net/bnxt: fix dynamic VNIC count

[ upstream commit a0c2315 ]

Ensure that the current count of in-use VNICs is decremented
when a VNIC is freed. Don't attempt VNIC allocation when the
maximum supported number of VNICs is currently allocated.

Fixes: 49d0709 ("net/bnxt: delete and flush L2 filters cleanly")
Fixes: d24610f ("net/bnxt: allow flow creation when RSS is enabled")

Signed-off-by: Lance Richardson <lance.richardson@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Reported-by: Stephen Hemminger <sthemmin@microsoft.com>

drivers/net/bnxt/bnxt.h

@@ -705,7 +705,7 @@ struct bnxt {
 	uint32_t		max_ring_grps;
 	struct bnxt_ring_grp_info	*grp_info;
 
-	unsigned int		nr_vnics;
+	uint16_t			nr_vnics;
 
 #define BNXT_GET_DEFAULT_VNIC(bp)	(&(bp)->vnic_info[0])
 	struct bnxt_vnic_info	*vnic_info;

drivers/net/bnxt/bnxt_flow.c

@@ -925,6 +925,9 @@ static int bnxt_vnic_prep(struct bnxt *bp, struct bnxt_vnic_info *vnic)
 	uint64_t rx_offloads = dev_conf->rxmode.offloads;
 	int rc;
 
+	if (bp->nr_vnics > bp->max_vnics - 1)
+		return -ENOMEM;
+
 	rc = bnxt_vnic_grp_alloc(bp, vnic);
 	if (rc)
 		goto ret;
@@ -1543,6 +1546,7 @@ bnxt_flow_validate(struct rte_eth_dev *dev,
 			bnxt_hwrm_vnic_ctx_free(bp, vnic);
 			bnxt_hwrm_vnic_free(bp, vnic);
 			vnic->rx_queue_cnt = 0;
+			bp->nr_vnics--;
 			PMD_DRV_LOG(DEBUG, "Free VNIC\n");
 		}
 	}
@@ -2001,6 +2005,7 @@ _bnxt_flow_destroy(struct bnxt *bp,
 
 			bnxt_hwrm_vnic_free(bp, vnic);
 			vnic->rx_queue_cnt = 0;
+			bp->nr_vnics--;
 		}
 	} else {
 		rte_flow_error_set(error, -ret,