ses: add enclosure logical id

Export the NAA logical id for the enclosure.  This is optionally
available from the sas_transport_class, but it is really a property of
the enclosure.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Jens Axboe <axboe@fb.com>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/misc/enclosure.c

@@ -432,8 +432,21 @@ static ssize_t components_show(struct device *cdev,
 }
 static DEVICE_ATTR_RO(components);
 
+static ssize_t id_show(struct device *cdev,
+				 struct device_attribute *attr,
+				 char *buf)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev);
+
+	if (edev->cb->show_id)
+		return edev->cb->show_id(edev, buf);
+	return -EINVAL;
+}
+static DEVICE_ATTR_RO(id);
+
 static struct attribute *enclosure_class_attrs[] = {
 	&dev_attr_components.attr,
+	&dev_attr_id.attr,
 	NULL,
 };
 ATTRIBUTE_GROUPS(enclosure_class);

drivers/scsi/ses.c

@@ -258,6 +258,14 @@ static int ses_set_active(struct enclosure_device *edev,
 	return ses_set_page2_descriptor(edev, ecomp, desc);
 }
 
+static int ses_show_id(struct enclosure_device *edev, char *buf)
+{
+	struct ses_device *ses_dev = edev->scratch;
+	unsigned long long id = get_unaligned_be64(ses_dev->page1+8+4);
+
+	return sprintf(buf, "%#llx\n", id);
+}
+
 static struct enclosure_component_callbacks ses_enclosure_callbacks = {
 	.get_fault		= ses_get_fault,
 	.set_fault		= ses_set_fault,
@@ -265,6 +273,7 @@ static struct enclosure_component_callbacks ses_enclosure_callbacks = {
 	.get_locate		= ses_get_locate,
 	.set_locate		= ses_set_locate,
 	.set_active		= ses_set_active,
+	.show_id		= ses_show_id,
 };
 
 struct ses_host_edev {

include/linux/enclosure.h

@@ -79,6 +79,7 @@ struct enclosure_component_callbacks {
 	int (*set_locate)(struct enclosure_device *,
 			  struct enclosure_component *,
 			  enum enclosure_component_setting);
+	int (*show_id)(struct enclosure_device *, char *buf);
 };