octeontx2-pf: Simplify the receive buffer size calculation

This patch separates the logic of configuring hardware
maximum transmit frame size and receive frame size.
This simplifies the logic to calculate receive buffer
size and using cqe descriptor of different size.
Also additional size of skb_shared_info structure is
allocated for each receive buffer pointer given to
hardware which is not necessary. Hence change the
size calculation to remove the size of
skb_shared_info. Add a check for array out of
bounds while adding fragments to the network stack.

Signed-off-by: Subbaraya Sundeep <sbhatta@marvell.com>
Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 8 deletions

diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c
index f24e920324eb..1e0d0c9c1dac 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c
@@ -1312,16 +1312,14 @@ static int otx2_get_rbuf_size(struct otx2_nic *pf, int mtu)
 	 * NIX transfers entire data using 6 segments/buffers and writes
 	 * a CQE_RX descriptor with those segment addresses. First segment
 	 * has additional data prepended to packet. Also software omits a
-	 * headroom of 128 bytes and sizeof(struct skb_shared_info) in
-	 * each segment. Hence the total size of memory needed
-	 * to receive a packet with 'mtu' is:
+	 * headroom of 128 bytes in each segment. Hence the total size of
+	 * memory needed to receive a packet with 'mtu' is:
 	 * frame size =  mtu + additional data;
-	 * memory = frame_size + (headroom + struct skb_shared_info size) * 6;
+	 * memory = frame_size + headroom * 6;
 	 * each receive buffer size = memory / 6;
 	 */
 	frame_size = mtu + OTX2_ETH_HLEN + OTX2_HW_TIMESTAMP_LEN;
-	total_size = frame_size + (OTX2_HEAD_ROOM +
-		     OTX2_DATA_ALIGN(sizeof(struct skb_shared_info))) * 6;
+	total_size = frame_size + OTX2_HEAD_ROOM * 6;
 	rbuf_size = total_size / 6;
 
 	return ALIGN(rbuf_size, 2048);
@@ -1343,7 +1341,8 @@ static int otx2_init_hw_resources(struct otx2_nic *pf)
 	hw->sqpool_cnt = hw->tot_tx_queues;
 	hw->pool_cnt = hw->rqpool_cnt + hw->sqpool_cnt;
 
-	pf->max_frs = pf->netdev->mtu + OTX2_ETH_HLEN + OTX2_HW_TIMESTAMP_LEN;
+	/* Maximum hardware supported transmit length */
+	pf->tx_max_pktlen = pf->netdev->max_mtu + OTX2_ETH_HLEN;
 
 	pf->rbsize = otx2_get_rbuf_size(pf, pf->netdev->mtu);
 
@@ -1807,7 +1806,7 @@ static netdev_tx_t otx2_xmit(struct sk_buff *skb, struct net_device *netdev)
 
 	/* Check for minimum and maximum packet length */
 	if (skb->len <= ETH_HLEN ||
-	    (!skb_shinfo(skb)->gso_size && skb->len > pf->max_frs)) {
+	    (!skb_shinfo(skb)->gso_size && skb->len > pf->tx_max_pktlen)) {
 		dev_kfree_skb(skb);
 		return NETDEV_TX_OK;
 	}