[SCSI] bnx2fc: Avoid holding cq_lock when iounmap() is called

With kernel debugging enabled, holding cq_lock when calling
bnx2fc_free_session_resc() which calls iounmap() leads to a warning
stack trace [INFO: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected].
iounmap() grabs a HARDIRQ-unsafe vmlist lock, so holding
spin_lock_bh(cq_lock) when calling iounmap() will trigger the LOCKDEP
warning.  Since cq_lock is required only to guard against deletion, hold
the lock just before freeing the cq.
Signed-off-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: Nithin Nayak Sujir <nsujir@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

drivers/scsi/bnx2fc/bnx2fc_tgt.c

@@ -304,10 +304,8 @@ static void bnx2fc_upload_session(struct fcoe_port *port,
 				" not sent to FW\n");
 
 	/* Free session resources */
-	spin_lock_bh(&tgt->cq_lock);
 	bnx2fc_free_session_resc(hba, tgt);
 	bnx2fc_free_conn_id(hba, tgt->fcoe_conn_id);
-	spin_unlock_bh(&tgt->cq_lock);
 }
 
 static int bnx2fc_init_tgt(struct bnx2fc_rport *tgt,
@@ -830,11 +828,13 @@ static void bnx2fc_free_session_resc(struct bnx2fc_hba *hba,
 		tgt->rq = NULL;
 	}
 	/* Free CQ */
+	spin_lock_bh(&tgt->cq_lock);
 	if (tgt->cq) {
 		dma_free_coherent(&hba->pcidev->dev, tgt->cq_mem_size,
 				    tgt->cq, tgt->cq_dma);
 		tgt->cq = NULL;
 	}
+	spin_unlock_bh(&tgt->cq_lock);
 	/* Free SQ */
 	if (tgt->sq) {
 		dma_free_coherent(&hba->pcidev->dev, tgt->sq_mem_size,