[PATCH 03/15] bnge: reserve TX/completion rings for the RoCE MPC channel

[Siva Reddy Kallam <siva.kallam@broadcom.com>]

From: Sachin Holla <sachin.holla@broadcom.com>

When RoCE is enabled, the bng_re driver allocates its own TX/CQ rings
for the MPC control channel out of the same per-function FW ring pool.
Enhanced bnge_reserve_rings() to account for this extra ring count to
avoid pool overflow while allocating netdev rings.

Signed-off-by: Sachin Holla <sachin.holla@broadcom.com>
Signed-off-by: Siva Reddy Kallam <siva.kallam@broadcom.com>
Reviewed-by: Vikas Gupta <vikas.gupta@broadcom.com>
Reviewed-by: Dharmender Garg <dharmender.garg@broadcom.com>
---
 .../net/ethernet/broadcom/bnge/bnge_resc.c    | 32 ++++++++++++++++---
 1 file changed, 28 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnge/bnge_resc.c b/drivers/net/ethernet/broadcom/bnge/bnge_resc.c
index 4711dd4945ff..9dfb22b7c7c7 100644
--- a/drivers/net/ethernet/broadcom/bnge/bnge_resc.c
+++ b/drivers/net/ethernet/broadcom/bnge/bnge_resc.c
@@ -110,9 +110,24 @@ static u16 bnge_nqs_demand(struct bnge_dev *bd)
 	return bd->nq_nr_rings + bnge_aux_get_msix(bd);
 }
 
+static u16 bnge_tx_rings_demand(struct bnge_dev *bd)
+{
+	u16 tx_rings = bd->tx_nr_rings;
+
+	if (bnge_is_roce_en(bd))
+		tx_rings += 1; /* For MPC TX ring */
+
+	return tx_rings;
+}
+
 static u16 bnge_cprs_demand(struct bnge_dev *bd)
 {
-	return bd->tx_nr_rings + bd->rx_nr_rings;
+	u16 cprs = bd->tx_nr_rings + bd->rx_nr_rings;
+
+	if (bnge_is_roce_en(bd))
+		cprs += 1; /* For MPC CQ ring */
+
+	return cprs;
 }
 
 static u16 bnge_get_avail_msix(struct bnge_dev *bd, int num)
@@ -250,7 +265,7 @@ static bool bnge_need_reserve_rings(struct bnge_dev *bd)
 	u16 nqs = bnge_nqs_demand(bd);
 	u16 vnic;
 
-	if (hw_resc->resv_tx_rings != bd->tx_nr_rings)
+	if (hw_resc->resv_tx_rings != bnge_tx_rings_demand(bd))
 		return true;
 
 	vnic = bnge_get_total_vnics(bd, rx);
@@ -275,6 +290,7 @@ int bnge_reserve_rings(struct bnge_dev *bd)
 	u16 nq = bd->nq_nr_rings;
 	u16 aux_msix = 0;
 	bool sh = false;
+	u16 tx_demand;
 	u16 tx_cp;
 	int rc;
 
@@ -293,11 +309,12 @@ int bnge_reserve_rings(struct bnge_dev *bd)
 		hwr.nq = bnge_nqs_demand(bd);
 	}
 
-	hwr.tx = bd->tx_nr_rings;
+	tx_demand = bnge_tx_rings_demand(bd);
+	hwr.tx = tx_demand;
 	hwr.rx = bd->rx_nr_rings;
 	if (bd->flags & BNGE_EN_SHARED_CHNL)
 		sh = true;
-	hwr.cmpl = hwr.rx + hwr.tx;
+	hwr.cmpl = bnge_cprs_demand(bd);
 
 	hwr.vnic = bnge_get_total_vnics(bd, hwr.rx);
 
@@ -327,6 +344,13 @@ int bnge_reserve_rings(struct bnge_dev *bd)
 	if (hwr.stat > bnge_aux_get_stat_ctxs(bd))
 		hwr.stat -= bnge_aux_get_stat_ctxs(bd);
 	hwr.nq = min_t(u16, hwr.nq, hwr.stat);
+	/* Drop MPC TX ring from L2 TX ring count; it is owned by RoCE driver */
+	if (bnge_is_roce_en(bd)) {
+		if (hwr.tx >= tx_demand)
+			hwr.tx -= 1;
+		else
+			return -ENOMEM;
+	}
 
 	/* Adjust the rings */
 	rc = bnge_adjust_rings(bd, &rx_rings, &hwr.tx, hwr.nq, sh);
-- 
2.43.5