bna: tx rx cleanup fix

This patch removes busy wait in tx/rx cleanup. bnad_cb_tx_cleanup() and
bnad_cb_rx_cleanup() functions are called from irq context, and currently
they do busy wait for the in-flight transmit or the currently executing napi
polling routine to complete. To fix the issue, we create a workqueue to defer
tx & rx cleanup processing, an in the tx rx cleanup handler, we will
wait respective in flight processing to complete, before freeing the buffers.
Signed-off-by: Jing Huang <huangj@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/brocade/bna/bnad.h

@@ -210,6 +210,7 @@ struct bnad_tx_info {
 	struct bna_tx *tx; /* 1:1 between tx_info & tx */
 	struct bna_tcb *tcb[BNAD_MAX_TXQ_PER_TX];
 	u32 tx_id;
+	struct delayed_work tx_cleanup_work;
 } ____cacheline_aligned;
 
 struct bnad_rx_info {
@@ -217,6 +218,7 @@ struct bnad_rx_info {
 
 	struct bnad_rx_ctrl rx_ctrl[BNAD_MAX_RXP_PER_RX];
 	u32 rx_id;
+	struct work_struct rx_cleanup_work;
 } ____cacheline_aligned;
 
 /* Unmap queues for Tx / Rx cleanup */
@@ -319,6 +321,7 @@ struct bnad {
 	mac_t			perm_addr;
 
 	struct tasklet_struct	tx_free_tasklet;
+	struct workqueue_struct *work_q;
 
 	/* Statistics */
 	struct bnad_stats stats;
@@ -328,6 +331,7 @@ struct bnad {
 	char			adapter_name[BNAD_NAME_LEN];
 	char			port_name[BNAD_NAME_LEN];
 	char			mbox_irq_name[BNAD_NAME_LEN];
+	char			wq_name[BNAD_NAME_LEN];
 
 	/* debugfs specific data */
 	char	*regdata;