net/mlx4: Add a check if there are too many reserved QPs

The number of reserved QPs is affected both from the firmware and
from the driver's requirements. This patch adds a check that
validates that this number is indeed feasable.
Signed-off-by: Dotan Barak <dotanb@dev.mellanox.co.il>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx4/qp.c

@@ -478,6 +478,7 @@ int mlx4_init_qp_table(struct mlx4_dev *dev)
 	struct mlx4_qp_table *qp_table = &mlx4_priv(dev)->qp_table;
 	int err;
 	int reserved_from_top = 0;
+	int reserved_from_bot;
 	int k;
 
 	spin_lock_init(&qp_table->lock);
@@ -534,9 +535,14 @@ int mlx4_init_qp_table(struct mlx4_dev *dev)
 	* b. All the proxy SQPs (8 per function)
 	* c. All the tunnel QPs (8 per function)
 	*/
+	reserved_from_bot = mlx4_num_reserved_sqps(dev);
+	if (reserved_from_bot + reserved_from_top > dev->caps.num_qps) {
+		mlx4_err(dev, "Number of reserved QPs is higher than number of QPs\n");
+		return -EINVAL;
+	}
 
 	err = mlx4_bitmap_init(&qp_table->bitmap, dev->caps.num_qps,
-			       (1 << 23) - 1, mlx4_num_reserved_sqps(dev),
+			       (1 << 23) - 1, reserved_from_bot,
 			       reserved_from_top);
 	if (err)
 		return err;