xref: /linux/drivers/pci/hotplug/pci_hotplug_core.c (revision 5499b45190237ca90dd2ac86395cf464fe1f4cc7)
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 #ifdef CONFIG_HOTPLUG_PCI_CPCI
68 extern int cpci_hotplug_init(int debug);
69 extern void cpci_hotplug_exit(void);
70 #else
71 static inline int cpci_hotplug_init(int debug) { return 0; }
72 static inline void cpci_hotplug_exit(void) { }
73 #endif
74 
75 /* Weee, fun with macros... */
76 #define GET_STATUS(name,type)	\
77 static int get_##name (struct hotplug_slot *slot, type *value)		\
78 {									\
79 	struct hotplug_slot_ops *ops = slot->ops;			\
80 	int retval = 0;							\
81 	if (!try_module_get(ops->owner))				\
82 		return -ENODEV;						\
83 	if (ops->get_##name)						\
84 		retval = ops->get_##name(slot, value);			\
85 	else								\
86 		*value = slot->info->name;				\
87 	module_put(ops->owner);						\
88 	return retval;							\
89 }
90 
91 GET_STATUS(power_status, u8)
92 GET_STATUS(attention_status, u8)
93 GET_STATUS(latch_status, u8)
94 GET_STATUS(adapter_status, u8)
95 
96 static ssize_t power_read_file(struct pci_slot *slot, char *buf)
97 {
98 	int retval;
99 	u8 value;
100 
101 	retval = get_power_status(slot->hotplug, &value);
102 	if (retval)
103 		goto exit;
104 	retval = sprintf (buf, "%d\n", value);
105 exit:
106 	return retval;
107 }
108 
109 static ssize_t power_write_file(struct pci_slot *pci_slot, const char *buf,
110 		size_t count)
111 {
112 	struct hotplug_slot *slot = pci_slot->hotplug;
113 	unsigned long lpower;
114 	u8 power;
115 	int retval = 0;
116 
117 	lpower = simple_strtoul (buf, NULL, 10);
118 	power = (u8)(lpower & 0xff);
119 	dbg ("power = %d\n", power);
120 
121 	if (!try_module_get(slot->ops->owner)) {
122 		retval = -ENODEV;
123 		goto exit;
124 	}
125 	switch (power) {
126 		case 0:
127 			if (slot->ops->disable_slot)
128 				retval = slot->ops->disable_slot(slot);
129 			break;
130 
131 		case 1:
132 			if (slot->ops->enable_slot)
133 				retval = slot->ops->enable_slot(slot);
134 			break;
135 
136 		default:
137 			err ("Illegal value specified for power\n");
138 			retval = -EINVAL;
139 	}
140 	module_put(slot->ops->owner);
141 
142 exit:
143 	if (retval)
144 		return retval;
145 	return count;
146 }
147 
148 static struct pci_slot_attribute hotplug_slot_attr_power = {
149 	.attr = {.name = "power", .mode = S_IFREG | S_IRUGO | S_IWUSR},
150 	.show = power_read_file,
151 	.store = power_write_file
152 };
153 
154 static ssize_t attention_read_file(struct pci_slot *slot, char *buf)
155 {
156 	int retval;
157 	u8 value;
158 
159 	retval = get_attention_status(slot->hotplug, &value);
160 	if (retval)
161 		goto exit;
162 	retval = sprintf(buf, "%d\n", value);
163 
164 exit:
165 	return retval;
166 }
167 
168 static ssize_t attention_write_file(struct pci_slot *slot, const char *buf,
169 		size_t count)
170 {
171 	struct hotplug_slot_ops *ops = slot->hotplug->ops;
172 	unsigned long lattention;
173 	u8 attention;
174 	int retval = 0;
175 
176 	lattention = simple_strtoul (buf, NULL, 10);
177 	attention = (u8)(lattention & 0xff);
178 	dbg (" - attention = %d\n", attention);
179 
180 	if (!try_module_get(ops->owner)) {
181 		retval = -ENODEV;
182 		goto exit;
183 	}
184 	if (ops->set_attention_status)
185 		retval = ops->set_attention_status(slot->hotplug, attention);
186 	module_put(ops->owner);
187 
188 exit:
189 	if (retval)
190 		return retval;
191 	return count;
192 }
193 
194 static struct pci_slot_attribute hotplug_slot_attr_attention = {
195 	.attr = {.name = "attention", .mode = S_IFREG | S_IRUGO | S_IWUSR},
196 	.show = attention_read_file,
197 	.store = attention_write_file
198 };
199 
200 static ssize_t latch_read_file(struct pci_slot *slot, char *buf)
201 {
202 	int retval;
203 	u8 value;
204 
205 	retval = get_latch_status(slot->hotplug, &value);
206 	if (retval)
207 		goto exit;
208 	retval = sprintf (buf, "%d\n", value);
209 
210 exit:
211 	return retval;
212 }
213 
214 static struct pci_slot_attribute hotplug_slot_attr_latch = {
215 	.attr = {.name = "latch", .mode = S_IFREG | S_IRUGO},
216 	.show = latch_read_file,
217 };
218 
219 static ssize_t presence_read_file(struct pci_slot *slot, char *buf)
220 {
221 	int retval;
222 	u8 value;
223 
224 	retval = get_adapter_status(slot->hotplug, &value);
225 	if (retval)
226 		goto exit;
227 	retval = sprintf (buf, "%d\n", value);
228 
229 exit:
230 	return retval;
231 }
232 
233 static struct pci_slot_attribute hotplug_slot_attr_presence = {
234 	.attr = {.name = "adapter", .mode = S_IFREG | S_IRUGO},
235 	.show = presence_read_file,
236 };
237 
238 static ssize_t test_write_file(struct pci_slot *pci_slot, const char *buf,
239 		size_t count)
240 {
241 	struct hotplug_slot *slot = pci_slot->hotplug;
242 	unsigned long ltest;
243 	u32 test;
244 	int retval = 0;
245 
246 	ltest = simple_strtoul (buf, NULL, 10);
247 	test = (u32)(ltest & 0xffffffff);
248 	dbg ("test = %d\n", test);
249 
250 	if (!try_module_get(slot->ops->owner)) {
251 		retval = -ENODEV;
252 		goto exit;
253 	}
254 	if (slot->ops->hardware_test)
255 		retval = slot->ops->hardware_test(slot, test);
256 	module_put(slot->ops->owner);
257 
258 exit:
259 	if (retval)
260 		return retval;
261 	return count;
262 }
263 
264 static struct pci_slot_attribute hotplug_slot_attr_test = {
265 	.attr = {.name = "test", .mode = S_IFREG | S_IRUGO | S_IWUSR},
266 	.store = test_write_file
267 };
268 
269 static bool has_power_file(struct pci_slot *pci_slot)
270 {
271 	struct hotplug_slot *slot = pci_slot->hotplug;
272 	if ((!slot) || (!slot->ops))
273 		return false;
274 	if ((slot->ops->enable_slot) ||
275 	    (slot->ops->disable_slot) ||
276 	    (slot->ops->get_power_status))
277 		return true;
278 	return false;
279 }
280 
281 static bool has_attention_file(struct pci_slot *pci_slot)
282 {
283 	struct hotplug_slot *slot = pci_slot->hotplug;
284 	if ((!slot) || (!slot->ops))
285 		return false;
286 	if ((slot->ops->set_attention_status) ||
287 	    (slot->ops->get_attention_status))
288 		return true;
289 	return false;
290 }
291 
292 static bool has_latch_file(struct pci_slot *pci_slot)
293 {
294 	struct hotplug_slot *slot = pci_slot->hotplug;
295 	if ((!slot) || (!slot->ops))
296 		return false;
297 	if (slot->ops->get_latch_status)
298 		return true;
299 	return false;
300 }
301 
302 static bool has_adapter_file(struct pci_slot *pci_slot)
303 {
304 	struct hotplug_slot *slot = pci_slot->hotplug;
305 	if ((!slot) || (!slot->ops))
306 		return false;
307 	if (slot->ops->get_adapter_status)
308 		return true;
309 	return false;
310 }
311 
312 static bool has_test_file(struct pci_slot *pci_slot)
313 {
314 	struct hotplug_slot *slot = pci_slot->hotplug;
315 	if ((!slot) || (!slot->ops))
316 		return false;
317 	if (slot->ops->hardware_test)
318 		return true;
319 	return false;
320 }
321 
322 static int fs_add_slot(struct pci_slot *slot)
323 {
324 	int retval = 0;
325 
326 	/* Create symbolic link to the hotplug driver module */
327 	pci_hp_create_module_link(slot);
328 
329 	if (has_power_file(slot)) {
330 		retval = sysfs_create_file(&slot->kobj,
331 					   &hotplug_slot_attr_power.attr);
332 		if (retval)
333 			goto exit_power;
334 	}
335 
336 	if (has_attention_file(slot)) {
337 		retval = sysfs_create_file(&slot->kobj,
338 					   &hotplug_slot_attr_attention.attr);
339 		if (retval)
340 			goto exit_attention;
341 	}
342 
343 	if (has_latch_file(slot)) {
344 		retval = sysfs_create_file(&slot->kobj,
345 					   &hotplug_slot_attr_latch.attr);
346 		if (retval)
347 			goto exit_latch;
348 	}
349 
350 	if (has_adapter_file(slot)) {
351 		retval = sysfs_create_file(&slot->kobj,
352 					   &hotplug_slot_attr_presence.attr);
353 		if (retval)
354 			goto exit_adapter;
355 	}
356 
357 	if (has_test_file(slot)) {
358 		retval = sysfs_create_file(&slot->kobj,
359 					   &hotplug_slot_attr_test.attr);
360 		if (retval)
361 			goto exit_test;
362 	}
363 
364 	goto exit;
365 
366 exit_test:
367 	if (has_adapter_file(slot))
368 		sysfs_remove_file(&slot->kobj,
369 				  &hotplug_slot_attr_presence.attr);
370 exit_adapter:
371 	if (has_latch_file(slot))
372 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_latch.attr);
373 exit_latch:
374 	if (has_attention_file(slot))
375 		sysfs_remove_file(&slot->kobj,
376 				  &hotplug_slot_attr_attention.attr);
377 exit_attention:
378 	if (has_power_file(slot))
379 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_power.attr);
380 exit_power:
381 	pci_hp_remove_module_link(slot);
382 exit:
383 	return retval;
384 }
385 
386 static void fs_remove_slot(struct pci_slot *slot)
387 {
388 	if (has_power_file(slot))
389 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_power.attr);
390 
391 	if (has_attention_file(slot))
392 		sysfs_remove_file(&slot->kobj,
393 				  &hotplug_slot_attr_attention.attr);
394 
395 	if (has_latch_file(slot))
396 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_latch.attr);
397 
398 	if (has_adapter_file(slot))
399 		sysfs_remove_file(&slot->kobj,
400 				  &hotplug_slot_attr_presence.attr);
401 
402 	if (has_test_file(slot))
403 		sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_test.attr);
404 
405 	pci_hp_remove_module_link(slot);
406 }
407 
408 static struct hotplug_slot *get_slot_from_name (const char *name)
409 {
410 	struct hotplug_slot *slot;
411 	struct list_head *tmp;
412 
413 	list_for_each (tmp, &pci_hotplug_slot_list) {
414 		slot = list_entry (tmp, struct hotplug_slot, slot_list);
415 		if (strcmp(hotplug_slot_name(slot), name) == 0)
416 			return slot;
417 	}
418 	return NULL;
419 }
420 
421 /**
422  * __pci_hp_register - register a hotplug_slot with the PCI hotplug subsystem
423  * @bus: bus this slot is on
424  * @slot: pointer to the &struct hotplug_slot to register
425  * @devnr: device number
426  * @name: name registered with kobject core
427  * @owner: caller module owner
428  * @mod_name: caller module name
429  *
430  * Registers a hotplug slot with the pci hotplug subsystem, which will allow
431  * userspace interaction to the slot.
432  *
433  * Returns 0 if successful, anything else for an error.
434  */
435 int __pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus,
436 		      int devnr, const char *name,
437 		      struct module *owner, const char *mod_name)
438 {
439 	int result;
440 	struct pci_slot *pci_slot;
441 
442 	if (slot == NULL)
443 		return -ENODEV;
444 	if ((slot->info == NULL) || (slot->ops == NULL))
445 		return -EINVAL;
446 	if (slot->release == NULL) {
447 		dbg("Why are you trying to register a hotplug slot "
448 		    "without a proper release function?\n");
449 		return -EINVAL;
450 	}
451 
452 	slot->ops->owner = owner;
453 	slot->ops->mod_name = mod_name;
454 
455 	mutex_lock(&pci_hp_mutex);
456 	/*
457 	 * No problems if we call this interface from both ACPI_PCI_SLOT
458 	 * driver and call it here again. If we've already created the
459 	 * pci_slot, the interface will simply bump the refcount.
460 	 */
461 	pci_slot = pci_create_slot(bus, devnr, name, slot);
462 	if (IS_ERR(pci_slot)) {
463 		result = PTR_ERR(pci_slot);
464 		goto out;
465 	}
466 
467 	slot->pci_slot = pci_slot;
468 	pci_slot->hotplug = slot;
469 
470 	list_add(&slot->slot_list, &pci_hotplug_slot_list);
471 
472 	result = fs_add_slot(pci_slot);
473 	kobject_uevent(&pci_slot->kobj, KOBJ_ADD);
474 	dbg("Added slot %s to the list\n", name);
475 out:
476 	mutex_unlock(&pci_hp_mutex);
477 	return result;
478 }
479 
480 /**
481  * pci_hp_deregister - deregister a hotplug_slot with the PCI hotplug subsystem
482  * @hotplug: pointer to the &struct hotplug_slot to deregister
483  *
484  * The @slot must have been registered with the pci hotplug subsystem
485  * previously with a call to pci_hp_register().
486  *
487  * Returns 0 if successful, anything else for an error.
488  */
489 int pci_hp_deregister(struct hotplug_slot *hotplug)
490 {
491 	struct hotplug_slot *temp;
492 	struct pci_slot *slot;
493 
494 	if (!hotplug)
495 		return -ENODEV;
496 
497 	mutex_lock(&pci_hp_mutex);
498 	temp = get_slot_from_name(hotplug_slot_name(hotplug));
499 	if (temp != hotplug) {
500 		mutex_unlock(&pci_hp_mutex);
501 		return -ENODEV;
502 	}
503 
504 	list_del(&hotplug->slot_list);
505 
506 	slot = hotplug->pci_slot;
507 	fs_remove_slot(slot);
508 	dbg("Removed slot %s from the list\n", hotplug_slot_name(hotplug));
509 
510 	hotplug->release(hotplug);
511 	slot->hotplug = NULL;
512 	pci_destroy_slot(slot);
513 	mutex_unlock(&pci_hp_mutex);
514 
515 	return 0;
516 }
517 
518 /**
519  * pci_hp_change_slot_info - changes the slot's information structure in the core
520  * @hotplug: pointer to the slot whose info has changed
521  * @info: pointer to the info copy into the slot's info structure
522  *
523  * @slot must have been registered with the pci
524  * hotplug subsystem previously with a call to pci_hp_register().
525  *
526  * Returns 0 if successful, anything else for an error.
527  */
528 int __must_check pci_hp_change_slot_info(struct hotplug_slot *hotplug,
529 					 struct hotplug_slot_info *info)
530 {
531 	struct pci_slot *slot;
532 	if (!hotplug || !info)
533 		return -ENODEV;
534 	slot = hotplug->pci_slot;
535 
536 	memcpy(hotplug->info, info, sizeof(struct hotplug_slot_info));
537 
538 	return 0;
539 }
540 
541 static int __init pci_hotplug_init (void)
542 {
543 	int result;
544 
545 	result = cpci_hotplug_init(debug);
546 	if (result) {
547 		err ("cpci_hotplug_init with error %d\n", result);
548 		goto err_cpci;
549 	}
550 
551 	info (DRIVER_DESC " version: " DRIVER_VERSION "\n");
552 
553 err_cpci:
554 	return result;
555 }
556 
557 static void __exit pci_hotplug_exit (void)
558 {
559 	cpci_hotplug_exit();
560 }
561 
562 module_init(pci_hotplug_init);
563 module_exit(pci_hotplug_exit);
564 
565 MODULE_AUTHOR(DRIVER_AUTHOR);
566 MODULE_DESCRIPTION(DRIVER_DESC);
567 MODULE_LICENSE("GPL");
568 module_param(debug, bool, 0644);
569 MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
570 
571 EXPORT_SYMBOL_GPL(__pci_hp_register);
572 EXPORT_SYMBOL_GPL(pci_hp_deregister);
573 EXPORT_SYMBOL_GPL(pci_hp_change_slot_info);
574