[PATCH v3 3/5] net: ep93xx_eth: allocate buffers using kmalloc()

[Mika Westerberg]

We can use simply kmalloc() to allocate the buffers. This also simplifies the
code and allows us to perform DMA sync operations more easily.

Memory is allocated with only GFP_KERNEL since there are no DMA allocation
restrictions on this platform.

Signed-off-by: Mika Westerberg <mika.westerberg at iki.fi>
Acked-by: Russell King <rmk+kernel at arm.linux.org.uk>
Acked-by: H Hartley Sweeten <hsweeten at visionengravers.com>
Tested-by: Petr Stetiar <ynezz at true.cz>
---
 drivers/net/arm/ep93xx_eth.c |   51 ++++++++++++++++-------------------------
 1 files changed, 20 insertions(+), 31 deletions(-)

diff --git a/drivers/net/arm/ep93xx_eth.c b/drivers/net/arm/ep93xx_eth.c
index f65dfb6..97bf6b1 100644
--- a/drivers/net/arm/ep93xx_eth.c
+++ b/drivers/net/arm/ep93xx_eth.c
@@ -460,36 +460,32 @@ static void ep93xx_free_buffers(struct ep93xx_priv *ep)
 	struct device *dev = ep->dev->dev.parent;
 	int i;
 
-	for (i = 0; i < RX_QUEUE_ENTRIES; i += 2) {
+	for (i = 0; i < RX_QUEUE_ENTRIES; i++) {
 		dma_addr_t d;
 
 		d = ep->descs->rdesc[i].buf_addr;
 		if (d)
-			dma_unmap_single(dev, d, PAGE_SIZE, DMA_FROM_DEVICE);
+			dma_unmap_single(dev, d, PKT_BUF_SIZE, DMA_FROM_DEVICE);
 
 		if (ep->rx_buf[i] != NULL)
-			free_page((unsigned long)ep->rx_buf[i]);
+			kfree(ep->rx_buf[i]);
 	}
 
-	for (i = 0; i < TX_QUEUE_ENTRIES; i += 2) {
+	for (i = 0; i < TX_QUEUE_ENTRIES; i++) {
 		dma_addr_t d;
 
 		d = ep->descs->tdesc[i].buf_addr;
 		if (d)
-			dma_unmap_single(dev, d, PAGE_SIZE, DMA_TO_DEVICE);
+			dma_unmap_single(dev, d, PKT_BUF_SIZE, DMA_TO_DEVICE);
 
 		if (ep->tx_buf[i] != NULL)
-			free_page((unsigned long)ep->tx_buf[i]);
+			kfree(ep->tx_buf[i]);
 	}
 
 	dma_free_coherent(dev, sizeof(struct ep93xx_descs), ep->descs,
 							ep->descs_dma_addr);
 }
 
-/*
- * The hardware enforces a sub-2K maximum packet size, so we put
- * two buffers on every hardware page.
- */
 static int ep93xx_alloc_buffers(struct ep93xx_priv *ep)
 {
 	struct device *dev = ep->dev->dev.parent;
@@ -500,48 +496,41 @@ static int ep93xx_alloc_buffers(struct ep93xx_priv *ep)
 	if (ep->descs == NULL)
 		return 1;
 
-	for (i = 0; i < RX_QUEUE_ENTRIES; i += 2) {
-		void *page;
+	for (i = 0; i < RX_QUEUE_ENTRIES; i++) {
+		void *buf;
 		dma_addr_t d;
 
-		page = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
-		if (page == NULL)
+		buf = kmalloc(PKT_BUF_SIZE, GFP_KERNEL);
+		if (buf == NULL)
 			goto err;
 
-		d = dma_map_single(dev, page, PAGE_SIZE, DMA_FROM_DEVICE);
+		d = dma_map_single(dev, buf, PKT_BUF_SIZE, DMA_FROM_DEVICE);
 		if (dma_mapping_error(dev, d)) {
-			free_page((unsigned long)page);
+			kfree(buf);
 			goto err;
 		}
 
-		ep->rx_buf[i] = page;
+		ep->rx_buf[i] = buf;
 		ep->descs->rdesc[i].buf_addr = d;
 		ep->descs->rdesc[i].rdesc1 = (i << 16) | PKT_BUF_SIZE;
-
-		ep->rx_buf[i + 1] = page + PKT_BUF_SIZE;
-		ep->descs->rdesc[i + 1].buf_addr = d + PKT_BUF_SIZE;
-		ep->descs->rdesc[i + 1].rdesc1 = ((i + 1) << 16) | PKT_BUF_SIZE;
 	}
 
-	for (i = 0; i < TX_QUEUE_ENTRIES; i += 2) {
-		void *page;
+	for (i = 0; i < TX_QUEUE_ENTRIES; i++) {
+		void *buf;
 		dma_addr_t d;
 
-		page = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
-		if (page == NULL)
+		buf = kmalloc(PKT_BUF_SIZE, GFP_KERNEL);
+		if (buf == NULL)
 			goto err;
 
-		d = dma_map_single(dev, page, PAGE_SIZE, DMA_TO_DEVICE);
+		d = dma_map_single(dev, buf, PKT_BUF_SIZE, DMA_TO_DEVICE);
 		if (dma_mapping_error(dev, d)) {
-			free_page((unsigned long)page);
+			kfree(buf);
 			goto err;
 		}
 
-		ep->tx_buf[i] = page;
+		ep->tx_buf[i] = buf;
 		ep->descs->tdesc[i].buf_addr = d;
-
-		ep->tx_buf[i + 1] = page + PKT_BUF_SIZE;
-		ep->descs->tdesc[i + 1].buf_addr = d + PKT_BUF_SIZE;
 	}
 
 	return 0;
-- 
1.7.4.4