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

Commit Message

Mika Westerberg June 11, 2011, 6:39 p.m. UTC

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 <[e-mail]>
Acked-by: Russell King <[e-mail]>
Acked-by: H Hartley Sweeten <[e-mail]>
Tested-by: Petr Stetiar <[e-mail]>
---
 drivers/net/arm/ep93xx_eth.c |   51 ++++++++++++++++-------------------------
 1 files changed, 20 insertions(+), 31 deletions(-)

Comments

David Miller June 11, 2011, 11:25 p.m. UTC | #1

From: Mika Westerberg <[e-mail]>
Date: Sat, 11 Jun 2011 21:39:56 +0300

> 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 <[e-mail]>
> Acked-by: Russell King <[e-mail]>
> Acked-by: H Hartley Sweeten <[e-mail]>
> Tested-by: Petr Stetiar <[e-mail]>

Applied.

Patch

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;