MFC r303514: Fix NTBT_QP_LINKS negotiation.

I believe it never worked correctly for more the one queue even in Linux.
This fixes case when one of consumer drivers is not loaded on one side,
but its queues still announced as ready if something else brought link up.

While there, remove some pointless NULL checks.

1 files changed, 18 insertions, 29 deletions

diff --git a/sys/dev/ntb/ntb_transport.c b/sys/dev/ntb/ntb_transport.c
index c4b8fd0..c7bc4da 100644
--- a/sys/dev/ntb/ntb_transport.c
+++ b/sys/dev/ntb/ntb_transport.c
@@ -572,9 +572,6 @@ ntb_transport_free_queue(struct ntb_transport_qp *qp)
 	struct ntb_transport_ctx *nt = qp->transport;
 	struct ntb_queue_entry *entry;
 
-	if (qp == NULL)
-		return;
-
 	callout_drain(&qp->link_work);
 
 	ntb_db_set_mask(qp->dev, 1ull << qp->qp_num);
@@ -694,7 +691,7 @@ ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
 	struct ntb_queue_entry *entry;
 	int rc;
 
-	if (qp == NULL || !qp->link_is_up || len == 0) {
+	if (!qp->link_is_up || len == 0) {
 		CTR0(KTR_NTB, "TX: link not up");
 		return (EINVAL);
 	}
@@ -1059,11 +1056,9 @@ ntb_transport_link_work(void *arg)
 		    size >> 32);
 		ntb_peer_spad_write(dev, NTBT_MW0_SZ_LOW + (i * 2), size);
 	}
-
 	ntb_peer_spad_write(dev, NTBT_NUM_MWS, nt->mw_count);
-
 	ntb_peer_spad_write(dev, NTBT_NUM_QPS, nt->qp_count);
-
+	ntb_peer_spad_write(dev, NTBT_QP_LINKS, 0);
 	ntb_peer_spad_write(dev, NTBT_VERSION, NTB_TRANSPORT_VERSION);
 
 	/* Query the remote side for its info */
@@ -1245,16 +1240,18 @@ ntb_qp_link_work(void *arg)
 	struct ntb_transport_qp *qp = arg;
 	device_t dev = qp->dev;
 	struct ntb_transport_ctx *nt = qp->transport;
-	uint32_t val, dummy;
-
-	ntb_spad_read(dev, NTBT_QP_LINKS, &val);
-
-	ntb_peer_spad_write(dev, NTBT_QP_LINKS, val | (1ull << qp->qp_num));
+	int i;
+	uint32_t val;
 
-	/* query remote spad for qp ready bits */
-	ntb_peer_spad_read(dev, NTBT_QP_LINKS, &dummy);
+	/* Report queues that are up on our side */
+	for (i = 0, val = 0; i < nt->qp_count; i++) {
+		if (nt->qp_vec[i].client_ready)
+			val |= (1 << i);
+	}
+	ntb_peer_spad_write(dev, NTBT_QP_LINKS, val);
 
 	/* See if the remote side is up */
+	ntb_spad_read(dev, NTBT_QP_LINKS, &val);
 	if ((val & (1ull << qp->qp_num)) != 0) {
 		ntb_printf(2, "qp %d link up\n", qp->qp_num);
 		qp->link_is_up = true;
@@ -1350,17 +1347,16 @@ ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
 void
 ntb_transport_link_down(struct ntb_transport_qp *qp)
 {
+	struct ntb_transport_ctx *nt = qp->transport;
+	int i;
 	uint32_t val;
 
-	if (qp == NULL)
-		return;
-
 	qp->client_ready = false;
-
-	ntb_spad_read(qp->dev, NTBT_QP_LINKS, &val);
-
-	ntb_peer_spad_write(qp->dev, NTBT_QP_LINKS,
-	   val & ~(1 << qp->qp_num));
+	for (i = 0, val = 0; i < nt->qp_count; i++) {
+		if (nt->qp_vec[i].client_ready)
+			val |= (1 << i);
+	}
+	ntb_peer_spad_write(qp->dev, NTBT_QP_LINKS, val);
 
 	if (qp->link_is_up)
 		ntb_send_link_down(qp);
@@ -1379,8 +1375,6 @@ ntb_transport_link_down(struct ntb_transport_qp *qp)
 bool
 ntb_transport_link_query(struct ntb_transport_qp *qp)
 {
-	if (qp == NULL)
-		return (false);
 
 	return (qp->link_is_up);
 }
@@ -1479,8 +1473,6 @@ out:
  */
 unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
 {
-	if (qp == NULL)
-		return 0;
 
 	return (qp->qp_num);
 }
@@ -1497,9 +1489,6 @@ unsigned int
 ntb_transport_max_size(struct ntb_transport_qp *qp)
 {
 
-	if (qp == NULL)
-		return (0);
-
 	return (qp->tx_max_frame - sizeof(struct ntb_payload_header));
 }