1	// SPDX-License-Identifier: GPL-2.0
2	/*
3	* Scheduler topology setup/handling methods
4	*/
5
6	#include <linux/bsearch.h>
7
8	DEFINE_MUTEX(sched_domains_mutex);
9
10	/* Protected by sched_domains_mutex: */
11	static cpumask_var_t sched_domains_tmpmask;
12	static cpumask_var_t sched_domains_tmpmask2;
13
14	#ifdef CONFIG_SCHED_DEBUG
15
16	static int __init sched_debug_setup(char *str)
17	{
18	sched_debug_verbose = true;
19
20	return 0;
21	}
22	early_param("sched_verbose", sched_debug_setup);
23
24	static inline bool sched_debug(void)
25	{
26	return sched_debug_verbose;
27	}
28
29	#define SD_FLAG(_name, mflags) [__##_name] = { .meta_flags = mflags, .name = #_name },
30	const struct sd_flag_debug sd_flag_debug[] = {
31	#include <linux/sched/sd_flags.h>
32	};
33	#undef SD_FLAG
34
35	static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
36	struct cpumask *groupmask)
37	{
38	struct sched_group *group = sd->groups;
39	unsigned long flags = sd->flags;
40	unsigned int idx;
41
42	cpumask_clear(dstp: groupmask);
43
44	printk(KERN_DEBUG "%*s domain-%d: ", level, "", level);
45	printk(KERN_CONT "span=%*pbl level=%s\n",
46	cpumask_pr_args(sched_domain_span(sd)), sd->name);
47
48	if (!cpumask_test_cpu(cpu, cpumask: sched_domain_span(sd))) {
49	printk(KERN_ERR "ERROR: domain->span does not contain CPU%d\n", cpu);
50	}
51	if (group && !cpumask_test_cpu(cpu, cpumask: sched_group_span(sg: group))) {
52	printk(KERN_ERR "ERROR: domain->groups does not contain CPU%d\n", cpu);
53	}
54
55	for_each_set_bit(idx, &flags, __SD_FLAG_CNT) {
56	unsigned int flag = BIT(idx);
57	unsigned int meta_flags = sd_flag_debug[idx].meta_flags;
58
59	if ((meta_flags & SDF_SHARED_CHILD) && sd->child &&
60	!(sd->child->flags & flag))
61	printk(KERN_ERR "ERROR: flag %s set here but not in child\n",
62	sd_flag_debug[idx].name);
63
64	if ((meta_flags & SDF_SHARED_PARENT) && sd->parent &&
65	!(sd->parent->flags & flag))
66	printk(KERN_ERR "ERROR: flag %s set here but not in parent\n",
67	sd_flag_debug[idx].name);
68	}
69
70	printk(KERN_DEBUG "%*s groups:", level + 1, "");
71	do {
72	if (!group) {
73	printk("\n");
74	printk(KERN_ERR "ERROR: group is NULL\n");
75	break;
76	}
77
78	if (cpumask_empty(srcp: sched_group_span(sg: group))) {
79	printk(KERN_CONT "\n");
80	printk(KERN_ERR "ERROR: empty group\n");
81	break;
82	}
83
84	if (!(sd->flags & SD_OVERLAP) &&
85	cpumask_intersects(src1p: groupmask, src2p: sched_group_span(sg: group))) {
86	printk(KERN_CONT "\n");
87	printk(KERN_ERR "ERROR: repeated CPUs\n");
88	break;
89	}
90
91	cpumask_or(dstp: groupmask, src1p: groupmask, src2p: sched_group_span(sg: group));
92
93	printk(KERN_CONT " %d:{ span=%*pbl",
94	group->sgc->id,
95	cpumask_pr_args(sched_group_span(group)));
96
97	if ((sd->flags & SD_OVERLAP) &&
98	!cpumask_equal(src1p: group_balance_mask(sg: group), src2p: sched_group_span(sg: group))) {
99	printk(KERN_CONT " mask=%*pbl",
100	cpumask_pr_args(group_balance_mask(group)));
101	}
102
103	if (group->sgc->capacity != SCHED_CAPACITY_SCALE)
104	printk(KERN_CONT " cap=%lu", group->sgc->capacity);
105
106	if (group == sd->groups && sd->child &&
107	!cpumask_equal(src1p: sched_domain_span(sd: sd->child),
108	src2p: sched_group_span(sg: group))) {
109	printk(KERN_ERR "ERROR: domain->groups does not match domain->child\n");
110	}
111
112	printk(KERN_CONT " }");
113
114	group = group->next;
115
116	if (group != sd->groups)
117	printk(KERN_CONT ",");
118
119	} while (group != sd->groups);
120	printk(KERN_CONT "\n");
121
122	if (!cpumask_equal(src1p: sched_domain_span(sd), src2p: groupmask))
123	printk(KERN_ERR "ERROR: groups don't span domain->span\n");
124
125	if (sd->parent &&
126	!cpumask_subset(src1p: groupmask, src2p: sched_domain_span(sd: sd->parent)))
127	printk(KERN_ERR "ERROR: parent span is not a superset of domain->span\n");
128	return 0;
129	}
130
131	static void sched_domain_debug(struct sched_domain *sd, int cpu)
132	{
133	int level = 0;
134
135	if (!sched_debug_verbose)
136	return;
137
138	if (!sd) {
139	printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu);
140	return;
141	}
142
143	printk(KERN_DEBUG "CPU%d attaching sched-domain(s):\n", cpu);
144
145	for (;;) {
146	if (sched_domain_debug_one(sd, cpu, level, groupmask: sched_domains_tmpmask))
147	break;
148	level++;
149	sd = sd->parent;
150	if (!sd)
151	break;
152	}
153	}
154	#else /* !CONFIG_SCHED_DEBUG */
155
156	# define sched_debug_verbose 0
157	# define sched_domain_debug(sd, cpu) do { } while (0)
158	static inline bool sched_debug(void)
159	{
160	return false;
161	}
162	#endif /* CONFIG_SCHED_DEBUG */
163
164	/* Generate a mask of SD flags with the SDF_NEEDS_GROUPS metaflag */
165	#define SD_FLAG(name, mflags) (name * !!((mflags) & SDF_NEEDS_GROUPS)) |
166	static const unsigned int SD_DEGENERATE_GROUPS_MASK =
167	#include <linux/sched/sd_flags.h>
168	0;
169	#undef SD_FLAG
170
171	static int sd_degenerate(struct sched_domain *sd)
172	{
173	if (cpumask_weight(srcp: sched_domain_span(sd)) == 1)
174	return 1;
175
176	/* Following flags need at least 2 groups */
177	if ((sd->flags & SD_DEGENERATE_GROUPS_MASK) &&
178	(sd->groups != sd->groups->next))
179	return 0;
180
181	/* Following flags don't use groups */
182	if (sd->flags & (SD_WAKE_AFFINE))
183	return 0;
184
185	return 1;
186	}
187
188	static int
189	sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
190	{
191	unsigned long cflags = sd->flags, pflags = parent->flags;
192
193	if (sd_degenerate(sd: parent))
194	return 1;
195
196	if (!cpumask_equal(src1p: sched_domain_span(sd), src2p: sched_domain_span(sd: parent)))
197	return 0;
198
199	/* Flags needing groups don't count if only 1 group in parent */
200	if (parent->groups == parent->groups->next)
201	pflags &= ~SD_DEGENERATE_GROUPS_MASK;
202
203	if (~cflags & pflags)
204	return 0;
205
206	return 1;
207	}
208
209	#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL)
210	DEFINE_STATIC_KEY_FALSE(sched_energy_present);
211	static unsigned int sysctl_sched_energy_aware = 1;
212	static DEFINE_MUTEX(sched_energy_mutex);
213	static bool sched_energy_update;
214
215	static bool sched_is_eas_possible(const struct cpumask *cpu_mask)
216	{
217	bool any_asym_capacity = false;
218	struct cpufreq_policy *policy;
219	struct cpufreq_governor *gov;
220	int i;
221
222	/* EAS is enabled for asymmetric CPU capacity topologies. */
223	for_each_cpu(i, cpu_mask) {
224	if (rcu_access_pointer(per_cpu(sd_asym_cpucapacity, i))) {
225	any_asym_capacity = true;
226	break;
227	}
228	}
229	if (!any_asym_capacity) {
230	if (sched_debug()) {
231	pr_info("rd %*pbl: Checking EAS, CPUs do not have asymmetric capacities\n",
232	cpumask_pr_args(cpu_mask));
233	}
234	return false;
235	}
236
237	/* EAS definitely does *not* handle SMT */
238	if (sched_smt_active()) {
239	if (sched_debug()) {
240	pr_info("rd %*pbl: Checking EAS, SMT is not supported\n",
241	cpumask_pr_args(cpu_mask));
242	}
243	return false;
244	}
245
246	if (!arch_scale_freq_invariant()) {
247	if (sched_debug()) {
248	pr_info("rd %*pbl: Checking EAS: frequency-invariant load tracking not yet supported",
249	cpumask_pr_args(cpu_mask));
250	}
251	return false;
252	}
253
254	/* Do not attempt EAS if schedutil is not being used. */
255	for_each_cpu(i, cpu_mask) {
256	policy = cpufreq_cpu_get(cpu: i);
257	if (!policy) {
258	if (sched_debug()) {
259	pr_info("rd %*pbl: Checking EAS, cpufreq policy not set for CPU: %d",
260	cpumask_pr_args(cpu_mask), i);
261	}
262	return false;
263	}
264	gov = policy->governor;
265	cpufreq_cpu_put(policy);
266	if (gov != &schedutil_gov) {
267	if (sched_debug()) {
268	pr_info("rd %*pbl: Checking EAS, schedutil is mandatory\n",
269	cpumask_pr_args(cpu_mask));
270	}
271	return false;
272	}
273	}
274
275	return true;
276	}
277
278	void rebuild_sched_domains_energy(void)
279	{
280	mutex_lock(&sched_energy_mutex);
281	sched_energy_update = true;
282	rebuild_sched_domains();
283	sched_energy_update = false;
284	mutex_unlock(lock: &sched_energy_mutex);
285	}
286
287	#ifdef CONFIG_PROC_SYSCTL
288	static int sched_energy_aware_handler(struct ctl_table *table, int write,
289	void *buffer, size_t *lenp, loff_t *ppos)
290	{
291	int ret, state;
292
293	if (write && !capable(CAP_SYS_ADMIN))
294	return -EPERM;
295
296	if (!sched_is_eas_possible(cpu_active_mask)) {
297	if (write) {
298	return -EOPNOTSUPP;
299	} else {
300	*lenp = 0;
301	return 0;
302	}
303	}
304
305	ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
306	if (!ret && write) {
307	state = static_branch_unlikely(&sched_energy_present);
308	if (state != sysctl_sched_energy_aware)
309	rebuild_sched_domains_energy();
310	}
311
312	return ret;
313	}
314
315	static struct ctl_table sched_energy_aware_sysctls[] = {
316	{
317	.procname = "sched_energy_aware",
318	.data = &sysctl_sched_energy_aware,
319	.maxlen = sizeof(unsigned int),
320	.mode = 0644,
321	.proc_handler = sched_energy_aware_handler,
322	.extra1 = SYSCTL_ZERO,
323	.extra2 = SYSCTL_ONE,
324	},
325	{}
326	};
327
328	static int __init sched_energy_aware_sysctl_init(void)
329	{
330	register_sysctl_init("kernel", sched_energy_aware_sysctls);
331	return 0;
332	}
333
334	late_initcall(sched_energy_aware_sysctl_init);
335	#endif
336
337	static void free_pd(struct perf_domain *pd)
338	{
339	struct perf_domain *tmp;
340
341	while (pd) {
342	tmp = pd->next;
343	kfree(objp: pd);
344	pd = tmp;
345	}
346	}
347
348	static struct perf_domain *find_pd(struct perf_domain *pd, int cpu)
349	{
350	while (pd) {
351	if (cpumask_test_cpu(cpu, perf_domain_span(pd)))
352	return pd;
353	pd = pd->next;
354	}
355
356	return NULL;
357	}
358
359	static struct perf_domain *pd_init(int cpu)
360	{
361	struct em_perf_domain *obj = em_cpu_get(cpu);
362	struct perf_domain *pd;
363
364	if (!obj) {
365	if (sched_debug())
366	pr_info("%s: no EM found for CPU%d\n", __func__, cpu);
367	return NULL;
368	}
369
370	pd = kzalloc(size: sizeof(*pd), GFP_KERNEL);
371	if (!pd)
372	return NULL;
373	pd->em_pd = obj;
374
375	return pd;
376	}
377
378	static void perf_domain_debug(const struct cpumask *cpu_map,
379	struct perf_domain *pd)
380	{
381	if (!sched_debug() || !pd)
382	return;
383
384	printk(KERN_DEBUG "root_domain %*pbl:", cpumask_pr_args(cpu_map));
385
386	while (pd) {
387	printk(KERN_CONT " pd%d:{ cpus=%*pbl nr_pstate=%d }",
388	cpumask_first(perf_domain_span(pd)),
389	cpumask_pr_args(perf_domain_span(pd)),
390	em_pd_nr_perf_states(pd->em_pd));
391	pd = pd->next;
392	}
393
394	printk(KERN_CONT "\n");
395	}
396
397	static void destroy_perf_domain_rcu(struct rcu_head *rp)
398	{
399	struct perf_domain *pd;
400
401	pd = container_of(rp, struct perf_domain, rcu);
402	free_pd(pd);
403	}
404
405	static void sched_energy_set(bool has_eas)
406	{
407	if (!has_eas && static_branch_unlikely(&sched_energy_present)) {
408	if (sched_debug())
409	pr_info("%s: stopping EAS\n", __func__);
410	static_branch_disable_cpuslocked(&sched_energy_present);
411	} else if (has_eas && !static_branch_unlikely(&sched_energy_present)) {
412	if (sched_debug())
413	pr_info("%s: starting EAS\n", __func__);
414	static_branch_enable_cpuslocked(&sched_energy_present);
415	}
416	}
417
418	/*
419	* EAS can be used on a root domain if it meets all the following conditions:
420	* 1. an Energy Model (EM) is available;
421	* 2. the SD_ASYM_CPUCAPACITY flag is set in the sched_domain hierarchy.
422	* 3. no SMT is detected.
423	* 4. schedutil is driving the frequency of all CPUs of the rd;
424	* 5. frequency invariance support is present;
425	*/
426	static bool build_perf_domains(const struct cpumask *cpu_map)
427	{
428	int i;
429	struct perf_domain *pd = NULL, *tmp;
430	int cpu = cpumask_first(srcp: cpu_map);
431	struct root_domain *rd = cpu_rq(cpu)->rd;
432
433	if (!sysctl_sched_energy_aware)
434	goto free;
435
436	if (!sched_is_eas_possible(cpu_mask: cpu_map))
437	goto free;
438
439	for_each_cpu(i, cpu_map) {
440	/* Skip already covered CPUs. */
441	if (find_pd(pd, cpu: i))
442	continue;
443
444	/* Create the new pd and add it to the local list. */
445	tmp = pd_init(cpu: i);
446	if (!tmp)
447	goto free;
448	tmp->next = pd;
449	pd = tmp;
450	}
451
452	perf_domain_debug(cpu_map, pd);
453
454	/* Attach the new list of performance domains to the root domain. */
455	tmp = rd->pd;
456	rcu_assign_pointer(rd->pd, pd);
457	if (tmp)
458	call_rcu(head: &tmp->rcu, func: destroy_perf_domain_rcu);
459
460	return !!pd;
461
462	free:
463	free_pd(pd);
464	tmp = rd->pd;
465	rcu_assign_pointer(rd->pd, NULL);
466	if (tmp)
467	call_rcu(head: &tmp->rcu, func: destroy_perf_domain_rcu);
468
469	return false;
470	}
471	#else
472	static void free_pd(struct perf_domain *pd) { }
473	#endif /* CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL*/
474
475	static void free_rootdomain(struct rcu_head *rcu)
476	{
477	struct root_domain *rd = container_of(rcu, struct root_domain, rcu);
478
479	cpupri_cleanup(cp: &rd->cpupri);
480	cpudl_cleanup(cp: &rd->cpudl);
481	free_cpumask_var(mask: rd->dlo_mask);
482	free_cpumask_var(mask: rd->rto_mask);
483	free_cpumask_var(mask: rd->online);
484	free_cpumask_var(mask: rd->span);
485	free_pd(pd: rd->pd);
486	kfree(objp: rd);
487	}
488
489	void rq_attach_root(struct rq *rq, struct root_domain *rd)
490	{
491	struct root_domain *old_rd = NULL;
492	struct rq_flags rf;
493
494	rq_lock_irqsave(rq, rf: &rf);
495
496	if (rq->rd) {
497	old_rd = rq->rd;
498
499	if (cpumask_test_cpu(cpu: rq->cpu, cpumask: old_rd->online))
500	set_rq_offline(rq);
501
502	cpumask_clear_cpu(cpu: rq->cpu, dstp: old_rd->span);
503
504	/*
505	* If we dont want to free the old_rd yet then
506	* set old_rd to NULL to skip the freeing later
507	* in this function:
508	*/
509	if (!atomic_dec_and_test(v: &old_rd->refcount))
510	old_rd = NULL;
511	}
512
513	atomic_inc(v: &rd->refcount);
514	rq->rd = rd;
515
516	cpumask_set_cpu(cpu: rq->cpu, dstp: rd->span);
517	if (cpumask_test_cpu(cpu: rq->cpu, cpu_active_mask))
518	set_rq_online(rq);
519
520	rq_unlock_irqrestore(rq, rf: &rf);
521
522	if (old_rd)
523	call_rcu(head: &old_rd->rcu, func: free_rootdomain);
524	}
525
526	void sched_get_rd(struct root_domain *rd)
527	{
528	atomic_inc(v: &rd->refcount);
529	}
530
531	void sched_put_rd(struct root_domain *rd)
532	{
533	if (!atomic_dec_and_test(v: &rd->refcount))
534	return;
535
536	call_rcu(head: &rd->rcu, func: free_rootdomain);
537	}
538
539	static int init_rootdomain(struct root_domain *rd)
540	{
541	if (!zalloc_cpumask_var(mask: &rd->span, GFP_KERNEL))
542	goto out;
543	if (!zalloc_cpumask_var(mask: &rd->online, GFP_KERNEL))
544	goto free_span;
545	if (!zalloc_cpumask_var(mask: &rd->dlo_mask, GFP_KERNEL))
546	goto free_online;
547	if (!zalloc_cpumask_var(mask: &rd->rto_mask, GFP_KERNEL))
548	goto free_dlo_mask;
549
550	#ifdef HAVE_RT_PUSH_IPI
551	rd->rto_cpu = -1;
552	raw_spin_lock_init(&rd->rto_lock);
553	rd->rto_push_work = IRQ_WORK_INIT_HARD(rto_push_irq_work_func);
554	#endif
555
556	rd->visit_gen = 0;
557	init_dl_bw(dl_b: &rd->dl_bw);
558	if (cpudl_init(cp: &rd->cpudl) != 0)
559	goto free_rto_mask;
560
561	if (cpupri_init(cp: &rd->cpupri) != 0)
562	goto free_cpudl;
563	return 0;
564
565	free_cpudl:
566	cpudl_cleanup(cp: &rd->cpudl);
567	free_rto_mask:
568	free_cpumask_var(mask: rd->rto_mask);
569	free_dlo_mask:
570	free_cpumask_var(mask: rd->dlo_mask);
571	free_online:
572	free_cpumask_var(mask: rd->online);
573	free_span:
574	free_cpumask_var(mask: rd->span);
575	out:
576	return -ENOMEM;
577	}
578
579	/*
580	* By default the system creates a single root-domain with all CPUs as
581	* members (mimicking the global state we have today).
582	*/
583	struct root_domain def_root_domain;
584
585	void __init init_defrootdomain(void)
586	{
587	init_rootdomain(rd: &def_root_domain);
588
589	atomic_set(v: &def_root_domain.refcount, i: 1);
590	}
591
592	static struct root_domain *alloc_rootdomain(void)
593	{
594	struct root_domain *rd;
595
596	rd = kzalloc(size: sizeof(*rd), GFP_KERNEL);
597	if (!rd)
598	return NULL;
599
600	if (init_rootdomain(rd) != 0) {
601	kfree(objp: rd);
602	return NULL;
603	}
604
605	return rd;
606	}
607
608	static void free_sched_groups(struct sched_group *sg, int free_sgc)
609	{
610	struct sched_group *tmp, *first;
611
612	if (!sg)
613	return;
614
615	first = sg;
616	do {
617	tmp = sg->next;
618
619	if (free_sgc && atomic_dec_and_test(v: &sg->sgc->ref))
620	kfree(objp: sg->sgc);
621
622	if (atomic_dec_and_test(v: &sg->ref))
623	kfree(objp: sg);
624	sg = tmp;
625	} while (sg != first);
626	}
627
628	static void destroy_sched_domain(struct sched_domain *sd)
629	{
630	/*
631	* A normal sched domain may have multiple group references, an
632	* overlapping domain, having private groups, only one. Iterate,
633	* dropping group/capacity references, freeing where none remain.
634	*/
635	free_sched_groups(sg: sd->groups, free_sgc: 1);
636
637	if (sd->shared && atomic_dec_and_test(v: &sd->shared->ref))
638	kfree(objp: sd->shared);
639	kfree(objp: sd);
640	}
641
642	static void destroy_sched_domains_rcu(struct rcu_head *rcu)
643	{
644	struct sched_domain *sd = container_of(rcu, struct sched_domain, rcu);
645
646	while (sd) {
647	struct sched_domain *parent = sd->parent;
648	destroy_sched_domain(sd);
649	sd = parent;
650	}
651	}
652
653	static void destroy_sched_domains(struct sched_domain *sd)
654	{
655	if (sd)
656	call_rcu(head: &sd->rcu, func: destroy_sched_domains_rcu);
657	}
658
659	/*
660	* Keep a special pointer to the highest sched_domain that has
661	* SD_SHARE_PKG_RESOURCE set (Last Level Cache Domain) for this
662	* allows us to avoid some pointer chasing select_idle_sibling().
663	*
664	* Also keep a unique ID per domain (we use the first CPU number in
665	* the cpumask of the domain), this allows us to quickly tell if
666	* two CPUs are in the same cache domain, see cpus_share_cache().
667	*/
668	DEFINE_PER_CPU(struct sched_domain __rcu *, sd_llc);
669	DEFINE_PER_CPU(int, sd_llc_size);
670	DEFINE_PER_CPU(int, sd_llc_id);
671	DEFINE_PER_CPU(int, sd_share_id);
672	DEFINE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared);
673	DEFINE_PER_CPU(struct sched_domain __rcu *, sd_numa);
674	DEFINE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing);
675	DEFINE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity);
676
677	DEFINE_STATIC_KEY_FALSE(sched_asym_cpucapacity);
678	DEFINE_STATIC_KEY_FALSE(sched_cluster_active);
679
680	static void update_top_cache_domain(int cpu)
681	{
682	struct sched_domain_shared *sds = NULL;
683	struct sched_domain *sd;
684	int id = cpu;
685	int size = 1;
686
687	sd = highest_flag_domain(cpu, flag: SD_SHARE_PKG_RESOURCES);
688	if (sd) {
689	id = cpumask_first(srcp: sched_domain_span(sd));
690	size = cpumask_weight(srcp: sched_domain_span(sd));
691	sds = sd->shared;
692	}
693
694	rcu_assign_pointer(per_cpu(sd_llc, cpu), sd);
695	per_cpu(sd_llc_size, cpu) = size;
696	per_cpu(sd_llc_id, cpu) = id;
697	rcu_assign_pointer(per_cpu(sd_llc_shared, cpu), sds);
698
699	sd = lowest_flag_domain(cpu, flag: SD_CLUSTER);
700	if (sd)
701	id = cpumask_first(srcp: sched_domain_span(sd));
702
703	/*
704	* This assignment should be placed after the sd_llc_id as
705	* we want this id equals to cluster id on cluster machines
706	* but equals to LLC id on non-Cluster machines.
707	*/
708	per_cpu(sd_share_id, cpu) = id;
709
710	sd = lowest_flag_domain(cpu, flag: SD_NUMA);
711	rcu_assign_pointer(per_cpu(sd_numa, cpu), sd);
712
713	sd = highest_flag_domain(cpu, flag: SD_ASYM_PACKING);
714	rcu_assign_pointer(per_cpu(sd_asym_packing, cpu), sd);
715
716	sd = lowest_flag_domain(cpu, flag: SD_ASYM_CPUCAPACITY_FULL);
717	rcu_assign_pointer(per_cpu(sd_asym_cpucapacity, cpu), sd);
718	}
719
720	/*
721	* Attach the domain 'sd' to 'cpu' as its base domain. Callers must
722	* hold the hotplug lock.
723	*/
724	static void
725	cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
726	{
727	struct rq *rq = cpu_rq(cpu);
728	struct sched_domain *tmp;
729
730	/* Remove the sched domains which do not contribute to scheduling. */
731	for (tmp = sd; tmp; ) {
732	struct sched_domain *parent = tmp->parent;
733	if (!parent)
734	break;
735
736	if (sd_parent_degenerate(sd: tmp, parent)) {
737	tmp->parent = parent->parent;
738
739	if (parent->parent) {
740	parent->parent->child = tmp;
741	parent->parent->groups->flags = tmp->flags;
742	}
743
744	/*
745	* Transfer SD_PREFER_SIBLING down in case of a
746	* degenerate parent; the spans match for this
747	* so the property transfers.
748	*/
749	if (parent->flags & SD_PREFER_SIBLING)
750	tmp->flags |= SD_PREFER_SIBLING;
751	destroy_sched_domain(sd: parent);
752	} else
753	tmp = tmp->parent;
754	}
755
756	if (sd && sd_degenerate(sd)) {
757	tmp = sd;
758	sd = sd->parent;
759	destroy_sched_domain(sd: tmp);
760	if (sd) {
761	struct sched_group *sg = sd->groups;
762
763	/*
764	* sched groups hold the flags of the child sched
765	* domain for convenience. Clear such flags since
766	* the child is being destroyed.
767	*/
768	do {
769	sg->flags = 0;
770	} while (sg != sd->groups);
771
772	sd->child = NULL;
773	}
774	}
775
776	sched_domain_debug(sd, cpu);
777
778	rq_attach_root(rq, rd);
779	tmp = rq->sd;
780	rcu_assign_pointer(rq->sd, sd);
781	dirty_sched_domain_sysctl(cpu);
782	destroy_sched_domains(sd: tmp);
783
784	update_top_cache_domain(cpu);
785	}
786
787	struct s_data {
788	struct sched_domain * __percpu *sd;
789	struct root_domain *rd;
790	};
791
792	enum s_alloc {
793	sa_rootdomain,
794	sa_sd,
795	sa_sd_storage,
796	sa_none,
797	};
798
799	/*
800	* Return the canonical balance CPU for this group, this is the first CPU
801	* of this group that's also in the balance mask.
802	*
803	* The balance mask are all those CPUs that could actually end up at this
804	* group. See build_balance_mask().
805	*
806	* Also see should_we_balance().
807	*/
808	int group_balance_cpu(struct sched_group *sg)
809	{
810	return cpumask_first(srcp: group_balance_mask(sg));
811	}
812
813
814	/*
815	* NUMA topology (first read the regular topology blurb below)
816	*
817	* Given a node-distance table, for example:
818	*
819	* node 0 1 2 3
820	* 0: 10 20 30 20
821	* 1: 20 10 20 30
822	* 2: 30 20 10 20
823	* 3: 20 30 20 10
824	*
825	* which represents a 4 node ring topology like:
826	*
827	* 0 ----- 1
828	* | |
829	* | |
830	* | |
831	* 3 ----- 2
832	*
833	* We want to construct domains and groups to represent this. The way we go
834	* about doing this is to build the domains on 'hops'. For each NUMA level we
835	* construct the mask of all nodes reachable in @level hops.
836	*
837	* For the above NUMA topology that gives 3 levels:
838	*
839	* NUMA-2 0-3 0-3 0-3 0-3
840	* groups: {0-1,3},{1-3} {0-2},{0,2-3} {1-3},{0-1,3} {0,2-3},{0-2}
841	*
842	* NUMA-1 0-1,3 0-2 1-3 0,2-3
843	* groups: {0},{1},{3} {0},{1},{2} {1},{2},{3} {0},{2},{3}
844	*
845	* NUMA-0 0 1 2 3
846	*
847	*
848	* As can be seen; things don't nicely line up as with the regular topology.
849	* When we iterate a domain in child domain chunks some nodes can be
850	* represented multiple times -- hence the "overlap" naming for this part of
851	* the topology.
852	*
853	* In order to minimize this overlap, we only build enough groups to cover the
854	* domain. For instance Node-0 NUMA-2 would only get groups: 0-1,3 and 1-3.
855	*
856	* Because:
857	*
858	* - the first group of each domain is its child domain; this
859	* gets us the first 0-1,3
860	* - the only uncovered node is 2, who's child domain is 1-3.
861	*
862	* However, because of the overlap, computing a unique CPU for each group is
863	* more complicated. Consider for instance the groups of NODE-1 NUMA-2, both
864	* groups include the CPUs of Node-0, while those CPUs would not in fact ever
865	* end up at those groups (they would end up in group: 0-1,3).
866	*
867	* To correct this we have to introduce the group balance mask. This mask
868	* will contain those CPUs in the group that can reach this group given the
869	* (child) domain tree.
870	*
871	* With this we can once again compute balance_cpu and sched_group_capacity
872	* relations.
873	*
874	* XXX include words on how balance_cpu is unique and therefore can be
875	* used for sched_group_capacity links.
876	*
877	*
878	* Another 'interesting' topology is:
879	*
880	* node 0 1 2 3
881	* 0: 10 20 20 30
882	* 1: 20 10 20 20
883	* 2: 20 20 10 20
884	* 3: 30 20 20 10
885	*
886	* Which looks a little like:
887	*
888	* 0 ----- 1
889	* | / |
890	* | / |
891	* | / |
892	* 2 ----- 3
893	*
894	* This topology is asymmetric, nodes 1,2 are fully connected, but nodes 0,3
895	* are not.
896	*
897	* This leads to a few particularly weird cases where the sched_domain's are
898	* not of the same number for each CPU. Consider:
899	*
900	* NUMA-2 0-3 0-3
901	* groups: {0-2},{1-3} {1-3},{0-2}
902	*
903	* NUMA-1 0-2 0-3 0-3 1-3
904	*
905	* NUMA-0 0 1 2 3
906	*
907	*/
908
909
910	/*
911	* Build the balance mask; it contains only those CPUs that can arrive at this
912	* group and should be considered to continue balancing.
913	*
914	* We do this during the group creation pass, therefore the group information
915	* isn't complete yet, however since each group represents a (child) domain we
916	* can fully construct this using the sched_domain bits (which are already
917	* complete).
918	*/
919	static void
920	build_balance_mask(struct sched_domain *sd, struct sched_group *sg, struct cpumask *mask)
921	{
922	const struct cpumask *sg_span = sched_group_span(sg);
923	struct sd_data *sdd = sd->private;
924	struct sched_domain *sibling;
925	int i;
926
927	cpumask_clear(dstp: mask);
928
929	for_each_cpu(i, sg_span) {
930	sibling = *per_cpu_ptr(sdd->sd, i);
931
932	/*
933	* Can happen in the asymmetric case, where these siblings are
934	* unused. The mask will not be empty because those CPUs that
935	* do have the top domain _should_ span the domain.
936	*/
937	if (!sibling->child)
938	continue;
939
940	/* If we would not end up here, we can't continue from here */
941	if (!cpumask_equal(src1p: sg_span, src2p: sched_domain_span(sd: sibling->child)))
942	continue;
943
944	cpumask_set_cpu(cpu: i, dstp: mask);
945	}
946
947	/* We must not have empty masks here */
948	WARN_ON_ONCE(cpumask_empty(mask));
949	}
950
951	/*
952	* XXX: This creates per-node group entries; since the load-balancer will
953	* immediately access remote memory to construct this group's load-balance
954	* statistics having the groups node local is of dubious benefit.
955	*/
956	static struct sched_group *
957	build_group_from_child_sched_domain(struct sched_domain *sd, int cpu)
958	{
959	struct sched_group *sg;
960	struct cpumask *sg_span;
961
962	sg = kzalloc_node(size: sizeof(struct sched_group) + cpumask_size(),
963	GFP_KERNEL, cpu_to_node(cpu));
964
965	if (!sg)
966	return NULL;
967
968	sg_span = sched_group_span(sg);
969	if (sd->child) {
970	cpumask_copy(dstp: sg_span, srcp: sched_domain_span(sd: sd->child));
971	sg->flags = sd->child->flags;
972	} else {
973	cpumask_copy(dstp: sg_span, srcp: sched_domain_span(sd));
974	}
975
976	atomic_inc(v: &sg->ref);
977	return sg;
978	}
979
980	static void init_overlap_sched_group(struct sched_domain *sd,
981	struct sched_group *sg)
982	{
983	struct cpumask *mask = sched_domains_tmpmask2;
984	struct sd_data *sdd = sd->private;
985	struct cpumask *sg_span;
986	int cpu;
987
988	build_balance_mask(sd, sg, mask);
989	cpu = cpumask_first(srcp: mask);
990
991	sg->sgc = *per_cpu_ptr(sdd->sgc, cpu);
992	if (atomic_inc_return(v: &sg->sgc->ref) == 1)
993	cpumask_copy(dstp: group_balance_mask(sg), srcp: mask);
994	else
995	WARN_ON_ONCE(!cpumask_equal(group_balance_mask(sg), mask));
996
997	/*
998	* Initialize sgc->capacity such that even if we mess up the
999	* domains and no possible iteration will get us here, we won't
1000	* die on a /0 trap.
1001	*/
1002	sg_span = sched_group_span(sg);
1003	sg->sgc->capacity = SCHED_CAPACITY_SCALE * cpumask_weight(srcp: sg_span);
1004	sg->sgc->min_capacity = SCHED_CAPACITY_SCALE;
1005	sg->sgc->max_capacity = SCHED_CAPACITY_SCALE;
1006	}
1007
1008	static struct sched_domain *
1009	find_descended_sibling(struct sched_domain *sd, struct sched_domain *sibling)
1010	{
1011	/*
1012	* The proper descendant would be the one whose child won't span out
1013	* of sd
1014	*/
1015	while (sibling->child &&
1016	!cpumask_subset(src1p: sched_domain_span(sd: sibling->child),
1017	src2p: sched_domain_span(sd)))
1018	sibling = sibling->child;
1019
1020	/*
1021	* As we are referencing sgc across different topology level, we need
1022	* to go down to skip those sched_domains which don't contribute to
1023	* scheduling because they will be degenerated in cpu_attach_domain
1024	*/
1025	while (sibling->child &&
1026	cpumask_equal(src1p: sched_domain_span(sd: sibling->child),
1027	src2p: sched_domain_span(sd: sibling)))
1028	sibling = sibling->child;
1029
1030	return sibling;
1031	}
1032
1033	static int
1034	build_overlap_sched_groups(struct sched_domain *sd, int cpu)
1035	{
1036	struct sched_group *first = NULL, *last = NULL, *sg;
1037	const struct cpumask *span = sched_domain_span(sd);
1038	struct cpumask *covered = sched_domains_tmpmask;
1039	struct sd_data *sdd = sd->private;
1040	struct sched_domain *sibling;
1041	int i;
1042
1043	cpumask_clear(dstp: covered);
1044
1045	for_each_cpu_wrap(i, span, cpu) {
1046	struct cpumask *sg_span;
1047
1048	if (cpumask_test_cpu(cpu: i, cpumask: covered))
1049	continue;
1050
1051	sibling = *per_cpu_ptr(sdd->sd, i);
1052
1053	/*
1054	* Asymmetric node setups can result in situations where the
1055	* domain tree is of unequal depth, make sure to skip domains
1056	* that already cover the entire range.
1057	*
1058	* In that case build_sched_domains() will have terminated the
1059	* iteration early and our sibling sd spans will be empty.
1060	* Domains should always include the CPU they're built on, so
1061	* check that.
1062	*/
1063	if (!cpumask_test_cpu(cpu: i, cpumask: sched_domain_span(sd: sibling)))
1064	continue;
1065
1066	/*
1067	* Usually we build sched_group by sibling's child sched_domain
1068	* But for machines whose NUMA diameter are 3 or above, we move
1069	* to build sched_group by sibling's proper descendant's child
1070	* domain because sibling's child sched_domain will span out of
1071	* the sched_domain being built as below.
1072	*
1073	* Smallest diameter=3 topology is:
1074	*
1075	* node 0 1 2 3
1076	* 0: 10 20 30 40
1077	* 1: 20 10 20 30
1078	* 2: 30 20 10 20
1079	* 3: 40 30 20 10
1080	*
1081	* 0 --- 1 --- 2 --- 3
1082	*
1083	* NUMA-3 0-3 N/A N/A 0-3
1084	* groups: {0-2},{1-3} {1-3},{0-2}
1085	*
1086	* NUMA-2 0-2 0-3 0-3 1-3
1087	* groups: {0-1},{1-3} {0-2},{2-3} {1-3},{0-1} {2-3},{0-2}
1088	*
1089	* NUMA-1 0-1 0-2 1-3 2-3
1090	* groups: {0},{1} {1},{2},{0} {2},{3},{1} {3},{2}
1091	*
1092	* NUMA-0 0 1 2 3
1093	*
1094	* The NUMA-2 groups for nodes 0 and 3 are obviously buggered, as the
1095	* group span isn't a subset of the domain span.
1096	*/
1097	if (sibling->child &&
1098	!cpumask_subset(src1p: sched_domain_span(sd: sibling->child), src2p: span))
1099	sibling = find_descended_sibling(sd, sibling);
1100
1101	sg = build_group_from_child_sched_domain(sd: sibling, cpu);
1102	if (!sg)
1103	goto fail;
1104
1105	sg_span = sched_group_span(sg);
1106	cpumask_or(dstp: covered, src1p: covered, src2p: sg_span);
1107
1108	init_overlap_sched_group(sd: sibling, sg);
1109
1110	if (!first)
1111	first = sg;
1112	if (last)
1113	last->next = sg;
1114	last = sg;
1115	last->next = first;
1116	}
1117	sd->groups = first;
1118
1119	return 0;
1120
1121	fail:
1122	free_sched_groups(sg: first, free_sgc: 0);
1123
1124	return -ENOMEM;
1125	}
1126
1127
1128	/*
1129	* Package topology (also see the load-balance blurb in fair.c)
1130	*
1131	* The scheduler builds a tree structure to represent a number of important
1132	* topology features. By default (default_topology[]) these include:
1133	*
1134	* - Simultaneous multithreading (SMT)
1135	* - Multi-Core Cache (MC)
1136	* - Package (PKG)
1137	*
1138	* Where the last one more or less denotes everything up to a NUMA node.
1139	*
1140	* The tree consists of 3 primary data structures:
1141	*
1142	* sched_domain -> sched_group -> sched_group_capacity
1143	* ^ ^ ^ ^
1144	* `-' `-'
1145	*
1146	* The sched_domains are per-CPU and have a two way link (parent & child) and
1147	* denote the ever growing mask of CPUs belonging to that level of topology.
1148	*
1149	* Each sched_domain has a circular (double) linked list of sched_group's, each
1150	* denoting the domains of the level below (or individual CPUs in case of the
1151	* first domain level). The sched_group linked by a sched_domain includes the
1152	* CPU of that sched_domain [*].
1153	*
1154	* Take for instance a 2 threaded, 2 core, 2 cache cluster part:
1155	*
1156	* CPU 0 1 2 3 4 5 6 7
1157	*
1158	* PKG [ ]
1159	* MC [ ] [ ]
1160	* SMT [ ] [ ] [ ] [ ]
1161	*
1162	* - or -
1163	*
1164	* PKG 0-7 0-7 0-7 0-7 0-7 0-7 0-7 0-7
1165	* MC 0-3 0-3 0-3 0-3 4-7 4-7 4-7 4-7
1166	* SMT 0-1 0-1 2-3 2-3 4-5 4-5 6-7 6-7
1167	*
1168	* CPU 0 1 2 3 4 5 6 7
1169	*
1170	* One way to think about it is: sched_domain moves you up and down among these
1171	* topology levels, while sched_group moves you sideways through it, at child
1172	* domain granularity.
1173	*
1174	* sched_group_capacity ensures each unique sched_group has shared storage.
1175	*
1176	* There are two related construction problems, both require a CPU that
1177	* uniquely identify each group (for a given domain):
1178	*
1179	* - The first is the balance_cpu (see should_we_balance() and the
1180	* load-balance blub in fair.c); for each group we only want 1 CPU to
1181	* continue balancing at a higher domain.
1182	*
1183	* - The second is the sched_group_capacity; we want all identical groups
1184	* to share a single sched_group_capacity.
1185	*
1186	* Since these topologies are exclusive by construction. That is, its
1187	* impossible for an SMT thread to belong to multiple cores, and cores to
1188	* be part of multiple caches. There is a very clear and unique location
1189	* for each CPU in the hierarchy.
1190	*
1191	* Therefore computing a unique CPU for each group is trivial (the iteration
1192	* mask is redundant and set all 1s; all CPUs in a group will end up at _that_
1193	* group), we can simply pick the first CPU in each group.
1194	*
1195	*
1196	* [*] in other words, the first group of each domain is its child domain.
1197	*/
1198
1199	static struct sched_group *get_group(int cpu, struct sd_data *sdd)
1200	{
1201	struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu);
1202	struct sched_domain *child = sd->child;
1203	struct sched_group *sg;
1204	bool already_visited;
1205
1206	if (child)
1207	cpu = cpumask_first(srcp: sched_domain_span(sd: child));
1208
1209	sg = *per_cpu_ptr(sdd->sg, cpu);
1210	sg->sgc = *per_cpu_ptr(sdd->sgc, cpu);
1211
1212	/* Increase refcounts for claim_allocations: */
1213	already_visited = atomic_inc_return(v: &sg->ref) > 1;
1214	/* sgc visits should follow a similar trend as sg */
1215	WARN_ON(already_visited != (atomic_inc_return(&sg->sgc->ref) > 1));
1216
1217	/* If we have already visited that group, it's already initialized. */
1218	if (already_visited)
1219	return sg;
1220
1221	if (child) {
1222	cpumask_copy(dstp: sched_group_span(sg), srcp: sched_domain_span(sd: child));
1223	cpumask_copy(dstp: group_balance_mask(sg), srcp: sched_group_span(sg));
1224	sg->flags = child->flags;
1225	} else {
1226	cpumask_set_cpu(cpu, dstp: sched_group_span(sg));
1227	cpumask_set_cpu(cpu, dstp: group_balance_mask(sg));
1228	}
1229
1230	sg->sgc->capacity = SCHED_CAPACITY_SCALE * cpumask_weight(srcp: sched_group_span(sg));
1231	sg->sgc->min_capacity = SCHED_CAPACITY_SCALE;
1232	sg->sgc->max_capacity = SCHED_CAPACITY_SCALE;
1233
1234	return sg;
1235	}
1236
1237	/*
1238	* build_sched_groups will build a circular linked list of the groups
1239	* covered by the given span, will set each group's ->cpumask correctly,
1240	* and will initialize their ->sgc.
1241	*
1242	* Assumes the sched_domain tree is fully constructed
1243	*/
1244	static int
1245	build_sched_groups(struct sched_domain *sd, int cpu)
1246	{
1247	struct sched_group *first = NULL, *last = NULL;
1248	struct sd_data *sdd = sd->private;
1249	const struct cpumask *span = sched_domain_span(sd);
1250	struct cpumask *covered;
1251	int i;
1252
1253	lockdep_assert_held(&sched_domains_mutex);
1254	covered = sched_domains_tmpmask;
1255
1256	cpumask_clear(dstp: covered);
1257
1258	for_each_cpu_wrap(i, span, cpu) {
1259	struct sched_group *sg;
1260
1261	if (cpumask_test_cpu(cpu: i, cpumask: covered))
1262	continue;
1263
1264	sg = get_group(cpu: i, sdd);
1265
1266	cpumask_or(dstp: covered, src1p: covered, src2p: sched_group_span(sg));
1267
1268	if (!first)
1269	first = sg;
1270	if (last)
1271	last->next = sg;
1272	last = sg;
1273	}
1274	last->next = first;
1275	sd->groups = first;
1276
1277	return 0;
1278	}
1279
1280	/*
1281	* Initialize sched groups cpu_capacity.
1282	*
1283	* cpu_capacity indicates the capacity of sched group, which is used while
1284	* distributing the load between different sched groups in a sched domain.
1285	* Typically cpu_capacity for all the groups in a sched domain will be same
1286	* unless there are asymmetries in the topology. If there are asymmetries,
1287	* group having more cpu_capacity will pickup more load compared to the
1288	* group having less cpu_capacity.
1289	*/
1290	static void init_sched_groups_capacity(int cpu, struct sched_domain *sd)
1291	{
1292	struct sched_group *sg = sd->groups;
1293	struct cpumask *mask = sched_domains_tmpmask2;
1294
1295	WARN_ON(!sg);
1296
1297	do {
1298	int cpu, cores = 0, max_cpu = -1;
1299
1300	sg->group_weight = cpumask_weight(srcp: sched_group_span(sg));
1301
1302	cpumask_copy(dstp: mask, srcp: sched_group_span(sg));
1303	for_each_cpu(cpu, mask) {
1304	cores++;
1305	#ifdef CONFIG_SCHED_SMT
1306	cpumask_andnot(dstp: mask, src1p: mask, src2p: cpu_smt_mask(cpu));
1307	#endif
1308	}
1309	sg->cores = cores;
1310
1311	if (!(sd->flags & SD_ASYM_PACKING))
1312	goto next;
1313
1314	for_each_cpu(cpu, sched_group_span(sg)) {
1315	if (max_cpu < 0)
1316	max_cpu = cpu;
1317	else if (sched_asym_prefer(a: cpu, b: max_cpu))
1318	max_cpu = cpu;
1319	}
1320	sg->asym_prefer_cpu = max_cpu;
1321
1322	next:
1323	sg = sg->next;
1324	} while (sg != sd->groups);
1325
1326	if (cpu != group_balance_cpu(sg))
1327	return;
1328
1329	update_group_capacity(sd, cpu);
1330	}
1331
1332	/*
1333	* Asymmetric CPU capacity bits
1334	*/
1335	struct asym_cap_data {
1336	struct list_head link;
1337	unsigned long capacity;
1338	unsigned long cpus[];
1339	};
1340
1341	/*
1342	* Set of available CPUs grouped by their corresponding capacities
1343	* Each list entry contains a CPU mask reflecting CPUs that share the same
1344	* capacity.
1345	* The lifespan of data is unlimited.
1346	*/
1347	static LIST_HEAD(asym_cap_list);
1348
1349	#define cpu_capacity_span(asym_data) to_cpumask((asym_data)->cpus)
1350
1351	/*
1352	* Verify whether there is any CPU capacity asymmetry in a given sched domain.
1353	* Provides sd_flags reflecting the asymmetry scope.
1354	*/
1355	static inline int
1356	asym_cpu_capacity_classify(const struct cpumask *sd_span,
1357	const struct cpumask *cpu_map)
1358	{
1359	struct asym_cap_data *entry;
1360	int count = 0, miss = 0;
1361
1362	/*
1363	* Count how many unique CPU capacities this domain spans across
1364	* (compare sched_domain CPUs mask with ones representing available
1365	* CPUs capacities). Take into account CPUs that might be offline:
1366	* skip those.
1367	*/
1368	list_for_each_entry(entry, &asym_cap_list, link) {
1369	if (cpumask_intersects(src1p: sd_span, cpu_capacity_span(entry)))
1370	++count;
1371	else if (cpumask_intersects(src1p: cpu_map, cpu_capacity_span(entry)))
1372	++miss;
1373	}
1374
1375	WARN_ON_ONCE(!count && !list_empty(&asym_cap_list));
1376
1377	/* No asymmetry detected */
1378	if (count < 2)
1379	return 0;
1380	/* Some of the available CPU capacity values have not been detected */
1381	if (miss)
1382	return SD_ASYM_CPUCAPACITY;
1383
1384	/* Full asymmetry */
1385	return SD_ASYM_CPUCAPACITY | SD_ASYM_CPUCAPACITY_FULL;
1386
1387	}
1388
1389	static inline void asym_cpu_capacity_update_data(int cpu)
1390	{
1391	unsigned long capacity = arch_scale_cpu_capacity(cpu);
1392	struct asym_cap_data *entry = NULL;
1393
1394	list_for_each_entry(entry, &asym_cap_list, link) {
1395	if (capacity == entry->capacity)
1396	goto done;
1397	}
1398
1399	entry = kzalloc(size: sizeof(*entry) + cpumask_size(), GFP_KERNEL);
1400	if (WARN_ONCE(!entry, "Failed to allocate memory for asymmetry data\n"))
1401	return;
1402	entry->capacity = capacity;
1403	list_add(new: &entry->link, head: &asym_cap_list);
1404	done:
1405	__cpumask_set_cpu(cpu, cpu_capacity_span(entry));
1406	}
1407
1408	/*
1409	* Build-up/update list of CPUs grouped by their capacities
1410	* An update requires explicit request to rebuild sched domains
1411	* with state indicating CPU topology changes.
1412	*/
1413	static void asym_cpu_capacity_scan(void)
1414	{
1415	struct asym_cap_data *entry, *next;
1416	int cpu;
1417
1418	list_for_each_entry(entry, &asym_cap_list, link)
1419	cpumask_clear(cpu_capacity_span(entry));
1420
1421	for_each_cpu_and(cpu, cpu_possible_mask, housekeeping_cpumask(HK_TYPE_DOMAIN))
1422	asym_cpu_capacity_update_data(cpu);
1423
1424	list_for_each_entry_safe(entry, next, &asym_cap_list, link) {
1425	if (cpumask_empty(cpu_capacity_span(entry))) {
1426	list_del(entry: &entry->link);
1427	kfree(objp: entry);
1428	}
1429	}
1430
1431	/*
1432	* Only one capacity value has been detected i.e. this system is symmetric.
1433	* No need to keep this data around.
1434	*/
1435	if (list_is_singular(head: &asym_cap_list)) {
1436	entry = list_first_entry(&asym_cap_list, typeof(*entry), link);
1437	list_del(entry: &entry->link);
1438	kfree(objp: entry);
1439	}
1440	}
1441
1442	/*
1443	* Initializers for schedule domains
1444	* Non-inlined to reduce accumulated stack pressure in build_sched_domains()
1445	*/
1446
1447	static int default_relax_domain_level = -1;
1448	int sched_domain_level_max;
1449
1450	static int __init setup_relax_domain_level(char *str)
1451	{
1452	if (kstrtoint(s: str, base: 0, res: &default_relax_domain_level))
1453	pr_warn("Unable to set relax_domain_level\n");
1454
1455	return 1;
1456	}
1457	__setup("relax_domain_level=", setup_relax_domain_level);
1458
1459	static void set_domain_attribute(struct sched_domain *sd,
1460	struct sched_domain_attr *attr)
1461	{
1462	int request;
1463
1464	if (!attr || attr->relax_domain_level < 0) {
1465	if (default_relax_domain_level < 0)
1466	return;
1467	request = default_relax_domain_level;
1468	} else
1469	request = attr->relax_domain_level;
1470
1471	if (sd->level > request) {
1472	/* Turn off idle balance on this domain: */
1473	sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE);
1474	}
1475	}
1476
1477	static void __sdt_free(const struct cpumask *cpu_map);
1478	static int __sdt_alloc(const struct cpumask *cpu_map);
1479
1480	static void __free_domain_allocs(struct s_data *d, enum s_alloc what,
1481	const struct cpumask *cpu_map)
1482	{
1483	switch (what) {
1484	case sa_rootdomain:
1485	if (!atomic_read(v: &d->rd->refcount))
1486	free_rootdomain(rcu: &d->rd->rcu);
1487	fallthrough;
1488	case sa_sd:
1489	free_percpu(pdata: d->sd);
1490	fallthrough;
1491	case sa_sd_storage:
1492	__sdt_free(cpu_map);
1493	fallthrough;
1494	case sa_none:
1495	break;
1496	}
1497	}
1498
1499	static enum s_alloc
1500	__visit_domain_allocation_hell(struct s_data *d, const struct cpumask *cpu_map)
1501	{
1502	memset(d, 0, sizeof(*d));
1503
1504	if (__sdt_alloc(cpu_map))
1505	return sa_sd_storage;
1506	d->sd = alloc_percpu(struct sched_domain *);
1507	if (!d->sd)
1508	return sa_sd_storage;
1509	d->rd = alloc_rootdomain();
1510	if (!d->rd)
1511	return sa_sd;
1512
1513	return sa_rootdomain;
1514	}
1515
1516	/*
1517	* NULL the sd_data elements we've used to build the sched_domain and
1518	* sched_group structure so that the subsequent __free_domain_allocs()
1519	* will not free the data we're using.
1520	*/
1521	static void claim_allocations(int cpu, struct sched_domain *sd)
1522	{
1523	struct sd_data *sdd = sd->private;
1524
1525	WARN_ON_ONCE(*per_cpu_ptr(sdd->sd, cpu) != sd);
1526	*per_cpu_ptr(sdd->sd, cpu) = NULL;
1527
1528	if (atomic_read(v: &(*per_cpu_ptr(sdd->sds, cpu))->ref))
1529	*per_cpu_ptr(sdd->sds, cpu) = NULL;
1530
1531	if (atomic_read(v: &(*per_cpu_ptr(sdd->sg, cpu))->ref))
1532	*per_cpu_ptr(sdd->sg, cpu) = NULL;
1533
1534	if (atomic_read(v: &(*per_cpu_ptr(sdd->sgc, cpu))->ref))
1535	*per_cpu_ptr(sdd->sgc, cpu) = NULL;
1536	}
1537
1538	#ifdef CONFIG_NUMA
1539	enum numa_topology_type sched_numa_topology_type;
1540
1541	static int sched_domains_numa_levels;
1542	static int sched_domains_curr_level;
1543
1544	int sched_max_numa_distance;
1545	static int *sched_domains_numa_distance;
1546	static struct cpumask ***sched_domains_numa_masks;
1547	#endif
1548
1549	/*
1550	* SD_flags allowed in topology descriptions.
1551	*
1552	* These flags are purely descriptive of the topology and do not prescribe
1553	* behaviour. Behaviour is artificial and mapped in the below sd_init()
1554	* function:
1555	*
1556	* SD_SHARE_CPUCAPACITY - describes SMT topologies
1557	* SD_SHARE_PKG_RESOURCES - describes shared caches
1558	* SD_NUMA - describes NUMA topologies
1559	*
1560	* Odd one out, which beside describing the topology has a quirk also
1561	* prescribes the desired behaviour that goes along with it:
1562	*
1563	* SD_ASYM_PACKING - describes SMT quirks
1564	*/
1565	#define TOPOLOGY_SD_FLAGS \
1566	(SD_SHARE_CPUCAPACITY | \
1567	SD_CLUSTER | \
1568	SD_SHARE_PKG_RESOURCES | \
1569	SD_NUMA | \
1570	SD_ASYM_PACKING)
1571
1572	static struct sched_domain *
1573	sd_init(struct sched_domain_topology_level *tl,
1574	const struct cpumask *cpu_map,
1575	struct sched_domain *child, int cpu)
1576	{
1577	struct sd_data *sdd = &tl->data;
1578	struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu);
1579	int sd_id, sd_weight, sd_flags = 0;
1580	struct cpumask *sd_span;
1581
1582	#ifdef CONFIG_NUMA
1583	/*
1584	* Ugly hack to pass state to sd_numa_mask()...
1585	*/
1586	sched_domains_curr_level = tl->numa_level;
1587	#endif
1588
1589	sd_weight = cpumask_weight(srcp: tl->mask(cpu));
1590
1591	if (tl->sd_flags)
1592	sd_flags = (*tl->sd_flags)();
1593	if (WARN_ONCE(sd_flags & ~TOPOLOGY_SD_FLAGS,
1594	"wrong sd_flags in topology description\n"))
1595	sd_flags &= TOPOLOGY_SD_FLAGS;
1596
1597	*sd = (struct sched_domain){
1598	.min_interval = sd_weight,
1599	.max_interval = 2*sd_weight,
1600	.busy_factor = 16,
1601	.imbalance_pct = 117,
1602
1603	.cache_nice_tries = 0,
1604
1605	.flags = 1*SD_BALANCE_NEWIDLE
1606	| 1*SD_BALANCE_EXEC
1607	| 1*SD_BALANCE_FORK
1608	| 0*SD_BALANCE_WAKE
1609	| 1*SD_WAKE_AFFINE
1610	| 0*SD_SHARE_CPUCAPACITY
1611	| 0*SD_SHARE_PKG_RESOURCES
1612	| 0*SD_SERIALIZE
1613	| 1*SD_PREFER_SIBLING
1614	| 0*SD_NUMA
1615	| sd_flags
1616	,
1617
1618	.last_balance = jiffies,
1619	.balance_interval = sd_weight,
1620	.max_newidle_lb_cost = 0,
1621	.last_decay_max_lb_cost = jiffies,
1622	.child = child,
1623	#ifdef CONFIG_SCHED_DEBUG
1624	.name = tl->name,
1625	#endif
1626	};
1627
1628	sd_span = sched_domain_span(sd);
1629	cpumask_and(dstp: sd_span, src1p: cpu_map, src2p: tl->mask(cpu));
1630	sd_id = cpumask_first(srcp: sd_span);
1631
1632	sd->flags |= asym_cpu_capacity_classify(sd_span, cpu_map);
1633
1634	WARN_ONCE((sd->flags & (SD_SHARE_CPUCAPACITY | SD_ASYM_CPUCAPACITY)) ==
1635	(SD_SHARE_CPUCAPACITY | SD_ASYM_CPUCAPACITY),
1636	"CPU capacity asymmetry not supported on SMT\n");
1637
1638	/*
1639	* Convert topological properties into behaviour.
1640	*/
1641	/* Don't attempt to spread across CPUs of different capacities. */
1642	if ((sd->flags & SD_ASYM_CPUCAPACITY) && sd->child)
1643	sd->child->flags &= ~SD_PREFER_SIBLING;
1644
1645	if (sd->flags & SD_SHARE_CPUCAPACITY) {
1646	sd->imbalance_pct = 110;
1647
1648	} else if (sd->flags & SD_SHARE_PKG_RESOURCES) {
1649	sd->imbalance_pct = 117;
1650	sd->cache_nice_tries = 1;
1651
1652	#ifdef CONFIG_NUMA
1653	} else if (sd->flags & SD_NUMA) {
1654	sd->cache_nice_tries = 2;
1655
1656	sd->flags &= ~SD_PREFER_SIBLING;
1657	sd->flags |= SD_SERIALIZE;
1658	if (sched_domains_numa_distance[tl->numa_level] > node_reclaim_distance) {
1659	sd->flags &= ~(SD_BALANCE_EXEC |
1660	SD_BALANCE_FORK |
1661	SD_WAKE_AFFINE);
1662	}
1663
1664	#endif
1665	} else {
1666	sd->cache_nice_tries = 1;
1667	}
1668
1669	/*
1670	* For all levels sharing cache; connect a sched_domain_shared
1671	* instance.
1672	*/
1673	if (sd->flags & SD_SHARE_PKG_RESOURCES) {
1674	sd->shared = *per_cpu_ptr(sdd->sds, sd_id);
1675	atomic_inc(v: &sd->shared->ref);
1676	atomic_set(v: &sd->shared->nr_busy_cpus, i: sd_weight);
1677	}
1678
1679	sd->private = sdd;
1680
1681	return sd;
1682	}
1683
1684	/*
1685	* Topology list, bottom-up.
1686	*/
1687	static struct sched_domain_topology_level default_topology[] = {
1688	#ifdef CONFIG_SCHED_SMT
1689	{ cpu_smt_mask, cpu_smt_flags, SD_INIT_NAME(SMT) },
1690	#endif
1691
1692	#ifdef CONFIG_SCHED_CLUSTER
1693	{ cpu_clustergroup_mask, cpu_cluster_flags, SD_INIT_NAME(CLS) },
1694	#endif
1695
1696	#ifdef CONFIG_SCHED_MC
1697	{ cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) },
1698	#endif
1699	{ cpu_cpu_mask, SD_INIT_NAME(PKG) },
1700	{ NULL, },
1701	};
1702
1703	static struct sched_domain_topology_level *sched_domain_topology =
1704	default_topology;
1705	static struct sched_domain_topology_level *sched_domain_topology_saved;
1706
1707	#define for_each_sd_topology(tl) \
1708	for (tl = sched_domain_topology; tl->mask; tl++)
1709
1710	void __init set_sched_topology(struct sched_domain_topology_level *tl)
1711	{
1712	if (WARN_ON_ONCE(sched_smp_initialized))
1713	return;
1714
1715	sched_domain_topology = tl;
1716	sched_domain_topology_saved = NULL;
1717	}
1718
1719	#ifdef CONFIG_NUMA
1720
1721	static const struct cpumask *sd_numa_mask(int cpu)
1722	{
1723	return sched_domains_numa_masks[sched_domains_curr_level][cpu_to_node(cpu)];
1724	}
1725
1726	static void sched_numa_warn(const char *str)
1727	{
1728	static int done = false;
1729	int i,j;
1730
1731	if (done)
1732	return;
1733
1734	done = true;
1735
1736	printk(KERN_WARNING "ERROR: %s\n\n", str);
1737
1738	for (i = 0; i < nr_node_ids; i++) {
1739	printk(KERN_WARNING " ");
1740	for (j = 0; j < nr_node_ids; j++) {
1741	if (!node_state(node: i, state: N_CPU) || !node_state(node: j, state: N_CPU))
1742	printk(KERN_CONT "(%02d) ", node_distance(i,j));
1743	else
1744	printk(KERN_CONT " %02d ", node_distance(i,j));
1745	}
1746	printk(KERN_CONT "\n");
1747	}
1748	printk(KERN_WARNING "\n");
1749	}
1750
1751	bool find_numa_distance(int distance)
1752	{
1753	bool found = false;
1754	int i, *distances;
1755
1756	if (distance == node_distance(0, 0))
1757	return true;
1758
1759	rcu_read_lock();
1760	distances = rcu_dereference(sched_domains_numa_distance);
1761	if (!distances)
1762	goto unlock;
1763	for (i = 0; i < sched_domains_numa_levels; i++) {
1764	if (distances[i] == distance) {
1765	found = true;
1766	break;
1767	}
1768	}
1769	unlock:
1770	rcu_read_unlock();
1771
1772	return found;
1773	}
1774
1775	#define for_each_cpu_node_but(n, nbut) \
1776	for_each_node_state(n, N_CPU) \
1777	if (n == nbut) \
1778	continue; \
1779	else
1780
1781	/*
1782	* A system can have three types of NUMA topology:
1783	* NUMA_DIRECT: all nodes are directly connected, or not a NUMA system
1784	* NUMA_GLUELESS_MESH: some nodes reachable through intermediary nodes
1785	* NUMA_BACKPLANE: nodes can reach other nodes through a backplane
1786	*
1787	* The difference between a glueless mesh topology and a backplane
1788	* topology lies in whether communication between not directly
1789	* connected nodes goes through intermediary nodes (where programs
1790	* could run), or through backplane controllers. This affects
1791	* placement of programs.
1792	*
1793	* The type of topology can be discerned with the following tests:
1794	* - If the maximum distance between any nodes is 1 hop, the system
1795	* is directly connected.
1796	* - If for two nodes A and B, located N > 1 hops away from each other,
1797	* there is an intermediary node C, which is < N hops away from both
1798	* nodes A and B, the system is a glueless mesh.
1799	*/
1800	static void init_numa_topology_type(int offline_node)
1801	{
1802	int a, b, c, n;
1803
1804	n = sched_max_numa_distance;
1805
1806	if (sched_domains_numa_levels <= 2) {
1807	sched_numa_topology_type = NUMA_DIRECT;
1808	return;
1809	}
1810
1811	for_each_cpu_node_but(a, offline_node) {
1812	for_each_cpu_node_but(b, offline_node) {
1813	/* Find two nodes furthest removed from each other. */
1814	if (node_distance(a, b) < n)
1815	continue;
1816
1817	/* Is there an intermediary node between a and b? */
1818	for_each_cpu_node_but(c, offline_node) {
1819	if (node_distance(a, c) < n &&
1820	node_distance(b, c) < n) {
1821	sched_numa_topology_type =
1822	NUMA_GLUELESS_MESH;
1823	return;
1824	}
1825	}
1826
1827	sched_numa_topology_type = NUMA_BACKPLANE;
1828	return;
1829	}
1830	}
1831
1832	pr_err("Failed to find a NUMA topology type, defaulting to DIRECT\n");
1833	sched_numa_topology_type = NUMA_DIRECT;
1834	}
1835
1836
1837	#define NR_DISTANCE_VALUES (1 << DISTANCE_BITS)
1838
1839	void sched_init_numa(int offline_node)
1840	{
1841	struct sched_domain_topology_level *tl;
1842	unsigned long *distance_map;
1843	int nr_levels = 0;
1844	int i, j;
1845	int *distances;
1846	struct cpumask ***masks;
1847
1848	/*
1849	* O(nr_nodes^2) deduplicating selection sort -- in order to find the
1850	* unique distances in the node_distance() table.
1851	*/
1852	distance_map = bitmap_alloc(NR_DISTANCE_VALUES, GFP_KERNEL);
1853	if (!distance_map)
1854	return;
1855
1856	bitmap_zero(dst: distance_map, NR_DISTANCE_VALUES);
1857	for_each_cpu_node_but(i, offline_node) {
1858	for_each_cpu_node_but(j, offline_node) {
1859	int distance = node_distance(i, j);
1860
1861	if (distance < LOCAL_DISTANCE || distance >= NR_DISTANCE_VALUES) {
1862	sched_numa_warn(str: "Invalid distance value range");
1863	bitmap_free(bitmap: distance_map);
1864	return;
1865	}
1866
1867	bitmap_set(map: distance_map, start: distance, nbits: 1);
1868	}
1869	}
1870	/*
1871	* We can now figure out how many unique distance values there are and
1872	* allocate memory accordingly.
1873	*/
1874	nr_levels = bitmap_weight(src: distance_map, NR_DISTANCE_VALUES);
1875
1876	distances = kcalloc(n: nr_levels, size: sizeof(int), GFP_KERNEL);
1877	if (!distances) {
1878	bitmap_free(bitmap: distance_map);
1879	return;
1880	}
1881
1882	for (i = 0, j = 0; i < nr_levels; i++, j++) {
1883	j = find_next_bit(addr: distance_map, NR_DISTANCE_VALUES, offset: j);
1884	distances[i] = j;
1885	}
1886	rcu_assign_pointer(sched_domains_numa_distance, distances);
1887
1888	bitmap_free(bitmap: distance_map);
1889
1890	/*
1891	* 'nr_levels' contains the number of unique distances
1892	*
1893	* The sched_domains_numa_distance[] array includes the actual distance
1894	* numbers.
1895	*/
1896
1897	/*
1898	* Here, we should temporarily reset sched_domains_numa_levels to 0.
1899	* If it fails to allocate memory for array sched_domains_numa_masks[][],
1900	* the array will contain less then 'nr_levels' members. This could be
1901	* dangerous when we use it to iterate array sched_domains_numa_masks[][]
1902	* in other functions.
1903	*
1904	* We reset it to 'nr_levels' at the end of this function.
1905	*/
1906	sched_domains_numa_levels = 0;
1907
1908	masks = kzalloc(size: sizeof(void *) * nr_levels, GFP_KERNEL);
1909	if (!masks)
1910	return;
1911
1912	/*
1913	* Now for each level, construct a mask per node which contains all
1914	* CPUs of nodes that are that many hops away from us.
1915	*/
1916	for (i = 0; i < nr_levels; i++) {
1917	masks[i] = kzalloc(size: nr_node_ids * sizeof(void *), GFP_KERNEL);
1918	if (!masks[i])
1919	return;
1920
1921	for_each_cpu_node_but(j, offline_node) {
1922	struct cpumask *mask = kzalloc(size: cpumask_size(), GFP_KERNEL);
1923	int k;
1924
1925	if (!mask)
1926	return;
1927
1928	masks[i][j] = mask;
1929
1930	for_each_cpu_node_but(k, offline_node) {
1931	if (sched_debug() && (node_distance(j, k) != node_distance(k, j)))
1932	sched_numa_warn(str: "Node-distance not symmetric");
1933
1934	if (node_distance(j, k) > sched_domains_numa_distance[i])
1935	continue;
1936
1937	cpumask_or(dstp: mask, src1p: mask, src2p: cpumask_of_node(node: k));
1938	}
1939	}
1940	}
1941	rcu_assign_pointer(sched_domains_numa_masks, masks);
1942
1943	/* Compute default topology size */
1944	for (i = 0; sched_domain_topology[i].mask; i++);
1945
1946	tl = kzalloc(size: (i + nr_levels + 1) *
1947	sizeof(struct sched_domain_topology_level), GFP_KERNEL);
1948	if (!tl)
1949	return;
1950
1951	/*
1952	* Copy the default topology bits..
1953	*/
1954	for (i = 0; sched_domain_topology[i].mask; i++)
1955	tl[i] = sched_domain_topology[i];
1956
1957	/*
1958	* Add the NUMA identity distance, aka single NODE.
1959	*/
1960	tl[i++] = (struct sched_domain_topology_level){
1961	.mask = sd_numa_mask,
1962	.numa_level = 0,
1963	SD_INIT_NAME(NODE)
1964	};
1965
1966	/*
1967	* .. and append 'j' levels of NUMA goodness.
1968	*/
1969	for (j = 1; j < nr_levels; i++, j++) {
1970	tl[i] = (struct sched_domain_topology_level){
1971	.mask = sd_numa_mask,
1972	.sd_flags = cpu_numa_flags,
1973	.flags = SDTL_OVERLAP,
1974	.numa_level = j,
1975	SD_INIT_NAME(NUMA)
1976	};
1977	}
1978
1979	sched_domain_topology_saved = sched_domain_topology;
1980	sched_domain_topology = tl;
1981
1982	sched_domains_numa_levels = nr_levels;
1983	WRITE_ONCE(sched_max_numa_distance, sched_domains_numa_distance[nr_levels - 1]);
1984
1985	init_numa_topology_type(offline_node);
1986	}
1987
1988
1989	static void sched_reset_numa(void)
1990	{
1991	int nr_levels, *distances;
1992	struct cpumask ***masks;
1993
1994	nr_levels = sched_domains_numa_levels;
1995	sched_domains_numa_levels = 0;
1996	sched_max_numa_distance = 0;
1997	sched_numa_topology_type = NUMA_DIRECT;
1998	distances = sched_domains_numa_distance;
1999	rcu_assign_pointer(sched_domains_numa_distance, NULL);
2000	masks = sched_domains_numa_masks;
2001	rcu_assign_pointer(sched_domains_numa_masks, NULL);
2002	if (distances || masks) {
2003	int i, j;
2004
2005	synchronize_rcu();
2006	kfree(objp: distances);
2007	for (i = 0; i < nr_levels && masks; i++) {
2008	if (!masks[i])
2009	continue;
2010	for_each_node(j)
2011	kfree(objp: masks[i][j]);
2012	kfree(objp: masks[i]);
2013	}
2014	kfree(objp: masks);
2015	}
2016	if (sched_domain_topology_saved) {
2017	kfree(objp: sched_domain_topology);
2018	sched_domain_topology = sched_domain_topology_saved;
2019	sched_domain_topology_saved = NULL;
2020	}
2021	}
2022
2023	/*
2024	* Call with hotplug lock held
2025	*/
2026	void sched_update_numa(int cpu, bool online)
2027	{
2028	int node;
2029
2030	node = cpu_to_node(cpu);
2031	/*
2032	* Scheduler NUMA topology is updated when the first CPU of a
2033	* node is onlined or the last CPU of a node is offlined.
2034	*/
2035	if (cpumask_weight(srcp: cpumask_of_node(node)) != 1)
2036	return;
2037
2038	sched_reset_numa();
2039	sched_init_numa(offline_node: online ? NUMA_NO_NODE : node);
2040	}
2041
2042	void sched_domains_numa_masks_set(unsigned int cpu)
2043	{
2044	int node = cpu_to_node(cpu);
2045	int i, j;
2046
2047	for (i = 0; i < sched_domains_numa_levels; i++) {
2048	for (j = 0; j < nr_node_ids; j++) {
2049	if (!node_state(node: j, state: N_CPU))
2050	continue;
2051
2052	/* Set ourselves in the remote node's masks */
2053	if (node_distance(j, node) <= sched_domains_numa_distance[i])
2054	cpumask_set_cpu(cpu, dstp: sched_domains_numa_masks[i][j]);
2055	}
2056	}
2057	}
2058
2059	void sched_domains_numa_masks_clear(unsigned int cpu)
2060	{
2061	int i, j;
2062
2063	for (i = 0; i < sched_domains_numa_levels; i++) {
2064	for (j = 0; j < nr_node_ids; j++) {
2065	if (sched_domains_numa_masks[i][j])
2066	cpumask_clear_cpu(cpu, dstp: sched_domains_numa_masks[i][j]);
2067	}
2068	}
2069	}
2070
2071	/*
2072	* sched_numa_find_closest() - given the NUMA topology, find the cpu
2073	* closest to @cpu from @cpumask.
2074	* cpumask: cpumask to find a cpu from
2075	* cpu: cpu to be close to
2076	*
2077	* returns: cpu, or nr_cpu_ids when nothing found.
2078	*/
2079	int sched_numa_find_closest(const struct cpumask *cpus, int cpu)
2080	{
2081	int i, j = cpu_to_node(cpu), found = nr_cpu_ids;
2082	struct cpumask ***masks;
2083
2084	rcu_read_lock();
2085	masks = rcu_dereference(sched_domains_numa_masks);
2086	if (!masks)
2087	goto unlock;
2088	for (i = 0; i < sched_domains_numa_levels; i++) {
2089	if (!masks[i][j])
2090	break;
2091	cpu = cpumask_any_and(cpus, masks[i][j]);
2092	if (cpu < nr_cpu_ids) {
2093	found = cpu;
2094	break;
2095	}
2096	}
2097	unlock:
2098	rcu_read_unlock();
2099
2100	return found;
2101	}
2102
2103	struct __cmp_key {
2104	const struct cpumask *cpus;
2105	struct cpumask ***masks;
2106	int node;
2107	int cpu;
2108	int w;
2109	};
2110
2111	static int hop_cmp(const void *a, const void *b)
2112	{
2113	struct cpumask **prev_hop, **cur_hop = *(struct cpumask ***)b;
2114	struct __cmp_key *k = (struct __cmp_key *)a;
2115
2116	if (cpumask_weight_and(srcp1: k->cpus, srcp2: cur_hop[k->node]) <= k->cpu)
2117	return 1;
2118
2119	if (b == k->masks) {
2120	k->w = 0;
2121	return 0;
2122	}
2123
2124	prev_hop = *((struct cpumask ***)b - 1);
2125	k->w = cpumask_weight_and(srcp1: k->cpus, srcp2: prev_hop[k->node]);
2126	if (k->w <= k->cpu)
2127	return 0;
2128
2129	return -1;
2130	}
2131
2132	/**
2133	* sched_numa_find_nth_cpu() - given the NUMA topology, find the Nth closest CPU
2134	* from @cpus to @cpu, taking into account distance
2135	* from a given @node.
2136	* @cpus: cpumask to find a cpu from
2137	* @cpu: CPU to start searching
2138	* @node: NUMA node to order CPUs by distance
2139	*
2140	* Return: cpu, or nr_cpu_ids when nothing found.
2141	*/
2142	int sched_numa_find_nth_cpu(const struct cpumask *cpus, int cpu, int node)
2143	{
2144	struct __cmp_key k = { .cpus = cpus, .cpu = cpu };
2145	struct cpumask ***hop_masks;
2146	int hop, ret = nr_cpu_ids;
2147
2148	if (node == NUMA_NO_NODE)
2149	return cpumask_nth_and(cpu, srcp1: cpus, cpu_online_mask);
2150
2151	rcu_read_lock();
2152
2153	/* CPU-less node entries are uninitialized in sched_domains_numa_masks */
2154	node = numa_nearest_node(node, state: N_CPU);
2155	k.node = node;
2156
2157	k.masks = rcu_dereference(sched_domains_numa_masks);
2158	if (!k.masks)
2159	goto unlock;
2160
2161	hop_masks = bsearch(key: &k, base: k.masks, num: sched_domains_numa_levels, size: sizeof(k.masks[0]), cmp: hop_cmp);
2162	hop = hop_masks - k.masks;
2163
2164	ret = hop ?
2165	cpumask_nth_and_andnot(cpu: cpu - k.w, srcp1: cpus, srcp2: k.masks[hop][node], srcp3: k.masks[hop-1][node]) :
2166	cpumask_nth_and(cpu, srcp1: cpus, srcp2: k.masks[0][node]);
2167	unlock:
2168	rcu_read_unlock();
2169	return ret;
2170	}
2171	EXPORT_SYMBOL_GPL(sched_numa_find_nth_cpu);
2172
2173	/**
2174	* sched_numa_hop_mask() - Get the cpumask of CPUs at most @hops hops away from
2175	* @node
2176	* @node: The node to count hops from.
2177	* @hops: Include CPUs up to that many hops away. 0 means local node.
2178	*
2179	* Return: On success, a pointer to a cpumask of CPUs at most @hops away from
2180	* @node, an error value otherwise.
2181	*
2182	* Requires rcu_lock to be held. Returned cpumask is only valid within that
2183	* read-side section, copy it if required beyond that.
2184	*
2185	* Note that not all hops are equal in distance; see sched_init_numa() for how
2186	* distances and masks are handled.
2187	* Also note that this is a reflection of sched_domains_numa_masks, which may change
2188	* during the lifetime of the system (offline nodes are taken out of the masks).
2189	*/
2190	const struct cpumask *sched_numa_hop_mask(unsigned int node, unsigned int hops)
2191	{
2192	struct cpumask ***masks;
2193
2194	if (node >= nr_node_ids || hops >= sched_domains_numa_levels)
2195	return ERR_PTR(error: -EINVAL);
2196
2197	masks = rcu_dereference(sched_domains_numa_masks);
2198	if (!masks)
2199	return ERR_PTR(error: -EBUSY);
2200
2201	return masks[hops][node];
2202	}
2203	EXPORT_SYMBOL_GPL(sched_numa_hop_mask);
2204
2205	#endif /* CONFIG_NUMA */
2206
2207	static int __sdt_alloc(const struct cpumask *cpu_map)
2208	{
2209	struct sched_domain_topology_level *tl;
2210	int j;
2211
2212	for_each_sd_topology(tl) {
2213	struct sd_data *sdd = &tl->data;
2214
2215	sdd->sd = alloc_percpu(struct sched_domain *);
2216	if (!sdd->sd)
2217	return -ENOMEM;
2218
2219	sdd->sds = alloc_percpu(struct sched_domain_shared *);
2220	if (!sdd->sds)
2221	return -ENOMEM;
2222
2223	sdd->sg = alloc_percpu(struct sched_group *);
2224	if (!sdd->sg)
2225	return -ENOMEM;
2226
2227	sdd->sgc = alloc_percpu(struct sched_group_capacity *);
2228	if (!sdd->sgc)
2229	return -ENOMEM;
2230
2231	for_each_cpu(j, cpu_map) {
2232	struct sched_domain *sd;
2233	struct sched_domain_shared *sds;
2234	struct sched_group *sg;
2235	struct sched_group_capacity *sgc;
2236
2237	sd = kzalloc_node(size: sizeof(struct sched_domain) + cpumask_size(),
2238	GFP_KERNEL, cpu_to_node(cpu: j));
2239	if (!sd)
2240	return -ENOMEM;
2241
2242	*per_cpu_ptr(sdd->sd, j) = sd;
2243
2244	sds = kzalloc_node(size: sizeof(struct sched_domain_shared),
2245	GFP_KERNEL, cpu_to_node(cpu: j));
2246	if (!sds)
2247	return -ENOMEM;
2248
2249	*per_cpu_ptr(sdd->sds, j) = sds;
2250
2251	sg = kzalloc_node(size: sizeof(struct sched_group) + cpumask_size(),
2252	GFP_KERNEL, cpu_to_node(cpu: j));
2253	if (!sg)
2254	return -ENOMEM;
2255
2256	sg->next = sg;
2257
2258	*per_cpu_ptr(sdd->sg, j) = sg;
2259
2260	sgc = kzalloc_node(size: sizeof(struct sched_group_capacity) + cpumask_size(),
2261	GFP_KERNEL, cpu_to_node(cpu: j));
2262	if (!sgc)
2263	return -ENOMEM;
2264
2265	#ifdef CONFIG_SCHED_DEBUG
2266	sgc->id = j;
2267	#endif
2268
2269	*per_cpu_ptr(sdd->sgc, j) = sgc;
2270	}
2271	}
2272
2273	return 0;
2274	}
2275
2276	static void __sdt_free(const struct cpumask *cpu_map)
2277	{
2278	struct sched_domain_topology_level *tl;
2279	int j;
2280
2281	for_each_sd_topology(tl) {
2282	struct sd_data *sdd = &tl->data;
2283
2284	for_each_cpu(j, cpu_map) {
2285	struct sched_domain *sd;
2286
2287	if (sdd->sd) {
2288	sd = *per_cpu_ptr(sdd->sd, j);
2289	if (sd && (sd->flags & SD_OVERLAP))
2290	free_sched_groups(sg: sd->groups, free_sgc: 0);
2291	kfree(objp: *per_cpu_ptr(sdd->sd, j));
2292	}
2293
2294	if (sdd->sds)
2295	kfree(objp: *per_cpu_ptr(sdd->sds, j));
2296	if (sdd->sg)
2297	kfree(objp: *per_cpu_ptr(sdd->sg, j));
2298	if (sdd->sgc)
2299	kfree(objp: *per_cpu_ptr(sdd->sgc, j));
2300	}
2301	free_percpu(pdata: sdd->sd);
2302	sdd->sd = NULL;
2303	free_percpu(pdata: sdd->sds);
2304	sdd->sds = NULL;
2305	free_percpu(pdata: sdd->sg);
2306	sdd->sg = NULL;
2307	free_percpu(pdata: sdd->sgc);
2308	sdd->sgc = NULL;
2309	}
2310	}
2311
2312	static struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl,
2313	const struct cpumask *cpu_map, struct sched_domain_attr *attr,
2314	struct sched_domain *child, int cpu)
2315	{
2316	struct sched_domain *sd = sd_init(tl, cpu_map, child, cpu);
2317
2318	if (child) {
2319	sd->level = child->level + 1;
2320	sched_domain_level_max = max(sched_domain_level_max, sd->level);
2321	child->parent = sd;
2322
2323	if (!cpumask_subset(src1p: sched_domain_span(sd: child),
2324	src2p: sched_domain_span(sd))) {
2325	pr_err("BUG: arch topology borken\n");
2326	#ifdef CONFIG_SCHED_DEBUG
2327	pr_err(" the %s domain not a subset of the %s domain\n",
2328	child->name, sd->name);
2329	#endif
2330	/* Fixup, ensure @sd has at least @child CPUs. */
2331	cpumask_or(dstp: sched_domain_span(sd),
2332	src1p: sched_domain_span(sd),
2333	src2p: sched_domain_span(sd: child));
2334	}
2335
2336	}
2337	set_domain_attribute(sd, attr);
2338
2339	return sd;
2340	}
2341
2342	/*
2343	* Ensure topology masks are sane, i.e. there are no conflicts (overlaps) for
2344	* any two given CPUs at this (non-NUMA) topology level.
2345	*/
2346	static bool topology_span_sane(struct sched_domain_topology_level *tl,
2347	const struct cpumask *cpu_map, int cpu)
2348	{
2349	int i;
2350
2351	/* NUMA levels are allowed to overlap */
2352	if (tl->flags & SDTL_OVERLAP)
2353	return true;
2354
2355	/*
2356	* Non-NUMA levels cannot partially overlap - they must be either
2357	* completely equal or completely disjoint. Otherwise we can end up
2358	* breaking the sched_group lists - i.e. a later get_group() pass
2359	* breaks the linking done for an earlier span.
2360	*/
2361	for_each_cpu(i, cpu_map) {
2362	if (i == cpu)
2363	continue;
2364	/*
2365	* We should 'and' all those masks with 'cpu_map' to exactly
2366	* match the topology we're about to build, but that can only
2367	* remove CPUs, which only lessens our ability to detect
2368	* overlaps
2369	*/
2370	if (!cpumask_equal(src1p: tl->mask(cpu), src2p: tl->mask(i)) &&
2371	cpumask_intersects(src1p: tl->mask(cpu), src2p: tl->mask(i)))
2372	return false;
2373	}
2374
2375	return true;
2376	}
2377
2378	/*
2379	* Build sched domains for a given set of CPUs and attach the sched domains
2380	* to the individual CPUs
2381	*/
2382	static int
2383	build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *attr)
2384	{
2385	enum s_alloc alloc_state = sa_none;
2386	struct sched_domain *sd;
2387	struct s_data d;
2388	struct rq *rq = NULL;
2389	int i, ret = -ENOMEM;
2390	bool has_asym = false;
2391	bool has_cluster = false;
2392
2393	if (WARN_ON(cpumask_empty(cpu_map)))
2394	goto error;
2395
2396	alloc_state = __visit_domain_allocation_hell(d: &d, cpu_map);
2397	if (alloc_state != sa_rootdomain)
2398	goto error;
2399
2400	/* Set up domains for CPUs specified by the cpu_map: */
2401	for_each_cpu(i, cpu_map) {
2402	struct sched_domain_topology_level *tl;
2403
2404	sd = NULL;
2405	for_each_sd_topology(tl) {
2406
2407	if (WARN_ON(!topology_span_sane(tl, cpu_map, i)))
2408	goto error;
2409
2410	sd = build_sched_domain(tl, cpu_map, attr, child: sd, cpu: i);
2411
2412	has_asym |= sd->flags & SD_ASYM_CPUCAPACITY;
2413
2414	if (tl == sched_domain_topology)
2415	*per_cpu_ptr(d.sd, i) = sd;
2416	if (tl->flags & SDTL_OVERLAP)
2417	sd->flags |= SD_OVERLAP;
2418	if (cpumask_equal(src1p: cpu_map, src2p: sched_domain_span(sd)))
2419	break;
2420	}
2421	}
2422
2423	/* Build the groups for the domains */
2424	for_each_cpu(i, cpu_map) {
2425	for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) {
2426	sd->span_weight = cpumask_weight(srcp: sched_domain_span(sd));
2427	if (sd->flags & SD_OVERLAP) {
2428	if (build_overlap_sched_groups(sd, cpu: i))
2429	goto error;
2430	} else {
2431	if (build_sched_groups(sd, cpu: i))
2432	goto error;
2433	}
2434	}
2435	}
2436
2437	/*
2438	* Calculate an allowed NUMA imbalance such that LLCs do not get
2439	* imbalanced.
2440	*/
2441	for_each_cpu(i, cpu_map) {
2442	unsigned int imb = 0;
2443	unsigned int imb_span = 1;
2444
2445	for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) {
2446	struct sched_domain *child = sd->child;
2447
2448	if (!(sd->flags & SD_SHARE_PKG_RESOURCES) && child &&
2449	(child->flags & SD_SHARE_PKG_RESOURCES)) {
2450	struct sched_domain __rcu *top_p;
2451	unsigned int nr_llcs;
2452
2453	/*
2454	* For a single LLC per node, allow an
2455	* imbalance up to 12.5% of the node. This is
2456	* arbitrary cutoff based two factors -- SMT and
2457	* memory channels. For SMT-2, the intent is to
2458	* avoid premature sharing of HT resources but
2459	* SMT-4 or SMT-8 *may* benefit from a different
2460	* cutoff. For memory channels, this is a very
2461	* rough estimate of how many channels may be
2462	* active and is based on recent CPUs with
2463	* many cores.
2464	*
2465	* For multiple LLCs, allow an imbalance
2466	* until multiple tasks would share an LLC
2467	* on one node while LLCs on another node
2468	* remain idle. This assumes that there are
2469	* enough logical CPUs per LLC to avoid SMT
2470	* factors and that there is a correlation
2471	* between LLCs and memory channels.
2472	*/
2473	nr_llcs = sd->span_weight / child->span_weight;
2474	if (nr_llcs == 1)
2475	imb = sd->span_weight >> 3;
2476	else
2477	imb = nr_llcs;
2478	imb = max(1U, imb);
2479	sd->imb_numa_nr = imb;
2480
2481	/* Set span based on the first NUMA domain. */
2482	top_p = sd->parent;
2483	while (top_p && !(top_p->flags & SD_NUMA)) {
2484	top_p = top_p->parent;
2485	}
2486	imb_span = top_p ? top_p->span_weight : sd->span_weight;
2487	} else {
2488	int factor = max(1U, (sd->span_weight / imb_span));
2489
2490	sd->imb_numa_nr = imb * factor;
2491	}
2492	}
2493	}
2494
2495	/* Calculate CPU capacity for physical packages and nodes */
2496	for (i = nr_cpumask_bits-1; i >= 0; i--) {
2497	if (!cpumask_test_cpu(cpu: i, cpumask: cpu_map))
2498	continue;
2499
2500	for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) {
2501	claim_allocations(cpu: i, sd);
2502	init_sched_groups_capacity(cpu: i, sd);
2503	}
2504	}
2505
2506	/* Attach the domains */
2507	rcu_read_lock();
2508	for_each_cpu(i, cpu_map) {
2509	unsigned long capacity;
2510
2511	rq = cpu_rq(i);
2512	sd = *per_cpu_ptr(d.sd, i);
2513
2514	capacity = arch_scale_cpu_capacity(cpu: i);
2515	/* Use READ_ONCE()/WRITE_ONCE() to avoid load/store tearing: */
2516	if (capacity > READ_ONCE(d.rd->max_cpu_capacity))
2517	WRITE_ONCE(d.rd->max_cpu_capacity, capacity);
2518
2519	cpu_attach_domain(sd, rd: d.rd, cpu: i);
2520
2521	if (lowest_flag_domain(cpu: i, flag: SD_CLUSTER))
2522	has_cluster = true;
2523	}
2524	rcu_read_unlock();
2525
2526	if (has_asym)
2527	static_branch_inc_cpuslocked(&sched_asym_cpucapacity);
2528
2529	if (has_cluster)
2530	static_branch_inc_cpuslocked(&sched_cluster_active);
2531
2532	if (rq && sched_debug_verbose) {
2533	pr_info("root domain span: %*pbl (max cpu_capacity = %lu)\n",
2534	cpumask_pr_args(cpu_map), rq->rd->max_cpu_capacity);
2535	}
2536
2537	ret = 0;
2538	error:
2539	__free_domain_allocs(d: &d, what: alloc_state, cpu_map);
2540
2541	return ret;
2542	}
2543
2544	/* Current sched domains: */
2545	static cpumask_var_t *doms_cur;
2546
2547	/* Number of sched domains in 'doms_cur': */
2548	static int ndoms_cur;
2549
2550	/* Attributes of custom domains in 'doms_cur' */
2551	static struct sched_domain_attr *dattr_cur;
2552
2553	/*
2554	* Special case: If a kmalloc() of a doms_cur partition (array of
2555	* cpumask) fails, then fallback to a single sched domain,
2556	* as determined by the single cpumask fallback_doms.
2557	*/
2558	static cpumask_var_t fallback_doms;
2559
2560	/*
2561	* arch_update_cpu_topology lets virtualized architectures update the
2562	* CPU core maps. It is supposed to return 1 if the topology changed
2563	* or 0 if it stayed the same.
2564	*/
2565	int __weak arch_update_cpu_topology(void)
2566	{
2567	return 0;
2568	}
2569
2570	cpumask_var_t *alloc_sched_domains(unsigned int ndoms)
2571	{
2572	int i;
2573	cpumask_var_t *doms;
2574
2575	doms = kmalloc_array(n: ndoms, size: sizeof(*doms), GFP_KERNEL);
2576	if (!doms)
2577	return NULL;
2578	for (i = 0; i < ndoms; i++) {
2579	if (!alloc_cpumask_var(mask: &doms[i], GFP_KERNEL)) {
2580	free_sched_domains(doms, ndoms: i);
2581	return NULL;
2582	}
2583	}
2584	return doms;
2585	}
2586
2587	void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms)
2588	{
2589	unsigned int i;
2590	for (i = 0; i < ndoms; i++)
2591	free_cpumask_var(mask: doms[i]);
2592	kfree(objp: doms);
2593	}
2594
2595	/*
2596	* Set up scheduler domains and groups. For now this just excludes isolated
2597	* CPUs, but could be used to exclude other special cases in the future.
2598	*/
2599	int __init sched_init_domains(const struct cpumask *cpu_map)
2600	{
2601	int err;
2602
2603	zalloc_cpumask_var(mask: &sched_domains_tmpmask, GFP_KERNEL);
2604	zalloc_cpumask_var(mask: &sched_domains_tmpmask2, GFP_KERNEL);
2605	zalloc_cpumask_var(mask: &fallback_doms, GFP_KERNEL);
2606
2607	arch_update_cpu_topology();
2608	asym_cpu_capacity_scan();
2609	ndoms_cur = 1;
2610	doms_cur = alloc_sched_domains(ndoms: ndoms_cur);
2611	if (!doms_cur)
2612	doms_cur = &fallback_doms;
2613	cpumask_and(dstp: doms_cur[0], src1p: cpu_map, src2p: housekeeping_cpumask(type: HK_TYPE_DOMAIN));
2614	err = build_sched_domains(cpu_map: doms_cur[0], NULL);
2615
2616	return err;
2617	}
2618
2619	/*
2620	* Detach sched domains from a group of CPUs specified in cpu_map
2621	* These CPUs will now be attached to the NULL domain
2622	*/
2623	static void detach_destroy_domains(const struct cpumask *cpu_map)
2624	{
2625	unsigned int cpu = cpumask_any(cpu_map);
2626	int i;
2627
2628	if (rcu_access_pointer(per_cpu(sd_asym_cpucapacity, cpu)))
2629	static_branch_dec_cpuslocked(&sched_asym_cpucapacity);
2630
2631	if (static_branch_unlikely(&sched_cluster_active))
2632	static_branch_dec_cpuslocked(&sched_cluster_active);
2633
2634	rcu_read_lock();
2635	for_each_cpu(i, cpu_map)
2636	cpu_attach_domain(NULL, rd: &def_root_domain, cpu: i);
2637	rcu_read_unlock();
2638	}
2639
2640	/* handle null as "default" */
2641	static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur,
2642	struct sched_domain_attr *new, int idx_new)
2643	{
2644	struct sched_domain_attr tmp;
2645
2646	/* Fast path: */
2647	if (!new && !cur)
2648	return 1;
2649
2650	tmp = SD_ATTR_INIT;
2651
2652	return !memcmp(p: cur ? (cur + idx_cur) : &tmp,
2653	q: new ? (new + idx_new) : &tmp,
2654	size: sizeof(struct sched_domain_attr));
2655	}
2656
2657	/*
2658	* Partition sched domains as specified by the 'ndoms_new'
2659	* cpumasks in the array doms_new[] of cpumasks. This compares
2660	* doms_new[] to the current sched domain partitioning, doms_cur[].
2661	* It destroys each deleted domain and builds each new domain.
2662	*
2663	* 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'.
2664	* The masks don't intersect (don't overlap.) We should setup one
2665	* sched domain for each mask. CPUs not in any of the cpumasks will
2666	* not be load balanced. If the same cpumask appears both in the
2667	* current 'doms_cur' domains and in the new 'doms_new', we can leave
2668	* it as it is.
2669	*
2670	* The passed in 'doms_new' should be allocated using
2671	* alloc_sched_domains. This routine takes ownership of it and will
2672	* free_sched_domains it when done with it. If the caller failed the
2673	* alloc call, then it can pass in doms_new == NULL && ndoms_new == 1,
2674	* and partition_sched_domains() will fallback to the single partition
2675	* 'fallback_doms', it also forces the domains to be rebuilt.
2676	*
2677	* If doms_new == NULL it will be replaced with cpu_online_mask.
2678	* ndoms_new == 0 is a special case for destroying existing domains,
2679	* and it will not create the default domain.
2680	*
2681	* Call with hotplug lock and sched_domains_mutex held
2682	*/
2683	void partition_sched_domains_locked(int ndoms_new, cpumask_var_t doms_new[],
2684	struct sched_domain_attr *dattr_new)
2685	{
2686	bool __maybe_unused has_eas = false;
2687	int i, j, n;
2688	int new_topology;
2689
2690	lockdep_assert_held(&sched_domains_mutex);
2691
2692	/* Let the architecture update CPU core mappings: */
2693	new_topology = arch_update_cpu_topology();
2694	/* Trigger rebuilding CPU capacity asymmetry data */
2695	if (new_topology)
2696	asym_cpu_capacity_scan();
2697
2698	if (!doms_new) {
2699	WARN_ON_ONCE(dattr_new);
2700	n = 0;
2701	doms_new = alloc_sched_domains(ndoms: 1);
2702	if (doms_new) {
2703	n = 1;
2704	cpumask_and(dstp: doms_new[0], cpu_active_mask,
2705	src2p: housekeeping_cpumask(type: HK_TYPE_DOMAIN));
2706	}
2707	} else {
2708	n = ndoms_new;
2709	}
2710
2711	/* Destroy deleted domains: */
2712	for (i = 0; i < ndoms_cur; i++) {
2713	for (j = 0; j < n && !new_topology; j++) {
2714	if (cpumask_equal(src1p: doms_cur[i], src2p: doms_new[j]) &&
2715	dattrs_equal(cur: dattr_cur, idx_cur: i, new: dattr_new, idx_new: j)) {
2716	struct root_domain *rd;
2717
2718	/*
2719	* This domain won't be destroyed and as such
2720	* its dl_bw->total_bw needs to be cleared. It
2721	* will be recomputed in function
2722	* update_tasks_root_domain().
2723	*/
2724	rd = cpu_rq(cpumask_any(doms_cur[i]))->rd;
2725	dl_clear_root_domain(rd);
2726	goto match1;
2727	}
2728	}
2729	/* No match - a current sched domain not in new doms_new[] */
2730	detach_destroy_domains(cpu_map: doms_cur[i]);
2731	match1:
2732	;
2733	}
2734
2735	n = ndoms_cur;
2736	if (!doms_new) {
2737	n = 0;
2738	doms_new = &fallback_doms;
2739	cpumask_and(dstp: doms_new[0], cpu_active_mask,
2740	src2p: housekeeping_cpumask(type: HK_TYPE_DOMAIN));
2741	}
2742
2743	/* Build new domains: */
2744	for (i = 0; i < ndoms_new; i++) {
2745	for (j = 0; j < n && !new_topology; j++) {
2746	if (cpumask_equal(src1p: doms_new[i], src2p: doms_cur[j]) &&
2747	dattrs_equal(cur: dattr_new, idx_cur: i, new: dattr_cur, idx_new: j))
2748	goto match2;
2749	}
2750	/* No match - add a new doms_new */
2751	build_sched_domains(cpu_map: doms_new[i], attr: dattr_new ? dattr_new + i : NULL);
2752	match2:
2753	;
2754	}
2755
2756	#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL)
2757	/* Build perf. domains: */
2758	for (i = 0; i < ndoms_new; i++) {
2759	for (j = 0; j < n && !sched_energy_update; j++) {
2760	if (cpumask_equal(src1p: doms_new[i], src2p: doms_cur[j]) &&
2761	cpu_rq(cpumask_first(doms_cur[j]))->rd->pd) {
2762	has_eas = true;
2763	goto match3;
2764	}
2765	}
2766	/* No match - add perf. domains for a new rd */
2767	has_eas |= build_perf_domains(cpu_map: doms_new[i]);
2768	match3:
2769	;
2770	}
2771	sched_energy_set(has_eas);
2772	#endif
2773
2774	/* Remember the new sched domains: */
2775	if (doms_cur != &fallback_doms)
2776	free_sched_domains(doms: doms_cur, ndoms: ndoms_cur);
2777
2778	kfree(objp: dattr_cur);
2779	doms_cur = doms_new;
2780	dattr_cur = dattr_new;
2781	ndoms_cur = ndoms_new;
2782
2783	update_sched_domain_debugfs();
2784	}
2785
2786	/*
2787	* Call with hotplug lock held
2788	*/
2789	void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
2790	struct sched_domain_attr *dattr_new)
2791	{
2792	mutex_lock(&sched_domains_mutex);
2793	partition_sched_domains_locked(ndoms_new, doms_new, dattr_new);
2794	mutex_unlock(lock: &sched_domains_mutex);
2795	}
2796