diff --git a/drivers/net/ethoc.c b/drivers/net/ethoc.c
index 0c6c7f4..6d82dc6 100644
--- a/drivers/net/ethoc.c
+++ b/drivers/net/ethoc.c
@@ -19,6 +19,10 @@
 #include <linux/platform_device.h>
 #include <net/ethoc.h>
 
+static int buffer_size = 0x8000; /* 32 KBytes */
+module_param(buffer_size, int, 0);
+MODULE_PARM_DESC(buffer_size, "DMA buffer allocation size");
+
 /* register offsets */
 #define	MODER		0x00
 #define	INT_SOURCE	0x04
@@ -167,6 +171,7 @@
  * struct ethoc - driver-private device structure
  * @iobase:	pointer to I/O memory region
  * @membase:	pointer to buffer memory region
+ * @dma_alloc:	dma allocated buffer size
  * @num_tx:	number of send buffers
  * @cur_tx:	last send buffer written
  * @dty_tx:	last buffer actually sent
@@ -185,6 +190,7 @@
 struct ethoc {
 	void __iomem *iobase;
 	void __iomem *membase;
+	int dma_alloc;
 
 	unsigned int num_tx;
 	unsigned int cur_tx;
@@ -906,22 +912,19 @@
 
 	/* obtain buffer memory space */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
-	if (!res) {
-		dev_err(&pdev->dev, "cannot obtain memory space\n");
-		ret = -ENXIO;
-		goto free;
-	}
-
-	mem = devm_request_mem_region(&pdev->dev, res->start,
+	if (res) {
+		mem = devm_request_mem_region(&pdev->dev, res->start,
 			res->end - res->start + 1, res->name);
-	if (!mem) {
-		dev_err(&pdev->dev, "cannot request memory space\n");
-		ret = -ENXIO;
-		goto free;
+		if (!mem) {
+			dev_err(&pdev->dev, "cannot request memory space\n");
+			ret = -ENXIO;
+			goto free;
+		}
+
+		netdev->mem_start = mem->start;
+		netdev->mem_end   = mem->end;
 	}
 
-	netdev->mem_start = mem->start;
-	netdev->mem_end   = mem->end;
 
 	/* obtain device IRQ number */
 	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
@@ -936,6 +939,7 @@
 	/* setup driver-private data */
 	priv = netdev_priv(netdev);
 	priv->netdev = netdev;
+	priv->dma_alloc = 0;
 
 	priv->iobase = devm_ioremap_nocache(&pdev->dev, netdev->base_addr,
 			mmio->end - mmio->start + 1);
@@ -945,12 +949,27 @@
 		goto error;
 	}
 
-	priv->membase = devm_ioremap_nocache(&pdev->dev, netdev->mem_start,
-			mem->end - mem->start + 1);
-	if (!priv->membase) {
-		dev_err(&pdev->dev, "cannot remap memory space\n");
-		ret = -ENXIO;
-		goto error;
+	if (netdev->mem_end) {
+		priv->membase = devm_ioremap_nocache(&pdev->dev,
+			netdev->mem_start, mem->end - mem->start + 1);
+		if (!priv->membase) {
+			dev_err(&pdev->dev, "cannot remap memory space\n");
+			ret = -ENXIO;
+			goto error;
+		}
+	} else {
+		/* Allocate buffer memory */
+		priv->membase = dma_alloc_coherent(NULL,
+			buffer_size, (void *)&netdev->mem_start,
+			GFP_KERNEL);
+		if (!priv->membase) {
+			dev_err(&pdev->dev, "cannot allocate %dB buffer\n",
+				buffer_size);
+			ret = -ENOMEM;
+			goto error;
+		}
+		netdev->mem_end = netdev->mem_start + buffer_size;
+		priv->dma_alloc = buffer_size;
 	}
 
 	/* Allow the platform setup code to pass in a MAC address. */
@@ -1037,6 +1056,9 @@
 	kfree(priv->mdio->irq);
 	mdiobus_free(priv->mdio);
 free:
+	if (priv->dma_alloc)
+		dma_free_coherent(NULL, priv->dma_alloc, priv->membase,
+			netdev->mem_start);
 	free_netdev(netdev);
 out:
 	return ret;
@@ -1062,7 +1084,9 @@
 			kfree(priv->mdio->irq);
 			mdiobus_free(priv->mdio);
 		}
-
+		if (priv->dma_alloc)
+			dma_free_coherent(NULL, priv->dma_alloc, priv->membase,
+				netdev->mem_start);
 		unregister_netdev(netdev);
 		free_netdev(netdev);
 	}