1 files changed, 16 insertions, 13 deletions

diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index 4eb8adb34508..f81aa4b18d9f 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -66,6 +66,7 @@
 #define NTB_TRANSPORT_VER	"4"
 #define NTB_TRANSPORT_NAME	"ntb_transport"
 #define NTB_TRANSPORT_DESC	"Software Queue-Pair Transport over NTB"
+#define NTB_TRANSPORT_MIN_SPADS (MW0_SZ_HIGH + 2)
 
 MODULE_DESCRIPTION(NTB_TRANSPORT_DESC);
 MODULE_VERSION(NTB_TRANSPORT_VER);
@@ -242,9 +243,6 @@ enum {
 	NUM_MWS,
 	MW0_SZ_HIGH,
 	MW0_SZ_LOW,
-	MW1_SZ_HIGH,
-	MW1_SZ_LOW,
-	MAX_SPAD,
 };
 
 #define dev_client_dev(__dev) \
@@ -811,7 +809,7 @@ static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
 {
 	struct ntb_transport_qp *qp;
 	u64 qp_bitmap_alloc;
-	int i;
+	unsigned int i, count;
 
 	qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
 
@@ -831,7 +829,8 @@ static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
 	 * goes down, blast them now to give them a sane value the next
 	 * time they are accessed
 	 */
-	for (i = 0; i < MAX_SPAD; i++)
+	count = ntb_spad_count(nt->ndev);
+	for (i = 0; i < count; i++)
 		ntb_spad_write(nt->ndev, i, 0);
 }
 
@@ -960,7 +959,6 @@ static void ntb_qp_link_work(struct work_struct *work)
 	ntb_peer_spad_write(nt->ndev, QP_LINKS, val | BIT(qp->qp_num));
 
 	/* query remote spad for qp ready bits */
-	ntb_peer_spad_read(nt->ndev, QP_LINKS);
 	dev_dbg_ratelimited(&pdev->dev, "Remote QP link status = %x\n", val);
 
 	/* See if the remote side is up */
@@ -1064,17 +1062,12 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
 {
 	struct ntb_transport_ctx *nt;
 	struct ntb_transport_mw *mw;
-	unsigned int mw_count, qp_count;
+	unsigned int mw_count, qp_count, spad_count, max_mw_count_for_spads;
 	u64 qp_bitmap;
 	int node;
 	int rc, i;
 
 	mw_count = ntb_mw_count(ndev);
-	if (ntb_spad_count(ndev) < (NUM_MWS + 1 + mw_count * 2)) {
-		dev_err(&ndev->dev, "Not enough scratch pad registers for %s",
-			NTB_TRANSPORT_NAME);
-		return -EIO;
-	}
 
 	if (ntb_db_is_unsafe(ndev))
 		dev_dbg(&ndev->dev,
@@ -1090,8 +1083,18 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
 		return -ENOMEM;
 
 	nt->ndev = ndev;
+	spad_count = ntb_spad_count(ndev);
+
+	/* Limit the MW's based on the availability of scratchpads */
+
+	if (spad_count < NTB_TRANSPORT_MIN_SPADS) {
+		nt->mw_count = 0;
+		rc = -EINVAL;
+		goto err;
+	}
 
-	nt->mw_count = mw_count;
+	max_mw_count_for_spads = (spad_count - MW0_SZ_HIGH) / 2;
+	nt->mw_count = min(mw_count, max_mw_count_for_spads);
 
 	nt->mw_vec = kzalloc_node(mw_count * sizeof(*nt->mw_vec),
 				  GFP_KERNEL, node);