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/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         priv->alloc_rxb_page--;
 148         free_pages(cmd.reply_page, priv->hw_params.rx_page_order);
 149
 150         return ret;
 151 }
 152
 153 /* Service response to REPLY_SCAN_CMD (0x80) */
 154 static void iwl_rx_reply_scan(struct iwl_priv *priv,
 155                               struct iwl_rx_mem_buffer *rxb)
 156 {
 157 #ifdef CONFIG_IWLWIFI_DEBUG
 158         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 159         struct iwl_scanreq_notification *notif =
 160             (struct iwl_scanreq_notification *)pkt->u.raw;
 161
 162         IWL_DEBUG_RX(priv, "Scan request status = 0x%x\n", notif->status);
 163 #endif
 164 }
 165
 166 /* Service SCAN_START_NOTIFICATION (0x82) */
 167 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
 168                                     struct iwl_rx_mem_buffer *rxb)
 169 {
 170         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 171         struct iwl_scanstart_notification *notif =
 172             (struct iwl_scanstart_notification *)pkt->u.raw;
 173         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 174         IWL_DEBUG_SCAN(priv, "Scan start: "
 175                        "%d [802.11%s] "
 176                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 177                        notif->channel,
 178                        notif->band ? "bg" : "a",
 179                        le32_to_cpu(notif->tsf_high),
 180                        le32_to_cpu(notif->tsf_low),
 181                        notif->status, notif->beacon_timer);
 182 }
 183
 184 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 185 static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
 186                                       struct iwl_rx_mem_buffer *rxb)
 187 {
 188 #ifdef CONFIG_IWLWIFI_DEBUG
 189         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 190         struct iwl_scanresults_notification *notif =
 191             (struct iwl_scanresults_notification *)pkt->u.raw;
 192
 193         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
 194                        "%d [802.11%s] "
 195                        "(TSF: 0x%08X:%08X) - %d "
 196                        "elapsed=%lu usec (%dms since last)\n",
 197                        notif->channel,
 198                        notif->band ? "bg" : "a",
 199                        le32_to_cpu(notif->tsf_high),
 200                        le32_to_cpu(notif->tsf_low),
 201                        le32_to_cpu(notif->statistics[0]),
 202                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf,
 203                        jiffies_to_msecs(elapsed_jiffies
 204                                         (priv->last_scan_jiffies, jiffies)));
 205 #endif
 206
 207         priv->last_scan_jiffies = jiffies;
 208         priv->next_scan_jiffies = 0;
 209 }
 210
 211 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 212 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 213                                        struct iwl_rx_mem_buffer *rxb)
 214 {
 215 #ifdef CONFIG_IWLWIFI_DEBUG
 216         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 217         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
 218
 219         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 220                        scan_notif->scanned_channels,
 221                        scan_notif->tsf_low,
 222                        scan_notif->tsf_high, scan_notif->status);
 223 #endif
 224
 225         /* The HW is no longer scanning */
 226         clear_bit(STATUS_SCAN_HW, &priv->status);
 227
 228         IWL_DEBUG_INFO(priv, "Scan pass on %sGHz took %dms\n",
 229                        (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) ?
 230                                                 "2.4" : "5.2",
 231                        jiffies_to_msecs(elapsed_jiffies
 232                                         (priv->scan_pass_start, jiffies)));
 233
 234         /* Remove this scanned band from the list of pending
 235          * bands to scan, band G precedes A in order of scanning
 236          * as seen in iwl_bg_request_scan */
 237         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ))
 238                 priv->scan_bands &= ~BIT(IEEE80211_BAND_2GHZ);
 239         else if (priv->scan_bands &  BIT(IEEE80211_BAND_5GHZ))
 240                 priv->scan_bands &= ~BIT(IEEE80211_BAND_5GHZ);
 241
 242         /* If a request to abort was given, or the scan did not succeed
 243          * then we reset the scan state machine and terminate,
 244          * re-queuing another scan if one has been requested */
 245         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 246                 IWL_DEBUG_INFO(priv, "Aborted scan completed.\n");
 247                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 248         } else {
 249                 /* If there are more bands on this scan pass reschedule */
 250                 if (priv->scan_bands)
 251                         goto reschedule;
 252         }
 253
 254         priv->last_scan_jiffies = jiffies;
 255         priv->next_scan_jiffies = 0;
 256         IWL_DEBUG_INFO(priv, "Setting scan to off\n");
 257
 258         clear_bit(STATUS_SCANNING, &priv->status);
 259
 260         IWL_DEBUG_INFO(priv, "Scan took %dms\n",
 261                 jiffies_to_msecs(elapsed_jiffies(priv->scan_start, jiffies)));
 262
 263         queue_work(priv->workqueue, &priv->scan_completed);
 264
 265         return;
 266
 267 reschedule:
 268         priv->scan_pass_start = jiffies;
 269         queue_work(priv->workqueue, &priv->request_scan);
 270 }
 271
 272 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 273 {
 274         /* scan handlers */
 275         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 276         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 277         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 278                                         iwl_rx_scan_results_notif;
 279         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 280                                         iwl_rx_scan_complete_notif;
 281 }
 282 EXPORT_SYMBOL(iwl_setup_rx_scan_handlers);
 283
 284 inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 285                                      enum ieee80211_band band,
 286                                      u8 n_probes)
 287 {
 288         if (band == IEEE80211_BAND_5GHZ)
 289                 return IWL_ACTIVE_DWELL_TIME_52 +
 290                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 291         else
 292                 return IWL_ACTIVE_DWELL_TIME_24 +
 293                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 294 }
 295 EXPORT_SYMBOL(iwl_get_active_dwell_time);
 296
 297 u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 298                                enum ieee80211_band band)
 299 {
 300         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
 301             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 302             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 303
 304         if (iwl_is_associated(priv)) {
 305                 /* If we're associated, we clamp the maximum passive
 306                  * dwell time to be 98% of the beacon interval (minus
 307                  * 2 * channel tune time) */
 308                 passive = priv->beacon_int;
 309                 if ((passive > IWL_PASSIVE_DWELL_BASE) || !passive)
 310                         passive = IWL_PASSIVE_DWELL_BASE;
 311                 passive = (passive * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 312         }
 313
 314         return passive;
 315 }
 316 EXPORT_SYMBOL(iwl_get_passive_dwell_time);
 317
 318 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 319                                      enum ieee80211_band band,
 320                                      u8 is_active, u8 n_probes,
 321                                      struct iwl_scan_channel *scan_ch)
 322 {
 323         struct ieee80211_channel *chan;
 324         const struct ieee80211_supported_band *sband;
 325         const struct iwl_channel_info *ch_info;
 326         u16 passive_dwell = 0;
 327         u16 active_dwell = 0;
 328         int added, i;
 329         u16 channel;
 330
 331         sband = iwl_get_hw_mode(priv, band);
 332         if (!sband)
 333                 return 0;
 334
 335         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 336         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 337
 338         if (passive_dwell <= active_dwell)
 339                 passive_dwell = active_dwell + 1;
 340
 341         for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
 342                 chan = priv->scan_request->channels[i];
 343
 344                 if (chan->band != band)
 345                         continue;
 346
 347                 channel = ieee80211_frequency_to_channel(chan->center_freq);
 348                 scan_ch->channel = cpu_to_le16(channel);
 349
 350                 ch_info = iwl_get_channel_info(priv, band, channel);
 351                 if (!is_channel_valid(ch_info)) {
 352                         IWL_DEBUG_SCAN(priv, "Channel %d is INVALID for this band.\n",
 353                                         channel);
 354                         continue;
 355                 }
 356
 357                 if (!is_active || is_channel_passive(ch_info) ||
 358                     (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN))
 359                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 360                 else
 361                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 362
 363                 if (n_probes)
 364                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 365
 366                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 367                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 368
 369                 /* Set txpower levels to defaults */
 370                 scan_ch->dsp_atten = 110;
 371
 372                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 373                  * power level:
 374                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 375                  */
 376                 if (band == IEEE80211_BAND_5GHZ)
 377                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 378                 else
 379                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 380
 381                 IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
 382                                channel, le32_to_cpu(scan_ch->type),
 383                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 384                                 "ACTIVE" : "PASSIVE",
 385                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 386                                active_dwell : passive_dwell);
 387
 388                 scan_ch++;
 389                 added++;
 390         }
 391
 392         IWL_DEBUG_SCAN(priv, "total channels to scan %d \n", added);
 393         return added;
 394 }
 395
 396 void iwl_init_scan_params(struct iwl_priv *priv)
 397 {
 398         u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
 399         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
 400                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
 401         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
 402                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
 403 }
 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
 584         conf = ieee80211_get_hw_conf(priv->hw);
 585
 586         mutex_lock(&priv->mutex);
 587
 588         cancel_delayed_work(&priv->scan_check);
 589
 590         if (!iwl_is_ready(priv)) {
 591                 IWL_WARN(priv, "request scan called when driver not ready.\n");
 592                 goto done;
 593         }
 594
 595         /* Make sure the scan wasn't canceled before this queued work
 596          * was given the chance to run... */
 597         if (!test_bit(STATUS_SCANNING, &priv->status))
 598                 goto done;
 599
 600         /* This should never be called or scheduled if there is currently
 601          * a scan active in the hardware. */
 602         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
 603                 IWL_DEBUG_INFO(priv, "Multiple concurrent scan requests in parallel. "
 604                                "Ignoring second request.\n");
 605                 ret = -EIO;
 606                 goto done;
 607         }
 608
 609         if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
 610                 IWL_DEBUG_SCAN(priv, "Aborting scan due to device shutdown\n");
 611                 goto done;
 612         }
 613
 614         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 615                 IWL_DEBUG_HC(priv, "Scan request while abort pending.  Queuing.\n");
 616                 goto done;
 617         }
 618
 619         if (iwl_is_rfkill(priv)) {
 620                 IWL_DEBUG_HC(priv, "Aborting scan due to RF Kill activation\n");
 621                 goto done;
 622         }
 623
 624         if (!test_bit(STATUS_READY, &priv->status)) {
 625                 IWL_DEBUG_HC(priv, "Scan request while uninitialized.  Queuing.\n");
 626                 goto done;
 627         }
 628
 629         if (!priv->scan_bands) {
 630                 IWL_DEBUG_HC(priv, "Aborting scan due to no requested bands\n");
 631                 goto done;
 632         }
 633
 634         if (!priv->scan) {
 635                 priv->scan = kmalloc(sizeof(struct iwl_scan_cmd) +
 636                                      IWL_MAX_SCAN_SIZE, GFP_KERNEL);
 637                 if (!priv->scan) {
 638                         ret = -ENOMEM;
 639                         goto done;
 640                 }
 641         }
 642         scan = priv->scan;
 643         memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
 644
 645         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
 646         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
 647
 648         if (iwl_is_associated(priv)) {
 649                 u16 interval = 0;
 650                 u32 extra;
 651                 u32 suspend_time = 100;
 652                 u32 scan_suspend_time = 100;
 653                 unsigned long flags;
 654
 655                 IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
 656
 657                 spin_lock_irqsave(&priv->lock, flags);
 658                 interval = priv->beacon_int;
 659                 spin_unlock_irqrestore(&priv->lock, flags);
 660
 661                 scan->suspend_time = 0;
 662                 scan->max_out_time = cpu_to_le32(200 * 1024);
 663                 if (!interval)
 664                         interval = suspend_time;
 665
 666                 extra = (suspend_time / interval) << 22;
 667                 scan_suspend_time = (extra |
 668                     ((suspend_time % interval) * 1024));
 669                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
 670                 IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
 671                                scan_suspend_time, interval);
 672         }
 673
 674         if (priv->scan_request->n_ssids) {
 675                 int i, p = 0;
 676                 IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
 677                 for (i = 0; i < priv->scan_request->n_ssids; i++) {
 678                         /* always does wildcard anyway */
 679                         if (!priv->scan_request->ssids[i].ssid_len)
 680                                 continue;
 681                         scan->direct_scan[p].id = WLAN_EID_SSID;
 682                         scan->direct_scan[p].len =
 683                                 priv->scan_request->ssids[i].ssid_len;
 684                         memcpy(scan->direct_scan[p].ssid,
 685                                priv->scan_request->ssids[i].ssid,
 686                                priv->scan_request->ssids[i].ssid_len);
 687                         n_probes++;
 688                         p++;
 689                 }
 690                 is_active = true;
 691         } else
 692                 IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
 693
 694         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
 695         scan->tx_cmd.sta_id = priv->hw_params.bcast_sta_id;
 696         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
 697
 698
 699         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) {
 700                 band = IEEE80211_BAND_2GHZ;
 701                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
 702                 chan_mod = le32_to_cpu(priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_MSK)
 703                                        >> RXON_FLG_CHANNEL_MODE_POS;
 704                 if (chan_mod == CHANNEL_MODE_PURE_40) {
 705                         rate = IWL_RATE_6M_PLCP;
 706                 } else {
 707                         rate = IWL_RATE_1M_PLCP;
 708                         rate_flags = RATE_MCS_CCK_MSK;
 709                 }
 710                 scan->good_CRC_th = 0;
 711         } else if (priv->scan_bands & BIT(IEEE80211_BAND_5GHZ)) {
 712                 band = IEEE80211_BAND_5GHZ;
 713                 rate = IWL_RATE_6M_PLCP;
 714                 /*
 715                  * If active scaning is requested but a certain channel
 716                  * is marked passive, we can do active scanning if we
 717                  * detect transmissions.
 718                  */
 719                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH : 0;
 720
 721                 /* Force use of chains B and C (0x6) for scan Rx for 4965
 722                  * Avoid A (0x1) because of its off-channel reception on A-band.
 723                  */
 724                 if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) == CSR_HW_REV_TYPE_4965)
 725                         rx_ant = ANT_BC;
 726         } else {
 727                 IWL_WARN(priv, "Invalid scan band count\n");
 728                 goto done;
 729         }
 730
 731         priv->scan_tx_ant[band] =
 732                          iwl_toggle_tx_ant(priv, priv->scan_tx_ant[band]);
 733         rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
 734         scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
 735
 736         /* MIMO is not used here, but value is required */
 737         rx_chain |= ANT_ABC << RXON_RX_CHAIN_VALID_POS;
 738         rx_chain |= ANT_ABC << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
 739         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
 740         rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
 741         scan->rx_chain = cpu_to_le16(rx_chain);
 742         cmd_len = iwl_fill_probe_req(priv,
 743                                 (struct ieee80211_mgmt *)scan->data,
 744                                 priv->scan_request->ie,
 745                                 priv->scan_request->ie_len,
 746                                 IWL_MAX_SCAN_SIZE - sizeof(*scan));
 747
 748         scan->tx_cmd.len = cpu_to_le16(cmd_len);
 749
 750         if (iwl_is_monitor_mode(priv))
 751                 scan->filter_flags = RXON_FILTER_PROMISC_MSK;
 752
 753         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 754                                RXON_FILTER_BCON_AWARE_MSK);
 755
 756         scan->channel_count =
 757                 iwl_get_channels_for_scan(priv, band, is_active, n_probes,
 758                         (void *)&scan->data[le16_to_cpu(scan->tx_cmd.len)]);
 759
 760         if (scan->channel_count == 0) {
 761                 IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
 762                 goto done;
 763         }
 764
 765         cmd.len += le16_to_cpu(scan->tx_cmd.len) +
 766             scan->channel_count * sizeof(struct iwl_scan_channel);
 767         cmd.data = scan;
 768         scan->len = cpu_to_le16(cmd.len);
 769
 770         set_bit(STATUS_SCAN_HW, &priv->status);
 771         ret = iwl_send_cmd_sync(priv, &cmd);
 772         if (ret)
 773                 goto done;
 774
 775         queue_delayed_work(priv->workqueue, &priv->scan_check,
 776                            IWL_SCAN_CHECK_WATCHDOG);
 777
 778         mutex_unlock(&priv->mutex);
 779         return;
 780
 781  done:
 782         /* Cannot perform scan. Make sure we clear scanning
 783         * bits from status so next scan request can be performed.
 784         * If we don't clear scanning status bit here all next scan
 785         * will fail
 786         */
 787         clear_bit(STATUS_SCAN_HW, &priv->status);
 788         clear_bit(STATUS_SCANNING, &priv->status);
 789         /* inform mac80211 scan aborted */
 790         queue_work(priv->workqueue, &priv->scan_completed);
 791         mutex_unlock(&priv->mutex);
 792 }
 793
 794 void iwl_bg_abort_scan(struct work_struct *work)
 795 {
 796         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
 797
 798         if (!test_bit(STATUS_READY, &priv->status) ||
 799             !test_bit(STATUS_GEO_CONFIGURED, &priv->status))
 800                 return;
 801
 802         mutex_lock(&priv->mutex);
 803
 804         set_bit(STATUS_SCAN_ABORTING, &priv->status);
 805         iwl_send_scan_abort(priv);
 806
 807         mutex_unlock(&priv->mutex);
 808 }
 809 EXPORT_SYMBOL(iwl_bg_abort_scan);
 810
 811 void iwl_bg_scan_completed(struct work_struct *work)
 812 {
 813         struct iwl_priv *priv =
 814             container_of(work, struct iwl_priv, scan_completed);
 815
 816         IWL_DEBUG_SCAN(priv, "SCAN complete scan\n");
 817
 818         cancel_delayed_work(&priv->scan_check);
 819
 820         ieee80211_scan_completed(priv->hw, false);
 821
 822         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 823                 return;
 824
 825         /* Since setting the TXPOWER may have been deferred while
 826          * performing the scan, fire one off */
 827         mutex_lock(&priv->mutex);
 828         iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);
 829         mutex_unlock(&priv->mutex);
 830 }
 831 EXPORT_SYMBOL(iwl_bg_scan_completed);
 832
 833 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
 834 {
 835         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
 836         INIT_WORK(&priv->request_scan, iwl_bg_request_scan);
 837         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
 838         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
 839 }
 840 EXPORT_SYMBOL(iwl_setup_scan_deferred_work);
 841