drivers/edac: fix edac_device sysfs corner case bug

Some simple fixes to properly reference counter values from the block
attribute level of edac_device objects.  Properly sequencing the array pointer
was added, resulting in correct identification of block level attributes from
their base class functions.

Added more verbose debug statement for event tracking.

Also during some corner testing, found a bug in the store/show sequence
of operations for the block attribute/controls management.

An old intermediate structure for 'blocks' was still in the processing
pipeline.  This patch removes that old structure and correctly utilizes the
new struct edac_dev_sysfs_block_attribute for passing control from the sysfs
to the low level store/show function of the edac driver.

Now the proper kobj pointer to passed downward to the store/show
functions.

Signed-off-by: Doug Thompson <dougthompson@xmission.com>
Cc: Greg KH <greg@kroah.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 85 insertions, 51 deletions

diff --git a/drivers/edac/edac_core.h b/drivers/edac/edac_core.h
index 4e31ac43876..4e6bad15c4b 100644
--- a/drivers/edac/edac_core.h
+++ b/drivers/edac/edac_core.h
@@ -485,7 +485,16 @@ struct edac_dev_sysfs_attribute {
 };
 
 /* edac_dev_sysfs_block_attribute structure
+ *
  *	used in leaf 'block' nodes for adding controls/attributes
+ *
+ *	each block in each instance of the containing control structure
+ *	can have an array of the following. The show and store functions
+ *	will be filled in with the show/store function in the
+ *	low level driver.
+ *
+ *	The 'value' field will be the actual value field used for
+ *	counting
  */
 struct edac_dev_sysfs_block_attribute {
 	struct attribute attr;
@@ -494,8 +503,6 @@ struct edac_dev_sysfs_block_attribute {
 			const char *, size_t);
 	struct edac_device_block *block;
 
-	/* low driver use */
-	void *arg;
 	unsigned int value;
 };
 
diff --git a/drivers/edac/edac_device.c b/drivers/edac/edac_device.c
index 7e3723768ac..f3690a697cf 100644
--- a/drivers/edac/edac_device.c
+++ b/drivers/edac/edac_device.c
@@ -83,7 +83,7 @@ struct edac_device_ctl_info *edac_device_alloc_ctl_info(
 	void *pvt;
 	int err;
 
-	debugf1("%s() instances=%d blocks=%d\n",
+	debugf4("%s() instances=%d blocks=%d\n",
 		__func__, nr_instances, nr_blocks);
 
 	/* Calculate the size of memory we need to allocate AND
@@ -158,6 +158,9 @@ struct edac_device_ctl_info *edac_device_alloc_ctl_info(
 	/* Name of this edac device */
 	snprintf(dev_ctl->name,sizeof(dev_ctl->name),"%s",edac_device_name);
 
+	debugf4("%s() edac_dev=%p next after end=%p\n",
+		__func__, dev_ctl, pvt + sz_private );
+
 	/* Initialize every Instance */
 	for (instance = 0; instance < nr_instances; instance++) {
 		inst = &dev_inst[instance];
@@ -177,8 +180,10 @@ struct edac_device_ctl_info *edac_device_alloc_ctl_info(
 			snprintf(blk->name, sizeof(blk->name),
 				 "%s%d", edac_block_name, block+offset_value);
 
-			debugf1("%s() instance=%d block=%d name=%s\n",
-				__func__, instance, block, blk->name);
+			debugf4("%s() instance=%d inst_p=%p block=#%d "
+				"block_p=%p name='%s'\n",
+				__func__, instance, inst, block,
+				blk, blk->name);
 
 			/* if there are NO attributes OR no attribute pointer
 			 * then continue on to next block iteration
@@ -191,20 +196,32 @@ struct edac_device_ctl_info *edac_device_alloc_ctl_info(
 			attrib_p = &dev_attrib[block*nr_instances*nr_attrib];
 			blk->block_attributes = attrib_p;
 
+			debugf4("%s() THIS BLOCK_ATTRIB=%p\n",
+				__func__, blk->block_attributes);
+
 			/* Initialize every user specified attribute in this
 			 * block with the data the caller passed in
+			 * Each block gets its own copy of pointers,
+			 * and its unique 'value'
 			 */
 			for (attr = 0; attr < nr_attrib; attr++) {
 				attrib = &attrib_p[attr];
-				attrib->attr = attrib_spec->attr;
-				attrib->show = attrib_spec->show;
-				attrib->store = attrib_spec->store;
-
-				/* up reference this block */
-				attrib->block = blk;
 
-				/* bump the attrib_spec */
-				attrib_spec++;
+				/* populate the unique per attrib
+				 * with the code pointers and info
+				 */
+				attrib->attr = attrib_spec[attr].attr;
+				attrib->show = attrib_spec[attr].show;
+				attrib->store = attrib_spec[attr].store;
+
+				attrib->block = blk;	/* up link */
+
+				debugf4("%s() alloc-attrib=%p attrib_name='%s' "
+					"attrib-spec=%p spec-name=%s\n",
+					__func__, attrib, attrib->attr.name,
+					&attrib_spec[attr],
+					attrib_spec[attr].attr.name
+					);
 			}
 		}
 	}
@@ -258,7 +275,7 @@ static struct edac_device_ctl_info *find_edac_device_by_dev(struct device *dev)
 	struct edac_device_ctl_info *edac_dev;
 	struct list_head *item;
 
-	debugf3("%s()\n", __func__);
+	debugf0("%s()\n", __func__);
 
 	list_for_each(item, &edac_device_list) {
 		edac_dev = list_entry(item, struct edac_device_ctl_info, link);
@@ -402,7 +419,6 @@ static void edac_device_workq_function(struct work_struct *work_req)
 	struct delayed_work *d_work = (struct delayed_work *)work_req;
 	struct edac_device_ctl_info *edac_dev = to_edac_device_ctl_work(d_work);
 
-	//debugf0("%s() here and running\n", __func__);
 	mutex_lock(&device_ctls_mutex);
 
 	/* Only poll controllers that are running polled and have a check */
@@ -582,7 +598,7 @@ struct edac_device_ctl_info *edac_device_del_device(struct device *dev)
 {
 	struct edac_device_ctl_info *edac_dev;
 
-	debugf0("MC: %s()\n", __func__);
+	debugf0("%s()\n", __func__);
 
 	mutex_lock(&device_ctls_mutex);
 
diff --git a/drivers/edac/edac_device_sysfs.c b/drivers/edac/edac_device_sysfs.c
index 52769ae69bd..70b837f23c4 100644
--- a/drivers/edac/edac_device_sysfs.c
+++ b/drivers/edac/edac_device_sysfs.c
@@ -200,7 +200,7 @@ static void edac_device_ctrl_master_release(struct kobject *kobj)
 {
 	struct edac_device_ctl_info *edac_dev = to_edacdev(kobj);
 
-	debugf1("%s() control index=%d\n", __func__, edac_dev->dev_idx);
+	debugf4("%s() control index=%d\n", __func__, edac_dev->dev_idx);
 
 	/* decrement the EDAC CORE module ref count */
 	module_put(edac_dev->owner);
@@ -252,7 +252,7 @@ int edac_device_register_sysfs_main_kobj(struct edac_device_ctl_info *edac_dev)
 	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);
+	debugf4("%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)
 		goto err_out;
@@ -279,7 +279,7 @@ int edac_device_register_sysfs_main_kobj(struct edac_device_ctl_info *edac_dev)
 	 * edac_device_unregister_sysfs_main_kobj() must be used
 	 */
 
-	debugf1("%s() Registered '.../edac/%s' kobject\n",
+	debugf4("%s() Registered '.../edac/%s' kobject\n",
 		__func__, edac_dev->name);
 
 	return 0;
@@ -300,7 +300,7 @@ void edac_device_unregister_sysfs_main_kobj(
 					struct edac_device_ctl_info *edac_dev)
 {
 	debugf0("%s()\n", __func__);
-	debugf1("%s() name of kobject is: %s\n",
+	debugf4("%s() name of kobject is: %s\n",
 		__func__, kobject_name(&edac_dev->kobj));
 
 	/*
@@ -416,22 +416,29 @@ static struct kobj_type ktype_instance_ctrl = {
 
 /* 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 edac_device_block *block, char *data)
+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\n", block->counters.ue_count);
 }
 
-static ssize_t block_ce_count_show(struct edac_device_block *block, char *data)
+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\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)
 {
@@ -448,22 +455,16 @@ static void edac_device_ctrl_block_release(struct kobject *kobj)
 	kobject_put(&block->instance->ctl->kobj);
 }
 
-/* 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);
+	struct edac_dev_sysfs_block_attribute *block_attr =
+						to_block_attr(attr);
 
 	if (block_attr->show)
-		return block_attr->show(block, buffer);
+		return block_attr->show(kobj, attr, buffer);
 	return -EIO;
 }
 
@@ -472,11 +473,12 @@ 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);
+	struct edac_dev_sysfs_block_attribute *block_attr;
+
+	block_attr = to_block_attr(attr);
 
 	if (block_attr->store)
-		return block_attr->store(block, buffer, count);
+		return block_attr->store(kobj, attr, buffer, count);
 	return -EIO;
 }
 
@@ -487,7 +489,7 @@ static struct sysfs_ops device_block_ops = {
 };
 
 #define BLOCK_ATTR(_name,_mode,_show,_store)        \
-static struct block_attribute attr_block_##_name = {                       \
+static struct edac_dev_sysfs_block_attribute attr_block_##_name = {	\
 	.attr = {.name = __stringify(_name), .mode = _mode },   \
 	.show   = _show,                                        \
 	.store  = _store,                                       \
@@ -497,7 +499,7 @@ 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[] = {
+static struct edac_dev_sysfs_block_attribute *device_block_attr[] = {
 	&attr_block_ce_count,
 	&attr_block_ue_count,
 	NULL,
@@ -524,14 +526,15 @@ static int edac_device_create_block(struct edac_device_ctl_info *edac_dev,
 	struct edac_dev_sysfs_block_attribute *sysfs_attrib;
 	struct kobject *main_kobj;
 
-	debugf1("%s() Instance '%s' block '%s'\n",
-		__func__, instance->name, block->name);
+	debugf4("%s() Instance '%s' inst_p=%p  block '%s'  block_p=%p\n",
+		__func__, instance->name, instance, block->name, block);
+	debugf4("%s() block kobj=%p  block kobj->parent=%p\n",
+		__func__, &block->kobj, &block->kobj.parent);
 
 	/* init this block's kobject */
 	memset(&block->kobj, 0, sizeof(struct kobject));
 	block->kobj.parent = &instance->kobj;
 	block->kobj.ktype = &ktype_block_ctrl;
-	block->instance = instance;
 
 	err = kobject_set_name(&block->kobj, "%s", block->name);
 	if (err)
@@ -560,14 +563,20 @@ static int edac_device_create_block(struct edac_device_ctl_info *edac_dev,
 	 * to the block kobject
 	 */
 	sysfs_attrib = block->block_attributes;
-	if (sysfs_attrib) {
-		for (i = 0; i < block->nr_attribs; i++) {
+	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\n",
+				__func__,
+				sysfs_attrib->attr.name,
+				sysfs_attrib, &block->kobj);
+
+			/* Create each block_attribute file */
 			err = sysfs_create_file(&block->kobj,
-				(struct attribute *) sysfs_attrib);
+				&sysfs_attrib->attr);
 			if (err)
 				goto err_on_attrib;
-
-			sysfs_attrib++;
 		}
 	}
 
@@ -595,7 +604,9 @@ static void edac_device_delete_block(struct edac_device_ctl_info *edac_dev,
 	 */
 	sysfs_attrib = block->block_attributes;
 	if (sysfs_attrib && block->nr_attribs) {
-		for (i = 0; i < block->nr_attribs; i++) {
+		for (i = 0; i < block->nr_attribs; i++, sysfs_attrib++) {
+
+			/* remove each block_attrib file */
 			sysfs_remove_file(&block->kobj,
 				(struct attribute *) sysfs_attrib);
 		}
@@ -653,7 +664,7 @@ static int edac_device_create_instance(struct edac_device_ctl_info *edac_dev,
 		goto err_out;
 	}
 
-	debugf1("%s() now register '%d' blocks for instance %d\n",
+	debugf4("%s() now register '%d' blocks for instance %d\n",
 		__func__, instance->nr_blocks, idx);
 
 	/* register all blocks of this instance */
@@ -669,7 +680,7 @@ static int edac_device_create_instance(struct edac_device_ctl_info *edac_dev,
 		}
 	}
 
-	debugf1("%s() Registered instance %d '%s' kobject\n",
+	debugf4("%s() Registered instance %d '%s' kobject\n",
 		__func__, idx, instance->name);
 
 	return 0;
@@ -848,7 +859,7 @@ int edac_device_create_sysfs(struct edac_device_ctl_info *edac_dev)
 	}
 
 
-	debugf0("%s() calling create-instances, idx=%d\n",
+	debugf4("%s() create-instances done, idx=%d\n",
 		__func__, edac_dev->dev_idx);
 
 	return 0;