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