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("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("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                 .meta.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.meta.u.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("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.meta.u.skb);
 150
 151         return ret;
 152 }
 153
 154
 155 /* Service response to REPLY_SCAN_CMD (0x80) */
 156 static void iwl_rx_reply_scan(struct iwl_priv *priv,
 157                               struct iwl_rx_mem_buffer *rxb)
 158 {
 159 #ifdef CONFIG_IWLWIFI_DEBUG
 160         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
 161         struct iwl_scanreq_notification *notif =
 162             (struct iwl_scanreq_notification *)pkt->u.raw;
 163
 164         IWL_DEBUG_RX("Scan request status = 0x%x\n", notif->status);
 165 #endif
 166 }
 167
 168 /* Service SCAN_START_NOTIFICATION (0x82) */
 169 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
 170                                     struct iwl_rx_mem_buffer *rxb)
 171 {
 172         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
 173         struct iwl_scanstart_notification *notif =
 174             (struct iwl_scanstart_notification *)pkt->u.raw;
 175         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 176         IWL_DEBUG_SCAN("Scan start: "
 177                        "%d [802.11%s] "
 178                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 179                        notif->channel,
 180                        notif->band ? "bg" : "a",
 181                        le32_to_cpu(notif->tsf_high),
 182                        le32_to_cpu(notif->tsf_low),
 183                        notif->status, notif->beacon_timer);
 184 }
 185
 186 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 187 static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
 188                                       struct iwl_rx_mem_buffer *rxb)
 189 {
 190 #ifdef CONFIG_IWLWIFI_DEBUG
 191         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
 192         struct iwl_scanresults_notification *notif =
 193             (struct iwl_scanresults_notification *)pkt->u.raw;
 194
 195         IWL_DEBUG_SCAN("Scan ch.res: "
 196                        "%d [802.11%s] "
 197                        "(TSF: 0x%08X:%08X) - %d "
 198                        "elapsed=%lu usec (%dms since last)\n",
 199                        notif->channel,
 200                        notif->band ? "bg" : "a",
 201                        le32_to_cpu(notif->tsf_high),
 202                        le32_to_cpu(notif->tsf_low),
 203                        le32_to_cpu(notif->statistics[0]),
 204                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf,
 205                        jiffies_to_msecs(elapsed_jiffies
 206                                         (priv->last_scan_jiffies, jiffies)));
 207 #endif
 208
 209         priv->last_scan_jiffies = jiffies;
 210         priv->next_scan_jiffies = 0;
 211 }
 212
 213 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 214 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 215                                        struct iwl_rx_mem_buffer *rxb)
 216 {
 217 #ifdef CONFIG_IWLWIFI_DEBUG
 218         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
 219         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
 220
 221         IWL_DEBUG_SCAN("Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 222                        scan_notif->scanned_channels,
 223                        scan_notif->tsf_low,
 224                        scan_notif->tsf_high, scan_notif->status);
 225 #endif
 226
 227         /* The HW is no longer scanning */
 228         clear_bit(STATUS_SCAN_HW, &priv->status);
 229
 230         /* The scan completion notification came in, so kill that timer... */
 231         cancel_delayed_work(&priv->scan_check);
 232
 233         IWL_DEBUG_INFO("Scan pass on %sGHz took %dms\n",
 234                        (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) ?
 235                                                 "2.4" : "5.2",
 236                        jiffies_to_msecs(elapsed_jiffies
 237                                         (priv->scan_pass_start, jiffies)));
 238
 239         /* Remove this scanned band from the list of pending
 240          * bands to scan, band G precedes A in order of scanning
 241          * as seen in iwl_bg_request_scan */
 242         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ))
 243                 priv->scan_bands &= ~BIT(IEEE80211_BAND_2GHZ);
 244         else if (priv->scan_bands &  BIT(IEEE80211_BAND_5GHZ))
 245                 priv->scan_bands &= ~BIT(IEEE80211_BAND_5GHZ);
 246
 247         /* If a request to abort was given, or the scan did not succeed
 248          * then we reset the scan state machine and terminate,
 249          * re-queuing another scan if one has been requested */
 250         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 251                 IWL_DEBUG_INFO("Aborted scan completed.\n");
 252                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 253         } else {
 254                 /* If there are more bands on this scan pass reschedule */
 255                 if (priv->scan_bands)
 256                         goto reschedule;
 257         }
 258
 259         priv->last_scan_jiffies = jiffies;
 260         priv->next_scan_jiffies = 0;
 261         IWL_DEBUG_INFO("Setting scan to off\n");
 262
 263         clear_bit(STATUS_SCANNING, &priv->status);
 264
 265         IWL_DEBUG_INFO("Scan took %dms\n",
 266                 jiffies_to_msecs(elapsed_jiffies(priv->scan_start, jiffies)));
 267
 268         queue_work(priv->workqueue, &priv->scan_completed);
 269
 270         return;
 271
 272 reschedule:
 273         priv->scan_pass_start = jiffies;
 274         queue_work(priv->workqueue, &priv->request_scan);
 275 }
 276
 277 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 278 {
 279         /* scan handlers */
 280         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 281         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 282         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 283                                         iwl_rx_scan_results_notif;
 284         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 285                                         iwl_rx_scan_complete_notif;
 286 }
 287 EXPORT_SYMBOL(iwl_setup_rx_scan_handlers);
 288
 289 inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 290                                      enum ieee80211_band band,
 291                                      u8 n_probes)
 292 {
 293         if (band == IEEE80211_BAND_5GHZ)
 294                 return IWL_ACTIVE_DWELL_TIME_52 +
 295                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 296         else
 297                 return IWL_ACTIVE_DWELL_TIME_24 +
 298                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 299 }
 300 EXPORT_SYMBOL(iwl_get_active_dwell_time);
 301
 302 u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 303                                enum ieee80211_band band)
 304 {
 305         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
 306             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 307             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 308
 309         if (iwl_is_associated(priv)) {
 310                 /* If we're associated, we clamp the maximum passive
 311                  * dwell time to be 98% of the beacon interval (minus
 312                  * 2 * channel tune time) */
 313                 passive = priv->beacon_int;
 314                 if ((passive > IWL_PASSIVE_DWELL_BASE) || !passive)
 315                         passive = IWL_PASSIVE_DWELL_BASE;
 316                 passive = (passive * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 317         }
 318
 319         return passive;
 320 }
 321 EXPORT_SYMBOL(iwl_get_passive_dwell_time);
 322
 323 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 324                                      enum ieee80211_band band,
 325                                      u8 is_active, u8 n_probes,
 326                                      struct iwl_scan_channel *scan_ch)
 327 {
 328         const struct ieee80211_channel *channels = NULL;
 329         const struct ieee80211_supported_band *sband;
 330         const struct iwl_channel_info *ch_info;
 331         u16 passive_dwell = 0;
 332         u16 active_dwell = 0;
 333         int added, i;
 334         u16 channel;
 335
 336         sband = iwl_get_hw_mode(priv, band);
 337         if (!sband)
 338                 return 0;
 339
 340         channels = sband->channels;
 341
 342         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 343         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 344
 345         if (passive_dwell <= active_dwell)
 346                 passive_dwell = active_dwell + 1;
 347
 348         for (i = 0, added = 0; i < sband->n_channels; i++) {
 349                 if (channels[i].flags & IEEE80211_CHAN_DISABLED)
 350                         continue;
 351
 352                 channel =
 353                         ieee80211_frequency_to_channel(channels[i].center_freq);
 354                 scan_ch->channel = cpu_to_le16(channel);
 355
 356                 ch_info = iwl_get_channel_info(priv, band, channel);
 357                 if (!is_channel_valid(ch_info)) {
 358                         IWL_DEBUG_SCAN("Channel %d is INVALID for this band.\n",
 359                                         channel);
 360                         continue;
 361                 }
 362
 363                 if (!is_active || is_channel_passive(ch_info) ||
 364                     (channels[i].flags & IEEE80211_CHAN_PASSIVE_SCAN))
 365                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 366                 else
 367                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 368
 369                 if (n_probes)
 370                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 371
 372                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 373                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 374
 375                 /* Set txpower levels to defaults */
 376                 scan_ch->dsp_atten = 110;
 377
 378                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 379                  * power level:
 380                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 381                  */
 382                 if (band == IEEE80211_BAND_5GHZ)
 383                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 384                 else
 385                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 386
 387                 IWL_DEBUG_SCAN("Scanning ch=%d prob=0x%X [%s %d]\n",
 388                                channel, le32_to_cpu(scan_ch->type),
 389                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 390                                 "ACTIVE" : "PASSIVE",
 391                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 392                                active_dwell : passive_dwell);
 393
 394                 scan_ch++;
 395                 added++;
 396         }
 397
 398         IWL_DEBUG_SCAN("total channels to scan %d \n", added);
 399         return added;
 400 }
 401
 402 void iwl_init_scan_params(struct iwl_priv *priv)
 403 {
 404         u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
 405         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
 406                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
 407         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
 408                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
 409 }
 410
 411 int iwl_scan_initiate(struct iwl_priv *priv)
 412 {
 413         if (!iwl_is_ready_rf(priv)) {
 414                 IWL_DEBUG_SCAN("Aborting scan due to not ready.\n");
 415                 return -EIO;
 416         }
 417
 418         if (test_bit(STATUS_SCANNING, &priv->status)) {
 419                 IWL_DEBUG_SCAN("Scan already in progress.\n");
 420                 return -EAGAIN;
 421         }
 422
 423         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 424                 IWL_DEBUG_SCAN("Scan request while abort pending\n");
 425                 return -EAGAIN;
 426         }
 427
 428         IWL_DEBUG_INFO("Starting scan...\n");
 429         if (priv->cfg->sku & IWL_SKU_G)
 430                 priv->scan_bands |= BIT(IEEE80211_BAND_2GHZ);
 431         if (priv->cfg->sku & IWL_SKU_A)
 432                 priv->scan_bands |= BIT(IEEE80211_BAND_5GHZ);
 433         set_bit(STATUS_SCANNING, &priv->status);
 434         priv->scan_start = jiffies;
 435         priv->scan_pass_start = priv->scan_start;
 436
 437         queue_work(priv->workqueue, &priv->request_scan);
 438
 439         return 0;
 440 }
 441 EXPORT_SYMBOL(iwl_scan_initiate);
 442
 443 #define IWL_SCAN_CHECK_WATCHDOG (7 * HZ)
 444
 445 void iwl_bg_scan_check(struct work_struct *data)
 446 {
 447         struct iwl_priv *priv =
 448             container_of(data, struct iwl_priv, scan_check.work);
 449
 450         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 451                 return;
 452
 453         mutex_lock(&priv->mutex);
 454         if (test_bit(STATUS_SCANNING, &priv->status) ||
 455             test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 456                 IWL_DEBUG(IWL_DL_SCAN, "Scan completion watchdog resetting "
 457                         "adapter (%dms)\n",
 458                         jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG));
 459
 460                 if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
 461                         iwl_send_scan_abort(priv);
 462         }
 463         mutex_unlock(&priv->mutex);
 464 }
 465 EXPORT_SYMBOL(iwl_bg_scan_check);
 466
 467 /**
 468  * iwl_supported_rate_to_ie - fill in the supported rate in IE field
 469  *
 470  * return : set the bit for each supported rate insert in ie
 471  */
 472 static u16 iwl_supported_rate_to_ie(u8 *ie, u16 supported_rate,
 473                                     u16 basic_rate, int *left)
 474 {
 475         u16 ret_rates = 0, bit;
 476         int i;
 477         u8 *cnt = ie;
 478         u8 *rates = ie + 1;
 479
 480         for (bit = 1, i = 0; i < IWL_RATE_COUNT; i++, bit <<= 1) {
 481                 if (bit & supported_rate) {
 482                         ret_rates |= bit;
 483                         rates[*cnt] = iwl_rates[i].ieee |
 484                                 ((bit & basic_rate) ? 0x80 : 0x00);
 485                         (*cnt)++;
 486                         (*left)--;
 487                         if ((*left <= 0) ||
 488                             (*cnt >= IWL_SUPPORTED_RATES_IE_LEN))
 489                                 break;
 490                 }
 491         }
 492
 493         return ret_rates;
 494 }
 495
 496
 497 static void iwl_ht_cap_to_ie(const struct ieee80211_supported_band *sband,
 498                              u8 *pos, int *left)
 499 {
 500         struct ieee80211_ht_cap *ht_cap;
 501
 502         if (!sband || !sband->ht_cap.ht_supported)
 503                 return;
 504
 505         if (*left < sizeof(struct ieee80211_ht_cap))
 506                 return;
 507
 508         *pos++ = sizeof(struct ieee80211_ht_cap);
 509         ht_cap = (struct ieee80211_ht_cap *) pos;
 510
 511         ht_cap->cap_info = cpu_to_le16(sband->ht_cap.cap);
 512         memcpy(&ht_cap->mcs, &sband->ht_cap.mcs, 16);
 513         ht_cap->ampdu_params_info =
 514                 (sband->ht_cap.ampdu_factor & IEEE80211_HT_AMPDU_PARM_FACTOR) |
 515                 ((sband->ht_cap.ampdu_density << 2) &
 516                         IEEE80211_HT_AMPDU_PARM_DENSITY);
 517         *left -= sizeof(struct ieee80211_ht_cap);
 518 }
 519
 520 /**
 521  * iwl_fill_probe_req - fill in all required fields and IE for probe request
 522  */
 523
 524 u16 iwl_fill_probe_req(struct iwl_priv *priv,
 525                        enum ieee80211_band band,
 526                        struct ieee80211_mgmt *frame,
 527                        int left)
 528 {
 529         int len = 0;
 530         u8 *pos = NULL;
 531         u16 active_rates, ret_rates, cck_rates, active_rate_basic;
 532         const struct ieee80211_supported_band *sband =
 533                                                 iwl_get_hw_mode(priv, band);
 534
 535
 536         /* Make sure there is enough space for the probe request,
 537          * two mandatory IEs and the data */
 538         left -= 24;
 539         if (left < 0)
 540                 return 0;
 541
 542         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 543         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
 544         memcpy(frame->sa, priv->mac_addr, ETH_ALEN);
 545         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
 546         frame->seq_ctrl = 0;
 547
 548         len += 24;
 549
 550         /* ...next IE... */
 551         pos = &frame->u.probe_req.variable[0];
 552
 553         /* fill in our indirect SSID IE */
 554         left -= 2;
 555         if (left < 0)
 556                 return 0;
 557         *pos++ = WLAN_EID_SSID;
 558         *pos++ = 0;
 559
 560         len += 2;
 561
 562         /* fill in supported rate */
 563         left -= 2;
 564         if (left < 0)
 565                 return 0;
 566
 567         *pos++ = WLAN_EID_SUPP_RATES;
 568         *pos = 0;
 569
 570         /* exclude 60M rate */
 571         active_rates = priv->rates_mask;
 572         active_rates &= ~IWL_RATE_60M_MASK;
 573
 574         active_rate_basic = active_rates & IWL_BASIC_RATES_MASK;
 575
 576         cck_rates = IWL_CCK_RATES_MASK & active_rates;
 577         ret_rates = iwl_supported_rate_to_ie(pos, cck_rates,
 578                                              active_rate_basic, &left);
 579         active_rates &= ~ret_rates;
 580
 581         ret_rates = iwl_supported_rate_to_ie(pos, active_rates,
 582                                              active_rate_basic, &left);
 583         active_rates &= ~ret_rates;
 584
 585         len += 2 + *pos;
 586         pos += (*pos) + 1;
 587
 588         if (active_rates == 0)
 589                 goto fill_end;
 590
 591         /* fill in supported extended rate */
 592         /* ...next IE... */
 593         left -= 2;
 594         if (left < 0)
 595                 return 0;
 596         /* ... fill it in... */
 597         *pos++ = WLAN_EID_EXT_SUPP_RATES;
 598         *pos = 0;
 599         iwl_supported_rate_to_ie(pos, active_rates, active_rate_basic, &left);
 600         if (*pos > 0) {
 601                 len += 2 + *pos;
 602                 pos += (*pos) + 1;
 603         } else {
 604                 pos--;
 605         }
 606
 607  fill_end:
 608
 609         left -= 2;
 610         if (left < 0)
 611                 return 0;
 612
 613         *pos++ = WLAN_EID_HT_CAPABILITY;
 614         *pos = 0;
 615         iwl_ht_cap_to_ie(sband, pos, &left);
 616         if (*pos > 0)
 617                 len += 2 + *pos;
 618
 619         return (u16)len;
 620 }
 621 EXPORT_SYMBOL(iwl_fill_probe_req);
 622
 623 static void iwl_bg_request_scan(struct work_struct *data)
 624 {
 625         struct iwl_priv *priv =
 626             container_of(data, struct iwl_priv, request_scan);
 627         struct iwl_host_cmd cmd = {
 628                 .id = REPLY_SCAN_CMD,
 629                 .len = sizeof(struct iwl_scan_cmd),
 630                 .meta.flags = CMD_SIZE_HUGE,
 631         };
 632         struct iwl_scan_cmd *scan;
 633         struct ieee80211_conf *conf = NULL;
 634         int ret = 0;
 635         u32 rate_flags = 0;
 636         u16 cmd_len;
 637         enum ieee80211_band band;
 638         u8 n_probes = 2;
 639         u8 rx_chain = priv->hw_params.valid_rx_ant;
 640         u8 rate;
 641         DECLARE_SSID_BUF(ssid);
 642
 643         conf = ieee80211_get_hw_conf(priv->hw);
 644
 645         mutex_lock(&priv->mutex);
 646
 647         if (!iwl_is_ready(priv)) {
 648                 IWL_WARN(priv, "request scan called when driver not ready.\n");
 649                 goto done;
 650         }
 651
 652         /* Make sure the scan wasn't canceled before this queued work
 653          * was given the chance to run... */
 654         if (!test_bit(STATUS_SCANNING, &priv->status))
 655                 goto done;
 656
 657         /* This should never be called or scheduled if there is currently
 658          * a scan active in the hardware. */
 659         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
 660                 IWL_DEBUG_INFO("Multiple concurrent scan requests in parallel. "
 661                                "Ignoring second request.\n");
 662                 ret = -EIO;
 663                 goto done;
 664         }
 665
 666         if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
 667                 IWL_DEBUG_SCAN("Aborting scan due to device shutdown\n");
 668                 goto done;
 669         }
 670
 671         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 672                 IWL_DEBUG_HC("Scan request while abort pending.  Queuing.\n");
 673                 goto done;
 674         }
 675
 676         if (iwl_is_rfkill(priv)) {
 677                 IWL_DEBUG_HC("Aborting scan due to RF Kill activation\n");
 678                 goto done;
 679         }
 680
 681         if (!test_bit(STATUS_READY, &priv->status)) {
 682                 IWL_DEBUG_HC("Scan request while uninitialized.  Queuing.\n");
 683                 goto done;
 684         }
 685
 686         if (!priv->scan_bands) {
 687                 IWL_DEBUG_HC("Aborting scan due to no requested bands\n");
 688                 goto done;
 689         }
 690
 691         if (!priv->scan) {
 692                 priv->scan = kmalloc(sizeof(struct iwl_scan_cmd) +
 693                                      IWL_MAX_SCAN_SIZE, GFP_KERNEL);
 694                 if (!priv->scan) {
 695                         ret = -ENOMEM;
 696                         goto done;
 697                 }
 698         }
 699         scan = priv->scan;
 700         memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
 701
 702         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
 703         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
 704
 705         if (iwl_is_associated(priv)) {
 706                 u16 interval = 0;
 707                 u32 extra;
 708                 u32 suspend_time = 100;
 709                 u32 scan_suspend_time = 100;
 710                 unsigned long flags;
 711
 712                 IWL_DEBUG_INFO("Scanning while associated...\n");
 713
 714                 spin_lock_irqsave(&priv->lock, flags);
 715                 interval = priv->beacon_int;
 716                 spin_unlock_irqrestore(&priv->lock, flags);
 717
 718                 scan->suspend_time = 0;
 719                 scan->max_out_time = cpu_to_le32(200 * 1024);
 720                 if (!interval)
 721                         interval = suspend_time;
 722
 723                 extra = (suspend_time / interval) << 22;
 724                 scan_suspend_time = (extra |
 725                     ((suspend_time % interval) * 1024));
 726                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
 727                 IWL_DEBUG_SCAN("suspend_time 0x%X beacon interval %d\n",
 728                                scan_suspend_time, interval);
 729         }
 730
 731         /* We should add the ability for user to lock to PASSIVE ONLY */
 732         if (priv->one_direct_scan) {
 733                 IWL_DEBUG_SCAN("Start direct scan for '%s'\n",
 734                                 print_ssid(ssid, priv->direct_ssid,
 735                                            priv->direct_ssid_len));
 736                 scan->direct_scan[0].id = WLAN_EID_SSID;
 737                 scan->direct_scan[0].len = priv->direct_ssid_len;
 738                 memcpy(scan->direct_scan[0].ssid,
 739                        priv->direct_ssid, priv->direct_ssid_len);
 740                 n_probes++;
 741         } else {
 742                 IWL_DEBUG_SCAN("Start indirect scan.\n");
 743         }
 744
 745         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
 746         scan->tx_cmd.sta_id = priv->hw_params.bcast_sta_id;
 747         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
 748
 749
 750         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) {
 751                 band = IEEE80211_BAND_2GHZ;
 752                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
 753                 if (priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_PURE_40_MSK) {
 754                         rate = IWL_RATE_6M_PLCP;
 755                 } else {
 756                         rate = IWL_RATE_1M_PLCP;
 757                         rate_flags = RATE_MCS_CCK_MSK;
 758                 }
 759                 scan->good_CRC_th = 0;
 760         } else if (priv->scan_bands & BIT(IEEE80211_BAND_5GHZ)) {
 761                 band = IEEE80211_BAND_5GHZ;
 762                 rate = IWL_RATE_6M_PLCP;
 763                 scan->good_CRC_th = IWL_GOOD_CRC_TH;
 764
 765                 /* Force use of chains B and C (0x6) for scan Rx for 4965
 766                  * Avoid A (0x1) because of its off-channel reception on A-band.
 767                  */
 768                 if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) == CSR_HW_REV_TYPE_4965)
 769                         rx_chain = 0x6;
 770         } else {
 771                 IWL_WARN(priv, "Invalid scan band count\n");
 772                 goto done;
 773         }
 774
 775         priv->scan_tx_ant[band] =
 776                          iwl_toggle_tx_ant(priv, priv->scan_tx_ant[band]);
 777         rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
 778         scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
 779
 780         /* MIMO is not used here, but value is required */
 781         scan->rx_chain = RXON_RX_CHAIN_DRIVER_FORCE_MSK |
 782                                 cpu_to_le16((0x7 << RXON_RX_CHAIN_VALID_POS) |
 783                                 (rx_chain << RXON_RX_CHAIN_FORCE_SEL_POS) |
 784                                 (0x7 << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS));
 785
 786         cmd_len = iwl_fill_probe_req(priv, band,
 787                                      (struct ieee80211_mgmt *)scan->data,
 788                                      IWL_MAX_SCAN_SIZE - sizeof(*scan));
 789
 790         scan->tx_cmd.len = cpu_to_le16(cmd_len);
 791
 792         if (priv->iw_mode == NL80211_IFTYPE_MONITOR)
 793                 scan->filter_flags = RXON_FILTER_PROMISC_MSK;
 794
 795         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 796                                RXON_FILTER_BCON_AWARE_MSK);
 797
 798         scan->channel_count =
 799                 iwl_get_channels_for_scan(priv, band, 1, /* active */
 800                         n_probes,
 801                         (void *)&scan->data[le16_to_cpu(scan->tx_cmd.len)]);
 802
 803         if (scan->channel_count == 0) {
 804                 IWL_DEBUG_SCAN("channel count %d\n", scan->channel_count);
 805                 goto done;
 806         }
 807
 808         cmd.len += le16_to_cpu(scan->tx_cmd.len) +
 809             scan->channel_count * sizeof(struct iwl_scan_channel);
 810         cmd.data = scan;
 811         scan->len = cpu_to_le16(cmd.len);
 812
 813         set_bit(STATUS_SCAN_HW, &priv->status);
 814         ret = iwl_send_cmd_sync(priv, &cmd);
 815         if (ret)
 816                 goto done;
 817
 818         queue_delayed_work(priv->workqueue, &priv->scan_check,
 819                            IWL_SCAN_CHECK_WATCHDOG);
 820
 821         mutex_unlock(&priv->mutex);
 822         return;
 823
 824  done:
 825         /* Cannot perform scan. Make sure we clear scanning
 826         * bits from status so next scan request can be performed.
 827         * If we don't clear scanning status bit here all next scan
 828         * will fail
 829         */
 830         clear_bit(STATUS_SCAN_HW, &priv->status);
 831         clear_bit(STATUS_SCANNING, &priv->status);
 832         /* inform mac80211 scan aborted */
 833         queue_work(priv->workqueue, &priv->scan_completed);
 834         mutex_unlock(&priv->mutex);
 835 }
 836
 837 void iwl_bg_abort_scan(struct work_struct *work)
 838 {
 839         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
 840
 841         if (!iwl_is_ready(priv))
 842                 return;
 843
 844         mutex_lock(&priv->mutex);
 845
 846         set_bit(STATUS_SCAN_ABORTING, &priv->status);
 847         iwl_send_scan_abort(priv);
 848
 849         mutex_unlock(&priv->mutex);
 850 }
 851 EXPORT_SYMBOL(iwl_bg_abort_scan);
 852
 853 void iwl_bg_scan_completed(struct work_struct *work)
 854 {
 855         struct iwl_priv *priv =
 856             container_of(work, struct iwl_priv, scan_completed);
 857
 858         IWL_DEBUG_SCAN("SCAN complete scan\n");
 859
 860         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 861                 return;
 862
 863         ieee80211_scan_completed(priv->hw);
 864
 865         /* Since setting the TXPOWER may have been deferred while
 866          * performing the scan, fire one off */
 867         mutex_lock(&priv->mutex);
 868         iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);
 869         mutex_unlock(&priv->mutex);
 870 }
 871 EXPORT_SYMBOL(iwl_bg_scan_completed);
 872
 873 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
 874 {
 875         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
 876         INIT_WORK(&priv->request_scan, iwl_bg_request_scan);
 877         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
 878         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
 879 }
 880 EXPORT_SYMBOL(iwl_setup_scan_deferred_work);
 881