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

   1 /******************************************************************************
   2  *
   3  * GPL LICENSE SUMMARY
   4  *
   5  * Copyright(c) 2008 - 2014 Intel Corporation. All rights reserved.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of version 2 of the GNU General Public License as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
  19  * USA
  20  *
  21  * The full GNU General Public License is included in this distribution
  22  * in the file called COPYING.
  23  *
  24  * Contact Information:
  25  *  Intel Linux Wireless <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 "dev.h"
  34 #include "agn.h"
  35
  36 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
  37  * sending probe req.  This should be set long enough to hear probe responses
  38  * from more than one AP.  */
  39 #define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
  40 #define IWL_ACTIVE_DWELL_TIME_52    (20)
  41
  42 #define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
  43 #define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
  44
  45 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
  46  * Must be set longer than active dwell time.
  47  * For the most reliable scan, set > AP beacon interval (typically 100msec). */
  48 #define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
  49 #define IWL_PASSIVE_DWELL_TIME_52   (10)
  50 #define IWL_PASSIVE_DWELL_BASE      (100)
  51 #define IWL_CHANNEL_TUNE_TIME       5
  52 #define MAX_SCAN_CHANNEL            50
  53
  54 /* For reset radio, need minimal dwell time only */
  55 #define IWL_RADIO_RESET_DWELL_TIME      5
  56
  57 static int iwl_send_scan_abort(struct iwl_priv *priv)
  58 {
  59         int ret;
  60         struct iwl_host_cmd cmd = {
  61                 .id = REPLY_SCAN_ABORT_CMD,
  62                 .flags = CMD_WANT_SKB,
  63         };
  64         __le32 *status;
  65
  66         /* Exit instantly with error when device is not ready
  67          * to receive scan abort command or it does not perform
  68          * hardware scan currently */
  69         if (!test_bit(STATUS_READY, &priv->status) ||
  70             !test_bit(STATUS_SCAN_HW, &priv->status) ||
  71             test_bit(STATUS_FW_ERROR, &priv->status))
  72                 return -EIO;
  73
  74         ret = iwl_dvm_send_cmd(priv, &cmd);
  75         if (ret)
  76                 return ret;
  77
  78         status = (void *)cmd.resp_pkt->data;
  79         if (*status != CAN_ABORT_STATUS) {
  80                 /* The scan abort will return 1 for success or
  81                  * 2 for "failure".  A failure condition can be
  82                  * due to simply not being in an active scan which
  83                  * can occur if we send the scan abort before we
  84                  * the microcode has notified us that a scan is
  85                  * completed. */
  86                 IWL_DEBUG_SCAN(priv, "SCAN_ABORT ret %d.\n",
  87                                le32_to_cpu(*status));
  88                 ret = -EIO;
  89         }
  90
  91         iwl_free_resp(&cmd);
  92         return ret;
  93 }
  94
  95 static void iwl_complete_scan(struct iwl_priv *priv, bool aborted)
  96 {
  97         /* check if scan was requested from mac80211 */
  98         if (priv->scan_request) {
  99                 IWL_DEBUG_SCAN(priv, "Complete scan in mac80211\n");
 100                 ieee80211_scan_completed(priv->hw, aborted);
 101         }
 102
 103         priv->scan_type = IWL_SCAN_NORMAL;
 104         priv->scan_vif = NULL;
 105         priv->scan_request = NULL;
 106 }
 107
 108 static void iwl_process_scan_complete(struct iwl_priv *priv)
 109 {
 110         bool aborted;
 111
 112         lockdep_assert_held(&priv->mutex);
 113
 114         if (!test_and_clear_bit(STATUS_SCAN_COMPLETE, &priv->status))
 115                 return;
 116
 117         IWL_DEBUG_SCAN(priv, "Completed scan.\n");
 118
 119         cancel_delayed_work(&priv->scan_check);
 120
 121         aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 122         if (aborted)
 123                 IWL_DEBUG_SCAN(priv, "Aborted scan completed.\n");
 124
 125         if (!test_and_clear_bit(STATUS_SCANNING, &priv->status)) {
 126                 IWL_DEBUG_SCAN(priv, "Scan already completed.\n");
 127                 goto out_settings;
 128         }
 129
 130         if (priv->scan_type != IWL_SCAN_NORMAL && !aborted) {
 131                 int err;
 132
 133                 /* Check if mac80211 requested scan during our internal scan */
 134                 if (priv->scan_request == NULL)
 135                         goto out_complete;
 136
 137                 /* If so request a new scan */
 138                 err = iwl_scan_initiate(priv, priv->scan_vif, IWL_SCAN_NORMAL,
 139                                         priv->scan_request->channels[0]->band);
 140                 if (err) {
 141                         IWL_DEBUG_SCAN(priv,
 142                                 "failed to initiate pending scan: %d\n", err);
 143                         aborted = true;
 144                         goto out_complete;
 145                 }
 146
 147                 return;
 148         }
 149
 150 out_complete:
 151         iwl_complete_scan(priv, aborted);
 152
 153 out_settings:
 154         /* Can we still talk to firmware ? */
 155         if (!iwl_is_ready_rf(priv))
 156                 return;
 157
 158         iwlagn_post_scan(priv);
 159 }
 160
 161 void iwl_force_scan_end(struct iwl_priv *priv)
 162 {
 163         lockdep_assert_held(&priv->mutex);
 164
 165         if (!test_bit(STATUS_SCANNING, &priv->status)) {
 166                 IWL_DEBUG_SCAN(priv, "Forcing scan end while not scanning\n");
 167                 return;
 168         }
 169
 170         IWL_DEBUG_SCAN(priv, "Forcing scan end\n");
 171         clear_bit(STATUS_SCANNING, &priv->status);
 172         clear_bit(STATUS_SCAN_HW, &priv->status);
 173         clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 174         clear_bit(STATUS_SCAN_COMPLETE, &priv->status);
 175         iwl_complete_scan(priv, true);
 176 }
 177
 178 static void iwl_do_scan_abort(struct iwl_priv *priv)
 179 {
 180         int ret;
 181
 182         lockdep_assert_held(&priv->mutex);
 183
 184         if (!test_bit(STATUS_SCANNING, &priv->status)) {
 185                 IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
 186                 return;
 187         }
 188
 189         if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 190                 IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
 191                 return;
 192         }
 193
 194         ret = iwl_send_scan_abort(priv);
 195         if (ret) {
 196                 IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
 197                 iwl_force_scan_end(priv);
 198         } else
 199                 IWL_DEBUG_SCAN(priv, "Successfully send scan abort\n");
 200 }
 201
 202 /**
 203  * iwl_scan_cancel - Cancel any currently executing HW scan
 204  */
 205 int iwl_scan_cancel(struct iwl_priv *priv)
 206 {
 207         IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
 208         queue_work(priv->workqueue, &priv->abort_scan);
 209         return 0;
 210 }
 211
 212 /**
 213  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
 214  * @ms: amount of time to wait (in milliseconds) for scan to abort
 215  *
 216  */
 217 void iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
 218 {
 219         unsigned long timeout = jiffies + msecs_to_jiffies(ms);
 220
 221         lockdep_assert_held(&priv->mutex);
 222
 223         IWL_DEBUG_SCAN(priv, "Scan cancel timeout\n");
 224
 225         iwl_do_scan_abort(priv);
 226
 227         while (time_before_eq(jiffies, timeout)) {
 228                 if (!test_bit(STATUS_SCAN_HW, &priv->status))
 229                         goto finished;
 230                 msleep(20);
 231         }
 232
 233         return;
 234
 235  finished:
 236         /*
 237          * Now STATUS_SCAN_HW is clear. This means that the
 238          * device finished, but the background work is going
 239          * to execute at best as soon as we release the mutex.
 240          * Since we need to be able to issue a new scan right
 241          * after this function returns, run the complete here.
 242          * The STATUS_SCAN_COMPLETE bit will then be cleared
 243          * and prevent the background work from "completing"
 244          * a possible new scan.
 245          */
 246         iwl_process_scan_complete(priv);
 247 }
 248
 249 /* Service response to REPLY_SCAN_CMD (0x80) */
 250 static int iwl_rx_reply_scan(struct iwl_priv *priv,
 251                               struct iwl_rx_cmd_buffer *rxb,
 252                               struct iwl_device_cmd *cmd)
 253 {
 254 #ifdef CONFIG_IWLWIFI_DEBUG
 255         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 256         struct iwl_scanreq_notification *notif = (void *)pkt->data;
 257
 258         IWL_DEBUG_SCAN(priv, "Scan request status = 0x%x\n", notif->status);
 259 #endif
 260         return 0;
 261 }
 262
 263 /* Service SCAN_START_NOTIFICATION (0x82) */
 264 static int iwl_rx_scan_start_notif(struct iwl_priv *priv,
 265                                     struct iwl_rx_cmd_buffer *rxb,
 266                                     struct iwl_device_cmd *cmd)
 267 {
 268         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 269         struct iwl_scanstart_notification *notif = (void *)pkt->data;
 270
 271         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 272         IWL_DEBUG_SCAN(priv, "Scan start: "
 273                        "%d [802.11%s] "
 274                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 275                        notif->channel,
 276                        notif->band ? "bg" : "a",
 277                        le32_to_cpu(notif->tsf_high),
 278                        le32_to_cpu(notif->tsf_low),
 279                        notif->status, notif->beacon_timer);
 280
 281         return 0;
 282 }
 283
 284 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 285 static int iwl_rx_scan_results_notif(struct iwl_priv *priv,
 286                                       struct iwl_rx_cmd_buffer *rxb,
 287                                       struct iwl_device_cmd *cmd)
 288 {
 289 #ifdef CONFIG_IWLWIFI_DEBUG
 290         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 291         struct iwl_scanresults_notification *notif = (void *)pkt->data;
 292
 293         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
 294                        "%d [802.11%s] "
 295                        "probe status: %u:%u "
 296                        "(TSF: 0x%08X:%08X) - %d "
 297                        "elapsed=%lu usec\n",
 298                        notif->channel,
 299                        notif->band ? "bg" : "a",
 300                        notif->probe_status, notif->num_probe_not_sent,
 301                        le32_to_cpu(notif->tsf_high),
 302                        le32_to_cpu(notif->tsf_low),
 303                        le32_to_cpu(notif->statistics[0]),
 304                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
 305 #endif
 306         return 0;
 307 }
 308
 309 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 310 static int iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 311                                        struct iwl_rx_cmd_buffer *rxb,
 312                                        struct iwl_device_cmd *cmd)
 313 {
 314         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 315         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->data;
 316
 317         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 318                        scan_notif->scanned_channels,
 319                        scan_notif->tsf_low,
 320                        scan_notif->tsf_high, scan_notif->status);
 321
 322         IWL_DEBUG_SCAN(priv, "Scan on %sGHz took %dms\n",
 323                        (priv->scan_band == IEEE80211_BAND_2GHZ) ? "2.4" : "5.2",
 324                        jiffies_to_msecs(jiffies - priv->scan_start));
 325
 326         /*
 327          * When aborting, we run the scan completed background work inline
 328          * and the background work must then do nothing. The SCAN_COMPLETE
 329          * bit helps implement that logic and thus needs to be set before
 330          * queueing the work. Also, since the scan abort waits for SCAN_HW
 331          * to clear, we need to set SCAN_COMPLETE before clearing SCAN_HW
 332          * to avoid a race there.
 333          */
 334         set_bit(STATUS_SCAN_COMPLETE, &priv->status);
 335         clear_bit(STATUS_SCAN_HW, &priv->status);
 336         queue_work(priv->workqueue, &priv->scan_completed);
 337
 338         if (priv->iw_mode != NL80211_IFTYPE_ADHOC &&
 339             iwl_advanced_bt_coexist(priv) &&
 340             priv->bt_status != scan_notif->bt_status) {
 341                 if (scan_notif->bt_status) {
 342                         /* BT on */
 343                         if (!priv->bt_ch_announce)
 344                                 priv->bt_traffic_load =
 345                                         IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
 346                         /*
 347                          * otherwise, no traffic load information provided
 348                          * no changes made
 349                          */
 350                 } else {
 351                         /* BT off */
 352                         priv->bt_traffic_load =
 353                                 IWL_BT_COEX_TRAFFIC_LOAD_NONE;
 354                 }
 355                 priv->bt_status = scan_notif->bt_status;
 356                 queue_work(priv->workqueue,
 357                            &priv->bt_traffic_change_work);
 358         }
 359         return 0;
 360 }
 361
 362 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 363 {
 364         /* scan handlers */
 365         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 366         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 367         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 368                                         iwl_rx_scan_results_notif;
 369         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 370                                         iwl_rx_scan_complete_notif;
 371 }
 372
 373 static u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 374                                      enum ieee80211_band band, u8 n_probes)
 375 {
 376         if (band == IEEE80211_BAND_5GHZ)
 377                 return IWL_ACTIVE_DWELL_TIME_52 +
 378                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 379         else
 380                 return IWL_ACTIVE_DWELL_TIME_24 +
 381                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 382 }
 383
 384 static u16 iwl_limit_dwell(struct iwl_priv *priv, u16 dwell_time)
 385 {
 386         struct iwl_rxon_context *ctx;
 387         int limits[NUM_IWL_RXON_CTX] = {};
 388         int n_active = 0;
 389         u16 limit;
 390
 391         BUILD_BUG_ON(NUM_IWL_RXON_CTX != 2);
 392
 393         /*
 394          * If we're associated, we clamp the dwell time 98%
 395          * of the beacon interval (minus 2 * channel tune time)
 396          * If both contexts are active, we have to restrict to
 397          * 1/2 of the minimum of them, because they might be in
 398          * lock-step with the time inbetween only half of what
 399          * time we'd have in each of them.
 400          */
 401         for_each_context(priv, ctx) {
 402                 switch (ctx->staging.dev_type) {
 403                 case RXON_DEV_TYPE_P2P:
 404                         /* no timing constraints */
 405                         continue;
 406                 case RXON_DEV_TYPE_ESS:
 407                 default:
 408                         /* timing constraints if associated */
 409                         if (!iwl_is_associated_ctx(ctx))
 410                                 continue;
 411                         break;
 412                 case RXON_DEV_TYPE_CP:
 413                 case RXON_DEV_TYPE_2STA:
 414                         /*
 415                          * These seem to always have timers for TBTT
 416                          * active in uCode even when not associated yet.
 417                          */
 418                         break;
 419                 }
 420
 421                 limits[n_active++] = ctx->beacon_int ?: IWL_PASSIVE_DWELL_BASE;
 422         }
 423
 424         switch (n_active) {
 425         case 0:
 426                 return dwell_time;
 427         case 2:
 428                 limit = (limits[1] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 429                 limit /= 2;
 430                 dwell_time = min(limit, dwell_time);
 431                 /* fall through to limit further */
 432         case 1:
 433                 limit = (limits[0] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 434                 limit /= n_active;
 435                 return min(limit, dwell_time);
 436         default:
 437                 WARN_ON_ONCE(1);
 438                 return dwell_time;
 439         }
 440 }
 441
 442 static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 443                                       enum ieee80211_band band)
 444 {
 445         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
 446             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 447             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 448
 449         return iwl_limit_dwell(priv, passive);
 450 }
 451
 452 /* Return valid, unused, channel for a passive scan to reset the RF */
 453 static u8 iwl_get_single_channel_number(struct iwl_priv *priv,
 454                                         enum ieee80211_band band)
 455 {
 456         struct ieee80211_supported_band *sband = priv->hw->wiphy->bands[band];
 457         struct iwl_rxon_context *ctx;
 458         int i;
 459
 460         for (i = 0; i < sband->n_channels; i++) {
 461                 bool busy = false;
 462
 463                 for_each_context(priv, ctx) {
 464                         busy = sband->channels[i].hw_value ==
 465                                 le16_to_cpu(ctx->staging.channel);
 466                         if (busy)
 467                                 break;
 468                 }
 469
 470                 if (busy)
 471                         continue;
 472
 473                 if (!(sband->channels[i].flags & IEEE80211_CHAN_DISABLED))
 474                         return sband->channels[i].hw_value;
 475         }
 476
 477         return 0;
 478 }
 479
 480 static int iwl_get_channel_for_reset_scan(struct iwl_priv *priv,
 481                                           struct ieee80211_vif *vif,
 482                                           enum ieee80211_band band,
 483                                           struct iwl_scan_channel *scan_ch)
 484 {
 485         const struct ieee80211_supported_band *sband;
 486         u16 channel;
 487
 488         sband = iwl_get_hw_mode(priv, band);
 489         if (!sband) {
 490                 IWL_ERR(priv, "invalid band\n");
 491                 return 0;
 492         }
 493
 494         channel = iwl_get_single_channel_number(priv, band);
 495         if (channel) {
 496                 scan_ch->channel = cpu_to_le16(channel);
 497                 scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 498                 scan_ch->active_dwell =
 499                         cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
 500                 scan_ch->passive_dwell =
 501                         cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
 502                 /* Set txpower levels to defaults */
 503                 scan_ch->dsp_atten = 110;
 504                 if (band == IEEE80211_BAND_5GHZ)
 505                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 506                 else
 507                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 508                 return 1;
 509         }
 510
 511         IWL_ERR(priv, "no valid channel found\n");
 512         return 0;
 513 }
 514
 515 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 516                                      struct ieee80211_vif *vif,
 517                                      enum ieee80211_band band,
 518                                      u8 is_active, u8 n_probes,
 519                                      struct iwl_scan_channel *scan_ch)
 520 {
 521         struct ieee80211_channel *chan;
 522         const struct ieee80211_supported_band *sband;
 523         u16 passive_dwell = 0;
 524         u16 active_dwell = 0;
 525         int added, i;
 526         u16 channel;
 527
 528         sband = iwl_get_hw_mode(priv, band);
 529         if (!sband)
 530                 return 0;
 531
 532         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 533         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 534
 535         if (passive_dwell <= active_dwell)
 536                 passive_dwell = active_dwell + 1;
 537
 538         for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
 539                 chan = priv->scan_request->channels[i];
 540
 541                 if (chan->band != band)
 542                         continue;
 543
 544                 channel = chan->hw_value;
 545                 scan_ch->channel = cpu_to_le16(channel);
 546
 547                 if (!is_active || (chan->flags & IEEE80211_CHAN_NO_IR))
 548                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 549                 else
 550                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 551
 552                 if (n_probes)
 553                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 554
 555                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 556                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 557
 558                 /* Set txpower levels to defaults */
 559                 scan_ch->dsp_atten = 110;
 560
 561                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 562                  * power level:
 563                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 564                  */
 565                 if (band == IEEE80211_BAND_5GHZ)
 566                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 567                 else
 568                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 569
 570                 IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
 571                                channel, le32_to_cpu(scan_ch->type),
 572                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 573                                 "ACTIVE" : "PASSIVE",
 574                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 575                                active_dwell : passive_dwell);
 576
 577                 scan_ch++;
 578                 added++;
 579         }
 580
 581         IWL_DEBUG_SCAN(priv, "total channels to scan %d\n", added);
 582         return added;
 583 }
 584
 585 /**
 586  * iwl_fill_probe_req - fill in all required fields and IE for probe request
 587  */
 588
 589 static u16 iwl_fill_probe_req(struct ieee80211_mgmt *frame, const u8 *ta,
 590                               const u8 *ies, int ie_len, const u8 *ssid,
 591                               u8 ssid_len, int left)
 592 {
 593         int len = 0;
 594         u8 *pos = NULL;
 595
 596         /* Make sure there is enough space for the probe request,
 597          * two mandatory IEs and the data */
 598         left -= 24;
 599         if (left < 0)
 600                 return 0;
 601
 602         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 603         eth_broadcast_addr(frame->da);
 604         memcpy(frame->sa, ta, ETH_ALEN);
 605         eth_broadcast_addr(frame->bssid);
 606         frame->seq_ctrl = 0;
 607
 608         len += 24;
 609
 610         /* ...next IE... */
 611         pos = &frame->u.probe_req.variable[0];
 612
 613         /* fill in our SSID IE */
 614         left -= ssid_len + 2;
 615         if (left < 0)
 616                 return 0;
 617         *pos++ = WLAN_EID_SSID;
 618         *pos++ = ssid_len;
 619         if (ssid && ssid_len) {
 620                 memcpy(pos, ssid, ssid_len);
 621                 pos += ssid_len;
 622         }
 623
 624         len += ssid_len + 2;
 625
 626         if (WARN_ON(left < ie_len))
 627                 return len;
 628
 629         if (ies && ie_len) {
 630                 memcpy(pos, ies, ie_len);
 631                 len += ie_len;
 632         }
 633
 634         return (u16)len;
 635 }
 636
 637 static int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
 638 {
 639         struct iwl_host_cmd cmd = {
 640                 .id = REPLY_SCAN_CMD,
 641                 .len = { sizeof(struct iwl_scan_cmd), },
 642         };
 643         struct iwl_scan_cmd *scan;
 644         struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
 645         u32 rate_flags = 0;
 646         u16 cmd_len = 0;
 647         u16 rx_chain = 0;
 648         enum ieee80211_band band;
 649         u8 n_probes = 0;
 650         u8 rx_ant = priv->nvm_data->valid_rx_ant;
 651         u8 rate;
 652         bool is_active = false;
 653         int  chan_mod;
 654         u8 active_chains;
 655         u8 scan_tx_antennas = priv->nvm_data->valid_tx_ant;
 656         int ret;
 657         int scan_cmd_size = sizeof(struct iwl_scan_cmd) +
 658                             MAX_SCAN_CHANNEL * sizeof(struct iwl_scan_channel) +
 659                             priv->fw->ucode_capa.max_probe_length;
 660         const u8 *ssid = NULL;
 661         u8 ssid_len = 0;
 662
 663         if (WARN_ON(priv->scan_type == IWL_SCAN_NORMAL &&
 664                     (!priv->scan_request ||
 665                      priv->scan_request->n_channels > MAX_SCAN_CHANNEL)))
 666                 return -EINVAL;
 667
 668         lockdep_assert_held(&priv->mutex);
 669
 670         if (vif)
 671                 ctx = iwl_rxon_ctx_from_vif(vif);
 672
 673         if (!priv->scan_cmd) {
 674                 priv->scan_cmd = kmalloc(scan_cmd_size, GFP_KERNEL);
 675                 if (!priv->scan_cmd) {
 676                         IWL_DEBUG_SCAN(priv,
 677                                        "fail to allocate memory for scan\n");
 678                         return -ENOMEM;
 679                 }
 680         }
 681         scan = priv->scan_cmd;
 682         memset(scan, 0, scan_cmd_size);
 683
 684         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
 685         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
 686
 687         if (iwl_is_any_associated(priv)) {
 688                 u16 interval = 0;
 689                 u32 extra;
 690                 u32 suspend_time = 100;
 691                 u32 scan_suspend_time = 100;
 692
 693                 IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
 694                 switch (priv->scan_type) {
 695                 case IWL_SCAN_RADIO_RESET:
 696                         interval = 0;
 697                         break;
 698                 case IWL_SCAN_NORMAL:
 699                         interval = vif->bss_conf.beacon_int;
 700                         break;
 701                 }
 702
 703                 scan->suspend_time = 0;
 704                 scan->max_out_time = cpu_to_le32(200 * 1024);
 705                 if (!interval)
 706                         interval = suspend_time;
 707
 708                 extra = (suspend_time / interval) << 22;
 709                 scan_suspend_time = (extra |
 710                     ((suspend_time % interval) * 1024));
 711                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
 712                 IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
 713                                scan_suspend_time, interval);
 714         }
 715
 716         switch (priv->scan_type) {
 717         case IWL_SCAN_RADIO_RESET:
 718                 IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
 719                 /*
 720                  * Override quiet time as firmware checks that active
 721                  * dwell is >= quiet; since we use passive scan it'll
 722                  * not actually be used.
 723                  */
 724                 scan->quiet_time = cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
 725                 break;
 726         case IWL_SCAN_NORMAL:
 727                 if (priv->scan_request->n_ssids) {
 728                         int i, p = 0;
 729                         IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
 730                         /*
 731                          * The highest priority SSID is inserted to the
 732                          * probe request template.
 733                          */
 734                         ssid_len = priv->scan_request->ssids[0].ssid_len;
 735                         ssid = priv->scan_request->ssids[0].ssid;
 736
 737                         /*
 738                          * Invert the order of ssids, the firmware will invert
 739                          * it back.
 740                          */
 741                         for (i = priv->scan_request->n_ssids - 1; i >= 1; i--) {
 742                                 scan->direct_scan[p].id = WLAN_EID_SSID;
 743                                 scan->direct_scan[p].len =
 744                                         priv->scan_request->ssids[i].ssid_len;
 745                                 memcpy(scan->direct_scan[p].ssid,
 746                                        priv->scan_request->ssids[i].ssid,
 747                                        priv->scan_request->ssids[i].ssid_len);
 748                                 n_probes++;
 749                                 p++;
 750                         }
 751                         is_active = true;
 752                 } else
 753                         IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
 754                 break;
 755         }
 756
 757         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
 758         scan->tx_cmd.sta_id = ctx->bcast_sta_id;
 759         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
 760
 761         switch (priv->scan_band) {
 762         case IEEE80211_BAND_2GHZ:
 763                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
 764                 chan_mod = le32_to_cpu(
 765                         priv->contexts[IWL_RXON_CTX_BSS].active.flags &
 766                                                 RXON_FLG_CHANNEL_MODE_MSK)
 767                                        >> RXON_FLG_CHANNEL_MODE_POS;
 768                 if ((priv->scan_request && priv->scan_request->no_cck) ||
 769                     chan_mod == CHANNEL_MODE_PURE_40) {
 770                         rate = IWL_RATE_6M_PLCP;
 771                 } else {
 772                         rate = IWL_RATE_1M_PLCP;
 773                         rate_flags = RATE_MCS_CCK_MSK;
 774                 }
 775                 /*
 776                  * Internal scans are passive, so we can indiscriminately set
 777                  * the BT ignore flag on 2.4 GHz since it applies to TX only.
 778                  */
 779                 if (priv->lib->bt_params &&
 780                     priv->lib->bt_params->advanced_bt_coexist)
 781                         scan->tx_cmd.tx_flags |= TX_CMD_FLG_IGNORE_BT;
 782                 break;
 783         case IEEE80211_BAND_5GHZ:
 784                 rate = IWL_RATE_6M_PLCP;
 785                 break;
 786         default:
 787                 IWL_WARN(priv, "Invalid scan band\n");
 788                 return -EIO;
 789         }
 790
 791         /*
 792          * If active scanning is requested but a certain channel is
 793          * marked passive, we can do active scanning if we detect
 794          * transmissions.
 795          *
 796          * There is an issue with some firmware versions that triggers
 797          * a sysassert on a "good CRC threshold" of zero (== disabled),
 798          * on a radar channel even though this means that we should NOT
 799          * send probes.
 800          *
 801          * The "good CRC threshold" is the number of frames that we
 802          * need to receive during our dwell time on a channel before
 803          * sending out probes -- setting this to a huge value will
 804          * mean we never reach it, but at the same time work around
 805          * the aforementioned issue. Thus use IWL_GOOD_CRC_TH_NEVER
 806          * here instead of IWL_GOOD_CRC_TH_DISABLED.
 807          *
 808          * This was fixed in later versions along with some other
 809          * scan changes, and the threshold behaves as a flag in those
 810          * versions.
 811          */
 812         if (priv->new_scan_threshold_behaviour)
 813                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 814                                                 IWL_GOOD_CRC_TH_DISABLED;
 815         else
 816                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 817                                                 IWL_GOOD_CRC_TH_NEVER;
 818
 819         band = priv->scan_band;
 820
 821         if (band == IEEE80211_BAND_2GHZ &&
 822             priv->lib->bt_params &&
 823             priv->lib->bt_params->advanced_bt_coexist) {
 824                 /* transmit 2.4 GHz probes only on first antenna */
 825                 scan_tx_antennas = first_antenna(scan_tx_antennas);
 826         }
 827
 828         priv->scan_tx_ant[band] = iwl_toggle_tx_ant(priv,
 829                                                     priv->scan_tx_ant[band],
 830                                                     scan_tx_antennas);
 831         rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
 832         scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
 833
 834         /*
 835          * In power save mode while associated use one chain,
 836          * otherwise use all chains
 837          */
 838         if (test_bit(STATUS_POWER_PMI, &priv->status) &&
 839             !(priv->hw->conf.flags & IEEE80211_CONF_IDLE)) {
 840                 /* rx_ant has been set to all valid chains previously */
 841                 active_chains = rx_ant &
 842                                 ((u8)(priv->chain_noise_data.active_chains));
 843                 if (!active_chains)
 844                         active_chains = rx_ant;
 845
 846                 IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
 847                                 priv->chain_noise_data.active_chains);
 848
 849                 rx_ant = first_antenna(active_chains);
 850         }
 851         if (priv->lib->bt_params &&
 852             priv->lib->bt_params->advanced_bt_coexist &&
 853             priv->bt_full_concurrent) {
 854                 /* operated as 1x1 in full concurrency mode */
 855                 rx_ant = first_antenna(rx_ant);
 856         }
 857
 858         /* MIMO is not used here, but value is required */
 859         rx_chain |=
 860                 priv->nvm_data->valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
 861         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
 862         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
 863         rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
 864         scan->rx_chain = cpu_to_le16(rx_chain);
 865         switch (priv->scan_type) {
 866         case IWL_SCAN_NORMAL:
 867                 cmd_len = iwl_fill_probe_req(
 868                                         (struct ieee80211_mgmt *)scan->data,
 869                                         vif->addr,
 870                                         priv->scan_request->ie,
 871                                         priv->scan_request->ie_len,
 872                                         ssid, ssid_len,
 873                                         scan_cmd_size - sizeof(*scan));
 874                 break;
 875         case IWL_SCAN_RADIO_RESET:
 876                 /* use bcast addr, will not be transmitted but must be valid */
 877                 cmd_len = iwl_fill_probe_req(
 878                                         (struct ieee80211_mgmt *)scan->data,
 879                                         iwl_bcast_addr, NULL, 0,
 880                                         NULL, 0,
 881                                         scan_cmd_size - sizeof(*scan));
 882                 break;
 883         default:
 884                 BUG();
 885         }
 886         scan->tx_cmd.len = cpu_to_le16(cmd_len);
 887
 888         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 889                                RXON_FILTER_BCON_AWARE_MSK);
 890
 891         switch (priv->scan_type) {
 892         case IWL_SCAN_RADIO_RESET:
 893                 scan->channel_count =
 894                         iwl_get_channel_for_reset_scan(priv, vif, band,
 895                                 (void *)&scan->data[cmd_len]);
 896                 break;
 897         case IWL_SCAN_NORMAL:
 898                 scan->channel_count =
 899                         iwl_get_channels_for_scan(priv, vif, band,
 900                                 is_active, n_probes,
 901                                 (void *)&scan->data[cmd_len]);
 902                 break;
 903         }
 904
 905         if (scan->channel_count == 0) {
 906                 IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
 907                 return -EIO;
 908         }
 909
 910         cmd.len[0] += le16_to_cpu(scan->tx_cmd.len) +
 911             scan->channel_count * sizeof(struct iwl_scan_channel);
 912         cmd.data[0] = scan;
 913         cmd.dataflags[0] = IWL_HCMD_DFL_NOCOPY;
 914         scan->len = cpu_to_le16(cmd.len[0]);
 915
 916         /* set scan bit here for PAN params */
 917         set_bit(STATUS_SCAN_HW, &priv->status);
 918
 919         ret = iwlagn_set_pan_params(priv);
 920         if (ret) {
 921                 clear_bit(STATUS_SCAN_HW, &priv->status);
 922                 return ret;
 923         }
 924
 925         ret = iwl_dvm_send_cmd(priv, &cmd);
 926         if (ret) {
 927                 clear_bit(STATUS_SCAN_HW, &priv->status);
 928                 iwlagn_set_pan_params(priv);
 929         }
 930
 931         return ret;
 932 }
 933
 934 void iwl_init_scan_params(struct iwl_priv *priv)
 935 {
 936         u8 ant_idx = fls(priv->nvm_data->valid_tx_ant) - 1;
 937         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
 938                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
 939         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
 940                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
 941 }
 942
 943 int __must_check iwl_scan_initiate(struct iwl_priv *priv,
 944                                    struct ieee80211_vif *vif,
 945                                    enum iwl_scan_type scan_type,
 946                                    enum ieee80211_band band)
 947 {
 948         int ret;
 949
 950         lockdep_assert_held(&priv->mutex);
 951
 952         cancel_delayed_work(&priv->scan_check);
 953
 954         if (!iwl_is_ready_rf(priv)) {
 955                 IWL_WARN(priv, "Request scan called when driver not ready.\n");
 956                 return -EIO;
 957         }
 958
 959         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
 960                 IWL_DEBUG_SCAN(priv,
 961                         "Multiple concurrent scan requests in parallel.\n");
 962                 return -EBUSY;
 963         }
 964
 965         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 966                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending.\n");
 967                 return -EBUSY;
 968         }
 969
 970         IWL_DEBUG_SCAN(priv, "Starting %sscan...\n",
 971                         scan_type == IWL_SCAN_NORMAL ? "" :
 972                         "internal short ");
 973
 974         set_bit(STATUS_SCANNING, &priv->status);
 975         priv->scan_type = scan_type;
 976         priv->scan_start = jiffies;
 977         priv->scan_band = band;
 978
 979         ret = iwlagn_request_scan(priv, vif);
 980         if (ret) {
 981                 clear_bit(STATUS_SCANNING, &priv->status);
 982                 priv->scan_type = IWL_SCAN_NORMAL;
 983                 return ret;
 984         }
 985
 986         queue_delayed_work(priv->workqueue, &priv->scan_check,
 987                            IWL_SCAN_CHECK_WATCHDOG);
 988
 989         return 0;
 990 }
 991
 992
 993 /*
 994  * internal short scan, this function should only been called while associated.
 995  * It will reset and tune the radio to prevent possible RF related problem
 996  */
 997 void iwl_internal_short_hw_scan(struct iwl_priv *priv)
 998 {
 999         queue_work(priv->workqueue, &priv->start_internal_scan);
1000 }
1001
1002 static void iwl_bg_start_internal_scan(struct work_struct *work)
1003 {
1004         struct iwl_priv *priv =
1005                 container_of(work, struct iwl_priv, start_internal_scan);
1006
1007         IWL_DEBUG_SCAN(priv, "Start internal scan\n");
1008
1009         mutex_lock(&priv->mutex);
1010
1011         if (priv->scan_type == IWL_SCAN_RADIO_RESET) {
1012                 IWL_DEBUG_SCAN(priv, "Internal scan already in progress\n");
1013                 goto unlock;
1014         }
1015
1016         if (test_bit(STATUS_SCANNING, &priv->status)) {
1017                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
1018                 goto unlock;
1019         }
1020
1021         if (iwl_scan_initiate(priv, NULL, IWL_SCAN_RADIO_RESET, priv->band))
1022                 IWL_DEBUG_SCAN(priv, "failed to start internal short scan\n");
1023  unlock:
1024         mutex_unlock(&priv->mutex);
1025 }
1026
1027 static void iwl_bg_scan_check(struct work_struct *data)
1028 {
1029         struct iwl_priv *priv =
1030             container_of(data, struct iwl_priv, scan_check.work);
1031
1032         IWL_DEBUG_SCAN(priv, "Scan check work\n");
1033
1034         /* Since we are here firmware does not finish scan and
1035          * most likely is in bad shape, so we don't bother to
1036          * send abort command, just force scan complete to mac80211 */
1037         mutex_lock(&priv->mutex);
1038         iwl_force_scan_end(priv);
1039         mutex_unlock(&priv->mutex);
1040 }
1041
1042 static void iwl_bg_abort_scan(struct work_struct *work)
1043 {
1044         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
1045
1046         IWL_DEBUG_SCAN(priv, "Abort scan work\n");
1047
1048         /* We keep scan_check work queued in case when firmware will not
1049          * report back scan completed notification */
1050         mutex_lock(&priv->mutex);
1051         iwl_scan_cancel_timeout(priv, 200);
1052         mutex_unlock(&priv->mutex);
1053 }
1054
1055 static void iwl_bg_scan_completed(struct work_struct *work)
1056 {
1057         struct iwl_priv *priv =
1058                 container_of(work, struct iwl_priv, scan_completed);
1059
1060         mutex_lock(&priv->mutex);
1061         iwl_process_scan_complete(priv);
1062         mutex_unlock(&priv->mutex);
1063 }
1064
1065 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
1066 {
1067         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
1068         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
1069         INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
1070         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
1071 }
1072
1073 void iwl_cancel_scan_deferred_work(struct iwl_priv *priv)
1074 {
1075         cancel_work_sync(&priv->start_internal_scan);
1076         cancel_work_sync(&priv->abort_scan);
1077         cancel_work_sync(&priv->scan_completed);
1078
1079         if (cancel_delayed_work_sync(&priv->scan_check)) {
1080                 mutex_lock(&priv->mutex);
1081                 iwl_force_scan_end(priv);
1082                 mutex_unlock(&priv->mutex);
1083         }
1084 }