GNU Linux-libre 4.9.288-gnu1
[releases.git] / arch / s390 / kernel / topology.c
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 DECLARE_WORK(topology_work, topology_work_fn);
41
42 /*
43  * Socket/Book linked lists and per_cpu(cpu_topology) updates are
44  * protected by "sched_domains_mutex".
45  */
46 static struct mask_info socket_info;
47 static struct mask_info book_info;
48 static struct mask_info drawer_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 (!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 (!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 void add_cpus_to_mask(struct topology_core *tl_core,
83                              struct mask_info *drawer,
84                              struct mask_info *book,
85                              struct mask_info *socket)
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->drawer_id = drawer->id;
101                         topo->book_id = book->id;
102                         topo->socket_id = socket->id;
103                         topo->core_id = rcore;
104                         topo->thread_id = lcpu + i;
105                         cpumask_set_cpu(lcpu + i, &drawer->mask);
106                         cpumask_set_cpu(lcpu + i, &book->mask);
107                         cpumask_set_cpu(lcpu + i, &socket->mask);
108                         smp_cpu_set_polarization(lcpu + i, tl_core->pp);
109                 }
110         }
111 }
112
113 static void clear_masks(void)
114 {
115         struct mask_info *info;
116
117         info = &socket_info;
118         while (info) {
119                 cpumask_clear(&info->mask);
120                 info = info->next;
121         }
122         info = &book_info;
123         while (info) {
124                 cpumask_clear(&info->mask);
125                 info = info->next;
126         }
127         info = &drawer_info;
128         while (info) {
129                 cpumask_clear(&info->mask);
130                 info = info->next;
131         }
132 }
133
134 static union topology_entry *next_tle(union topology_entry *tle)
135 {
136         if (!tle->nl)
137                 return (union topology_entry *)((struct topology_core *)tle + 1);
138         return (union topology_entry *)((struct topology_container *)tle + 1);
139 }
140
141 static void tl_to_masks(struct sysinfo_15_1_x *info)
142 {
143         struct mask_info *socket = &socket_info;
144         struct mask_info *book = &book_info;
145         struct mask_info *drawer = &drawer_info;
146         union topology_entry *tle, *end;
147
148         clear_masks();
149         tle = info->tle;
150         end = (union topology_entry *)((unsigned long)info + info->length);
151         while (tle < end) {
152                 switch (tle->nl) {
153                 case 3:
154                         drawer = drawer->next;
155                         drawer->id = tle->container.id;
156                         break;
157                 case 2:
158                         book = book->next;
159                         book->id = tle->container.id;
160                         break;
161                 case 1:
162                         socket = socket->next;
163                         socket->id = tle->container.id;
164                         break;
165                 case 0:
166                         add_cpus_to_mask(&tle->cpu, drawer, book, socket);
167                         break;
168                 default:
169                         clear_masks();
170                         return;
171                 }
172                 tle = next_tle(tle);
173         }
174 }
175
176 static void topology_update_polarization_simple(void)
177 {
178         int cpu;
179
180         mutex_lock(&smp_cpu_state_mutex);
181         for_each_possible_cpu(cpu)
182                 smp_cpu_set_polarization(cpu, POLARIZATION_HRZ);
183         mutex_unlock(&smp_cpu_state_mutex);
184 }
185
186 static int ptf(unsigned long fc)
187 {
188         int rc;
189
190         asm volatile(
191                 "       .insn   rre,0xb9a20000,%1,%1\n"
192                 "       ipm     %0\n"
193                 "       srl     %0,28\n"
194                 : "=d" (rc)
195                 : "d" (fc)  : "cc");
196         return rc;
197 }
198
199 int topology_set_cpu_management(int fc)
200 {
201         int cpu, rc;
202
203         if (!MACHINE_HAS_TOPOLOGY)
204                 return -EOPNOTSUPP;
205         if (fc)
206                 rc = ptf(PTF_VERTICAL);
207         else
208                 rc = ptf(PTF_HORIZONTAL);
209         if (rc)
210                 return -EBUSY;
211         for_each_possible_cpu(cpu)
212                 smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
213         return rc;
214 }
215
216 static void update_cpu_masks(void)
217 {
218         struct cpu_topology_s390 *topo;
219         int cpu;
220
221         for_each_possible_cpu(cpu) {
222                 topo = &per_cpu(cpu_topology, cpu);
223                 topo->thread_mask = cpu_thread_map(cpu);
224                 topo->core_mask = cpu_group_map(&socket_info, cpu);
225                 topo->book_mask = cpu_group_map(&book_info, cpu);
226                 topo->drawer_mask = cpu_group_map(&drawer_info, cpu);
227                 if (!MACHINE_HAS_TOPOLOGY) {
228                         topo->thread_id = cpu;
229                         topo->core_id = cpu;
230                         topo->socket_id = cpu;
231                         topo->book_id = cpu;
232                         topo->drawer_id = cpu;
233                 }
234         }
235         numa_update_cpu_topology();
236 }
237
238 void store_topology(struct sysinfo_15_1_x *info)
239 {
240         stsi(info, 15, 1, min(topology_max_mnest, 4));
241 }
242
243 int arch_update_cpu_topology(void)
244 {
245         struct sysinfo_15_1_x *info = tl_info;
246         struct device *dev;
247         int cpu, rc = 0;
248
249         if (MACHINE_HAS_TOPOLOGY) {
250                 rc = 1;
251                 store_topology(info);
252                 tl_to_masks(info);
253         }
254         update_cpu_masks();
255         if (!MACHINE_HAS_TOPOLOGY)
256                 topology_update_polarization_simple();
257         for_each_online_cpu(cpu) {
258                 dev = get_cpu_device(cpu);
259                 if (dev)
260                         kobject_uevent(&dev->kobj, KOBJ_CHANGE);
261         }
262         return rc;
263 }
264
265 static void topology_work_fn(struct work_struct *work)
266 {
267         rebuild_sched_domains();
268 }
269
270 void topology_schedule_update(void)
271 {
272         schedule_work(&topology_work);
273 }
274
275 static void topology_timer_fn(unsigned long ignored)
276 {
277         if (ptf(PTF_CHECK))
278                 topology_schedule_update();
279         set_topology_timer();
280 }
281
282 static struct timer_list topology_timer =
283         TIMER_DEFERRED_INITIALIZER(topology_timer_fn, 0, 0);
284
285 static atomic_t topology_poll = ATOMIC_INIT(0);
286
287 static void set_topology_timer(void)
288 {
289         if (atomic_add_unless(&topology_poll, -1, 0))
290                 mod_timer(&topology_timer, jiffies + HZ / 10);
291         else
292                 mod_timer(&topology_timer, jiffies + HZ * 60);
293 }
294
295 void topology_expect_change(void)
296 {
297         if (!MACHINE_HAS_TOPOLOGY)
298                 return;
299         /* This is racy, but it doesn't matter since it is just a heuristic.
300          * Worst case is that we poll in a higher frequency for a bit longer.
301          */
302         if (atomic_read(&topology_poll) > 60)
303                 return;
304         atomic_add(60, &topology_poll);
305         set_topology_timer();
306 }
307
308 static int cpu_management;
309
310 static ssize_t dispatching_show(struct device *dev,
311                                 struct device_attribute *attr,
312                                 char *buf)
313 {
314         ssize_t count;
315
316         mutex_lock(&smp_cpu_state_mutex);
317         count = sprintf(buf, "%d\n", cpu_management);
318         mutex_unlock(&smp_cpu_state_mutex);
319         return count;
320 }
321
322 static ssize_t dispatching_store(struct device *dev,
323                                  struct device_attribute *attr,
324                                  const char *buf,
325                                  size_t count)
326 {
327         int val, rc;
328         char delim;
329
330         if (sscanf(buf, "%d %c", &val, &delim) != 1)
331                 return -EINVAL;
332         if (val != 0 && val != 1)
333                 return -EINVAL;
334         rc = 0;
335         get_online_cpus();
336         mutex_lock(&smp_cpu_state_mutex);
337         if (cpu_management == val)
338                 goto out;
339         rc = topology_set_cpu_management(val);
340         if (rc)
341                 goto out;
342         cpu_management = val;
343         topology_expect_change();
344 out:
345         mutex_unlock(&smp_cpu_state_mutex);
346         put_online_cpus();
347         return rc ? rc : count;
348 }
349 static DEVICE_ATTR(dispatching, 0644, dispatching_show,
350                          dispatching_store);
351
352 static ssize_t cpu_polarization_show(struct device *dev,
353                                      struct device_attribute *attr, char *buf)
354 {
355         int cpu = dev->id;
356         ssize_t count;
357
358         mutex_lock(&smp_cpu_state_mutex);
359         switch (smp_cpu_get_polarization(cpu)) {
360         case POLARIZATION_HRZ:
361                 count = sprintf(buf, "horizontal\n");
362                 break;
363         case POLARIZATION_VL:
364                 count = sprintf(buf, "vertical:low\n");
365                 break;
366         case POLARIZATION_VM:
367                 count = sprintf(buf, "vertical:medium\n");
368                 break;
369         case POLARIZATION_VH:
370                 count = sprintf(buf, "vertical:high\n");
371                 break;
372         default:
373                 count = sprintf(buf, "unknown\n");
374                 break;
375         }
376         mutex_unlock(&smp_cpu_state_mutex);
377         return count;
378 }
379 static DEVICE_ATTR(polarization, 0444, cpu_polarization_show, NULL);
380
381 static struct attribute *topology_cpu_attrs[] = {
382         &dev_attr_polarization.attr,
383         NULL,
384 };
385
386 static struct attribute_group topology_cpu_attr_group = {
387         .attrs = topology_cpu_attrs,
388 };
389
390 int topology_cpu_init(struct cpu *cpu)
391 {
392         return sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
393 }
394
395 static const struct cpumask *cpu_thread_mask(int cpu)
396 {
397         return &per_cpu(cpu_topology, cpu).thread_mask;
398 }
399
400
401 const struct cpumask *cpu_coregroup_mask(int cpu)
402 {
403         return &per_cpu(cpu_topology, cpu).core_mask;
404 }
405
406 static const struct cpumask *cpu_book_mask(int cpu)
407 {
408         return &per_cpu(cpu_topology, cpu).book_mask;
409 }
410
411 static const struct cpumask *cpu_drawer_mask(int cpu)
412 {
413         return &per_cpu(cpu_topology, cpu).drawer_mask;
414 }
415
416 static struct sched_domain_topology_level s390_topology[] = {
417         { cpu_thread_mask, cpu_smt_flags, SD_INIT_NAME(SMT) },
418         { cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) },
419         { cpu_book_mask, SD_INIT_NAME(BOOK) },
420         { cpu_drawer_mask, SD_INIT_NAME(DRAWER) },
421         { cpu_cpu_mask, SD_INIT_NAME(DIE) },
422         { NULL, },
423 };
424
425 static void __init alloc_masks(struct sysinfo_15_1_x *info,
426                                struct mask_info *mask, int offset)
427 {
428         int i, nr_masks;
429
430         nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
431         for (i = 0; i < info->mnest - offset; i++)
432                 nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
433         nr_masks = max(nr_masks, 1);
434         for (i = 0; i < nr_masks; i++) {
435                 mask->next = kzalloc(sizeof(*mask->next), GFP_KERNEL);
436                 mask = mask->next;
437         }
438 }
439
440 static int __init s390_topology_init(void)
441 {
442         struct sysinfo_15_1_x *info;
443         int i;
444
445         set_sched_topology(s390_topology);
446         if (!MACHINE_HAS_TOPOLOGY)
447                 return 0;
448         tl_info = (struct sysinfo_15_1_x *)__get_free_page(GFP_KERNEL);
449         info = tl_info;
450         store_topology(info);
451         pr_info("The CPU configuration topology of the machine is:");
452         for (i = 0; i < TOPOLOGY_NR_MAG; i++)
453                 printk(KERN_CONT " %d", info->mag[i]);
454         printk(KERN_CONT " / %d\n", info->mnest);
455         alloc_masks(info, &socket_info, 1);
456         alloc_masks(info, &book_info, 2);
457         alloc_masks(info, &drawer_info, 3);
458         return 0;
459 }
460 early_initcall(s390_topology_init);
461
462 static int __init topology_init(void)
463 {
464         if (MACHINE_HAS_TOPOLOGY)
465                 set_topology_timer();
466         else
467                 topology_update_polarization_simple();
468         return device_create_file(cpu_subsys.dev_root, &dev_attr_dispatching);
469 }
470 device_initcall(topology_init);