rt2x00: Split rt2x00lib_write_tx_desc()
[linux-2.6.git] / drivers / net / wireless / rt2x00 / rt2x00queue.c
1 /*
2         Copyright (C) 2004 - 2008 rt2x00 SourceForge Project
3         <http://rt2x00.serialmonkey.com>
4
5         This program is free software; you can redistribute it and/or modify
6         it under the terms of the GNU General Public License as published by
7         the Free Software Foundation; either version 2 of the License, or
8         (at your option) any later version.
9
10         This program is distributed in the hope that it will be useful,
11         but WITHOUT ANY WARRANTY; without even the implied warranty of
12         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13         GNU General Public License for more details.
14
15         You should have received a copy of the GNU General Public License
16         along with this program; if not, write to the
17         Free Software Foundation, Inc.,
18         59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19  */
20
21 /*
22         Module: rt2x00lib
23         Abstract: rt2x00 queue specific routines.
24  */
25
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28
29 #include "rt2x00.h"
30 #include "rt2x00lib.h"
31
32 void rt2x00queue_create_tx_descriptor(struct queue_entry *entry,
33                                       struct txentry_desc *txdesc,
34                                       struct ieee80211_tx_control *control)
35 {
36         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)entry->skb->data;
37         struct ieee80211_rate *rate = control->tx_rate;
38         const struct rt2x00_rate *hwrate;
39         unsigned int data_length;
40         unsigned int duration;
41         unsigned int residual;
42         u16 frame_control;
43
44         memset(txdesc, 0, sizeof(*txdesc));
45
46         /*
47          * Initialize information from queue
48          */
49         txdesc->queue = entry->queue->qid;
50         txdesc->cw_min = entry->queue->cw_min;
51         txdesc->cw_max = entry->queue->cw_max;
52         txdesc->aifs = entry->queue->aifs;
53
54         /* Data length should be extended with 4 bytes for CRC */
55         data_length = entry->skb->len + 4;
56
57         /*
58          * Read required fields from ieee80211 header.
59          */
60         frame_control = le16_to_cpu(hdr->frame_control);
61
62         /*
63          * Check whether this frame is to be acked.
64          */
65         if (!(control->flags & IEEE80211_TXCTL_NO_ACK))
66                 __set_bit(ENTRY_TXD_ACK, &txdesc->flags);
67
68         /*
69          * Check if this is a RTS/CTS frame
70          */
71         if (is_rts_frame(frame_control) || is_cts_frame(frame_control)) {
72                 __set_bit(ENTRY_TXD_BURST, &txdesc->flags);
73                 if (is_rts_frame(frame_control)) {
74                         __set_bit(ENTRY_TXD_RTS_FRAME, &txdesc->flags);
75                         __set_bit(ENTRY_TXD_ACK, &txdesc->flags);
76                 } else {
77                         __set_bit(ENTRY_TXD_CTS_FRAME, &txdesc->flags);
78                         __clear_bit(ENTRY_TXD_ACK, &txdesc->flags);
79                 }
80                 if (control->rts_cts_rate)
81                         rate = control->rts_cts_rate;
82         }
83
84         /*
85          * Determine retry information.
86          */
87         txdesc->retry_limit = control->retry_limit;
88         if (control->flags & IEEE80211_TXCTL_LONG_RETRY_LIMIT)
89                 __set_bit(ENTRY_TXD_RETRY_MODE, &txdesc->flags);
90
91         /*
92          * Check if more fragments are pending
93          */
94         if (ieee80211_get_morefrag(hdr)) {
95                 __set_bit(ENTRY_TXD_BURST, &txdesc->flags);
96                 __set_bit(ENTRY_TXD_MORE_FRAG, &txdesc->flags);
97         }
98
99         /*
100          * Beacons and probe responses require the tsf timestamp
101          * to be inserted into the frame.
102          */
103         if (txdesc->queue == QID_BEACON || is_probe_resp(frame_control))
104                 __set_bit(ENTRY_TXD_REQ_TIMESTAMP, &txdesc->flags);
105
106         /*
107          * Determine with what IFS priority this frame should be send.
108          * Set ifs to IFS_SIFS when the this is not the first fragment,
109          * or this fragment came after RTS/CTS.
110          */
111         if (test_bit(ENTRY_TXD_RTS_FRAME, &txdesc->flags)) {
112                 txdesc->ifs = IFS_SIFS;
113         } else if (control->flags & IEEE80211_TXCTL_FIRST_FRAGMENT) {
114                 __set_bit(ENTRY_TXD_FIRST_FRAGMENT, &txdesc->flags);
115                 txdesc->ifs = IFS_BACKOFF;
116         } else {
117                 txdesc->ifs = IFS_SIFS;
118         }
119
120         /*
121          * PLCP setup
122          * Length calculation depends on OFDM/CCK rate.
123          */
124         hwrate = rt2x00_get_rate(rate->hw_value);
125         txdesc->signal = hwrate->plcp;
126         txdesc->service = 0x04;
127
128         if (hwrate->flags & DEV_RATE_OFDM) {
129                 __set_bit(ENTRY_TXD_OFDM_RATE, &txdesc->flags);
130
131                 txdesc->length_high = (data_length >> 6) & 0x3f;
132                 txdesc->length_low = data_length & 0x3f;
133         } else {
134                 /*
135                  * Convert length to microseconds.
136                  */
137                 residual = get_duration_res(data_length, hwrate->bitrate);
138                 duration = get_duration(data_length, hwrate->bitrate);
139
140                 if (residual != 0) {
141                         duration++;
142
143                         /*
144                          * Check if we need to set the Length Extension
145                          */
146                         if (hwrate->bitrate == 110 && residual <= 30)
147                                 txdesc->service |= 0x80;
148                 }
149
150                 txdesc->length_high = (duration >> 8) & 0xff;
151                 txdesc->length_low = duration & 0xff;
152
153                 /*
154                  * When preamble is enabled we should set the
155                  * preamble bit for the signal.
156                  */
157                 if (rt2x00_get_rate_preamble(rate->hw_value))
158                         txdesc->signal |= 0x08;
159         }
160 }
161 EXPORT_SYMBOL_GPL(rt2x00queue_create_tx_descriptor);
162
163 void rt2x00queue_write_tx_descriptor(struct queue_entry *entry,
164                                      struct txentry_desc *txdesc)
165 {
166         struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
167         struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
168
169         rt2x00dev->ops->lib->write_tx_desc(rt2x00dev, entry->skb, txdesc);
170
171         /*
172          * All processing on the frame has been completed, this means
173          * it is now ready to be dumped to userspace through debugfs.
174          */
175         rt2x00debug_dump_frame(rt2x00dev, DUMP_FRAME_TX, entry->skb);
176
177         /*
178          * We are done writing the frame to the queue entry,
179          * if this entry is a RTS of CTS-to-self frame we are done,
180          * otherwise we need to kick the queue.
181          */
182         if (rt2x00dev->ops->lib->kick_tx_queue &&
183             !(skbdesc->flags & FRAME_DESC_DRIVER_GENERATED))
184                 rt2x00dev->ops->lib->kick_tx_queue(rt2x00dev,
185                                                    entry->queue->qid);
186 }
187 EXPORT_SYMBOL_GPL(rt2x00queue_write_tx_descriptor);
188
189 struct data_queue *rt2x00queue_get_queue(struct rt2x00_dev *rt2x00dev,
190                                          const enum data_queue_qid queue)
191 {
192         int atim = test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags);
193
194         if (queue < rt2x00dev->ops->tx_queues && rt2x00dev->tx)
195                 return &rt2x00dev->tx[queue];
196
197         if (!rt2x00dev->bcn)
198                 return NULL;
199
200         if (queue == QID_BEACON)
201                 return &rt2x00dev->bcn[0];
202         else if (queue == QID_ATIM && atim)
203                 return &rt2x00dev->bcn[1];
204
205         return NULL;
206 }
207 EXPORT_SYMBOL_GPL(rt2x00queue_get_queue);
208
209 struct queue_entry *rt2x00queue_get_entry(struct data_queue *queue,
210                                           enum queue_index index)
211 {
212         struct queue_entry *entry;
213         unsigned long irqflags;
214
215         if (unlikely(index >= Q_INDEX_MAX)) {
216                 ERROR(queue->rt2x00dev,
217                       "Entry requested from invalid index type (%d)\n", index);
218                 return NULL;
219         }
220
221         spin_lock_irqsave(&queue->lock, irqflags);
222
223         entry = &queue->entries[queue->index[index]];
224
225         spin_unlock_irqrestore(&queue->lock, irqflags);
226
227         return entry;
228 }
229 EXPORT_SYMBOL_GPL(rt2x00queue_get_entry);
230
231 void rt2x00queue_index_inc(struct data_queue *queue, enum queue_index index)
232 {
233         unsigned long irqflags;
234
235         if (unlikely(index >= Q_INDEX_MAX)) {
236                 ERROR(queue->rt2x00dev,
237                       "Index change on invalid index type (%d)\n", index);
238                 return;
239         }
240
241         spin_lock_irqsave(&queue->lock, irqflags);
242
243         queue->index[index]++;
244         if (queue->index[index] >= queue->limit)
245                 queue->index[index] = 0;
246
247         if (index == Q_INDEX) {
248                 queue->length++;
249         } else if (index == Q_INDEX_DONE) {
250                 queue->length--;
251                 queue->count ++;
252         }
253
254         spin_unlock_irqrestore(&queue->lock, irqflags);
255 }
256 EXPORT_SYMBOL_GPL(rt2x00queue_index_inc);
257
258 static void rt2x00queue_reset(struct data_queue *queue)
259 {
260         unsigned long irqflags;
261
262         spin_lock_irqsave(&queue->lock, irqflags);
263
264         queue->count = 0;
265         queue->length = 0;
266         memset(queue->index, 0, sizeof(queue->index));
267
268         spin_unlock_irqrestore(&queue->lock, irqflags);
269 }
270
271 void rt2x00queue_init_rx(struct rt2x00_dev *rt2x00dev)
272 {
273         struct data_queue *queue = rt2x00dev->rx;
274         unsigned int i;
275
276         rt2x00queue_reset(queue);
277
278         if (!rt2x00dev->ops->lib->init_rxentry)
279                 return;
280
281         for (i = 0; i < queue->limit; i++)
282                 rt2x00dev->ops->lib->init_rxentry(rt2x00dev,
283                                                   &queue->entries[i]);
284 }
285
286 void rt2x00queue_init_tx(struct rt2x00_dev *rt2x00dev)
287 {
288         struct data_queue *queue;
289         unsigned int i;
290
291         txall_queue_for_each(rt2x00dev, queue) {
292                 rt2x00queue_reset(queue);
293
294                 if (!rt2x00dev->ops->lib->init_txentry)
295                         continue;
296
297                 for (i = 0; i < queue->limit; i++)
298                         rt2x00dev->ops->lib->init_txentry(rt2x00dev,
299                                                           &queue->entries[i]);
300         }
301 }
302
303 static int rt2x00queue_alloc_entries(struct data_queue *queue,
304                                      const struct data_queue_desc *qdesc)
305 {
306         struct queue_entry *entries;
307         unsigned int entry_size;
308         unsigned int i;
309
310         rt2x00queue_reset(queue);
311
312         queue->limit = qdesc->entry_num;
313         queue->data_size = qdesc->data_size;
314         queue->desc_size = qdesc->desc_size;
315
316         /*
317          * Allocate all queue entries.
318          */
319         entry_size = sizeof(*entries) + qdesc->priv_size;
320         entries = kzalloc(queue->limit * entry_size, GFP_KERNEL);
321         if (!entries)
322                 return -ENOMEM;
323
324 #define QUEUE_ENTRY_PRIV_OFFSET(__base, __index, __limit, __esize, __psize) \
325         ( ((char *)(__base)) + ((__limit) * (__esize)) + \
326             ((__index) * (__psize)) )
327
328         for (i = 0; i < queue->limit; i++) {
329                 entries[i].flags = 0;
330                 entries[i].queue = queue;
331                 entries[i].skb = NULL;
332                 entries[i].entry_idx = i;
333                 entries[i].priv_data =
334                     QUEUE_ENTRY_PRIV_OFFSET(entries, i, queue->limit,
335                                             sizeof(*entries), qdesc->priv_size);
336         }
337
338 #undef QUEUE_ENTRY_PRIV_OFFSET
339
340         queue->entries = entries;
341
342         return 0;
343 }
344
345 int rt2x00queue_initialize(struct rt2x00_dev *rt2x00dev)
346 {
347         struct data_queue *queue;
348         int status;
349
350
351         status = rt2x00queue_alloc_entries(rt2x00dev->rx, rt2x00dev->ops->rx);
352         if (status)
353                 goto exit;
354
355         tx_queue_for_each(rt2x00dev, queue) {
356                 status = rt2x00queue_alloc_entries(queue, rt2x00dev->ops->tx);
357                 if (status)
358                         goto exit;
359         }
360
361         status = rt2x00queue_alloc_entries(rt2x00dev->bcn, rt2x00dev->ops->bcn);
362         if (status)
363                 goto exit;
364
365         if (!test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags))
366                 return 0;
367
368         status = rt2x00queue_alloc_entries(&rt2x00dev->bcn[1],
369                                            rt2x00dev->ops->atim);
370         if (status)
371                 goto exit;
372
373         return 0;
374
375 exit:
376         ERROR(rt2x00dev, "Queue entries allocation failed.\n");
377
378         rt2x00queue_uninitialize(rt2x00dev);
379
380         return status;
381 }
382
383 void rt2x00queue_uninitialize(struct rt2x00_dev *rt2x00dev)
384 {
385         struct data_queue *queue;
386
387         queue_for_each(rt2x00dev, queue) {
388                 kfree(queue->entries);
389                 queue->entries = NULL;
390         }
391 }
392
393 static void rt2x00queue_init(struct rt2x00_dev *rt2x00dev,
394                              struct data_queue *queue, enum data_queue_qid qid)
395 {
396         spin_lock_init(&queue->lock);
397
398         queue->rt2x00dev = rt2x00dev;
399         queue->qid = qid;
400         queue->aifs = 2;
401         queue->cw_min = 5;
402         queue->cw_max = 10;
403 }
404
405 int rt2x00queue_allocate(struct rt2x00_dev *rt2x00dev)
406 {
407         struct data_queue *queue;
408         enum data_queue_qid qid;
409         unsigned int req_atim =
410             !!test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags);
411
412         /*
413          * We need the following queues:
414          * RX: 1
415          * TX: ops->tx_queues
416          * Beacon: 1
417          * Atim: 1 (if required)
418          */
419         rt2x00dev->data_queues = 2 + rt2x00dev->ops->tx_queues + req_atim;
420
421         queue = kzalloc(rt2x00dev->data_queues * sizeof(*queue), GFP_KERNEL);
422         if (!queue) {
423                 ERROR(rt2x00dev, "Queue allocation failed.\n");
424                 return -ENOMEM;
425         }
426
427         /*
428          * Initialize pointers
429          */
430         rt2x00dev->rx = queue;
431         rt2x00dev->tx = &queue[1];
432         rt2x00dev->bcn = &queue[1 + rt2x00dev->ops->tx_queues];
433
434         /*
435          * Initialize queue parameters.
436          * RX: qid = QID_RX
437          * TX: qid = QID_AC_BE + index
438          * TX: cw_min: 2^5 = 32.
439          * TX: cw_max: 2^10 = 1024.
440          * BCN & Atim: qid = QID_MGMT
441          */
442         rt2x00queue_init(rt2x00dev, rt2x00dev->rx, QID_RX);
443
444         qid = QID_AC_BE;
445         tx_queue_for_each(rt2x00dev, queue)
446                 rt2x00queue_init(rt2x00dev, queue, qid++);
447
448         rt2x00queue_init(rt2x00dev, &rt2x00dev->bcn[0], QID_MGMT);
449         if (req_atim)
450                 rt2x00queue_init(rt2x00dev, &rt2x00dev->bcn[1], QID_MGMT);
451
452         return 0;
453 }
454
455 void rt2x00queue_free(struct rt2x00_dev *rt2x00dev)
456 {
457         kfree(rt2x00dev->rx);
458         rt2x00dev->rx = NULL;
459         rt2x00dev->tx = NULL;
460         rt2x00dev->bcn = NULL;
461 }