bnxt_en: Check the FW's VNIC flush capability

Check the HWRM_VNIC_QCAPS FW response for the receive engine flush
capability.  This capability indicates that we can reliably support
RX ring restart when calling HWRM_VNIC_UPDATE with MRU set to 0.
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David Wei <dw@davidwei.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -6715,6 +6715,8 @@ static int bnxt_hwrm_vnic_qcaps(struct bnxt *bp)
 			bp->rss_cap |= BNXT_RSS_CAP_ESP_V4_RSS_CAP;
 		if (flags & VNIC_QCAPS_RESP_FLAGS_RSS_IPSEC_ESP_SPI_IPV6_CAP)
 			bp->rss_cap |= BNXT_RSS_CAP_ESP_V6_RSS_CAP;
+		if (flags & VNIC_QCAPS_RESP_FLAGS_RE_FLUSH_CAP)
+			bp->fw_cap |= BNXT_FW_CAP_VNIC_RE_FLUSH;
 	}
 	hwrm_req_drop(bp, req);
 	return rc;

drivers/net/ethernet/broadcom/bnxt/bnxt.h

@@ -2438,6 +2438,7 @@ struct bnxt {
 	#define BNXT_FW_CAP_VNIC_TUNNEL_TPA		BIT_ULL(37)
 	#define BNXT_FW_CAP_CFA_NTUPLE_RX_EXT_IP_PROTO	BIT_ULL(38)
 	#define BNXT_FW_CAP_CFA_RFS_RING_TBL_IDX_V3	BIT_ULL(39)
+	#define BNXT_FW_CAP_VNIC_RE_FLUSH		BIT_ULL(40)
 
 	u32			fw_dbg_cap;