/*
   * file for managing the edac_device class of devices for EDAC
   *

   * (C) 2007 SoftwareBitMaker (http://www.softwarebitmaker.com)
   *

   * This file may be distributed under the terms of the
   * GNU General Public License.
   *
   * Written Doug Thompson <norsk5@xmission.com>
   *
   */

  #include <linux/ctype.h>

  #include <linux/module.h>

  #include <linux/slab.h>

  #include <linux/edac.h>

  
  #include "edac_core.h"
  #include "edac_module.h"

  #define EDAC_DEVICE_SYMLINK	"device"
  
  #define to_edacdev(k) container_of(k, struct edac_device_ctl_info, kobj)
  #define to_edacdev_attr(a) container_of(a, struct edacdev_attribute, attr)

  
  /*
   * Set of edac_device_ctl_info attribute store/show functions
   */
  
  /* 'log_ue' */

  static ssize_t edac_device_ctl_log_ue_show(struct edac_device_ctl_info

  					*ctl_info, char *data)

  {

  	return sprintf(data, "%u
  ", ctl_info->log_ue);

  }

  static ssize_t edac_device_ctl_log_ue_store(struct edac_device_ctl_info

  					*ctl_info, const char *data,
  					size_t count)

  {
  	/* if parameter is zero, turn off flag, if non-zero turn on flag */

  	ctl_info->log_ue = (simple_strtoul(data, NULL, 0) != 0);

  	return count;

  }
  
  /* 'log_ce' */

  static ssize_t edac_device_ctl_log_ce_show(struct edac_device_ctl_info

  					*ctl_info, char *data)

  {

  	return sprintf(data, "%u
  ", ctl_info->log_ce);

  }

  static ssize_t edac_device_ctl_log_ce_store(struct edac_device_ctl_info

  					*ctl_info, const char *data,
  					size_t count)

  {
  	/* if parameter is zero, turn off flag, if non-zero turn on flag */

  	ctl_info->log_ce = (simple_strtoul(data, NULL, 0) != 0);

  	return count;

  }

  /* 'panic_on_ue' */

  static ssize_t edac_device_ctl_panic_on_ue_show(struct edac_device_ctl_info
  						*ctl_info, char *data)

  {

  	return sprintf(data, "%u
  ", ctl_info->panic_on_ue);

  }

  static ssize_t edac_device_ctl_panic_on_ue_store(struct edac_device_ctl_info
  						 *ctl_info, const char *data,
  						 size_t count)

  {
  	/* if parameter is zero, turn off flag, if non-zero turn on flag */

  	ctl_info->panic_on_ue = (simple_strtoul(data, NULL, 0) != 0);

  
  	return count;
  }
  
  /* 'poll_msec' show and store functions*/

  static ssize_t edac_device_ctl_poll_msec_show(struct edac_device_ctl_info

  					*ctl_info, char *data)

  {

  	return sprintf(data, "%u
  ", ctl_info->poll_msec);

  }

  static ssize_t edac_device_ctl_poll_msec_store(struct edac_device_ctl_info

  					*ctl_info, const char *data,
  					size_t count)

  {
  	unsigned long value;
  
  	/* get the value and enforce that it is non-zero, must be at least
  	 * one millisecond for the delay period, between scans
  	 * Then cancel last outstanding delay for the work request
  	 * and set a new one.
  	 */

  	value = simple_strtoul(data, NULL, 0);
  	edac_device_reset_delay_period(ctl_info, value);

  	return count;

  }

  /* edac_device_ctl_info specific attribute structure */
  struct ctl_info_attribute {

  	struct attribute attr;

  	ssize_t(*show) (struct edac_device_ctl_info *, char *);
  	ssize_t(*store) (struct edac_device_ctl_info *, const char *, size_t);

  };
  
  #define to_ctl_info(k) container_of(k, struct edac_device_ctl_info, kobj)
  #define to_ctl_info_attr(a) container_of(a,struct ctl_info_attribute,attr)
  
  /* Function to 'show' fields from the edac_dev 'ctl_info' structure */
  static ssize_t edac_dev_ctl_info_show(struct kobject *kobj,

  				struct attribute *attr, char *buffer)

  {

  	struct edac_device_ctl_info *edac_dev = to_ctl_info(kobj);
  	struct ctl_info_attribute *ctl_info_attr = to_ctl_info_attr(attr);

  	if (ctl_info_attr->show)
  		return ctl_info_attr->show(edac_dev, buffer);
  	return -EIO;

  }
  
  /* Function to 'store' fields into the edac_dev 'ctl_info' structure */
  static ssize_t edac_dev_ctl_info_store(struct kobject *kobj,

  				struct attribute *attr,
  				const char *buffer, size_t count)

  {

  	struct edac_device_ctl_info *edac_dev = to_ctl_info(kobj);
  	struct ctl_info_attribute *ctl_info_attr = to_ctl_info_attr(attr);

  	if (ctl_info_attr->store)
  		return ctl_info_attr->store(edac_dev, buffer, count);
  	return -EIO;

  }
  
  /* edac_dev file operations for an 'ctl_info' */

  static const struct sysfs_ops device_ctl_info_ops = {

  	.show = edac_dev_ctl_info_show,
  	.store = edac_dev_ctl_info_store

  };
  
  #define CTL_INFO_ATTR(_name,_mode,_show,_store)        \
  static struct ctl_info_attribute attr_ctl_info_##_name = {      \

  	.attr = {.name = __stringify(_name), .mode = _mode },   \
  	.show   = _show,                                        \
  	.store  = _store,                                       \

  };

  /* Declare the various ctl_info attributes here and their respective ops */

  CTL_INFO_ATTR(log_ue, S_IRUGO | S_IWUSR,

  	edac_device_ctl_log_ue_show, edac_device_ctl_log_ue_store);

  CTL_INFO_ATTR(log_ce, S_IRUGO | S_IWUSR,

  	edac_device_ctl_log_ce_show, edac_device_ctl_log_ce_store);

  CTL_INFO_ATTR(panic_on_ue, S_IRUGO | S_IWUSR,

  	edac_device_ctl_panic_on_ue_show,
  	edac_device_ctl_panic_on_ue_store);

  CTL_INFO_ATTR(poll_msec, S_IRUGO | S_IWUSR,

  	edac_device_ctl_poll_msec_show, edac_device_ctl_poll_msec_store);

  
  /* Base Attributes of the EDAC_DEVICE ECC object */
  static struct ctl_info_attribute *device_ctrl_attr[] = {
  	&attr_ctl_info_panic_on_ue,
  	&attr_ctl_info_log_ue,
  	&attr_ctl_info_log_ce,
  	&attr_ctl_info_poll_msec,
  	NULL,
  };

  /*
   * edac_device_ctrl_master_release
   *
   *	called when the reference count for the 'main' kobj
   *	for a edac_device control struct reaches zero
   *
   *	Reference count model:
   *		One 'main' kobject for each control structure allocated.
   *		That main kobj is initially set to one AND
   *		the reference count for the EDAC 'core' module is
   *		bumped by one, thus added 'keep in memory' dependency.
   *
   *		Each new internal kobj (in instances and blocks) then
   *		bumps the 'main' kobject.
   *
   *		When they are released their release functions decrement
   *		the 'main' kobj.
   *
   *		When the main kobj reaches zero (0) then THIS function
   *		is called which then decrements the EDAC 'core' module.
   *		When the module reference count reaches zero then the
   *		module no longer has dependency on keeping the release
   *		function code in memory and module can be unloaded.
   *
   *		This will support several control objects as well, each
   *		with its own 'main' kobj.
   */

  static void edac_device_ctrl_master_release(struct kobject *kobj)
  {

  	struct edac_device_ctl_info *edac_dev = to_edacdev(kobj);

  	debugf4("%s() control index=%d
  ", __func__, edac_dev->dev_idx);

  	/* decrement the EDAC CORE module ref count */
  	module_put(edac_dev->owner);
  
  	/* free the control struct containing the 'main' kobj
  	 * passed in to this routine
  	 */
  	kfree(edac_dev);

  }

  /* ktype for the main (master) kobject */

  static struct kobj_type ktype_device_ctrl = {
  	.release = edac_device_ctrl_master_release,
  	.sysfs_ops = &device_ctl_info_ops,

  	.default_attrs = (struct attribute **)device_ctrl_attr,

  };

  /*

   * edac_device_register_sysfs_main_kobj

   *
   *	perform the high level setup for the new edac_device instance
   *
   * Return:  0 SUCCESS
   *         !0 FAILURE
   */

  int edac_device_register_sysfs_main_kobj(struct edac_device_ctl_info *edac_dev)

  {

  	struct sysdev_class *edac_class;

  	int err;

  
  	debugf1("%s()
  ", __func__);

  	/* get the /sys/devices/system/edac reference */

  	edac_class = edac_get_sysfs_class();

  	if (edac_class == NULL) {

  		debugf1("%s() no edac_class error
  ", __func__);
  		err = -ENODEV;
  		goto err_out;

  	}

  
  	/* Point to the 'edac_class' this instance 'reports' to */
  	edac_dev->edac_class = edac_class;
  
  	/* Init the devices's kobject */

  	memset(&edac_dev->kobj, 0, sizeof(struct kobject));

  
  	/* Record which module 'owns' this control structure
  	 * and bump the ref count of the module
  	 */
  	edac_dev->owner = THIS_MODULE;
  
  	if (!try_module_get(edac_dev->owner)) {
  		err = -ENODEV;

  		goto err_mod_get;

  	}
  
  	/* register */

  	err = kobject_init_and_add(&edac_dev->kobj, &ktype_device_ctrl,
  				   &edac_class->kset.kobj,
  				   "%s", edac_dev->name);

  	if (err) {
  		debugf1("%s()Failed to register '.../edac/%s'
  ",

  			__func__, edac_dev->name);

  		goto err_kobj_reg;

  	}

  	kobject_uevent(&edac_dev->kobj, KOBJ_ADD);

  	/* At this point, to 'free' the control struct,
  	 * edac_device_unregister_sysfs_main_kobj() must be used
  	 */

  	debugf4("%s() Registered '.../edac/%s' kobject
  ",

  		__func__, edac_dev->name);
  
  	return 0;

  
  	/* Error exit stack */
  err_kobj_reg:
  	module_put(edac_dev->owner);

  err_mod_get:
  	edac_put_sysfs_class();

  err_out:
  	return err;

  }
  
  /*

   * edac_device_unregister_sysfs_main_kobj:

   *	the '..../edac/<name>' kobject
   */

  void edac_device_unregister_sysfs_main_kobj(struct edac_device_ctl_info *dev)

  {
  	debugf0("%s()
  ", __func__);

  	debugf4("%s() name of kobject is: %s
  ",

  		__func__, kobject_name(&dev->kobj));

  	/*
  	 * Unregister the edac device's kobject and

  	 * allow for reference count to reach 0 at which point
  	 * the callback will be called to:
  	 *   a) module_put() this module
  	 *   b) 'kfree' the memory

  	 */

  	kobject_put(&dev->kobj);
  	edac_put_sysfs_class();

  }

  /* edac_dev -> instance information */

  
  /*
   * Set of low-level instance attribute show functions
   */

  static ssize_t instance_ue_count_show(struct edac_device_instance *instance,

  				char *data)

  {

  	return sprintf(data, "%u
  ", instance->counters.ue_count);

  }

  static ssize_t instance_ce_count_show(struct edac_device_instance *instance,

  				char *data)

  {

  	return sprintf(data, "%u
  ", instance->counters.ce_count);

  }

  #define to_instance(k) container_of(k, struct edac_device_instance, kobj)
  #define to_instance_attr(a) container_of(a,struct instance_attribute,attr)
  
  /* DEVICE instance kobject release() function */
  static void edac_device_ctrl_instance_release(struct kobject *kobj)
  {
  	struct edac_device_instance *instance;
  
  	debugf1("%s()
  ", __func__);

  	/* map from this kobj to the main control struct
  	 * and then dec the main kobj count
  	 */

  	instance = to_instance(kobj);

  	kobject_put(&instance->ctl->kobj);

  }

  /* instance specific attribute structure */
  struct instance_attribute {

  	struct attribute attr;

  	ssize_t(*show) (struct edac_device_instance *, char *);
  	ssize_t(*store) (struct edac_device_instance *, const char *, size_t);

  };

  /* Function to 'show' fields from the edac_dev 'instance' structure */
  static ssize_t edac_dev_instance_show(struct kobject *kobj,

  				struct attribute *attr, char *buffer)

  {

  	struct edac_device_instance *instance = to_instance(kobj);
  	struct instance_attribute *instance_attr = to_instance_attr(attr);

  	if (instance_attr->show)
  		return instance_attr->show(instance, buffer);
  	return -EIO;

  }

  /* Function to 'store' fields into the edac_dev 'instance' structure */
  static ssize_t edac_dev_instance_store(struct kobject *kobj,

  				struct attribute *attr,
  				const char *buffer, size_t count)

  {

  	struct edac_device_instance *instance = to_instance(kobj);
  	struct instance_attribute *instance_attr = to_instance_attr(attr);

  	if (instance_attr->store)
  		return instance_attr->store(instance, buffer, count);
  	return -EIO;

  }

  /* edac_dev file operations for an 'instance' */

  static const struct sysfs_ops device_instance_ops = {

  	.show = edac_dev_instance_show,
  	.store = edac_dev_instance_store

  };
  
  #define INSTANCE_ATTR(_name,_mode,_show,_store)        \
  static struct instance_attribute attr_instance_##_name = {      \

  	.attr = {.name = __stringify(_name), .mode = _mode },   \
  	.show   = _show,                                        \
  	.store  = _store,                                       \

  };
  
  /*
   * Define attributes visible for the edac_device instance object
   *	Each contains a pointer to a show and an optional set
   *	function pointer that does the low level output/input
   */

  INSTANCE_ATTR(ce_count, S_IRUGO, instance_ce_count_show, NULL);
  INSTANCE_ATTR(ue_count, S_IRUGO, instance_ue_count_show, NULL);

  
  /* list of edac_dev 'instance' attributes */
  static struct instance_attribute *device_instance_attr[] = {
  	&attr_instance_ce_count,
  	&attr_instance_ue_count,
  	NULL,
  };
  
  /* The 'ktype' for each edac_dev 'instance' */
  static struct kobj_type ktype_instance_ctrl = {
  	.release = edac_device_ctrl_instance_release,
  	.sysfs_ops = &device_instance_ops,

  	.default_attrs = (struct attribute **)device_instance_attr,

  };

  /* edac_dev -> instance -> block information */

  #define to_block(k) container_of(k, struct edac_device_block, kobj)
  #define to_block_attr(a) \
  	container_of(a, struct edac_dev_sysfs_block_attribute, attr)

  /*
   * Set of low-level block attribute show functions
   */

  static ssize_t block_ue_count_show(struct kobject *kobj,
  					struct attribute *attr, char *data)

  {

  	struct edac_device_block *block = to_block(kobj);

  	return sprintf(data, "%u
  ", block->counters.ue_count);

  }

  static ssize_t block_ce_count_show(struct kobject *kobj,
  					struct attribute *attr, char *data)

  {

  	struct edac_device_block *block = to_block(kobj);

  	return sprintf(data, "%u
  ", block->counters.ce_count);

  }

  /* DEVICE block kobject release() function */
  static void edac_device_ctrl_block_release(struct kobject *kobj)
  {
  	struct edac_device_block *block;
  
  	debugf1("%s()
  ", __func__);

  	/* get the container of the kobj */

  	block = to_block(kobj);

  
  	/* map from 'block kobj' to 'block->instance->controller->main_kobj'
  	 * now 'release' the block kobject
  	 */
  	kobject_put(&block->instance->ctl->kobj);

  }

  
  /* Function to 'show' fields from the edac_dev 'block' structure */
  static ssize_t edac_dev_block_show(struct kobject *kobj,

  				struct attribute *attr, char *buffer)

  {

  	struct edac_dev_sysfs_block_attribute *block_attr =
  						to_block_attr(attr);

  	if (block_attr->show)

  		return block_attr->show(kobj, attr, buffer);

  	return -EIO;

  }

  /* Function to 'store' fields into the edac_dev 'block' structure */
  static ssize_t edac_dev_block_store(struct kobject *kobj,

  				struct attribute *attr,
  				const char *buffer, size_t count)

  {

  	struct edac_dev_sysfs_block_attribute *block_attr;
  
  	block_attr = to_block_attr(attr);

  	if (block_attr->store)

  		return block_attr->store(kobj, attr, buffer, count);

  	return -EIO;

  }

  /* edac_dev file operations for a 'block' */

  static const struct sysfs_ops device_block_ops = {

  	.show = edac_dev_block_show,
  	.store = edac_dev_block_store

  };

  #define BLOCK_ATTR(_name,_mode,_show,_store)        \

  static struct edac_dev_sysfs_block_attribute attr_block_##_name = {	\

  	.attr = {.name = __stringify(_name), .mode = _mode },   \
  	.show   = _show,                                        \
  	.store  = _store,                                       \

  };

  BLOCK_ATTR(ce_count, S_IRUGO, block_ce_count_show, NULL);
  BLOCK_ATTR(ue_count, S_IRUGO, block_ue_count_show, NULL);

  
  /* list of edac_dev 'block' attributes */

  static struct edac_dev_sysfs_block_attribute *device_block_attr[] = {

  	&attr_block_ce_count,
  	&attr_block_ue_count,
  	NULL,
  };
  
  /* The 'ktype' for each edac_dev 'block' */
  static struct kobj_type ktype_block_ctrl = {
  	.release = edac_device_ctrl_block_release,
  	.sysfs_ops = &device_block_ops,

  	.default_attrs = (struct attribute **)device_block_attr,

  };

  /* block ctor/dtor  code */

  
  /*
   * edac_device_create_block
   */

  static int edac_device_create_block(struct edac_device_ctl_info *edac_dev,

  				struct edac_device_instance *instance,

  				struct edac_device_block *block)

  {

  	int i;

  	int err;

  	struct edac_dev_sysfs_block_attribute *sysfs_attrib;

  	struct kobject *main_kobj;

  	debugf4("%s() Instance '%s' inst_p=%p  block '%s'  block_p=%p
  ",
  		__func__, instance->name, instance, block->name, block);
  	debugf4("%s() block kobj=%p  block kobj->parent=%p
  ",
  		__func__, &block->kobj, &block->kobj.parent);

  
  	/* init this block's kobject */

  	memset(&block->kobj, 0, sizeof(struct kobject));

  	/* bump the main kobject's reference count for this controller
  	 * and this instance is dependant on the main
  	 */
  	main_kobj = kobject_get(&edac_dev->kobj);
  	if (!main_kobj) {
  		err = -ENODEV;
  		goto err_out;
  	}
  
  	/* Add this block's kobject */

  	err = kobject_init_and_add(&block->kobj, &ktype_block_ctrl,
  				   &instance->kobj,
  				   "%s", block->name);

  	if (err) {

  		debugf1("%s() Failed to register instance '%s'
  ",

  			__func__, block->name);

  		kobject_put(main_kobj);
  		err = -ENODEV;
  		goto err_out;

  	}

  	/* If there are driver level block attributes, then added them
  	 * to the block kobject
  	 */
  	sysfs_attrib = block->block_attributes;

  	if (sysfs_attrib && block->nr_attribs) {
  		for (i = 0; i < block->nr_attribs; i++, sysfs_attrib++) {
  
  			debugf4("%s() creating block attrib='%s' "
  				"attrib->%p to kobj=%p
  ",
  				__func__,
  				sysfs_attrib->attr.name,
  				sysfs_attrib, &block->kobj);
  
  			/* Create each block_attribute file */

  			err = sysfs_create_file(&block->kobj,

  				&sysfs_attrib->attr);

  			if (err)
  				goto err_on_attrib;

  		}
  	}

  	kobject_uevent(&block->kobj, KOBJ_ADD);

  	return 0;

  	/* Error unwind stack */

  err_on_attrib:

  	kobject_put(&block->kobj);

  err_out:

  	return err;

  }
  
  /*

   * edac_device_delete_block(edac_dev,block);

   */

  static void edac_device_delete_block(struct edac_device_ctl_info *edac_dev,

  				struct edac_device_block *block)

  {

  	struct edac_dev_sysfs_block_attribute *sysfs_attrib;
  	int i;

  	/* if this block has 'attributes' then we need to iterate over the list
  	 * and 'remove' the attributes on this block
  	 */
  	sysfs_attrib = block->block_attributes;
  	if (sysfs_attrib && block->nr_attribs) {

  		for (i = 0; i < block->nr_attribs; i++, sysfs_attrib++) {
  
  			/* remove each block_attrib file */

  			sysfs_remove_file(&block->kobj,
  				(struct attribute *) sysfs_attrib);
  		}
  	}

  	/* unregister this block's kobject, SEE:
  	 *	edac_device_ctrl_block_release() callback operation
  	 */

  	kobject_put(&block->kobj);

  }

  /* instance ctor/dtor code */

  
  /*
   * edac_device_create_instance
   *	create just one instance of an edac_device 'instance'
   */

  static int edac_device_create_instance(struct edac_device_ctl_info *edac_dev,

  				int idx)

  {
  	int i, j;
  	int err;
  	struct edac_device_instance *instance;

  	struct kobject *main_kobj;

  
  	instance = &edac_dev->instances[idx];
  
  	/* Init the instance's kobject */

  	memset(&instance->kobj, 0, sizeof(struct kobject));

  	instance->ctl = edac_dev;

  	/* bump the main kobject's reference count for this controller
  	 * and this instance is dependant on the main
  	 */
  	main_kobj = kobject_get(&edac_dev->kobj);
  	if (!main_kobj) {
  		err = -ENODEV;
  		goto err_out;
  	}

  	/* Formally register this instance's kobject under the edac_device */
  	err = kobject_init_and_add(&instance->kobj, &ktype_instance_ctrl,
  				   &edac_dev->kobj, "%s", instance->name);

  	if (err != 0) {
  		debugf2("%s() Failed to register instance '%s'
  ",

  			__func__, instance->name);

  		kobject_put(main_kobj);
  		goto err_out;

  	}

  	debugf4("%s() now register '%d' blocks for instance %d
  ",

  		__func__, instance->nr_blocks, idx);

  
  	/* register all blocks of this instance */

  	for (i = 0; i < instance->nr_blocks; i++) {

  		err = edac_device_create_block(edac_dev, instance,
  						&instance->blocks[i]);

  		if (err) {

  			/* If any fail, remove all previous ones */

  			for (j = 0; j < i; j++)

  				edac_device_delete_block(edac_dev,
  							&instance->blocks[j]);
  			goto err_release_instance_kobj;

  		}
  	}

  	kobject_uevent(&instance->kobj, KOBJ_ADD);

  	debugf4("%s() Registered instance %d '%s' kobject
  ",

  		__func__, idx, instance->name);
  
  	return 0;

  
  	/* error unwind stack */
  err_release_instance_kobj:

  	kobject_put(&instance->kobj);

  
  err_out:
  	return err;

  }
  
  /*
   * edac_device_remove_instance
   *	remove an edac_device instance
   */

  static void edac_device_delete_instance(struct edac_device_ctl_info *edac_dev,
  					int idx)

  {

  	struct edac_device_instance *instance;

  	int i;

  
  	instance = &edac_dev->instances[idx];
  
  	/* unregister all blocks in this instance */

  	for (i = 0; i < instance->nr_blocks; i++)

  		edac_device_delete_block(edac_dev, &instance->blocks[i]);

  	/* unregister this instance's kobject, SEE:
  	 *	edac_device_ctrl_instance_release() for callback operation
  	 */

  	kobject_put(&instance->kobj);

  }
  
  /*
   * edac_device_create_instances
   *	create the first level of 'instances' for this device
   *	(ie  'cache' might have 'cache0', 'cache1', 'cache2', etc
   */
  static int edac_device_create_instances(struct edac_device_ctl_info *edac_dev)
  {
  	int i, j;
  	int err;
  
  	debugf0("%s()
  ", __func__);
  
  	/* iterate over creation of the instances */

  	for (i = 0; i < edac_dev->nr_instances; i++) {
  		err = edac_device_create_instance(edac_dev, i);

  		if (err) {
  			/* unwind previous instances on error */

  			for (j = 0; j < i; j++)

  				edac_device_delete_instance(edac_dev, j);

  			return err;
  		}
  	}
  
  	return 0;
  }
  
  /*
   * edac_device_delete_instances(edac_dev);
   *	unregister all the kobjects of the instances
   */
  static void edac_device_delete_instances(struct edac_device_ctl_info *edac_dev)
  {
  	int i;
  
  	/* iterate over creation of the instances */

  	for (i = 0; i < edac_dev->nr_instances; i++)

  		edac_device_delete_instance(edac_dev, i);

  }

  /* edac_dev sysfs ctor/dtor  code */

  
  /*

   * edac_device_add_main_sysfs_attributes

   *	add some attributes to this instance's main kobject
   */

  static int edac_device_add_main_sysfs_attributes(

  			struct edac_device_ctl_info *edac_dev)
  {

  	struct edac_dev_sysfs_attribute *sysfs_attrib;

  	int err = 0;

  	sysfs_attrib = edac_dev->sysfs_attributes;

  	if (sysfs_attrib) {
  		/* iterate over the array and create an attribute for each
  		 * entry in the list
  		 */
  		while (sysfs_attrib->attr.name != NULL) {
  			err = sysfs_create_file(&edac_dev->kobj,

  				(struct attribute*) sysfs_attrib);

  			if (err)
  				goto err_out;

  			sysfs_attrib++;
  		}

  	}

  err_out:
  	return err;
  }
  
  /*
   * edac_device_remove_main_sysfs_attributes
   *	remove any attributes to this instance's main kobject
   */
  static void edac_device_remove_main_sysfs_attributes(
  			struct edac_device_ctl_info *edac_dev)
  {
  	struct edac_dev_sysfs_attribute *sysfs_attrib;
  
  	/* if there are main attributes, defined, remove them. First,
  	 * point to the start of the array and iterate over it
  	 * removing each attribute listed from this device's instance's kobject
  	 */
  	sysfs_attrib = edac_dev->sysfs_attributes;
  	if (sysfs_attrib) {
  		while (sysfs_attrib->attr.name != NULL) {
  			sysfs_remove_file(&edac_dev->kobj,
  					(struct attribute *) sysfs_attrib);
  			sysfs_attrib++;
  		}
  	}

  }
  
  /*

   * edac_device_create_sysfs() Constructor
   *

   * accept a created edac_device control structure
   * and 'export' it to sysfs. The 'main' kobj should already have been
   * created. 'instance' and 'block' kobjects should be registered
   * along with any 'block' attributes from the low driver. In addition,
   * the main attributes (if any) are connected to the main kobject of
   * the control structure.

   *
   * Return:
   *	0	Success
   *	!0	Failure
   */
  int edac_device_create_sysfs(struct edac_device_ctl_info *edac_dev)
  {
  	int err;

  	struct kobject *edac_kobj = &edac_dev->kobj;

  	debugf0("%s() idx=%d
  ", __func__, edac_dev->dev_idx);

  	/*  go create any main attributes callers wants */
  	err = edac_device_add_main_sysfs_attributes(edac_dev);
  	if (err) {
  		debugf0("%s() failed to add sysfs attribs
  ", __func__);
  		goto err_out;

  	}

  	/* create a symlink from the edac device
  	 * to the platform 'device' being used for this
  	 */
  	err = sysfs_create_link(edac_kobj,

  				&edac_dev->dev->kobj, EDAC_DEVICE_SYMLINK);

  	if (err) {
  		debugf0("%s() sysfs_create_link() returned err= %d
  ",
  			__func__, err);

  		goto err_remove_main_attribs;

  	}

  	/* Create the first level instance directories
  	 * In turn, the nested blocks beneath the instances will
  	 * be registered as well
  	 */

  	err = edac_device_create_instances(edac_dev);

  	if (err) {
  		debugf0("%s() edac_device_create_instances() "
  			"returned err= %d
  ", __func__, err);

  		goto err_remove_link;

  	}

  	debugf4("%s() create-instances done, idx=%d
  ",

  		__func__, edac_dev->dev_idx);

  
  	return 0;
  
  	/* Error unwind stack */

  err_remove_link:
  	/* remove the sym link */
  	sysfs_remove_link(&edac_dev->kobj, EDAC_DEVICE_SYMLINK);

  err_remove_main_attribs:
  	edac_device_remove_main_sysfs_attributes(edac_dev);

  err_out:

  	return err;
  }
  
  /*
   * edac_device_remove_sysfs() destructor
   *

   * given an edac_device struct, tear down the kobject resources

   */
  void edac_device_remove_sysfs(struct edac_device_ctl_info *edac_dev)
  {
  	debugf0("%s()
  ", __func__);

  	/* remove any main attributes for this device */
  	edac_device_remove_main_sysfs_attributes(edac_dev);

  	/* remove the device sym link */

  	sysfs_remove_link(&edac_dev->kobj, EDAC_DEVICE_SYMLINK);

  	/* walk the instance/block kobject tree, deconstructing it */
  	edac_device_delete_instances(edac_dev);

  }