xref: /openbmc/linux/arch/powerpc/kernel/sysfs.c (revision b627b4ed)
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/machdep.h>
19 #include <asm/smp.h>
20 
21 #include "cacheinfo.h"
22 
23 #ifdef CONFIG_PPC64
24 #include <asm/paca.h>
25 #include <asm/lppaca.h>
26 #endif
27 
28 static DEFINE_PER_CPU(struct cpu, cpu_devices);
29 
30 /*
31  * SMT snooze delay stuff, 64-bit only for now
32  */
33 
34 #ifdef CONFIG_PPC64
35 
36 /* Time in microseconds we delay before sleeping in the idle loop */
37 DEFINE_PER_CPU(unsigned long, smt_snooze_delay) = { 100 };
38 
39 static ssize_t store_smt_snooze_delay(struct sys_device *dev,
40 				      struct sysdev_attribute *attr,
41 				      const char *buf,
42 				      size_t count)
43 {
44 	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
45 	ssize_t ret;
46 	unsigned long snooze;
47 
48 	ret = sscanf(buf, "%lu", &snooze);
49 	if (ret != 1)
50 		return -EINVAL;
51 
52 	per_cpu(smt_snooze_delay, cpu->sysdev.id) = snooze;
53 
54 	return count;
55 }
56 
57 static ssize_t show_smt_snooze_delay(struct sys_device *dev,
58 				     struct sysdev_attribute *attr,
59 				     char *buf)
60 {
61 	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
62 
63 	return sprintf(buf, "%lu\n", per_cpu(smt_snooze_delay, cpu->sysdev.id));
64 }
65 
66 static SYSDEV_ATTR(smt_snooze_delay, 0644, show_smt_snooze_delay,
67 		   store_smt_snooze_delay);
68 
69 /* Only parse OF options if the matching cmdline option was not specified */
70 static int smt_snooze_cmdline;
71 
72 static int __init smt_setup(void)
73 {
74 	struct device_node *options;
75 	const unsigned int *val;
76 	unsigned int cpu;
77 
78 	if (!cpu_has_feature(CPU_FTR_SMT))
79 		return -ENODEV;
80 
81 	options = of_find_node_by_path("/options");
82 	if (!options)
83 		return -ENODEV;
84 
85 	val = of_get_property(options, "ibm,smt-snooze-delay", NULL);
86 	if (!smt_snooze_cmdline && val) {
87 		for_each_possible_cpu(cpu)
88 			per_cpu(smt_snooze_delay, cpu) = *val;
89 	}
90 
91 	of_node_put(options);
92 	return 0;
93 }
94 __initcall(smt_setup);
95 
96 static int __init setup_smt_snooze_delay(char *str)
97 {
98 	unsigned int cpu;
99 	int snooze;
100 
101 	if (!cpu_has_feature(CPU_FTR_SMT))
102 		return 1;
103 
104 	smt_snooze_cmdline = 1;
105 
106 	if (get_option(&str, &snooze)) {
107 		for_each_possible_cpu(cpu)
108 			per_cpu(smt_snooze_delay, cpu) = snooze;
109 	}
110 
111 	return 1;
112 }
113 __setup("smt-snooze-delay=", setup_smt_snooze_delay);
114 
115 #endif /* CONFIG_PPC64 */
116 
117 /*
118  * Enabling PMCs will slow partition context switch times so we only do
119  * it the first time we write to the PMCs.
120  */
121 
122 static DEFINE_PER_CPU(char, pmcs_enabled);
123 
124 void ppc_enable_pmcs(void)
125 {
126 	/* Only need to enable them once */
127 	if (__get_cpu_var(pmcs_enabled))
128 		return;
129 
130 	__get_cpu_var(pmcs_enabled) = 1;
131 
132 	if (ppc_md.enable_pmcs)
133 		ppc_md.enable_pmcs();
134 }
135 EXPORT_SYMBOL(ppc_enable_pmcs);
136 
137 #define SYSFS_PMCSETUP(NAME, ADDRESS) \
138 static void read_##NAME(void *val) \
139 { \
140 	*(unsigned long *)val = mfspr(ADDRESS);	\
141 } \
142 static void write_##NAME(void *val) \
143 { \
144 	ppc_enable_pmcs(); \
145 	mtspr(ADDRESS, *(unsigned long *)val);	\
146 } \
147 static ssize_t show_##NAME(struct sys_device *dev, \
148 			struct sysdev_attribute *attr, \
149 			char *buf) \
150 { \
151 	struct cpu *cpu = container_of(dev, struct cpu, sysdev); \
152 	unsigned long val; \
153 	smp_call_function_single(cpu->sysdev.id, read_##NAME, &val, 1);	\
154 	return sprintf(buf, "%lx\n", val); \
155 } \
156 static ssize_t __used \
157 	store_##NAME(struct sys_device *dev, struct sysdev_attribute *attr, \
158 			const char *buf, size_t count) \
159 { \
160 	struct cpu *cpu = container_of(dev, struct cpu, sysdev); \
161 	unsigned long val; \
162 	int ret = sscanf(buf, "%lx", &val); \
163 	if (ret != 1) \
164 		return -EINVAL; \
165 	smp_call_function_single(cpu->sysdev.id, write_##NAME, &val, 1); \
166 	return count; \
167 }
168 
169 
170 /* Let's define all possible registers, we'll only hook up the ones
171  * that are implemented on the current processor
172  */
173 
174 #if defined(CONFIG_PPC64)
175 #define HAS_PPC_PMC_CLASSIC	1
176 #define HAS_PPC_PMC_IBM		1
177 #define HAS_PPC_PMC_PA6T	1
178 #elif defined(CONFIG_6xx)
179 #define HAS_PPC_PMC_CLASSIC	1
180 #define HAS_PPC_PMC_IBM		1
181 #define HAS_PPC_PMC_G4		1
182 #endif
183 
184 
185 #ifdef HAS_PPC_PMC_CLASSIC
186 SYSFS_PMCSETUP(mmcr0, SPRN_MMCR0);
187 SYSFS_PMCSETUP(mmcr1, SPRN_MMCR1);
188 SYSFS_PMCSETUP(pmc1, SPRN_PMC1);
189 SYSFS_PMCSETUP(pmc2, SPRN_PMC2);
190 SYSFS_PMCSETUP(pmc3, SPRN_PMC3);
191 SYSFS_PMCSETUP(pmc4, SPRN_PMC4);
192 SYSFS_PMCSETUP(pmc5, SPRN_PMC5);
193 SYSFS_PMCSETUP(pmc6, SPRN_PMC6);
194 
195 #ifdef HAS_PPC_PMC_G4
196 SYSFS_PMCSETUP(mmcr2, SPRN_MMCR2);
197 #endif
198 
199 #ifdef CONFIG_PPC64
200 SYSFS_PMCSETUP(pmc7, SPRN_PMC7);
201 SYSFS_PMCSETUP(pmc8, SPRN_PMC8);
202 
203 SYSFS_PMCSETUP(mmcra, SPRN_MMCRA);
204 SYSFS_PMCSETUP(purr, SPRN_PURR);
205 SYSFS_PMCSETUP(spurr, SPRN_SPURR);
206 SYSFS_PMCSETUP(dscr, SPRN_DSCR);
207 
208 static SYSDEV_ATTR(mmcra, 0600, show_mmcra, store_mmcra);
209 static SYSDEV_ATTR(spurr, 0600, show_spurr, NULL);
210 static SYSDEV_ATTR(dscr, 0600, show_dscr, store_dscr);
211 static SYSDEV_ATTR(purr, 0600, show_purr, store_purr);
212 #endif /* CONFIG_PPC64 */
213 
214 #ifdef HAS_PPC_PMC_PA6T
215 SYSFS_PMCSETUP(pa6t_pmc0, SPRN_PA6T_PMC0);
216 SYSFS_PMCSETUP(pa6t_pmc1, SPRN_PA6T_PMC1);
217 SYSFS_PMCSETUP(pa6t_pmc2, SPRN_PA6T_PMC2);
218 SYSFS_PMCSETUP(pa6t_pmc3, SPRN_PA6T_PMC3);
219 SYSFS_PMCSETUP(pa6t_pmc4, SPRN_PA6T_PMC4);
220 SYSFS_PMCSETUP(pa6t_pmc5, SPRN_PA6T_PMC5);
221 #ifdef CONFIG_DEBUG_KERNEL
222 SYSFS_PMCSETUP(hid0, SPRN_HID0);
223 SYSFS_PMCSETUP(hid1, SPRN_HID1);
224 SYSFS_PMCSETUP(hid4, SPRN_HID4);
225 SYSFS_PMCSETUP(hid5, SPRN_HID5);
226 SYSFS_PMCSETUP(ima0, SPRN_PA6T_IMA0);
227 SYSFS_PMCSETUP(ima1, SPRN_PA6T_IMA1);
228 SYSFS_PMCSETUP(ima2, SPRN_PA6T_IMA2);
229 SYSFS_PMCSETUP(ima3, SPRN_PA6T_IMA3);
230 SYSFS_PMCSETUP(ima4, SPRN_PA6T_IMA4);
231 SYSFS_PMCSETUP(ima5, SPRN_PA6T_IMA5);
232 SYSFS_PMCSETUP(ima6, SPRN_PA6T_IMA6);
233 SYSFS_PMCSETUP(ima7, SPRN_PA6T_IMA7);
234 SYSFS_PMCSETUP(ima8, SPRN_PA6T_IMA8);
235 SYSFS_PMCSETUP(ima9, SPRN_PA6T_IMA9);
236 SYSFS_PMCSETUP(imaat, SPRN_PA6T_IMAAT);
237 SYSFS_PMCSETUP(btcr, SPRN_PA6T_BTCR);
238 SYSFS_PMCSETUP(pccr, SPRN_PA6T_PCCR);
239 SYSFS_PMCSETUP(rpccr, SPRN_PA6T_RPCCR);
240 SYSFS_PMCSETUP(der, SPRN_PA6T_DER);
241 SYSFS_PMCSETUP(mer, SPRN_PA6T_MER);
242 SYSFS_PMCSETUP(ber, SPRN_PA6T_BER);
243 SYSFS_PMCSETUP(ier, SPRN_PA6T_IER);
244 SYSFS_PMCSETUP(sier, SPRN_PA6T_SIER);
245 SYSFS_PMCSETUP(siar, SPRN_PA6T_SIAR);
246 SYSFS_PMCSETUP(tsr0, SPRN_PA6T_TSR0);
247 SYSFS_PMCSETUP(tsr1, SPRN_PA6T_TSR1);
248 SYSFS_PMCSETUP(tsr2, SPRN_PA6T_TSR2);
249 SYSFS_PMCSETUP(tsr3, SPRN_PA6T_TSR3);
250 #endif /* CONFIG_DEBUG_KERNEL */
251 #endif /* HAS_PPC_PMC_PA6T */
252 
253 #ifdef HAS_PPC_PMC_IBM
254 static struct sysdev_attribute ibm_common_attrs[] = {
255 	_SYSDEV_ATTR(mmcr0, 0600, show_mmcr0, store_mmcr0),
256 	_SYSDEV_ATTR(mmcr1, 0600, show_mmcr1, store_mmcr1),
257 };
258 #endif /* HAS_PPC_PMC_G4 */
259 
260 #ifdef HAS_PPC_PMC_G4
261 static struct sysdev_attribute g4_common_attrs[] = {
262 	_SYSDEV_ATTR(mmcr0, 0600, show_mmcr0, store_mmcr0),
263 	_SYSDEV_ATTR(mmcr1, 0600, show_mmcr1, store_mmcr1),
264 	_SYSDEV_ATTR(mmcr2, 0600, show_mmcr2, store_mmcr2),
265 };
266 #endif /* HAS_PPC_PMC_G4 */
267 
268 static struct sysdev_attribute classic_pmc_attrs[] = {
269 	_SYSDEV_ATTR(pmc1, 0600, show_pmc1, store_pmc1),
270 	_SYSDEV_ATTR(pmc2, 0600, show_pmc2, store_pmc2),
271 	_SYSDEV_ATTR(pmc3, 0600, show_pmc3, store_pmc3),
272 	_SYSDEV_ATTR(pmc4, 0600, show_pmc4, store_pmc4),
273 	_SYSDEV_ATTR(pmc5, 0600, show_pmc5, store_pmc5),
274 	_SYSDEV_ATTR(pmc6, 0600, show_pmc6, store_pmc6),
275 #ifdef CONFIG_PPC64
276 	_SYSDEV_ATTR(pmc7, 0600, show_pmc7, store_pmc7),
277 	_SYSDEV_ATTR(pmc8, 0600, show_pmc8, store_pmc8),
278 #endif
279 };
280 
281 #ifdef HAS_PPC_PMC_PA6T
282 static struct sysdev_attribute pa6t_attrs[] = {
283 	_SYSDEV_ATTR(mmcr0, 0600, show_mmcr0, store_mmcr0),
284 	_SYSDEV_ATTR(mmcr1, 0600, show_mmcr1, store_mmcr1),
285 	_SYSDEV_ATTR(pmc0, 0600, show_pa6t_pmc0, store_pa6t_pmc0),
286 	_SYSDEV_ATTR(pmc1, 0600, show_pa6t_pmc1, store_pa6t_pmc1),
287 	_SYSDEV_ATTR(pmc2, 0600, show_pa6t_pmc2, store_pa6t_pmc2),
288 	_SYSDEV_ATTR(pmc3, 0600, show_pa6t_pmc3, store_pa6t_pmc3),
289 	_SYSDEV_ATTR(pmc4, 0600, show_pa6t_pmc4, store_pa6t_pmc4),
290 	_SYSDEV_ATTR(pmc5, 0600, show_pa6t_pmc5, store_pa6t_pmc5),
291 #ifdef CONFIG_DEBUG_KERNEL
292 	_SYSDEV_ATTR(hid0, 0600, show_hid0, store_hid0),
293 	_SYSDEV_ATTR(hid1, 0600, show_hid1, store_hid1),
294 	_SYSDEV_ATTR(hid4, 0600, show_hid4, store_hid4),
295 	_SYSDEV_ATTR(hid5, 0600, show_hid5, store_hid5),
296 	_SYSDEV_ATTR(ima0, 0600, show_ima0, store_ima0),
297 	_SYSDEV_ATTR(ima1, 0600, show_ima1, store_ima1),
298 	_SYSDEV_ATTR(ima2, 0600, show_ima2, store_ima2),
299 	_SYSDEV_ATTR(ima3, 0600, show_ima3, store_ima3),
300 	_SYSDEV_ATTR(ima4, 0600, show_ima4, store_ima4),
301 	_SYSDEV_ATTR(ima5, 0600, show_ima5, store_ima5),
302 	_SYSDEV_ATTR(ima6, 0600, show_ima6, store_ima6),
303 	_SYSDEV_ATTR(ima7, 0600, show_ima7, store_ima7),
304 	_SYSDEV_ATTR(ima8, 0600, show_ima8, store_ima8),
305 	_SYSDEV_ATTR(ima9, 0600, show_ima9, store_ima9),
306 	_SYSDEV_ATTR(imaat, 0600, show_imaat, store_imaat),
307 	_SYSDEV_ATTR(btcr, 0600, show_btcr, store_btcr),
308 	_SYSDEV_ATTR(pccr, 0600, show_pccr, store_pccr),
309 	_SYSDEV_ATTR(rpccr, 0600, show_rpccr, store_rpccr),
310 	_SYSDEV_ATTR(der, 0600, show_der, store_der),
311 	_SYSDEV_ATTR(mer, 0600, show_mer, store_mer),
312 	_SYSDEV_ATTR(ber, 0600, show_ber, store_ber),
313 	_SYSDEV_ATTR(ier, 0600, show_ier, store_ier),
314 	_SYSDEV_ATTR(sier, 0600, show_sier, store_sier),
315 	_SYSDEV_ATTR(siar, 0600, show_siar, store_siar),
316 	_SYSDEV_ATTR(tsr0, 0600, show_tsr0, store_tsr0),
317 	_SYSDEV_ATTR(tsr1, 0600, show_tsr1, store_tsr1),
318 	_SYSDEV_ATTR(tsr2, 0600, show_tsr2, store_tsr2),
319 	_SYSDEV_ATTR(tsr3, 0600, show_tsr3, store_tsr3),
320 #endif /* CONFIG_DEBUG_KERNEL */
321 };
322 #endif /* HAS_PPC_PMC_PA6T */
323 #endif /* HAS_PPC_PMC_CLASSIC */
324 
325 static void __cpuinit register_cpu_online(unsigned int cpu)
326 {
327 	struct cpu *c = &per_cpu(cpu_devices, cpu);
328 	struct sys_device *s = &c->sysdev;
329 	struct sysdev_attribute *attrs, *pmc_attrs;
330 	int i, nattrs;
331 
332 #ifdef CONFIG_PPC64
333 	if (!firmware_has_feature(FW_FEATURE_ISERIES) &&
334 			cpu_has_feature(CPU_FTR_SMT))
335 		sysdev_create_file(s, &attr_smt_snooze_delay);
336 #endif
337 
338 	/* PMC stuff */
339 	switch (cur_cpu_spec->pmc_type) {
340 #ifdef HAS_PPC_PMC_IBM
341 	case PPC_PMC_IBM:
342 		attrs = ibm_common_attrs;
343 		nattrs = sizeof(ibm_common_attrs) / sizeof(struct sysdev_attribute);
344 		pmc_attrs = classic_pmc_attrs;
345 		break;
346 #endif /* HAS_PPC_PMC_IBM */
347 #ifdef HAS_PPC_PMC_G4
348 	case PPC_PMC_G4:
349 		attrs = g4_common_attrs;
350 		nattrs = sizeof(g4_common_attrs) / sizeof(struct sysdev_attribute);
351 		pmc_attrs = classic_pmc_attrs;
352 		break;
353 #endif /* HAS_PPC_PMC_G4 */
354 #ifdef HAS_PPC_PMC_PA6T
355 	case PPC_PMC_PA6T:
356 		/* PA Semi starts counting at PMC0 */
357 		attrs = pa6t_attrs;
358 		nattrs = sizeof(pa6t_attrs) / sizeof(struct sysdev_attribute);
359 		pmc_attrs = NULL;
360 		break;
361 #endif /* HAS_PPC_PMC_PA6T */
362 	default:
363 		attrs = NULL;
364 		nattrs = 0;
365 		pmc_attrs = NULL;
366 	}
367 
368 	for (i = 0; i < nattrs; i++)
369 		sysdev_create_file(s, &attrs[i]);
370 
371 	if (pmc_attrs)
372 		for (i = 0; i < cur_cpu_spec->num_pmcs; i++)
373 			sysdev_create_file(s, &pmc_attrs[i]);
374 
375 #ifdef CONFIG_PPC64
376 	if (cpu_has_feature(CPU_FTR_MMCRA))
377 		sysdev_create_file(s, &attr_mmcra);
378 
379 	if (cpu_has_feature(CPU_FTR_PURR))
380 		sysdev_create_file(s, &attr_purr);
381 
382 	if (cpu_has_feature(CPU_FTR_SPURR))
383 		sysdev_create_file(s, &attr_spurr);
384 
385 	if (cpu_has_feature(CPU_FTR_DSCR))
386 		sysdev_create_file(s, &attr_dscr);
387 #endif /* CONFIG_PPC64 */
388 
389 	cacheinfo_cpu_online(cpu);
390 }
391 
392 #ifdef CONFIG_HOTPLUG_CPU
393 static void unregister_cpu_online(unsigned int cpu)
394 {
395 	struct cpu *c = &per_cpu(cpu_devices, cpu);
396 	struct sys_device *s = &c->sysdev;
397 	struct sysdev_attribute *attrs, *pmc_attrs;
398 	int i, nattrs;
399 
400 	BUG_ON(!c->hotpluggable);
401 
402 #ifdef CONFIG_PPC64
403 	if (!firmware_has_feature(FW_FEATURE_ISERIES) &&
404 			cpu_has_feature(CPU_FTR_SMT))
405 		sysdev_remove_file(s, &attr_smt_snooze_delay);
406 #endif
407 
408 	/* PMC stuff */
409 	switch (cur_cpu_spec->pmc_type) {
410 #ifdef HAS_PPC_PMC_IBM
411 	case PPC_PMC_IBM:
412 		attrs = ibm_common_attrs;
413 		nattrs = sizeof(ibm_common_attrs) / sizeof(struct sysdev_attribute);
414 		pmc_attrs = classic_pmc_attrs;
415 		break;
416 #endif /* HAS_PPC_PMC_IBM */
417 #ifdef HAS_PPC_PMC_G4
418 	case PPC_PMC_G4:
419 		attrs = g4_common_attrs;
420 		nattrs = sizeof(g4_common_attrs) / sizeof(struct sysdev_attribute);
421 		pmc_attrs = classic_pmc_attrs;
422 		break;
423 #endif /* HAS_PPC_PMC_G4 */
424 #ifdef HAS_PPC_PMC_PA6T
425 	case PPC_PMC_PA6T:
426 		/* PA Semi starts counting at PMC0 */
427 		attrs = pa6t_attrs;
428 		nattrs = sizeof(pa6t_attrs) / sizeof(struct sysdev_attribute);
429 		pmc_attrs = NULL;
430 		break;
431 #endif /* HAS_PPC_PMC_PA6T */
432 	default:
433 		attrs = NULL;
434 		nattrs = 0;
435 		pmc_attrs = NULL;
436 	}
437 
438 	for (i = 0; i < nattrs; i++)
439 		sysdev_remove_file(s, &attrs[i]);
440 
441 	if (pmc_attrs)
442 		for (i = 0; i < cur_cpu_spec->num_pmcs; i++)
443 			sysdev_remove_file(s, &pmc_attrs[i]);
444 
445 #ifdef CONFIG_PPC64
446 	if (cpu_has_feature(CPU_FTR_MMCRA))
447 		sysdev_remove_file(s, &attr_mmcra);
448 
449 	if (cpu_has_feature(CPU_FTR_PURR))
450 		sysdev_remove_file(s, &attr_purr);
451 
452 	if (cpu_has_feature(CPU_FTR_SPURR))
453 		sysdev_remove_file(s, &attr_spurr);
454 
455 	if (cpu_has_feature(CPU_FTR_DSCR))
456 		sysdev_remove_file(s, &attr_dscr);
457 #endif /* CONFIG_PPC64 */
458 
459 	cacheinfo_cpu_offline(cpu);
460 }
461 #endif /* CONFIG_HOTPLUG_CPU */
462 
463 static int __cpuinit sysfs_cpu_notify(struct notifier_block *self,
464 				      unsigned long action, void *hcpu)
465 {
466 	unsigned int cpu = (unsigned int)(long)hcpu;
467 
468 	switch (action) {
469 	case CPU_ONLINE:
470 	case CPU_ONLINE_FROZEN:
471 		register_cpu_online(cpu);
472 		break;
473 #ifdef CONFIG_HOTPLUG_CPU
474 	case CPU_DEAD:
475 	case CPU_DEAD_FROZEN:
476 		unregister_cpu_online(cpu);
477 		break;
478 #endif
479 	}
480 	return NOTIFY_OK;
481 }
482 
483 static struct notifier_block __cpuinitdata sysfs_cpu_nb = {
484 	.notifier_call	= sysfs_cpu_notify,
485 };
486 
487 static DEFINE_MUTEX(cpu_mutex);
488 
489 int cpu_add_sysdev_attr(struct sysdev_attribute *attr)
490 {
491 	int cpu;
492 
493 	mutex_lock(&cpu_mutex);
494 
495 	for_each_possible_cpu(cpu) {
496 		sysdev_create_file(get_cpu_sysdev(cpu), attr);
497 	}
498 
499 	mutex_unlock(&cpu_mutex);
500 	return 0;
501 }
502 EXPORT_SYMBOL_GPL(cpu_add_sysdev_attr);
503 
504 int cpu_add_sysdev_attr_group(struct attribute_group *attrs)
505 {
506 	int cpu;
507 	struct sys_device *sysdev;
508 	int ret;
509 
510 	mutex_lock(&cpu_mutex);
511 
512 	for_each_possible_cpu(cpu) {
513 		sysdev = get_cpu_sysdev(cpu);
514 		ret = sysfs_create_group(&sysdev->kobj, attrs);
515 		WARN_ON(ret != 0);
516 	}
517 
518 	mutex_unlock(&cpu_mutex);
519 	return 0;
520 }
521 EXPORT_SYMBOL_GPL(cpu_add_sysdev_attr_group);
522 
523 
524 void cpu_remove_sysdev_attr(struct sysdev_attribute *attr)
525 {
526 	int cpu;
527 
528 	mutex_lock(&cpu_mutex);
529 
530 	for_each_possible_cpu(cpu) {
531 		sysdev_remove_file(get_cpu_sysdev(cpu), attr);
532 	}
533 
534 	mutex_unlock(&cpu_mutex);
535 }
536 EXPORT_SYMBOL_GPL(cpu_remove_sysdev_attr);
537 
538 void cpu_remove_sysdev_attr_group(struct attribute_group *attrs)
539 {
540 	int cpu;
541 	struct sys_device *sysdev;
542 
543 	mutex_lock(&cpu_mutex);
544 
545 	for_each_possible_cpu(cpu) {
546 		sysdev = get_cpu_sysdev(cpu);
547 		sysfs_remove_group(&sysdev->kobj, attrs);
548 	}
549 
550 	mutex_unlock(&cpu_mutex);
551 }
552 EXPORT_SYMBOL_GPL(cpu_remove_sysdev_attr_group);
553 
554 
555 /* NUMA stuff */
556 
557 #ifdef CONFIG_NUMA
558 static void register_nodes(void)
559 {
560 	int i;
561 
562 	for (i = 0; i < MAX_NUMNODES; i++)
563 		register_one_node(i);
564 }
565 
566 int sysfs_add_device_to_node(struct sys_device *dev, int nid)
567 {
568 	struct node *node = &node_devices[nid];
569 	return sysfs_create_link(&node->sysdev.kobj, &dev->kobj,
570 			kobject_name(&dev->kobj));
571 }
572 EXPORT_SYMBOL_GPL(sysfs_add_device_to_node);
573 
574 void sysfs_remove_device_from_node(struct sys_device *dev, int nid)
575 {
576 	struct node *node = &node_devices[nid];
577 	sysfs_remove_link(&node->sysdev.kobj, kobject_name(&dev->kobj));
578 }
579 EXPORT_SYMBOL_GPL(sysfs_remove_device_from_node);
580 
581 #else
582 static void register_nodes(void)
583 {
584 	return;
585 }
586 
587 #endif
588 
589 /* Only valid if CPU is present. */
590 static ssize_t show_physical_id(struct sys_device *dev,
591 				struct sysdev_attribute *attr, char *buf)
592 {
593 	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
594 
595 	return sprintf(buf, "%d\n", get_hard_smp_processor_id(cpu->sysdev.id));
596 }
597 static SYSDEV_ATTR(physical_id, 0444, show_physical_id, NULL);
598 
599 static int __init topology_init(void)
600 {
601 	int cpu;
602 
603 	register_nodes();
604 	register_cpu_notifier(&sysfs_cpu_nb);
605 
606 	for_each_possible_cpu(cpu) {
607 		struct cpu *c = &per_cpu(cpu_devices, cpu);
608 
609 		/*
610 		 * For now, we just see if the system supports making
611 		 * the RTAS calls for CPU hotplug.  But, there may be a
612 		 * more comprehensive way to do this for an individual
613 		 * CPU.  For instance, the boot cpu might never be valid
614 		 * for hotplugging.
615 		 */
616 		if (ppc_md.cpu_die)
617 			c->hotpluggable = 1;
618 
619 		if (cpu_online(cpu) || c->hotpluggable) {
620 			register_cpu(c, cpu);
621 
622 			sysdev_create_file(&c->sysdev, &attr_physical_id);
623 		}
624 
625 		if (cpu_online(cpu))
626 			register_cpu_online(cpu);
627 	}
628 
629 	return 0;
630 }
631 subsys_initcall(topology_init);
632