bnxt_en: Fix DMA unmapping of the RX buffers in XDP mode during shutdown.

In bnxt_free_rx_skbs(), which is called to free up all RX buffers during
shutdown, we need to unmap the page if we are running in XDP mode.

Fixes: c61fb99c ("bnxt_en: Add RX page mode support.")
Signed-off-by: NMichael Chan <michael.chan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -1983,20 +1983,25 @@ static void bnxt_free_rx_skbs(struct bnxt *bp)
 
 		for (j = 0; j < max_idx; j++) {
 			struct bnxt_sw_rx_bd *rx_buf = &rxr->rx_buf_ring[j];
+			dma_addr_t mapping = rx_buf->mapping;
 			void *data = rx_buf->data;
 
 			if (!data)
 				continue;
 
-			dma_unmap_single(&pdev->dev, rx_buf->mapping,
-					 bp->rx_buf_use_size, bp->rx_dir);
-
 			rx_buf->data = NULL;
 
-			if (BNXT_RX_PAGE_MODE(bp))
+			if (BNXT_RX_PAGE_MODE(bp)) {
+				mapping -= bp->rx_dma_offset;
+				dma_unmap_page(&pdev->dev, mapping,
+					       PAGE_SIZE, bp->rx_dir);
 				__free_page(data);
-			else
+			} else {
+				dma_unmap_single(&pdev->dev, mapping,
+						 bp->rx_buf_use_size,
+						 bp->rx_dir);
 				kfree(data);
+			}
 		}
 
 		for (j = 0; j < max_agg_idx; j++) {