Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...
[linux-2.6.git] / drivers / net / wireless / iwlwifi / iwl-scan.c
1 /******************************************************************************
2  *
3  * GPL LICENSE SUMMARY
4  *
5  * Copyright(c) 2008 - 2010 Intel Corporation. All rights reserved.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of version 2 of the GNU General Public License as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
19  * USA
20  *
21  * The full GNU General Public License is included in this distribution
22  * in the file called LICENSE.GPL.
23  *
24  * Contact Information:
25  *  Intel Linux Wireless <ilw@linux.intel.com>
26  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
27  *****************************************************************************/
28 #include <linux/slab.h>
29 #include <linux/types.h>
30 #include <linux/etherdevice.h>
31 #include <net/mac80211.h>
32
33 #include "iwl-eeprom.h"
34 #include "iwl-dev.h"
35 #include "iwl-core.h"
36 #include "iwl-sta.h"
37 #include "iwl-io.h"
38 #include "iwl-helpers.h"
39
40 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
41  * sending probe req.  This should be set long enough to hear probe responses
42  * from more than one AP.  */
43 #define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
44 #define IWL_ACTIVE_DWELL_TIME_52    (20)
45
46 #define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
47 #define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
48
49 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
50  * Must be set longer than active dwell time.
51  * For the most reliable scan, set > AP beacon interval (typically 100msec). */
52 #define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
53 #define IWL_PASSIVE_DWELL_TIME_52   (10)
54 #define IWL_PASSIVE_DWELL_BASE      (100)
55 #define IWL_CHANNEL_TUNE_TIME       5
56
57
58
59 /**
60  * iwl_scan_cancel - Cancel any currently executing HW scan
61  *
62  * NOTE: priv->mutex is not required before calling this function
63  */
64 int iwl_scan_cancel(struct iwl_priv *priv)
65 {
66         if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
67                 clear_bit(STATUS_SCANNING, &priv->status);
68                 return 0;
69         }
70
71         if (test_bit(STATUS_SCANNING, &priv->status)) {
72                 if (!test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
73                         IWL_DEBUG_SCAN(priv, "Queuing scan abort.\n");
74                         set_bit(STATUS_SCAN_ABORTING, &priv->status);
75                         queue_work(priv->workqueue, &priv->abort_scan);
76
77                 } else
78                         IWL_DEBUG_SCAN(priv, "Scan abort already in progress.\n");
79
80                 return test_bit(STATUS_SCANNING, &priv->status);
81         }
82
83         return 0;
84 }
85 EXPORT_SYMBOL(iwl_scan_cancel);
86 /**
87  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
88  * @ms: amount of time to wait (in milliseconds) for scan to abort
89  *
90  * NOTE: priv->mutex must be held before calling this function
91  */
92 int iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
93 {
94         unsigned long now = jiffies;
95         int ret;
96
97         ret = iwl_scan_cancel(priv);
98         if (ret && ms) {
99                 mutex_unlock(&priv->mutex);
100                 while (!time_after(jiffies, now + msecs_to_jiffies(ms)) &&
101                                 test_bit(STATUS_SCANNING, &priv->status))
102                         msleep(1);
103                 mutex_lock(&priv->mutex);
104
105                 return test_bit(STATUS_SCANNING, &priv->status);
106         }
107
108         return ret;
109 }
110 EXPORT_SYMBOL(iwl_scan_cancel_timeout);
111
112 static int iwl_send_scan_abort(struct iwl_priv *priv)
113 {
114         int ret = 0;
115         struct iwl_rx_packet *pkt;
116         struct iwl_host_cmd cmd = {
117                 .id = REPLY_SCAN_ABORT_CMD,
118                 .flags = CMD_WANT_SKB,
119         };
120
121         /* If there isn't a scan actively going on in the hardware
122          * then we are in between scan bands and not actually
123          * actively scanning, so don't send the abort command */
124         if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
125                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
126                 return 0;
127         }
128
129         ret = iwl_send_cmd_sync(priv, &cmd);
130         if (ret) {
131                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
132                 return ret;
133         }
134
135         pkt = (struct iwl_rx_packet *)cmd.reply_page;
136         if (pkt->u.status != CAN_ABORT_STATUS) {
137                 /* The scan abort will return 1 for success or
138                  * 2 for "failure".  A failure condition can be
139                  * due to simply not being in an active scan which
140                  * can occur if we send the scan abort before we
141                  * the microcode has notified us that a scan is
142                  * completed. */
143                 IWL_DEBUG_INFO(priv, "SCAN_ABORT returned %d.\n", pkt->u.status);
144                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
145                 clear_bit(STATUS_SCAN_HW, &priv->status);
146         }
147
148         iwl_free_pages(priv, cmd.reply_page);
149
150         return ret;
151 }
152
153 /* Service response to REPLY_SCAN_CMD (0x80) */
154 static void iwl_rx_reply_scan(struct iwl_priv *priv,
155                               struct iwl_rx_mem_buffer *rxb)
156 {
157 #ifdef CONFIG_IWLWIFI_DEBUG
158         struct iwl_rx_packet *pkt = rxb_addr(rxb);
159         struct iwl_scanreq_notification *notif =
160             (struct iwl_scanreq_notification *)pkt->u.raw;
161
162         IWL_DEBUG_RX(priv, "Scan request status = 0x%x\n", notif->status);
163 #endif
164 }
165
166 /* Service SCAN_START_NOTIFICATION (0x82) */
167 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
168                                     struct iwl_rx_mem_buffer *rxb)
169 {
170         struct iwl_rx_packet *pkt = rxb_addr(rxb);
171         struct iwl_scanstart_notification *notif =
172             (struct iwl_scanstart_notification *)pkt->u.raw;
173         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
174         IWL_DEBUG_SCAN(priv, "Scan start: "
175                        "%d [802.11%s] "
176                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
177                        notif->channel,
178                        notif->band ? "bg" : "a",
179                        le32_to_cpu(notif->tsf_high),
180                        le32_to_cpu(notif->tsf_low),
181                        notif->status, notif->beacon_timer);
182 }
183
184 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
185 static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
186                                       struct iwl_rx_mem_buffer *rxb)
187 {
188 #ifdef CONFIG_IWLWIFI_DEBUG
189         struct iwl_rx_packet *pkt = rxb_addr(rxb);
190         struct iwl_scanresults_notification *notif =
191             (struct iwl_scanresults_notification *)pkt->u.raw;
192
193         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
194                        "%d [802.11%s] "
195                        "(TSF: 0x%08X:%08X) - %d "
196                        "elapsed=%lu usec\n",
197                        notif->channel,
198                        notif->band ? "bg" : "a",
199                        le32_to_cpu(notif->tsf_high),
200                        le32_to_cpu(notif->tsf_low),
201                        le32_to_cpu(notif->statistics[0]),
202                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
203 #endif
204
205         if (!priv->is_internal_short_scan)
206                 priv->next_scan_jiffies = 0;
207 }
208
209 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
210 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
211                                        struct iwl_rx_mem_buffer *rxb)
212 {
213 #ifdef CONFIG_IWLWIFI_DEBUG
214         struct iwl_rx_packet *pkt = rxb_addr(rxb);
215         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
216
217         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
218                        scan_notif->scanned_channels,
219                        scan_notif->tsf_low,
220                        scan_notif->tsf_high, scan_notif->status);
221 #endif
222
223         /* The HW is no longer scanning */
224         clear_bit(STATUS_SCAN_HW, &priv->status);
225
226         IWL_DEBUG_INFO(priv, "Scan pass on %sGHz took %dms\n",
227                        (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) ?
228                                                 "2.4" : "5.2",
229                        jiffies_to_msecs(elapsed_jiffies
230                                         (priv->scan_pass_start, jiffies)));
231
232         /* Remove this scanned band from the list of pending
233          * bands to scan, band G precedes A in order of scanning
234          * as seen in iwl_bg_request_scan */
235         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ))
236                 priv->scan_bands &= ~BIT(IEEE80211_BAND_2GHZ);
237         else if (priv->scan_bands &  BIT(IEEE80211_BAND_5GHZ))
238                 priv->scan_bands &= ~BIT(IEEE80211_BAND_5GHZ);
239
240         /* If a request to abort was given, or the scan did not succeed
241          * then we reset the scan state machine and terminate,
242          * re-queuing another scan if one has been requested */
243         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
244                 IWL_DEBUG_INFO(priv, "Aborted scan completed.\n");
245                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
246         } else {
247                 /* If there are more bands on this scan pass reschedule */
248                 if (priv->scan_bands)
249                         goto reschedule;
250         }
251
252         if (!priv->is_internal_short_scan)
253                 priv->next_scan_jiffies = 0;
254
255         IWL_DEBUG_INFO(priv, "Setting scan to off\n");
256
257         clear_bit(STATUS_SCANNING, &priv->status);
258
259         IWL_DEBUG_INFO(priv, "Scan took %dms\n",
260                 jiffies_to_msecs(elapsed_jiffies(priv->scan_start, jiffies)));
261
262         queue_work(priv->workqueue, &priv->scan_completed);
263
264         return;
265
266 reschedule:
267         priv->scan_pass_start = jiffies;
268         queue_work(priv->workqueue, &priv->request_scan);
269 }
270
271 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
272 {
273         /* scan handlers */
274         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
275         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
276         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
277                                         iwl_rx_scan_results_notif;
278         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
279                                         iwl_rx_scan_complete_notif;
280 }
281 EXPORT_SYMBOL(iwl_setup_rx_scan_handlers);
282
283 inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
284                                      enum ieee80211_band band,
285                                      u8 n_probes)
286 {
287         if (band == IEEE80211_BAND_5GHZ)
288                 return IWL_ACTIVE_DWELL_TIME_52 +
289                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
290         else
291                 return IWL_ACTIVE_DWELL_TIME_24 +
292                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
293 }
294 EXPORT_SYMBOL(iwl_get_active_dwell_time);
295
296 u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
297                                enum ieee80211_band band)
298 {
299         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
300             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
301             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
302
303         if (iwl_is_associated(priv)) {
304                 /* If we're associated, we clamp the maximum passive
305                  * dwell time to be 98% of the beacon interval (minus
306                  * 2 * channel tune time) */
307                 passive = priv->beacon_int;
308                 if ((passive > IWL_PASSIVE_DWELL_BASE) || !passive)
309                         passive = IWL_PASSIVE_DWELL_BASE;
310                 passive = (passive * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
311         }
312
313         return passive;
314 }
315 EXPORT_SYMBOL(iwl_get_passive_dwell_time);
316
317 static int iwl_get_single_channel_for_scan(struct iwl_priv *priv,
318                                      enum ieee80211_band band,
319                                      struct iwl_scan_channel *scan_ch)
320 {
321         const struct ieee80211_supported_band *sband;
322         const struct iwl_channel_info *ch_info;
323         u16 passive_dwell = 0;
324         u16 active_dwell = 0;
325         int i, added = 0;
326         u16 channel = 0;
327
328         sband = iwl_get_hw_mode(priv, band);
329         if (!sband) {
330                 IWL_ERR(priv, "invalid band\n");
331                 return added;
332         }
333
334         active_dwell = iwl_get_active_dwell_time(priv, band, 0);
335         passive_dwell = iwl_get_passive_dwell_time(priv, band);
336
337         if (passive_dwell <= active_dwell)
338                 passive_dwell = active_dwell + 1;
339
340         /* only scan single channel, good enough to reset the RF */
341         /* pick the first valid not in-use channel */
342         if (band == IEEE80211_BAND_5GHZ) {
343                 for (i = 14; i < priv->channel_count; i++) {
344                         if (priv->channel_info[i].channel !=
345                             le16_to_cpu(priv->staging_rxon.channel)) {
346                                 channel = priv->channel_info[i].channel;
347                                 ch_info = iwl_get_channel_info(priv,
348                                         band, channel);
349                                 if (is_channel_valid(ch_info))
350                                         break;
351                         }
352                 }
353         } else {
354                 for (i = 0; i < 14; i++) {
355                         if (priv->channel_info[i].channel !=
356                             le16_to_cpu(priv->staging_rxon.channel)) {
357                                         channel =
358                                                 priv->channel_info[i].channel;
359                                         ch_info = iwl_get_channel_info(priv,
360                                                 band, channel);
361                                         if (is_channel_valid(ch_info))
362                                                 break;
363                         }
364                 }
365         }
366         if (channel) {
367                 scan_ch->channel = cpu_to_le16(channel);
368                 scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
369                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
370                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
371                 /* Set txpower levels to defaults */
372                 scan_ch->dsp_atten = 110;
373                 if (band == IEEE80211_BAND_5GHZ)
374                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
375                 else
376                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
377                 added++;
378         } else
379                 IWL_ERR(priv, "no valid channel found\n");
380         return added;
381 }
382
383 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
384                                      enum ieee80211_band band,
385                                      u8 is_active, u8 n_probes,
386                                      struct iwl_scan_channel *scan_ch)
387 {
388         struct ieee80211_channel *chan;
389         const struct ieee80211_supported_band *sband;
390         const struct iwl_channel_info *ch_info;
391         u16 passive_dwell = 0;
392         u16 active_dwell = 0;
393         int added, i;
394         u16 channel;
395
396         sband = iwl_get_hw_mode(priv, band);
397         if (!sband)
398                 return 0;
399
400         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
401         passive_dwell = iwl_get_passive_dwell_time(priv, band);
402
403         if (passive_dwell <= active_dwell)
404                 passive_dwell = active_dwell + 1;
405
406         for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
407                 chan = priv->scan_request->channels[i];
408
409                 if (chan->band != band)
410                         continue;
411
412                 channel = ieee80211_frequency_to_channel(chan->center_freq);
413                 scan_ch->channel = cpu_to_le16(channel);
414
415                 ch_info = iwl_get_channel_info(priv, band, channel);
416                 if (!is_channel_valid(ch_info)) {
417                         IWL_DEBUG_SCAN(priv, "Channel %d is INVALID for this band.\n",
418                                         channel);
419                         continue;
420                 }
421
422                 if (!is_active || is_channel_passive(ch_info) ||
423                     (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN))
424                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
425                 else
426                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
427
428                 if (n_probes)
429                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
430
431                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
432                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
433
434                 /* Set txpower levels to defaults */
435                 scan_ch->dsp_atten = 110;
436
437                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
438                  * power level:
439                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
440                  */
441                 if (band == IEEE80211_BAND_5GHZ)
442                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
443                 else
444                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
445
446                 IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
447                                channel, le32_to_cpu(scan_ch->type),
448                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
449                                 "ACTIVE" : "PASSIVE",
450                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
451                                active_dwell : passive_dwell);
452
453                 scan_ch++;
454                 added++;
455         }
456
457         IWL_DEBUG_SCAN(priv, "total channels to scan %d \n", added);
458         return added;
459 }
460
461 void iwl_init_scan_params(struct iwl_priv *priv)
462 {
463         u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
464         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
465                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
466         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
467                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
468 }
469 EXPORT_SYMBOL(iwl_init_scan_params);
470
471 static int iwl_scan_initiate(struct iwl_priv *priv)
472 {
473         WARN_ON(!mutex_is_locked(&priv->mutex));
474
475         IWL_DEBUG_INFO(priv, "Starting scan...\n");
476         set_bit(STATUS_SCANNING, &priv->status);
477         priv->is_internal_short_scan = false;
478         priv->scan_start = jiffies;
479         priv->scan_pass_start = priv->scan_start;
480
481         queue_work(priv->workqueue, &priv->request_scan);
482
483         return 0;
484 }
485
486 #define IWL_DELAY_NEXT_SCAN (HZ*2)
487
488 int iwl_mac_hw_scan(struct ieee80211_hw *hw,
489                      struct cfg80211_scan_request *req)
490 {
491         unsigned long flags;
492         struct iwl_priv *priv = hw->priv;
493         int ret, i;
494
495         IWL_DEBUG_MAC80211(priv, "enter\n");
496
497         mutex_lock(&priv->mutex);
498         spin_lock_irqsave(&priv->lock, flags);
499
500         if (!iwl_is_ready_rf(priv)) {
501                 ret = -EIO;
502                 IWL_DEBUG_MAC80211(priv, "leave - not ready or exit pending\n");
503                 goto out_unlock;
504         }
505
506         if (test_bit(STATUS_SCANNING, &priv->status)) {
507                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
508                 ret = -EAGAIN;
509                 goto out_unlock;
510         }
511
512         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
513                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
514                 ret = -EAGAIN;
515                 goto out_unlock;
516         }
517
518         /* We don't schedule scan within next_scan_jiffies period.
519          * Avoid scanning during possible EAPOL exchange, return
520          * success immediately.
521          */
522         if (priv->next_scan_jiffies &&
523             time_after(priv->next_scan_jiffies, jiffies)) {
524                 IWL_DEBUG_SCAN(priv, "scan rejected: within next scan period\n");
525                 queue_work(priv->workqueue, &priv->scan_completed);
526                 ret = 0;
527                 goto out_unlock;
528         }
529
530         priv->scan_bands = 0;
531         for (i = 0; i < req->n_channels; i++)
532                 priv->scan_bands |= BIT(req->channels[i]->band);
533
534         priv->scan_request = req;
535
536         ret = iwl_scan_initiate(priv);
537
538         IWL_DEBUG_MAC80211(priv, "leave\n");
539
540 out_unlock:
541         spin_unlock_irqrestore(&priv->lock, flags);
542         mutex_unlock(&priv->mutex);
543
544         return ret;
545 }
546 EXPORT_SYMBOL(iwl_mac_hw_scan);
547
548 /*
549  * internal short scan, this function should only been called while associated.
550  * It will reset and tune the radio to prevent possible RF related problem
551  */
552 void iwl_internal_short_hw_scan(struct iwl_priv *priv)
553 {
554         queue_work(priv->workqueue, &priv->start_internal_scan);
555 }
556
557 static void iwl_bg_start_internal_scan(struct work_struct *work)
558 {
559         struct iwl_priv *priv =
560                 container_of(work, struct iwl_priv, start_internal_scan);
561
562         mutex_lock(&priv->mutex);
563
564         if (!iwl_is_ready_rf(priv)) {
565                 IWL_DEBUG_SCAN(priv, "not ready or exit pending\n");
566                 goto unlock;
567         }
568
569         if (test_bit(STATUS_SCANNING, &priv->status)) {
570                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
571                 goto unlock;
572         }
573
574         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
575                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
576                 goto unlock;
577         }
578
579         priv->scan_bands = 0;
580         if (priv->band == IEEE80211_BAND_5GHZ)
581                 priv->scan_bands |= BIT(IEEE80211_BAND_5GHZ);
582         else
583                 priv->scan_bands |= BIT(IEEE80211_BAND_2GHZ);
584
585         IWL_DEBUG_SCAN(priv, "Start internal short scan...\n");
586         set_bit(STATUS_SCANNING, &priv->status);
587         priv->is_internal_short_scan = true;
588         queue_work(priv->workqueue, &priv->request_scan);
589  unlock:
590         mutex_unlock(&priv->mutex);
591 }
592 EXPORT_SYMBOL(iwl_internal_short_hw_scan);
593
594 #define IWL_SCAN_CHECK_WATCHDOG (7 * HZ)
595
596 void iwl_bg_scan_check(struct work_struct *data)
597 {
598         struct iwl_priv *priv =
599             container_of(data, struct iwl_priv, scan_check.work);
600
601         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
602                 return;
603
604         mutex_lock(&priv->mutex);
605         if (test_bit(STATUS_SCANNING, &priv->status) ||
606             test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
607                 IWL_DEBUG_SCAN(priv, "Scan completion watchdog resetting "
608                         "adapter (%dms)\n",
609                         jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG));
610
611                 if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
612                         iwl_send_scan_abort(priv);
613         }
614         mutex_unlock(&priv->mutex);
615 }
616 EXPORT_SYMBOL(iwl_bg_scan_check);
617
618 /**
619  * iwl_fill_probe_req - fill in all required fields and IE for probe request
620  */
621
622 u16 iwl_fill_probe_req(struct iwl_priv *priv, struct ieee80211_mgmt *frame,
623                        const u8 *ies, int ie_len, int left)
624 {
625         int len = 0;
626         u8 *pos = NULL;
627
628         /* Make sure there is enough space for the probe request,
629          * two mandatory IEs and the data */
630         left -= 24;
631         if (left < 0)
632                 return 0;
633
634         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
635         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
636         memcpy(frame->sa, priv->mac_addr, ETH_ALEN);
637         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
638         frame->seq_ctrl = 0;
639
640         len += 24;
641
642         /* ...next IE... */
643         pos = &frame->u.probe_req.variable[0];
644
645         /* fill in our indirect SSID IE */
646         left -= 2;
647         if (left < 0)
648                 return 0;
649         *pos++ = WLAN_EID_SSID;
650         *pos++ = 0;
651
652         len += 2;
653
654         if (WARN_ON(left < ie_len))
655                 return len;
656
657         if (ies)
658                 memcpy(pos, ies, ie_len);
659         len += ie_len;
660         left -= ie_len;
661
662         return (u16)len;
663 }
664 EXPORT_SYMBOL(iwl_fill_probe_req);
665
666 static void iwl_bg_request_scan(struct work_struct *data)
667 {
668         struct iwl_priv *priv =
669             container_of(data, struct iwl_priv, request_scan);
670         struct iwl_host_cmd cmd = {
671                 .id = REPLY_SCAN_CMD,
672                 .len = sizeof(struct iwl_scan_cmd),
673                 .flags = CMD_SIZE_HUGE,
674         };
675         struct iwl_scan_cmd *scan;
676         struct ieee80211_conf *conf = NULL;
677         int ret = 0;
678         u32 rate_flags = 0;
679         u16 cmd_len;
680         u16 rx_chain = 0;
681         enum ieee80211_band band;
682         u8 n_probes = 0;
683         u8 rx_ant = priv->hw_params.valid_rx_ant;
684         u8 rate;
685         bool is_active = false;
686         int  chan_mod;
687         u8 active_chains;
688
689         conf = ieee80211_get_hw_conf(priv->hw);
690
691         mutex_lock(&priv->mutex);
692
693         cancel_delayed_work(&priv->scan_check);
694
695         if (!iwl_is_ready(priv)) {
696                 IWL_WARN(priv, "request scan called when driver not ready.\n");
697                 goto done;
698         }
699
700         /* Make sure the scan wasn't canceled before this queued work
701          * was given the chance to run... */
702         if (!test_bit(STATUS_SCANNING, &priv->status))
703                 goto done;
704
705         /* This should never be called or scheduled if there is currently
706          * a scan active in the hardware. */
707         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
708                 IWL_DEBUG_INFO(priv, "Multiple concurrent scan requests in parallel. "
709                                "Ignoring second request.\n");
710                 ret = -EIO;
711                 goto done;
712         }
713
714         if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
715                 IWL_DEBUG_SCAN(priv, "Aborting scan due to device shutdown\n");
716                 goto done;
717         }
718
719         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
720                 IWL_DEBUG_HC(priv, "Scan request while abort pending.  Queuing.\n");
721                 goto done;
722         }
723
724         if (iwl_is_rfkill(priv)) {
725                 IWL_DEBUG_HC(priv, "Aborting scan due to RF Kill activation\n");
726                 goto done;
727         }
728
729         if (!test_bit(STATUS_READY, &priv->status)) {
730                 IWL_DEBUG_HC(priv, "Scan request while uninitialized.  Queuing.\n");
731                 goto done;
732         }
733
734         if (!priv->scan_bands) {
735                 IWL_DEBUG_HC(priv, "Aborting scan due to no requested bands\n");
736                 goto done;
737         }
738
739         if (!priv->scan) {
740                 priv->scan = kmalloc(sizeof(struct iwl_scan_cmd) +
741                                      IWL_MAX_SCAN_SIZE, GFP_KERNEL);
742                 if (!priv->scan) {
743                         ret = -ENOMEM;
744                         goto done;
745                 }
746         }
747         scan = priv->scan;
748         memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
749
750         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
751         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
752
753         if (iwl_is_associated(priv)) {
754                 u16 interval = 0;
755                 u32 extra;
756                 u32 suspend_time = 100;
757                 u32 scan_suspend_time = 100;
758                 unsigned long flags;
759
760                 IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
761                 spin_lock_irqsave(&priv->lock, flags);
762                 interval = priv->beacon_int;
763                 spin_unlock_irqrestore(&priv->lock, flags);
764
765                 scan->suspend_time = 0;
766                 scan->max_out_time = cpu_to_le32(200 * 1024);
767                 if (!interval)
768                         interval = suspend_time;
769
770                 extra = (suspend_time / interval) << 22;
771                 scan_suspend_time = (extra |
772                     ((suspend_time % interval) * 1024));
773                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
774                 IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
775                                scan_suspend_time, interval);
776         }
777
778         if (priv->is_internal_short_scan) {
779                 IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
780         } else if (priv->scan_request->n_ssids) {
781                 int i, p = 0;
782                 IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
783                 for (i = 0; i < priv->scan_request->n_ssids; i++) {
784                         /* always does wildcard anyway */
785                         if (!priv->scan_request->ssids[i].ssid_len)
786                                 continue;
787                         scan->direct_scan[p].id = WLAN_EID_SSID;
788                         scan->direct_scan[p].len =
789                                 priv->scan_request->ssids[i].ssid_len;
790                         memcpy(scan->direct_scan[p].ssid,
791                                priv->scan_request->ssids[i].ssid,
792                                priv->scan_request->ssids[i].ssid_len);
793                         n_probes++;
794                         p++;
795                 }
796                 is_active = true;
797         } else
798                 IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
799
800         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
801         scan->tx_cmd.sta_id = priv->hw_params.bcast_sta_id;
802         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
803
804
805         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) {
806                 band = IEEE80211_BAND_2GHZ;
807                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
808                 chan_mod = le32_to_cpu(priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_MSK)
809                                        >> RXON_FLG_CHANNEL_MODE_POS;
810                 if (chan_mod == CHANNEL_MODE_PURE_40) {
811                         rate = IWL_RATE_6M_PLCP;
812                 } else {
813                         rate = IWL_RATE_1M_PLCP;
814                         rate_flags = RATE_MCS_CCK_MSK;
815                 }
816                 scan->good_CRC_th = IWL_GOOD_CRC_TH_DISABLED;
817         } else if (priv->scan_bands & BIT(IEEE80211_BAND_5GHZ)) {
818                 band = IEEE80211_BAND_5GHZ;
819                 rate = IWL_RATE_6M_PLCP;
820                 /*
821                  * If active scanning is requested but a certain channel is
822                  * marked passive, we can do active scanning if we detect
823                  * transmissions.
824                  *
825                  * There is an issue with some firmware versions that triggers
826                  * a sysassert on a "good CRC threshold" of zero (== disabled),
827                  * on a radar channel even though this means that we should NOT
828                  * send probes.
829                  *
830                  * The "good CRC threshold" is the number of frames that we
831                  * need to receive during our dwell time on a channel before
832                  * sending out probes -- setting this to a huge value will
833                  * mean we never reach it, but at the same time work around
834                  * the aforementioned issue. Thus use IWL_GOOD_CRC_TH_NEVER
835                  * here instead of IWL_GOOD_CRC_TH_DISABLED.
836                  */
837                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
838                                                 IWL_GOOD_CRC_TH_NEVER;
839
840                 /* Force use of chains B and C (0x6) for scan Rx for 4965
841                  * Avoid A (0x1) because of its off-channel reception on A-band.
842                  */
843                 if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) == CSR_HW_REV_TYPE_4965)
844                         rx_ant = ANT_BC;
845         } else {
846                 IWL_WARN(priv, "Invalid scan band count\n");
847                 goto done;
848         }
849
850         priv->scan_tx_ant[band] =
851                          iwl_toggle_tx_ant(priv, priv->scan_tx_ant[band]);
852         rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
853         scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
854
855         /* In power save mode use one chain, otherwise use all chains */
856         if (test_bit(STATUS_POWER_PMI, &priv->status)) {
857                 /* rx_ant has been set to all valid chains previously */
858                 active_chains = rx_ant &
859                                 ((u8)(priv->chain_noise_data.active_chains));
860                 if (!active_chains)
861                         active_chains = rx_ant;
862
863                 IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
864                                 priv->chain_noise_data.active_chains);
865
866                 rx_ant = first_antenna(active_chains);
867         }
868         /* MIMO is not used here, but value is required */
869         rx_chain |= priv->hw_params.valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
870         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
871         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
872         rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
873         scan->rx_chain = cpu_to_le16(rx_chain);
874         if (!priv->is_internal_short_scan) {
875                 cmd_len = iwl_fill_probe_req(priv,
876                                         (struct ieee80211_mgmt *)scan->data,
877                                         priv->scan_request->ie,
878                                         priv->scan_request->ie_len,
879                                         IWL_MAX_SCAN_SIZE - sizeof(*scan));
880         } else {
881                 cmd_len = iwl_fill_probe_req(priv,
882                                         (struct ieee80211_mgmt *)scan->data,
883                                         NULL, 0,
884                                         IWL_MAX_SCAN_SIZE - sizeof(*scan));
885
886         }
887         scan->tx_cmd.len = cpu_to_le16(cmd_len);
888         if (iwl_is_monitor_mode(priv))
889                 scan->filter_flags = RXON_FILTER_PROMISC_MSK;
890
891         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
892                                RXON_FILTER_BCON_AWARE_MSK);
893
894         if (priv->is_internal_short_scan) {
895                 scan->channel_count =
896                         iwl_get_single_channel_for_scan(priv, band,
897                                 (void *)&scan->data[le16_to_cpu(
898                                 scan->tx_cmd.len)]);
899         } else {
900                 scan->channel_count =
901                         iwl_get_channels_for_scan(priv, band,
902                                 is_active, n_probes,
903                                 (void *)&scan->data[le16_to_cpu(
904                                 scan->tx_cmd.len)]);
905         }
906         if (scan->channel_count == 0) {
907                 IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
908                 goto done;
909         }
910
911         cmd.len += le16_to_cpu(scan->tx_cmd.len) +
912             scan->channel_count * sizeof(struct iwl_scan_channel);
913         cmd.data = scan;
914         scan->len = cpu_to_le16(cmd.len);
915
916         set_bit(STATUS_SCAN_HW, &priv->status);
917         ret = iwl_send_cmd_sync(priv, &cmd);
918         if (ret)
919                 goto done;
920
921         queue_delayed_work(priv->workqueue, &priv->scan_check,
922                            IWL_SCAN_CHECK_WATCHDOG);
923
924         mutex_unlock(&priv->mutex);
925         return;
926
927  done:
928         /* Cannot perform scan. Make sure we clear scanning
929         * bits from status so next scan request can be performed.
930         * If we don't clear scanning status bit here all next scan
931         * will fail
932         */
933         clear_bit(STATUS_SCAN_HW, &priv->status);
934         clear_bit(STATUS_SCANNING, &priv->status);
935         /* inform mac80211 scan aborted */
936         queue_work(priv->workqueue, &priv->scan_completed);
937         mutex_unlock(&priv->mutex);
938 }
939
940 void iwl_bg_abort_scan(struct work_struct *work)
941 {
942         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
943
944         if (!test_bit(STATUS_READY, &priv->status) ||
945             !test_bit(STATUS_GEO_CONFIGURED, &priv->status))
946                 return;
947
948         mutex_lock(&priv->mutex);
949
950         set_bit(STATUS_SCAN_ABORTING, &priv->status);
951         iwl_send_scan_abort(priv);
952
953         mutex_unlock(&priv->mutex);
954 }
955 EXPORT_SYMBOL(iwl_bg_abort_scan);
956
957 void iwl_bg_scan_completed(struct work_struct *work)
958 {
959         struct iwl_priv *priv =
960             container_of(work, struct iwl_priv, scan_completed);
961
962         IWL_DEBUG_SCAN(priv, "SCAN complete scan\n");
963
964         cancel_delayed_work(&priv->scan_check);
965
966         if (!priv->is_internal_short_scan)
967                 ieee80211_scan_completed(priv->hw, false);
968         else {
969                 priv->is_internal_short_scan = false;
970                 IWL_DEBUG_SCAN(priv, "internal short scan completed\n");
971         }
972
973         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
974                 return;
975
976         /* Since setting the TXPOWER may have been deferred while
977          * performing the scan, fire one off */
978         mutex_lock(&priv->mutex);
979         iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);
980         mutex_unlock(&priv->mutex);
981 }
982 EXPORT_SYMBOL(iwl_bg_scan_completed);
983
984 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
985 {
986         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
987         INIT_WORK(&priv->request_scan, iwl_bg_request_scan);
988         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
989         INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
990         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
991 }
992 EXPORT_SYMBOL(iwl_setup_scan_deferred_work);
993