xref: /linux/arch/s390/kernel/topology.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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 
30 struct mask_info {
31 	struct mask_info *next;
32 	unsigned char id;
33 	cpumask_t mask;
34 };
35 
36 static void set_topology_timer(void);
37 static void topology_work_fn(struct work_struct *work);
38 static struct sysinfo_15_1_x *tl_info;
39 
40 static int topology_enabled = 1;
41 static 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  */
47 static struct mask_info socket_info;
48 static struct mask_info book_info;
49 
50 DEFINE_PER_CPU(struct cpu_topology_s390, cpu_topology);
51 EXPORT_PER_CPU_SYMBOL_GPL(cpu_topology);
52 
53 static 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 
67 static 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 
82 static 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 	unsigned int core;
88 
89 	for_each_set_bit(core, &tl_core->mask[0], TOPOLOGY_CORE_BITS) {
90 		unsigned int rcore;
91 		int lcpu, i;
92 
93 		rcore = TOPOLOGY_CORE_BITS - 1 - core + tl_core->origin;
94 		lcpu = smp_find_processor_id(rcore << smp_cpu_mt_shift);
95 		if (lcpu < 0)
96 			continue;
97 		for (i = 0; i <= smp_cpu_mtid; i++) {
98 			per_cpu(cpu_topology, lcpu + i).book_id = book->id;
99 			per_cpu(cpu_topology, lcpu + i).core_id = rcore;
100 			per_cpu(cpu_topology, lcpu + i).thread_id = lcpu + i;
101 			cpumask_set_cpu(lcpu + i, &book->mask);
102 			cpumask_set_cpu(lcpu + i, &socket->mask);
103 			if (one_socket_per_cpu)
104 				per_cpu(cpu_topology, lcpu + i).socket_id = rcore;
105 			else
106 				per_cpu(cpu_topology, lcpu + i).socket_id = socket->id;
107 			smp_cpu_set_polarization(lcpu + i, tl_core->pp);
108 		}
109 		if (one_socket_per_cpu)
110 			socket = socket->next;
111 	}
112 	return socket;
113 }
114 
115 static void clear_masks(void)
116 {
117 	struct mask_info *info;
118 
119 	info = &socket_info;
120 	while (info) {
121 		cpumask_clear(&info->mask);
122 		info = info->next;
123 	}
124 	info = &book_info;
125 	while (info) {
126 		cpumask_clear(&info->mask);
127 		info = info->next;
128 	}
129 }
130 
131 static union topology_entry *next_tle(union topology_entry *tle)
132 {
133 	if (!tle->nl)
134 		return (union topology_entry *)((struct topology_core *)tle + 1);
135 	return (union topology_entry *)((struct topology_container *)tle + 1);
136 }
137 
138 static void __tl_to_masks_generic(struct sysinfo_15_1_x *info)
139 {
140 	struct mask_info *socket = &socket_info;
141 	struct mask_info *book = &book_info;
142 	union topology_entry *tle, *end;
143 
144 	tle = info->tle;
145 	end = (union topology_entry *)((unsigned long)info + info->length);
146 	while (tle < end) {
147 		switch (tle->nl) {
148 		case 2:
149 			book = book->next;
150 			book->id = tle->container.id;
151 			break;
152 		case 1:
153 			socket = socket->next;
154 			socket->id = tle->container.id;
155 			break;
156 		case 0:
157 			add_cpus_to_mask(&tle->cpu, book, socket, 0);
158 			break;
159 		default:
160 			clear_masks();
161 			return;
162 		}
163 		tle = next_tle(tle);
164 	}
165 }
166 
167 static void __tl_to_masks_z10(struct sysinfo_15_1_x *info)
168 {
169 	struct mask_info *socket = &socket_info;
170 	struct mask_info *book = &book_info;
171 	union topology_entry *tle, *end;
172 
173 	tle = info->tle;
174 	end = (union topology_entry *)((unsigned long)info + info->length);
175 	while (tle < end) {
176 		switch (tle->nl) {
177 		case 1:
178 			book = book->next;
179 			book->id = tle->container.id;
180 			break;
181 		case 0:
182 			socket = add_cpus_to_mask(&tle->cpu, book, socket, 1);
183 			break;
184 		default:
185 			clear_masks();
186 			return;
187 		}
188 		tle = next_tle(tle);
189 	}
190 }
191 
192 static void tl_to_masks(struct sysinfo_15_1_x *info)
193 {
194 	struct cpuid cpu_id;
195 
196 	get_cpu_id(&cpu_id);
197 	clear_masks();
198 	switch (cpu_id.machine) {
199 	case 0x2097:
200 	case 0x2098:
201 		__tl_to_masks_z10(info);
202 		break;
203 	default:
204 		__tl_to_masks_generic(info);
205 	}
206 }
207 
208 static void topology_update_polarization_simple(void)
209 {
210 	int cpu;
211 
212 	mutex_lock(&smp_cpu_state_mutex);
213 	for_each_possible_cpu(cpu)
214 		smp_cpu_set_polarization(cpu, POLARIZATION_HRZ);
215 	mutex_unlock(&smp_cpu_state_mutex);
216 }
217 
218 static int ptf(unsigned long fc)
219 {
220 	int rc;
221 
222 	asm volatile(
223 		"	.insn	rre,0xb9a20000,%1,%1\n"
224 		"	ipm	%0\n"
225 		"	srl	%0,28\n"
226 		: "=d" (rc)
227 		: "d" (fc)  : "cc");
228 	return rc;
229 }
230 
231 int topology_set_cpu_management(int fc)
232 {
233 	int cpu, rc;
234 
235 	if (!MACHINE_HAS_TOPOLOGY)
236 		return -EOPNOTSUPP;
237 	if (fc)
238 		rc = ptf(PTF_VERTICAL);
239 	else
240 		rc = ptf(PTF_HORIZONTAL);
241 	if (rc)
242 		return -EBUSY;
243 	for_each_possible_cpu(cpu)
244 		smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
245 	return rc;
246 }
247 
248 static void update_cpu_masks(void)
249 {
250 	int cpu;
251 
252 	for_each_possible_cpu(cpu) {
253 		per_cpu(cpu_topology, cpu).thread_mask = cpu_thread_map(cpu);
254 		per_cpu(cpu_topology, cpu).core_mask = cpu_group_map(&socket_info, cpu);
255 		per_cpu(cpu_topology, cpu).book_mask = cpu_group_map(&book_info, cpu);
256 		if (!MACHINE_HAS_TOPOLOGY) {
257 			per_cpu(cpu_topology, cpu).thread_id = cpu;
258 			per_cpu(cpu_topology, cpu).core_id = cpu;
259 			per_cpu(cpu_topology, cpu).socket_id = cpu;
260 			per_cpu(cpu_topology, cpu).book_id = cpu;
261 		}
262 	}
263 	numa_update_cpu_topology();
264 }
265 
266 void store_topology(struct sysinfo_15_1_x *info)
267 {
268 	if (topology_max_mnest >= 3)
269 		stsi(info, 15, 1, 3);
270 	else
271 		stsi(info, 15, 1, 2);
272 }
273 
274 int arch_update_cpu_topology(void)
275 {
276 	struct sysinfo_15_1_x *info = tl_info;
277 	struct device *dev;
278 	int cpu, rc = 0;
279 
280 	if (MACHINE_HAS_TOPOLOGY) {
281 		rc = 1;
282 		store_topology(info);
283 		tl_to_masks(info);
284 	}
285 	update_cpu_masks();
286 	if (!MACHINE_HAS_TOPOLOGY)
287 		topology_update_polarization_simple();
288 	for_each_online_cpu(cpu) {
289 		dev = get_cpu_device(cpu);
290 		kobject_uevent(&dev->kobj, KOBJ_CHANGE);
291 	}
292 	return rc;
293 }
294 
295 static void topology_work_fn(struct work_struct *work)
296 {
297 	rebuild_sched_domains();
298 }
299 
300 void topology_schedule_update(void)
301 {
302 	schedule_work(&topology_work);
303 }
304 
305 static void topology_timer_fn(unsigned long ignored)
306 {
307 	if (ptf(PTF_CHECK))
308 		topology_schedule_update();
309 	set_topology_timer();
310 }
311 
312 static struct timer_list topology_timer =
313 	TIMER_DEFERRED_INITIALIZER(topology_timer_fn, 0, 0);
314 
315 static atomic_t topology_poll = ATOMIC_INIT(0);
316 
317 static void set_topology_timer(void)
318 {
319 	if (atomic_add_unless(&topology_poll, -1, 0))
320 		mod_timer(&topology_timer, jiffies + HZ / 10);
321 	else
322 		mod_timer(&topology_timer, jiffies + HZ * 60);
323 }
324 
325 void topology_expect_change(void)
326 {
327 	if (!MACHINE_HAS_TOPOLOGY)
328 		return;
329 	/* This is racy, but it doesn't matter since it is just a heuristic.
330 	 * Worst case is that we poll in a higher frequency for a bit longer.
331 	 */
332 	if (atomic_read(&topology_poll) > 60)
333 		return;
334 	atomic_add(60, &topology_poll);
335 	set_topology_timer();
336 }
337 
338 static int cpu_management;
339 
340 static ssize_t dispatching_show(struct device *dev,
341 				struct device_attribute *attr,
342 				char *buf)
343 {
344 	ssize_t count;
345 
346 	mutex_lock(&smp_cpu_state_mutex);
347 	count = sprintf(buf, "%d\n", cpu_management);
348 	mutex_unlock(&smp_cpu_state_mutex);
349 	return count;
350 }
351 
352 static ssize_t dispatching_store(struct device *dev,
353 				 struct device_attribute *attr,
354 				 const char *buf,
355 				 size_t count)
356 {
357 	int val, rc;
358 	char delim;
359 
360 	if (sscanf(buf, "%d %c", &val, &delim) != 1)
361 		return -EINVAL;
362 	if (val != 0 && val != 1)
363 		return -EINVAL;
364 	rc = 0;
365 	get_online_cpus();
366 	mutex_lock(&smp_cpu_state_mutex);
367 	if (cpu_management == val)
368 		goto out;
369 	rc = topology_set_cpu_management(val);
370 	if (rc)
371 		goto out;
372 	cpu_management = val;
373 	topology_expect_change();
374 out:
375 	mutex_unlock(&smp_cpu_state_mutex);
376 	put_online_cpus();
377 	return rc ? rc : count;
378 }
379 static DEVICE_ATTR(dispatching, 0644, dispatching_show,
380 			 dispatching_store);
381 
382 static ssize_t cpu_polarization_show(struct device *dev,
383 				     struct device_attribute *attr, char *buf)
384 {
385 	int cpu = dev->id;
386 	ssize_t count;
387 
388 	mutex_lock(&smp_cpu_state_mutex);
389 	switch (smp_cpu_get_polarization(cpu)) {
390 	case POLARIZATION_HRZ:
391 		count = sprintf(buf, "horizontal\n");
392 		break;
393 	case POLARIZATION_VL:
394 		count = sprintf(buf, "vertical:low\n");
395 		break;
396 	case POLARIZATION_VM:
397 		count = sprintf(buf, "vertical:medium\n");
398 		break;
399 	case POLARIZATION_VH:
400 		count = sprintf(buf, "vertical:high\n");
401 		break;
402 	default:
403 		count = sprintf(buf, "unknown\n");
404 		break;
405 	}
406 	mutex_unlock(&smp_cpu_state_mutex);
407 	return count;
408 }
409 static DEVICE_ATTR(polarization, 0444, cpu_polarization_show, NULL);
410 
411 static struct attribute *topology_cpu_attrs[] = {
412 	&dev_attr_polarization.attr,
413 	NULL,
414 };
415 
416 static struct attribute_group topology_cpu_attr_group = {
417 	.attrs = topology_cpu_attrs,
418 };
419 
420 int topology_cpu_init(struct cpu *cpu)
421 {
422 	return sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
423 }
424 
425 static const struct cpumask *cpu_thread_mask(int cpu)
426 {
427 	return &per_cpu(cpu_topology, cpu).thread_mask;
428 }
429 
430 
431 const struct cpumask *cpu_coregroup_mask(int cpu)
432 {
433 	return &per_cpu(cpu_topology, cpu).core_mask;
434 }
435 
436 static const struct cpumask *cpu_book_mask(int cpu)
437 {
438 	return &per_cpu(cpu_topology, cpu).book_mask;
439 }
440 
441 static int __init early_parse_topology(char *p)
442 {
443 	if (strncmp(p, "off", 3))
444 		return 0;
445 	topology_enabled = 0;
446 	return 0;
447 }
448 early_param("topology", early_parse_topology);
449 
450 static struct sched_domain_topology_level s390_topology[] = {
451 	{ cpu_thread_mask, cpu_smt_flags, SD_INIT_NAME(SMT) },
452 	{ cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) },
453 	{ cpu_book_mask, SD_INIT_NAME(BOOK) },
454 	{ cpu_cpu_mask, SD_INIT_NAME(DIE) },
455 	{ NULL, },
456 };
457 
458 static void __init alloc_masks(struct sysinfo_15_1_x *info,
459 			       struct mask_info *mask, int offset)
460 {
461 	int i, nr_masks;
462 
463 	nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
464 	for (i = 0; i < info->mnest - offset; i++)
465 		nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
466 	nr_masks = max(nr_masks, 1);
467 	for (i = 0; i < nr_masks; i++) {
468 		mask->next = kzalloc(sizeof(*mask->next), GFP_KERNEL);
469 		mask = mask->next;
470 	}
471 }
472 
473 static int __init s390_topology_init(void)
474 {
475 	struct sysinfo_15_1_x *info;
476 	int i;
477 
478 	if (!MACHINE_HAS_TOPOLOGY)
479 		return 0;
480 	tl_info = (struct sysinfo_15_1_x *)__get_free_page(GFP_KERNEL);
481 	info = tl_info;
482 	store_topology(info);
483 	pr_info("The CPU configuration topology of the machine is:");
484 	for (i = 0; i < TOPOLOGY_NR_MAG; i++)
485 		printk(KERN_CONT " %d", info->mag[i]);
486 	printk(KERN_CONT " / %d\n", info->mnest);
487 	alloc_masks(info, &socket_info, 1);
488 	alloc_masks(info, &book_info, 2);
489 	set_sched_topology(s390_topology);
490 	return 0;
491 }
492 early_initcall(s390_topology_init);
493 
494 static int __init topology_init(void)
495 {
496 	if (MACHINE_HAS_TOPOLOGY)
497 		set_topology_timer();
498 	else
499 		topology_update_polarization_simple();
500 	return device_create_file(cpu_subsys.dev_root, &dev_attr_dispatching);
501 }
502 device_initcall(topology_init);
503