xref: /linux/drivers/pci/hotplug/pci_hotplug_core.c (revision 367b8112fe2ea5c39a7bb4d263dcdd9b612fae18)
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/mutex.h>
41 #include <linux/pci.h>
42 #include <linux/pci_hotplug.h>
43 #include <asm/uaccess.h>
44 #include "../pci.h"
45 
46 #define MY_NAME	"pci_hotplug"
47 
48 #define dbg(fmt, arg...) do { if (debug) printk(KERN_DEBUG "%s: %s: " fmt , MY_NAME , __func__ , ## arg); } while (0)
49 #define err(format, arg...) printk(KERN_ERR "%s: " format , MY_NAME , ## arg)
50 #define info(format, arg...) printk(KERN_INFO "%s: " format , MY_NAME , ## arg)
51 #define warn(format, arg...) printk(KERN_WARNING "%s: " format , MY_NAME , ## arg)
52 
53 
54 /* local variables */
55 static int debug;
56 
57 #define DRIVER_VERSION	"0.5"
58 #define DRIVER_AUTHOR	"Greg Kroah-Hartman <greg@kroah.com>, Scott Murray <scottm@somanetworks.com>"
59 #define DRIVER_DESC	"PCI Hot Plug PCI Core"
60 
61 
62 //////////////////////////////////////////////////////////////////
63 
64 static LIST_HEAD(pci_hotplug_slot_list);
65 static DEFINE_MUTEX(pci_hp_mutex);
66 
67 /* these strings match up with the values in pci_bus_speed */
68 static char *pci_bus_speed_strings[] = {
69 	"33 MHz PCI",		/* 0x00 */
70 	"66 MHz PCI",		/* 0x01 */
71 	"66 MHz PCIX", 		/* 0x02 */
72 	"100 MHz PCIX",		/* 0x03 */
73 	"133 MHz PCIX",		/* 0x04 */
74 	NULL,			/* 0x05 */
75 	NULL,			/* 0x06 */
76 	NULL,			/* 0x07 */
77 	NULL,			/* 0x08 */
78 	"66 MHz PCIX 266",	/* 0x09 */
79 	"100 MHz PCIX 266",	/* 0x0a */
80 	"133 MHz PCIX 266",	/* 0x0b */
81 	NULL,			/* 0x0c */
82 	NULL,			/* 0x0d */
83 	NULL,			/* 0x0e */
84 	NULL,			/* 0x0f */
85 	NULL,			/* 0x10 */
86 	"66 MHz PCIX 533",	/* 0x11 */
87 	"100 MHz PCIX 533",	/* 0x12 */
88 	"133 MHz PCIX 533",	/* 0x13 */
89 	"25 GBps PCI-E",	/* 0x14 */
90 };
91 
92 #ifdef CONFIG_HOTPLUG_PCI_CPCI
93 extern int cpci_hotplug_init(int debug);
94 extern void cpci_hotplug_exit(void);
95 #else
96 static inline int cpci_hotplug_init(int debug) { return 0; }
97 static inline void cpci_hotplug_exit(void) { }
98 #endif
99 
100 /* Weee, fun with macros... */
101 #define GET_STATUS(name,type)	\
102 static int get_##name (struct hotplug_slot *slot, type *value)		\
103 {									\
104 	struct hotplug_slot_ops *ops = slot->ops;			\
105 	int retval = 0;							\
106 	if (!try_module_get(ops->owner))				\
107 		return -ENODEV;						\
108 	if (ops->get_##name)						\
109 		retval = ops->get_##name(slot, value);			\
110 	else								\
111 		*value = slot->info->name;				\
112 	module_put(ops->owner);						\
113 	return retval;							\
114 }
115 
116 GET_STATUS(power_status, u8)
117 GET_STATUS(attention_status, u8)
118 GET_STATUS(latch_status, u8)
119 GET_STATUS(adapter_status, u8)
120 GET_STATUS(max_bus_speed, enum pci_bus_speed)
121 GET_STATUS(cur_bus_speed, enum pci_bus_speed)
122 
123 static ssize_t power_read_file(struct pci_slot *slot, char *buf)
124 {
125 	int retval;
126 	u8 value;
127 
128 	retval = get_power_status(slot->hotplug, &value);
129 	if (retval)
130 		goto exit;
131 	retval = sprintf (buf, "%d\n", value);
132 exit:
133 	return retval;
134 }
135 
136 static ssize_t power_write_file(struct pci_slot *pci_slot, const char *buf,
137 		size_t count)
138 {
139 	struct hotplug_slot *slot = pci_slot->hotplug;
140 	unsigned long lpower;
141 	u8 power;
142 	int retval = 0;
143 
144 	lpower = simple_strtoul (buf, NULL, 10);
145 	power = (u8)(lpower & 0xff);
146 	dbg ("power = %d\n", power);
147 
148 	if (!try_module_get(slot->ops->owner)) {
149 		retval = -ENODEV;
150 		goto exit;
151 	}
152 	switch (power) {
153 		case 0:
154 			if (slot->ops->disable_slot)
155 				retval = slot->ops->disable_slot(slot);
156 			break;
157 
158 		case 1:
159 			if (slot->ops->enable_slot)
160 				retval = slot->ops->enable_slot(slot);
161 			break;
162 
163 		default:
164 			err ("Illegal value specified for power\n");
165 			retval = -EINVAL;
166 	}
167 	module_put(slot->ops->owner);
168 
169 exit:
170 	if (retval)
171 		return retval;
172 	return count;
173 }
174 
175 static struct pci_slot_attribute hotplug_slot_attr_power = {
176 	.attr = {.name = "power", .mode = S_IFREG | S_IRUGO | S_IWUSR},
177 	.show = power_read_file,
178 	.store = power_write_file
179 };
180 
181 static ssize_t attention_read_file(struct pci_slot *slot, char *buf)
182 {
183 	int retval;
184 	u8 value;
185 
186 	retval = get_attention_status(slot->hotplug, &value);
187 	if (retval)
188 		goto exit;
189 	retval = sprintf(buf, "%d\n", value);
190 
191 exit:
192 	return retval;
193 }
194 
195 static ssize_t attention_write_file(struct pci_slot *slot, const char *buf,
196 		size_t count)
197 {
198 	struct hotplug_slot_ops *ops = slot->hotplug->ops;
199 	unsigned long lattention;
200 	u8 attention;
201 	int retval = 0;
202 
203 	lattention = simple_strtoul (buf, NULL, 10);
204 	attention = (u8)(lattention & 0xff);
205 	dbg (" - attention = %d\n", attention);
206 
207 	if (!try_module_get(ops->owner)) {
208 		retval = -ENODEV;
209 		goto exit;
210 	}
211 	if (ops->set_attention_status)
212 		retval = ops->set_attention_status(slot->hotplug, attention);
213 	module_put(ops->owner);
214 
215 exit:
216 	if (retval)
217 		return retval;
218 	return count;
219 }
220 
221 static struct pci_slot_attribute hotplug_slot_attr_attention = {
222 	.attr = {.name = "attention", .mode = S_IFREG | S_IRUGO | S_IWUSR},
223 	.show = attention_read_file,
224 	.store = attention_write_file
225 };
226 
227 static ssize_t latch_read_file(struct pci_slot *slot, char *buf)
228 {
229 	int retval;
230 	u8 value;
231 
232 	retval = get_latch_status(slot->hotplug, &value);
233 	if (retval)
234 		goto exit;
235 	retval = sprintf (buf, "%d\n", value);
236 
237 exit:
238 	return retval;
239 }
240 
241 static struct pci_slot_attribute hotplug_slot_attr_latch = {
242 	.attr = {.name = "latch", .mode = S_IFREG | S_IRUGO},
243 	.show = latch_read_file,
244 };
245 
246 static ssize_t presence_read_file(struct pci_slot *slot, char *buf)
247 {
248 	int retval;
249 	u8 value;
250 
251 	retval = get_adapter_status(slot->hotplug, &value);
252 	if (retval)
253 		goto exit;
254 	retval = sprintf (buf, "%d\n", value);
255 
256 exit:
257 	return retval;
258 }
259 
260 static struct pci_slot_attribute hotplug_slot_attr_presence = {
261 	.attr = {.name = "adapter", .mode = S_IFREG | S_IRUGO},
262 	.show = presence_read_file,
263 };
264 
265 static char *unknown_speed = "Unknown bus speed";
266 
267 static ssize_t max_bus_speed_read_file(struct pci_slot *slot, char *buf)
268 {
269 	char *speed_string;
270 	int retval;
271 	enum pci_bus_speed value;
272 
273 	retval = get_max_bus_speed(slot->hotplug, &value);
274 	if (retval)
275 		goto exit;
276 
277 	if (value == PCI_SPEED_UNKNOWN)
278 		speed_string = unknown_speed;
279 	else
280 		speed_string = pci_bus_speed_strings[value];
281 
282 	retval = sprintf (buf, "%s\n", speed_string);
283 
284 exit:
285 	return retval;
286 }
287 
288 static struct pci_slot_attribute hotplug_slot_attr_max_bus_speed = {
289 	.attr = {.name = "max_bus_speed", .mode = S_IFREG | S_IRUGO},
290 	.show = max_bus_speed_read_file,
291 };
292 
293 static ssize_t cur_bus_speed_read_file(struct pci_slot *slot, char *buf)
294 {
295 	char *speed_string;
296 	int retval;
297 	enum pci_bus_speed value;
298 
299 	retval = get_cur_bus_speed(slot->hotplug, &value);
300 	if (retval)
301 		goto exit;
302 
303 	if (value == PCI_SPEED_UNKNOWN)
304 		speed_string = unknown_speed;
305 	else
306 		speed_string = pci_bus_speed_strings[value];
307 
308 	retval = sprintf (buf, "%s\n", speed_string);
309 
310 exit:
311 	return retval;
312 }
313 
314 static struct pci_slot_attribute hotplug_slot_attr_cur_bus_speed = {
315 	.attr = {.name = "cur_bus_speed", .mode = S_IFREG | S_IRUGO},
316 	.show = cur_bus_speed_read_file,
317 };
318 
319 static ssize_t test_write_file(struct pci_slot *pci_slot, const char *buf,
320 		size_t count)
321 {
322 	struct hotplug_slot *slot = pci_slot->hotplug;
323 	unsigned long ltest;
324 	u32 test;
325 	int retval = 0;
326 
327 	ltest = simple_strtoul (buf, NULL, 10);
328 	test = (u32)(ltest & 0xffffffff);
329 	dbg ("test = %d\n", test);
330 
331 	if (!try_module_get(slot->ops->owner)) {
332 		retval = -ENODEV;
333 		goto exit;
334 	}
335 	if (slot->ops->hardware_test)
336 		retval = slot->ops->hardware_test(slot, test);
337 	module_put(slot->ops->owner);
338 
339 exit:
340 	if (retval)
341 		return retval;
342 	return count;
343 }
344 
345 static struct pci_slot_attribute hotplug_slot_attr_test = {
346 	.attr = {.name = "test", .mode = S_IFREG | S_IRUGO | S_IWUSR},
347 	.store = test_write_file
348 };
349 
350 static int has_power_file(struct pci_slot *pci_slot)
351 {
352 	struct hotplug_slot *slot = pci_slot->hotplug;
353 	if ((!slot) || (!slot->ops))
354 		return -ENODEV;
355 	if ((slot->ops->enable_slot) ||
356 	    (slot->ops->disable_slot) ||
357 	    (slot->ops->get_power_status))
358 		return 0;
359 	return -ENOENT;
360 }
361 
362 static int has_attention_file(struct pci_slot *pci_slot)
363 {
364 	struct hotplug_slot *slot = pci_slot->hotplug;
365 	if ((!slot) || (!slot->ops))
366 		return -ENODEV;
367 	if ((slot->ops->set_attention_status) ||
368 	    (slot->ops->get_attention_status))
369 		return 0;
370 	return -ENOENT;
371 }
372 
373 static int has_latch_file(struct pci_slot *pci_slot)
374 {
375 	struct hotplug_slot *slot = pci_slot->hotplug;
376 	if ((!slot) || (!slot->ops))
377 		return -ENODEV;
378 	if (slot->ops->get_latch_status)
379 		return 0;
380 	return -ENOENT;
381 }
382 
383 static int has_adapter_file(struct pci_slot *pci_slot)
384 {
385 	struct hotplug_slot *slot = pci_slot->hotplug;
386 	if ((!slot) || (!slot->ops))
387 		return -ENODEV;
388 	if (slot->ops->get_adapter_status)
389 		return 0;
390 	return -ENOENT;
391 }
392 
393 static int has_max_bus_speed_file(struct pci_slot *pci_slot)
394 {
395 	struct hotplug_slot *slot = pci_slot->hotplug;
396 	if ((!slot) || (!slot->ops))
397 		return -ENODEV;
398 	if (slot->ops->get_max_bus_speed)
399 		return 0;
400 	return -ENOENT;
401 }
402 
403 static int has_cur_bus_speed_file(struct pci_slot *pci_slot)
404 {
405 	struct hotplug_slot *slot = pci_slot->hotplug;
406 	if ((!slot) || (!slot->ops))
407 		return -ENODEV;
408 	if (slot->ops->get_cur_bus_speed)
409 		return 0;
410 	return -ENOENT;
411 }
412 
413 static int has_test_file(struct pci_slot *pci_slot)
414 {
415 	struct hotplug_slot *slot = pci_slot->hotplug;
416 	if ((!slot) || (!slot->ops))
417 		return -ENODEV;
418 	if (slot->ops->hardware_test)
419 		return 0;
420 	return -ENOENT;
421 }
422 
423 static int fs_add_slot(struct pci_slot *slot)
424 {
425 	int retval = 0;
426 
427 	if (has_power_file(slot) == 0) {
428 		retval = sysfs_create_file(&slot->kobj, &hotplug_slot_attr_power.attr);
429 		if (retval)
430 			goto exit_power;
431 	}
432 
433 	if (has_attention_file(slot) == 0) {
434 		retval = sysfs_create_file(&slot->kobj,
435 					   &hotplug_slot_attr_attention.attr);
436 		if (retval)
437 			goto exit_attention;
438 	}
439 
440 	if (has_latch_file(slot) == 0) {
441 		retval = sysfs_create_file(&slot->kobj,
442 					   &hotplug_slot_attr_latch.attr);
443 		if (retval)
444 			goto exit_latch;
445 	}
446 
447 	if (has_adapter_file(slot) == 0) {
448 		retval = sysfs_create_file(&slot->kobj,
449 					   &hotplug_slot_attr_presence.attr);
450 		if (retval)
451 			goto exit_adapter;
452 	}
453 
454 	if (has_max_bus_speed_file(slot) == 0) {
455 		retval = sysfs_create_file(&slot->kobj,
456 					   &hotplug_slot_attr_max_bus_speed.attr);
457 		if (retval)
458 			goto exit_max_speed;
459 	}
460 
461 	if (has_cur_bus_speed_file(slot) == 0) {
462 		retval = sysfs_create_file(&slot->kobj,
463 					   &hotplug_slot_attr_cur_bus_speed.attr);
464 		if (retval)
465 			goto exit_cur_speed;
466 	}
467 
468 	if (has_test_file(slot) == 0) {
469 		retval = sysfs_create_file(&slot->kobj,
470 					   &hotplug_slot_attr_test.attr);
471 		if (retval)
472 			goto exit_test;
473 	}
474 
475 	goto exit;
476 
477 exit_test:
478 	if (has_cur_bus_speed_file(slot) == 0)
479 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_cur_bus_speed.attr);
480 
481 exit_cur_speed:
482 	if (has_max_bus_speed_file(slot) == 0)
483 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_max_bus_speed.attr);
484 
485 exit_max_speed:
486 	if (has_adapter_file(slot) == 0)
487 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_presence.attr);
488 
489 exit_adapter:
490 	if (has_latch_file(slot) == 0)
491 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_latch.attr);
492 
493 exit_latch:
494 	if (has_attention_file(slot) == 0)
495 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_attention.attr);
496 
497 exit_attention:
498 	if (has_power_file(slot) == 0)
499 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_power.attr);
500 exit_power:
501 exit:
502 	return retval;
503 }
504 
505 static void fs_remove_slot(struct pci_slot *slot)
506 {
507 	if (has_power_file(slot) == 0)
508 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_power.attr);
509 
510 	if (has_attention_file(slot) == 0)
511 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_attention.attr);
512 
513 	if (has_latch_file(slot) == 0)
514 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_latch.attr);
515 
516 	if (has_adapter_file(slot) == 0)
517 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_presence.attr);
518 
519 	if (has_max_bus_speed_file(slot) == 0)
520 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_max_bus_speed.attr);
521 
522 	if (has_cur_bus_speed_file(slot) == 0)
523 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_cur_bus_speed.attr);
524 
525 	if (has_test_file(slot) == 0)
526 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_test.attr);
527 }
528 
529 static struct hotplug_slot *get_slot_from_name (const char *name)
530 {
531 	struct hotplug_slot *slot;
532 	struct list_head *tmp;
533 
534 	list_for_each (tmp, &pci_hotplug_slot_list) {
535 		slot = list_entry (tmp, struct hotplug_slot, slot_list);
536 		if (strcmp(hotplug_slot_name(slot), name) == 0)
537 			return slot;
538 	}
539 	return NULL;
540 }
541 
542 /**
543  * pci_hp_register - register a hotplug_slot with the PCI hotplug subsystem
544  * @bus: bus this slot is on
545  * @slot: pointer to the &struct hotplug_slot to register
546  * @slot_nr: slot number
547  * @name: name registered with kobject core
548  *
549  * Registers a hotplug slot with the pci hotplug subsystem, which will allow
550  * userspace interaction to the slot.
551  *
552  * Returns 0 if successful, anything else for an error.
553  */
554 int pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus, int slot_nr,
555 			const char *name)
556 {
557 	int result;
558 	struct pci_slot *pci_slot;
559 
560 	if (slot == NULL)
561 		return -ENODEV;
562 	if ((slot->info == NULL) || (slot->ops == NULL))
563 		return -EINVAL;
564 	if (slot->release == NULL) {
565 		dbg("Why are you trying to register a hotplug slot "
566 		    "without a proper release function?\n");
567 		return -EINVAL;
568 	}
569 
570 	mutex_lock(&pci_hp_mutex);
571 
572 	/*
573 	 * No problems if we call this interface from both ACPI_PCI_SLOT
574 	 * driver and call it here again. If we've already created the
575 	 * pci_slot, the interface will simply bump the refcount.
576 	 */
577 	pci_slot = pci_create_slot(bus, slot_nr, name, slot);
578 	if (IS_ERR(pci_slot)) {
579 		result = PTR_ERR(pci_slot);
580 		goto out;
581 	}
582 
583 	slot->pci_slot = pci_slot;
584 	pci_slot->hotplug = slot;
585 
586 	list_add(&slot->slot_list, &pci_hotplug_slot_list);
587 
588 	result = fs_add_slot(pci_slot);
589 	kobject_uevent(&pci_slot->kobj, KOBJ_ADD);
590 	dbg("Added slot %s to the list\n", name);
591 out:
592 	mutex_unlock(&pci_hp_mutex);
593 	return result;
594 }
595 
596 /**
597  * pci_hp_deregister - deregister a hotplug_slot with the PCI hotplug subsystem
598  * @hotplug: pointer to the &struct hotplug_slot to deregister
599  *
600  * The @slot must have been registered with the pci hotplug subsystem
601  * previously with a call to pci_hp_register().
602  *
603  * Returns 0 if successful, anything else for an error.
604  */
605 int pci_hp_deregister(struct hotplug_slot *hotplug)
606 {
607 	struct hotplug_slot *temp;
608 	struct pci_slot *slot;
609 
610 	if (!hotplug)
611 		return -ENODEV;
612 
613 	mutex_lock(&pci_hp_mutex);
614 	temp = get_slot_from_name(hotplug_slot_name(hotplug));
615 	if (temp != hotplug) {
616 		mutex_unlock(&pci_hp_mutex);
617 		return -ENODEV;
618 	}
619 
620 	list_del(&hotplug->slot_list);
621 
622 	slot = hotplug->pci_slot;
623 	fs_remove_slot(slot);
624 	dbg("Removed slot %s from the list\n", hotplug_slot_name(hotplug));
625 
626 	hotplug->release(hotplug);
627 	slot->hotplug = NULL;
628 	pci_destroy_slot(slot);
629 	mutex_unlock(&pci_hp_mutex);
630 
631 	return 0;
632 }
633 
634 /**
635  * pci_hp_change_slot_info - changes the slot's information structure in the core
636  * @hotplug: pointer to the slot whose info has changed
637  * @info: pointer to the info copy into the slot's info structure
638  *
639  * @slot must have been registered with the pci
640  * hotplug subsystem previously with a call to pci_hp_register().
641  *
642  * Returns 0 if successful, anything else for an error.
643  */
644 int __must_check pci_hp_change_slot_info(struct hotplug_slot *hotplug,
645 					 struct hotplug_slot_info *info)
646 {
647 	struct pci_slot *slot;
648 	if (!hotplug || !info)
649 		return -ENODEV;
650 	slot = hotplug->pci_slot;
651 
652 	memcpy(hotplug->info, info, sizeof(struct hotplug_slot_info));
653 
654 	return 0;
655 }
656 
657 static int __init pci_hotplug_init (void)
658 {
659 	int result;
660 
661 	result = cpci_hotplug_init(debug);
662 	if (result) {
663 		err ("cpci_hotplug_init with error %d\n", result);
664 		goto err_cpci;
665 	}
666 
667 	info (DRIVER_DESC " version: " DRIVER_VERSION "\n");
668 
669 err_cpci:
670 	return result;
671 }
672 
673 static void __exit pci_hotplug_exit (void)
674 {
675 	cpci_hotplug_exit();
676 }
677 
678 module_init(pci_hotplug_init);
679 module_exit(pci_hotplug_exit);
680 
681 MODULE_AUTHOR(DRIVER_AUTHOR);
682 MODULE_DESCRIPTION(DRIVER_DESC);
683 MODULE_LICENSE("GPL");
684 module_param(debug, bool, 0644);
685 MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
686 
687 EXPORT_SYMBOL_GPL(pci_hp_register);
688 EXPORT_SYMBOL_GPL(pci_hp_deregister);
689 EXPORT_SYMBOL_GPL(pci_hp_change_slot_info);
690