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

   1 /******************************************************************************
   2  *
   3  * GPL LICENSE SUMMARY
   4  *
   5  * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of version 2 of the GNU General Public License as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
  19  * USA
  20  *
  21  * The full GNU General Public License is included in this distribution
  22  * in the file called LICENSE.GPL.
  23  *
  24  * Contact Information:
  25  *  Intel Linux Wireless <ilw@linux.intel.com>
  26  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  27  *****************************************************************************/
  28 #include <linux/slab.h>
  29 #include <linux/types.h>
  30 #include <linux/etherdevice.h>
  31 #include <net/mac80211.h>
  32
  33 #include "iwl-eeprom.h"
  34 #include "iwl-dev.h"
  35 #include "iwl-core.h"
  36 #include "iwl-sta.h"
  37 #include "iwl-io.h"
  38 #include "iwl-helpers.h"
  39 #include "iwl-agn.h"
  40 #include "iwl-trans.h"
  41
  42 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
  43  * sending probe req.  This should be set long enough to hear probe responses
  44  * from more than one AP.  */
  45 #define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
  46 #define IWL_ACTIVE_DWELL_TIME_52    (20)
  47
  48 #define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
  49 #define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
  50
  51 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
  52  * Must be set longer than active dwell time.
  53  * For the most reliable scan, set > AP beacon interval (typically 100msec). */
  54 #define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
  55 #define IWL_PASSIVE_DWELL_TIME_52   (10)
  56 #define IWL_PASSIVE_DWELL_BASE      (100)
  57 #define IWL_CHANNEL_TUNE_TIME       5
  58
  59 static int iwl_send_scan_abort(struct iwl_priv *priv)
  60 {
  61         int ret;
  62         struct iwl_rx_packet *pkt;
  63         struct iwl_host_cmd cmd = {
  64                 .id = REPLY_SCAN_ABORT_CMD,
  65                 .flags = CMD_SYNC | CMD_WANT_SKB,
  66         };
  67
  68         /* Exit instantly with error when device is not ready
  69          * to receive scan abort command or it does not perform
  70          * hardware scan currently */
  71         if (!test_bit(STATUS_READY, &priv->shrd->status) ||
  72             !test_bit(STATUS_GEO_CONFIGURED, &priv->shrd->status) ||
  73             !test_bit(STATUS_SCAN_HW, &priv->shrd->status) ||
  74             test_bit(STATUS_FW_ERROR, &priv->shrd->status) ||
  75             test_bit(STATUS_EXIT_PENDING, &priv->shrd->status))
  76                 return -EIO;
  77
  78         ret = iwl_trans_send_cmd(trans(priv), &cmd);
  79         if (ret)
  80                 return ret;
  81
  82         pkt = (struct iwl_rx_packet *)cmd.reply_page;
  83         if (pkt->u.status != CAN_ABORT_STATUS) {
  84                 /* The scan abort will return 1 for success or
  85                  * 2 for "failure".  A failure condition can be
  86                  * due to simply not being in an active scan which
  87                  * can occur if we send the scan abort before we
  88                  * the microcode has notified us that a scan is
  89                  * completed. */
  90                 IWL_DEBUG_SCAN(priv, "SCAN_ABORT ret %d.\n", pkt->u.status);
  91                 ret = -EIO;
  92         }
  93
  94         iwl_free_pages(priv->shrd, cmd.reply_page);
  95         return ret;
  96 }
  97
  98 static void iwl_complete_scan(struct iwl_priv *priv, bool aborted)
  99 {
 100         /* check if scan was requested from mac80211 */
 101         if (priv->scan_request) {
 102                 IWL_DEBUG_SCAN(priv, "Complete scan in mac80211\n");
 103                 ieee80211_scan_completed(priv->hw, aborted);
 104         }
 105
 106         if (priv->scan_type == IWL_SCAN_ROC) {
 107                 ieee80211_remain_on_channel_expired(priv->hw);
 108                 priv->hw_roc_channel = NULL;
 109                 schedule_delayed_work(&priv->hw_roc_disable_work, 10 * HZ);
 110         }
 111
 112         priv->scan_type = IWL_SCAN_NORMAL;
 113         priv->scan_vif = NULL;
 114         priv->scan_request = NULL;
 115 }
 116
 117 static void iwl_process_scan_complete(struct iwl_priv *priv)
 118 {
 119         bool aborted;
 120
 121         lockdep_assert_held(&priv->shrd->mutex);
 122
 123         if (!test_and_clear_bit(STATUS_SCAN_COMPLETE, &priv->shrd->status))
 124                 return;
 125
 126         IWL_DEBUG_SCAN(priv, "Completed scan.\n");
 127
 128         cancel_delayed_work(&priv->scan_check);
 129
 130         aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->shrd->status);
 131         if (aborted)
 132                 IWL_DEBUG_SCAN(priv, "Aborted scan completed.\n");
 133
 134         if (!test_and_clear_bit(STATUS_SCANNING, &priv->shrd->status)) {
 135                 IWL_DEBUG_SCAN(priv, "Scan already completed.\n");
 136                 goto out_settings;
 137         }
 138
 139         if (priv->scan_type == IWL_SCAN_ROC) {
 140                 ieee80211_remain_on_channel_expired(priv->hw);
 141                 priv->hw_roc_channel = NULL;
 142                 schedule_delayed_work(&priv->hw_roc_disable_work, 10 * HZ);
 143         }
 144
 145         if (priv->scan_type != IWL_SCAN_NORMAL && !aborted) {
 146                 int err;
 147
 148                 /* Check if mac80211 requested scan during our internal scan */
 149                 if (priv->scan_request == NULL)
 150                         goto out_complete;
 151
 152                 /* If so request a new scan */
 153                 err = iwl_scan_initiate(priv, priv->scan_vif, IWL_SCAN_NORMAL,
 154                                         priv->scan_request->channels[0]->band);
 155                 if (err) {
 156                         IWL_DEBUG_SCAN(priv,
 157                                 "failed to initiate pending scan: %d\n", err);
 158                         aborted = true;
 159                         goto out_complete;
 160                 }
 161
 162                 return;
 163         }
 164
 165 out_complete:
 166         iwl_complete_scan(priv, aborted);
 167
 168 out_settings:
 169         /* Can we still talk to firmware ? */
 170         if (!iwl_is_ready_rf(priv->shrd))
 171                 return;
 172
 173         iwlagn_post_scan(priv);
 174 }
 175
 176 void iwl_force_scan_end(struct iwl_priv *priv)
 177 {
 178         lockdep_assert_held(&priv->shrd->mutex);
 179
 180         if (!test_bit(STATUS_SCANNING, &priv->shrd->status)) {
 181                 IWL_DEBUG_SCAN(priv, "Forcing scan end while not scanning\n");
 182                 return;
 183         }
 184
 185         IWL_DEBUG_SCAN(priv, "Forcing scan end\n");
 186         clear_bit(STATUS_SCANNING, &priv->shrd->status);
 187         clear_bit(STATUS_SCAN_HW, &priv->shrd->status);
 188         clear_bit(STATUS_SCAN_ABORTING, &priv->shrd->status);
 189         clear_bit(STATUS_SCAN_COMPLETE, &priv->shrd->status);
 190         iwl_complete_scan(priv, true);
 191 }
 192
 193 static void iwl_do_scan_abort(struct iwl_priv *priv)
 194 {
 195         int ret;
 196
 197         lockdep_assert_held(&priv->shrd->mutex);
 198
 199         if (!test_bit(STATUS_SCANNING, &priv->shrd->status)) {
 200                 IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
 201                 return;
 202         }
 203
 204         if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->shrd->status)) {
 205                 IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
 206                 return;
 207         }
 208
 209         ret = iwl_send_scan_abort(priv);
 210         if (ret) {
 211                 IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
 212                 iwl_force_scan_end(priv);
 213         } else
 214                 IWL_DEBUG_SCAN(priv, "Successfully send scan abort\n");
 215 }
 216
 217 /**
 218  * iwl_scan_cancel - Cancel any currently executing HW scan
 219  */
 220 int iwl_scan_cancel(struct iwl_priv *priv)
 221 {
 222         IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
 223         queue_work(priv->shrd->workqueue, &priv->abort_scan);
 224         return 0;
 225 }
 226
 227 /**
 228  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
 229  * @ms: amount of time to wait (in milliseconds) for scan to abort
 230  *
 231  */
 232 void iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
 233 {
 234         unsigned long timeout = jiffies + msecs_to_jiffies(ms);
 235
 236         lockdep_assert_held(&priv->shrd->mutex);
 237
 238         IWL_DEBUG_SCAN(priv, "Scan cancel timeout\n");
 239
 240         iwl_do_scan_abort(priv);
 241
 242         while (time_before_eq(jiffies, timeout)) {
 243                 if (!test_bit(STATUS_SCAN_HW, &priv->shrd->status))
 244                         goto finished;
 245                 msleep(20);
 246         }
 247
 248         return;
 249
 250  finished:
 251         /*
 252          * Now STATUS_SCAN_HW is clear. This means that the
 253          * device finished, but the background work is going
 254          * to execute at best as soon as we release the mutex.
 255          * Since we need to be able to issue a new scan right
 256          * after this function returns, run the complete here.
 257          * The STATUS_SCAN_COMPLETE bit will then be cleared
 258          * and prevent the background work from "completing"
 259          * a possible new scan.
 260          */
 261         iwl_process_scan_complete(priv);
 262 }
 263
 264 /* Service response to REPLY_SCAN_CMD (0x80) */
 265 static int iwl_rx_reply_scan(struct iwl_priv *priv,
 266                               struct iwl_rx_mem_buffer *rxb,
 267                               struct iwl_device_cmd *cmd)
 268 {
 269 #ifdef CONFIG_IWLWIFI_DEBUG
 270         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 271         struct iwl_scanreq_notification *notif =
 272             (struct iwl_scanreq_notification *)pkt->u.raw;
 273
 274         IWL_DEBUG_SCAN(priv, "Scan request status = 0x%x\n", notif->status);
 275 #endif
 276         return 0;
 277 }
 278
 279 /* Service SCAN_START_NOTIFICATION (0x82) */
 280 static int iwl_rx_scan_start_notif(struct iwl_priv *priv,
 281                                     struct iwl_rx_mem_buffer *rxb,
 282                                     struct iwl_device_cmd *cmd)
 283 {
 284         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 285         struct iwl_scanstart_notification *notif =
 286             (struct iwl_scanstart_notification *)pkt->u.raw;
 287         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 288         IWL_DEBUG_SCAN(priv, "Scan start: "
 289                        "%d [802.11%s] "
 290                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 291                        notif->channel,
 292                        notif->band ? "bg" : "a",
 293                        le32_to_cpu(notif->tsf_high),
 294                        le32_to_cpu(notif->tsf_low),
 295                        notif->status, notif->beacon_timer);
 296
 297         if (priv->scan_type == IWL_SCAN_ROC &&
 298             !priv->hw_roc_start_notified) {
 299                 ieee80211_ready_on_channel(priv->hw);
 300                 priv->hw_roc_start_notified = true;
 301         }
 302
 303         return 0;
 304 }
 305
 306 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 307 static int iwl_rx_scan_results_notif(struct iwl_priv *priv,
 308                                       struct iwl_rx_mem_buffer *rxb,
 309                                       struct iwl_device_cmd *cmd)
 310 {
 311 #ifdef CONFIG_IWLWIFI_DEBUG
 312         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 313         struct iwl_scanresults_notification *notif =
 314             (struct iwl_scanresults_notification *)pkt->u.raw;
 315
 316         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
 317                        "%d [802.11%s] "
 318                        "probe status: %u:%u "
 319                        "(TSF: 0x%08X:%08X) - %d "
 320                        "elapsed=%lu usec\n",
 321                        notif->channel,
 322                        notif->band ? "bg" : "a",
 323                        notif->probe_status, notif->num_probe_not_sent,
 324                        le32_to_cpu(notif->tsf_high),
 325                        le32_to_cpu(notif->tsf_low),
 326                        le32_to_cpu(notif->statistics[0]),
 327                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
 328 #endif
 329         return 0;
 330 }
 331
 332 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 333 static int iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 334                                        struct iwl_rx_mem_buffer *rxb,
 335                                        struct iwl_device_cmd *cmd)
 336 {
 337         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 338         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
 339
 340         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 341                        scan_notif->scanned_channels,
 342                        scan_notif->tsf_low,
 343                        scan_notif->tsf_high, scan_notif->status);
 344
 345         IWL_DEBUG_SCAN(priv, "Scan on %sGHz took %dms\n",
 346                        (priv->scan_band == IEEE80211_BAND_2GHZ) ? "2.4" : "5.2",
 347                        jiffies_to_msecs(jiffies - priv->scan_start));
 348
 349         /*
 350          * When aborting, we run the scan completed background work inline
 351          * and the background work must then do nothing. The SCAN_COMPLETE
 352          * bit helps implement that logic and thus needs to be set before
 353          * queueing the work. Also, since the scan abort waits for SCAN_HW
 354          * to clear, we need to set SCAN_COMPLETE before clearing SCAN_HW
 355          * to avoid a race there.
 356          */
 357         set_bit(STATUS_SCAN_COMPLETE, &priv->shrd->status);
 358         clear_bit(STATUS_SCAN_HW, &priv->shrd->status);
 359         queue_work(priv->shrd->workqueue, &priv->scan_completed);
 360
 361         if (priv->iw_mode != NL80211_IFTYPE_ADHOC &&
 362             iwl_advanced_bt_coexist(priv) &&
 363             priv->bt_status != scan_notif->bt_status) {
 364                 if (scan_notif->bt_status) {
 365                         /* BT on */
 366                         if (!priv->bt_ch_announce)
 367                                 priv->bt_traffic_load =
 368                                         IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
 369                         /*
 370                          * otherwise, no traffic load information provided
 371                          * no changes made
 372                          */
 373                 } else {
 374                         /* BT off */
 375                         priv->bt_traffic_load =
 376                                 IWL_BT_COEX_TRAFFIC_LOAD_NONE;
 377                 }
 378                 priv->bt_status = scan_notif->bt_status;
 379                 queue_work(priv->shrd->workqueue,
 380                            &priv->bt_traffic_change_work);
 381         }
 382         return 0;
 383 }
 384
 385 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 386 {
 387         /* scan handlers */
 388         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 389         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 390         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 391                                         iwl_rx_scan_results_notif;
 392         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 393                                         iwl_rx_scan_complete_notif;
 394 }
 395
 396 static u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 397                                      enum ieee80211_band band, u8 n_probes)
 398 {
 399         if (band == IEEE80211_BAND_5GHZ)
 400                 return IWL_ACTIVE_DWELL_TIME_52 +
 401                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 402         else
 403                 return IWL_ACTIVE_DWELL_TIME_24 +
 404                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 405 }
 406
 407 static u16 iwl_limit_dwell(struct iwl_priv *priv, u16 dwell_time)
 408 {
 409         struct iwl_rxon_context *ctx;
 410
 411         /*
 412          * If we're associated, we clamp the dwell time 98%
 413          * of the smallest beacon interval (minus 2 * channel
 414          * tune time)
 415          */
 416         for_each_context(priv, ctx) {
 417                 u16 value;
 418
 419                 if (!iwl_is_associated_ctx(ctx))
 420                         continue;
 421                 value = ctx->beacon_int;
 422                 if (!value)
 423                         value = IWL_PASSIVE_DWELL_BASE;
 424                 value = (value * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 425                 dwell_time = min(value, dwell_time);
 426         }
 427
 428         return dwell_time;
 429 }
 430
 431 static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 432                                       enum ieee80211_band band)
 433 {
 434         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
 435             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 436             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 437
 438         return iwl_limit_dwell(priv, passive);
 439 }
 440
 441 static int iwl_get_single_channel_for_scan(struct iwl_priv *priv,
 442                                            struct ieee80211_vif *vif,
 443                                            enum ieee80211_band band,
 444                                            struct iwl_scan_channel *scan_ch)
 445 {
 446         const struct ieee80211_supported_band *sband;
 447         u16 passive_dwell = 0;
 448         u16 active_dwell = 0;
 449         int added = 0;
 450         u16 channel = 0;
 451
 452         sband = iwl_get_hw_mode(priv, band);
 453         if (!sband) {
 454                 IWL_ERR(priv, "invalid band\n");
 455                 return added;
 456         }
 457
 458         active_dwell = iwl_get_active_dwell_time(priv, band, 0);
 459         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 460
 461         if (passive_dwell <= active_dwell)
 462                 passive_dwell = active_dwell + 1;
 463
 464         channel = iwl_get_single_channel_number(priv, band);
 465         if (channel) {
 466                 scan_ch->channel = cpu_to_le16(channel);
 467                 scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 468                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 469                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 470                 /* Set txpower levels to defaults */
 471                 scan_ch->dsp_atten = 110;
 472                 if (band == IEEE80211_BAND_5GHZ)
 473                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 474                 else
 475                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 476                 added++;
 477         } else
 478                 IWL_ERR(priv, "no valid channel found\n");
 479         return added;
 480 }
 481
 482 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 483                                      struct ieee80211_vif *vif,
 484                                      enum ieee80211_band band,
 485                                      u8 is_active, u8 n_probes,
 486                                      struct iwl_scan_channel *scan_ch)
 487 {
 488         struct ieee80211_channel *chan;
 489         const struct ieee80211_supported_band *sband;
 490         const struct iwl_channel_info *ch_info;
 491         u16 passive_dwell = 0;
 492         u16 active_dwell = 0;
 493         int added, i;
 494         u16 channel;
 495
 496         sband = iwl_get_hw_mode(priv, band);
 497         if (!sband)
 498                 return 0;
 499
 500         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 501         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 502
 503         if (passive_dwell <= active_dwell)
 504                 passive_dwell = active_dwell + 1;
 505
 506         for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
 507                 chan = priv->scan_request->channels[i];
 508
 509                 if (chan->band != band)
 510                         continue;
 511
 512                 channel = chan->hw_value;
 513                 scan_ch->channel = cpu_to_le16(channel);
 514
 515                 ch_info = iwl_get_channel_info(priv, band, channel);
 516                 if (!is_channel_valid(ch_info)) {
 517                         IWL_DEBUG_SCAN(priv,
 518                                        "Channel %d is INVALID for this band.\n",
 519                                        channel);
 520                         continue;
 521                 }
 522
 523                 if (!is_active || is_channel_passive(ch_info) ||
 524                     (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN))
 525                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 526                 else
 527                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 528
 529                 if (n_probes)
 530                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 531
 532                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 533                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 534
 535                 /* Set txpower levels to defaults */
 536                 scan_ch->dsp_atten = 110;
 537
 538                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 539                  * power level:
 540                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 541                  */
 542                 if (band == IEEE80211_BAND_5GHZ)
 543                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 544                 else
 545                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 546
 547                 IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
 548                                channel, le32_to_cpu(scan_ch->type),
 549                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 550                                 "ACTIVE" : "PASSIVE",
 551                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 552                                active_dwell : passive_dwell);
 553
 554                 scan_ch++;
 555                 added++;
 556         }
 557
 558         IWL_DEBUG_SCAN(priv, "total channels to scan %d\n", added);
 559         return added;
 560 }
 561
 562 static int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
 563 {
 564         struct iwl_host_cmd cmd = {
 565                 .id = REPLY_SCAN_CMD,
 566                 .len = { sizeof(struct iwl_scan_cmd), },
 567                 .flags = CMD_SYNC,
 568         };
 569         struct iwl_scan_cmd *scan;
 570         struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
 571         u32 rate_flags = 0;
 572         u16 cmd_len;
 573         u16 rx_chain = 0;
 574         enum ieee80211_band band;
 575         u8 n_probes = 0;
 576         u8 rx_ant = hw_params(priv).valid_rx_ant;
 577         u8 rate;
 578         bool is_active = false;
 579         int  chan_mod;
 580         u8 active_chains;
 581         u8 scan_tx_antennas = hw_params(priv).valid_tx_ant;
 582         int ret;
 583
 584         lockdep_assert_held(&priv->shrd->mutex);
 585
 586         if (vif)
 587                 ctx = iwl_rxon_ctx_from_vif(vif);
 588
 589         if (!priv->scan_cmd) {
 590                 priv->scan_cmd = kmalloc(sizeof(struct iwl_scan_cmd) +
 591                                          IWL_MAX_SCAN_SIZE, GFP_KERNEL);
 592                 if (!priv->scan_cmd) {
 593                         IWL_DEBUG_SCAN(priv,
 594                                        "fail to allocate memory for scan\n");
 595                         return -ENOMEM;
 596                 }
 597         }
 598         scan = priv->scan_cmd;
 599         memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
 600
 601         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
 602         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
 603
 604         if (priv->scan_type != IWL_SCAN_ROC &&
 605             iwl_is_any_associated(priv)) {
 606                 u16 interval = 0;
 607                 u32 extra;
 608                 u32 suspend_time = 100;
 609                 u32 scan_suspend_time = 100;
 610
 611                 IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
 612                 switch (priv->scan_type) {
 613                 case IWL_SCAN_ROC:
 614                         WARN_ON(1);
 615                         break;
 616                 case IWL_SCAN_RADIO_RESET:
 617                         interval = 0;
 618                         break;
 619                 case IWL_SCAN_NORMAL:
 620                         interval = vif->bss_conf.beacon_int;
 621                         break;
 622                 }
 623
 624                 scan->suspend_time = 0;
 625                 scan->max_out_time = cpu_to_le32(200 * 1024);
 626                 if (!interval)
 627                         interval = suspend_time;
 628
 629                 extra = (suspend_time / interval) << 22;
 630                 scan_suspend_time = (extra |
 631                     ((suspend_time % interval) * 1024));
 632                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
 633                 IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
 634                                scan_suspend_time, interval);
 635         } else if (priv->scan_type == IWL_SCAN_ROC) {
 636                 scan->suspend_time = 0;
 637                 scan->max_out_time = 0;
 638                 scan->quiet_time = 0;
 639                 scan->quiet_plcp_th = 0;
 640         }
 641
 642         switch (priv->scan_type) {
 643         case IWL_SCAN_RADIO_RESET:
 644                 IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
 645                 break;
 646         case IWL_SCAN_NORMAL:
 647                 if (priv->scan_request->n_ssids) {
 648                         int i, p = 0;
 649                         IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
 650                         for (i = 0; i < priv->scan_request->n_ssids; i++) {
 651                                 /* always does wildcard anyway */
 652                                 if (!priv->scan_request->ssids[i].ssid_len)
 653                                         continue;
 654                                 scan->direct_scan[p].id = WLAN_EID_SSID;
 655                                 scan->direct_scan[p].len =
 656                                         priv->scan_request->ssids[i].ssid_len;
 657                                 memcpy(scan->direct_scan[p].ssid,
 658                                        priv->scan_request->ssids[i].ssid,
 659                                        priv->scan_request->ssids[i].ssid_len);
 660                                 n_probes++;
 661                                 p++;
 662                         }
 663                         is_active = true;
 664                 } else
 665                         IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
 666                 break;
 667         case IWL_SCAN_ROC:
 668                 IWL_DEBUG_SCAN(priv, "Start ROC scan.\n");
 669                 break;
 670         }
 671
 672         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
 673         scan->tx_cmd.sta_id = ctx->bcast_sta_id;
 674         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
 675
 676         switch (priv->scan_band) {
 677         case IEEE80211_BAND_2GHZ:
 678                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
 679                 chan_mod = le32_to_cpu(
 680                         priv->contexts[IWL_RXON_CTX_BSS].active.flags &
 681                                                 RXON_FLG_CHANNEL_MODE_MSK)
 682                                        >> RXON_FLG_CHANNEL_MODE_POS;
 683                 if (chan_mod == CHANNEL_MODE_PURE_40) {
 684                         rate = IWL_RATE_6M_PLCP;
 685                 } else {
 686                         rate = IWL_RATE_1M_PLCP;
 687                         rate_flags = RATE_MCS_CCK_MSK;
 688                 }
 689                 /*
 690                  * Internal scans are passive, so we can indiscriminately set
 691                  * the BT ignore flag on 2.4 GHz since it applies to TX only.
 692                  */
 693                 if (priv->cfg->bt_params &&
 694                     priv->cfg->bt_params->advanced_bt_coexist)
 695                         scan->tx_cmd.tx_flags |= TX_CMD_FLG_IGNORE_BT;
 696                 break;
 697         case IEEE80211_BAND_5GHZ:
 698                 rate = IWL_RATE_6M_PLCP;
 699                 break;
 700         default:
 701                 IWL_WARN(priv, "Invalid scan band\n");
 702                 return -EIO;
 703         }
 704
 705         /*
 706          * If active scanning is requested but a certain channel is
 707          * marked passive, we can do active scanning if we detect
 708          * transmissions.
 709          *
 710          * There is an issue with some firmware versions that triggers
 711          * a sysassert on a "good CRC threshold" of zero (== disabled),
 712          * on a radar channel even though this means that we should NOT
 713          * send probes.
 714          *
 715          * The "good CRC threshold" is the number of frames that we
 716          * need to receive during our dwell time on a channel before
 717          * sending out probes -- setting this to a huge value will
 718          * mean we never reach it, but at the same time work around
 719          * the aforementioned issue. Thus use IWL_GOOD_CRC_TH_NEVER
 720          * here instead of IWL_GOOD_CRC_TH_DISABLED.
 721          *
 722          * This was fixed in later versions along with some other
 723          * scan changes, and the threshold behaves as a flag in those
 724          * versions.
 725          */
 726         if (priv->new_scan_threshold_behaviour)
 727                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 728                                                 IWL_GOOD_CRC_TH_DISABLED;
 729         else
 730                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 731                                                 IWL_GOOD_CRC_TH_NEVER;
 732
 733         band = priv->scan_band;
 734
 735         if (priv->cfg->scan_rx_antennas[band])
 736                 rx_ant = priv->cfg->scan_rx_antennas[band];
 737
 738         if (band == IEEE80211_BAND_2GHZ &&
 739             priv->cfg->bt_params &&
 740             priv->cfg->bt_params->advanced_bt_coexist) {
 741                 /* transmit 2.4 GHz probes only on first antenna */
 742                 scan_tx_antennas = first_antenna(scan_tx_antennas);
 743         }
 744
 745         priv->scan_tx_ant[band] = iwl_toggle_tx_ant(priv,
 746                                                     priv->scan_tx_ant[band],
 747                                                     scan_tx_antennas);
 748         rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
 749         scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
 750
 751         /* In power save mode use one chain, otherwise use all chains */
 752         if (test_bit(STATUS_POWER_PMI, &priv->shrd->status)) {
 753                 /* rx_ant has been set to all valid chains previously */
 754                 active_chains = rx_ant &
 755                                 ((u8)(priv->chain_noise_data.active_chains));
 756                 if (!active_chains)
 757                         active_chains = rx_ant;
 758
 759                 IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
 760                                 priv->chain_noise_data.active_chains);
 761
 762                 rx_ant = first_antenna(active_chains);
 763         }
 764         if (priv->cfg->bt_params &&
 765             priv->cfg->bt_params->advanced_bt_coexist &&
 766             priv->bt_full_concurrent) {
 767                 /* operated as 1x1 in full concurrency mode */
 768                 rx_ant = first_antenna(rx_ant);
 769         }
 770
 771         /* MIMO is not used here, but value is required */
 772         rx_chain |=
 773                 hw_params(priv).valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
 774         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
 775         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
 776         rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
 777         scan->rx_chain = cpu_to_le16(rx_chain);
 778         switch (priv->scan_type) {
 779         case IWL_SCAN_NORMAL:
 780                 cmd_len = iwl_fill_probe_req(priv,
 781                                         (struct ieee80211_mgmt *)scan->data,
 782                                         vif->addr,
 783                                         priv->scan_request->ie,
 784                                         priv->scan_request->ie_len,
 785                                         IWL_MAX_SCAN_SIZE - sizeof(*scan));
 786                 break;
 787         case IWL_SCAN_RADIO_RESET:
 788         case IWL_SCAN_ROC:
 789                 /* use bcast addr, will not be transmitted but must be valid */
 790                 cmd_len = iwl_fill_probe_req(priv,
 791                                         (struct ieee80211_mgmt *)scan->data,
 792                                         iwl_bcast_addr, NULL, 0,
 793                                         IWL_MAX_SCAN_SIZE - sizeof(*scan));
 794                 break;
 795         default:
 796                 BUG();
 797         }
 798         scan->tx_cmd.len = cpu_to_le16(cmd_len);
 799
 800         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 801                                RXON_FILTER_BCON_AWARE_MSK);
 802
 803         switch (priv->scan_type) {
 804         case IWL_SCAN_RADIO_RESET:
 805                 scan->channel_count =
 806                         iwl_get_single_channel_for_scan(priv, vif, band,
 807                                 (void *)&scan->data[cmd_len]);
 808                 break;
 809         case IWL_SCAN_NORMAL:
 810                 scan->channel_count =
 811                         iwl_get_channels_for_scan(priv, vif, band,
 812                                 is_active, n_probes,
 813                                 (void *)&scan->data[cmd_len]);
 814                 break;
 815         case IWL_SCAN_ROC: {
 816                 struct iwl_scan_channel *scan_ch;
 817                 int n_chan, i;
 818                 u16 dwell;
 819
 820                 dwell = iwl_limit_dwell(priv, priv->hw_roc_duration);
 821                 n_chan = DIV_ROUND_UP(priv->hw_roc_duration, dwell);
 822
 823                 scan->channel_count = n_chan;
 824
 825                 scan_ch = (void *)&scan->data[cmd_len];
 826
 827                 for (i = 0; i < n_chan; i++) {
 828                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 829                         scan_ch->channel =
 830                                 cpu_to_le16(priv->hw_roc_channel->hw_value);
 831
 832                         if (i == n_chan - 1)
 833                                 dwell = priv->hw_roc_duration - i * dwell;
 834
 835                         scan_ch->active_dwell =
 836                         scan_ch->passive_dwell = cpu_to_le16(dwell);
 837
 838                         /* Set txpower levels to defaults */
 839                         scan_ch->dsp_atten = 110;
 840
 841                         /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 842                          * power level:
 843                          * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 844                          */
 845                         if (priv->hw_roc_channel->band == IEEE80211_BAND_5GHZ)
 846                                 scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 847                         else
 848                                 scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 849
 850                         scan_ch++;
 851                 }
 852                 }
 853
 854                 break;
 855         }
 856
 857         if (scan->channel_count == 0) {
 858                 IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
 859                 return -EIO;
 860         }
 861
 862         cmd.len[0] += le16_to_cpu(scan->tx_cmd.len) +
 863             scan->channel_count * sizeof(struct iwl_scan_channel);
 864         cmd.data[0] = scan;
 865         cmd.dataflags[0] = IWL_HCMD_DFL_NOCOPY;
 866         scan->len = cpu_to_le16(cmd.len[0]);
 867
 868         /* set scan bit here for PAN params */
 869         set_bit(STATUS_SCAN_HW, &priv->shrd->status);
 870
 871         ret = iwlagn_set_pan_params(priv);
 872         if (ret)
 873                 return ret;
 874
 875         ret = iwl_trans_send_cmd(trans(priv), &cmd);
 876         if (ret) {
 877                 clear_bit(STATUS_SCAN_HW, &priv->shrd->status);
 878                 iwlagn_set_pan_params(priv);
 879         }
 880
 881         return ret;
 882 }
 883
 884 void iwl_init_scan_params(struct iwl_priv *priv)
 885 {
 886         u8 ant_idx = fls(hw_params(priv).valid_tx_ant) - 1;
 887         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
 888                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
 889         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
 890                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
 891 }
 892
 893 int __must_check iwl_scan_initiate(struct iwl_priv *priv,
 894                                    struct ieee80211_vif *vif,
 895                                    enum iwl_scan_type scan_type,
 896                                    enum ieee80211_band band)
 897 {
 898         int ret;
 899
 900         lockdep_assert_held(&priv->shrd->mutex);
 901
 902         cancel_delayed_work(&priv->scan_check);
 903
 904         if (!iwl_is_ready_rf(priv->shrd)) {
 905                 IWL_WARN(priv, "Request scan called when driver not ready.\n");
 906                 return -EIO;
 907         }
 908
 909         if (test_bit(STATUS_SCAN_HW, &priv->shrd->status)) {
 910                 IWL_DEBUG_SCAN(priv,
 911                         "Multiple concurrent scan requests in parallel.\n");
 912                 return -EBUSY;
 913         }
 914
 915         if (test_bit(STATUS_SCAN_ABORTING, &priv->shrd->status)) {
 916                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending.\n");
 917                 return -EBUSY;
 918         }
 919
 920         IWL_DEBUG_SCAN(priv, "Starting %sscan...\n",
 921                         scan_type == IWL_SCAN_NORMAL ? "" :
 922                         scan_type == IWL_SCAN_ROC ? "remain-on-channel " :
 923                         "internal short ");
 924
 925         set_bit(STATUS_SCANNING, &priv->shrd->status);
 926         priv->scan_type = scan_type;
 927         priv->scan_start = jiffies;
 928         priv->scan_band = band;
 929
 930         ret = iwlagn_request_scan(priv, vif);
 931         if (ret) {
 932                 clear_bit(STATUS_SCANNING, &priv->shrd->status);
 933                 priv->scan_type = IWL_SCAN_NORMAL;
 934                 return ret;
 935         }
 936
 937         queue_delayed_work(priv->shrd->workqueue, &priv->scan_check,
 938                            IWL_SCAN_CHECK_WATCHDOG);
 939
 940         return 0;
 941 }
 942
 943 int iwl_mac_hw_scan(struct ieee80211_hw *hw,
 944                     struct ieee80211_vif *vif,
 945                     struct cfg80211_scan_request *req)
 946 {
 947         struct iwl_priv *priv = hw->priv;
 948         int ret;
 949
 950         IWL_DEBUG_MAC80211(priv, "enter\n");
 951
 952         if (req->n_channels == 0)
 953                 return -EINVAL;
 954
 955         mutex_lock(&priv->shrd->mutex);
 956
 957         /*
 958          * If an internal scan is in progress, just set
 959          * up the scan_request as per above.
 960          */
 961         if (priv->scan_type != IWL_SCAN_NORMAL) {
 962                 IWL_DEBUG_SCAN(priv,
 963                                "SCAN request during internal scan - defer\n");
 964                 priv->scan_request = req;
 965                 priv->scan_vif = vif;
 966                 ret = 0;
 967         } else {
 968                 priv->scan_request = req;
 969                 priv->scan_vif = vif;
 970                 /*
 971                  * mac80211 will only ask for one band at a time
 972                  * so using channels[0] here is ok
 973                  */
 974                 ret = iwl_scan_initiate(priv, vif, IWL_SCAN_NORMAL,
 975                                         req->channels[0]->band);
 976                 if (ret) {
 977                         priv->scan_request = NULL;
 978                         priv->scan_vif = NULL;
 979                 }
 980         }
 981
 982         IWL_DEBUG_MAC80211(priv, "leave\n");
 983
 984         mutex_unlock(&priv->shrd->mutex);
 985
 986         return ret;
 987 }
 988
 989 /*
 990  * internal short scan, this function should only been called while associated.
 991  * It will reset and tune the radio to prevent possible RF related problem
 992  */
 993 void iwl_internal_short_hw_scan(struct iwl_priv *priv)
 994 {
 995         queue_work(priv->shrd->workqueue, &priv->start_internal_scan);
 996 }
 997
 998 static void iwl_bg_start_internal_scan(struct work_struct *work)
 999 {
1000         struct iwl_priv *priv =
1001                 container_of(work, struct iwl_priv, start_internal_scan);
1002
1003         IWL_DEBUG_SCAN(priv, "Start internal scan\n");
1004
1005         mutex_lock(&priv->shrd->mutex);
1006
1007         if (priv->scan_type == IWL_SCAN_RADIO_RESET) {
1008                 IWL_DEBUG_SCAN(priv, "Internal scan already in progress\n");
1009                 goto unlock;
1010         }
1011
1012         if (test_bit(STATUS_SCANNING, &priv->shrd->status)) {
1013                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
1014                 goto unlock;
1015         }
1016
1017         if (iwl_scan_initiate(priv, NULL, IWL_SCAN_RADIO_RESET, priv->band))
1018                 IWL_DEBUG_SCAN(priv, "failed to start internal short scan\n");
1019  unlock:
1020         mutex_unlock(&priv->shrd->mutex);
1021 }
1022
1023 static void iwl_bg_scan_check(struct work_struct *data)
1024 {
1025         struct iwl_priv *priv =
1026             container_of(data, struct iwl_priv, scan_check.work);
1027
1028         IWL_DEBUG_SCAN(priv, "Scan check work\n");
1029
1030         /* Since we are here firmware does not finish scan and
1031          * most likely is in bad shape, so we don't bother to
1032          * send abort command, just force scan complete to mac80211 */
1033         mutex_lock(&priv->shrd->mutex);
1034         iwl_force_scan_end(priv);
1035         mutex_unlock(&priv->shrd->mutex);
1036 }
1037
1038 /**
1039  * iwl_fill_probe_req - fill in all required fields and IE for probe request
1040  */
1041
1042 u16 iwl_fill_probe_req(struct iwl_priv *priv, struct ieee80211_mgmt *frame,
1043                        const u8 *ta, const u8 *ies, int ie_len, int left)
1044 {
1045         int len = 0;
1046         u8 *pos = NULL;
1047
1048         /* Make sure there is enough space for the probe request,
1049          * two mandatory IEs and the data */
1050         left -= 24;
1051         if (left < 0)
1052                 return 0;
1053
1054         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
1055         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
1056         memcpy(frame->sa, ta, ETH_ALEN);
1057         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
1058         frame->seq_ctrl = 0;
1059
1060         len += 24;
1061
1062         /* ...next IE... */
1063         pos = &frame->u.probe_req.variable[0];
1064
1065         /* fill in our indirect SSID IE */
1066         left -= 2;
1067         if (left < 0)
1068                 return 0;
1069         *pos++ = WLAN_EID_SSID;
1070         *pos++ = 0;
1071
1072         len += 2;
1073
1074         if (WARN_ON(left < ie_len))
1075                 return len;
1076
1077         if (ies && ie_len) {
1078                 memcpy(pos, ies, ie_len);
1079                 len += ie_len;
1080         }
1081
1082         return (u16)len;
1083 }
1084
1085 static void iwl_bg_abort_scan(struct work_struct *work)
1086 {
1087         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
1088
1089         IWL_DEBUG_SCAN(priv, "Abort scan work\n");
1090
1091         /* We keep scan_check work queued in case when firmware will not
1092          * report back scan completed notification */
1093         mutex_lock(&priv->shrd->mutex);
1094         iwl_scan_cancel_timeout(priv, 200);
1095         mutex_unlock(&priv->shrd->mutex);
1096 }
1097
1098 static void iwl_bg_scan_completed(struct work_struct *work)
1099 {
1100         struct iwl_priv *priv =
1101                 container_of(work, struct iwl_priv, scan_completed);
1102
1103         mutex_lock(&priv->shrd->mutex);
1104         iwl_process_scan_complete(priv);
1105         mutex_unlock(&priv->shrd->mutex);
1106 }
1107
1108 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
1109 {
1110         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
1111         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
1112         INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
1113         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
1114 }
1115
1116 void iwl_cancel_scan_deferred_work(struct iwl_priv *priv)
1117 {
1118         cancel_work_sync(&priv->start_internal_scan);
1119         cancel_work_sync(&priv->abort_scan);
1120         cancel_work_sync(&priv->scan_completed);
1121
1122         if (cancel_delayed_work_sync(&priv->scan_check)) {
1123                 mutex_lock(&priv->shrd->mutex);
1124                 iwl_force_scan_end(priv);
1125                 mutex_unlock(&priv->shrd->mutex);
1126         }
1127 }