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

   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 #include <linux/slab.h>
   8 #include <linux/types.h>
   9 #include <linux/etherdevice.h>
  10 #include <net/mac80211.h>
  11
  12 #include "dev.h"
  13 #include "agn.h"
  14
  15 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
  16  * sending probe req.  This should be set long enough to hear probe responses
  17  * from more than one AP.  */
  18 #define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
  19 #define IWL_ACTIVE_DWELL_TIME_52    (20)
  20
  21 #define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
  22 #define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
  23
  24 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
  25  * Must be set longer than active dwell time.
  26  * For the most reliable scan, set > AP beacon interval (typically 100msec). */
  27 #define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
  28 #define IWL_PASSIVE_DWELL_TIME_52   (10)
  29 #define IWL_PASSIVE_DWELL_BASE      (100)
  30 #define IWL_CHANNEL_TUNE_TIME       5
  31 #define MAX_SCAN_CHANNEL            50
  32
  33 /* For reset radio, need minimal dwell time only */
  34 #define IWL_RADIO_RESET_DWELL_TIME      5
  35
  36 static int iwl_send_scan_abort(struct iwl_priv *priv)
  37 {
  38         int ret;
  39         struct iwl_host_cmd cmd = {
  40                 .id = REPLY_SCAN_ABORT_CMD,
  41                 .flags = CMD_WANT_SKB,
  42         };
  43         __le32 *status;
  44
  45         /* Exit instantly with error when device is not ready
  46          * to receive scan abort command or it does not perform
  47          * hardware scan currently */
  48         if (!test_bit(STATUS_READY, &priv->status) ||
  49             !test_bit(STATUS_SCAN_HW, &priv->status) ||
  50             test_bit(STATUS_FW_ERROR, &priv->status))
  51                 return -EIO;
  52
  53         ret = iwl_dvm_send_cmd(priv, &cmd);
  54         if (ret)
  55                 return ret;
  56
  57         status = (void *)cmd.resp_pkt->data;
  58         if (*status != CAN_ABORT_STATUS) {
  59                 /* The scan abort will return 1 for success or
  60                  * 2 for "failure".  A failure condition can be
  61                  * due to simply not being in an active scan which
  62                  * can occur if we send the scan abort before we
  63                  * the microcode has notified us that a scan is
  64                  * completed. */
  65                 IWL_DEBUG_SCAN(priv, "SCAN_ABORT ret %d.\n",
  66                                le32_to_cpu(*status));
  67                 ret = -EIO;
  68         }
  69
  70         iwl_free_resp(&cmd);
  71         return ret;
  72 }
  73
  74 static void iwl_complete_scan(struct iwl_priv *priv, bool aborted)
  75 {
  76         struct cfg80211_scan_info info = {
  77                 .aborted = aborted,
  78         };
  79
  80         /* check if scan was requested from mac80211 */
  81         if (priv->scan_request) {
  82                 IWL_DEBUG_SCAN(priv, "Complete scan in mac80211\n");
  83                 ieee80211_scan_completed(priv->hw, &info);
  84         }
  85
  86         priv->scan_type = IWL_SCAN_NORMAL;
  87         priv->scan_vif = NULL;
  88         priv->scan_request = NULL;
  89 }
  90
  91 static void iwl_process_scan_complete(struct iwl_priv *priv)
  92 {
  93         bool aborted;
  94
  95         lockdep_assert_held(&priv->mutex);
  96
  97         if (!test_and_clear_bit(STATUS_SCAN_COMPLETE, &priv->status))
  98                 return;
  99
 100         IWL_DEBUG_SCAN(priv, "Completed scan.\n");
 101
 102         cancel_delayed_work(&priv->scan_check);
 103
 104         aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 105         if (aborted)
 106                 IWL_DEBUG_SCAN(priv, "Aborted scan completed.\n");
 107
 108         if (!test_and_clear_bit(STATUS_SCANNING, &priv->status)) {
 109                 IWL_DEBUG_SCAN(priv, "Scan already completed.\n");
 110                 goto out_settings;
 111         }
 112
 113         if (priv->scan_type != IWL_SCAN_NORMAL && !aborted) {
 114                 int err;
 115
 116                 /* Check if mac80211 requested scan during our internal scan */
 117                 if (priv->scan_request == NULL)
 118                         goto out_complete;
 119
 120                 /* If so request a new scan */
 121                 err = iwl_scan_initiate(priv, priv->scan_vif, IWL_SCAN_NORMAL,
 122                                         priv->scan_request->channels[0]->band);
 123                 if (err) {
 124                         IWL_DEBUG_SCAN(priv,
 125                                 "failed to initiate pending scan: %d\n", err);
 126                         aborted = true;
 127                         goto out_complete;
 128                 }
 129
 130                 return;
 131         }
 132
 133 out_complete:
 134         iwl_complete_scan(priv, aborted);
 135
 136 out_settings:
 137         /* Can we still talk to firmware ? */
 138         if (!iwl_is_ready_rf(priv))
 139                 return;
 140
 141         iwlagn_post_scan(priv);
 142 }
 143
 144 void iwl_force_scan_end(struct iwl_priv *priv)
 145 {
 146         lockdep_assert_held(&priv->mutex);
 147
 148         if (!test_bit(STATUS_SCANNING, &priv->status)) {
 149                 IWL_DEBUG_SCAN(priv, "Forcing scan end while not scanning\n");
 150                 return;
 151         }
 152
 153         IWL_DEBUG_SCAN(priv, "Forcing scan end\n");
 154         clear_bit(STATUS_SCANNING, &priv->status);
 155         clear_bit(STATUS_SCAN_HW, &priv->status);
 156         clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 157         clear_bit(STATUS_SCAN_COMPLETE, &priv->status);
 158         iwl_complete_scan(priv, true);
 159 }
 160
 161 static void iwl_do_scan_abort(struct iwl_priv *priv)
 162 {
 163         int ret;
 164
 165         lockdep_assert_held(&priv->mutex);
 166
 167         if (!test_bit(STATUS_SCANNING, &priv->status)) {
 168                 IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
 169                 return;
 170         }
 171
 172         if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 173                 IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
 174                 return;
 175         }
 176
 177         ret = iwl_send_scan_abort(priv);
 178         if (ret) {
 179                 IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
 180                 iwl_force_scan_end(priv);
 181         } else
 182                 IWL_DEBUG_SCAN(priv, "Successfully send scan abort\n");
 183 }
 184
 185 /*
 186  * iwl_scan_cancel - Cancel any currently executing HW scan
 187  */
 188 int iwl_scan_cancel(struct iwl_priv *priv)
 189 {
 190         IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
 191         queue_work(priv->workqueue, &priv->abort_scan);
 192         return 0;
 193 }
 194
 195 /*
 196  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
 197  * @ms: amount of time to wait (in milliseconds) for scan to abort
 198  */
 199 void iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
 200 {
 201         unsigned long timeout = jiffies + msecs_to_jiffies(ms);
 202
 203         lockdep_assert_held(&priv->mutex);
 204
 205         IWL_DEBUG_SCAN(priv, "Scan cancel timeout\n");
 206
 207         iwl_do_scan_abort(priv);
 208
 209         while (time_before_eq(jiffies, timeout)) {
 210                 if (!test_bit(STATUS_SCAN_HW, &priv->status))
 211                         goto finished;
 212                 msleep(20);
 213         }
 214
 215         return;
 216
 217  finished:
 218         /*
 219          * Now STATUS_SCAN_HW is clear. This means that the
 220          * device finished, but the background work is going
 221          * to execute at best as soon as we release the mutex.
 222          * Since we need to be able to issue a new scan right
 223          * after this function returns, run the complete here.
 224          * The STATUS_SCAN_COMPLETE bit will then be cleared
 225          * and prevent the background work from "completing"
 226          * a possible new scan.
 227          */
 228         iwl_process_scan_complete(priv);
 229 }
 230
 231 /* Service response to REPLY_SCAN_CMD (0x80) */
 232 static void iwl_rx_reply_scan(struct iwl_priv *priv,
 233                               struct iwl_rx_cmd_buffer *rxb)
 234 {
 235 #ifdef CONFIG_IWLWIFI_DEBUG
 236         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 237         struct iwl_scanreq_notification *notif = (void *)pkt->data;
 238
 239         IWL_DEBUG_SCAN(priv, "Scan request status = 0x%x\n", notif->status);
 240 #endif
 241 }
 242
 243 /* Service SCAN_START_NOTIFICATION (0x82) */
 244 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
 245                                     struct iwl_rx_cmd_buffer *rxb)
 246 {
 247         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 248         struct iwl_scanstart_notification *notif = (void *)pkt->data;
 249
 250         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 251         IWL_DEBUG_SCAN(priv, "Scan start: "
 252                        "%d [802.11%s] "
 253                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 254                        notif->channel,
 255                        notif->band ? "bg" : "a",
 256                        le32_to_cpu(notif->tsf_high),
 257                        le32_to_cpu(notif->tsf_low),
 258                        notif->status, notif->beacon_timer);
 259 }
 260
 261 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 262 static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
 263                                       struct iwl_rx_cmd_buffer *rxb)
 264 {
 265 #ifdef CONFIG_IWLWIFI_DEBUG
 266         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 267         struct iwl_scanresults_notification *notif = (void *)pkt->data;
 268
 269         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
 270                        "%d [802.11%s] "
 271                        "probe status: %u:%u "
 272                        "(TSF: 0x%08X:%08X) - %d "
 273                        "elapsed=%lu usec\n",
 274                        notif->channel,
 275                        notif->band ? "bg" : "a",
 276                        notif->probe_status, notif->num_probe_not_sent,
 277                        le32_to_cpu(notif->tsf_high),
 278                        le32_to_cpu(notif->tsf_low),
 279                        le32_to_cpu(notif->statistics[0]),
 280                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
 281 #endif
 282 }
 283
 284 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 285 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 286                                        struct iwl_rx_cmd_buffer *rxb)
 287 {
 288         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 289         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->data;
 290
 291         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 292                        scan_notif->scanned_channels,
 293                        scan_notif->tsf_low,
 294                        scan_notif->tsf_high, scan_notif->status);
 295
 296         IWL_DEBUG_SCAN(priv, "Scan on %sGHz took %dms\n",
 297                        (priv->scan_band == NL80211_BAND_2GHZ) ? "2.4" : "5.2",
 298                        jiffies_to_msecs(jiffies - priv->scan_start));
 299
 300         /*
 301          * When aborting, we run the scan completed background work inline
 302          * and the background work must then do nothing. The SCAN_COMPLETE
 303          * bit helps implement that logic and thus needs to be set before
 304          * queueing the work. Also, since the scan abort waits for SCAN_HW
 305          * to clear, we need to set SCAN_COMPLETE before clearing SCAN_HW
 306          * to avoid a race there.
 307          */
 308         set_bit(STATUS_SCAN_COMPLETE, &priv->status);
 309         clear_bit(STATUS_SCAN_HW, &priv->status);
 310         queue_work(priv->workqueue, &priv->scan_completed);
 311
 312         if (priv->iw_mode != NL80211_IFTYPE_ADHOC &&
 313             iwl_advanced_bt_coexist(priv) &&
 314             priv->bt_status != scan_notif->bt_status) {
 315                 if (scan_notif->bt_status) {
 316                         /* BT on */
 317                         if (!priv->bt_ch_announce)
 318                                 priv->bt_traffic_load =
 319                                         IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
 320                         /*
 321                          * otherwise, no traffic load information provided
 322                          * no changes made
 323                          */
 324                 } else {
 325                         /* BT off */
 326                         priv->bt_traffic_load =
 327                                 IWL_BT_COEX_TRAFFIC_LOAD_NONE;
 328                 }
 329                 priv->bt_status = scan_notif->bt_status;
 330                 queue_work(priv->workqueue,
 331                            &priv->bt_traffic_change_work);
 332         }
 333 }
 334
 335 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 336 {
 337         /* scan handlers */
 338         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 339         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 340         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 341                                         iwl_rx_scan_results_notif;
 342         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 343                                         iwl_rx_scan_complete_notif;
 344 }
 345
 346 static u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 347                                      enum nl80211_band band, u8 n_probes)
 348 {
 349         if (band == NL80211_BAND_5GHZ)
 350                 return IWL_ACTIVE_DWELL_TIME_52 +
 351                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 352         else
 353                 return IWL_ACTIVE_DWELL_TIME_24 +
 354                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 355 }
 356
 357 static u16 iwl_limit_dwell(struct iwl_priv *priv, u16 dwell_time)
 358 {
 359         struct iwl_rxon_context *ctx;
 360         int limits[NUM_IWL_RXON_CTX] = {};
 361         int n_active = 0;
 362         u16 limit;
 363
 364         BUILD_BUG_ON(NUM_IWL_RXON_CTX != 2);
 365
 366         /*
 367          * If we're associated, we clamp the dwell time 98%
 368          * of the beacon interval (minus 2 * channel tune time)
 369          * If both contexts are active, we have to restrict to
 370          * 1/2 of the minimum of them, because they might be in
 371          * lock-step with the time inbetween only half of what
 372          * time we'd have in each of them.
 373          */
 374         for_each_context(priv, ctx) {
 375                 switch (ctx->staging.dev_type) {
 376                 case RXON_DEV_TYPE_P2P:
 377                         /* no timing constraints */
 378                         continue;
 379                 case RXON_DEV_TYPE_ESS:
 380                 default:
 381                         /* timing constraints if associated */
 382                         if (!iwl_is_associated_ctx(ctx))
 383                                 continue;
 384                         break;
 385                 case RXON_DEV_TYPE_CP:
 386                 case RXON_DEV_TYPE_2STA:
 387                         /*
 388                          * These seem to always have timers for TBTT
 389                          * active in uCode even when not associated yet.
 390                          */
 391                         break;
 392                 }
 393
 394                 limits[n_active++] = ctx->beacon_int ?: IWL_PASSIVE_DWELL_BASE;
 395         }
 396
 397         switch (n_active) {
 398         case 0:
 399                 return dwell_time;
 400         case 2:
 401                 limit = (limits[1] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 402                 limit /= 2;
 403                 dwell_time = min(limit, dwell_time);
 404                 fallthrough;
 405         case 1:
 406                 limit = (limits[0] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 407                 limit /= n_active;
 408                 return min(limit, dwell_time);
 409         default:
 410                 WARN_ON_ONCE(1);
 411                 return dwell_time;
 412         }
 413 }
 414
 415 static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 416                                       enum nl80211_band band)
 417 {
 418         u16 passive = (band == NL80211_BAND_2GHZ) ?
 419             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 420             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 421
 422         return iwl_limit_dwell(priv, passive);
 423 }
 424
 425 /* Return valid, unused, channel for a passive scan to reset the RF */
 426 static u8 iwl_get_single_channel_number(struct iwl_priv *priv,
 427                                         enum nl80211_band band)
 428 {
 429         struct ieee80211_supported_band *sband = priv->hw->wiphy->bands[band];
 430         struct iwl_rxon_context *ctx;
 431         int i;
 432
 433         for (i = 0; i < sband->n_channels; i++) {
 434                 bool busy = false;
 435
 436                 for_each_context(priv, ctx) {
 437                         busy = sband->channels[i].hw_value ==
 438                                 le16_to_cpu(ctx->staging.channel);
 439                         if (busy)
 440                                 break;
 441                 }
 442
 443                 if (busy)
 444                         continue;
 445
 446                 if (!(sband->channels[i].flags & IEEE80211_CHAN_DISABLED))
 447                         return sband->channels[i].hw_value;
 448         }
 449
 450         return 0;
 451 }
 452
 453 static int iwl_get_channel_for_reset_scan(struct iwl_priv *priv,
 454                                           struct ieee80211_vif *vif,
 455                                           enum nl80211_band band,
 456                                           struct iwl_scan_channel *scan_ch)
 457 {
 458         const struct ieee80211_supported_band *sband;
 459         u16 channel;
 460
 461         sband = iwl_get_hw_mode(priv, band);
 462         if (!sband) {
 463                 IWL_ERR(priv, "invalid band\n");
 464                 return 0;
 465         }
 466
 467         channel = iwl_get_single_channel_number(priv, band);
 468         if (channel) {
 469                 scan_ch->channel = cpu_to_le16(channel);
 470                 scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 471                 scan_ch->active_dwell =
 472                         cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
 473                 scan_ch->passive_dwell =
 474                         cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
 475                 /* Set txpower levels to defaults */
 476                 scan_ch->dsp_atten = 110;
 477                 if (band == NL80211_BAND_5GHZ)
 478                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 479                 else
 480                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 481                 return 1;
 482         }
 483
 484         IWL_ERR(priv, "no valid channel found\n");
 485         return 0;
 486 }
 487
 488 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 489                                      struct ieee80211_vif *vif,
 490                                      enum nl80211_band band,
 491                                      u8 is_active, u8 n_probes,
 492                                      struct iwl_scan_channel *scan_ch)
 493 {
 494         struct ieee80211_channel *chan;
 495         const struct ieee80211_supported_band *sband;
 496         u16 passive_dwell = 0;
 497         u16 active_dwell = 0;
 498         int added, i;
 499         u16 channel;
 500
 501         sband = iwl_get_hw_mode(priv, band);
 502         if (!sband)
 503                 return 0;
 504
 505         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 506         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 507
 508         if (passive_dwell <= active_dwell)
 509                 passive_dwell = active_dwell + 1;
 510
 511         for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
 512                 chan = priv->scan_request->channels[i];
 513
 514                 if (chan->band != band)
 515                         continue;
 516
 517                 channel = chan->hw_value;
 518                 scan_ch->channel = cpu_to_le16(channel);
 519
 520                 if (!is_active || (chan->flags & IEEE80211_CHAN_NO_IR))
 521                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 522                 else
 523                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 524
 525                 if (n_probes)
 526                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 527
 528                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 529                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 530
 531                 /* Set txpower levels to defaults */
 532                 scan_ch->dsp_atten = 110;
 533
 534                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 535                  * power level:
 536                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 537                  */
 538                 if (band == NL80211_BAND_5GHZ)
 539                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 540                 else
 541                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 542
 543                 IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
 544                                channel, le32_to_cpu(scan_ch->type),
 545                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 546                                 "ACTIVE" : "PASSIVE",
 547                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 548                                active_dwell : passive_dwell);
 549
 550                 scan_ch++;
 551                 added++;
 552         }
 553
 554         IWL_DEBUG_SCAN(priv, "total channels to scan %d\n", added);
 555         return added;
 556 }
 557
 558 /*
 559  * iwl_fill_probe_req - fill in all required fields and IE for probe request
 560  */
 561 static u16 iwl_fill_probe_req(struct ieee80211_mgmt *frame, const u8 *ta,
 562                               const u8 *ies, int ie_len, const u8 *ssid,
 563                               u8 ssid_len, int left)
 564 {
 565         int len = 0;
 566         u8 *pos = NULL;
 567
 568         /* Make sure there is enough space for the probe request,
 569          * two mandatory IEs and the data */
 570         left -= 24;
 571         if (left < 0)
 572                 return 0;
 573
 574         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 575         eth_broadcast_addr(frame->da);
 576         memcpy(frame->sa, ta, ETH_ALEN);
 577         eth_broadcast_addr(frame->bssid);
 578         frame->seq_ctrl = 0;
 579
 580         len += 24;
 581
 582         /* ...next IE... */
 583         pos = &frame->u.probe_req.variable[0];
 584
 585         /* fill in our SSID IE */
 586         left -= ssid_len + 2;
 587         if (left < 0)
 588                 return 0;
 589         *pos++ = WLAN_EID_SSID;
 590         *pos++ = ssid_len;
 591         if (ssid && ssid_len) {
 592                 memcpy(pos, ssid, ssid_len);
 593                 pos += ssid_len;
 594         }
 595
 596         len += ssid_len + 2;
 597
 598         if (WARN_ON(left < ie_len))
 599                 return len;
 600
 601         if (ies && ie_len) {
 602                 memcpy(pos, ies, ie_len);
 603                 len += ie_len;
 604         }
 605
 606         return (u16)len;
 607 }
 608
 609 static int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
 610 {
 611         struct iwl_host_cmd cmd = {
 612                 .id = REPLY_SCAN_CMD,
 613                 .len = { sizeof(struct iwl_scan_cmd), },
 614         };
 615         struct iwl_scan_cmd *scan;
 616         struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
 617         u32 rate_flags = 0;
 618         u16 cmd_len = 0;
 619         u16 rx_chain = 0;
 620         enum nl80211_band band;
 621         u8 n_probes = 0;
 622         u8 rx_ant = priv->nvm_data->valid_rx_ant;
 623         u8 rate;
 624         bool is_active = false;
 625         int  chan_mod;
 626         u8 active_chains;
 627         u8 scan_tx_antennas = priv->nvm_data->valid_tx_ant;
 628         int ret;
 629         size_t scan_cmd_size = sizeof(struct iwl_scan_cmd) +
 630                             MAX_SCAN_CHANNEL * sizeof(struct iwl_scan_channel) +
 631                             priv->fw->ucode_capa.max_probe_length;
 632         const u8 *ssid = NULL;
 633         u8 ssid_len = 0;
 634
 635         if (WARN_ON(priv->scan_type == IWL_SCAN_NORMAL &&
 636                     (!priv->scan_request ||
 637                      priv->scan_request->n_channels > MAX_SCAN_CHANNEL)))
 638                 return -EINVAL;
 639
 640         lockdep_assert_held(&priv->mutex);
 641
 642         if (vif)
 643                 ctx = iwl_rxon_ctx_from_vif(vif);
 644
 645         if (!priv->scan_cmd) {
 646                 priv->scan_cmd = kmalloc(scan_cmd_size, GFP_KERNEL);
 647                 if (!priv->scan_cmd) {
 648                         IWL_DEBUG_SCAN(priv,
 649                                        "fail to allocate memory for scan\n");
 650                         return -ENOMEM;
 651                 }
 652                 priv->scan_cmd_size = scan_cmd_size;
 653         }
 654         if (priv->scan_cmd_size < scan_cmd_size) {
 655                 IWL_DEBUG_SCAN(priv,
 656                                "memory needed for scan grew unexpectedly\n");
 657                 return -ENOMEM;
 658         }
 659         scan = priv->scan_cmd;
 660         memset(scan, 0, priv->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 }