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, 38 insertions, 52 deletions

diff --git a/drivers/net/wireless/p54/p54common.c b/drivers/net/wireless/p54/p54common.c
index 3ca9386561ff..850857932e29 100644
--- a/drivers/net/wireless/p54/p54common.c
+++ b/drivers/net/wireless/p54/p54common.c
@@ -394,7 +394,7 @@ static void p54_rx_frame_sent(struct ieee80211_hw *dev, struct sk_buff *skb)
         while (entry != (struct sk_buff *)&priv->tx_queue) {
                 range = (struct memrecord *)&entry->cb;
                 if (range->start_addr == addr) {
-                        struct ieee80211_tx_status status;
+                        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(entry);
                         struct p54_control_hdr *entry_hdr;
                         struct p54_tx_control_allocdata *entry_data;
                         int pad = 0;
@@ -406,30 +406,23 @@ static void p54_rx_frame_sent(struct ieee80211_hw *dev, struct sk_buff *skb)
 
                         last_addr = range->end_addr;
                         __skb_unlink(entry, &priv->tx_queue);
-                        if (!range->control) {
-                                kfree_skb(entry);
-                                break;
-                        }
-                        memset(&status, 0, sizeof(status));
-                        memcpy(&status.control, range->control,
-                               sizeof(status.control));
-                        kfree(range->control);
-                        priv->tx_stats[status.control.queue].len--;
+                        memset(&info->status, 0, sizeof(info->status));
+                        priv->tx_stats[info->queue].len--;
                         entry_hdr = (struct p54_control_hdr *) entry->data;
                         entry_data = (struct p54_tx_control_allocdata *) entry_hdr->data;
                         if ((entry_hdr->magic1 & cpu_to_le16(0x4000)) != 0)
                                 pad = entry_data->align[0];
 
-                        if (!(status.control.flags & IEEE80211_TXCTL_NO_ACK)) {
+                        if (!(info->flags & IEEE80211_TX_CTL_NO_ACK)) {
                                 if (!(payload->status & 0x01))
-                                        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 = payload->retries - 1;
-                        status.ack_signal = le16_to_cpu(payload->ack_rssi);
+                        info->status.retry_count = payload->retries - 1;
+                        info->status.ack_signal = le16_to_cpu(payload->ack_rssi);
                         skb_pull(entry, sizeof(*hdr) + pad + sizeof(*entry_data));
-                        ieee80211_tx_status_irqsafe(dev, entry, &status);
+                        ieee80211_tx_status_irqsafe(dev, entry);
                         break;
                 } else
                         last_addr = range->end_addr;
@@ -494,13 +487,11 @@ EXPORT_SYMBOL_GPL(p54_rx);
  * allocated areas.
  */
 static void p54_assign_address(struct ieee80211_hw *dev, struct sk_buff *skb,
-                               struct p54_control_hdr *data, u32 len,
-                               struct ieee80211_tx_control *control)
+                               struct p54_control_hdr *data, u32 len)
 {
         struct p54_common *priv = dev->priv;
         struct sk_buff *entry = priv->tx_queue.next;
         struct sk_buff *target_skb = NULL;
-        struct memrecord *range;
         u32 last_addr = priv->rx_start;
         u32 largest_hole = 0;
         u32 target_addr = priv->rx_start;
@@ -512,7 +503,8 @@ static void p54_assign_address(struct ieee80211_hw *dev, struct sk_buff *skb,
         left = skb_queue_len(&priv->tx_queue);
         while (left--) {
                 u32 hole_size;
-                range = (struct memrecord *)&entry->cb;
+                struct ieee80211_tx_info *info = IEEE80211_SKB_CB(entry);
+                struct memrecord *range = (void *)info->driver_data;
                 hole_size = range->start_addr - last_addr;
                 if (!target_skb && hole_size >= len) {
                         target_skb = entry->prev;
@@ -527,17 +519,18 @@ static void p54_assign_address(struct ieee80211_hw *dev, struct sk_buff *skb,
                 target_skb = priv->tx_queue.prev;
                 largest_hole = max(largest_hole, priv->rx_end - last_addr - len);
                 if (!skb_queue_empty(&priv->tx_queue)) {
-                        range = (struct memrecord *)&target_skb->cb;
+                        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(target_skb);
+                        struct memrecord *range = (void *)info->driver_data;
                         target_addr = range->end_addr;
                 }
         } else
                 largest_hole = max(largest_hole, priv->rx_end - last_addr);
 
         if (skb) {
-                range = (struct memrecord *)&skb->cb;
+                struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+                struct memrecord *range = (void *)info->driver_data;
                 range->start_addr = target_addr;
                 range->end_addr = target_addr + len;
-                range->control = control;
                 __skb_queue_after(&priv->tx_queue, target_skb, skb);
                 if (largest_hole < IEEE80211_MAX_RTS_THRESHOLD + 0x170 +
                                    sizeof(struct p54_control_hdr))
@@ -548,32 +541,27 @@ static void p54_assign_address(struct ieee80211_hw *dev, struct sk_buff *skb,
         data->req_id = cpu_to_le32(target_addr + 0x70);
 }
 
-static int p54_tx(struct ieee80211_hw *dev, struct sk_buff *skb,
-                  struct ieee80211_tx_control *control)
+static int p54_tx(struct ieee80211_hw *dev, struct sk_buff *skb)
 {
+        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
         struct ieee80211_tx_queue_stats *current_queue;
         struct p54_common *priv = dev->priv;
         struct p54_control_hdr *hdr;
         struct p54_tx_control_allocdata *txhdr;
-        struct ieee80211_tx_control *control_copy;
         size_t padding, len;
         u8 rate;
 
-        current_queue = &priv->tx_stats[control->queue];
+        current_queue = &priv->tx_stats[info->queue];
         if (unlikely(current_queue->len > current_queue->limit))
                 return NETDEV_TX_BUSY;
         current_queue->len++;
         current_queue->count++;
         if (current_queue->len == current_queue->limit)
-                ieee80211_stop_queue(dev, control->queue);
+                ieee80211_stop_queue(dev, info->queue);
 
         padding = (unsigned long)(skb->data - (sizeof(*hdr) + sizeof(*txhdr))) & 3;
         len = skb->len;
 
-        control_copy = kmalloc(sizeof(*control), GFP_ATOMIC);
-        if (control_copy)
-                memcpy(control_copy, control, sizeof(*control));
-
         txhdr = (struct p54_tx_control_allocdata *)
                         skb_push(skb, sizeof(*txhdr) + padding);
         hdr = (struct p54_control_hdr *) skb_push(skb, sizeof(*hdr));
@@ -583,35 +571,37 @@ static int p54_tx(struct ieee80211_hw *dev, struct sk_buff *skb,
         else
                 hdr->magic1 = cpu_to_le16(0x0010);
         hdr->len = cpu_to_le16(len);
-        hdr->type = (control->flags & IEEE80211_TXCTL_NO_ACK) ? 0 : cpu_to_le16(1);
-        hdr->retry1 = hdr->retry2 = control->retry_limit;
-        p54_assign_address(dev, skb, hdr, skb->len, control_copy);
+        hdr->type = (info->flags & IEEE80211_TX_CTL_NO_ACK) ? 0 : cpu_to_le16(1);
+        hdr->retry1 = hdr->retry2 = info->control.retry_limit;
 
         memset(txhdr->wep_key, 0x0, 16);
         txhdr->padding = 0;
         txhdr->padding2 = 0;
 
         /* TODO: add support for alternate retry TX rates */
-        rate = ieee80211_get_tx_rate(dev, control)->hw_value;
-        if (control->flags & IEEE80211_TXCTL_SHORT_PREAMBLE)
+        rate = ieee80211_get_tx_rate(dev, info)->hw_value;
+        if (info->flags & IEEE80211_TX_CTL_SHORT_PREAMBLE)
                 rate |= 0x10;
-        if (control->flags & IEEE80211_TXCTL_USE_RTS_CTS)
+        if (info->flags & IEEE80211_TX_CTL_USE_RTS_CTS)
                 rate |= 0x40;
-        else if (control->flags & IEEE80211_TXCTL_USE_CTS_PROTECT)
+        else if (info->flags & IEEE80211_TX_CTL_USE_CTS_PROTECT)
                 rate |= 0x20;
         memset(txhdr->rateset, rate, 8);
         txhdr->wep_key_present = 0;
         txhdr->wep_key_len = 0;
-        txhdr->frame_type = cpu_to_le32(control->queue + 4);
+        txhdr->frame_type = cpu_to_le32(info->queue + 4);
         txhdr->magic4 = 0;
-        txhdr->antenna = (control->antenna_sel_tx == 0) ?
-                2 : control->antenna_sel_tx - 1;
+        txhdr->antenna = (info->antenna_sel_tx == 0) ?
+                2 : info->antenna_sel_tx - 1;
         txhdr->output_power = 0x7f; // HW Maximum
-        txhdr->magic5 = (control->flags & IEEE80211_TXCTL_NO_ACK) ?
+        txhdr->magic5 = (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
                 0 : ((rate > 0x3) ? cpu_to_le32(0x33) : cpu_to_le32(0x23));
         if (padding)
                 txhdr->align[0] = padding;
 
+        /* modifies skb->cb and with it info, so must be last! */
+        p54_assign_address(dev, skb, hdr, skb->len);
+
         priv->tx(dev, hdr, skb->len, 0);
         return 0;
 }
@@ -634,7 +624,7 @@ static int p54_set_filter(struct ieee80211_hw *dev, u16 filter_type,
         filter = (struct p54_tx_control_filter *) hdr->data;
         hdr->magic1 = cpu_to_le16(0x8001);
         hdr->len = cpu_to_le16(sizeof(*filter));
-        p54_assign_address(dev, NULL, hdr, sizeof(*hdr) + sizeof(*filter), NULL);
+        p54_assign_address(dev, NULL, hdr, sizeof(*hdr) + sizeof(*filter));
         hdr->type = cpu_to_le16(P54_CONTROL_TYPE_FILTER_SET);
 
         filter->filter_type = cpu_to_le16(filter_type);
@@ -678,7 +668,7 @@ static int p54_set_freq(struct ieee80211_hw *dev, __le16 freq)
         hdr->magic1 = cpu_to_le16(0x8001);
         hdr->len = cpu_to_le16(sizeof(*chan));
         hdr->type = cpu_to_le16(P54_CONTROL_TYPE_CHANNEL_CHANGE);
-        p54_assign_address(dev, NULL, hdr, sizeof(*hdr) + payload_len, NULL);
+        p54_assign_address(dev, NULL, hdr, sizeof(*hdr) + payload_len);
 
         chan->magic1 = cpu_to_le16(0x1);
         chan->magic2 = cpu_to_le16(0x0);
@@ -751,7 +741,7 @@ static int p54_set_leds(struct ieee80211_hw *dev, int mode, int link, int act)
         hdr->magic1 = cpu_to_le16(0x8001);
         hdr->len = cpu_to_le16(sizeof(*led));
         hdr->type = cpu_to_le16(P54_CONTROL_TYPE_LED);
-        p54_assign_address(dev, NULL, hdr, sizeof(*hdr) + sizeof(*led), NULL);
+        p54_assign_address(dev, NULL, hdr, sizeof(*hdr) + sizeof(*led));
 
         led = (struct p54_tx_control_led *) hdr->data;
         led->mode = cpu_to_le16(mode);
@@ -801,7 +791,7 @@ static void p54_set_vdcf(struct ieee80211_hw *dev)
 
         hdr = (void *)priv->cached_vdcf + priv->tx_hdr_len;
 
-        p54_assign_address(dev, NULL, hdr, sizeof(*hdr) + sizeof(*vdcf), NULL);
+        p54_assign_address(dev, NULL, hdr, sizeof(*hdr) + sizeof(*vdcf));
 
         vdcf = (struct p54_tx_control_vdcf *) hdr->data;
 
@@ -837,12 +827,8 @@ static void p54_stop(struct ieee80211_hw *dev)
 {
         struct p54_common *priv = dev->priv;
         struct sk_buff *skb;
-        while ((skb = skb_dequeue(&priv->tx_queue))) {
-                struct memrecord *range = (struct memrecord *)&skb->cb;
-                if (range->control)
-                        kfree(range->control);
+        while ((skb = skb_dequeue(&priv->tx_queue)))
                 kfree_skb(skb);
-        }
         priv->stop(dev);
         priv->mode = IEEE80211_IF_TYPE_INVALID;
 }