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