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 (%dms since last)\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                        jiffies_to_msecs(elapsed_jiffies
 203                                         (priv->last_scan_jiffies, jiffies)));
 204 #endif
 205
 206         priv->last_scan_jiffies = jiffies;
 207         priv->next_scan_jiffies = 0;
 208 }
 209
 210 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 211 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 212                                        struct iwl_rx_mem_buffer *rxb)
 213 {
 214 #ifdef CONFIG_IWLWIFI_DEBUG
 215         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 216         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
 217
 218         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 219                        scan_notif->scanned_channels,
 220                        scan_notif->tsf_low,
 221                        scan_notif->tsf_high, scan_notif->status);
 222 #endif
 223
 224         /* The HW is no longer scanning */
 225         clear_bit(STATUS_SCAN_HW, &priv->status);
 226
 227         IWL_DEBUG_INFO(priv, "Scan pass on %sGHz took %dms\n",
 228                        (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) ?
 229                                                 "2.4" : "5.2",
 230                        jiffies_to_msecs(elapsed_jiffies
 231                                         (priv->scan_pass_start, jiffies)));
 232
 233         /* Remove this scanned band from the list of pending
 234          * bands to scan, band G precedes A in order of scanning
 235          * as seen in iwl_bg_request_scan */
 236         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ))
 237                 priv->scan_bands &= ~BIT(IEEE80211_BAND_2GHZ);
 238         else if (priv->scan_bands &  BIT(IEEE80211_BAND_5GHZ))
 239                 priv->scan_bands &= ~BIT(IEEE80211_BAND_5GHZ);
 240
 241         /* If a request to abort was given, or the scan did not succeed
 242          * then we reset the scan state machine and terminate,
 243          * re-queuing another scan if one has been requested */
 244         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 245                 IWL_DEBUG_INFO(priv, "Aborted scan completed.\n");
 246                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 247         } else {
 248                 /* If there are more bands on this scan pass reschedule */
 249                 if (priv->scan_bands)
 250                         goto reschedule;
 251         }
 252
 253         priv->last_scan_jiffies = jiffies;
 254         priv->next_scan_jiffies = 0;
 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_channels_for_scan(struct iwl_priv *priv,
 318                                      enum ieee80211_band band,
 319                                      u8 is_active, u8 n_probes,
 320                                      struct iwl_scan_channel *scan_ch)
 321 {
 322         struct ieee80211_channel *chan;
 323         const struct ieee80211_supported_band *sband;
 324         const struct iwl_channel_info *ch_info;
 325         u16 passive_dwell = 0;
 326         u16 active_dwell = 0;
 327         int added, i;
 328         u16 channel;
 329
 330         sband = iwl_get_hw_mode(priv, band);
 331         if (!sband)
 332                 return 0;
 333
 334         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 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         for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
 341                 chan = priv->scan_request->channels[i];
 342
 343                 if (chan->band != band)
 344                         continue;
 345
 346                 channel = ieee80211_frequency_to_channel(chan->center_freq);
 347                 scan_ch->channel = cpu_to_le16(channel);
 348
 349                 ch_info = iwl_get_channel_info(priv, band, channel);
 350                 if (!is_channel_valid(ch_info)) {
 351                         IWL_DEBUG_SCAN(priv, "Channel %d is INVALID for this band.\n",
 352                                         channel);
 353                         continue;
 354                 }
 355
 356                 if (!is_active || is_channel_passive(ch_info) ||
 357                     (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN))
 358                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 359                 else
 360                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 361
 362                 if (n_probes)
 363                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 364
 365                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 366                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 367
 368                 /* Set txpower levels to defaults */
 369                 scan_ch->dsp_atten = 110;
 370
 371                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 372                  * power level:
 373                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 374                  */
 375                 if (band == IEEE80211_BAND_5GHZ)
 376                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 377                 else
 378                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 379
 380                 IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
 381                                channel, le32_to_cpu(scan_ch->type),
 382                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 383                                 "ACTIVE" : "PASSIVE",
 384                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 385                                active_dwell : passive_dwell);
 386
 387                 scan_ch++;
 388                 added++;
 389         }
 390
 391         IWL_DEBUG_SCAN(priv, "total channels to scan %d \n", added);
 392         return added;
 393 }
 394
 395 void iwl_init_scan_params(struct iwl_priv *priv)
 396 {
 397         u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
 398         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
 399                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
 400         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
 401                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
 402 }
 403 EXPORT_SYMBOL(iwl_init_scan_params);
 404
 405 static int iwl_scan_initiate(struct iwl_priv *priv)
 406 {
 407         if (!iwl_is_ready_rf(priv)) {
 408                 IWL_DEBUG_SCAN(priv, "Aborting scan due to not ready.\n");
 409                 return -EIO;
 410         }
 411
 412         if (test_bit(STATUS_SCANNING, &priv->status)) {
 413                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
 414                 return -EAGAIN;
 415         }
 416
 417         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 418                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
 419                 return -EAGAIN;
 420         }
 421
 422         IWL_DEBUG_INFO(priv, "Starting scan...\n");
 423         set_bit(STATUS_SCANNING, &priv->status);
 424         priv->scan_start = jiffies;
 425         priv->scan_pass_start = priv->scan_start;
 426
 427         queue_work(priv->workqueue, &priv->request_scan);
 428
 429         return 0;
 430 }
 431
 432 #define IWL_DELAY_NEXT_SCAN (HZ*2)
 433
 434 int iwl_mac_hw_scan(struct ieee80211_hw *hw,
 435                      struct cfg80211_scan_request *req)
 436 {
 437         unsigned long flags;
 438         struct iwl_priv *priv = hw->priv;
 439         int ret, i;
 440
 441         IWL_DEBUG_MAC80211(priv, "enter\n");
 442
 443         mutex_lock(&priv->mutex);
 444         spin_lock_irqsave(&priv->lock, flags);
 445
 446         if (!iwl_is_ready_rf(priv)) {
 447                 ret = -EIO;
 448                 IWL_DEBUG_MAC80211(priv, "leave - not ready or exit pending\n");
 449                 goto out_unlock;
 450         }
 451
 452         /* We don't schedule scan within next_scan_jiffies period.
 453          * Avoid scanning during possible EAPOL exchange, return
 454          * success immediately.
 455          */
 456         if (priv->next_scan_jiffies &&
 457             time_after(priv->next_scan_jiffies, jiffies)) {
 458                 IWL_DEBUG_SCAN(priv, "scan rejected: within next scan period\n");
 459                 queue_work(priv->workqueue, &priv->scan_completed);
 460                 ret = 0;
 461                 goto out_unlock;
 462         }
 463
 464         /* if we just finished scan ask for delay */
 465         if (iwl_is_associated(priv) && priv->last_scan_jiffies &&
 466             time_after(priv->last_scan_jiffies + IWL_DELAY_NEXT_SCAN, jiffies)) {
 467                 IWL_DEBUG_SCAN(priv, "scan rejected: within previous scan period\n");
 468                 queue_work(priv->workqueue, &priv->scan_completed);
 469                 ret = 0;
 470                 goto out_unlock;
 471         }
 472
 473         priv->scan_bands = 0;
 474         for (i = 0; i < req->n_channels; i++)
 475                 priv->scan_bands |= BIT(req->channels[i]->band);
 476
 477         priv->scan_request = req;
 478
 479         ret = iwl_scan_initiate(priv);
 480
 481         IWL_DEBUG_MAC80211(priv, "leave\n");
 482
 483 out_unlock:
 484         spin_unlock_irqrestore(&priv->lock, flags);
 485         mutex_unlock(&priv->mutex);
 486
 487         return ret;
 488 }
 489 EXPORT_SYMBOL(iwl_mac_hw_scan);
 490
 491 #define IWL_SCAN_CHECK_WATCHDOG (7 * HZ)
 492
 493 void iwl_bg_scan_check(struct work_struct *data)
 494 {
 495         struct iwl_priv *priv =
 496             container_of(data, struct iwl_priv, scan_check.work);
 497
 498         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 499                 return;
 500
 501         mutex_lock(&priv->mutex);
 502         if (test_bit(STATUS_SCANNING, &priv->status) ||
 503             test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 504                 IWL_DEBUG_SCAN(priv, "Scan completion watchdog resetting "
 505                         "adapter (%dms)\n",
 506                         jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG));
 507
 508                 if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
 509                         iwl_send_scan_abort(priv);
 510         }
 511         mutex_unlock(&priv->mutex);
 512 }
 513 EXPORT_SYMBOL(iwl_bg_scan_check);
 514
 515 /**
 516  * iwl_fill_probe_req - fill in all required fields and IE for probe request
 517  */
 518
 519 u16 iwl_fill_probe_req(struct iwl_priv *priv, struct ieee80211_mgmt *frame,
 520                        const u8 *ies, int ie_len, int left)
 521 {
 522         int len = 0;
 523         u8 *pos = NULL;
 524
 525         /* Make sure there is enough space for the probe request,
 526          * two mandatory IEs and the data */
 527         left -= 24;
 528         if (left < 0)
 529                 return 0;
 530
 531         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 532         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
 533         memcpy(frame->sa, priv->mac_addr, ETH_ALEN);
 534         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
 535         frame->seq_ctrl = 0;
 536
 537         len += 24;
 538
 539         /* ...next IE... */
 540         pos = &frame->u.probe_req.variable[0];
 541
 542         /* fill in our indirect SSID IE */
 543         left -= 2;
 544         if (left < 0)
 545                 return 0;
 546         *pos++ = WLAN_EID_SSID;
 547         *pos++ = 0;
 548
 549         len += 2;
 550
 551         if (WARN_ON(left < ie_len))
 552                 return len;
 553
 554         memcpy(pos, ies, ie_len);
 555         len += ie_len;
 556         left -= ie_len;
 557
 558         return (u16)len;
 559 }
 560 EXPORT_SYMBOL(iwl_fill_probe_req);
 561
 562 static void iwl_bg_request_scan(struct work_struct *data)
 563 {
 564         struct iwl_priv *priv =
 565             container_of(data, struct iwl_priv, request_scan);
 566         struct iwl_host_cmd cmd = {
 567                 .id = REPLY_SCAN_CMD,
 568                 .len = sizeof(struct iwl_scan_cmd),
 569                 .flags = CMD_SIZE_HUGE,
 570         };
 571         struct iwl_scan_cmd *scan;
 572         struct ieee80211_conf *conf = NULL;
 573         int ret = 0;
 574         u32 rate_flags = 0;
 575         u16 cmd_len;
 576         u16 rx_chain = 0;
 577         enum ieee80211_band band;
 578         u8 n_probes = 0;
 579         u8 rx_ant = priv->hw_params.valid_rx_ant;
 580         u8 rate;
 581         bool is_active = false;
 582         int  chan_mod;
 583         u8 active_chains;
 584
 585         conf = ieee80211_get_hw_conf(priv->hw);
 586
 587         mutex_lock(&priv->mutex);
 588
 589         cancel_delayed_work(&priv->scan_check);
 590
 591         if (!iwl_is_ready(priv)) {
 592                 IWL_WARN(priv, "request scan called when driver not ready.\n");
 593                 goto done;
 594         }
 595
 596         /* Make sure the scan wasn't canceled before this queued work
 597          * was given the chance to run... */
 598         if (!test_bit(STATUS_SCANNING, &priv->status))
 599                 goto done;
 600
 601         /* This should never be called or scheduled if there is currently
 602          * a scan active in the hardware. */
 603         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
 604                 IWL_DEBUG_INFO(priv, "Multiple concurrent scan requests in parallel. "
 605                                "Ignoring second request.\n");
 606                 ret = -EIO;
 607                 goto done;
 608         }
 609
 610         if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
 611                 IWL_DEBUG_SCAN(priv, "Aborting scan due to device shutdown\n");
 612                 goto done;
 613         }
 614
 615         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 616                 IWL_DEBUG_HC(priv, "Scan request while abort pending.  Queuing.\n");
 617                 goto done;
 618         }
 619
 620         if (iwl_is_rfkill(priv)) {
 621                 IWL_DEBUG_HC(priv, "Aborting scan due to RF Kill activation\n");
 622                 goto done;
 623         }
 624
 625         if (!test_bit(STATUS_READY, &priv->status)) {
 626                 IWL_DEBUG_HC(priv, "Scan request while uninitialized.  Queuing.\n");
 627                 goto done;
 628         }
 629
 630         if (!priv->scan_bands) {
 631                 IWL_DEBUG_HC(priv, "Aborting scan due to no requested bands\n");
 632                 goto done;
 633         }
 634
 635         if (!priv->scan) {
 636                 priv->scan = kmalloc(sizeof(struct iwl_scan_cmd) +
 637                                      IWL_MAX_SCAN_SIZE, GFP_KERNEL);
 638                 if (!priv->scan) {
 639                         ret = -ENOMEM;
 640                         goto done;
 641                 }
 642         }
 643         scan = priv->scan;
 644         memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
 645
 646         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
 647         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
 648
 649         if (iwl_is_associated(priv)) {
 650                 u16 interval = 0;
 651                 u32 extra;
 652                 u32 suspend_time = 100;
 653                 u32 scan_suspend_time = 100;
 654                 unsigned long flags;
 655
 656                 IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
 657
 658                 spin_lock_irqsave(&priv->lock, flags);
 659                 interval = priv->beacon_int;
 660                 spin_unlock_irqrestore(&priv->lock, flags);
 661
 662                 scan->suspend_time = 0;
 663                 scan->max_out_time = cpu_to_le32(200 * 1024);
 664                 if (!interval)
 665                         interval = suspend_time;
 666
 667                 extra = (suspend_time / interval) << 22;
 668                 scan_suspend_time = (extra |
 669                     ((suspend_time % interval) * 1024));
 670                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
 671                 IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
 672                                scan_suspend_time, interval);
 673         }
 674
 675         if (priv->scan_request->n_ssids) {
 676                 int i, p = 0;
 677                 IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
 678                 for (i = 0; i < priv->scan_request->n_ssids; i++) {
 679                         /* always does wildcard anyway */
 680                         if (!priv->scan_request->ssids[i].ssid_len)
 681                                 continue;
 682                         scan->direct_scan[p].id = WLAN_EID_SSID;
 683                         scan->direct_scan[p].len =
 684                                 priv->scan_request->ssids[i].ssid_len;
 685                         memcpy(scan->direct_scan[p].ssid,
 686                                priv->scan_request->ssids[i].ssid,
 687                                priv->scan_request->ssids[i].ssid_len);
 688                         n_probes++;
 689                         p++;
 690                 }
 691                 is_active = true;
 692         } else
 693                 IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
 694
 695         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
 696         scan->tx_cmd.sta_id = priv->hw_params.bcast_sta_id;
 697         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
 698
 699
 700         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) {
 701                 band = IEEE80211_BAND_2GHZ;
 702                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
 703                 chan_mod = le32_to_cpu(priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_MSK)
 704                                        >> RXON_FLG_CHANNEL_MODE_POS;
 705                 if (chan_mod == CHANNEL_MODE_PURE_40) {
 706                         rate = IWL_RATE_6M_PLCP;
 707                 } else {
 708                         rate = IWL_RATE_1M_PLCP;
 709                         rate_flags = RATE_MCS_CCK_MSK;
 710                 }
 711                 scan->good_CRC_th = 0;
 712         } else if (priv->scan_bands & BIT(IEEE80211_BAND_5GHZ)) {
 713                 band = IEEE80211_BAND_5GHZ;
 714                 rate = IWL_RATE_6M_PLCP;
 715                 /*
 716                  * If active scaning is requested but a certain channel
 717                  * is marked passive, we can do active scanning if we
 718                  * detect transmissions.
 719                  */
 720                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH : 0;
 721
 722                 /* Force use of chains B and C (0x6) for scan Rx for 4965
 723                  * Avoid A (0x1) because of its off-channel reception on A-band.
 724                  */
 725                 if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) == CSR_HW_REV_TYPE_4965)
 726                         rx_ant = ANT_BC;
 727         } else {
 728                 IWL_WARN(priv, "Invalid scan band count\n");
 729                 goto done;
 730         }
 731
 732         priv->scan_tx_ant[band] =
 733                          iwl_toggle_tx_ant(priv, priv->scan_tx_ant[band]);
 734         rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
 735         scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
 736
 737         /* In power save mode use one chain, otherwise use all chains */
 738         if (test_bit(STATUS_POWER_PMI, &priv->status)) {
 739                 /* rx_ant has been set to all valid chains previously */
 740                 active_chains = rx_ant &
 741                                 ((u8)(priv->chain_noise_data.active_chains));
 742                 if (!active_chains)
 743                         active_chains = rx_ant;
 744
 745                 IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
 746                                 priv->chain_noise_data.active_chains);
 747
 748                 rx_ant = first_antenna(active_chains);
 749         }
 750         /* MIMO is not used here, but value is required */
 751         rx_chain |= priv->hw_params.valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
 752         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
 753         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
 754         rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
 755         scan->rx_chain = cpu_to_le16(rx_chain);
 756         cmd_len = iwl_fill_probe_req(priv,
 757                                 (struct ieee80211_mgmt *)scan->data,
 758                                 priv->scan_request->ie,
 759                                 priv->scan_request->ie_len,
 760                                 IWL_MAX_SCAN_SIZE - sizeof(*scan));
 761
 762         scan->tx_cmd.len = cpu_to_le16(cmd_len);
 763
 764         if (iwl_is_monitor_mode(priv))
 765                 scan->filter_flags = RXON_FILTER_PROMISC_MSK;
 766
 767         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 768                                RXON_FILTER_BCON_AWARE_MSK);
 769
 770         scan->channel_count =
 771                 iwl_get_channels_for_scan(priv, band, is_active, n_probes,
 772                         (void *)&scan->data[le16_to_cpu(scan->tx_cmd.len)]);
 773
 774         if (scan->channel_count == 0) {
 775                 IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
 776                 goto done;
 777         }
 778
 779         cmd.len += le16_to_cpu(scan->tx_cmd.len) +
 780             scan->channel_count * sizeof(struct iwl_scan_channel);
 781         cmd.data = scan;
 782         scan->len = cpu_to_le16(cmd.len);
 783
 784         set_bit(STATUS_SCAN_HW, &priv->status);
 785         ret = iwl_send_cmd_sync(priv, &cmd);
 786         if (ret)
 787                 goto done;
 788
 789         queue_delayed_work(priv->workqueue, &priv->scan_check,
 790                            IWL_SCAN_CHECK_WATCHDOG);
 791
 792         mutex_unlock(&priv->mutex);
 793         return;
 794
 795  done:
 796         /* Cannot perform scan. Make sure we clear scanning
 797         * bits from status so next scan request can be performed.
 798         * If we don't clear scanning status bit here all next scan
 799         * will fail
 800         */
 801         clear_bit(STATUS_SCAN_HW, &priv->status);
 802         clear_bit(STATUS_SCANNING, &priv->status);
 803         /* inform mac80211 scan aborted */
 804         queue_work(priv->workqueue, &priv->scan_completed);
 805         mutex_unlock(&priv->mutex);
 806 }
 807
 808 void iwl_bg_abort_scan(struct work_struct *work)
 809 {
 810         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
 811
 812         if (!test_bit(STATUS_READY, &priv->status) ||
 813             !test_bit(STATUS_GEO_CONFIGURED, &priv->status))
 814                 return;
 815
 816         mutex_lock(&priv->mutex);
 817
 818         set_bit(STATUS_SCAN_ABORTING, &priv->status);
 819         iwl_send_scan_abort(priv);
 820
 821         mutex_unlock(&priv->mutex);
 822 }
 823 EXPORT_SYMBOL(iwl_bg_abort_scan);
 824
 825 void iwl_bg_scan_completed(struct work_struct *work)
 826 {
 827         struct iwl_priv *priv =
 828             container_of(work, struct iwl_priv, scan_completed);
 829
 830         IWL_DEBUG_SCAN(priv, "SCAN complete scan\n");
 831
 832         cancel_delayed_work(&priv->scan_check);
 833
 834         ieee80211_scan_completed(priv->hw, false);
 835
 836         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 837                 return;
 838
 839         /* Since setting the TXPOWER may have been deferred while
 840          * performing the scan, fire one off */
 841         mutex_lock(&priv->mutex);
 842         iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);
 843         mutex_unlock(&priv->mutex);
 844 }
 845 EXPORT_SYMBOL(iwl_bg_scan_completed);
 846
 847 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
 848 {
 849         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
 850         INIT_WORK(&priv->request_scan, iwl_bg_request_scan);
 851         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
 852         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
 853 }
 854 EXPORT_SYMBOL(iwl_setup_scan_deferred_work);
 855