drivers/edac: add edac_device class

This patch adds the new 'class' of object to be managed, named: 'edac_device'.

As a peer of the 'edac_mc' class of object, it provides a non-memory centric
view of an ERROR DETECTING device in hardware. It provides a sysfs interface
and an abstraction for varioius EDAC type devices.

Multiple 'instances' within the class are possible, with each 'instance'
able to have multiple 'blocks', and each 'block' having 'attributes'.

At the 'block' level there are the 'ce_count' and 'ue_count' fields
which the device driver can update and/or call edac_device_handle_XX()
functions. At each higher level are additional 'total' count fields,
which are a summation of counts below that level.

This 'edac_device' has been used to capture and present ECC errors
which are found in a a L1 and L2 system on a per CORE/CPU basis.

Signed-off-by: Douglas Thompson <dougthompson@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 837 insertions, 0 deletions

diff --git a/drivers/edac/edac_device_sysfs.c b/drivers/edac/edac_device_sysfs.c
new file mode 100644
index 00000000000..afb19050264
--- /dev/null
+++ b/drivers/edac/edac_device_sysfs.c
@@ -0,0 +1,837 @@
+/*
+ * 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/module.h>
+#include <linux/sysdev.h>
+#include <linux/ctype.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)
+
+#ifdef DKT
+
+static ssize_t edac_dev_ue_count_show(struct edac_device_ctl_info *edac_dev,
+					char *data)
+{
+	return sprintf(data,"%d\n", edac_dev->ue_count);
+}
+
+static ssize_t edac_dev_ce_count_show(struct edac_device_ctl_info *edac_dev,
+					char *data)
+{
+	return sprintf(data,"%d\n", edac_dev->ce_count);
+}
+
+static ssize_t edac_dev_seconds_show(struct edac_device_ctl_info *edac_dev,
+					char *data)
+{
+	return sprintf(data,"%ld\n", (jiffies - edac_dev->start_time) / HZ);
+}
+
+static ssize_t edac_dev_ctl_name_show(struct edac_device_ctl_info *edac_dev,
+					char *data)
+{
+	return sprintf(data,"%s\n", edac_dev->ctl_name);
+}
+
+
+struct edacdev_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);
+};
+
+
+/* EDAC DEVICE show/store functions for top most object */
+static ssize_t edacdev_show(struct kobject *kobj, struct attribute *attr,
+		char *buffer)
+{
+	struct edac_device_ctl_info *edac_dev = to_edacdev(kobj);
+	struct edacdev_attribute * edacdev_attr = to_edacdev_attr(attr);
+
+	if (edacdev_attr->show)
+		return edacdev_attr->show(edac_dev, buffer);
+
+	return -EIO;
+}
+
+static ssize_t edacdev_store(struct kobject *kobj, struct attribute *attr,
+		const char *buffer, size_t count)
+{
+	struct edac_device_ctl_info *edac_dev = to_edacdev(kobj);
+	struct edacdev_attribute * edacdev_attr = to_edacdev_attr(attr);
+
+	if (edacdev_attr->store)
+		return edacdev_attr->store(edac_dev, buffer, count);
+
+	return -EIO;
+}
+
+static struct sysfs_ops edac_dev_ops = {
+	.show = edacdev_show,
+	.store = edacdev_store
+};
+
+#define EDACDEV_ATTR(_name,_mode,_show,_store)			\
+static struct edacdev_attribute edac_dev_attr_##_name = {			\
+	.attr = {.name = __stringify(_name), .mode = _mode },	\
+	.show   = _show,					\
+	.store  = _store,					\
+};
+
+/* default Control file */
+EDACDEV_ATTR(reset_counters,S_IWUSR,NULL,edac_dev_reset_counters_store);
+
+/* default Attribute files */
+EDACDEV_ATTR(mc_name,S_IRUGO,edac_dev_ctl_name_show,NULL);
+EDACDEV_ATTR(seconds_since_reset,S_IRUGO,edac_dev_seconds_show,NULL);
+EDACDEV_ATTR(ue_count,S_IRUGO,edac_dev_ue_count_show,NULL);
+EDACDEV_ATTR(ce_count,S_IRUGO,edac_dev_ce_count_show,NULL);
+
+
+static struct edacdev_attribute *edacdev_attr[] = {
+	&edacdev_attr_reset_counters,
+	&edacdev_attr_mc_name,
+	&edacdev_attr_seconds_since_reset,
+	&edacdev_attr_ue_count,
+	&edacdev_attr_ce_count,
+	NULL
+};
+
+/*
+ * Release of a Edac Device controlling instance
+ */
+static void edac_dev_instance_release(struct kobject *kobj)
+{
+	struct edac_device_ctl_info *edac_dev;
+
+	edac_dev = to_edacdev(kobj);
+	debugf0("%s() idx=%d\n", __func__, edac_dev->dev_idx);
+	complete(&edac_dev->kobj_complete);
+}
+
+static struct kobj_type ktype_device = {
+	.release = edac_dev_instance_release,
+	.sysfs_ops = &edacdev_ops,
+	.default_attrs = (struct attribute **) edacdev_attr,
+};
+
+#endif
+
+/************************** edac_device sysfs code and data **************/
+
+/*
+ * 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\n", 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\n", 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\n", 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\n", 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 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,
+};
+
+/* Main DEVICE kobject release() function */
+static void edac_device_ctrl_master_release(struct kobject *kobj)
+{
+	struct edac_device_ctl_info *edac_dev;
+
+	edac_dev = to_edacdev(kobj);
+
+	debugf1("%s()\n", __func__);
+	complete(&edac_dev->kobj_complete);
+}
+
+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 main kobj ctor/dtor code *********************/
+
+/*
+ * edac_device_register_main_kobj
+ *
+ *	perform the high level setup for the new edac_device instance
+ *
+ * Return:  0 SUCCESS
+ *         !0 FAILURE
+ */
+static int edac_device_register_main_kobj(
+		struct edac_device_ctl_info *edac_dev)
+{
+	int err = 0;
+	struct sysdev_class *edac_class;
+
+	debugf1("%s()\n", __func__);
+
+        /* get the /sys/devices/system/edac reference */
+        edac_class = edac_get_edac_class();
+        if (edac_class == NULL) {
+                debugf1("%s() no edac_class error=%d\n", __func__, err);
+                return err;
+        }
+
+	/* 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));
+	edac_dev->kobj.ktype = &ktype_device_ctrl;
+
+	/* set this new device under the edac_class kobject */
+	edac_dev->kobj.parent = &edac_class->kset.kobj;
+
+	/* generate sysfs "..../edac/<name>"   */
+	debugf1("%s() set name of kobject to: %s\n",
+		__func__, edac_dev->name);
+	err = kobject_set_name(&edac_dev->kobj,"%s",edac_dev->name);
+	if (err)
+		return err;
+	err = kobject_register(&edac_dev->kobj);
+	if (err) {
+		debugf1("%s()Failed to register '.../edac/%s'\n",
+			__func__,edac_dev->name);
+		return err;
+	}
+
+	debugf1("%s() Registered '.../edac/%s' kobject\n",
+		__func__, edac_dev->name);
+
+	return 0;
+}
+
+/*
+ * edac_device_unregister_main_kobj:
+ *	the '..../edac/<name>' kobject
+ */
+static void edac_device_unregister_main_kobj(
+			struct edac_device_ctl_info *edac_dev)
+{
+	debugf0("%s()\n", __func__);
+	debugf1("%s() name of kobject is: %s\n",
+		__func__, kobject_name(&edac_dev->kobj));
+
+	init_completion(&edac_dev->kobj_complete);
+
+	/*
+	 * Unregister the edac device's kobject and
+	 * wait for reference count to reach 0.
+	 */
+	kobject_unregister(&edac_dev->kobj);
+	wait_for_completion(&edac_dev->kobj_complete);
+}
+
+
+/*************** 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\n", instance->counters.ue_count);
+}
+
+static ssize_t instance_ce_count_show(
+		struct edac_device_instance *instance, char *data)
+{
+        return sprintf(data,"%u\n", 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()\n", __func__);
+
+	instance = to_instance(kobj);
+	complete(&instance->kobj_complete);
+}
+
+
+/* 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 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 *********/
+
+/*
+ * Set of low-level block attribute show functions
+ */
+static ssize_t block_ue_count_show(
+		struct edac_device_block *block, char *data)
+{
+        return sprintf(data,"%u\n", block->counters.ue_count);
+}
+
+static ssize_t block_ce_count_show(
+		struct edac_device_block *block, char *data)
+{
+        return sprintf(data,"%u\n", block->counters.ce_count);
+}
+
+
+
+#define to_block(k) container_of(k, struct edac_device_block, kobj)
+#define to_block_attr(a) container_of(a,struct block_attribute,attr)
+
+/* DEVICE block kobject release() function */
+static void edac_device_ctrl_block_release(struct kobject *kobj)
+{
+	struct edac_device_block *block;
+
+	debugf1("%s()\n", __func__);
+
+	block = to_block(kobj);
+	complete(&block->kobj_complete);
+}
+
+/* block specific attribute structure */
+struct block_attribute {
+        struct attribute attr;
+        ssize_t (*show)(struct edac_device_block *,char *);
+        ssize_t (*store)(struct edac_device_block *,const char *,size_t);
+};
+
+/* 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_device_block *block = to_block(kobj);
+        struct block_attribute *block_attr = to_block_attr(attr);
+
+        if (block_attr->show)
+                return block_attr->show(block,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_device_block *block = to_block(kobj);
+        struct block_attribute *block_attr = to_block_attr(attr);
+
+        if (block_attr->store)
+                return block_attr->store(block, buffer, count);
+        return -EIO;
+}
+
+
+/* edac_dev file operations for a 'block' */
+static 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 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 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,
+		int idx)
+{
+	int err;
+	struct edac_device_block *block;
+
+	block = &instance->blocks[idx];
+
+	debugf1("%s() Instance '%s' block[%d] '%s'\n",
+		__func__,instance->name, idx, block->name);
+
+	/* init this block's kobject */
+	memset(&block->kobj, 0, sizeof (struct kobject));
+	block->kobj.parent = &instance->kobj;
+	block->kobj.ktype = &ktype_block_ctrl;
+
+	err = kobject_set_name(&block->kobj,"%s",block->name);
+	if (err)
+		return err;
+
+	err = kobject_register(&block->kobj);
+	if (err) {
+		debugf1("%s()Failed to register instance '%s'\n",
+			__func__,block->name);
+		return err;
+	}
+
+	return 0;
+}
+
+/*
+ * edac_device_delete_block(edac_dev,j);
+ */
+static void edac_device_delete_block(
+		struct edac_device_ctl_info *edac_dev,
+		struct edac_device_instance *instance,
+		int idx)
+{
+	struct edac_device_block *block;
+
+	block = &instance->blocks[idx];
+
+	/* unregister this block's kobject */
+	init_completion(&block->kobj_complete);
+	kobject_unregister(&block->kobj);
+	wait_for_completion(&block->kobj_complete);
+}
+
+/************** 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;
+
+	instance = &edac_dev->instances[idx];
+
+	/* Init the instance's kobject */
+	memset(&instance->kobj, 0, sizeof (struct kobject));
+
+	/* set this new device under the edac_device main kobject */
+	instance->kobj.parent = &edac_dev->kobj;
+	instance->kobj.ktype = &ktype_instance_ctrl;
+
+	err = kobject_set_name(&instance->kobj,"%s",instance->name);
+	if (err)
+		return err;
+
+	err = kobject_register(&instance->kobj);
+	if (err != 0) {
+		debugf2("%s() Failed to register instance '%s'\n",
+			__func__,instance->name);
+		return err;
+	}
+
+	debugf1("%s() now register '%d' blocks for instance %d\n",
+			__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,i);
+		if (err) {
+			for (j = 0; j < i; j++) {
+				edac_device_delete_block(edac_dev,instance,j);
+			}
+			return err;
+		}
+	}
+
+	debugf1("%s() Registered instance %d '%s' kobject\n",
+		__func__, idx, instance->name);
+
+	return 0;
+}
+
+/*
+ * edac_device_remove_instance
+ *	remove an edac_device instance
+ */
+static void edac_device_delete_instance(
+		struct edac_device_ctl_info *edac_dev, int idx)
+{
+	int i;
+	struct edac_device_instance *instance;
+
+	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,i);
+	}
+
+	/* unregister this instance's kobject */
+	init_completion(&instance->kobj_complete);
+	kobject_unregister(&instance->kobj);
+	wait_for_completion(&instance->kobj_complete);
+}
+
+/*
+ * 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()\n", __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_create_sysfs() Constructor
+ *
+ * Create a new edac_device kobject instance,
+ *
+ * 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;
+
+	/* register this instance's main kobj with the edac class kobj */
+	err = edac_device_register_main_kobj(edac_dev);
+	if (err)
+		return err;
+
+	debugf0("%s() idx=%d\n", __func__, edac_dev->dev_idx);
+
+	/* 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\n",
+			__func__, err);
+		return err;
+	}
+
+	debugf0("%s() calling create-instances, idx=%d\n",
+		__func__, edac_dev->dev_idx);
+
+	/* Create the first level instance directories */
+	err = edac_device_create_instances(edac_dev);
+	if (err) {
+		goto error0;
+	}
+
+	return 0;
+
+	/* Error unwind stack */
+
+error0:
+	edac_device_unregister_main_kobj(edac_dev);
+
+	return err;
+}
+
+/*
+ * edac_device_remove_sysfs() destructor
+ *
+ * remove a edac_device instance
+ */
+void edac_device_remove_sysfs(struct edac_device_ctl_info *edac_dev)
+{
+	debugf0("%s()\n", __func__);
+
+	edac_device_delete_instances(edac_dev);
+
+	/* remove the sym link */
+	sysfs_remove_link(&edac_dev->kobj, EDAC_DEVICE_SYMLINK);
+
+	/* unregister the instance's main kobj */
+	edac_device_unregister_main_kobj(edac_dev);
+}
+