sysfs.c 14 KB

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