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

   1 /******************************************************************************
   2  *
   3  * GPL LICENSE SUMMARY
   4  *
   5  * Copyright(c) 2008 - 2012 Intel Corporation. All rights reserved.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of version 2 of the GNU General Public License as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
  19  * USA
  20  *
  21  * The full GNU General Public License is included in this distribution
  22  * in the file called LICENSE.GPL.
  23  *
  24  * Contact Information:
  25  *  Intel Linux Wireless <ilw@linux.intel.com>
  26  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  27  *****************************************************************************/
  28 #include <linux/slab.h>
  29 #include <linux/types.h>
  30 #include <linux/etherdevice.h>
  31 #include <net/mac80211.h>
  32
  33 #include "iwl-eeprom.h"
  34 #include "iwl-dev.h"
  35 #include "iwl-core.h"
  36 #include "iwl-io.h"
  37 #include "iwl-agn.h"
  38 #include "iwl-trans.h"
  39
  40 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
  41  * sending probe req.  This should be set long enough to hear probe responses
  42  * from more than one AP.  */
  43 #define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
  44 #define IWL_ACTIVE_DWELL_TIME_52    (20)
  45
  46 #define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
  47 #define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
  48
  49 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
  50  * Must be set longer than active dwell time.
  51  * For the most reliable scan, set > AP beacon interval (typically 100msec). */
  52 #define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
  53 #define IWL_PASSIVE_DWELL_TIME_52   (10)
  54 #define IWL_PASSIVE_DWELL_BASE      (100)
  55 #define IWL_CHANNEL_TUNE_TIME       5
  56
  57 static int iwl_send_scan_abort(struct iwl_priv *priv)
  58 {
  59         int ret;
  60         struct iwl_host_cmd cmd = {
  61                 .id = REPLY_SCAN_ABORT_CMD,
  62                 .flags = CMD_SYNC | 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_GEO_CONFIGURED, &priv->status) ||
  71             !test_bit(STATUS_SCAN_HW, &priv->status) ||
  72             test_bit(STATUS_FW_ERROR, &priv->status))
  73                 return -EIO;
  74
  75         ret = iwl_dvm_send_cmd(priv, &cmd);
  76         if (ret)
  77                 return ret;
  78
  79         status = (void *)cmd.resp_pkt->data;
  80         if (*status != CAN_ABORT_STATUS) {
  81                 /* The scan abort will return 1 for success or
  82                  * 2 for "failure".  A failure condition can be
  83                  * due to simply not being in an active scan which
  84                  * can occur if we send the scan abort before we
  85                  * the microcode has notified us that a scan is
  86                  * completed. */
  87                 IWL_DEBUG_SCAN(priv, "SCAN_ABORT ret %d.\n",
  88                                le32_to_cpu(*status));
  89                 ret = -EIO;
  90         }
  91
  92         iwl_free_resp(&cmd);
  93         return ret;
  94 }
  95
  96 static void iwl_complete_scan(struct iwl_priv *priv, bool aborted)
  97 {
  98         /* check if scan was requested from mac80211 */
  99         if (priv->scan_request) {
 100                 IWL_DEBUG_SCAN(priv, "Complete scan in mac80211\n");
 101                 ieee80211_scan_completed(priv->hw, aborted);
 102         }
 103
 104         if (priv->scan_type == IWL_SCAN_ROC) {
 105                 ieee80211_remain_on_channel_expired(priv->hw);
 106                 priv->hw_roc_channel = NULL;
 107                 schedule_delayed_work(&priv->hw_roc_disable_work, 10 * HZ);
 108         }
 109
 110         priv->scan_type = IWL_SCAN_NORMAL;
 111         priv->scan_vif = NULL;
 112         priv->scan_request = NULL;
 113 }
 114
 115 static void iwl_process_scan_complete(struct iwl_priv *priv)
 116 {
 117         bool aborted;
 118
 119         lockdep_assert_held(&priv->mutex);
 120
 121         if (!test_and_clear_bit(STATUS_SCAN_COMPLETE, &priv->status))
 122                 return;
 123
 124         IWL_DEBUG_SCAN(priv, "Completed scan.\n");
 125
 126         cancel_delayed_work(&priv->scan_check);
 127
 128         aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 129         if (aborted)
 130                 IWL_DEBUG_SCAN(priv, "Aborted scan completed.\n");
 131
 132         if (!test_and_clear_bit(STATUS_SCANNING, &priv->status)) {
 133                 IWL_DEBUG_SCAN(priv, "Scan already completed.\n");
 134                 goto out_settings;
 135         }
 136
 137         if (priv->scan_type == IWL_SCAN_ROC) {
 138                 ieee80211_remain_on_channel_expired(priv->hw);
 139                 priv->hw_roc_channel = NULL;
 140                 schedule_delayed_work(&priv->hw_roc_disable_work, 10 * HZ);
 141         }
 142
 143         if (priv->scan_type != IWL_SCAN_NORMAL && !aborted) {
 144                 int err;
 145
 146                 /* Check if mac80211 requested scan during our internal scan */
 147                 if (priv->scan_request == NULL)
 148                         goto out_complete;
 149
 150                 /* If so request a new scan */
 151                 err = iwl_scan_initiate(priv, priv->scan_vif, IWL_SCAN_NORMAL,
 152                                         priv->scan_request->channels[0]->band);
 153                 if (err) {
 154                         IWL_DEBUG_SCAN(priv,
 155                                 "failed to initiate pending scan: %d\n", err);
 156                         aborted = true;
 157                         goto out_complete;
 158                 }
 159
 160                 return;
 161         }
 162
 163 out_complete:
 164         iwl_complete_scan(priv, aborted);
 165
 166 out_settings:
 167         /* Can we still talk to firmware ? */
 168         if (!iwl_is_ready_rf(priv))
 169                 return;
 170
 171         iwlagn_post_scan(priv);
 172 }
 173
 174 void iwl_force_scan_end(struct iwl_priv *priv)
 175 {
 176         lockdep_assert_held(&priv->mutex);
 177
 178         if (!test_bit(STATUS_SCANNING, &priv->status)) {
 179                 IWL_DEBUG_SCAN(priv, "Forcing scan end while not scanning\n");
 180                 return;
 181         }
 182
 183         IWL_DEBUG_SCAN(priv, "Forcing scan end\n");
 184         clear_bit(STATUS_SCANNING, &priv->status);
 185         clear_bit(STATUS_SCAN_HW, &priv->status);
 186         clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 187         clear_bit(STATUS_SCAN_COMPLETE, &priv->status);
 188         iwl_complete_scan(priv, true);
 189 }
 190
 191 static void iwl_do_scan_abort(struct iwl_priv *priv)
 192 {
 193         int ret;
 194
 195         lockdep_assert_held(&priv->mutex);
 196
 197         if (!test_bit(STATUS_SCANNING, &priv->status)) {
 198                 IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
 199                 return;
 200         }
 201
 202         if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 203                 IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
 204                 return;
 205         }
 206
 207         ret = iwl_send_scan_abort(priv);
 208         if (ret) {
 209                 IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
 210                 iwl_force_scan_end(priv);
 211         } else
 212                 IWL_DEBUG_SCAN(priv, "Successfully send scan abort\n");
 213 }
 214
 215 /**
 216  * iwl_scan_cancel - Cancel any currently executing HW scan
 217  */
 218 int iwl_scan_cancel(struct iwl_priv *priv)
 219 {
 220         IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
 221         queue_work(priv->workqueue, &priv->abort_scan);
 222         return 0;
 223 }
 224
 225 /**
 226  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
 227  * @ms: amount of time to wait (in milliseconds) for scan to abort
 228  *
 229  */
 230 void iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
 231 {
 232         unsigned long timeout = jiffies + msecs_to_jiffies(ms);
 233
 234         lockdep_assert_held(&priv->mutex);
 235
 236         IWL_DEBUG_SCAN(priv, "Scan cancel timeout\n");
 237
 238         iwl_do_scan_abort(priv);
 239
 240         while (time_before_eq(jiffies, timeout)) {
 241                 if (!test_bit(STATUS_SCAN_HW, &priv->status))
 242                         goto finished;
 243                 msleep(20);
 244         }
 245
 246         return;
 247
 248  finished:
 249         /*
 250          * Now STATUS_SCAN_HW is clear. This means that the
 251          * device finished, but the background work is going
 252          * to execute at best as soon as we release the mutex.
 253          * Since we need to be able to issue a new scan right
 254          * after this function returns, run the complete here.
 255          * The STATUS_SCAN_COMPLETE bit will then be cleared
 256          * and prevent the background work from "completing"
 257          * a possible new scan.
 258          */
 259         iwl_process_scan_complete(priv);
 260 }
 261
 262 /* Service response to REPLY_SCAN_CMD (0x80) */
 263 static int iwl_rx_reply_scan(struct iwl_priv *priv,
 264                               struct iwl_rx_cmd_buffer *rxb,
 265                               struct iwl_device_cmd *cmd)
 266 {
 267 #ifdef CONFIG_IWLWIFI_DEBUG
 268         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 269         struct iwl_scanreq_notification *notif = (void *)pkt->data;
 270
 271         IWL_DEBUG_SCAN(priv, "Scan request status = 0x%x\n", notif->status);
 272 #endif
 273         return 0;
 274 }
 275
 276 /* Service SCAN_START_NOTIFICATION (0x82) */
 277 static int iwl_rx_scan_start_notif(struct iwl_priv *priv,
 278                                     struct iwl_rx_cmd_buffer *rxb,
 279                                     struct iwl_device_cmd *cmd)
 280 {
 281         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 282         struct iwl_scanstart_notification *notif = (void *)pkt->data;
 283
 284         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 285         IWL_DEBUG_SCAN(priv, "Scan start: "
 286                        "%d [802.11%s] "
 287                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 288                        notif->channel,
 289                        notif->band ? "bg" : "a",
 290                        le32_to_cpu(notif->tsf_high),
 291                        le32_to_cpu(notif->tsf_low),
 292                        notif->status, notif->beacon_timer);
 293
 294         if (priv->scan_type == IWL_SCAN_ROC &&
 295             !priv->hw_roc_start_notified) {
 296                 ieee80211_ready_on_channel(priv->hw);
 297                 priv->hw_roc_start_notified = true;
 298         }
 299
 300         return 0;
 301 }
 302
 303 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 304 static int iwl_rx_scan_results_notif(struct iwl_priv *priv,
 305                                       struct iwl_rx_cmd_buffer *rxb,
 306                                       struct iwl_device_cmd *cmd)
 307 {
 308 #ifdef CONFIG_IWLWIFI_DEBUG
 309         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 310         struct iwl_scanresults_notification *notif = (void *)pkt->data;
 311
 312         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
 313                        "%d [802.11%s] "
 314                        "probe status: %u:%u "
 315                        "(TSF: 0x%08X:%08X) - %d "
 316                        "elapsed=%lu usec\n",
 317                        notif->channel,
 318                        notif->band ? "bg" : "a",
 319                        notif->probe_status, notif->num_probe_not_sent,
 320                        le32_to_cpu(notif->tsf_high),
 321                        le32_to_cpu(notif->tsf_low),
 322                        le32_to_cpu(notif->statistics[0]),
 323                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
 324 #endif
 325         return 0;
 326 }
 327
 328 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 329 static int iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 330                                        struct iwl_rx_cmd_buffer *rxb,
 331                                        struct iwl_device_cmd *cmd)
 332 {
 333         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 334         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->data;
 335
 336         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 337                        scan_notif->scanned_channels,
 338                        scan_notif->tsf_low,
 339                        scan_notif->tsf_high, scan_notif->status);
 340
 341         IWL_DEBUG_SCAN(priv, "Scan on %sGHz took %dms\n",
 342                        (priv->scan_band == IEEE80211_BAND_2GHZ) ? "2.4" : "5.2",
 343                        jiffies_to_msecs(jiffies - priv->scan_start));
 344
 345         /*
 346          * When aborting, we run the scan completed background work inline
 347          * and the background work must then do nothing. The SCAN_COMPLETE
 348          * bit helps implement that logic and thus needs to be set before
 349          * queueing the work. Also, since the scan abort waits for SCAN_HW
 350          * to clear, we need to set SCAN_COMPLETE before clearing SCAN_HW
 351          * to avoid a race there.
 352          */
 353         set_bit(STATUS_SCAN_COMPLETE, &priv->status);
 354         clear_bit(STATUS_SCAN_HW, &priv->status);
 355         queue_work(priv->workqueue, &priv->scan_completed);
 356
 357         if (priv->iw_mode != NL80211_IFTYPE_ADHOC &&
 358             iwl_advanced_bt_coexist(priv) &&
 359             priv->bt_status != scan_notif->bt_status) {
 360                 if (scan_notif->bt_status) {
 361                         /* BT on */
 362                         if (!priv->bt_ch_announce)
 363                                 priv->bt_traffic_load =
 364                                         IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
 365                         /*
 366                          * otherwise, no traffic load information provided
 367                          * no changes made
 368                          */
 369                 } else {
 370                         /* BT off */
 371                         priv->bt_traffic_load =
 372                                 IWL_BT_COEX_TRAFFIC_LOAD_NONE;
 373                 }
 374                 priv->bt_status = scan_notif->bt_status;
 375                 queue_work(priv->workqueue,
 376                            &priv->bt_traffic_change_work);
 377         }
 378         return 0;
 379 }
 380
 381 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 382 {
 383         /* scan handlers */
 384         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 385         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 386         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 387                                         iwl_rx_scan_results_notif;
 388         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 389                                         iwl_rx_scan_complete_notif;
 390 }
 391
 392 static u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 393                                      enum ieee80211_band band, u8 n_probes)
 394 {
 395         if (band == IEEE80211_BAND_5GHZ)
 396                 return IWL_ACTIVE_DWELL_TIME_52 +
 397                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 398         else
 399                 return IWL_ACTIVE_DWELL_TIME_24 +
 400                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 401 }
 402
 403 static u16 iwl_limit_dwell(struct iwl_priv *priv, u16 dwell_time)
 404 {
 405         struct iwl_rxon_context *ctx;
 406
 407         /*
 408          * If we're associated, we clamp the dwell time 98%
 409          * of the smallest beacon interval (minus 2 * channel
 410          * tune time)
 411          */
 412         for_each_context(priv, ctx) {
 413                 u16 value;
 414
 415                 switch (ctx->staging.dev_type) {
 416                 case RXON_DEV_TYPE_P2P:
 417                         /* no timing constraints */
 418                         continue;
 419                 case RXON_DEV_TYPE_ESS:
 420                 default:
 421                         /* timing constraints if associated */
 422                         if (!iwl_is_associated_ctx(ctx))
 423                                 continue;
 424                         break;
 425                 case RXON_DEV_TYPE_CP:
 426                 case RXON_DEV_TYPE_2STA:
 427                         /*
 428                          * These seem to always have timers for TBTT
 429                          * active in uCode even when not associated yet.
 430                          */
 431                         break;
 432                 }
 433
 434                 value = ctx->beacon_int;
 435                 if (!value)
 436                         value = IWL_PASSIVE_DWELL_BASE;
 437                 value = (value * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 438                 dwell_time = min(value, dwell_time);
 439         }
 440
 441         return dwell_time;
 442 }
 443
 444 static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 445                                       enum ieee80211_band band)
 446 {
 447         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
 448             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 449             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 450
 451         return iwl_limit_dwell(priv, passive);
 452 }
 453
 454 /* Return valid, unused, channel for a passive scan to reset the RF */
 455 static u8 iwl_get_single_channel_number(struct iwl_priv *priv,
 456                                  enum ieee80211_band band)
 457 {
 458         const struct iwl_channel_info *ch_info;
 459         int i;
 460         u8 channel = 0;
 461         u8 min, max;
 462         struct iwl_rxon_context *ctx;
 463
 464         if (band == IEEE80211_BAND_5GHZ) {
 465                 min = 14;
 466                 max = priv->channel_count;
 467         } else {
 468                 min = 0;
 469                 max = 14;
 470         }
 471
 472         for (i = min; i < max; i++) {
 473                 bool busy = false;
 474
 475                 for_each_context(priv, ctx) {
 476                         busy = priv->channel_info[i].channel ==
 477                                 le16_to_cpu(ctx->staging.channel);
 478                         if (busy)
 479                                 break;
 480                 }
 481
 482                 if (busy)
 483                         continue;
 484
 485                 channel = priv->channel_info[i].channel;
 486                 ch_info = iwl_get_channel_info(priv, band, channel);
 487                 if (is_channel_valid(ch_info))
 488                         break;
 489         }
 490
 491         return channel;
 492 }
 493
 494 static int iwl_get_single_channel_for_scan(struct iwl_priv *priv,
 495                                            struct ieee80211_vif *vif,
 496                                            enum ieee80211_band band,
 497                                            struct iwl_scan_channel *scan_ch)
 498 {
 499         const struct ieee80211_supported_band *sband;
 500         u16 passive_dwell = 0;
 501         u16 active_dwell = 0;
 502         int added = 0;
 503         u16 channel = 0;
 504
 505         sband = iwl_get_hw_mode(priv, band);
 506         if (!sband) {
 507                 IWL_ERR(priv, "invalid band\n");
 508                 return added;
 509         }
 510
 511         active_dwell = iwl_get_active_dwell_time(priv, band, 0);
 512         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 513
 514         if (passive_dwell <= active_dwell)
 515                 passive_dwell = active_dwell + 1;
 516
 517         channel = iwl_get_single_channel_number(priv, band);
 518         if (channel) {
 519                 scan_ch->channel = cpu_to_le16(channel);
 520                 scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 521                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 522                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 523                 /* Set txpower levels to defaults */
 524                 scan_ch->dsp_atten = 110;
 525                 if (band == IEEE80211_BAND_5GHZ)
 526                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 527                 else
 528                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 529                 added++;
 530         } else
 531                 IWL_ERR(priv, "no valid channel found\n");
 532         return added;
 533 }
 534
 535 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 536                                      struct ieee80211_vif *vif,
 537                                      enum ieee80211_band band,
 538                                      u8 is_active, u8 n_probes,
 539                                      struct iwl_scan_channel *scan_ch)
 540 {
 541         struct ieee80211_channel *chan;
 542         const struct ieee80211_supported_band *sband;
 543         const struct iwl_channel_info *ch_info;
 544         u16 passive_dwell = 0;
 545         u16 active_dwell = 0;
 546         int added, i;
 547         u16 channel;
 548
 549         sband = iwl_get_hw_mode(priv, band);
 550         if (!sband)
 551                 return 0;
 552
 553         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 554         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 555
 556         if (passive_dwell <= active_dwell)
 557                 passive_dwell = active_dwell + 1;
 558
 559         for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
 560                 chan = priv->scan_request->channels[i];
 561
 562                 if (chan->band != band)
 563                         continue;
 564
 565                 channel = chan->hw_value;
 566                 scan_ch->channel = cpu_to_le16(channel);
 567
 568                 ch_info = iwl_get_channel_info(priv, band, channel);
 569                 if (!is_channel_valid(ch_info)) {
 570                         IWL_DEBUG_SCAN(priv,
 571                                        "Channel %d is INVALID for this band.\n",
 572                                        channel);
 573                         continue;
 574                 }
 575
 576                 if (!is_active || is_channel_passive(ch_info) ||
 577                     (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN))
 578                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 579                 else
 580                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 581
 582                 if (n_probes)
 583                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 584
 585                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 586                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 587
 588                 /* Set txpower levels to defaults */
 589                 scan_ch->dsp_atten = 110;
 590
 591                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 592                  * power level:
 593                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 594                  */
 595                 if (band == IEEE80211_BAND_5GHZ)
 596                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 597                 else
 598                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 599
 600                 IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
 601                                channel, le32_to_cpu(scan_ch->type),
 602                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 603                                 "ACTIVE" : "PASSIVE",
 604                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 605                                active_dwell : passive_dwell);
 606
 607                 scan_ch++;
 608                 added++;
 609         }
 610
 611         IWL_DEBUG_SCAN(priv, "total channels to scan %d\n", added);
 612         return added;
 613 }
 614
 615 /**
 616  * iwl_fill_probe_req - fill in all required fields and IE for probe request
 617  */
 618
 619 static u16 iwl_fill_probe_req(struct ieee80211_mgmt *frame, const u8 *ta,
 620                               const u8 *ies, int ie_len, int left)
 621 {
 622         int len = 0;
 623         u8 *pos = NULL;
 624
 625         /* Make sure there is enough space for the probe request,
 626          * two mandatory IEs and the data */
 627         left -= 24;
 628         if (left < 0)
 629                 return 0;
 630
 631         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 632         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
 633         memcpy(frame->sa, ta, ETH_ALEN);
 634         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
 635         frame->seq_ctrl = 0;
 636
 637         len += 24;
 638
 639         /* ...next IE... */
 640         pos = &frame->u.probe_req.variable[0];
 641
 642         /* fill in our indirect SSID IE */
 643         left -= 2;
 644         if (left < 0)
 645                 return 0;
 646         *pos++ = WLAN_EID_SSID;
 647         *pos++ = 0;
 648
 649         len += 2;
 650
 651         if (WARN_ON(left < ie_len))
 652                 return len;
 653
 654         if (ies && ie_len) {
 655                 memcpy(pos, ies, ie_len);
 656                 len += ie_len;
 657         }
 658
 659         return (u16)len;
 660 }
 661
 662 static int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
 663 {
 664         struct iwl_host_cmd cmd = {
 665                 .id = REPLY_SCAN_CMD,
 666                 .len = { sizeof(struct iwl_scan_cmd), },
 667                 .flags = CMD_SYNC,
 668         };
 669         struct iwl_scan_cmd *scan;
 670         struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
 671         u32 rate_flags = 0;
 672         u16 cmd_len = 0;
 673         u16 rx_chain = 0;
 674         enum ieee80211_band band;
 675         u8 n_probes = 0;
 676         u8 rx_ant = priv->hw_params.valid_rx_ant;
 677         u8 rate;
 678         bool is_active = false;
 679         int  chan_mod;
 680         u8 active_chains;
 681         u8 scan_tx_antennas = priv->hw_params.valid_tx_ant;
 682         int ret;
 683
 684         lockdep_assert_held(&priv->mutex);
 685
 686         if (vif)
 687                 ctx = iwl_rxon_ctx_from_vif(vif);
 688
 689         if (!priv->scan_cmd) {
 690                 priv->scan_cmd = kmalloc(sizeof(struct iwl_scan_cmd) +
 691                                          IWL_MAX_SCAN_SIZE, GFP_KERNEL);
 692                 if (!priv->scan_cmd) {
 693                         IWL_DEBUG_SCAN(priv,
 694                                        "fail to allocate memory for scan\n");
 695                         return -ENOMEM;
 696                 }
 697         }
 698         scan = priv->scan_cmd;
 699         memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
 700
 701         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
 702         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
 703
 704         if (priv->scan_type != IWL_SCAN_ROC &&
 705             iwl_is_any_associated(priv)) {
 706                 u16 interval = 0;
 707                 u32 extra;
 708                 u32 suspend_time = 100;
 709                 u32 scan_suspend_time = 100;
 710
 711                 IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
 712                 switch (priv->scan_type) {
 713                 case IWL_SCAN_ROC:
 714                         WARN_ON(1);
 715                         break;
 716                 case IWL_SCAN_RADIO_RESET:
 717                         interval = 0;
 718                         break;
 719                 case IWL_SCAN_NORMAL:
 720                         interval = vif->bss_conf.beacon_int;
 721                         break;
 722                 }
 723
 724                 scan->suspend_time = 0;
 725                 scan->max_out_time = cpu_to_le32(200 * 1024);
 726                 if (!interval)
 727                         interval = suspend_time;
 728
 729                 extra = (suspend_time / interval) << 22;
 730                 scan_suspend_time = (extra |
 731                     ((suspend_time % interval) * 1024));
 732                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
 733                 IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
 734                                scan_suspend_time, interval);
 735         } else if (priv->scan_type == IWL_SCAN_ROC) {
 736                 scan->suspend_time = 0;
 737                 scan->max_out_time = 0;
 738                 scan->quiet_time = 0;
 739                 scan->quiet_plcp_th = 0;
 740         }
 741
 742         switch (priv->scan_type) {
 743         case IWL_SCAN_RADIO_RESET:
 744                 IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
 745                 break;
 746         case IWL_SCAN_NORMAL:
 747                 if (priv->scan_request->n_ssids) {
 748                         int i, p = 0;
 749                         IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
 750                         for (i = 0; i < priv->scan_request->n_ssids; i++) {
 751                                 /* always does wildcard anyway */
 752                                 if (!priv->scan_request->ssids[i].ssid_len)
 753                                         continue;
 754                                 scan->direct_scan[p].id = WLAN_EID_SSID;
 755                                 scan->direct_scan[p].len =
 756                                         priv->scan_request->ssids[i].ssid_len;
 757                                 memcpy(scan->direct_scan[p].ssid,
 758                                        priv->scan_request->ssids[i].ssid,
 759                                        priv->scan_request->ssids[i].ssid_len);
 760                                 n_probes++;
 761                                 p++;
 762                         }
 763                         is_active = true;
 764                 } else
 765                         IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
 766                 break;
 767         case IWL_SCAN_ROC:
 768                 IWL_DEBUG_SCAN(priv, "Start ROC scan.\n");
 769                 break;
 770         }
 771
 772         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
 773         scan->tx_cmd.sta_id = ctx->bcast_sta_id;
 774         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
 775
 776         switch (priv->scan_band) {
 777         case IEEE80211_BAND_2GHZ:
 778                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
 779                 chan_mod = le32_to_cpu(
 780                         priv->contexts[IWL_RXON_CTX_BSS].active.flags &
 781                                                 RXON_FLG_CHANNEL_MODE_MSK)
 782                                        >> RXON_FLG_CHANNEL_MODE_POS;
 783                 if ((priv->scan_request && priv->scan_request->no_cck) ||
 784                     chan_mod == CHANNEL_MODE_PURE_40) {
 785                         rate = IWL_RATE_6M_PLCP;
 786                 } else {
 787                         rate = IWL_RATE_1M_PLCP;
 788                         rate_flags = RATE_MCS_CCK_MSK;
 789                 }
 790                 /*
 791                  * Internal scans are passive, so we can indiscriminately set
 792                  * the BT ignore flag on 2.4 GHz since it applies to TX only.
 793                  */
 794                 if (priv->cfg->bt_params &&
 795                     priv->cfg->bt_params->advanced_bt_coexist)
 796                         scan->tx_cmd.tx_flags |= TX_CMD_FLG_IGNORE_BT;
 797                 break;
 798         case IEEE80211_BAND_5GHZ:
 799                 rate = IWL_RATE_6M_PLCP;
 800                 break;
 801         default:
 802                 IWL_WARN(priv, "Invalid scan band\n");
 803                 return -EIO;
 804         }
 805
 806         /*
 807          * If active scanning is requested but a certain channel is
 808          * marked passive, we can do active scanning if we detect
 809          * transmissions.
 810          *
 811          * There is an issue with some firmware versions that triggers
 812          * a sysassert on a "good CRC threshold" of zero (== disabled),
 813          * on a radar channel even though this means that we should NOT
 814          * send probes.
 815          *
 816          * The "good CRC threshold" is the number of frames that we
 817          * need to receive during our dwell time on a channel before
 818          * sending out probes -- setting this to a huge value will
 819          * mean we never reach it, but at the same time work around
 820          * the aforementioned issue. Thus use IWL_GOOD_CRC_TH_NEVER
 821          * here instead of IWL_GOOD_CRC_TH_DISABLED.
 822          *
 823          * This was fixed in later versions along with some other
 824          * scan changes, and the threshold behaves as a flag in those
 825          * versions.
 826          */
 827         if (priv->new_scan_threshold_behaviour)
 828                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 829                                                 IWL_GOOD_CRC_TH_DISABLED;
 830         else
 831                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 832                                                 IWL_GOOD_CRC_TH_NEVER;
 833
 834         band = priv->scan_band;
 835
 836         if (band == IEEE80211_BAND_2GHZ &&
 837             priv->cfg->bt_params &&
 838             priv->cfg->bt_params->advanced_bt_coexist) {
 839                 /* transmit 2.4 GHz probes only on first antenna */
 840                 scan_tx_antennas = first_antenna(scan_tx_antennas);
 841         }
 842
 843         priv->scan_tx_ant[band] = iwl_toggle_tx_ant(priv,
 844                                                     priv->scan_tx_ant[band],
 845                                                     scan_tx_antennas);
 846         rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
 847         scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
 848
 849         /*
 850          * In power save mode while associated use one chain,
 851          * otherwise use all chains
 852          */
 853         if (test_bit(STATUS_POWER_PMI, &priv->status) &&
 854             !(priv->hw->conf.flags & IEEE80211_CONF_IDLE)) {
 855                 /* rx_ant has been set to all valid chains previously */
 856                 active_chains = rx_ant &
 857                                 ((u8)(priv->chain_noise_data.active_chains));
 858                 if (!active_chains)
 859                         active_chains = rx_ant;
 860
 861                 IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
 862                                 priv->chain_noise_data.active_chains);
 863
 864                 rx_ant = first_antenna(active_chains);
 865         }
 866         if (priv->cfg->bt_params &&
 867             priv->cfg->bt_params->advanced_bt_coexist &&
 868             priv->bt_full_concurrent) {
 869                 /* operated as 1x1 in full concurrency mode */
 870                 rx_ant = first_antenna(rx_ant);
 871         }
 872
 873         /* MIMO is not used here, but value is required */
 874         rx_chain |=
 875                 priv->hw_params.valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
 876         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
 877         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
 878         rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
 879         scan->rx_chain = cpu_to_le16(rx_chain);
 880         switch (priv->scan_type) {
 881         case IWL_SCAN_NORMAL:
 882                 cmd_len = iwl_fill_probe_req(
 883                                         (struct ieee80211_mgmt *)scan->data,
 884                                         vif->addr,
 885                                         priv->scan_request->ie,
 886                                         priv->scan_request->ie_len,
 887                                         IWL_MAX_SCAN_SIZE - sizeof(*scan));
 888                 break;
 889         case IWL_SCAN_RADIO_RESET:
 890         case IWL_SCAN_ROC:
 891                 /* use bcast addr, will not be transmitted but must be valid */
 892                 cmd_len = iwl_fill_probe_req(
 893                                         (struct ieee80211_mgmt *)scan->data,
 894                                         iwl_bcast_addr, NULL, 0,
 895                                         IWL_MAX_SCAN_SIZE - sizeof(*scan));
 896                 break;
 897         default:
 898                 BUG();
 899         }
 900         scan->tx_cmd.len = cpu_to_le16(cmd_len);
 901
 902         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 903                                RXON_FILTER_BCON_AWARE_MSK);
 904
 905         switch (priv->scan_type) {
 906         case IWL_SCAN_RADIO_RESET:
 907                 scan->channel_count =
 908                         iwl_get_single_channel_for_scan(priv, vif, band,
 909                                 (void *)&scan->data[cmd_len]);
 910                 break;
 911         case IWL_SCAN_NORMAL:
 912                 scan->channel_count =
 913                         iwl_get_channels_for_scan(priv, vif, band,
 914                                 is_active, n_probes,
 915                                 (void *)&scan->data[cmd_len]);
 916                 break;
 917         case IWL_SCAN_ROC: {
 918                 struct iwl_scan_channel *scan_ch;
 919                 int n_chan, i;
 920                 u16 dwell;
 921
 922                 dwell = iwl_limit_dwell(priv, priv->hw_roc_duration);
 923                 n_chan = DIV_ROUND_UP(priv->hw_roc_duration, dwell);
 924
 925                 scan->channel_count = n_chan;
 926
 927                 scan_ch = (void *)&scan->data[cmd_len];
 928
 929                 for (i = 0; i < n_chan; i++) {
 930                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 931                         scan_ch->channel =
 932                                 cpu_to_le16(priv->hw_roc_channel->hw_value);
 933
 934                         if (i == n_chan - 1)
 935                                 dwell = priv->hw_roc_duration - i * dwell;
 936
 937                         scan_ch->active_dwell =
 938                         scan_ch->passive_dwell = cpu_to_le16(dwell);
 939
 940                         /* Set txpower levels to defaults */
 941                         scan_ch->dsp_atten = 110;
 942
 943                         /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 944                          * power level:
 945                          * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 946                          */
 947                         if (priv->hw_roc_channel->band == IEEE80211_BAND_5GHZ)
 948                                 scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 949                         else
 950                                 scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 951
 952                         scan_ch++;
 953                 }
 954                 }
 955
 956                 break;
 957         }
 958
 959         if (scan->channel_count == 0) {
 960                 IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
 961                 return -EIO;
 962         }
 963
 964         cmd.len[0] += le16_to_cpu(scan->tx_cmd.len) +
 965             scan->channel_count * sizeof(struct iwl_scan_channel);
 966         cmd.data[0] = scan;
 967         cmd.dataflags[0] = IWL_HCMD_DFL_NOCOPY;
 968         scan->len = cpu_to_le16(cmd.len[0]);
 969
 970         /* set scan bit here for PAN params */
 971         set_bit(STATUS_SCAN_HW, &priv->status);
 972
 973         ret = iwlagn_set_pan_params(priv);
 974         if (ret)
 975                 return ret;
 976
 977         ret = iwl_dvm_send_cmd(priv, &cmd);
 978         if (ret) {
 979                 clear_bit(STATUS_SCAN_HW, &priv->status);
 980                 iwlagn_set_pan_params(priv);
 981         }
 982
 983         return ret;
 984 }
 985
 986 void iwl_init_scan_params(struct iwl_priv *priv)
 987 {
 988         u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
 989         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
 990                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
 991         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
 992                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
 993 }
 994
 995 int __must_check iwl_scan_initiate(struct iwl_priv *priv,
 996                                    struct ieee80211_vif *vif,
 997                                    enum iwl_scan_type scan_type,
 998                                    enum ieee80211_band band)
 999 {
1000         int ret;
1001
1002         lockdep_assert_held(&priv->mutex);
1003
1004         cancel_delayed_work(&priv->scan_check);
1005
1006         if (!iwl_is_ready_rf(priv)) {
1007                 IWL_WARN(priv, "Request scan called when driver not ready.\n");
1008                 return -EIO;
1009         }
1010
1011         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
1012                 IWL_DEBUG_SCAN(priv,
1013                         "Multiple concurrent scan requests in parallel.\n");
1014                 return -EBUSY;
1015         }
1016
1017         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
1018                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending.\n");
1019                 return -EBUSY;
1020         }
1021
1022         IWL_DEBUG_SCAN(priv, "Starting %sscan...\n",
1023                         scan_type == IWL_SCAN_NORMAL ? "" :
1024                         scan_type == IWL_SCAN_ROC ? "remain-on-channel " :
1025                         "internal short ");
1026
1027         set_bit(STATUS_SCANNING, &priv->status);
1028         priv->scan_type = scan_type;
1029         priv->scan_start = jiffies;
1030         priv->scan_band = band;
1031
1032         ret = iwlagn_request_scan(priv, vif);
1033         if (ret) {
1034                 clear_bit(STATUS_SCANNING, &priv->status);
1035                 priv->scan_type = IWL_SCAN_NORMAL;
1036                 return ret;
1037         }
1038
1039         queue_delayed_work(priv->workqueue, &priv->scan_check,
1040                            IWL_SCAN_CHECK_WATCHDOG);
1041
1042         return 0;
1043 }
1044
1045
1046 /*
1047  * internal short scan, this function should only been called while associated.
1048  * It will reset and tune the radio to prevent possible RF related problem
1049  */
1050 void iwl_internal_short_hw_scan(struct iwl_priv *priv)
1051 {
1052         queue_work(priv->workqueue, &priv->start_internal_scan);
1053 }
1054
1055 static void iwl_bg_start_internal_scan(struct work_struct *work)
1056 {
1057         struct iwl_priv *priv =
1058                 container_of(work, struct iwl_priv, start_internal_scan);
1059
1060         IWL_DEBUG_SCAN(priv, "Start internal scan\n");
1061
1062         mutex_lock(&priv->mutex);
1063
1064         if (priv->scan_type == IWL_SCAN_RADIO_RESET) {
1065                 IWL_DEBUG_SCAN(priv, "Internal scan already in progress\n");
1066                 goto unlock;
1067         }
1068
1069         if (test_bit(STATUS_SCANNING, &priv->status)) {
1070                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
1071                 goto unlock;
1072         }
1073
1074         if (iwl_scan_initiate(priv, NULL, IWL_SCAN_RADIO_RESET, priv->band))
1075                 IWL_DEBUG_SCAN(priv, "failed to start internal short scan\n");
1076  unlock:
1077         mutex_unlock(&priv->mutex);
1078 }
1079
1080 static void iwl_bg_scan_check(struct work_struct *data)
1081 {
1082         struct iwl_priv *priv =
1083             container_of(data, struct iwl_priv, scan_check.work);
1084
1085         IWL_DEBUG_SCAN(priv, "Scan check work\n");
1086
1087         /* Since we are here firmware does not finish scan and
1088          * most likely is in bad shape, so we don't bother to
1089          * send abort command, just force scan complete to mac80211 */
1090         mutex_lock(&priv->mutex);
1091         iwl_force_scan_end(priv);
1092         mutex_unlock(&priv->mutex);
1093 }
1094
1095 static void iwl_bg_abort_scan(struct work_struct *work)
1096 {
1097         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
1098
1099         IWL_DEBUG_SCAN(priv, "Abort scan work\n");
1100
1101         /* We keep scan_check work queued in case when firmware will not
1102          * report back scan completed notification */
1103         mutex_lock(&priv->mutex);
1104         iwl_scan_cancel_timeout(priv, 200);
1105         mutex_unlock(&priv->mutex);
1106 }
1107
1108 static void iwl_bg_scan_completed(struct work_struct *work)
1109 {
1110         struct iwl_priv *priv =
1111                 container_of(work, struct iwl_priv, scan_completed);
1112
1113         mutex_lock(&priv->mutex);
1114         iwl_process_scan_complete(priv);
1115         mutex_unlock(&priv->mutex);
1116 }
1117
1118 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
1119 {
1120         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
1121         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
1122         INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
1123         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
1124 }
1125
1126 void iwl_cancel_scan_deferred_work(struct iwl_priv *priv)
1127 {
1128         cancel_work_sync(&priv->start_internal_scan);
1129         cancel_work_sync(&priv->abort_scan);
1130         cancel_work_sync(&priv->scan_completed);
1131
1132         if (cancel_delayed_work_sync(&priv->scan_check)) {
1133                 mutex_lock(&priv->mutex);
1134                 iwl_force_scan_end(priv);
1135                 mutex_unlock(&priv->mutex);
1136         }
1137 }