1/*
2 *    Copyright IBM Corp. 2007, 2011
3 *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
4 */
5
6#define KMSG_COMPONENT "cpu"
7#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
8
9#include <linux/workqueue.h>
10#include <linux/cpuset.h>
11#include <linux/device.h>
12#include <linux/export.h>
13#include <linux/kernel.h>
14#include <linux/sched.h>
15#include <linux/delay.h>
16#include <linux/init.h>
17#include <linux/slab.h>
18#include <linux/cpu.h>
19#include <linux/smp.h>
20#include <linux/mm.h>
21#include <asm/sysinfo.h>
22
23#define PTF_HORIZONTAL	(0UL)
24#define PTF_VERTICAL	(1UL)
25#define PTF_CHECK	(2UL)
26
27struct mask_info {
28	struct mask_info *next;
29	unsigned char id;
30	cpumask_t mask;
31};
32
33static void set_topology_timer(void);
34static void topology_work_fn(struct work_struct *work);
35static struct sysinfo_15_1_x *tl_info;
36
37static int topology_enabled = 1;
38static DECLARE_WORK(topology_work, topology_work_fn);
39
40/* topology_lock protects the socket and book linked lists */
41static DEFINE_SPINLOCK(topology_lock);
42static struct mask_info socket_info;
43static struct mask_info book_info;
44
45DEFINE_PER_CPU(struct cpu_topology_s390, cpu_topology);
46EXPORT_PER_CPU_SYMBOL_GPL(cpu_topology);
47
48static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
49{
50	cpumask_t mask;
51
52	cpumask_copy(&mask, cpumask_of(cpu));
53	if (!topology_enabled || !MACHINE_HAS_TOPOLOGY)
54		return mask;
55	for (; info; info = info->next) {
56		if (cpumask_test_cpu(cpu, &info->mask))
57			return info->mask;
58	}
59	return mask;
60}
61
62static cpumask_t cpu_thread_map(unsigned int cpu)
63{
64	cpumask_t mask;
65	int i;
66
67	cpumask_copy(&mask, cpumask_of(cpu));
68	if (!topology_enabled || !MACHINE_HAS_TOPOLOGY)
69		return mask;
70	cpu -= cpu % (smp_cpu_mtid + 1);
71	for (i = 0; i <= smp_cpu_mtid; i++)
72		if (cpu_present(cpu + i))
73			cpumask_set_cpu(cpu + i, &mask);
74	return mask;
75}
76
77static struct mask_info *add_cpus_to_mask(struct topology_core *tl_core,
78					  struct mask_info *book,
79					  struct mask_info *socket,
80					  int one_socket_per_cpu)
81{
82	unsigned int core;
83
84	for_each_set_bit(core, &tl_core->mask[0], TOPOLOGY_CORE_BITS) {
85		unsigned int rcore;
86		int lcpu, i;
87
88		rcore = TOPOLOGY_CORE_BITS - 1 - core + tl_core->origin;
89		lcpu = smp_find_processor_id(rcore << smp_cpu_mt_shift);
90		if (lcpu < 0)
91			continue;
92		for (i = 0; i <= smp_cpu_mtid; i++) {
93			per_cpu(cpu_topology, lcpu + i).book_id = book->id;
94			per_cpu(cpu_topology, lcpu + i).core_id = rcore;
95			per_cpu(cpu_topology, lcpu + i).thread_id = lcpu + i;
96			cpumask_set_cpu(lcpu + i, &book->mask);
97			cpumask_set_cpu(lcpu + i, &socket->mask);
98			if (one_socket_per_cpu)
99				per_cpu(cpu_topology, lcpu + i).socket_id = rcore;
100			else
101				per_cpu(cpu_topology, lcpu + i).socket_id = socket->id;
102			smp_cpu_set_polarization(lcpu + i, tl_core->pp);
103		}
104		if (one_socket_per_cpu)
105			socket = socket->next;
106	}
107	return socket;
108}
109
110static void clear_masks(void)
111{
112	struct mask_info *info;
113
114	info = &socket_info;
115	while (info) {
116		cpumask_clear(&info->mask);
117		info = info->next;
118	}
119	info = &book_info;
120	while (info) {
121		cpumask_clear(&info->mask);
122		info = info->next;
123	}
124}
125
126static union topology_entry *next_tle(union topology_entry *tle)
127{
128	if (!tle->nl)
129		return (union topology_entry *)((struct topology_core *)tle + 1);
130	return (union topology_entry *)((struct topology_container *)tle + 1);
131}
132
133static void __tl_to_masks_generic(struct sysinfo_15_1_x *info)
134{
135	struct mask_info *socket = &socket_info;
136	struct mask_info *book = &book_info;
137	union topology_entry *tle, *end;
138
139	tle = info->tle;
140	end = (union topology_entry *)((unsigned long)info + info->length);
141	while (tle < end) {
142		switch (tle->nl) {
143		case 2:
144			book = book->next;
145			book->id = tle->container.id;
146			break;
147		case 1:
148			socket = socket->next;
149			socket->id = tle->container.id;
150			break;
151		case 0:
152			add_cpus_to_mask(&tle->cpu, book, socket, 0);
153			break;
154		default:
155			clear_masks();
156			return;
157		}
158		tle = next_tle(tle);
159	}
160}
161
162static void __tl_to_masks_z10(struct sysinfo_15_1_x *info)
163{
164	struct mask_info *socket = &socket_info;
165	struct mask_info *book = &book_info;
166	union topology_entry *tle, *end;
167
168	tle = info->tle;
169	end = (union topology_entry *)((unsigned long)info + info->length);
170	while (tle < end) {
171		switch (tle->nl) {
172		case 1:
173			book = book->next;
174			book->id = tle->container.id;
175			break;
176		case 0:
177			socket = add_cpus_to_mask(&tle->cpu, book, socket, 1);
178			break;
179		default:
180			clear_masks();
181			return;
182		}
183		tle = next_tle(tle);
184	}
185}
186
187static void tl_to_masks(struct sysinfo_15_1_x *info)
188{
189	struct cpuid cpu_id;
190
191	spin_lock_irq(&topology_lock);
192	get_cpu_id(&cpu_id);
193	clear_masks();
194	switch (cpu_id.machine) {
195	case 0x2097:
196	case 0x2098:
197		__tl_to_masks_z10(info);
198		break;
199	default:
200		__tl_to_masks_generic(info);
201	}
202	spin_unlock_irq(&topology_lock);
203}
204
205static void topology_update_polarization_simple(void)
206{
207	int cpu;
208
209	mutex_lock(&smp_cpu_state_mutex);
210	for_each_possible_cpu(cpu)
211		smp_cpu_set_polarization(cpu, POLARIZATION_HRZ);
212	mutex_unlock(&smp_cpu_state_mutex);
213}
214
215static int ptf(unsigned long fc)
216{
217	int rc;
218
219	asm volatile(
220		"	.insn	rre,0xb9a20000,%1,%1\n"
221		"	ipm	%0\n"
222		"	srl	%0,28\n"
223		: "=d" (rc)
224		: "d" (fc)  : "cc");
225	return rc;
226}
227
228int topology_set_cpu_management(int fc)
229{
230	int cpu, rc;
231
232	if (!MACHINE_HAS_TOPOLOGY)
233		return -EOPNOTSUPP;
234	if (fc)
235		rc = ptf(PTF_VERTICAL);
236	else
237		rc = ptf(PTF_HORIZONTAL);
238	if (rc)
239		return -EBUSY;
240	for_each_possible_cpu(cpu)
241		smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
242	return rc;
243}
244
245static void update_cpu_masks(void)
246{
247	unsigned long flags;
248	int cpu;
249
250	spin_lock_irqsave(&topology_lock, flags);
251	for_each_possible_cpu(cpu) {
252		per_cpu(cpu_topology, cpu).thread_mask = cpu_thread_map(cpu);
253		per_cpu(cpu_topology, cpu).core_mask = cpu_group_map(&socket_info, cpu);
254		per_cpu(cpu_topology, cpu).book_mask = cpu_group_map(&book_info, cpu);
255		if (!MACHINE_HAS_TOPOLOGY) {
256			per_cpu(cpu_topology, cpu).thread_id = cpu;
257			per_cpu(cpu_topology, cpu).core_id = cpu;
258			per_cpu(cpu_topology, cpu).socket_id = cpu;
259			per_cpu(cpu_topology, cpu).book_id = cpu;
260		}
261	}
262	spin_unlock_irqrestore(&topology_lock, flags);
263}
264
265void store_topology(struct sysinfo_15_1_x *info)
266{
267	if (topology_max_mnest >= 3)
268		stsi(info, 15, 1, 3);
269	else
270		stsi(info, 15, 1, 2);
271}
272
273int arch_update_cpu_topology(void)
274{
275	struct sysinfo_15_1_x *info = tl_info;
276	struct device *dev;
277	int cpu;
278
279	if (!MACHINE_HAS_TOPOLOGY) {
280		update_cpu_masks();
281		topology_update_polarization_simple();
282		return 0;
283	}
284	store_topology(info);
285	tl_to_masks(info);
286	update_cpu_masks();
287	for_each_online_cpu(cpu) {
288		dev = get_cpu_device(cpu);
289		kobject_uevent(&dev->kobj, KOBJ_CHANGE);
290	}
291	return 1;
292}
293
294static void topology_work_fn(struct work_struct *work)
295{
296	rebuild_sched_domains();
297}
298
299void topology_schedule_update(void)
300{
301	schedule_work(&topology_work);
302}
303
304static void topology_timer_fn(unsigned long ignored)
305{
306	if (ptf(PTF_CHECK))
307		topology_schedule_update();
308	set_topology_timer();
309}
310
311static struct timer_list topology_timer =
312	TIMER_DEFERRED_INITIALIZER(topology_timer_fn, 0, 0);
313
314static atomic_t topology_poll = ATOMIC_INIT(0);
315
316static void set_topology_timer(void)
317{
318	if (atomic_add_unless(&topology_poll, -1, 0))
319		mod_timer(&topology_timer, jiffies + HZ / 10);
320	else
321		mod_timer(&topology_timer, jiffies + HZ * 60);
322}
323
324void topology_expect_change(void)
325{
326	if (!MACHINE_HAS_TOPOLOGY)
327		return;
328	/* This is racy, but it doesn't matter since it is just a heuristic.
329	 * Worst case is that we poll in a higher frequency for a bit longer.
330	 */
331	if (atomic_read(&topology_poll) > 60)
332		return;
333	atomic_add(60, &topology_poll);
334	set_topology_timer();
335}
336
337static int cpu_management;
338
339static ssize_t dispatching_show(struct device *dev,
340				struct device_attribute *attr,
341				char *buf)
342{
343	ssize_t count;
344
345	mutex_lock(&smp_cpu_state_mutex);
346	count = sprintf(buf, "%d\n", cpu_management);
347	mutex_unlock(&smp_cpu_state_mutex);
348	return count;
349}
350
351static ssize_t dispatching_store(struct device *dev,
352				 struct device_attribute *attr,
353				 const char *buf,
354				 size_t count)
355{
356	int val, rc;
357	char delim;
358
359	if (sscanf(buf, "%d %c", &val, &delim) != 1)
360		return -EINVAL;
361	if (val != 0 && val != 1)
362		return -EINVAL;
363	rc = 0;
364	get_online_cpus();
365	mutex_lock(&smp_cpu_state_mutex);
366	if (cpu_management == val)
367		goto out;
368	rc = topology_set_cpu_management(val);
369	if (rc)
370		goto out;
371	cpu_management = val;
372	topology_expect_change();
373out:
374	mutex_unlock(&smp_cpu_state_mutex);
375	put_online_cpus();
376	return rc ? rc : count;
377}
378static DEVICE_ATTR(dispatching, 0644, dispatching_show,
379			 dispatching_store);
380
381static ssize_t cpu_polarization_show(struct device *dev,
382				     struct device_attribute *attr, char *buf)
383{
384	int cpu = dev->id;
385	ssize_t count;
386
387	mutex_lock(&smp_cpu_state_mutex);
388	switch (smp_cpu_get_polarization(cpu)) {
389	case POLARIZATION_HRZ:
390		count = sprintf(buf, "horizontal\n");
391		break;
392	case POLARIZATION_VL:
393		count = sprintf(buf, "vertical:low\n");
394		break;
395	case POLARIZATION_VM:
396		count = sprintf(buf, "vertical:medium\n");
397		break;
398	case POLARIZATION_VH:
399		count = sprintf(buf, "vertical:high\n");
400		break;
401	default:
402		count = sprintf(buf, "unknown\n");
403		break;
404	}
405	mutex_unlock(&smp_cpu_state_mutex);
406	return count;
407}
408static DEVICE_ATTR(polarization, 0444, cpu_polarization_show, NULL);
409
410static struct attribute *topology_cpu_attrs[] = {
411	&dev_attr_polarization.attr,
412	NULL,
413};
414
415static struct attribute_group topology_cpu_attr_group = {
416	.attrs = topology_cpu_attrs,
417};
418
419int topology_cpu_init(struct cpu *cpu)
420{
421	return sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
422}
423
424static const struct cpumask *cpu_thread_mask(int cpu)
425{
426	return &per_cpu(cpu_topology, cpu).thread_mask;
427}
428
429
430const struct cpumask *cpu_coregroup_mask(int cpu)
431{
432	return &per_cpu(cpu_topology, cpu).core_mask;
433}
434
435static const struct cpumask *cpu_book_mask(int cpu)
436{
437	return &per_cpu(cpu_topology, cpu).book_mask;
438}
439
440static int __init early_parse_topology(char *p)
441{
442	if (strncmp(p, "off", 3))
443		return 0;
444	topology_enabled = 0;
445	return 0;
446}
447early_param("topology", early_parse_topology);
448
449static struct sched_domain_topology_level s390_topology[] = {
450	{ cpu_thread_mask, cpu_smt_flags, SD_INIT_NAME(SMT) },
451	{ cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) },
452	{ cpu_book_mask, SD_INIT_NAME(BOOK) },
453	{ cpu_cpu_mask, SD_INIT_NAME(DIE) },
454	{ NULL, },
455};
456
457static void __init alloc_masks(struct sysinfo_15_1_x *info,
458			       struct mask_info *mask, int offset)
459{
460	int i, nr_masks;
461
462	nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
463	for (i = 0; i < info->mnest - offset; i++)
464		nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
465	nr_masks = max(nr_masks, 1);
466	for (i = 0; i < nr_masks; i++) {
467		mask->next = kzalloc(sizeof(*mask->next), GFP_KERNEL);
468		mask = mask->next;
469	}
470}
471
472static int __init s390_topology_init(void)
473{
474	struct sysinfo_15_1_x *info;
475	int i;
476
477	if (!MACHINE_HAS_TOPOLOGY)
478		return 0;
479	tl_info = (struct sysinfo_15_1_x *)__get_free_page(GFP_KERNEL);
480	info = tl_info;
481	store_topology(info);
482	pr_info("The CPU configuration topology of the machine is:");
483	for (i = 0; i < TOPOLOGY_NR_MAG; i++)
484		printk(KERN_CONT " %d", info->mag[i]);
485	printk(KERN_CONT " / %d\n", info->mnest);
486	alloc_masks(info, &socket_info, 1);
487	alloc_masks(info, &book_info, 2);
488	set_sched_topology(s390_topology);
489	return 0;
490}
491early_initcall(s390_topology_init);
492
493static int __init topology_init(void)
494{
495	if (MACHINE_HAS_TOPOLOGY)
496		set_topology_timer();
497	else
498		topology_update_polarization_simple();
499	return device_create_file(cpu_subsys.dev_root, &dev_attr_dispatching);
500}
501device_initcall(topology_init);
502