packet: use macro GET_PBDQC_FROM_RB to simplify the codes

Signed-off-by: NDuan Jiong <duanj.fnst@cn.fujitsu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/packet/af_packet.c

@@ -437,7 +437,8 @@ static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
 {
 	struct tpacket_kbdq_core *pkc;
 
-	pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
+	pkc = tx_ring ? GET_PBDQC_FROM_RB(&po->tx_ring) :
+			GET_PBDQC_FROM_RB(&po->rx_ring);
 
 	spin_lock_bh(&rb_queue->lock);
 	pkc->delete_blk_timer = 1;
@@ -463,7 +464,8 @@ static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring)
 	if (tx_ring)
 		BUG();
 
-	pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
+	pkc = tx_ring ? GET_PBDQC_FROM_RB(&po->tx_ring) :
+			GET_PBDQC_FROM_RB(&po->rx_ring);
 	prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
 }
 
@@ -521,7 +523,7 @@ static void init_prb_bdqc(struct packet_sock *po,
 			struct pgv *pg_vec,
 			union tpacket_req_u *req_u, int tx_ring)
 {
-	struct tpacket_kbdq_core *p1 = &rb->prb_bdqc;
+	struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
 	struct tpacket_block_desc *pbd;
 
 	memset(p1, 0x0, sizeof(*p1));
@@ -585,7 +587,7 @@ static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
 static void prb_retire_rx_blk_timer_expired(unsigned long data)
 {
 	struct packet_sock *po = (struct packet_sock *)data;
-	struct tpacket_kbdq_core *pkc = &po->rx_ring.prb_bdqc;
+	struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
 	unsigned int frozen;
 	struct tpacket_block_desc *pbd;