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         IWL_DEBUG_INFO(priv, "Starting scan...\n");
474         set_bit(STATUS_SCANNING, &priv->status);
475         priv->is_internal_short_scan = false;
476         priv->scan_start = jiffies;
477         priv->scan_pass_start = priv->scan_start;
478
479         queue_work(priv->workqueue, &priv->request_scan);
480
481         return 0;
482 }
483
484 #define IWL_DELAY_NEXT_SCAN (HZ*2)
485
486 int iwl_mac_hw_scan(struct ieee80211_hw *hw,
487                      struct cfg80211_scan_request *req)
488 {
489         unsigned long flags;
490         struct iwl_priv *priv = hw->priv;
491         int ret, i;
492
493         IWL_DEBUG_MAC80211(priv, "enter\n");
494
495         mutex_lock(&priv->mutex);
496         spin_lock_irqsave(&priv->lock, flags);
497
498         if (!iwl_is_ready_rf(priv)) {
499                 ret = -EIO;
500                 IWL_DEBUG_MAC80211(priv, "leave - not ready or exit pending\n");
501                 goto out_unlock;
502         }
503
504         if (test_bit(STATUS_SCANNING, &priv->status)) {
505                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
506                 ret = -EAGAIN;
507                 goto out_unlock;
508         }
509
510         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
511                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
512                 ret = -EAGAIN;
513                 goto out_unlock;
514         }
515
516         /* We don't schedule scan within next_scan_jiffies period.
517          * Avoid scanning during possible EAPOL exchange, return
518          * success immediately.
519          */
520         if (priv->next_scan_jiffies &&
521             time_after(priv->next_scan_jiffies, jiffies)) {
522                 IWL_DEBUG_SCAN(priv, "scan rejected: within next scan period\n");
523                 queue_work(priv->workqueue, &priv->scan_completed);
524                 ret = 0;
525                 goto out_unlock;
526         }
527
528         priv->scan_bands = 0;
529         for (i = 0; i < req->n_channels; i++)
530                 priv->scan_bands |= BIT(req->channels[i]->band);
531
532         priv->scan_request = req;
533
534         ret = iwl_scan_initiate(priv);
535
536         IWL_DEBUG_MAC80211(priv, "leave\n");
537
538 out_unlock:
539         spin_unlock_irqrestore(&priv->lock, flags);
540         mutex_unlock(&priv->mutex);
541
542         return ret;
543 }
544 EXPORT_SYMBOL(iwl_mac_hw_scan);
545
546 /*
547  * internal short scan, this function should only been called while associated.
548  * It will reset and tune the radio to prevent possible RF related problem
549  */
550 int iwl_internal_short_hw_scan(struct iwl_priv *priv)
551 {
552         int ret = 0;
553
554         if (!iwl_is_ready_rf(priv)) {
555                 ret = -EIO;
556                 IWL_DEBUG_SCAN(priv, "not ready or exit pending\n");
557                 goto out;
558         }
559         if (test_bit(STATUS_SCANNING, &priv->status)) {
560                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
561                 ret = -EAGAIN;
562                 goto out;
563         }
564         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
565                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
566                 ret = -EAGAIN;
567                 goto out;
568         }
569
570         priv->scan_bands = 0;
571         if (priv->band == IEEE80211_BAND_5GHZ)
572                 priv->scan_bands |= BIT(IEEE80211_BAND_5GHZ);
573         else
574                 priv->scan_bands |= BIT(IEEE80211_BAND_2GHZ);
575
576         IWL_DEBUG_SCAN(priv, "Start internal short scan...\n");
577         set_bit(STATUS_SCANNING, &priv->status);
578         priv->is_internal_short_scan = true;
579         queue_work(priv->workqueue, &priv->request_scan);
580
581 out:
582         return ret;
583 }
584
585 #define IWL_SCAN_CHECK_WATCHDOG (7 * HZ)
586
587 void iwl_bg_scan_check(struct work_struct *data)
588 {
589         struct iwl_priv *priv =
590             container_of(data, struct iwl_priv, scan_check.work);
591
592         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
593                 return;
594
595         mutex_lock(&priv->mutex);
596         if (test_bit(STATUS_SCANNING, &priv->status) ||
597             test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
598                 IWL_DEBUG_SCAN(priv, "Scan completion watchdog resetting "
599                         "adapter (%dms)\n",
600                         jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG));
601
602                 if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
603                         iwl_send_scan_abort(priv);
604         }
605         mutex_unlock(&priv->mutex);
606 }
607 EXPORT_SYMBOL(iwl_bg_scan_check);
608
609 /**
610  * iwl_fill_probe_req - fill in all required fields and IE for probe request
611  */
612
613 u16 iwl_fill_probe_req(struct iwl_priv *priv, struct ieee80211_mgmt *frame,
614                        const u8 *ies, int ie_len, int left)
615 {
616         int len = 0;
617         u8 *pos = NULL;
618
619         /* Make sure there is enough space for the probe request,
620          * two mandatory IEs and the data */
621         left -= 24;
622         if (left < 0)
623                 return 0;
624
625         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
626         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
627         memcpy(frame->sa, priv->mac_addr, ETH_ALEN);
628         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
629         frame->seq_ctrl = 0;
630
631         len += 24;
632
633         /* ...next IE... */
634         pos = &frame->u.probe_req.variable[0];
635
636         /* fill in our indirect SSID IE */
637         left -= 2;
638         if (left < 0)
639                 return 0;
640         *pos++ = WLAN_EID_SSID;
641         *pos++ = 0;
642
643         len += 2;
644
645         if (WARN_ON(left < ie_len))
646                 return len;
647
648         if (ies)
649                 memcpy(pos, ies, ie_len);
650         len += ie_len;
651         left -= ie_len;
652
653         return (u16)len;
654 }
655 EXPORT_SYMBOL(iwl_fill_probe_req);
656
657 static void iwl_bg_request_scan(struct work_struct *data)
658 {
659         struct iwl_priv *priv =
660             container_of(data, struct iwl_priv, request_scan);
661         struct iwl_host_cmd cmd = {
662                 .id = REPLY_SCAN_CMD,
663                 .len = sizeof(struct iwl_scan_cmd),
664                 .flags = CMD_SIZE_HUGE,
665         };
666         struct iwl_scan_cmd *scan;
667         struct ieee80211_conf *conf = NULL;
668         u32 rate_flags = 0;
669         u16 cmd_len;
670         u16 rx_chain = 0;
671         enum ieee80211_band band;
672         u8 n_probes = 0;
673         u8 rx_ant = priv->hw_params.valid_rx_ant;
674         u8 rate;
675         bool is_active = false;
676         int  chan_mod;
677         u8 active_chains;
678
679         conf = ieee80211_get_hw_conf(priv->hw);
680
681         mutex_lock(&priv->mutex);
682
683         cancel_delayed_work(&priv->scan_check);
684
685         if (!iwl_is_ready(priv)) {
686                 IWL_WARN(priv, "request scan called when driver not ready.\n");
687                 goto done;
688         }
689
690         /* Make sure the scan wasn't canceled before this queued work
691          * was given the chance to run... */
692         if (!test_bit(STATUS_SCANNING, &priv->status))
693                 goto done;
694
695         /* This should never be called or scheduled if there is currently
696          * a scan active in the hardware. */
697         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
698                 IWL_DEBUG_INFO(priv, "Multiple concurrent scan requests in parallel. "
699                                "Ignoring second request.\n");
700                 goto done;
701         }
702
703         if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
704                 IWL_DEBUG_SCAN(priv, "Aborting scan due to device shutdown\n");
705                 goto done;
706         }
707
708         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
709                 IWL_DEBUG_HC(priv, "Scan request while abort pending.  Queuing.\n");
710                 goto done;
711         }
712
713         if (iwl_is_rfkill(priv)) {
714                 IWL_DEBUG_HC(priv, "Aborting scan due to RF Kill activation\n");
715                 goto done;
716         }
717
718         if (!test_bit(STATUS_READY, &priv->status)) {
719                 IWL_DEBUG_HC(priv, "Scan request while uninitialized.  Queuing.\n");
720                 goto done;
721         }
722
723         if (!priv->scan_bands) {
724                 IWL_DEBUG_HC(priv, "Aborting scan due to no requested bands\n");
725                 goto done;
726         }
727
728         if (!priv->scan) {
729                 priv->scan = kmalloc(sizeof(struct iwl_scan_cmd) +
730                                      IWL_MAX_SCAN_SIZE, GFP_KERNEL);
731                 if (!priv->scan) {
732                         IWL_DEBUG_SCAN(priv,
733                                        "fail to allocate memory for scan\n");
734                         goto done;
735                 }
736         }
737         scan = priv->scan;
738         memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
739
740         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
741         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
742
743         if (iwl_is_associated(priv)) {
744                 u16 interval = 0;
745                 u32 extra;
746                 u32 suspend_time = 100;
747                 u32 scan_suspend_time = 100;
748                 unsigned long flags;
749
750                 IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
751                 spin_lock_irqsave(&priv->lock, flags);
752                 interval = priv->beacon_int;
753                 spin_unlock_irqrestore(&priv->lock, flags);
754
755                 scan->suspend_time = 0;
756                 scan->max_out_time = cpu_to_le32(200 * 1024);
757                 if (!interval)
758                         interval = suspend_time;
759
760                 extra = (suspend_time / interval) << 22;
761                 scan_suspend_time = (extra |
762                     ((suspend_time % interval) * 1024));
763                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
764                 IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
765                                scan_suspend_time, interval);
766         }
767
768         if (priv->is_internal_short_scan) {
769                 IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
770         } else if (priv->scan_request->n_ssids) {
771                 int i, p = 0;
772                 IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
773                 for (i = 0; i < priv->scan_request->n_ssids; i++) {
774                         /* always does wildcard anyway */
775                         if (!priv->scan_request->ssids[i].ssid_len)
776                                 continue;
777                         scan->direct_scan[p].id = WLAN_EID_SSID;
778                         scan->direct_scan[p].len =
779                                 priv->scan_request->ssids[i].ssid_len;
780                         memcpy(scan->direct_scan[p].ssid,
781                                priv->scan_request->ssids[i].ssid,
782                                priv->scan_request->ssids[i].ssid_len);
783                         n_probes++;
784                         p++;
785                 }
786                 is_active = true;
787         } else
788                 IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
789
790         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
791         scan->tx_cmd.sta_id = priv->hw_params.bcast_sta_id;
792         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
793
794
795         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) {
796                 band = IEEE80211_BAND_2GHZ;
797                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
798                 chan_mod = le32_to_cpu(priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_MSK)
799                                        >> RXON_FLG_CHANNEL_MODE_POS;
800                 if (chan_mod == CHANNEL_MODE_PURE_40) {
801                         rate = IWL_RATE_6M_PLCP;
802                 } else {
803                         rate = IWL_RATE_1M_PLCP;
804                         rate_flags = RATE_MCS_CCK_MSK;
805                 }
806                 scan->good_CRC_th = 0;
807         } else if (priv->scan_bands & BIT(IEEE80211_BAND_5GHZ)) {
808                 band = IEEE80211_BAND_5GHZ;
809                 rate = IWL_RATE_6M_PLCP;
810                 /*
811                  * If active scaning is requested but a certain channel
812                  * is marked passive, we can do active scanning if we
813                  * detect transmissions.
814                  */
815                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH : 0;
816
817                 /* Force use of chains B and C (0x6) for scan Rx
818                  * Avoid A (0x1) for the device has off-channel reception
819                  * on A-band.
820                  */
821                 if (priv->cfg->off_channel_workaround)
822                         rx_ant = ANT_BC;
823         } else {
824                 IWL_WARN(priv, "Invalid scan band count\n");
825                 goto done;
826         }
827
828         priv->scan_tx_ant[band] =
829                          iwl_toggle_tx_ant(priv, priv->scan_tx_ant[band]);
830         rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
831         scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
832
833         /* In power save mode use one chain, otherwise use all chains */
834         if (test_bit(STATUS_POWER_PMI, &priv->status)) {
835                 /* rx_ant has been set to all valid chains previously */
836                 active_chains = rx_ant &
837                                 ((u8)(priv->chain_noise_data.active_chains));
838                 if (!active_chains)
839                         active_chains = rx_ant;
840
841                 IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
842                                 priv->chain_noise_data.active_chains);
843
844                 rx_ant = first_antenna(active_chains);
845         }
846         /* MIMO is not used here, but value is required */
847         rx_chain |= priv->hw_params.valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
848         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
849         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
850         rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
851         scan->rx_chain = cpu_to_le16(rx_chain);
852         if (!priv->is_internal_short_scan) {
853                 cmd_len = iwl_fill_probe_req(priv,
854                                         (struct ieee80211_mgmt *)scan->data,
855                                         priv->scan_request->ie,
856                                         priv->scan_request->ie_len,
857                                         IWL_MAX_SCAN_SIZE - sizeof(*scan));
858         } else {
859                 cmd_len = iwl_fill_probe_req(priv,
860                                         (struct ieee80211_mgmt *)scan->data,
861                                         NULL, 0,
862                                         IWL_MAX_SCAN_SIZE - sizeof(*scan));
863
864         }
865         scan->tx_cmd.len = cpu_to_le16(cmd_len);
866         if (iwl_is_monitor_mode(priv))
867                 scan->filter_flags = RXON_FILTER_PROMISC_MSK;
868
869         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
870                                RXON_FILTER_BCON_AWARE_MSK);
871
872         if (priv->is_internal_short_scan) {
873                 scan->channel_count =
874                         iwl_get_single_channel_for_scan(priv, band,
875                                 (void *)&scan->data[le16_to_cpu(
876                                 scan->tx_cmd.len)]);
877         } else {
878                 scan->channel_count =
879                         iwl_get_channels_for_scan(priv, band,
880                                 is_active, n_probes,
881                                 (void *)&scan->data[le16_to_cpu(
882                                 scan->tx_cmd.len)]);
883         }
884         if (scan->channel_count == 0) {
885                 IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
886                 goto done;
887         }
888
889         cmd.len += le16_to_cpu(scan->tx_cmd.len) +
890             scan->channel_count * sizeof(struct iwl_scan_channel);
891         cmd.data = scan;
892         scan->len = cpu_to_le16(cmd.len);
893
894         set_bit(STATUS_SCAN_HW, &priv->status);
895         if (iwl_send_cmd_sync(priv, &cmd))
896                 goto done;
897
898         queue_delayed_work(priv->workqueue, &priv->scan_check,
899                            IWL_SCAN_CHECK_WATCHDOG);
900
901         mutex_unlock(&priv->mutex);
902         return;
903
904  done:
905         /* Cannot perform scan. Make sure we clear scanning
906         * bits from status so next scan request can be performed.
907         * If we don't clear scanning status bit here all next scan
908         * will fail
909         */
910         clear_bit(STATUS_SCAN_HW, &priv->status);
911         clear_bit(STATUS_SCANNING, &priv->status);
912         /* inform mac80211 scan aborted */
913         queue_work(priv->workqueue, &priv->scan_completed);
914         mutex_unlock(&priv->mutex);
915 }
916
917 void iwl_bg_abort_scan(struct work_struct *work)
918 {
919         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
920
921         if (!test_bit(STATUS_READY, &priv->status) ||
922             !test_bit(STATUS_GEO_CONFIGURED, &priv->status))
923                 return;
924
925         mutex_lock(&priv->mutex);
926
927         set_bit(STATUS_SCAN_ABORTING, &priv->status);
928         iwl_send_scan_abort(priv);
929
930         mutex_unlock(&priv->mutex);
931 }
932 EXPORT_SYMBOL(iwl_bg_abort_scan);
933
934 void iwl_bg_scan_completed(struct work_struct *work)
935 {
936         struct iwl_priv *priv =
937             container_of(work, struct iwl_priv, scan_completed);
938
939         IWL_DEBUG_SCAN(priv, "SCAN complete scan\n");
940
941         cancel_delayed_work(&priv->scan_check);
942
943         if (!priv->is_internal_short_scan)
944                 ieee80211_scan_completed(priv->hw, false);
945         else {
946                 priv->is_internal_short_scan = false;
947                 IWL_DEBUG_SCAN(priv, "internal short scan completed\n");
948         }
949
950         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
951                 return;
952
953         /* Since setting the TXPOWER may have been deferred while
954          * performing the scan, fire one off */
955         mutex_lock(&priv->mutex);
956         iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);
957         mutex_unlock(&priv->mutex);
958 }
959 EXPORT_SYMBOL(iwl_bg_scan_completed);
960
961 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
962 {
963         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
964         INIT_WORK(&priv->request_scan, iwl_bg_request_scan);
965         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
966         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
967 }
968 EXPORT_SYMBOL(iwl_setup_scan_deferred_work);
969