ecf57f8f34b28063fbe240d993a5f92657a9e3e1
[kernel.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 #include <linux/dma-mapping.h>
29
30 #include "rt2x00.h"
31 #include "rt2x00lib.h"
32
33 struct sk_buff *rt2x00queue_alloc_rxskb(struct rt2x00_dev *rt2x00dev,
34                                         struct queue_entry *entry)
35 {
36         unsigned int frame_size;
37         unsigned int reserved_size;
38         struct sk_buff *skb;
39         struct skb_frame_desc *skbdesc;
40
41         /*
42          * The frame size includes descriptor size, because the
43          * hardware directly receive the frame into the skbuffer.
44          */
45         frame_size = entry->queue->data_size + entry->queue->desc_size;
46
47         /*
48          * The payload should be aligned to a 4-byte boundary,
49          * this means we need at least 3 bytes for moving the frame
50          * into the correct offset.
51          */
52         reserved_size = 4;
53
54         /*
55          * Allocate skbuffer.
56          */
57         skb = dev_alloc_skb(frame_size + reserved_size);
58         if (!skb)
59                 return NULL;
60
61         skb_reserve(skb, reserved_size);
62         skb_put(skb, frame_size);
63
64         /*
65          * Populate skbdesc.
66          */
67         skbdesc = get_skb_frame_desc(skb);
68         memset(skbdesc, 0, sizeof(*skbdesc));
69         skbdesc->entry = entry;
70
71         if (test_bit(DRIVER_REQUIRE_DMA, &rt2x00dev->flags)) {
72                 skbdesc->skb_dma = dma_map_single(rt2x00dev->dev,
73                                                   skb->data,
74                                                   skb->len,
75                                                   DMA_FROM_DEVICE);
76                 skbdesc->flags |= SKBDESC_DMA_MAPPED_RX;
77         }
78
79         return skb;
80 }
81
82 void rt2x00queue_map_txskb(struct rt2x00_dev *rt2x00dev, struct sk_buff *skb)
83 {
84         struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
85
86         skbdesc->skb_dma = dma_map_single(rt2x00dev->dev, skb->data, skb->len,
87                                           DMA_TO_DEVICE);
88         skbdesc->flags |= SKBDESC_DMA_MAPPED_TX;
89 }
90 EXPORT_SYMBOL_GPL(rt2x00queue_map_txskb);
91
92 void rt2x00queue_unmap_skb(struct rt2x00_dev *rt2x00dev, struct sk_buff *skb)
93 {
94         struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
95
96         if (skbdesc->flags & SKBDESC_DMA_MAPPED_RX) {
97                 dma_unmap_single(rt2x00dev->dev, skbdesc->skb_dma, skb->len,
98                                  DMA_FROM_DEVICE);
99                 skbdesc->flags &= ~SKBDESC_DMA_MAPPED_RX;
100         }
101
102         if (skbdesc->flags & SKBDESC_DMA_MAPPED_TX) {
103                 dma_unmap_single(rt2x00dev->dev, skbdesc->skb_dma, skb->len,
104                                  DMA_TO_DEVICE);
105                 skbdesc->flags &= ~SKBDESC_DMA_MAPPED_TX;
106         }
107 }
108
109 void rt2x00queue_free_skb(struct rt2x00_dev *rt2x00dev, struct sk_buff *skb)
110 {
111         if (!skb)
112                 return;
113
114         rt2x00queue_unmap_skb(rt2x00dev, skb);
115         dev_kfree_skb_any(skb);
116 }
117
118 void rt2x00queue_create_tx_descriptor(struct queue_entry *entry,
119                                       struct txentry_desc *txdesc)
120 {
121         struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
122         struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(entry->skb);
123         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)entry->skb->data;
124         struct ieee80211_rate *rate =
125             ieee80211_get_tx_rate(rt2x00dev->hw, tx_info);
126         const struct rt2x00_rate *hwrate;
127         unsigned int data_length;
128         unsigned int duration;
129         unsigned int residual;
130
131         memset(txdesc, 0, sizeof(*txdesc));
132
133         /*
134          * Initialize information from queue
135          */
136         txdesc->queue = entry->queue->qid;
137         txdesc->cw_min = entry->queue->cw_min;
138         txdesc->cw_max = entry->queue->cw_max;
139         txdesc->aifs = entry->queue->aifs;
140
141         /* Data length should be extended with 4 bytes for CRC */
142         data_length = entry->skb->len + 4;
143
144         /*
145          * Check whether this frame is to be acked.
146          */
147         if (!(tx_info->flags & IEEE80211_TX_CTL_NO_ACK))
148                 __set_bit(ENTRY_TXD_ACK, &txdesc->flags);
149
150         /*
151          * Check if this is a RTS/CTS frame
152          */
153         if (ieee80211_is_rts(hdr->frame_control) ||
154             ieee80211_is_cts(hdr->frame_control)) {
155                 __set_bit(ENTRY_TXD_BURST, &txdesc->flags);
156                 if (ieee80211_is_rts(hdr->frame_control))
157                         __set_bit(ENTRY_TXD_RTS_FRAME, &txdesc->flags);
158                 else
159                         __set_bit(ENTRY_TXD_CTS_FRAME, &txdesc->flags);
160                 if (tx_info->control.rts_cts_rate_idx >= 0)
161                         rate =
162                             ieee80211_get_rts_cts_rate(rt2x00dev->hw, tx_info);
163         }
164
165         /*
166          * Determine retry information.
167          */
168         txdesc->retry_limit = tx_info->control.retry_limit;
169         if (tx_info->flags & IEEE80211_TX_CTL_LONG_RETRY_LIMIT)
170                 __set_bit(ENTRY_TXD_RETRY_MODE, &txdesc->flags);
171
172         /*
173          * Check if more fragments are pending
174          */
175         if (ieee80211_has_morefrags(hdr->frame_control)) {
176                 __set_bit(ENTRY_TXD_BURST, &txdesc->flags);
177                 __set_bit(ENTRY_TXD_MORE_FRAG, &txdesc->flags);
178         }
179
180         /*
181          * Beacons and probe responses require the tsf timestamp
182          * to be inserted into the frame.
183          */
184         if (ieee80211_is_beacon(hdr->frame_control) ||
185             ieee80211_is_probe_resp(hdr->frame_control))
186                 __set_bit(ENTRY_TXD_REQ_TIMESTAMP, &txdesc->flags);
187
188         /*
189          * Determine with what IFS priority this frame should be send.
190          * Set ifs to IFS_SIFS when the this is not the first fragment,
191          * or this fragment came after RTS/CTS.
192          */
193         if (test_bit(ENTRY_TXD_RTS_FRAME, &txdesc->flags)) {
194                 txdesc->ifs = IFS_SIFS;
195         } else if (tx_info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT) {
196                 __set_bit(ENTRY_TXD_FIRST_FRAGMENT, &txdesc->flags);
197                 txdesc->ifs = IFS_BACKOFF;
198         } else {
199                 txdesc->ifs = IFS_SIFS;
200         }
201
202         /*
203          * PLCP setup
204          * Length calculation depends on OFDM/CCK rate.
205          */
206         hwrate = rt2x00_get_rate(rate->hw_value);
207         txdesc->signal = hwrate->plcp;
208         txdesc->service = 0x04;
209
210         if (hwrate->flags & DEV_RATE_OFDM) {
211                 __set_bit(ENTRY_TXD_OFDM_RATE, &txdesc->flags);
212
213                 txdesc->length_high = (data_length >> 6) & 0x3f;
214                 txdesc->length_low = data_length & 0x3f;
215         } else {
216                 /*
217                  * Convert length to microseconds.
218                  */
219                 residual = get_duration_res(data_length, hwrate->bitrate);
220                 duration = get_duration(data_length, hwrate->bitrate);
221
222                 if (residual != 0) {
223                         duration++;
224
225                         /*
226                          * Check if we need to set the Length Extension
227                          */
228                         if (hwrate->bitrate == 110 && residual <= 30)
229                                 txdesc->service |= 0x80;
230                 }
231
232                 txdesc->length_high = (duration >> 8) & 0xff;
233                 txdesc->length_low = duration & 0xff;
234
235                 /*
236                  * When preamble is enabled we should set the
237                  * preamble bit for the signal.
238                  */
239                 if (rt2x00_get_rate_preamble(rate->hw_value))
240                         txdesc->signal |= 0x08;
241         }
242 }
243 EXPORT_SYMBOL_GPL(rt2x00queue_create_tx_descriptor);
244
245 void rt2x00queue_write_tx_descriptor(struct queue_entry *entry,
246                                      struct txentry_desc *txdesc)
247 {
248         struct data_queue *queue = entry->queue;
249         struct rt2x00_dev *rt2x00dev = queue->rt2x00dev;
250
251         rt2x00dev->ops->lib->write_tx_desc(rt2x00dev, entry->skb, txdesc);
252
253         /*
254          * All processing on the frame has been completed, this means
255          * it is now ready to be dumped to userspace through debugfs.
256          */
257         rt2x00debug_dump_frame(rt2x00dev, DUMP_FRAME_TX, entry->skb);
258
259         /*
260          * Check if we need to kick the queue, there are however a few rules
261          *      1) Don't kick beacon queue
262          *      2) Don't kick unless this is the last in frame in a burst.
263          *         When the burst flag is set, this frame is always followed
264          *         by another frame which in some way are related to eachother.
265          *         This is true for fragments, RTS or CTS-to-self frames.
266          *      3) Rule 2 can be broken when the available entries
267          *         in the queue are less then a certain threshold.
268          */
269         if (entry->queue->qid == QID_BEACON)
270                 return;
271
272         if (rt2x00queue_threshold(queue) ||
273             !test_bit(ENTRY_TXD_BURST, &txdesc->flags))
274                 rt2x00dev->ops->lib->kick_tx_queue(rt2x00dev, queue->qid);
275 }
276 EXPORT_SYMBOL_GPL(rt2x00queue_write_tx_descriptor);
277
278 int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb)
279 {
280         struct queue_entry *entry = rt2x00queue_get_entry(queue, Q_INDEX);
281         struct txentry_desc txdesc;
282         struct skb_frame_desc *skbdesc;
283
284         if (unlikely(rt2x00queue_full(queue)))
285                 return -EINVAL;
286
287         if (__test_and_set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags)) {
288                 ERROR(queue->rt2x00dev,
289                       "Arrived at non-free entry in the non-full queue %d.\n"
290                       "Please file bug report to %s.\n",
291                       queue->qid, DRV_PROJECT);
292                 return -EINVAL;
293         }
294
295         /*
296          * Copy all TX descriptor information into txdesc,
297          * after that we are free to use the skb->cb array
298          * for our information.
299          */
300         entry->skb = skb;
301         rt2x00queue_create_tx_descriptor(entry, &txdesc);
302
303         /*
304          * skb->cb array is now ours and we are free to use it.
305          */
306         skbdesc = get_skb_frame_desc(entry->skb);
307         memset(skbdesc, 0, sizeof(*skbdesc));
308         skbdesc->entry = entry;
309
310         if (unlikely(queue->rt2x00dev->ops->lib->write_tx_data(entry))) {
311                 __clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
312                 return -EIO;
313         }
314
315         if (test_bit(DRIVER_REQUIRE_DMA, &queue->rt2x00dev->flags))
316                 rt2x00queue_map_txskb(queue->rt2x00dev, skb);
317
318         __set_bit(ENTRY_DATA_PENDING, &entry->flags);
319
320         rt2x00queue_index_inc(queue, Q_INDEX);
321         rt2x00queue_write_tx_descriptor(entry, &txdesc);
322
323         return 0;
324 }
325
326 struct data_queue *rt2x00queue_get_queue(struct rt2x00_dev *rt2x00dev,
327                                          const enum data_queue_qid queue)
328 {
329         int atim = test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags);
330
331         if (queue < rt2x00dev->ops->tx_queues && rt2x00dev->tx)
332                 return &rt2x00dev->tx[queue];
333
334         if (!rt2x00dev->bcn)
335                 return NULL;
336
337         if (queue == QID_BEACON)
338                 return &rt2x00dev->bcn[0];
339         else if (queue == QID_ATIM && atim)
340                 return &rt2x00dev->bcn[1];
341
342         return NULL;
343 }
344 EXPORT_SYMBOL_GPL(rt2x00queue_get_queue);
345
346 struct queue_entry *rt2x00queue_get_entry(struct data_queue *queue,
347                                           enum queue_index index)
348 {
349         struct queue_entry *entry;
350         unsigned long irqflags;
351
352         if (unlikely(index >= Q_INDEX_MAX)) {
353                 ERROR(queue->rt2x00dev,
354                       "Entry requested from invalid index type (%d)\n", index);
355                 return NULL;
356         }
357
358         spin_lock_irqsave(&queue->lock, irqflags);
359
360         entry = &queue->entries[queue->index[index]];
361
362         spin_unlock_irqrestore(&queue->lock, irqflags);
363
364         return entry;
365 }
366 EXPORT_SYMBOL_GPL(rt2x00queue_get_entry);
367
368 void rt2x00queue_index_inc(struct data_queue *queue, enum queue_index index)
369 {
370         unsigned long irqflags;
371
372         if (unlikely(index >= Q_INDEX_MAX)) {
373                 ERROR(queue->rt2x00dev,
374                       "Index change on invalid index type (%d)\n", index);
375                 return;
376         }
377
378         spin_lock_irqsave(&queue->lock, irqflags);
379
380         queue->index[index]++;
381         if (queue->index[index] >= queue->limit)
382                 queue->index[index] = 0;
383
384         if (index == Q_INDEX) {
385                 queue->length++;
386         } else if (index == Q_INDEX_DONE) {
387                 queue->length--;
388                 queue->count ++;
389         }
390
391         spin_unlock_irqrestore(&queue->lock, irqflags);
392 }
393
394 static void rt2x00queue_reset(struct data_queue *queue)
395 {
396         unsigned long irqflags;
397
398         spin_lock_irqsave(&queue->lock, irqflags);
399
400         queue->count = 0;
401         queue->length = 0;
402         memset(queue->index, 0, sizeof(queue->index));
403
404         spin_unlock_irqrestore(&queue->lock, irqflags);
405 }
406
407 void rt2x00queue_init_rx(struct rt2x00_dev *rt2x00dev)
408 {
409         struct data_queue *queue = rt2x00dev->rx;
410         unsigned int i;
411
412         rt2x00queue_reset(queue);
413
414         if (!rt2x00dev->ops->lib->init_rxentry)
415                 return;
416
417         for (i = 0; i < queue->limit; i++)
418                 rt2x00dev->ops->lib->init_rxentry(rt2x00dev,
419                                                   &queue->entries[i]);
420 }
421
422 void rt2x00queue_init_tx(struct rt2x00_dev *rt2x00dev)
423 {
424         struct data_queue *queue;
425         unsigned int i;
426
427         txall_queue_for_each(rt2x00dev, queue) {
428                 rt2x00queue_reset(queue);
429
430                 if (!rt2x00dev->ops->lib->init_txentry)
431                         continue;
432
433                 for (i = 0; i < queue->limit; i++)
434                         rt2x00dev->ops->lib->init_txentry(rt2x00dev,
435                                                           &queue->entries[i]);
436         }
437 }
438
439 static int rt2x00queue_alloc_entries(struct data_queue *queue,
440                                      const struct data_queue_desc *qdesc)
441 {
442         struct queue_entry *entries;
443         unsigned int entry_size;
444         unsigned int i;
445
446         rt2x00queue_reset(queue);
447
448         queue->limit = qdesc->entry_num;
449         queue->threshold = DIV_ROUND_UP(qdesc->entry_num, 10);
450         queue->data_size = qdesc->data_size;
451         queue->desc_size = qdesc->desc_size;
452
453         /*
454          * Allocate all queue entries.
455          */
456         entry_size = sizeof(*entries) + qdesc->priv_size;
457         entries = kzalloc(queue->limit * entry_size, GFP_KERNEL);
458         if (!entries)
459                 return -ENOMEM;
460
461 #define QUEUE_ENTRY_PRIV_OFFSET(__base, __index, __limit, __esize, __psize) \
462         ( ((char *)(__base)) + ((__limit) * (__esize)) + \
463             ((__index) * (__psize)) )
464
465         for (i = 0; i < queue->limit; i++) {
466                 entries[i].flags = 0;
467                 entries[i].queue = queue;
468                 entries[i].skb = NULL;
469                 entries[i].entry_idx = i;
470                 entries[i].priv_data =
471                     QUEUE_ENTRY_PRIV_OFFSET(entries, i, queue->limit,
472                                             sizeof(*entries), qdesc->priv_size);
473         }
474
475 #undef QUEUE_ENTRY_PRIV_OFFSET
476
477         queue->entries = entries;
478
479         return 0;
480 }
481
482 static void rt2x00queue_free_skbs(struct rt2x00_dev *rt2x00dev,
483                                   struct data_queue *queue)
484 {
485         unsigned int i;
486
487         if (!queue->entries)
488                 return;
489
490         for (i = 0; i < queue->limit; i++) {
491                 if (queue->entries[i].skb)
492                         rt2x00queue_free_skb(rt2x00dev, queue->entries[i].skb);
493         }
494 }
495
496 static int rt2x00queue_alloc_rxskbs(struct rt2x00_dev *rt2x00dev,
497                                     struct data_queue *queue)
498 {
499         unsigned int i;
500         struct sk_buff *skb;
501
502         for (i = 0; i < queue->limit; i++) {
503                 skb = rt2x00queue_alloc_rxskb(rt2x00dev, &queue->entries[i]);
504                 if (!skb)
505                         return -ENOMEM;
506                 queue->entries[i].skb = skb;
507         }
508
509         return 0;
510 }
511
512 int rt2x00queue_initialize(struct rt2x00_dev *rt2x00dev)
513 {
514         struct data_queue *queue;
515         int status;
516
517         status = rt2x00queue_alloc_entries(rt2x00dev->rx, rt2x00dev->ops->rx);
518         if (status)
519                 goto exit;
520
521         tx_queue_for_each(rt2x00dev, queue) {
522                 status = rt2x00queue_alloc_entries(queue, rt2x00dev->ops->tx);
523                 if (status)
524                         goto exit;
525         }
526
527         status = rt2x00queue_alloc_entries(rt2x00dev->bcn, rt2x00dev->ops->bcn);
528         if (status)
529                 goto exit;
530
531         if (test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags)) {
532                 status = rt2x00queue_alloc_entries(&rt2x00dev->bcn[1],
533                                                    rt2x00dev->ops->atim);
534                 if (status)
535                         goto exit;
536         }
537
538         status = rt2x00queue_alloc_rxskbs(rt2x00dev, rt2x00dev->rx);
539         if (status)
540                 goto exit;
541
542         return 0;
543
544 exit:
545         ERROR(rt2x00dev, "Queue entries allocation failed.\n");
546
547         rt2x00queue_uninitialize(rt2x00dev);
548
549         return status;
550 }
551
552 void rt2x00queue_uninitialize(struct rt2x00_dev *rt2x00dev)
553 {
554         struct data_queue *queue;
555
556         rt2x00queue_free_skbs(rt2x00dev, rt2x00dev->rx);
557
558         queue_for_each(rt2x00dev, queue) {
559                 kfree(queue->entries);
560                 queue->entries = NULL;
561         }
562 }
563
564 static void rt2x00queue_init(struct rt2x00_dev *rt2x00dev,
565                              struct data_queue *queue, enum data_queue_qid qid)
566 {
567         spin_lock_init(&queue->lock);
568
569         queue->rt2x00dev = rt2x00dev;
570         queue->qid = qid;
571         queue->aifs = 2;
572         queue->cw_min = 5;
573         queue->cw_max = 10;
574 }
575
576 int rt2x00queue_allocate(struct rt2x00_dev *rt2x00dev)
577 {
578         struct data_queue *queue;
579         enum data_queue_qid qid;
580         unsigned int req_atim =
581             !!test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags);
582
583         /*
584          * We need the following queues:
585          * RX: 1
586          * TX: ops->tx_queues
587          * Beacon: 1
588          * Atim: 1 (if required)
589          */
590         rt2x00dev->data_queues = 2 + rt2x00dev->ops->tx_queues + req_atim;
591
592         queue = kzalloc(rt2x00dev->data_queues * sizeof(*queue), GFP_KERNEL);
593         if (!queue) {
594                 ERROR(rt2x00dev, "Queue allocation failed.\n");
595                 return -ENOMEM;
596         }
597
598         /*
599          * Initialize pointers
600          */
601         rt2x00dev->rx = queue;
602         rt2x00dev->tx = &queue[1];
603         rt2x00dev->bcn = &queue[1 + rt2x00dev->ops->tx_queues];
604
605         /*
606          * Initialize queue parameters.
607          * RX: qid = QID_RX
608          * TX: qid = QID_AC_BE + index
609          * TX: cw_min: 2^5 = 32.
610          * TX: cw_max: 2^10 = 1024.
611          * BCN: qid = QID_BEACON
612          * ATIM: qid = QID_ATIM
613          */
614         rt2x00queue_init(rt2x00dev, rt2x00dev->rx, QID_RX);
615
616         qid = QID_AC_BE;
617         tx_queue_for_each(rt2x00dev, queue)
618                 rt2x00queue_init(rt2x00dev, queue, qid++);
619
620         rt2x00queue_init(rt2x00dev, &rt2x00dev->bcn[0], QID_BEACON);
621         if (req_atim)
622                 rt2x00queue_init(rt2x00dev, &rt2x00dev->bcn[1], QID_ATIM);
623
624         return 0;
625 }
626
627 void rt2x00queue_free(struct rt2x00_dev *rt2x00dev)
628 {
629         kfree(rt2x00dev->rx);
630         rt2x00dev->rx = NULL;
631         rt2x00dev->tx = NULL;
632         rt2x00dev->bcn = NULL;
633 }