firewire: add parent-of-unit accessor

Retrieval of an fw_unit's parent is a common pattern in high-level code.
Wrap it up as device = fw_parent_device(unit).

Signed-off-by: Stefan Richter <[e-mail]>

drivers/firewire/core-device.c

···
 	if (!is_fw_unit(dev))
 		return 0;
 
-	device = fw_device(unit->device.parent);
+	device = fw_parent_device(unit);
 	id = container_of(drv, struct fw_driver, driver)->id_table;
 
 	for (; id->match_flags != 0; id++) {
···
 
 static int get_modalias(struct fw_unit *unit, char *buffer, size_t buffer_size)
 {
-	struct fw_device *device = fw_device(unit->device.parent);
+	struct fw_device *device = fw_parent_device(unit);
 	struct fw_csr_iterator ci;
 
 	int key, value;

drivers/firewire/sbp2.c

···
 	int blocked;	/* ditto */
 };
 
+static struct fw_device *target_device(struct sbp2_target *tgt)
+{
+	return fw_parent_device(tgt->unit);
+}
+
 /* Impossible login_id, to detect logout attempt before successful login */
 #define INVALID_LOGIN_ID 0x10000
 
···
 static void sbp2_send_orb(struct sbp2_orb *orb, struct sbp2_logical_unit *lu,
 			  int node_id, int generation, u64 offset)
 {
-	struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
+	struct fw_device *device = target_device(lu->tgt);
 	unsigned long flags;
 
 	orb->pointer.high = 0;
···
 
 static int sbp2_cancel_orbs(struct sbp2_logical_unit *lu)
 {
-	struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
+	struct fw_device *device = target_device(lu->tgt);
 	struct sbp2_orb *orb, *next;
 	struct list_head list;
 	unsigned long flags;
···
 				    int generation, int function,
 				    int lun_or_login_id, void *response)
 {
-	struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
+	struct fw_device *device = target_device(lu->tgt);
 	struct sbp2_management_orb *orb;
 	unsigned int timeout;
 	int retval = -ENOMEM;
···
 
 static void sbp2_agent_reset(struct sbp2_logical_unit *lu)
 {
-	struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
+	struct fw_device *device = target_device(lu->tgt);
 	__be32 d = 0;
 
 	fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
···
 
 static void sbp2_agent_reset_no_wait(struct sbp2_logical_unit *lu)
 {
-	struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
+	struct fw_device *device = target_device(lu->tgt);
 	struct fw_transaction *t;
 	static __be32 d;
 
···
 static void sbp2_conditionally_block(struct sbp2_logical_unit *lu)
 {
 	struct sbp2_target *tgt = lu->tgt;
-	struct fw_card *card = fw_device(tgt->unit->device.parent)->card;
+	struct fw_card *card = target_device(tgt)->card;
 	struct Scsi_Host *shost =
 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 	unsigned long flags;
···
 static void sbp2_conditionally_unblock(struct sbp2_logical_unit *lu)
 {
 	struct sbp2_target *tgt = lu->tgt;
-	struct fw_card *card = fw_device(tgt->unit->device.parent)->card;
+	struct fw_card *card = target_device(tgt)->card;
 	struct Scsi_Host *shost =
 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 	unsigned long flags;
···
  */
 static void sbp2_unblock(struct sbp2_target *tgt)
 {
-	struct fw_card *card = fw_device(tgt->unit->device.parent)->card;
+	struct fw_card *card = target_device(tgt)->card;
 	struct Scsi_Host *shost =
 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 	unsigned long flags;
···
 	struct Scsi_Host *shost =
 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 	struct scsi_device *sdev;
-	struct fw_device *device = fw_device(tgt->unit->device.parent);
+	struct fw_device *device = target_device(tgt);
 
 	/* prevent deadlocks */
 	sbp2_unblock(tgt);
···
  */
 static void sbp2_set_busy_timeout(struct sbp2_logical_unit *lu)
 {
-	struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
+	struct fw_device *device = target_device(lu->tgt);
 	__be32 d = cpu_to_be32(SBP2_CYCLE_LIMIT | SBP2_RETRY_LIMIT);
 
 	fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
···
 	struct sbp2_logical_unit *lu =
 		container_of(work, struct sbp2_logical_unit, work.work);
 	struct sbp2_target *tgt = lu->tgt;
-	struct fw_device *device = fw_device(tgt->unit->device.parent);
+	struct fw_device *device = target_device(tgt);
 	struct Scsi_Host *shost;
 	struct scsi_device *sdev;
 	struct sbp2_login_response response;
···
 static int sbp2_probe(struct device *dev)
 {
 	struct fw_unit *unit = fw_unit(dev);
-	struct fw_device *device = fw_device(unit->device.parent);
+	struct fw_device *device = fw_parent_device(unit);
 	struct sbp2_target *tgt;
 	struct sbp2_logical_unit *lu;
 	struct Scsi_Host *shost;
···
 	struct sbp2_logical_unit *lu =
 		container_of(work, struct sbp2_logical_unit, work.work);
 	struct sbp2_target *tgt = lu->tgt;
-	struct fw_device *device = fw_device(tgt->unit->device.parent);
+	struct fw_device *device = target_device(tgt);
 	int generation, node_id, local_node_id;
 
 	if (fw_device_is_shutdown(device))
···
 	struct sbp2_target *tgt = unit->device.driver_data;
 	struct sbp2_logical_unit *lu;
 
-	fw_device_enable_phys_dma(fw_device(unit->device.parent));
+	fw_device_enable_phys_dma(fw_parent_device(unit));
 
 	/*
 	 * Fw-core serializes sbp2_update() against sbp2_remove().
···
 {
 	struct sbp2_command_orb *orb =
 		container_of(base_orb, struct sbp2_command_orb, base);
-	struct fw_device *device = fw_device(orb->lu->tgt->unit->device.parent);
+	struct fw_device *device = target_device(orb->lu->tgt);
 	int result;
 
 	if (status != NULL) {
···
 static int sbp2_scsi_queuecommand(struct scsi_cmnd *cmd, scsi_done_fn_t done)
 {
 	struct sbp2_logical_unit *lu = cmd->device->hostdata;
-	struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
+	struct fw_device *device = target_device(lu->tgt);
 	struct sbp2_command_orb *orb;
 	int generation, retval = SCSI_MLQUEUE_HOST_BUSY;
 

include/linux/firewire.h

···
 	put_device(&unit->device);
 }
 
+static inline struct fw_device *fw_parent_device(struct fw_unit *unit)
+{
+	return fw_device(unit->device.parent);
+}
+
 struct ieee1394_device_id;
 
 struct fw_driver {