1 /*
2  * file for managing the edac_device class of devices for EDAC
3  *
4  * (C) 2007 SoftwareBitMaker
5  *
6  * This file may be distributed under the terms of the
7  * GNU General Public License.
8  *
9  * Written Doug Thompson <norsk5@xmission.com>
10  *
11  */
12 
13 #include <linux/ctype.h>
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/edac.h>
17 
18 #include "edac_core.h"
19 #include "edac_module.h"
20 
21 #define EDAC_DEVICE_SYMLINK	"device"
22 
23 #define to_edacdev(k) container_of(k, struct edac_device_ctl_info, kobj)
24 #define to_edacdev_attr(a) container_of(a, struct edacdev_attribute, attr)
25 
26 
27 /*
28  * Set of edac_device_ctl_info attribute store/show functions
29  */
30 
31 /* 'log_ue' */
32 static ssize_t edac_device_ctl_log_ue_show(struct edac_device_ctl_info
33 					*ctl_info, char *data)
34 {
35 	return sprintf(data, "%u\n", ctl_info->log_ue);
36 }
37 
38 static ssize_t edac_device_ctl_log_ue_store(struct edac_device_ctl_info
39 					*ctl_info, const char *data,
40 					size_t count)
41 {
42 	/* if parameter is zero, turn off flag, if non-zero turn on flag */
43 	ctl_info->log_ue = (simple_strtoul(data, NULL, 0) != 0);
44 
45 	return count;
46 }
47 
48 /* 'log_ce' */
49 static ssize_t edac_device_ctl_log_ce_show(struct edac_device_ctl_info
50 					*ctl_info, char *data)
51 {
52 	return sprintf(data, "%u\n", ctl_info->log_ce);
53 }
54 
55 static ssize_t edac_device_ctl_log_ce_store(struct edac_device_ctl_info
56 					*ctl_info, const char *data,
57 					size_t count)
58 {
59 	/* if parameter is zero, turn off flag, if non-zero turn on flag */
60 	ctl_info->log_ce = (simple_strtoul(data, NULL, 0) != 0);
61 
62 	return count;
63 }
64 
65 /* 'panic_on_ue' */
66 static ssize_t edac_device_ctl_panic_on_ue_show(struct edac_device_ctl_info
67 						*ctl_info, char *data)
68 {
69 	return sprintf(data, "%u\n", ctl_info->panic_on_ue);
70 }
71 
72 static ssize_t edac_device_ctl_panic_on_ue_store(struct edac_device_ctl_info
73 						 *ctl_info, const char *data,
74 						 size_t count)
75 {
76 	/* if parameter is zero, turn off flag, if non-zero turn on flag */
77 	ctl_info->panic_on_ue = (simple_strtoul(data, NULL, 0) != 0);
78 
79 	return count;
80 }
81 
82 /* 'poll_msec' show and store functions*/
83 static ssize_t edac_device_ctl_poll_msec_show(struct edac_device_ctl_info
84 					*ctl_info, char *data)
85 {
86 	return sprintf(data, "%u\n", ctl_info->poll_msec);
87 }
88 
89 static ssize_t edac_device_ctl_poll_msec_store(struct edac_device_ctl_info
90 					*ctl_info, const char *data,
91 					size_t count)
92 {
93 	unsigned long value;
94 
95 	/* get the value and enforce that it is non-zero, must be at least
96 	 * one millisecond for the delay period, between scans
97 	 * Then cancel last outstanding delay for the work request
98 	 * and set a new one.
99 	 */
100 	value = simple_strtoul(data, NULL, 0);
101 	edac_device_reset_delay_period(ctl_info, value);
102 
103 	return count;
104 }
105 
106 /* edac_device_ctl_info specific attribute structure */
107 struct ctl_info_attribute {
108 	struct attribute attr;
109 	ssize_t(*show) (struct edac_device_ctl_info *, char *);
110 	ssize_t(*store) (struct edac_device_ctl_info *, const char *, size_t);
111 };
112 
113 #define to_ctl_info(k) container_of(k, struct edac_device_ctl_info, kobj)
114 #define to_ctl_info_attr(a) container_of(a,struct ctl_info_attribute,attr)
115 
116 /* Function to 'show' fields from the edac_dev 'ctl_info' structure */
117 static ssize_t edac_dev_ctl_info_show(struct kobject *kobj,
118 				struct attribute *attr, char *buffer)
119 {
120 	struct edac_device_ctl_info *edac_dev = to_ctl_info(kobj);
121 	struct ctl_info_attribute *ctl_info_attr = to_ctl_info_attr(attr);
122 
123 	if (ctl_info_attr->show)
124 		return ctl_info_attr->show(edac_dev, buffer);
125 	return -EIO;
126 }
127 
128 /* Function to 'store' fields into the edac_dev 'ctl_info' structure */
129 static ssize_t edac_dev_ctl_info_store(struct kobject *kobj,
130 				struct attribute *attr,
131 				const char *buffer, size_t count)
132 {
133 	struct edac_device_ctl_info *edac_dev = to_ctl_info(kobj);
134 	struct ctl_info_attribute *ctl_info_attr = to_ctl_info_attr(attr);
135 
136 	if (ctl_info_attr->store)
137 		return ctl_info_attr->store(edac_dev, buffer, count);
138 	return -EIO;
139 }
140 
141 /* edac_dev file operations for an 'ctl_info' */
142 static const struct sysfs_ops device_ctl_info_ops = {
143 	.show = edac_dev_ctl_info_show,
144 	.store = edac_dev_ctl_info_store
145 };
146 
147 #define CTL_INFO_ATTR(_name,_mode,_show,_store)        \
148 static struct ctl_info_attribute attr_ctl_info_##_name = {      \
149 	.attr = {.name = __stringify(_name), .mode = _mode },   \
150 	.show   = _show,                                        \
151 	.store  = _store,                                       \
152 };
153 
154 /* Declare the various ctl_info attributes here and their respective ops */
155 CTL_INFO_ATTR(log_ue, S_IRUGO | S_IWUSR,
156 	edac_device_ctl_log_ue_show, edac_device_ctl_log_ue_store);
157 CTL_INFO_ATTR(log_ce, S_IRUGO | S_IWUSR,
158 	edac_device_ctl_log_ce_show, edac_device_ctl_log_ce_store);
159 CTL_INFO_ATTR(panic_on_ue, S_IRUGO | S_IWUSR,
160 	edac_device_ctl_panic_on_ue_show,
161 	edac_device_ctl_panic_on_ue_store);
162 CTL_INFO_ATTR(poll_msec, S_IRUGO | S_IWUSR,
163 	edac_device_ctl_poll_msec_show, edac_device_ctl_poll_msec_store);
164 
165 /* Base Attributes of the EDAC_DEVICE ECC object */
166 static struct ctl_info_attribute *device_ctrl_attr[] = {
167 	&attr_ctl_info_panic_on_ue,
168 	&attr_ctl_info_log_ue,
169 	&attr_ctl_info_log_ce,
170 	&attr_ctl_info_poll_msec,
171 	NULL,
172 };
173 
174 /*
175  * edac_device_ctrl_master_release
176  *
177  *	called when the reference count for the 'main' kobj
178  *	for a edac_device control struct reaches zero
179  *
180  *	Reference count model:
181  *		One 'main' kobject for each control structure allocated.
182  *		That main kobj is initially set to one AND
183  *		the reference count for the EDAC 'core' module is
184  *		bumped by one, thus added 'keep in memory' dependency.
185  *
186  *		Each new internal kobj (in instances and blocks) then
187  *		bumps the 'main' kobject.
188  *
189  *		When they are released their release functions decrement
190  *		the 'main' kobj.
191  *
192  *		When the main kobj reaches zero (0) then THIS function
193  *		is called which then decrements the EDAC 'core' module.
194  *		When the module reference count reaches zero then the
195  *		module no longer has dependency on keeping the release
196  *		function code in memory and module can be unloaded.
197  *
198  *		This will support several control objects as well, each
199  *		with its own 'main' kobj.
200  */
201 static void edac_device_ctrl_master_release(struct kobject *kobj)
202 {
203 	struct edac_device_ctl_info *edac_dev = to_edacdev(kobj);
204 
205 	debugf4("%s() control index=%d\n", __func__, edac_dev->dev_idx);
206 
207 	/* decrement the EDAC CORE module ref count */
208 	module_put(edac_dev->owner);
209 
210 	/* free the control struct containing the 'main' kobj
211 	 * passed in to this routine
212 	 */
213 	kfree(edac_dev);
214 }
215 
216 /* ktype for the main (master) kobject */
217 static struct kobj_type ktype_device_ctrl = {
218 	.release = edac_device_ctrl_master_release,
219 	.sysfs_ops = &device_ctl_info_ops,
220 	.default_attrs = (struct attribute **)device_ctrl_attr,
221 };
222 
223 /*
224  * edac_device_register_sysfs_main_kobj
225  *
226  *	perform the high level setup for the new edac_device instance
227  *
228  * Return:  0 SUCCESS
229  *         !0 FAILURE
230  */
231 int edac_device_register_sysfs_main_kobj(struct edac_device_ctl_info *edac_dev)
232 {
233 	struct sysdev_class *edac_class;
234 	int err;
235 
236 	debugf1("%s()\n", __func__);
237 
238 	/* get the /sys/devices/system/edac reference */
239 	edac_class = edac_get_sysfs_class();
240 	if (edac_class == NULL) {
241 		debugf1("%s() no edac_class error\n", __func__);
242 		err = -ENODEV;
243 		goto err_out;
244 	}
245 
246 	/* Point to the 'edac_class' this instance 'reports' to */
247 	edac_dev->edac_class = edac_class;
248 
249 	/* Init the devices's kobject */
250 	memset(&edac_dev->kobj, 0, sizeof(struct kobject));
251 
252 	/* Record which module 'owns' this control structure
253 	 * and bump the ref count of the module
254 	 */
255 	edac_dev->owner = THIS_MODULE;
256 
257 	if (!try_module_get(edac_dev->owner)) {
258 		err = -ENODEV;
259 		goto err_mod_get;
260 	}
261 
262 	/* register */
263 	err = kobject_init_and_add(&edac_dev->kobj, &ktype_device_ctrl,
264 				   &edac_class->kset.kobj,
265 				   "%s", edac_dev->name);
266 	if (err) {
267 		debugf1("%s()Failed to register '.../edac/%s'\n",
268 			__func__, edac_dev->name);
269 		goto err_kobj_reg;
270 	}
271 	kobject_uevent(&edac_dev->kobj, KOBJ_ADD);
272 
273 	/* At this point, to 'free' the control struct,
274 	 * edac_device_unregister_sysfs_main_kobj() must be used
275 	 */
276 
277 	debugf4("%s() Registered '.../edac/%s' kobject\n",
278 		__func__, edac_dev->name);
279 
280 	return 0;
281 
282 	/* Error exit stack */
283 err_kobj_reg:
284 	module_put(edac_dev->owner);
285 
286 err_mod_get:
287 	edac_put_sysfs_class();
288 
289 err_out:
290 	return err;
291 }
292 
293 /*
294  * edac_device_unregister_sysfs_main_kobj:
295  *	the '..../edac/<name>' kobject
296  */
297 void edac_device_unregister_sysfs_main_kobj(struct edac_device_ctl_info *dev)
298 {
299 	debugf0("%s()\n", __func__);
300 	debugf4("%s() name of kobject is: %s\n",
301 		__func__, kobject_name(&dev->kobj));
302 
303 	/*
304 	 * Unregister the edac device's kobject and
305 	 * allow for reference count to reach 0 at which point
306 	 * the callback will be called to:
307 	 *   a) module_put() this module
308 	 *   b) 'kfree' the memory
309 	 */
310 	kobject_put(&dev->kobj);
311 	edac_put_sysfs_class();
312 }
313 
314 /* edac_dev -> instance information */
315 
316 /*
317  * Set of low-level instance attribute show functions
318  */
319 static ssize_t instance_ue_count_show(struct edac_device_instance *instance,
320 				char *data)
321 {
322 	return sprintf(data, "%u\n", instance->counters.ue_count);
323 }
324 
325 static ssize_t instance_ce_count_show(struct edac_device_instance *instance,
326 				char *data)
327 {
328 	return sprintf(data, "%u\n", instance->counters.ce_count);
329 }
330 
331 #define to_instance(k) container_of(k, struct edac_device_instance, kobj)
332 #define to_instance_attr(a) container_of(a,struct instance_attribute,attr)
333 
334 /* DEVICE instance kobject release() function */
335 static void edac_device_ctrl_instance_release(struct kobject *kobj)
336 {
337 	struct edac_device_instance *instance;
338 
339 	debugf1("%s()\n", __func__);
340 
341 	/* map from this kobj to the main control struct
342 	 * and then dec the main kobj count
343 	 */
344 	instance = to_instance(kobj);
345 	kobject_put(&instance->ctl->kobj);
346 }
347 
348 /* instance specific attribute structure */
349 struct instance_attribute {
350 	struct attribute attr;
351 	ssize_t(*show) (struct edac_device_instance *, char *);
352 	ssize_t(*store) (struct edac_device_instance *, const char *, size_t);
353 };
354 
355 /* Function to 'show' fields from the edac_dev 'instance' structure */
356 static ssize_t edac_dev_instance_show(struct kobject *kobj,
357 				struct attribute *attr, char *buffer)
358 {
359 	struct edac_device_instance *instance = to_instance(kobj);
360 	struct instance_attribute *instance_attr = to_instance_attr(attr);
361 
362 	if (instance_attr->show)
363 		return instance_attr->show(instance, buffer);
364 	return -EIO;
365 }
366 
367 /* Function to 'store' fields into the edac_dev 'instance' structure */
368 static ssize_t edac_dev_instance_store(struct kobject *kobj,
369 				struct attribute *attr,
370 				const char *buffer, size_t count)
371 {
372 	struct edac_device_instance *instance = to_instance(kobj);
373 	struct instance_attribute *instance_attr = to_instance_attr(attr);
374 
375 	if (instance_attr->store)
376 		return instance_attr->store(instance, buffer, count);
377 	return -EIO;
378 }
379 
380 /* edac_dev file operations for an 'instance' */
381 static const struct sysfs_ops device_instance_ops = {
382 	.show = edac_dev_instance_show,
383 	.store = edac_dev_instance_store
384 };
385 
386 #define INSTANCE_ATTR(_name,_mode,_show,_store)        \
387 static struct instance_attribute attr_instance_##_name = {      \
388 	.attr = {.name = __stringify(_name), .mode = _mode },   \
389 	.show   = _show,                                        \
390 	.store  = _store,                                       \
391 };
392 
393 /*
394  * Define attributes visible for the edac_device instance object
395  *	Each contains a pointer to a show and an optional set
396  *	function pointer that does the low level output/input
397  */
398 INSTANCE_ATTR(ce_count, S_IRUGO, instance_ce_count_show, NULL);
399 INSTANCE_ATTR(ue_count, S_IRUGO, instance_ue_count_show, NULL);
400 
401 /* list of edac_dev 'instance' attributes */
402 static struct instance_attribute *device_instance_attr[] = {
403 	&attr_instance_ce_count,
404 	&attr_instance_ue_count,
405 	NULL,
406 };
407 
408 /* The 'ktype' for each edac_dev 'instance' */
409 static struct kobj_type ktype_instance_ctrl = {
410 	.release = edac_device_ctrl_instance_release,
411 	.sysfs_ops = &device_instance_ops,
412 	.default_attrs = (struct attribute **)device_instance_attr,
413 };
414 
415 /* edac_dev -> instance -> block information */
416 
417 #define to_block(k) container_of(k, struct edac_device_block, kobj)
418 #define to_block_attr(a) \
419 	container_of(a, struct edac_dev_sysfs_block_attribute, attr)
420 
421 /*
422  * Set of low-level block attribute show functions
423  */
424 static ssize_t block_ue_count_show(struct kobject *kobj,
425 					struct attribute *attr, char *data)
426 {
427 	struct edac_device_block *block = to_block(kobj);
428 
429 	return sprintf(data, "%u\n", block->counters.ue_count);
430 }
431 
432 static ssize_t block_ce_count_show(struct kobject *kobj,
433 					struct attribute *attr, char *data)
434 {
435 	struct edac_device_block *block = to_block(kobj);
436 
437 	return sprintf(data, "%u\n", block->counters.ce_count);
438 }
439 
440 /* DEVICE block kobject release() function */
441 static void edac_device_ctrl_block_release(struct kobject *kobj)
442 {
443 	struct edac_device_block *block;
444 
445 	debugf1("%s()\n", __func__);
446 
447 	/* get the container of the kobj */
448 	block = to_block(kobj);
449 
450 	/* map from 'block kobj' to 'block->instance->controller->main_kobj'
451 	 * now 'release' the block kobject
452 	 */
453 	kobject_put(&block->instance->ctl->kobj);
454 }
455 
456 
457 /* Function to 'show' fields from the edac_dev 'block' structure */
458 static ssize_t edac_dev_block_show(struct kobject *kobj,
459 				struct attribute *attr, char *buffer)
460 {
461 	struct edac_dev_sysfs_block_attribute *block_attr =
462 						to_block_attr(attr);
463 
464 	if (block_attr->show)
465 		return block_attr->show(kobj, attr, buffer);
466 	return -EIO;
467 }
468 
469 /* Function to 'store' fields into the edac_dev 'block' structure */
470 static ssize_t edac_dev_block_store(struct kobject *kobj,
471 				struct attribute *attr,
472 				const char *buffer, size_t count)
473 {
474 	struct edac_dev_sysfs_block_attribute *block_attr;
475 
476 	block_attr = to_block_attr(attr);
477 
478 	if (block_attr->store)
479 		return block_attr->store(kobj, attr, buffer, count);
480 	return -EIO;
481 }
482 
483 /* edac_dev file operations for a 'block' */
484 static const struct sysfs_ops device_block_ops = {
485 	.show = edac_dev_block_show,
486 	.store = edac_dev_block_store
487 };
488 
489 #define BLOCK_ATTR(_name,_mode,_show,_store)        \
490 static struct edac_dev_sysfs_block_attribute attr_block_##_name = {	\
491 	.attr = {.name = __stringify(_name), .mode = _mode },   \
492 	.show   = _show,                                        \
493 	.store  = _store,                                       \
494 };
495 
496 BLOCK_ATTR(ce_count, S_IRUGO, block_ce_count_show, NULL);
497 BLOCK_ATTR(ue_count, S_IRUGO, block_ue_count_show, NULL);
498 
499 /* list of edac_dev 'block' attributes */
500 static struct edac_dev_sysfs_block_attribute *device_block_attr[] = {
501 	&attr_block_ce_count,
502 	&attr_block_ue_count,
503 	NULL,
504 };
505 
506 /* The 'ktype' for each edac_dev 'block' */
507 static struct kobj_type ktype_block_ctrl = {
508 	.release = edac_device_ctrl_block_release,
509 	.sysfs_ops = &device_block_ops,
510 	.default_attrs = (struct attribute **)device_block_attr,
511 };
512 
513 /* block ctor/dtor  code */
514 
515 /*
516  * edac_device_create_block
517  */
518 static int edac_device_create_block(struct edac_device_ctl_info *edac_dev,
519 				struct edac_device_instance *instance,
520 				struct edac_device_block *block)
521 {
522 	int i;
523 	int err;
524 	struct edac_dev_sysfs_block_attribute *sysfs_attrib;
525 	struct kobject *main_kobj;
526 
527 	debugf4("%s() Instance '%s' inst_p=%p  block '%s'  block_p=%p\n",
528 		__func__, instance->name, instance, block->name, block);
529 	debugf4("%s() block kobj=%p  block kobj->parent=%p\n",
530 		__func__, &block->kobj, &block->kobj.parent);
531 
532 	/* init this block's kobject */
533 	memset(&block->kobj, 0, sizeof(struct kobject));
534 
535 	/* bump the main kobject's reference count for this controller
536 	 * and this instance is dependant on the main
537 	 */
538 	main_kobj = kobject_get(&edac_dev->kobj);
539 	if (!main_kobj) {
540 		err = -ENODEV;
541 		goto err_out;
542 	}
543 
544 	/* Add this block's kobject */
545 	err = kobject_init_and_add(&block->kobj, &ktype_block_ctrl,
546 				   &instance->kobj,
547 				   "%s", block->name);
548 	if (err) {
549 		debugf1("%s() Failed to register instance '%s'\n",
550 			__func__, block->name);
551 		kobject_put(main_kobj);
552 		err = -ENODEV;
553 		goto err_out;
554 	}
555 
556 	/* If there are driver level block attributes, then added them
557 	 * to the block kobject
558 	 */
559 	sysfs_attrib = block->block_attributes;
560 	if (sysfs_attrib && block->nr_attribs) {
561 		for (i = 0; i < block->nr_attribs; i++, sysfs_attrib++) {
562 
563 			debugf4("%s() creating block attrib='%s' "
564 				"attrib->%p to kobj=%p\n",
565 				__func__,
566 				sysfs_attrib->attr.name,
567 				sysfs_attrib, &block->kobj);
568 
569 			/* Create each block_attribute file */
570 			err = sysfs_create_file(&block->kobj,
571 				&sysfs_attrib->attr);
572 			if (err)
573 				goto err_on_attrib;
574 		}
575 	}
576 	kobject_uevent(&block->kobj, KOBJ_ADD);
577 
578 	return 0;
579 
580 	/* Error unwind stack */
581 err_on_attrib:
582 	kobject_put(&block->kobj);
583 
584 err_out:
585 	return err;
586 }
587 
588 /*
589  * edac_device_delete_block(edac_dev,block);
590  */
591 static void edac_device_delete_block(struct edac_device_ctl_info *edac_dev,
592 				struct edac_device_block *block)
593 {
594 	struct edac_dev_sysfs_block_attribute *sysfs_attrib;
595 	int i;
596 
597 	/* if this block has 'attributes' then we need to iterate over the list
598 	 * and 'remove' the attributes on this block
599 	 */
600 	sysfs_attrib = block->block_attributes;
601 	if (sysfs_attrib && block->nr_attribs) {
602 		for (i = 0; i < block->nr_attribs; i++, sysfs_attrib++) {
603 
604 			/* remove each block_attrib file */
605 			sysfs_remove_file(&block->kobj,
606 				(struct attribute *) sysfs_attrib);
607 		}
608 	}
609 
610 	/* unregister this block's kobject, SEE:
611 	 *	edac_device_ctrl_block_release() callback operation
612 	 */
613 	kobject_put(&block->kobj);
614 }
615 
616 /* instance ctor/dtor code */
617 
618 /*
619  * edac_device_create_instance
620  *	create just one instance of an edac_device 'instance'
621  */
622 static int edac_device_create_instance(struct edac_device_ctl_info *edac_dev,
623 				int idx)
624 {
625 	int i, j;
626 	int err;
627 	struct edac_device_instance *instance;
628 	struct kobject *main_kobj;
629 
630 	instance = &edac_dev->instances[idx];
631 
632 	/* Init the instance's kobject */
633 	memset(&instance->kobj, 0, sizeof(struct kobject));
634 
635 	instance->ctl = edac_dev;
636 
637 	/* bump the main kobject's reference count for this controller
638 	 * and this instance is dependant on the main
639 	 */
640 	main_kobj = kobject_get(&edac_dev->kobj);
641 	if (!main_kobj) {
642 		err = -ENODEV;
643 		goto err_out;
644 	}
645 
646 	/* Formally register this instance's kobject under the edac_device */
647 	err = kobject_init_and_add(&instance->kobj, &ktype_instance_ctrl,
648 				   &edac_dev->kobj, "%s", instance->name);
649 	if (err != 0) {
650 		debugf2("%s() Failed to register instance '%s'\n",
651 			__func__, instance->name);
652 		kobject_put(main_kobj);
653 		goto err_out;
654 	}
655 
656 	debugf4("%s() now register '%d' blocks for instance %d\n",
657 		__func__, instance->nr_blocks, idx);
658 
659 	/* register all blocks of this instance */
660 	for (i = 0; i < instance->nr_blocks; i++) {
661 		err = edac_device_create_block(edac_dev, instance,
662 						&instance->blocks[i]);
663 		if (err) {
664 			/* If any fail, remove all previous ones */
665 			for (j = 0; j < i; j++)
666 				edac_device_delete_block(edac_dev,
667 							&instance->blocks[j]);
668 			goto err_release_instance_kobj;
669 		}
670 	}
671 	kobject_uevent(&instance->kobj, KOBJ_ADD);
672 
673 	debugf4("%s() Registered instance %d '%s' kobject\n",
674 		__func__, idx, instance->name);
675 
676 	return 0;
677 
678 	/* error unwind stack */
679 err_release_instance_kobj:
680 	kobject_put(&instance->kobj);
681 
682 err_out:
683 	return err;
684 }
685 
686 /*
687  * edac_device_remove_instance
688  *	remove an edac_device instance
689  */
690 static void edac_device_delete_instance(struct edac_device_ctl_info *edac_dev,
691 					int idx)
692 {
693 	struct edac_device_instance *instance;
694 	int i;
695 
696 	instance = &edac_dev->instances[idx];
697 
698 	/* unregister all blocks in this instance */
699 	for (i = 0; i < instance->nr_blocks; i++)
700 		edac_device_delete_block(edac_dev, &instance->blocks[i]);
701 
702 	/* unregister this instance's kobject, SEE:
703 	 *	edac_device_ctrl_instance_release() for callback operation
704 	 */
705 	kobject_put(&instance->kobj);
706 }
707 
708 /*
709  * edac_device_create_instances
710  *	create the first level of 'instances' for this device
711  *	(ie  'cache' might have 'cache0', 'cache1', 'cache2', etc
712  */
713 static int edac_device_create_instances(struct edac_device_ctl_info *edac_dev)
714 {
715 	int i, j;
716 	int err;
717 
718 	debugf0("%s()\n", __func__);
719 
720 	/* iterate over creation of the instances */
721 	for (i = 0; i < edac_dev->nr_instances; i++) {
722 		err = edac_device_create_instance(edac_dev, i);
723 		if (err) {
724 			/* unwind previous instances on error */
725 			for (j = 0; j < i; j++)
726 				edac_device_delete_instance(edac_dev, j);
727 			return err;
728 		}
729 	}
730 
731 	return 0;
732 }
733 
734 /*
735  * edac_device_delete_instances(edac_dev);
736  *	unregister all the kobjects of the instances
737  */
738 static void edac_device_delete_instances(struct edac_device_ctl_info *edac_dev)
739 {
740 	int i;
741 
742 	/* iterate over creation of the instances */
743 	for (i = 0; i < edac_dev->nr_instances; i++)
744 		edac_device_delete_instance(edac_dev, i);
745 }
746 
747 /* edac_dev sysfs ctor/dtor  code */
748 
749 /*
750  * edac_device_add_main_sysfs_attributes
751  *	add some attributes to this instance's main kobject
752  */
753 static int edac_device_add_main_sysfs_attributes(
754 			struct edac_device_ctl_info *edac_dev)
755 {
756 	struct edac_dev_sysfs_attribute *sysfs_attrib;
757 	int err = 0;
758 
759 	sysfs_attrib = edac_dev->sysfs_attributes;
760 	if (sysfs_attrib) {
761 		/* iterate over the array and create an attribute for each
762 		 * entry in the list
763 		 */
764 		while (sysfs_attrib->attr.name != NULL) {
765 			err = sysfs_create_file(&edac_dev->kobj,
766 				(struct attribute*) sysfs_attrib);
767 			if (err)
768 				goto err_out;
769 
770 			sysfs_attrib++;
771 		}
772 	}
773 
774 err_out:
775 	return err;
776 }
777 
778 /*
779  * edac_device_remove_main_sysfs_attributes
780  *	remove any attributes to this instance's main kobject
781  */
782 static void edac_device_remove_main_sysfs_attributes(
783 			struct edac_device_ctl_info *edac_dev)
784 {
785 	struct edac_dev_sysfs_attribute *sysfs_attrib;
786 
787 	/* if there are main attributes, defined, remove them. First,
788 	 * point to the start of the array and iterate over it
789 	 * removing each attribute listed from this device's instance's kobject
790 	 */
791 	sysfs_attrib = edac_dev->sysfs_attributes;
792 	if (sysfs_attrib) {
793 		while (sysfs_attrib->attr.name != NULL) {
794 			sysfs_remove_file(&edac_dev->kobj,
795 					(struct attribute *) sysfs_attrib);
796 			sysfs_attrib++;
797 		}
798 	}
799 }
800 
801 /*
802  * edac_device_create_sysfs() Constructor
803  *
804  * accept a created edac_device control structure
805  * and 'export' it to sysfs. The 'main' kobj should already have been
806  * created. 'instance' and 'block' kobjects should be registered
807  * along with any 'block' attributes from the low driver. In addition,
808  * the main attributes (if any) are connected to the main kobject of
809  * the control structure.
810  *
811  * Return:
812  *	0	Success
813  *	!0	Failure
814  */
815 int edac_device_create_sysfs(struct edac_device_ctl_info *edac_dev)
816 {
817 	int err;
818 	struct kobject *edac_kobj = &edac_dev->kobj;
819 
820 	debugf0("%s() idx=%d\n", __func__, edac_dev->dev_idx);
821 
822 	/*  go create any main attributes callers wants */
823 	err = edac_device_add_main_sysfs_attributes(edac_dev);
824 	if (err) {
825 		debugf0("%s() failed to add sysfs attribs\n", __func__);
826 		goto err_out;
827 	}
828 
829 	/* create a symlink from the edac device
830 	 * to the platform 'device' being used for this
831 	 */
832 	err = sysfs_create_link(edac_kobj,
833 				&edac_dev->dev->kobj, EDAC_DEVICE_SYMLINK);
834 	if (err) {
835 		debugf0("%s() sysfs_create_link() returned err= %d\n",
836 			__func__, err);
837 		goto err_remove_main_attribs;
838 	}
839 
840 	/* Create the first level instance directories
841 	 * In turn, the nested blocks beneath the instances will
842 	 * be registered as well
843 	 */
844 	err = edac_device_create_instances(edac_dev);
845 	if (err) {
846 		debugf0("%s() edac_device_create_instances() "
847 			"returned err= %d\n", __func__, err);
848 		goto err_remove_link;
849 	}
850 
851 
852 	debugf4("%s() create-instances done, idx=%d\n",
853 		__func__, edac_dev->dev_idx);
854 
855 	return 0;
856 
857 	/* Error unwind stack */
858 err_remove_link:
859 	/* remove the sym link */
860 	sysfs_remove_link(&edac_dev->kobj, EDAC_DEVICE_SYMLINK);
861 
862 err_remove_main_attribs:
863 	edac_device_remove_main_sysfs_attributes(edac_dev);
864 
865 err_out:
866 	return err;
867 }
868 
869 /*
870  * edac_device_remove_sysfs() destructor
871  *
872  * given an edac_device struct, tear down the kobject resources
873  */
874 void edac_device_remove_sysfs(struct edac_device_ctl_info *edac_dev)
875 {
876 	debugf0("%s()\n", __func__);
877 
878 	/* remove any main attributes for this device */
879 	edac_device_remove_main_sysfs_attributes(edac_dev);
880 
881 	/* remove the device sym link */
882 	sysfs_remove_link(&edac_dev->kobj, EDAC_DEVICE_SYMLINK);
883 
884 	/* walk the instance/block kobject tree, deconstructing it */
885 	edac_device_delete_instances(edac_dev);
886 }
887