drivers/net/wireless/intel/iwlwifi/dvm/scan.c

   1 /******************************************************************************
   2  *
   3  * GPL LICENSE SUMMARY
   4  *
   5  * Copyright(c) 2008 - 2014 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 COPYING.
  23  *
  24  * Contact Information:
  25  *  Intel Linux Wireless <linuxwifi@intel.com>
  26  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  27  *****************************************************************************/
  28 #include <linux/slab.h>
  29 #include <linux/types.h>
  30 #include <linux/etherdevice.h>
  31 #include <net/mac80211.h>
  32
  33 #include "dev.h"
  34 #include "agn.h"
  35
  36 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
  37  * sending probe req.  This should be set long enough to hear probe responses
  38  * from more than one AP.  */
  39 #define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
  40 #define IWL_ACTIVE_DWELL_TIME_52    (20)
  41
  42 #define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
  43 #define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
  44
  45 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
  46  * Must be set longer than active dwell time.
  47  * For the most reliable scan, set > AP beacon interval (typically 100msec). */
  48 #define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
  49 #define IWL_PASSIVE_DWELL_TIME_52   (10)
  50 #define IWL_PASSIVE_DWELL_BASE      (100)
  51 #define IWL_CHANNEL_TUNE_TIME       5
  52 #define MAX_SCAN_CHANNEL            50
  53
  54 /* For reset radio, need minimal dwell time only */
  55 #define IWL_RADIO_RESET_DWELL_TIME      5
  56
  57 static int iwl_send_scan_abort(struct iwl_priv *priv)
  58 {
  59         int ret;
  60         struct iwl_host_cmd cmd = {
  61                 .id = REPLY_SCAN_ABORT_CMD,
  62                 .flags = CMD_WANT_SKB,
  63         };
  64         __le32 *status;
  65
  66         /* Exit instantly with error when device is not ready
  67          * to receive scan abort command or it does not perform
  68          * hardware scan currently */
  69         if (!test_bit(STATUS_READY, &priv->status) ||
  70             !test_bit(STATUS_SCAN_HW, &priv->status) ||
  71             test_bit(STATUS_FW_ERROR, &priv->status))
  72                 return -EIO;
  73
  74         ret = iwl_dvm_send_cmd(priv, &cmd);
  75         if (ret)
  76                 return ret;
  77
  78         status = (void *)cmd.resp_pkt->data;
  79         if (*status != CAN_ABORT_STATUS) {
  80                 /* The scan abort will return 1 for success or
  81                  * 2 for "failure".  A failure condition can be
  82                  * due to simply not being in an active scan which
  83                  * can occur if we send the scan abort before we
  84                  * the microcode has notified us that a scan is
  85                  * completed. */
  86                 IWL_DEBUG_SCAN(priv, "SCAN_ABORT ret %d.\n",
  87                                le32_to_cpu(*status));
  88                 ret = -EIO;
  89         }
  90
  91         iwl_free_resp(&cmd);
  92         return ret;
  93 }
  94
  95 static void iwl_complete_scan(struct iwl_priv *priv, bool aborted)
  96 {
  97         /* check if scan was requested from mac80211 */
  98         if (priv->scan_request) {
  99                 IWL_DEBUG_SCAN(priv, "Complete scan in mac80211\n");
 100                 ieee80211_scan_completed(priv->hw, aborted);
 101         }
 102
 103         priv->scan_type = IWL_SCAN_NORMAL;
 104         priv->scan_vif = NULL;
 105         priv->scan_request = NULL;
 106 }
 107
 108 static void iwl_process_scan_complete(struct iwl_priv *priv)
 109 {
 110         bool aborted;
 111
 112         lockdep_assert_held(&priv->mutex);
 113
 114         if (!test_and_clear_bit(STATUS_SCAN_COMPLETE, &priv->status))
 115                 return;
 116
 117         IWL_DEBUG_SCAN(priv, "Completed scan.\n");
 118
 119         cancel_delayed_work(&priv->scan_check);
 120
 121         aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 122         if (aborted)
 123                 IWL_DEBUG_SCAN(priv, "Aborted scan completed.\n");
 124
 125         if (!test_and_clear_bit(STATUS_SCANNING, &priv->status)) {
 126                 IWL_DEBUG_SCAN(priv, "Scan already completed.\n");
 127                 goto out_settings;
 128         }
 129
 130         if (priv->scan_type != IWL_SCAN_NORMAL && !aborted) {
 131                 int err;
 132
 133                 /* Check if mac80211 requested scan during our internal scan */
 134                 if (priv->scan_request == NULL)
 135                         goto out_complete;
 136
 137                 /* If so request a new scan */
 138                 err = iwl_scan_initiate(priv, priv->scan_vif, IWL_SCAN_NORMAL,
 139                                         priv->scan_request->channels[0]->band);
 140                 if (err) {
 141                         IWL_DEBUG_SCAN(priv,
 142                                 "failed to initiate pending scan: %d\n", err);
 143                         aborted = true;
 144                         goto out_complete;
 145                 }
 146
 147                 return;
 148         }
 149
 150 out_complete:
 151         iwl_complete_scan(priv, aborted);
 152
 153 out_settings:
 154         /* Can we still talk to firmware ? */
 155         if (!iwl_is_ready_rf(priv))
 156                 return;
 157
 158         iwlagn_post_scan(priv);
 159 }
 160
 161 void iwl_force_scan_end(struct iwl_priv *priv)
 162 {
 163         lockdep_assert_held(&priv->mutex);
 164
 165         if (!test_bit(STATUS_SCANNING, &priv->status)) {
 166                 IWL_DEBUG_SCAN(priv, "Forcing scan end while not scanning\n");
 167                 return;
 168         }
 169
 170         IWL_DEBUG_SCAN(priv, "Forcing scan end\n");
 171         clear_bit(STATUS_SCANNING, &priv->status);
 172         clear_bit(STATUS_SCAN_HW, &priv->status);
 173         clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 174         clear_bit(STATUS_SCAN_COMPLETE, &priv->status);
 175         iwl_complete_scan(priv, true);
 176 }
 177
 178 static void iwl_do_scan_abort(struct iwl_priv *priv)
 179 {
 180         int ret;
 181
 182         lockdep_assert_held(&priv->mutex);
 183
 184         if (!test_bit(STATUS_SCANNING, &priv->status)) {
 185                 IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
 186                 return;
 187         }
 188
 189         if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 190                 IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
 191                 return;
 192         }
 193
 194         ret = iwl_send_scan_abort(priv);
 195         if (ret) {
 196                 IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
 197                 iwl_force_scan_end(priv);
 198         } else
 199                 IWL_DEBUG_SCAN(priv, "Successfully send scan abort\n");
 200 }
 201
 202 /**
 203  * iwl_scan_cancel - Cancel any currently executing HW scan
 204  */
 205 int iwl_scan_cancel(struct iwl_priv *priv)
 206 {
 207         IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
 208         queue_work(priv->workqueue, &priv->abort_scan);
 209         return 0;
 210 }
 211
 212 /**
 213  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
 214  * @ms: amount of time to wait (in milliseconds) for scan to abort
 215  *
 216  */
 217 void iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
 218 {
 219         unsigned long timeout = jiffies + msecs_to_jiffies(ms);
 220
 221         lockdep_assert_held(&priv->mutex);
 222
 223         IWL_DEBUG_SCAN(priv, "Scan cancel timeout\n");
 224
 225         iwl_do_scan_abort(priv);
 226
 227         while (time_before_eq(jiffies, timeout)) {
 228                 if (!test_bit(STATUS_SCAN_HW, &priv->status))
 229                         goto finished;
 230                 msleep(20);
 231         }
 232
 233         return;
 234
 235  finished:
 236         /*
 237          * Now STATUS_SCAN_HW is clear. This means that the
 238          * device finished, but the background work is going
 239          * to execute at best as soon as we release the mutex.
 240          * Since we need to be able to issue a new scan right
 241          * after this function returns, run the complete here.
 242          * The STATUS_SCAN_COMPLETE bit will then be cleared
 243          * and prevent the background work from "completing"
 244          * a possible new scan.
 245          */
 246         iwl_process_scan_complete(priv);
 247 }
 248
 249 /* Service response to REPLY_SCAN_CMD (0x80) */
 250 static void iwl_rx_reply_scan(struct iwl_priv *priv,
 251                               struct iwl_rx_cmd_buffer *rxb)
 252 {
 253 #ifdef CONFIG_IWLWIFI_DEBUG
 254         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 255         struct iwl_scanreq_notification *notif = (void *)pkt->data;
 256
 257         IWL_DEBUG_SCAN(priv, "Scan request status = 0x%x\n", notif->status);
 258 #endif
 259 }
 260
 261 /* Service SCAN_START_NOTIFICATION (0x82) */
 262 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
 263                                     struct iwl_rx_cmd_buffer *rxb)
 264 {
 265         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 266         struct iwl_scanstart_notification *notif = (void *)pkt->data;
 267
 268         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 269         IWL_DEBUG_SCAN(priv, "Scan start: "
 270                        "%d [802.11%s] "
 271                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 272                        notif->channel,
 273                        notif->band ? "bg" : "a",
 274                        le32_to_cpu(notif->tsf_high),
 275                        le32_to_cpu(notif->tsf_low),
 276                        notif->status, notif->beacon_timer);
 277 }
 278
 279 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 280 static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
 281                                       struct iwl_rx_cmd_buffer *rxb)
 282 {
 283 #ifdef CONFIG_IWLWIFI_DEBUG
 284         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 285         struct iwl_scanresults_notification *notif = (void *)pkt->data;
 286
 287         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
 288                        "%d [802.11%s] "
 289                        "probe status: %u:%u "
 290                        "(TSF: 0x%08X:%08X) - %d "
 291                        "elapsed=%lu usec\n",
 292                        notif->channel,
 293                        notif->band ? "bg" : "a",
 294                        notif->probe_status, notif->num_probe_not_sent,
 295                        le32_to_cpu(notif->tsf_high),
 296                        le32_to_cpu(notif->tsf_low),
 297                        le32_to_cpu(notif->statistics[0]),
 298                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
 299 #endif
 300 }
 301
 302 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 303 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 304                                        struct iwl_rx_cmd_buffer *rxb)
 305 {
 306         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 307         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->data;
 308
 309         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 310                        scan_notif->scanned_channels,
 311                        scan_notif->tsf_low,
 312                        scan_notif->tsf_high, scan_notif->status);
 313
 314         IWL_DEBUG_SCAN(priv, "Scan on %sGHz took %dms\n",
 315                        (priv->scan_band == NL80211_BAND_2GHZ) ? "2.4" : "5.2",
 316                        jiffies_to_msecs(jiffies - priv->scan_start));
 317
 318         /*
 319          * When aborting, we run the scan completed background work inline
 320          * and the background work must then do nothing. The SCAN_COMPLETE
 321          * bit helps implement that logic and thus needs to be set before
 322          * queueing the work. Also, since the scan abort waits for SCAN_HW
 323          * to clear, we need to set SCAN_COMPLETE before clearing SCAN_HW
 324          * to avoid a race there.
 325          */
 326         set_bit(STATUS_SCAN_COMPLETE, &priv->status);
 327         clear_bit(STATUS_SCAN_HW, &priv->status);
 328         queue_work(priv->workqueue, &priv->scan_completed);
 329
 330         if (priv->iw_mode != NL80211_IFTYPE_ADHOC &&
 331             iwl_advanced_bt_coexist(priv) &&
 332             priv->bt_status != scan_notif->bt_status) {
 333                 if (scan_notif->bt_status) {
 334                         /* BT on */
 335                         if (!priv->bt_ch_announce)
 336                                 priv->bt_traffic_load =
 337                                         IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
 338                         /*
 339                          * otherwise, no traffic load information provided
 340                          * no changes made
 341                          */
 342                 } else {
 343                         /* BT off */
 344                         priv->bt_traffic_load =
 345                                 IWL_BT_COEX_TRAFFIC_LOAD_NONE;
 346                 }
 347                 priv->bt_status = scan_notif->bt_status;
 348                 queue_work(priv->workqueue,
 349                            &priv->bt_traffic_change_work);
 350         }
 351 }
 352
 353 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 354 {
 355         /* scan handlers */
 356         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 357         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 358         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 359                                         iwl_rx_scan_results_notif;
 360         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 361                                         iwl_rx_scan_complete_notif;
 362 }
 363
 364 static u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 365                                      enum nl80211_band band, u8 n_probes)
 366 {
 367         if (band == NL80211_BAND_5GHZ)
 368                 return IWL_ACTIVE_DWELL_TIME_52 +
 369                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 370         else
 371                 return IWL_ACTIVE_DWELL_TIME_24 +
 372                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 373 }
 374
 375 static u16 iwl_limit_dwell(struct iwl_priv *priv, u16 dwell_time)
 376 {
 377         struct iwl_rxon_context *ctx;
 378         int limits[NUM_IWL_RXON_CTX] = {};
 379         int n_active = 0;
 380         u16 limit;
 381
 382         BUILD_BUG_ON(NUM_IWL_RXON_CTX != 2);
 383
 384         /*
 385          * If we're associated, we clamp the dwell time 98%
 386          * of the beacon interval (minus 2 * channel tune time)
 387          * If both contexts are active, we have to restrict to
 388          * 1/2 of the minimum of them, because they might be in
 389          * lock-step with the time inbetween only half of what
 390          * time we'd have in each of them.
 391          */
 392         for_each_context(priv, ctx) {
 393                 switch (ctx->staging.dev_type) {
 394                 case RXON_DEV_TYPE_P2P:
 395                         /* no timing constraints */
 396                         continue;
 397                 case RXON_DEV_TYPE_ESS:
 398                 default:
 399                         /* timing constraints if associated */
 400                         if (!iwl_is_associated_ctx(ctx))
 401                                 continue;
 402                         break;
 403                 case RXON_DEV_TYPE_CP:
 404                 case RXON_DEV_TYPE_2STA:
 405                         /*
 406                          * These seem to always have timers for TBTT
 407                          * active in uCode even when not associated yet.
 408                          */
 409                         break;
 410                 }
 411
 412                 limits[n_active++] = ctx->beacon_int ?: IWL_PASSIVE_DWELL_BASE;
 413         }
 414
 415         switch (n_active) {
 416         case 0:
 417                 return dwell_time;
 418         case 2:
 419                 limit = (limits[1] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 420                 limit /= 2;
 421                 dwell_time = min(limit, dwell_time);
 422                 /* fall through to limit further */
 423         case 1:
 424                 limit = (limits[0] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 425                 limit /= n_active;
 426                 return min(limit, dwell_time);
 427         default:
 428                 WARN_ON_ONCE(1);
 429                 return dwell_time;
 430         }
 431 }
 432
 433 static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 434                                       enum nl80211_band band)
 435 {
 436         u16 passive = (band == NL80211_BAND_2GHZ) ?
 437             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 438             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 439
 440         return iwl_limit_dwell(priv, passive);
 441 }
 442
 443 /* Return valid, unused, channel for a passive scan to reset the RF */
 444 static u8 iwl_get_single_channel_number(struct iwl_priv *priv,
 445                                         enum nl80211_band band)
 446 {
 447         struct ieee80211_supported_band *sband = priv->hw->wiphy->bands[band];
 448         struct iwl_rxon_context *ctx;
 449         int i;
 450
 451         for (i = 0; i < sband->n_channels; i++) {
 452                 bool busy = false;
 453
 454                 for_each_context(priv, ctx) {
 455                         busy = sband->channels[i].hw_value ==
 456                                 le16_to_cpu(ctx->staging.channel);
 457                         if (busy)
 458                                 break;
 459                 }
 460
 461                 if (busy)
 462                         continue;
 463
 464                 if (!(sband->channels[i].flags & IEEE80211_CHAN_DISABLED))
 465                         return sband->channels[i].hw_value;
 466         }
 467
 468         return 0;
 469 }
 470
 471 static int iwl_get_channel_for_reset_scan(struct iwl_priv *priv,
 472                                           struct ieee80211_vif *vif,
 473                                           enum nl80211_band band,
 474                                           struct iwl_scan_channel *scan_ch)
 475 {
 476         const struct ieee80211_supported_band *sband;
 477         u16 channel;
 478
 479         sband = iwl_get_hw_mode(priv, band);
 480         if (!sband) {
 481                 IWL_ERR(priv, "invalid band\n");
 482                 return 0;
 483         }
 484
 485         channel = iwl_get_single_channel_number(priv, band);
 486         if (channel) {
 487                 scan_ch->channel = cpu_to_le16(channel);
 488                 scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 489                 scan_ch->active_dwell =
 490                         cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
 491                 scan_ch->passive_dwell =
 492                         cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
 493                 /* Set txpower levels to defaults */
 494                 scan_ch->dsp_atten = 110;
 495                 if (band == NL80211_BAND_5GHZ)
 496                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 497                 else
 498                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 499                 return 1;
 500         }
 501
 502         IWL_ERR(priv, "no valid channel found\n");
 503         return 0;
 504 }
 505
 506 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 507                                      struct ieee80211_vif *vif,
 508                                      enum nl80211_band band,
 509                                      u8 is_active, u8 n_probes,
 510                                      struct iwl_scan_channel *scan_ch)
 511 {
 512         struct ieee80211_channel *chan;
 513         const struct ieee80211_supported_band *sband;
 514         u16 passive_dwell = 0;
 515         u16 active_dwell = 0;
 516         int added, i;
 517         u16 channel;
 518
 519         sband = iwl_get_hw_mode(priv, band);
 520         if (!sband)
 521                 return 0;
 522
 523         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 524         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 525
 526         if (passive_dwell <= active_dwell)
 527                 passive_dwell = active_dwell + 1;
 528
 529         for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
 530                 chan = priv->scan_request->channels[i];
 531
 532                 if (chan->band != band)
 533                         continue;
 534
 535                 channel = chan->hw_value;
 536                 scan_ch->channel = cpu_to_le16(channel);
 537
 538                 if (!is_active || (chan->flags & IEEE80211_CHAN_NO_IR))
 539                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 540                 else
 541                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 542
 543                 if (n_probes)
 544                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 545
 546                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 547                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 548
 549                 /* Set txpower levels to defaults */
 550                 scan_ch->dsp_atten = 110;
 551
 552                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 553                  * power level:
 554                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 555                  */
 556                 if (band == NL80211_BAND_5GHZ)
 557                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 558                 else
 559                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 560
 561                 IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
 562                                channel, le32_to_cpu(scan_ch->type),
 563                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 564                                 "ACTIVE" : "PASSIVE",
 565                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 566                                active_dwell : passive_dwell);
 567
 568                 scan_ch++;
 569                 added++;
 570         }
 571
 572         IWL_DEBUG_SCAN(priv, "total channels to scan %d\n", added);
 573         return added;
 574 }
 575
 576 /**
 577  * iwl_fill_probe_req - fill in all required fields and IE for probe request
 578  */
 579
 580 static u16 iwl_fill_probe_req(struct ieee80211_mgmt *frame, const u8 *ta,
 581                               const u8 *ies, int ie_len, const u8 *ssid,
 582                               u8 ssid_len, int left)
 583 {
 584         int len = 0;
 585         u8 *pos = NULL;
 586
 587         /* Make sure there is enough space for the probe request,
 588          * two mandatory IEs and the data */
 589         left -= 24;
 590         if (left < 0)
 591                 return 0;
 592
 593         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 594         eth_broadcast_addr(frame->da);
 595         memcpy(frame->sa, ta, ETH_ALEN);
 596         eth_broadcast_addr(frame->bssid);
 597         frame->seq_ctrl = 0;
 598
 599         len += 24;
 600
 601         /* ...next IE... */
 602         pos = &frame->u.probe_req.variable[0];
 603
 604         /* fill in our SSID IE */
 605         left -= ssid_len + 2;
 606         if (left < 0)
 607                 return 0;
 608         *pos++ = WLAN_EID_SSID;
 609         *pos++ = ssid_len;
 610         if (ssid && ssid_len) {
 611                 memcpy(pos, ssid, ssid_len);
 612                 pos += ssid_len;
 613         }
 614
 615         len += ssid_len + 2;
 616
 617         if (WARN_ON(left < ie_len))
 618                 return len;
 619
 620         if (ies && ie_len) {
 621                 memcpy(pos, ies, ie_len);
 622                 len += ie_len;
 623         }
 624
 625         return (u16)len;
 626 }
 627
 628 static int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
 629 {
 630         struct iwl_host_cmd cmd = {
 631                 .id = REPLY_SCAN_CMD,
 632                 .len = { sizeof(struct iwl_scan_cmd), },
 633         };
 634         struct iwl_scan_cmd *scan;
 635         struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
 636         u32 rate_flags = 0;
 637         u16 cmd_len = 0;
 638         u16 rx_chain = 0;
 639         enum nl80211_band band;
 640         u8 n_probes = 0;
 641         u8 rx_ant = priv->nvm_data->valid_rx_ant;
 642         u8 rate;
 643         bool is_active = false;
 644         int  chan_mod;
 645         u8 active_chains;
 646         u8 scan_tx_antennas = priv->nvm_data->valid_tx_ant;
 647         int ret;
 648         int scan_cmd_size = sizeof(struct iwl_scan_cmd) +
 649                             MAX_SCAN_CHANNEL * sizeof(struct iwl_scan_channel) +
 650                             priv->fw->ucode_capa.max_probe_length;
 651         const u8 *ssid = NULL;
 652         u8 ssid_len = 0;
 653
 654         if (WARN_ON(priv->scan_type == IWL_SCAN_NORMAL &&
 655                     (!priv->scan_request ||
 656                      priv->scan_request->n_channels > MAX_SCAN_CHANNEL)))
 657                 return -EINVAL;
 658
 659         lockdep_assert_held(&priv->mutex);
 660
 661         if (vif)
 662                 ctx = iwl_rxon_ctx_from_vif(vif);
 663
 664         if (!priv->scan_cmd) {
 665                 priv->scan_cmd = kmalloc(scan_cmd_size, GFP_KERNEL);
 666                 if (!priv->scan_cmd) {
 667                         IWL_DEBUG_SCAN(priv,
 668                                        "fail to allocate memory for scan\n");
 669                         return -ENOMEM;
 670                 }
 671         }
 672         scan = priv->scan_cmd;
 673         memset(scan, 0, scan_cmd_size);
 674
 675         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
 676         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
 677
 678         if (iwl_is_any_associated(priv)) {
 679                 u16 interval = 0;
 680                 u32 extra;
 681                 u32 suspend_time = 100;
 682                 u32 scan_suspend_time = 100;
 683
 684                 IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
 685                 switch (priv->scan_type) {
 686                 case IWL_SCAN_RADIO_RESET:
 687                         interval = 0;
 688                         break;
 689                 case IWL_SCAN_NORMAL:
 690                         interval = vif->bss_conf.beacon_int;
 691                         break;
 692                 }
 693
 694                 scan->suspend_time = 0;
 695                 scan->max_out_time = cpu_to_le32(200 * 1024);
 696                 if (!interval)
 697                         interval = suspend_time;
 698
 699                 extra = (suspend_time / interval) << 22;
 700                 scan_suspend_time = (extra |
 701                     ((suspend_time % interval) * 1024));
 702                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
 703                 IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
 704                                scan_suspend_time, interval);
 705         }
 706
 707         switch (priv->scan_type) {
 708         case IWL_SCAN_RADIO_RESET:
 709                 IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
 710                 /*
 711                  * Override quiet time as firmware checks that active
 712                  * dwell is >= quiet; since we use passive scan it'll
 713                  * not actually be used.
 714                  */
 715                 scan->quiet_time = cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
 716                 break;
 717         case IWL_SCAN_NORMAL:
 718                 if (priv->scan_request->n_ssids) {
 719                         int i, p = 0;
 720                         IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
 721                         /*
 722                          * The highest priority SSID is inserted to the
 723                          * probe request template.
 724                          */
 725                         ssid_len = priv->scan_request->ssids[0].ssid_len;
 726                         ssid = priv->scan_request->ssids[0].ssid;
 727
 728                         /*
 729                          * Invert the order of ssids, the firmware will invert
 730                          * it back.
 731                          */
 732                         for (i = priv->scan_request->n_ssids - 1; i >= 1; i--) {
 733                                 scan->direct_scan[p].id = WLAN_EID_SSID;
 734                                 scan->direct_scan[p].len =
 735                                         priv->scan_request->ssids[i].ssid_len;
 736                                 memcpy(scan->direct_scan[p].ssid,
 737                                        priv->scan_request->ssids[i].ssid,
 738                                        priv->scan_request->ssids[i].ssid_len);
 739                                 n_probes++;
 740                                 p++;
 741                         }
 742                         is_active = true;
 743                 } else
 744                         IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
 745                 break;
 746         }
 747
 748         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
 749         scan->tx_cmd.sta_id = ctx->bcast_sta_id;
 750         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
 751
 752         switch (priv->scan_band) {
 753         case NL80211_BAND_2GHZ:
 754                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
 755                 chan_mod = le32_to_cpu(
 756                         priv->contexts[IWL_RXON_CTX_BSS].active.flags &
 757                                                 RXON_FLG_CHANNEL_MODE_MSK)
 758                                        >> RXON_FLG_CHANNEL_MODE_POS;
 759                 if ((priv->scan_request && priv->scan_request->no_cck) ||
 760                     chan_mod == CHANNEL_MODE_PURE_40) {
 761                         rate = IWL_RATE_6M_PLCP;
 762                 } else {
 763                         rate = IWL_RATE_1M_PLCP;
 764                         rate_flags = RATE_MCS_CCK_MSK;
 765                 }
 766                 /*
 767                  * Internal scans are passive, so we can indiscriminately set
 768                  * the BT ignore flag on 2.4 GHz since it applies to TX only.
 769                  */
 770                 if (priv->lib->bt_params &&
 771                     priv->lib->bt_params->advanced_bt_coexist)
 772                         scan->tx_cmd.tx_flags |= TX_CMD_FLG_IGNORE_BT;
 773                 break;
 774         case NL80211_BAND_5GHZ:
 775                 rate = IWL_RATE_6M_PLCP;
 776                 break;
 777         default:
 778                 IWL_WARN(priv, "Invalid scan band\n");
 779                 return -EIO;
 780         }
 781
 782         /*
 783          * If active scanning is requested but a certain channel is
 784          * marked passive, we can do active scanning if we detect
 785          * transmissions.
 786          *
 787          * There is an issue with some firmware versions that triggers
 788          * a sysassert on a "good CRC threshold" of zero (== disabled),
 789          * on a radar channel even though this means that we should NOT
 790          * send probes.
 791          *
 792          * The "good CRC threshold" is the number of frames that we
 793          * need to receive during our dwell time on a channel before
 794          * sending out probes -- setting this to a huge value will
 795          * mean we never reach it, but at the same time work around
 796          * the aforementioned issue. Thus use IWL_GOOD_CRC_TH_NEVER
 797          * here instead of IWL_GOOD_CRC_TH_DISABLED.
 798          *
 799          * This was fixed in later versions along with some other
 800          * scan changes, and the threshold behaves as a flag in those
 801          * versions.
 802          */
 803         if (priv->new_scan_threshold_behaviour)
 804                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 805                                                 IWL_GOOD_CRC_TH_DISABLED;
 806         else
 807                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 808                                                 IWL_GOOD_CRC_TH_NEVER;
 809
 810         band = priv->scan_band;
 811
 812         if (band == NL80211_BAND_2GHZ &&
 813             priv->lib->bt_params &&
 814             priv->lib->bt_params->advanced_bt_coexist) {
 815                 /* transmit 2.4 GHz probes only on first antenna */
 816                 scan_tx_antennas = first_antenna(scan_tx_antennas);
 817         }
 818
 819         priv->scan_tx_ant[band] = iwl_toggle_tx_ant(priv,
 820                                                     priv->scan_tx_ant[band],
 821                                                     scan_tx_antennas);
 822         rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
 823         scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
 824
 825         /*
 826          * In power save mode while associated use one chain,
 827          * otherwise use all chains
 828          */
 829         if (test_bit(STATUS_POWER_PMI, &priv->status) &&
 830             !(priv->hw->conf.flags & IEEE80211_CONF_IDLE)) {
 831                 /* rx_ant has been set to all valid chains previously */
 832                 active_chains = rx_ant &
 833                                 ((u8)(priv->chain_noise_data.active_chains));
 834                 if (!active_chains)
 835                         active_chains = rx_ant;
 836
 837                 IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
 838                                 priv->chain_noise_data.active_chains);
 839
 840                 rx_ant = first_antenna(active_chains);
 841         }
 842         if (priv->lib->bt_params &&
 843             priv->lib->bt_params->advanced_bt_coexist &&
 844             priv->bt_full_concurrent) {
 845                 /* operated as 1x1 in full concurrency mode */
 846                 rx_ant = first_antenna(rx_ant);
 847         }
 848
 849         /* MIMO is not used here, but value is required */
 850         rx_chain |=
 851                 priv->nvm_data->valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
 852         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
 853         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
 854         rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
 855         scan->rx_chain = cpu_to_le16(rx_chain);
 856         switch (priv->scan_type) {
 857         case IWL_SCAN_NORMAL:
 858                 cmd_len = iwl_fill_probe_req(
 859                                         (struct ieee80211_mgmt *)scan->data,
 860                                         vif->addr,
 861                                         priv->scan_request->ie,
 862                                         priv->scan_request->ie_len,
 863                                         ssid, ssid_len,
 864                                         scan_cmd_size - sizeof(*scan));
 865                 break;
 866         case IWL_SCAN_RADIO_RESET:
 867                 /* use bcast addr, will not be transmitted but must be valid */
 868                 cmd_len = iwl_fill_probe_req(
 869                                         (struct ieee80211_mgmt *)scan->data,
 870                                         iwl_bcast_addr, NULL, 0,
 871                                         NULL, 0,
 872                                         scan_cmd_size - sizeof(*scan));
 873                 break;
 874         default:
 875                 BUG();
 876         }
 877         scan->tx_cmd.len = cpu_to_le16(cmd_len);
 878
 879         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 880                                RXON_FILTER_BCON_AWARE_MSK);
 881
 882         switch (priv->scan_type) {
 883         case IWL_SCAN_RADIO_RESET:
 884                 scan->channel_count =
 885                         iwl_get_channel_for_reset_scan(priv, vif, band,
 886                                 (void *)&scan->data[cmd_len]);
 887                 break;
 888         case IWL_SCAN_NORMAL:
 889                 scan->channel_count =
 890                         iwl_get_channels_for_scan(priv, vif, band,
 891                                 is_active, n_probes,
 892                                 (void *)&scan->data[cmd_len]);
 893                 break;
 894         }
 895
 896         if (scan->channel_count == 0) {
 897                 IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
 898                 return -EIO;
 899         }
 900
 901         cmd.len[0] += le16_to_cpu(scan->tx_cmd.len) +
 902             scan->channel_count * sizeof(struct iwl_scan_channel);
 903         cmd.data[0] = scan;
 904         cmd.dataflags[0] = IWL_HCMD_DFL_NOCOPY;
 905         scan->len = cpu_to_le16(cmd.len[0]);
 906
 907         /* set scan bit here for PAN params */
 908         set_bit(STATUS_SCAN_HW, &priv->status);
 909
 910         ret = iwlagn_set_pan_params(priv);
 911         if (ret) {
 912                 clear_bit(STATUS_SCAN_HW, &priv->status);
 913                 return ret;
 914         }
 915
 916         ret = iwl_dvm_send_cmd(priv, &cmd);
 917         if (ret) {
 918                 clear_bit(STATUS_SCAN_HW, &priv->status);
 919                 iwlagn_set_pan_params(priv);
 920         }
 921
 922         return ret;
 923 }
 924
 925 void iwl_init_scan_params(struct iwl_priv *priv)
 926 {
 927         u8 ant_idx = fls(priv->nvm_data->valid_tx_ant) - 1;
 928         if (!priv->scan_tx_ant[NL80211_BAND_5GHZ])
 929                 priv->scan_tx_ant[NL80211_BAND_5GHZ] = ant_idx;
 930         if (!priv->scan_tx_ant[NL80211_BAND_2GHZ])
 931                 priv->scan_tx_ant[NL80211_BAND_2GHZ] = ant_idx;
 932 }
 933
 934 int __must_check iwl_scan_initiate(struct iwl_priv *priv,
 935                                    struct ieee80211_vif *vif,
 936                                    enum iwl_scan_type scan_type,
 937                                    enum nl80211_band band)
 938 {
 939         int ret;
 940
 941         lockdep_assert_held(&priv->mutex);
 942
 943         cancel_delayed_work(&priv->scan_check);
 944
 945         if (!iwl_is_ready_rf(priv)) {
 946                 IWL_WARN(priv, "Request scan called when driver not ready.\n");
 947                 return -EIO;
 948         }
 949
 950         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
 951                 IWL_DEBUG_SCAN(priv,
 952                         "Multiple concurrent scan requests in parallel.\n");
 953                 return -EBUSY;
 954         }
 955
 956         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 957                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending.\n");
 958                 return -EBUSY;
 959         }
 960
 961         IWL_DEBUG_SCAN(priv, "Starting %sscan...\n",
 962                         scan_type == IWL_SCAN_NORMAL ? "" :
 963                         "internal short ");
 964
 965         set_bit(STATUS_SCANNING, &priv->status);
 966         priv->scan_type = scan_type;
 967         priv->scan_start = jiffies;
 968         priv->scan_band = band;
 969
 970         ret = iwlagn_request_scan(priv, vif);
 971         if (ret) {
 972                 clear_bit(STATUS_SCANNING, &priv->status);
 973                 priv->scan_type = IWL_SCAN_NORMAL;
 974                 return ret;
 975         }
 976
 977         queue_delayed_work(priv->workqueue, &priv->scan_check,
 978                            IWL_SCAN_CHECK_WATCHDOG);
 979
 980         return 0;
 981 }
 982
 983
 984 /*
 985  * internal short scan, this function should only been called while associated.
 986  * It will reset and tune the radio to prevent possible RF related problem
 987  */
 988 void iwl_internal_short_hw_scan(struct iwl_priv *priv)
 989 {
 990         queue_work(priv->workqueue, &priv->start_internal_scan);
 991 }
 992
 993 static void iwl_bg_start_internal_scan(struct work_struct *work)
 994 {
 995         struct iwl_priv *priv =
 996                 container_of(work, struct iwl_priv, start_internal_scan);
 997
 998         IWL_DEBUG_SCAN(priv, "Start internal scan\n");
 999
1000         mutex_lock(&priv->mutex);
1001
1002         if (priv->scan_type == IWL_SCAN_RADIO_RESET) {
1003                 IWL_DEBUG_SCAN(priv, "Internal scan already in progress\n");
1004                 goto unlock;
1005         }
1006
1007         if (test_bit(STATUS_SCANNING, &priv->status)) {
1008                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
1009                 goto unlock;
1010         }
1011
1012         if (iwl_scan_initiate(priv, NULL, IWL_SCAN_RADIO_RESET, priv->band))
1013                 IWL_DEBUG_SCAN(priv, "failed to start internal short scan\n");
1014  unlock:
1015         mutex_unlock(&priv->mutex);
1016 }
1017
1018 static void iwl_bg_scan_check(struct work_struct *data)
1019 {
1020         struct iwl_priv *priv =
1021             container_of(data, struct iwl_priv, scan_check.work);
1022
1023         IWL_DEBUG_SCAN(priv, "Scan check work\n");
1024
1025         /* Since we are here firmware does not finish scan and
1026          * most likely is in bad shape, so we don't bother to
1027          * send abort command, just force scan complete to mac80211 */
1028         mutex_lock(&priv->mutex);
1029         iwl_force_scan_end(priv);
1030         mutex_unlock(&priv->mutex);
1031 }
1032
1033 static void iwl_bg_abort_scan(struct work_struct *work)
1034 {
1035         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
1036
1037         IWL_DEBUG_SCAN(priv, "Abort scan work\n");
1038
1039         /* We keep scan_check work queued in case when firmware will not
1040          * report back scan completed notification */
1041         mutex_lock(&priv->mutex);
1042         iwl_scan_cancel_timeout(priv, 200);
1043         mutex_unlock(&priv->mutex);
1044 }
1045
1046 static void iwl_bg_scan_completed(struct work_struct *work)
1047 {
1048         struct iwl_priv *priv =
1049                 container_of(work, struct iwl_priv, scan_completed);
1050
1051         mutex_lock(&priv->mutex);
1052         iwl_process_scan_complete(priv);
1053         mutex_unlock(&priv->mutex);
1054 }
1055
1056 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
1057 {
1058         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
1059         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
1060         INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
1061         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
1062 }
1063
1064 void iwl_cancel_scan_deferred_work(struct iwl_priv *priv)
1065 {
1066         cancel_work_sync(&priv->start_internal_scan);
1067         cancel_work_sync(&priv->abort_scan);
1068         cancel_work_sync(&priv->scan_completed);
1069
1070         if (cancel_delayed_work_sync(&priv->scan_check)) {
1071                 mutex_lock(&priv->mutex);
1072                 iwl_force_scan_end(priv);
1073                 mutex_unlock(&priv->mutex);
1074         }
1075 }