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