xref: /openbmc/linux/arch/s390/kernel/topology.c (revision 9b9c2cd4)
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 	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 
117 static 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 
133 static 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 
140 static 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 
169 static 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 
194 static 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 
210 static 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 
220 static 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 
233 int 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 
250 static 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 
270 void 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 
278 int 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 
299 static void topology_work_fn(struct work_struct *work)
300 {
301 	rebuild_sched_domains();
302 }
303 
304 void topology_schedule_update(void)
305 {
306 	schedule_work(&topology_work);
307 }
308 
309 static void topology_timer_fn(unsigned long ignored)
310 {
311 	if (ptf(PTF_CHECK))
312 		topology_schedule_update();
313 	set_topology_timer();
314 }
315 
316 static struct timer_list topology_timer =
317 	TIMER_DEFERRED_INITIALIZER(topology_timer_fn, 0, 0);
318 
319 static atomic_t topology_poll = ATOMIC_INIT(0);
320 
321 static 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 
329 void 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 
342 static int cpu_management;
343 
344 static 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 
356 static 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();
378 out:
379 	mutex_unlock(&smp_cpu_state_mutex);
380 	put_online_cpus();
381 	return rc ? rc : count;
382 }
383 static DEVICE_ATTR(dispatching, 0644, dispatching_show,
384 			 dispatching_store);
385 
386 static 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 }
413 static DEVICE_ATTR(polarization, 0444, cpu_polarization_show, NULL);
414 
415 static struct attribute *topology_cpu_attrs[] = {
416 	&dev_attr_polarization.attr,
417 	NULL,
418 };
419 
420 static struct attribute_group topology_cpu_attr_group = {
421 	.attrs = topology_cpu_attrs,
422 };
423 
424 int topology_cpu_init(struct cpu *cpu)
425 {
426 	return sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
427 }
428 
429 static const struct cpumask *cpu_thread_mask(int cpu)
430 {
431 	return &per_cpu(cpu_topology, cpu).thread_mask;
432 }
433 
434 
435 const struct cpumask *cpu_coregroup_mask(int cpu)
436 {
437 	return &per_cpu(cpu_topology, cpu).core_mask;
438 }
439 
440 static const struct cpumask *cpu_book_mask(int cpu)
441 {
442 	return &per_cpu(cpu_topology, cpu).book_mask;
443 }
444 
445 static 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 }
452 early_param("topology", early_parse_topology);
453 
454 static 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 
462 static 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 
477 static 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 }
496 early_initcall(s390_topology_init);
497 
498 static 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 }
506 device_initcall(topology_init);
507