drivers/net/wireless/iwlwifi/iwl-scan.c

   1 /******************************************************************************
   2  *
   3  * GPL LICENSE SUMMARY
   4  *
   5  * Copyright(c) 2008 - 2010 Intel Corporation. All rights reserved.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of version 2 of the GNU General Public License as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
  19  * USA
  20  *
  21  * The full GNU General Public License is included in this distribution
  22  * in the file called LICENSE.GPL.
  23  *
  24  * Contact Information:
  25  *  Intel Linux Wireless <ilw@linux.intel.com>
  26  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  27  *****************************************************************************/
  28 #include <linux/slab.h>
  29 #include <linux/types.h>
  30 #include <linux/etherdevice.h>
  31 #include <net/mac80211.h>
  32
  33 #include "iwl-eeprom.h"
  34 #include "iwl-dev.h"
  35 #include "iwl-core.h"
  36 #include "iwl-sta.h"
  37 #include "iwl-io.h"
  38 #include "iwl-helpers.h"
  39
  40 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
  41  * sending probe req.  This should be set long enough to hear probe responses
  42  * from more than one AP.  */
  43 #define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
  44 #define IWL_ACTIVE_DWELL_TIME_52    (20)
  45
  46 #define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
  47 #define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
  48
  49 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
  50  * Must be set longer than active dwell time.
  51  * For the most reliable scan, set > AP beacon interval (typically 100msec). */
  52 #define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
  53 #define IWL_PASSIVE_DWELL_TIME_52   (10)
  54 #define IWL_PASSIVE_DWELL_BASE      (100)
  55 #define IWL_CHANNEL_TUNE_TIME       5
  56
  57
  58
  59 /**
  60  * iwl_scan_cancel - Cancel any currently executing HW scan
  61  *
  62  * NOTE: priv->mutex is not required before calling this function
  63  */
  64 int iwl_scan_cancel(struct iwl_priv *priv)
  65 {
  66         if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
  67                 clear_bit(STATUS_SCANNING, &priv->status);
  68                 return 0;
  69         }
  70
  71         if (test_bit(STATUS_SCANNING, &priv->status)) {
  72                 if (!test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
  73                         IWL_DEBUG_SCAN(priv, "Queuing scan abort.\n");
  74                         set_bit(STATUS_SCAN_ABORTING, &priv->status);
  75                         queue_work(priv->workqueue, &priv->abort_scan);
  76
  77                 } else
  78                         IWL_DEBUG_SCAN(priv, "Scan abort already in progress.\n");
  79
  80                 return test_bit(STATUS_SCANNING, &priv->status);
  81         }
  82
  83         return 0;
  84 }
  85 EXPORT_SYMBOL(iwl_scan_cancel);
  86 /**
  87  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
  88  * @ms: amount of time to wait (in milliseconds) for scan to abort
  89  *
  90  * NOTE: priv->mutex must be held before calling this function
  91  */
  92 int iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
  93 {
  94         unsigned long now = jiffies;
  95         int ret;
  96
  97         ret = iwl_scan_cancel(priv);
  98         if (ret && ms) {
  99                 mutex_unlock(&priv->mutex);
 100                 while (!time_after(jiffies, now + msecs_to_jiffies(ms)) &&
 101                                 test_bit(STATUS_SCANNING, &priv->status))
 102                         msleep(1);
 103                 mutex_lock(&priv->mutex);
 104
 105                 return test_bit(STATUS_SCANNING, &priv->status);
 106         }
 107
 108         return ret;
 109 }
 110 EXPORT_SYMBOL(iwl_scan_cancel_timeout);
 111
 112 static int iwl_send_scan_abort(struct iwl_priv *priv)
 113 {
 114         int ret = 0;
 115         struct iwl_rx_packet *pkt;
 116         struct iwl_host_cmd cmd = {
 117                 .id = REPLY_SCAN_ABORT_CMD,
 118                 .flags = CMD_WANT_SKB,
 119         };
 120
 121         /* If there isn't a scan actively going on in the hardware
 122          * then we are in between scan bands and not actually
 123          * actively scanning, so don't send the abort command */
 124         if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
 125                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 126                 return 0;
 127         }
 128
 129         ret = iwl_send_cmd_sync(priv, &cmd);
 130         if (ret) {
 131                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 132                 return ret;
 133         }
 134
 135         pkt = (struct iwl_rx_packet *)cmd.reply_page;
 136         if (pkt->u.status != CAN_ABORT_STATUS) {
 137                 /* The scan abort will return 1 for success or
 138                  * 2 for "failure".  A failure condition can be
 139                  * due to simply not being in an active scan which
 140                  * can occur if we send the scan abort before we
 141                  * the microcode has notified us that a scan is
 142                  * completed. */
 143                 IWL_DEBUG_INFO(priv, "SCAN_ABORT returned %d.\n", pkt->u.status);
 144                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 145                 clear_bit(STATUS_SCAN_HW, &priv->status);
 146         }
 147
 148         iwl_free_pages(priv, cmd.reply_page);
 149
 150         return ret;
 151 }
 152
 153 /* Service response to REPLY_SCAN_CMD (0x80) */
 154 static void iwl_rx_reply_scan(struct iwl_priv *priv,
 155                               struct iwl_rx_mem_buffer *rxb)
 156 {
 157 #ifdef CONFIG_IWLWIFI_DEBUG
 158         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 159         struct iwl_scanreq_notification *notif =
 160             (struct iwl_scanreq_notification *)pkt->u.raw;
 161
 162         IWL_DEBUG_RX(priv, "Scan request status = 0x%x\n", notif->status);
 163 #endif
 164 }
 165
 166 /* Service SCAN_START_NOTIFICATION (0x82) */
 167 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
 168                                     struct iwl_rx_mem_buffer *rxb)
 169 {
 170         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 171         struct iwl_scanstart_notification *notif =
 172             (struct iwl_scanstart_notification *)pkt->u.raw;
 173         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 174         IWL_DEBUG_SCAN(priv, "Scan start: "
 175                        "%d [802.11%s] "
 176                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 177                        notif->channel,
 178                        notif->band ? "bg" : "a",
 179                        le32_to_cpu(notif->tsf_high),
 180                        le32_to_cpu(notif->tsf_low),
 181                        notif->status, notif->beacon_timer);
 182 }
 183
 184 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 185 static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
 186                                       struct iwl_rx_mem_buffer *rxb)
 187 {
 188 #ifdef CONFIG_IWLWIFI_DEBUG
 189         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 190         struct iwl_scanresults_notification *notif =
 191             (struct iwl_scanresults_notification *)pkt->u.raw;
 192
 193         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
 194                        "%d [802.11%s] "
 195                        "(TSF: 0x%08X:%08X) - %d "
 196                        "elapsed=%lu usec\n",
 197                        notif->channel,
 198                        notif->band ? "bg" : "a",
 199                        le32_to_cpu(notif->tsf_high),
 200                        le32_to_cpu(notif->tsf_low),
 201                        le32_to_cpu(notif->statistics[0]),
 202                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
 203 #endif
 204
 205         if (!priv->is_internal_short_scan)
 206                 priv->next_scan_jiffies = 0;
 207 }
 208
 209 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 210 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 211                                        struct iwl_rx_mem_buffer *rxb)
 212 {
 213 #ifdef CONFIG_IWLWIFI_DEBUG
 214         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 215         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
 216
 217         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 218                        scan_notif->scanned_channels,
 219                        scan_notif->tsf_low,
 220                        scan_notif->tsf_high, scan_notif->status);
 221 #endif
 222
 223         /* The HW is no longer scanning */
 224         clear_bit(STATUS_SCAN_HW, &priv->status);
 225
 226         IWL_DEBUG_INFO(priv, "Scan pass on %sGHz took %dms\n",
 227                        (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) ?
 228                                                 "2.4" : "5.2",
 229                        jiffies_to_msecs(elapsed_jiffies
 230                                         (priv->scan_pass_start, jiffies)));
 231
 232         /* Remove this scanned band from the list of pending
 233          * bands to scan, band G precedes A in order of scanning
 234          * as seen in iwl_bg_request_scan */
 235         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ))
 236                 priv->scan_bands &= ~BIT(IEEE80211_BAND_2GHZ);
 237         else if (priv->scan_bands &  BIT(IEEE80211_BAND_5GHZ))
 238                 priv->scan_bands &= ~BIT(IEEE80211_BAND_5GHZ);
 239
 240         /* If a request to abort was given, or the scan did not succeed
 241          * then we reset the scan state machine and terminate,
 242          * re-queuing another scan if one has been requested */
 243         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 244                 IWL_DEBUG_INFO(priv, "Aborted scan completed.\n");
 245                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 246         } else {
 247                 /* If there are more bands on this scan pass reschedule */
 248                 if (priv->scan_bands)
 249                         goto reschedule;
 250         }
 251
 252         if (!priv->is_internal_short_scan)
 253                 priv->next_scan_jiffies = 0;
 254
 255         IWL_DEBUG_INFO(priv, "Setting scan to off\n");
 256
 257         clear_bit(STATUS_SCANNING, &priv->status);
 258
 259         IWL_DEBUG_INFO(priv, "Scan took %dms\n",
 260                 jiffies_to_msecs(elapsed_jiffies(priv->scan_start, jiffies)));
 261
 262         queue_work(priv->workqueue, &priv->scan_completed);
 263
 264         return;
 265
 266 reschedule:
 267         priv->scan_pass_start = jiffies;
 268         queue_work(priv->workqueue, &priv->request_scan);
 269 }
 270
 271 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 272 {
 273         /* scan handlers */
 274         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 275         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 276         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 277                                         iwl_rx_scan_results_notif;
 278         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 279                                         iwl_rx_scan_complete_notif;
 280 }
 281 EXPORT_SYMBOL(iwl_setup_rx_scan_handlers);
 282
 283 inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 284                                      enum ieee80211_band band,
 285                                      u8 n_probes)
 286 {
 287         if (band == IEEE80211_BAND_5GHZ)
 288                 return IWL_ACTIVE_DWELL_TIME_52 +
 289                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 290         else
 291                 return IWL_ACTIVE_DWELL_TIME_24 +
 292                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 293 }
 294 EXPORT_SYMBOL(iwl_get_active_dwell_time);
 295
 296 u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 297                                enum ieee80211_band band)
 298 {
 299         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
 300             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 301             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 302
 303         if (iwl_is_associated(priv)) {
 304                 /* If we're associated, we clamp the maximum passive
 305                  * dwell time to be 98% of the beacon interval (minus
 306                  * 2 * channel tune time) */
 307                 passive = priv->beacon_int;
 308                 if ((passive > IWL_PASSIVE_DWELL_BASE) || !passive)
 309                         passive = IWL_PASSIVE_DWELL_BASE;
 310                 passive = (passive * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 311         }
 312
 313         return passive;
 314 }
 315 EXPORT_SYMBOL(iwl_get_passive_dwell_time);
 316
 317 static int iwl_get_single_channel_for_scan(struct iwl_priv *priv,
 318                                      enum ieee80211_band band,
 319                                      struct iwl_scan_channel *scan_ch)
 320 {
 321         const struct ieee80211_supported_band *sband;
 322         const struct iwl_channel_info *ch_info;
 323         u16 passive_dwell = 0;
 324         u16 active_dwell = 0;
 325         int i, added = 0;
 326         u16 channel = 0;
 327
 328         sband = iwl_get_hw_mode(priv, band);
 329         if (!sband) {
 330                 IWL_ERR(priv, "invalid band\n");
 331                 return added;
 332         }
 333
 334         active_dwell = iwl_get_active_dwell_time(priv, band, 0);
 335         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 336
 337         if (passive_dwell <= active_dwell)
 338                 passive_dwell = active_dwell + 1;
 339
 340         /* only scan single channel, good enough to reset the RF */
 341         /* pick the first valid not in-use channel */
 342         if (band == IEEE80211_BAND_5GHZ) {
 343                 for (i = 14; i < priv->channel_count; i++) {
 344                         if (priv->channel_info[i].channel !=
 345                             le16_to_cpu(priv->staging_rxon.channel)) {
 346                                 channel = priv->channel_info[i].channel;
 347                                 ch_info = iwl_get_channel_info(priv,
 348                                         band, channel);
 349                                 if (is_channel_valid(ch_info))
 350                                         break;
 351                         }
 352                 }
 353         } else {
 354                 for (i = 0; i < 14; i++) {
 355                         if (priv->channel_info[i].channel !=
 356                             le16_to_cpu(priv->staging_rxon.channel)) {
 357                                         channel =
 358                                                 priv->channel_info[i].channel;
 359                                         ch_info = iwl_get_channel_info(priv,
 360                                                 band, channel);
 361                                         if (is_channel_valid(ch_info))
 362                                                 break;
 363                         }
 364                 }
 365         }
 366         if (channel) {
 367                 scan_ch->channel = cpu_to_le16(channel);
 368                 scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 369                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 370                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 371                 /* Set txpower levels to defaults */
 372                 scan_ch->dsp_atten = 110;
 373                 if (band == IEEE80211_BAND_5GHZ)
 374                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 375                 else
 376                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 377                 added++;
 378         } else
 379                 IWL_ERR(priv, "no valid channel found\n");
 380         return added;
 381 }
 382
 383 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 384                                      enum ieee80211_band band,
 385                                      u8 is_active, u8 n_probes,
 386                                      struct iwl_scan_channel *scan_ch)
 387 {
 388         struct ieee80211_channel *chan;
 389         const struct ieee80211_supported_band *sband;
 390         const struct iwl_channel_info *ch_info;
 391         u16 passive_dwell = 0;
 392         u16 active_dwell = 0;
 393         int added, i;
 394         u16 channel;
 395
 396         sband = iwl_get_hw_mode(priv, band);
 397         if (!sband)
 398                 return 0;
 399
 400         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 401         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 402
 403         if (passive_dwell <= active_dwell)
 404                 passive_dwell = active_dwell + 1;
 405
 406         for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
 407                 chan = priv->scan_request->channels[i];
 408
 409                 if (chan->band != band)
 410                         continue;
 411
 412                 channel = ieee80211_frequency_to_channel(chan->center_freq);
 413                 scan_ch->channel = cpu_to_le16(channel);
 414
 415                 ch_info = iwl_get_channel_info(priv, band, channel);
 416                 if (!is_channel_valid(ch_info)) {
 417                         IWL_DEBUG_SCAN(priv, "Channel %d is INVALID for this band.\n",
 418                                         channel);
 419                         continue;
 420                 }
 421
 422                 if (!is_active || is_channel_passive(ch_info) ||
 423                     (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN))
 424                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 425                 else
 426                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 427
 428                 if (n_probes)
 429                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 430
 431                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 432                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 433
 434                 /* Set txpower levels to defaults */
 435                 scan_ch->dsp_atten = 110;
 436
 437                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 438                  * power level:
 439                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 440                  */
 441                 if (band == IEEE80211_BAND_5GHZ)
 442                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 443                 else
 444                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 445
 446                 IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
 447                                channel, le32_to_cpu(scan_ch->type),
 448                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 449                                 "ACTIVE" : "PASSIVE",
 450                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 451                                active_dwell : passive_dwell);
 452
 453                 scan_ch++;
 454                 added++;
 455         }
 456
 457         IWL_DEBUG_SCAN(priv, "total channels to scan %d\n", added);
 458         return added;
 459 }
 460
 461 void iwl_init_scan_params(struct iwl_priv *priv)
 462 {
 463         u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
 464         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
 465                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
 466         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
 467                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
 468 }
 469 EXPORT_SYMBOL(iwl_init_scan_params);
 470
 471 static int iwl_scan_initiate(struct iwl_priv *priv)
 472 {
 473         IWL_DEBUG_INFO(priv, "Starting scan...\n");
 474         set_bit(STATUS_SCANNING, &priv->status);
 475         priv->is_internal_short_scan = false;
 476         priv->scan_start = jiffies;
 477         priv->scan_pass_start = priv->scan_start;
 478
 479         queue_work(priv->workqueue, &priv->request_scan);
 480
 481         return 0;
 482 }
 483
 484 #define IWL_DELAY_NEXT_SCAN (HZ*2)
 485
 486 int iwl_mac_hw_scan(struct ieee80211_hw *hw,
 487                      struct cfg80211_scan_request *req)
 488 {
 489         unsigned long flags;
 490         struct iwl_priv *priv = hw->priv;
 491         int ret, i;
 492
 493         IWL_DEBUG_MAC80211(priv, "enter\n");
 494
 495         mutex_lock(&priv->mutex);
 496         spin_lock_irqsave(&priv->lock, flags);
 497
 498         if (!iwl_is_ready_rf(priv)) {
 499                 ret = -EIO;
 500                 IWL_DEBUG_MAC80211(priv, "leave - not ready or exit pending\n");
 501                 goto out_unlock;
 502         }
 503
 504         if (test_bit(STATUS_SCANNING, &priv->status)) {
 505                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
 506                 ret = -EAGAIN;
 507                 goto out_unlock;
 508         }
 509
 510         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 511                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
 512                 ret = -EAGAIN;
 513                 goto out_unlock;
 514         }
 515
 516         /* We don't schedule scan within next_scan_jiffies period.
 517          * Avoid scanning during possible EAPOL exchange, return
 518          * success immediately.
 519          */
 520         if (priv->next_scan_jiffies &&
 521             time_after(priv->next_scan_jiffies, jiffies)) {
 522                 IWL_DEBUG_SCAN(priv, "scan rejected: within next scan period\n");
 523                 queue_work(priv->workqueue, &priv->scan_completed);
 524                 ret = 0;
 525                 goto out_unlock;
 526         }
 527
 528         priv->scan_bands = 0;
 529         for (i = 0; i < req->n_channels; i++)
 530                 priv->scan_bands |= BIT(req->channels[i]->band);
 531
 532         priv->scan_request = req;
 533
 534         ret = iwl_scan_initiate(priv);
 535
 536         IWL_DEBUG_MAC80211(priv, "leave\n");
 537
 538 out_unlock:
 539         spin_unlock_irqrestore(&priv->lock, flags);
 540         mutex_unlock(&priv->mutex);
 541
 542         return ret;
 543 }
 544 EXPORT_SYMBOL(iwl_mac_hw_scan);
 545
 546 /*
 547  * internal short scan, this function should only been called while associated.
 548  * It will reset and tune the radio to prevent possible RF related problem
 549  */
 550 int iwl_internal_short_hw_scan(struct iwl_priv *priv)
 551 {
 552         int ret = 0;
 553
 554         if (!iwl_is_ready_rf(priv)) {
 555                 ret = -EIO;
 556                 IWL_DEBUG_SCAN(priv, "not ready or exit pending\n");
 557                 goto out;
 558         }
 559         if (test_bit(STATUS_SCANNING, &priv->status)) {
 560                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
 561                 ret = -EAGAIN;
 562                 goto out;
 563         }
 564         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 565                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
 566                 ret = -EAGAIN;
 567                 goto out;
 568         }
 569
 570         priv->scan_bands = 0;
 571         if (priv->band == IEEE80211_BAND_5GHZ)
 572                 priv->scan_bands |= BIT(IEEE80211_BAND_5GHZ);
 573         else
 574                 priv->scan_bands |= BIT(IEEE80211_BAND_2GHZ);
 575
 576         IWL_DEBUG_SCAN(priv, "Start internal short scan...\n");
 577         set_bit(STATUS_SCANNING, &priv->status);
 578         priv->is_internal_short_scan = true;
 579         queue_work(priv->workqueue, &priv->request_scan);
 580
 581 out:
 582         return ret;
 583 }
 584
 585 #define IWL_SCAN_CHECK_WATCHDOG (7 * HZ)
 586
 587 void iwl_bg_scan_check(struct work_struct *data)
 588 {
 589         struct iwl_priv *priv =
 590             container_of(data, struct iwl_priv, scan_check.work);
 591
 592         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 593                 return;
 594
 595         mutex_lock(&priv->mutex);
 596         if (test_bit(STATUS_SCANNING, &priv->status) ||
 597             test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 598                 IWL_DEBUG_SCAN(priv, "Scan completion watchdog resetting "
 599                         "adapter (%dms)\n",
 600                         jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG));
 601
 602                 if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
 603                         iwl_send_scan_abort(priv);
 604         }
 605         mutex_unlock(&priv->mutex);
 606 }
 607 EXPORT_SYMBOL(iwl_bg_scan_check);
 608
 609 /**
 610  * iwl_fill_probe_req - fill in all required fields and IE for probe request
 611  */
 612
 613 u16 iwl_fill_probe_req(struct iwl_priv *priv, struct ieee80211_mgmt *frame,
 614                        const u8 *ies, int ie_len, int left)
 615 {
 616         int len = 0;
 617         u8 *pos = NULL;
 618
 619         /* Make sure there is enough space for the probe request,
 620          * two mandatory IEs and the data */
 621         left -= 24;
 622         if (left < 0)
 623                 return 0;
 624
 625         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 626         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
 627         memcpy(frame->sa, priv->mac_addr, ETH_ALEN);
 628         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
 629         frame->seq_ctrl = 0;
 630
 631         len += 24;
 632
 633         /* ...next IE... */
 634         pos = &frame->u.probe_req.variable[0];
 635
 636         /* fill in our indirect SSID IE */
 637         left -= 2;
 638         if (left < 0)
 639                 return 0;
 640         *pos++ = WLAN_EID_SSID;
 641         *pos++ = 0;
 642
 643         len += 2;
 644
 645         if (WARN_ON(left < ie_len))
 646                 return len;
 647
 648         if (ies)
 649                 memcpy(pos, ies, ie_len);
 650         len += ie_len;
 651         left -= ie_len;
 652
 653         return (u16)len;
 654 }
 655 EXPORT_SYMBOL(iwl_fill_probe_req);
 656
 657 static void iwl_bg_request_scan(struct work_struct *data)
 658 {
 659         struct iwl_priv *priv =
 660             container_of(data, struct iwl_priv, request_scan);
 661         struct iwl_host_cmd cmd = {
 662                 .id = REPLY_SCAN_CMD,
 663                 .len = sizeof(struct iwl_scan_cmd),
 664                 .flags = CMD_SIZE_HUGE,
 665         };
 666         struct iwl_scan_cmd *scan;
 667         struct ieee80211_conf *conf = NULL;
 668         u32 rate_flags = 0;
 669         u16 cmd_len;
 670         u16 rx_chain = 0;
 671         enum ieee80211_band band;
 672         u8 n_probes = 0;
 673         u8 rx_ant = priv->hw_params.valid_rx_ant;
 674         u8 rate;
 675         bool is_active = false;
 676         int  chan_mod;
 677         u8 active_chains;
 678
 679         conf = ieee80211_get_hw_conf(priv->hw);
 680
 681         mutex_lock(&priv->mutex);
 682
 683         cancel_delayed_work(&priv->scan_check);
 684
 685         if (!iwl_is_ready(priv)) {
 686                 IWL_WARN(priv, "request scan called when driver not ready.\n");
 687                 goto done;
 688         }
 689
 690         /* Make sure the scan wasn't canceled before this queued work
 691          * was given the chance to run... */
 692         if (!test_bit(STATUS_SCANNING, &priv->status))
 693                 goto done;
 694
 695         /* This should never be called or scheduled if there is currently
 696          * a scan active in the hardware. */
 697         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
 698                 IWL_DEBUG_INFO(priv, "Multiple concurrent scan requests in parallel. "
 699                                "Ignoring second request.\n");
 700                 goto done;
 701         }
 702
 703         if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
 704                 IWL_DEBUG_SCAN(priv, "Aborting scan due to device shutdown\n");
 705                 goto done;
 706         }
 707
 708         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 709                 IWL_DEBUG_HC(priv, "Scan request while abort pending.  Queuing.\n");
 710                 goto done;
 711         }
 712
 713         if (iwl_is_rfkill(priv)) {
 714                 IWL_DEBUG_HC(priv, "Aborting scan due to RF Kill activation\n");
 715                 goto done;
 716         }
 717
 718         if (!test_bit(STATUS_READY, &priv->status)) {
 719                 IWL_DEBUG_HC(priv, "Scan request while uninitialized.  Queuing.\n");
 720                 goto done;
 721         }
 722
 723         if (!priv->scan_bands) {
 724                 IWL_DEBUG_HC(priv, "Aborting scan due to no requested bands\n");
 725                 goto done;
 726         }
 727
 728         if (!priv->scan) {
 729                 priv->scan = kmalloc(sizeof(struct iwl_scan_cmd) +
 730                                      IWL_MAX_SCAN_SIZE, GFP_KERNEL);
 731                 if (!priv->scan) {
 732                         IWL_DEBUG_SCAN(priv,
 733                                        "fail to allocate memory for scan\n");
 734                         goto done;
 735                 }
 736         }
 737         scan = priv->scan;
 738         memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
 739
 740         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
 741         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
 742
 743         if (iwl_is_associated(priv)) {
 744                 u16 interval = 0;
 745                 u32 extra;
 746                 u32 suspend_time = 100;
 747                 u32 scan_suspend_time = 100;
 748                 unsigned long flags;
 749
 750                 IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
 751                 spin_lock_irqsave(&priv->lock, flags);
 752                 interval = priv->beacon_int;
 753                 spin_unlock_irqrestore(&priv->lock, flags);
 754
 755                 scan->suspend_time = 0;
 756                 scan->max_out_time = cpu_to_le32(200 * 1024);
 757                 if (!interval)
 758                         interval = suspend_time;
 759
 760                 extra = (suspend_time / interval) << 22;
 761                 scan_suspend_time = (extra |
 762                     ((suspend_time % interval) * 1024));
 763                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
 764                 IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
 765                                scan_suspend_time, interval);
 766         }
 767
 768         if (priv->is_internal_short_scan) {
 769                 IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
 770         } else if (priv->scan_request->n_ssids) {
 771                 int i, p = 0;
 772                 IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
 773                 for (i = 0; i < priv->scan_request->n_ssids; i++) {
 774                         /* always does wildcard anyway */
 775                         if (!priv->scan_request->ssids[i].ssid_len)
 776                                 continue;
 777                         scan->direct_scan[p].id = WLAN_EID_SSID;
 778                         scan->direct_scan[p].len =
 779                                 priv->scan_request->ssids[i].ssid_len;
 780                         memcpy(scan->direct_scan[p].ssid,
 781                                priv->scan_request->ssids[i].ssid,
 782                                priv->scan_request->ssids[i].ssid_len);
 783                         n_probes++;
 784                         p++;
 785                 }
 786                 is_active = true;
 787         } else
 788                 IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
 789
 790         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
 791         scan->tx_cmd.sta_id = priv->hw_params.bcast_sta_id;
 792         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
 793
 794
 795         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) {
 796                 band = IEEE80211_BAND_2GHZ;
 797                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
 798                 chan_mod = le32_to_cpu(priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_MSK)
 799                                        >> RXON_FLG_CHANNEL_MODE_POS;
 800                 if (chan_mod == CHANNEL_MODE_PURE_40) {
 801                         rate = IWL_RATE_6M_PLCP;
 802                 } else {
 803                         rate = IWL_RATE_1M_PLCP;
 804                         rate_flags = RATE_MCS_CCK_MSK;
 805                 }
 806                 scan->good_CRC_th = 0;
 807         } else if (priv->scan_bands & BIT(IEEE80211_BAND_5GHZ)) {
 808                 band = IEEE80211_BAND_5GHZ;
 809                 rate = IWL_RATE_6M_PLCP;
 810                 /*
 811                  * If active scaning is requested but a certain channel
 812                  * is marked passive, we can do active scanning if we
 813                  * detect transmissions.
 814                  */
 815                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH : 0;
 816
 817                 /* Force use of chains B and C (0x6) for scan Rx
 818                  * Avoid A (0x1) for the device has off-channel reception
 819                  * on A-band.
 820                  */
 821                 if (priv->cfg->off_channel_workaround)
 822                         rx_ant = ANT_BC;
 823         } else {
 824                 IWL_WARN(priv, "Invalid scan band count\n");
 825                 goto done;
 826         }
 827
 828         priv->scan_tx_ant[band] =
 829                          iwl_toggle_tx_ant(priv, priv->scan_tx_ant[band]);
 830         rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
 831         scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
 832
 833         /* In power save mode use one chain, otherwise use all chains */
 834         if (test_bit(STATUS_POWER_PMI, &priv->status)) {
 835                 /* rx_ant has been set to all valid chains previously */
 836                 active_chains = rx_ant &
 837                                 ((u8)(priv->chain_noise_data.active_chains));
 838                 if (!active_chains)
 839                         active_chains = rx_ant;
 840
 841                 IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
 842                                 priv->chain_noise_data.active_chains);
 843
 844                 rx_ant = first_antenna(active_chains);
 845         }
 846         /* MIMO is not used here, but value is required */
 847         rx_chain |= priv->hw_params.valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
 848         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
 849         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
 850         rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
 851         scan->rx_chain = cpu_to_le16(rx_chain);
 852         if (!priv->is_internal_short_scan) {
 853                 cmd_len = iwl_fill_probe_req(priv,
 854                                         (struct ieee80211_mgmt *)scan->data,
 855                                         priv->scan_request->ie,
 856                                         priv->scan_request->ie_len,
 857                                         IWL_MAX_SCAN_SIZE - sizeof(*scan));
 858         } else {
 859                 cmd_len = iwl_fill_probe_req(priv,
 860                                         (struct ieee80211_mgmt *)scan->data,
 861                                         NULL, 0,
 862                                         IWL_MAX_SCAN_SIZE - sizeof(*scan));
 863
 864         }
 865         scan->tx_cmd.len = cpu_to_le16(cmd_len);
 866         if (iwl_is_monitor_mode(priv))
 867                 scan->filter_flags = RXON_FILTER_PROMISC_MSK;
 868
 869         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 870                                RXON_FILTER_BCON_AWARE_MSK);
 871
 872         if (priv->is_internal_short_scan) {
 873                 scan->channel_count =
 874                         iwl_get_single_channel_for_scan(priv, band,
 875                                 (void *)&scan->data[le16_to_cpu(
 876                                 scan->tx_cmd.len)]);
 877         } else {
 878                 scan->channel_count =
 879                         iwl_get_channels_for_scan(priv, band,
 880                                 is_active, n_probes,
 881                                 (void *)&scan->data[le16_to_cpu(
 882                                 scan->tx_cmd.len)]);
 883         }
 884         if (scan->channel_count == 0) {
 885                 IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
 886                 goto done;
 887         }
 888
 889         cmd.len += le16_to_cpu(scan->tx_cmd.len) +
 890             scan->channel_count * sizeof(struct iwl_scan_channel);
 891         cmd.data = scan;
 892         scan->len = cpu_to_le16(cmd.len);
 893
 894         set_bit(STATUS_SCAN_HW, &priv->status);
 895         if (iwl_send_cmd_sync(priv, &cmd))
 896                 goto done;
 897
 898         queue_delayed_work(priv->workqueue, &priv->scan_check,
 899                            IWL_SCAN_CHECK_WATCHDOG);
 900
 901         mutex_unlock(&priv->mutex);
 902         return;
 903
 904  done:
 905         /* Cannot perform scan. Make sure we clear scanning
 906         * bits from status so next scan request can be performed.
 907         * If we don't clear scanning status bit here all next scan
 908         * will fail
 909         */
 910         clear_bit(STATUS_SCAN_HW, &priv->status);
 911         clear_bit(STATUS_SCANNING, &priv->status);
 912         /* inform mac80211 scan aborted */
 913         queue_work(priv->workqueue, &priv->scan_completed);
 914         mutex_unlock(&priv->mutex);
 915 }
 916
 917 void iwl_bg_abort_scan(struct work_struct *work)
 918 {
 919         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
 920
 921         if (!test_bit(STATUS_READY, &priv->status) ||
 922             !test_bit(STATUS_GEO_CONFIGURED, &priv->status))
 923                 return;
 924
 925         mutex_lock(&priv->mutex);
 926
 927         set_bit(STATUS_SCAN_ABORTING, &priv->status);
 928         iwl_send_scan_abort(priv);
 929
 930         mutex_unlock(&priv->mutex);
 931 }
 932 EXPORT_SYMBOL(iwl_bg_abort_scan);
 933
 934 void iwl_bg_scan_completed(struct work_struct *work)
 935 {
 936         struct iwl_priv *priv =
 937             container_of(work, struct iwl_priv, scan_completed);
 938
 939         IWL_DEBUG_SCAN(priv, "SCAN complete scan\n");
 940
 941         cancel_delayed_work(&priv->scan_check);
 942
 943         if (!priv->is_internal_short_scan)
 944                 ieee80211_scan_completed(priv->hw, false);
 945         else {
 946                 priv->is_internal_short_scan = false;
 947                 IWL_DEBUG_SCAN(priv, "internal short scan completed\n");
 948         }
 949
 950         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 951                 return;
 952
 953         /* Since setting the TXPOWER may have been deferred while
 954          * performing the scan, fire one off */
 955         mutex_lock(&priv->mutex);
 956         iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);
 957         mutex_unlock(&priv->mutex);
 958 }
 959 EXPORT_SYMBOL(iwl_bg_scan_completed);
 960
 961 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
 962 {
 963         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
 964         INIT_WORK(&priv->request_scan, iwl_bg_request_scan);
 965         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
 966         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
 967 }
 968 EXPORT_SYMBOL(iwl_setup_scan_deferred_work);
 969