summaryrefslogtreecommitdiff
path: root/drivers/net/wireless/iwlwifi/iwl-sta.c
blob: 7028f907e60037aadc8ab9a115978ac40b644cff (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
/******************************************************************************
 *
 * Copyright(c) 2003 - 2011 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:
 *  Intel Linux Wireless <ilw@linux.intel.com>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 *
 *****************************************************************************/

#include <net/mac80211.h>
#include <linux/etherdevice.h>
#include <linux/sched.h>
#include <linux/lockdep.h>

#include "iwl-dev.h"
#include "iwl-core.h"
#include "iwl-sta.h"
#include "iwl-trans.h"
#include "iwl-agn.h"

/* priv->shrd->sta_lock must be held */
static void iwl_sta_ucode_activate(struct iwl_priv *priv, u8 sta_id)
{

	if (!(priv->stations[sta_id].used & IWL_STA_DRIVER_ACTIVE))
		IWL_ERR(priv, "ACTIVATE a non DRIVER active station id %u addr %pM\n",
			sta_id, priv->stations[sta_id].sta.sta.addr);

	if (priv->stations[sta_id].used & IWL_STA_UCODE_ACTIVE) {
		IWL_DEBUG_ASSOC(priv,
				"STA id %u addr %pM already present in uCode (according to driver)\n",
				sta_id, priv->stations[sta_id].sta.sta.addr);
	} else {
		priv->stations[sta_id].used |= IWL_STA_UCODE_ACTIVE;
		IWL_DEBUG_ASSOC(priv, "Added STA id %u addr %pM to uCode\n",
				sta_id, priv->stations[sta_id].sta.sta.addr);
	}
}

static int iwl_process_add_sta_resp(struct iwl_priv *priv,
				    struct iwl_addsta_cmd *addsta,
				    struct iwl_rx_packet *pkt)
{
	u8 sta_id = addsta->sta.sta_id;
	unsigned long flags;
	int ret = -EIO;

	if (pkt->hdr.flags & IWL_CMD_FAILED_MSK) {
		IWL_ERR(priv, "Bad return from REPLY_ADD_STA (0x%08X)\n",
			pkt->hdr.flags);
		return ret;
	}

	IWL_DEBUG_INFO(priv, "Processing response for adding station %u\n",
		       sta_id);

	spin_lock_irqsave(&priv->shrd->sta_lock, flags);

	switch (pkt->u.add_sta.status) {
	case ADD_STA_SUCCESS_MSK:
		IWL_DEBUG_INFO(priv, "REPLY_ADD_STA PASSED\n");
		iwl_sta_ucode_activate(priv, sta_id);
		ret = 0;
		break;
	case ADD_STA_NO_ROOM_IN_TABLE:
		IWL_ERR(priv, "Adding station %d failed, no room in table.\n",
			sta_id);
		break;
	case ADD_STA_NO_BLOCK_ACK_RESOURCE:
		IWL_ERR(priv, "Adding station %d failed, no block ack resource.\n",
			sta_id);
		break;
	case ADD_STA_MODIFY_NON_EXIST_STA:
		IWL_ERR(priv, "Attempting to modify non-existing station %d\n",
			sta_id);
		break;
	default:
		IWL_DEBUG_ASSOC(priv, "Received REPLY_ADD_STA:(0x%08X)\n",
				pkt->u.add_sta.status);
		break;
	}

	IWL_DEBUG_INFO(priv, "%s station id %u addr %pM\n",
		       priv->stations[sta_id].sta.mode ==
		       STA_CONTROL_MODIFY_MSK ?  "Modified" : "Added",
		       sta_id, priv->stations[sta_id].sta.sta.addr);

	/*
	 * XXX: The MAC address in the command buffer is often changed from
	 * the original sent to the device. That is, the MAC address
	 * written to the command buffer often is not the same MAC address
	 * read from the command buffer when the command returns. This
	 * issue has not yet been resolved and this debugging is left to
	 * observe the problem.
	 */
	IWL_DEBUG_INFO(priv, "%s station according to cmd buffer %pM\n",
		       priv->stations[sta_id].sta.mode ==
		       STA_CONTROL_MODIFY_MSK ? "Modified" : "Added",
		       addsta->sta.addr);
	spin_unlock_irqrestore(&priv->shrd->sta_lock, flags);

	return ret;
}

int iwl_add_sta_callback(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb,
			       struct iwl_device_cmd *cmd)
{
	struct iwl_rx_packet *pkt = rxb_addr(rxb);
	struct iwl_addsta_cmd *addsta =
		(struct iwl_addsta_cmd *)cmd->cmd.payload;

	return iwl_process_add_sta_resp(priv, addsta, pkt);
}

static u16 iwlagn_build_addsta_hcmd(const struct iwl_addsta_cmd *cmd, u8 *data)
{
	u16 size = (u16)sizeof(struct iwl_addsta_cmd);
	struct iwl_addsta_cmd *addsta = (struct iwl_addsta_cmd *)data;
	memcpy(addsta, cmd, size);
	/* resrved in 5000 */
	addsta->rate_n_flags = cpu_to_le16(0);
	return size;
}

int iwl_send_add_sta(struct iwl_priv *priv,
		     struct iwl_addsta_cmd *sta, u8 flags)
{
	int ret = 0;
	u8 data[sizeof(*sta)];
	struct iwl_host_cmd cmd = {
		.id = REPLY_ADD_STA,
		.flags = flags,
		.data = { data, },
	};
	u8 sta_id __maybe_unused = sta->sta.sta_id;

	IWL_DEBUG_INFO(priv, "Adding sta %u (%pM) %ssynchronously\n",
		       sta_id, sta->sta.addr, flags & CMD_ASYNC ?  "a" : "");

	if (!(flags & CMD_ASYNC)) {
		cmd.flags |= CMD_WANT_SKB;
		might_sleep();
	}

	cmd.len[0] = iwlagn_build_addsta_hcmd(sta, data);
	ret = iwl_trans_send_cmd(trans(priv), &cmd);

	if (ret || (flags & CMD_ASYNC))
		return ret;
	/*else the command was successfully sent in SYNC mode, need to free
	 * the reply page */

	iwl_free_pages(priv->shrd, cmd.reply_page);

	if (cmd.handler_status)
		IWL_ERR(priv, "%s - error in the CMD response %d", __func__,
			cmd.handler_status);

	return cmd.handler_status;
}

static void iwl_set_ht_add_station(struct iwl_priv *priv, u8 index,
				   struct ieee80211_sta *sta,
				   struct iwl_rxon_context *ctx)
{
	struct ieee80211_sta_ht_cap *sta_ht_inf = &sta->ht_cap;
	__le32 sta_flags;
	u8 mimo_ps_mode;

	if (!sta || !sta_ht_inf->ht_supported)
		goto done;

	mimo_ps_mode = (sta_ht_inf->cap & IEEE80211_HT_CAP_SM_PS) >> 2;
	IWL_DEBUG_ASSOC(priv, "spatial multiplexing power save mode: %s\n",
			(mimo_ps_mode == WLAN_HT_CAP_SM_PS_STATIC) ?
			"static" :
			(mimo_ps_mode == WLAN_HT_CAP_SM_PS_DYNAMIC) ?
			"dynamic" : "disabled");

	sta_flags = priv->stations[index].sta.station_flags;

	sta_flags &= ~(STA_FLG_RTS_MIMO_PROT_MSK | STA_FLG_MIMO_DIS_MSK);

	switch (mimo_ps_mode) {
	case WLAN_HT_CAP_SM_PS_STATIC:
		sta_flags |= STA_FLG_MIMO_DIS_MSK;
		break;
	case WLAN_HT_CAP_SM_PS_DYNAMIC:
		sta_flags |= STA_FLG_RTS_MIMO_PROT_MSK;
		break;
	case WLAN_HT_CAP_SM_PS_DISABLED:
		break;
	default:
		IWL_WARN(priv, "Invalid MIMO PS mode %d\n", mimo_ps_mode);
		break;
	}

	sta_flags |= cpu_to_le32(
	      (u32)sta_ht_inf->ampdu_factor << STA_FLG_MAX_AGG_SIZE_POS);

	sta_flags |= cpu_to_le32(
	      (u32)sta_ht_inf->ampdu_density << STA_FLG_AGG_MPDU_DENSITY_POS);

	if (iwl_is_ht40_tx_allowed(priv, ctx, &sta->ht_cap))
		sta_flags |= STA_FLG_HT40_EN_MSK;
	else
		sta_flags &= ~STA_FLG_HT40_EN_MSK;

	priv->stations[index].sta.station_flags = sta_flags;
 done:
	return;
}

/**
 * iwl_prep_station - Prepare station information for addition
 *
 * should be called with sta_lock held
 */
u8 iwl_prep_station(struct iwl_priv *priv, struct iwl_rxon_context *ctx,
		    const u8 *addr, bool is_ap, struct ieee80211_sta *sta)
{
	struct iwl_station_entry *station;
	int i;
	u8 sta_id = IWL_INVALID_STATION;

	if (is_ap)
		sta_id = ctx->ap_sta_id;
	else if (is_broadcast_ether_addr(addr))
		sta_id = ctx->bcast_sta_id;
	else
		for (i = IWL_STA_ID;
		     i < hw_params(priv).max_stations; i++) {
			if (!compare_ether_addr(priv->stations[i].sta.sta.addr,
						addr)) {
				sta_id = i;
				break;
			}

			if (!priv->stations[i].used &&
			    sta_id == IWL_INVALID_STATION)
				sta_id = i;
		}

	/*
	 * These two conditions have the same outcome, but keep them
	 * separate
	 */
	if (unlikely(sta_id == IWL_INVALID_STATION))
		return sta_id;

	/*
	 * uCode is not able to deal with multiple requests to add a
	 * station. Keep track if one is in progress so that we do not send
	 * another.
	 */
	if (priv->stations[sta_id].used & IWL_STA_UCODE_INPROGRESS) {
		IWL_DEBUG_INFO(priv, "STA %d already in process of being added.\n",
				sta_id);
		return sta_id;
	}

	if ((priv->stations[sta_id].used & IWL_STA_DRIVER_ACTIVE) &&
	    (priv->stations[sta_id].used & IWL_STA_UCODE_ACTIVE) &&
	    !compare_ether_addr(priv->stations[sta_id].sta.sta.addr, addr)) {
		IWL_DEBUG_ASSOC(priv, "STA %d (%pM) already added, not adding again.\n",
				sta_id, addr);
		return sta_id;
	}

	station = &priv->stations[sta_id];
	station->used = IWL_STA_DRIVER_ACTIVE;
	IWL_DEBUG_ASSOC(priv, "Add STA to driver ID %d: %pM\n",
			sta_id, addr);
	priv->num_stations++;

	/* Set up the REPLY_ADD_STA command to send to device */
	memset(&station->sta, 0, sizeof(struct iwl_addsta_cmd));
	memcpy(station->sta.sta.addr, addr, ETH_ALEN);
	station->sta.mode = 0;
	station->sta.sta.sta_id = sta_id;
	station->sta.station_flags = ctx->station_flags;
	station->ctxid = ctx->ctxid;

	if (sta) {
		struct iwl_station_priv *sta_priv;

		sta_priv = (void *)sta->drv_priv;
		sta_priv->ctx = ctx;
	}

	/*
	 * OK to call unconditionally, since local stations (IBSS BSSID
	 * STA and broadcast STA) pass in a NULL sta, and mac80211
	 * doesn't allow HT IBSS.
	 */
	iwl_set_ht_add_station(priv, sta_id, sta, ctx);

	return sta_id;

}

#define STA_WAIT_TIMEOUT (HZ/2)

/**
 * iwl_add_station_common -
 */
int iwl_add_station_common(struct iwl_priv *priv, struct iwl_rxon_context *ctx,
			   const u8 *addr, bool is_ap,
			   struct ieee80211_sta *sta, u8 *sta_id_r)
{
	unsigned long flags_spin;
	int ret = 0;
	u8 sta_id;
	struct iwl_addsta_cmd sta_cmd;

	*sta_id_r = 0;
	spin_lock_irqsave(&priv->shrd->sta_lock, flags_spin);
	sta_id = iwl_prep_station(priv, ctx, addr, is_ap, sta);
	if (sta_id == IWL_INVALID_STATION) {
		IWL_ERR(priv, "Unable to prepare station %pM for addition\n",
			addr);
		spin_unlock_irqrestore(&priv->shrd->sta_lock, flags_spin);
		return -EINVAL;
	}

	/*
	 * uCode is not able to deal with multiple requests to add a
	 * station. Keep track if one is in progress so that we do not send
	 * another.
	 */
	if (priv->stations[sta_id].used & IWL_STA_UCODE_INPROGRESS) {
		IWL_DEBUG_INFO(priv, "STA %d already in process of being added.\n",
			       sta_id);
		spin_unlock_irqrestore(&priv->shrd->sta_lock, flags_spin);
		return -EEXIST;
	}

	if ((priv->stations[sta_id].used & IWL_STA_DRIVER_ACTIVE) &&
	    (priv->stations[sta_id].used & IWL_STA_UCODE_ACTIVE)) {
		IWL_DEBUG_ASSOC(priv, "STA %d (%pM) already added, not adding again.\n",
				sta_id, addr);
		spin_unlock_irqrestore(&priv->shrd->sta_lock, flags_spin);
		return -EEXIST;
	}

	priv->stations[sta_id].used |= IWL_STA_UCODE_INPROGRESS;
	memcpy(&sta_cmd, &priv->stations[sta_id].sta, sizeof(struct iwl_addsta_cmd));
	spin_unlock_irqrestore(&priv->shrd->sta_lock, flags_spin);

	/* Add station to device's station table */
	ret = iwl_send_add_sta(priv, &sta_cmd, CMD_SYNC);
	if (ret) {
		spin_lock_irqsave(&priv->shrd->sta_lock, flags_spin);
		IWL_ERR(priv, "Adding station %pM failed.\n",
			priv->stations[sta_id].sta.sta.addr);
		priv->stations[sta_id].used &= ~IWL_STA_DRIVER_ACTIVE;
		priv->stations[sta_id].used &= ~IWL_STA_UCODE_INPROGRESS;
		spin_unlock_irqrestore(&priv->shrd->sta_lock, flags_spin);
	}
	*sta_id_r = sta_id;
	return ret;
}

/**
 * iwl_sta_ucode_deactivate - deactivate ucode status for a station
 *
 * priv->shrd->sta_lock must be held
 */
static void iwl_sta_ucode_deactivate(struct iwl_priv *priv, u8 sta_id)
{
	/* Ucode must be active and driver must be non active */
	if ((priv->stations[sta_id].used &
	     (IWL_STA_UCODE_ACTIVE | IWL_STA_DRIVER_ACTIVE)) != IWL_STA_UCODE_ACTIVE)
		IWL_ERR(priv, "removed non active STA %u\n", sta_id);

	priv->stations[sta_id].used &= ~IWL_STA_UCODE_ACTIVE;

	memset(&priv->stations[sta_id], 0, sizeof(struct iwl_station_entry));
	IWL_DEBUG_ASSOC(priv, "Removed STA %u\n", sta_id);
}

static int iwl_send_remove_station(struct iwl_priv *priv,
				   const u8 *addr, int sta_id,
				   bool temporary)
{
	struct iwl_rx_packet *pkt;
	int ret;

	unsigned long flags_spin;
	struct iwl_rem_sta_cmd rm_sta_cmd;

	struct iwl_host_cmd cmd = {
		.id = REPLY_REMOVE_STA,
		.len = { sizeof(struct iwl_rem_sta_cmd), },
		.flags = CMD_SYNC,
		.data = { &rm_sta_cmd, },
	};

	memset(&rm_sta_cmd, 0, sizeof(rm_sta_cmd));
	rm_sta_cmd.num_sta = 1;
	memcpy(&rm_sta_cmd.addr, addr, ETH_ALEN);

	cmd.flags |= CMD_WANT_SKB;

	ret = iwl_trans_send_cmd(trans(priv), &cmd);

	if (ret)
		return ret;

	pkt = (struct iwl_rx_packet *)cmd.reply_page;
	if (pkt->hdr.flags & IWL_CMD_FAILED_MSK) {
		IWL_ERR(priv, "Bad return from REPLY_REMOVE_STA (0x%08X)\n",
			  pkt->hdr.flags);
		ret = -EIO;
	}

	if (!ret) {
		switch (pkt->u.rem_sta.status) {
		case REM_STA_SUCCESS_MSK:
			if (!temporary) {
				spin_lock_irqsave(&priv->shrd->sta_lock,
					flags_spin);
				iwl_sta_ucode_deactivate(priv, sta_id);
				spin_unlock_irqrestore(&priv->shrd->sta_lock,
					flags_spin);
			}
			IWL_DEBUG_ASSOC(priv, "REPLY_REMOVE_STA PASSED\n");
			break;
		default:
			ret = -EIO;
			IWL_ERR(priv, "REPLY_REMOVE_STA failed\n");
			break;
		}
	}
	iwl_free_pages(priv->shrd, cmd.reply_page);

	return ret;
}

/**
 * iwl_remove_station - Remove driver's knowledge of station.
 */
int iwl_remove_station(struct iwl_priv *priv, const u8 sta_id,
		       const u8 *addr)
{
	unsigned long flags;

	if (!iwl_is_ready(priv->shrd)) {
		IWL_DEBUG_INFO(priv,
			"Unable to remove station %pM, device not ready.\n",
			addr);
		/*
		 * It is typical for stations to be removed when we are
		 * going down. Return success since device will be down
		 * soon anyway
		 */
		return 0;
	}

	IWL_DEBUG_ASSOC(priv, "Removing STA from driver:%d  %pM\n",
			sta_id, addr);

	if (WARN_ON(sta_id == IWL_INVALID_STATION))
		return -EINVAL;

	spin_lock_irqsave(&priv->shrd->sta_lock, flags);

	if (!(priv->stations[sta_id].used & IWL_STA_DRIVER_ACTIVE)) {
		IWL_DEBUG_INFO(priv, "Removing %pM but non DRIVER active\n",
				addr);
		goto out_err;
	}

	if (!(priv->stations[sta_id].used & IWL_STA_UCODE_ACTIVE)) {
		IWL_DEBUG_INFO(priv, "Removing %pM but non UCODE active\n",
				addr);
		goto out_err;
	}

	if (priv->stations[sta_id].used & IWL_STA_LOCAL) {
		kfree(priv->stations[sta_id].lq);
		priv->stations[sta_id].lq = NULL;
	}

	priv->stations[sta_id].used &= ~IWL_STA_DRIVER_ACTIVE;

	priv->num_stations--;

	if (WARN_ON(priv->num_stations < 0))
		priv->num_stations = 0;

	spin_unlock_irqrestore(&priv->shrd->sta_lock, flags);

	return iwl_send_remove_station(priv, addr, sta_id, false);
out_err:
	spin_unlock_irqrestore(&priv->shrd->sta_lock, flags);
	return -EINVAL;
}

/**
 * iwl_clear_ucode_stations - clear ucode station table bits
 *
 * This function clears all the bits in the driver indicating
 * which stations are active in the ucode. Call when something
 * other than explicit station management would cause this in
 * the ucode, e.g. unassociated RXON.
 */
void iwl_clear_ucode_stations(struct iwl_priv *priv,
			      struct iwl_rxon_context *ctx)
{
	int i;
	unsigned long flags_spin;
	bool cleared = false;

	IWL_DEBUG_INFO(priv, "Clearing ucode stations in driver\n");

	spin_lock_irqsave(&priv->shrd->sta_lock, flags_spin);
	for (i = 0; i < hw_params(priv).max_stations; i++) {
		if (ctx && ctx->ctxid != priv->stations[i].ctxid)
			continue;

		if (priv->stations[i].used & IWL_STA_UCODE_ACTIVE) {
			IWL_DEBUG_INFO(priv, "Clearing ucode active for station %d\n", i);
			priv->stations[i].used &= ~IWL_STA_UCODE_ACTIVE;
			cleared = true;
		}
	}
	spin_unlock_irqrestore(&priv->shrd->sta_lock, flags_spin);

	if (!cleared)
		IWL_DEBUG_INFO(priv, "No active stations found to be cleared\n");
}

/**
 * iwl_restore_stations() - Restore driver known stations to device
 *
 * All stations considered active by driver, but not present in ucode, is
 * restored.
 *
 * Function sleeps.
 */
void iwl_restore_stations(struct iwl_priv *priv, struct iwl_rxon_context *ctx)
{
	struct iwl_addsta_cmd sta_cmd;
	struct iwl_link_quality_cmd lq;
	unsigned long flags_spin;
	int i;
	bool found = false;
	int ret;
	bool send_lq;

	if (!iwl_is_ready(priv->shrd)) {
		IWL_DEBUG_INFO(priv, "Not ready yet, not restoring any stations.\n");
		return;
	}

	IWL_DEBUG_ASSOC(priv, "Restoring all known stations ... start.\n");
	spin_lock_irqsave(&priv->shrd->sta_lock, flags_spin);
	for (i = 0; i < hw_params(priv).max_stations; i++) {
		if (ctx->ctxid != priv->stations[i].ctxid)
			continue;
		if ((priv->stations[i].used & IWL_STA_DRIVER_ACTIVE) &&
			    !(priv->stations[i].used & IWL_STA_UCODE_ACTIVE)) {
			IWL_DEBUG_ASSOC(priv, "Restoring sta %pM\n",
					priv->stations[i].sta.sta.addr);
			priv->stations[i].sta.mode = 0;
			priv->stations[i].used |= IWL_STA_UCODE_INPROGRESS;
			found = true;
		}
	}

	for (i = 0; i < hw_params(priv).max_stations; i++) {
		if ((priv->stations[i].used & IWL_STA_UCODE_INPROGRESS)) {
			memcpy(&sta_cmd, &priv->stations[i].sta,
			       sizeof(struct iwl_addsta_cmd));
			send_lq = false;
			if (priv->stations[i].lq) {
				memcpy(&lq, priv->stations[i].lq,
				       sizeof(struct iwl_link_quality_cmd));
				send_lq = true;
			}
			spin_unlock_irqrestore(&priv->shrd->sta_lock,
					       flags_spin);
			ret = iwl_send_add_sta(priv, &sta_cmd, CMD_SYNC);
			if (ret) {
				spin_lock_irqsave(&priv->shrd->sta_lock,
						  flags_spin);
				IWL_ERR(priv, "Adding station %pM failed.\n",
					priv->stations[i].sta.sta.addr);
				priv->stations[i].used &= ~IWL_STA_DRIVER_ACTIVE;
				priv->stations[i].used &= ~IWL_STA_UCODE_INPROGRESS;
				spin_unlock_irqrestore(&priv->shrd->sta_lock,
						       flags_spin);
			}
			/*
			 * Rate scaling has already been initialized, send
			 * current LQ command
			 */
			if (send_lq)
				iwl_send_lq_cmd(priv, ctx, &lq, CMD_SYNC, true);
			spin_lock_irqsave(&priv->shrd->sta_lock, flags_spin);
			priv->stations[i].used &= ~IWL_STA_UCODE_INPROGRESS;
		}
	}

	spin_unlock_irqrestore(&priv->shrd->sta_lock, flags_spin);
	if (!found)
		IWL_DEBUG_INFO(priv, "Restoring all known stations .... no stations to be restored.\n");
	else
		IWL_DEBUG_INFO(priv, "Restoring all known stations .... complete.\n");
}

void iwl_reprogram_ap_sta(struct iwl_priv *priv, struct iwl_rxon_context *ctx)
{
	unsigned long flags;
	int sta_id = ctx->ap_sta_id;
	int ret;
	struct iwl_addsta_cmd sta_cmd;
	struct iwl_link_quality_cmd lq;
	bool active;

	spin_lock_irqsave(&priv->shrd->sta_lock, flags);
	if (!(priv->stations[sta_id].used & IWL_STA_DRIVER_ACTIVE)) {
		spin_unlock_irqrestore(&priv->shrd->sta_lock, flags);
		return;
	}

	memcpy(&sta_cmd, &priv->stations[sta_id].sta, sizeof(sta_cmd));
	sta_cmd.mode = 0;
	memcpy(&lq, priv->stations[sta_id].lq, sizeof(lq));

	active = priv->stations[sta_id].used & IWL_STA_UCODE_ACTIVE;
	priv->stations[sta_id].used &= ~IWL_STA_DRIVER_ACTIVE;
	spin_unlock_irqrestore(&priv->shrd->sta_lock, flags);

	if (active) {
		ret = iwl_send_remove_station(
			priv, priv->stations[sta_id].sta.sta.addr,
			sta_id, true);
		if (ret)
			IWL_ERR(priv, "failed to remove STA %pM (%d)\n",
				priv->stations[sta_id].sta.sta.addr, ret);
	}
	spin_lock_irqsave(&priv->shrd->sta_lock, flags);
	priv->stations[sta_id].used |= IWL_STA_DRIVER_ACTIVE;
	spin_unlock_irqrestore(&priv->shrd->sta_lock, flags);

	ret = iwl_send_add_sta(priv, &sta_cmd, CMD_SYNC);
	if (ret)
		IWL_ERR(priv, "failed to re-add STA %pM (%d)\n",
			priv->stations[sta_id].sta.sta.addr, ret);
	iwl_send_lq_cmd(priv, ctx, &lq, CMD_SYNC, true);
}

int iwl_get_free_ucode_key_offset(struct iwl_priv *priv)
{
	int i;

	for (i = 0; i < priv->sta_key_max_num; i++)
		if (!test_and_set_bit(i, &priv->ucode_key_table))
			return i;

	return WEP_INVALID_OFFSET;
}

void iwl_dealloc_bcast_stations(struct iwl_priv *priv)
{
	unsigned long flags;
	int i;

	spin_lock_irqsave(&priv->shrd->sta_lock, flags);
	for (i = 0; i < hw_params(priv).max_stations; i++) {
		if (!(priv->stations[i].used & IWL_STA_BCAST))
			continue;

		priv->stations[i].used &= ~IWL_STA_UCODE_ACTIVE;
		priv->num_stations--;
		if (WARN_ON(priv->num_stations < 0))
			priv->num_stations = 0;
		kfree(priv->stations[i].lq);
		priv->stations[i].lq = NULL;
	}
	spin_unlock_irqrestore(&priv->shrd->sta_lock, flags);
}

#ifdef CONFIG_IWLWIFI_DEBUG
static void iwl_dump_lq_cmd(struct iwl_priv *priv,
			   struct iwl_link_quality_cmd *lq)
{
	int i;
	IWL_DEBUG_RATE(priv, "lq station id 0x%x\n", lq->sta_id);
	IWL_DEBUG_RATE(priv, "lq ant 0x%X 0x%X\n",
		       lq->general_params.single_stream_ant_msk,
		       lq->general_params.dual_stream_ant_msk);

	for (i = 0; i < LINK_QUAL_MAX_RETRY_NUM; i++)
		IWL_DEBUG_RATE(priv, "lq index %d 0x%X\n",
			       i, lq->rs_table[i].rate_n_flags);
}
#else
static inline void iwl_dump_lq_cmd(struct iwl_priv *priv,
				   struct iwl_link_quality_cmd *lq)
{
}
#endif

/**
 * is_lq_table_valid() - Test one aspect of LQ cmd for validity
 *
 * It sometimes happens when a HT rate has been in use and we
 * loose connectivity with AP then mac80211 will first tell us that the
 * current channel is not HT anymore before removing the station. In such a
 * scenario the RXON flags will be updated to indicate we are not
 * communicating HT anymore, but the LQ command may still contain HT rates.
 * Test for this to prevent driver from sending LQ command between the time
 * RXON flags are updated and when LQ command is updated.
 */
static bool is_lq_table_valid(struct iwl_priv *priv,
			      struct iwl_rxon_context *ctx,
			      struct iwl_link_quality_cmd *lq)
{
	int i;

	if (ctx->ht.enabled)
		return true;

	IWL_DEBUG_INFO(priv, "Channel %u is not an HT channel\n",
		       ctx->active.channel);
	for (i = 0; i < LINK_QUAL_MAX_RETRY_NUM; i++) {
		if (le32_to_cpu(lq->rs_table[i].rate_n_flags) & RATE_MCS_HT_MSK) {
			IWL_DEBUG_INFO(priv,
				       "index %d of LQ expects HT channel\n",
				       i);
			return false;
		}
	}
	return true;
}

/**
 * iwl_send_lq_cmd() - Send link quality command
 * @init: This command is sent as part of station initialization right
 *        after station has been added.
 *
 * The link quality command is sent as the last step of station creation.
 * This is the special case in which init is set and we call a callback in
 * this case to clear the state indicating that station creation is in
 * progress.
 */
int iwl_send_lq_cmd(struct iwl_priv *priv, struct iwl_rxon_context *ctx,
		    struct iwl_link_quality_cmd *lq, u8 flags, bool init)
{
	int ret = 0;
	unsigned long flags_spin;

	struct iwl_host_cmd cmd = {
		.id = REPLY_TX_LINK_QUALITY_CMD,
		.len = { sizeof(struct iwl_link_quality_cmd), },
		.flags = flags,
		.data = { lq, },
	};

	if (WARN_ON(lq->sta_id == IWL_INVALID_STATION))
		return -EINVAL;


	spin_lock_irqsave(&priv->shrd->sta_lock, flags_spin);
	if (!(priv->stations[lq->sta_id].used & IWL_STA_DRIVER_ACTIVE)) {
		spin_unlock_irqrestore(&priv->shrd->sta_lock, flags_spin);
		return -EINVAL;
	}
	spin_unlock_irqrestore(&priv->shrd->sta_lock, flags_spin);

	iwl_dump_lq_cmd(priv, lq);
	if (WARN_ON(init && (cmd.flags & CMD_ASYNC)))
		return -EINVAL;

	if (is_lq_table_valid(priv, ctx, lq))
		ret = iwl_trans_send_cmd(trans(priv), &cmd);
	else
		ret = -EINVAL;

	if (cmd.flags & CMD_ASYNC)
		return ret;

	if (init) {
		IWL_DEBUG_INFO(priv, "init LQ command complete, clearing sta addition status for sta %d\n",
			       lq->sta_id);
		spin_lock_irqsave(&priv->shrd->sta_lock, flags_spin);
		priv->stations[lq->sta_id].used &= ~IWL_STA_UCODE_INPROGRESS;
		spin_unlock_irqrestore(&priv->shrd->sta_lock, flags_spin);
	}
	return ret;
}

int iwl_mac_sta_remove(struct ieee80211_hw *hw,
		       struct ieee80211_vif *vif,
		       struct ieee80211_sta *sta)
{
	struct iwl_priv *priv = hw->priv;
	struct iwl_station_priv *sta_priv = (void *)sta->drv_priv;
	int ret;

	IWL_DEBUG_INFO(priv, "received request to remove station %pM\n",
			sta->addr);
	mutex_lock(&priv->shrd->mutex);
	IWL_DEBUG_INFO(priv, "proceeding to remove station %pM\n",
			sta->addr);
	ret = iwl_remove_station(priv, sta_priv->sta_id, sta->addr);
	if (ret)
		IWL_ERR(priv, "Error removing station %pM\n",
			sta->addr);
	mutex_unlock(&priv->shrd->mutex);
	return ret;
}