1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright IBM Corp. 2007, 2011
4 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
5 */
6
7 #define KMSG_COMPONENT "cpu"
8 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
9
10 #include <linux/workqueue.h>
11 #include <linux/memblock.h>
12 #include <linux/uaccess.h>
13 #include <linux/sysctl.h>
14 #include <linux/cpuset.h>
15 #include <linux/device.h>
16 #include <linux/export.h>
17 #include <linux/kernel.h>
18 #include <linux/sched.h>
19 #include <linux/sched/topology.h>
20 #include <linux/delay.h>
21 #include <linux/init.h>
22 #include <linux/slab.h>
23 #include <linux/cpu.h>
24 #include <linux/smp.h>
25 #include <linux/mm.h>
26 #include <linux/nodemask.h>
27 #include <linux/node.h>
28 #include <asm/sysinfo.h>
29 #include <asm/numa.h>
30
31 #define PTF_HORIZONTAL (0UL)
32 #define PTF_VERTICAL (1UL)
33 #define PTF_CHECK (2UL)
34
35 enum {
36 TOPOLOGY_MODE_HW,
37 TOPOLOGY_MODE_SINGLE,
38 TOPOLOGY_MODE_PACKAGE,
39 TOPOLOGY_MODE_UNINITIALIZED
40 };
41
42 struct mask_info {
43 struct mask_info *next;
44 unsigned char id;
45 cpumask_t mask;
46 };
47
48 static int topology_mode = TOPOLOGY_MODE_UNINITIALIZED;
49 static void set_topology_timer(void);
50 static void topology_work_fn(struct work_struct *work);
51 static struct sysinfo_15_1_x *tl_info;
52
53 static DECLARE_WORK(topology_work, topology_work_fn);
54
55 /*
56 * Socket/Book linked lists and cpu_topology updates are
57 * protected by "sched_domains_mutex".
58 */
59 static struct mask_info socket_info;
60 static struct mask_info book_info;
61 static struct mask_info drawer_info;
62
63 struct cpu_topology_s390 cpu_topology[NR_CPUS];
64 EXPORT_SYMBOL_GPL(cpu_topology);
65
66 cpumask_t cpus_with_topology;
67
cpu_group_map(struct mask_info * info,unsigned int cpu)68 static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
69 {
70 cpumask_t mask;
71
72 cpumask_copy(&mask, cpumask_of(cpu));
73 switch (topology_mode) {
74 case TOPOLOGY_MODE_HW:
75 while (info) {
76 if (cpumask_test_cpu(cpu, &info->mask)) {
77 mask = info->mask;
78 break;
79 }
80 info = info->next;
81 }
82 if (cpumask_empty(&mask))
83 cpumask_copy(&mask, cpumask_of(cpu));
84 break;
85 case TOPOLOGY_MODE_PACKAGE:
86 cpumask_copy(&mask, cpu_present_mask);
87 break;
88 default:
89 /* fallthrough */
90 case TOPOLOGY_MODE_SINGLE:
91 cpumask_copy(&mask, cpumask_of(cpu));
92 break;
93 }
94 return mask;
95 }
96
cpu_thread_map(unsigned int cpu)97 static cpumask_t cpu_thread_map(unsigned int cpu)
98 {
99 cpumask_t mask;
100 int i;
101
102 cpumask_copy(&mask, cpumask_of(cpu));
103 if (topology_mode != TOPOLOGY_MODE_HW)
104 return mask;
105 cpu -= cpu % (smp_cpu_mtid + 1);
106 for (i = 0; i <= smp_cpu_mtid; i++)
107 if (cpu_present(cpu + i))
108 cpumask_set_cpu(cpu + i, &mask);
109 return mask;
110 }
111
112 #define TOPOLOGY_CORE_BITS 64
113
add_cpus_to_mask(struct topology_core * tl_core,struct mask_info * drawer,struct mask_info * book,struct mask_info * socket)114 static void add_cpus_to_mask(struct topology_core *tl_core,
115 struct mask_info *drawer,
116 struct mask_info *book,
117 struct mask_info *socket)
118 {
119 struct cpu_topology_s390 *topo;
120 unsigned int core;
121
122 for_each_set_bit(core, &tl_core->mask, TOPOLOGY_CORE_BITS) {
123 unsigned int rcore;
124 int lcpu, i;
125
126 rcore = TOPOLOGY_CORE_BITS - 1 - core + tl_core->origin;
127 lcpu = smp_find_processor_id(rcore << smp_cpu_mt_shift);
128 if (lcpu < 0)
129 continue;
130 for (i = 0; i <= smp_cpu_mtid; i++) {
131 topo = &cpu_topology[lcpu + i];
132 topo->drawer_id = drawer->id;
133 topo->book_id = book->id;
134 topo->socket_id = socket->id;
135 topo->core_id = rcore;
136 topo->thread_id = lcpu + i;
137 topo->dedicated = tl_core->d;
138 cpumask_set_cpu(lcpu + i, &drawer->mask);
139 cpumask_set_cpu(lcpu + i, &book->mask);
140 cpumask_set_cpu(lcpu + i, &socket->mask);
141 cpumask_set_cpu(lcpu + i, &cpus_with_topology);
142 smp_cpu_set_polarization(lcpu + i, tl_core->pp);
143 }
144 }
145 }
146
clear_masks(void)147 static void clear_masks(void)
148 {
149 struct mask_info *info;
150
151 info = &socket_info;
152 while (info) {
153 cpumask_clear(&info->mask);
154 info = info->next;
155 }
156 info = &book_info;
157 while (info) {
158 cpumask_clear(&info->mask);
159 info = info->next;
160 }
161 info = &drawer_info;
162 while (info) {
163 cpumask_clear(&info->mask);
164 info = info->next;
165 }
166 }
167
next_tle(union topology_entry * tle)168 static union topology_entry *next_tle(union topology_entry *tle)
169 {
170 if (!tle->nl)
171 return (union topology_entry *)((struct topology_core *)tle + 1);
172 return (union topology_entry *)((struct topology_container *)tle + 1);
173 }
174
tl_to_masks(struct sysinfo_15_1_x * info)175 static void tl_to_masks(struct sysinfo_15_1_x *info)
176 {
177 struct mask_info *socket = &socket_info;
178 struct mask_info *book = &book_info;
179 struct mask_info *drawer = &drawer_info;
180 union topology_entry *tle, *end;
181
182 clear_masks();
183 tle = info->tle;
184 end = (union topology_entry *)((unsigned long)info + info->length);
185 while (tle < end) {
186 switch (tle->nl) {
187 case 3:
188 drawer = drawer->next;
189 drawer->id = tle->container.id;
190 break;
191 case 2:
192 book = book->next;
193 book->id = tle->container.id;
194 break;
195 case 1:
196 socket = socket->next;
197 socket->id = tle->container.id;
198 break;
199 case 0:
200 add_cpus_to_mask(&tle->cpu, drawer, book, socket);
201 break;
202 default:
203 clear_masks();
204 return;
205 }
206 tle = next_tle(tle);
207 }
208 }
209
topology_update_polarization_simple(void)210 static void topology_update_polarization_simple(void)
211 {
212 int cpu;
213
214 for_each_possible_cpu(cpu)
215 smp_cpu_set_polarization(cpu, POLARIZATION_HRZ);
216 }
217
ptf(unsigned long fc)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
topology_set_cpu_management(int fc)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
update_cpu_masks(void)248 static void update_cpu_masks(void)
249 {
250 struct cpu_topology_s390 *topo;
251 int cpu, id;
252
253 for_each_possible_cpu(cpu) {
254 topo = &cpu_topology[cpu];
255 topo->thread_mask = cpu_thread_map(cpu);
256 topo->core_mask = cpu_group_map(&socket_info, cpu);
257 topo->book_mask = cpu_group_map(&book_info, cpu);
258 topo->drawer_mask = cpu_group_map(&drawer_info, cpu);
259 if (topology_mode != TOPOLOGY_MODE_HW) {
260 id = topology_mode == TOPOLOGY_MODE_PACKAGE ? 0 : cpu;
261 topo->thread_id = cpu;
262 topo->core_id = cpu;
263 topo->socket_id = id;
264 topo->book_id = id;
265 topo->drawer_id = id;
266 if (cpu_present(cpu))
267 cpumask_set_cpu(cpu, &cpus_with_topology);
268 }
269 }
270 numa_update_cpu_topology();
271 }
272
store_topology(struct sysinfo_15_1_x * info)273 void store_topology(struct sysinfo_15_1_x *info)
274 {
275 stsi(info, 15, 1, topology_mnest_limit());
276 }
277
__arch_update_dedicated_flag(void * arg)278 static void __arch_update_dedicated_flag(void *arg)
279 {
280 if (topology_cpu_dedicated(smp_processor_id()))
281 set_cpu_flag(CIF_DEDICATED_CPU);
282 else
283 clear_cpu_flag(CIF_DEDICATED_CPU);
284 }
285
__arch_update_cpu_topology(void)286 static int __arch_update_cpu_topology(void)
287 {
288 struct sysinfo_15_1_x *info = tl_info;
289 int rc = 0;
290
291 mutex_lock(&smp_cpu_state_mutex);
292 cpumask_clear(&cpus_with_topology);
293 if (MACHINE_HAS_TOPOLOGY) {
294 rc = 1;
295 store_topology(info);
296 tl_to_masks(info);
297 }
298 update_cpu_masks();
299 if (!MACHINE_HAS_TOPOLOGY)
300 topology_update_polarization_simple();
301 mutex_unlock(&smp_cpu_state_mutex);
302 return rc;
303 }
304
arch_update_cpu_topology(void)305 int arch_update_cpu_topology(void)
306 {
307 struct device *dev;
308 int cpu, rc;
309
310 rc = __arch_update_cpu_topology();
311 on_each_cpu(__arch_update_dedicated_flag, NULL, 0);
312 for_each_online_cpu(cpu) {
313 dev = get_cpu_device(cpu);
314 if (dev)
315 kobject_uevent(&dev->kobj, KOBJ_CHANGE);
316 }
317 return rc;
318 }
319
topology_work_fn(struct work_struct * work)320 static void topology_work_fn(struct work_struct *work)
321 {
322 rebuild_sched_domains();
323 }
324
topology_schedule_update(void)325 void topology_schedule_update(void)
326 {
327 schedule_work(&topology_work);
328 }
329
topology_flush_work(void)330 static void topology_flush_work(void)
331 {
332 flush_work(&topology_work);
333 }
334
topology_timer_fn(struct timer_list * unused)335 static void topology_timer_fn(struct timer_list *unused)
336 {
337 if (ptf(PTF_CHECK))
338 topology_schedule_update();
339 set_topology_timer();
340 }
341
342 static struct timer_list topology_timer;
343
344 static atomic_t topology_poll = ATOMIC_INIT(0);
345
set_topology_timer(void)346 static void set_topology_timer(void)
347 {
348 if (atomic_add_unless(&topology_poll, -1, 0))
349 mod_timer(&topology_timer, jiffies + HZ / 10);
350 else
351 mod_timer(&topology_timer, jiffies + HZ * 60);
352 }
353
topology_expect_change(void)354 void topology_expect_change(void)
355 {
356 if (!MACHINE_HAS_TOPOLOGY)
357 return;
358 /* This is racy, but it doesn't matter since it is just a heuristic.
359 * Worst case is that we poll in a higher frequency for a bit longer.
360 */
361 if (atomic_read(&topology_poll) > 60)
362 return;
363 atomic_add(60, &topology_poll);
364 set_topology_timer();
365 }
366
367 static int cpu_management;
368
dispatching_show(struct device * dev,struct device_attribute * attr,char * buf)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
dispatching_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)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_RW(dispatching);
409
cpu_polarization_show(struct device * dev,struct device_attribute * attr,char * buf)410 static ssize_t cpu_polarization_show(struct device *dev,
411 struct device_attribute *attr, char *buf)
412 {
413 int cpu = dev->id;
414 ssize_t count;
415
416 mutex_lock(&smp_cpu_state_mutex);
417 switch (smp_cpu_get_polarization(cpu)) {
418 case POLARIZATION_HRZ:
419 count = sprintf(buf, "horizontal\n");
420 break;
421 case POLARIZATION_VL:
422 count = sprintf(buf, "vertical:low\n");
423 break;
424 case POLARIZATION_VM:
425 count = sprintf(buf, "vertical:medium\n");
426 break;
427 case POLARIZATION_VH:
428 count = sprintf(buf, "vertical:high\n");
429 break;
430 default:
431 count = sprintf(buf, "unknown\n");
432 break;
433 }
434 mutex_unlock(&smp_cpu_state_mutex);
435 return count;
436 }
437 static DEVICE_ATTR(polarization, 0444, cpu_polarization_show, NULL);
438
439 static struct attribute *topology_cpu_attrs[] = {
440 &dev_attr_polarization.attr,
441 NULL,
442 };
443
444 static struct attribute_group topology_cpu_attr_group = {
445 .attrs = topology_cpu_attrs,
446 };
447
cpu_dedicated_show(struct device * dev,struct device_attribute * attr,char * buf)448 static ssize_t cpu_dedicated_show(struct device *dev,
449 struct device_attribute *attr, char *buf)
450 {
451 int cpu = dev->id;
452 ssize_t count;
453
454 mutex_lock(&smp_cpu_state_mutex);
455 count = sprintf(buf, "%d\n", topology_cpu_dedicated(cpu));
456 mutex_unlock(&smp_cpu_state_mutex);
457 return count;
458 }
459 static DEVICE_ATTR(dedicated, 0444, cpu_dedicated_show, NULL);
460
461 static struct attribute *topology_extra_cpu_attrs[] = {
462 &dev_attr_dedicated.attr,
463 NULL,
464 };
465
466 static struct attribute_group topology_extra_cpu_attr_group = {
467 .attrs = topology_extra_cpu_attrs,
468 };
469
topology_cpu_init(struct cpu * cpu)470 int topology_cpu_init(struct cpu *cpu)
471 {
472 int rc;
473
474 rc = sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
475 if (rc || !MACHINE_HAS_TOPOLOGY)
476 return rc;
477 rc = sysfs_create_group(&cpu->dev.kobj, &topology_extra_cpu_attr_group);
478 if (rc)
479 sysfs_remove_group(&cpu->dev.kobj, &topology_cpu_attr_group);
480 return rc;
481 }
482
cpu_thread_mask(int cpu)483 static const struct cpumask *cpu_thread_mask(int cpu)
484 {
485 return &cpu_topology[cpu].thread_mask;
486 }
487
488
cpu_coregroup_mask(int cpu)489 const struct cpumask *cpu_coregroup_mask(int cpu)
490 {
491 return &cpu_topology[cpu].core_mask;
492 }
493
cpu_book_mask(int cpu)494 static const struct cpumask *cpu_book_mask(int cpu)
495 {
496 return &cpu_topology[cpu].book_mask;
497 }
498
cpu_drawer_mask(int cpu)499 static const struct cpumask *cpu_drawer_mask(int cpu)
500 {
501 return &cpu_topology[cpu].drawer_mask;
502 }
503
504 static struct sched_domain_topology_level s390_topology[] = {
505 { cpu_thread_mask, cpu_smt_flags, SD_INIT_NAME(SMT) },
506 { cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) },
507 { cpu_book_mask, SD_INIT_NAME(BOOK) },
508 { cpu_drawer_mask, SD_INIT_NAME(DRAWER) },
509 { cpu_cpu_mask, SD_INIT_NAME(DIE) },
510 { NULL, },
511 };
512
alloc_masks(struct sysinfo_15_1_x * info,struct mask_info * mask,int offset)513 static void __init alloc_masks(struct sysinfo_15_1_x *info,
514 struct mask_info *mask, int offset)
515 {
516 int i, nr_masks;
517
518 nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
519 for (i = 0; i < info->mnest - offset; i++)
520 nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
521 nr_masks = max(nr_masks, 1);
522 for (i = 0; i < nr_masks; i++) {
523 mask->next = memblock_alloc(sizeof(*mask->next), 8);
524 if (!mask->next)
525 panic("%s: Failed to allocate %zu bytes align=0x%x\n",
526 __func__, sizeof(*mask->next), 8);
527 mask = mask->next;
528 }
529 }
530
topology_init_early(void)531 void __init topology_init_early(void)
532 {
533 struct sysinfo_15_1_x *info;
534
535 set_sched_topology(s390_topology);
536 if (topology_mode == TOPOLOGY_MODE_UNINITIALIZED) {
537 if (MACHINE_HAS_TOPOLOGY)
538 topology_mode = TOPOLOGY_MODE_HW;
539 else
540 topology_mode = TOPOLOGY_MODE_SINGLE;
541 }
542 if (!MACHINE_HAS_TOPOLOGY)
543 goto out;
544 tl_info = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
545 if (!tl_info)
546 panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
547 __func__, PAGE_SIZE, PAGE_SIZE);
548 info = tl_info;
549 store_topology(info);
550 pr_info("The CPU configuration topology of the machine is: %d %d %d %d %d %d / %d\n",
551 info->mag[0], info->mag[1], info->mag[2], info->mag[3],
552 info->mag[4], info->mag[5], info->mnest);
553 alloc_masks(info, &socket_info, 1);
554 alloc_masks(info, &book_info, 2);
555 alloc_masks(info, &drawer_info, 3);
556 out:
557 __arch_update_cpu_topology();
558 __arch_update_dedicated_flag(NULL);
559 }
560
topology_get_mode(int enabled)561 static inline int topology_get_mode(int enabled)
562 {
563 if (!enabled)
564 return TOPOLOGY_MODE_SINGLE;
565 return MACHINE_HAS_TOPOLOGY ? TOPOLOGY_MODE_HW : TOPOLOGY_MODE_PACKAGE;
566 }
567
topology_is_enabled(void)568 static inline int topology_is_enabled(void)
569 {
570 return topology_mode != TOPOLOGY_MODE_SINGLE;
571 }
572
topology_setup(char * str)573 static int __init topology_setup(char *str)
574 {
575 bool enabled;
576 int rc;
577
578 rc = kstrtobool(str, &enabled);
579 if (rc)
580 return rc;
581 topology_mode = topology_get_mode(enabled);
582 return 0;
583 }
584 early_param("topology", topology_setup);
585
topology_ctl_handler(struct ctl_table * ctl,int write,void __user * buffer,size_t * lenp,loff_t * ppos)586 static int topology_ctl_handler(struct ctl_table *ctl, int write,
587 void __user *buffer, size_t *lenp, loff_t *ppos)
588 {
589 int enabled = topology_is_enabled();
590 int new_mode;
591 int rc;
592 struct ctl_table ctl_entry = {
593 .procname = ctl->procname,
594 .data = &enabled,
595 .maxlen = sizeof(int),
596 .extra1 = SYSCTL_ZERO,
597 .extra2 = SYSCTL_ONE,
598 };
599
600 rc = proc_douintvec_minmax(&ctl_entry, write, buffer, lenp, ppos);
601 if (rc < 0 || !write)
602 return rc;
603
604 mutex_lock(&smp_cpu_state_mutex);
605 new_mode = topology_get_mode(enabled);
606 if (topology_mode != new_mode) {
607 topology_mode = new_mode;
608 topology_schedule_update();
609 }
610 mutex_unlock(&smp_cpu_state_mutex);
611 topology_flush_work();
612
613 return rc;
614 }
615
616 static struct ctl_table topology_ctl_table[] = {
617 {
618 .procname = "topology",
619 .mode = 0644,
620 .proc_handler = topology_ctl_handler,
621 },
622 { },
623 };
624
625 static struct ctl_table topology_dir_table[] = {
626 {
627 .procname = "s390",
628 .maxlen = 0,
629 .mode = 0555,
630 .child = topology_ctl_table,
631 },
632 { },
633 };
634
topology_init(void)635 static int __init topology_init(void)
636 {
637 timer_setup(&topology_timer, topology_timer_fn, TIMER_DEFERRABLE);
638 if (MACHINE_HAS_TOPOLOGY)
639 set_topology_timer();
640 else
641 topology_update_polarization_simple();
642 register_sysctl_table(topology_dir_table);
643 return device_create_file(cpu_subsys.dev_root, &dev_attr_dispatching);
644 }
645 device_initcall(topology_init);
646
