1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index 611fef48bdc3..e9bf2f47b61a 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -576,6 +576,19 @@ static int ntb_set_mw(struct ntb_transport *nt, int num_mw, unsigned int size)
                 return -ENOMEM;
         }
 
+        /*
+         * we must ensure that the memory address allocated is BAR size
+         * aligned in order for the XLAT register to take the value. This
+         * is a requirement of the hardware. It is recommended to setup CMA
+         * for BAR sizes equal or greater than 4MB.
+         */
+        if (!IS_ALIGNED(mw->dma_addr, mw->size)) {
+                dev_err(&pdev->dev, "DMA memory %pad not aligned to BAR size\n",
+                        &mw->dma_addr);
+                ntb_free_mw(nt, num_mw);
+                return -ENOMEM;
+        }
+
         /* Notify HW the memory location of the receive buffer */
         ntb_set_mw_addr(nt->ndev, num_mw, mw->dma_addr);