4f3a108fa9901e1c9ee314ea59020838dfb99120
[linux-2.6.git] / drivers / net / wireless / iwlwifi / iwl-scan.c
1 /******************************************************************************
2  *
3  * GPL LICENSE SUMMARY
4  *
5  * Copyright(c) 2008 - 2009 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/types.h>
29 #include <linux/etherdevice.h>
30 #include <net/lib80211.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 *res;
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         res = (struct iwl_rx_packet *)cmd.reply_skb->data;
136         if (res->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", res->u.status);
144                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
145                 clear_bit(STATUS_SCAN_HW, &priv->status);
146         }
147
148         priv->alloc_rxb_skb--;
149         dev_kfree_skb_any(cmd.reply_skb);
150
151         return ret;
152 }
153
154 /* Service response to REPLY_SCAN_CMD (0x80) */
155 static void iwl_rx_reply_scan(struct iwl_priv *priv,
156                               struct iwl_rx_mem_buffer *rxb)
157 {
158 #ifdef CONFIG_IWLWIFI_DEBUG
159         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
160         struct iwl_scanreq_notification *notif =
161             (struct iwl_scanreq_notification *)pkt->u.raw;
162
163         IWL_DEBUG_RX(priv, "Scan request status = 0x%x\n", notif->status);
164 #endif
165 }
166
167 /* Service SCAN_START_NOTIFICATION (0x82) */
168 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
169                                     struct iwl_rx_mem_buffer *rxb)
170 {
171         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
172         struct iwl_scanstart_notification *notif =
173             (struct iwl_scanstart_notification *)pkt->u.raw;
174         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
175         IWL_DEBUG_SCAN(priv, "Scan start: "
176                        "%d [802.11%s] "
177                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
178                        notif->channel,
179                        notif->band ? "bg" : "a",
180                        le32_to_cpu(notif->tsf_high),
181                        le32_to_cpu(notif->tsf_low),
182                        notif->status, notif->beacon_timer);
183 }
184
185 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
186 static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
187                                       struct iwl_rx_mem_buffer *rxb)
188 {
189 #ifdef CONFIG_IWLWIFI_DEBUG
190         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
191         struct iwl_scanresults_notification *notif =
192             (struct iwl_scanresults_notification *)pkt->u.raw;
193
194         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
195                        "%d [802.11%s] "
196                        "(TSF: 0x%08X:%08X) - %d "
197                        "elapsed=%lu usec (%dms since last)\n",
198                        notif->channel,
199                        notif->band ? "bg" : "a",
200                        le32_to_cpu(notif->tsf_high),
201                        le32_to_cpu(notif->tsf_low),
202                        le32_to_cpu(notif->statistics[0]),
203                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf,
204                        jiffies_to_msecs(elapsed_jiffies
205                                         (priv->last_scan_jiffies, jiffies)));
206 #endif
207
208         priv->last_scan_jiffies = jiffies;
209         priv->next_scan_jiffies = 0;
210 }
211
212 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
213 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
214                                        struct iwl_rx_mem_buffer *rxb)
215 {
216 #ifdef CONFIG_IWLWIFI_DEBUG
217         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
218         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
219
220         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
221                        scan_notif->scanned_channels,
222                        scan_notif->tsf_low,
223                        scan_notif->tsf_high, scan_notif->status);
224 #endif
225
226         /* The HW is no longer scanning */
227         clear_bit(STATUS_SCAN_HW, &priv->status);
228
229         IWL_DEBUG_INFO(priv, "Scan pass on %sGHz took %dms\n",
230                        (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) ?
231                                                 "2.4" : "5.2",
232                        jiffies_to_msecs(elapsed_jiffies
233                                         (priv->scan_pass_start, jiffies)));
234
235         /* Remove this scanned band from the list of pending
236          * bands to scan, band G precedes A in order of scanning
237          * as seen in iwl_bg_request_scan */
238         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ))
239                 priv->scan_bands &= ~BIT(IEEE80211_BAND_2GHZ);
240         else if (priv->scan_bands &  BIT(IEEE80211_BAND_5GHZ))
241                 priv->scan_bands &= ~BIT(IEEE80211_BAND_5GHZ);
242
243         /* If a request to abort was given, or the scan did not succeed
244          * then we reset the scan state machine and terminate,
245          * re-queuing another scan if one has been requested */
246         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
247                 IWL_DEBUG_INFO(priv, "Aborted scan completed.\n");
248                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
249         } else {
250                 /* If there are more bands on this scan pass reschedule */
251                 if (priv->scan_bands)
252                         goto reschedule;
253         }
254
255         priv->last_scan_jiffies = jiffies;
256         priv->next_scan_jiffies = 0;
257         IWL_DEBUG_INFO(priv, "Setting scan to off\n");
258
259         clear_bit(STATUS_SCANNING, &priv->status);
260
261         IWL_DEBUG_INFO(priv, "Scan took %dms\n",
262                 jiffies_to_msecs(elapsed_jiffies(priv->scan_start, jiffies)));
263
264         queue_work(priv->workqueue, &priv->scan_completed);
265
266         return;
267
268 reschedule:
269         priv->scan_pass_start = jiffies;
270         queue_work(priv->workqueue, &priv->request_scan);
271 }
272
273 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
274 {
275         /* scan handlers */
276         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
277         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
278         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
279                                         iwl_rx_scan_results_notif;
280         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
281                                         iwl_rx_scan_complete_notif;
282 }
283 EXPORT_SYMBOL(iwl_setup_rx_scan_handlers);
284
285 inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
286                                      enum ieee80211_band band,
287                                      u8 n_probes)
288 {
289         if (band == IEEE80211_BAND_5GHZ)
290                 return IWL_ACTIVE_DWELL_TIME_52 +
291                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
292         else
293                 return IWL_ACTIVE_DWELL_TIME_24 +
294                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
295 }
296 EXPORT_SYMBOL(iwl_get_active_dwell_time);
297
298 u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
299                                enum ieee80211_band band)
300 {
301         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
302             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
303             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
304
305         if (iwl_is_associated(priv)) {
306                 /* If we're associated, we clamp the maximum passive
307                  * dwell time to be 98% of the beacon interval (minus
308                  * 2 * channel tune time) */
309                 passive = priv->beacon_int;
310                 if ((passive > IWL_PASSIVE_DWELL_BASE) || !passive)
311                         passive = IWL_PASSIVE_DWELL_BASE;
312                 passive = (passive * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
313         }
314
315         return passive;
316 }
317 EXPORT_SYMBOL(iwl_get_passive_dwell_time);
318
319 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
320                                      enum ieee80211_band band,
321                                      u8 is_active, u8 n_probes,
322                                      struct iwl_scan_channel *scan_ch)
323 {
324         struct ieee80211_channel *chan;
325         const struct ieee80211_supported_band *sband;
326         const struct iwl_channel_info *ch_info;
327         u16 passive_dwell = 0;
328         u16 active_dwell = 0;
329         int added, i;
330         u16 channel;
331
332         sband = iwl_get_hw_mode(priv, band);
333         if (!sband)
334                 return 0;
335
336         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
337         passive_dwell = iwl_get_passive_dwell_time(priv, band);
338
339         if (passive_dwell <= active_dwell)
340                 passive_dwell = active_dwell + 1;
341
342         for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
343                 chan = priv->scan_request->channels[i];
344
345                 if (chan->band != band)
346                         continue;
347
348                 channel = ieee80211_frequency_to_channel(chan->center_freq);
349                 scan_ch->channel = cpu_to_le16(channel);
350
351                 ch_info = iwl_get_channel_info(priv, band, channel);
352                 if (!is_channel_valid(ch_info)) {
353                         IWL_DEBUG_SCAN(priv, "Channel %d is INVALID for this band.\n",
354                                         channel);
355                         continue;
356                 }
357
358                 if (!is_active || is_channel_passive(ch_info) ||
359                     (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN))
360                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
361                 else
362                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
363
364                 if (n_probes)
365                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
366
367                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
368                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
369
370                 /* Set txpower levels to defaults */
371                 scan_ch->dsp_atten = 110;
372
373                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
374                  * power level:
375                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
376                  */
377                 if (band == IEEE80211_BAND_5GHZ)
378                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
379                 else
380                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
381
382                 IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
383                                channel, le32_to_cpu(scan_ch->type),
384                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
385                                 "ACTIVE" : "PASSIVE",
386                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
387                                active_dwell : passive_dwell);
388
389                 scan_ch++;
390                 added++;
391         }
392
393         IWL_DEBUG_SCAN(priv, "total channels to scan %d \n", added);
394         return added;
395 }
396
397 void iwl_init_scan_params(struct iwl_priv *priv)
398 {
399         u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
400         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
401                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
402         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
403                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
404 }
405
406 static int iwl_scan_initiate(struct iwl_priv *priv)
407 {
408         if (!iwl_is_ready_rf(priv)) {
409                 IWL_DEBUG_SCAN(priv, "Aborting scan due to not ready.\n");
410                 return -EIO;
411         }
412
413         if (test_bit(STATUS_SCANNING, &priv->status)) {
414                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
415                 return -EAGAIN;
416         }
417
418         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
419                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
420                 return -EAGAIN;
421         }
422
423         IWL_DEBUG_INFO(priv, "Starting scan...\n");
424         set_bit(STATUS_SCANNING, &priv->status);
425         priv->scan_start = jiffies;
426         priv->scan_pass_start = priv->scan_start;
427
428         queue_work(priv->workqueue, &priv->request_scan);
429
430         return 0;
431 }
432
433 #define IWL_DELAY_NEXT_SCAN (HZ*2)
434
435 int iwl_mac_hw_scan(struct ieee80211_hw *hw,
436                      struct cfg80211_scan_request *req)
437 {
438         unsigned long flags;
439         struct iwl_priv *priv = hw->priv;
440         int ret, i;
441
442         IWL_DEBUG_MAC80211(priv, "enter\n");
443
444         mutex_lock(&priv->mutex);
445         spin_lock_irqsave(&priv->lock, flags);
446
447         if (!iwl_is_ready_rf(priv)) {
448                 ret = -EIO;
449                 IWL_DEBUG_MAC80211(priv, "leave - not ready or exit pending\n");
450                 goto out_unlock;
451         }
452
453         /* We don't schedule scan within next_scan_jiffies period.
454          * Avoid scanning during possible EAPOL exchange, return
455          * success immediately.
456          */
457         if (priv->next_scan_jiffies &&
458             time_after(priv->next_scan_jiffies, jiffies)) {
459                 IWL_DEBUG_SCAN(priv, "scan rejected: within next scan period\n");
460                 queue_work(priv->workqueue, &priv->scan_completed);
461                 ret = 0;
462                 goto out_unlock;
463         }
464
465         /* if we just finished scan ask for delay */
466         if (iwl_is_associated(priv) && priv->last_scan_jiffies &&
467             time_after(priv->last_scan_jiffies + IWL_DELAY_NEXT_SCAN, jiffies)) {
468                 IWL_DEBUG_SCAN(priv, "scan rejected: within previous scan period\n");
469                 queue_work(priv->workqueue, &priv->scan_completed);
470                 ret = 0;
471                 goto out_unlock;
472         }
473
474         priv->scan_bands = 0;
475         for (i = 0; i < req->n_channels; i++)
476                 priv->scan_bands |= BIT(req->channels[i]->band);
477
478         priv->scan_request = req;
479
480         ret = iwl_scan_initiate(priv);
481
482         IWL_DEBUG_MAC80211(priv, "leave\n");
483
484 out_unlock:
485         spin_unlock_irqrestore(&priv->lock, flags);
486         mutex_unlock(&priv->mutex);
487
488         return ret;
489 }
490 EXPORT_SYMBOL(iwl_mac_hw_scan);
491
492 #define IWL_SCAN_CHECK_WATCHDOG (7 * HZ)
493
494 void iwl_bg_scan_check(struct work_struct *data)
495 {
496         struct iwl_priv *priv =
497             container_of(data, struct iwl_priv, scan_check.work);
498
499         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
500                 return;
501
502         mutex_lock(&priv->mutex);
503         if (test_bit(STATUS_SCANNING, &priv->status) ||
504             test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
505                 IWL_DEBUG_SCAN(priv, "Scan completion watchdog resetting "
506                         "adapter (%dms)\n",
507                         jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG));
508
509                 if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
510                         iwl_send_scan_abort(priv);
511         }
512         mutex_unlock(&priv->mutex);
513 }
514 EXPORT_SYMBOL(iwl_bg_scan_check);
515
516 /**
517  * iwl_fill_probe_req - fill in all required fields and IE for probe request
518  */
519
520 u16 iwl_fill_probe_req(struct iwl_priv *priv, struct ieee80211_mgmt *frame,
521                        const u8 *ies, int ie_len, int left)
522 {
523         int len = 0;
524         u8 *pos = NULL;
525
526         /* Make sure there is enough space for the probe request,
527          * two mandatory IEs and the data */
528         left -= 24;
529         if (left < 0)
530                 return 0;
531
532         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
533         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
534         memcpy(frame->sa, priv->mac_addr, ETH_ALEN);
535         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
536         frame->seq_ctrl = 0;
537
538         len += 24;
539
540         /* ...next IE... */
541         pos = &frame->u.probe_req.variable[0];
542
543         /* fill in our indirect SSID IE */
544         left -= 2;
545         if (left < 0)
546                 return 0;
547         *pos++ = WLAN_EID_SSID;
548         *pos++ = 0;
549
550         len += 2;
551
552         if (WARN_ON(left < ie_len))
553                 return len;
554
555         memcpy(pos, ies, ie_len);
556         len += ie_len;
557         left -= ie_len;
558
559         return (u16)len;
560 }
561 EXPORT_SYMBOL(iwl_fill_probe_req);
562
563 static void iwl_bg_request_scan(struct work_struct *data)
564 {
565         struct iwl_priv *priv =
566             container_of(data, struct iwl_priv, request_scan);
567         struct iwl_host_cmd cmd = {
568                 .id = REPLY_SCAN_CMD,
569                 .len = sizeof(struct iwl_scan_cmd),
570                 .flags = CMD_SIZE_HUGE,
571         };
572         struct iwl_scan_cmd *scan;
573         struct ieee80211_conf *conf = NULL;
574         int ret = 0;
575         u32 rate_flags = 0;
576         u16 cmd_len;
577         u16 rx_chain = 0;
578         enum ieee80211_band band;
579         u8 n_probes = 0;
580         u8 rx_ant = priv->hw_params.valid_rx_ant;
581         u8 rate;
582         bool is_active = false;
583         int  chan_mod;
584
585         conf = ieee80211_get_hw_conf(priv->hw);
586
587         mutex_lock(&priv->mutex);
588
589         cancel_delayed_work(&priv->scan_check);
590
591         if (!iwl_is_ready(priv)) {
592                 IWL_WARN(priv, "request scan called when driver not ready.\n");
593                 goto done;
594         }
595
596         /* Make sure the scan wasn't canceled before this queued work
597          * was given the chance to run... */
598         if (!test_bit(STATUS_SCANNING, &priv->status))
599                 goto done;
600
601         /* This should never be called or scheduled if there is currently
602          * a scan active in the hardware. */
603         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
604                 IWL_DEBUG_INFO(priv, "Multiple concurrent scan requests in parallel. "
605                                "Ignoring second request.\n");
606                 ret = -EIO;
607                 goto done;
608         }
609
610         if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
611                 IWL_DEBUG_SCAN(priv, "Aborting scan due to device shutdown\n");
612                 goto done;
613         }
614
615         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
616                 IWL_DEBUG_HC(priv, "Scan request while abort pending.  Queuing.\n");
617                 goto done;
618         }
619
620         if (iwl_is_rfkill(priv)) {
621                 IWL_DEBUG_HC(priv, "Aborting scan due to RF Kill activation\n");
622                 goto done;
623         }
624
625         if (!test_bit(STATUS_READY, &priv->status)) {
626                 IWL_DEBUG_HC(priv, "Scan request while uninitialized.  Queuing.\n");
627                 goto done;
628         }
629
630         if (!priv->scan_bands) {
631                 IWL_DEBUG_HC(priv, "Aborting scan due to no requested bands\n");
632                 goto done;
633         }
634
635         if (!priv->scan) {
636                 priv->scan = kmalloc(sizeof(struct iwl_scan_cmd) +
637                                      IWL_MAX_SCAN_SIZE, GFP_KERNEL);
638                 if (!priv->scan) {
639                         ret = -ENOMEM;
640                         goto done;
641                 }
642         }
643         scan = priv->scan;
644         memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
645
646         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
647         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
648
649         if (iwl_is_associated(priv)) {
650                 u16 interval = 0;
651                 u32 extra;
652                 u32 suspend_time = 100;
653                 u32 scan_suspend_time = 100;
654                 unsigned long flags;
655
656                 IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
657
658                 spin_lock_irqsave(&priv->lock, flags);
659                 interval = priv->beacon_int;
660                 spin_unlock_irqrestore(&priv->lock, flags);
661
662                 scan->suspend_time = 0;
663                 scan->max_out_time = cpu_to_le32(200 * 1024);
664                 if (!interval)
665                         interval = suspend_time;
666
667                 extra = (suspend_time / interval) << 22;
668                 scan_suspend_time = (extra |
669                     ((suspend_time % interval) * 1024));
670                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
671                 IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
672                                scan_suspend_time, interval);
673         }
674
675         if (priv->scan_request->n_ssids) {
676                 int i, p = 0;
677                 IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
678                 for (i = 0; i < priv->scan_request->n_ssids; i++) {
679                         /* always does wildcard anyway */
680                         if (!priv->scan_request->ssids[i].ssid_len)
681                                 continue;
682                         scan->direct_scan[p].id = WLAN_EID_SSID;
683                         scan->direct_scan[p].len =
684                                 priv->scan_request->ssids[i].ssid_len;
685                         memcpy(scan->direct_scan[p].ssid,
686                                priv->scan_request->ssids[i].ssid,
687                                priv->scan_request->ssids[i].ssid_len);
688                         n_probes++;
689                         p++;
690                 }
691                 is_active = true;
692         } else
693                 IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
694
695         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
696         scan->tx_cmd.sta_id = priv->hw_params.bcast_sta_id;
697         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
698
699
700         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) {
701                 band = IEEE80211_BAND_2GHZ;
702                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
703                 chan_mod = le32_to_cpu(priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_MSK)
704                                        >> RXON_FLG_CHANNEL_MODE_POS;
705                 if (chan_mod == CHANNEL_MODE_PURE_40) {
706                         rate = IWL_RATE_6M_PLCP;
707                 } else {
708                         rate = IWL_RATE_1M_PLCP;
709                         rate_flags = RATE_MCS_CCK_MSK;
710                 }
711                 scan->good_CRC_th = 0;
712         } else if (priv->scan_bands & BIT(IEEE80211_BAND_5GHZ)) {
713                 band = IEEE80211_BAND_5GHZ;
714                 rate = IWL_RATE_6M_PLCP;
715                 /*
716                  * If active scaning is requested but a certain channel
717                  * is marked passive, we can do active scanning if we
718                  * detect transmissions.
719                  */
720                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH : 0;
721
722                 /* Force use of chains B and C (0x6) for scan Rx for 4965
723                  * Avoid A (0x1) because of its off-channel reception on A-band.
724                  */
725                 if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) == CSR_HW_REV_TYPE_4965)
726                         rx_ant = ANT_BC;
727         } else {
728                 IWL_WARN(priv, "Invalid scan band count\n");
729                 goto done;
730         }
731
732         priv->scan_tx_ant[band] =
733                          iwl_toggle_tx_ant(priv, priv->scan_tx_ant[band]);
734         rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
735         scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
736
737         /* MIMO is not used here, but value is required */
738         rx_chain |= ANT_ABC << RXON_RX_CHAIN_VALID_POS;
739         rx_chain |= ANT_ABC << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
740         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
741         rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
742         scan->rx_chain = cpu_to_le16(rx_chain);
743         cmd_len = iwl_fill_probe_req(priv,
744                                 (struct ieee80211_mgmt *)scan->data,
745                                 priv->scan_request->ie,
746                                 priv->scan_request->ie_len,
747                                 IWL_MAX_SCAN_SIZE - sizeof(*scan));
748
749         scan->tx_cmd.len = cpu_to_le16(cmd_len);
750
751         if (iwl_is_monitor_mode(priv))
752                 scan->filter_flags = RXON_FILTER_PROMISC_MSK;
753
754         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
755                                RXON_FILTER_BCON_AWARE_MSK);
756
757         scan->channel_count =
758                 iwl_get_channels_for_scan(priv, band, is_active, n_probes,
759                         (void *)&scan->data[le16_to_cpu(scan->tx_cmd.len)]);
760
761         if (scan->channel_count == 0) {
762                 IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
763                 goto done;
764         }
765
766         cmd.len += le16_to_cpu(scan->tx_cmd.len) +
767             scan->channel_count * sizeof(struct iwl_scan_channel);
768         cmd.data = scan;
769         scan->len = cpu_to_le16(cmd.len);
770
771         set_bit(STATUS_SCAN_HW, &priv->status);
772         ret = iwl_send_cmd_sync(priv, &cmd);
773         if (ret)
774                 goto done;
775
776         queue_delayed_work(priv->workqueue, &priv->scan_check,
777                            IWL_SCAN_CHECK_WATCHDOG);
778
779         mutex_unlock(&priv->mutex);
780         return;
781
782  done:
783         /* Cannot perform scan. Make sure we clear scanning
784         * bits from status so next scan request can be performed.
785         * If we don't clear scanning status bit here all next scan
786         * will fail
787         */
788         clear_bit(STATUS_SCAN_HW, &priv->status);
789         clear_bit(STATUS_SCANNING, &priv->status);
790         /* inform mac80211 scan aborted */
791         queue_work(priv->workqueue, &priv->scan_completed);
792         mutex_unlock(&priv->mutex);
793 }
794
795 void iwl_bg_abort_scan(struct work_struct *work)
796 {
797         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
798
799         if (!test_bit(STATUS_READY, &priv->status) ||
800             !test_bit(STATUS_GEO_CONFIGURED, &priv->status))
801                 return;
802
803         mutex_lock(&priv->mutex);
804
805         set_bit(STATUS_SCAN_ABORTING, &priv->status);
806         iwl_send_scan_abort(priv);
807
808         mutex_unlock(&priv->mutex);
809 }
810 EXPORT_SYMBOL(iwl_bg_abort_scan);
811
812 void iwl_bg_scan_completed(struct work_struct *work)
813 {
814         struct iwl_priv *priv =
815             container_of(work, struct iwl_priv, scan_completed);
816
817         IWL_DEBUG_SCAN(priv, "SCAN complete scan\n");
818
819         cancel_delayed_work(&priv->scan_check);
820
821         ieee80211_scan_completed(priv->hw, false);
822
823         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
824                 return;
825
826         /* Since setting the TXPOWER may have been deferred while
827          * performing the scan, fire one off */
828         mutex_lock(&priv->mutex);
829         iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);
830         mutex_unlock(&priv->mutex);
831 }
832 EXPORT_SYMBOL(iwl_bg_scan_completed);
833
834 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
835 {
836         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
837         INIT_WORK(&priv->request_scan, iwl_bg_request_scan);
838         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
839         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
840 }
841 EXPORT_SYMBOL(iwl_setup_scan_deferred_work);
842