1 files changed, 44 insertions, 20 deletions

diff --git a/drivers/net/ethoc.c b/drivers/net/ethoc.c
index 0c6c7f47ace4..6d82dc646ac0 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 @@ static int ethoc_probe(struct platform_device *pdev)
 
         /* 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 @@ static int ethoc_probe(struct platform_device *pdev)
         /* 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 @@ static int ethoc_probe(struct platform_device *pdev)
                 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 @@ free_mdio:
         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 @@ static int ethoc_remove(struct platform_device *pdev)
                         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);
         }