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-rw-r--r--drivers/misc/enclosure.c44
1 files changed, 32 insertions, 12 deletions
diff --git a/drivers/misc/enclosure.c b/drivers/misc/enclosure.c
index 348443bdb23..789d12128c2 100644
--- a/drivers/misc/enclosure.c
+++ b/drivers/misc/enclosure.c
@@ -33,24 +33,44 @@ static DEFINE_MUTEX(container_list_lock);
static struct class enclosure_class;
/**
- * enclosure_find - find an enclosure given a device
- * @dev: the device to find for
+ * enclosure_find - find an enclosure given a parent device
+ * @dev: the parent to match against
+ * @start: Optional enclosure device to start from (NULL if none)
*
- * Looks through the list of registered enclosures to see
- * if it can find a match for a device. Returns NULL if no
- * enclosure is found. Obtains a reference to the enclosure class
- * device which must be released with device_put().
+ * Looks through the list of registered enclosures to find all those
+ * with @dev as a parent. Returns NULL if no enclosure is
+ * found. @start can be used as a starting point to obtain multiple
+ * enclosures per parent (should begin with NULL and then be set to
+ * each returned enclosure device). Obtains a reference to the
+ * enclosure class device which must be released with device_put().
+ * If @start is not NULL, a reference must be taken on it which is
+ * released before returning (this allows a loop through all
+ * enclosures to exit with only the reference on the enclosure of
+ * interest held). Note that the @dev may correspond to the actual
+ * device housing the enclosure, in which case no iteration via @start
+ * is required.
*/
-struct enclosure_device *enclosure_find(struct device *dev)
+struct enclosure_device *enclosure_find(struct device *dev,
+ struct enclosure_device *start)
{
struct enclosure_device *edev;
mutex_lock(&container_list_lock);
- list_for_each_entry(edev, &container_list, node) {
- if (edev->edev.parent == dev) {
- get_device(&edev->edev);
- mutex_unlock(&container_list_lock);
- return edev;
+ edev = list_prepare_entry(start, &container_list, node);
+ if (start)
+ put_device(&start->edev);
+
+ list_for_each_entry_continue(edev, &container_list, node) {
+ struct device *parent = edev->edev.parent;
+ /* parent might not be immediate, so iterate up to
+ * the root of the tree if necessary */
+ while (parent) {
+ if (parent == dev) {
+ get_device(&edev->edev);
+ mutex_unlock(&container_list_lock);
+ return edev;
+ }
+ parent = parent->parent;
}
}
mutex_unlock(&container_list_lock);