rt2x00: Split rt2x00lib_write_tx_desc()

Split rt2x00lib_write_tx_desc() up into a TX descriptor initializor
and TX descriptor writer.

This split is required to properly allow mac80211 to move its
tx_control structure into the skb->cb array.
The rt2x00queue_create_tx_descriptor() function will read all tx control
information and convert it into a rt2x00 TX descriptor information structure.
After that function is complete, we have all information we needed from the
tx control structure and are free to start writing into the skb->cb array
for our own purposes.
rt2x00queue_write_tx_descriptor() will be in charge of really sending
the TX descriptor to the hardware and kicking the TX queue.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 157 insertions, 0 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c
index 95f8dd3462f6..19c10629c767 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.c
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.c
@@ -29,6 +29,163 @@
 #include "rt2x00.h"
 #include "rt2x00lib.h"
 
+void rt2x00queue_create_tx_descriptor(struct queue_entry *entry,
+                                      struct txentry_desc *txdesc,
+                                      struct ieee80211_tx_control *control)
+{
+        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)entry->skb->data;
+        struct ieee80211_rate *rate = control->tx_rate;
+        const struct rt2x00_rate *hwrate;
+        unsigned int data_length;
+        unsigned int duration;
+        unsigned int residual;
+        u16 frame_control;
+
+        memset(txdesc, 0, sizeof(*txdesc));
+
+        /*
+         * Initialize information from queue
+         */
+        txdesc->queue = entry->queue->qid;
+        txdesc->cw_min = entry->queue->cw_min;
+        txdesc->cw_max = entry->queue->cw_max;
+        txdesc->aifs = entry->queue->aifs;
+
+        /* Data length should be extended with 4 bytes for CRC */
+        data_length = entry->skb->len + 4;
+
+        /*
+         * Read required fields from ieee80211 header.
+         */
+        frame_control = le16_to_cpu(hdr->frame_control);
+
+        /*
+         * Check whether this frame is to be acked.
+         */
+        if (!(control->flags & IEEE80211_TXCTL_NO_ACK))
+                __set_bit(ENTRY_TXD_ACK, &txdesc->flags);
+
+        /*
+         * Check if this is a RTS/CTS frame
+         */
+        if (is_rts_frame(frame_control) || is_cts_frame(frame_control)) {
+                __set_bit(ENTRY_TXD_BURST, &txdesc->flags);
+                if (is_rts_frame(frame_control)) {
+                        __set_bit(ENTRY_TXD_RTS_FRAME, &txdesc->flags);
+                        __set_bit(ENTRY_TXD_ACK, &txdesc->flags);
+                } else {
+                        __set_bit(ENTRY_TXD_CTS_FRAME, &txdesc->flags);
+                        __clear_bit(ENTRY_TXD_ACK, &txdesc->flags);
+                }
+                if (control->rts_cts_rate)
+                        rate = control->rts_cts_rate;
+        }
+
+        /*
+         * Determine retry information.
+         */
+        txdesc->retry_limit = control->retry_limit;
+        if (control->flags & IEEE80211_TXCTL_LONG_RETRY_LIMIT)
+                __set_bit(ENTRY_TXD_RETRY_MODE, &txdesc->flags);
+
+        /*
+         * Check if more fragments are pending
+         */
+        if (ieee80211_get_morefrag(hdr)) {
+                __set_bit(ENTRY_TXD_BURST, &txdesc->flags);
+                __set_bit(ENTRY_TXD_MORE_FRAG, &txdesc->flags);
+        }
+
+        /*
+         * Beacons and probe responses require the tsf timestamp
+         * to be inserted into the frame.
+         */
+        if (txdesc->queue == QID_BEACON || is_probe_resp(frame_control))
+                __set_bit(ENTRY_TXD_REQ_TIMESTAMP, &txdesc->flags);
+
+        /*
+         * Determine with what IFS priority this frame should be send.
+         * Set ifs to IFS_SIFS when the this is not the first fragment,
+         * or this fragment came after RTS/CTS.
+         */
+        if (test_bit(ENTRY_TXD_RTS_FRAME, &txdesc->flags)) {
+                txdesc->ifs = IFS_SIFS;
+        } else if (control->flags & IEEE80211_TXCTL_FIRST_FRAGMENT) {
+                __set_bit(ENTRY_TXD_FIRST_FRAGMENT, &txdesc->flags);
+                txdesc->ifs = IFS_BACKOFF;
+        } else {
+                txdesc->ifs = IFS_SIFS;
+        }
+
+        /*
+         * PLCP setup
+         * Length calculation depends on OFDM/CCK rate.
+         */
+        hwrate = rt2x00_get_rate(rate->hw_value);
+        txdesc->signal = hwrate->plcp;
+        txdesc->service = 0x04;
+
+        if (hwrate->flags & DEV_RATE_OFDM) {
+                __set_bit(ENTRY_TXD_OFDM_RATE, &txdesc->flags);
+
+                txdesc->length_high = (data_length >> 6) & 0x3f;
+                txdesc->length_low = data_length & 0x3f;
+        } else {
+                /*
+                 * Convert length to microseconds.
+                 */
+                residual = get_duration_res(data_length, hwrate->bitrate);
+                duration = get_duration(data_length, hwrate->bitrate);
+
+                if (residual != 0) {
+                        duration++;
+
+                        /*
+                         * Check if we need to set the Length Extension
+                         */
+                        if (hwrate->bitrate == 110 && residual <= 30)
+                                txdesc->service |= 0x80;
+                }
+
+                txdesc->length_high = (duration >> 8) & 0xff;
+                txdesc->length_low = duration & 0xff;
+
+                /*
+                 * When preamble is enabled we should set the
+                 * preamble bit for the signal.
+                 */
+                if (rt2x00_get_rate_preamble(rate->hw_value))
+                        txdesc->signal |= 0x08;
+        }
+}
+EXPORT_SYMBOL_GPL(rt2x00queue_create_tx_descriptor);
+
+void rt2x00queue_write_tx_descriptor(struct queue_entry *entry,
+                                     struct txentry_desc *txdesc)
+{
+        struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
+        struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
+
+        rt2x00dev->ops->lib->write_tx_desc(rt2x00dev, entry->skb, txdesc);
+
+        /*
+         * All processing on the frame has been completed, this means
+         * it is now ready to be dumped to userspace through debugfs.
+         */
+        rt2x00debug_dump_frame(rt2x00dev, DUMP_FRAME_TX, entry->skb);
+
+        /*
+         * We are done writing the frame to the queue entry,
+         * if this entry is a RTS of CTS-to-self frame we are done,
+         * otherwise we need to kick the queue.
+         */
+        if (rt2x00dev->ops->lib->kick_tx_queue &&
+            !(skbdesc->flags & FRAME_DESC_DRIVER_GENERATED))
+                rt2x00dev->ops->lib->kick_tx_queue(rt2x00dev,
+                                                   entry->queue->qid);
+}
+EXPORT_SYMBOL_GPL(rt2x00queue_write_tx_descriptor);
+
 struct data_queue *rt2x00queue_get_queue(struct rt2x00_dev *rt2x00dev,
                                          const enum data_queue_qid queue)
 {