1 /*
2  * file for managing the edac_device subsystem 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_device.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 	edac_dbg(4, "control index=%d\n", 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 bus_type *edac_subsys;
234 	int err;
235 
236 	edac_dbg(1, "\n");
237 
238 	/* get the /sys/devices/system/edac reference */
239 	edac_subsys = edac_get_sysfs_subsys();
240 
241 	/* Point to the 'edac_subsys' this instance 'reports' to */
242 	edac_dev->edac_subsys = edac_subsys;
243 
244 	/* Init the devices's kobject */
245 	memset(&edac_dev->kobj, 0, sizeof(struct kobject));
246 
247 	/* Record which module 'owns' this control structure
248 	 * and bump the ref count of the module
249 	 */
250 	edac_dev->owner = THIS_MODULE;
251 
252 	if (!try_module_get(edac_dev->owner)) {
253 		err = -ENODEV;
254 		goto err_out;
255 	}
256 
257 	/* register */
258 	err = kobject_init_and_add(&edac_dev->kobj, &ktype_device_ctrl,
259 				   &edac_subsys->dev_root->kobj,
260 				   "%s", edac_dev->name);
261 	if (err) {
262 		edac_dbg(1, "Failed to register '.../edac/%s'\n",
263 			 edac_dev->name);
264 		goto err_kobj_reg;
265 	}
266 	kobject_uevent(&edac_dev->kobj, KOBJ_ADD);
267 
268 	/* At this point, to 'free' the control struct,
269 	 * edac_device_unregister_sysfs_main_kobj() must be used
270 	 */
271 
272 	edac_dbg(4, "Registered '.../edac/%s' kobject\n", edac_dev->name);
273 
274 	return 0;
275 
276 	/* Error exit stack */
277 err_kobj_reg:
278 	kobject_put(&edac_dev->kobj);
279 	module_put(edac_dev->owner);
280 
281 err_out:
282 	return err;
283 }
284 
285 /*
286  * edac_device_unregister_sysfs_main_kobj:
287  *	the '..../edac/<name>' kobject
288  */
289 void edac_device_unregister_sysfs_main_kobj(struct edac_device_ctl_info *dev)
290 {
291 	edac_dbg(0, "\n");
292 	edac_dbg(4, "name of kobject is: %s\n", kobject_name(&dev->kobj));
293 
294 	/*
295 	 * Unregister the edac device's kobject and
296 	 * allow for reference count to reach 0 at which point
297 	 * the callback will be called to:
298 	 *   a) module_put() this module
299 	 *   b) 'kfree' the memory
300 	 */
301 	kobject_put(&dev->kobj);
302 }
303 
304 /* edac_dev -> instance information */
305 
306 /*
307  * Set of low-level instance attribute show functions
308  */
309 static ssize_t instance_ue_count_show(struct edac_device_instance *instance,
310 				char *data)
311 {
312 	return sprintf(data, "%u\n", instance->counters.ue_count);
313 }
314 
315 static ssize_t instance_ce_count_show(struct edac_device_instance *instance,
316 				char *data)
317 {
318 	return sprintf(data, "%u\n", instance->counters.ce_count);
319 }
320 
321 #define to_instance(k) container_of(k, struct edac_device_instance, kobj)
322 #define to_instance_attr(a) container_of(a,struct instance_attribute,attr)
323 
324 /* DEVICE instance kobject release() function */
325 static void edac_device_ctrl_instance_release(struct kobject *kobj)
326 {
327 	struct edac_device_instance *instance;
328 
329 	edac_dbg(1, "\n");
330 
331 	/* map from this kobj to the main control struct
332 	 * and then dec the main kobj count
333 	 */
334 	instance = to_instance(kobj);
335 	kobject_put(&instance->ctl->kobj);
336 }
337 
338 /* instance specific attribute structure */
339 struct instance_attribute {
340 	struct attribute attr;
341 	ssize_t(*show) (struct edac_device_instance *, char *);
342 	ssize_t(*store) (struct edac_device_instance *, const char *, size_t);
343 };
344 
345 /* Function to 'show' fields from the edac_dev 'instance' structure */
346 static ssize_t edac_dev_instance_show(struct kobject *kobj,
347 				struct attribute *attr, char *buffer)
348 {
349 	struct edac_device_instance *instance = to_instance(kobj);
350 	struct instance_attribute *instance_attr = to_instance_attr(attr);
351 
352 	if (instance_attr->show)
353 		return instance_attr->show(instance, buffer);
354 	return -EIO;
355 }
356 
357 /* Function to 'store' fields into the edac_dev 'instance' structure */
358 static ssize_t edac_dev_instance_store(struct kobject *kobj,
359 				struct attribute *attr,
360 				const char *buffer, size_t count)
361 {
362 	struct edac_device_instance *instance = to_instance(kobj);
363 	struct instance_attribute *instance_attr = to_instance_attr(attr);
364 
365 	if (instance_attr->store)
366 		return instance_attr->store(instance, buffer, count);
367 	return -EIO;
368 }
369 
370 /* edac_dev file operations for an 'instance' */
371 static const struct sysfs_ops device_instance_ops = {
372 	.show = edac_dev_instance_show,
373 	.store = edac_dev_instance_store
374 };
375 
376 #define INSTANCE_ATTR(_name,_mode,_show,_store)        \
377 static struct instance_attribute attr_instance_##_name = {      \
378 	.attr = {.name = __stringify(_name), .mode = _mode },   \
379 	.show   = _show,                                        \
380 	.store  = _store,                                       \
381 };
382 
383 /*
384  * Define attributes visible for the edac_device instance object
385  *	Each contains a pointer to a show and an optional set
386  *	function pointer that does the low level output/input
387  */
388 INSTANCE_ATTR(ce_count, S_IRUGO, instance_ce_count_show, NULL);
389 INSTANCE_ATTR(ue_count, S_IRUGO, instance_ue_count_show, NULL);
390 
391 /* list of edac_dev 'instance' attributes */
392 static struct instance_attribute *device_instance_attr[] = {
393 	&attr_instance_ce_count,
394 	&attr_instance_ue_count,
395 	NULL,
396 };
397 
398 /* The 'ktype' for each edac_dev 'instance' */
399 static struct kobj_type ktype_instance_ctrl = {
400 	.release = edac_device_ctrl_instance_release,
401 	.sysfs_ops = &device_instance_ops,
402 	.default_attrs = (struct attribute **)device_instance_attr,
403 };
404 
405 /* edac_dev -> instance -> block information */
406 
407 #define to_block(k) container_of(k, struct edac_device_block, kobj)
408 #define to_block_attr(a) \
409 	container_of(a, struct edac_dev_sysfs_block_attribute, attr)
410 
411 /*
412  * Set of low-level block attribute show functions
413  */
414 static ssize_t block_ue_count_show(struct kobject *kobj,
415 					struct attribute *attr, char *data)
416 {
417 	struct edac_device_block *block = to_block(kobj);
418 
419 	return sprintf(data, "%u\n", block->counters.ue_count);
420 }
421 
422 static ssize_t block_ce_count_show(struct kobject *kobj,
423 					struct attribute *attr, char *data)
424 {
425 	struct edac_device_block *block = to_block(kobj);
426 
427 	return sprintf(data, "%u\n", block->counters.ce_count);
428 }
429 
430 /* DEVICE block kobject release() function */
431 static void edac_device_ctrl_block_release(struct kobject *kobj)
432 {
433 	struct edac_device_block *block;
434 
435 	edac_dbg(1, "\n");
436 
437 	/* get the container of the kobj */
438 	block = to_block(kobj);
439 
440 	/* map from 'block kobj' to 'block->instance->controller->main_kobj'
441 	 * now 'release' the block kobject
442 	 */
443 	kobject_put(&block->instance->ctl->kobj);
444 }
445 
446 
447 /* Function to 'show' fields from the edac_dev 'block' structure */
448 static ssize_t edac_dev_block_show(struct kobject *kobj,
449 				struct attribute *attr, char *buffer)
450 {
451 	struct edac_dev_sysfs_block_attribute *block_attr =
452 						to_block_attr(attr);
453 
454 	if (block_attr->show)
455 		return block_attr->show(kobj, attr, buffer);
456 	return -EIO;
457 }
458 
459 /* Function to 'store' fields into the edac_dev 'block' structure */
460 static ssize_t edac_dev_block_store(struct kobject *kobj,
461 				struct attribute *attr,
462 				const char *buffer, size_t count)
463 {
464 	struct edac_dev_sysfs_block_attribute *block_attr;
465 
466 	block_attr = to_block_attr(attr);
467 
468 	if (block_attr->store)
469 		return block_attr->store(kobj, attr, buffer, count);
470 	return -EIO;
471 }
472 
473 /* edac_dev file operations for a 'block' */
474 static const struct sysfs_ops device_block_ops = {
475 	.show = edac_dev_block_show,
476 	.store = edac_dev_block_store
477 };
478 
479 #define BLOCK_ATTR(_name,_mode,_show,_store)        \
480 static struct edac_dev_sysfs_block_attribute attr_block_##_name = {	\
481 	.attr = {.name = __stringify(_name), .mode = _mode },   \
482 	.show   = _show,                                        \
483 	.store  = _store,                                       \
484 };
485 
486 BLOCK_ATTR(ce_count, S_IRUGO, block_ce_count_show, NULL);
487 BLOCK_ATTR(ue_count, S_IRUGO, block_ue_count_show, NULL);
488 
489 /* list of edac_dev 'block' attributes */
490 static struct edac_dev_sysfs_block_attribute *device_block_attr[] = {
491 	&attr_block_ce_count,
492 	&attr_block_ue_count,
493 	NULL,
494 };
495 
496 /* The 'ktype' for each edac_dev 'block' */
497 static struct kobj_type ktype_block_ctrl = {
498 	.release = edac_device_ctrl_block_release,
499 	.sysfs_ops = &device_block_ops,
500 	.default_attrs = (struct attribute **)device_block_attr,
501 };
502 
503 /* block ctor/dtor  code */
504 
505 /*
506  * edac_device_create_block
507  */
508 static int edac_device_create_block(struct edac_device_ctl_info *edac_dev,
509 				struct edac_device_instance *instance,
510 				struct edac_device_block *block)
511 {
512 	int i;
513 	int err;
514 	struct edac_dev_sysfs_block_attribute *sysfs_attrib;
515 	struct kobject *main_kobj;
516 
517 	edac_dbg(4, "Instance '%s' inst_p=%p  block '%s'  block_p=%p\n",
518 		 instance->name, instance, block->name, block);
519 	edac_dbg(4, "block kobj=%p  block kobj->parent=%p\n",
520 		 &block->kobj, &block->kobj.parent);
521 
522 	/* init this block's kobject */
523 	memset(&block->kobj, 0, sizeof(struct kobject));
524 
525 	/* bump the main kobject's reference count for this controller
526 	 * and this instance is dependent on the main
527 	 */
528 	main_kobj = kobject_get(&edac_dev->kobj);
529 	if (!main_kobj) {
530 		err = -ENODEV;
531 		goto err_out;
532 	}
533 
534 	/* Add this block's kobject */
535 	err = kobject_init_and_add(&block->kobj, &ktype_block_ctrl,
536 				   &instance->kobj,
537 				   "%s", block->name);
538 	if (err) {
539 		edac_dbg(1, "Failed to register instance '%s'\n", block->name);
540 		kobject_put(main_kobj);
541 		err = -ENODEV;
542 		goto err_out;
543 	}
544 
545 	/* If there are driver level block attributes, then added them
546 	 * to the block kobject
547 	 */
548 	sysfs_attrib = block->block_attributes;
549 	if (sysfs_attrib && block->nr_attribs) {
550 		for (i = 0; i < block->nr_attribs; i++, sysfs_attrib++) {
551 
552 			edac_dbg(4, "creating block attrib='%s' attrib->%p to kobj=%p\n",
553 				 sysfs_attrib->attr.name,
554 				 sysfs_attrib, &block->kobj);
555 
556 			/* Create each block_attribute file */
557 			err = sysfs_create_file(&block->kobj,
558 				&sysfs_attrib->attr);
559 			if (err)
560 				goto err_on_attrib;
561 		}
562 	}
563 	kobject_uevent(&block->kobj, KOBJ_ADD);
564 
565 	return 0;
566 
567 	/* Error unwind stack */
568 err_on_attrib:
569 	kobject_put(&block->kobj);
570 
571 err_out:
572 	return err;
573 }
574 
575 /*
576  * edac_device_delete_block(edac_dev,block);
577  */
578 static void edac_device_delete_block(struct edac_device_ctl_info *edac_dev,
579 				struct edac_device_block *block)
580 {
581 	struct edac_dev_sysfs_block_attribute *sysfs_attrib;
582 	int i;
583 
584 	/* if this block has 'attributes' then we need to iterate over the list
585 	 * and 'remove' the attributes on this block
586 	 */
587 	sysfs_attrib = block->block_attributes;
588 	if (sysfs_attrib && block->nr_attribs) {
589 		for (i = 0; i < block->nr_attribs; i++, sysfs_attrib++) {
590 
591 			/* remove each block_attrib file */
592 			sysfs_remove_file(&block->kobj,
593 				(struct attribute *) sysfs_attrib);
594 		}
595 	}
596 
597 	/* unregister this block's kobject, SEE:
598 	 *	edac_device_ctrl_block_release() callback operation
599 	 */
600 	kobject_put(&block->kobj);
601 }
602 
603 /* instance ctor/dtor code */
604 
605 /*
606  * edac_device_create_instance
607  *	create just one instance of an edac_device 'instance'
608  */
609 static int edac_device_create_instance(struct edac_device_ctl_info *edac_dev,
610 				int idx)
611 {
612 	int i, j;
613 	int err;
614 	struct edac_device_instance *instance;
615 	struct kobject *main_kobj;
616 
617 	instance = &edac_dev->instances[idx];
618 
619 	/* Init the instance's kobject */
620 	memset(&instance->kobj, 0, sizeof(struct kobject));
621 
622 	instance->ctl = edac_dev;
623 
624 	/* bump the main kobject's reference count for this controller
625 	 * and this instance is dependent on the main
626 	 */
627 	main_kobj = kobject_get(&edac_dev->kobj);
628 	if (!main_kobj) {
629 		err = -ENODEV;
630 		goto err_out;
631 	}
632 
633 	/* Formally register this instance's kobject under the edac_device */
634 	err = kobject_init_and_add(&instance->kobj, &ktype_instance_ctrl,
635 				   &edac_dev->kobj, "%s", instance->name);
636 	if (err != 0) {
637 		edac_dbg(2, "Failed to register instance '%s'\n",
638 			 instance->name);
639 		kobject_put(main_kobj);
640 		goto err_out;
641 	}
642 
643 	edac_dbg(4, "now register '%d' blocks for instance %d\n",
644 		 instance->nr_blocks, idx);
645 
646 	/* register all blocks of this instance */
647 	for (i = 0; i < instance->nr_blocks; i++) {
648 		err = edac_device_create_block(edac_dev, instance,
649 						&instance->blocks[i]);
650 		if (err) {
651 			/* If any fail, remove all previous ones */
652 			for (j = 0; j < i; j++)
653 				edac_device_delete_block(edac_dev,
654 							&instance->blocks[j]);
655 			goto err_release_instance_kobj;
656 		}
657 	}
658 	kobject_uevent(&instance->kobj, KOBJ_ADD);
659 
660 	edac_dbg(4, "Registered instance %d '%s' kobject\n",
661 		 idx, instance->name);
662 
663 	return 0;
664 
665 	/* error unwind stack */
666 err_release_instance_kobj:
667 	kobject_put(&instance->kobj);
668 
669 err_out:
670 	return err;
671 }
672 
673 /*
674  * edac_device_remove_instance
675  *	remove an edac_device instance
676  */
677 static void edac_device_delete_instance(struct edac_device_ctl_info *edac_dev,
678 					int idx)
679 {
680 	struct edac_device_instance *instance;
681 	int i;
682 
683 	instance = &edac_dev->instances[idx];
684 
685 	/* unregister all blocks in this instance */
686 	for (i = 0; i < instance->nr_blocks; i++)
687 		edac_device_delete_block(edac_dev, &instance->blocks[i]);
688 
689 	/* unregister this instance's kobject, SEE:
690 	 *	edac_device_ctrl_instance_release() for callback operation
691 	 */
692 	kobject_put(&instance->kobj);
693 }
694 
695 /*
696  * edac_device_create_instances
697  *	create the first level of 'instances' for this device
698  *	(ie  'cache' might have 'cache0', 'cache1', 'cache2', etc
699  */
700 static int edac_device_create_instances(struct edac_device_ctl_info *edac_dev)
701 {
702 	int i, j;
703 	int err;
704 
705 	edac_dbg(0, "\n");
706 
707 	/* iterate over creation of the instances */
708 	for (i = 0; i < edac_dev->nr_instances; i++) {
709 		err = edac_device_create_instance(edac_dev, i);
710 		if (err) {
711 			/* unwind previous instances on error */
712 			for (j = 0; j < i; j++)
713 				edac_device_delete_instance(edac_dev, j);
714 			return err;
715 		}
716 	}
717 
718 	return 0;
719 }
720 
721 /*
722  * edac_device_delete_instances(edac_dev);
723  *	unregister all the kobjects of the instances
724  */
725 static void edac_device_delete_instances(struct edac_device_ctl_info *edac_dev)
726 {
727 	int i;
728 
729 	/* iterate over creation of the instances */
730 	for (i = 0; i < edac_dev->nr_instances; i++)
731 		edac_device_delete_instance(edac_dev, i);
732 }
733 
734 /* edac_dev sysfs ctor/dtor  code */
735 
736 /*
737  * edac_device_add_main_sysfs_attributes
738  *	add some attributes to this instance's main kobject
739  */
740 static int edac_device_add_main_sysfs_attributes(
741 			struct edac_device_ctl_info *edac_dev)
742 {
743 	struct edac_dev_sysfs_attribute *sysfs_attrib;
744 	int err = 0;
745 
746 	sysfs_attrib = edac_dev->sysfs_attributes;
747 	if (sysfs_attrib) {
748 		/* iterate over the array and create an attribute for each
749 		 * entry in the list
750 		 */
751 		while (sysfs_attrib->attr.name != NULL) {
752 			err = sysfs_create_file(&edac_dev->kobj,
753 				(struct attribute*) sysfs_attrib);
754 			if (err)
755 				goto err_out;
756 
757 			sysfs_attrib++;
758 		}
759 	}
760 
761 err_out:
762 	return err;
763 }
764 
765 /*
766  * edac_device_remove_main_sysfs_attributes
767  *	remove any attributes to this instance's main kobject
768  */
769 static void edac_device_remove_main_sysfs_attributes(
770 			struct edac_device_ctl_info *edac_dev)
771 {
772 	struct edac_dev_sysfs_attribute *sysfs_attrib;
773 
774 	/* if there are main attributes, defined, remove them. First,
775 	 * point to the start of the array and iterate over it
776 	 * removing each attribute listed from this device's instance's kobject
777 	 */
778 	sysfs_attrib = edac_dev->sysfs_attributes;
779 	if (sysfs_attrib) {
780 		while (sysfs_attrib->attr.name != NULL) {
781 			sysfs_remove_file(&edac_dev->kobj,
782 					(struct attribute *) sysfs_attrib);
783 			sysfs_attrib++;
784 		}
785 	}
786 }
787 
788 /*
789  * edac_device_create_sysfs() Constructor
790  *
791  * accept a created edac_device control structure
792  * and 'export' it to sysfs. The 'main' kobj should already have been
793  * created. 'instance' and 'block' kobjects should be registered
794  * along with any 'block' attributes from the low driver. In addition,
795  * the main attributes (if any) are connected to the main kobject of
796  * the control structure.
797  *
798  * Return:
799  *	0	Success
800  *	!0	Failure
801  */
802 int edac_device_create_sysfs(struct edac_device_ctl_info *edac_dev)
803 {
804 	int err;
805 	struct kobject *edac_kobj = &edac_dev->kobj;
806 
807 	edac_dbg(0, "idx=%d\n", edac_dev->dev_idx);
808 
809 	/*  go create any main attributes callers wants */
810 	err = edac_device_add_main_sysfs_attributes(edac_dev);
811 	if (err) {
812 		edac_dbg(0, "failed to add sysfs attribs\n");
813 		goto err_out;
814 	}
815 
816 	/* create a symlink from the edac device
817 	 * to the platform 'device' being used for this
818 	 */
819 	err = sysfs_create_link(edac_kobj,
820 				&edac_dev->dev->kobj, EDAC_DEVICE_SYMLINK);
821 	if (err) {
822 		edac_dbg(0, "sysfs_create_link() returned err= %d\n", err);
823 		goto err_remove_main_attribs;
824 	}
825 
826 	/* Create the first level instance directories
827 	 * In turn, the nested blocks beneath the instances will
828 	 * be registered as well
829 	 */
830 	err = edac_device_create_instances(edac_dev);
831 	if (err) {
832 		edac_dbg(0, "edac_device_create_instances() returned err= %d\n",
833 			 err);
834 		goto err_remove_link;
835 	}
836 
837 
838 	edac_dbg(4, "create-instances done, idx=%d\n", edac_dev->dev_idx);
839 
840 	return 0;
841 
842 	/* Error unwind stack */
843 err_remove_link:
844 	/* remove the sym link */
845 	sysfs_remove_link(&edac_dev->kobj, EDAC_DEVICE_SYMLINK);
846 
847 err_remove_main_attribs:
848 	edac_device_remove_main_sysfs_attributes(edac_dev);
849 
850 err_out:
851 	return err;
852 }
853 
854 /*
855  * edac_device_remove_sysfs() destructor
856  *
857  * given an edac_device struct, tear down the kobject resources
858  */
859 void edac_device_remove_sysfs(struct edac_device_ctl_info *edac_dev)
860 {
861 	edac_dbg(0, "\n");
862 
863 	/* remove any main attributes for this device */
864 	edac_device_remove_main_sysfs_attributes(edac_dev);
865 
866 	/* remove the device sym link */
867 	sysfs_remove_link(&edac_dev->kobj, EDAC_DEVICE_SYMLINK);
868 
869 	/* walk the instance/block kobject tree, deconstructing it */
870 	edac_device_delete_instances(edac_dev);
871 }
872