aboutsummaryrefslogtreecommitdiff
path: root/drivers/net/wireless/rt2x00/rt2x00queue.c
blob: 9915a09141ef294ea94bf70d1afea8ac2ae9c5cc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
/*
	Copyright (C) 2004 - 2009 Ivo van Doorn <IvDoorn@gmail.com>
	Copyright (C) 2004 - 2009 Gertjan van Wingerde <gwingerde@gmail.com>
	<http://rt2x00.serialmonkey.com>

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to the
	Free Software Foundation, Inc.,
	59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/*
	Module: rt2x00lib
	Abstract: rt2x00 queue specific routines.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/dma-mapping.h>

#include "rt2x00.h"
#include "rt2x00lib.h"

struct sk_buff *rt2x00queue_alloc_rxskb(struct rt2x00_dev *rt2x00dev,
					struct queue_entry *entry)
{
	struct sk_buff *skb;
	struct skb_frame_desc *skbdesc;
	unsigned int frame_size;
	unsigned int head_size = 0;
	unsigned int tail_size = 0;

	/*
	 * The frame size includes descriptor size, because the
	 * hardware directly receive the frame into the skbuffer.
	 */
	frame_size = entry->queue->data_size + entry->queue->desc_size;

	/*
	 * The payload should be aligned to a 4-byte boundary,
	 * this means we need at least 3 bytes for moving the frame
	 * into the correct offset.
	 */
	head_size = 4;

	/*
	 * For IV/EIV/ICV assembly we must make sure there is
	 * at least 8 bytes bytes available in headroom for IV/EIV
	 * and 8 bytes for ICV data as tailroon.
	 */
	if (test_bit(CONFIG_SUPPORT_HW_CRYPTO, &rt2x00dev->flags)) {
		head_size += 8;
		tail_size += 8;
	}

	/*
	 * Allocate skbuffer.
	 */
	skb = dev_alloc_skb(frame_size + head_size + tail_size);
	if (!skb)
		return NULL;

	/*
	 * Make sure we not have a frame with the requested bytes
	 * available in the head and tail.
	 */
	skb_reserve(skb, head_size);
	skb_put(skb, frame_size);

	/*
	 * Populate skbdesc.
	 */
	skbdesc = get_skb_frame_desc(skb);
	memset(skbdesc, 0, sizeof(*skbdesc));
	skbdesc->entry = entry;

	if (test_bit(DRIVER_REQUIRE_DMA, &rt2x00dev->flags)) {
		skbdesc->skb_dma = dma_map_single(rt2x00dev->dev,
						  skb->data,
						  skb->len,
						  DMA_FROM_DEVICE);
		skbdesc->flags |= SKBDESC_DMA_MAPPED_RX;
	}

	return skb;
}

void rt2x00queue_map_txskb(struct rt2x00_dev *rt2x00dev, struct sk_buff *skb)
{
	struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);

	/*
	 * If device has requested headroom, we should make sure that
	 * is also mapped to the DMA so it can be used for transfering
	 * additional descriptor information to the hardware.
	 */
	skb_push(skb, rt2x00dev->ops->extra_tx_headroom);

	skbdesc->skb_dma =
	    dma_map_single(rt2x00dev->dev, skb->data, skb->len, DMA_TO_DEVICE);

	/*
	 * Restore data pointer to original location again.
	 */
	skb_pull(skb, rt2x00dev->ops->extra_tx_headroom);

	skbdesc->flags |= SKBDESC_DMA_MAPPED_TX;
}
EXPORT_SYMBOL_GPL(rt2x00queue_map_txskb);

void rt2x00queue_unmap_skb(struct rt2x00_dev *rt2x00dev, struct sk_buff *skb)
{
	struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);

	if (skbdesc->flags & SKBDESC_DMA_MAPPED_RX) {
		dma_unmap_single(rt2x00dev->dev, skbdesc->skb_dma, skb->len,
				 DMA_FROM_DEVICE);
		skbdesc->flags &= ~SKBDESC_DMA_MAPPED_RX;
	}

	if (skbdesc->flags & SKBDESC_DMA_MAPPED_TX) {
		/*
		 * Add headroom to the skb length, it has been removed
		 * by the driver, but it was actually mapped to DMA.
		 */
		dma_unmap_single(rt2x00dev->dev, skbdesc->skb_dma,
				 skb->len + rt2x00dev->ops->extra_tx_headroom,
				 DMA_TO_DEVICE);
		skbdesc->flags &= ~SKBDESC_DMA_MAPPED_TX;
	}
}

void rt2x00queue_free_skb(struct rt2x00_dev *rt2x00dev, struct sk_buff *skb)
{
	if (!skb)
		return;

	rt2x00queue_unmap_skb(rt2x00dev, skb);
	dev_kfree_skb_any(skb);
}

void rt2x00queue_align_frame(struct sk_buff *skb)
{
	unsigned int frame_length = skb->len;
	unsigned int align = ALIGN_SIZE(skb, 0);

	if (!align)
		return;

	skb_push(skb, align);
	memmove(skb->data, skb->data + align, frame_length);
	skb_trim(skb, frame_length);
}

void rt2x00queue_align_payload(struct sk_buff *skb, unsigned int header_length)
{
	unsigned int frame_length = skb->len;
	unsigned int align = ALIGN_SIZE(skb, header_length);

	if (!align)
		return;

	skb_push(skb, align);
	memmove(skb->data, skb->data + align, frame_length);
	skb_trim(skb, frame_length);
}

void rt2x00queue_insert_l2pad(struct sk_buff *skb, unsigned int header_length)
{
	struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
	unsigned int frame_length = skb->len;
	unsigned int header_align = ALIGN_SIZE(skb, 0);
	unsigned int payload_align = ALIGN_SIZE(skb, header_length);
	unsigned int l2pad = 4 - (payload_align - header_align);

	if (header_align == payload_align) {
		/*
		 * Both header and payload must be moved the same
		 * amount of bytes to align them properly. This means
		 * we don't use the L2 padding but just move the entire
		 * frame.
		 */
		rt2x00queue_align_frame(skb);
	} else if (!payload_align) {
		/*
		 * Simple L2 padding, only the header needs to be moved,
		 * the payload is already properly aligned.
		 */
		skb_push(skb, header_align);
		memmove(skb->data, skb->data + header_align, frame_length);
		skbdesc->flags |= SKBDESC_L2_PADDED;
	} else {
		/*
		 *
		 * Complicated L2 padding, both header and payload need
		 * to be moved. By default we only move to the start
		 * of the buffer, so our header alignment needs to be
		 * increased if there is not enough room for the header
		 * to be moved.
		 */
		if (payload_align > header_align)
			header_align += 4;

		skb_push(skb, header_align);
		memmove(skb->data, skb->data + header_align, header_length);
		memmove(skb->data + header_length + l2pad,
			skb->data + header_length + l2pad + payload_align,
			frame_length - header_length);
		skbdesc->flags |= SKBDESC_L2_PADDED;
	}
}

void rt2x00queue_remove_l2pad(struct sk_buff *skb, unsigned int header_length)
{
	struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
	unsigned int l2pad = 4 - (header_length & 3);

	if (!l2pad || (skbdesc->flags & SKBDESC_L2_PADDED))
		return;

	memmove(skb->data + l2pad, skb->data, header_length);
	skb_pull(skb, l2pad);
}

static void rt2x00queue_create_tx_descriptor_seq(struct queue_entry *entry,
						 struct txentry_desc *txdesc)
{
	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(entry->skb);
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)entry->skb->data;
	struct rt2x00_intf *intf = vif_to_intf(tx_info->control.vif);
	unsigned long irqflags;

	if (!(tx_info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) ||
	    unlikely(!tx_info->control.vif))
		return;

	/*
	 * Hardware should insert sequence counter.
	 * FIXME: We insert a software sequence counter first for
	 * hardware that doesn't support hardware sequence counting.
	 *
	 * This is wrong because beacons are not getting sequence
	 * numbers assigned properly.
	 *
	 * A secondary problem exists for drivers that cannot toggle
	 * sequence counting per-frame, since those will override the
	 * sequence counter given by mac80211.
	 */
	spin_lock_irqsave(&intf->seqlock, irqflags);

	if (test_bit(ENTRY_TXD_FIRST_FRAGMENT, &txdesc->flags))
		intf->seqno += 0x10;
	hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG);
	hdr->seq_ctrl |= cpu_to_le16(intf->seqno);

	spin_unlock_irqrestore(&intf->seqlock, irqflags);

	__set_bit(ENTRY_TXD_GENERATE_SEQ, &txdesc->flags);
}

static void rt2x00queue_create_tx_descriptor_plcp(struct queue_entry *entry,
						  struct txentry_desc *txdesc,
						  const struct rt2x00_rate *hwrate)
{
	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(entry->skb);
	struct ieee80211_tx_rate *txrate = &tx_info->control.rates[0];
	unsigned int data_length;
	unsigned int duration;
	unsigned int residual;

	/* Data length + CRC + Crypto overhead (IV/EIV/ICV/MIC) */
	data_length = entry->skb->len + 4;
	data_length += rt2x00crypto_tx_overhead(rt2x00dev, entry->skb);

	/*
	 * PLCP setup
	 * Length calculation depends on OFDM/CCK rate.
	 */
	txdesc->signal = hwrate->plcp;
	txdesc->service = 0x04;

	if (hwrate->flags & DEV_RATE_OFDM) {
		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 (txrate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)
			txdesc->signal |= 0x08;
	}
}

static void rt2x00queue_create_tx_descriptor(struct queue_entry *entry,
					     struct txentry_desc *txdesc)
{
	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(entry->skb);
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)entry->skb->data;
	struct ieee80211_rate *rate =
	    ieee80211_get_tx_rate(rt2x00dev->hw, tx_info);
	const struct rt2x00_rate *hwrate;

	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;

	/*
	 * Header and alignment information.
	 */
	txdesc->header_length = ieee80211_get_hdrlen_from_skb(entry->skb);
	txdesc->l2pad = ALIGN_SIZE(entry->skb, txdesc->header_length);

	/*
	 * Check whether this frame is to be acked.
	 */
	if (!(tx_info->flags & IEEE80211_TX_CTL_NO_ACK))
		__set_bit(ENTRY_TXD_ACK, &txdesc->flags);

	/*
	 * Check if this is a RTS/CTS frame
	 */
	if (ieee80211_is_rts(hdr->frame_control) ||
	    ieee80211_is_cts(hdr->frame_control)) {
		__set_bit(ENTRY_TXD_BURST, &txdesc->flags);
		if (ieee80211_is_rts(hdr->frame_control))
			__set_bit(ENTRY_TXD_RTS_FRAME, &txdesc->flags);
		else
			__set_bit(ENTRY_TXD_CTS_FRAME, &txdesc->flags);
		if (tx_info->control.rts_cts_rate_idx >= 0)
			rate =
			    ieee80211_get_rts_cts_rate(rt2x00dev->hw, tx_info);
	}

	/*
	 * Determine retry information.
	 */
	txdesc->retry_limit = tx_info->control.rates[0].count - 1;
	if (txdesc->retry_limit >= rt2x00dev->long_retry)
		__set_bit(ENTRY_TXD_RETRY_MODE, &txdesc->flags);

	/*
	 * Check if more fragments are pending
	 */
	if (ieee80211_has_morefrags(hdr->frame_control) ||
	    (tx_info->flags & IEEE80211_TX_CTL_MORE_FRAMES)) {
		__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 (ieee80211_is_beacon(hdr->frame_control) ||
	    ieee80211_is_probe_resp(hdr->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 ((tx_info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT) &&
	    !test_bit(ENTRY_TXD_RTS_FRAME, &txdesc->flags)) {
		__set_bit(ENTRY_TXD_FIRST_FRAGMENT, &txdesc->flags);
		txdesc->ifs = IFS_BACKOFF;
	} else
		txdesc->ifs = IFS_SIFS;

	/*
	 * Determine rate modulation.
	 */
	hwrate = rt2x00_get_rate(rate->hw_value);
	txdesc->rate_mode = RATE_MODE_CCK;
	if (hwrate->flags & DEV_RATE_OFDM)
		txdesc->rate_mode = RATE_MODE_OFDM;

	/*
	 * Apply TX descriptor handling by components
	 */
	rt2x00crypto_create_tx_descriptor(entry, txdesc);
	rt2x00ht_create_tx_descriptor(entry, txdesc, hwrate);
	rt2x00queue_create_tx_descriptor_seq(entry, txdesc);
	rt2x00queue_create_tx_descriptor_plcp(entry, txdesc, hwrate);
}

static void rt2x00queue_write_tx_descriptor(struct queue_entry *entry,
					    struct txentry_desc *txdesc)
{
	struct data_queue *queue = entry->queue;
	struct rt2x00_dev *rt2x00dev = queue->rt2x00dev;

	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);

	/*
	 * Check if we need to kick the queue, there are however a few rules
	 *	1) Don't kick beacon queue
	 *	2) Don't kick unless this is the last in frame in a burst.
	 *	   When the burst flag is set, this frame is always followed
	 *	   by another frame which in some way are related to eachother.
	 *	   This is true for fragments, RTS or CTS-to-self frames.
	 *	3) Rule 2 can be broken when the available entries
	 *	   in the queue are less then a certain threshold.
	 */
	if (entry->queue->qid == QID_BEACON)
		return;

	if (rt2x00queue_threshold(queue) ||
	    !test_bit(ENTRY_TXD_BURST, &txdesc->flags))
		rt2x00dev->ops->lib->kick_tx_queue(rt2x00dev, queue->qid);
}

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 txentry_desc txdesc;
	struct skb_frame_desc *skbdesc;
	u8 rate_idx, rate_flags;

	if (unlikely(rt2x00queue_full(queue)))
		return -ENOBUFS;

	if (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;
	}

	/*
	 * Copy all TX descriptor information into txdesc,
	 * after that we are free to use the skb->cb array
	 * for our information.
	 */
	entry->skb = skb;
	rt2x00queue_create_tx_descriptor(entry, &txdesc);

	/*
	 * All information is retrieved from the skb->cb array,
	 * now we should claim ownership of the driver part of that
	 * array, preserving the bitrate index and flags.
	 */
	tx_info = IEEE80211_SKB_CB(skb);
	rate_idx = tx_info->control.rates[0].idx;
	rate_flags = tx_info->control.rates[0].flags;
	skbdesc = get_skb_frame_desc(skb);
	memset(skbdesc, 0, sizeof(*skbdesc));
	skbdesc->entry = entry;
	skbdesc->tx_rate_idx = rate_idx;
	skbdesc->tx_rate_flags = rate_flags;

	if (local)
		skbdesc->flags |= SKBDESC_NOT_MAC80211;

	/*
	 * When hardware encryption is supported, and this frame
	 * is to be encrypted, we should strip the IV/EIV data from
	 * the frame so we can provide it to the driver seperately.
	 */
	if (test_bit(ENTRY_TXD_ENCRYPT, &txdesc.flags) &&
	    !test_bit(ENTRY_TXD_ENCRYPT_IV, &txdesc.flags)) {
		if (test_bit(DRIVER_REQUIRE_COPY_IV, &queue->rt2x00dev->flags))
			rt2x00crypto_tx_copy_iv(skb, &txdesc);
		else
			rt2x00crypto_tx_remove_iv(skb, &txdesc);
	}

	/*
	 * When DMA allocation is required we should guarentee to the
	 * driver that the DMA is aligned to a 4-byte boundary.
	 * However some drivers require L2 padding to pad the payload
	 * rather then the header. This could be a requirement for
	 * PCI and USB devices, while header alignment only is valid
	 * for PCI devices.
	 */
	if (test_bit(DRIVER_REQUIRE_L2PAD, &queue->rt2x00dev->flags))
		rt2x00queue_insert_l2pad(entry->skb, txdesc.header_length);
	else if (test_bit(DRIVER_REQUIRE_DMA, &queue->rt2x00dev->flags))
		rt2x00queue_align_frame(entry->skb);

	/*
	 * It could be possible that the queue was corrupted and this
	 * call failed. Since we always return NETDEV_TX_OK to mac80211,
	 * this frame will simply be dropped.
	 */
	if (unlikely(queue->rt2x00dev->ops->lib->write_tx_data(entry))) {
		clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
		entry->skb = NULL;
		return -EIO;
	}

	if (test_bit(DRIVER_REQUIRE_DMA, &queue->rt2x00dev->flags))
		rt2x00queue_map_txskb(queue->rt2x00dev, skb);

	set_bit(ENTRY_DATA_PENDING, &entry->flags);

	rt2x00queue_index_inc(queue, Q_INDEX);
	rt2x00queue_write_tx_descriptor(entry, &txdesc);

	return 0;
}

int rt2x00queue_update_beacon(struct rt2x00_dev *rt2x00dev,
			      struct ieee80211_vif *vif,
			      const bool enable_beacon)
{
	struct rt2x00_intf *intf = vif_to_intf(vif);
	struct skb_frame_desc *skbdesc;
	struct txentry_desc txdesc;
	__le32 desc[16];

	if (unlikely(!intf->beacon))
		return -ENOBUFS;

	mutex_lock(&intf->beacon_skb_mutex);

	/*
	 * Clean up the beacon skb.
	 */
	rt2x00queue_free_skb(rt2x00dev, intf->beacon->skb);
	intf->beacon->skb = NULL;

	if (!enable_beacon) {
		rt2x00dev->ops->lib->kill_tx_queue(rt2x00dev, QID_BEACON);
		mutex_unlock(&intf->beacon_skb_mutex);
		return 0;
	}

	intf->beacon->skb = ieee80211_beacon_get(rt2x00dev->hw, vif);
	if (!intf->beacon->skb) {
		mutex_unlock(&intf->beacon_skb_mutex);
		return -ENOMEM;
	}

	/*
	 * Copy all TX descriptor information into txdesc,
	 * after that we are free to use the skb->cb array
	 * for our information.
	 */
	rt2x00queue_create_tx_descriptor(intf->beacon, &txdesc);

	/*
	 * For the descriptor we use a local array from where the
	 * driver can move it to the correct location required for
	 * the hardware.
	 */
	memset(desc, 0, sizeof(desc));

	/*
	 * Fill in skb descriptor
	 */
	skbdesc = get_skb_frame_desc(intf->beacon->skb);
	memset(skbdesc, 0, sizeof(*skbdesc));
	skbdesc->desc = desc;
	skbdesc->desc_len = intf->beacon->queue->desc_size;
	skbdesc->entry = intf->beacon;

	/*
	 * Write TX descriptor into reserved room in front of the beacon.
	 */
	rt2x00queue_write_tx_descriptor(intf->beacon, &txdesc);

	/*
	 * Send beacon to hardware.
	 * Also enable beacon generation, which might have been disabled
	 * by the driver during the config_beacon() callback function.
	 */
	rt2x00dev->ops->lib->write_beacon(intf->beacon);
	rt2x00dev->ops->lib->kick_tx_queue(rt2x00dev, QID_BEACON);

	mutex_unlock(&intf->beacon_skb_mutex);

	return 0;
}

struct data_queue *rt2x00queue_get_queue(struct rt2x00_dev *rt2x00dev,
					 const enum data_queue_qid queue)
{
	int atim = test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags);

	if (queue == QID_RX)
		return rt2x00dev->rx;

	if (queue < rt2x00dev->ops->tx_queues && rt2x00dev->tx)
		return &rt2x00dev->tx[queue];

	if (!rt2x00dev->bcn)
		return NULL;

	if (queue == QID_BEACON)
		return &rt2x00dev->bcn[0];
	else if (queue == QID_ATIM && atim)
		return &rt2x00dev->bcn[1];

	return NULL;
}
EXPORT_SYMBOL_GPL(rt2x00queue_get_queue);

struct queue_entry *rt2x00queue_get_entry(struct data_queue *queue,
					  enum queue_index index)
{
	struct queue_entry *entry;
	unsigned long irqflags;

	if (unlikely(index >= Q_INDEX_MAX)) {
		ERROR(queue->rt2x00dev,
		      "Entry requested from invalid index type (%d)\n", index);
		return NULL;
	}

	spin_lock_irqsave(&queue->lock, irqflags);

	entry = &queue->entries[queue->index[index]];

	spin_unlock_irqrestore(&queue->lock, irqflags);

	return entry;
}
EXPORT_SYMBOL_GPL(rt2x00queue_get_entry);

void rt2x00queue_index_inc(struct data_queue *queue, enum queue_index index)
{
	unsigned long irqflags;

	if (unlikely(index >= Q_INDEX_MAX)) {
		ERROR(queue->rt2x00dev,
		      "Index change on invalid index type (%d)\n", index);
		return;
	}

	spin_lock_irqsave(&queue->lock, irqflags);

	queue->index[index]++;
	if (queue->index[index] >= queue->limit)
		queue->index[index] = 0;

	if (index == Q_INDEX) {
		queue->length++;
	} else if (index == Q_INDEX_DONE) {
		queue->length--;
		queue->count++;
	}

	spin_unlock_irqrestore(&queue->lock, irqflags);
}

static void rt2x00queue_reset(struct data_queue *queue)
{
	unsigned long irqflags;

	spin_lock_irqsave(&queue->lock, irqflags);

	queue->count = 0;
	queue->length = 0;
	memset(queue->index, 0, sizeof(queue->index));

	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(rt2x00dev, queue->qid);
}

void rt2x00queue_init_queues(struct rt2x00_dev *rt2x00dev)
{
	struct data_queue *queue;
	unsigned int i;

	queue_for_each(rt2x00dev, queue) {
		rt2x00queue_reset(queue);

		for (i = 0; i < queue->limit; i++) {
			queue->entries[i].flags = 0;

			rt2x00dev->ops->lib->clear_entry(&queue->entries[i]);
		}
	}
}

static int rt2x00queue_alloc_entries(struct data_queue *queue,
				     const struct data_queue_desc *qdesc)
{
	struct queue_entry *entries;
	unsigned int entry_size;
	unsigned int i;

	rt2x00queue_reset(queue);

	queue->limit = qdesc->entry_num;
	queue->threshold = DIV_ROUND_UP(qdesc->entry_num, 10);
	queue->data_size = qdesc->data_size;
	queue->desc_size = qdesc->desc_size;

	/*
	 * Allocate all queue entries.
	 */
	entry_size = sizeof(*entries) + qdesc->priv_size;
	entries = kzalloc(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)) )

	for (i = 0; i < queue->limit; i++) {
		entries[i].flags = 0;
		entries[i].queue = queue;
		entries[i].skb = NULL;
		entries[i].entry_idx = i;
		entries[i].priv_data =
		    QUEUE_ENTRY_PRIV_OFFSET(entries, i, queue->limit,
					    sizeof(*entries), qdesc->priv_size);
	}

#undef QUEUE_ENTRY_PRIV_OFFSET

	queue->entries = entries;

	return 0;
}

static void rt2x00queue_free_skbs(struct rt2x00_dev *rt2x00dev,
				  struct data_queue *queue)
{
	unsigned int i;

	if (!queue->entries)
		return;

	for (i = 0; i < queue->limit; i++) {
		if (queue->entries[i].skb)
			rt2x00queue_free_skb(rt2x00dev, queue->entries[i].skb);
	}
}

static int rt2x00queue_alloc_rxskbs(struct rt2x00_dev *rt2x00dev,
				    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]);
		if (!skb)
			return -ENOMEM;
		queue->entries[i].skb = skb;
	}

	return 0;
}

int rt2x00queue_initialize(struct rt2x00_dev *rt2x00dev)
{
	struct data_queue *queue;
	int status;

	status = rt2x00queue_alloc_entries(rt2x00dev->rx, rt2x00dev->ops->rx);
	if (status)
		goto exit;

	tx_queue_for_each(rt2x00dev, queue) {
		status = rt2x00queue_alloc_entries(queue, rt2x00dev->ops->tx);
		if (status)
			goto exit;
	}

	status = rt2x00queue_alloc_entries(rt2x00dev->bcn, rt2x00dev->ops->bcn);
	if (status)
		goto exit;

	if (test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags)) {
		status = rt2x00queue_alloc_entries(&rt2x00dev->bcn[1],
						   rt2x00dev->ops->atim);
		if (status)
			goto exit;
	}

	status = rt2x00queue_alloc_rxskbs(rt2x00dev, rt2x00dev->rx);
	if (status)
		goto exit;

	return 0;

exit:
	ERROR(rt2x00dev, "Queue entries allocation failed.\n");

	rt2x00queue_uninitialize(rt2x00dev);

	return status;
}

void rt2x00queue_uninitialize(struct rt2x00_dev *rt2x00dev)
{
	struct data_queue *queue;

	rt2x00queue_free_skbs(rt2x00dev, rt2x00dev->rx);

	queue_for_each(rt2x00dev, queue) {
		kfree(queue->entries);
		queue->entries = NULL;
	}
}

static void rt2x00queue_init(struct rt2x00_dev *rt2x00dev,
			     struct data_queue *queue, enum data_queue_qid qid)
{
	spin_lock_init(&queue->lock);

	queue->rt2x00dev = rt2x00dev;
	queue->qid = qid;
	queue->txop = 0;
	queue->aifs = 2;
	queue->cw_min = 5;
	queue->cw_max = 10;
}

int rt2x00queue_allocate(struct rt2x00_dev *rt2x00dev)
{
	struct data_queue *queue;
	enum data_queue_qid qid;
	unsigned int req_atim =
	    !!test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags);

	/*
	 * We need the following queues:
	 * RX: 1
	 * TX: ops->tx_queues
	 * Beacon: 1
	 * Atim: 1 (if required)
	 */
	rt2x00dev->data_queues = 2 + rt2x00dev->ops->tx_queues + req_atim;

	queue = kzalloc(rt2x00dev->data_queues * sizeof(*queue), GFP_KERNEL);
	if (!queue) {
		ERROR(rt2x00dev, "Queue allocation failed.\n");
		return -ENOMEM;
	}

	/*
	 * Initialize pointers
	 */
	rt2x00dev->rx = queue;
	rt2x00dev->tx = &queue[1];
	rt2x00dev->bcn = &queue[1 + rt2x00dev->ops->tx_queues];

	/*
	 * Initialize queue parameters.
	 * RX: qid = QID_RX
	 * TX: qid = QID_AC_BE + index
	 * TX: cw_min: 2^5 = 32.
	 * TX: cw_max: 2^10 = 1024.
	 * BCN: qid = QID_BEACON
	 * ATIM: qid = QID_ATIM
	 */
	rt2x00queue_init(rt2x00dev, rt2x00dev->rx, QID_RX);

	qid = QID_AC_BE;
	tx_queue_for_each(rt2x00dev, queue)
		rt2x00queue_init(rt2x00dev, queue, qid++);

	rt2x00queue_init(rt2x00dev, &rt2x00dev->bcn[0], QID_BEACON);
	if (req_atim)
		rt2x00queue_init(rt2x00dev, &rt2x00dev->bcn[1], QID_ATIM);

	return 0;
}

void rt2x00queue_free(struct rt2x00_dev *rt2x00dev)
{
	kfree(rt2x00dev->rx);
	rt2x00dev->rx = NULL;
	rt2x00dev->tx = NULL;
	rt2x00dev->bcn = NULL;
}