bnxt_en: Refactor bnxt_poll_work().

Separate the CP ring polling logic in bnxt_poll_work() into 2 separate
functions __bnxt_poll_work() and __bnxt_poll_work_done().  Since the logic
is separated, we need to add tx_pkts and events fields to struct bnxt_napi
to keep track of the events to handle between the 2 functions.  We also
add had_work_done field to struct bnxt_cp_ring_info to indicate whether
some work was performed on the CP ring.

This is needed to better support the 57500 chips.  We need to poll up to
2 separate CP rings before we update or ARM the CP rings on the 57500 chips.
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -1889,8 +1889,8 @@ static irqreturn_t bnxt_inta(int irq, void *dev_instance)
 	return IRQ_HANDLED;
 }
 
-static int bnxt_poll_work(struct bnxt *bp, struct bnxt_cp_ring_info *cpr,
-			  int budget)
+static int __bnxt_poll_work(struct bnxt *bp, struct bnxt_cp_ring_info *cpr,
+			    int budget)
 {
 	struct bnxt_napi *bnapi = cpr->bnapi;
 	u32 raw_cons = cpr->cp_raw_cons;
@@ -1913,6 +1913,7 @@ static int bnxt_poll_work(struct bnxt *bp, struct bnxt_cp_ring_info *cpr,
 		 * reading any further.
 		 */
 		dma_rmb();
+		cpr->had_work_done = 1;
 		if (TX_CMP_TYPE(txcmp) == CMP_TYPE_TX_L2_CMP) {
 			tx_pkts++;
 			/* return full budget so NAPI will complete. */
@@ -1963,22 +1964,43 @@ static int bnxt_poll_work(struct bnxt *bp, struct bnxt_cp_ring_info *cpr,
 	}
 
 	cpr->cp_raw_cons = raw_cons;
-	/* ACK completion ring before freeing tx ring and producing new
-	 * buffers in rx/agg rings to prevent overflowing the completion
-	 * ring.
-	 */
-	bnxt_db_cq(bp, &cpr->cp_db, cpr->cp_raw_cons);
+	bnapi->tx_pkts += tx_pkts;
+	bnapi->events |= event;
+	return rx_pkts;
+}
 
-	if (tx_pkts)
-		bnapi->tx_int(bp, bnapi, tx_pkts);
+static void __bnxt_poll_work_done(struct bnxt *bp, struct bnxt_napi *bnapi)
+{
+	if (bnapi->tx_pkts) {
+		bnapi->tx_int(bp, bnapi, bnapi->tx_pkts);
+		bnapi->tx_pkts = 0;
+	}
 
-	if (event & BNXT_RX_EVENT) {
+	if (bnapi->events & BNXT_RX_EVENT) {
 		struct bnxt_rx_ring_info *rxr = bnapi->rx_ring;
 
 		bnxt_db_write(bp, &rxr->rx_db, rxr->rx_prod);
-		if (event & BNXT_AGG_EVENT)
+		if (bnapi->events & BNXT_AGG_EVENT)
 			bnxt_db_write(bp, &rxr->rx_agg_db, rxr->rx_agg_prod);
 	}
+	bnapi->events = 0;
+}
+
+static int bnxt_poll_work(struct bnxt *bp, struct bnxt_cp_ring_info *cpr,
+			  int budget)
+{
+	struct bnxt_napi *bnapi = cpr->bnapi;
+	int rx_pkts;
+
+	rx_pkts = __bnxt_poll_work(bp, cpr, budget);
+
+	/* ACK completion ring before freeing tx ring and producing new
+	 * buffers in rx/agg rings to prevent overflowing the completion
+	 * ring.
+	 */
+	bnxt_db_cq(bp, &cpr->cp_db, cpr->cp_raw_cons);
+
+	__bnxt_poll_work_done(bp, bnapi);
 	return rx_pkts;
 }
 

drivers/net/ethernet/broadcom/bnxt/bnxt.h

@@ -792,6 +792,8 @@ struct bnxt_cp_ring_info {
 	u32			cp_raw_cons;
 	struct bnxt_db_info	cp_db;
 
+	u8			had_work_done:1;
+
 	struct bnxt_coal	rx_ring_coal;
 	u64			rx_packets;
 	u64			rx_bytes;
@@ -829,6 +831,9 @@ struct bnxt_napi {
 
 	void			(*tx_int)(struct bnxt *, struct bnxt_napi *,
 					  int);
+	int			tx_pkts;
+	u8			events;
+
 	u32			flags;
 #define BNXT_NAPI_FLAG_XDP	0x1