bnxt_en: Workaround Nitro A0 hardware RX bug (part 2).

The hardware is unable to drop rx packets not matching the RX filters.  To
workaround it, we create a special VNIC and configure the hardware to
direct all packets not matching the filters to it.  We then setup the
driver to drop packets received on this VNIC.

This patch creates the infrastructure for this VNIC, reserves a
completion ring, and rx rings.  Only shared completion ring mode is
supported.  The next 2 patches add a NAPI to handle packets from this
VNIC and the setup of the VNIC.

Signed-off-by: Prashant Sreedharan <prashant.sreedharan@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index de74012..75a8b30 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -3433,6 +3433,8 @@
 		ring = 0;
 	else if (vnic->flags & BNXT_VNIC_RFS_FLAG)
 		ring = vnic_id - 1;
+	else if ((vnic_id == 1) && BNXT_CHIP_TYPE_NITRO_A0(bp))
+		ring = bp->rx_nr_rings - 1;
 
 	grp_idx = bp->rx_ring[ring].bnapi->index;
 	req.vnic_id = cpu_to_le16(vnic->fw_vnic_id);
@@ -4365,6 +4367,7 @@
 {
 	struct bnxt_vnic_info *vnic = &bp->vnic_info[0];
 	int rc = 0;
+	unsigned int rx_nr_rings = bp->rx_nr_rings;
 
 	if (irq_re_init) {
 		rc = bnxt_hwrm_stat_ctx_alloc(bp);
@@ -4387,8 +4390,11 @@
 		goto err_out;
 	}
 
+	if (BNXT_CHIP_TYPE_NITRO_A0(bp))
+		rx_nr_rings--;
+
 	/* default vnic 0 */
-	rc = bnxt_hwrm_vnic_alloc(bp, 0, 0, bp->rx_nr_rings);
+	rc = bnxt_hwrm_vnic_alloc(bp, 0, 0, rx_nr_rings);
 	if (rc) {
 		netdev_err(bp->dev, "hwrm vnic alloc failure rc: %x\n", rc);
 		goto err_out;
@@ -6519,7 +6525,10 @@
 		*max_cp = min_t(int, *max_cp, bp->pf.max_stat_ctxs);
 		max_ring_grps = bp->pf.max_hw_ring_grps;
 	}
-
+	if (BNXT_CHIP_TYPE_NITRO_A0(bp) && BNXT_PF(bp)) {
+		*max_cp -= 1;
+		*max_rx -= 2;
+	}
 	if (bp->flags & BNXT_FLAG_AGG_RINGS)
 		*max_rx >>= 1;
 	*max_rx = min_t(int, *max_rx, max_ring_grps);
@@ -6555,6 +6564,10 @@
 	bp->cp_nr_rings = sh ? max_t(int, bp->tx_nr_rings, bp->rx_nr_rings) :
 			       bp->tx_nr_rings + bp->rx_nr_rings;
 	bp->num_stat_ctxs = bp->cp_nr_rings;
+	if (BNXT_CHIP_TYPE_NITRO_A0(bp)) {
+		bp->rx_nr_rings++;
+		bp->cp_nr_rings++;
+	}
 	return rc;
 }
 
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
index 0f7dd86..492c06b 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
@@ -362,9 +362,13 @@
 	channel->max_other = 0;
 	if (bp->flags & BNXT_FLAG_SHARED_RINGS) {
 		channel->combined_count = bp->rx_nr_rings;
+		if (BNXT_CHIP_TYPE_NITRO_A0(bp))
+			channel->combined_count--;
 	} else {
-		channel->rx_count = bp->rx_nr_rings;
-		channel->tx_count = bp->tx_nr_rings_per_tc;
+		if (!BNXT_CHIP_TYPE_NITRO_A0(bp)) {
+			channel->rx_count = bp->rx_nr_rings;
+			channel->tx_count = bp->tx_nr_rings_per_tc;
+		}
 	}
 }
 
@@ -387,6 +391,10 @@
 	    (channel->rx_count || channel->tx_count))
 		return -EINVAL;
 
+	if (BNXT_CHIP_TYPE_NITRO_A0(bp) && (channel->rx_count ||
+					    channel->tx_count))
+		return -EINVAL;
+
 	if (channel->combined_count)
 		sh = true;