1 files changed, 23 insertions, 0 deletions

diff --git a/drivers/scsi/isci/remote_device.h b/drivers/scsi/isci/remote_device.h
index 2b6a5bb7bd60..05842b5f1e3b 100644
--- a/drivers/scsi/isci/remote_device.h
+++ b/drivers/scsi/isci/remote_device.h
@@ -56,6 +56,7 @@
 #ifndef _ISCI_REMOTE_DEVICE_H_
 #define _ISCI_REMOTE_DEVICE_H_
 #include <scsi/libsas.h>
+#include <linux/kref.h>
 #include "scu_remote_node_context.h"
 #include "remote_node_context.h"
 #include "port.h"
@@ -134,7 +135,9 @@ struct isci_remote_device {
         #define IDEV_STOP_PENDING 1
         #define IDEV_ALLOCATED 2
         #define IDEV_EH 3
+        #define IDEV_GONE 4
         unsigned long flags;
+        struct kref kref;
         struct isci_port *isci_port;
         struct domain_device *domain_dev;
         struct list_head node;
@@ -145,6 +148,26 @@ struct isci_remote_device {
 
 #define ISCI_REMOTE_DEVICE_START_TIMEOUT 5000
 
+/* device reference routines must be called under scic_lock */
+static inline struct isci_remote_device *isci_lookup_device(struct domain_device *dev)
+{
+        struct isci_remote_device *idev = dev->lldd_dev;
+
+        if (idev && !test_bit(IDEV_GONE, &idev->flags)) {
+                kref_get(&idev->kref);
+                return idev;
+        }
+
+        return NULL;
+}
+
+void isci_remote_device_release(struct kref *kref);
+static inline void isci_put_device(struct isci_remote_device *idev)
+{
+        if (idev)
+                kref_put(&idev->kref, isci_remote_device_release);
+}
+
 enum sci_status isci_remote_device_stop(struct isci_host *ihost,
                                         struct isci_remote_device *idev);
 void isci_remote_device_nuke_requests(struct isci_host *ihost,