xref: /linux/arch/s390/kernel/topology.c (revision 93df8a1ed6231727c5db94a80b1a6bd5ee67cec3)
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 
27 struct mask_info {
28 	struct mask_info *next;
29 	unsigned char id;
30 	cpumask_t mask;
31 };
32 
33 static void set_topology_timer(void);
34 static void topology_work_fn(struct work_struct *work);
35 static struct sysinfo_15_1_x *tl_info;
36 
37 static int topology_enabled = 1;
38 static DECLARE_WORK(topology_work, topology_work_fn);
39 
40 /* topology_lock protects the socket and book linked lists */
41 static DEFINE_SPINLOCK(topology_lock);
42 static struct mask_info socket_info;
43 static struct mask_info book_info;
44 
45 DEFINE_PER_CPU(struct cpu_topology_s390, cpu_topology);
46 EXPORT_PER_CPU_SYMBOL_GPL(cpu_topology);
47 
48 static 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 
62 static 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 
77 static 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 
110 static 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 
126 static 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 
133 static 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 
162 static 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 
187 static 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 
205 static 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 
215 static 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 
228 int 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 
245 static 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 
265 void 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 
273 int 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 
294 static void topology_work_fn(struct work_struct *work)
295 {
296 	rebuild_sched_domains();
297 }
298 
299 void topology_schedule_update(void)
300 {
301 	schedule_work(&topology_work);
302 }
303 
304 static void topology_timer_fn(unsigned long ignored)
305 {
306 	if (ptf(PTF_CHECK))
307 		topology_schedule_update();
308 	set_topology_timer();
309 }
310 
311 static struct timer_list topology_timer =
312 	TIMER_DEFERRED_INITIALIZER(topology_timer_fn, 0, 0);
313 
314 static atomic_t topology_poll = ATOMIC_INIT(0);
315 
316 static 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 
324 void 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 
337 static int cpu_management;
338 
339 static 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 
351 static 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();
373 out:
374 	mutex_unlock(&smp_cpu_state_mutex);
375 	put_online_cpus();
376 	return rc ? rc : count;
377 }
378 static DEVICE_ATTR(dispatching, 0644, dispatching_show,
379 			 dispatching_store);
380 
381 static 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 }
408 static DEVICE_ATTR(polarization, 0444, cpu_polarization_show, NULL);
409 
410 static struct attribute *topology_cpu_attrs[] = {
411 	&dev_attr_polarization.attr,
412 	NULL,
413 };
414 
415 static struct attribute_group topology_cpu_attr_group = {
416 	.attrs = topology_cpu_attrs,
417 };
418 
419 int topology_cpu_init(struct cpu *cpu)
420 {
421 	return sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
422 }
423 
424 static const struct cpumask *cpu_thread_mask(int cpu)
425 {
426 	return &per_cpu(cpu_topology, cpu).thread_mask;
427 }
428 
429 
430 const struct cpumask *cpu_coregroup_mask(int cpu)
431 {
432 	return &per_cpu(cpu_topology, cpu).core_mask;
433 }
434 
435 static const struct cpumask *cpu_book_mask(int cpu)
436 {
437 	return &per_cpu(cpu_topology, cpu).book_mask;
438 }
439 
440 static 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 }
447 early_param("topology", early_parse_topology);
448 
449 static 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 
457 static 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 
472 static 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 }
491 early_initcall(s390_topology_init);
492 
493 static 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 }
501 device_initcall(topology_init);
502