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/bootmem.h>
11 #include <linux/uaccess.h>
12 #include <linux/sysctl.h>
13 #include <linux/cpuset.h>
14 #include <linux/device.h>
15 #include <linux/export.h>
16 #include <linux/kernel.h>
17 #include <linux/sched.h>
18 #include <linux/sched/topology.h>
19 #include <linux/delay.h>
20 #include <linux/init.h>
21 #include <linux/slab.h>
22 #include <linux/cpu.h>
23 #include <linux/smp.h>
24 #include <linux/mm.h>
25 #include <linux/nodemask.h>
26 #include <linux/node.h>
27 #include <asm/sysinfo.h>
28 #include <asm/numa.h>
29
30 #define PTF_HORIZONTAL (0UL)
31 #define PTF_VERTICAL (1UL)
32 #define PTF_CHECK (2UL)
33
34 enum {
35 TOPOLOGY_MODE_HW,
36 TOPOLOGY_MODE_SINGLE,
37 TOPOLOGY_MODE_PACKAGE,
38 TOPOLOGY_MODE_UNINITIALIZED
39 };
40
41 struct mask_info {
42 struct mask_info *next;
43 unsigned char id;
44 cpumask_t mask;
45 };
46
47 static int topology_mode = TOPOLOGY_MODE_UNINITIALIZED;
48 static void set_topology_timer(void);
49 static void topology_work_fn(struct work_struct *work);
50 static struct sysinfo_15_1_x *tl_info;
51
52 static DECLARE_WORK(topology_work, topology_work_fn);
53
54 /*
55 * Socket/Book linked lists and cpu_topology updates are
56 * protected by "sched_domains_mutex".
57 */
58 static struct mask_info socket_info;
59 static struct mask_info book_info;
60 static struct mask_info drawer_info;
61
62 struct cpu_topology_s390 cpu_topology[NR_CPUS];
63 EXPORT_SYMBOL_GPL(cpu_topology);
64
65 cpumask_t cpus_with_topology;
66
cpu_group_map(struct mask_info * info,unsigned int cpu)67 static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
68 {
69 cpumask_t mask;
70
71 cpumask_copy(&mask, cpumask_of(cpu));
72 switch (topology_mode) {
73 case TOPOLOGY_MODE_HW:
74 while (info) {
75 if (cpumask_test_cpu(cpu, &info->mask)) {
76 mask = info->mask;
77 break;
78 }
79 info = info->next;
80 }
81 if (cpumask_empty(&mask))
82 cpumask_copy(&mask, cpumask_of(cpu));
83 break;
84 case TOPOLOGY_MODE_PACKAGE:
85 cpumask_copy(&mask, cpu_present_mask);
86 break;
87 default:
88 /* fallthrough */
89 case TOPOLOGY_MODE_SINGLE:
90 cpumask_copy(&mask, cpumask_of(cpu));
91 break;
92 }
93 return mask;
94 }
95
cpu_thread_map(unsigned int cpu)96 static cpumask_t cpu_thread_map(unsigned int cpu)
97 {
98 cpumask_t mask;
99 int i;
100
101 cpumask_copy(&mask, cpumask_of(cpu));
102 if (topology_mode != TOPOLOGY_MODE_HW)
103 return mask;
104 cpu -= cpu % (smp_cpu_mtid + 1);
105 for (i = 0; i <= smp_cpu_mtid; i++)
106 if (cpu_present(cpu + i))
107 cpumask_set_cpu(cpu + i, &mask);
108 return mask;
109 }
110
111 #define TOPOLOGY_CORE_BITS 64
112
add_cpus_to_mask(struct topology_core * tl_core,struct mask_info * drawer,struct mask_info * book,struct mask_info * socket)113 static void add_cpus_to_mask(struct topology_core *tl_core,
114 struct mask_info *drawer,
115 struct mask_info *book,
116 struct mask_info *socket)
117 {
118 struct cpu_topology_s390 *topo;
119 unsigned int core;
120
121 for_each_set_bit(core, &tl_core->mask, TOPOLOGY_CORE_BITS) {
122 unsigned int rcore;
123 int lcpu, i;
124
125 rcore = TOPOLOGY_CORE_BITS - 1 - core + tl_core->origin;
126 lcpu = smp_find_processor_id(rcore << smp_cpu_mt_shift);
127 if (lcpu < 0)
128 continue;
129 for (i = 0; i <= smp_cpu_mtid; i++) {
130 topo = &cpu_topology[lcpu + i];
131 topo->drawer_id = drawer->id;
132 topo->book_id = book->id;
133 topo->socket_id = socket->id;
134 topo->core_id = rcore;
135 topo->thread_id = lcpu + i;
136 cpumask_set_cpu(lcpu + i, &drawer->mask);
137 cpumask_set_cpu(lcpu + i, &book->mask);
138 cpumask_set_cpu(lcpu + i, &socket->mask);
139 cpumask_set_cpu(lcpu + i, &cpus_with_topology);
140 smp_cpu_set_polarization(lcpu + i, tl_core->pp);
141 }
142 }
143 }
144
clear_masks(void)145 static void clear_masks(void)
146 {
147 struct mask_info *info;
148
149 info = &socket_info;
150 while (info) {
151 cpumask_clear(&info->mask);
152 info = info->next;
153 }
154 info = &book_info;
155 while (info) {
156 cpumask_clear(&info->mask);
157 info = info->next;
158 }
159 info = &drawer_info;
160 while (info) {
161 cpumask_clear(&info->mask);
162 info = info->next;
163 }
164 }
165
next_tle(union topology_entry * tle)166 static union topology_entry *next_tle(union topology_entry *tle)
167 {
168 if (!tle->nl)
169 return (union topology_entry *)((struct topology_core *)tle + 1);
170 return (union topology_entry *)((struct topology_container *)tle + 1);
171 }
172
tl_to_masks(struct sysinfo_15_1_x * info)173 static void tl_to_masks(struct sysinfo_15_1_x *info)
174 {
175 struct mask_info *socket = &socket_info;
176 struct mask_info *book = &book_info;
177 struct mask_info *drawer = &drawer_info;
178 union topology_entry *tle, *end;
179
180 clear_masks();
181 tle = info->tle;
182 end = (union topology_entry *)((unsigned long)info + info->length);
183 while (tle < end) {
184 switch (tle->nl) {
185 case 3:
186 drawer = drawer->next;
187 drawer->id = tle->container.id;
188 break;
189 case 2:
190 book = book->next;
191 book->id = tle->container.id;
192 break;
193 case 1:
194 socket = socket->next;
195 socket->id = tle->container.id;
196 break;
197 case 0:
198 add_cpus_to_mask(&tle->cpu, drawer, book, socket);
199 break;
200 default:
201 clear_masks();
202 return;
203 }
204 tle = next_tle(tle);
205 }
206 }
207
topology_update_polarization_simple(void)208 static void topology_update_polarization_simple(void)
209 {
210 int cpu;
211
212 for_each_possible_cpu(cpu)
213 smp_cpu_set_polarization(cpu, POLARIZATION_HRZ);
214 }
215
ptf(unsigned long fc)216 static int ptf(unsigned long fc)
217 {
218 int rc;
219
220 asm volatile(
221 " .insn rre,0xb9a20000,%1,%1\n"
222 " ipm %0\n"
223 " srl %0,28\n"
224 : "=d" (rc)
225 : "d" (fc) : "cc");
226 return rc;
227 }
228
topology_set_cpu_management(int fc)229 int topology_set_cpu_management(int fc)
230 {
231 int cpu, rc;
232
233 if (!MACHINE_HAS_TOPOLOGY)
234 return -EOPNOTSUPP;
235 if (fc)
236 rc = ptf(PTF_VERTICAL);
237 else
238 rc = ptf(PTF_HORIZONTAL);
239 if (rc)
240 return -EBUSY;
241 for_each_possible_cpu(cpu)
242 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
243 return rc;
244 }
245
update_cpu_masks(void)246 static void update_cpu_masks(void)
247 {
248 struct cpu_topology_s390 *topo;
249 int cpu, id;
250
251 for_each_possible_cpu(cpu) {
252 topo = &cpu_topology[cpu];
253 topo->thread_mask = cpu_thread_map(cpu);
254 topo->core_mask = cpu_group_map(&socket_info, cpu);
255 topo->book_mask = cpu_group_map(&book_info, cpu);
256 topo->drawer_mask = cpu_group_map(&drawer_info, cpu);
257 if (topology_mode != TOPOLOGY_MODE_HW) {
258 id = topology_mode == TOPOLOGY_MODE_PACKAGE ? 0 : cpu;
259 topo->thread_id = cpu;
260 topo->core_id = cpu;
261 topo->socket_id = id;
262 topo->book_id = id;
263 topo->drawer_id = id;
264 if (cpu_present(cpu))
265 cpumask_set_cpu(cpu, &cpus_with_topology);
266 }
267 }
268 numa_update_cpu_topology();
269 }
270
store_topology(struct sysinfo_15_1_x * info)271 void store_topology(struct sysinfo_15_1_x *info)
272 {
273 stsi(info, 15, 1, topology_mnest_limit());
274 }
275
__arch_update_cpu_topology(void)276 static int __arch_update_cpu_topology(void)
277 {
278 struct sysinfo_15_1_x *info = tl_info;
279 int rc = 0;
280
281 mutex_lock(&smp_cpu_state_mutex);
282 cpumask_clear(&cpus_with_topology);
283 if (MACHINE_HAS_TOPOLOGY) {
284 rc = 1;
285 store_topology(info);
286 tl_to_masks(info);
287 }
288 update_cpu_masks();
289 if (!MACHINE_HAS_TOPOLOGY)
290 topology_update_polarization_simple();
291 mutex_unlock(&smp_cpu_state_mutex);
292 return rc;
293 }
294
arch_update_cpu_topology(void)295 int arch_update_cpu_topology(void)
296 {
297 struct device *dev;
298 int cpu, rc;
299
300 rc = __arch_update_cpu_topology();
301 for_each_online_cpu(cpu) {
302 dev = get_cpu_device(cpu);
303 if (dev)
304 kobject_uevent(&dev->kobj, KOBJ_CHANGE);
305 }
306 return rc;
307 }
308
topology_work_fn(struct work_struct * work)309 static void topology_work_fn(struct work_struct *work)
310 {
311 rebuild_sched_domains();
312 }
313
topology_schedule_update(void)314 void topology_schedule_update(void)
315 {
316 schedule_work(&topology_work);
317 }
318
topology_flush_work(void)319 static void topology_flush_work(void)
320 {
321 flush_work(&topology_work);
322 }
323
topology_timer_fn(unsigned long ignored)324 static void topology_timer_fn(unsigned long ignored)
325 {
326 if (ptf(PTF_CHECK))
327 topology_schedule_update();
328 set_topology_timer();
329 }
330
331 static struct timer_list topology_timer =
332 TIMER_DEFERRED_INITIALIZER(topology_timer_fn, 0, 0);
333
334 static atomic_t topology_poll = ATOMIC_INIT(0);
335
set_topology_timer(void)336 static void set_topology_timer(void)
337 {
338 if (atomic_add_unless(&topology_poll, -1, 0))
339 mod_timer(&topology_timer, jiffies + HZ / 10);
340 else
341 mod_timer(&topology_timer, jiffies + HZ * 60);
342 }
343
topology_expect_change(void)344 void topology_expect_change(void)
345 {
346 if (!MACHINE_HAS_TOPOLOGY)
347 return;
348 /* This is racy, but it doesn't matter since it is just a heuristic.
349 * Worst case is that we poll in a higher frequency for a bit longer.
350 */
351 if (atomic_read(&topology_poll) > 60)
352 return;
353 atomic_add(60, &topology_poll);
354 set_topology_timer();
355 }
356
357 static int cpu_management;
358
dispatching_show(struct device * dev,struct device_attribute * attr,char * buf)359 static ssize_t dispatching_show(struct device *dev,
360 struct device_attribute *attr,
361 char *buf)
362 {
363 ssize_t count;
364
365 mutex_lock(&smp_cpu_state_mutex);
366 count = sprintf(buf, "%d\n", cpu_management);
367 mutex_unlock(&smp_cpu_state_mutex);
368 return count;
369 }
370
dispatching_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)371 static ssize_t dispatching_store(struct device *dev,
372 struct device_attribute *attr,
373 const char *buf,
374 size_t count)
375 {
376 int val, rc;
377 char delim;
378
379 if (sscanf(buf, "%d %c", &val, &delim) != 1)
380 return -EINVAL;
381 if (val != 0 && val != 1)
382 return -EINVAL;
383 rc = 0;
384 get_online_cpus();
385 mutex_lock(&smp_cpu_state_mutex);
386 if (cpu_management == val)
387 goto out;
388 rc = topology_set_cpu_management(val);
389 if (rc)
390 goto out;
391 cpu_management = val;
392 topology_expect_change();
393 out:
394 mutex_unlock(&smp_cpu_state_mutex);
395 put_online_cpus();
396 return rc ? rc : count;
397 }
398 static DEVICE_ATTR(dispatching, 0644, dispatching_show,
399 dispatching_store);
400
cpu_polarization_show(struct device * dev,struct device_attribute * attr,char * buf)401 static ssize_t cpu_polarization_show(struct device *dev,
402 struct device_attribute *attr, char *buf)
403 {
404 int cpu = dev->id;
405 ssize_t count;
406
407 mutex_lock(&smp_cpu_state_mutex);
408 switch (smp_cpu_get_polarization(cpu)) {
409 case POLARIZATION_HRZ:
410 count = sprintf(buf, "horizontal\n");
411 break;
412 case POLARIZATION_VL:
413 count = sprintf(buf, "vertical:low\n");
414 break;
415 case POLARIZATION_VM:
416 count = sprintf(buf, "vertical:medium\n");
417 break;
418 case POLARIZATION_VH:
419 count = sprintf(buf, "vertical:high\n");
420 break;
421 default:
422 count = sprintf(buf, "unknown\n");
423 break;
424 }
425 mutex_unlock(&smp_cpu_state_mutex);
426 return count;
427 }
428 static DEVICE_ATTR(polarization, 0444, cpu_polarization_show, NULL);
429
430 static struct attribute *topology_cpu_attrs[] = {
431 &dev_attr_polarization.attr,
432 NULL,
433 };
434
435 static struct attribute_group topology_cpu_attr_group = {
436 .attrs = topology_cpu_attrs,
437 };
438
topology_cpu_init(struct cpu * cpu)439 int topology_cpu_init(struct cpu *cpu)
440 {
441 return sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
442 }
443
cpu_thread_mask(int cpu)444 static const struct cpumask *cpu_thread_mask(int cpu)
445 {
446 return &cpu_topology[cpu].thread_mask;
447 }
448
449
cpu_coregroup_mask(int cpu)450 const struct cpumask *cpu_coregroup_mask(int cpu)
451 {
452 return &cpu_topology[cpu].core_mask;
453 }
454
cpu_book_mask(int cpu)455 static const struct cpumask *cpu_book_mask(int cpu)
456 {
457 return &cpu_topology[cpu].book_mask;
458 }
459
cpu_drawer_mask(int cpu)460 static const struct cpumask *cpu_drawer_mask(int cpu)
461 {
462 return &cpu_topology[cpu].drawer_mask;
463 }
464
465 static struct sched_domain_topology_level s390_topology[] = {
466 { cpu_thread_mask, cpu_smt_flags, SD_INIT_NAME(SMT) },
467 { cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) },
468 { cpu_book_mask, SD_INIT_NAME(BOOK) },
469 { cpu_drawer_mask, SD_INIT_NAME(DRAWER) },
470 { cpu_cpu_mask, SD_INIT_NAME(DIE) },
471 { NULL, },
472 };
473
alloc_masks(struct sysinfo_15_1_x * info,struct mask_info * mask,int offset)474 static void __init alloc_masks(struct sysinfo_15_1_x *info,
475 struct mask_info *mask, int offset)
476 {
477 int i, nr_masks;
478
479 nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
480 for (i = 0; i < info->mnest - offset; i++)
481 nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
482 nr_masks = max(nr_masks, 1);
483 for (i = 0; i < nr_masks; i++) {
484 mask->next = memblock_virt_alloc(sizeof(*mask->next), 8);
485 mask = mask->next;
486 }
487 }
488
topology_init_early(void)489 void __init topology_init_early(void)
490 {
491 struct sysinfo_15_1_x *info;
492
493 set_sched_topology(s390_topology);
494 if (topology_mode == TOPOLOGY_MODE_UNINITIALIZED) {
495 if (MACHINE_HAS_TOPOLOGY)
496 topology_mode = TOPOLOGY_MODE_HW;
497 else
498 topology_mode = TOPOLOGY_MODE_SINGLE;
499 }
500 if (!MACHINE_HAS_TOPOLOGY)
501 goto out;
502 tl_info = memblock_virt_alloc(PAGE_SIZE, PAGE_SIZE);
503 info = tl_info;
504 store_topology(info);
505 pr_info("The CPU configuration topology of the machine is: %d %d %d %d %d %d / %d\n",
506 info->mag[0], info->mag[1], info->mag[2], info->mag[3],
507 info->mag[4], info->mag[5], info->mnest);
508 alloc_masks(info, &socket_info, 1);
509 alloc_masks(info, &book_info, 2);
510 alloc_masks(info, &drawer_info, 3);
511 out:
512 __arch_update_cpu_topology();
513 }
514
topology_get_mode(int enabled)515 static inline int topology_get_mode(int enabled)
516 {
517 if (!enabled)
518 return TOPOLOGY_MODE_SINGLE;
519 return MACHINE_HAS_TOPOLOGY ? TOPOLOGY_MODE_HW : TOPOLOGY_MODE_PACKAGE;
520 }
521
topology_is_enabled(void)522 static inline int topology_is_enabled(void)
523 {
524 return topology_mode != TOPOLOGY_MODE_SINGLE;
525 }
526
topology_setup(char * str)527 static int __init topology_setup(char *str)
528 {
529 bool enabled;
530 int rc;
531
532 rc = kstrtobool(str, &enabled);
533 if (rc)
534 return rc;
535 topology_mode = topology_get_mode(enabled);
536 return 0;
537 }
538 early_param("topology", topology_setup);
539
topology_ctl_handler(struct ctl_table * ctl,int write,void __user * buffer,size_t * lenp,loff_t * ppos)540 static int topology_ctl_handler(struct ctl_table *ctl, int write,
541 void __user *buffer, size_t *lenp, loff_t *ppos)
542 {
543 unsigned int len;
544 int new_mode;
545 char buf[2];
546
547 if (!*lenp || *ppos) {
548 *lenp = 0;
549 return 0;
550 }
551 if (!write) {
552 strncpy(buf, topology_is_enabled() ? "1\n" : "0\n",
553 ARRAY_SIZE(buf));
554 len = strnlen(buf, ARRAY_SIZE(buf));
555 if (len > *lenp)
556 len = *lenp;
557 if (copy_to_user(buffer, buf, len))
558 return -EFAULT;
559 goto out;
560 }
561 len = *lenp;
562 if (copy_from_user(buf, buffer, len > sizeof(buf) ? sizeof(buf) : len))
563 return -EFAULT;
564 if (buf[0] != '0' && buf[0] != '1')
565 return -EINVAL;
566 mutex_lock(&smp_cpu_state_mutex);
567 new_mode = topology_get_mode(buf[0] == '1');
568 if (topology_mode != new_mode) {
569 topology_mode = new_mode;
570 topology_schedule_update();
571 }
572 mutex_unlock(&smp_cpu_state_mutex);
573 topology_flush_work();
574 out:
575 *lenp = len;
576 *ppos += len;
577 return 0;
578 }
579
580 static struct ctl_table topology_ctl_table[] = {
581 {
582 .procname = "topology",
583 .mode = 0644,
584 .proc_handler = topology_ctl_handler,
585 },
586 { },
587 };
588
589 static struct ctl_table topology_dir_table[] = {
590 {
591 .procname = "s390",
592 .maxlen = 0,
593 .mode = 0555,
594 .child = topology_ctl_table,
595 },
596 { },
597 };
598
topology_init(void)599 static int __init topology_init(void)
600 {
601 if (MACHINE_HAS_TOPOLOGY)
602 set_topology_timer();
603 else
604 topology_update_polarization_simple();
605 register_sysctl_table(topology_dir_table);
606 return device_create_file(cpu_subsys.dev_root, &dev_attr_dispatching);
607 }
608 device_initcall(topology_init);
609