1 files changed, 15 insertions, 2 deletions

diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index 9dd63b822025..e9bf2f47b61a 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -510,7 +510,7 @@ static void ntb_transport_setup_qp_mw(struct ntb_transport *nt,
 
         WARN_ON(nt->mw[mw_num].virt_addr == NULL);
 
-        if (nt->max_qps % mw_max && mw_num < nt->max_qps % mw_max)
+        if (nt->max_qps % mw_max && mw_num + 1 < nt->max_qps / mw_max)
                 num_qps_mw = nt->max_qps / mw_max + 1;
         else
                 num_qps_mw = nt->max_qps / mw_max;
@@ -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);
 
@@ -856,7 +869,7 @@ static int ntb_transport_init_queue(struct ntb_transport *nt,
         qp->client_ready = NTB_LINK_DOWN;
         qp->event_handler = NULL;
 
-        if (nt->max_qps % mw_max && mw_num < nt->max_qps % mw_max)
+        if (nt->max_qps % mw_max && mw_num + 1 < nt->max_qps / mw_max)
                 num_qps_mw = nt->max_qps / mw_max + 1;
         else
                 num_qps_mw = nt->max_qps / mw_max;