linux/drivers/net/wireless/intel/iwlwifi/dvm/scan.c
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   1/******************************************************************************
   2 *
   3 * GPL LICENSE SUMMARY
   4 *
   5 * Copyright(c) 2008 - 2014 Intel Corporation. All rights reserved.
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of version 2 of the GNU General Public License as
   9 * published by the Free Software Foundation.
  10 *
  11 * This program is distributed in the hope that it will be useful, but
  12 * WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 * General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software
  18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
  19 * USA
  20 *
  21 * The full GNU General Public License is included in this distribution
  22 * in the file called COPYING.
  23 *
  24 * Contact Information:
  25 *  Intel Linux Wireless <linuxwifi@intel.com>
  26 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  27 *****************************************************************************/
  28#include <linux/slab.h>
  29#include <linux/types.h>
  30#include <linux/etherdevice.h>
  31#include <net/mac80211.h>
  32
  33#include "dev.h"
  34#include "agn.h"
  35
  36/* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
  37 * sending probe req.  This should be set long enough to hear probe responses
  38 * from more than one AP.  */
  39#define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
  40#define IWL_ACTIVE_DWELL_TIME_52    (20)
  41
  42#define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
  43#define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
  44
  45/* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
  46 * Must be set longer than active dwell time.
  47 * For the most reliable scan, set > AP beacon interval (typically 100msec). */
  48#define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
  49#define IWL_PASSIVE_DWELL_TIME_52   (10)
  50#define IWL_PASSIVE_DWELL_BASE      (100)
  51#define IWL_CHANNEL_TUNE_TIME       5
  52#define MAX_SCAN_CHANNEL            50
  53
  54/* For reset radio, need minimal dwell time only */
  55#define IWL_RADIO_RESET_DWELL_TIME      5
  56
  57static int iwl_send_scan_abort(struct iwl_priv *priv)
  58{
  59        int ret;
  60        struct iwl_host_cmd cmd = {
  61                .id = REPLY_SCAN_ABORT_CMD,
  62                .flags = CMD_WANT_SKB,
  63        };
  64        __le32 *status;
  65
  66        /* Exit instantly with error when device is not ready
  67         * to receive scan abort command or it does not perform
  68         * hardware scan currently */
  69        if (!test_bit(STATUS_READY, &priv->status) ||
  70            !test_bit(STATUS_SCAN_HW, &priv->status) ||
  71            test_bit(STATUS_FW_ERROR, &priv->status))
  72                return -EIO;
  73
  74        ret = iwl_dvm_send_cmd(priv, &cmd);
  75        if (ret)
  76                return ret;
  77
  78        status = (void *)cmd.resp_pkt->data;
  79        if (*status != CAN_ABORT_STATUS) {
  80                /* The scan abort will return 1 for success or
  81                 * 2 for "failure".  A failure condition can be
  82                 * due to simply not being in an active scan which
  83                 * can occur if we send the scan abort before we
  84                 * the microcode has notified us that a scan is
  85                 * completed. */
  86                IWL_DEBUG_SCAN(priv, "SCAN_ABORT ret %d.\n",
  87                               le32_to_cpu(*status));
  88                ret = -EIO;
  89        }
  90
  91        iwl_free_resp(&cmd);
  92        return ret;
  93}
  94
  95static void iwl_complete_scan(struct iwl_priv *priv, bool aborted)
  96{
  97        struct cfg80211_scan_info info = {
  98                .aborted = aborted,
  99        };
 100
 101        /* check if scan was requested from mac80211 */
 102        if (priv->scan_request) {
 103                IWL_DEBUG_SCAN(priv, "Complete scan in mac80211\n");
 104                ieee80211_scan_completed(priv->hw, &info);
 105        }
 106
 107        priv->scan_type = IWL_SCAN_NORMAL;
 108        priv->scan_vif = NULL;
 109        priv->scan_request = NULL;
 110}
 111
 112static void iwl_process_scan_complete(struct iwl_priv *priv)
 113{
 114        bool aborted;
 115
 116        lockdep_assert_held(&priv->mutex);
 117
 118        if (!test_and_clear_bit(STATUS_SCAN_COMPLETE, &priv->status))
 119                return;
 120
 121        IWL_DEBUG_SCAN(priv, "Completed scan.\n");
 122
 123        cancel_delayed_work(&priv->scan_check);
 124
 125        aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 126        if (aborted)
 127                IWL_DEBUG_SCAN(priv, "Aborted scan completed.\n");
 128
 129        if (!test_and_clear_bit(STATUS_SCANNING, &priv->status)) {
 130                IWL_DEBUG_SCAN(priv, "Scan already completed.\n");
 131                goto out_settings;
 132        }
 133
 134        if (priv->scan_type != IWL_SCAN_NORMAL && !aborted) {
 135                int err;
 136
 137                /* Check if mac80211 requested scan during our internal scan */
 138                if (priv->scan_request == NULL)
 139                        goto out_complete;
 140
 141                /* If so request a new scan */
 142                err = iwl_scan_initiate(priv, priv->scan_vif, IWL_SCAN_NORMAL,
 143                                        priv->scan_request->channels[0]->band);
 144                if (err) {
 145                        IWL_DEBUG_SCAN(priv,
 146                                "failed to initiate pending scan: %d\n", err);
 147                        aborted = true;
 148                        goto out_complete;
 149                }
 150
 151                return;
 152        }
 153
 154out_complete:
 155        iwl_complete_scan(priv, aborted);
 156
 157out_settings:
 158        /* Can we still talk to firmware ? */
 159        if (!iwl_is_ready_rf(priv))
 160                return;
 161
 162        iwlagn_post_scan(priv);
 163}
 164
 165void iwl_force_scan_end(struct iwl_priv *priv)
 166{
 167        lockdep_assert_held(&priv->mutex);
 168
 169        if (!test_bit(STATUS_SCANNING, &priv->status)) {
 170                IWL_DEBUG_SCAN(priv, "Forcing scan end while not scanning\n");
 171                return;
 172        }
 173
 174        IWL_DEBUG_SCAN(priv, "Forcing scan end\n");
 175        clear_bit(STATUS_SCANNING, &priv->status);
 176        clear_bit(STATUS_SCAN_HW, &priv->status);
 177        clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 178        clear_bit(STATUS_SCAN_COMPLETE, &priv->status);
 179        iwl_complete_scan(priv, true);
 180}
 181
 182static void iwl_do_scan_abort(struct iwl_priv *priv)
 183{
 184        int ret;
 185
 186        lockdep_assert_held(&priv->mutex);
 187
 188        if (!test_bit(STATUS_SCANNING, &priv->status)) {
 189                IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
 190                return;
 191        }
 192
 193        if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 194                IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
 195                return;
 196        }
 197
 198        ret = iwl_send_scan_abort(priv);
 199        if (ret) {
 200                IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
 201                iwl_force_scan_end(priv);
 202        } else
 203                IWL_DEBUG_SCAN(priv, "Successfully send scan abort\n");
 204}
 205
 206/**
 207 * iwl_scan_cancel - Cancel any currently executing HW scan
 208 */
 209int iwl_scan_cancel(struct iwl_priv *priv)
 210{
 211        IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
 212        queue_work(priv->workqueue, &priv->abort_scan);
 213        return 0;
 214}
 215
 216/**
 217 * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
 218 * @ms: amount of time to wait (in milliseconds) for scan to abort
 219 *
 220 */
 221void iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
 222{
 223        unsigned long timeout = jiffies + msecs_to_jiffies(ms);
 224
 225        lockdep_assert_held(&priv->mutex);
 226
 227        IWL_DEBUG_SCAN(priv, "Scan cancel timeout\n");
 228
 229        iwl_do_scan_abort(priv);
 230
 231        while (time_before_eq(jiffies, timeout)) {
 232                if (!test_bit(STATUS_SCAN_HW, &priv->status))
 233                        goto finished;
 234                msleep(20);
 235        }
 236
 237        return;
 238
 239 finished:
 240        /*
 241         * Now STATUS_SCAN_HW is clear. This means that the
 242         * device finished, but the background work is going
 243         * to execute at best as soon as we release the mutex.
 244         * Since we need to be able to issue a new scan right
 245         * after this function returns, run the complete here.
 246         * The STATUS_SCAN_COMPLETE bit will then be cleared
 247         * and prevent the background work from "completing"
 248         * a possible new scan.
 249         */
 250        iwl_process_scan_complete(priv);
 251}
 252
 253/* Service response to REPLY_SCAN_CMD (0x80) */
 254static void iwl_rx_reply_scan(struct iwl_priv *priv,
 255                              struct iwl_rx_cmd_buffer *rxb)
 256{
 257#ifdef CONFIG_IWLWIFI_DEBUG
 258        struct iwl_rx_packet *pkt = rxb_addr(rxb);
 259        struct iwl_scanreq_notification *notif = (void *)pkt->data;
 260
 261        IWL_DEBUG_SCAN(priv, "Scan request status = 0x%x\n", notif->status);
 262#endif
 263}
 264
 265/* Service SCAN_START_NOTIFICATION (0x82) */
 266static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
 267                                    struct iwl_rx_cmd_buffer *rxb)
 268{
 269        struct iwl_rx_packet *pkt = rxb_addr(rxb);
 270        struct iwl_scanstart_notification *notif = (void *)pkt->data;
 271
 272        priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 273        IWL_DEBUG_SCAN(priv, "Scan start: "
 274                       "%d [802.11%s] "
 275                       "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 276                       notif->channel,
 277                       notif->band ? "bg" : "a",
 278                       le32_to_cpu(notif->tsf_high),
 279                       le32_to_cpu(notif->tsf_low),
 280                       notif->status, notif->beacon_timer);
 281}
 282
 283/* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 284static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
 285                                      struct iwl_rx_cmd_buffer *rxb)
 286{
 287#ifdef CONFIG_IWLWIFI_DEBUG
 288        struct iwl_rx_packet *pkt = rxb_addr(rxb);
 289        struct iwl_scanresults_notification *notif = (void *)pkt->data;
 290
 291        IWL_DEBUG_SCAN(priv, "Scan ch.res: "
 292                       "%d [802.11%s] "
 293                       "probe status: %u:%u "
 294                       "(TSF: 0x%08X:%08X) - %d "
 295                       "elapsed=%lu usec\n",
 296                       notif->channel,
 297                       notif->band ? "bg" : "a",
 298                       notif->probe_status, notif->num_probe_not_sent,
 299                       le32_to_cpu(notif->tsf_high),
 300                       le32_to_cpu(notif->tsf_low),
 301                       le32_to_cpu(notif->statistics[0]),
 302                       le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
 303#endif
 304}
 305
 306/* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 307static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 308                                       struct iwl_rx_cmd_buffer *rxb)
 309{
 310        struct iwl_rx_packet *pkt = rxb_addr(rxb);
 311        struct iwl_scancomplete_notification *scan_notif = (void *)pkt->data;
 312
 313        IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 314                       scan_notif->scanned_channels,
 315                       scan_notif->tsf_low,
 316                       scan_notif->tsf_high, scan_notif->status);
 317
 318        IWL_DEBUG_SCAN(priv, "Scan on %sGHz took %dms\n",
 319                       (priv->scan_band == NL80211_BAND_2GHZ) ? "2.4" : "5.2",
 320                       jiffies_to_msecs(jiffies - priv->scan_start));
 321
 322        /*
 323         * When aborting, we run the scan completed background work inline
 324         * and the background work must then do nothing. The SCAN_COMPLETE
 325         * bit helps implement that logic and thus needs to be set before
 326         * queueing the work. Also, since the scan abort waits for SCAN_HW
 327         * to clear, we need to set SCAN_COMPLETE before clearing SCAN_HW
 328         * to avoid a race there.
 329         */
 330        set_bit(STATUS_SCAN_COMPLETE, &priv->status);
 331        clear_bit(STATUS_SCAN_HW, &priv->status);
 332        queue_work(priv->workqueue, &priv->scan_completed);
 333
 334        if (priv->iw_mode != NL80211_IFTYPE_ADHOC &&
 335            iwl_advanced_bt_coexist(priv) &&
 336            priv->bt_status != scan_notif->bt_status) {
 337                if (scan_notif->bt_status) {
 338                        /* BT on */
 339                        if (!priv->bt_ch_announce)
 340                                priv->bt_traffic_load =
 341                                        IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
 342                        /*
 343                         * otherwise, no traffic load information provided
 344                         * no changes made
 345                         */
 346                } else {
 347                        /* BT off */
 348                        priv->bt_traffic_load =
 349                                IWL_BT_COEX_TRAFFIC_LOAD_NONE;
 350                }
 351                priv->bt_status = scan_notif->bt_status;
 352                queue_work(priv->workqueue,
 353                           &priv->bt_traffic_change_work);
 354        }
 355}
 356
 357void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 358{
 359        /* scan handlers */
 360        priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 361        priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 362        priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 363                                        iwl_rx_scan_results_notif;
 364        priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 365                                        iwl_rx_scan_complete_notif;
 366}
 367
 368static u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 369                                     enum nl80211_band band, u8 n_probes)
 370{
 371        if (band == NL80211_BAND_5GHZ)
 372                return IWL_ACTIVE_DWELL_TIME_52 +
 373                        IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 374        else
 375                return IWL_ACTIVE_DWELL_TIME_24 +
 376                        IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 377}
 378
 379static u16 iwl_limit_dwell(struct iwl_priv *priv, u16 dwell_time)
 380{
 381        struct iwl_rxon_context *ctx;
 382        int limits[NUM_IWL_RXON_CTX] = {};
 383        int n_active = 0;
 384        u16 limit;
 385
 386        BUILD_BUG_ON(NUM_IWL_RXON_CTX != 2);
 387
 388        /*
 389         * If we're associated, we clamp the dwell time 98%
 390         * of the beacon interval (minus 2 * channel tune time)
 391         * If both contexts are active, we have to restrict to
 392         * 1/2 of the minimum of them, because they might be in
 393         * lock-step with the time inbetween only half of what
 394         * time we'd have in each of them.
 395         */
 396        for_each_context(priv, ctx) {
 397                switch (ctx->staging.dev_type) {
 398                case RXON_DEV_TYPE_P2P:
 399                        /* no timing constraints */
 400                        continue;
 401                case RXON_DEV_TYPE_ESS:
 402                default:
 403                        /* timing constraints if associated */
 404                        if (!iwl_is_associated_ctx(ctx))
 405                                continue;
 406                        break;
 407                case RXON_DEV_TYPE_CP:
 408                case RXON_DEV_TYPE_2STA:
 409                        /*
 410                         * These seem to always have timers for TBTT
 411                         * active in uCode even when not associated yet.
 412                         */
 413                        break;
 414                }
 415
 416                limits[n_active++] = ctx->beacon_int ?: IWL_PASSIVE_DWELL_BASE;
 417        }
 418
 419        switch (n_active) {
 420        case 0:
 421                return dwell_time;
 422        case 2:
 423                limit = (limits[1] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 424                limit /= 2;
 425                dwell_time = min(limit, dwell_time);
 426                /* fall through to limit further */
 427        case 1:
 428                limit = (limits[0] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 429                limit /= n_active;
 430                return min(limit, dwell_time);
 431        default:
 432                WARN_ON_ONCE(1);
 433                return dwell_time;
 434        }
 435}
 436
 437static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 438                                      enum nl80211_band band)
 439{
 440        u16 passive = (band == NL80211_BAND_2GHZ) ?
 441            IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 442            IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 443
 444        return iwl_limit_dwell(priv, passive);
 445}
 446
 447/* Return valid, unused, channel for a passive scan to reset the RF */
 448static u8 iwl_get_single_channel_number(struct iwl_priv *priv,
 449                                        enum nl80211_band band)
 450{
 451        struct ieee80211_supported_band *sband = priv->hw->wiphy->bands[band];
 452        struct iwl_rxon_context *ctx;
 453        int i;
 454
 455        for (i = 0; i < sband->n_channels; i++) {
 456                bool busy = false;
 457
 458                for_each_context(priv, ctx) {
 459                        busy = sband->channels[i].hw_value ==
 460                                le16_to_cpu(ctx->staging.channel);
 461                        if (busy)
 462                                break;
 463                }
 464
 465                if (busy)
 466                        continue;
 467
 468                if (!(sband->channels[i].flags & IEEE80211_CHAN_DISABLED))
 469                        return sband->channels[i].hw_value;
 470        }
 471
 472        return 0;
 473}
 474
 475static int iwl_get_channel_for_reset_scan(struct iwl_priv *priv,
 476                                          struct ieee80211_vif *vif,
 477                                          enum nl80211_band band,
 478                                          struct iwl_scan_channel *scan_ch)
 479{
 480        const struct ieee80211_supported_band *sband;
 481        u16 channel;
 482
 483        sband = iwl_get_hw_mode(priv, band);
 484        if (!sband) {
 485                IWL_ERR(priv, "invalid band\n");
 486                return 0;
 487        }
 488
 489        channel = iwl_get_single_channel_number(priv, band);
 490        if (channel) {
 491                scan_ch->channel = cpu_to_le16(channel);
 492                scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 493                scan_ch->active_dwell =
 494                        cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
 495                scan_ch->passive_dwell =
 496                        cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
 497                /* Set txpower levels to defaults */
 498                scan_ch->dsp_atten = 110;
 499                if (band == NL80211_BAND_5GHZ)
 500                        scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 501                else
 502                        scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 503                return 1;
 504        }
 505
 506        IWL_ERR(priv, "no valid channel found\n");
 507        return 0;
 508}
 509
 510static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 511                                     struct ieee80211_vif *vif,
 512                                     enum nl80211_band band,
 513                                     u8 is_active, u8 n_probes,
 514                                     struct iwl_scan_channel *scan_ch)
 515{
 516        struct ieee80211_channel *chan;
 517        const struct ieee80211_supported_band *sband;
 518        u16 passive_dwell = 0;
 519        u16 active_dwell = 0;
 520        int added, i;
 521        u16 channel;
 522
 523        sband = iwl_get_hw_mode(priv, band);
 524        if (!sband)
 525                return 0;
 526
 527        active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 528        passive_dwell = iwl_get_passive_dwell_time(priv, band);
 529
 530        if (passive_dwell <= active_dwell)
 531                passive_dwell = active_dwell + 1;
 532
 533        for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
 534                chan = priv->scan_request->channels[i];
 535
 536                if (chan->band != band)
 537                        continue;
 538
 539                channel = chan->hw_value;
 540                scan_ch->channel = cpu_to_le16(channel);
 541
 542                if (!is_active || (chan->flags & IEEE80211_CHAN_NO_IR))
 543                        scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 544                else
 545                        scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 546
 547                if (n_probes)
 548                        scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 549
 550                scan_ch->active_dwell = cpu_to_le16(active_dwell);
 551                scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 552
 553                /* Set txpower levels to defaults */
 554                scan_ch->dsp_atten = 110;
 555
 556                /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 557                 * power level:
 558                 * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 559                 */
 560                if (band == NL80211_BAND_5GHZ)
 561                        scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 562                else
 563                        scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 564
 565                IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
 566                               channel, le32_to_cpu(scan_ch->type),
 567                               (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 568                                "ACTIVE" : "PASSIVE",
 569                               (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 570                               active_dwell : passive_dwell);
 571
 572                scan_ch++;
 573                added++;
 574        }
 575
 576        IWL_DEBUG_SCAN(priv, "total channels to scan %d\n", added);
 577        return added;
 578}
 579
 580/**
 581 * iwl_fill_probe_req - fill in all required fields and IE for probe request
 582 */
 583
 584static u16 iwl_fill_probe_req(struct ieee80211_mgmt *frame, const u8 *ta,
 585                              const u8 *ies, int ie_len, const u8 *ssid,
 586                              u8 ssid_len, int left)
 587{
 588        int len = 0;
 589        u8 *pos = NULL;
 590
 591        /* Make sure there is enough space for the probe request,
 592         * two mandatory IEs and the data */
 593        left -= 24;
 594        if (left < 0)
 595                return 0;
 596
 597        frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 598        eth_broadcast_addr(frame->da);
 599        memcpy(frame->sa, ta, ETH_ALEN);
 600        eth_broadcast_addr(frame->bssid);
 601        frame->seq_ctrl = 0;
 602
 603        len += 24;
 604
 605        /* ...next IE... */
 606        pos = &frame->u.probe_req.variable[0];
 607
 608        /* fill in our SSID IE */
 609        left -= ssid_len + 2;
 610        if (left < 0)
 611                return 0;
 612        *pos++ = WLAN_EID_SSID;
 613        *pos++ = ssid_len;
 614        if (ssid && ssid_len) {
 615                memcpy(pos, ssid, ssid_len);
 616                pos += ssid_len;
 617        }
 618
 619        len += ssid_len + 2;
 620
 621        if (WARN_ON(left < ie_len))
 622                return len;
 623
 624        if (ies && ie_len) {
 625                memcpy(pos, ies, ie_len);
 626                len += ie_len;
 627        }
 628
 629        return (u16)len;
 630}
 631
 632static int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
 633{
 634        struct iwl_host_cmd cmd = {
 635                .id = REPLY_SCAN_CMD,
 636                .len = { sizeof(struct iwl_scan_cmd), },
 637        };
 638        struct iwl_scan_cmd *scan;
 639        struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
 640        u32 rate_flags = 0;
 641        u16 cmd_len = 0;
 642        u16 rx_chain = 0;
 643        enum nl80211_band band;
 644        u8 n_probes = 0;
 645        u8 rx_ant = priv->nvm_data->valid_rx_ant;
 646        u8 rate;
 647        bool is_active = false;
 648        int  chan_mod;
 649        u8 active_chains;
 650        u8 scan_tx_antennas = priv->nvm_data->valid_tx_ant;
 651        int ret;
 652        int scan_cmd_size = sizeof(struct iwl_scan_cmd) +
 653                            MAX_SCAN_CHANNEL * sizeof(struct iwl_scan_channel) +
 654                            priv->fw->ucode_capa.max_probe_length;
 655        const u8 *ssid = NULL;
 656        u8 ssid_len = 0;
 657
 658        if (WARN_ON(priv->scan_type == IWL_SCAN_NORMAL &&
 659                    (!priv->scan_request ||
 660                     priv->scan_request->n_channels > MAX_SCAN_CHANNEL)))
 661                return -EINVAL;
 662
 663        lockdep_assert_held(&priv->mutex);
 664
 665        if (vif)
 666                ctx = iwl_rxon_ctx_from_vif(vif);
 667
 668        if (!priv->scan_cmd) {
 669                priv->scan_cmd = kmalloc(scan_cmd_size, GFP_KERNEL);
 670                if (!priv->scan_cmd) {
 671                        IWL_DEBUG_SCAN(priv,
 672                                       "fail to allocate memory for scan\n");
 673                        return -ENOMEM;
 674                }
 675        }
 676        scan = priv->scan_cmd;
 677        memset(scan, 0, scan_cmd_size);
 678
 679        scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
 680        scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
 681
 682        if (iwl_is_any_associated(priv)) {
 683                u16 interval = 0;
 684                u32 extra;
 685                u32 suspend_time = 100;
 686                u32 scan_suspend_time = 100;
 687
 688                IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
 689                switch (priv->scan_type) {
 690                case IWL_SCAN_RADIO_RESET:
 691                        interval = 0;
 692                        break;
 693                case IWL_SCAN_NORMAL:
 694                        interval = vif->bss_conf.beacon_int;
 695                        break;
 696                }
 697
 698                scan->suspend_time = 0;
 699                scan->max_out_time = cpu_to_le32(200 * 1024);
 700                if (!interval)
 701                        interval = suspend_time;
 702
 703                extra = (suspend_time / interval) << 22;
 704                scan_suspend_time = (extra |
 705                    ((suspend_time % interval) * 1024));
 706                scan->suspend_time = cpu_to_le32(scan_suspend_time);
 707                IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
 708                               scan_suspend_time, interval);
 709        }
 710
 711        switch (priv->scan_type) {
 712        case IWL_SCAN_RADIO_RESET:
 713                IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
 714                /*
 715                 * Override quiet time as firmware checks that active
 716                 * dwell is >= quiet; since we use passive scan it'll
 717                 * not actually be used.
 718                 */
 719                scan->quiet_time = cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
 720                break;
 721        case IWL_SCAN_NORMAL:
 722                if (priv->scan_request->n_ssids) {
 723                        int i, p = 0;
 724                        IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
 725                        /*
 726                         * The highest priority SSID is inserted to the
 727                         * probe request template.
 728                         */
 729                        ssid_len = priv->scan_request->ssids[0].ssid_len;
 730                        ssid = priv->scan_request->ssids[0].ssid;
 731
 732                        /*
 733                         * Invert the order of ssids, the firmware will invert
 734                         * it back.
 735                         */
 736                        for (i = priv->scan_request->n_ssids - 1; i >= 1; i--) {
 737                                scan->direct_scan[p].id = WLAN_EID_SSID;
 738                                scan->direct_scan[p].len =
 739                                        priv->scan_request->ssids[i].ssid_len;
 740                                memcpy(scan->direct_scan[p].ssid,
 741                                       priv->scan_request->ssids[i].ssid,
 742                                       priv->scan_request->ssids[i].ssid_len);
 743                                n_probes++;
 744                                p++;
 745                        }
 746                        is_active = true;
 747                } else
 748                        IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
 749                break;
 750        }
 751
 752        scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
 753        scan->tx_cmd.sta_id = ctx->bcast_sta_id;
 754        scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
 755
 756        switch (priv->scan_band) {
 757        case NL80211_BAND_2GHZ:
 758                scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
 759                chan_mod = le32_to_cpu(
 760                        priv->contexts[IWL_RXON_CTX_BSS].active.flags &
 761                                                RXON_FLG_CHANNEL_MODE_MSK)
 762                                       >> RXON_FLG_CHANNEL_MODE_POS;
 763                if ((priv->scan_request && priv->scan_request->no_cck) ||
 764                    chan_mod == CHANNEL_MODE_PURE_40) {
 765                        rate = IWL_RATE_6M_PLCP;
 766                } else {
 767                        rate = IWL_RATE_1M_PLCP;
 768                        rate_flags = RATE_MCS_CCK_MSK;
 769                }
 770                /*
 771                 * Internal scans are passive, so we can indiscriminately set
 772                 * the BT ignore flag on 2.4 GHz since it applies to TX only.
 773                 */
 774                if (priv->lib->bt_params &&
 775                    priv->lib->bt_params->advanced_bt_coexist)
 776                        scan->tx_cmd.tx_flags |= TX_CMD_FLG_IGNORE_BT;
 777                break;
 778        case NL80211_BAND_5GHZ:
 779                rate = IWL_RATE_6M_PLCP;
 780                break;
 781        default:
 782                IWL_WARN(priv, "Invalid scan band\n");
 783                return -EIO;
 784        }
 785
 786        /*
 787         * If active scanning is requested but a certain channel is
 788         * marked passive, we can do active scanning if we detect
 789         * transmissions.
 790         *
 791         * There is an issue with some firmware versions that triggers
 792         * a sysassert on a "good CRC threshold" of zero (== disabled),
 793         * on a radar channel even though this means that we should NOT
 794         * send probes.
 795         *
 796         * The "good CRC threshold" is the number of frames that we
 797         * need to receive during our dwell time on a channel before
 798         * sending out probes -- setting this to a huge value will
 799         * mean we never reach it, but at the same time work around
 800         * the aforementioned issue. Thus use IWL_GOOD_CRC_TH_NEVER
 801         * here instead of IWL_GOOD_CRC_TH_DISABLED.
 802         *
 803         * This was fixed in later versions along with some other
 804         * scan changes, and the threshold behaves as a flag in those
 805         * versions.
 806         */
 807        if (priv->new_scan_threshold_behaviour)
 808                scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 809                                                IWL_GOOD_CRC_TH_DISABLED;
 810        else
 811                scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 812                                                IWL_GOOD_CRC_TH_NEVER;
 813
 814        band = priv->scan_band;
 815
 816        if (band == NL80211_BAND_2GHZ &&
 817            priv->lib->bt_params &&
 818            priv->lib->bt_params->advanced_bt_coexist) {
 819                /* transmit 2.4 GHz probes only on first antenna */
 820                scan_tx_antennas = first_antenna(scan_tx_antennas);
 821        }
 822
 823        priv->scan_tx_ant[band] = iwl_toggle_tx_ant(priv,
 824                                                    priv->scan_tx_ant[band],
 825                                                    scan_tx_antennas);
 826        rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
 827        scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
 828
 829        /*
 830         * In power save mode while associated use one chain,
 831         * otherwise use all chains
 832         */
 833        if (test_bit(STATUS_POWER_PMI, &priv->status) &&
 834            !(priv->hw->conf.flags & IEEE80211_CONF_IDLE)) {
 835                /* rx_ant has been set to all valid chains previously */
 836                active_chains = rx_ant &
 837                                ((u8)(priv->chain_noise_data.active_chains));
 838                if (!active_chains)
 839                        active_chains = rx_ant;
 840
 841                IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
 842                                priv->chain_noise_data.active_chains);
 843
 844                rx_ant = first_antenna(active_chains);
 845        }
 846        if (priv->lib->bt_params &&
 847            priv->lib->bt_params->advanced_bt_coexist &&
 848            priv->bt_full_concurrent) {
 849                /* operated as 1x1 in full concurrency mode */
 850                rx_ant = first_antenna(rx_ant);
 851        }
 852
 853        /* MIMO is not used here, but value is required */
 854        rx_chain |=
 855                priv->nvm_data->valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
 856        rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
 857        rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
 858        rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
 859        scan->rx_chain = cpu_to_le16(rx_chain);
 860        switch (priv->scan_type) {
 861        case IWL_SCAN_NORMAL:
 862                cmd_len = iwl_fill_probe_req(
 863                                        (struct ieee80211_mgmt *)scan->data,
 864                                        vif->addr,
 865                                        priv->scan_request->ie,
 866                                        priv->scan_request->ie_len,
 867                                        ssid, ssid_len,
 868                                        scan_cmd_size - sizeof(*scan));
 869                break;
 870        case IWL_SCAN_RADIO_RESET:
 871                /* use bcast addr, will not be transmitted but must be valid */
 872                cmd_len = iwl_fill_probe_req(
 873                                        (struct ieee80211_mgmt *)scan->data,
 874                                        iwl_bcast_addr, NULL, 0,
 875                                        NULL, 0,
 876                                        scan_cmd_size - sizeof(*scan));
 877                break;
 878        default:
 879                BUG();
 880        }
 881        scan->tx_cmd.len = cpu_to_le16(cmd_len);
 882
 883        scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 884                               RXON_FILTER_BCON_AWARE_MSK);
 885
 886        switch (priv->scan_type) {
 887        case IWL_SCAN_RADIO_RESET:
 888                scan->channel_count =
 889                        iwl_get_channel_for_reset_scan(priv, vif, band,
 890                                (void *)&scan->data[cmd_len]);
 891                break;
 892        case IWL_SCAN_NORMAL:
 893                scan->channel_count =
 894                        iwl_get_channels_for_scan(priv, vif, band,
 895                                is_active, n_probes,
 896                                (void *)&scan->data[cmd_len]);
 897                break;
 898        }
 899
 900        if (scan->channel_count == 0) {
 901                IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
 902                return -EIO;
 903        }
 904
 905        cmd.len[0] += le16_to_cpu(scan->tx_cmd.len) +
 906            scan->channel_count * sizeof(struct iwl_scan_channel);
 907        cmd.data[0] = scan;
 908        cmd.dataflags[0] = IWL_HCMD_DFL_NOCOPY;
 909        scan->len = cpu_to_le16(cmd.len[0]);
 910
 911        /* set scan bit here for PAN params */
 912        set_bit(STATUS_SCAN_HW, &priv->status);
 913
 914        ret = iwlagn_set_pan_params(priv);
 915        if (ret) {
 916                clear_bit(STATUS_SCAN_HW, &priv->status);
 917                return ret;
 918        }
 919
 920        ret = iwl_dvm_send_cmd(priv, &cmd);
 921        if (ret) {
 922                clear_bit(STATUS_SCAN_HW, &priv->status);
 923                iwlagn_set_pan_params(priv);
 924        }
 925
 926        return ret;
 927}
 928
 929void iwl_init_scan_params(struct iwl_priv *priv)
 930{
 931        u8 ant_idx = fls(priv->nvm_data->valid_tx_ant) - 1;
 932        if (!priv->scan_tx_ant[NL80211_BAND_5GHZ])
 933                priv->scan_tx_ant[NL80211_BAND_5GHZ] = ant_idx;
 934        if (!priv->scan_tx_ant[NL80211_BAND_2GHZ])
 935                priv->scan_tx_ant[NL80211_BAND_2GHZ] = ant_idx;
 936}
 937
 938int __must_check iwl_scan_initiate(struct iwl_priv *priv,
 939                                   struct ieee80211_vif *vif,
 940                                   enum iwl_scan_type scan_type,
 941                                   enum nl80211_band band)
 942{
 943        int ret;
 944
 945        lockdep_assert_held(&priv->mutex);
 946
 947        cancel_delayed_work(&priv->scan_check);
 948
 949        if (!iwl_is_ready_rf(priv)) {
 950                IWL_WARN(priv, "Request scan called when driver not ready.\n");
 951                return -EIO;
 952        }
 953
 954        if (test_bit(STATUS_SCAN_HW, &priv->status)) {
 955                IWL_DEBUG_SCAN(priv,
 956                        "Multiple concurrent scan requests in parallel.\n");
 957                return -EBUSY;
 958        }
 959
 960        if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 961                IWL_DEBUG_SCAN(priv, "Scan request while abort pending.\n");
 962                return -EBUSY;
 963        }
 964
 965        IWL_DEBUG_SCAN(priv, "Starting %sscan...\n",
 966                        scan_type == IWL_SCAN_NORMAL ? "" :
 967                        "internal short ");
 968
 969        set_bit(STATUS_SCANNING, &priv->status);
 970        priv->scan_type = scan_type;
 971        priv->scan_start = jiffies;
 972        priv->scan_band = band;
 973
 974        ret = iwlagn_request_scan(priv, vif);
 975        if (ret) {
 976                clear_bit(STATUS_SCANNING, &priv->status);
 977                priv->scan_type = IWL_SCAN_NORMAL;
 978                return ret;
 979        }
 980
 981        queue_delayed_work(priv->workqueue, &priv->scan_check,
 982                           IWL_SCAN_CHECK_WATCHDOG);
 983
 984        return 0;
 985}
 986
 987
 988/*
 989 * internal short scan, this function should only been called while associated.
 990 * It will reset and tune the radio to prevent possible RF related problem
 991 */
 992void iwl_internal_short_hw_scan(struct iwl_priv *priv)
 993{
 994        queue_work(priv->workqueue, &priv->start_internal_scan);
 995}
 996
 997static void iwl_bg_start_internal_scan(struct work_struct *work)
 998{
 999        struct iwl_priv *priv =
1000                container_of(work, struct iwl_priv, start_internal_scan);
1001
1002        IWL_DEBUG_SCAN(priv, "Start internal scan\n");
1003
1004        mutex_lock(&priv->mutex);
1005
1006        if (priv->scan_type == IWL_SCAN_RADIO_RESET) {
1007                IWL_DEBUG_SCAN(priv, "Internal scan already in progress\n");
1008                goto unlock;
1009        }
1010
1011        if (test_bit(STATUS_SCANNING, &priv->status)) {
1012                IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
1013                goto unlock;
1014        }
1015
1016        if (iwl_scan_initiate(priv, NULL, IWL_SCAN_RADIO_RESET, priv->band))
1017                IWL_DEBUG_SCAN(priv, "failed to start internal short scan\n");
1018 unlock:
1019        mutex_unlock(&priv->mutex);
1020}
1021
1022static void iwl_bg_scan_check(struct work_struct *data)
1023{
1024        struct iwl_priv *priv =
1025            container_of(data, struct iwl_priv, scan_check.work);
1026
1027        IWL_DEBUG_SCAN(priv, "Scan check work\n");
1028
1029        /* Since we are here firmware does not finish scan and
1030         * most likely is in bad shape, so we don't bother to
1031         * send abort command, just force scan complete to mac80211 */
1032        mutex_lock(&priv->mutex);
1033        iwl_force_scan_end(priv);
1034        mutex_unlock(&priv->mutex);
1035}
1036
1037static void iwl_bg_abort_scan(struct work_struct *work)
1038{
1039        struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
1040
1041        IWL_DEBUG_SCAN(priv, "Abort scan work\n");
1042
1043        /* We keep scan_check work queued in case when firmware will not
1044         * report back scan completed notification */
1045        mutex_lock(&priv->mutex);
1046        iwl_scan_cancel_timeout(priv, 200);
1047        mutex_unlock(&priv->mutex);
1048}
1049
1050static void iwl_bg_scan_completed(struct work_struct *work)
1051{
1052        struct iwl_priv *priv =
1053                container_of(work, struct iwl_priv, scan_completed);
1054
1055        mutex_lock(&priv->mutex);
1056        iwl_process_scan_complete(priv);
1057        mutex_unlock(&priv->mutex);
1058}
1059
1060void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
1061{
1062        INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
1063        INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
1064        INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
1065        INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
1066}
1067
1068void iwl_cancel_scan_deferred_work(struct iwl_priv *priv)
1069{
1070        cancel_work_sync(&priv->start_internal_scan);
1071        cancel_work_sync(&priv->abort_scan);
1072        cancel_work_sync(&priv->scan_completed);
1073
1074        if (cancel_delayed_work_sync(&priv->scan_check)) {
1075                mutex_lock(&priv->mutex);
1076                iwl_force_scan_end(priv);
1077                mutex_unlock(&priv->mutex);
1078        }
1079}
1080