xref: /linux/drivers/pci/hotplug/pci_hotplug_core.c (revision 47902f3611b392209e2a412bf7ec02dca95e666d)
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/init.h>
37 #include <linux/mount.h>
38 #include <linux/namei.h>
39 #include <linux/mutex.h>
40 #include <linux/pci.h>
41 #include <linux/pci_hotplug.h>
42 #include <asm/uaccess.h>
43 #include "../pci.h"
44 
45 #define MY_NAME	"pci_hotplug"
46 
47 #define dbg(fmt, arg...) do { if (debug) printk(KERN_DEBUG "%s: %s: " fmt , MY_NAME , __func__ , ## arg); } while (0)
48 #define err(format, arg...) printk(KERN_ERR "%s: " format , MY_NAME , ## arg)
49 #define info(format, arg...) printk(KERN_INFO "%s: " format , MY_NAME , ## arg)
50 #define warn(format, arg...) printk(KERN_WARNING "%s: " format , MY_NAME , ## arg)
51 
52 
53 /* local variables */
54 static int debug;
55 
56 #define DRIVER_VERSION	"0.5"
57 #define DRIVER_AUTHOR	"Greg Kroah-Hartman <greg@kroah.com>, Scott Murray <scottm@somanetworks.com>"
58 #define DRIVER_DESC	"PCI Hot Plug PCI Core"
59 
60 
61 //////////////////////////////////////////////////////////////////
62 
63 static LIST_HEAD(pci_hotplug_slot_list);
64 static DEFINE_MUTEX(pci_hp_mutex);
65 
66 #ifdef CONFIG_HOTPLUG_PCI_CPCI
67 extern int cpci_hotplug_init(int debug);
68 extern void cpci_hotplug_exit(void);
69 #else
70 static inline int cpci_hotplug_init(int debug) { return 0; }
71 static inline void cpci_hotplug_exit(void) { }
72 #endif
73 
74 /* Weee, fun with macros... */
75 #define GET_STATUS(name,type)	\
76 static int get_##name (struct hotplug_slot *slot, type *value)		\
77 {									\
78 	struct hotplug_slot_ops *ops = slot->ops;			\
79 	int retval = 0;							\
80 	if (!try_module_get(ops->owner))				\
81 		return -ENODEV;						\
82 	if (ops->get_##name)						\
83 		retval = ops->get_##name(slot, value);			\
84 	else								\
85 		*value = slot->info->name;				\
86 	module_put(ops->owner);						\
87 	return retval;							\
88 }
89 
90 GET_STATUS(power_status, u8)
91 GET_STATUS(attention_status, u8)
92 GET_STATUS(latch_status, u8)
93 GET_STATUS(adapter_status, u8)
94 
95 static ssize_t power_read_file(struct pci_slot *slot, char *buf)
96 {
97 	int retval;
98 	u8 value;
99 
100 	retval = get_power_status(slot->hotplug, &value);
101 	if (retval)
102 		goto exit;
103 	retval = sprintf (buf, "%d\n", value);
104 exit:
105 	return retval;
106 }
107 
108 static ssize_t power_write_file(struct pci_slot *pci_slot, const char *buf,
109 		size_t count)
110 {
111 	struct hotplug_slot *slot = pci_slot->hotplug;
112 	unsigned long lpower;
113 	u8 power;
114 	int retval = 0;
115 
116 	lpower = simple_strtoul (buf, NULL, 10);
117 	power = (u8)(lpower & 0xff);
118 	dbg ("power = %d\n", power);
119 
120 	if (!try_module_get(slot->ops->owner)) {
121 		retval = -ENODEV;
122 		goto exit;
123 	}
124 	switch (power) {
125 		case 0:
126 			if (slot->ops->disable_slot)
127 				retval = slot->ops->disable_slot(slot);
128 			break;
129 
130 		case 1:
131 			if (slot->ops->enable_slot)
132 				retval = slot->ops->enable_slot(slot);
133 			break;
134 
135 		default:
136 			err ("Illegal value specified for power\n");
137 			retval = -EINVAL;
138 	}
139 	module_put(slot->ops->owner);
140 
141 exit:
142 	if (retval)
143 		return retval;
144 	return count;
145 }
146 
147 static struct pci_slot_attribute hotplug_slot_attr_power = {
148 	.attr = {.name = "power", .mode = S_IFREG | S_IRUGO | S_IWUSR},
149 	.show = power_read_file,
150 	.store = power_write_file
151 };
152 
153 static ssize_t attention_read_file(struct pci_slot *slot, char *buf)
154 {
155 	int retval;
156 	u8 value;
157 
158 	retval = get_attention_status(slot->hotplug, &value);
159 	if (retval)
160 		goto exit;
161 	retval = sprintf(buf, "%d\n", value);
162 
163 exit:
164 	return retval;
165 }
166 
167 static ssize_t attention_write_file(struct pci_slot *slot, const char *buf,
168 		size_t count)
169 {
170 	struct hotplug_slot_ops *ops = slot->hotplug->ops;
171 	unsigned long lattention;
172 	u8 attention;
173 	int retval = 0;
174 
175 	lattention = simple_strtoul (buf, NULL, 10);
176 	attention = (u8)(lattention & 0xff);
177 	dbg (" - attention = %d\n", attention);
178 
179 	if (!try_module_get(ops->owner)) {
180 		retval = -ENODEV;
181 		goto exit;
182 	}
183 	if (ops->set_attention_status)
184 		retval = ops->set_attention_status(slot->hotplug, attention);
185 	module_put(ops->owner);
186 
187 exit:
188 	if (retval)
189 		return retval;
190 	return count;
191 }
192 
193 static struct pci_slot_attribute hotplug_slot_attr_attention = {
194 	.attr = {.name = "attention", .mode = S_IFREG | S_IRUGO | S_IWUSR},
195 	.show = attention_read_file,
196 	.store = attention_write_file
197 };
198 
199 static ssize_t latch_read_file(struct pci_slot *slot, char *buf)
200 {
201 	int retval;
202 	u8 value;
203 
204 	retval = get_latch_status(slot->hotplug, &value);
205 	if (retval)
206 		goto exit;
207 	retval = sprintf (buf, "%d\n", value);
208 
209 exit:
210 	return retval;
211 }
212 
213 static struct pci_slot_attribute hotplug_slot_attr_latch = {
214 	.attr = {.name = "latch", .mode = S_IFREG | S_IRUGO},
215 	.show = latch_read_file,
216 };
217 
218 static ssize_t presence_read_file(struct pci_slot *slot, char *buf)
219 {
220 	int retval;
221 	u8 value;
222 
223 	retval = get_adapter_status(slot->hotplug, &value);
224 	if (retval)
225 		goto exit;
226 	retval = sprintf (buf, "%d\n", value);
227 
228 exit:
229 	return retval;
230 }
231 
232 static struct pci_slot_attribute hotplug_slot_attr_presence = {
233 	.attr = {.name = "adapter", .mode = S_IFREG | S_IRUGO},
234 	.show = presence_read_file,
235 };
236 
237 static ssize_t test_write_file(struct pci_slot *pci_slot, const char *buf,
238 		size_t count)
239 {
240 	struct hotplug_slot *slot = pci_slot->hotplug;
241 	unsigned long ltest;
242 	u32 test;
243 	int retval = 0;
244 
245 	ltest = simple_strtoul (buf, NULL, 10);
246 	test = (u32)(ltest & 0xffffffff);
247 	dbg ("test = %d\n", test);
248 
249 	if (!try_module_get(slot->ops->owner)) {
250 		retval = -ENODEV;
251 		goto exit;
252 	}
253 	if (slot->ops->hardware_test)
254 		retval = slot->ops->hardware_test(slot, test);
255 	module_put(slot->ops->owner);
256 
257 exit:
258 	if (retval)
259 		return retval;
260 	return count;
261 }
262 
263 static struct pci_slot_attribute hotplug_slot_attr_test = {
264 	.attr = {.name = "test", .mode = S_IFREG | S_IRUGO | S_IWUSR},
265 	.store = test_write_file
266 };
267 
268 static bool has_power_file(struct pci_slot *pci_slot)
269 {
270 	struct hotplug_slot *slot = pci_slot->hotplug;
271 	if ((!slot) || (!slot->ops))
272 		return false;
273 	if ((slot->ops->enable_slot) ||
274 	    (slot->ops->disable_slot) ||
275 	    (slot->ops->get_power_status))
276 		return true;
277 	return false;
278 }
279 
280 static bool has_attention_file(struct pci_slot *pci_slot)
281 {
282 	struct hotplug_slot *slot = pci_slot->hotplug;
283 	if ((!slot) || (!slot->ops))
284 		return false;
285 	if ((slot->ops->set_attention_status) ||
286 	    (slot->ops->get_attention_status))
287 		return true;
288 	return false;
289 }
290 
291 static bool has_latch_file(struct pci_slot *pci_slot)
292 {
293 	struct hotplug_slot *slot = pci_slot->hotplug;
294 	if ((!slot) || (!slot->ops))
295 		return false;
296 	if (slot->ops->get_latch_status)
297 		return true;
298 	return false;
299 }
300 
301 static bool has_adapter_file(struct pci_slot *pci_slot)
302 {
303 	struct hotplug_slot *slot = pci_slot->hotplug;
304 	if ((!slot) || (!slot->ops))
305 		return false;
306 	if (slot->ops->get_adapter_status)
307 		return true;
308 	return false;
309 }
310 
311 static bool has_test_file(struct pci_slot *pci_slot)
312 {
313 	struct hotplug_slot *slot = pci_slot->hotplug;
314 	if ((!slot) || (!slot->ops))
315 		return false;
316 	if (slot->ops->hardware_test)
317 		return true;
318 	return false;
319 }
320 
321 static int fs_add_slot(struct pci_slot *slot)
322 {
323 	int retval = 0;
324 
325 	/* Create symbolic link to the hotplug driver module */
326 	pci_hp_create_module_link(slot);
327 
328 	if (has_power_file(slot)) {
329 		retval = sysfs_create_file(&slot->kobj,
330 					   &hotplug_slot_attr_power.attr);
331 		if (retval)
332 			goto exit_power;
333 	}
334 
335 	if (has_attention_file(slot)) {
336 		retval = sysfs_create_file(&slot->kobj,
337 					   &hotplug_slot_attr_attention.attr);
338 		if (retval)
339 			goto exit_attention;
340 	}
341 
342 	if (has_latch_file(slot)) {
343 		retval = sysfs_create_file(&slot->kobj,
344 					   &hotplug_slot_attr_latch.attr);
345 		if (retval)
346 			goto exit_latch;
347 	}
348 
349 	if (has_adapter_file(slot)) {
350 		retval = sysfs_create_file(&slot->kobj,
351 					   &hotplug_slot_attr_presence.attr);
352 		if (retval)
353 			goto exit_adapter;
354 	}
355 
356 	if (has_test_file(slot)) {
357 		retval = sysfs_create_file(&slot->kobj,
358 					   &hotplug_slot_attr_test.attr);
359 		if (retval)
360 			goto exit_test;
361 	}
362 
363 	goto exit;
364 
365 exit_test:
366 	if (has_adapter_file(slot))
367 		sysfs_remove_file(&slot->kobj,
368 				  &hotplug_slot_attr_presence.attr);
369 exit_adapter:
370 	if (has_latch_file(slot))
371 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_latch.attr);
372 exit_latch:
373 	if (has_attention_file(slot))
374 		sysfs_remove_file(&slot->kobj,
375 				  &hotplug_slot_attr_attention.attr);
376 exit_attention:
377 	if (has_power_file(slot))
378 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_power.attr);
379 exit_power:
380 	pci_hp_remove_module_link(slot);
381 exit:
382 	return retval;
383 }
384 
385 static void fs_remove_slot(struct pci_slot *slot)
386 {
387 	if (has_power_file(slot))
388 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_power.attr);
389 
390 	if (has_attention_file(slot))
391 		sysfs_remove_file(&slot->kobj,
392 				  &hotplug_slot_attr_attention.attr);
393 
394 	if (has_latch_file(slot))
395 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_latch.attr);
396 
397 	if (has_adapter_file(slot))
398 		sysfs_remove_file(&slot->kobj,
399 				  &hotplug_slot_attr_presence.attr);
400 
401 	if (has_test_file(slot))
402 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_test.attr);
403 
404 	pci_hp_remove_module_link(slot);
405 }
406 
407 static struct hotplug_slot *get_slot_from_name (const char *name)
408 {
409 	struct hotplug_slot *slot;
410 	struct list_head *tmp;
411 
412 	list_for_each (tmp, &pci_hotplug_slot_list) {
413 		slot = list_entry (tmp, struct hotplug_slot, slot_list);
414 		if (strcmp(hotplug_slot_name(slot), name) == 0)
415 			return slot;
416 	}
417 	return NULL;
418 }
419 
420 /**
421  * __pci_hp_register - register a hotplug_slot with the PCI hotplug subsystem
422  * @bus: bus this slot is on
423  * @slot: pointer to the &struct hotplug_slot to register
424  * @devnr: device number
425  * @name: name registered with kobject core
426  * @owner: caller module owner
427  * @mod_name: caller module name
428  *
429  * Registers a hotplug slot with the pci hotplug subsystem, which will allow
430  * userspace interaction to the slot.
431  *
432  * Returns 0 if successful, anything else for an error.
433  */
434 int __pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus,
435 		      int devnr, const char *name,
436 		      struct module *owner, const char *mod_name)
437 {
438 	int result;
439 	struct pci_slot *pci_slot;
440 
441 	if (slot == NULL)
442 		return -ENODEV;
443 	if ((slot->info == NULL) || (slot->ops == NULL))
444 		return -EINVAL;
445 	if (slot->release == NULL) {
446 		dbg("Why are you trying to register a hotplug slot "
447 		    "without a proper release function?\n");
448 		return -EINVAL;
449 	}
450 
451 	slot->ops->owner = owner;
452 	slot->ops->mod_name = mod_name;
453 
454 	mutex_lock(&pci_hp_mutex);
455 	/*
456 	 * No problems if we call this interface from both ACPI_PCI_SLOT
457 	 * driver and call it here again. If we've already created the
458 	 * pci_slot, the interface will simply bump the refcount.
459 	 */
460 	pci_slot = pci_create_slot(bus, devnr, name, slot);
461 	if (IS_ERR(pci_slot)) {
462 		result = PTR_ERR(pci_slot);
463 		goto out;
464 	}
465 
466 	slot->pci_slot = pci_slot;
467 	pci_slot->hotplug = slot;
468 
469 	list_add(&slot->slot_list, &pci_hotplug_slot_list);
470 
471 	result = fs_add_slot(pci_slot);
472 	kobject_uevent(&pci_slot->kobj, KOBJ_ADD);
473 	dbg("Added slot %s to the list\n", name);
474 out:
475 	mutex_unlock(&pci_hp_mutex);
476 	return result;
477 }
478 
479 /**
480  * pci_hp_deregister - deregister a hotplug_slot with the PCI hotplug subsystem
481  * @hotplug: pointer to the &struct hotplug_slot to deregister
482  *
483  * The @slot must have been registered with the pci hotplug subsystem
484  * previously with a call to pci_hp_register().
485  *
486  * Returns 0 if successful, anything else for an error.
487  */
488 int pci_hp_deregister(struct hotplug_slot *hotplug)
489 {
490 	struct hotplug_slot *temp;
491 	struct pci_slot *slot;
492 
493 	if (!hotplug)
494 		return -ENODEV;
495 
496 	mutex_lock(&pci_hp_mutex);
497 	temp = get_slot_from_name(hotplug_slot_name(hotplug));
498 	if (temp != hotplug) {
499 		mutex_unlock(&pci_hp_mutex);
500 		return -ENODEV;
501 	}
502 
503 	list_del(&hotplug->slot_list);
504 
505 	slot = hotplug->pci_slot;
506 	fs_remove_slot(slot);
507 	dbg("Removed slot %s from the list\n", hotplug_slot_name(hotplug));
508 
509 	hotplug->release(hotplug);
510 	slot->hotplug = NULL;
511 	pci_destroy_slot(slot);
512 	mutex_unlock(&pci_hp_mutex);
513 
514 	return 0;
515 }
516 
517 /**
518  * pci_hp_change_slot_info - changes the slot's information structure in the core
519  * @hotplug: pointer to the slot whose info has changed
520  * @info: pointer to the info copy into the slot's info structure
521  *
522  * @slot must have been registered with the pci
523  * hotplug subsystem previously with a call to pci_hp_register().
524  *
525  * Returns 0 if successful, anything else for an error.
526  */
527 int __must_check pci_hp_change_slot_info(struct hotplug_slot *hotplug,
528 					 struct hotplug_slot_info *info)
529 {
530 	struct pci_slot *slot;
531 	if (!hotplug || !info)
532 		return -ENODEV;
533 	slot = hotplug->pci_slot;
534 
535 	memcpy(hotplug->info, info, sizeof(struct hotplug_slot_info));
536 
537 	return 0;
538 }
539 
540 static int __init pci_hotplug_init (void)
541 {
542 	int result;
543 
544 	result = cpci_hotplug_init(debug);
545 	if (result) {
546 		err ("cpci_hotplug_init with error %d\n", result);
547 		goto err_cpci;
548 	}
549 
550 	info (DRIVER_DESC " version: " DRIVER_VERSION "\n");
551 
552 err_cpci:
553 	return result;
554 }
555 
556 static void __exit pci_hotplug_exit (void)
557 {
558 	cpci_hotplug_exit();
559 }
560 
561 module_init(pci_hotplug_init);
562 module_exit(pci_hotplug_exit);
563 
564 MODULE_AUTHOR(DRIVER_AUTHOR);
565 MODULE_DESCRIPTION(DRIVER_DESC);
566 MODULE_LICENSE("GPL");
567 module_param(debug, bool, 0644);
568 MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
569 
570 EXPORT_SYMBOL_GPL(__pci_hp_register);
571 EXPORT_SYMBOL_GPL(pci_hp_deregister);
572 EXPORT_SYMBOL_GPL(pci_hp_change_slot_info);
573