diff --git a/drivers/ntb/test/ntb_perf.c b/drivers/ntb/test/ntb_perf.c
index c8a37ba..6bdc1e7 100644
--- a/drivers/ntb/test/ntb_perf.c
+++ b/drivers/ntb/test/ntb_perf.c
@@ -178,7 +178,7 @@
 	atomic_dec(&pctx->dma_sync);
 }
 
-static ssize_t perf_copy(struct pthr_ctx *pctx, char *dst,
+static ssize_t perf_copy(struct pthr_ctx *pctx, char __iomem *dst,
 			 char *src, size_t size)
 {
 	struct perf_ctx *perf = pctx->perf;
@@ -189,7 +189,8 @@
 	dma_cookie_t cookie;
 	size_t src_off, dst_off;
 	struct perf_mw *mw = &perf->mw;
-	u64 vbase, dst_vaddr;
+	void __iomem *vbase;
+	void __iomem *dst_vaddr;
 	dma_addr_t dst_phys;
 	int retries = 0;
 
@@ -204,14 +205,14 @@
 	}
 
 	device = chan->device;
-	src_off = (size_t)src & ~PAGE_MASK;
-	dst_off = (size_t)dst & ~PAGE_MASK;
+	src_off = (uintptr_t)src & ~PAGE_MASK;
+	dst_off = (uintptr_t __force)dst & ~PAGE_MASK;
 
 	if (!is_dma_copy_aligned(device, src_off, dst_off, size))
 		return -ENODEV;
 
-	vbase = (u64)(u64 *)mw->vbase;
-	dst_vaddr = (u64)(u64 *)dst;
+	vbase = mw->vbase;
+	dst_vaddr = dst;
 	dst_phys = mw->phys_addr + (dst_vaddr - vbase);
 
 	unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
@@ -261,13 +262,13 @@
 	return 0;
 }
 
-static int perf_move_data(struct pthr_ctx *pctx, char *dst, char *src,
+static int perf_move_data(struct pthr_ctx *pctx, char __iomem *dst, char *src,
 			  u64 buf_size, u64 win_size, u64 total)
 {
 	int chunks, total_chunks, i;
 	int copied_chunks = 0;
 	u64 copied = 0, result;
-	char *tmp = dst;
+	char __iomem *tmp = dst;
 	u64 perf, diff_us;
 	ktime_t kstart, kstop, kdiff;
 
@@ -324,7 +325,7 @@
 	struct perf_ctx *perf = pctx->perf;
 	struct pci_dev *pdev = perf->ntb->pdev;
 	struct perf_mw *mw = &perf->mw;
-	char *dst;
+	char __iomem *dst;
 	u64 win_size, buf_size, total;
 	void *src;
 	int rc, node, i;
@@ -364,7 +365,7 @@
 	if (buf_size > MAX_TEST_SIZE)
 		buf_size = MAX_TEST_SIZE;
 
-	dst = (char *)mw->vbase;
+	dst = (char __iomem *)mw->vbase;
 
 	atomic_inc(&perf->tsync);
 	while (atomic_read(&perf->tsync) != perf->perf_threads)