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

   1 /******************************************************************************
   2  *
   3  * GPL LICENSE SUMMARY
   4  *
   5  * Copyright(c) 2008 - 2010 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/types.h>
  29 #include <linux/etherdevice.h>
  30 #include <net/mac80211.h>
  31
  32 #include "iwl-eeprom.h"
  33 #include "iwl-dev.h"
  34 #include "iwl-core.h"
  35 #include "iwl-sta.h"
  36 #include "iwl-io.h"
  37 #include "iwl-helpers.h"
  38
  39 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
  40  * sending probe req.  This should be set long enough to hear probe responses
  41  * from more than one AP.  */
  42 #define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
  43 #define IWL_ACTIVE_DWELL_TIME_52    (20)
  44
  45 #define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
  46 #define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
  47
  48 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
  49  * Must be set longer than active dwell time.
  50  * For the most reliable scan, set > AP beacon interval (typically 100msec). */
  51 #define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
  52 #define IWL_PASSIVE_DWELL_TIME_52   (10)
  53 #define IWL_PASSIVE_DWELL_BASE      (100)
  54 #define IWL_CHANNEL_TUNE_TIME       5
  55
  56
  57
  58 /**
  59  * iwl_scan_cancel - Cancel any currently executing HW scan
  60  *
  61  * NOTE: priv->mutex is not required before calling this function
  62  */
  63 int iwl_scan_cancel(struct iwl_priv *priv)
  64 {
  65         if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
  66                 clear_bit(STATUS_SCANNING, &priv->status);
  67                 return 0;
  68         }
  69
  70         if (test_bit(STATUS_SCANNING, &priv->status)) {
  71                 if (!test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
  72                         IWL_DEBUG_SCAN(priv, "Queuing scan abort.\n");
  73                         set_bit(STATUS_SCAN_ABORTING, &priv->status);
  74                         queue_work(priv->workqueue, &priv->abort_scan);
  75
  76                 } else
  77                         IWL_DEBUG_SCAN(priv, "Scan abort already in progress.\n");
  78
  79                 return test_bit(STATUS_SCANNING, &priv->status);
  80         }
  81
  82         return 0;
  83 }
  84 EXPORT_SYMBOL(iwl_scan_cancel);
  85 /**
  86  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
  87  * @ms: amount of time to wait (in milliseconds) for scan to abort
  88  *
  89  * NOTE: priv->mutex must be held before calling this function
  90  */
  91 int iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
  92 {
  93         unsigned long now = jiffies;
  94         int ret;
  95
  96         ret = iwl_scan_cancel(priv);
  97         if (ret && ms) {
  98                 mutex_unlock(&priv->mutex);
  99                 while (!time_after(jiffies, now + msecs_to_jiffies(ms)) &&
 100                                 test_bit(STATUS_SCANNING, &priv->status))
 101                         msleep(1);
 102                 mutex_lock(&priv->mutex);
 103
 104                 return test_bit(STATUS_SCANNING, &priv->status);
 105         }
 106
 107         return ret;
 108 }
 109 EXPORT_SYMBOL(iwl_scan_cancel_timeout);
 110
 111 static int iwl_send_scan_abort(struct iwl_priv *priv)
 112 {
 113         int ret = 0;
 114         struct iwl_rx_packet *pkt;
 115         struct iwl_host_cmd cmd = {
 116                 .id = REPLY_SCAN_ABORT_CMD,
 117                 .flags = CMD_WANT_SKB,
 118         };
 119
 120         /* If there isn't a scan actively going on in the hardware
 121          * then we are in between scan bands and not actually
 122          * actively scanning, so don't send the abort command */
 123         if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
 124                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 125                 return 0;
 126         }
 127
 128         ret = iwl_send_cmd_sync(priv, &cmd);
 129         if (ret) {
 130                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 131                 return ret;
 132         }
 133
 134         pkt = (struct iwl_rx_packet *)cmd.reply_page;
 135         if (pkt->u.status != CAN_ABORT_STATUS) {
 136                 /* The scan abort will return 1 for success or
 137                  * 2 for "failure".  A failure condition can be
 138                  * due to simply not being in an active scan which
 139                  * can occur if we send the scan abort before we
 140                  * the microcode has notified us that a scan is
 141                  * completed. */
 142                 IWL_DEBUG_INFO(priv, "SCAN_ABORT returned %d.\n", pkt->u.status);
 143                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 144                 clear_bit(STATUS_SCAN_HW, &priv->status);
 145         }
 146
 147         iwl_free_pages(priv, cmd.reply_page);
 148
 149         return ret;
 150 }
 151
 152 /* Service response to REPLY_SCAN_CMD (0x80) */
 153 static void iwl_rx_reply_scan(struct iwl_priv *priv,
 154                               struct iwl_rx_mem_buffer *rxb)
 155 {
 156 #ifdef CONFIG_IWLWIFI_DEBUG
 157         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 158         struct iwl_scanreq_notification *notif =
 159             (struct iwl_scanreq_notification *)pkt->u.raw;
 160
 161         IWL_DEBUG_RX(priv, "Scan request status = 0x%x\n", notif->status);
 162 #endif
 163 }
 164
 165 /* Service SCAN_START_NOTIFICATION (0x82) */
 166 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
 167                                     struct iwl_rx_mem_buffer *rxb)
 168 {
 169         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 170         struct iwl_scanstart_notification *notif =
 171             (struct iwl_scanstart_notification *)pkt->u.raw;
 172         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 173         IWL_DEBUG_SCAN(priv, "Scan start: "
 174                        "%d [802.11%s] "
 175                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 176                        notif->channel,
 177                        notif->band ? "bg" : "a",
 178                        le32_to_cpu(notif->tsf_high),
 179                        le32_to_cpu(notif->tsf_low),
 180                        notif->status, notif->beacon_timer);
 181 }
 182
 183 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 184 static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
 185                                       struct iwl_rx_mem_buffer *rxb)
 186 {
 187 #ifdef CONFIG_IWLWIFI_DEBUG
 188         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 189         struct iwl_scanresults_notification *notif =
 190             (struct iwl_scanresults_notification *)pkt->u.raw;
 191
 192         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
 193                        "%d [802.11%s] "
 194                        "(TSF: 0x%08X:%08X) - %d "
 195                        "elapsed=%lu usec (%dms since last)\n",
 196                        notif->channel,
 197                        notif->band ? "bg" : "a",
 198                        le32_to_cpu(notif->tsf_high),
 199                        le32_to_cpu(notif->tsf_low),
 200                        le32_to_cpu(notif->statistics[0]),
 201                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf,
 202                        jiffies_to_msecs(elapsed_jiffies
 203                                         (priv->last_scan_jiffies, jiffies)));
 204 #endif
 205
 206         priv->last_scan_jiffies = jiffies;
 207         priv->next_scan_jiffies = 0;
 208 }
 209
 210 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 211 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 212                                        struct iwl_rx_mem_buffer *rxb)
 213 {
 214 #ifdef CONFIG_IWLWIFI_DEBUG
 215         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 216         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
 217
 218         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 219                        scan_notif->scanned_channels,
 220                        scan_notif->tsf_low,
 221                        scan_notif->tsf_high, scan_notif->status);
 222 #endif
 223
 224         /* The HW is no longer scanning */
 225         clear_bit(STATUS_SCAN_HW, &priv->status);
 226
 227         IWL_DEBUG_INFO(priv, "Scan pass on %sGHz took %dms\n",
 228                        (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) ?
 229                                                 "2.4" : "5.2",
 230                        jiffies_to_msecs(elapsed_jiffies
 231                                         (priv->scan_pass_start, jiffies)));
 232
 233         /* Remove this scanned band from the list of pending
 234          * bands to scan, band G precedes A in order of scanning
 235          * as seen in iwl_bg_request_scan */
 236         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ))
 237                 priv->scan_bands &= ~BIT(IEEE80211_BAND_2GHZ);
 238         else if (priv->scan_bands &  BIT(IEEE80211_BAND_5GHZ))
 239                 priv->scan_bands &= ~BIT(IEEE80211_BAND_5GHZ);
 240
 241         /* If a request to abort was given, or the scan did not succeed
 242          * then we reset the scan state machine and terminate,
 243          * re-queuing another scan if one has been requested */
 244         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 245                 IWL_DEBUG_INFO(priv, "Aborted scan completed.\n");
 246                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 247         } else {
 248                 /* If there are more bands on this scan pass reschedule */
 249                 if (priv->scan_bands)
 250                         goto reschedule;
 251         }
 252
 253         priv->last_scan_jiffies = jiffies;
 254         priv->next_scan_jiffies = 0;
 255         IWL_DEBUG_INFO(priv, "Setting scan to off\n");
 256
 257         clear_bit(STATUS_SCANNING, &priv->status);
 258
 259         IWL_DEBUG_INFO(priv, "Scan took %dms\n",
 260                 jiffies_to_msecs(elapsed_jiffies(priv->scan_start, jiffies)));
 261
 262         queue_work(priv->workqueue, &priv->scan_completed);
 263
 264         return;
 265
 266 reschedule:
 267         priv->scan_pass_start = jiffies;
 268         queue_work(priv->workqueue, &priv->request_scan);
 269 }
 270
 271 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 272 {
 273         /* scan handlers */
 274         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 275         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 276         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 277                                         iwl_rx_scan_results_notif;
 278         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 279                                         iwl_rx_scan_complete_notif;
 280 }
 281 EXPORT_SYMBOL(iwl_setup_rx_scan_handlers);
 282
 283 inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 284                                      enum ieee80211_band band,
 285                                      u8 n_probes)
 286 {
 287         if (band == IEEE80211_BAND_5GHZ)
 288                 return IWL_ACTIVE_DWELL_TIME_52 +
 289                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 290         else
 291                 return IWL_ACTIVE_DWELL_TIME_24 +
 292                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 293 }
 294 EXPORT_SYMBOL(iwl_get_active_dwell_time);
 295
 296 u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 297                                enum ieee80211_band band)
 298 {
 299         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
 300             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 301             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 302
 303         if (iwl_is_associated(priv)) {
 304                 /* If we're associated, we clamp the maximum passive
 305                  * dwell time to be 98% of the beacon interval (minus
 306                  * 2 * channel tune time) */
 307                 passive = priv->beacon_int;
 308                 if ((passive > IWL_PASSIVE_DWELL_BASE) || !passive)
 309                         passive = IWL_PASSIVE_DWELL_BASE;
 310                 passive = (passive * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 311         }
 312
 313         return passive;
 314 }
 315 EXPORT_SYMBOL(iwl_get_passive_dwell_time);
 316
 317 static int iwl_get_single_channel_for_scan(struct iwl_priv *priv,
 318                                      enum ieee80211_band band,
 319                                      struct iwl_scan_channel *scan_ch)
 320 {
 321         const struct ieee80211_supported_band *sband;
 322         const struct iwl_channel_info *ch_info;
 323         u16 passive_dwell = 0;
 324         u16 active_dwell = 0;
 325         int i, added = 0;
 326         u16 channel = 0;
 327
 328         sband = iwl_get_hw_mode(priv, band);
 329         if (!sband) {
 330                 IWL_ERR(priv, "invalid band\n");
 331                 return added;
 332         }
 333
 334         active_dwell = iwl_get_active_dwell_time(priv, band, 0);
 335         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 336
 337         if (passive_dwell <= active_dwell)
 338                 passive_dwell = active_dwell + 1;
 339
 340         /* only scan single channel, good enough to reset the RF */
 341         /* pick the first valid not in-use channel */
 342         if (band == IEEE80211_BAND_5GHZ) {
 343                 for (i = 14; i < priv->channel_count; i++) {
 344                         if (priv->channel_info[i].channel !=
 345                             le16_to_cpu(priv->staging_rxon.channel)) {
 346                                 channel = priv->channel_info[i].channel;
 347                                 ch_info = iwl_get_channel_info(priv,
 348                                         band, channel);
 349                                 if (is_channel_valid(ch_info))
 350                                         break;
 351                         }
 352                 }
 353         } else {
 354                 for (i = 0; i < 14; i++) {
 355                         if (priv->channel_info[i].channel !=
 356                             le16_to_cpu(priv->staging_rxon.channel)) {
 357                                         channel =
 358                                                 priv->channel_info[i].channel;
 359                                         ch_info = iwl_get_channel_info(priv,
 360                                                 band, channel);
 361                                         if (is_channel_valid(ch_info))
 362                                                 break;
 363                         }
 364                 }
 365         }
 366         if (channel) {
 367                 scan_ch->channel = cpu_to_le16(channel);
 368                 scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 369                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 370                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 371                 /* Set txpower levels to defaults */
 372                 scan_ch->dsp_atten = 110;
 373                 if (band == IEEE80211_BAND_5GHZ)
 374                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 375                 else
 376                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 377                 added++;
 378         } else
 379                 IWL_ERR(priv, "no valid channel found\n");
 380         return added;
 381 }
 382
 383 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 384                                      enum ieee80211_band band,
 385                                      u8 is_active, u8 n_probes,
 386                                      struct iwl_scan_channel *scan_ch)
 387 {
 388         struct ieee80211_channel *chan;
 389         const struct ieee80211_supported_band *sband;
 390         const struct iwl_channel_info *ch_info;
 391         u16 passive_dwell = 0;
 392         u16 active_dwell = 0;
 393         int added, i;
 394         u16 channel;
 395
 396         sband = iwl_get_hw_mode(priv, band);
 397         if (!sband)
 398                 return 0;
 399
 400         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 401         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 402
 403         if (passive_dwell <= active_dwell)
 404                 passive_dwell = active_dwell + 1;
 405
 406         for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
 407                 chan = priv->scan_request->channels[i];
 408
 409                 if (chan->band != band)
 410                         continue;
 411
 412                 channel = ieee80211_frequency_to_channel(chan->center_freq);
 413                 scan_ch->channel = cpu_to_le16(channel);
 414
 415                 ch_info = iwl_get_channel_info(priv, band, channel);
 416                 if (!is_channel_valid(ch_info)) {
 417                         IWL_DEBUG_SCAN(priv, "Channel %d is INVALID for this band.\n",
 418                                         channel);
 419                         continue;
 420                 }
 421
 422                 if (!is_active || is_channel_passive(ch_info) ||
 423                     (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN))
 424                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 425                 else
 426                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 427
 428                 if (n_probes)
 429                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 430
 431                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 432                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 433
 434                 /* Set txpower levels to defaults */
 435                 scan_ch->dsp_atten = 110;
 436
 437                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 438                  * power level:
 439                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 440                  */
 441                 if (band == IEEE80211_BAND_5GHZ)
 442                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 443                 else
 444                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 445
 446                 IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
 447                                channel, le32_to_cpu(scan_ch->type),
 448                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 449                                 "ACTIVE" : "PASSIVE",
 450                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 451                                active_dwell : passive_dwell);
 452
 453                 scan_ch++;
 454                 added++;
 455         }
 456
 457         IWL_DEBUG_SCAN(priv, "total channels to scan %d \n", added);
 458         return added;
 459 }
 460
 461 void iwl_init_scan_params(struct iwl_priv *priv)
 462 {
 463         u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
 464         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
 465                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
 466         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
 467                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
 468 }
 469 EXPORT_SYMBOL(iwl_init_scan_params);
 470
 471 static int iwl_scan_initiate(struct iwl_priv *priv)
 472 {
 473         if (!iwl_is_ready_rf(priv)) {
 474                 IWL_DEBUG_SCAN(priv, "Aborting scan due to not ready.\n");
 475                 return -EIO;
 476         }
 477
 478         if (test_bit(STATUS_SCANNING, &priv->status)) {
 479                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
 480                 return -EAGAIN;
 481         }
 482
 483         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 484                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
 485                 return -EAGAIN;
 486         }
 487
 488         IWL_DEBUG_INFO(priv, "Starting scan...\n");
 489         set_bit(STATUS_SCANNING, &priv->status);
 490         priv->is_internal_short_scan = false;
 491         priv->scan_start = jiffies;
 492         priv->scan_pass_start = priv->scan_start;
 493
 494         queue_work(priv->workqueue, &priv->request_scan);
 495
 496         return 0;
 497 }
 498
 499 #define IWL_DELAY_NEXT_SCAN (HZ*2)
 500
 501 int iwl_mac_hw_scan(struct ieee80211_hw *hw,
 502                      struct cfg80211_scan_request *req)
 503 {
 504         unsigned long flags;
 505         struct iwl_priv *priv = hw->priv;
 506         int ret, i;
 507
 508         IWL_DEBUG_MAC80211(priv, "enter\n");
 509
 510         mutex_lock(&priv->mutex);
 511         spin_lock_irqsave(&priv->lock, flags);
 512
 513         if (!iwl_is_ready_rf(priv)) {
 514                 ret = -EIO;
 515                 IWL_DEBUG_MAC80211(priv, "leave - not ready or exit pending\n");
 516                 goto out_unlock;
 517         }
 518
 519         /* We don't schedule scan within next_scan_jiffies period.
 520          * Avoid scanning during possible EAPOL exchange, return
 521          * success immediately.
 522          */
 523         if (priv->next_scan_jiffies &&
 524             time_after(priv->next_scan_jiffies, jiffies)) {
 525                 IWL_DEBUG_SCAN(priv, "scan rejected: within next scan period\n");
 526                 queue_work(priv->workqueue, &priv->scan_completed);
 527                 ret = 0;
 528                 goto out_unlock;
 529         }
 530
 531         /* if we just finished scan ask for delay */
 532         if (iwl_is_associated(priv) && priv->last_scan_jiffies &&
 533             time_after(priv->last_scan_jiffies + IWL_DELAY_NEXT_SCAN, jiffies)) {
 534                 IWL_DEBUG_SCAN(priv, "scan rejected: within previous scan period\n");
 535                 queue_work(priv->workqueue, &priv->scan_completed);
 536                 ret = 0;
 537                 goto out_unlock;
 538         }
 539
 540         priv->scan_bands = 0;
 541         for (i = 0; i < req->n_channels; i++)
 542                 priv->scan_bands |= BIT(req->channels[i]->band);
 543
 544         priv->scan_request = req;
 545
 546         ret = iwl_scan_initiate(priv);
 547
 548         IWL_DEBUG_MAC80211(priv, "leave\n");
 549
 550 out_unlock:
 551         spin_unlock_irqrestore(&priv->lock, flags);
 552         mutex_unlock(&priv->mutex);
 553
 554         return ret;
 555 }
 556 EXPORT_SYMBOL(iwl_mac_hw_scan);
 557
 558 /*
 559  * internal short scan, this function should only been called while associated.
 560  * It will reset and tune the radio to prevent possible RF related problem
 561  */
 562 int iwl_internal_short_hw_scan(struct iwl_priv *priv)
 563 {
 564         int ret = 0;
 565
 566         if (!iwl_is_ready_rf(priv)) {
 567                 ret = -EIO;
 568                 IWL_DEBUG_SCAN(priv, "not ready or exit pending\n");
 569                 goto out;
 570         }
 571         if (test_bit(STATUS_SCANNING, &priv->status)) {
 572                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
 573                 ret = -EAGAIN;
 574                 goto out;
 575         }
 576         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 577                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
 578                 ret = -EAGAIN;
 579                 goto out;
 580         }
 581         priv->scan_bands = 0;
 582         if (priv->band == IEEE80211_BAND_5GHZ)
 583                 priv->scan_bands |= BIT(IEEE80211_BAND_5GHZ);
 584         else
 585                 priv->scan_bands |= BIT(IEEE80211_BAND_2GHZ);
 586
 587         IWL_DEBUG_SCAN(priv, "Start internal short scan...\n");
 588         set_bit(STATUS_SCANNING, &priv->status);
 589         priv->is_internal_short_scan = true;
 590         queue_work(priv->workqueue, &priv->request_scan);
 591
 592 out:
 593         return ret;
 594 }
 595 EXPORT_SYMBOL(iwl_internal_short_hw_scan);
 596
 597 #define IWL_SCAN_CHECK_WATCHDOG (7 * HZ)
 598
 599 void iwl_bg_scan_check(struct work_struct *data)
 600 {
 601         struct iwl_priv *priv =
 602             container_of(data, struct iwl_priv, scan_check.work);
 603
 604         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 605                 return;
 606
 607         mutex_lock(&priv->mutex);
 608         if (test_bit(STATUS_SCANNING, &priv->status) ||
 609             test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 610                 IWL_DEBUG_SCAN(priv, "Scan completion watchdog resetting "
 611                         "adapter (%dms)\n",
 612                         jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG));
 613
 614                 if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
 615                         iwl_send_scan_abort(priv);
 616         }
 617         mutex_unlock(&priv->mutex);
 618 }
 619 EXPORT_SYMBOL(iwl_bg_scan_check);
 620
 621 /**
 622  * iwl_fill_probe_req - fill in all required fields and IE for probe request
 623  */
 624
 625 u16 iwl_fill_probe_req(struct iwl_priv *priv, struct ieee80211_mgmt *frame,
 626                        const u8 *ies, int ie_len, int left)
 627 {
 628         int len = 0;
 629         u8 *pos = NULL;
 630
 631         /* Make sure there is enough space for the probe request,
 632          * two mandatory IEs and the data */
 633         left -= 24;
 634         if (left < 0)
 635                 return 0;
 636
 637         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 638         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
 639         memcpy(frame->sa, priv->mac_addr, ETH_ALEN);
 640         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
 641         frame->seq_ctrl = 0;
 642
 643         len += 24;
 644
 645         /* ...next IE... */
 646         pos = &frame->u.probe_req.variable[0];
 647
 648         /* fill in our indirect SSID IE */
 649         left -= 2;
 650         if (left < 0)
 651                 return 0;
 652         *pos++ = WLAN_EID_SSID;
 653         *pos++ = 0;
 654
 655         len += 2;
 656
 657         if (WARN_ON(left < ie_len))
 658                 return len;
 659
 660         if (ies)
 661                 memcpy(pos, ies, ie_len);
 662         len += ie_len;
 663         left -= ie_len;
 664
 665         return (u16)len;
 666 }
 667 EXPORT_SYMBOL(iwl_fill_probe_req);
 668
 669 static void iwl_bg_request_scan(struct work_struct *data)
 670 {
 671         struct iwl_priv *priv =
 672             container_of(data, struct iwl_priv, request_scan);
 673         struct iwl_host_cmd cmd = {
 674                 .id = REPLY_SCAN_CMD,
 675                 .len = sizeof(struct iwl_scan_cmd),
 676                 .flags = CMD_SIZE_HUGE,
 677         };
 678         struct iwl_scan_cmd *scan;
 679         struct ieee80211_conf *conf = NULL;
 680         int ret = 0;
 681         u32 rate_flags = 0;
 682         u16 cmd_len;
 683         u16 rx_chain = 0;
 684         enum ieee80211_band band;
 685         u8 n_probes = 0;
 686         u8 rx_ant = priv->hw_params.valid_rx_ant;
 687         u8 rate;
 688         bool is_active = false;
 689         int  chan_mod;
 690         u8 active_chains;
 691
 692         conf = ieee80211_get_hw_conf(priv->hw);
 693
 694         mutex_lock(&priv->mutex);
 695
 696         cancel_delayed_work(&priv->scan_check);
 697
 698         if (!iwl_is_ready(priv)) {
 699                 IWL_WARN(priv, "request scan called when driver not ready.\n");
 700                 goto done;
 701         }
 702
 703         /* Make sure the scan wasn't canceled before this queued work
 704          * was given the chance to run... */
 705         if (!test_bit(STATUS_SCANNING, &priv->status))
 706                 goto done;
 707
 708         /* This should never be called or scheduled if there is currently
 709          * a scan active in the hardware. */
 710         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
 711                 IWL_DEBUG_INFO(priv, "Multiple concurrent scan requests in parallel. "
 712                                "Ignoring second request.\n");
 713                 ret = -EIO;
 714                 goto done;
 715         }
 716
 717         if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
 718                 IWL_DEBUG_SCAN(priv, "Aborting scan due to device shutdown\n");
 719                 goto done;
 720         }
 721
 722         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 723                 IWL_DEBUG_HC(priv, "Scan request while abort pending.  Queuing.\n");
 724                 goto done;
 725         }
 726
 727         if (iwl_is_rfkill(priv)) {
 728                 IWL_DEBUG_HC(priv, "Aborting scan due to RF Kill activation\n");
 729                 goto done;
 730         }
 731
 732         if (!test_bit(STATUS_READY, &priv->status)) {
 733                 IWL_DEBUG_HC(priv, "Scan request while uninitialized.  Queuing.\n");
 734                 goto done;
 735         }
 736
 737         if (!priv->scan_bands) {
 738                 IWL_DEBUG_HC(priv, "Aborting scan due to no requested bands\n");
 739                 goto done;
 740         }
 741
 742         if (!priv->scan) {
 743                 priv->scan = kmalloc(sizeof(struct iwl_scan_cmd) +
 744                                      IWL_MAX_SCAN_SIZE, GFP_KERNEL);
 745                 if (!priv->scan) {
 746                         ret = -ENOMEM;
 747                         goto done;
 748                 }
 749         }
 750         scan = priv->scan;
 751         memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
 752
 753         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
 754         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
 755
 756         if (iwl_is_associated(priv)) {
 757                 u16 interval = 0;
 758                 u32 extra;
 759                 u32 suspend_time = 100;
 760                 u32 scan_suspend_time = 100;
 761                 unsigned long flags;
 762
 763                 IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
 764                 spin_lock_irqsave(&priv->lock, flags);
 765                 interval = priv->beacon_int;
 766                 spin_unlock_irqrestore(&priv->lock, flags);
 767
 768                 scan->suspend_time = 0;
 769                 scan->max_out_time = cpu_to_le32(200 * 1024);
 770                 if (!interval)
 771                         interval = suspend_time;
 772
 773                 extra = (suspend_time / interval) << 22;
 774                 scan_suspend_time = (extra |
 775                     ((suspend_time % interval) * 1024));
 776                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
 777                 IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
 778                                scan_suspend_time, interval);
 779         }
 780
 781         if (priv->is_internal_short_scan) {
 782                 IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
 783         } else if (priv->scan_request->n_ssids) {
 784                 int i, p = 0;
 785                 IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
 786                 for (i = 0; i < priv->scan_request->n_ssids; i++) {
 787                         /* always does wildcard anyway */
 788                         if (!priv->scan_request->ssids[i].ssid_len)
 789                                 continue;
 790                         scan->direct_scan[p].id = WLAN_EID_SSID;
 791                         scan->direct_scan[p].len =
 792                                 priv->scan_request->ssids[i].ssid_len;
 793                         memcpy(scan->direct_scan[p].ssid,
 794                                priv->scan_request->ssids[i].ssid,
 795                                priv->scan_request->ssids[i].ssid_len);
 796                         n_probes++;
 797                         p++;
 798                 }
 799                 is_active = true;
 800         } else
 801                 IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
 802
 803         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
 804         scan->tx_cmd.sta_id = priv->hw_params.bcast_sta_id;
 805         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
 806
 807
 808         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) {
 809                 band = IEEE80211_BAND_2GHZ;
 810                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
 811                 chan_mod = le32_to_cpu(priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_MSK)
 812                                        >> RXON_FLG_CHANNEL_MODE_POS;
 813                 if (chan_mod == CHANNEL_MODE_PURE_40) {
 814                         rate = IWL_RATE_6M_PLCP;
 815                 } else {
 816                         rate = IWL_RATE_1M_PLCP;
 817                         rate_flags = RATE_MCS_CCK_MSK;
 818                 }
 819                 scan->good_CRC_th = 0;
 820         } else if (priv->scan_bands & BIT(IEEE80211_BAND_5GHZ)) {
 821                 band = IEEE80211_BAND_5GHZ;
 822                 rate = IWL_RATE_6M_PLCP;
 823                 /*
 824                  * If active scaning is requested but a certain channel
 825                  * is marked passive, we can do active scanning if we
 826                  * detect transmissions.
 827                  */
 828                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH : 0;
 829
 830                 /* Force use of chains B and C (0x6) for scan Rx for 4965
 831                  * Avoid A (0x1) because of its off-channel reception on A-band.
 832                  */
 833                 if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) == CSR_HW_REV_TYPE_4965)
 834                         rx_ant = ANT_BC;
 835         } else {
 836                 IWL_WARN(priv, "Invalid scan band count\n");
 837                 goto done;
 838         }
 839
 840         priv->scan_tx_ant[band] =
 841                          iwl_toggle_tx_ant(priv, priv->scan_tx_ant[band]);
 842         rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
 843         scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
 844
 845         /* In power save mode use one chain, otherwise use all chains */
 846         if (test_bit(STATUS_POWER_PMI, &priv->status)) {
 847                 /* rx_ant has been set to all valid chains previously */
 848                 active_chains = rx_ant &
 849                                 ((u8)(priv->chain_noise_data.active_chains));
 850                 if (!active_chains)
 851                         active_chains = rx_ant;
 852
 853                 IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
 854                                 priv->chain_noise_data.active_chains);
 855
 856                 rx_ant = first_antenna(active_chains);
 857         }
 858         /* MIMO is not used here, but value is required */
 859         rx_chain |= priv->hw_params.valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
 860         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
 861         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
 862         rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
 863         scan->rx_chain = cpu_to_le16(rx_chain);
 864         if (!priv->is_internal_short_scan) {
 865                 cmd_len = iwl_fill_probe_req(priv,
 866                                         (struct ieee80211_mgmt *)scan->data,
 867                                         priv->scan_request->ie,
 868                                         priv->scan_request->ie_len,
 869                                         IWL_MAX_SCAN_SIZE - sizeof(*scan));
 870         } else {
 871                 cmd_len = iwl_fill_probe_req(priv,
 872                                         (struct ieee80211_mgmt *)scan->data,
 873                                         NULL, 0,
 874                                         IWL_MAX_SCAN_SIZE - sizeof(*scan));
 875
 876         }
 877         scan->tx_cmd.len = cpu_to_le16(cmd_len);
 878         if (iwl_is_monitor_mode(priv))
 879                 scan->filter_flags = RXON_FILTER_PROMISC_MSK;
 880
 881         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 882                                RXON_FILTER_BCON_AWARE_MSK);
 883
 884         if (priv->is_internal_short_scan) {
 885                 scan->channel_count =
 886                         iwl_get_single_channel_for_scan(priv, band,
 887                                 (void *)&scan->data[le16_to_cpu(
 888                                 scan->tx_cmd.len)]);
 889         } else {
 890                 scan->channel_count =
 891                         iwl_get_channels_for_scan(priv, band,
 892                                 is_active, n_probes,
 893                                 (void *)&scan->data[le16_to_cpu(
 894                                 scan->tx_cmd.len)]);
 895         }
 896         if (scan->channel_count == 0) {
 897                 IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
 898                 goto done;
 899         }
 900
 901         cmd.len += le16_to_cpu(scan->tx_cmd.len) +
 902             scan->channel_count * sizeof(struct iwl_scan_channel);
 903         cmd.data = scan;
 904         scan->len = cpu_to_le16(cmd.len);
 905
 906         set_bit(STATUS_SCAN_HW, &priv->status);
 907         ret = iwl_send_cmd_sync(priv, &cmd);
 908         if (ret)
 909                 goto done;
 910
 911         queue_delayed_work(priv->workqueue, &priv->scan_check,
 912                            IWL_SCAN_CHECK_WATCHDOG);
 913
 914         mutex_unlock(&priv->mutex);
 915         return;
 916
 917  done:
 918         /* Cannot perform scan. Make sure we clear scanning
 919         * bits from status so next scan request can be performed.
 920         * If we don't clear scanning status bit here all next scan
 921         * will fail
 922         */
 923         clear_bit(STATUS_SCAN_HW, &priv->status);
 924         clear_bit(STATUS_SCANNING, &priv->status);
 925         /* inform mac80211 scan aborted */
 926         queue_work(priv->workqueue, &priv->scan_completed);
 927         mutex_unlock(&priv->mutex);
 928 }
 929
 930 void iwl_bg_abort_scan(struct work_struct *work)
 931 {
 932         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
 933
 934         if (!test_bit(STATUS_READY, &priv->status) ||
 935             !test_bit(STATUS_GEO_CONFIGURED, &priv->status))
 936                 return;
 937
 938         mutex_lock(&priv->mutex);
 939
 940         set_bit(STATUS_SCAN_ABORTING, &priv->status);
 941         iwl_send_scan_abort(priv);
 942
 943         mutex_unlock(&priv->mutex);
 944 }
 945 EXPORT_SYMBOL(iwl_bg_abort_scan);
 946
 947 void iwl_bg_scan_completed(struct work_struct *work)
 948 {
 949         struct iwl_priv *priv =
 950             container_of(work, struct iwl_priv, scan_completed);
 951
 952         IWL_DEBUG_SCAN(priv, "SCAN complete scan\n");
 953
 954         cancel_delayed_work(&priv->scan_check);
 955
 956         if (!priv->is_internal_short_scan)
 957                 ieee80211_scan_completed(priv->hw, false);
 958         else {
 959                 priv->is_internal_short_scan = false;
 960                 IWL_DEBUG_SCAN(priv, "internal short scan completed\n");
 961         }
 962
 963         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 964                 return;
 965
 966         /* Since setting the TXPOWER may have been deferred while
 967          * performing the scan, fire one off */
 968         mutex_lock(&priv->mutex);
 969         iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);
 970         mutex_unlock(&priv->mutex);
 971 }
 972 EXPORT_SYMBOL(iwl_bg_scan_completed);
 973
 974 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
 975 {
 976         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
 977         INIT_WORK(&priv->request_scan, iwl_bg_request_scan);
 978         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
 979         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
 980 }
 981 EXPORT_SYMBOL(iwl_setup_scan_deferred_work);
 982