[PATCH 14/16] NTB: ntb_transport: Enable direct-DMA queues

[Koichiro Den]

Advertise direct RX when a DMA mapping device is available, and direct
TX only when every QP has a suitable channel. Negotiation can then
enable either direction independently.

Signed-off-by: Koichiro Den <den@xxxxxxxxxxxxx>
---
 drivers/ntb/ntb_transport.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index f2fa145994b9..9f5d6a407be7 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -554,7 +554,7 @@ static bool ntb_direct_tx_mode(struct ntb_transport_qp *qp)
 
 static bool ntb_direct_link_capable(struct ntb_transport_qp *qp)
 {
-	return ntb_direct_rx_mode(qp) || ntb_direct_tx_mode(qp);
+	return ntb_direct_layout(qp->transport);
 }
 
 static void ntb_transport_notify_peer(struct ntb_transport_qp *qp)
@@ -2058,6 +2058,11 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
 	else if (use_direct_dma)
 		dev_info(&ndev->dev,
 			 "not enough scratchpads for direct DMA negotiation\n");
+	if (nt->direct_dma_dev) {
+		nt->direct_features = NTB_DIRECT_FEAT_RX;
+		if (nt->qp_count && nt->qp_vec[0].direct_dma_chan)
+			nt->direct_features |= NTB_DIRECT_FEAT_TX;
+	}
 
 	mutex_init(&nt->link_event_lock);
 	INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
-- 
2.51.0