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

   1 /******************************************************************************
   2  *
   3  * GPL LICENSE SUMMARY
   4  *
   5  * Copyright(c) 2008 - 2011 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             test_bit(STATUS_EXIT_PENDING, &priv->shrd->status))
  74                 return -EIO;
  75
  76         ret = iwl_trans_send_cmd(trans(priv), &cmd);
  77         if (ret)
  78                 return ret;
  79
  80         pkt = (struct iwl_rx_packet *)cmd.reply_page;
  81         if (pkt->u.status != CAN_ABORT_STATUS) {
  82                 /* The scan abort will return 1 for success or
  83                  * 2 for "failure".  A failure condition can be
  84                  * due to simply not being in an active scan which
  85                  * can occur if we send the scan abort before we
  86                  * the microcode has notified us that a scan is
  87                  * completed. */
  88                 IWL_DEBUG_SCAN(priv, "SCAN_ABORT ret %d.\n", pkt->u.status);
  89                 ret = -EIO;
  90         }
  91
  92         iwl_free_pages(priv->shrd, cmd.reply_page);
  93         return ret;
  94 }
  95
  96 static void iwl_complete_scan(struct iwl_priv *priv, bool aborted)
  97 {
  98         /* check if scan was requested from mac80211 */
  99         if (priv->scan_request) {
 100                 IWL_DEBUG_SCAN(priv, "Complete scan in mac80211\n");
 101                 ieee80211_scan_completed(priv->hw, aborted);
 102         }
 103
 104         if (priv->scan_type == IWL_SCAN_ROC) {
 105                 ieee80211_remain_on_channel_expired(priv->hw);
 106                 priv->hw_roc_channel = NULL;
 107                 schedule_delayed_work(&priv->hw_roc_disable_work, 10 * HZ);
 108         }
 109
 110         priv->scan_type = IWL_SCAN_NORMAL;
 111         priv->scan_vif = NULL;
 112         priv->scan_request = NULL;
 113 }
 114
 115 static void iwl_process_scan_complete(struct iwl_priv *priv)
 116 {
 117         bool aborted;
 118
 119         lockdep_assert_held(&priv->shrd->mutex);
 120
 121         if (!test_and_clear_bit(STATUS_SCAN_COMPLETE, &priv->shrd->status))
 122                 return;
 123
 124         IWL_DEBUG_SCAN(priv, "Completed scan.\n");
 125
 126         cancel_delayed_work(&priv->scan_check);
 127
 128         aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->shrd->status);
 129         if (aborted)
 130                 IWL_DEBUG_SCAN(priv, "Aborted scan completed.\n");
 131
 132         if (!test_and_clear_bit(STATUS_SCANNING, &priv->shrd->status)) {
 133                 IWL_DEBUG_SCAN(priv, "Scan already completed.\n");
 134                 goto out_settings;
 135         }
 136
 137         if (priv->scan_type == IWL_SCAN_ROC) {
 138                 ieee80211_remain_on_channel_expired(priv->hw);
 139                 priv->hw_roc_channel = NULL;
 140                 schedule_delayed_work(&priv->hw_roc_disable_work, 10 * HZ);
 141         }
 142
 143         if (priv->scan_type != IWL_SCAN_NORMAL && !aborted) {
 144                 int err;
 145
 146                 /* Check if mac80211 requested scan during our internal scan */
 147                 if (priv->scan_request == NULL)
 148                         goto out_complete;
 149
 150                 /* If so request a new scan */
 151                 err = iwl_scan_initiate(priv, priv->scan_vif, IWL_SCAN_NORMAL,
 152                                         priv->scan_request->channels[0]->band);
 153                 if (err) {
 154                         IWL_DEBUG_SCAN(priv,
 155                                 "failed to initiate pending scan: %d\n", err);
 156                         aborted = true;
 157                         goto out_complete;
 158                 }
 159
 160                 return;
 161         }
 162
 163 out_complete:
 164         iwl_complete_scan(priv, aborted);
 165
 166 out_settings:
 167         /* Can we still talk to firmware ? */
 168         if (!iwl_is_ready_rf(priv->shrd))
 169                 return;
 170
 171         iwlagn_post_scan(priv);
 172 }
 173
 174 void iwl_force_scan_end(struct iwl_priv *priv)
 175 {
 176         lockdep_assert_held(&priv->shrd->mutex);
 177
 178         if (!test_bit(STATUS_SCANNING, &priv->shrd->status)) {
 179                 IWL_DEBUG_SCAN(priv, "Forcing scan end while not scanning\n");
 180                 return;
 181         }
 182
 183         IWL_DEBUG_SCAN(priv, "Forcing scan end\n");
 184         clear_bit(STATUS_SCANNING, &priv->shrd->status);
 185         clear_bit(STATUS_SCAN_HW, &priv->shrd->status);
 186         clear_bit(STATUS_SCAN_ABORTING, &priv->shrd->status);
 187         clear_bit(STATUS_SCAN_COMPLETE, &priv->shrd->status);
 188         iwl_complete_scan(priv, true);
 189 }
 190
 191 static void iwl_do_scan_abort(struct iwl_priv *priv)
 192 {
 193         int ret;
 194
 195         lockdep_assert_held(&priv->shrd->mutex);
 196
 197         if (!test_bit(STATUS_SCANNING, &priv->shrd->status)) {
 198                 IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
 199                 return;
 200         }
 201
 202         if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->shrd->status)) {
 203                 IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
 204                 return;
 205         }
 206
 207         ret = iwl_send_scan_abort(priv);
 208         if (ret) {
 209                 IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
 210                 iwl_force_scan_end(priv);
 211         } else
 212                 IWL_DEBUG_SCAN(priv, "Successfully send scan abort\n");
 213 }
 214
 215 /**
 216  * iwl_scan_cancel - Cancel any currently executing HW scan
 217  */
 218 int iwl_scan_cancel(struct iwl_priv *priv)
 219 {
 220         IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
 221         queue_work(priv->shrd->workqueue, &priv->abort_scan);
 222         return 0;
 223 }
 224
 225 /**
 226  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
 227  * @ms: amount of time to wait (in milliseconds) for scan to abort
 228  *
 229  */
 230 void iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
 231 {
 232         unsigned long timeout = jiffies + msecs_to_jiffies(ms);
 233
 234         lockdep_assert_held(&priv->shrd->mutex);
 235
 236         IWL_DEBUG_SCAN(priv, "Scan cancel timeout\n");
 237
 238         iwl_do_scan_abort(priv);
 239
 240         while (time_before_eq(jiffies, timeout)) {
 241                 if (!test_bit(STATUS_SCAN_HW, &priv->shrd->status))
 242                         goto finished;
 243                 msleep(20);
 244         }
 245
 246         return;
 247
 248  finished:
 249         /*
 250          * Now STATUS_SCAN_HW is clear. This means that the
 251          * device finished, but the background work is going
 252          * to execute at best as soon as we release the mutex.
 253          * Since we need to be able to issue a new scan right
 254          * after this function returns, run the complete here.
 255          * The STATUS_SCAN_COMPLETE bit will then be cleared
 256          * and prevent the background work from "completing"
 257          * a possible new scan.
 258          */
 259         iwl_process_scan_complete(priv);
 260 }
 261
 262 /* Service response to REPLY_SCAN_CMD (0x80) */
 263 static int iwl_rx_reply_scan(struct iwl_priv *priv,
 264                               struct iwl_rx_mem_buffer *rxb,
 265                               struct iwl_device_cmd *cmd)
 266 {
 267 #ifdef CONFIG_IWLWIFI_DEBUG
 268         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 269         struct iwl_scanreq_notification *notif =
 270             (struct iwl_scanreq_notification *)pkt->u.raw;
 271
 272         IWL_DEBUG_SCAN(priv, "Scan request status = 0x%x\n", notif->status);
 273 #endif
 274         return 0;
 275 }
 276
 277 /* Service SCAN_START_NOTIFICATION (0x82) */
 278 static int iwl_rx_scan_start_notif(struct iwl_priv *priv,
 279                                     struct iwl_rx_mem_buffer *rxb,
 280                                     struct iwl_device_cmd *cmd)
 281 {
 282         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 283         struct iwl_scanstart_notification *notif =
 284             (struct iwl_scanstart_notification *)pkt->u.raw;
 285         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 286         IWL_DEBUG_SCAN(priv, "Scan start: "
 287                        "%d [802.11%s] "
 288                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 289                        notif->channel,
 290                        notif->band ? "bg" : "a",
 291                        le32_to_cpu(notif->tsf_high),
 292                        le32_to_cpu(notif->tsf_low),
 293                        notif->status, notif->beacon_timer);
 294
 295         if (priv->scan_type == IWL_SCAN_ROC &&
 296             !priv->hw_roc_start_notified) {
 297                 ieee80211_ready_on_channel(priv->hw);
 298                 priv->hw_roc_start_notified = true;
 299         }
 300
 301         return 0;
 302 }
 303
 304 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 305 static int iwl_rx_scan_results_notif(struct iwl_priv *priv,
 306                                       struct iwl_rx_mem_buffer *rxb,
 307                                       struct iwl_device_cmd *cmd)
 308 {
 309 #ifdef CONFIG_IWLWIFI_DEBUG
 310         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 311         struct iwl_scanresults_notification *notif =
 312             (struct iwl_scanresults_notification *)pkt->u.raw;
 313
 314         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
 315                        "%d [802.11%s] "
 316                        "probe status: %u:%u "
 317                        "(TSF: 0x%08X:%08X) - %d "
 318                        "elapsed=%lu usec\n",
 319                        notif->channel,
 320                        notif->band ? "bg" : "a",
 321                        notif->probe_status, notif->num_probe_not_sent,
 322                        le32_to_cpu(notif->tsf_high),
 323                        le32_to_cpu(notif->tsf_low),
 324                        le32_to_cpu(notif->statistics[0]),
 325                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
 326 #endif
 327         return 0;
 328 }
 329
 330 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 331 static int iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 332                                        struct iwl_rx_mem_buffer *rxb,
 333                                        struct iwl_device_cmd *cmd)
 334 {
 335         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 336         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
 337
 338         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 339                        scan_notif->scanned_channels,
 340                        scan_notif->tsf_low,
 341                        scan_notif->tsf_high, scan_notif->status);
 342
 343         IWL_DEBUG_SCAN(priv, "Scan on %sGHz took %dms\n",
 344                        (priv->scan_band == IEEE80211_BAND_2GHZ) ? "2.4" : "5.2",
 345                        jiffies_to_msecs(jiffies - priv->scan_start));
 346
 347         /*
 348          * When aborting, we run the scan completed background work inline
 349          * and the background work must then do nothing. The SCAN_COMPLETE
 350          * bit helps implement that logic and thus needs to be set before
 351          * queueing the work. Also, since the scan abort waits for SCAN_HW
 352          * to clear, we need to set SCAN_COMPLETE before clearing SCAN_HW
 353          * to avoid a race there.
 354          */
 355         set_bit(STATUS_SCAN_COMPLETE, &priv->shrd->status);
 356         clear_bit(STATUS_SCAN_HW, &priv->shrd->status);
 357         queue_work(priv->shrd->workqueue, &priv->scan_completed);
 358
 359         if (priv->iw_mode != NL80211_IFTYPE_ADHOC &&
 360             iwl_advanced_bt_coexist(priv) &&
 361             priv->bt_status != scan_notif->bt_status) {
 362                 if (scan_notif->bt_status) {
 363                         /* BT on */
 364                         if (!priv->bt_ch_announce)
 365                                 priv->bt_traffic_load =
 366                                         IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
 367                         /*
 368                          * otherwise, no traffic load information provided
 369                          * no changes made
 370                          */
 371                 } else {
 372                         /* BT off */
 373                         priv->bt_traffic_load =
 374                                 IWL_BT_COEX_TRAFFIC_LOAD_NONE;
 375                 }
 376                 priv->bt_status = scan_notif->bt_status;
 377                 queue_work(priv->shrd->workqueue,
 378                            &priv->bt_traffic_change_work);
 379         }
 380         return 0;
 381 }
 382
 383 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 384 {
 385         /* scan handlers */
 386         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 387         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 388         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 389                                         iwl_rx_scan_results_notif;
 390         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 391                                         iwl_rx_scan_complete_notif;
 392 }
 393
 394 static u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 395                                      enum ieee80211_band band, u8 n_probes)
 396 {
 397         if (band == IEEE80211_BAND_5GHZ)
 398                 return IWL_ACTIVE_DWELL_TIME_52 +
 399                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 400         else
 401                 return IWL_ACTIVE_DWELL_TIME_24 +
 402                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 403 }
 404
 405 static u16 iwl_limit_dwell(struct iwl_priv *priv, u16 dwell_time)
 406 {
 407         struct iwl_rxon_context *ctx;
 408
 409         /*
 410          * If we're associated, we clamp the dwell time 98%
 411          * of the smallest beacon interval (minus 2 * channel
 412          * tune time)
 413          */
 414         for_each_context(priv, ctx) {
 415                 u16 value;
 416
 417                 if (!iwl_is_associated_ctx(ctx))
 418                         continue;
 419                 value = ctx->beacon_int;
 420                 if (!value)
 421                         value = IWL_PASSIVE_DWELL_BASE;
 422                 value = (value * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 423                 dwell_time = min(value, dwell_time);
 424         }
 425
 426         return dwell_time;
 427 }
 428
 429 static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 430                                       enum ieee80211_band band)
 431 {
 432         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
 433             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 434             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 435
 436         return iwl_limit_dwell(priv, passive);
 437 }
 438
 439 static int iwl_get_single_channel_for_scan(struct iwl_priv *priv,
 440                                            struct ieee80211_vif *vif,
 441                                            enum ieee80211_band band,
 442                                            struct iwl_scan_channel *scan_ch)
 443 {
 444         const struct ieee80211_supported_band *sband;
 445         u16 passive_dwell = 0;
 446         u16 active_dwell = 0;
 447         int added = 0;
 448         u16 channel = 0;
 449
 450         sband = iwl_get_hw_mode(priv, band);
 451         if (!sband) {
 452                 IWL_ERR(priv, "invalid band\n");
 453                 return added;
 454         }
 455
 456         active_dwell = iwl_get_active_dwell_time(priv, band, 0);
 457         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 458
 459         if (passive_dwell <= active_dwell)
 460                 passive_dwell = active_dwell + 1;
 461
 462         channel = iwl_get_single_channel_number(priv, band);
 463         if (channel) {
 464                 scan_ch->channel = cpu_to_le16(channel);
 465                 scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 466                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 467                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 468                 /* Set txpower levels to defaults */
 469                 scan_ch->dsp_atten = 110;
 470                 if (band == IEEE80211_BAND_5GHZ)
 471                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 472                 else
 473                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 474                 added++;
 475         } else
 476                 IWL_ERR(priv, "no valid channel found\n");
 477         return added;
 478 }
 479
 480 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 481                                      struct ieee80211_vif *vif,
 482                                      enum ieee80211_band band,
 483                                      u8 is_active, u8 n_probes,
 484                                      struct iwl_scan_channel *scan_ch)
 485 {
 486         struct ieee80211_channel *chan;
 487         const struct ieee80211_supported_band *sband;
 488         const struct iwl_channel_info *ch_info;
 489         u16 passive_dwell = 0;
 490         u16 active_dwell = 0;
 491         int added, i;
 492         u16 channel;
 493
 494         sband = iwl_get_hw_mode(priv, band);
 495         if (!sband)
 496                 return 0;
 497
 498         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 499         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 500
 501         if (passive_dwell <= active_dwell)
 502                 passive_dwell = active_dwell + 1;
 503
 504         for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
 505                 chan = priv->scan_request->channels[i];
 506
 507                 if (chan->band != band)
 508                         continue;
 509
 510                 channel = chan->hw_value;
 511                 scan_ch->channel = cpu_to_le16(channel);
 512
 513                 ch_info = iwl_get_channel_info(priv, band, channel);
 514                 if (!is_channel_valid(ch_info)) {
 515                         IWL_DEBUG_SCAN(priv,
 516                                        "Channel %d is INVALID for this band.\n",
 517                                        channel);
 518                         continue;
 519                 }
 520
 521                 if (!is_active || is_channel_passive(ch_info) ||
 522                     (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN))
 523                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 524                 else
 525                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 526
 527                 if (n_probes)
 528                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 529
 530                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 531                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 532
 533                 /* Set txpower levels to defaults */
 534                 scan_ch->dsp_atten = 110;
 535
 536                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 537                  * power level:
 538                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 539                  */
 540                 if (band == IEEE80211_BAND_5GHZ)
 541                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 542                 else
 543                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 544
 545                 IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
 546                                channel, le32_to_cpu(scan_ch->type),
 547                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 548                                 "ACTIVE" : "PASSIVE",
 549                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 550                                active_dwell : passive_dwell);
 551
 552                 scan_ch++;
 553                 added++;
 554         }
 555
 556         IWL_DEBUG_SCAN(priv, "total channels to scan %d\n", added);
 557         return added;
 558 }
 559
 560 static int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
 561 {
 562         struct iwl_host_cmd cmd = {
 563                 .id = REPLY_SCAN_CMD,
 564                 .len = { sizeof(struct iwl_scan_cmd), },
 565                 .flags = CMD_SYNC,
 566         };
 567         struct iwl_scan_cmd *scan;
 568         struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
 569         u32 rate_flags = 0;
 570         u16 cmd_len;
 571         u16 rx_chain = 0;
 572         enum ieee80211_band band;
 573         u8 n_probes = 0;
 574         u8 rx_ant = hw_params(priv).valid_rx_ant;
 575         u8 rate;
 576         bool is_active = false;
 577         int  chan_mod;
 578         u8 active_chains;
 579         u8 scan_tx_antennas = hw_params(priv).valid_tx_ant;
 580         int ret;
 581
 582         lockdep_assert_held(&priv->shrd->mutex);
 583
 584         if (vif)
 585                 ctx = iwl_rxon_ctx_from_vif(vif);
 586
 587         if (!priv->scan_cmd) {
 588                 priv->scan_cmd = kmalloc(sizeof(struct iwl_scan_cmd) +
 589                                          IWL_MAX_SCAN_SIZE, GFP_KERNEL);
 590                 if (!priv->scan_cmd) {
 591                         IWL_DEBUG_SCAN(priv,
 592                                        "fail to allocate memory for scan\n");
 593                         return -ENOMEM;
 594                 }
 595         }
 596         scan = priv->scan_cmd;
 597         memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
 598
 599         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
 600         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
 601
 602         if (priv->scan_type != IWL_SCAN_ROC &&
 603             iwl_is_any_associated(priv)) {
 604                 u16 interval = 0;
 605                 u32 extra;
 606                 u32 suspend_time = 100;
 607                 u32 scan_suspend_time = 100;
 608
 609                 IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
 610                 switch (priv->scan_type) {
 611                 case IWL_SCAN_ROC:
 612                         WARN_ON(1);
 613                         break;
 614                 case IWL_SCAN_RADIO_RESET:
 615                         interval = 0;
 616                         break;
 617                 case IWL_SCAN_NORMAL:
 618                         interval = vif->bss_conf.beacon_int;
 619                         break;
 620                 }
 621
 622                 scan->suspend_time = 0;
 623                 scan->max_out_time = cpu_to_le32(200 * 1024);
 624                 if (!interval)
 625                         interval = suspend_time;
 626
 627                 extra = (suspend_time / interval) << 22;
 628                 scan_suspend_time = (extra |
 629                     ((suspend_time % interval) * 1024));
 630                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
 631                 IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
 632                                scan_suspend_time, interval);
 633         } else if (priv->scan_type == IWL_SCAN_ROC) {
 634                 scan->suspend_time = 0;
 635                 scan->max_out_time = 0;
 636                 scan->quiet_time = 0;
 637                 scan->quiet_plcp_th = 0;
 638         }
 639
 640         switch (priv->scan_type) {
 641         case IWL_SCAN_RADIO_RESET:
 642                 IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
 643                 break;
 644         case IWL_SCAN_NORMAL:
 645                 if (priv->scan_request->n_ssids) {
 646                         int i, p = 0;
 647                         IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
 648                         for (i = 0; i < priv->scan_request->n_ssids; i++) {
 649                                 /* always does wildcard anyway */
 650                                 if (!priv->scan_request->ssids[i].ssid_len)
 651                                         continue;
 652                                 scan->direct_scan[p].id = WLAN_EID_SSID;
 653                                 scan->direct_scan[p].len =
 654                                         priv->scan_request->ssids[i].ssid_len;
 655                                 memcpy(scan->direct_scan[p].ssid,
 656                                        priv->scan_request->ssids[i].ssid,
 657                                        priv->scan_request->ssids[i].ssid_len);
 658                                 n_probes++;
 659                                 p++;
 660                         }
 661                         is_active = true;
 662                 } else
 663                         IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
 664                 break;
 665         case IWL_SCAN_ROC:
 666                 IWL_DEBUG_SCAN(priv, "Start ROC scan.\n");
 667                 break;
 668         }
 669
 670         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
 671         scan->tx_cmd.sta_id = ctx->bcast_sta_id;
 672         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
 673
 674         switch (priv->scan_band) {
 675         case IEEE80211_BAND_2GHZ:
 676                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
 677                 chan_mod = le32_to_cpu(
 678                         priv->contexts[IWL_RXON_CTX_BSS].active.flags &
 679                                                 RXON_FLG_CHANNEL_MODE_MSK)
 680                                        >> RXON_FLG_CHANNEL_MODE_POS;
 681                 if (chan_mod == CHANNEL_MODE_PURE_40) {
 682                         rate = IWL_RATE_6M_PLCP;
 683                 } else {
 684                         rate = IWL_RATE_1M_PLCP;
 685                         rate_flags = RATE_MCS_CCK_MSK;
 686                 }
 687                 /*
 688                  * Internal scans are passive, so we can indiscriminately set
 689                  * the BT ignore flag on 2.4 GHz since it applies to TX only.
 690                  */
 691                 if (priv->cfg->bt_params &&
 692                     priv->cfg->bt_params->advanced_bt_coexist)
 693                         scan->tx_cmd.tx_flags |= TX_CMD_FLG_IGNORE_BT;
 694                 break;
 695         case IEEE80211_BAND_5GHZ:
 696                 rate = IWL_RATE_6M_PLCP;
 697                 break;
 698         default:
 699                 IWL_WARN(priv, "Invalid scan band\n");
 700                 return -EIO;
 701         }
 702
 703         /*
 704          * If active scanning is requested but a certain channel is
 705          * marked passive, we can do active scanning if we detect
 706          * transmissions.
 707          *
 708          * There is an issue with some firmware versions that triggers
 709          * a sysassert on a "good CRC threshold" of zero (== disabled),
 710          * on a radar channel even though this means that we should NOT
 711          * send probes.
 712          *
 713          * The "good CRC threshold" is the number of frames that we
 714          * need to receive during our dwell time on a channel before
 715          * sending out probes -- setting this to a huge value will
 716          * mean we never reach it, but at the same time work around
 717          * the aforementioned issue. Thus use IWL_GOOD_CRC_TH_NEVER
 718          * here instead of IWL_GOOD_CRC_TH_DISABLED.
 719          *
 720          * This was fixed in later versions along with some other
 721          * scan changes, and the threshold behaves as a flag in those
 722          * versions.
 723          */
 724         if (priv->new_scan_threshold_behaviour)
 725                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 726                                                 IWL_GOOD_CRC_TH_DISABLED;
 727         else
 728                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 729                                                 IWL_GOOD_CRC_TH_NEVER;
 730
 731         band = priv->scan_band;
 732
 733         if (priv->cfg->scan_rx_antennas[band])
 734                 rx_ant = priv->cfg->scan_rx_antennas[band];
 735
 736         if (band == IEEE80211_BAND_2GHZ &&
 737             priv->cfg->bt_params &&
 738             priv->cfg->bt_params->advanced_bt_coexist) {
 739                 /* transmit 2.4 GHz probes only on first antenna */
 740                 scan_tx_antennas = first_antenna(scan_tx_antennas);
 741         }
 742
 743         priv->scan_tx_ant[band] = iwl_toggle_tx_ant(priv,
 744                                                     priv->scan_tx_ant[band],
 745                                                     scan_tx_antennas);
 746         rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
 747         scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
 748
 749         /* In power save mode use one chain, otherwise use all chains */
 750         if (test_bit(STATUS_POWER_PMI, &priv->shrd->status)) {
 751                 /* rx_ant has been set to all valid chains previously */
 752                 active_chains = rx_ant &
 753                                 ((u8)(priv->chain_noise_data.active_chains));
 754                 if (!active_chains)
 755                         active_chains = rx_ant;
 756
 757                 IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
 758                                 priv->chain_noise_data.active_chains);
 759
 760                 rx_ant = first_antenna(active_chains);
 761         }
 762         if (priv->cfg->bt_params &&
 763             priv->cfg->bt_params->advanced_bt_coexist &&
 764             priv->bt_full_concurrent) {
 765                 /* operated as 1x1 in full concurrency mode */
 766                 rx_ant = first_antenna(rx_ant);
 767         }
 768
 769         /* MIMO is not used here, but value is required */
 770         rx_chain |=
 771                 hw_params(priv).valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
 772         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
 773         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
 774         rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
 775         scan->rx_chain = cpu_to_le16(rx_chain);
 776         switch (priv->scan_type) {
 777         case IWL_SCAN_NORMAL:
 778                 cmd_len = iwl_fill_probe_req(priv,
 779                                         (struct ieee80211_mgmt *)scan->data,
 780                                         vif->addr,
 781                                         priv->scan_request->ie,
 782                                         priv->scan_request->ie_len,
 783                                         IWL_MAX_SCAN_SIZE - sizeof(*scan));
 784                 break;
 785         case IWL_SCAN_RADIO_RESET:
 786         case IWL_SCAN_ROC:
 787                 /* use bcast addr, will not be transmitted but must be valid */
 788                 cmd_len = iwl_fill_probe_req(priv,
 789                                         (struct ieee80211_mgmt *)scan->data,
 790                                         iwl_bcast_addr, NULL, 0,
 791                                         IWL_MAX_SCAN_SIZE - sizeof(*scan));
 792                 break;
 793         default:
 794                 BUG();
 795         }
 796         scan->tx_cmd.len = cpu_to_le16(cmd_len);
 797
 798         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 799                                RXON_FILTER_BCON_AWARE_MSK);
 800
 801         switch (priv->scan_type) {
 802         case IWL_SCAN_RADIO_RESET:
 803                 scan->channel_count =
 804                         iwl_get_single_channel_for_scan(priv, vif, band,
 805                                 (void *)&scan->data[cmd_len]);
 806                 break;
 807         case IWL_SCAN_NORMAL:
 808                 scan->channel_count =
 809                         iwl_get_channels_for_scan(priv, vif, band,
 810                                 is_active, n_probes,
 811                                 (void *)&scan->data[cmd_len]);
 812                 break;
 813         case IWL_SCAN_ROC: {
 814                 struct iwl_scan_channel *scan_ch;
 815                 int n_chan, i;
 816                 u16 dwell;
 817
 818                 dwell = iwl_limit_dwell(priv, priv->hw_roc_duration);
 819                 n_chan = DIV_ROUND_UP(priv->hw_roc_duration, dwell);
 820
 821                 scan->channel_count = n_chan;
 822
 823                 scan_ch = (void *)&scan->data[cmd_len];
 824
 825                 for (i = 0; i < n_chan; i++) {
 826                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 827                         scan_ch->channel =
 828                                 cpu_to_le16(priv->hw_roc_channel->hw_value);
 829
 830                         if (i == n_chan - 1)
 831                                 dwell = priv->hw_roc_duration - i * dwell;
 832
 833                         scan_ch->active_dwell =
 834                         scan_ch->passive_dwell = cpu_to_le16(dwell);
 835
 836                         /* Set txpower levels to defaults */
 837                         scan_ch->dsp_atten = 110;
 838
 839                         /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 840                          * power level:
 841                          * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 842                          */
 843                         if (priv->hw_roc_channel->band == IEEE80211_BAND_5GHZ)
 844                                 scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 845                         else
 846                                 scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 847
 848                         scan_ch++;
 849                 }
 850                 }
 851
 852                 break;
 853         }
 854
 855         if (scan->channel_count == 0) {
 856                 IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
 857                 return -EIO;
 858         }
 859
 860         cmd.len[0] += le16_to_cpu(scan->tx_cmd.len) +
 861             scan->channel_count * sizeof(struct iwl_scan_channel);
 862         cmd.data[0] = scan;
 863         cmd.dataflags[0] = IWL_HCMD_DFL_NOCOPY;
 864         scan->len = cpu_to_le16(cmd.len[0]);
 865
 866         /* set scan bit here for PAN params */
 867         set_bit(STATUS_SCAN_HW, &priv->shrd->status);
 868
 869         ret = iwlagn_set_pan_params(priv);
 870         if (ret)
 871                 return ret;
 872
 873         ret = iwl_trans_send_cmd(trans(priv), &cmd);
 874         if (ret) {
 875                 clear_bit(STATUS_SCAN_HW, &priv->shrd->status);
 876                 iwlagn_set_pan_params(priv);
 877         }
 878
 879         return ret;
 880 }
 881
 882 void iwl_init_scan_params(struct iwl_priv *priv)
 883 {
 884         u8 ant_idx = fls(hw_params(priv).valid_tx_ant) - 1;
 885         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
 886                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
 887         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
 888                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
 889 }
 890
 891 int __must_check iwl_scan_initiate(struct iwl_priv *priv,
 892                                    struct ieee80211_vif *vif,
 893                                    enum iwl_scan_type scan_type,
 894                                    enum ieee80211_band band)
 895 {
 896         int ret;
 897
 898         lockdep_assert_held(&priv->shrd->mutex);
 899
 900         cancel_delayed_work(&priv->scan_check);
 901
 902         if (!iwl_is_ready_rf(priv->shrd)) {
 903                 IWL_WARN(priv, "Request scan called when driver not ready.\n");
 904                 return -EIO;
 905         }
 906
 907         if (test_bit(STATUS_SCAN_HW, &priv->shrd->status)) {
 908                 IWL_DEBUG_SCAN(priv,
 909                         "Multiple concurrent scan requests in parallel.\n");
 910                 return -EBUSY;
 911         }
 912
 913         if (test_bit(STATUS_SCAN_ABORTING, &priv->shrd->status)) {
 914                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending.\n");
 915                 return -EBUSY;
 916         }
 917
 918         IWL_DEBUG_SCAN(priv, "Starting %sscan...\n",
 919                         scan_type == IWL_SCAN_NORMAL ? "" :
 920                         scan_type == IWL_SCAN_ROC ? "remain-on-channel " :
 921                         "internal short ");
 922
 923         set_bit(STATUS_SCANNING, &priv->shrd->status);
 924         priv->scan_type = scan_type;
 925         priv->scan_start = jiffies;
 926         priv->scan_band = band;
 927
 928         ret = iwlagn_request_scan(priv, vif);
 929         if (ret) {
 930                 clear_bit(STATUS_SCANNING, &priv->shrd->status);
 931                 priv->scan_type = IWL_SCAN_NORMAL;
 932                 return ret;
 933         }
 934
 935         queue_delayed_work(priv->shrd->workqueue, &priv->scan_check,
 936                            IWL_SCAN_CHECK_WATCHDOG);
 937
 938         return 0;
 939 }
 940
 941 int iwlagn_mac_hw_scan(struct ieee80211_hw *hw,
 942                     struct ieee80211_vif *vif,
 943                     struct cfg80211_scan_request *req)
 944 {
 945         struct iwl_priv *priv = hw->priv;
 946         int ret;
 947
 948         IWL_DEBUG_MAC80211(priv, "enter\n");
 949
 950         if (req->n_channels == 0)
 951                 return -EINVAL;
 952
 953         mutex_lock(&priv->shrd->mutex);
 954
 955         /*
 956          * If an internal scan is in progress, just set
 957          * up the scan_request as per above.
 958          */
 959         if (priv->scan_type != IWL_SCAN_NORMAL) {
 960                 IWL_DEBUG_SCAN(priv,
 961                                "SCAN request during internal scan - defer\n");
 962                 priv->scan_request = req;
 963                 priv->scan_vif = vif;
 964                 ret = 0;
 965         } else {
 966                 priv->scan_request = req;
 967                 priv->scan_vif = vif;
 968                 /*
 969                  * mac80211 will only ask for one band at a time
 970                  * so using channels[0] here is ok
 971                  */
 972                 ret = iwl_scan_initiate(priv, vif, IWL_SCAN_NORMAL,
 973                                         req->channels[0]->band);
 974                 if (ret) {
 975                         priv->scan_request = NULL;
 976                         priv->scan_vif = NULL;
 977                 }
 978         }
 979
 980         IWL_DEBUG_MAC80211(priv, "leave\n");
 981
 982         mutex_unlock(&priv->shrd->mutex);
 983
 984         return ret;
 985 }
 986
 987 /*
 988  * internal short scan, this function should only been called while associated.
 989  * It will reset and tune the radio to prevent possible RF related problem
 990  */
 991 void iwl_internal_short_hw_scan(struct iwl_priv *priv)
 992 {
 993         queue_work(priv->shrd->workqueue, &priv->start_internal_scan);
 994 }
 995
 996 static void iwl_bg_start_internal_scan(struct work_struct *work)
 997 {
 998         struct iwl_priv *priv =
 999                 container_of(work, struct iwl_priv, start_internal_scan);
1000
1001         IWL_DEBUG_SCAN(priv, "Start internal scan\n");
1002
1003         mutex_lock(&priv->shrd->mutex);
1004
1005         if (priv->scan_type == IWL_SCAN_RADIO_RESET) {
1006                 IWL_DEBUG_SCAN(priv, "Internal scan already in progress\n");
1007                 goto unlock;
1008         }
1009
1010         if (test_bit(STATUS_SCANNING, &priv->shrd->status)) {
1011                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
1012                 goto unlock;
1013         }
1014
1015         if (iwl_scan_initiate(priv, NULL, IWL_SCAN_RADIO_RESET, priv->band))
1016                 IWL_DEBUG_SCAN(priv, "failed to start internal short scan\n");
1017  unlock:
1018         mutex_unlock(&priv->shrd->mutex);
1019 }
1020
1021 static void iwl_bg_scan_check(struct work_struct *data)
1022 {
1023         struct iwl_priv *priv =
1024             container_of(data, struct iwl_priv, scan_check.work);
1025
1026         IWL_DEBUG_SCAN(priv, "Scan check work\n");
1027
1028         /* Since we are here firmware does not finish scan and
1029          * most likely is in bad shape, so we don't bother to
1030          * send abort command, just force scan complete to mac80211 */
1031         mutex_lock(&priv->shrd->mutex);
1032         iwl_force_scan_end(priv);
1033         mutex_unlock(&priv->shrd->mutex);
1034 }
1035
1036 /**
1037  * iwl_fill_probe_req - fill in all required fields and IE for probe request
1038  */
1039
1040 u16 iwl_fill_probe_req(struct iwl_priv *priv, struct ieee80211_mgmt *frame,
1041                        const u8 *ta, const u8 *ies, int ie_len, int left)
1042 {
1043         int len = 0;
1044         u8 *pos = NULL;
1045
1046         /* Make sure there is enough space for the probe request,
1047          * two mandatory IEs and the data */
1048         left -= 24;
1049         if (left < 0)
1050                 return 0;
1051
1052         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
1053         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
1054         memcpy(frame->sa, ta, ETH_ALEN);
1055         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
1056         frame->seq_ctrl = 0;
1057
1058         len += 24;
1059
1060         /* ...next IE... */
1061         pos = &frame->u.probe_req.variable[0];
1062
1063         /* fill in our indirect SSID IE */
1064         left -= 2;
1065         if (left < 0)
1066                 return 0;
1067         *pos++ = WLAN_EID_SSID;
1068         *pos++ = 0;
1069
1070         len += 2;
1071
1072         if (WARN_ON(left < ie_len))
1073                 return len;
1074
1075         if (ies && ie_len) {
1076                 memcpy(pos, ies, ie_len);
1077                 len += ie_len;
1078         }
1079
1080         return (u16)len;
1081 }
1082
1083 static void iwl_bg_abort_scan(struct work_struct *work)
1084 {
1085         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
1086
1087         IWL_DEBUG_SCAN(priv, "Abort scan work\n");
1088
1089         /* We keep scan_check work queued in case when firmware will not
1090          * report back scan completed notification */
1091         mutex_lock(&priv->shrd->mutex);
1092         iwl_scan_cancel_timeout(priv, 200);
1093         mutex_unlock(&priv->shrd->mutex);
1094 }
1095
1096 static void iwl_bg_scan_completed(struct work_struct *work)
1097 {
1098         struct iwl_priv *priv =
1099                 container_of(work, struct iwl_priv, scan_completed);
1100
1101         mutex_lock(&priv->shrd->mutex);
1102         iwl_process_scan_complete(priv);
1103         mutex_unlock(&priv->shrd->mutex);
1104 }
1105
1106 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
1107 {
1108         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
1109         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
1110         INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
1111         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
1112 }
1113
1114 void iwl_cancel_scan_deferred_work(struct iwl_priv *priv)
1115 {
1116         cancel_work_sync(&priv->start_internal_scan);
1117         cancel_work_sync(&priv->abort_scan);
1118         cancel_work_sync(&priv->scan_completed);
1119
1120         if (cancel_delayed_work_sync(&priv->scan_check)) {
1121                 mutex_lock(&priv->shrd->mutex);
1122                 iwl_force_scan_end(priv);
1123                 mutex_unlock(&priv->shrd->mutex);
1124         }
1125 }