mac80211: move TX info into skb->cb

This patch converts mac80211 and all drivers to have transmit
information and status in skb->cb rather than allocating extra
memory for it and copying all the data around. To make it fit,
a union is used where only data that is necessary for all steps
is kept outside of the union.

A number of fixes were done by Ivo, as well as the rt2x00 part
of this patch.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 24 insertions, 33 deletions

diff --git a/drivers/net/wireless/rtl8180_dev.c b/drivers/net/wireless/rtl8180_dev.c
index 6263209b889e..4427bc9f78a9 100644
--- a/drivers/net/wireless/rtl8180_dev.c
+++ b/drivers/net/wireless/rtl8180_dev.c
@@ -170,34 +170,29 @@ static void rtl8180_handle_tx(struct ieee80211_hw *dev, unsigned int prio)
 	while (skb_queue_len(&ring->queue)) {
 		struct rtl8180_tx_desc *entry = &ring->desc[ring->idx];
 		struct sk_buff *skb;
-		struct ieee80211_tx_status status;
-		struct ieee80211_tx_control *control;
+		struct ieee80211_tx_info *info;
 		u32 flags = le32_to_cpu(entry->flags);
 
 		if (flags & RTL8180_TX_DESC_FLAG_OWN)
 			return;
 
-		memset(&status, 0, sizeof(status));
-
 		ring->idx = (ring->idx + 1) % ring->entries;
 		skb = __skb_dequeue(&ring->queue);
 		pci_unmap_single(priv->pdev, le32_to_cpu(entry->tx_buf),
 				 skb->len, PCI_DMA_TODEVICE);
 
-		control = *((struct ieee80211_tx_control **)skb->cb);
-		if (control)
-			memcpy(&status.control, control, sizeof(*control));
-		kfree(control);
+		info = IEEE80211_SKB_CB(skb);
+		memset(&info->status, 0, sizeof(info->status));
 
-		if (!(status.control.flags & IEEE80211_TXCTL_NO_ACK)) {
+		if (!(info->flags & IEEE80211_TX_CTL_NO_ACK)) {
 			if (flags & RTL8180_TX_DESC_FLAG_TX_OK)
-				status.flags = IEEE80211_TX_STATUS_ACK;
+				info->flags |= IEEE80211_TX_STAT_ACK;
 			else
-				status.excessive_retries = 1;
+				info->status.excessive_retries = 1;
 		}
-		status.retry_count = flags & 0xFF;
+		info->status.retry_count = flags & 0xFF;
 
-		ieee80211_tx_status_irqsafe(dev, skb, &status);
+		ieee80211_tx_status_irqsafe(dev, skb);
 		if (ring->entries - skb_queue_len(&ring->queue) == 2)
 			ieee80211_wake_queue(dev, prio);
 	}
@@ -238,9 +233,9 @@ static irqreturn_t rtl8180_interrupt(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static int rtl8180_tx(struct ieee80211_hw *dev, struct sk_buff *skb,
-		      struct ieee80211_tx_control *control)
+static int rtl8180_tx(struct ieee80211_hw *dev, struct sk_buff *skb)
 {
+	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 	struct rtl8180_priv *priv = dev->priv;
 	struct rtl8180_tx_ring *ring;
 	struct rtl8180_tx_desc *entry;
@@ -251,7 +246,7 @@ static int rtl8180_tx(struct ieee80211_hw *dev, struct sk_buff *skb,
 	u16 plcp_len = 0;
 	__le16 rts_duration = 0;
 
-	prio = control->queue;
+	prio = info->queue;
 	ring = &priv->tx_ring[prio];
 
 	mapping = pci_map_single(priv->pdev, skb->data,
@@ -259,35 +254,32 @@ static int rtl8180_tx(struct ieee80211_hw *dev, struct sk_buff *skb,
 
 	tx_flags = RTL8180_TX_DESC_FLAG_OWN | RTL8180_TX_DESC_FLAG_FS |
 		   RTL8180_TX_DESC_FLAG_LS |
-		   (ieee80211_get_tx_rate(dev, control)->hw_value << 24) |
+		   (ieee80211_get_tx_rate(dev, info)->hw_value << 24) |
 		   skb->len;
 
 	if (priv->r8185)
 		tx_flags |= RTL8180_TX_DESC_FLAG_DMA |
 			    RTL8180_TX_DESC_FLAG_NO_ENC;
 
-	if (control->flags & IEEE80211_TXCTL_USE_RTS_CTS) {
+	if (info->flags & IEEE80211_TX_CTL_USE_RTS_CTS) {
 		tx_flags |= RTL8180_TX_DESC_FLAG_RTS;
-		tx_flags |= ieee80211_get_rts_cts_rate(dev, control)->hw_value << 19;
-	} else if (control->flags & IEEE80211_TXCTL_USE_CTS_PROTECT) {
+		tx_flags |= ieee80211_get_rts_cts_rate(dev, info)->hw_value << 19;
+	} else if (info->flags & IEEE80211_TX_CTL_USE_CTS_PROTECT) {
 		tx_flags |= RTL8180_TX_DESC_FLAG_CTS;
-		tx_flags |= ieee80211_get_rts_cts_rate(dev, control)->hw_value << 19;
+		tx_flags |= ieee80211_get_rts_cts_rate(dev, info)->hw_value << 19;
 	}
 
-	*((struct ieee80211_tx_control **) skb->cb) =
-		kmemdup(control, sizeof(*control), GFP_ATOMIC);
-
-	if (control->flags & IEEE80211_TXCTL_USE_RTS_CTS)
+	if (info->flags & IEEE80211_TX_CTL_USE_RTS_CTS)
 		rts_duration = ieee80211_rts_duration(dev, priv->vif, skb->len,
-						      control);
+						      info);
 
 	if (!priv->r8185) {
 		unsigned int remainder;
 
 		plcp_len = DIV_ROUND_UP(16 * (skb->len + 4),
-				(ieee80211_get_tx_rate(dev, control)->bitrate * 2) / 10);
+				(ieee80211_get_tx_rate(dev, info)->bitrate * 2) / 10);
 		remainder = (16 * (skb->len + 4)) %
-			    ((ieee80211_get_tx_rate(dev, control)->bitrate * 2) / 10);
+			    ((ieee80211_get_tx_rate(dev, info)->bitrate * 2) / 10);
 		if (remainder > 0 && remainder <= 6)
 			plcp_len |= 1 << 15;
 	}
@@ -300,13 +292,13 @@ static int rtl8180_tx(struct ieee80211_hw *dev, struct sk_buff *skb,
 	entry->plcp_len = cpu_to_le16(plcp_len);
 	entry->tx_buf = cpu_to_le32(mapping);
 	entry->frame_len = cpu_to_le32(skb->len);
-	entry->flags2 = control->alt_retry_rate_idx >= 0 ?
-		ieee80211_get_alt_retry_rate(dev, control)->bitrate << 4 : 0;
-	entry->retry_limit = control->retry_limit;
+	entry->flags2 = info->control.alt_retry_rate_idx >= 0 ?
+		ieee80211_get_alt_retry_rate(dev, info)->bitrate << 4 : 0;
+	entry->retry_limit = info->control.retry_limit;
 	entry->flags = cpu_to_le32(tx_flags);
 	__skb_queue_tail(&ring->queue, skb);
 	if (ring->entries - skb_queue_len(&ring->queue) < 2)
-		ieee80211_stop_queue(dev, control->queue);
+		ieee80211_stop_queue(dev, info->queue);
 	spin_unlock_irqrestore(&priv->lock, flags);
 
 	rtl818x_iowrite8(priv, &priv->map->TX_DMA_POLLING, (1 << (prio + 4)));
@@ -522,7 +514,6 @@ static void rtl8180_free_tx_ring(struct ieee80211_hw *dev, unsigned int prio)
 
 		pci_unmap_single(priv->pdev, le32_to_cpu(entry->tx_buf),
 				 skb->len, PCI_DMA_TODEVICE);
-		kfree(*((struct ieee80211_tx_control **) skb->cb));
 		kfree_skb(skb);
 		ring->idx = (ring->idx + 1) % ring->entries;
 	}