aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/net/wireless/iwlwifi/iwl-tx.c
blob: 9b50b1052b09fe6f750c1693b12dfafca4b3f2f6 (plain) (blame)
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
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
/******************************************************************************
 *
 * Copyright(c) 2003 - 2008 Intel Corporation. All rights reserved.
 *
 * Portions of this file are derived from the ipw3945 project, as well
 * as portions of the ieee80211 subsystem header files.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
 *
 * The full GNU General Public License is included in this distribution in the
 * file called LICENSE.
 *
 * Contact Information:
 * James P. Ketrenos <ipw2100-admin@linux.intel.com>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 *
 *****************************************************************************/

#include <linux/etherdevice.h>
#include <net/mac80211.h>
#include "iwl-eeprom.h"
#include "iwl-dev.h"
#include "iwl-core.h"
#include "iwl-sta.h"
#include "iwl-io.h"
#include "iwl-helpers.h"

static const u16 default_tid_to_tx_fifo[] = {
	IWL_TX_FIFO_AC1,
	IWL_TX_FIFO_AC0,
	IWL_TX_FIFO_AC0,
	IWL_TX_FIFO_AC1,
	IWL_TX_FIFO_AC2,
	IWL_TX_FIFO_AC2,
	IWL_TX_FIFO_AC3,
	IWL_TX_FIFO_AC3,
	IWL_TX_FIFO_NONE,
	IWL_TX_FIFO_NONE,
	IWL_TX_FIFO_NONE,
	IWL_TX_FIFO_NONE,
	IWL_TX_FIFO_NONE,
	IWL_TX_FIFO_NONE,
	IWL_TX_FIFO_NONE,
	IWL_TX_FIFO_NONE,
	IWL_TX_FIFO_AC3
};


/**
 * iwl_hw_txq_free_tfd - Free all chunks referenced by TFD [txq->q.read_ptr]
 *
 * Does NOT advance any TFD circular buffer read/write indexes
 * Does NOT free the TFD itself (which is within circular buffer)
 */
int iwl_hw_txq_free_tfd(struct iwl_priv *priv, struct iwl_tx_queue *txq)
{
	struct iwl_tfd_frame *bd_tmp = (struct iwl_tfd_frame *)&txq->bd[0];
	struct iwl_tfd_frame *bd = &bd_tmp[txq->q.read_ptr];
	struct pci_dev *dev = priv->pci_dev;
	int i;
	int counter = 0;
	int index, is_odd;

	/* Host command buffers stay mapped in memory, nothing to clean */
	if (txq->q.id == IWL_CMD_QUEUE_NUM)
		return 0;

	/* Sanity check on number of chunks */
	counter = IWL_GET_BITS(*bd, num_tbs);
	if (counter > MAX_NUM_OF_TBS) {
		IWL_ERROR("Too many chunks: %i\n", counter);
		/* @todo issue fatal error, it is quite serious situation */
		return 0;
	}

	/* Unmap chunks, if any.
	 * TFD info for odd chunks is different format than for even chunks. */
	for (i = 0; i < counter; i++) {
		index = i / 2;
		is_odd = i & 0x1;

		if (is_odd)
			pci_unmap_single(
				dev,
				IWL_GET_BITS(bd->pa[index], tb2_addr_lo16) |
				(IWL_GET_BITS(bd->pa[index],
					      tb2_addr_hi20) << 16),
				IWL_GET_BITS(bd->pa[index], tb2_len),
				PCI_DMA_TODEVICE);

		else if (i > 0)
			pci_unmap_single(dev,
					 le32_to_cpu(bd->pa[index].tb1_addr),
					 IWL_GET_BITS(bd->pa[index], tb1_len),
					 PCI_DMA_TODEVICE);

		/* Free SKB, if any, for this chunk */
		if (txq->txb[txq->q.read_ptr].skb[i]) {
			struct sk_buff *skb = txq->txb[txq->q.read_ptr].skb[i];

			dev_kfree_skb(skb);
			txq->txb[txq->q.read_ptr].skb[i] = NULL;
		}
	}
	return 0;
}
EXPORT_SYMBOL(iwl_hw_txq_free_tfd);


int iwl_hw_txq_attach_buf_to_tfd(struct iwl_priv *priv, void *ptr,
				 dma_addr_t addr, u16 len)
{
	int index, is_odd;
	struct iwl_tfd_frame *tfd = ptr;
	u32 num_tbs = IWL_GET_BITS(*tfd, num_tbs);

	/* Each TFD can point to a maximum 20 Tx buffers */
	if ((num_tbs >= MAX_NUM_OF_TBS) || (num_tbs < 0)) {
		IWL_ERROR("Error can not send more than %d chunks\n",
			  MAX_NUM_OF_TBS);
		return -EINVAL;
	}

	index = num_tbs / 2;
	is_odd = num_tbs & 0x1;

	if (!is_odd) {
		tfd->pa[index].tb1_addr = cpu_to_le32(addr);
		IWL_SET_BITS(tfd->pa[index], tb1_addr_hi,
			     iwl_get_dma_hi_address(addr));
		IWL_SET_BITS(tfd->pa[index], tb1_len, len);
	} else {
		IWL_SET_BITS(tfd->pa[index], tb2_addr_lo16,
			     (u32) (addr & 0xffff));
		IWL_SET_BITS(tfd->pa[index], tb2_addr_hi20, addr >> 16);
		IWL_SET_BITS(tfd->pa[index], tb2_len, len);
	}

	IWL_SET_BITS(*tfd, num_tbs, num_tbs + 1);

	return 0;
}
EXPORT_SYMBOL(iwl_hw_txq_attach_buf_to_tfd);

/**
 * iwl_txq_update_write_ptr - Send new write index to hardware
 */
int iwl_txq_update_write_ptr(struct iwl_priv *priv, struct iwl_tx_queue *txq)
{
	u32 reg = 0;
	int ret = 0;
	int txq_id = txq->q.id;

	if (txq->need_update == 0)
		return ret;

	/* if we're trying to save power */
	if (test_bit(STATUS_POWER_PMI, &priv->status)) {
		/* wake up nic if it's powered down ...
		 * uCode will wake up, and interrupt us again, so next
		 * time we'll skip this part. */
		reg = iwl_read32(priv, CSR_UCODE_DRV_GP1);

		if (reg & CSR_UCODE_DRV_GP1_BIT_MAC_SLEEP) {
			IWL_DEBUG_INFO("Requesting wakeup, GP1 = 0x%x\n", reg);
			iwl_set_bit(priv, CSR_GP_CNTRL,
				    CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);
			return ret;
		}

		/* restore this queue's parameters in nic hardware. */
		ret = iwl_grab_nic_access(priv);
		if (ret)
			return ret;
		iwl_write_direct32(priv, HBUS_TARG_WRPTR,
				     txq->q.write_ptr | (txq_id << 8));
		iwl_release_nic_access(priv);

	/* else not in power-save mode, uCode will never sleep when we're
	 * trying to tx (during RFKILL, we're not trying to tx). */
	} else
		iwl_write32(priv, HBUS_TARG_WRPTR,
			    txq->q.write_ptr | (txq_id << 8));

	txq->need_update = 0;

	return ret;
}
EXPORT_SYMBOL(iwl_txq_update_write_ptr);


/**
 * iwl_tx_queue_free - Deallocate DMA queue.
 * @txq: Transmit queue to deallocate.
 *
 * Empty queue by removing and destroying all BD's.
 * Free all buffers.
 * 0-fill, but do not free "txq" descriptor structure.
 */
static void iwl_tx_queue_free(struct iwl_priv *priv, struct iwl_tx_queue *txq)
{
	struct iwl_queue *q = &txq->q;
	struct pci_dev *dev = priv->pci_dev;
	int len;

	if (q->n_bd == 0)
		return;

	/* first, empty all BD's */
	for (; q->write_ptr != q->read_ptr;
	     q->read_ptr = iwl_queue_inc_wrap(q->read_ptr, q->n_bd))
		iwl_hw_txq_free_tfd(priv, txq);

	len = sizeof(struct iwl_cmd) * q->n_window;
	if (q->id == IWL_CMD_QUEUE_NUM)
		len += IWL_MAX_SCAN_SIZE;

	/* De-alloc array of command/tx buffers */
	pci_free_consistent(dev, len, txq->cmd, txq->dma_addr_cmd);

	/* De-alloc circular buffer of TFDs */
	if (txq->q.n_bd)
		pci_free_consistent(dev, sizeof(struct iwl_tfd_frame) *
				    txq->q.n_bd, txq->bd, txq->q.dma_addr);

	/* De-alloc array of per-TFD driver data */
	kfree(txq->txb);
	txq->txb = NULL;

	/* 0-fill queue descriptor structure */
	memset(txq, 0, sizeof(*txq));
}

/*************** DMA-QUEUE-GENERAL-FUNCTIONS  *****
 * DMA services
 *
 * Theory of operation
 *
 * A Tx or Rx queue resides in host DRAM, and is comprised of a circular buffer
 * of buffer descriptors, each of which points to one or more data buffers for
 * the device to read from or fill.  Driver and device exchange status of each
 * queue via "read" and "write" pointers.  Driver keeps minimum of 2 empty
 * entries in each circular buffer, to protect against confusing empty and full
 * queue states.
 *
 * The device reads or writes the data in the queues via the device's several
 * DMA/FIFO channels.  Each queue is mapped to a single DMA channel.
 *
 * For Tx queue, there are low mark and high mark limits. If, after queuing
 * the packet for Tx, free space become < low mark, Tx queue stopped. When
 * reclaiming packets (on 'tx done IRQ), if free space become > high mark,
 * Tx queue resumed.
 *
 * See more detailed info in iwl-4965-hw.h.
 ***************************************************/

int iwl_queue_space(const struct iwl_queue *q)
{
	int s = q->read_ptr - q->write_ptr;

	if (q->read_ptr > q->write_ptr)
		s -= q->n_bd;

	if (s <= 0)
		s += q->n_window;
	/* keep some reserve to not confuse empty and full situations */
	s -= 2;
	if (s < 0)
		s = 0;
	return s;
}
EXPORT_SYMBOL(iwl_queue_space);


/**
 * iwl_queue_init - Initialize queue's high/low-water and read/write indexes
 */
static int iwl_queue_init(struct iwl_priv *priv, struct iwl_queue *q,
			  int count, int slots_num, u32 id)
{
	q->n_bd = count;
	q->n_window = slots_num;
	q->id = id;

	/* count must be power-of-two size, otherwise iwl_queue_inc_wrap
	 * and iwl_queue_dec_wrap are broken. */
	BUG_ON(!is_power_of_2(count));

	/* slots_num must be power-of-two size, otherwise
	 * get_cmd_index is broken. */
	BUG_ON(!is_power_of_2(slots_num));

	q->low_mark = q->n_window / 4;
	if (q->low_mark < 4)
		q->low_mark = 4;

	q->high_mark = q->n_window / 8;
	if (q->high_mark < 2)
		q->high_mark = 2;

	q->write_ptr = q->read_ptr = 0;

	return 0;
}

/**
 * iwl_tx_queue_alloc - Alloc driver data and TFD CB for one Tx/cmd queue
 */
static int iwl_tx_queue_alloc(struct iwl_priv *priv,
			      struct iwl_tx_queue *txq, u32 id)
{
	struct pci_dev *dev = priv->pci_dev;

	/* Driver private data, only for Tx (not command) queues,
	 * not shared with device. */
	if (id != IWL_CMD_QUEUE_NUM) {
		txq->txb = kmalloc(sizeof(txq->txb[0]) *
				   TFD_QUEUE_SIZE_MAX, GFP_KERNEL);
		if (!txq->txb) {
			IWL_ERROR("kmalloc for auxiliary BD "
				  "structures failed\n");
			goto error;
		}
	} else
		txq->txb = NULL;

	/* Circular buffer of transmit frame descriptors (TFDs),
	 * shared with device */
	txq->bd = pci_alloc_consistent(dev,
			sizeof(txq->bd[0]) * TFD_QUEUE_SIZE_MAX,
			&txq->q.dma_addr);

	if (!txq->bd) {
		IWL_ERROR("pci_alloc_consistent(%zd) failed\n",
			  sizeof(txq->bd[0]) * TFD_QUEUE_SIZE_MAX);
		goto error;
	}
	txq->q.id = id;

	return 0;

 error:
	kfree(txq->txb);
	txq->txb = NULL;

	return -ENOMEM;
}

/*
 * Tell nic where to find circular buffer of Tx Frame Descriptors for
 * given Tx queue, and enable the DMA channel used for that queue.
 *
 * 4965 supports up to 16 Tx queues in DRAM, mapped to up to 8 Tx DMA
 * channels supported in hardware.
 */
static int iwl_hw_tx_queue_init(struct iwl_priv *priv,
				struct iwl_tx_queue *txq)
{
	int rc;
	unsigned long flags;
	int txq_id = txq->q.id;

	spin_lock_irqsave(&priv->lock, flags);
	rc = iwl_grab_nic_access(priv);
	if (rc) {
		spin_unlock_irqrestore(&priv->lock, flags);
		return rc;
	}

	/* Circular buffer (TFD queue in DRAM) physical base address */
	iwl_write_direct32(priv, FH_MEM_CBBC_QUEUE(txq_id),
			     txq->q.dma_addr >> 8);

	/* Enable DMA channel, using same id as for TFD queue */
	iwl_write_direct32(
		priv, FH_TCSR_CHNL_TX_CONFIG_REG(txq_id),
		FH_TCSR_TX_CONFIG_REG_VAL_DMA_CHNL_ENABLE |
		FH_TCSR_TX_CONFIG_REG_VAL_DMA_CREDIT_ENABLE_VAL);
	iwl_release_nic_access(priv);
	spin_unlock_irqrestore(&priv->lock, flags);

	return 0;
}

/**
 * iwl_tx_queue_init - Allocate and initialize one tx/cmd queue
 */
static int iwl_tx_queue_init(struct iwl_priv *priv,
			     struct iwl_tx_queue *txq,
			     int slots_num, u32 txq_id)
{
	struct pci_dev *dev = priv->pci_dev;
	int len;
	int rc = 0;

	/*
	 * Alloc buffer array for commands (Tx or other types of commands).
	 * For the command queue (#4), allocate command space + one big
	 * command for scan, since scan command is very huge; the system will
	 * not have two scans at the same time, so only one is needed.
	 * For normal Tx queues (all other queues), no super-size command
	 * space is needed.
	 */
	len = sizeof(struct iwl_cmd) * slots_num;
	if (txq_id == IWL_CMD_QUEUE_NUM)
		len +=  IWL_MAX_SCAN_SIZE;
	txq->cmd = pci_alloc_consistent(dev, len, &txq->dma_addr_cmd);
	if (!txq->cmd)
		return -ENOMEM;

	/* Alloc driver data array and TFD circular buffer */
	rc = iwl_tx_queue_alloc(priv, txq, txq_id);
	if (rc) {
		pci_free_consistent(dev, len, txq->cmd, txq->dma_addr_cmd);

		return -ENOMEM;
	}
	txq->need_update = 0;

	/* TFD_QUEUE_SIZE_MAX must be power-of-two size, otherwise
	 * iwl_queue_inc_wrap and iwl_queue_dec_wrap are broken. */
	BUILD_BUG_ON(TFD_QUEUE_SIZE_MAX & (TFD_QUEUE_SIZE_MAX - 1));

	/* Initialize queue's high/low-water marks, and head/tail indexes */
	iwl_queue_init(priv, &txq->q, TFD_QUEUE_SIZE_MAX, slots_num, txq_id);

	/* Tell device where to find queue */
	iwl_hw_tx_queue_init(priv, txq);

	return 0;
}
/**
 * iwl_hw_txq_ctx_free - Free TXQ Context
 *
 * Destroy all TX DMA queues and structures
 */
void iwl_hw_txq_ctx_free(struct iwl_priv *priv)
{
	int txq_id;

	/* Tx queues */
	for (txq_id = 0; txq_id < priv->hw_params.max_txq_num; txq_id++)
		iwl_tx_queue_free(priv, &priv->txq[txq_id]);

	/* Keep-warm buffer */
	iwl_kw_free(priv);
}
EXPORT_SYMBOL(iwl_hw_txq_ctx_free);


/**
 * iwl_txq_ctx_reset - Reset TX queue context
 * Destroys all DMA structures and initialise them again
 *
 * @param priv
 * @return error code
 */
int iwl_txq_ctx_reset(struct iwl_priv *priv)
{
	int ret = 0;
	int txq_id, slots_num;
	unsigned long flags;

	iwl_kw_free(priv);

	/* Free all tx/cmd queues and keep-warm buffer */
	iwl_hw_txq_ctx_free(priv);

	/* Alloc keep-warm buffer */
	ret = iwl_kw_alloc(priv);
	if (ret) {
		IWL_ERROR("Keep Warm allocation failed");
		goto error_kw;
	}
	spin_lock_irqsave(&priv->lock, flags);
	ret = iwl_grab_nic_access(priv);
	if (unlikely(ret)) {
		spin_unlock_irqrestore(&priv->lock, flags);
		goto error_reset;
	}

	/* Turn off all Tx DMA fifos */
	priv->cfg->ops->lib->txq_set_sched(priv, 0);

	iwl_release_nic_access(priv);
	spin_unlock_irqrestore(&priv->lock, flags);


	/* Tell nic where to find the keep-warm buffer */
	ret = iwl_kw_init(priv);
	if (ret) {
		IWL_ERROR("kw_init failed\n");
		goto error_reset;
	}

	/* Alloc and init all Tx queues, including the command queue (#4) */
	for (txq_id = 0; txq_id < priv->hw_params.max_txq_num; txq_id++) {
		slots_num = (txq_id == IWL_CMD_QUEUE_NUM) ?
					TFD_CMD_SLOTS : TFD_TX_CMD_SLOTS;
		ret = iwl_tx_queue_init(priv, &priv->txq[txq_id], slots_num,
				       txq_id);
		if (ret) {
			IWL_ERROR("Tx %d queue init failed\n", txq_id);
			goto error;
		}
	}

	return ret;

 error:
	iwl_hw_txq_ctx_free(priv);
 error_reset:
	iwl_kw_free(priv);
 error_kw:
	return ret;
}
/**
 * iwl_txq_ctx_stop - Stop all Tx DMA channels, free Tx queue memory
 */
void iwl_txq_ctx_stop(struct iwl_priv *priv)
{

	int txq_id;
	unsigned long flags;


	/* Turn off all Tx DMA fifos */
	spin_lock_irqsave(&priv->lock, flags);
	if (iwl_grab_nic_access(priv)) {
		spin_unlock_irqrestore(&priv->lock, flags);
		return;
	}

	priv->cfg->ops->lib->txq_set_sched(priv, 0);

	/* Stop each Tx DMA channel, and wait for it to be idle */
	for (txq_id = 0; txq_id < priv->hw_params.max_txq_num; txq_id++) {
		iwl_write_direct32(priv,
				   FH_TCSR_CHNL_TX_CONFIG_REG(txq_id), 0x0);
		iwl_poll_direct_bit(priv, FH_TSSR_TX_STATUS_REG,
				    FH_TSSR_TX_STATUS_REG_MSK_CHNL_IDLE
				    (txq_id), 200);
	}
	iwl_release_nic_access(priv);
	spin_unlock_irqrestore(&priv->lock, flags);

	/* Deallocate memory for all Tx queues */
	iwl_hw_txq_ctx_free(priv);
}
EXPORT_SYMBOL(iwl_txq_ctx_stop);

/*
 * handle build REPLY_TX command notification.
 */
static void iwl_tx_cmd_build_basic(struct iwl_priv *priv,
				  struct iwl_tx_cmd *tx_cmd,
				  struct ieee80211_tx_info *info,
				  struct ieee80211_hdr *hdr,
				  int is_unicast, u8 std_id)
{
	__le16 fc = hdr->frame_control;
	__le32 tx_flags = tx_cmd->tx_flags;

	tx_cmd->stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
	if (!(info->flags & IEEE80211_TX_CTL_NO_ACK)) {
		tx_flags |= TX_CMD_FLG_ACK_MSK;
		if (ieee80211_is_mgmt(fc))
			tx_flags |= TX_CMD_FLG_SEQ_CTL_MSK;
		if (ieee80211_is_probe_resp(fc) &&
		    !(le16_to_cpu(hdr->seq_ctrl) & 0xf))
			tx_flags |= TX_CMD_FLG_TSF_MSK;
	} else {
		tx_flags &= (~TX_CMD_FLG_ACK_MSK);
		tx_flags |= TX_CMD_FLG_SEQ_CTL_MSK;
	}

	if (ieee80211_is_back_req(fc))
		tx_flags |= TX_CMD_FLG_ACK_MSK | TX_CMD_FLG_IMM_BA_RSP_MASK;


	tx_cmd->sta_id = std_id;
	if (ieee80211_has_morefrags(fc))
		tx_flags |= TX_CMD_FLG_MORE_FRAG_MSK;

	if (ieee80211_is_data_qos(fc)) {
		u8 *qc = ieee80211_get_qos_ctl(hdr);
		tx_cmd->tid_tspec = qc[0] & 0xf;
		tx_flags &= ~TX_CMD_FLG_SEQ_CTL_MSK;
	} else {
		tx_flags |= TX_CMD_FLG_SEQ_CTL_MSK;
	}

	priv->cfg->ops->utils->rts_tx_cmd_flag(info, &tx_flags);

	if ((tx_flags & TX_CMD_FLG_RTS_MSK) || (tx_flags & TX_CMD_FLG_CTS_MSK))
		tx_flags |= TX_CMD_FLG_FULL_TXOP_PROT_MSK;

	tx_flags &= ~(TX_CMD_FLG_ANT_SEL_MSK);
	if (ieee80211_is_mgmt(fc)) {
		if (ieee80211_is_assoc_req(fc) || ieee80211_is_reassoc_req(fc))
			tx_cmd->timeout.pm_frame_timeout = cpu_to_le16(3);
		else
			tx_cmd->timeout.pm_frame_timeout = cpu_to_le16(2);
	} else {
		tx_cmd->timeout.pm_frame_timeout = 0;
	}

	tx_cmd->driver_txop = 0;
	tx_cmd->tx_flags = tx_flags;
	tx_cmd->next_frame_len = 0;
}

#define RTS_HCCA_RETRY_LIMIT		3
#define RTS_DFAULT_RETRY_LIMIT		60

static void iwl_tx_cmd_build_rate(struct iwl_priv *priv,
			      struct iwl_tx_cmd *tx_cmd,
			      struct ieee80211_tx_info *info,
			      __le16 fc, int sta_id,
			      int is_hcca)
{
	u8 rts_retry_limit = 0;
	u8 data_retry_limit = 0;
	u8 rate_plcp;
	u16 rate_flags = 0;
	int rate_idx;

	rate_idx = min(ieee80211_get_tx_rate(priv->hw, info)->hw_value & 0xffff,
			IWL_RATE_COUNT - 1);

	rate_plcp = iwl_rates[rate_idx].plcp;

	rts_retry_limit = (is_hcca) ?
	    RTS_HCCA_RETRY_LIMIT : RTS_DFAULT_RETRY_LIMIT;

	if ((rate_idx >= IWL_FIRST_CCK_RATE) && (rate_idx <= IWL_LAST_CCK_RATE))
		rate_flags |= RATE_MCS_CCK_MSK;


	if (ieee80211_is_probe_resp(fc)) {
		data_retry_limit = 3;
		if (data_retry_limit < rts_retry_limit)
			rts_retry_limit = data_retry_limit;
	} else
		data_retry_limit = IWL_DEFAULT_TX_RETRY;

	if (priv->data_retry_limit != -1)
		data_retry_limit = priv->data_retry_limit;


	if (ieee80211_is_data(fc)) {
		tx_cmd->initial_rate_index = 0;
		tx_cmd->tx_flags |= TX_CMD_FLG_STA_RATE_MSK;
	} else {
		switch (fc & cpu_to_le16(IEEE80211_FCTL_STYPE)) {
		case cpu_to_le16(IEEE80211_STYPE_AUTH):
		case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
		case cpu_to_le16(IEEE80211_STYPE_ASSOC_REQ):
		case cpu_to_le16(IEEE80211_STYPE_REASSOC_REQ):
			if (tx_cmd->tx_flags & TX_CMD_FLG_RTS_MSK) {
				tx_cmd->tx_flags &= ~TX_CMD_FLG_RTS_MSK;
				tx_cmd->tx_flags |= TX_CMD_FLG_CTS_MSK;
			}
			break;
		default:
			break;
		}

		/* Alternate between antenna A and B for successive frames */
		if (priv->use_ant_b_for_management_frame) {
			priv->use_ant_b_for_management_frame = 0;
			rate_flags |= RATE_MCS_ANT_B_MSK;
		} else {
			priv->use_ant_b_for_management_frame = 1;
			rate_flags |= RATE_MCS_ANT_A_MSK;
		}
	}

	tx_cmd->rts_retry_limit = rts_retry_limit;
	tx_cmd->data_retry_limit = data_retry_limit;
	tx_cmd->rate_n_flags = iwl_hw_set_rate_n_flags(rate_plcp, rate_flags);
}

static void iwl_tx_cmd_build_hwcrypto(struct iwl_priv *priv,
				      struct ieee80211_tx_info *info,
				      struct iwl_tx_cmd *tx_cmd,
				      struct sk_buff *skb_frag,
				      int sta_id)
{
	struct ieee80211_key_conf *keyconf = info->control.hw_key;

	switch (keyconf->alg) {
	case ALG_CCMP:
		tx_cmd->sec_ctl = TX_CMD_SEC_CCM;
		memcpy(tx_cmd->key, keyconf->key, keyconf->keylen);
		if (info->flags & IEEE80211_TX_CTL_AMPDU)
			tx_cmd->tx_flags |= TX_CMD_FLG_AGG_CCMP_MSK;
		IWL_DEBUG_TX("tx_cmd with aes hwcrypto\n");
		break;

	case ALG_TKIP:
		tx_cmd->sec_ctl = TX_CMD_SEC_TKIP;
		ieee80211_get_tkip_key(keyconf, skb_frag,
			IEEE80211_TKIP_P2_KEY, tx_cmd->key);
		IWL_DEBUG_TX("tx_cmd with tkip hwcrypto\n");
		break;

	case ALG_WEP:
		tx_cmd->sec_ctl |= (TX_CMD_SEC_WEP |
			(keyconf->keyidx & TX_CMD_SEC_MSK) << TX_CMD_SEC_SHIFT);

		if (keyconf->keylen == WEP_KEY_LEN_128)
			tx_cmd->sec_ctl |= TX_CMD_SEC_KEY128;

		memcpy(&tx_cmd->key[3], keyconf->key, keyconf->keylen);

		IWL_DEBUG_TX("Configuring packet for WEP encryption "
			     "with key %d\n", keyconf->keyidx);
		break;

	default:
		printk(KERN_ERR "Unknown encode alg %d\n", keyconf->alg);
		break;
	}
}

static void iwl_update_tx_stats(struct iwl_priv *priv, u16 fc, u16 len)
{
	/* 0 - mgmt, 1 - cnt, 2 - data */
	int idx = (fc & IEEE80211_FCTL_FTYPE) >> 2;
	priv->tx_stats[idx].cnt++;
	priv->tx_stats[idx].bytes += len;
}

/*
 * start REPLY_TX command process
 */
int iwl_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	struct iwl_tfd_frame *tfd;
	u32 *control_flags;
	int txq_id = skb_get_queue_mapping(skb);
	struct iwl_tx_queue *txq = NULL;
	struct iwl_queue *q = NULL;
	dma_addr_t phys_addr;
	dma_addr_t txcmd_phys;
	dma_addr_t scratch_phys;
	struct iwl_cmd *out_cmd = NULL;
	struct iwl_tx_cmd *tx_cmd;
	u16 len, idx, len_org;
	u16 seq_number = 0;
	u8 id, hdr_len, unicast;
	u8 sta_id;
	__le16 fc;
	u8 wait_write_ptr = 0;
	u8 tid = 0;
	u8 *qc = NULL;
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&priv->lock, flags);
	if (iwl_is_rfkill(priv)) {
		IWL_DEBUG_DROP("Dropping - RF KILL\n");
		goto drop_unlock;
	}

	if (!priv->vif) {
		IWL_DEBUG_DROP("Dropping - !priv->vif\n");
		goto drop_unlock;
	}

	if ((ieee80211_get_tx_rate(priv->hw, info)->hw_value & 0xFF) ==
	     IWL_INVALID_RATE) {
		IWL_ERROR("ERROR: No TX rate available.\n");
		goto drop_unlock;
	}

	unicast = !is_multicast_ether_addr(hdr->addr1);
	id = 0;

	fc = hdr->frame_control;

#ifdef CONFIG_IWLWIFI_DEBUG
	if (ieee80211_is_auth(fc))
		IWL_DEBUG_TX("Sending AUTH frame\n");
	else if (ieee80211_is_assoc_req(fc))
		IWL_DEBUG_TX("Sending ASSOC frame\n");
	else if (ieee80211_is_reassoc_req(fc))
		IWL_DEBUG_TX("Sending REASSOC frame\n");
#endif

	/* drop all data frame if we are not associated */
	if (ieee80211_is_data(fc) &&
	   (!iwl_is_associated(priv) ||
	    ((priv->iw_mode == IEEE80211_IF_TYPE_STA) && !priv->assoc_id) ||
	    !priv->assoc_station_added)) {
		IWL_DEBUG_DROP("Dropping - !iwl_is_associated\n");
		goto drop_unlock;
	}

	spin_unlock_irqrestore(&priv->lock, flags);

	hdr_len = ieee80211_get_hdrlen(le16_to_cpu(fc));

	/* Find (or create) index into station table for destination station */
	sta_id = iwl_get_sta_id(priv, hdr);
	if (sta_id == IWL_INVALID_STATION) {
		DECLARE_MAC_BUF(mac);

		IWL_DEBUG_DROP("Dropping - INVALID STATION: %s\n",
			       print_mac(mac, hdr->addr1));
		goto drop;
	}

	IWL_DEBUG_TX("station Id %d\n", sta_id);

	if (ieee80211_is_data_qos(fc)) {
		qc = ieee80211_get_qos_ctl(hdr);
		tid = qc[0] & 0xf;
		seq_number = priv->stations[sta_id].tid[tid].seq_number &
				IEEE80211_SCTL_SEQ;
		hdr->seq_ctrl = cpu_to_le16(seq_number) |
			(hdr->seq_ctrl &
				__constant_cpu_to_le16(IEEE80211_SCTL_FRAG));
		seq_number += 0x10;
		/* aggregation is on for this <sta,tid> */
		if (info->flags & IEEE80211_TX_CTL_AMPDU)
			txq_id = priv->stations[sta_id].tid[tid].agg.txq_id;
		priv->stations[sta_id].tid[tid].tfds_in_queue++;
	}

	/* Descriptor for chosen Tx queue */
	txq = &priv->txq[txq_id];
	q = &txq->q;

	spin_lock_irqsave(&priv->lock, flags);

	/* Set up first empty TFD within this queue's circular TFD buffer */
	tfd = &txq->bd[q->write_ptr];
	memset(tfd, 0, sizeof(*tfd));
	control_flags = (u32 *) tfd;
	idx = get_cmd_index(q, q->write_ptr, 0);

	/* Set up driver data for this TFD */
	memset(&(txq->txb[q->write_ptr]), 0, sizeof(struct iwl_tx_info));
	txq->txb[q->write_ptr].skb[0] = skb;

	/* Set up first empty entry in queue's array of Tx/cmd buffers */
	out_cmd = &txq->cmd[idx];
	tx_cmd = &out_cmd->cmd.tx;
	memset(&out_cmd->hdr, 0, sizeof(out_cmd->hdr));
	memset(tx_cmd, 0, sizeof(struct iwl_tx_cmd));

	/*
	 * Set up the Tx-command (not MAC!) header.
	 * Store the chosen Tx queue and TFD index within the sequence field;
	 * after Tx, uCode's Tx response will return this value so driver can
	 * locate the frame within the tx queue and do post-tx processing.
	 */
	out_cmd->hdr.cmd = REPLY_TX;
	out_cmd->hdr.sequence = cpu_to_le16((u16)(QUEUE_TO_SEQ(txq_id) |
				INDEX_TO_SEQ(q->write_ptr)));

	/* Copy MAC header from skb into command buffer */
	memcpy(tx_cmd->hdr, hdr, hdr_len);

	/*
	 * Use the first empty entry in this queue's command buffer array
	 * to contain the Tx command and MAC header concatenated together
	 * (payload data will be in another buffer).
	 * Size of this varies, due to varying MAC header length.
	 * If end is not dword aligned, we'll have 2 extra bytes at the end
	 * of the MAC header (device reads on dword boundaries).
	 * We'll tell device about this padding later.
	 */
	len = sizeof(struct iwl_tx_cmd) +
		sizeof(struct iwl_cmd_header) + hdr_len;

	len_org = len;
	len = (len + 3) & ~3;

	if (len_org != len)
		len_org = 1;
	else
		len_org = 0;

	/* Physical address of this Tx command's header (not MAC header!),
	 * within command buffer array. */
	txcmd_phys = txq->dma_addr_cmd + sizeof(struct iwl_cmd) * idx +
		     offsetof(struct iwl_cmd, hdr);

	/* Add buffer containing Tx command and MAC(!) header to TFD's
	 * first entry */
	iwl_hw_txq_attach_buf_to_tfd(priv, tfd, txcmd_phys, len);

	if (!(info->flags & IEEE80211_TX_CTL_DO_NOT_ENCRYPT))
		iwl_tx_cmd_build_hwcrypto(priv, info, tx_cmd, skb, sta_id);

	/* Set up TFD's 2nd entry to point directly to remainder of skb,
	 * if any (802.11 null frames have no payload). */
	len = skb->len - hdr_len;
	if (len) {
		phys_addr = pci_map_single(priv->pci_dev, skb->data + hdr_len,
					   len, PCI_DMA_TODEVICE);
		iwl_hw_txq_attach_buf_to_tfd(priv, tfd, phys_addr, len);
	}

	/* Tell NIC about any 2-byte padding after MAC header */
	if (len_org)
		tx_cmd->tx_flags |= TX_CMD_FLG_MH_PAD_MSK;

	/* Total # bytes to be transmitted */
	len = (u16)skb->len;
	tx_cmd->len = cpu_to_le16(len);
	/* TODO need this for burst mode later on */
	iwl_tx_cmd_build_basic(priv, tx_cmd, info, hdr, unicast, sta_id);

	/* set is_hcca to 0; it probably will never be implemented */
	iwl_tx_cmd_build_rate(priv, tx_cmd, info, fc, sta_id, 0);

	iwl_update_tx_stats(priv, le16_to_cpu(fc), len);

	scratch_phys = txcmd_phys + sizeof(struct iwl_cmd_header) +
		offsetof(struct iwl_tx_cmd, scratch);
	tx_cmd->dram_lsb_ptr = cpu_to_le32(scratch_phys);
	tx_cmd->dram_msb_ptr = iwl_get_dma_hi_address(scratch_phys);

	if (!ieee80211_has_morefrags(hdr->frame_control)) {
		txq->need_update = 1;
		if (qc)
			priv->stations[sta_id].tid[tid].seq_number = seq_number;
	} else {
		wait_write_ptr = 1;
		txq->need_update = 0;
	}

	iwl_print_hex_dump(priv, IWL_DL_TX, (u8 *)tx_cmd, sizeof(*tx_cmd));

	iwl_print_hex_dump(priv, IWL_DL_TX, (u8 *)tx_cmd->hdr, hdr_len);

	/* Set up entry for this TFD in Tx byte-count array */
	priv->cfg->ops->lib->txq_update_byte_cnt_tbl(priv, txq, len);

	/* Tell device the write index *just past* this latest filled TFD */
	q->write_ptr = iwl_queue_inc_wrap(q->write_ptr, q->n_bd);
	ret = iwl_txq_update_write_ptr(priv, txq);
	spin_unlock_irqrestore(&priv->lock, flags);

	if (ret)
		return ret;

	if ((iwl_queue_space(q) < q->high_mark)
	    && priv->mac80211_registered) {
		if (wait_write_ptr) {
			spin_lock_irqsave(&priv->lock, flags);
			txq->need_update = 1;
			iwl_txq_update_write_ptr(priv, txq);
			spin_unlock_irqrestore(&priv->lock, flags);
		}

		ieee80211_stop_queue(priv->hw, skb_get_queue_mapping(skb));
	}

	return 0;

drop_unlock:
	spin_unlock_irqrestore(&priv->lock, flags);
drop:
	return -1;
}
EXPORT_SYMBOL(iwl_tx_skb);

/*************** HOST COMMAND QUEUE FUNCTIONS   *****/

/**
 * iwl_enqueue_hcmd - enqueue a uCode command
 * @priv: device private data point
 * @cmd: a point to the ucode command structure
 *
 * The function returns < 0 values to indicate the operation is
 * failed. On success, it turns the index (> 0) of command in the
 * command queue.
 */
int iwl_enqueue_hcmd(struct iwl_priv *priv, struct iwl_host_cmd *cmd)
{
	struct iwl_tx_queue *txq = &priv->txq[IWL_CMD_QUEUE_NUM];
	struct iwl_queue *q = &txq->q;
	struct iwl_tfd_frame *tfd;
	u32 *control_flags;
	struct iwl_cmd *out_cmd;
	u32 idx;
	u16 fix_size;
	dma_addr_t phys_addr;
	int ret;
	unsigned long flags;

	cmd->len = priv->cfg->ops->utils->get_hcmd_size(cmd->id, cmd->len);
	fix_size = (u16)(cmd->len + sizeof(out_cmd->hdr));

	/* If any of the command structures end up being larger than
	 * the TFD_MAX_PAYLOAD_SIZE, and it sent as a 'small' command then
	 * we will need to increase the size of the TFD entries */
	BUG_ON((fix_size > TFD_MAX_PAYLOAD_SIZE) &&
	       !(cmd->meta.flags & CMD_SIZE_HUGE));

	if (iwl_is_rfkill(priv)) {
		IWL_DEBUG_INFO("Not sending command - RF KILL");
		return -EIO;
	}

	if (iwl_queue_space(q) < ((cmd->meta.flags & CMD_ASYNC) ? 2 : 1)) {
		IWL_ERROR("No space for Tx\n");
		return -ENOSPC;
	}

	spin_lock_irqsave(&priv->hcmd_lock, flags);

	tfd = &txq->bd[q->write_ptr];
	memset(tfd, 0, sizeof(*tfd));

	control_flags = (u32 *) tfd;

	idx = get_cmd_index(q, q->write_ptr, cmd->meta.flags & CMD_SIZE_HUGE);
	out_cmd = &txq->cmd[idx];

	out_cmd->hdr.cmd = cmd->id;
	memcpy(&out_cmd->meta, &cmd->meta, sizeof(cmd->meta));
	memcpy(&out_cmd->cmd.payload, cmd->data, cmd->len);

	/* At this point, the out_cmd now has all of the incoming cmd
	 * information */

	out_cmd->hdr.flags = 0;
	out_cmd->hdr.sequence = cpu_to_le16(QUEUE_TO_SEQ(IWL_CMD_QUEUE_NUM) |
			INDEX_TO_SEQ(q->write_ptr));
	if (out_cmd->meta.flags & CMD_SIZE_HUGE)
		out_cmd->hdr.sequence |= cpu_to_le16(SEQ_HUGE_FRAME);

	phys_addr = txq->dma_addr_cmd + sizeof(txq->cmd[0]) * idx +
			offsetof(struct iwl_cmd, hdr);
	iwl_hw_txq_attach_buf_to_tfd(priv, tfd, phys_addr, fix_size);

	IWL_DEBUG_HC("Sending command %s (#%x), seq: 0x%04X, "
		     "%d bytes at %d[%d]:%d\n",
		     get_cmd_string(out_cmd->hdr.cmd),
		     out_cmd->hdr.cmd, le16_to_cpu(out_cmd->hdr.sequence),
		     fix_size, q->write_ptr, idx, IWL_CMD_QUEUE_NUM);

	txq->need_update = 1;

	/* Set up entry in queue's byte count circular buffer */
	priv->cfg->ops->lib->txq_update_byte_cnt_tbl(priv, txq, 0);

	/* Increment and update queue's write index */
	q->write_ptr = iwl_queue_inc_wrap(q->write_ptr, q->n_bd);
	ret = iwl_txq_update_write_ptr(priv, txq);

	spin_unlock_irqrestore(&priv->hcmd_lock, flags);
	return ret ? ret : idx;
}

int iwl_tx_queue_reclaim(struct iwl_priv *priv, int txq_id, int index)
{
	struct iwl_tx_queue *txq = &priv->txq[txq_id];
	struct iwl_queue *q = &txq->q;
	struct iwl_tx_info *tx_info;
	int nfreed = 0;

	if ((index >= q->n_bd) || (iwl_queue_used(q, index) == 0)) {
		IWL_ERROR("Read index for DMA queue txq id (%d), index %d, "
			  "is out of range [0-%d] %d %d.\n", txq_id,
			  index, q->n_bd, q->write_ptr, q->read_ptr);
		return 0;
	}

	for (index = iwl_queue_inc_wrap(index, q->n_bd); q->read_ptr != index;
		q->read_ptr = iwl_queue_inc_wrap(q->read_ptr, q->n_bd)) {

		tx_info = &txq->txb[txq->q.read_ptr];
		ieee80211_tx_status_irqsafe(priv->hw, tx_info->skb[0]);
		tx_info->skb[0] = NULL;

		if (priv->cfg->ops->lib->txq_inval_byte_cnt_tbl)
			priv->cfg->ops->lib->txq_inval_byte_cnt_tbl(priv, txq);

		iwl_hw_txq_free_tfd(priv, txq);
		nfreed++;
	}
	return nfreed;
}
EXPORT_SYMBOL(iwl_tx_queue_reclaim);


/**
 * iwl_hcmd_queue_reclaim - Reclaim TX command queue entries already Tx'd
 *
 * When FW advances 'R' index, all entries between old and new 'R' index
 * need to be reclaimed. As result, some free space forms.  If there is
 * enough free space (> low mark), wake the stack that feeds us.
 */
static void iwl_hcmd_queue_reclaim(struct iwl_priv *priv, int txq_id, int index)
{
	struct iwl_tx_queue *txq = &priv->txq[txq_id];
	struct iwl_queue *q = &txq->q;
	int nfreed = 0;

	if ((index >= q->n_bd) || (iwl_queue_used(q, index) == 0)) {
		IWL_ERROR("Read index for DMA queue txq id (%d), index %d, "
			  "is out of range [0-%d] %d %d.\n", txq_id,
			  index, q->n_bd, q->write_ptr, q->read_ptr);
		return;
	}

	for (index = iwl_queue_inc_wrap(index, q->n_bd); q->read_ptr != index;
		q->read_ptr = iwl_queue_inc_wrap(q->read_ptr, q->n_bd)) {

		if (nfreed > 1) {
			IWL_ERROR("HCMD skipped: index (%d) %d %d\n", index,
					q->write_ptr, q->read_ptr);
			queue_work(priv->workqueue, &priv->restart);
		}
		nfreed++;
	}
}

/**
 * iwl_tx_cmd_complete - Pull unused buffers off the queue and reclaim them
 * @rxb: Rx buffer to reclaim
 *
 * If an Rx buffer has an async callback associated with it the callback
 * will be executed.  The attached skb (if present) will only be freed
 * if the callback returns 1
 */
void iwl_tx_cmd_complete(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb)
{
	struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
	u16 sequence = le16_to_cpu(pkt->hdr.sequence);
	int txq_id = SEQ_TO_QUEUE(sequence);
	int index = SEQ_TO_INDEX(sequence);
	int huge = sequence & SEQ_HUGE_FRAME;
	int cmd_index;
	struct iwl_cmd *cmd;

	/* If a Tx command is being handled and it isn't in the actual
	 * command queue then there a command routing bug has been introduced
	 * in the queue management code. */
	if (txq_id != IWL_CMD_QUEUE_NUM)
		IWL_ERROR("Error wrong command queue %d command id 0x%X\n",
			  txq_id, pkt->hdr.cmd);
	BUG_ON(txq_id != IWL_CMD_QUEUE_NUM);

	cmd_index = get_cmd_index(&priv->txq[IWL_CMD_QUEUE_NUM].q, index, huge);
	cmd = &priv->txq[IWL_CMD_QUEUE_NUM].cmd[cmd_index];

	/* Input error checking is done when commands are added to queue. */
	if (cmd->meta.flags & CMD_WANT_SKB) {
		cmd->meta.source->u.skb = rxb->skb;
		rxb->skb = NULL;
	} else if (cmd->meta.u.callback &&
		   !cmd->meta.u.callback(priv, cmd, rxb->skb))
		rxb->skb = NULL;

	iwl_hcmd_queue_reclaim(priv, txq_id, index);

	if (!(cmd->meta.flags & CMD_ASYNC)) {
		clear_bit(STATUS_HCMD_ACTIVE, &priv->status);
		wake_up_interruptible(&priv->wait_command_queue);
	}
}
EXPORT_SYMBOL(iwl_tx_cmd_complete);

/*
 * Find first available (lowest unused) Tx Queue, mark it "active".
 * Called only when finding queue for aggregation.
 * Should never return anything < 7, because they should already
 * be in use as EDCA AC (0-3), Command (4), HCCA (5, 6).
 */
static int iwl_txq_ctx_activate_free(struct iwl_priv *priv)
{
	int txq_id;

	for (txq_id = 0; txq_id < priv->hw_params.max_txq_num; txq_id++)
		if (!test_and_set_bit(txq_id, &priv->txq_ctx_active_msk))
			return txq_id;
	return -1;
}

int iwl_tx_agg_start(struct iwl_priv *priv, const u8 *ra, u16 tid, u16 *ssn)
{
	int sta_id;
	int tx_fifo;
	int txq_id;
	int ret;
	unsigned long flags;
	struct iwl_tid_data *tid_data;
	DECLARE_MAC_BUF(mac);

	if (likely(tid < ARRAY_SIZE(default_tid_to_tx_fifo)))
		tx_fifo = default_tid_to_tx_fifo[tid];
	else
		return -EINVAL;

	IWL_WARNING("%s on ra = %s tid = %d\n",
			__func__, print_mac(mac, ra), tid);

	sta_id = iwl_find_station(priv, ra);
	if (sta_id == IWL_INVALID_STATION)
		return -ENXIO;

	if (priv->stations[sta_id].tid[tid].agg.state != IWL_AGG_OFF) {
		IWL_ERROR("Start AGG when state is not IWL_AGG_OFF !\n");
		return -ENXIO;
	}

	txq_id = iwl_txq_ctx_activate_free(priv);
	if (txq_id == -1)
		return -ENXIO;

	spin_lock_irqsave(&priv->sta_lock, flags);
	tid_data = &priv->stations[sta_id].tid[tid];
	*ssn = SEQ_TO_SN(tid_data->seq_number);
	tid_data->agg.txq_id = txq_id;
	spin_unlock_irqrestore(&priv->sta_lock, flags);

	ret = priv->cfg->ops->lib->txq_agg_enable(priv, txq_id, tx_fifo,
						  sta_id, tid, *ssn);
	if (ret)
		return ret;

	if (tid_data->tfds_in_queue == 0) {
		printk(KERN_ERR "HW queue is empty\n");
		tid_data->agg.state = IWL_AGG_ON;
		ieee80211_start_tx_ba_cb_irqsafe(priv->hw, ra, tid);
	} else {
		IWL_DEBUG_HT("HW queue is NOT empty: %d packets in HW queue\n",
			     tid_data->tfds_in_queue);
		tid_data->agg.state = IWL_EMPTYING_HW_QUEUE_ADDBA;
	}
	return ret;
}
EXPORT_SYMBOL(iwl_tx_agg_start);

int iwl_tx_agg_stop(struct iwl_priv *priv , const u8 *ra, u16 tid)
{
	int tx_fifo_id, txq_id, sta_id, ssn = -1;
	struct iwl_tid_data *tid_data;
	int ret, write_ptr, read_ptr;
	unsigned long flags;
	DECLARE_MAC_BUF(mac);

	if (!ra) {
		IWL_ERROR("ra = NULL\n");
		return -EINVAL;
	}

	if (likely(tid < ARRAY_SIZE(default_tid_to_tx_fifo)))
		tx_fifo_id = default_tid_to_tx_fifo[tid];
	else
		return -EINVAL;

	sta_id = iwl_find_station(priv, ra);

	if (sta_id == IWL_INVALID_STATION)
		return -ENXIO;

	if (priv->stations[sta_id].tid[tid].agg.state != IWL_AGG_ON)
		IWL_WARNING("Stopping AGG while state not IWL_AGG_ON\n");

	tid_data = &priv->stations[sta_id].tid[tid];
	ssn = (tid_data->seq_number & IEEE80211_SCTL_SEQ) >> 4;
	txq_id = tid_data->agg.txq_id;
	write_ptr = priv->txq[txq_id].q.write_ptr;
	read_ptr = priv->txq[txq_id].q.read_ptr;

	/* The queue is not empty */
	if (write_ptr != read_ptr) {
		IWL_DEBUG_HT("Stopping a non empty AGG HW QUEUE\n");
		priv->stations[sta_id].tid[tid].agg.state =
				IWL_EMPTYING_HW_QUEUE_DELBA;
		return 0;
	}

	IWL_DEBUG_HT("HW queue is empty\n");
	priv->stations[sta_id].tid[tid].agg.state = IWL_AGG_OFF;

	spin_lock_irqsave(&priv->lock, flags);
	ret = priv->cfg->ops->lib->txq_agg_disable(priv, txq_id, ssn,
						   tx_fifo_id);
	spin_unlock_irqrestore(&priv->lock, flags);

	if (ret)
		return ret;

	ieee80211_stop_tx_ba_cb_irqsafe(priv->hw, ra, tid);

	return 0;
}
EXPORT_SYMBOL(iwl_tx_agg_stop);

int iwl_txq_check_empty(struct iwl_priv *priv, int sta_id, u8 tid, int txq_id)
{
	struct iwl_queue *q = &priv->txq[txq_id].q;
	u8 *addr = priv->stations[sta_id].sta.sta.addr;
	struct iwl_tid_data *tid_data = &priv->stations[sta_id].tid[tid];

	switch (priv->stations[sta_id].tid[tid].agg.state) {
	case IWL_EMPTYING_HW_QUEUE_DELBA:
		/* We are reclaiming the last packet of the */
		/* aggregated HW queue */
		if (txq_id  == tid_data->agg.txq_id &&
		    q->read_ptr == q->write_ptr) {
			u16 ssn = SEQ_TO_SN(tid_data->seq_number);
			int tx_fifo = default_tid_to_tx_fifo[tid];
			IWL_DEBUG_HT("HW queue empty: continue DELBA flow\n");
			priv->cfg->ops->lib->txq_agg_disable(priv, txq_id,
							     ssn, tx_fifo);
			tid_data->agg.state = IWL_AGG_OFF;
			ieee80211_stop_tx_ba_cb_irqsafe(priv->hw, addr, tid);
		}
		break;
	case IWL_EMPTYING_HW_QUEUE_ADDBA:
		/* We are reclaiming the last packet of the queue */
		if (tid_data->tfds_in_queue == 0) {
			IWL_DEBUG_HT("HW queue empty: continue ADDBA flow\n");
			tid_data->agg.state = IWL_AGG_ON;
			ieee80211_start_tx_ba_cb_irqsafe(priv->hw, addr, tid);
		}
		break;
	}
	return 0;
}
EXPORT_SYMBOL(iwl_txq_check_empty);

/**
 * iwl_tx_status_reply_compressed_ba - Update tx status from block-ack
 *
 * Go through block-ack's bitmap of ACK'd frames, update driver's record of
 * ACK vs. not.  This gets sent to mac80211, then to rate scaling algo.
 */
static int iwl_tx_status_reply_compressed_ba(struct iwl_priv *priv,
				 struct iwl_ht_agg *agg,
				 struct iwl_compressed_ba_resp *ba_resp)

{
	int i, sh, ack;
	u16 seq_ctl = le16_to_cpu(ba_resp->seq_ctl);
	u16 scd_flow = le16_to_cpu(ba_resp->scd_flow);
	u64 bitmap;
	int successes = 0;
	struct ieee80211_tx_info *info;

	if (unlikely(!agg->wait_for_ba))  {
		IWL_ERROR("Received BA when not expected\n");
		return -EINVAL;
	}

	/* Mark that the expected block-ack response arrived */
	agg->wait_for_ba = 0;
	IWL_DEBUG_TX_REPLY("BA %d %d\n", agg->start_idx, ba_resp->seq_ctl);

	/* Calculate shift to align block-ack bits with our Tx window bits */
	sh = agg->start_idx - SEQ_TO_INDEX(seq_ctl>>4);
	if (sh < 0) /* tbw something is wrong with indices */
		sh += 0x100;

	/* don't use 64-bit values for now */
	bitmap = le64_to_cpu(ba_resp->bitmap) >> sh;

	if (agg->frame_count > (64 - sh)) {
		IWL_DEBUG_TX_REPLY("more frames than bitmap size");
		return -1;
	}

	/* check for success or failure according to the
	 * transmitted bitmap and block-ack bitmap */
	bitmap &= agg->bitmap;

	/* For each frame attempted in aggregation,
	 * update driver's record of tx frame's status. */
	for (i = 0; i < agg->frame_count ; i++) {
		ack = bitmap & (1 << i);
		successes += !!ack;
		IWL_DEBUG_TX_REPLY("%s ON i=%d idx=%d raw=%d\n",
			ack? "ACK":"NACK", i, (agg->start_idx + i) & 0xff,
			agg->start_idx + i);
	}

	info = IEEE80211_SKB_CB(priv->txq[scd_flow].txb[agg->start_idx].skb[0]);
	memset(&info->status, 0, sizeof(info->status));
	info->flags = IEEE80211_TX_STAT_ACK;
	info->flags |= IEEE80211_TX_STAT_AMPDU;
	info->status.ampdu_ack_map = successes;
	info->status.ampdu_ack_len = agg->frame_count;
	iwl_hwrate_to_tx_control(priv, agg->rate_n_flags, info);

	IWL_DEBUG_TX_REPLY("Bitmap %llx\n", (unsigned long long)bitmap);

	return 0;
}

/**
 * iwl_rx_reply_compressed_ba - Handler for REPLY_COMPRESSED_BA
 *
 * Handles block-acknowledge notification from device, which reports success
 * of frames sent via aggregation.
 */
void iwl_rx_reply_compressed_ba(struct iwl_priv *priv,
					   struct iwl_rx_mem_buffer *rxb)
{
	struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
	struct iwl_compressed_ba_resp *ba_resp = &pkt->u.compressed_ba;
	int index;
	struct iwl_tx_queue *txq = NULL;
	struct iwl_ht_agg *agg;
	DECLARE_MAC_BUF(mac);

	/* "flow" corresponds to Tx queue */
	u16 scd_flow = le16_to_cpu(ba_resp->scd_flow);

	/* "ssn" is start of block-ack Tx window, corresponds to index
	 * (in Tx queue's circular buffer) of first TFD/frame in window */
	u16 ba_resp_scd_ssn = le16_to_cpu(ba_resp->scd_ssn);

	if (scd_flow >= priv->hw_params.max_txq_num) {
		IWL_ERROR("BUG_ON scd_flow is bigger than number of queues");
		return;
	}

	txq = &priv->txq[scd_flow];
	agg = &priv->stations[ba_resp->sta_id].tid[ba_resp->tid].agg;

	/* Find index just before block-ack window */
	index = iwl_queue_dec_wrap(ba_resp_scd_ssn & 0xff, txq->q.n_bd);

	/* TODO: Need to get this copy more safely - now good for debug */

	IWL_DEBUG_TX_REPLY("REPLY_COMPRESSED_BA [%d]Received from %s, "
			   "sta_id = %d\n",
			   agg->wait_for_ba,
			   print_mac(mac, (u8 *) &ba_resp->sta_addr_lo32),
			   ba_resp->sta_id);
	IWL_DEBUG_TX_REPLY("TID = %d, SeqCtl = %d, bitmap = 0x%llx, scd_flow = "
			   "%d, scd_ssn = %d\n",
			   ba_resp->tid,
			   ba_resp->seq_ctl,
			   (unsigned long long)le64_to_cpu(ba_resp->bitmap),
			   ba_resp->scd_flow,
			   ba_resp->scd_ssn);
	IWL_DEBUG_TX_REPLY("DAT start_idx = %d, bitmap = 0x%llx \n",
			   agg->start_idx,
			   (unsigned long long)agg->bitmap);

	/* Update driver's record of ACK vs. not for each frame in window */
	iwl_tx_status_reply_compressed_ba(priv, agg, ba_resp);

	/* Release all TFDs before the SSN, i.e. all TFDs in front of
	 * block-ack window (we assume that they've been successfully
	 * transmitted ... if not, it's too late anyway). */
	if (txq->q.read_ptr != (ba_resp_scd_ssn & 0xff)) {
		/* calculate mac80211 ampdu sw queue to wake */
		int ampdu_q =
		   scd_flow - priv->hw_params.first_ampdu_q + priv->hw->queues;
		int freed = iwl_tx_queue_reclaim(priv, scd_flow, index);
		priv->stations[ba_resp->sta_id].
			tid[ba_resp->tid].tfds_in_queue -= freed;
		if (iwl_queue_space(&txq->q) > txq->q.low_mark &&
			priv->mac80211_registered &&
			agg->state != IWL_EMPTYING_HW_QUEUE_DELBA)
			ieee80211_wake_queue(priv->hw, ampdu_q);

		iwl_txq_check_empty(priv, ba_resp->sta_id,
				    ba_resp->tid, scd_flow);
	}
}
EXPORT_SYMBOL(iwl_rx_reply_compressed_ba);

#ifdef CONFIG_IWLWIFI_DEBUG
#define TX_STATUS_ENTRY(x) case TX_STATUS_FAIL_ ## x: return #x

const char *iwl_get_tx_fail_reason(u32 status)
{
	switch (status & TX_STATUS_MSK) {
	case TX_STATUS_SUCCESS:
		return "SUCCESS";
		TX_STATUS_ENTRY(SHORT_LIMIT);
		TX_STATUS_ENTRY(LONG_LIMIT);
		TX_STATUS_ENTRY(FIFO_UNDERRUN);
		TX_STATUS_ENTRY(MGMNT_ABORT);
		TX_STATUS_ENTRY(NEXT_FRAG);
		TX_STATUS_ENTRY(LIFE_EXPIRE);
		TX_STATUS_ENTRY(DEST_PS);
		TX_STATUS_ENTRY(ABORTED);
		TX_STATUS_ENTRY(BT_RETRY);
		TX_STATUS_ENTRY(STA_INVALID);
		TX_STATUS_ENTRY(FRAG_DROPPED);
		TX_STATUS_ENTRY(TID_DISABLE);
		TX_STATUS_ENTRY(FRAME_FLUSHED);
		TX_STATUS_ENTRY(INSUFFICIENT_CF_POLL);
		TX_STATUS_ENTRY(TX_LOCKED);
		TX_STATUS_ENTRY(NO_BEACON_ON_RADAR);
	}

	return "UNKNOWN";
}
EXPORT_SYMBOL(iwl_get_tx_fail_reason);
#endif /* CONFIG_IWLWIFI_DEBUG */