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>

1 files changed, 45 insertions, 19 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
index b8e0c4c3ed0a..99b14ba99d97 100644
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
@@ -468,6 +468,7 @@ static void rt2x00lib_intf_scheduled(struct work_struct *work)
 static void rt2x00lib_beacondone_iter(void *data, u8 *mac,
                                       struct ieee80211_vif *vif)
 {
+        struct rt2x00_dev *rt2x00dev = data;
         struct rt2x00_intf *intf = vif_to_intf(vif);
 
         if (vif->type != IEEE80211_IF_TYPE_AP &&
@@ -477,7 +478,7 @@ static void rt2x00lib_beacondone_iter(void *data, u8 *mac,
         /*
          * Clean up the beacon skb.
          */
-        dev_kfree_skb_irq(intf->beacon->skb);
+        rt2x00queue_free_skb(rt2x00dev, intf->beacon->skb);
         intf->beacon->skb = NULL;
 
         spin_lock(&intf->lock);
@@ -555,34 +556,55 @@ void rt2x00lib_txdone(struct queue_entry *entry,
 }
 EXPORT_SYMBOL_GPL(rt2x00lib_txdone);
 
-void rt2x00lib_rxdone(struct queue_entry *entry,
-                      struct rxdone_entry_desc *rxdesc)
+void rt2x00lib_rxdone(struct rt2x00_dev *rt2x00dev,
+                      struct queue_entry *entry)
 {
-        struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
+        struct rxdone_entry_desc rxdesc;
+        struct sk_buff *skb;
         struct ieee80211_rx_status *rx_status = &rt2x00dev->rx_status;
-        unsigned int header_size = ieee80211_get_hdrlen_from_skb(entry->skb);
         struct ieee80211_supported_band *sband;
         struct ieee80211_hdr *hdr;
         const struct rt2x00_rate *rate;
+        unsigned int header_size;
         unsigned int align;
         unsigned int i;
         int idx = -1;
 
         /*
+         * Allocate a new sk_buffer. If no new buffer available, drop the
+         * received frame and reuse the existing buffer.
+         */
+        skb = rt2x00queue_alloc_rxskb(rt2x00dev, entry);
+        if (!skb)
+                return;
+
+        /*
+         * Unmap the skb.
+         */
+        rt2x00queue_unmap_skb(rt2x00dev, entry->skb);
+
+        /*
+         * Extract the RXD details.
+         */
+        memset(&rxdesc, 0, sizeof(rxdesc));
+        rt2x00dev->ops->lib->fill_rxdone(entry, &rxdesc);
+
+        /*
          * The data behind the ieee80211 header must be
          * aligned on a 4 byte boundary.
          */
+        header_size = ieee80211_get_hdrlen_from_skb(entry->skb);
         align = ((unsigned long)(entry->skb->data + header_size)) & 3;
 
         if (align) {
                 skb_push(entry->skb, align);
                 /* Move entire frame in 1 command */
                 memmove(entry->skb->data, entry->skb->data + align,
-                        rxdesc->size);
+                        rxdesc.size);
         }
 
         /* Update data pointers, trim buffer to correct size */
-        skb_trim(entry->skb, rxdesc->size);
+        skb_trim(entry->skb, rxdesc.size);
 
         /*
          * Update RX statistics.
@@ -591,10 +613,10 @@ void rt2x00lib_rxdone(struct queue_entry *entry,
         for (i = 0; i < sband->n_bitrates; i++) {
                 rate = rt2x00_get_rate(sband->bitrates[i].hw_value);
 
-                if (((rxdesc->dev_flags & RXDONE_SIGNAL_PLCP) &&
-                     (rate->plcp == rxdesc->signal)) ||
-                    (!(rxdesc->dev_flags & RXDONE_SIGNAL_PLCP) &&
-                      (rate->bitrate == rxdesc->signal))) {
+                if (((rxdesc.dev_flags & RXDONE_SIGNAL_PLCP) &&
+                     (rate->plcp == rxdesc.signal)) ||
+                    (!(rxdesc.dev_flags & RXDONE_SIGNAL_PLCP) &&
+                      (rate->bitrate == rxdesc.signal))) {
                         idx = i;
                         break;
                 }
@@ -602,8 +624,8 @@ void rt2x00lib_rxdone(struct queue_entry *entry,
 
         if (idx < 0) {
                 WARNING(rt2x00dev, "Frame received with unrecognized signal,"
-                        "signal=0x%.2x, plcp=%d.\n", rxdesc->signal,
-                        !!(rxdesc->dev_flags & RXDONE_SIGNAL_PLCP));
+                        "signal=0x%.2x, plcp=%d.\n", rxdesc.signal,
+                        !!(rxdesc.dev_flags & RXDONE_SIGNAL_PLCP));
                 idx = 0;
         }
 
@@ -612,16 +634,16 @@ void rt2x00lib_rxdone(struct queue_entry *entry,
          */
         hdr = (struct ieee80211_hdr *)entry->skb->data;
         if (ieee80211_is_beacon(hdr->frame_control) &&
-            (rxdesc->dev_flags & RXDONE_MY_BSS))
-                rt2x00lib_update_link_stats(&rt2x00dev->link, rxdesc->rssi);
+            (rxdesc.dev_flags & RXDONE_MY_BSS))
+                rt2x00lib_update_link_stats(&rt2x00dev->link, rxdesc.rssi);
 
         rt2x00dev->link.qual.rx_success++;
 
         rx_status->rate_idx = idx;
         rx_status->qual =
-            rt2x00lib_calculate_link_signal(rt2x00dev, rxdesc->rssi);
-        rx_status->signal = rxdesc->rssi;
-        rx_status->flag = rxdesc->flags;
+            rt2x00lib_calculate_link_signal(rt2x00dev, rxdesc.rssi);
+        rx_status->signal = rxdesc.rssi;
+        rx_status->flag = rxdesc.flags;
         rx_status->antenna = rt2x00dev->link.ant.active.rx;
 
         /*
@@ -630,7 +652,11 @@ void rt2x00lib_rxdone(struct queue_entry *entry,
          */
         rt2x00debug_dump_frame(rt2x00dev, DUMP_FRAME_RXDONE, entry->skb);
         ieee80211_rx_irqsafe(rt2x00dev->hw, entry->skb, rx_status);
-        entry->skb = NULL;
+
+        /*
+         * Replace the skb with the freshly allocated one.
+         */
+        entry->skb = skb;
 }
 EXPORT_SYMBOL_GPL(rt2x00lib_rxdone);