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

   1 /******************************************************************************
   2  *
   3  * GPL LICENSE SUMMARY
   4  *
   5  * Copyright(c) 2008 - 2012 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/slab.h>
  29 #include <linux/types.h>
  30 #include <linux/etherdevice.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-io.h"
  37 #include "iwl-agn.h"
  38 #include "iwl-trans.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 static int iwl_send_scan_abort(struct iwl_priv *priv)
  58 {
  59         int ret;
  60         struct iwl_rx_packet *pkt;
  61         struct iwl_host_cmd cmd = {
  62                 .id = REPLY_SCAN_ABORT_CMD,
  63                 .flags = CMD_SYNC | CMD_WANT_SKB,
  64         };
  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->shrd->status) ||
  70             !test_bit(STATUS_GEO_CONFIGURED, &priv->shrd->status) ||
  71             !test_bit(STATUS_SCAN_HW, &priv->shrd->status) ||
  72             test_bit(STATUS_FW_ERROR, &priv->shrd->status))
  73                 return -EIO;
  74
  75         ret = iwl_dvm_send_cmd(priv, &cmd);
  76         if (ret)
  77                 return ret;
  78
  79         pkt = cmd.resp_pkt;
  80         if (pkt->u.status != CAN_ABORT_STATUS) {
  81                 /* The scan abort will return 1 for success or
  82                  * 2 for "failure".  A failure condition can be
  83                  * due to simply not being in an active scan which
  84                  * can occur if we send the scan abort before we
  85                  * the microcode has notified us that a scan is
  86                  * completed. */
  87                 IWL_DEBUG_SCAN(priv, "SCAN_ABORT ret %d.\n", pkt->u.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         if (priv->scan_type == IWL_SCAN_ROC) {
 104                 ieee80211_remain_on_channel_expired(priv->hw);
 105                 priv->hw_roc_channel = NULL;
 106                 schedule_delayed_work(&priv->hw_roc_disable_work, 10 * HZ);
 107         }
 108
 109         priv->scan_type = IWL_SCAN_NORMAL;
 110         priv->scan_vif = NULL;
 111         priv->scan_request = NULL;
 112 }
 113
 114 static void iwl_process_scan_complete(struct iwl_priv *priv)
 115 {
 116         bool aborted;
 117
 118         lockdep_assert_held(&priv->shrd->mutex);
 119
 120         if (!test_and_clear_bit(STATUS_SCAN_COMPLETE, &priv->shrd->status))
 121                 return;
 122
 123         IWL_DEBUG_SCAN(priv, "Completed scan.\n");
 124
 125         cancel_delayed_work(&priv->scan_check);
 126
 127         aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->shrd->status);
 128         if (aborted)
 129                 IWL_DEBUG_SCAN(priv, "Aborted scan completed.\n");
 130
 131         if (!test_and_clear_bit(STATUS_SCANNING, &priv->shrd->status)) {
 132                 IWL_DEBUG_SCAN(priv, "Scan already completed.\n");
 133                 goto out_settings;
 134         }
 135
 136         if (priv->scan_type == IWL_SCAN_ROC) {
 137                 ieee80211_remain_on_channel_expired(priv->hw);
 138                 priv->hw_roc_channel = NULL;
 139                 schedule_delayed_work(&priv->hw_roc_disable_work, 10 * HZ);
 140         }
 141
 142         if (priv->scan_type != IWL_SCAN_NORMAL && !aborted) {
 143                 int err;
 144
 145                 /* Check if mac80211 requested scan during our internal scan */
 146                 if (priv->scan_request == NULL)
 147                         goto out_complete;
 148
 149                 /* If so request a new scan */
 150                 err = iwl_scan_initiate(priv, priv->scan_vif, IWL_SCAN_NORMAL,
 151                                         priv->scan_request->channels[0]->band);
 152                 if (err) {
 153                         IWL_DEBUG_SCAN(priv,
 154                                 "failed to initiate pending scan: %d\n", err);
 155                         aborted = true;
 156                         goto out_complete;
 157                 }
 158
 159                 return;
 160         }
 161
 162 out_complete:
 163         iwl_complete_scan(priv, aborted);
 164
 165 out_settings:
 166         /* Can we still talk to firmware ? */
 167         if (!iwl_is_ready_rf(priv->shrd))
 168                 return;
 169
 170         iwlagn_post_scan(priv);
 171 }
 172
 173 void iwl_force_scan_end(struct iwl_priv *priv)
 174 {
 175         lockdep_assert_held(&priv->shrd->mutex);
 176
 177         if (!test_bit(STATUS_SCANNING, &priv->shrd->status)) {
 178                 IWL_DEBUG_SCAN(priv, "Forcing scan end while not scanning\n");
 179                 return;
 180         }
 181
 182         IWL_DEBUG_SCAN(priv, "Forcing scan end\n");
 183         clear_bit(STATUS_SCANNING, &priv->shrd->status);
 184         clear_bit(STATUS_SCAN_HW, &priv->shrd->status);
 185         clear_bit(STATUS_SCAN_ABORTING, &priv->shrd->status);
 186         clear_bit(STATUS_SCAN_COMPLETE, &priv->shrd->status);
 187         iwl_complete_scan(priv, true);
 188 }
 189
 190 static void iwl_do_scan_abort(struct iwl_priv *priv)
 191 {
 192         int ret;
 193
 194         lockdep_assert_held(&priv->shrd->mutex);
 195
 196         if (!test_bit(STATUS_SCANNING, &priv->shrd->status)) {
 197                 IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
 198                 return;
 199         }
 200
 201         if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->shrd->status)) {
 202                 IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
 203                 return;
 204         }
 205
 206         ret = iwl_send_scan_abort(priv);
 207         if (ret) {
 208                 IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
 209                 iwl_force_scan_end(priv);
 210         } else
 211                 IWL_DEBUG_SCAN(priv, "Successfully send scan abort\n");
 212 }
 213
 214 /**
 215  * iwl_scan_cancel - Cancel any currently executing HW scan
 216  */
 217 int iwl_scan_cancel(struct iwl_priv *priv)
 218 {
 219         IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
 220         queue_work(priv->workqueue, &priv->abort_scan);
 221         return 0;
 222 }
 223
 224 /**
 225  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
 226  * @ms: amount of time to wait (in milliseconds) for scan to abort
 227  *
 228  */
 229 void iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
 230 {
 231         unsigned long timeout = jiffies + msecs_to_jiffies(ms);
 232
 233         lockdep_assert_held(&priv->shrd->mutex);
 234
 235         IWL_DEBUG_SCAN(priv, "Scan cancel timeout\n");
 236
 237         iwl_do_scan_abort(priv);
 238
 239         while (time_before_eq(jiffies, timeout)) {
 240                 if (!test_bit(STATUS_SCAN_HW, &priv->shrd->status))
 241                         goto finished;
 242                 msleep(20);
 243         }
 244
 245         return;
 246
 247  finished:
 248         /*
 249          * Now STATUS_SCAN_HW is clear. This means that the
 250          * device finished, but the background work is going
 251          * to execute at best as soon as we release the mutex.
 252          * Since we need to be able to issue a new scan right
 253          * after this function returns, run the complete here.
 254          * The STATUS_SCAN_COMPLETE bit will then be cleared
 255          * and prevent the background work from "completing"
 256          * a possible new scan.
 257          */
 258         iwl_process_scan_complete(priv);
 259 }
 260
 261 /* Service response to REPLY_SCAN_CMD (0x80) */
 262 static int iwl_rx_reply_scan(struct iwl_priv *priv,
 263                               struct iwl_rx_cmd_buffer *rxb,
 264                               struct iwl_device_cmd *cmd)
 265 {
 266 #ifdef CONFIG_IWLWIFI_DEBUG
 267         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 268         struct iwl_scanreq_notification *notif =
 269             (struct iwl_scanreq_notification *)pkt->u.raw;
 270
 271         IWL_DEBUG_SCAN(priv, "Scan request status = 0x%x\n", notif->status);
 272 #endif
 273         return 0;
 274 }
 275
 276 /* Service SCAN_START_NOTIFICATION (0x82) */
 277 static int iwl_rx_scan_start_notif(struct iwl_priv *priv,
 278                                     struct iwl_rx_cmd_buffer *rxb,
 279                                     struct iwl_device_cmd *cmd)
 280 {
 281         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 282         struct iwl_scanstart_notification *notif =
 283             (struct iwl_scanstart_notification *)pkt->u.raw;
 284         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 285         IWL_DEBUG_SCAN(priv, "Scan start: "
 286                        "%d [802.11%s] "
 287                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 288                        notif->channel,
 289                        notif->band ? "bg" : "a",
 290                        le32_to_cpu(notif->tsf_high),
 291                        le32_to_cpu(notif->tsf_low),
 292                        notif->status, notif->beacon_timer);
 293
 294         if (priv->scan_type == IWL_SCAN_ROC &&
 295             !priv->hw_roc_start_notified) {
 296                 ieee80211_ready_on_channel(priv->hw);
 297                 priv->hw_roc_start_notified = true;
 298         }
 299
 300         return 0;
 301 }
 302
 303 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 304 static int iwl_rx_scan_results_notif(struct iwl_priv *priv,
 305                                       struct iwl_rx_cmd_buffer *rxb,
 306                                       struct iwl_device_cmd *cmd)
 307 {
 308 #ifdef CONFIG_IWLWIFI_DEBUG
 309         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 310         struct iwl_scanresults_notification *notif =
 311             (struct iwl_scanresults_notification *)pkt->u.raw;
 312
 313         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
 314                        "%d [802.11%s] "
 315                        "probe status: %u:%u "
 316                        "(TSF: 0x%08X:%08X) - %d "
 317                        "elapsed=%lu usec\n",
 318                        notif->channel,
 319                        notif->band ? "bg" : "a",
 320                        notif->probe_status, notif->num_probe_not_sent,
 321                        le32_to_cpu(notif->tsf_high),
 322                        le32_to_cpu(notif->tsf_low),
 323                        le32_to_cpu(notif->statistics[0]),
 324                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
 325 #endif
 326         return 0;
 327 }
 328
 329 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 330 static int iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 331                                        struct iwl_rx_cmd_buffer *rxb,
 332                                        struct iwl_device_cmd *cmd)
 333 {
 334         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 335         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
 336
 337         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 338                        scan_notif->scanned_channels,
 339                        scan_notif->tsf_low,
 340                        scan_notif->tsf_high, scan_notif->status);
 341
 342         IWL_DEBUG_SCAN(priv, "Scan on %sGHz took %dms\n",
 343                        (priv->scan_band == IEEE80211_BAND_2GHZ) ? "2.4" : "5.2",
 344                        jiffies_to_msecs(jiffies - priv->scan_start));
 345
 346         /*
 347          * When aborting, we run the scan completed background work inline
 348          * and the background work must then do nothing. The SCAN_COMPLETE
 349          * bit helps implement that logic and thus needs to be set before
 350          * queueing the work. Also, since the scan abort waits for SCAN_HW
 351          * to clear, we need to set SCAN_COMPLETE before clearing SCAN_HW
 352          * to avoid a race there.
 353          */
 354         set_bit(STATUS_SCAN_COMPLETE, &priv->shrd->status);
 355         clear_bit(STATUS_SCAN_HW, &priv->shrd->status);
 356         queue_work(priv->workqueue, &priv->scan_completed);
 357
 358         if (priv->iw_mode != NL80211_IFTYPE_ADHOC &&
 359             iwl_advanced_bt_coexist(priv) &&
 360             priv->bt_status != scan_notif->bt_status) {
 361                 if (scan_notif->bt_status) {
 362                         /* BT on */
 363                         if (!priv->bt_ch_announce)
 364                                 priv->bt_traffic_load =
 365                                         IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
 366                         /*
 367                          * otherwise, no traffic load information provided
 368                          * no changes made
 369                          */
 370                 } else {
 371                         /* BT off */
 372                         priv->bt_traffic_load =
 373                                 IWL_BT_COEX_TRAFFIC_LOAD_NONE;
 374                 }
 375                 priv->bt_status = scan_notif->bt_status;
 376                 queue_work(priv->workqueue,
 377                            &priv->bt_traffic_change_work);
 378         }
 379         return 0;
 380 }
 381
 382 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 383 {
 384         /* scan handlers */
 385         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 386         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 387         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 388                                         iwl_rx_scan_results_notif;
 389         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 390                                         iwl_rx_scan_complete_notif;
 391 }
 392
 393 static u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 394                                      enum ieee80211_band band, u8 n_probes)
 395 {
 396         if (band == IEEE80211_BAND_5GHZ)
 397                 return IWL_ACTIVE_DWELL_TIME_52 +
 398                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 399         else
 400                 return IWL_ACTIVE_DWELL_TIME_24 +
 401                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 402 }
 403
 404 static u16 iwl_limit_dwell(struct iwl_priv *priv, u16 dwell_time)
 405 {
 406         struct iwl_rxon_context *ctx;
 407
 408         /*
 409          * If we're associated, we clamp the dwell time 98%
 410          * of the smallest beacon interval (minus 2 * channel
 411          * tune time)
 412          */
 413         for_each_context(priv, ctx) {
 414                 u16 value;
 415
 416                 switch (ctx->staging.dev_type) {
 417                 case RXON_DEV_TYPE_P2P:
 418                         /* no timing constraints */
 419                         continue;
 420                 case RXON_DEV_TYPE_ESS:
 421                 default:
 422                         /* timing constraints if associated */
 423                         if (!iwl_is_associated_ctx(ctx))
 424                                 continue;
 425                         break;
 426                 case RXON_DEV_TYPE_CP:
 427                 case RXON_DEV_TYPE_2STA:
 428                         /*
 429                          * These seem to always have timers for TBTT
 430                          * active in uCode even when not associated yet.
 431                          */
 432                         break;
 433                 }
 434
 435                 value = ctx->beacon_int;
 436                 if (!value)
 437                         value = IWL_PASSIVE_DWELL_BASE;
 438                 value = (value * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 439                 dwell_time = min(value, dwell_time);
 440         }
 441
 442         return dwell_time;
 443 }
 444
 445 static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 446                                       enum ieee80211_band band)
 447 {
 448         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
 449             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 450             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 451
 452         return iwl_limit_dwell(priv, passive);
 453 }
 454
 455 static int iwl_get_single_channel_for_scan(struct iwl_priv *priv,
 456                                            struct ieee80211_vif *vif,
 457                                            enum ieee80211_band band,
 458                                            struct iwl_scan_channel *scan_ch)
 459 {
 460         const struct ieee80211_supported_band *sband;
 461         u16 passive_dwell = 0;
 462         u16 active_dwell = 0;
 463         int added = 0;
 464         u16 channel = 0;
 465
 466         sband = iwl_get_hw_mode(priv, band);
 467         if (!sband) {
 468                 IWL_ERR(priv, "invalid band\n");
 469                 return added;
 470         }
 471
 472         active_dwell = iwl_get_active_dwell_time(priv, band, 0);
 473         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 474
 475         if (passive_dwell <= active_dwell)
 476                 passive_dwell = active_dwell + 1;
 477
 478         channel = iwl_get_single_channel_number(priv, band);
 479         if (channel) {
 480                 scan_ch->channel = cpu_to_le16(channel);
 481                 scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 482                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 483                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 484                 /* Set txpower levels to defaults */
 485                 scan_ch->dsp_atten = 110;
 486                 if (band == IEEE80211_BAND_5GHZ)
 487                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 488                 else
 489                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 490                 added++;
 491         } else
 492                 IWL_ERR(priv, "no valid channel found\n");
 493         return added;
 494 }
 495
 496 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 497                                      struct ieee80211_vif *vif,
 498                                      enum ieee80211_band band,
 499                                      u8 is_active, u8 n_probes,
 500                                      struct iwl_scan_channel *scan_ch)
 501 {
 502         struct ieee80211_channel *chan;
 503         const struct ieee80211_supported_band *sband;
 504         const struct iwl_channel_info *ch_info;
 505         u16 passive_dwell = 0;
 506         u16 active_dwell = 0;
 507         int added, i;
 508         u16 channel;
 509
 510         sband = iwl_get_hw_mode(priv, band);
 511         if (!sband)
 512                 return 0;
 513
 514         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 515         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 516
 517         if (passive_dwell <= active_dwell)
 518                 passive_dwell = active_dwell + 1;
 519
 520         for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
 521                 chan = priv->scan_request->channels[i];
 522
 523                 if (chan->band != band)
 524                         continue;
 525
 526                 channel = chan->hw_value;
 527                 scan_ch->channel = cpu_to_le16(channel);
 528
 529                 ch_info = iwl_get_channel_info(priv, band, channel);
 530                 if (!is_channel_valid(ch_info)) {
 531                         IWL_DEBUG_SCAN(priv,
 532                                        "Channel %d is INVALID for this band.\n",
 533                                        channel);
 534                         continue;
 535                 }
 536
 537                 if (!is_active || is_channel_passive(ch_info) ||
 538                     (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN))
 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 == IEEE80211_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 static int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
 577 {
 578         struct iwl_host_cmd cmd = {
 579                 .id = REPLY_SCAN_CMD,
 580                 .len = { sizeof(struct iwl_scan_cmd), },
 581                 .flags = CMD_SYNC,
 582         };
 583         struct iwl_scan_cmd *scan;
 584         struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
 585         u32 rate_flags = 0;
 586         u16 cmd_len = 0;
 587         u16 rx_chain = 0;
 588         enum ieee80211_band band;
 589         u8 n_probes = 0;
 590         u8 rx_ant = hw_params(priv).valid_rx_ant;
 591         u8 rate;
 592         bool is_active = false;
 593         int  chan_mod;
 594         u8 active_chains;
 595         u8 scan_tx_antennas = hw_params(priv).valid_tx_ant;
 596         int ret;
 597
 598         lockdep_assert_held(&priv->shrd->mutex);
 599
 600         if (vif)
 601                 ctx = iwl_rxon_ctx_from_vif(vif);
 602
 603         if (!priv->scan_cmd) {
 604                 priv->scan_cmd = kmalloc(sizeof(struct iwl_scan_cmd) +
 605                                          IWL_MAX_SCAN_SIZE, GFP_KERNEL);
 606                 if (!priv->scan_cmd) {
 607                         IWL_DEBUG_SCAN(priv,
 608                                        "fail to allocate memory for scan\n");
 609                         return -ENOMEM;
 610                 }
 611         }
 612         scan = priv->scan_cmd;
 613         memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
 614
 615         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
 616         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
 617
 618         if (priv->scan_type != IWL_SCAN_ROC &&
 619             iwl_is_any_associated(priv)) {
 620                 u16 interval = 0;
 621                 u32 extra;
 622                 u32 suspend_time = 100;
 623                 u32 scan_suspend_time = 100;
 624
 625                 IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
 626                 switch (priv->scan_type) {
 627                 case IWL_SCAN_ROC:
 628                         WARN_ON(1);
 629                         break;
 630                 case IWL_SCAN_RADIO_RESET:
 631                         interval = 0;
 632                         break;
 633                 case IWL_SCAN_NORMAL:
 634                         interval = vif->bss_conf.beacon_int;
 635                         break;
 636                 }
 637
 638                 scan->suspend_time = 0;
 639                 scan->max_out_time = cpu_to_le32(200 * 1024);
 640                 if (!interval)
 641                         interval = suspend_time;
 642
 643                 extra = (suspend_time / interval) << 22;
 644                 scan_suspend_time = (extra |
 645                     ((suspend_time % interval) * 1024));
 646                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
 647                 IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
 648                                scan_suspend_time, interval);
 649         } else if (priv->scan_type == IWL_SCAN_ROC) {
 650                 scan->suspend_time = 0;
 651                 scan->max_out_time = 0;
 652                 scan->quiet_time = 0;
 653                 scan->quiet_plcp_th = 0;
 654         }
 655
 656         switch (priv->scan_type) {
 657         case IWL_SCAN_RADIO_RESET:
 658                 IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
 659                 break;
 660         case IWL_SCAN_NORMAL:
 661                 if (priv->scan_request->n_ssids) {
 662                         int i, p = 0;
 663                         IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
 664                         for (i = 0; i < priv->scan_request->n_ssids; i++) {
 665                                 /* always does wildcard anyway */
 666                                 if (!priv->scan_request->ssids[i].ssid_len)
 667                                         continue;
 668                                 scan->direct_scan[p].id = WLAN_EID_SSID;
 669                                 scan->direct_scan[p].len =
 670                                         priv->scan_request->ssids[i].ssid_len;
 671                                 memcpy(scan->direct_scan[p].ssid,
 672                                        priv->scan_request->ssids[i].ssid,
 673                                        priv->scan_request->ssids[i].ssid_len);
 674                                 n_probes++;
 675                                 p++;
 676                         }
 677                         is_active = true;
 678                 } else
 679                         IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
 680                 break;
 681         case IWL_SCAN_ROC:
 682                 IWL_DEBUG_SCAN(priv, "Start ROC scan.\n");
 683                 break;
 684         }
 685
 686         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
 687         scan->tx_cmd.sta_id = ctx->bcast_sta_id;
 688         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
 689
 690         switch (priv->scan_band) {
 691         case IEEE80211_BAND_2GHZ:
 692                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
 693                 chan_mod = le32_to_cpu(
 694                         priv->contexts[IWL_RXON_CTX_BSS].active.flags &
 695                                                 RXON_FLG_CHANNEL_MODE_MSK)
 696                                        >> RXON_FLG_CHANNEL_MODE_POS;
 697                 if ((priv->scan_request && priv->scan_request->no_cck) ||
 698                     chan_mod == CHANNEL_MODE_PURE_40) {
 699                         rate = IWL_RATE_6M_PLCP;
 700                 } else {
 701                         rate = IWL_RATE_1M_PLCP;
 702                         rate_flags = RATE_MCS_CCK_MSK;
 703                 }
 704                 /*
 705                  * Internal scans are passive, so we can indiscriminately set
 706                  * the BT ignore flag on 2.4 GHz since it applies to TX only.
 707                  */
 708                 if (cfg(priv)->bt_params &&
 709                     cfg(priv)->bt_params->advanced_bt_coexist)
 710                         scan->tx_cmd.tx_flags |= TX_CMD_FLG_IGNORE_BT;
 711                 break;
 712         case IEEE80211_BAND_5GHZ:
 713                 rate = IWL_RATE_6M_PLCP;
 714                 break;
 715         default:
 716                 IWL_WARN(priv, "Invalid scan band\n");
 717                 return -EIO;
 718         }
 719
 720         /*
 721          * If active scanning is requested but a certain channel is
 722          * marked passive, we can do active scanning if we detect
 723          * transmissions.
 724          *
 725          * There is an issue with some firmware versions that triggers
 726          * a sysassert on a "good CRC threshold" of zero (== disabled),
 727          * on a radar channel even though this means that we should NOT
 728          * send probes.
 729          *
 730          * The "good CRC threshold" is the number of frames that we
 731          * need to receive during our dwell time on a channel before
 732          * sending out probes -- setting this to a huge value will
 733          * mean we never reach it, but at the same time work around
 734          * the aforementioned issue. Thus use IWL_GOOD_CRC_TH_NEVER
 735          * here instead of IWL_GOOD_CRC_TH_DISABLED.
 736          *
 737          * This was fixed in later versions along with some other
 738          * scan changes, and the threshold behaves as a flag in those
 739          * versions.
 740          */
 741         if (priv->new_scan_threshold_behaviour)
 742                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 743                                                 IWL_GOOD_CRC_TH_DISABLED;
 744         else
 745                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 746                                                 IWL_GOOD_CRC_TH_NEVER;
 747
 748         band = priv->scan_band;
 749
 750         if (cfg(priv)->scan_rx_antennas[band])
 751                 rx_ant = cfg(priv)->scan_rx_antennas[band];
 752
 753         if (band == IEEE80211_BAND_2GHZ &&
 754             cfg(priv)->bt_params &&
 755             cfg(priv)->bt_params->advanced_bt_coexist) {
 756                 /* transmit 2.4 GHz probes only on first antenna */
 757                 scan_tx_antennas = first_antenna(scan_tx_antennas);
 758         }
 759
 760         priv->scan_tx_ant[band] = iwl_toggle_tx_ant(priv,
 761                                                     priv->scan_tx_ant[band],
 762                                                     scan_tx_antennas);
 763         rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
 764         scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
 765
 766         /* In power save mode use one chain, otherwise use all chains */
 767         if (test_bit(STATUS_POWER_PMI, &priv->shrd->status)) {
 768                 /* rx_ant has been set to all valid chains previously */
 769                 active_chains = rx_ant &
 770                                 ((u8)(priv->chain_noise_data.active_chains));
 771                 if (!active_chains)
 772                         active_chains = rx_ant;
 773
 774                 IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
 775                                 priv->chain_noise_data.active_chains);
 776
 777                 rx_ant = first_antenna(active_chains);
 778         }
 779         if (cfg(priv)->bt_params &&
 780             cfg(priv)->bt_params->advanced_bt_coexist &&
 781             priv->bt_full_concurrent) {
 782                 /* operated as 1x1 in full concurrency mode */
 783                 rx_ant = first_antenna(rx_ant);
 784         }
 785
 786         /* MIMO is not used here, but value is required */
 787         rx_chain |=
 788                 hw_params(priv).valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
 789         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
 790         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
 791         rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
 792         scan->rx_chain = cpu_to_le16(rx_chain);
 793         switch (priv->scan_type) {
 794         case IWL_SCAN_NORMAL:
 795                 cmd_len = iwl_fill_probe_req(priv,
 796                                         (struct ieee80211_mgmt *)scan->data,
 797                                         vif->addr,
 798                                         priv->scan_request->ie,
 799                                         priv->scan_request->ie_len,
 800                                         IWL_MAX_SCAN_SIZE - sizeof(*scan));
 801                 break;
 802         case IWL_SCAN_RADIO_RESET:
 803         case IWL_SCAN_ROC:
 804                 /* use bcast addr, will not be transmitted but must be valid */
 805                 cmd_len = iwl_fill_probe_req(priv,
 806                                         (struct ieee80211_mgmt *)scan->data,
 807                                         iwl_bcast_addr, NULL, 0,
 808                                         IWL_MAX_SCAN_SIZE - sizeof(*scan));
 809                 break;
 810         default:
 811                 BUG();
 812         }
 813         scan->tx_cmd.len = cpu_to_le16(cmd_len);
 814
 815         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 816                                RXON_FILTER_BCON_AWARE_MSK);
 817
 818         switch (priv->scan_type) {
 819         case IWL_SCAN_RADIO_RESET:
 820                 scan->channel_count =
 821                         iwl_get_single_channel_for_scan(priv, vif, band,
 822                                 (void *)&scan->data[cmd_len]);
 823                 break;
 824         case IWL_SCAN_NORMAL:
 825                 scan->channel_count =
 826                         iwl_get_channels_for_scan(priv, vif, band,
 827                                 is_active, n_probes,
 828                                 (void *)&scan->data[cmd_len]);
 829                 break;
 830         case IWL_SCAN_ROC: {
 831                 struct iwl_scan_channel *scan_ch;
 832                 int n_chan, i;
 833                 u16 dwell;
 834
 835                 dwell = iwl_limit_dwell(priv, priv->hw_roc_duration);
 836                 n_chan = DIV_ROUND_UP(priv->hw_roc_duration, dwell);
 837
 838                 scan->channel_count = n_chan;
 839
 840                 scan_ch = (void *)&scan->data[cmd_len];
 841
 842                 for (i = 0; i < n_chan; i++) {
 843                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 844                         scan_ch->channel =
 845                                 cpu_to_le16(priv->hw_roc_channel->hw_value);
 846
 847                         if (i == n_chan - 1)
 848                                 dwell = priv->hw_roc_duration - i * dwell;
 849
 850                         scan_ch->active_dwell =
 851                         scan_ch->passive_dwell = cpu_to_le16(dwell);
 852
 853                         /* Set txpower levels to defaults */
 854                         scan_ch->dsp_atten = 110;
 855
 856                         /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 857                          * power level:
 858                          * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 859                          */
 860                         if (priv->hw_roc_channel->band == IEEE80211_BAND_5GHZ)
 861                                 scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 862                         else
 863                                 scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 864
 865                         scan_ch++;
 866                 }
 867                 }
 868
 869                 break;
 870         }
 871
 872         if (scan->channel_count == 0) {
 873                 IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
 874                 return -EIO;
 875         }
 876
 877         cmd.len[0] += le16_to_cpu(scan->tx_cmd.len) +
 878             scan->channel_count * sizeof(struct iwl_scan_channel);
 879         cmd.data[0] = scan;
 880         cmd.dataflags[0] = IWL_HCMD_DFL_NOCOPY;
 881         scan->len = cpu_to_le16(cmd.len[0]);
 882
 883         /* set scan bit here for PAN params */
 884         set_bit(STATUS_SCAN_HW, &priv->shrd->status);
 885
 886         ret = iwlagn_set_pan_params(priv);
 887         if (ret)
 888                 return ret;
 889
 890         ret = iwl_dvm_send_cmd(priv, &cmd);
 891         if (ret) {
 892                 clear_bit(STATUS_SCAN_HW, &priv->shrd->status);
 893                 iwlagn_set_pan_params(priv);
 894         }
 895
 896         return ret;
 897 }
 898
 899 void iwl_init_scan_params(struct iwl_priv *priv)
 900 {
 901         u8 ant_idx = fls(hw_params(priv).valid_tx_ant) - 1;
 902         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
 903                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
 904         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
 905                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
 906 }
 907
 908 int __must_check iwl_scan_initiate(struct iwl_priv *priv,
 909                                    struct ieee80211_vif *vif,
 910                                    enum iwl_scan_type scan_type,
 911                                    enum ieee80211_band band)
 912 {
 913         int ret;
 914
 915         lockdep_assert_held(&priv->shrd->mutex);
 916
 917         cancel_delayed_work(&priv->scan_check);
 918
 919         if (!iwl_is_ready_rf(priv->shrd)) {
 920                 IWL_WARN(priv, "Request scan called when driver not ready.\n");
 921                 return -EIO;
 922         }
 923
 924         if (test_bit(STATUS_SCAN_HW, &priv->shrd->status)) {
 925                 IWL_DEBUG_SCAN(priv,
 926                         "Multiple concurrent scan requests in parallel.\n");
 927                 return -EBUSY;
 928         }
 929
 930         if (test_bit(STATUS_SCAN_ABORTING, &priv->shrd->status)) {
 931                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending.\n");
 932                 return -EBUSY;
 933         }
 934
 935         IWL_DEBUG_SCAN(priv, "Starting %sscan...\n",
 936                         scan_type == IWL_SCAN_NORMAL ? "" :
 937                         scan_type == IWL_SCAN_ROC ? "remain-on-channel " :
 938                         "internal short ");
 939
 940         set_bit(STATUS_SCANNING, &priv->shrd->status);
 941         priv->scan_type = scan_type;
 942         priv->scan_start = jiffies;
 943         priv->scan_band = band;
 944
 945         ret = iwlagn_request_scan(priv, vif);
 946         if (ret) {
 947                 clear_bit(STATUS_SCANNING, &priv->shrd->status);
 948                 priv->scan_type = IWL_SCAN_NORMAL;
 949                 return ret;
 950         }
 951
 952         queue_delayed_work(priv->workqueue, &priv->scan_check,
 953                            IWL_SCAN_CHECK_WATCHDOG);
 954
 955         return 0;
 956 }
 957
 958
 959 /*
 960  * internal short scan, this function should only been called while associated.
 961  * It will reset and tune the radio to prevent possible RF related problem
 962  */
 963 void iwl_internal_short_hw_scan(struct iwl_priv *priv)
 964 {
 965         queue_work(priv->workqueue, &priv->start_internal_scan);
 966 }
 967
 968 static void iwl_bg_start_internal_scan(struct work_struct *work)
 969 {
 970         struct iwl_priv *priv =
 971                 container_of(work, struct iwl_priv, start_internal_scan);
 972
 973         IWL_DEBUG_SCAN(priv, "Start internal scan\n");
 974
 975         mutex_lock(&priv->shrd->mutex);
 976
 977         if (priv->scan_type == IWL_SCAN_RADIO_RESET) {
 978                 IWL_DEBUG_SCAN(priv, "Internal scan already in progress\n");
 979                 goto unlock;
 980         }
 981
 982         if (test_bit(STATUS_SCANNING, &priv->shrd->status)) {
 983                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
 984                 goto unlock;
 985         }
 986
 987         if (iwl_scan_initiate(priv, NULL, IWL_SCAN_RADIO_RESET, priv->band))
 988                 IWL_DEBUG_SCAN(priv, "failed to start internal short scan\n");
 989  unlock:
 990         mutex_unlock(&priv->shrd->mutex);
 991 }
 992
 993 static void iwl_bg_scan_check(struct work_struct *data)
 994 {
 995         struct iwl_priv *priv =
 996             container_of(data, struct iwl_priv, scan_check.work);
 997
 998         IWL_DEBUG_SCAN(priv, "Scan check work\n");
 999
1000         /* Since we are here firmware does not finish scan and
1001          * most likely is in bad shape, so we don't bother to
1002          * send abort command, just force scan complete to mac80211 */
1003         mutex_lock(&priv->shrd->mutex);
1004         iwl_force_scan_end(priv);
1005         mutex_unlock(&priv->shrd->mutex);
1006 }
1007
1008 /**
1009  * iwl_fill_probe_req - fill in all required fields and IE for probe request
1010  */
1011
1012 u16 iwl_fill_probe_req(struct iwl_priv *priv, struct ieee80211_mgmt *frame,
1013                        const u8 *ta, const u8 *ies, int ie_len, int left)
1014 {
1015         int len = 0;
1016         u8 *pos = NULL;
1017
1018         /* Make sure there is enough space for the probe request,
1019          * two mandatory IEs and the data */
1020         left -= 24;
1021         if (left < 0)
1022                 return 0;
1023
1024         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
1025         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
1026         memcpy(frame->sa, ta, ETH_ALEN);
1027         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
1028         frame->seq_ctrl = 0;
1029
1030         len += 24;
1031
1032         /* ...next IE... */
1033         pos = &frame->u.probe_req.variable[0];
1034
1035         /* fill in our indirect SSID IE */
1036         left -= 2;
1037         if (left < 0)
1038                 return 0;
1039         *pos++ = WLAN_EID_SSID;
1040         *pos++ = 0;
1041
1042         len += 2;
1043
1044         if (WARN_ON(left < ie_len))
1045                 return len;
1046
1047         if (ies && ie_len) {
1048                 memcpy(pos, ies, ie_len);
1049                 len += ie_len;
1050         }
1051
1052         return (u16)len;
1053 }
1054
1055 static void iwl_bg_abort_scan(struct work_struct *work)
1056 {
1057         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
1058
1059         IWL_DEBUG_SCAN(priv, "Abort scan work\n");
1060
1061         /* We keep scan_check work queued in case when firmware will not
1062          * report back scan completed notification */
1063         mutex_lock(&priv->shrd->mutex);
1064         iwl_scan_cancel_timeout(priv, 200);
1065         mutex_unlock(&priv->shrd->mutex);
1066 }
1067
1068 static void iwl_bg_scan_completed(struct work_struct *work)
1069 {
1070         struct iwl_priv *priv =
1071                 container_of(work, struct iwl_priv, scan_completed);
1072
1073         mutex_lock(&priv->shrd->mutex);
1074         iwl_process_scan_complete(priv);
1075         mutex_unlock(&priv->shrd->mutex);
1076 }
1077
1078 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
1079 {
1080         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
1081         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
1082         INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
1083         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
1084 }
1085
1086 void iwl_cancel_scan_deferred_work(struct iwl_priv *priv)
1087 {
1088         cancel_work_sync(&priv->start_internal_scan);
1089         cancel_work_sync(&priv->abort_scan);
1090         cancel_work_sync(&priv->scan_completed);
1091
1092         if (cancel_delayed_work_sync(&priv->scan_check)) {
1093                 mutex_lock(&priv->shrd->mutex);
1094                 iwl_force_scan_end(priv);
1095                 mutex_unlock(&priv->shrd->mutex);
1096         }
1097 }