rt2x00: Serialize TX operations on a queue.
[linux-flexiantxendom0-natty.git] / drivers / net / wireless / rt2x00 / rt2x00queue.c
index 6d41599..b1a9078 100644 (file)
@@ -33,9 +33,9 @@
 #include "rt2x00.h"
 #include "rt2x00lib.h"
 
-struct sk_buff *rt2x00queue_alloc_rxskb(struct rt2x00_dev *rt2x00dev,
-                                       struct queue_entry *entry)
+struct sk_buff *rt2x00queue_alloc_rxskb(struct queue_entry *entry)
 {
+       struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
        struct sk_buff *skb;
        struct skb_frame_desc *skbdesc;
        unsigned int frame_size;
@@ -97,41 +97,42 @@ struct sk_buff *rt2x00queue_alloc_rxskb(struct rt2x00_dev *rt2x00dev,
        return skb;
 }
 
-void rt2x00queue_map_txskb(struct rt2x00_dev *rt2x00dev, struct sk_buff *skb)
+void rt2x00queue_map_txskb(struct queue_entry *entry)
 {
-       struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
+       struct device *dev = entry->queue->rt2x00dev->dev;
+       struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
 
        skbdesc->skb_dma =
-           dma_map_single(rt2x00dev->dev, skb->data, skb->len, DMA_TO_DEVICE);
+           dma_map_single(dev, entry->skb->data, entry->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)
+void rt2x00queue_unmap_skb(struct queue_entry *entry)
 {
-       struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
+       struct device *dev = entry->queue->rt2x00dev->dev;
+       struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
 
        if (skbdesc->flags & SKBDESC_DMA_MAPPED_RX) {
-               dma_unmap_single(rt2x00dev->dev, skbdesc->skb_dma, skb->len,
+               dma_unmap_single(dev, skbdesc->skb_dma, entry->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,
+       } else if (skbdesc->flags & SKBDESC_DMA_MAPPED_TX) {
+               dma_unmap_single(dev, skbdesc->skb_dma, entry->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)
+void rt2x00queue_free_skb(struct queue_entry *entry)
 {
-       if (!skb)
+       if (!entry->skb)
                return;
 
-       rt2x00queue_unmap_skb(rt2x00dev, skb);
-       dev_kfree_skb_any(skb);
+       rt2x00queue_unmap_skb(entry);
+       dev_kfree_skb_any(entry->skb);
+       entry->skb = NULL;
 }
 
 void rt2x00queue_align_frame(struct sk_buff *skb)
@@ -198,7 +199,12 @@ void rt2x00queue_insert_l2pad(struct sk_buff *skb, unsigned int header_length)
 
 void rt2x00queue_remove_l2pad(struct sk_buff *skb, unsigned int header_length)
 {
-       unsigned int l2pad = L2PAD_SIZE(header_length);
+       /*
+        * L2 padding is only present if the skb contains more than just the
+        * IEEE 802.11 header.
+        */
+       unsigned int l2pad = (skb->len > header_length) ?
+                               L2PAD_SIZE(header_length) : 0;
 
        if (!l2pad)
                return;
@@ -310,14 +316,6 @@ static void rt2x00queue_create_tx_descriptor(struct queue_entry *entry,
        memset(txdesc, 0, sizeof(*txdesc));
 
        /*
-        * Initialize information from queue
-        */
-       txdesc->qid = entry->queue->qid;
-       txdesc->cw_min = entry->queue->cw_min;
-       txdesc->cw_max = entry->queue->cw_max;
-       txdesc->aifs = entry->queue->aifs;
-
-       /*
         * Header and frame information.
         */
        txdesc->length = entry->skb->len;
@@ -440,7 +438,7 @@ static int rt2x00queue_write_tx_data(struct queue_entry *entry,
         * Map the skb to DMA.
         */
        if (test_bit(DRIVER_REQUIRE_DMA, &rt2x00dev->flags))
-               rt2x00queue_map_txskb(rt2x00dev, entry->skb);
+               rt2x00queue_map_txskb(entry);
 
        return 0;
 }
@@ -459,12 +457,9 @@ static void rt2x00queue_write_tx_descriptor(struct queue_entry *entry,
        rt2x00debug_dump_frame(queue->rt2x00dev, DUMP_FRAME_TX, entry->skb);
 }
 
-static void rt2x00queue_kick_tx_queue(struct queue_entry *entry,
+static void rt2x00queue_kick_tx_queue(struct data_queue *queue,
                                      struct txentry_desc *txdesc)
 {
-       struct data_queue *queue = entry->queue;
-       struct rt2x00_dev *rt2x00dev = queue->rt2x00dev;
-
        /*
         * Check if we need to kick the queue, there are however a few rules
         *      1) Don't kick unless this is the last in frame in a burst.
@@ -476,27 +471,38 @@ static void rt2x00queue_kick_tx_queue(struct queue_entry *entry,
         */
        if (rt2x00queue_threshold(queue) ||
            !test_bit(ENTRY_TXD_BURST, &txdesc->flags))
-               rt2x00dev->ops->lib->kick_tx_queue(queue);
+               queue->rt2x00dev->ops->lib->kick_queue(queue);
 }
 
 int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb,
                               bool local)
 {
        struct ieee80211_tx_info *tx_info;
-       struct queue_entry *entry = rt2x00queue_get_entry(queue, Q_INDEX);
+       struct queue_entry *entry;
        struct txentry_desc txdesc;
        struct skb_frame_desc *skbdesc;
        u8 rate_idx, rate_flags;
+       int ret = 0;
 
-       if (unlikely(rt2x00queue_full(queue)))
-               return -ENOBUFS;
+       spin_lock(&queue->tx_lock);
+
+       entry = rt2x00queue_get_entry(queue, Q_INDEX);
+
+       if (unlikely(rt2x00queue_full(queue))) {
+               ERROR(queue->rt2x00dev,
+                     "Dropping frame due to full tx queue %d.\n", queue->qid);
+               ret = -ENOBUFS;
+               goto out;
+       }
 
-       if (test_and_set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags)) {
+       if (unlikely(test_and_set_bit(ENTRY_OWNER_DEVICE_DATA,
+                                     &entry->flags))) {
                ERROR(queue->rt2x00dev,
                      "Arrived at non-free entry in the non-full queue %d.\n"
                      "Please file bug report to %s.\n",
                      queue->qid, DRV_PROJECT);
-               return -EINVAL;
+               ret = -EINVAL;
+               goto out;
        }
 
        /*
@@ -558,16 +564,19 @@ int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb,
        if (unlikely(rt2x00queue_write_tx_data(entry, &txdesc))) {
                clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
                entry->skb = NULL;
-               return -EIO;
+               ret = -EIO;
+               goto out;
        }
 
        set_bit(ENTRY_DATA_PENDING, &entry->flags);
 
        rt2x00queue_index_inc(queue, Q_INDEX);
        rt2x00queue_write_tx_descriptor(entry, &txdesc);
-       rt2x00queue_kick_tx_queue(entry, &txdesc);
+       rt2x00queue_kick_tx_queue(queue, &txdesc);
 
-       return 0;
+out:
+       spin_unlock(&queue->tx_lock);
+       return ret;
 }
 
 int rt2x00queue_update_beacon(struct rt2x00_dev *rt2x00dev,
@@ -586,11 +595,10 @@ int rt2x00queue_update_beacon(struct rt2x00_dev *rt2x00dev,
        /*
         * Clean up the beacon skb.
         */
-       rt2x00queue_free_skb(rt2x00dev, intf->beacon->skb);
-       intf->beacon->skb = NULL;
+       rt2x00queue_free_skb(intf->beacon);
 
        if (!enable_beacon) {
-               rt2x00dev->ops->lib->kill_tx_queue(intf->beacon->queue);
+               rt2x00queue_stop_queue(intf->beacon->queue);
                mutex_unlock(&intf->beacon_skb_mutex);
                return 0;
        }
@@ -648,10 +656,10 @@ void rt2x00queue_for_each_entry(struct data_queue *queue,
         * it should not be kicked during this run, since it
         * is part of another TX operation.
         */
-       spin_lock_irqsave(&queue->lock, irqflags);
+       spin_lock_irqsave(&queue->index_lock, irqflags);
        index_start = queue->index[start];
        index_end = queue->index[end];
-       spin_unlock_irqrestore(&queue->lock, irqflags);
+       spin_unlock_irqrestore(&queue->index_lock, irqflags);
 
        /*
         * Start from the TX done pointer, this guarentees that we will
@@ -705,11 +713,11 @@ struct queue_entry *rt2x00queue_get_entry(struct data_queue *queue,
                return NULL;
        }
 
-       spin_lock_irqsave(&queue->lock, irqflags);
+       spin_lock_irqsave(&queue->index_lock, irqflags);
 
        entry = &queue->entries[queue->index[index]];
 
-       spin_unlock_irqrestore(&queue->lock, irqflags);
+       spin_unlock_irqrestore(&queue->index_lock, irqflags);
 
        return entry;
 }
@@ -725,7 +733,7 @@ void rt2x00queue_index_inc(struct data_queue *queue, enum queue_index index)
                return;
        }
 
-       spin_lock_irqsave(&queue->lock, irqflags);
+       spin_lock_irqsave(&queue->index_lock, irqflags);
 
        queue->index[index]++;
        if (queue->index[index] >= queue->limit)
@@ -740,15 +748,219 @@ void rt2x00queue_index_inc(struct data_queue *queue, enum queue_index index)
                queue->count++;
        }
 
-       spin_unlock_irqrestore(&queue->lock, irqflags);
+       spin_unlock_irqrestore(&queue->index_lock, irqflags);
 }
 
+void rt2x00queue_pause_queue(struct data_queue *queue)
+{
+       if (!test_bit(DEVICE_STATE_PRESENT, &queue->rt2x00dev->flags) ||
+           !test_bit(QUEUE_STARTED, &queue->flags) ||
+           test_and_set_bit(QUEUE_PAUSED, &queue->flags))
+               return;
+
+       switch (queue->qid) {
+       case QID_AC_VO:
+       case QID_AC_VI:
+       case QID_AC_BE:
+       case QID_AC_BK:
+               /*
+                * For TX queues, we have to disable the queue
+                * inside mac80211.
+                */
+               ieee80211_stop_queue(queue->rt2x00dev->hw, queue->qid);
+               break;
+       default:
+               break;
+       }
+}
+EXPORT_SYMBOL_GPL(rt2x00queue_pause_queue);
+
+void rt2x00queue_unpause_queue(struct data_queue *queue)
+{
+       if (!test_bit(DEVICE_STATE_PRESENT, &queue->rt2x00dev->flags) ||
+           !test_bit(QUEUE_STARTED, &queue->flags) ||
+           !test_and_clear_bit(QUEUE_PAUSED, &queue->flags))
+               return;
+
+       switch (queue->qid) {
+       case QID_AC_VO:
+       case QID_AC_VI:
+       case QID_AC_BE:
+       case QID_AC_BK:
+               /*
+                * For TX queues, we have to enable the queue
+                * inside mac80211.
+                */
+               ieee80211_wake_queue(queue->rt2x00dev->hw, queue->qid);
+               break;
+       case QID_RX:
+               /*
+                * For RX we need to kick the queue now in order to
+                * receive frames.
+                */
+               queue->rt2x00dev->ops->lib->kick_queue(queue);
+       default:
+               break;
+       }
+}
+EXPORT_SYMBOL_GPL(rt2x00queue_unpause_queue);
+
+void rt2x00queue_start_queue(struct data_queue *queue)
+{
+       mutex_lock(&queue->status_lock);
+
+       if (!test_bit(DEVICE_STATE_PRESENT, &queue->rt2x00dev->flags) ||
+           test_and_set_bit(QUEUE_STARTED, &queue->flags)) {
+               mutex_unlock(&queue->status_lock);
+               return;
+       }
+
+       set_bit(QUEUE_PAUSED, &queue->flags);
+
+       queue->rt2x00dev->ops->lib->start_queue(queue);
+
+       rt2x00queue_unpause_queue(queue);
+
+       mutex_unlock(&queue->status_lock);
+}
+EXPORT_SYMBOL_GPL(rt2x00queue_start_queue);
+
+void rt2x00queue_stop_queue(struct data_queue *queue)
+{
+       mutex_lock(&queue->status_lock);
+
+       if (!test_and_clear_bit(QUEUE_STARTED, &queue->flags)) {
+               mutex_unlock(&queue->status_lock);
+               return;
+       }
+
+       rt2x00queue_pause_queue(queue);
+
+       queue->rt2x00dev->ops->lib->stop_queue(queue);
+
+       mutex_unlock(&queue->status_lock);
+}
+EXPORT_SYMBOL_GPL(rt2x00queue_stop_queue);
+
+void rt2x00queue_flush_queue(struct data_queue *queue, bool drop)
+{
+       unsigned int i;
+       bool started;
+       bool tx_queue =
+               (queue->qid == QID_AC_VO) ||
+               (queue->qid == QID_AC_VI) ||
+               (queue->qid == QID_AC_BE) ||
+               (queue->qid == QID_AC_BK);
+
+       mutex_lock(&queue->status_lock);
+
+       /*
+        * If the queue has been started, we must stop it temporarily
+        * to prevent any new frames to be queued on the device. If
+        * we are not dropping the pending frames, the queue must
+        * only be stopped in the software and not the hardware,
+        * otherwise the queue will never become empty on its own.
+        */
+       started = test_bit(QUEUE_STARTED, &queue->flags);
+       if (started) {
+               /*
+                * Pause the queue
+                */
+               rt2x00queue_pause_queue(queue);
+
+               /*
+                * If we are not supposed to drop any pending
+                * frames, this means we must force a start (=kick)
+                * to the queue to make sure the hardware will
+                * start transmitting.
+                */
+               if (!drop && tx_queue)
+                       queue->rt2x00dev->ops->lib->kick_queue(queue);
+       }
+
+       /*
+        * Check if driver supports flushing, we can only guarentee
+        * full support for flushing if the driver is able
+        * to cancel all pending frames (drop = true).
+        */
+       if (drop && queue->rt2x00dev->ops->lib->flush_queue)
+               queue->rt2x00dev->ops->lib->flush_queue(queue);
+
+       /*
+        * When we don't want to drop any frames, or when
+        * the driver doesn't fully flush the queue correcly,
+        * we must wait for the queue to become empty.
+        */
+       for (i = 0; !rt2x00queue_empty(queue) && i < 100; i++)
+               msleep(10);
+
+       /*
+        * The queue flush has failed...
+        */
+       if (unlikely(!rt2x00queue_empty(queue)))
+               WARNING(queue->rt2x00dev, "Queue %d failed to flush", queue->qid);
+
+       /*
+        * Restore the queue to the previous status
+        */
+       if (started)
+               rt2x00queue_unpause_queue(queue);
+
+       mutex_unlock(&queue->status_lock);
+}
+EXPORT_SYMBOL_GPL(rt2x00queue_flush_queue);
+
+void rt2x00queue_start_queues(struct rt2x00_dev *rt2x00dev)
+{
+       struct data_queue *queue;
+
+       /*
+        * rt2x00queue_start_queue will call ieee80211_wake_queue
+        * for each queue after is has been properly initialized.
+        */
+       tx_queue_for_each(rt2x00dev, queue)
+               rt2x00queue_start_queue(queue);
+
+       rt2x00queue_start_queue(rt2x00dev->rx);
+}
+EXPORT_SYMBOL_GPL(rt2x00queue_start_queues);
+
+void rt2x00queue_stop_queues(struct rt2x00_dev *rt2x00dev)
+{
+       struct data_queue *queue;
+
+       /*
+        * rt2x00queue_stop_queue will call ieee80211_stop_queue
+        * as well, but we are completely shutting doing everything
+        * now, so it is much safer to stop all TX queues at once,
+        * and use rt2x00queue_stop_queue for cleaning up.
+        */
+       ieee80211_stop_queues(rt2x00dev->hw);
+
+       tx_queue_for_each(rt2x00dev, queue)
+               rt2x00queue_stop_queue(queue);
+
+       rt2x00queue_stop_queue(rt2x00dev->rx);
+}
+EXPORT_SYMBOL_GPL(rt2x00queue_stop_queues);
+
+void rt2x00queue_flush_queues(struct rt2x00_dev *rt2x00dev, bool drop)
+{
+       struct data_queue *queue;
+
+       tx_queue_for_each(rt2x00dev, queue)
+               rt2x00queue_flush_queue(queue, drop);
+
+       rt2x00queue_flush_queue(rt2x00dev->rx, drop);
+}
+EXPORT_SYMBOL_GPL(rt2x00queue_flush_queues);
+
 static void rt2x00queue_reset(struct data_queue *queue)
 {
        unsigned long irqflags;
        unsigned int i;
 
-       spin_lock_irqsave(&queue->lock, irqflags);
+       spin_lock_irqsave(&queue->index_lock, irqflags);
 
        queue->count = 0;
        queue->length = 0;
@@ -758,15 +970,7 @@ static void rt2x00queue_reset(struct data_queue *queue)
                queue->last_action[i] = jiffies;
        }
 
-       spin_unlock_irqrestore(&queue->lock, irqflags);
-}
-
-void rt2x00queue_stop_queues(struct rt2x00_dev *rt2x00dev)
-{
-       struct data_queue *queue;
-
-       txall_queue_for_each(rt2x00dev, queue)
-               rt2x00dev->ops->lib->kill_tx_queue(queue);
+       spin_unlock_irqrestore(&queue->index_lock, irqflags);
 }
 
 void rt2x00queue_init_queues(struct rt2x00_dev *rt2x00dev)
@@ -777,11 +981,8 @@ void rt2x00queue_init_queues(struct rt2x00_dev *rt2x00dev)
        queue_for_each(rt2x00dev, queue) {
                rt2x00queue_reset(queue);
 
-               for (i = 0; i < queue->limit; i++) {
+               for (i = 0; i < queue->limit; i++)
                        rt2x00dev->ops->lib->clear_entry(&queue->entries[i]);
-                       if (queue->qid == QID_RX)
-                               rt2x00queue_index_inc(queue, Q_INDEX);
-               }
        }
 }
 
@@ -803,13 +1004,13 @@ static int rt2x00queue_alloc_entries(struct data_queue *queue,
         * Allocate all queue entries.
         */
        entry_size = sizeof(*entries) + qdesc->priv_size;
-       entries = kzalloc(queue->limit * entry_size, GFP_KERNEL);
+       entries = kcalloc(queue->limit, entry_size, GFP_KERNEL);
        if (!entries)
                return -ENOMEM;
 
 #define QUEUE_ENTRY_PRIV_OFFSET(__base, __index, __limit, __esize, __psize) \
-       ( ((char *)(__base)) + ((__limit) * (__esize)) + \
-           ((__index) * (__psize)) )
+       (((char *)(__base)) + ((__limit) * (__esize)) + \
+           ((__index) * (__psize)))
 
        for (i = 0; i < queue->limit; i++) {
                entries[i].flags = 0;
@@ -828,8 +1029,7 @@ static int rt2x00queue_alloc_entries(struct data_queue *queue,
        return 0;
 }
 
-static void rt2x00queue_free_skbs(struct rt2x00_dev *rt2x00dev,
-                                 struct data_queue *queue)
+static void rt2x00queue_free_skbs(struct data_queue *queue)
 {
        unsigned int i;
 
@@ -837,19 +1037,17 @@ static void rt2x00queue_free_skbs(struct rt2x00_dev *rt2x00dev,
                return;
 
        for (i = 0; i < queue->limit; i++) {
-               if (queue->entries[i].skb)
-                       rt2x00queue_free_skb(rt2x00dev, queue->entries[i].skb);
+               rt2x00queue_free_skb(&queue->entries[i]);
        }
 }
 
-static int rt2x00queue_alloc_rxskbs(struct rt2x00_dev *rt2x00dev,
-                                   struct data_queue *queue)
+static int rt2x00queue_alloc_rxskbs(struct data_queue *queue)
 {
        unsigned int i;
        struct sk_buff *skb;
 
        for (i = 0; i < queue->limit; i++) {
-               skb = rt2x00queue_alloc_rxskb(rt2x00dev, &queue->entries[i]);
+               skb = rt2x00queue_alloc_rxskb(&queue->entries[i]);
                if (!skb)
                        return -ENOMEM;
                queue->entries[i].skb = skb;
@@ -884,7 +1082,7 @@ int rt2x00queue_initialize(struct rt2x00_dev *rt2x00dev)
                        goto exit;
        }
 
-       status = rt2x00queue_alloc_rxskbs(rt2x00dev, rt2x00dev->rx);
+       status = rt2x00queue_alloc_rxskbs(rt2x00dev->rx);
        if (status)
                goto exit;
 
@@ -902,7 +1100,7 @@ void rt2x00queue_uninitialize(struct rt2x00_dev *rt2x00dev)
 {
        struct data_queue *queue;
 
-       rt2x00queue_free_skbs(rt2x00dev, rt2x00dev->rx);
+       rt2x00queue_free_skbs(rt2x00dev->rx);
 
        queue_for_each(rt2x00dev, queue) {
                kfree(queue->entries);
@@ -913,7 +1111,9 @@ void rt2x00queue_uninitialize(struct rt2x00_dev *rt2x00dev)
 static void rt2x00queue_init(struct rt2x00_dev *rt2x00dev,
                             struct data_queue *queue, enum data_queue_qid qid)
 {
-       spin_lock_init(&queue->lock);
+       mutex_init(&queue->status_lock);
+       spin_lock_init(&queue->tx_lock);
+       spin_lock_init(&queue->index_lock);
 
        queue->rt2x00dev = rt2x00dev;
        queue->qid = qid;
@@ -939,7 +1139,7 @@ int rt2x00queue_allocate(struct rt2x00_dev *rt2x00dev)
         */
        rt2x00dev->data_queues = 2 + rt2x00dev->ops->tx_queues + req_atim;
 
-       queue = kzalloc(rt2x00dev->data_queues * sizeof(*queue), GFP_KERNEL);
+       queue = kcalloc(rt2x00dev->data_queues, sizeof(*queue), GFP_KERNEL);
        if (!queue) {
                ERROR(rt2x00dev, "Queue allocation failed.\n");
                return -ENOMEM;
@@ -955,7 +1155,7 @@ int rt2x00queue_allocate(struct rt2x00_dev *rt2x00dev)
        /*
         * Initialize queue parameters.
         * RX: qid = QID_RX
-        * TX: qid = QID_AC_BE + index
+        * TX: qid = QID_AC_VO + index
         * TX: cw_min: 2^5 = 32.
         * TX: cw_max: 2^10 = 1024.
         * BCN: qid = QID_BEACON
@@ -963,7 +1163,7 @@ int rt2x00queue_allocate(struct rt2x00_dev *rt2x00dev)
         */
        rt2x00queue_init(rt2x00dev, rt2x00dev->rx, QID_RX);
 
-       qid = QID_AC_BE;
+       qid = QID_AC_VO;
        tx_queue_for_each(rt2x00dev, queue)
                rt2x00queue_init(rt2x00dev, queue, qid++);