xref: /linux/arch/powerpc/kernel/sysfs.c (revision ec2212088c42ff7d1362629ec26dda4f3e8bdad3)
1 #include <linux/device.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/export.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/hvcall.h>
16 #include <asm/prom.h>
17 #include <asm/machdep.h>
18 #include <asm/smp.h>
19 #include <asm/pmc.h>
20 #include <asm/system.h>
21 
22 #include "cacheinfo.h"
23 
24 #ifdef CONFIG_PPC64
25 #include <asm/paca.h>
26 #include <asm/lppaca.h>
27 #endif
28 
29 static DEFINE_PER_CPU(struct cpu, cpu_devices);
30 
31 /*
32  * SMT snooze delay stuff, 64-bit only for now
33  */
34 
35 #ifdef CONFIG_PPC64
36 
37 /* Time in microseconds we delay before sleeping in the idle loop */
38 DEFINE_PER_CPU(long, smt_snooze_delay) = { 100 };
39 
40 static ssize_t store_smt_snooze_delay(struct device *dev,
41 				      struct device_attribute *attr,
42 				      const char *buf,
43 				      size_t count)
44 {
45 	struct cpu *cpu = container_of(dev, struct cpu, dev);
46 	ssize_t ret;
47 	long snooze;
48 
49 	ret = sscanf(buf, "%ld", &snooze);
50 	if (ret != 1)
51 		return -EINVAL;
52 
53 	per_cpu(smt_snooze_delay, cpu->dev.id) = snooze;
54 	update_smt_snooze_delay(snooze);
55 
56 	return count;
57 }
58 
59 static ssize_t show_smt_snooze_delay(struct device *dev,
60 				     struct device_attribute *attr,
61 				     char *buf)
62 {
63 	struct cpu *cpu = container_of(dev, struct cpu, dev);
64 
65 	return sprintf(buf, "%ld\n", per_cpu(smt_snooze_delay, cpu->dev.id));
66 }
67 
68 static DEVICE_ATTR(smt_snooze_delay, 0644, show_smt_snooze_delay,
69 		   store_smt_snooze_delay);
70 
71 static int __init setup_smt_snooze_delay(char *str)
72 {
73 	unsigned int cpu;
74 	long snooze;
75 
76 	if (!cpu_has_feature(CPU_FTR_SMT))
77 		return 1;
78 
79 	snooze = simple_strtol(str, NULL, 10);
80 	for_each_possible_cpu(cpu)
81 		per_cpu(smt_snooze_delay, cpu) = snooze;
82 
83 	return 1;
84 }
85 __setup("smt-snooze-delay=", setup_smt_snooze_delay);
86 
87 #endif /* CONFIG_PPC64 */
88 
89 /*
90  * Enabling PMCs will slow partition context switch times so we only do
91  * it the first time we write to the PMCs.
92  */
93 
94 static DEFINE_PER_CPU(char, pmcs_enabled);
95 
96 void ppc_enable_pmcs(void)
97 {
98 	ppc_set_pmu_inuse(1);
99 
100 	/* Only need to enable them once */
101 	if (__get_cpu_var(pmcs_enabled))
102 		return;
103 
104 	__get_cpu_var(pmcs_enabled) = 1;
105 
106 	if (ppc_md.enable_pmcs)
107 		ppc_md.enable_pmcs();
108 }
109 EXPORT_SYMBOL(ppc_enable_pmcs);
110 
111 #define SYSFS_PMCSETUP(NAME, ADDRESS) \
112 static void read_##NAME(void *val) \
113 { \
114 	*(unsigned long *)val = mfspr(ADDRESS);	\
115 } \
116 static void write_##NAME(void *val) \
117 { \
118 	ppc_enable_pmcs(); \
119 	mtspr(ADDRESS, *(unsigned long *)val);	\
120 } \
121 static ssize_t show_##NAME(struct device *dev, \
122 			struct device_attribute *attr, \
123 			char *buf) \
124 { \
125 	struct cpu *cpu = container_of(dev, struct cpu, dev); \
126 	unsigned long val; \
127 	smp_call_function_single(cpu->dev.id, read_##NAME, &val, 1);	\
128 	return sprintf(buf, "%lx\n", val); \
129 } \
130 static ssize_t __used \
131 	store_##NAME(struct device *dev, struct device_attribute *attr, \
132 			const char *buf, size_t count) \
133 { \
134 	struct cpu *cpu = container_of(dev, struct cpu, dev); \
135 	unsigned long val; \
136 	int ret = sscanf(buf, "%lx", &val); \
137 	if (ret != 1) \
138 		return -EINVAL; \
139 	smp_call_function_single(cpu->dev.id, write_##NAME, &val, 1); \
140 	return count; \
141 }
142 
143 
144 /* Let's define all possible registers, we'll only hook up the ones
145  * that are implemented on the current processor
146  */
147 
148 #if defined(CONFIG_PPC64)
149 #define HAS_PPC_PMC_CLASSIC	1
150 #define HAS_PPC_PMC_IBM		1
151 #define HAS_PPC_PMC_PA6T	1
152 #elif defined(CONFIG_6xx)
153 #define HAS_PPC_PMC_CLASSIC	1
154 #define HAS_PPC_PMC_IBM		1
155 #define HAS_PPC_PMC_G4		1
156 #endif
157 
158 
159 #ifdef HAS_PPC_PMC_CLASSIC
160 SYSFS_PMCSETUP(mmcr0, SPRN_MMCR0);
161 SYSFS_PMCSETUP(mmcr1, SPRN_MMCR1);
162 SYSFS_PMCSETUP(pmc1, SPRN_PMC1);
163 SYSFS_PMCSETUP(pmc2, SPRN_PMC2);
164 SYSFS_PMCSETUP(pmc3, SPRN_PMC3);
165 SYSFS_PMCSETUP(pmc4, SPRN_PMC4);
166 SYSFS_PMCSETUP(pmc5, SPRN_PMC5);
167 SYSFS_PMCSETUP(pmc6, SPRN_PMC6);
168 
169 #ifdef HAS_PPC_PMC_G4
170 SYSFS_PMCSETUP(mmcr2, SPRN_MMCR2);
171 #endif
172 
173 #ifdef CONFIG_PPC64
174 SYSFS_PMCSETUP(pmc7, SPRN_PMC7);
175 SYSFS_PMCSETUP(pmc8, SPRN_PMC8);
176 
177 SYSFS_PMCSETUP(mmcra, SPRN_MMCRA);
178 SYSFS_PMCSETUP(purr, SPRN_PURR);
179 SYSFS_PMCSETUP(spurr, SPRN_SPURR);
180 SYSFS_PMCSETUP(dscr, SPRN_DSCR);
181 SYSFS_PMCSETUP(pir, SPRN_PIR);
182 
183 static DEVICE_ATTR(mmcra, 0600, show_mmcra, store_mmcra);
184 static DEVICE_ATTR(spurr, 0600, show_spurr, NULL);
185 static DEVICE_ATTR(dscr, 0600, show_dscr, store_dscr);
186 static DEVICE_ATTR(purr, 0600, show_purr, store_purr);
187 static DEVICE_ATTR(pir, 0400, show_pir, NULL);
188 
189 unsigned long dscr_default = 0;
190 EXPORT_SYMBOL(dscr_default);
191 
192 static ssize_t show_dscr_default(struct device *dev,
193 		struct device_attribute *attr, char *buf)
194 {
195 	return sprintf(buf, "%lx\n", dscr_default);
196 }
197 
198 static ssize_t __used store_dscr_default(struct device *dev,
199 		struct device_attribute *attr, const char *buf,
200 		size_t count)
201 {
202 	unsigned long val;
203 	int ret = 0;
204 
205 	ret = sscanf(buf, "%lx", &val);
206 	if (ret != 1)
207 		return -EINVAL;
208 	dscr_default = val;
209 
210 	return count;
211 }
212 
213 static DEVICE_ATTR(dscr_default, 0600,
214 		show_dscr_default, store_dscr_default);
215 
216 static void sysfs_create_dscr_default(void)
217 {
218 	int err = 0;
219 	if (cpu_has_feature(CPU_FTR_DSCR))
220 		err = device_create_file(cpu_subsys.dev_root, &dev_attr_dscr_default);
221 }
222 #endif /* CONFIG_PPC64 */
223 
224 #ifdef HAS_PPC_PMC_PA6T
225 SYSFS_PMCSETUP(pa6t_pmc0, SPRN_PA6T_PMC0);
226 SYSFS_PMCSETUP(pa6t_pmc1, SPRN_PA6T_PMC1);
227 SYSFS_PMCSETUP(pa6t_pmc2, SPRN_PA6T_PMC2);
228 SYSFS_PMCSETUP(pa6t_pmc3, SPRN_PA6T_PMC3);
229 SYSFS_PMCSETUP(pa6t_pmc4, SPRN_PA6T_PMC4);
230 SYSFS_PMCSETUP(pa6t_pmc5, SPRN_PA6T_PMC5);
231 #ifdef CONFIG_DEBUG_KERNEL
232 SYSFS_PMCSETUP(hid0, SPRN_HID0);
233 SYSFS_PMCSETUP(hid1, SPRN_HID1);
234 SYSFS_PMCSETUP(hid4, SPRN_HID4);
235 SYSFS_PMCSETUP(hid5, SPRN_HID5);
236 SYSFS_PMCSETUP(ima0, SPRN_PA6T_IMA0);
237 SYSFS_PMCSETUP(ima1, SPRN_PA6T_IMA1);
238 SYSFS_PMCSETUP(ima2, SPRN_PA6T_IMA2);
239 SYSFS_PMCSETUP(ima3, SPRN_PA6T_IMA3);
240 SYSFS_PMCSETUP(ima4, SPRN_PA6T_IMA4);
241 SYSFS_PMCSETUP(ima5, SPRN_PA6T_IMA5);
242 SYSFS_PMCSETUP(ima6, SPRN_PA6T_IMA6);
243 SYSFS_PMCSETUP(ima7, SPRN_PA6T_IMA7);
244 SYSFS_PMCSETUP(ima8, SPRN_PA6T_IMA8);
245 SYSFS_PMCSETUP(ima9, SPRN_PA6T_IMA9);
246 SYSFS_PMCSETUP(imaat, SPRN_PA6T_IMAAT);
247 SYSFS_PMCSETUP(btcr, SPRN_PA6T_BTCR);
248 SYSFS_PMCSETUP(pccr, SPRN_PA6T_PCCR);
249 SYSFS_PMCSETUP(rpccr, SPRN_PA6T_RPCCR);
250 SYSFS_PMCSETUP(der, SPRN_PA6T_DER);
251 SYSFS_PMCSETUP(mer, SPRN_PA6T_MER);
252 SYSFS_PMCSETUP(ber, SPRN_PA6T_BER);
253 SYSFS_PMCSETUP(ier, SPRN_PA6T_IER);
254 SYSFS_PMCSETUP(sier, SPRN_PA6T_SIER);
255 SYSFS_PMCSETUP(siar, SPRN_PA6T_SIAR);
256 SYSFS_PMCSETUP(tsr0, SPRN_PA6T_TSR0);
257 SYSFS_PMCSETUP(tsr1, SPRN_PA6T_TSR1);
258 SYSFS_PMCSETUP(tsr2, SPRN_PA6T_TSR2);
259 SYSFS_PMCSETUP(tsr3, SPRN_PA6T_TSR3);
260 #endif /* CONFIG_DEBUG_KERNEL */
261 #endif /* HAS_PPC_PMC_PA6T */
262 
263 #ifdef HAS_PPC_PMC_IBM
264 static struct device_attribute ibm_common_attrs[] = {
265 	__ATTR(mmcr0, 0600, show_mmcr0, store_mmcr0),
266 	__ATTR(mmcr1, 0600, show_mmcr1, store_mmcr1),
267 };
268 #endif /* HAS_PPC_PMC_G4 */
269 
270 #ifdef HAS_PPC_PMC_G4
271 static struct device_attribute g4_common_attrs[] = {
272 	__ATTR(mmcr0, 0600, show_mmcr0, store_mmcr0),
273 	__ATTR(mmcr1, 0600, show_mmcr1, store_mmcr1),
274 	__ATTR(mmcr2, 0600, show_mmcr2, store_mmcr2),
275 };
276 #endif /* HAS_PPC_PMC_G4 */
277 
278 static struct device_attribute classic_pmc_attrs[] = {
279 	__ATTR(pmc1, 0600, show_pmc1, store_pmc1),
280 	__ATTR(pmc2, 0600, show_pmc2, store_pmc2),
281 	__ATTR(pmc3, 0600, show_pmc3, store_pmc3),
282 	__ATTR(pmc4, 0600, show_pmc4, store_pmc4),
283 	__ATTR(pmc5, 0600, show_pmc5, store_pmc5),
284 	__ATTR(pmc6, 0600, show_pmc6, store_pmc6),
285 #ifdef CONFIG_PPC64
286 	__ATTR(pmc7, 0600, show_pmc7, store_pmc7),
287 	__ATTR(pmc8, 0600, show_pmc8, store_pmc8),
288 #endif
289 };
290 
291 #ifdef HAS_PPC_PMC_PA6T
292 static struct device_attribute pa6t_attrs[] = {
293 	__ATTR(mmcr0, 0600, show_mmcr0, store_mmcr0),
294 	__ATTR(mmcr1, 0600, show_mmcr1, store_mmcr1),
295 	__ATTR(pmc0, 0600, show_pa6t_pmc0, store_pa6t_pmc0),
296 	__ATTR(pmc1, 0600, show_pa6t_pmc1, store_pa6t_pmc1),
297 	__ATTR(pmc2, 0600, show_pa6t_pmc2, store_pa6t_pmc2),
298 	__ATTR(pmc3, 0600, show_pa6t_pmc3, store_pa6t_pmc3),
299 	__ATTR(pmc4, 0600, show_pa6t_pmc4, store_pa6t_pmc4),
300 	__ATTR(pmc5, 0600, show_pa6t_pmc5, store_pa6t_pmc5),
301 #ifdef CONFIG_DEBUG_KERNEL
302 	__ATTR(hid0, 0600, show_hid0, store_hid0),
303 	__ATTR(hid1, 0600, show_hid1, store_hid1),
304 	__ATTR(hid4, 0600, show_hid4, store_hid4),
305 	__ATTR(hid5, 0600, show_hid5, store_hid5),
306 	__ATTR(ima0, 0600, show_ima0, store_ima0),
307 	__ATTR(ima1, 0600, show_ima1, store_ima1),
308 	__ATTR(ima2, 0600, show_ima2, store_ima2),
309 	__ATTR(ima3, 0600, show_ima3, store_ima3),
310 	__ATTR(ima4, 0600, show_ima4, store_ima4),
311 	__ATTR(ima5, 0600, show_ima5, store_ima5),
312 	__ATTR(ima6, 0600, show_ima6, store_ima6),
313 	__ATTR(ima7, 0600, show_ima7, store_ima7),
314 	__ATTR(ima8, 0600, show_ima8, store_ima8),
315 	__ATTR(ima9, 0600, show_ima9, store_ima9),
316 	__ATTR(imaat, 0600, show_imaat, store_imaat),
317 	__ATTR(btcr, 0600, show_btcr, store_btcr),
318 	__ATTR(pccr, 0600, show_pccr, store_pccr),
319 	__ATTR(rpccr, 0600, show_rpccr, store_rpccr),
320 	__ATTR(der, 0600, show_der, store_der),
321 	__ATTR(mer, 0600, show_mer, store_mer),
322 	__ATTR(ber, 0600, show_ber, store_ber),
323 	__ATTR(ier, 0600, show_ier, store_ier),
324 	__ATTR(sier, 0600, show_sier, store_sier),
325 	__ATTR(siar, 0600, show_siar, store_siar),
326 	__ATTR(tsr0, 0600, show_tsr0, store_tsr0),
327 	__ATTR(tsr1, 0600, show_tsr1, store_tsr1),
328 	__ATTR(tsr2, 0600, show_tsr2, store_tsr2),
329 	__ATTR(tsr3, 0600, show_tsr3, store_tsr3),
330 #endif /* CONFIG_DEBUG_KERNEL */
331 };
332 #endif /* HAS_PPC_PMC_PA6T */
333 #endif /* HAS_PPC_PMC_CLASSIC */
334 
335 static void __cpuinit register_cpu_online(unsigned int cpu)
336 {
337 	struct cpu *c = &per_cpu(cpu_devices, cpu);
338 	struct device *s = &c->dev;
339 	struct device_attribute *attrs, *pmc_attrs;
340 	int i, nattrs;
341 
342 #ifdef CONFIG_PPC64
343 	if (cpu_has_feature(CPU_FTR_SMT))
344 		device_create_file(s, &dev_attr_smt_snooze_delay);
345 #endif
346 
347 	/* PMC stuff */
348 	switch (cur_cpu_spec->pmc_type) {
349 #ifdef HAS_PPC_PMC_IBM
350 	case PPC_PMC_IBM:
351 		attrs = ibm_common_attrs;
352 		nattrs = sizeof(ibm_common_attrs) / sizeof(struct device_attribute);
353 		pmc_attrs = classic_pmc_attrs;
354 		break;
355 #endif /* HAS_PPC_PMC_IBM */
356 #ifdef HAS_PPC_PMC_G4
357 	case PPC_PMC_G4:
358 		attrs = g4_common_attrs;
359 		nattrs = sizeof(g4_common_attrs) / sizeof(struct device_attribute);
360 		pmc_attrs = classic_pmc_attrs;
361 		break;
362 #endif /* HAS_PPC_PMC_G4 */
363 #ifdef HAS_PPC_PMC_PA6T
364 	case PPC_PMC_PA6T:
365 		/* PA Semi starts counting at PMC0 */
366 		attrs = pa6t_attrs;
367 		nattrs = sizeof(pa6t_attrs) / sizeof(struct device_attribute);
368 		pmc_attrs = NULL;
369 		break;
370 #endif /* HAS_PPC_PMC_PA6T */
371 	default:
372 		attrs = NULL;
373 		nattrs = 0;
374 		pmc_attrs = NULL;
375 	}
376 
377 	for (i = 0; i < nattrs; i++)
378 		device_create_file(s, &attrs[i]);
379 
380 	if (pmc_attrs)
381 		for (i = 0; i < cur_cpu_spec->num_pmcs; i++)
382 			device_create_file(s, &pmc_attrs[i]);
383 
384 #ifdef CONFIG_PPC64
385 	if (cpu_has_feature(CPU_FTR_MMCRA))
386 		device_create_file(s, &dev_attr_mmcra);
387 
388 	if (cpu_has_feature(CPU_FTR_PURR))
389 		device_create_file(s, &dev_attr_purr);
390 
391 	if (cpu_has_feature(CPU_FTR_SPURR))
392 		device_create_file(s, &dev_attr_spurr);
393 
394 	if (cpu_has_feature(CPU_FTR_DSCR))
395 		device_create_file(s, &dev_attr_dscr);
396 
397 	if (cpu_has_feature(CPU_FTR_PPCAS_ARCH_V2))
398 		device_create_file(s, &dev_attr_pir);
399 #endif /* CONFIG_PPC64 */
400 
401 	cacheinfo_cpu_online(cpu);
402 }
403 
404 #ifdef CONFIG_HOTPLUG_CPU
405 static void unregister_cpu_online(unsigned int cpu)
406 {
407 	struct cpu *c = &per_cpu(cpu_devices, cpu);
408 	struct device *s = &c->dev;
409 	struct device_attribute *attrs, *pmc_attrs;
410 	int i, nattrs;
411 
412 	BUG_ON(!c->hotpluggable);
413 
414 #ifdef CONFIG_PPC64
415 	if (cpu_has_feature(CPU_FTR_SMT))
416 		device_remove_file(s, &dev_attr_smt_snooze_delay);
417 #endif
418 
419 	/* PMC stuff */
420 	switch (cur_cpu_spec->pmc_type) {
421 #ifdef HAS_PPC_PMC_IBM
422 	case PPC_PMC_IBM:
423 		attrs = ibm_common_attrs;
424 		nattrs = sizeof(ibm_common_attrs) / sizeof(struct device_attribute);
425 		pmc_attrs = classic_pmc_attrs;
426 		break;
427 #endif /* HAS_PPC_PMC_IBM */
428 #ifdef HAS_PPC_PMC_G4
429 	case PPC_PMC_G4:
430 		attrs = g4_common_attrs;
431 		nattrs = sizeof(g4_common_attrs) / sizeof(struct device_attribute);
432 		pmc_attrs = classic_pmc_attrs;
433 		break;
434 #endif /* HAS_PPC_PMC_G4 */
435 #ifdef HAS_PPC_PMC_PA6T
436 	case PPC_PMC_PA6T:
437 		/* PA Semi starts counting at PMC0 */
438 		attrs = pa6t_attrs;
439 		nattrs = sizeof(pa6t_attrs) / sizeof(struct device_attribute);
440 		pmc_attrs = NULL;
441 		break;
442 #endif /* HAS_PPC_PMC_PA6T */
443 	default:
444 		attrs = NULL;
445 		nattrs = 0;
446 		pmc_attrs = NULL;
447 	}
448 
449 	for (i = 0; i < nattrs; i++)
450 		device_remove_file(s, &attrs[i]);
451 
452 	if (pmc_attrs)
453 		for (i = 0; i < cur_cpu_spec->num_pmcs; i++)
454 			device_remove_file(s, &pmc_attrs[i]);
455 
456 #ifdef CONFIG_PPC64
457 	if (cpu_has_feature(CPU_FTR_MMCRA))
458 		device_remove_file(s, &dev_attr_mmcra);
459 
460 	if (cpu_has_feature(CPU_FTR_PURR))
461 		device_remove_file(s, &dev_attr_purr);
462 
463 	if (cpu_has_feature(CPU_FTR_SPURR))
464 		device_remove_file(s, &dev_attr_spurr);
465 
466 	if (cpu_has_feature(CPU_FTR_DSCR))
467 		device_remove_file(s, &dev_attr_dscr);
468 
469 	if (cpu_has_feature(CPU_FTR_PPCAS_ARCH_V2))
470 		device_remove_file(s, &dev_attr_pir);
471 #endif /* CONFIG_PPC64 */
472 
473 	cacheinfo_cpu_offline(cpu);
474 }
475 
476 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
477 ssize_t arch_cpu_probe(const char *buf, size_t count)
478 {
479 	if (ppc_md.cpu_probe)
480 		return ppc_md.cpu_probe(buf, count);
481 
482 	return -EINVAL;
483 }
484 
485 ssize_t arch_cpu_release(const char *buf, size_t count)
486 {
487 	if (ppc_md.cpu_release)
488 		return ppc_md.cpu_release(buf, count);
489 
490 	return -EINVAL;
491 }
492 #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
493 
494 #endif /* CONFIG_HOTPLUG_CPU */
495 
496 static int __cpuinit sysfs_cpu_notify(struct notifier_block *self,
497 				      unsigned long action, void *hcpu)
498 {
499 	unsigned int cpu = (unsigned int)(long)hcpu;
500 
501 	switch (action) {
502 	case CPU_ONLINE:
503 	case CPU_ONLINE_FROZEN:
504 		register_cpu_online(cpu);
505 		break;
506 #ifdef CONFIG_HOTPLUG_CPU
507 	case CPU_DEAD:
508 	case CPU_DEAD_FROZEN:
509 		unregister_cpu_online(cpu);
510 		break;
511 #endif
512 	}
513 	return NOTIFY_OK;
514 }
515 
516 static struct notifier_block __cpuinitdata sysfs_cpu_nb = {
517 	.notifier_call	= sysfs_cpu_notify,
518 };
519 
520 static DEFINE_MUTEX(cpu_mutex);
521 
522 int cpu_add_dev_attr(struct device_attribute *attr)
523 {
524 	int cpu;
525 
526 	mutex_lock(&cpu_mutex);
527 
528 	for_each_possible_cpu(cpu) {
529 		device_create_file(get_cpu_device(cpu), attr);
530 	}
531 
532 	mutex_unlock(&cpu_mutex);
533 	return 0;
534 }
535 EXPORT_SYMBOL_GPL(cpu_add_dev_attr);
536 
537 int cpu_add_dev_attr_group(struct attribute_group *attrs)
538 {
539 	int cpu;
540 	struct device *dev;
541 	int ret;
542 
543 	mutex_lock(&cpu_mutex);
544 
545 	for_each_possible_cpu(cpu) {
546 		dev = get_cpu_device(cpu);
547 		ret = sysfs_create_group(&dev->kobj, attrs);
548 		WARN_ON(ret != 0);
549 	}
550 
551 	mutex_unlock(&cpu_mutex);
552 	return 0;
553 }
554 EXPORT_SYMBOL_GPL(cpu_add_dev_attr_group);
555 
556 
557 void cpu_remove_dev_attr(struct device_attribute *attr)
558 {
559 	int cpu;
560 
561 	mutex_lock(&cpu_mutex);
562 
563 	for_each_possible_cpu(cpu) {
564 		device_remove_file(get_cpu_device(cpu), attr);
565 	}
566 
567 	mutex_unlock(&cpu_mutex);
568 }
569 EXPORT_SYMBOL_GPL(cpu_remove_dev_attr);
570 
571 void cpu_remove_dev_attr_group(struct attribute_group *attrs)
572 {
573 	int cpu;
574 	struct device *dev;
575 
576 	mutex_lock(&cpu_mutex);
577 
578 	for_each_possible_cpu(cpu) {
579 		dev = get_cpu_device(cpu);
580 		sysfs_remove_group(&dev->kobj, attrs);
581 	}
582 
583 	mutex_unlock(&cpu_mutex);
584 }
585 EXPORT_SYMBOL_GPL(cpu_remove_dev_attr_group);
586 
587 
588 /* NUMA stuff */
589 
590 #ifdef CONFIG_NUMA
591 static void register_nodes(void)
592 {
593 	int i;
594 
595 	for (i = 0; i < MAX_NUMNODES; i++)
596 		register_one_node(i);
597 }
598 
599 int sysfs_add_device_to_node(struct device *dev, int nid)
600 {
601 	struct node *node = &node_devices[nid];
602 	return sysfs_create_link(&node->dev.kobj, &dev->kobj,
603 			kobject_name(&dev->kobj));
604 }
605 EXPORT_SYMBOL_GPL(sysfs_add_device_to_node);
606 
607 void sysfs_remove_device_from_node(struct device *dev, int nid)
608 {
609 	struct node *node = &node_devices[nid];
610 	sysfs_remove_link(&node->dev.kobj, kobject_name(&dev->kobj));
611 }
612 EXPORT_SYMBOL_GPL(sysfs_remove_device_from_node);
613 
614 #else
615 static void register_nodes(void)
616 {
617 	return;
618 }
619 
620 #endif
621 
622 /* Only valid if CPU is present. */
623 static ssize_t show_physical_id(struct device *dev,
624 				struct device_attribute *attr, char *buf)
625 {
626 	struct cpu *cpu = container_of(dev, struct cpu, dev);
627 
628 	return sprintf(buf, "%d\n", get_hard_smp_processor_id(cpu->dev.id));
629 }
630 static DEVICE_ATTR(physical_id, 0444, show_physical_id, NULL);
631 
632 static int __init topology_init(void)
633 {
634 	int cpu;
635 
636 	register_nodes();
637 	register_cpu_notifier(&sysfs_cpu_nb);
638 
639 	for_each_possible_cpu(cpu) {
640 		struct cpu *c = &per_cpu(cpu_devices, cpu);
641 
642 		/*
643 		 * For now, we just see if the system supports making
644 		 * the RTAS calls for CPU hotplug.  But, there may be a
645 		 * more comprehensive way to do this for an individual
646 		 * CPU.  For instance, the boot cpu might never be valid
647 		 * for hotplugging.
648 		 */
649 		if (ppc_md.cpu_die)
650 			c->hotpluggable = 1;
651 
652 		if (cpu_online(cpu) || c->hotpluggable) {
653 			register_cpu(c, cpu);
654 
655 			device_create_file(&c->dev, &dev_attr_physical_id);
656 		}
657 
658 		if (cpu_online(cpu))
659 			register_cpu_online(cpu);
660 	}
661 #ifdef CONFIG_PPC64
662 	sysfs_create_dscr_default();
663 #endif /* CONFIG_PPC64 */
664 
665 	return 0;
666 }
667 subsys_initcall(topology_init);
668