ntb_transport: Check the number of spads the hardware supports

I'm working on hardware that currently has a limited number of scratchpad registers and ntb_ndev fails with no clue as to why. I feel it is better to fail early and provide a reasonable error message then to fail later on. The same is done to ntb_perf, but it doesn't currently require enough spads to actually fail. I've also removed the unused SPAD_MSG and SPAD_ACK enums so that MAX_SPAD accurately reflects the number of spads used. Signed-off-by: Logan Gunthorpe <[email protected]> Acked-by: Dave Jiang <[email protected]> Signed-off-by: Jon Mason <[email protected]>
jledet · Aug 5, 2016 · 19645a0 · 19645a0
1 parent 8b71d28
commit 19645a0
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Showing 2 changed files with 13 additions and 4 deletions.
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
@@ -1060,6 +1060,13 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
 	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,
 			"doorbell is unsafe, proceed anyway...\n");
@@ -1075,8 +1082,6 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
 
 	nt->ndev = ndev;
 
-	mw_count = ntb_mw_count(ndev);
-
 	nt->mw_count = mw_count;
 
 	nt->mw_vec = kzalloc_node(mw_count * sizeof(*nt->mw_vec),

diff --git a/drivers/ntb/test/ntb_perf.c b/drivers/ntb/test/ntb_perf.c
@@ -143,8 +143,6 @@ enum {
 	VERSION = 0,
 	MW_SZ_HIGH,
 	MW_SZ_LOW,
-	SPAD_MSG,
-	SPAD_ACK,
 	MAX_SPAD
 };
 
@@ -696,6 +694,12 @@ static int perf_probe(struct ntb_client *client, struct ntb_dev *ntb)
 	int node;
 	int rc = 0;
 
+	if (ntb_spad_count(ntb) < MAX_SPAD) {
+		dev_err(&ntb->dev, "Not enough scratch pad registers for %s",
+			DRIVER_NAME);
+		return -EIO;
+	}
+
 	node = dev_to_node(&pdev->dev);
 
 	perf = kzalloc_node(sizeof(*perf), GFP_KERNEL, node);