rt2x00: Replace statically allocated DMA buffers with mapped skb's.
The current PCI drivers require a lot of pre-allocated DMA buffers. Reduce this
by using dynamically mapped skb's (using pci_map_single) instead of the pre-
allocated DMA buffers that are allocated at device start-up time.
At the same time move common RX path code into rt2x00lib from rt2x00pci and
rt2x00usb, as the RX paths now are now almost the same.
Signed-off-by: Gertjan van Wingerde <gwingerde@kpnplanet.nl>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c
index 278f1a1..29d2b91 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.c
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.c
@@ -25,21 +25,24 @@
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/dma-mapping.h>
#include "rt2x00.h"
#include "rt2x00lib.h"
-struct sk_buff *rt2x00queue_alloc_skb(struct data_queue *queue)
+struct sk_buff *rt2x00queue_alloc_rxskb(struct rt2x00_dev *rt2x00dev,
+ struct queue_entry *entry)
{
- struct sk_buff *skb;
unsigned int frame_size;
unsigned int reserved_size;
+ struct sk_buff *skb;
+ struct skb_frame_desc *skbdesc;
/*
* The frame size includes descriptor size, because the
* hardware directly receive the frame into the skbuffer.
*/
- frame_size = queue->data_size + queue->desc_size;
+ frame_size = entry->queue->data_size + entry->queue->desc_size;
/*
* Reserve a few bytes extra headroom to allow drivers some moving
@@ -57,12 +60,67 @@
skb_reserve(skb, reserved_size);
skb_put(skb, frame_size);
+ /*
+ * Populate skbdesc.
+ */
+ skbdesc = get_skb_frame_desc(skb);
+ memset(skbdesc, 0, sizeof(*skbdesc));
+ skbdesc->entry = entry;
+
+ if (test_bit(DRIVER_REQUIRE_DMA, &rt2x00dev->flags)) {
+ skbdesc->skb_dma = dma_map_single(rt2x00dev->dev,
+ skb->data,
+ skb->len,
+ DMA_FROM_DEVICE);
+ skbdesc->flags |= SKBDESC_DMA_MAPPED_RX;
+ }
+
return skb;
}
-EXPORT_SYMBOL_GPL(rt2x00queue_alloc_skb);
+EXPORT_SYMBOL_GPL(rt2x00queue_alloc_rxskb);
-void rt2x00queue_free_skb(struct sk_buff *skb)
+void rt2x00queue_map_txskb(struct rt2x00_dev *rt2x00dev, struct sk_buff *skb)
{
+ struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
+
+ skbdesc->skb_dma = dma_map_single(rt2x00dev->dev, skb->data, skb->len,
+ DMA_TO_DEVICE);
+ skbdesc->flags |= SKBDESC_DMA_MAPPED_TX;
+}
+EXPORT_SYMBOL_GPL(rt2x00queue_map_txskb);
+
+void rt2x00queue_unmap_skb(struct rt2x00_dev *rt2x00dev, struct sk_buff *skb)
+{
+ struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
+
+ if (skbdesc->flags & SKBDESC_DMA_MAPPED_RX) {
+ dma_unmap_single(rt2x00dev->dev, skbdesc->skb_dma, skb->len,
+ DMA_FROM_DEVICE);
+ skbdesc->flags &= ~SKBDESC_DMA_MAPPED_RX;
+ }
+
+ if (skbdesc->flags & SKBDESC_DMA_MAPPED_TX) {
+ dma_unmap_single(rt2x00dev->dev, skbdesc->skb_dma, skb->len,
+ DMA_TO_DEVICE);
+ skbdesc->flags &= ~SKBDESC_DMA_MAPPED_TX;
+ }
+}
+EXPORT_SYMBOL_GPL(rt2x00queue_unmap_skb);
+
+void rt2x00queue_free_skb(struct rt2x00_dev *rt2x00dev, struct sk_buff *skb)
+{
+ struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
+
+ if (skbdesc->flags & SKBDESC_DMA_MAPPED_RX) {
+ dma_unmap_single(rt2x00dev->dev, skbdesc->skb_dma, skb->len,
+ DMA_FROM_DEVICE);
+ }
+
+ if (skbdesc->flags & SKBDESC_DMA_MAPPED_TX) {
+ dma_unmap_single(rt2x00dev->dev, skbdesc->skb_dma, skb->len,
+ DMA_TO_DEVICE);
+ }
+
dev_kfree_skb_any(skb);
}
EXPORT_SYMBOL_GPL(rt2x00queue_free_skb);
@@ -421,7 +479,8 @@
return 0;
}
-static void rt2x00queue_free_skbs(struct data_queue *queue)
+static void rt2x00queue_free_skbs(struct rt2x00_dev *rt2x00dev,
+ struct data_queue *queue)
{
unsigned int i;
@@ -430,27 +489,27 @@
for (i = 0; i < queue->limit; i++) {
if (queue->entries[i].skb)
- rt2x00queue_free_skb(queue->entries[i].skb);
+ rt2x00queue_free_skb(rt2x00dev, queue->entries[i].skb);
}
}
-static int rt2x00queue_alloc_skbs(struct data_queue *queue)
+static int rt2x00queue_alloc_rxskbs(struct rt2x00_dev *rt2x00dev,
+ struct data_queue *queue)
{
unsigned int i;
struct sk_buff *skb;
for (i = 0; i < queue->limit; i++) {
- skb = rt2x00queue_alloc_skb(queue);
+ skb = rt2x00queue_alloc_rxskb(rt2x00dev, &queue->entries[i]);
if (!skb)
goto exit;
-
queue->entries[i].skb = skb;
}
return 0;
exit:
- rt2x00queue_free_skbs(queue);
+ rt2x00queue_free_skbs(rt2x00dev, queue);
return -ENOMEM;
}
@@ -481,7 +540,7 @@
goto exit;
}
- status = rt2x00queue_alloc_skbs(rt2x00dev->rx);
+ status = rt2x00queue_alloc_rxskbs(rt2x00dev, rt2x00dev->rx);
if (status)
goto exit;
@@ -499,7 +558,7 @@
{
struct data_queue *queue;
- rt2x00queue_free_skbs(rt2x00dev->rx);
+ rt2x00queue_free_skbs(rt2x00dev, rt2x00dev->rx);
queue_for_each(rt2x00dev, queue) {
kfree(queue->entries);