amd8111e: add GRO support

Use napi_complete_done() instead of __napi_complete() to :

1) Get support of gro_flush_timeout if opt-in
2) Not rearm interrupts for busy-polling users.
3) use standard NAPI API.
4) get rid of baroque code and ease maintenance.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/amd/amd8111e.c

@@ -695,23 +695,13 @@ static int amd8111e_rx_poll(struct napi_struct *napi, int budget)
 	void __iomem *mmio = lp->mmio;
 	struct sk_buff *skb,*new_skb;
 	int min_pkt_len, status;
-	unsigned int intr0;
 	int num_rx_pkt = 0;
 	short pkt_len;
 #if AMD8111E_VLAN_TAG_USED
 	short vtag;
 #endif
-	int rx_pkt_limit = budget;
-	unsigned long flags;
-
-	if (rx_pkt_limit <= 0)
-		goto rx_not_empty;
 
-	do{
-		/* process receive packets until we use the quota.
-		 * If we own the next entry, it's a new packet. Send it up.
-		 */
-		while(1) {
+	while (num_rx_pkt < budget) {
 		status = le16_to_cpu(lp->rx_ring[rx_index].rx_flags);
 		if (status & OWN_BIT)
 			break;
@@ -722,13 +712,13 @@ static int amd8111e_rx_poll(struct napi_struct *napi, int budget)
 		 * jabber packet to use two buffers, with only
 		 * the last correctly noting the error.
 		 */
-			if(status & ERR_BIT) {
+		if (status & ERR_BIT) {
 			/* resetting flags */
 			lp->rx_ring[rx_index].rx_flags &= RESET_RX_FLAGS;
 			goto err_next_pkt;
 		}
 		/* check for STP and ENP */
-			if(!((status & STP_BIT) && (status & ENP_BIT))){
+		if (!((status & STP_BIT) && (status & ENP_BIT))){
 			/* resetting flags */
 			lp->rx_ring[rx_index].rx_flags &= RESET_RX_FLAGS;
 			goto err_next_pkt;
@@ -737,20 +727,18 @@ static int amd8111e_rx_poll(struct napi_struct *napi, int budget)
 
 #if AMD8111E_VLAN_TAG_USED
 		vtag = status & TT_MASK;
-			/*MAC will strip vlan tag*/
+		/* MAC will strip vlan tag */
 		if (vtag != 0)
-				min_pkt_len =MIN_PKT_LEN - 4;
+			min_pkt_len = MIN_PKT_LEN - 4;
 			else
 #endif
-				min_pkt_len =MIN_PKT_LEN;
+			min_pkt_len = MIN_PKT_LEN;
 
 		if (pkt_len < min_pkt_len) {
 			lp->rx_ring[rx_index].rx_flags &= RESET_RX_FLAGS;
 			lp->drv_rx_errors++;
 			goto err_next_pkt;
 		}
-			if(--rx_pkt_limit < 0)
-				goto rx_not_empty;
 		new_skb = netdev_alloc_skb(dev, lp->rx_buff_len);
 		if (!new_skb) {
 			/* if allocation fail,
@@ -780,13 +768,13 @@ static int amd8111e_rx_poll(struct napi_struct *napi, int budget)
 			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tag);
 		}
 #endif
-			netif_receive_skb(skb);
-			/*COAL update rx coalescing parameters*/
+		napi_gro_receive(napi, skb);
+		/* COAL update rx coalescing parameters */
 		lp->coal_conf.rx_packets++;
 		lp->coal_conf.rx_bytes += pkt_len;
 		num_rx_pkt++;
 
-		err_next_pkt:
+err_next_pkt:
 		lp->rx_ring[rx_index].buff_phy_addr
 			= cpu_to_le32(lp->rx_dma_addr[rx_index]);
 		lp->rx_ring[rx_index].buff_count =
@@ -795,25 +783,17 @@ static int amd8111e_rx_poll(struct napi_struct *napi, int budget)
 		lp->rx_ring[rx_index].rx_flags |= cpu_to_le16(OWN_BIT);
 		rx_index = (++lp->rx_idx) & RX_RING_DR_MOD_MASK;
 	}
-		/* Check the interrupt status register for more packets in the
-		 * mean time. Process them since we have not used up our quota.
-		 */
-		intr0 = readl(mmio + INT0);
-		/*Ack receive packets */
-		writel(intr0 & RINT0,mmio + INT0);
 
-	} while(intr0 & RINT0);
+	if (num_rx_pkt < budget && napi_complete_done(napi, num_rx_pkt)) {
+		unsigned long flags;
 
-	if (rx_pkt_limit > 0) {
 		/* Receive descriptor is empty now */
 		spin_lock_irqsave(&lp->lock, flags);
-		__napi_complete(napi);
 		writel(VAL0|RINTEN0, mmio + INTEN0);
 		writel(VAL2 | RDMD0, mmio + CMD0);
 		spin_unlock_irqrestore(&lp->lock, flags);
 	}
 
-rx_not_empty:
 	return num_rx_pkt;
 }