
580 {
581 return topology_mode != TOPOLOGY_MODE_SINGLE;
582 }
583
584 static int __init topology_setup(char *str)
585 {
586 bool enabled;
587 int rc;
588
589 rc = kstrtobool(str, &enabled);
590 if (rc)
591 return rc;
592 topology_mode = topology_get_mode(enabled);
593 return 0;
594 }
595 early_param("topology", topology_setup);
596
597 static int topology_ctl_handler(const struct ctl_table *ctl, int write,
598 void *buffer, size_t *lenp, loff_t *ppos)
599 {
600 int enabled = topology_is_enabled();
601 int new_mode;
602 int rc;
603 struct ctl_table ctl_entry = {
604 .procname = ctl->procname,
605 .data = &enabled,
606 .maxlen = sizeof(int),
607 .extra1 = SYSCTL_ZERO,
608 .extra2 = SYSCTL_ONE,
609 };
610
611 rc = proc_douintvec_minmax(&ctl_entry, write, buffer, lenp, ppos);
612 if (rc < 0 || !write)
613 return rc;
614
615 mutex_lock(&smp_cpu_state_mutex);
616 new_mode = topology_get_mode(enabled);
617 if (topology_mode != new_mode) {
618 topology_mode = new_mode;
619 topology_schedule_update();
620 }
621 mutex_unlock(&smp_cpu_state_mutex);
622 topology_flush_work();
623
624 return rc;
625 }
626
627 static struct ctl_table topology_ctl_table[] = {
628 {
629 .procname = "topology",
630 .mode = 0644,
631 .proc_handler = topology_ctl_handler,
632 },
633 };
634
635 static int __init topology_init(void)
636 {
637 struct device *dev_root;
638 int rc = 0;
639
640 timer_setup(&topology_timer, topology_timer_fn, TIMER_DEFERRABLE);
641 if (MACHINE_HAS_TOPOLOGY)
642 set_topology_timer();
643 else
644 topology_update_polarization_simple();
645 register_sysctl("s390", topology_ctl_table);
646
647 dev_root = bus_get_dev_root(&cpu_subsys);
648 if (dev_root) {
649 rc = device_create_file(dev_root, &dev_attr_dispatching);
650 put_device(dev_root);
651 }
652 return rc;
653 }
654 device_initcall(topology_init);
655
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