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 <linux/nodemask.h>
22#include <linux/node.h>
23#include <asm/sysinfo.h>
24#include <asm/numa.h>
25
26#define PTF_HORIZONTAL	(0UL)
27#define PTF_VERTICAL	(1UL)
28#define PTF_CHECK	(2UL)
29
30struct mask_info {
31	struct mask_info *next;
32	unsigned char id;
33	cpumask_t mask;
34};
35
36static void set_topology_timer(void);
37static void topology_work_fn(struct work_struct *work);
38static struct sysinfo_15_1_x *tl_info;
39
40static int topology_enabled = 1;
41static DECLARE_WORK(topology_work, topology_work_fn);
42
43/*
44 * Socket/Book linked lists and per_cpu(cpu_topology) updates are
45 * protected by "sched_domains_mutex".
46 */
47static struct mask_info socket_info;
48static struct mask_info book_info;
49
50DEFINE_PER_CPU(struct cpu_topology_s390, cpu_topology);
51EXPORT_PER_CPU_SYMBOL_GPL(cpu_topology);
52
53static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
54{
55	cpumask_t mask;
56
57	cpumask_copy(&mask, cpumask_of(cpu));
58	if (!topology_enabled || !MACHINE_HAS_TOPOLOGY)
59		return mask;
60	for (; info; info = info->next) {
61		if (cpumask_test_cpu(cpu, &info->mask))
62			return info->mask;
63	}
64	return mask;
65}
66
67static cpumask_t cpu_thread_map(unsigned int cpu)
68{
69	cpumask_t mask;
70	int i;
71
72	cpumask_copy(&mask, cpumask_of(cpu));
73	if (!topology_enabled || !MACHINE_HAS_TOPOLOGY)
74		return mask;
75	cpu -= cpu % (smp_cpu_mtid + 1);
76	for (i = 0; i <= smp_cpu_mtid; i++)
77		if (cpu_present(cpu + i))
78			cpumask_set_cpu(cpu + i, &mask);
79	return mask;
80}
81
82static struct mask_info *add_cpus_to_mask(struct topology_core *tl_core,
83					  struct mask_info *book,
84					  struct mask_info *socket,
85					  int one_socket_per_cpu)
86{
87	struct cpu_topology_s390 *topo;
88	unsigned int core;
89
90	for_each_set_bit(core, &tl_core->mask[0], TOPOLOGY_CORE_BITS) {
91		unsigned int rcore;
92		int lcpu, i;
93
94		rcore = TOPOLOGY_CORE_BITS - 1 - core + tl_core->origin;
95		lcpu = smp_find_processor_id(rcore << smp_cpu_mt_shift);
96		if (lcpu < 0)
97			continue;
98		for (i = 0; i <= smp_cpu_mtid; i++) {
99			topo = &per_cpu(cpu_topology, lcpu + i);
100			topo->book_id = book->id;
101			topo->core_id = rcore;
102			topo->thread_id = lcpu + i;
103			cpumask_set_cpu(lcpu + i, &book->mask);
104			cpumask_set_cpu(lcpu + i, &socket->mask);
105			if (one_socket_per_cpu)
106				topo->socket_id = rcore;
107			else
108				topo->socket_id = socket->id;
109			smp_cpu_set_polarization(lcpu + i, tl_core->pp);
110		}
111		if (one_socket_per_cpu)
112			socket = socket->next;
113	}
114	return socket;
115}
116
117static void clear_masks(void)
118{
119	struct mask_info *info;
120
121	info = &socket_info;
122	while (info) {
123		cpumask_clear(&info->mask);
124		info = info->next;
125	}
126	info = &book_info;
127	while (info) {
128		cpumask_clear(&info->mask);
129		info = info->next;
130	}
131}
132
133static union topology_entry *next_tle(union topology_entry *tle)
134{
135	if (!tle->nl)
136		return (union topology_entry *)((struct topology_core *)tle + 1);
137	return (union topology_entry *)((struct topology_container *)tle + 1);
138}
139
140static void __tl_to_masks_generic(struct sysinfo_15_1_x *info)
141{
142	struct mask_info *socket = &socket_info;
143	struct mask_info *book = &book_info;
144	union topology_entry *tle, *end;
145
146	tle = info->tle;
147	end = (union topology_entry *)((unsigned long)info + info->length);
148	while (tle < end) {
149		switch (tle->nl) {
150		case 2:
151			book = book->next;
152			book->id = tle->container.id;
153			break;
154		case 1:
155			socket = socket->next;
156			socket->id = tle->container.id;
157			break;
158		case 0:
159			add_cpus_to_mask(&tle->cpu, book, socket, 0);
160			break;
161		default:
162			clear_masks();
163			return;
164		}
165		tle = next_tle(tle);
166	}
167}
168
169static void __tl_to_masks_z10(struct sysinfo_15_1_x *info)
170{
171	struct mask_info *socket = &socket_info;
172	struct mask_info *book = &book_info;
173	union topology_entry *tle, *end;
174
175	tle = info->tle;
176	end = (union topology_entry *)((unsigned long)info + info->length);
177	while (tle < end) {
178		switch (tle->nl) {
179		case 1:
180			book = book->next;
181			book->id = tle->container.id;
182			break;
183		case 0:
184			socket = add_cpus_to_mask(&tle->cpu, book, socket, 1);
185			break;
186		default:
187			clear_masks();
188			return;
189		}
190		tle = next_tle(tle);
191	}
192}
193
194static void tl_to_masks(struct sysinfo_15_1_x *info)
195{
196	struct cpuid cpu_id;
197
198	get_cpu_id(&cpu_id);
199	clear_masks();
200	switch (cpu_id.machine) {
201	case 0x2097:
202	case 0x2098:
203		__tl_to_masks_z10(info);
204		break;
205	default:
206		__tl_to_masks_generic(info);
207	}
208}
209
210static void topology_update_polarization_simple(void)
211{
212	int cpu;
213
214	mutex_lock(&smp_cpu_state_mutex);
215	for_each_possible_cpu(cpu)
216		smp_cpu_set_polarization(cpu, POLARIZATION_HRZ);
217	mutex_unlock(&smp_cpu_state_mutex);
218}
219
220static int ptf(unsigned long fc)
221{
222	int rc;
223
224	asm volatile(
225		"	.insn	rre,0xb9a20000,%1,%1\n"
226		"	ipm	%0\n"
227		"	srl	%0,28\n"
228		: "=d" (rc)
229		: "d" (fc)  : "cc");
230	return rc;
231}
232
233int topology_set_cpu_management(int fc)
234{
235	int cpu, rc;
236
237	if (!MACHINE_HAS_TOPOLOGY)
238		return -EOPNOTSUPP;
239	if (fc)
240		rc = ptf(PTF_VERTICAL);
241	else
242		rc = ptf(PTF_HORIZONTAL);
243	if (rc)
244		return -EBUSY;
245	for_each_possible_cpu(cpu)
246		smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
247	return rc;
248}
249
250static void update_cpu_masks(void)
251{
252	struct cpu_topology_s390 *topo;
253	int cpu;
254
255	for_each_possible_cpu(cpu) {
256		topo = &per_cpu(cpu_topology, cpu);
257		topo->thread_mask = cpu_thread_map(cpu);
258		topo->core_mask = cpu_group_map(&socket_info, cpu);
259		topo->book_mask = cpu_group_map(&book_info, cpu);
260		if (!MACHINE_HAS_TOPOLOGY) {
261			topo->thread_id = cpu;
262			topo->core_id = cpu;
263			topo->socket_id = cpu;
264			topo->book_id = cpu;
265		}
266	}
267	numa_update_cpu_topology();
268}
269
270void store_topology(struct sysinfo_15_1_x *info)
271{
272	if (topology_max_mnest >= 3)
273		stsi(info, 15, 1, 3);
274	else
275		stsi(info, 15, 1, 2);
276}
277
278int arch_update_cpu_topology(void)
279{
280	struct sysinfo_15_1_x *info = tl_info;
281	struct device *dev;
282	int cpu, rc = 0;
283
284	if (MACHINE_HAS_TOPOLOGY) {
285		rc = 1;
286		store_topology(info);
287		tl_to_masks(info);
288	}
289	update_cpu_masks();
290	if (!MACHINE_HAS_TOPOLOGY)
291		topology_update_polarization_simple();
292	for_each_online_cpu(cpu) {
293		dev = get_cpu_device(cpu);
294		kobject_uevent(&dev->kobj, KOBJ_CHANGE);
295	}
296	return rc;
297}
298
299static void topology_work_fn(struct work_struct *work)
300{
301	rebuild_sched_domains();
302}
303
304void topology_schedule_update(void)
305{
306	schedule_work(&topology_work);
307}
308
309static void topology_timer_fn(unsigned long ignored)
310{
311	if (ptf(PTF_CHECK))
312		topology_schedule_update();
313	set_topology_timer();
314}
315
316static struct timer_list topology_timer =
317	TIMER_DEFERRED_INITIALIZER(topology_timer_fn, 0, 0);
318
319static atomic_t topology_poll = ATOMIC_INIT(0);
320
321static void set_topology_timer(void)
322{
323	if (atomic_add_unless(&topology_poll, -1, 0))
324		mod_timer(&topology_timer, jiffies + HZ / 10);
325	else
326		mod_timer(&topology_timer, jiffies + HZ * 60);
327}
328
329void topology_expect_change(void)
330{
331	if (!MACHINE_HAS_TOPOLOGY)
332		return;
333	/* This is racy, but it doesn't matter since it is just a heuristic.
334	 * Worst case is that we poll in a higher frequency for a bit longer.
335	 */
336	if (atomic_read(&topology_poll) > 60)
337		return;
338	atomic_add(60, &topology_poll);
339	set_topology_timer();
340}
341
342static int cpu_management;
343
344static ssize_t dispatching_show(struct device *dev,
345				struct device_attribute *attr,
346				char *buf)
347{
348	ssize_t count;
349
350	mutex_lock(&smp_cpu_state_mutex);
351	count = sprintf(buf, "%d\n", cpu_management);
352	mutex_unlock(&smp_cpu_state_mutex);
353	return count;
354}
355
356static ssize_t dispatching_store(struct device *dev,
357				 struct device_attribute *attr,
358				 const char *buf,
359				 size_t count)
360{
361	int val, rc;
362	char delim;
363
364	if (sscanf(buf, "%d %c", &val, &delim) != 1)
365		return -EINVAL;
366	if (val != 0 && val != 1)
367		return -EINVAL;
368	rc = 0;
369	get_online_cpus();
370	mutex_lock(&smp_cpu_state_mutex);
371	if (cpu_management == val)
372		goto out;
373	rc = topology_set_cpu_management(val);
374	if (rc)
375		goto out;
376	cpu_management = val;
377	topology_expect_change();
378out:
379	mutex_unlock(&smp_cpu_state_mutex);
380	put_online_cpus();
381	return rc ? rc : count;
382}
383static DEVICE_ATTR(dispatching, 0644, dispatching_show,
384			 dispatching_store);
385
386static ssize_t cpu_polarization_show(struct device *dev,
387				     struct device_attribute *attr, char *buf)
388{
389	int cpu = dev->id;
390	ssize_t count;
391
392	mutex_lock(&smp_cpu_state_mutex);
393	switch (smp_cpu_get_polarization(cpu)) {
394	case POLARIZATION_HRZ:
395		count = sprintf(buf, "horizontal\n");
396		break;
397	case POLARIZATION_VL:
398		count = sprintf(buf, "vertical:low\n");
399		break;
400	case POLARIZATION_VM:
401		count = sprintf(buf, "vertical:medium\n");
402		break;
403	case POLARIZATION_VH:
404		count = sprintf(buf, "vertical:high\n");
405		break;
406	default:
407		count = sprintf(buf, "unknown\n");
408		break;
409	}
410	mutex_unlock(&smp_cpu_state_mutex);
411	return count;
412}
413static DEVICE_ATTR(polarization, 0444, cpu_polarization_show, NULL);
414
415static struct attribute *topology_cpu_attrs[] = {
416	&dev_attr_polarization.attr,
417	NULL,
418};
419
420static struct attribute_group topology_cpu_attr_group = {
421	.attrs = topology_cpu_attrs,
422};
423
424int topology_cpu_init(struct cpu *cpu)
425{
426	return sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
427}
428
429static const struct cpumask *cpu_thread_mask(int cpu)
430{
431	return &per_cpu(cpu_topology, cpu).thread_mask;
432}
433
434
435const struct cpumask *cpu_coregroup_mask(int cpu)
436{
437	return &per_cpu(cpu_topology, cpu).core_mask;
438}
439
440static const struct cpumask *cpu_book_mask(int cpu)
441{
442	return &per_cpu(cpu_topology, cpu).book_mask;
443}
444
445static int __init early_parse_topology(char *p)
446{
447	if (strncmp(p, "off", 3))
448		return 0;
449	topology_enabled = 0;
450	return 0;
451}
452early_param("topology", early_parse_topology);
453
454static struct sched_domain_topology_level s390_topology[] = {
455	{ cpu_thread_mask, cpu_smt_flags, SD_INIT_NAME(SMT) },
456	{ cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) },
457	{ cpu_book_mask, SD_INIT_NAME(BOOK) },
458	{ cpu_cpu_mask, SD_INIT_NAME(DIE) },
459	{ NULL, },
460};
461
462static void __init alloc_masks(struct sysinfo_15_1_x *info,
463			       struct mask_info *mask, int offset)
464{
465	int i, nr_masks;
466
467	nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
468	for (i = 0; i < info->mnest - offset; i++)
469		nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
470	nr_masks = max(nr_masks, 1);
471	for (i = 0; i < nr_masks; i++) {
472		mask->next = kzalloc(sizeof(*mask->next), GFP_KERNEL);
473		mask = mask->next;
474	}
475}
476
477static int __init s390_topology_init(void)
478{
479	struct sysinfo_15_1_x *info;
480	int i;
481
482	if (!MACHINE_HAS_TOPOLOGY)
483		return 0;
484	tl_info = (struct sysinfo_15_1_x *)__get_free_page(GFP_KERNEL);
485	info = tl_info;
486	store_topology(info);
487	pr_info("The CPU configuration topology of the machine is:");
488	for (i = 0; i < TOPOLOGY_NR_MAG; i++)
489		printk(KERN_CONT " %d", info->mag[i]);
490	printk(KERN_CONT " / %d\n", info->mnest);
491	alloc_masks(info, &socket_info, 1);
492	alloc_masks(info, &book_info, 2);
493	set_sched_topology(s390_topology);
494	return 0;
495}
496early_initcall(s390_topology_init);
497
498static int __init topology_init(void)
499{
500	if (MACHINE_HAS_TOPOLOGY)
501		set_topology_timer();
502	else
503		topology_update_polarization_simple();
504	return device_create_file(cpu_subsys.dev_root, &dev_attr_dispatching);
505}
506device_initcall(topology_init);
507