Index: sys/compat/linuxkpi/common/include/linux/dma-mapping.h
===================================================================
--- sys/compat/linuxkpi/common/include/linux/dma-mapping.h
+++ sys/compat/linuxkpi/common/include/linux/dma-mapping.h
@@ -103,6 +103,7 @@
 void linux_dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg,
     int nents __unused, enum dma_data_direction dir __unused,
     unsigned long attrs __unused);
+void linuxkpi_dma_sync(struct device *, dma_addr_t, size_t, bus_dmasync_op_t);
 
 static inline int
 dma_supported(struct device *dev, u64 dma_mask)
@@ -208,6 +209,21 @@
 dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size,
     enum dma_data_direction direction)
 {
+	bus_dmasync_op_t op;
+
+	switch (direction) {
+	case DMA_BIDIRECTIONAL:
+		op = BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE | \
+		    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE;
+	case DMA_TO_DEVICE:
+		op = BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE;
+	case DMA_FROM_DEVICE:
+		op = BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE;
+	default:
+		return;
+	}
+
+	linuxkpi_dma_sync(dev, dma_handle, size, op);
 }
 
 static inline void
@@ -221,6 +237,21 @@
 dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle,
     size_t size, enum dma_data_direction direction)
 {
+	bus_dmasync_op_t op;
+
+	switch (direction) {
+	case DMA_BIDIRECTIONAL:
+		op = BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE | \
+		    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE;
+	case DMA_TO_DEVICE:
+		op = BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE;
+	case DMA_FROM_DEVICE:
+		op = BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE;
+	default:
+		return;
+	}
+
+	linuxkpi_dma_sync(dev, dma_handle, size, op);
 }
 
 static inline void
Index: sys/compat/linuxkpi/common/src/linux_pci.c
===================================================================
--- sys/compat/linuxkpi/common/src/linux_pci.c
+++ sys/compat/linuxkpi/common/src/linux_pci.c
@@ -935,6 +935,29 @@
 	return (mem);
 }
 
+void
+linuxkpi_dma_sync(struct device *dev, dma_addr_t dma_addr, size_t size,
+    bus_dmasync_op_t op)
+{
+	struct linux_dma_priv *priv;
+	struct linux_dma_obj *obj;
+
+	priv = dev->dma_priv;
+
+	if (pctrie_is_empty(&priv->ptree))
+		return;
+
+	DMA_PRIV_LOCK(priv);
+	obj = LINUX_DMA_PCTRIE_LOOKUP(&priv->ptree, dma_addr);
+	if (obj == NULL) {
+		DMA_PRIV_UNLOCK(priv);
+		return;
+	}
+
+	bus_dmamap_sync(obj->dmat, obj->dmamap, op);
+	DMA_PRIV_UNLOCK(priv);
+}
+
 int
 linux_dma_map_sg_attrs(struct device *dev, struct scatterlist *sgl, int nents,
     enum dma_data_direction dir __unused, unsigned long attrs __unused)