octeontx2-pf: Add check for non zero mcam flows

This patch ensures that mcam flows are allocated
before adding or destroying the flows.

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

Author: sgoutham-marvell

drivers/net/ethernet/marvell/octeontx2/nic/otx2_flows.c

@@ -972,6 +972,12 @@ int otx2_add_flow(struct otx2_nic *pfvf, struct ethtool_rxnfc *nfc)
 	int err = 0;
 	u32 ring;
 
+	if (!flow_cfg->max_flows) {
+		netdev_err(pfvf->netdev,
+			   "Ntuple rule count is 0, allocate and retry\n");
+		return -EINVAL;
+	}
+
 	ring = ethtool_get_flow_spec_ring(fsp->ring_cookie);
 	if (!(pfvf->flags & OTX2_FLAG_NTUPLE_SUPPORT))
 		return -ENOMEM;
@@ -1183,6 +1189,9 @@ int otx2_destroy_ntuple_flows(struct otx2_nic *pfvf)
 	if (!(pfvf->flags & OTX2_FLAG_NTUPLE_SUPPORT))
 		return 0;
 
+	if (!flow_cfg->max_flows)
+		return 0;
+
 	mutex_lock(&pfvf->mbox.lock);
 	req = otx2_mbox_alloc_msg_npc_delete_flow(&pfvf->mbox);
 	if (!req) {

drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c

@@ -1860,6 +1860,22 @@ static int otx2_set_features(struct net_device *netdev,
 	if ((changed & NETIF_F_NTUPLE) && !ntuple)
 		otx2_destroy_ntuple_flows(pf);
 
+	if ((changed & NETIF_F_NTUPLE) && ntuple) {
+		if (!pf->flow_cfg->max_flows) {
+			netdev_err(netdev,
+				   "Can't enable NTUPLE, MCAM entries not allocated\n");
+			return -EINVAL;
+		}
+	}
+
+	if ((changed & NETIF_F_HW_TC) && tc) {
+		if (!pf->flow_cfg->max_flows) {
+			netdev_err(netdev,
+				   "Can't enable TC, MCAM entries not allocated\n");
+			return -EINVAL;
+		}
+	}
+
 	if ((changed & NETIF_F_HW_TC) && !tc &&
 	    pf->flow_cfg && pf->flow_cfg->nr_flows) {
 		netdev_err(netdev, "Can't disable TC hardware offload while flows are active\n");