xref: /linux/drivers/pci/hotplug/pci_hotplug_core.c (revision 2b8232ce512105e28453f301d1510de8363bccd1)
1 /*
2  * PCI HotPlug Controller Core
3  *
4  * Copyright (C) 2001-2002 Greg Kroah-Hartman (greg@kroah.com)
5  * Copyright (C) 2001-2002 IBM Corp.
6  *
7  * All rights reserved.
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or (at
12  * your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
17  * NON INFRINGEMENT.  See the GNU General Public License for more
18  * details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23  *
24  * Send feedback to <kristen.c.accardi@intel.com>
25  *
26  */
27 
28 #include <linux/module.h>
29 #include <linux/moduleparam.h>
30 #include <linux/kernel.h>
31 #include <linux/types.h>
32 #include <linux/list.h>
33 #include <linux/kobject.h>
34 #include <linux/sysfs.h>
35 #include <linux/pagemap.h>
36 #include <linux/slab.h>
37 #include <linux/init.h>
38 #include <linux/mount.h>
39 #include <linux/namei.h>
40 #include <linux/pci.h>
41 #include <linux/pci_hotplug.h>
42 #include <asm/uaccess.h>
43 
44 #define MY_NAME	"pci_hotplug"
45 
46 #define dbg(fmt, arg...) do { if (debug) printk(KERN_DEBUG "%s: %s: " fmt , MY_NAME , __FUNCTION__ , ## arg); } while (0)
47 #define err(format, arg...) printk(KERN_ERR "%s: " format , MY_NAME , ## arg)
48 #define info(format, arg...) printk(KERN_INFO "%s: " format , MY_NAME , ## arg)
49 #define warn(format, arg...) printk(KERN_WARNING "%s: " format , MY_NAME , ## arg)
50 
51 
52 /* local variables */
53 static int debug;
54 
55 #define DRIVER_VERSION	"0.5"
56 #define DRIVER_AUTHOR	"Greg Kroah-Hartman <greg@kroah.com>, Scott Murray <scottm@somanetworks.com>"
57 #define DRIVER_DESC	"PCI Hot Plug PCI Core"
58 
59 
60 //////////////////////////////////////////////////////////////////
61 
62 static LIST_HEAD(pci_hotplug_slot_list);
63 
64 struct kset pci_hotplug_slots_subsys;
65 
66 static ssize_t hotplug_slot_attr_show(struct kobject *kobj,
67 		struct attribute *attr, char *buf)
68 {
69 	struct hotplug_slot *slot = to_hotplug_slot(kobj);
70 	struct hotplug_slot_attribute *attribute = to_hotplug_attr(attr);
71 	return attribute->show ? attribute->show(slot, buf) : -EIO;
72 }
73 
74 static ssize_t hotplug_slot_attr_store(struct kobject *kobj,
75 		struct attribute *attr, const char *buf, size_t len)
76 {
77 	struct hotplug_slot *slot = to_hotplug_slot(kobj);
78 	struct hotplug_slot_attribute *attribute = to_hotplug_attr(attr);
79 	return attribute->store ? attribute->store(slot, buf, len) : -EIO;
80 }
81 
82 static struct sysfs_ops hotplug_slot_sysfs_ops = {
83 	.show = hotplug_slot_attr_show,
84 	.store = hotplug_slot_attr_store,
85 };
86 
87 static void hotplug_slot_release(struct kobject *kobj)
88 {
89 	struct hotplug_slot *slot = to_hotplug_slot(kobj);
90 	if (slot->release)
91 		slot->release(slot);
92 }
93 
94 static struct kobj_type hotplug_slot_ktype = {
95 	.sysfs_ops = &hotplug_slot_sysfs_ops,
96 	.release = &hotplug_slot_release,
97 };
98 
99 decl_subsys_name(pci_hotplug_slots, slots, &hotplug_slot_ktype, NULL);
100 
101 /* these strings match up with the values in pci_bus_speed */
102 static char *pci_bus_speed_strings[] = {
103 	"33 MHz PCI",		/* 0x00 */
104 	"66 MHz PCI",		/* 0x01 */
105 	"66 MHz PCIX", 		/* 0x02 */
106 	"100 MHz PCIX",		/* 0x03 */
107 	"133 MHz PCIX",		/* 0x04 */
108 	NULL,			/* 0x05 */
109 	NULL,			/* 0x06 */
110 	NULL,			/* 0x07 */
111 	NULL,			/* 0x08 */
112 	"66 MHz PCIX 266",	/* 0x09 */
113 	"100 MHz PCIX 266",	/* 0x0a */
114 	"133 MHz PCIX 266",	/* 0x0b */
115 	NULL,			/* 0x0c */
116 	NULL,			/* 0x0d */
117 	NULL,			/* 0x0e */
118 	NULL,			/* 0x0f */
119 	NULL,			/* 0x10 */
120 	"66 MHz PCIX 533",	/* 0x11 */
121 	"100 MHz PCIX 533",	/* 0x12 */
122 	"133 MHz PCIX 533",	/* 0x13 */
123 	"25 GBps PCI-E",	/* 0x14 */
124 };
125 
126 #ifdef CONFIG_HOTPLUG_PCI_CPCI
127 extern int cpci_hotplug_init(int debug);
128 extern void cpci_hotplug_exit(void);
129 #else
130 static inline int cpci_hotplug_init(int debug) { return 0; }
131 static inline void cpci_hotplug_exit(void) { }
132 #endif
133 
134 /* Weee, fun with macros... */
135 #define GET_STATUS(name,type)	\
136 static int get_##name (struct hotplug_slot *slot, type *value)		\
137 {									\
138 	struct hotplug_slot_ops *ops = slot->ops;			\
139 	int retval = 0;							\
140 	if (try_module_get(ops->owner)) {				\
141 		if (ops->get_##name)					\
142 			retval = ops->get_##name (slot, value);		\
143 		else							\
144 			*value = slot->info->name;			\
145 		module_put(ops->owner);					\
146 	}								\
147 	return retval;							\
148 }
149 
150 GET_STATUS(power_status, u8)
151 GET_STATUS(attention_status, u8)
152 GET_STATUS(latch_status, u8)
153 GET_STATUS(adapter_status, u8)
154 GET_STATUS(address, u32)
155 GET_STATUS(max_bus_speed, enum pci_bus_speed)
156 GET_STATUS(cur_bus_speed, enum pci_bus_speed)
157 
158 static ssize_t power_read_file (struct hotplug_slot *slot, char *buf)
159 {
160 	int retval;
161 	u8 value;
162 
163 	retval = get_power_status (slot, &value);
164 	if (retval)
165 		goto exit;
166 	retval = sprintf (buf, "%d\n", value);
167 exit:
168 	return retval;
169 }
170 
171 static ssize_t power_write_file (struct hotplug_slot *slot, const char *buf,
172 		size_t count)
173 {
174 	unsigned long lpower;
175 	u8 power;
176 	int retval = 0;
177 
178 	lpower = simple_strtoul (buf, NULL, 10);
179 	power = (u8)(lpower & 0xff);
180 	dbg ("power = %d\n", power);
181 
182 	if (!try_module_get(slot->ops->owner)) {
183 		retval = -ENODEV;
184 		goto exit;
185 	}
186 	switch (power) {
187 		case 0:
188 			if (slot->ops->disable_slot)
189 				retval = slot->ops->disable_slot(slot);
190 			break;
191 
192 		case 1:
193 			if (slot->ops->enable_slot)
194 				retval = slot->ops->enable_slot(slot);
195 			break;
196 
197 		default:
198 			err ("Illegal value specified for power\n");
199 			retval = -EINVAL;
200 	}
201 	module_put(slot->ops->owner);
202 
203 exit:
204 	if (retval)
205 		return retval;
206 	return count;
207 }
208 
209 static struct hotplug_slot_attribute hotplug_slot_attr_power = {
210 	.attr = {.name = "power", .mode = S_IFREG | S_IRUGO | S_IWUSR},
211 	.show = power_read_file,
212 	.store = power_write_file
213 };
214 
215 static ssize_t attention_read_file (struct hotplug_slot *slot, char *buf)
216 {
217 	int retval;
218 	u8 value;
219 
220 	retval = get_attention_status (slot, &value);
221 	if (retval)
222 		goto exit;
223 	retval = sprintf (buf, "%d\n", value);
224 
225 exit:
226 	return retval;
227 }
228 
229 static ssize_t attention_write_file (struct hotplug_slot *slot, const char *buf,
230 		size_t count)
231 {
232 	unsigned long lattention;
233 	u8 attention;
234 	int retval = 0;
235 
236 	lattention = simple_strtoul (buf, NULL, 10);
237 	attention = (u8)(lattention & 0xff);
238 	dbg (" - attention = %d\n", attention);
239 
240 	if (!try_module_get(slot->ops->owner)) {
241 		retval = -ENODEV;
242 		goto exit;
243 	}
244 	if (slot->ops->set_attention_status)
245 		retval = slot->ops->set_attention_status(slot, attention);
246 	module_put(slot->ops->owner);
247 
248 exit:
249 	if (retval)
250 		return retval;
251 	return count;
252 }
253 
254 static struct hotplug_slot_attribute hotplug_slot_attr_attention = {
255 	.attr = {.name = "attention", .mode = S_IFREG | S_IRUGO | S_IWUSR},
256 	.show = attention_read_file,
257 	.store = attention_write_file
258 };
259 
260 static ssize_t latch_read_file (struct hotplug_slot *slot, char *buf)
261 {
262 	int retval;
263 	u8 value;
264 
265 	retval = get_latch_status (slot, &value);
266 	if (retval)
267 		goto exit;
268 	retval = sprintf (buf, "%d\n", value);
269 
270 exit:
271 	return retval;
272 }
273 
274 static struct hotplug_slot_attribute hotplug_slot_attr_latch = {
275 	.attr = {.name = "latch", .mode = S_IFREG | S_IRUGO},
276 	.show = latch_read_file,
277 };
278 
279 static ssize_t presence_read_file (struct hotplug_slot *slot, char *buf)
280 {
281 	int retval;
282 	u8 value;
283 
284 	retval = get_adapter_status (slot, &value);
285 	if (retval)
286 		goto exit;
287 	retval = sprintf (buf, "%d\n", value);
288 
289 exit:
290 	return retval;
291 }
292 
293 static struct hotplug_slot_attribute hotplug_slot_attr_presence = {
294 	.attr = {.name = "adapter", .mode = S_IFREG | S_IRUGO},
295 	.show = presence_read_file,
296 };
297 
298 static ssize_t address_read_file (struct hotplug_slot *slot, char *buf)
299 {
300 	int retval;
301 	u32 address;
302 
303 	retval = get_address (slot, &address);
304 	if (retval)
305 		goto exit;
306 	retval = sprintf (buf, "%04x:%02x:%02x\n",
307 			  (address >> 16) & 0xffff,
308 			  (address >> 8) & 0xff,
309 			  address & 0xff);
310 
311 exit:
312 	return retval;
313 }
314 
315 static struct hotplug_slot_attribute hotplug_slot_attr_address = {
316 	.attr = {.name = "address", .mode = S_IFREG | S_IRUGO},
317 	.show = address_read_file,
318 };
319 
320 static char *unknown_speed = "Unknown bus speed";
321 
322 static ssize_t max_bus_speed_read_file (struct hotplug_slot *slot, char *buf)
323 {
324 	char *speed_string;
325 	int retval;
326 	enum pci_bus_speed value;
327 
328 	retval = get_max_bus_speed (slot, &value);
329 	if (retval)
330 		goto exit;
331 
332 	if (value == PCI_SPEED_UNKNOWN)
333 		speed_string = unknown_speed;
334 	else
335 		speed_string = pci_bus_speed_strings[value];
336 
337 	retval = sprintf (buf, "%s\n", speed_string);
338 
339 exit:
340 	return retval;
341 }
342 
343 static struct hotplug_slot_attribute hotplug_slot_attr_max_bus_speed = {
344 	.attr = {.name = "max_bus_speed", .mode = S_IFREG | S_IRUGO},
345 	.show = max_bus_speed_read_file,
346 };
347 
348 static ssize_t cur_bus_speed_read_file (struct hotplug_slot *slot, char *buf)
349 {
350 	char *speed_string;
351 	int retval;
352 	enum pci_bus_speed value;
353 
354 	retval = get_cur_bus_speed (slot, &value);
355 	if (retval)
356 		goto exit;
357 
358 	if (value == PCI_SPEED_UNKNOWN)
359 		speed_string = unknown_speed;
360 	else
361 		speed_string = pci_bus_speed_strings[value];
362 
363 	retval = sprintf (buf, "%s\n", speed_string);
364 
365 exit:
366 	return retval;
367 }
368 
369 static struct hotplug_slot_attribute hotplug_slot_attr_cur_bus_speed = {
370 	.attr = {.name = "cur_bus_speed", .mode = S_IFREG | S_IRUGO},
371 	.show = cur_bus_speed_read_file,
372 };
373 
374 static ssize_t test_write_file (struct hotplug_slot *slot, const char *buf,
375 		size_t count)
376 {
377 	unsigned long ltest;
378 	u32 test;
379 	int retval = 0;
380 
381 	ltest = simple_strtoul (buf, NULL, 10);
382 	test = (u32)(ltest & 0xffffffff);
383 	dbg ("test = %d\n", test);
384 
385 	if (!try_module_get(slot->ops->owner)) {
386 		retval = -ENODEV;
387 		goto exit;
388 	}
389 	if (slot->ops->hardware_test)
390 		retval = slot->ops->hardware_test(slot, test);
391 	module_put(slot->ops->owner);
392 
393 exit:
394 	if (retval)
395 		return retval;
396 	return count;
397 }
398 
399 static struct hotplug_slot_attribute hotplug_slot_attr_test = {
400 	.attr = {.name = "test", .mode = S_IFREG | S_IRUGO | S_IWUSR},
401 	.store = test_write_file
402 };
403 
404 static int has_power_file (struct hotplug_slot *slot)
405 {
406 	if ((!slot) || (!slot->ops))
407 		return -ENODEV;
408 	if ((slot->ops->enable_slot) ||
409 	    (slot->ops->disable_slot) ||
410 	    (slot->ops->get_power_status))
411 		return 0;
412 	return -ENOENT;
413 }
414 
415 static int has_attention_file (struct hotplug_slot *slot)
416 {
417 	if ((!slot) || (!slot->ops))
418 		return -ENODEV;
419 	if ((slot->ops->set_attention_status) ||
420 	    (slot->ops->get_attention_status))
421 		return 0;
422 	return -ENOENT;
423 }
424 
425 static int has_latch_file (struct hotplug_slot *slot)
426 {
427 	if ((!slot) || (!slot->ops))
428 		return -ENODEV;
429 	if (slot->ops->get_latch_status)
430 		return 0;
431 	return -ENOENT;
432 }
433 
434 static int has_adapter_file (struct hotplug_slot *slot)
435 {
436 	if ((!slot) || (!slot->ops))
437 		return -ENODEV;
438 	if (slot->ops->get_adapter_status)
439 		return 0;
440 	return -ENOENT;
441 }
442 
443 static int has_address_file (struct hotplug_slot *slot)
444 {
445 	if ((!slot) || (!slot->ops))
446 		return -ENODEV;
447 	if (slot->ops->get_address)
448 		return 0;
449 	return -ENOENT;
450 }
451 
452 static int has_max_bus_speed_file (struct hotplug_slot *slot)
453 {
454 	if ((!slot) || (!slot->ops))
455 		return -ENODEV;
456 	if (slot->ops->get_max_bus_speed)
457 		return 0;
458 	return -ENOENT;
459 }
460 
461 static int has_cur_bus_speed_file (struct hotplug_slot *slot)
462 {
463 	if ((!slot) || (!slot->ops))
464 		return -ENODEV;
465 	if (slot->ops->get_cur_bus_speed)
466 		return 0;
467 	return -ENOENT;
468 }
469 
470 static int has_test_file (struct hotplug_slot *slot)
471 {
472 	if ((!slot) || (!slot->ops))
473 		return -ENODEV;
474 	if (slot->ops->hardware_test)
475 		return 0;
476 	return -ENOENT;
477 }
478 
479 static int fs_add_slot (struct hotplug_slot *slot)
480 {
481 	int retval = 0;
482 
483 	if (has_power_file(slot) == 0) {
484 		retval = sysfs_create_file(&slot->kobj, &hotplug_slot_attr_power.attr);
485 		if (retval)
486 			goto exit_power;
487 	}
488 
489 	if (has_attention_file(slot) == 0) {
490 		retval = sysfs_create_file(&slot->kobj,
491 					   &hotplug_slot_attr_attention.attr);
492 		if (retval)
493 			goto exit_attention;
494 	}
495 
496 	if (has_latch_file(slot) == 0) {
497 		retval = sysfs_create_file(&slot->kobj,
498 					   &hotplug_slot_attr_latch.attr);
499 		if (retval)
500 			goto exit_latch;
501 	}
502 
503 	if (has_adapter_file(slot) == 0) {
504 		retval = sysfs_create_file(&slot->kobj,
505 					   &hotplug_slot_attr_presence.attr);
506 		if (retval)
507 			goto exit_adapter;
508 	}
509 
510 	if (has_address_file(slot) == 0) {
511 		retval = sysfs_create_file(&slot->kobj,
512 					   &hotplug_slot_attr_address.attr);
513 		if (retval)
514 			goto exit_address;
515 	}
516 
517 	if (has_max_bus_speed_file(slot) == 0) {
518 		retval = sysfs_create_file(&slot->kobj,
519 					   &hotplug_slot_attr_max_bus_speed.attr);
520 		if (retval)
521 			goto exit_max_speed;
522 	}
523 
524 	if (has_cur_bus_speed_file(slot) == 0) {
525 		retval = sysfs_create_file(&slot->kobj,
526 					   &hotplug_slot_attr_cur_bus_speed.attr);
527 		if (retval)
528 			goto exit_cur_speed;
529 	}
530 
531 	if (has_test_file(slot) == 0) {
532 		retval = sysfs_create_file(&slot->kobj,
533 					   &hotplug_slot_attr_test.attr);
534 		if (retval)
535 			goto exit_test;
536 	}
537 
538 	goto exit;
539 
540 exit_test:
541 	if (has_cur_bus_speed_file(slot) == 0)
542 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_cur_bus_speed.attr);
543 
544 exit_cur_speed:
545 	if (has_max_bus_speed_file(slot) == 0)
546 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_max_bus_speed.attr);
547 
548 exit_max_speed:
549 	if (has_address_file(slot) == 0)
550 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_address.attr);
551 
552 exit_address:
553 	if (has_adapter_file(slot) == 0)
554 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_presence.attr);
555 
556 exit_adapter:
557 	if (has_latch_file(slot) == 0)
558 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_latch.attr);
559 
560 exit_latch:
561 	if (has_attention_file(slot) == 0)
562 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_attention.attr);
563 
564 exit_attention:
565 	if (has_power_file(slot) == 0)
566 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_power.attr);
567 exit_power:
568 exit:
569 	return retval;
570 }
571 
572 static void fs_remove_slot (struct hotplug_slot *slot)
573 {
574 	if (has_power_file(slot) == 0)
575 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_power.attr);
576 
577 	if (has_attention_file(slot) == 0)
578 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_attention.attr);
579 
580 	if (has_latch_file(slot) == 0)
581 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_latch.attr);
582 
583 	if (has_adapter_file(slot) == 0)
584 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_presence.attr);
585 
586 	if (has_address_file(slot) == 0)
587 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_address.attr);
588 
589 	if (has_max_bus_speed_file(slot) == 0)
590 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_max_bus_speed.attr);
591 
592 	if (has_cur_bus_speed_file(slot) == 0)
593 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_cur_bus_speed.attr);
594 
595 	if (has_test_file(slot) == 0)
596 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_test.attr);
597 }
598 
599 static struct hotplug_slot *get_slot_from_name (const char *name)
600 {
601 	struct hotplug_slot *slot;
602 	struct list_head *tmp;
603 
604 	list_for_each (tmp, &pci_hotplug_slot_list) {
605 		slot = list_entry (tmp, struct hotplug_slot, slot_list);
606 		if (strcmp(slot->name, name) == 0)
607 			return slot;
608 	}
609 	return NULL;
610 }
611 
612 /**
613  * pci_hp_register - register a hotplug_slot with the PCI hotplug subsystem
614  * @slot: pointer to the &struct hotplug_slot to register
615  *
616  * Registers a hotplug slot with the pci hotplug subsystem, which will allow
617  * userspace interaction to the slot.
618  *
619  * Returns 0 if successful, anything else for an error.
620  */
621 int pci_hp_register (struct hotplug_slot *slot)
622 {
623 	int result;
624 
625 	if (slot == NULL)
626 		return -ENODEV;
627 	if ((slot->info == NULL) || (slot->ops == NULL))
628 		return -EINVAL;
629 	if (slot->release == NULL) {
630 		dbg("Why are you trying to register a hotplug slot"
631 		    "without a proper release function?\n");
632 		return -EINVAL;
633 	}
634 
635 	kobject_set_name(&slot->kobj, "%s", slot->name);
636 	kobj_set_kset_s(slot, pci_hotplug_slots_subsys);
637 
638 	/* this can fail if we have already registered a slot with the same name */
639 	if (kobject_register(&slot->kobj)) {
640 		err("Unable to register kobject");
641 		return -EINVAL;
642 	}
643 
644 	list_add (&slot->slot_list, &pci_hotplug_slot_list);
645 
646 	result = fs_add_slot (slot);
647 	dbg ("Added slot %s to the list\n", slot->name);
648 	return result;
649 }
650 
651 /**
652  * pci_hp_deregister - deregister a hotplug_slot with the PCI hotplug subsystem
653  * @slot: pointer to the &struct hotplug_slot to deregister
654  *
655  * The @slot must have been registered with the pci hotplug subsystem
656  * previously with a call to pci_hp_register().
657  *
658  * Returns 0 if successful, anything else for an error.
659  */
660 int pci_hp_deregister (struct hotplug_slot *slot)
661 {
662 	struct hotplug_slot *temp;
663 
664 	if (slot == NULL)
665 		return -ENODEV;
666 
667 	temp = get_slot_from_name (slot->name);
668 	if (temp != slot) {
669 		return -ENODEV;
670 	}
671 	list_del (&slot->slot_list);
672 
673 	fs_remove_slot (slot);
674 	dbg ("Removed slot %s from the list\n", slot->name);
675 	kobject_unregister(&slot->kobj);
676 	return 0;
677 }
678 
679 /**
680  * pci_hp_change_slot_info - changes the slot's information structure in the core
681  * @slot: pointer to the slot whose info has changed
682  * @info: pointer to the info copy into the slot's info structure
683  *
684  * @slot must have been registered with the pci
685  * hotplug subsystem previously with a call to pci_hp_register().
686  *
687  * Returns 0 if successful, anything else for an error.
688  */
689 int __must_check pci_hp_change_slot_info(struct hotplug_slot *slot,
690 					 struct hotplug_slot_info *info)
691 {
692 	int retval;
693 
694 	if ((slot == NULL) || (info == NULL))
695 		return -ENODEV;
696 
697 	memcpy (slot->info, info, sizeof (struct hotplug_slot_info));
698 
699 	return 0;
700 }
701 
702 static int __init pci_hotplug_init (void)
703 {
704 	int result;
705 
706 	kobj_set_kset_s(&pci_hotplug_slots_subsys, pci_bus_type.subsys);
707 	result = subsystem_register(&pci_hotplug_slots_subsys);
708 	if (result) {
709 		err("Register subsys with error %d\n", result);
710 		goto exit;
711 	}
712 	result = cpci_hotplug_init(debug);
713 	if (result) {
714 		err ("cpci_hotplug_init with error %d\n", result);
715 		goto err_subsys;
716 	}
717 
718 	info (DRIVER_DESC " version: " DRIVER_VERSION "\n");
719 	goto exit;
720 
721 err_subsys:
722 	subsystem_unregister(&pci_hotplug_slots_subsys);
723 exit:
724 	return result;
725 }
726 
727 static void __exit pci_hotplug_exit (void)
728 {
729 	cpci_hotplug_exit();
730 	subsystem_unregister(&pci_hotplug_slots_subsys);
731 }
732 
733 module_init(pci_hotplug_init);
734 module_exit(pci_hotplug_exit);
735 
736 MODULE_AUTHOR(DRIVER_AUTHOR);
737 MODULE_DESCRIPTION(DRIVER_DESC);
738 MODULE_LICENSE("GPL");
739 module_param(debug, bool, 0644);
740 MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
741 
742 EXPORT_SYMBOL_GPL(pci_hotplug_slots_subsys);
743 EXPORT_SYMBOL_GPL(pci_hp_register);
744 EXPORT_SYMBOL_GPL(pci_hp_deregister);
745 EXPORT_SYMBOL_GPL(pci_hp_change_slot_info);
746