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

   1 /******************************************************************************
   2  *
   3  * GPL LICENSE SUMMARY
   4  *
   5  * Copyright(c) 2008 - 2009 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/lib80211.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 *res;
 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         res = (struct iwl_rx_packet *)cmd.reply_skb->data;
 136         if (res->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", res->u.status);
 144                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 145                 clear_bit(STATUS_SCAN_HW, &priv->status);
 146         }
 147
 148         priv->alloc_rxb_skb--;
 149         dev_kfree_skb_any(cmd.reply_skb);
 150
 151         return ret;
 152 }
 153
 154 /* Service response to REPLY_SCAN_CMD (0x80) */
 155 static void iwl_rx_reply_scan(struct iwl_priv *priv,
 156                               struct iwl_rx_mem_buffer *rxb)
 157 {
 158 #ifdef CONFIG_IWLWIFI_DEBUG
 159         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
 160         struct iwl_scanreq_notification *notif =
 161             (struct iwl_scanreq_notification *)pkt->u.raw;
 162
 163         IWL_DEBUG_RX(priv, "Scan request status = 0x%x\n", notif->status);
 164 #endif
 165 }
 166
 167 /* Service SCAN_START_NOTIFICATION (0x82) */
 168 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
 169                                     struct iwl_rx_mem_buffer *rxb)
 170 {
 171         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
 172         struct iwl_scanstart_notification *notif =
 173             (struct iwl_scanstart_notification *)pkt->u.raw;
 174         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 175         IWL_DEBUG_SCAN(priv, "Scan start: "
 176                        "%d [802.11%s] "
 177                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 178                        notif->channel,
 179                        notif->band ? "bg" : "a",
 180                        le32_to_cpu(notif->tsf_high),
 181                        le32_to_cpu(notif->tsf_low),
 182                        notif->status, notif->beacon_timer);
 183 }
 184
 185 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 186 static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
 187                                       struct iwl_rx_mem_buffer *rxb)
 188 {
 189 #ifdef CONFIG_IWLWIFI_DEBUG
 190         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
 191         struct iwl_scanresults_notification *notif =
 192             (struct iwl_scanresults_notification *)pkt->u.raw;
 193
 194         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
 195                        "%d [802.11%s] "
 196                        "(TSF: 0x%08X:%08X) - %d "
 197                        "elapsed=%lu usec (%dms since last)\n",
 198                        notif->channel,
 199                        notif->band ? "bg" : "a",
 200                        le32_to_cpu(notif->tsf_high),
 201                        le32_to_cpu(notif->tsf_low),
 202                        le32_to_cpu(notif->statistics[0]),
 203                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf,
 204                        jiffies_to_msecs(elapsed_jiffies
 205                                         (priv->last_scan_jiffies, jiffies)));
 206 #endif
 207
 208         priv->last_scan_jiffies = jiffies;
 209         priv->next_scan_jiffies = 0;
 210 }
 211
 212 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 213 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 214                                        struct iwl_rx_mem_buffer *rxb)
 215 {
 216 #ifdef CONFIG_IWLWIFI_DEBUG
 217         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
 218         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
 219
 220         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 221                        scan_notif->scanned_channels,
 222                        scan_notif->tsf_low,
 223                        scan_notif->tsf_high, scan_notif->status);
 224 #endif
 225
 226         /* The HW is no longer scanning */
 227         clear_bit(STATUS_SCAN_HW, &priv->status);
 228
 229         IWL_DEBUG_INFO(priv, "Scan pass on %sGHz took %dms\n",
 230                        (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) ?
 231                                                 "2.4" : "5.2",
 232                        jiffies_to_msecs(elapsed_jiffies
 233                                         (priv->scan_pass_start, jiffies)));
 234
 235         /* Remove this scanned band from the list of pending
 236          * bands to scan, band G precedes A in order of scanning
 237          * as seen in iwl_bg_request_scan */
 238         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ))
 239                 priv->scan_bands &= ~BIT(IEEE80211_BAND_2GHZ);
 240         else if (priv->scan_bands &  BIT(IEEE80211_BAND_5GHZ))
 241                 priv->scan_bands &= ~BIT(IEEE80211_BAND_5GHZ);
 242
 243         /* If a request to abort was given, or the scan did not succeed
 244          * then we reset the scan state machine and terminate,
 245          * re-queuing another scan if one has been requested */
 246         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 247                 IWL_DEBUG_INFO(priv, "Aborted scan completed.\n");
 248                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 249         } else {
 250                 /* If there are more bands on this scan pass reschedule */
 251                 if (priv->scan_bands)
 252                         goto reschedule;
 253         }
 254
 255         priv->last_scan_jiffies = jiffies;
 256         priv->next_scan_jiffies = 0;
 257         IWL_DEBUG_INFO(priv, "Setting scan to off\n");
 258
 259         clear_bit(STATUS_SCANNING, &priv->status);
 260
 261         IWL_DEBUG_INFO(priv, "Scan took %dms\n",
 262                 jiffies_to_msecs(elapsed_jiffies(priv->scan_start, jiffies)));
 263
 264         queue_work(priv->workqueue, &priv->scan_completed);
 265
 266         return;
 267
 268 reschedule:
 269         priv->scan_pass_start = jiffies;
 270         queue_work(priv->workqueue, &priv->request_scan);
 271 }
 272
 273 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 274 {
 275         /* scan handlers */
 276         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 277         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 278         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 279                                         iwl_rx_scan_results_notif;
 280         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 281                                         iwl_rx_scan_complete_notif;
 282 }
 283 EXPORT_SYMBOL(iwl_setup_rx_scan_handlers);
 284
 285 inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 286                                      enum ieee80211_band band,
 287                                      u8 n_probes)
 288 {
 289         if (band == IEEE80211_BAND_5GHZ)
 290                 return IWL_ACTIVE_DWELL_TIME_52 +
 291                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 292         else
 293                 return IWL_ACTIVE_DWELL_TIME_24 +
 294                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 295 }
 296 EXPORT_SYMBOL(iwl_get_active_dwell_time);
 297
 298 u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 299                                enum ieee80211_band band)
 300 {
 301         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
 302             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 303             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 304
 305         if (iwl_is_associated(priv)) {
 306                 /* If we're associated, we clamp the maximum passive
 307                  * dwell time to be 98% of the beacon interval (minus
 308                  * 2 * channel tune time) */
 309                 passive = priv->beacon_int;
 310                 if ((passive > IWL_PASSIVE_DWELL_BASE) || !passive)
 311                         passive = IWL_PASSIVE_DWELL_BASE;
 312                 passive = (passive * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 313         }
 314
 315         return passive;
 316 }
 317 EXPORT_SYMBOL(iwl_get_passive_dwell_time);
 318
 319 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 320                                      enum ieee80211_band band,
 321                                      u8 is_active, u8 n_probes,
 322                                      struct iwl_scan_channel *scan_ch)
 323 {
 324         struct ieee80211_channel *chan;
 325         const struct ieee80211_supported_band *sband;
 326         const struct iwl_channel_info *ch_info;
 327         u16 passive_dwell = 0;
 328         u16 active_dwell = 0;
 329         int added, i;
 330         u16 channel;
 331
 332         sband = iwl_get_hw_mode(priv, band);
 333         if (!sband)
 334                 return 0;
 335
 336         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 337         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 338
 339         if (passive_dwell <= active_dwell)
 340                 passive_dwell = active_dwell + 1;
 341
 342         for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
 343                 chan = priv->scan_request->channels[i];
 344
 345                 if (chan->band != band)
 346                         continue;
 347
 348                 channel = ieee80211_frequency_to_channel(chan->center_freq);
 349                 scan_ch->channel = cpu_to_le16(channel);
 350
 351                 ch_info = iwl_get_channel_info(priv, band, channel);
 352                 if (!is_channel_valid(ch_info)) {
 353                         IWL_DEBUG_SCAN(priv, "Channel %d is INVALID for this band.\n",
 354                                         channel);
 355                         continue;
 356                 }
 357
 358                 if (!is_active || is_channel_passive(ch_info) ||
 359                     (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN))
 360                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 361                 else
 362                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 363
 364                 if (n_probes)
 365                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 366
 367                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 368                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 369
 370                 /* Set txpower levels to defaults */
 371                 scan_ch->dsp_atten = 110;
 372
 373                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 374                  * power level:
 375                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 376                  */
 377                 if (band == IEEE80211_BAND_5GHZ)
 378                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 379                 else
 380                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 381
 382                 IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
 383                                channel, le32_to_cpu(scan_ch->type),
 384                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 385                                 "ACTIVE" : "PASSIVE",
 386                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 387                                active_dwell : passive_dwell);
 388
 389                 scan_ch++;
 390                 added++;
 391         }
 392
 393         IWL_DEBUG_SCAN(priv, "total channels to scan %d \n", added);
 394         return added;
 395 }
 396
 397 void iwl_init_scan_params(struct iwl_priv *priv)
 398 {
 399         u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
 400         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
 401                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
 402         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
 403                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
 404 }
 405
 406 static int iwl_scan_initiate(struct iwl_priv *priv)
 407 {
 408         if (!iwl_is_ready_rf(priv)) {
 409                 IWL_DEBUG_SCAN(priv, "Aborting scan due to not ready.\n");
 410                 return -EIO;
 411         }
 412
 413         if (test_bit(STATUS_SCANNING, &priv->status)) {
 414                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
 415                 return -EAGAIN;
 416         }
 417
 418         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 419                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
 420                 return -EAGAIN;
 421         }
 422
 423         IWL_DEBUG_INFO(priv, "Starting scan...\n");
 424         set_bit(STATUS_SCANNING, &priv->status);
 425         priv->scan_start = jiffies;
 426         priv->scan_pass_start = priv->scan_start;
 427
 428         queue_work(priv->workqueue, &priv->request_scan);
 429
 430         return 0;
 431 }
 432
 433 #define IWL_DELAY_NEXT_SCAN (HZ*2)
 434
 435 int iwl_mac_hw_scan(struct ieee80211_hw *hw,
 436                      struct cfg80211_scan_request *req)
 437 {
 438         unsigned long flags;
 439         struct iwl_priv *priv = hw->priv;
 440         int ret, i;
 441
 442         IWL_DEBUG_MAC80211(priv, "enter\n");
 443
 444         mutex_lock(&priv->mutex);
 445         spin_lock_irqsave(&priv->lock, flags);
 446
 447         if (!iwl_is_ready_rf(priv)) {
 448                 ret = -EIO;
 449                 IWL_DEBUG_MAC80211(priv, "leave - not ready or exit pending\n");
 450                 goto out_unlock;
 451         }
 452
 453         /* We don't schedule scan within next_scan_jiffies period.
 454          * Avoid scanning during possible EAPOL exchange, return
 455          * success immediately.
 456          */
 457         if (priv->next_scan_jiffies &&
 458             time_after(priv->next_scan_jiffies, jiffies)) {
 459                 IWL_DEBUG_SCAN(priv, "scan rejected: within next scan period\n");
 460                 queue_work(priv->workqueue, &priv->scan_completed);
 461                 ret = 0;
 462                 goto out_unlock;
 463         }
 464
 465         /* if we just finished scan ask for delay */
 466         if (iwl_is_associated(priv) && priv->last_scan_jiffies &&
 467             time_after(priv->last_scan_jiffies + IWL_DELAY_NEXT_SCAN, jiffies)) {
 468                 IWL_DEBUG_SCAN(priv, "scan rejected: within previous scan period\n");
 469                 queue_work(priv->workqueue, &priv->scan_completed);
 470                 ret = 0;
 471                 goto out_unlock;
 472         }
 473
 474         priv->scan_bands = 0;
 475         for (i = 0; i < req->n_channels; i++)
 476                 priv->scan_bands |= BIT(req->channels[i]->band);
 477
 478         priv->scan_request = req;
 479
 480         ret = iwl_scan_initiate(priv);
 481
 482         IWL_DEBUG_MAC80211(priv, "leave\n");
 483
 484 out_unlock:
 485         spin_unlock_irqrestore(&priv->lock, flags);
 486         mutex_unlock(&priv->mutex);
 487
 488         return ret;
 489 }
 490 EXPORT_SYMBOL(iwl_mac_hw_scan);
 491
 492 #define IWL_SCAN_CHECK_WATCHDOG (7 * HZ)
 493
 494 void iwl_bg_scan_check(struct work_struct *data)
 495 {
 496         struct iwl_priv *priv =
 497             container_of(data, struct iwl_priv, scan_check.work);
 498
 499         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 500                 return;
 501
 502         mutex_lock(&priv->mutex);
 503         if (test_bit(STATUS_SCANNING, &priv->status) ||
 504             test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 505                 IWL_DEBUG_SCAN(priv, "Scan completion watchdog resetting "
 506                         "adapter (%dms)\n",
 507                         jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG));
 508
 509                 if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
 510                         iwl_send_scan_abort(priv);
 511         }
 512         mutex_unlock(&priv->mutex);
 513 }
 514 EXPORT_SYMBOL(iwl_bg_scan_check);
 515
 516 /**
 517  * iwl_fill_probe_req - fill in all required fields and IE for probe request
 518  */
 519
 520 u16 iwl_fill_probe_req(struct iwl_priv *priv, struct ieee80211_mgmt *frame,
 521                        const u8 *ies, int ie_len, int left)
 522 {
 523         int len = 0;
 524         u8 *pos = NULL;
 525
 526         /* Make sure there is enough space for the probe request,
 527          * two mandatory IEs and the data */
 528         left -= 24;
 529         if (left < 0)
 530                 return 0;
 531
 532         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 533         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
 534         memcpy(frame->sa, priv->mac_addr, ETH_ALEN);
 535         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
 536         frame->seq_ctrl = 0;
 537
 538         len += 24;
 539
 540         /* ...next IE... */
 541         pos = &frame->u.probe_req.variable[0];
 542
 543         /* fill in our indirect SSID IE */
 544         left -= 2;
 545         if (left < 0)
 546                 return 0;
 547         *pos++ = WLAN_EID_SSID;
 548         *pos++ = 0;
 549
 550         len += 2;
 551
 552         if (WARN_ON(left < ie_len))
 553                 return len;
 554
 555         memcpy(pos, ies, ie_len);
 556         len += ie_len;
 557         left -= ie_len;
 558
 559         return (u16)len;
 560 }
 561 EXPORT_SYMBOL(iwl_fill_probe_req);
 562
 563 static void iwl_bg_request_scan(struct work_struct *data)
 564 {
 565         struct iwl_priv *priv =
 566             container_of(data, struct iwl_priv, request_scan);
 567         struct iwl_host_cmd cmd = {
 568                 .id = REPLY_SCAN_CMD,
 569                 .len = sizeof(struct iwl_scan_cmd),
 570                 .flags = CMD_SIZE_HUGE,
 571         };
 572         struct iwl_scan_cmd *scan;
 573         struct ieee80211_conf *conf = NULL;
 574         int ret = 0;
 575         u32 rate_flags = 0;
 576         u16 cmd_len;
 577         u16 rx_chain = 0;
 578         enum ieee80211_band band;
 579         u8 n_probes = 0;
 580         u8 rx_ant = priv->hw_params.valid_rx_ant;
 581         u8 rate;
 582         bool is_active = false;
 583         int  chan_mod;
 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         /* MIMO is not used here, but value is required */
 738         rx_chain |= ANT_ABC << RXON_RX_CHAIN_VALID_POS;
 739         rx_chain |= ANT_ABC << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
 740         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
 741         rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
 742         scan->rx_chain = cpu_to_le16(rx_chain);
 743         cmd_len = iwl_fill_probe_req(priv,
 744                                 (struct ieee80211_mgmt *)scan->data,
 745                                 priv->scan_request->ie,
 746                                 priv->scan_request->ie_len,
 747                                 IWL_MAX_SCAN_SIZE - sizeof(*scan));
 748
 749         scan->tx_cmd.len = cpu_to_le16(cmd_len);
 750
 751         if (iwl_is_monitor_mode(priv))
 752                 scan->filter_flags = RXON_FILTER_PROMISC_MSK;
 753
 754         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 755                                RXON_FILTER_BCON_AWARE_MSK);
 756
 757         scan->channel_count =
 758                 iwl_get_channels_for_scan(priv, band, is_active, n_probes,
 759                         (void *)&scan->data[le16_to_cpu(scan->tx_cmd.len)]);
 760
 761         if (scan->channel_count == 0) {
 762                 IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
 763                 goto done;
 764         }
 765
 766         cmd.len += le16_to_cpu(scan->tx_cmd.len) +
 767             scan->channel_count * sizeof(struct iwl_scan_channel);
 768         cmd.data = scan;
 769         scan->len = cpu_to_le16(cmd.len);
 770
 771         set_bit(STATUS_SCAN_HW, &priv->status);
 772         ret = iwl_send_cmd_sync(priv, &cmd);
 773         if (ret)
 774                 goto done;
 775
 776         queue_delayed_work(priv->workqueue, &priv->scan_check,
 777                            IWL_SCAN_CHECK_WATCHDOG);
 778
 779         mutex_unlock(&priv->mutex);
 780         return;
 781
 782  done:
 783         /* Cannot perform scan. Make sure we clear scanning
 784         * bits from status so next scan request can be performed.
 785         * If we don't clear scanning status bit here all next scan
 786         * will fail
 787         */
 788         clear_bit(STATUS_SCAN_HW, &priv->status);
 789         clear_bit(STATUS_SCANNING, &priv->status);
 790         /* inform mac80211 scan aborted */
 791         queue_work(priv->workqueue, &priv->scan_completed);
 792         mutex_unlock(&priv->mutex);
 793 }
 794
 795 void iwl_bg_abort_scan(struct work_struct *work)
 796 {
 797         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
 798
 799         if (!test_bit(STATUS_READY, &priv->status) ||
 800             !test_bit(STATUS_GEO_CONFIGURED, &priv->status))
 801                 return;
 802
 803         mutex_lock(&priv->mutex);
 804
 805         set_bit(STATUS_SCAN_ABORTING, &priv->status);
 806         iwl_send_scan_abort(priv);
 807
 808         mutex_unlock(&priv->mutex);
 809 }
 810 EXPORT_SYMBOL(iwl_bg_abort_scan);
 811
 812 void iwl_bg_scan_completed(struct work_struct *work)
 813 {
 814         struct iwl_priv *priv =
 815             container_of(work, struct iwl_priv, scan_completed);
 816
 817         IWL_DEBUG_SCAN(priv, "SCAN complete scan\n");
 818
 819         cancel_delayed_work(&priv->scan_check);
 820
 821         ieee80211_scan_completed(priv->hw, false);
 822
 823         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 824                 return;
 825
 826         /* Since setting the TXPOWER may have been deferred while
 827          * performing the scan, fire one off */
 828         mutex_lock(&priv->mutex);
 829         iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);
 830         mutex_unlock(&priv->mutex);
 831 }
 832 EXPORT_SYMBOL(iwl_bg_scan_completed);
 833
 834 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
 835 {
 836         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
 837         INIT_WORK(&priv->request_scan, iwl_bg_request_scan);
 838         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
 839         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
 840 }
 841 EXPORT_SYMBOL(iwl_setup_scan_deferred_work);
 842