Merge branch 'davem-next' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik...
[linux-2.6] / drivers / net / wireless / iwlwifi / iwl-scan.c
1 /******************************************************************************
2  *
3  * GPL LICENSE SUMMARY
4  *
5  * Copyright(c) 2008 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  * Tomas Winkler <tomas.winkler@intel.com>
26  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
27  *****************************************************************************/
28 #include <net/mac80211.h>
29 #include <linux/etherdevice.h>
30
31 #include "iwl-eeprom.h"
32 #include "iwl-dev.h"
33 #include "iwl-core.h"
34 #include "iwl-sta.h"
35 #include "iwl-io.h"
36 #include "iwl-helpers.h"
37
38 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
39  * sending probe req.  This should be set long enough to hear probe responses
40  * from more than one AP.  */
41 #define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
42 #define IWL_ACTIVE_DWELL_TIME_52    (20)
43
44 #define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
45 #define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
46
47 /* For faster active scanning, scan will move to the next channel if fewer than
48  * PLCP_QUIET_THRESH packets are heard on this channel within
49  * ACTIVE_QUIET_TIME after sending probe request.  This shortens the dwell
50  * time if it's a quiet channel (nothing responded to our probe, and there's
51  * no other traffic).
52  * Disable "quiet" feature by setting PLCP_QUIET_THRESH to 0. */
53 #define IWL_PLCP_QUIET_THRESH       __constant_cpu_to_le16(1)  /* packets */
54 #define IWL_ACTIVE_QUIET_TIME       __constant_cpu_to_le16(10)  /* msec */
55
56 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
57  * Must be set longer than active dwell time.
58  * For the most reliable scan, set > AP beacon interval (typically 100msec). */
59 #define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
60 #define IWL_PASSIVE_DWELL_TIME_52   (10)
61 #define IWL_PASSIVE_DWELL_BASE      (100)
62 #define IWL_CHANNEL_TUNE_TIME       5
63
64 #define IWL_SCAN_PROBE_MASK(n)  cpu_to_le32((BIT(n) | (BIT(n) - BIT(1))))
65
66
67 static int scan_tx_ant[3] = {
68         RATE_MCS_ANT_A_MSK, RATE_MCS_ANT_B_MSK, RATE_MCS_ANT_C_MSK
69 };
70
71
72
73 static int iwl_is_empty_essid(const char *essid, int essid_len)
74 {
75         /* Single white space is for Linksys APs */
76         if (essid_len == 1 && essid[0] == ' ')
77                 return 1;
78
79         /* Otherwise, if the entire essid is 0, we assume it is hidden */
80         while (essid_len) {
81                 essid_len--;
82                 if (essid[essid_len] != '\0')
83                         return 0;
84         }
85
86         return 1;
87 }
88
89
90
91 const char *iwl_escape_essid(const char *essid, u8 essid_len)
92 {
93         static char escaped[IW_ESSID_MAX_SIZE * 2 + 1];
94         const char *s = essid;
95         char *d = escaped;
96
97         if (iwl_is_empty_essid(essid, essid_len)) {
98                 memcpy(escaped, "<hidden>", sizeof("<hidden>"));
99                 return escaped;
100         }
101
102         essid_len = min(essid_len, (u8) IW_ESSID_MAX_SIZE);
103         while (essid_len--) {
104                 if (*s == '\0') {
105                         *d++ = '\\';
106                         *d++ = '0';
107                         s++;
108                 } else
109                         *d++ = *s++;
110         }
111         *d = '\0';
112         return escaped;
113 }
114 EXPORT_SYMBOL(iwl_escape_essid);
115
116 /**
117  * iwl_scan_cancel - Cancel any currently executing HW scan
118  *
119  * NOTE: priv->mutex is not required before calling this function
120  */
121 int iwl_scan_cancel(struct iwl_priv *priv)
122 {
123         if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
124                 clear_bit(STATUS_SCANNING, &priv->status);
125                 return 0;
126         }
127
128         if (test_bit(STATUS_SCANNING, &priv->status)) {
129                 if (!test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
130                         IWL_DEBUG_SCAN("Queuing scan abort.\n");
131                         set_bit(STATUS_SCAN_ABORTING, &priv->status);
132                         queue_work(priv->workqueue, &priv->abort_scan);
133
134                 } else
135                         IWL_DEBUG_SCAN("Scan abort already in progress.\n");
136
137                 return test_bit(STATUS_SCANNING, &priv->status);
138         }
139
140         return 0;
141 }
142 EXPORT_SYMBOL(iwl_scan_cancel);
143 /**
144  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
145  * @ms: amount of time to wait (in milliseconds) for scan to abort
146  *
147  * NOTE: priv->mutex must be held before calling this function
148  */
149 int iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
150 {
151         unsigned long now = jiffies;
152         int ret;
153
154         ret = iwl_scan_cancel(priv);
155         if (ret && ms) {
156                 mutex_unlock(&priv->mutex);
157                 while (!time_after(jiffies, now + msecs_to_jiffies(ms)) &&
158                                 test_bit(STATUS_SCANNING, &priv->status))
159                         msleep(1);
160                 mutex_lock(&priv->mutex);
161
162                 return test_bit(STATUS_SCANNING, &priv->status);
163         }
164
165         return ret;
166 }
167 EXPORT_SYMBOL(iwl_scan_cancel_timeout);
168
169 static int iwl_send_scan_abort(struct iwl_priv *priv)
170 {
171         int ret = 0;
172         struct iwl_rx_packet *res;
173         struct iwl_host_cmd cmd = {
174                 .id = REPLY_SCAN_ABORT_CMD,
175                 .meta.flags = CMD_WANT_SKB,
176         };
177
178         /* If there isn't a scan actively going on in the hardware
179          * then we are in between scan bands and not actually
180          * actively scanning, so don't send the abort command */
181         if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
182                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
183                 return 0;
184         }
185
186         ret = iwl_send_cmd_sync(priv, &cmd);
187         if (ret) {
188                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
189                 return ret;
190         }
191
192         res = (struct iwl_rx_packet *)cmd.meta.u.skb->data;
193         if (res->u.status != CAN_ABORT_STATUS) {
194                 /* The scan abort will return 1 for success or
195                  * 2 for "failure".  A failure condition can be
196                  * due to simply not being in an active scan which
197                  * can occur if we send the scan abort before we
198                  * the microcode has notified us that a scan is
199                  * completed. */
200                 IWL_DEBUG_INFO("SCAN_ABORT returned %d.\n", res->u.status);
201                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
202                 clear_bit(STATUS_SCAN_HW, &priv->status);
203         }
204
205         dev_kfree_skb_any(cmd.meta.u.skb);
206
207         return ret;
208 }
209
210
211 /* Service response to REPLY_SCAN_CMD (0x80) */
212 static void iwl_rx_reply_scan(struct iwl_priv *priv,
213                               struct iwl_rx_mem_buffer *rxb)
214 {
215 #ifdef CONFIG_IWLWIFI_DEBUG
216         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
217         struct iwl_scanreq_notification *notif =
218             (struct iwl_scanreq_notification *)pkt->u.raw;
219
220         IWL_DEBUG_RX("Scan request status = 0x%x\n", notif->status);
221 #endif
222 }
223
224 /* Service SCAN_START_NOTIFICATION (0x82) */
225 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
226                                     struct iwl_rx_mem_buffer *rxb)
227 {
228         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
229         struct iwl_scanstart_notification *notif =
230             (struct iwl_scanstart_notification *)pkt->u.raw;
231         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
232         IWL_DEBUG_SCAN("Scan start: "
233                        "%d [802.11%s] "
234                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
235                        notif->channel,
236                        notif->band ? "bg" : "a",
237                        le32_to_cpu(notif->tsf_high),
238                        le32_to_cpu(notif->tsf_low),
239                        notif->status, notif->beacon_timer);
240 }
241
242 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
243 static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
244                                       struct iwl_rx_mem_buffer *rxb)
245 {
246 #ifdef CONFIG_IWLWIFI_DEBUG
247         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
248         struct iwl_scanresults_notification *notif =
249             (struct iwl_scanresults_notification *)pkt->u.raw;
250
251         IWL_DEBUG_SCAN("Scan ch.res: "
252                        "%d [802.11%s] "
253                        "(TSF: 0x%08X:%08X) - %d "
254                        "elapsed=%lu usec (%dms since last)\n",
255                        notif->channel,
256                        notif->band ? "bg" : "a",
257                        le32_to_cpu(notif->tsf_high),
258                        le32_to_cpu(notif->tsf_low),
259                        le32_to_cpu(notif->statistics[0]),
260                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf,
261                        jiffies_to_msecs(elapsed_jiffies
262                                         (priv->last_scan_jiffies, jiffies)));
263 #endif
264
265         priv->last_scan_jiffies = jiffies;
266         priv->next_scan_jiffies = 0;
267 }
268
269 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
270 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
271                                        struct iwl_rx_mem_buffer *rxb)
272 {
273         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
274         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
275
276         IWL_DEBUG_SCAN("Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
277                        scan_notif->scanned_channels,
278                        scan_notif->tsf_low,
279                        scan_notif->tsf_high, scan_notif->status);
280
281         /* The HW is no longer scanning */
282         clear_bit(STATUS_SCAN_HW, &priv->status);
283
284         /* The scan completion notification came in, so kill that timer... */
285         cancel_delayed_work(&priv->scan_check);
286
287         IWL_DEBUG_INFO("Scan pass on %sGHz took %dms\n",
288                        (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) ?
289                                                 "2.4" : "5.2",
290                        jiffies_to_msecs(elapsed_jiffies
291                                         (priv->scan_pass_start, jiffies)));
292
293         /* Remove this scanned band from the list of pending
294          * bands to scan, band G precedes A in order of scanning
295          * as seen in iwl_bg_request_scan */
296         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ))
297                 priv->scan_bands &= ~BIT(IEEE80211_BAND_2GHZ);
298         else if (priv->scan_bands &  BIT(IEEE80211_BAND_5GHZ))
299                 priv->scan_bands &= ~BIT(IEEE80211_BAND_5GHZ);
300
301         /* If a request to abort was given, or the scan did not succeed
302          * then we reset the scan state machine and terminate,
303          * re-queuing another scan if one has been requested */
304         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
305                 IWL_DEBUG_INFO("Aborted scan completed.\n");
306                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
307         } else {
308                 /* If there are more bands on this scan pass reschedule */
309                 if (priv->scan_bands)
310                         goto reschedule;
311         }
312
313         priv->last_scan_jiffies = jiffies;
314         priv->next_scan_jiffies = 0;
315         IWL_DEBUG_INFO("Setting scan to off\n");
316
317         clear_bit(STATUS_SCANNING, &priv->status);
318
319         IWL_DEBUG_INFO("Scan took %dms\n",
320                 jiffies_to_msecs(elapsed_jiffies(priv->scan_start, jiffies)));
321
322         queue_work(priv->workqueue, &priv->scan_completed);
323
324         return;
325
326 reschedule:
327         priv->scan_pass_start = jiffies;
328         queue_work(priv->workqueue, &priv->request_scan);
329 }
330
331 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
332 {
333         /* scan handlers */
334         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
335         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
336         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
337                                         iwl_rx_scan_results_notif;
338         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
339                                         iwl_rx_scan_complete_notif;
340 }
341 EXPORT_SYMBOL(iwl_setup_rx_scan_handlers);
342
343 static inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
344                                             enum ieee80211_band band,
345                                             u8 n_probes)
346 {
347         if (band == IEEE80211_BAND_5GHZ)
348                 return IWL_ACTIVE_DWELL_TIME_52 +
349                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
350         else
351                 return IWL_ACTIVE_DWELL_TIME_24 +
352                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
353 }
354
355 static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
356                                       enum ieee80211_band band)
357 {
358         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
359             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
360             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
361
362         if (iwl_is_associated(priv)) {
363                 /* If we're associated, we clamp the maximum passive
364                  * dwell time to be 98% of the beacon interval (minus
365                  * 2 * channel tune time) */
366                 passive = priv->beacon_int;
367                 if ((passive > IWL_PASSIVE_DWELL_BASE) || !passive)
368                         passive = IWL_PASSIVE_DWELL_BASE;
369                 passive = (passive * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
370         }
371
372         return passive;
373 }
374
375 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
376                                      enum ieee80211_band band,
377                                      u8 is_active, u8 n_probes,
378                                      struct iwl_scan_channel *scan_ch)
379 {
380         const struct ieee80211_channel *channels = NULL;
381         const struct ieee80211_supported_band *sband;
382         const struct iwl_channel_info *ch_info;
383         u16 passive_dwell = 0;
384         u16 active_dwell = 0;
385         int added, i;
386         u16 channel;
387
388         sband = iwl_get_hw_mode(priv, band);
389         if (!sband)
390                 return 0;
391
392         channels = sband->channels;
393
394         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
395         passive_dwell = iwl_get_passive_dwell_time(priv, band);
396
397         if (passive_dwell <= active_dwell)
398                 passive_dwell = active_dwell + 1;
399
400         for (i = 0, added = 0; i < sband->n_channels; i++) {
401                 if (channels[i].flags & IEEE80211_CHAN_DISABLED)
402                         continue;
403
404                 channel =
405                         ieee80211_frequency_to_channel(channels[i].center_freq);
406                 scan_ch->channel = cpu_to_le16(channel);
407
408                 ch_info = iwl_get_channel_info(priv, band, channel);
409                 if (!is_channel_valid(ch_info)) {
410                         IWL_DEBUG_SCAN("Channel %d is INVALID for this band.\n",
411                                         channel);
412                         continue;
413                 }
414
415                 if (!is_active || is_channel_passive(ch_info) ||
416                     (channels[i].flags & IEEE80211_CHAN_PASSIVE_SCAN))
417                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
418                 else
419                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
420
421                 if ((scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) && n_probes)
422                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
423
424                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
425                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
426
427                 /* Set txpower levels to defaults */
428                 scan_ch->dsp_atten = 110;
429
430                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
431                  * power level:
432                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
433                  */
434                 if (band == IEEE80211_BAND_5GHZ)
435                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
436                 else
437                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
438
439                 IWL_DEBUG_SCAN("Scanning ch=%d prob=0x%X [%s %d]\n",
440                                channel, le32_to_cpu(scan_ch->type),
441                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
442                                 "ACTIVE" : "PASSIVE",
443                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
444                                active_dwell : passive_dwell);
445
446                 scan_ch++;
447                 added++;
448         }
449
450         IWL_DEBUG_SCAN("total channels to scan %d \n", added);
451         return added;
452 }
453
454 void iwl_init_scan_params(struct iwl_priv *priv)
455 {
456         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
457                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = RATE_MCS_ANT_INIT_IND;
458         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
459                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = RATE_MCS_ANT_INIT_IND;
460 }
461
462 int iwl_scan_initiate(struct iwl_priv *priv)
463 {
464         if (priv->iw_mode == IEEE80211_IF_TYPE_AP) {
465                 IWL_ERROR("APs don't scan.\n");
466                 return 0;
467         }
468
469         if (!iwl_is_ready_rf(priv)) {
470                 IWL_DEBUG_SCAN("Aborting scan due to not ready.\n");
471                 return -EIO;
472         }
473
474         if (test_bit(STATUS_SCANNING, &priv->status)) {
475                 IWL_DEBUG_SCAN("Scan already in progress.\n");
476                 return -EAGAIN;
477         }
478
479         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
480                 IWL_DEBUG_SCAN("Scan request while abort pending.  "
481                                "Queuing.\n");
482                 return -EAGAIN;
483         }
484
485         IWL_DEBUG_INFO("Starting scan...\n");
486         if (priv->cfg->sku & IWL_SKU_G)
487                 priv->scan_bands |= BIT(IEEE80211_BAND_2GHZ);
488         if (priv->cfg->sku & IWL_SKU_A)
489                 priv->scan_bands |= BIT(IEEE80211_BAND_5GHZ);
490         set_bit(STATUS_SCANNING, &priv->status);
491         priv->scan_start = jiffies;
492         priv->scan_pass_start = priv->scan_start;
493
494         queue_work(priv->workqueue, &priv->request_scan);
495
496         return 0;
497 }
498 EXPORT_SYMBOL(iwl_scan_initiate);
499
500 #define IWL_SCAN_CHECK_WATCHDOG (7 * HZ)
501
502 static void iwl_bg_scan_check(struct work_struct *data)
503 {
504         struct iwl_priv *priv =
505             container_of(data, struct iwl_priv, scan_check.work);
506
507         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
508                 return;
509
510         mutex_lock(&priv->mutex);
511         if (test_bit(STATUS_SCANNING, &priv->status) ||
512             test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
513                 IWL_DEBUG(IWL_DL_SCAN, "Scan completion watchdog resetting "
514                         "adapter (%dms)\n",
515                         jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG));
516
517                 if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
518                         iwl_send_scan_abort(priv);
519         }
520         mutex_unlock(&priv->mutex);
521 }
522 /**
523  * iwl_supported_rate_to_ie - fill in the supported rate in IE field
524  *
525  * return : set the bit for each supported rate insert in ie
526  */
527 static u16 iwl_supported_rate_to_ie(u8 *ie, u16 supported_rate,
528                                     u16 basic_rate, int *left)
529 {
530         u16 ret_rates = 0, bit;
531         int i;
532         u8 *cnt = ie;
533         u8 *rates = ie + 1;
534
535         for (bit = 1, i = 0; i < IWL_RATE_COUNT; i++, bit <<= 1) {
536                 if (bit & supported_rate) {
537                         ret_rates |= bit;
538                         rates[*cnt] = iwl_rates[i].ieee |
539                                 ((bit & basic_rate) ? 0x80 : 0x00);
540                         (*cnt)++;
541                         (*left)--;
542                         if ((*left <= 0) ||
543                             (*cnt >= IWL_SUPPORTED_RATES_IE_LEN))
544                                 break;
545                 }
546         }
547
548         return ret_rates;
549 }
550
551
552 static void iwl_ht_cap_to_ie(const struct ieee80211_supported_band *sband,
553                              u8 *pos, int *left)
554 {
555         struct ieee80211_ht_cap *ht_cap;
556
557         if (!sband || !sband->ht_info.ht_supported)
558                 return;
559
560         if (*left < sizeof(struct ieee80211_ht_cap))
561                 return;
562
563         *pos++ = sizeof(struct ieee80211_ht_cap);
564         ht_cap = (struct ieee80211_ht_cap *) pos;
565
566         ht_cap->cap_info = cpu_to_le16(sband->ht_info.cap);
567         memcpy(ht_cap->supp_mcs_set, sband->ht_info.supp_mcs_set, 16);
568         ht_cap->ampdu_params_info =
569                 (sband->ht_info.ampdu_factor & IEEE80211_HT_CAP_AMPDU_FACTOR) |
570                 ((sband->ht_info.ampdu_density << 2) &
571                         IEEE80211_HT_CAP_AMPDU_DENSITY);
572         *left -= sizeof(struct ieee80211_ht_cap);
573 }
574
575 /**
576  * iwl_fill_probe_req - fill in all required fields and IE for probe request
577  */
578
579 static u16 iwl_fill_probe_req(struct iwl_priv *priv,
580                                   enum ieee80211_band band,
581                                   struct ieee80211_mgmt *frame,
582                                   int left)
583 {
584         int len = 0;
585         u8 *pos = NULL;
586         u16 active_rates, ret_rates, cck_rates, active_rate_basic;
587         const struct ieee80211_supported_band *sband =
588                                                 iwl_get_hw_mode(priv, band);
589
590
591         /* Make sure there is enough space for the probe request,
592          * two mandatory IEs and the data */
593         left -= 24;
594         if (left < 0)
595                 return 0;
596
597         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
598         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
599         memcpy(frame->sa, priv->mac_addr, ETH_ALEN);
600         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
601         frame->seq_ctrl = 0;
602
603         len += 24;
604
605         /* ...next IE... */
606         pos = &frame->u.probe_req.variable[0];
607
608         /* fill in our indirect SSID IE */
609         left -= 2;
610         if (left < 0)
611                 return 0;
612         *pos++ = WLAN_EID_SSID;
613         *pos++ = 0;
614
615         len += 2;
616
617         /* fill in supported rate */
618         left -= 2;
619         if (left < 0)
620                 return 0;
621
622         *pos++ = WLAN_EID_SUPP_RATES;
623         *pos = 0;
624
625         /* exclude 60M rate */
626         active_rates = priv->rates_mask;
627         active_rates &= ~IWL_RATE_60M_MASK;
628
629         active_rate_basic = active_rates & IWL_BASIC_RATES_MASK;
630
631         cck_rates = IWL_CCK_RATES_MASK & active_rates;
632         ret_rates = iwl_supported_rate_to_ie(pos, cck_rates,
633                                              active_rate_basic, &left);
634         active_rates &= ~ret_rates;
635
636         ret_rates = iwl_supported_rate_to_ie(pos, active_rates,
637                                              active_rate_basic, &left);
638         active_rates &= ~ret_rates;
639
640         len += 2 + *pos;
641         pos += (*pos) + 1;
642
643         if (active_rates == 0)
644                 goto fill_end;
645
646         /* fill in supported extended rate */
647         /* ...next IE... */
648         left -= 2;
649         if (left < 0)
650                 return 0;
651         /* ... fill it in... */
652         *pos++ = WLAN_EID_EXT_SUPP_RATES;
653         *pos = 0;
654         iwl_supported_rate_to_ie(pos, active_rates, active_rate_basic, &left);
655         if (*pos > 0) {
656                 len += 2 + *pos;
657                 pos += (*pos) + 1;
658         } else {
659                 pos--;
660         }
661
662  fill_end:
663
664         left -= 2;
665         if (left < 0)
666                 return 0;
667
668         *pos++ = WLAN_EID_HT_CAPABILITY;
669         *pos = 0;
670         iwl_ht_cap_to_ie(sband, pos, &left);
671         if (*pos > 0)
672                 len += 2 + *pos;
673
674         return (u16)len;
675 }
676
677 static u32 iwl_scan_tx_ant(struct iwl_priv *priv, enum ieee80211_band band)
678 {
679         int i, ind;
680
681         ind = priv->scan_tx_ant[band];
682         for (i = 0; i < priv->hw_params.tx_chains_num; i++) {
683                 ind = (ind+1) >= priv->hw_params.tx_chains_num ? 0 : ind+1;
684                 if (priv->hw_params.valid_tx_ant & (1 << ind)) {
685                         priv->scan_tx_ant[band] = ind;
686                         break;
687                 }
688         }
689         IWL_DEBUG_SCAN("select TX ANT = %c\n", 'A' + ind);
690         return scan_tx_ant[ind];
691 }
692
693
694 static void iwl_bg_request_scan(struct work_struct *data)
695 {
696         struct iwl_priv *priv =
697             container_of(data, struct iwl_priv, request_scan);
698         struct iwl_host_cmd cmd = {
699                 .id = REPLY_SCAN_CMD,
700                 .len = sizeof(struct iwl_scan_cmd),
701                 .meta.flags = CMD_SIZE_HUGE,
702         };
703         struct iwl_scan_cmd *scan;
704         struct ieee80211_conf *conf = NULL;
705         int ret = 0;
706         u32 tx_ant;
707         u16 cmd_len;
708         enum ieee80211_band band;
709         u8 n_probes = 2;
710         u8 rx_chain = 0x7; /* bitmap: ABC chains */
711
712         conf = ieee80211_get_hw_conf(priv->hw);
713
714         mutex_lock(&priv->mutex);
715
716         if (!iwl_is_ready(priv)) {
717                 IWL_WARNING("request scan called when driver not ready.\n");
718                 goto done;
719         }
720
721         /* Make sure the scan wasn't cancelled before this queued work
722          * was given the chance to run... */
723         if (!test_bit(STATUS_SCANNING, &priv->status))
724                 goto done;
725
726         /* This should never be called or scheduled if there is currently
727          * a scan active in the hardware. */
728         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
729                 IWL_DEBUG_INFO("Multiple concurrent scan requests in parallel. "
730                                "Ignoring second request.\n");
731                 ret = -EIO;
732                 goto done;
733         }
734
735         if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
736                 IWL_DEBUG_SCAN("Aborting scan due to device shutdown\n");
737                 goto done;
738         }
739
740         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
741                 IWL_DEBUG_HC("Scan request while abort pending.  Queuing.\n");
742                 goto done;
743         }
744
745         if (iwl_is_rfkill(priv)) {
746                 IWL_DEBUG_HC("Aborting scan due to RF Kill activation\n");
747                 goto done;
748         }
749
750         if (!test_bit(STATUS_READY, &priv->status)) {
751                 IWL_DEBUG_HC("Scan request while uninitialized.  Queuing.\n");
752                 goto done;
753         }
754
755         if (!priv->scan_bands) {
756                 IWL_DEBUG_HC("Aborting scan due to no requested bands\n");
757                 goto done;
758         }
759
760         if (!priv->scan) {
761                 priv->scan = kmalloc(sizeof(struct iwl_scan_cmd) +
762                                      IWL_MAX_SCAN_SIZE, GFP_KERNEL);
763                 if (!priv->scan) {
764                         ret = -ENOMEM;
765                         goto done;
766                 }
767         }
768         scan = priv->scan;
769         memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
770
771         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
772         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
773
774         if (iwl_is_associated(priv)) {
775                 u16 interval = 0;
776                 u32 extra;
777                 u32 suspend_time = 100;
778                 u32 scan_suspend_time = 100;
779                 unsigned long flags;
780
781                 IWL_DEBUG_INFO("Scanning while associated...\n");
782
783                 spin_lock_irqsave(&priv->lock, flags);
784                 interval = priv->beacon_int;
785                 spin_unlock_irqrestore(&priv->lock, flags);
786
787                 scan->suspend_time = 0;
788                 scan->max_out_time = cpu_to_le32(200 * 1024);
789                 if (!interval)
790                         interval = suspend_time;
791
792                 extra = (suspend_time / interval) << 22;
793                 scan_suspend_time = (extra |
794                     ((suspend_time % interval) * 1024));
795                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
796                 IWL_DEBUG_SCAN("suspend_time 0x%X beacon interval %d\n",
797                                scan_suspend_time, interval);
798         }
799
800         /* We should add the ability for user to lock to PASSIVE ONLY */
801         if (priv->one_direct_scan) {
802                 IWL_DEBUG_SCAN("Start direct scan for '%s'\n",
803                                 iwl_escape_essid(priv->direct_ssid,
804                                 priv->direct_ssid_len));
805                 scan->direct_scan[0].id = WLAN_EID_SSID;
806                 scan->direct_scan[0].len = priv->direct_ssid_len;
807                 memcpy(scan->direct_scan[0].ssid,
808                        priv->direct_ssid, priv->direct_ssid_len);
809                 n_probes++;
810         } else if (!iwl_is_associated(priv) && priv->essid_len) {
811                 IWL_DEBUG_SCAN("Start direct scan for '%s' (not associated)\n",
812                                 iwl_escape_essid(priv->essid, priv->essid_len));
813                 scan->direct_scan[0].id = WLAN_EID_SSID;
814                 scan->direct_scan[0].len = priv->essid_len;
815                 memcpy(scan->direct_scan[0].ssid, priv->essid, priv->essid_len);
816                 n_probes++;
817         } else {
818                 IWL_DEBUG_SCAN("Start indirect scan.\n");
819         }
820
821         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
822         scan->tx_cmd.sta_id = priv->hw_params.bcast_sta_id;
823         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
824
825
826         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) {
827                 band = IEEE80211_BAND_2GHZ;
828                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
829                 tx_ant = iwl_scan_tx_ant(priv, band);
830                 if (priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_PURE_40_MSK)
831                         scan->tx_cmd.rate_n_flags =
832                                 iwl_hw_set_rate_n_flags(IWL_RATE_6M_PLCP,
833                                                         tx_ant);
834                 else
835                         scan->tx_cmd.rate_n_flags =
836                                 iwl_hw_set_rate_n_flags(IWL_RATE_1M_PLCP,
837                                                         tx_ant |
838                                                         RATE_MCS_CCK_MSK);
839                 scan->good_CRC_th = 0;
840         } else if (priv->scan_bands & BIT(IEEE80211_BAND_5GHZ)) {
841                 band = IEEE80211_BAND_5GHZ;
842                 tx_ant = iwl_scan_tx_ant(priv, band);
843                 scan->tx_cmd.rate_n_flags =
844                                 iwl_hw_set_rate_n_flags(IWL_RATE_6M_PLCP,
845                                                         tx_ant);
846                 scan->good_CRC_th = IWL_GOOD_CRC_TH;
847
848                 /* Force use of chains B and C (0x6) for scan Rx for 4965
849                  * Avoid A (0x1) because of its off-channel reception on A-band.
850                  * MIMO is not used here, but value is required */
851                 if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) == CSR_HW_REV_TYPE_4965)
852                         rx_chain = 0x6;
853         } else {
854                 IWL_WARNING("Invalid scan band count\n");
855                 goto done;
856         }
857
858         scan->rx_chain = RXON_RX_CHAIN_DRIVER_FORCE_MSK |
859                                 cpu_to_le16((0x7 << RXON_RX_CHAIN_VALID_POS) |
860                                 (rx_chain << RXON_RX_CHAIN_FORCE_SEL_POS) |
861                                 (0x7 << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS));
862
863         cmd_len = iwl_fill_probe_req(priv, band,
864                                      (struct ieee80211_mgmt *)scan->data,
865                                      IWL_MAX_SCAN_SIZE - sizeof(*scan));
866
867         scan->tx_cmd.len = cpu_to_le16(cmd_len);
868
869         if (priv->iw_mode == IEEE80211_IF_TYPE_MNTR)
870                 scan->filter_flags = RXON_FILTER_PROMISC_MSK;
871
872         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
873                                RXON_FILTER_BCON_AWARE_MSK);
874
875         scan->channel_count =
876                 iwl_get_channels_for_scan(priv, band, 1, /* active */
877                         n_probes,
878                         (void *)&scan->data[le16_to_cpu(scan->tx_cmd.len)]);
879
880         if (scan->channel_count == 0) {
881                 IWL_DEBUG_SCAN("channel count %d\n", scan->channel_count);
882                 goto done;
883         }
884
885         cmd.len += le16_to_cpu(scan->tx_cmd.len) +
886             scan->channel_count * sizeof(struct iwl_scan_channel);
887         cmd.data = scan;
888         scan->len = cpu_to_le16(cmd.len);
889
890         set_bit(STATUS_SCAN_HW, &priv->status);
891         ret = iwl_send_cmd_sync(priv, &cmd);
892         if (ret)
893                 goto done;
894
895         queue_delayed_work(priv->workqueue, &priv->scan_check,
896                            IWL_SCAN_CHECK_WATCHDOG);
897
898         mutex_unlock(&priv->mutex);
899         return;
900
901  done:
902         /* inform mac80211 scan aborted */
903         queue_work(priv->workqueue, &priv->scan_completed);
904         mutex_unlock(&priv->mutex);
905 }
906
907 static void iwl_bg_abort_scan(struct work_struct *work)
908 {
909         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
910
911         if (!iwl_is_ready(priv))
912                 return;
913
914         mutex_lock(&priv->mutex);
915
916         set_bit(STATUS_SCAN_ABORTING, &priv->status);
917         iwl_send_scan_abort(priv);
918
919         mutex_unlock(&priv->mutex);
920 }
921
922 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
923 {
924         /*  FIXME: move here when resolved PENDING
925          *  INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed); */
926         INIT_WORK(&priv->request_scan, iwl_bg_request_scan);
927         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
928         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
929 }
930 EXPORT_SYMBOL(iwl_setup_scan_deferred_work);
931