xref: /linux/arch/s390/kernel/topology.c (revision 3fd6c59042dbba50391e30862beac979491145fe)
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/hiperdispatch.h>
28 #include <asm/sysinfo.h>
29 #include <asm/asm.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 static int cpu_management;
53 
54 static DECLARE_WORK(topology_work, topology_work_fn);
55 
56 /*
57  * Socket/Book linked lists and cpu_topology updates are
58  * protected by "sched_domains_mutex".
59  */
60 static struct mask_info socket_info;
61 static struct mask_info book_info;
62 static struct mask_info drawer_info;
63 
64 struct cpu_topology_s390 cpu_topology[NR_CPUS];
65 EXPORT_SYMBOL_GPL(cpu_topology);
66 
cpu_group_map(cpumask_t * dst,struct mask_info * info,unsigned int cpu)67 static void cpu_group_map(cpumask_t *dst, struct mask_info *info, unsigned int cpu)
68 {
69 	static cpumask_t mask;
70 
71 	cpumask_clear(&mask);
72 	if (!cpumask_test_cpu(cpu, &cpu_setup_mask))
73 		goto out;
74 	cpumask_set_cpu(cpu, &mask);
75 	switch (topology_mode) {
76 	case TOPOLOGY_MODE_HW:
77 		while (info) {
78 			if (cpumask_test_cpu(cpu, &info->mask)) {
79 				cpumask_copy(&mask, &info->mask);
80 				break;
81 			}
82 			info = info->next;
83 		}
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 		break;
92 	}
93 	cpumask_and(&mask, &mask, &cpu_setup_mask);
94 out:
95 	cpumask_copy(dst, &mask);
96 }
97 
cpu_thread_map(cpumask_t * dst,unsigned int cpu)98 static void cpu_thread_map(cpumask_t *dst, unsigned int cpu)
99 {
100 	static cpumask_t mask;
101 	unsigned int max_cpu;
102 
103 	cpumask_clear(&mask);
104 	if (!cpumask_test_cpu(cpu, &cpu_setup_mask))
105 		goto out;
106 	cpumask_set_cpu(cpu, &mask);
107 	if (topology_mode != TOPOLOGY_MODE_HW)
108 		goto out;
109 	cpu -= cpu % (smp_cpu_mtid + 1);
110 	max_cpu = min(cpu + smp_cpu_mtid, nr_cpu_ids - 1);
111 	for (; cpu <= max_cpu; cpu++) {
112 		if (cpumask_test_cpu(cpu, &cpu_setup_mask))
113 			cpumask_set_cpu(cpu, &mask);
114 	}
115 out:
116 	cpumask_copy(dst, &mask);
117 }
118 
119 #define TOPOLOGY_CORE_BITS	64
120 
add_cpus_to_mask(struct topology_core * tl_core,struct mask_info * drawer,struct mask_info * book,struct mask_info * socket)121 static void add_cpus_to_mask(struct topology_core *tl_core,
122 			     struct mask_info *drawer,
123 			     struct mask_info *book,
124 			     struct mask_info *socket)
125 {
126 	struct cpu_topology_s390 *topo;
127 	unsigned int core;
128 
129 	for_each_set_bit(core, &tl_core->mask, TOPOLOGY_CORE_BITS) {
130 		unsigned int max_cpu, rcore;
131 		int cpu;
132 
133 		rcore = TOPOLOGY_CORE_BITS - 1 - core + tl_core->origin;
134 		cpu = smp_find_processor_id(rcore << smp_cpu_mt_shift);
135 		if (cpu < 0)
136 			continue;
137 		max_cpu = min(cpu + smp_cpu_mtid, nr_cpu_ids - 1);
138 		for (; cpu <= max_cpu; cpu++) {
139 			topo = &cpu_topology[cpu];
140 			topo->drawer_id = drawer->id;
141 			topo->book_id = book->id;
142 			topo->socket_id = socket->id;
143 			topo->core_id = rcore;
144 			topo->thread_id = cpu;
145 			topo->dedicated = tl_core->d;
146 			cpumask_set_cpu(cpu, &drawer->mask);
147 			cpumask_set_cpu(cpu, &book->mask);
148 			cpumask_set_cpu(cpu, &socket->mask);
149 			smp_cpu_set_polarization(cpu, tl_core->pp);
150 			smp_cpu_set_capacity(cpu, CPU_CAPACITY_HIGH);
151 		}
152 	}
153 }
154 
clear_masks(void)155 static void clear_masks(void)
156 {
157 	struct mask_info *info;
158 
159 	info = &socket_info;
160 	while (info) {
161 		cpumask_clear(&info->mask);
162 		info = info->next;
163 	}
164 	info = &book_info;
165 	while (info) {
166 		cpumask_clear(&info->mask);
167 		info = info->next;
168 	}
169 	info = &drawer_info;
170 	while (info) {
171 		cpumask_clear(&info->mask);
172 		info = info->next;
173 	}
174 }
175 
next_tle(union topology_entry * tle)176 static union topology_entry *next_tle(union topology_entry *tle)
177 {
178 	if (!tle->nl)
179 		return (union topology_entry *)((struct topology_core *)tle + 1);
180 	return (union topology_entry *)((struct topology_container *)tle + 1);
181 }
182 
tl_to_masks(struct sysinfo_15_1_x * info)183 static void tl_to_masks(struct sysinfo_15_1_x *info)
184 {
185 	struct mask_info *socket = &socket_info;
186 	struct mask_info *book = &book_info;
187 	struct mask_info *drawer = &drawer_info;
188 	union topology_entry *tle, *end;
189 
190 	clear_masks();
191 	tle = info->tle;
192 	end = (union topology_entry *)((unsigned long)info + info->length);
193 	while (tle < end) {
194 		switch (tle->nl) {
195 		case 3:
196 			drawer = drawer->next;
197 			drawer->id = tle->container.id;
198 			break;
199 		case 2:
200 			book = book->next;
201 			book->id = tle->container.id;
202 			break;
203 		case 1:
204 			socket = socket->next;
205 			socket->id = tle->container.id;
206 			break;
207 		case 0:
208 			add_cpus_to_mask(&tle->cpu, drawer, book, socket);
209 			break;
210 		default:
211 			clear_masks();
212 			return;
213 		}
214 		tle = next_tle(tle);
215 	}
216 }
217 
topology_update_polarization_simple(void)218 static void topology_update_polarization_simple(void)
219 {
220 	int cpu;
221 
222 	for_each_possible_cpu(cpu)
223 		smp_cpu_set_polarization(cpu, POLARIZATION_HRZ);
224 }
225 
ptf(unsigned long fc)226 static int ptf(unsigned long fc)
227 {
228 	int cc;
229 
230 	asm volatile(
231 		"	.insn	rre,0xb9a20000,%[fc],%[fc]\n"
232 		CC_IPM(cc)
233 		: CC_OUT(cc, cc)
234 		: [fc] "d" (fc)
235 		: CC_CLOBBER);
236 	return CC_TRANSFORM(cc);
237 }
238 
topology_set_cpu_management(int fc)239 int topology_set_cpu_management(int fc)
240 {
241 	int cpu, rc;
242 
243 	if (!MACHINE_HAS_TOPOLOGY)
244 		return -EOPNOTSUPP;
245 	if (fc)
246 		rc = ptf(PTF_VERTICAL);
247 	else
248 		rc = ptf(PTF_HORIZONTAL);
249 	if (rc)
250 		return -EBUSY;
251 	for_each_possible_cpu(cpu)
252 		smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
253 	return rc;
254 }
255 
update_cpu_masks(void)256 void update_cpu_masks(void)
257 {
258 	struct cpu_topology_s390 *topo, *topo_package, *topo_sibling;
259 	int cpu, sibling, pkg_first, smt_first, id;
260 
261 	for_each_possible_cpu(cpu) {
262 		topo = &cpu_topology[cpu];
263 		cpu_thread_map(&topo->thread_mask, cpu);
264 		cpu_group_map(&topo->core_mask, &socket_info, cpu);
265 		cpu_group_map(&topo->book_mask, &book_info, cpu);
266 		cpu_group_map(&topo->drawer_mask, &drawer_info, cpu);
267 		topo->booted_cores = 0;
268 		if (topology_mode != TOPOLOGY_MODE_HW) {
269 			id = topology_mode == TOPOLOGY_MODE_PACKAGE ? 0 : cpu;
270 			topo->thread_id = cpu;
271 			topo->core_id = cpu;
272 			topo->socket_id = id;
273 			topo->book_id = id;
274 			topo->drawer_id = id;
275 		}
276 	}
277 	hd_reset_state();
278 	for_each_online_cpu(cpu) {
279 		topo = &cpu_topology[cpu];
280 		pkg_first = cpumask_first(&topo->core_mask);
281 		topo_package = &cpu_topology[pkg_first];
282 		if (cpu == pkg_first) {
283 			for_each_cpu(sibling, &topo->core_mask) {
284 				topo_sibling = &cpu_topology[sibling];
285 				smt_first = cpumask_first(&topo_sibling->thread_mask);
286 				if (sibling == smt_first) {
287 					topo_package->booted_cores++;
288 					hd_add_core(sibling);
289 				}
290 			}
291 		} else {
292 			topo->booted_cores = topo_package->booted_cores;
293 		}
294 	}
295 }
296 
store_topology(struct sysinfo_15_1_x * info)297 void store_topology(struct sysinfo_15_1_x *info)
298 {
299 	stsi(info, 15, 1, topology_mnest_limit());
300 }
301 
__arch_update_dedicated_flag(void * arg)302 static void __arch_update_dedicated_flag(void *arg)
303 {
304 	if (topology_cpu_dedicated(smp_processor_id()))
305 		set_cpu_flag(CIF_DEDICATED_CPU);
306 	else
307 		clear_cpu_flag(CIF_DEDICATED_CPU);
308 }
309 
__arch_update_cpu_topology(void)310 static int __arch_update_cpu_topology(void)
311 {
312 	struct sysinfo_15_1_x *info = tl_info;
313 	int rc, hd_status;
314 
315 	hd_status = 0;
316 	rc = 0;
317 	mutex_lock(&smp_cpu_state_mutex);
318 	if (MACHINE_HAS_TOPOLOGY) {
319 		rc = 1;
320 		store_topology(info);
321 		tl_to_masks(info);
322 	}
323 	update_cpu_masks();
324 	if (!MACHINE_HAS_TOPOLOGY)
325 		topology_update_polarization_simple();
326 	if (cpu_management == 1)
327 		hd_status = hd_enable_hiperdispatch();
328 	mutex_unlock(&smp_cpu_state_mutex);
329 	if (hd_status == 0)
330 		hd_disable_hiperdispatch();
331 	return rc;
332 }
333 
arch_update_cpu_topology(void)334 int arch_update_cpu_topology(void)
335 {
336 	int rc;
337 
338 	rc = __arch_update_cpu_topology();
339 	on_each_cpu(__arch_update_dedicated_flag, NULL, 0);
340 	return rc;
341 }
342 
topology_work_fn(struct work_struct * work)343 static void topology_work_fn(struct work_struct *work)
344 {
345 	rebuild_sched_domains();
346 }
347 
topology_schedule_update(void)348 void topology_schedule_update(void)
349 {
350 	schedule_work(&topology_work);
351 }
352 
topology_flush_work(void)353 static void topology_flush_work(void)
354 {
355 	flush_work(&topology_work);
356 }
357 
topology_timer_fn(struct timer_list * unused)358 static void topology_timer_fn(struct timer_list *unused)
359 {
360 	if (ptf(PTF_CHECK))
361 		topology_schedule_update();
362 	set_topology_timer();
363 }
364 
365 static struct timer_list topology_timer;
366 
367 static atomic_t topology_poll = ATOMIC_INIT(0);
368 
set_topology_timer(void)369 static void set_topology_timer(void)
370 {
371 	if (atomic_add_unless(&topology_poll, -1, 0))
372 		mod_timer(&topology_timer, jiffies + msecs_to_jiffies(100));
373 	else
374 		mod_timer(&topology_timer, jiffies + msecs_to_jiffies(60 * MSEC_PER_SEC));
375 }
376 
topology_expect_change(void)377 void topology_expect_change(void)
378 {
379 	if (!MACHINE_HAS_TOPOLOGY)
380 		return;
381 	/* This is racy, but it doesn't matter since it is just a heuristic.
382 	 * Worst case is that we poll in a higher frequency for a bit longer.
383 	 */
384 	if (atomic_read(&topology_poll) > 60)
385 		return;
386 	atomic_add(60, &topology_poll);
387 	set_topology_timer();
388 }
389 
set_polarization(int polarization)390 static int set_polarization(int polarization)
391 {
392 	int rc = 0;
393 
394 	cpus_read_lock();
395 	mutex_lock(&smp_cpu_state_mutex);
396 	if (cpu_management == polarization)
397 		goto out;
398 	rc = topology_set_cpu_management(polarization);
399 	if (rc)
400 		goto out;
401 	cpu_management = polarization;
402 	topology_expect_change();
403 out:
404 	mutex_unlock(&smp_cpu_state_mutex);
405 	cpus_read_unlock();
406 	return rc;
407 }
408 
dispatching_show(struct device * dev,struct device_attribute * attr,char * buf)409 static ssize_t dispatching_show(struct device *dev,
410 				struct device_attribute *attr,
411 				char *buf)
412 {
413 	ssize_t count;
414 
415 	mutex_lock(&smp_cpu_state_mutex);
416 	count = sysfs_emit(buf, "%d\n", cpu_management);
417 	mutex_unlock(&smp_cpu_state_mutex);
418 	return count;
419 }
420 
dispatching_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)421 static ssize_t dispatching_store(struct device *dev,
422 				 struct device_attribute *attr,
423 				 const char *buf,
424 				 size_t count)
425 {
426 	int val, rc;
427 	char delim;
428 
429 	if (sscanf(buf, "%d %c", &val, &delim) != 1)
430 		return -EINVAL;
431 	if (val != 0 && val != 1)
432 		return -EINVAL;
433 	rc = set_polarization(val);
434 	return rc ? rc : count;
435 }
436 static DEVICE_ATTR_RW(dispatching);
437 
cpu_polarization_show(struct device * dev,struct device_attribute * attr,char * buf)438 static ssize_t cpu_polarization_show(struct device *dev,
439 				     struct device_attribute *attr, char *buf)
440 {
441 	int cpu = dev->id;
442 	ssize_t count;
443 
444 	mutex_lock(&smp_cpu_state_mutex);
445 	switch (smp_cpu_get_polarization(cpu)) {
446 	case POLARIZATION_HRZ:
447 		count = sysfs_emit(buf, "horizontal\n");
448 		break;
449 	case POLARIZATION_VL:
450 		count = sysfs_emit(buf, "vertical:low\n");
451 		break;
452 	case POLARIZATION_VM:
453 		count = sysfs_emit(buf, "vertical:medium\n");
454 		break;
455 	case POLARIZATION_VH:
456 		count = sysfs_emit(buf, "vertical:high\n");
457 		break;
458 	default:
459 		count = sysfs_emit(buf, "unknown\n");
460 		break;
461 	}
462 	mutex_unlock(&smp_cpu_state_mutex);
463 	return count;
464 }
465 static DEVICE_ATTR(polarization, 0444, cpu_polarization_show, NULL);
466 
467 static struct attribute *topology_cpu_attrs[] = {
468 	&dev_attr_polarization.attr,
469 	NULL,
470 };
471 
472 static struct attribute_group topology_cpu_attr_group = {
473 	.attrs = topology_cpu_attrs,
474 };
475 
cpu_dedicated_show(struct device * dev,struct device_attribute * attr,char * buf)476 static ssize_t cpu_dedicated_show(struct device *dev,
477 				  struct device_attribute *attr, char *buf)
478 {
479 	int cpu = dev->id;
480 	ssize_t count;
481 
482 	mutex_lock(&smp_cpu_state_mutex);
483 	count = sysfs_emit(buf, "%d\n", topology_cpu_dedicated(cpu));
484 	mutex_unlock(&smp_cpu_state_mutex);
485 	return count;
486 }
487 static DEVICE_ATTR(dedicated, 0444, cpu_dedicated_show, NULL);
488 
489 static struct attribute *topology_extra_cpu_attrs[] = {
490 	&dev_attr_dedicated.attr,
491 	NULL,
492 };
493 
494 static struct attribute_group topology_extra_cpu_attr_group = {
495 	.attrs = topology_extra_cpu_attrs,
496 };
497 
topology_cpu_init(struct cpu * cpu)498 int topology_cpu_init(struct cpu *cpu)
499 {
500 	int rc;
501 
502 	rc = sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
503 	if (rc || !MACHINE_HAS_TOPOLOGY)
504 		return rc;
505 	rc = sysfs_create_group(&cpu->dev.kobj, &topology_extra_cpu_attr_group);
506 	if (rc)
507 		sysfs_remove_group(&cpu->dev.kobj, &topology_cpu_attr_group);
508 	return rc;
509 }
510 
cpu_thread_mask(int cpu)511 static const struct cpumask *cpu_thread_mask(int cpu)
512 {
513 	return &cpu_topology[cpu].thread_mask;
514 }
515 
516 
cpu_coregroup_mask(int cpu)517 const struct cpumask *cpu_coregroup_mask(int cpu)
518 {
519 	return &cpu_topology[cpu].core_mask;
520 }
521 
cpu_book_mask(int cpu)522 static const struct cpumask *cpu_book_mask(int cpu)
523 {
524 	return &cpu_topology[cpu].book_mask;
525 }
526 
cpu_drawer_mask(int cpu)527 static const struct cpumask *cpu_drawer_mask(int cpu)
528 {
529 	return &cpu_topology[cpu].drawer_mask;
530 }
531 
532 static struct sched_domain_topology_level s390_topology[] = {
533 	{ cpu_thread_mask, cpu_smt_flags, SD_INIT_NAME(SMT) },
534 	{ cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) },
535 	{ cpu_book_mask, SD_INIT_NAME(BOOK) },
536 	{ cpu_drawer_mask, SD_INIT_NAME(DRAWER) },
537 	{ cpu_cpu_mask, SD_INIT_NAME(PKG) },
538 	{ NULL, },
539 };
540 
alloc_masks(struct sysinfo_15_1_x * info,struct mask_info * mask,int offset)541 static void __init alloc_masks(struct sysinfo_15_1_x *info,
542 			       struct mask_info *mask, int offset)
543 {
544 	int i, nr_masks;
545 
546 	nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
547 	for (i = 0; i < info->mnest - offset; i++)
548 		nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
549 	nr_masks = max(nr_masks, 1);
550 	for (i = 0; i < nr_masks; i++) {
551 		mask->next = memblock_alloc(sizeof(*mask->next), 8);
552 		if (!mask->next)
553 			panic("%s: Failed to allocate %zu bytes align=0x%x\n",
554 			      __func__, sizeof(*mask->next), 8);
555 		mask = mask->next;
556 	}
557 }
558 
topology_init_early(void)559 void __init topology_init_early(void)
560 {
561 	struct sysinfo_15_1_x *info;
562 
563 	set_sched_topology(s390_topology);
564 	if (topology_mode == TOPOLOGY_MODE_UNINITIALIZED) {
565 		if (MACHINE_HAS_TOPOLOGY)
566 			topology_mode = TOPOLOGY_MODE_HW;
567 		else
568 			topology_mode = TOPOLOGY_MODE_SINGLE;
569 	}
570 	if (!MACHINE_HAS_TOPOLOGY)
571 		goto out;
572 	tl_info = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
573 	if (!tl_info)
574 		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
575 		      __func__, PAGE_SIZE, PAGE_SIZE);
576 	info = tl_info;
577 	store_topology(info);
578 	pr_info("The CPU configuration topology of the machine is: %d %d %d %d %d %d / %d\n",
579 		info->mag[0], info->mag[1], info->mag[2], info->mag[3],
580 		info->mag[4], info->mag[5], info->mnest);
581 	alloc_masks(info, &socket_info, 1);
582 	alloc_masks(info, &book_info, 2);
583 	alloc_masks(info, &drawer_info, 3);
584 out:
585 	cpumask_set_cpu(0, &cpu_setup_mask);
586 	__arch_update_cpu_topology();
587 	__arch_update_dedicated_flag(NULL);
588 }
589 
topology_get_mode(int enabled)590 static inline int topology_get_mode(int enabled)
591 {
592 	if (!enabled)
593 		return TOPOLOGY_MODE_SINGLE;
594 	return MACHINE_HAS_TOPOLOGY ? TOPOLOGY_MODE_HW : TOPOLOGY_MODE_PACKAGE;
595 }
596 
topology_is_enabled(void)597 static inline int topology_is_enabled(void)
598 {
599 	return topology_mode != TOPOLOGY_MODE_SINGLE;
600 }
601 
topology_setup(char * str)602 static int __init topology_setup(char *str)
603 {
604 	bool enabled;
605 	int rc;
606 
607 	rc = kstrtobool(str, &enabled);
608 	if (rc)
609 		return rc;
610 	topology_mode = topology_get_mode(enabled);
611 	return 0;
612 }
613 early_param("topology", topology_setup);
614 
topology_ctl_handler(const struct ctl_table * ctl,int write,void * buffer,size_t * lenp,loff_t * ppos)615 static int topology_ctl_handler(const struct ctl_table *ctl, int write,
616 				void *buffer, size_t *lenp, loff_t *ppos)
617 {
618 	int enabled = topology_is_enabled();
619 	int new_mode;
620 	int rc;
621 	struct ctl_table ctl_entry = {
622 		.procname	= ctl->procname,
623 		.data		= &enabled,
624 		.maxlen		= sizeof(int),
625 		.extra1		= SYSCTL_ZERO,
626 		.extra2		= SYSCTL_ONE,
627 	};
628 
629 	rc = proc_douintvec_minmax(&ctl_entry, write, buffer, lenp, ppos);
630 	if (rc < 0 || !write)
631 		return rc;
632 
633 	mutex_lock(&smp_cpu_state_mutex);
634 	new_mode = topology_get_mode(enabled);
635 	if (topology_mode != new_mode) {
636 		topology_mode = new_mode;
637 		topology_schedule_update();
638 	}
639 	mutex_unlock(&smp_cpu_state_mutex);
640 	topology_flush_work();
641 
642 	return rc;
643 }
644 
polarization_ctl_handler(const struct ctl_table * ctl,int write,void * buffer,size_t * lenp,loff_t * ppos)645 static int polarization_ctl_handler(const struct ctl_table *ctl, int write,
646 				    void *buffer, size_t *lenp, loff_t *ppos)
647 {
648 	int polarization;
649 	int rc;
650 	struct ctl_table ctl_entry = {
651 		.procname	= ctl->procname,
652 		.data		= &polarization,
653 		.maxlen		= sizeof(int),
654 		.extra1		= SYSCTL_ZERO,
655 		.extra2		= SYSCTL_ONE,
656 	};
657 
658 	polarization = cpu_management;
659 	rc = proc_douintvec_minmax(&ctl_entry, write, buffer, lenp, ppos);
660 	if (rc < 0 || !write)
661 		return rc;
662 	return set_polarization(polarization);
663 }
664 
665 static struct ctl_table topology_ctl_table[] = {
666 	{
667 		.procname	= "topology",
668 		.mode		= 0644,
669 		.proc_handler	= topology_ctl_handler,
670 	},
671 	{
672 		.procname	= "polarization",
673 		.mode		= 0644,
674 		.proc_handler	= polarization_ctl_handler,
675 	},
676 };
677 
topology_init(void)678 static int __init topology_init(void)
679 {
680 	struct device *dev_root;
681 	int rc = 0;
682 
683 	timer_setup(&topology_timer, topology_timer_fn, TIMER_DEFERRABLE);
684 	if (MACHINE_HAS_TOPOLOGY)
685 		set_topology_timer();
686 	else
687 		topology_update_polarization_simple();
688 	if (IS_ENABLED(CONFIG_SCHED_TOPOLOGY_VERTICAL))
689 		set_polarization(1);
690 	register_sysctl("s390", topology_ctl_table);
691 
692 	dev_root = bus_get_dev_root(&cpu_subsys);
693 	if (dev_root) {
694 		rc = device_create_file(dev_root, &dev_attr_dispatching);
695 		put_device(dev_root);
696 	}
697 	return rc;
698 }
699 device_initcall(topology_init);
700