be2net: do not use frag index in the RX-compl entry

Instead, use the tail of the RXQ to pick the associated RXQ entry

This fix is required in preparation for supporting RXQ lengths greater than 1K.
For such queues, the frag index in the RX-compl entry is not valid as it is only a 10 bit entry not capable of addressing RXQs longer than 1K.

Signed-off-by: Suresh Reddy <suresh.reddy@emulex.com>
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/emulex/benet/be.h

@@ -283,7 +283,6 @@ struct be_rx_compl_info {
 	u32 rss_hash;
 	u16 vlan_tag;
 	u16 pkt_size;
-	u16 rxq_idx;
 	u16 port;
 	u8 vlanf;
 	u8 num_rcvd;

drivers/net/ethernet/emulex/benet/be_main.c

@@ -1442,12 +1442,12 @@ static inline bool csum_passed(struct be_rx_compl_info *rxcp)
 				(rxcp->ip_csum || rxcp->ipv6);
 }
 
-static struct be_rx_page_info *get_rx_page_info(struct be_rx_obj *rxo,
-						u16 frag_idx)
+static struct be_rx_page_info *get_rx_page_info(struct be_rx_obj *rxo)
 {
 	struct be_adapter *adapter = rxo->adapter;
 	struct be_rx_page_info *rx_page_info;
 	struct be_queue_info *rxq = &rxo->q;
+	u16 frag_idx = rxq->tail;
 
 	rx_page_info = &rxo->page_info_tbl[frag_idx];
 	BUG_ON(!rx_page_info->page);
@@ -1459,6 +1459,7 @@ static struct be_rx_page_info *get_rx_page_info(struct be_rx_obj *rxo,
 		rx_page_info->last_page_user = false;
 	}
 
+	queue_tail_inc(rxq);
 	atomic_dec(&rxq->used);
 	return rx_page_info;
 }
@@ -1467,15 +1468,13 @@ static struct be_rx_page_info *get_rx_page_info(struct be_rx_obj *rxo,
 static void be_rx_compl_discard(struct be_rx_obj *rxo,
 				struct be_rx_compl_info *rxcp)
 {
-	struct be_queue_info *rxq = &rxo->q;
 	struct be_rx_page_info *page_info;
 	u16 i, num_rcvd = rxcp->num_rcvd;
 
 	for (i = 0; i < num_rcvd; i++) {
-		page_info = get_rx_page_info(rxo, rxcp->rxq_idx);
+		page_info = get_rx_page_info(rxo);
 		put_page(page_info->page);
 		memset(page_info, 0, sizeof(*page_info));
-		index_inc(&rxcp->rxq_idx, rxq->len);
 	}
 }
 
@@ -1486,13 +1485,12 @@ static void be_rx_compl_discard(struct be_rx_obj *rxo,
 static void skb_fill_rx_data(struct be_rx_obj *rxo, struct sk_buff *skb,
 			     struct be_rx_compl_info *rxcp)
 {
-	struct be_queue_info *rxq = &rxo->q;
 	struct be_rx_page_info *page_info;
 	u16 i, j;
 	u16 hdr_len, curr_frag_len, remaining;
 	u8 *start;
 
-	page_info = get_rx_page_info(rxo, rxcp->rxq_idx);
+	page_info = get_rx_page_info(rxo);
 	start = page_address(page_info->page) + page_info->page_offset;
 	prefetch(start);
 
@@ -1526,10 +1524,9 @@ static void skb_fill_rx_data(struct be_rx_obj *rxo, struct sk_buff *skb,
 	}
 
 	/* More frags present for this completion */
-	index_inc(&rxcp->rxq_idx, rxq->len);
 	remaining = rxcp->pkt_size - curr_frag_len;
 	for (i = 1, j = 0; i < rxcp->num_rcvd; i++) {
-		page_info = get_rx_page_info(rxo, rxcp->rxq_idx);
+		page_info = get_rx_page_info(rxo);
 		curr_frag_len = min(remaining, rx_frag_size);
 
 		/* Coalesce all frags from the same physical page in one slot */
@@ -1550,7 +1547,6 @@ static void skb_fill_rx_data(struct be_rx_obj *rxo, struct sk_buff *skb,
 		skb->data_len += curr_frag_len;
 		skb->truesize += rx_frag_size;
 		remaining -= curr_frag_len;
-		index_inc(&rxcp->rxq_idx, rxq->len);
 		page_info->page = NULL;
 	}
 	BUG_ON(j > MAX_SKB_FRAGS);
@@ -1598,7 +1594,6 @@ static void be_rx_compl_process_gro(struct be_rx_obj *rxo,
 	struct be_adapter *adapter = rxo->adapter;
 	struct be_rx_page_info *page_info;
 	struct sk_buff *skb = NULL;
-	struct be_queue_info *rxq = &rxo->q;
 	u16 remaining, curr_frag_len;
 	u16 i, j;
 
@@ -1610,7 +1605,7 @@ static void be_rx_compl_process_gro(struct be_rx_obj *rxo,
 
 	remaining = rxcp->pkt_size;
 	for (i = 0, j = -1; i < rxcp->num_rcvd; i++) {
-		page_info = get_rx_page_info(rxo, rxcp->rxq_idx);
+		page_info = get_rx_page_info(rxo);
 
 		curr_frag_len = min(remaining, rx_frag_size);
 
@@ -1628,7 +1623,6 @@ static void be_rx_compl_process_gro(struct be_rx_obj *rxo,
 		skb_frag_size_add(&skb_shinfo(skb)->frags[j], curr_frag_len);
 		skb->truesize += rx_frag_size;
 		remaining -= curr_frag_len;
-		index_inc(&rxcp->rxq_idx, rxq->len);
 		memset(page_info, 0, sizeof(*page_info));
 	}
 	BUG_ON(j > MAX_SKB_FRAGS);
@@ -1663,8 +1657,6 @@ static void be_parse_rx_compl_v1(struct be_eth_rx_compl *compl,
 		AMAP_GET_BITS(struct amap_eth_rx_compl_v1, l4_cksm, compl);
 	rxcp->ipv6 =
 		AMAP_GET_BITS(struct amap_eth_rx_compl_v1, ip_version, compl);
-	rxcp->rxq_idx =
-		AMAP_GET_BITS(struct amap_eth_rx_compl_v1, fragndx, compl);
 	rxcp->num_rcvd =
 		AMAP_GET_BITS(struct amap_eth_rx_compl_v1, numfrags, compl);
 	rxcp->pkt_type =
@@ -1695,8 +1687,6 @@ static void be_parse_rx_compl_v0(struct be_eth_rx_compl *compl,
 		AMAP_GET_BITS(struct amap_eth_rx_compl_v0, l4_cksm, compl);
 	rxcp->ipv6 =
 		AMAP_GET_BITS(struct amap_eth_rx_compl_v0, ip_version, compl);
-	rxcp->rxq_idx =
-		AMAP_GET_BITS(struct amap_eth_rx_compl_v0, fragndx, compl);
 	rxcp->num_rcvd =
 		AMAP_GET_BITS(struct amap_eth_rx_compl_v0, numfrags, compl);
 	rxcp->pkt_type =
@@ -1914,7 +1904,6 @@ static void be_rx_cq_clean(struct be_rx_obj *rxo)
 	struct be_rx_compl_info *rxcp;
 	struct be_adapter *adapter = rxo->adapter;
 	int flush_wait = 0;
-	u16 tail;
 
 	/* Consume pending rx completions.
 	 * Wait for the flush completion (identified by zero num_rcvd)
@@ -1947,9 +1936,8 @@ static void be_rx_cq_clean(struct be_rx_obj *rxo)
 	be_cq_notify(adapter, rx_cq->id, false, 0);
 
 	/* Then free posted rx buffers that were not used */
-	tail = (rxq->head + rxq->len - atomic_read(&rxq->used)) % rxq->len;
-	for (; atomic_read(&rxq->used) > 0; index_inc(&tail, rxq->len)) {
-		page_info = get_rx_page_info(rxo, tail);
+	while (atomic_read(&rxq->used) > 0) {
+		page_info = get_rx_page_info(rxo);
 		put_page(page_info->page);
 		memset(page_info, 0, sizeof(*page_info));
 	}