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

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
iwl_send_scan_abort
iwl_complete_scan
iwl_process_scan_complete
iwl_force_scan_end
iwl_do_scan_abort
iwl_scan_cancel
iwl_scan_cancel_timeout
iwl_rx_reply_scan
iwl_rx_scan_start_notif
iwl_rx_scan_results_notif
iwl_rx_scan_complete_notif
iwl_setup_rx_scan_handlers
iwl_get_active_dwell_time
iwl_limit_dwell
iwl_get_passive_dwell_time
iwl_get_single_channel_number
iwl_get_channel_for_reset_scan
iwl_get_channels_for_scan
iwl_fill_probe_req
iwlagn_request_scan
iwl_init_scan_params
iwl_scan_initiate
iwl_internal_short_hw_scan
iwl_bg_start_internal_scan
iwl_bg_scan_check
iwl_bg_abort_scan
iwl_bg_scan_completed
iwl_setup_scan_deferred_work
iwl_cancel_scan_deferred_work
   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /******************************************************************************
   3  *
   4  * Copyright(c) 2008 - 2014 Intel Corporation. All rights reserved.
   5  * Copyright(c) 2018        Intel Corporation
   6  *
   7  * Contact Information:
   8  *  Intel Linux Wireless <linuxwifi@intel.com>
   9  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  10  *****************************************************************************/
  11 #include <linux/slab.h>
  12 #include <linux/types.h>
  13 #include <linux/etherdevice.h>
  14 #include <net/mac80211.h>
  15 
  16 #include "dev.h"
  17 #include "agn.h"
  18 
  19 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
  20  * sending probe req.  This should be set long enough to hear probe responses
  21  * from more than one AP.  */
  22 #define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
  23 #define IWL_ACTIVE_DWELL_TIME_52    (20)
  24 
  25 #define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
  26 #define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
  27 
  28 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
  29  * Must be set longer than active dwell time.
  30  * For the most reliable scan, set > AP beacon interval (typically 100msec). */
  31 #define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
  32 #define IWL_PASSIVE_DWELL_TIME_52   (10)
  33 #define IWL_PASSIVE_DWELL_BASE      (100)
  34 #define IWL_CHANNEL_TUNE_TIME       5
  35 #define MAX_SCAN_CHANNEL            50
  36 
  37 /* For reset radio, need minimal dwell time only */
  38 #define IWL_RADIO_RESET_DWELL_TIME      5
  39 
  40 static int iwl_send_scan_abort(struct iwl_priv *priv)
  41 {
  42         int ret;
  43         struct iwl_host_cmd cmd = {
  44                 .id = REPLY_SCAN_ABORT_CMD,
  45                 .flags = CMD_WANT_SKB,
  46         };
  47         __le32 *status;
  48 
  49         /* Exit instantly with error when device is not ready
  50          * to receive scan abort command or it does not perform
  51          * hardware scan currently */
  52         if (!test_bit(STATUS_READY, &priv->status) ||
  53             !test_bit(STATUS_SCAN_HW, &priv->status) ||
  54             test_bit(STATUS_FW_ERROR, &priv->status))
  55                 return -EIO;
  56 
  57         ret = iwl_dvm_send_cmd(priv, &cmd);
  58         if (ret)
  59                 return ret;
  60 
  61         status = (void *)cmd.resp_pkt->data;
  62         if (*status != CAN_ABORT_STATUS) {
  63                 /* The scan abort will return 1 for success or
  64                  * 2 for "failure".  A failure condition can be
  65                  * due to simply not being in an active scan which
  66                  * can occur if we send the scan abort before we
  67                  * the microcode has notified us that a scan is
  68                  * completed. */
  69                 IWL_DEBUG_SCAN(priv, "SCAN_ABORT ret %d.\n",
  70                                le32_to_cpu(*status));
  71                 ret = -EIO;
  72         }
  73 
  74         iwl_free_resp(&cmd);
  75         return ret;
  76 }
  77 
  78 static void iwl_complete_scan(struct iwl_priv *priv, bool aborted)
  79 {
  80         struct cfg80211_scan_info info = {
  81                 .aborted = aborted,
  82         };
  83 
  84         /* check if scan was requested from mac80211 */
  85         if (priv->scan_request) {
  86                 IWL_DEBUG_SCAN(priv, "Complete scan in mac80211\n");
  87                 ieee80211_scan_completed(priv->hw, &info);
  88         }
  89 
  90         priv->scan_type = IWL_SCAN_NORMAL;
  91         priv->scan_vif = NULL;
  92         priv->scan_request = NULL;
  93 }
  94 
  95 static void iwl_process_scan_complete(struct iwl_priv *priv)
  96 {
  97         bool aborted;
  98 
  99         lockdep_assert_held(&priv->mutex);
 100 
 101         if (!test_and_clear_bit(STATUS_SCAN_COMPLETE, &priv->status))
 102                 return;
 103 
 104         IWL_DEBUG_SCAN(priv, "Completed scan.\n");
 105 
 106         cancel_delayed_work(&priv->scan_check);
 107 
 108         aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 109         if (aborted)
 110                 IWL_DEBUG_SCAN(priv, "Aborted scan completed.\n");
 111 
 112         if (!test_and_clear_bit(STATUS_SCANNING, &priv->status)) {
 113                 IWL_DEBUG_SCAN(priv, "Scan already completed.\n");
 114                 goto out_settings;
 115         }
 116 
 117         if (priv->scan_type != IWL_SCAN_NORMAL && !aborted) {
 118                 int err;
 119 
 120                 /* Check if mac80211 requested scan during our internal scan */
 121                 if (priv->scan_request == NULL)
 122                         goto out_complete;
 123 
 124                 /* If so request a new scan */
 125                 err = iwl_scan_initiate(priv, priv->scan_vif, IWL_SCAN_NORMAL,
 126                                         priv->scan_request->channels[0]->band);
 127                 if (err) {
 128                         IWL_DEBUG_SCAN(priv,
 129                                 "failed to initiate pending scan: %d\n", err);
 130                         aborted = true;
 131                         goto out_complete;
 132                 }
 133 
 134                 return;
 135         }
 136 
 137 out_complete:
 138         iwl_complete_scan(priv, aborted);
 139 
 140 out_settings:
 141         /* Can we still talk to firmware ? */
 142         if (!iwl_is_ready_rf(priv))
 143                 return;
 144 
 145         iwlagn_post_scan(priv);
 146 }
 147 
 148 void iwl_force_scan_end(struct iwl_priv *priv)
 149 {
 150         lockdep_assert_held(&priv->mutex);
 151 
 152         if (!test_bit(STATUS_SCANNING, &priv->status)) {
 153                 IWL_DEBUG_SCAN(priv, "Forcing scan end while not scanning\n");
 154                 return;
 155         }
 156 
 157         IWL_DEBUG_SCAN(priv, "Forcing scan end\n");
 158         clear_bit(STATUS_SCANNING, &priv->status);
 159         clear_bit(STATUS_SCAN_HW, &priv->status);
 160         clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 161         clear_bit(STATUS_SCAN_COMPLETE, &priv->status);
 162         iwl_complete_scan(priv, true);
 163 }
 164 
 165 static void iwl_do_scan_abort(struct iwl_priv *priv)
 166 {
 167         int ret;
 168 
 169         lockdep_assert_held(&priv->mutex);
 170 
 171         if (!test_bit(STATUS_SCANNING, &priv->status)) {
 172                 IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
 173                 return;
 174         }
 175 
 176         if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 177                 IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
 178                 return;
 179         }
 180 
 181         ret = iwl_send_scan_abort(priv);
 182         if (ret) {
 183                 IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
 184                 iwl_force_scan_end(priv);
 185         } else
 186                 IWL_DEBUG_SCAN(priv, "Successfully send scan abort\n");
 187 }
 188 
 189 /**
 190  * iwl_scan_cancel - Cancel any currently executing HW scan
 191  */
 192 int iwl_scan_cancel(struct iwl_priv *priv)
 193 {
 194         IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
 195         queue_work(priv->workqueue, &priv->abort_scan);
 196         return 0;
 197 }
 198 
 199 /**
 200  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
 201  * @ms: amount of time to wait (in milliseconds) for scan to abort
 202  *
 203  */
 204 void iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
 205 {
 206         unsigned long timeout = jiffies + msecs_to_jiffies(ms);
 207 
 208         lockdep_assert_held(&priv->mutex);
 209 
 210         IWL_DEBUG_SCAN(priv, "Scan cancel timeout\n");
 211 
 212         iwl_do_scan_abort(priv);
 213 
 214         while (time_before_eq(jiffies, timeout)) {
 215                 if (!test_bit(STATUS_SCAN_HW, &priv->status))
 216                         goto finished;
 217                 msleep(20);
 218         }
 219 
 220         return;
 221 
 222  finished:
 223         /*
 224          * Now STATUS_SCAN_HW is clear. This means that the
 225          * device finished, but the background work is going
 226          * to execute at best as soon as we release the mutex.
 227          * Since we need to be able to issue a new scan right
 228          * after this function returns, run the complete here.
 229          * The STATUS_SCAN_COMPLETE bit will then be cleared
 230          * and prevent the background work from "completing"
 231          * a possible new scan.
 232          */
 233         iwl_process_scan_complete(priv);
 234 }
 235 
 236 /* Service response to REPLY_SCAN_CMD (0x80) */
 237 static void iwl_rx_reply_scan(struct iwl_priv *priv,
 238                               struct iwl_rx_cmd_buffer *rxb)
 239 {
 240 #ifdef CONFIG_IWLWIFI_DEBUG
 241         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 242         struct iwl_scanreq_notification *notif = (void *)pkt->data;
 243 
 244         IWL_DEBUG_SCAN(priv, "Scan request status = 0x%x\n", notif->status);
 245 #endif
 246 }
 247 
 248 /* Service SCAN_START_NOTIFICATION (0x82) */
 249 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
 250                                     struct iwl_rx_cmd_buffer *rxb)
 251 {
 252         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 253         struct iwl_scanstart_notification *notif = (void *)pkt->data;
 254 
 255         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 256         IWL_DEBUG_SCAN(priv, "Scan start: "
 257                        "%d [802.11%s] "
 258                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 259                        notif->channel,
 260                        notif->band ? "bg" : "a",
 261                        le32_to_cpu(notif->tsf_high),
 262                        le32_to_cpu(notif->tsf_low),
 263                        notif->status, notif->beacon_timer);
 264 }
 265 
 266 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 267 static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
 268                                       struct iwl_rx_cmd_buffer *rxb)
 269 {
 270 #ifdef CONFIG_IWLWIFI_DEBUG
 271         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 272         struct iwl_scanresults_notification *notif = (void *)pkt->data;
 273 
 274         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
 275                        "%d [802.11%s] "
 276                        "probe status: %u:%u "
 277                        "(TSF: 0x%08X:%08X) - %d "
 278                        "elapsed=%lu usec\n",
 279                        notif->channel,
 280                        notif->band ? "bg" : "a",
 281                        notif->probe_status, notif->num_probe_not_sent,
 282                        le32_to_cpu(notif->tsf_high),
 283                        le32_to_cpu(notif->tsf_low),
 284                        le32_to_cpu(notif->statistics[0]),
 285                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
 286 #endif
 287 }
 288 
 289 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 290 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 291                                        struct iwl_rx_cmd_buffer *rxb)
 292 {
 293         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 294         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->data;
 295 
 296         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 297                        scan_notif->scanned_channels,
 298                        scan_notif->tsf_low,
 299                        scan_notif->tsf_high, scan_notif->status);
 300 
 301         IWL_DEBUG_SCAN(priv, "Scan on %sGHz took %dms\n",
 302                        (priv->scan_band == NL80211_BAND_2GHZ) ? "2.4" : "5.2",
 303                        jiffies_to_msecs(jiffies - priv->scan_start));
 304 
 305         /*
 306          * When aborting, we run the scan completed background work inline
 307          * and the background work must then do nothing. The SCAN_COMPLETE
 308          * bit helps implement that logic and thus needs to be set before
 309          * queueing the work. Also, since the scan abort waits for SCAN_HW
 310          * to clear, we need to set SCAN_COMPLETE before clearing SCAN_HW
 311          * to avoid a race there.
 312          */
 313         set_bit(STATUS_SCAN_COMPLETE, &priv->status);
 314         clear_bit(STATUS_SCAN_HW, &priv->status);
 315         queue_work(priv->workqueue, &priv->scan_completed);
 316 
 317         if (priv->iw_mode != NL80211_IFTYPE_ADHOC &&
 318             iwl_advanced_bt_coexist(priv) &&
 319             priv->bt_status != scan_notif->bt_status) {
 320                 if (scan_notif->bt_status) {
 321                         /* BT on */
 322                         if (!priv->bt_ch_announce)
 323                                 priv->bt_traffic_load =
 324                                         IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
 325                         /*
 326                          * otherwise, no traffic load information provided
 327                          * no changes made
 328                          */
 329                 } else {
 330                         /* BT off */
 331                         priv->bt_traffic_load =
 332                                 IWL_BT_COEX_TRAFFIC_LOAD_NONE;
 333                 }
 334                 priv->bt_status = scan_notif->bt_status;
 335                 queue_work(priv->workqueue,
 336                            &priv->bt_traffic_change_work);
 337         }
 338 }
 339 
 340 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 341 {
 342         /* scan handlers */
 343         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 344         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 345         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 346                                         iwl_rx_scan_results_notif;
 347         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 348                                         iwl_rx_scan_complete_notif;
 349 }
 350 
 351 static u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 352                                      enum nl80211_band band, u8 n_probes)
 353 {
 354         if (band == NL80211_BAND_5GHZ)
 355                 return IWL_ACTIVE_DWELL_TIME_52 +
 356                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 357         else
 358                 return IWL_ACTIVE_DWELL_TIME_24 +
 359                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 360 }
 361 
 362 static u16 iwl_limit_dwell(struct iwl_priv *priv, u16 dwell_time)
 363 {
 364         struct iwl_rxon_context *ctx;
 365         int limits[NUM_IWL_RXON_CTX] = {};
 366         int n_active = 0;
 367         u16 limit;
 368 
 369         BUILD_BUG_ON(NUM_IWL_RXON_CTX != 2);
 370 
 371         /*
 372          * If we're associated, we clamp the dwell time 98%
 373          * of the beacon interval (minus 2 * channel tune time)
 374          * If both contexts are active, we have to restrict to
 375          * 1/2 of the minimum of them, because they might be in
 376          * lock-step with the time inbetween only half of what
 377          * time we'd have in each of them.
 378          */
 379         for_each_context(priv, ctx) {
 380                 switch (ctx->staging.dev_type) {
 381                 case RXON_DEV_TYPE_P2P:
 382                         /* no timing constraints */
 383                         continue;
 384                 case RXON_DEV_TYPE_ESS:
 385                 default:
 386                         /* timing constraints if associated */
 387                         if (!iwl_is_associated_ctx(ctx))
 388                                 continue;
 389                         break;
 390                 case RXON_DEV_TYPE_CP:
 391                 case RXON_DEV_TYPE_2STA:
 392                         /*
 393                          * These seem to always have timers for TBTT
 394                          * active in uCode even when not associated yet.
 395                          */
 396                         break;
 397                 }
 398 
 399                 limits[n_active++] = ctx->beacon_int ?: IWL_PASSIVE_DWELL_BASE;
 400         }
 401 
 402         switch (n_active) {
 403         case 0:
 404                 return dwell_time;
 405         case 2:
 406                 limit = (limits[1] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 407                 limit /= 2;
 408                 dwell_time = min(limit, dwell_time);
 409                 /* fall through */
 410         case 1:
 411                 limit = (limits[0] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 412                 limit /= n_active;
 413                 return min(limit, dwell_time);
 414         default:
 415                 WARN_ON_ONCE(1);
 416                 return dwell_time;
 417         }
 418 }
 419 
 420 static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 421                                       enum nl80211_band band)
 422 {
 423         u16 passive = (band == NL80211_BAND_2GHZ) ?
 424             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 425             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 426 
 427         return iwl_limit_dwell(priv, passive);
 428 }
 429 
 430 /* Return valid, unused, channel for a passive scan to reset the RF */
 431 static u8 iwl_get_single_channel_number(struct iwl_priv *priv,
 432                                         enum nl80211_band band)
 433 {
 434         struct ieee80211_supported_band *sband = priv->hw->wiphy->bands[band];
 435         struct iwl_rxon_context *ctx;
 436         int i;
 437 
 438         for (i = 0; i < sband->n_channels; i++) {
 439                 bool busy = false;
 440 
 441                 for_each_context(priv, ctx) {
 442                         busy = sband->channels[i].hw_value ==
 443                                 le16_to_cpu(ctx->staging.channel);
 444                         if (busy)
 445                                 break;
 446                 }
 447 
 448                 if (busy)
 449                         continue;
 450 
 451                 if (!(sband->channels[i].flags & IEEE80211_CHAN_DISABLED))
 452                         return sband->channels[i].hw_value;
 453         }
 454 
 455         return 0;
 456 }
 457 
 458 static int iwl_get_channel_for_reset_scan(struct iwl_priv *priv,
 459                                           struct ieee80211_vif *vif,
 460                                           enum nl80211_band band,
 461                                           struct iwl_scan_channel *scan_ch)
 462 {
 463         const struct ieee80211_supported_band *sband;
 464         u16 channel;
 465 
 466         sband = iwl_get_hw_mode(priv, band);
 467         if (!sband) {
 468                 IWL_ERR(priv, "invalid band\n");
 469                 return 0;
 470         }
 471 
 472         channel = iwl_get_single_channel_number(priv, band);
 473         if (channel) {
 474                 scan_ch->channel = cpu_to_le16(channel);
 475                 scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 476                 scan_ch->active_dwell =
 477                         cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
 478                 scan_ch->passive_dwell =
 479                         cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
 480                 /* Set txpower levels to defaults */
 481                 scan_ch->dsp_atten = 110;
 482                 if (band == NL80211_BAND_5GHZ)
 483                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 484                 else
 485                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 486                 return 1;
 487         }
 488 
 489         IWL_ERR(priv, "no valid channel found\n");
 490         return 0;
 491 }
 492 
 493 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 494                                      struct ieee80211_vif *vif,
 495                                      enum nl80211_band band,
 496                                      u8 is_active, u8 n_probes,
 497                                      struct iwl_scan_channel *scan_ch)
 498 {
 499         struct ieee80211_channel *chan;
 500         const struct ieee80211_supported_band *sband;
 501         u16 passive_dwell = 0;
 502         u16 active_dwell = 0;
 503         int added, i;
 504         u16 channel;
 505 
 506         sband = iwl_get_hw_mode(priv, band);
 507         if (!sband)
 508                 return 0;
 509 
 510         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 511         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 512 
 513         if (passive_dwell <= active_dwell)
 514                 passive_dwell = active_dwell + 1;
 515 
 516         for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
 517                 chan = priv->scan_request->channels[i];
 518 
 519                 if (chan->band != band)
 520                         continue;
 521 
 522                 channel = chan->hw_value;
 523                 scan_ch->channel = cpu_to_le16(channel);
 524 
 525                 if (!is_active || (chan->flags & IEEE80211_CHAN_NO_IR))
 526                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 527                 else
 528                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 529 
 530                 if (n_probes)
 531                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 532 
 533                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 534                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 535 
 536                 /* Set txpower levels to defaults */
 537                 scan_ch->dsp_atten = 110;
 538 
 539                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 540                  * power level:
 541                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 542                  */
 543                 if (band == NL80211_BAND_5GHZ)
 544                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 545                 else
 546                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 547 
 548                 IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
 549                                channel, le32_to_cpu(scan_ch->type),
 550                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 551                                 "ACTIVE" : "PASSIVE",
 552                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 553                                active_dwell : passive_dwell);
 554 
 555                 scan_ch++;
 556                 added++;
 557         }
 558 
 559         IWL_DEBUG_SCAN(priv, "total channels to scan %d\n", added);
 560         return added;
 561 }
 562 
 563 /**
 564  * iwl_fill_probe_req - fill in all required fields and IE for probe request
 565  */
 566 
 567 static u16 iwl_fill_probe_req(struct ieee80211_mgmt *frame, const u8 *ta,
 568                               const u8 *ies, int ie_len, const u8 *ssid,
 569                               u8 ssid_len, int left)
 570 {
 571         int len = 0;
 572         u8 *pos = NULL;
 573 
 574         /* Make sure there is enough space for the probe request,
 575          * two mandatory IEs and the data */
 576         left -= 24;
 577         if (left < 0)
 578                 return 0;
 579 
 580         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 581         eth_broadcast_addr(frame->da);
 582         memcpy(frame->sa, ta, ETH_ALEN);
 583         eth_broadcast_addr(frame->bssid);
 584         frame->seq_ctrl = 0;
 585 
 586         len += 24;
 587 
 588         /* ...next IE... */
 589         pos = &frame->u.probe_req.variable[0];
 590 
 591         /* fill in our SSID IE */
 592         left -= ssid_len + 2;
 593         if (left < 0)
 594                 return 0;
 595         *pos++ = WLAN_EID_SSID;
 596         *pos++ = ssid_len;
 597         if (ssid && ssid_len) {
 598                 memcpy(pos, ssid, ssid_len);
 599                 pos += ssid_len;
 600         }
 601 
 602         len += ssid_len + 2;
 603 
 604         if (WARN_ON(left < ie_len))
 605                 return len;
 606 
 607         if (ies && ie_len) {
 608                 memcpy(pos, ies, ie_len);
 609                 len += ie_len;
 610         }
 611 
 612         return (u16)len;
 613 }
 614 
 615 static int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
 616 {
 617         struct iwl_host_cmd cmd = {
 618                 .id = REPLY_SCAN_CMD,
 619                 .len = { sizeof(struct iwl_scan_cmd), },
 620         };
 621         struct iwl_scan_cmd *scan;
 622         struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
 623         u32 rate_flags = 0;
 624         u16 cmd_len = 0;
 625         u16 rx_chain = 0;
 626         enum nl80211_band band;
 627         u8 n_probes = 0;
 628         u8 rx_ant = priv->nvm_data->valid_rx_ant;
 629         u8 rate;
 630         bool is_active = false;
 631         int  chan_mod;
 632         u8 active_chains;
 633         u8 scan_tx_antennas = priv->nvm_data->valid_tx_ant;
 634         int ret;
 635         int scan_cmd_size = sizeof(struct iwl_scan_cmd) +
 636                             MAX_SCAN_CHANNEL * sizeof(struct iwl_scan_channel) +
 637                             priv->fw->ucode_capa.max_probe_length;
 638         const u8 *ssid = NULL;
 639         u8 ssid_len = 0;
 640 
 641         if (WARN_ON(priv->scan_type == IWL_SCAN_NORMAL &&
 642                     (!priv->scan_request ||
 643                      priv->scan_request->n_channels > MAX_SCAN_CHANNEL)))
 644                 return -EINVAL;
 645 
 646         lockdep_assert_held(&priv->mutex);
 647 
 648         if (vif)
 649                 ctx = iwl_rxon_ctx_from_vif(vif);
 650 
 651         if (!priv->scan_cmd) {
 652                 priv->scan_cmd = kmalloc(scan_cmd_size, GFP_KERNEL);
 653                 if (!priv->scan_cmd) {
 654                         IWL_DEBUG_SCAN(priv,
 655                                        "fail to allocate memory for scan\n");
 656                         return -ENOMEM;
 657                 }
 658         }
 659         scan = priv->scan_cmd;
 660         memset(scan, 0, scan_cmd_size);
 661 
 662         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
 663         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
 664 
 665         if (iwl_is_any_associated(priv)) {
 666                 u16 interval = 0;
 667                 u32 extra;
 668                 u32 suspend_time = 100;
 669                 u32 scan_suspend_time = 100;
 670 
 671                 IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
 672                 switch (priv->scan_type) {
 673                 case IWL_SCAN_RADIO_RESET:
 674                         interval = 0;
 675                         break;
 676                 case IWL_SCAN_NORMAL:
 677                         interval = vif->bss_conf.beacon_int;
 678                         break;
 679                 }
 680 
 681                 scan->suspend_time = 0;
 682                 scan->max_out_time = cpu_to_le32(200 * 1024);
 683                 if (!interval)
 684                         interval = suspend_time;
 685 
 686                 extra = (suspend_time / interval) << 22;
 687                 scan_suspend_time = (extra |
 688                     ((suspend_time % interval) * 1024));
 689                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
 690                 IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
 691                                scan_suspend_time, interval);
 692         }
 693 
 694         switch (priv->scan_type) {
 695         case IWL_SCAN_RADIO_RESET:
 696                 IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
 697                 /*
 698                  * Override quiet time as firmware checks that active
 699                  * dwell is >= quiet; since we use passive scan it'll
 700                  * not actually be used.
 701                  */
 702                 scan->quiet_time = cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
 703                 break;
 704         case IWL_SCAN_NORMAL:
 705                 if (priv->scan_request->n_ssids) {
 706                         int i, p = 0;
 707                         IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
 708                         /*
 709                          * The highest priority SSID is inserted to the
 710                          * probe request template.
 711                          */
 712                         ssid_len = priv->scan_request->ssids[0].ssid_len;
 713                         ssid = priv->scan_request->ssids[0].ssid;
 714 
 715                         /*
 716                          * Invert the order of ssids, the firmware will invert
 717                          * it back.
 718                          */
 719                         for (i = priv->scan_request->n_ssids - 1; i >= 1; i--) {
 720                                 scan->direct_scan[p].id = WLAN_EID_SSID;
 721                                 scan->direct_scan[p].len =
 722                                         priv->scan_request->ssids[i].ssid_len;
 723                                 memcpy(scan->direct_scan[p].ssid,
 724                                        priv->scan_request->ssids[i].ssid,
 725                                        priv->scan_request->ssids[i].ssid_len);
 726                                 n_probes++;
 727                                 p++;
 728                         }
 729                         is_active = true;
 730                 } else
 731                         IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
 732                 break;
 733         }
 734 
 735         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
 736         scan->tx_cmd.sta_id = ctx->bcast_sta_id;
 737         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
 738 
 739         switch (priv->scan_band) {
 740         case NL80211_BAND_2GHZ:
 741                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
 742                 chan_mod = le32_to_cpu(
 743                         priv->contexts[IWL_RXON_CTX_BSS].active.flags &
 744                                                 RXON_FLG_CHANNEL_MODE_MSK)
 745                                        >> RXON_FLG_CHANNEL_MODE_POS;
 746                 if ((priv->scan_request && priv->scan_request->no_cck) ||
 747                     chan_mod == CHANNEL_MODE_PURE_40) {
 748                         rate = IWL_RATE_6M_PLCP;
 749                 } else {
 750                         rate = IWL_RATE_1M_PLCP;
 751                         rate_flags = RATE_MCS_CCK_MSK;
 752                 }
 753                 /*
 754                  * Internal scans are passive, so we can indiscriminately set
 755                  * the BT ignore flag on 2.4 GHz since it applies to TX only.
 756                  */
 757                 if (priv->lib->bt_params &&
 758                     priv->lib->bt_params->advanced_bt_coexist)
 759                         scan->tx_cmd.tx_flags |= TX_CMD_FLG_IGNORE_BT;
 760                 break;
 761         case NL80211_BAND_5GHZ:
 762                 rate = IWL_RATE_6M_PLCP;
 763                 break;
 764         default:
 765                 IWL_WARN(priv, "Invalid scan band\n");
 766                 return -EIO;
 767         }
 768 
 769         /*
 770          * If active scanning is requested but a certain channel is
 771          * marked passive, we can do active scanning if we detect
 772          * transmissions.
 773          *
 774          * There is an issue with some firmware versions that triggers
 775          * a sysassert on a "good CRC threshold" of zero (== disabled),
 776          * on a radar channel even though this means that we should NOT
 777          * send probes.
 778          *
 779          * The "good CRC threshold" is the number of frames that we
 780          * need to receive during our dwell time on a channel before
 781          * sending out probes -- setting this to a huge value will
 782          * mean we never reach it, but at the same time work around
 783          * the aforementioned issue. Thus use IWL_GOOD_CRC_TH_NEVER
 784          * here instead of IWL_GOOD_CRC_TH_DISABLED.
 785          *
 786          * This was fixed in later versions along with some other
 787          * scan changes, and the threshold behaves as a flag in those
 788          * versions.
 789          */
 790         if (priv->new_scan_threshold_behaviour)
 791                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 792                                                 IWL_GOOD_CRC_TH_DISABLED;
 793         else
 794                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 795                                                 IWL_GOOD_CRC_TH_NEVER;
 796 
 797         band = priv->scan_band;
 798 
 799         if (band == NL80211_BAND_2GHZ &&
 800             priv->lib->bt_params &&
 801             priv->lib->bt_params->advanced_bt_coexist) {
 802                 /* transmit 2.4 GHz probes only on first antenna */
 803                 scan_tx_antennas = first_antenna(scan_tx_antennas);
 804         }
 805 
 806         priv->scan_tx_ant[band] = iwl_toggle_tx_ant(priv,
 807                                                     priv->scan_tx_ant[band],
 808                                                     scan_tx_antennas);
 809         rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
 810         scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
 811 
 812         /*
 813          * In power save mode while associated use one chain,
 814          * otherwise use all chains
 815          */
 816         if (test_bit(STATUS_POWER_PMI, &priv->status) &&
 817             !(priv->hw->conf.flags & IEEE80211_CONF_IDLE)) {
 818                 /* rx_ant has been set to all valid chains previously */
 819                 active_chains = rx_ant &
 820                                 ((u8)(priv->chain_noise_data.active_chains));
 821                 if (!active_chains)
 822                         active_chains = rx_ant;
 823 
 824                 IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
 825                                 priv->chain_noise_data.active_chains);
 826 
 827                 rx_ant = first_antenna(active_chains);
 828         }
 829         if (priv->lib->bt_params &&
 830             priv->lib->bt_params->advanced_bt_coexist &&
 831             priv->bt_full_concurrent) {
 832                 /* operated as 1x1 in full concurrency mode */
 833                 rx_ant = first_antenna(rx_ant);
 834         }
 835 
 836         /* MIMO is not used here, but value is required */
 837         rx_chain |=
 838                 priv->nvm_data->valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
 839         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
 840         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
 841         rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
 842         scan->rx_chain = cpu_to_le16(rx_chain);
 843         switch (priv->scan_type) {
 844         case IWL_SCAN_NORMAL:
 845                 cmd_len = iwl_fill_probe_req(
 846                                         (struct ieee80211_mgmt *)scan->data,
 847                                         vif->addr,
 848                                         priv->scan_request->ie,
 849                                         priv->scan_request->ie_len,
 850                                         ssid, ssid_len,
 851                                         scan_cmd_size - sizeof(*scan));
 852                 break;
 853         case IWL_SCAN_RADIO_RESET:
 854                 /* use bcast addr, will not be transmitted but must be valid */
 855                 cmd_len = iwl_fill_probe_req(
 856                                         (struct ieee80211_mgmt *)scan->data,
 857                                         iwl_bcast_addr, NULL, 0,
 858                                         NULL, 0,
 859                                         scan_cmd_size - sizeof(*scan));
 860                 break;
 861         default:
 862                 BUG();
 863         }
 864         scan->tx_cmd.len = cpu_to_le16(cmd_len);
 865 
 866         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 867                                RXON_FILTER_BCON_AWARE_MSK);
 868 
 869         switch (priv->scan_type) {
 870         case IWL_SCAN_RADIO_RESET:
 871                 scan->channel_count =
 872                         iwl_get_channel_for_reset_scan(priv, vif, band,
 873                                 (void *)&scan->data[cmd_len]);
 874                 break;
 875         case IWL_SCAN_NORMAL:
 876                 scan->channel_count =
 877                         iwl_get_channels_for_scan(priv, vif, band,
 878                                 is_active, n_probes,
 879                                 (void *)&scan->data[cmd_len]);
 880                 break;
 881         }
 882 
 883         if (scan->channel_count == 0) {
 884                 IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
 885                 return -EIO;
 886         }
 887 
 888         cmd.len[0] += le16_to_cpu(scan->tx_cmd.len) +
 889             scan->channel_count * sizeof(struct iwl_scan_channel);
 890         cmd.data[0] = scan;
 891         cmd.dataflags[0] = IWL_HCMD_DFL_NOCOPY;
 892         scan->len = cpu_to_le16(cmd.len[0]);
 893 
 894         /* set scan bit here for PAN params */
 895         set_bit(STATUS_SCAN_HW, &priv->status);
 896 
 897         ret = iwlagn_set_pan_params(priv);
 898         if (ret) {
 899                 clear_bit(STATUS_SCAN_HW, &priv->status);
 900                 return ret;
 901         }
 902 
 903         ret = iwl_dvm_send_cmd(priv, &cmd);
 904         if (ret) {
 905                 clear_bit(STATUS_SCAN_HW, &priv->status);
 906                 iwlagn_set_pan_params(priv);
 907         }
 908 
 909         return ret;
 910 }
 911 
 912 void iwl_init_scan_params(struct iwl_priv *priv)
 913 {
 914         u8 ant_idx = fls(priv->nvm_data->valid_tx_ant) - 1;
 915         if (!priv->scan_tx_ant[NL80211_BAND_5GHZ])
 916                 priv->scan_tx_ant[NL80211_BAND_5GHZ] = ant_idx;
 917         if (!priv->scan_tx_ant[NL80211_BAND_2GHZ])
 918                 priv->scan_tx_ant[NL80211_BAND_2GHZ] = ant_idx;
 919 }
 920 
 921 int __must_check iwl_scan_initiate(struct iwl_priv *priv,
 922                                    struct ieee80211_vif *vif,
 923                                    enum iwl_scan_type scan_type,
 924                                    enum nl80211_band band)
 925 {
 926         int ret;
 927 
 928         lockdep_assert_held(&priv->mutex);
 929 
 930         cancel_delayed_work(&priv->scan_check);
 931 
 932         if (!iwl_is_ready_rf(priv)) {
 933                 IWL_WARN(priv, "Request scan called when driver not ready.\n");
 934                 return -EIO;
 935         }
 936 
 937         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
 938                 IWL_DEBUG_SCAN(priv,
 939                         "Multiple concurrent scan requests in parallel.\n");
 940                 return -EBUSY;
 941         }
 942 
 943         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 944                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending.\n");
 945                 return -EBUSY;
 946         }
 947 
 948         IWL_DEBUG_SCAN(priv, "Starting %sscan...\n",
 949                         scan_type == IWL_SCAN_NORMAL ? "" :
 950                         "internal short ");
 951 
 952         set_bit(STATUS_SCANNING, &priv->status);
 953         priv->scan_type = scan_type;
 954         priv->scan_start = jiffies;
 955         priv->scan_band = band;
 956 
 957         ret = iwlagn_request_scan(priv, vif);
 958         if (ret) {
 959                 clear_bit(STATUS_SCANNING, &priv->status);
 960                 priv->scan_type = IWL_SCAN_NORMAL;
 961                 return ret;
 962         }
 963 
 964         queue_delayed_work(priv->workqueue, &priv->scan_check,
 965                            IWL_SCAN_CHECK_WATCHDOG);
 966 
 967         return 0;
 968 }
 969 
 970 
 971 /*
 972  * internal short scan, this function should only been called while associated.
 973  * It will reset and tune the radio to prevent possible RF related problem
 974  */
 975 void iwl_internal_short_hw_scan(struct iwl_priv *priv)
 976 {
 977         queue_work(priv->workqueue, &priv->start_internal_scan);
 978 }
 979 
 980 static void iwl_bg_start_internal_scan(struct work_struct *work)
 981 {
 982         struct iwl_priv *priv =
 983                 container_of(work, struct iwl_priv, start_internal_scan);
 984 
 985         IWL_DEBUG_SCAN(priv, "Start internal scan\n");
 986 
 987         mutex_lock(&priv->mutex);
 988 
 989         if (priv->scan_type == IWL_SCAN_RADIO_RESET) {
 990                 IWL_DEBUG_SCAN(priv, "Internal scan already in progress\n");
 991                 goto unlock;
 992         }
 993 
 994         if (test_bit(STATUS_SCANNING, &priv->status)) {
 995                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
 996                 goto unlock;
 997         }
 998 
 999         if (iwl_scan_initiate(priv, NULL, IWL_SCAN_RADIO_RESET, priv->band))
1000                 IWL_DEBUG_SCAN(priv, "failed to start internal short scan\n");
1001  unlock:
1002         mutex_unlock(&priv->mutex);
1003 }
1004 
1005 static void iwl_bg_scan_check(struct work_struct *data)
1006 {
1007         struct iwl_priv *priv =
1008             container_of(data, struct iwl_priv, scan_check.work);
1009 
1010         IWL_DEBUG_SCAN(priv, "Scan check work\n");
1011 
1012         /* Since we are here firmware does not finish scan and
1013          * most likely is in bad shape, so we don't bother to
1014          * send abort command, just force scan complete to mac80211 */
1015         mutex_lock(&priv->mutex);
1016         iwl_force_scan_end(priv);
1017         mutex_unlock(&priv->mutex);
1018 }
1019 
1020 static void iwl_bg_abort_scan(struct work_struct *work)
1021 {
1022         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
1023 
1024         IWL_DEBUG_SCAN(priv, "Abort scan work\n");
1025 
1026         /* We keep scan_check work queued in case when firmware will not
1027          * report back scan completed notification */
1028         mutex_lock(&priv->mutex);
1029         iwl_scan_cancel_timeout(priv, 200);
1030         mutex_unlock(&priv->mutex);
1031 }
1032 
1033 static void iwl_bg_scan_completed(struct work_struct *work)
1034 {
1035         struct iwl_priv *priv =
1036                 container_of(work, struct iwl_priv, scan_completed);
1037 
1038         mutex_lock(&priv->mutex);
1039         iwl_process_scan_complete(priv);
1040         mutex_unlock(&priv->mutex);
1041 }
1042 
1043 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
1044 {
1045         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
1046         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
1047         INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
1048         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
1049 }
1050 
1051 void iwl_cancel_scan_deferred_work(struct iwl_priv *priv)
1052 {
1053         cancel_work_sync(&priv->start_internal_scan);
1054         cancel_work_sync(&priv->abort_scan);
1055         cancel_work_sync(&priv->scan_completed);
1056 
1057         if (cancel_delayed_work_sync(&priv->scan_check)) {
1058                 mutex_lock(&priv->mutex);
1059                 iwl_force_scan_end(priv);
1060                 mutex_unlock(&priv->mutex);
1061         }
1062 }
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/net/wireless/intel/iwlwifi/dvm/scan.c

DEFINITIONS
