diff --git a/arch/powerpc/sysdev/fsl_rio.c b/arch/powerpc/sysdev/fsl_rio.c
index f5bf38b9459585fcd1f8d4a34ed24c8067e67daa..386790cfa16ee7c5b2c031674d6a7183bc961e3d 100644
--- a/arch/powerpc/sysdev/fsl_rio.c
+++ b/arch/powerpc/sysdev/fsl_rio.c
@@ -289,7 +289,7 @@ static void fsl_rio_inbound_mem_init(struct rio_priv *priv)
 }
 
 int fsl_map_inb_mem(struct rio_mport *mport, dma_addr_t lstart,
-	u64 rstart, u32 size, u32 flags)
+	u64 rstart, u64 size, u32 flags)
 {
 	struct rio_priv *priv = mport->priv;
 	u32 base_size;
@@ -298,7 +298,7 @@ int fsl_map_inb_mem(struct rio_mport *mport, dma_addr_t lstart,
 	u32 riwar;
 	int i;
 
-	if ((size & (size - 1)) != 0)
+	if ((size & (size - 1)) != 0 || size > 0x400000000ULL)
 		return -EINVAL;
 
 	base_size_log = ilog2(size);
diff --git a/drivers/rapidio/devices/tsi721.c b/drivers/rapidio/devices/tsi721.c
index 8e07cd56abdc0c1ecfff9ad1b61975c09eb03195..53daf634a1ac4b1dbf7a3d302c9953dff3fde129 100644
--- a/drivers/rapidio/devices/tsi721.c
+++ b/drivers/rapidio/devices/tsi721.c
@@ -1090,7 +1090,7 @@ static void tsi721_init_pc2sr_mapping(struct tsi721_device *priv)
  * from rstart to lstart.
  */
 static int tsi721_rio_map_inb_mem(struct rio_mport *mport, dma_addr_t lstart,
-		u64 rstart, u32 size, u32 flags)
+		u64 rstart, u64 size, u32 flags)
 {
 	struct tsi721_device *priv = mport->priv;
 	int i, avail = -1;
@@ -1103,6 +1103,10 @@ static int tsi721_rio_map_inb_mem(struct rio_mport *mport, dma_addr_t lstart,
 	struct tsi721_ib_win_mapping *map = NULL;
 	int ret = -EBUSY;
 
+	/* Max IBW size supported by HW is 16GB */
+	if (size > 0x400000000UL)
+		return -EINVAL;
+
 	if (direct) {
 		/* Calculate minimal acceptable window size and base address */
 
@@ -1110,15 +1114,15 @@ static int tsi721_rio_map_inb_mem(struct rio_mport *mport, dma_addr_t lstart,
 		ibw_start = lstart & ~(ibw_size - 1);
 
 		tsi_debug(IBW, &priv->pdev->dev,
-			"Direct (RIO_0x%llx -> PCIe_%pad), size=0x%x, ibw_start = 0x%llx",
+			"Direct (RIO_0x%llx -> PCIe_%pad), size=0x%llx, ibw_start = 0x%llx",
 			rstart, &lstart, size, ibw_start);
 
 		while ((lstart + size) > (ibw_start + ibw_size)) {
 			ibw_size *= 2;
 			ibw_start = lstart & ~(ibw_size - 1);
-			if (ibw_size > 0x80000000) { /* Limit max size to 2GB */
+			/* Check for crossing IBW max size 16GB */
+			if (ibw_size > 0x400000000UL)
 				return -EBUSY;
-			}
 		}
 
 		loc_start = ibw_start;
@@ -1129,7 +1133,7 @@ static int tsi721_rio_map_inb_mem(struct rio_mport *mport, dma_addr_t lstart,
 
 	} else {
 		tsi_debug(IBW, &priv->pdev->dev,
-			"Translated (RIO_0x%llx -> PCIe_%pad), size=0x%x",
+			"Translated (RIO_0x%llx -> PCIe_%pad), size=0x%llx",
 			rstart, &lstart, size);
 
 		if (!is_power_of_2(size) || size < 0x1000 ||
diff --git a/include/linux/rio.h b/include/linux/rio.h
index aa2323893e8d68b8156fa6b9422ac12b20dc96a6..f7ec35b4880068818d4304905ebf8b2c2c6b7342 100644
--- a/include/linux/rio.h
+++ b/include/linux/rio.h
@@ -425,7 +425,7 @@ struct rio_ops {
 	int (*add_inb_buffer)(struct rio_mport *mport, int mbox, void *buf);
 	void *(*get_inb_message)(struct rio_mport *mport, int mbox);
 	int (*map_inb)(struct rio_mport *mport, dma_addr_t lstart,
-			u64 rstart, u32 size, u32 flags);
+			u64 rstart, u64 size, u32 flags);
 	void (*unmap_inb)(struct rio_mport *mport, dma_addr_t lstart);
 	int (*query_mport)(struct rio_mport *mport,
 			   struct rio_mport_attr *attr);