Pull cpuidle into release branch
[linux-2.6] / arch / powerpc / kernel / sysfs.c
1 #include <linux/sysdev.h>
2 #include <linux/cpu.h>
3 #include <linux/smp.h>
4 #include <linux/percpu.h>
5 #include <linux/init.h>
6 #include <linux/sched.h>
7 #include <linux/module.h>
8 #include <linux/nodemask.h>
9 #include <linux/cpumask.h>
10 #include <linux/notifier.h>
11
12 #include <asm/current.h>
13 #include <asm/processor.h>
14 #include <asm/cputable.h>
15 #include <asm/firmware.h>
16 #include <asm/hvcall.h>
17 #include <asm/prom.h>
18 #include <asm/paca.h>
19 #include <asm/lppaca.h>
20 #include <asm/machdep.h>
21 #include <asm/smp.h>
22
23 static DEFINE_PER_CPU(struct cpu, cpu_devices);
24
25 /* SMT stuff */
26
27 #ifdef CONFIG_PPC_MULTIPLATFORM
28 /* Time in microseconds we delay before sleeping in the idle loop */
29 DEFINE_PER_CPU(unsigned long, smt_snooze_delay) = { 100 };
30
31 static ssize_t store_smt_snooze_delay(struct sys_device *dev, const char *buf,
32                                       size_t count)
33 {
34         struct cpu *cpu = container_of(dev, struct cpu, sysdev);
35         ssize_t ret;
36         unsigned long snooze;
37
38         ret = sscanf(buf, "%lu", &snooze);
39         if (ret != 1)
40                 return -EINVAL;
41
42         per_cpu(smt_snooze_delay, cpu->sysdev.id) = snooze;
43
44         return count;
45 }
46
47 static ssize_t show_smt_snooze_delay(struct sys_device *dev, char *buf)
48 {
49         struct cpu *cpu = container_of(dev, struct cpu, sysdev);
50
51         return sprintf(buf, "%lu\n", per_cpu(smt_snooze_delay, cpu->sysdev.id));
52 }
53
54 static SYSDEV_ATTR(smt_snooze_delay, 0644, show_smt_snooze_delay,
55                    store_smt_snooze_delay);
56
57 /* Only parse OF options if the matching cmdline option was not specified */
58 static int smt_snooze_cmdline;
59
60 static int __init smt_setup(void)
61 {
62         struct device_node *options;
63         const unsigned int *val;
64         unsigned int cpu;
65
66         if (!cpu_has_feature(CPU_FTR_SMT))
67                 return -ENODEV;
68
69         options = of_find_node_by_path("/options");
70         if (!options)
71                 return -ENODEV;
72
73         val = of_get_property(options, "ibm,smt-snooze-delay", NULL);
74         if (!smt_snooze_cmdline && val) {
75                 for_each_possible_cpu(cpu)
76                         per_cpu(smt_snooze_delay, cpu) = *val;
77         }
78
79         of_node_put(options);
80         return 0;
81 }
82 __initcall(smt_setup);
83
84 static int __init setup_smt_snooze_delay(char *str)
85 {
86         unsigned int cpu;
87         int snooze;
88
89         if (!cpu_has_feature(CPU_FTR_SMT))
90                 return 1;
91
92         smt_snooze_cmdline = 1;
93
94         if (get_option(&str, &snooze)) {
95                 for_each_possible_cpu(cpu)
96                         per_cpu(smt_snooze_delay, cpu) = snooze;
97         }
98
99         return 1;
100 }
101 __setup("smt-snooze-delay=", setup_smt_snooze_delay);
102
103 #endif /* CONFIG_PPC_MULTIPLATFORM */
104
105 /*
106  * Enabling PMCs will slow partition context switch times so we only do
107  * it the first time we write to the PMCs.
108  */
109
110 static DEFINE_PER_CPU(char, pmcs_enabled);
111
112 void ppc64_enable_pmcs(void)
113 {
114         /* Only need to enable them once */
115         if (__get_cpu_var(pmcs_enabled))
116                 return;
117
118         __get_cpu_var(pmcs_enabled) = 1;
119
120         if (ppc_md.enable_pmcs)
121                 ppc_md.enable_pmcs();
122 }
123 EXPORT_SYMBOL(ppc64_enable_pmcs);
124
125 /* XXX convert to rusty's on_one_cpu */
126 static unsigned long run_on_cpu(unsigned long cpu,
127                                 unsigned long (*func)(unsigned long),
128                                 unsigned long arg)
129 {
130         cpumask_t old_affinity = current->cpus_allowed;
131         unsigned long ret;
132
133         /* should return -EINVAL to userspace */
134         if (set_cpus_allowed(current, cpumask_of_cpu(cpu)))
135                 return 0;
136
137         ret = func(arg);
138
139         set_cpus_allowed(current, old_affinity);
140
141         return ret;
142 }
143
144 #define SYSFS_PMCSETUP(NAME, ADDRESS) \
145 static unsigned long read_##NAME(unsigned long junk) \
146 { \
147         return mfspr(ADDRESS); \
148 } \
149 static unsigned long write_##NAME(unsigned long val) \
150 { \
151         ppc64_enable_pmcs(); \
152         mtspr(ADDRESS, val); \
153         return 0; \
154 } \
155 static ssize_t show_##NAME(struct sys_device *dev, char *buf) \
156 { \
157         struct cpu *cpu = container_of(dev, struct cpu, sysdev); \
158         unsigned long val = run_on_cpu(cpu->sysdev.id, read_##NAME, 0); \
159         return sprintf(buf, "%lx\n", val); \
160 } \
161 static ssize_t __attribute_used__ \
162         store_##NAME(struct sys_device *dev, const char *buf, size_t count) \
163 { \
164         struct cpu *cpu = container_of(dev, struct cpu, sysdev); \
165         unsigned long val; \
166         int ret = sscanf(buf, "%lx", &val); \
167         if (ret != 1) \
168                 return -EINVAL; \
169         run_on_cpu(cpu->sysdev.id, write_##NAME, val); \
170         return count; \
171 }
172
173
174 /* Let's define all possible registers, we'll only hook up the ones
175  * that are implemented on the current processor
176  */
177
178 SYSFS_PMCSETUP(mmcr0, SPRN_MMCR0);
179 SYSFS_PMCSETUP(mmcr1, SPRN_MMCR1);
180 SYSFS_PMCSETUP(mmcra, SPRN_MMCRA);
181 SYSFS_PMCSETUP(pmc1, SPRN_PMC1);
182 SYSFS_PMCSETUP(pmc2, SPRN_PMC2);
183 SYSFS_PMCSETUP(pmc3, SPRN_PMC3);
184 SYSFS_PMCSETUP(pmc4, SPRN_PMC4);
185 SYSFS_PMCSETUP(pmc5, SPRN_PMC5);
186 SYSFS_PMCSETUP(pmc6, SPRN_PMC6);
187 SYSFS_PMCSETUP(pmc7, SPRN_PMC7);
188 SYSFS_PMCSETUP(pmc8, SPRN_PMC8);
189 SYSFS_PMCSETUP(purr, SPRN_PURR);
190 SYSFS_PMCSETUP(spurr, SPRN_SPURR);
191 SYSFS_PMCSETUP(dscr, SPRN_DSCR);
192
193 SYSFS_PMCSETUP(pa6t_pmc0, SPRN_PA6T_PMC0);
194 SYSFS_PMCSETUP(pa6t_pmc1, SPRN_PA6T_PMC1);
195 SYSFS_PMCSETUP(pa6t_pmc2, SPRN_PA6T_PMC2);
196 SYSFS_PMCSETUP(pa6t_pmc3, SPRN_PA6T_PMC3);
197 SYSFS_PMCSETUP(pa6t_pmc4, SPRN_PA6T_PMC4);
198 SYSFS_PMCSETUP(pa6t_pmc5, SPRN_PA6T_PMC5);
199
200 #ifdef CONFIG_DEBUG_KERNEL
201 SYSFS_PMCSETUP(hid0, SPRN_HID0);
202 SYSFS_PMCSETUP(hid1, SPRN_HID1);
203 SYSFS_PMCSETUP(hid4, SPRN_HID4);
204 SYSFS_PMCSETUP(hid5, SPRN_HID5);
205 SYSFS_PMCSETUP(ima0, SPRN_PA6T_IMA0);
206 SYSFS_PMCSETUP(ima1, SPRN_PA6T_IMA1);
207 SYSFS_PMCSETUP(ima2, SPRN_PA6T_IMA2);
208 SYSFS_PMCSETUP(ima3, SPRN_PA6T_IMA3);
209 SYSFS_PMCSETUP(ima4, SPRN_PA6T_IMA4);
210 SYSFS_PMCSETUP(ima5, SPRN_PA6T_IMA5);
211 SYSFS_PMCSETUP(ima6, SPRN_PA6T_IMA6);
212 SYSFS_PMCSETUP(ima7, SPRN_PA6T_IMA7);
213 SYSFS_PMCSETUP(ima8, SPRN_PA6T_IMA8);
214 SYSFS_PMCSETUP(ima9, SPRN_PA6T_IMA9);
215 SYSFS_PMCSETUP(imaat, SPRN_PA6T_IMAAT);
216 SYSFS_PMCSETUP(btcr, SPRN_PA6T_BTCR);
217 SYSFS_PMCSETUP(pccr, SPRN_PA6T_PCCR);
218 SYSFS_PMCSETUP(rpccr, SPRN_PA6T_RPCCR);
219 SYSFS_PMCSETUP(der, SPRN_PA6T_DER);
220 SYSFS_PMCSETUP(mer, SPRN_PA6T_MER);
221 SYSFS_PMCSETUP(ber, SPRN_PA6T_BER);
222 SYSFS_PMCSETUP(ier, SPRN_PA6T_IER);
223 SYSFS_PMCSETUP(sier, SPRN_PA6T_SIER);
224 SYSFS_PMCSETUP(siar, SPRN_PA6T_SIAR);
225 SYSFS_PMCSETUP(tsr0, SPRN_PA6T_TSR0);
226 SYSFS_PMCSETUP(tsr1, SPRN_PA6T_TSR1);
227 SYSFS_PMCSETUP(tsr2, SPRN_PA6T_TSR2);
228 SYSFS_PMCSETUP(tsr3, SPRN_PA6T_TSR3);
229 #endif /* CONFIG_DEBUG_KERNEL */
230
231 static SYSDEV_ATTR(mmcra, 0600, show_mmcra, store_mmcra);
232 static SYSDEV_ATTR(spurr, 0600, show_spurr, NULL);
233 static SYSDEV_ATTR(dscr, 0600, show_dscr, store_dscr);
234 static SYSDEV_ATTR(purr, 0600, show_purr, store_purr);
235
236 static struct sysdev_attribute ibm_common_attrs[] = {
237         _SYSDEV_ATTR(mmcr0, 0600, show_mmcr0, store_mmcr0),
238         _SYSDEV_ATTR(mmcr1, 0600, show_mmcr1, store_mmcr1),
239 };
240
241 static struct sysdev_attribute ibm_pmc_attrs[] = {
242         _SYSDEV_ATTR(pmc1, 0600, show_pmc1, store_pmc1),
243         _SYSDEV_ATTR(pmc2, 0600, show_pmc2, store_pmc2),
244         _SYSDEV_ATTR(pmc3, 0600, show_pmc3, store_pmc3),
245         _SYSDEV_ATTR(pmc4, 0600, show_pmc4, store_pmc4),
246         _SYSDEV_ATTR(pmc5, 0600, show_pmc5, store_pmc5),
247         _SYSDEV_ATTR(pmc6, 0600, show_pmc6, store_pmc6),
248         _SYSDEV_ATTR(pmc7, 0600, show_pmc7, store_pmc7),
249         _SYSDEV_ATTR(pmc8, 0600, show_pmc8, store_pmc8),
250 };
251
252 static struct sysdev_attribute pa6t_attrs[] = {
253         _SYSDEV_ATTR(mmcr0, 0600, show_mmcr0, store_mmcr0),
254         _SYSDEV_ATTR(mmcr1, 0600, show_mmcr1, store_mmcr1),
255         _SYSDEV_ATTR(pmc0, 0600, show_pa6t_pmc0, store_pa6t_pmc0),
256         _SYSDEV_ATTR(pmc1, 0600, show_pa6t_pmc1, store_pa6t_pmc1),
257         _SYSDEV_ATTR(pmc2, 0600, show_pa6t_pmc2, store_pa6t_pmc2),
258         _SYSDEV_ATTR(pmc3, 0600, show_pa6t_pmc3, store_pa6t_pmc3),
259         _SYSDEV_ATTR(pmc4, 0600, show_pa6t_pmc4, store_pa6t_pmc4),
260         _SYSDEV_ATTR(pmc5, 0600, show_pa6t_pmc5, store_pa6t_pmc5),
261 #ifdef CONFIG_DEBUG_KERNEL
262         _SYSDEV_ATTR(hid0, 0600, show_hid0, store_hid0),
263         _SYSDEV_ATTR(hid1, 0600, show_hid1, store_hid1),
264         _SYSDEV_ATTR(hid4, 0600, show_hid4, store_hid4),
265         _SYSDEV_ATTR(hid5, 0600, show_hid5, store_hid5),
266         _SYSDEV_ATTR(ima0, 0600, show_ima0, store_ima0),
267         _SYSDEV_ATTR(ima1, 0600, show_ima1, store_ima1),
268         _SYSDEV_ATTR(ima2, 0600, show_ima2, store_ima2),
269         _SYSDEV_ATTR(ima3, 0600, show_ima3, store_ima3),
270         _SYSDEV_ATTR(ima4, 0600, show_ima4, store_ima4),
271         _SYSDEV_ATTR(ima5, 0600, show_ima5, store_ima5),
272         _SYSDEV_ATTR(ima6, 0600, show_ima6, store_ima6),
273         _SYSDEV_ATTR(ima7, 0600, show_ima7, store_ima7),
274         _SYSDEV_ATTR(ima8, 0600, show_ima8, store_ima8),
275         _SYSDEV_ATTR(ima9, 0600, show_ima9, store_ima9),
276         _SYSDEV_ATTR(imaat, 0600, show_imaat, store_imaat),
277         _SYSDEV_ATTR(btcr, 0600, show_btcr, store_btcr),
278         _SYSDEV_ATTR(pccr, 0600, show_pccr, store_pccr),
279         _SYSDEV_ATTR(rpccr, 0600, show_rpccr, store_rpccr),
280         _SYSDEV_ATTR(der, 0600, show_der, store_der),
281         _SYSDEV_ATTR(mer, 0600, show_mer, store_mer),
282         _SYSDEV_ATTR(ber, 0600, show_ber, store_ber),
283         _SYSDEV_ATTR(ier, 0600, show_ier, store_ier),
284         _SYSDEV_ATTR(sier, 0600, show_sier, store_sier),
285         _SYSDEV_ATTR(siar, 0600, show_siar, store_siar),
286         _SYSDEV_ATTR(tsr0, 0600, show_tsr0, store_tsr0),
287         _SYSDEV_ATTR(tsr1, 0600, show_tsr1, store_tsr1),
288         _SYSDEV_ATTR(tsr2, 0600, show_tsr2, store_tsr2),
289         _SYSDEV_ATTR(tsr3, 0600, show_tsr3, store_tsr3),
290 #endif /* CONFIG_DEBUG_KERNEL */
291 };
292
293
294 static void register_cpu_online(unsigned int cpu)
295 {
296         struct cpu *c = &per_cpu(cpu_devices, cpu);
297         struct sys_device *s = &c->sysdev;
298         struct sysdev_attribute *attrs, *pmc_attrs;
299         int i, nattrs;
300
301         if (!firmware_has_feature(FW_FEATURE_ISERIES) &&
302                         cpu_has_feature(CPU_FTR_SMT))
303                 sysdev_create_file(s, &attr_smt_snooze_delay);
304
305         /* PMC stuff */
306         switch (cur_cpu_spec->pmc_type) {
307         case PPC_PMC_IBM:
308                 attrs = ibm_common_attrs;
309                 nattrs = sizeof(ibm_common_attrs) / sizeof(struct sysdev_attribute);
310                 pmc_attrs = ibm_pmc_attrs;
311                 break;
312         case PPC_PMC_PA6T:
313                 /* PA Semi starts counting at PMC0 */
314                 attrs = pa6t_attrs;
315                 nattrs = sizeof(pa6t_attrs) / sizeof(struct sysdev_attribute);
316                 pmc_attrs = NULL;
317                 break;
318         default:
319                 attrs = NULL;
320                 nattrs = 0;
321                 pmc_attrs = NULL;
322         }
323
324         for (i = 0; i < nattrs; i++)
325                 sysdev_create_file(s, &attrs[i]);
326
327         if (pmc_attrs)
328                 for (i = 0; i < cur_cpu_spec->num_pmcs; i++)
329                         sysdev_create_file(s, &pmc_attrs[i]);
330
331         if (cpu_has_feature(CPU_FTR_MMCRA))
332                 sysdev_create_file(s, &attr_mmcra);
333
334         if (cpu_has_feature(CPU_FTR_PURR))
335                 sysdev_create_file(s, &attr_purr);
336
337         if (cpu_has_feature(CPU_FTR_SPURR))
338                 sysdev_create_file(s, &attr_spurr);
339
340         if (cpu_has_feature(CPU_FTR_DSCR))
341                 sysdev_create_file(s, &attr_dscr);
342 }
343
344 #ifdef CONFIG_HOTPLUG_CPU
345 static void unregister_cpu_online(unsigned int cpu)
346 {
347         struct cpu *c = &per_cpu(cpu_devices, cpu);
348         struct sys_device *s = &c->sysdev;
349         struct sysdev_attribute *attrs, *pmc_attrs;
350         int i, nattrs;
351
352         BUG_ON(!c->hotpluggable);
353
354         if (!firmware_has_feature(FW_FEATURE_ISERIES) &&
355                         cpu_has_feature(CPU_FTR_SMT))
356                 sysdev_remove_file(s, &attr_smt_snooze_delay);
357
358         /* PMC stuff */
359         switch (cur_cpu_spec->pmc_type) {
360         case PPC_PMC_IBM:
361                 attrs = ibm_common_attrs;
362                 nattrs = sizeof(ibm_common_attrs) / sizeof(struct sysdev_attribute);
363                 pmc_attrs = ibm_pmc_attrs;
364                 break;
365         case PPC_PMC_PA6T:
366                 /* PA Semi starts counting at PMC0 */
367                 attrs = pa6t_attrs;
368                 nattrs = sizeof(pa6t_attrs) / sizeof(struct sysdev_attribute);
369                 pmc_attrs = NULL;
370                 break;
371         default:
372                 attrs = NULL;
373                 nattrs = 0;
374                 pmc_attrs = NULL;
375         }
376
377         for (i = 0; i < nattrs; i++)
378                 sysdev_remove_file(s, &attrs[i]);
379
380         if (pmc_attrs)
381                 for (i = 0; i < cur_cpu_spec->num_pmcs; i++)
382                         sysdev_remove_file(s, &pmc_attrs[i]);
383
384         if (cpu_has_feature(CPU_FTR_MMCRA))
385                 sysdev_remove_file(s, &attr_mmcra);
386
387         if (cpu_has_feature(CPU_FTR_PURR))
388                 sysdev_remove_file(s, &attr_purr);
389
390         if (cpu_has_feature(CPU_FTR_SPURR))
391                 sysdev_remove_file(s, &attr_spurr);
392
393         if (cpu_has_feature(CPU_FTR_DSCR))
394                 sysdev_remove_file(s, &attr_dscr);
395 }
396 #endif /* CONFIG_HOTPLUG_CPU */
397
398 static int __cpuinit sysfs_cpu_notify(struct notifier_block *self,
399                                       unsigned long action, void *hcpu)
400 {
401         unsigned int cpu = (unsigned int)(long)hcpu;
402
403         switch (action) {
404         case CPU_ONLINE:
405         case CPU_ONLINE_FROZEN:
406                 register_cpu_online(cpu);
407                 break;
408 #ifdef CONFIG_HOTPLUG_CPU
409         case CPU_DEAD:
410         case CPU_DEAD_FROZEN:
411                 unregister_cpu_online(cpu);
412                 break;
413 #endif
414         }
415         return NOTIFY_OK;
416 }
417
418 static struct notifier_block __cpuinitdata sysfs_cpu_nb = {
419         .notifier_call  = sysfs_cpu_notify,
420 };
421
422 static DEFINE_MUTEX(cpu_mutex);
423
424 int cpu_add_sysdev_attr(struct sysdev_attribute *attr)
425 {
426         int cpu;
427
428         mutex_lock(&cpu_mutex);
429
430         for_each_possible_cpu(cpu) {
431                 sysdev_create_file(get_cpu_sysdev(cpu), attr);
432         }
433
434         mutex_unlock(&cpu_mutex);
435         return 0;
436 }
437 EXPORT_SYMBOL_GPL(cpu_add_sysdev_attr);
438
439 int cpu_add_sysdev_attr_group(struct attribute_group *attrs)
440 {
441         int cpu;
442         struct sys_device *sysdev;
443         int ret;
444
445         mutex_lock(&cpu_mutex);
446
447         for_each_possible_cpu(cpu) {
448                 sysdev = get_cpu_sysdev(cpu);
449                 ret = sysfs_create_group(&sysdev->kobj, attrs);
450                 WARN_ON(ret != 0);
451         }
452
453         mutex_unlock(&cpu_mutex);
454         return 0;
455 }
456 EXPORT_SYMBOL_GPL(cpu_add_sysdev_attr_group);
457
458
459 void cpu_remove_sysdev_attr(struct sysdev_attribute *attr)
460 {
461         int cpu;
462
463         mutex_lock(&cpu_mutex);
464
465         for_each_possible_cpu(cpu) {
466                 sysdev_remove_file(get_cpu_sysdev(cpu), attr);
467         }
468
469         mutex_unlock(&cpu_mutex);
470 }
471 EXPORT_SYMBOL_GPL(cpu_remove_sysdev_attr);
472
473 void cpu_remove_sysdev_attr_group(struct attribute_group *attrs)
474 {
475         int cpu;
476         struct sys_device *sysdev;
477
478         mutex_lock(&cpu_mutex);
479
480         for_each_possible_cpu(cpu) {
481                 sysdev = get_cpu_sysdev(cpu);
482                 sysfs_remove_group(&sysdev->kobj, attrs);
483         }
484
485         mutex_unlock(&cpu_mutex);
486 }
487 EXPORT_SYMBOL_GPL(cpu_remove_sysdev_attr_group);
488
489
490 /* NUMA stuff */
491
492 #ifdef CONFIG_NUMA
493 static void register_nodes(void)
494 {
495         int i;
496
497         for (i = 0; i < MAX_NUMNODES; i++)
498                 register_one_node(i);
499 }
500
501 int sysfs_add_device_to_node(struct sys_device *dev, int nid)
502 {
503         struct node *node = &node_devices[nid];
504         return sysfs_create_link(&node->sysdev.kobj, &dev->kobj,
505                         kobject_name(&dev->kobj));
506 }
507 EXPORT_SYMBOL_GPL(sysfs_add_device_to_node);
508
509 void sysfs_remove_device_from_node(struct sys_device *dev, int nid)
510 {
511         struct node *node = &node_devices[nid];
512         sysfs_remove_link(&node->sysdev.kobj, kobject_name(&dev->kobj));
513 }
514 EXPORT_SYMBOL_GPL(sysfs_remove_device_from_node);
515
516 #else
517 static void register_nodes(void)
518 {
519         return;
520 }
521
522 #endif
523
524 /* Only valid if CPU is present. */
525 static ssize_t show_physical_id(struct sys_device *dev, char *buf)
526 {
527         struct cpu *cpu = container_of(dev, struct cpu, sysdev);
528
529         return sprintf(buf, "%d\n", get_hard_smp_processor_id(cpu->sysdev.id));
530 }
531 static SYSDEV_ATTR(physical_id, 0444, show_physical_id, NULL);
532
533 static int __init topology_init(void)
534 {
535         int cpu;
536
537         register_nodes();
538         register_cpu_notifier(&sysfs_cpu_nb);
539
540         for_each_possible_cpu(cpu) {
541                 struct cpu *c = &per_cpu(cpu_devices, cpu);
542
543                 /*
544                  * For now, we just see if the system supports making
545                  * the RTAS calls for CPU hotplug.  But, there may be a
546                  * more comprehensive way to do this for an individual
547                  * CPU.  For instance, the boot cpu might never be valid
548                  * for hotplugging.
549                  */
550                 if (ppc_md.cpu_die)
551                         c->hotpluggable = 1;
552
553                 if (cpu_online(cpu) || c->hotpluggable) {
554                         register_cpu(c, cpu);
555
556                         sysdev_create_file(&c->sysdev, &attr_physical_id);
557                 }
558
559                 if (cpu_online(cpu))
560                         register_cpu_online(cpu);
561         }
562
563         return 0;
564 }
565 subsys_initcall(topology_init);