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

   1 /******************************************************************************
   2  *
   3  * GPL LICENSE SUMMARY
   4  *
   5  * Copyright(c) 2008 - 2009 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/lib80211.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
  40 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
  41  * sending probe req.  This should be set long enough to hear probe responses
  42  * from more than one AP.  */
  43 #define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
  44 #define IWL_ACTIVE_DWELL_TIME_52    (20)
  45
  46 #define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
  47 #define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
  48
  49 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
  50  * Must be set longer than active dwell time.
  51  * For the most reliable scan, set > AP beacon interval (typically 100msec). */
  52 #define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
  53 #define IWL_PASSIVE_DWELL_TIME_52   (10)
  54 #define IWL_PASSIVE_DWELL_BASE      (100)
  55 #define IWL_CHANNEL_TUNE_TIME       5
  56
  57
  58
  59 /**
  60  * iwl_scan_cancel - Cancel any currently executing HW scan
  61  *
  62  * NOTE: priv->mutex is not required before calling this function
  63  */
  64 int iwl_scan_cancel(struct iwl_priv *priv)
  65 {
  66         if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
  67                 clear_bit(STATUS_SCANNING, &priv->status);
  68                 return 0;
  69         }
  70
  71         if (test_bit(STATUS_SCANNING, &priv->status)) {
  72                 if (!test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
  73                         IWL_DEBUG_SCAN(priv, "Queuing scan abort.\n");
  74                         set_bit(STATUS_SCAN_ABORTING, &priv->status);
  75                         queue_work(priv->workqueue, &priv->abort_scan);
  76
  77                 } else
  78                         IWL_DEBUG_SCAN(priv, "Scan abort already in progress.\n");
  79
  80                 return test_bit(STATUS_SCANNING, &priv->status);
  81         }
  82
  83         return 0;
  84 }
  85 EXPORT_SYMBOL(iwl_scan_cancel);
  86 /**
  87  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
  88  * @ms: amount of time to wait (in milliseconds) for scan to abort
  89  *
  90  * NOTE: priv->mutex must be held before calling this function
  91  */
  92 int iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
  93 {
  94         unsigned long now = jiffies;
  95         int ret;
  96
  97         ret = iwl_scan_cancel(priv);
  98         if (ret && ms) {
  99                 mutex_unlock(&priv->mutex);
 100                 while (!time_after(jiffies, now + msecs_to_jiffies(ms)) &&
 101                                 test_bit(STATUS_SCANNING, &priv->status))
 102                         msleep(1);
 103                 mutex_lock(&priv->mutex);
 104
 105                 return test_bit(STATUS_SCANNING, &priv->status);
 106         }
 107
 108         return ret;
 109 }
 110 EXPORT_SYMBOL(iwl_scan_cancel_timeout);
 111
 112 int iwl_send_scan_abort(struct iwl_priv *priv)
 113 {
 114         int ret = 0;
 115         struct iwl_rx_packet *res;
 116         struct iwl_host_cmd cmd = {
 117                 .id = REPLY_SCAN_ABORT_CMD,
 118                 .meta.flags = CMD_WANT_SKB,
 119         };
 120
 121         /* If there isn't a scan actively going on in the hardware
 122          * then we are in between scan bands and not actually
 123          * actively scanning, so don't send the abort command */
 124         if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
 125                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 126                 return 0;
 127         }
 128
 129         ret = iwl_send_cmd_sync(priv, &cmd);
 130         if (ret) {
 131                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 132                 return ret;
 133         }
 134
 135         res = (struct iwl_rx_packet *)cmd.meta.u.skb->data;
 136         if (res->u.status != CAN_ABORT_STATUS) {
 137                 /* The scan abort will return 1 for success or
 138                  * 2 for "failure".  A failure condition can be
 139                  * due to simply not being in an active scan which
 140                  * can occur if we send the scan abort before we
 141                  * the microcode has notified us that a scan is
 142                  * completed. */
 143                 IWL_DEBUG_INFO(priv, "SCAN_ABORT returned %d.\n", res->u.status);
 144                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 145                 clear_bit(STATUS_SCAN_HW, &priv->status);
 146         }
 147
 148         priv->alloc_rxb_skb--;
 149         dev_kfree_skb_any(cmd.meta.u.skb);
 150
 151         return ret;
 152 }
 153 EXPORT_SYMBOL(iwl_send_scan_abort);
 154
 155 /* Service response to REPLY_SCAN_CMD (0x80) */
 156 static void iwl_rx_reply_scan(struct iwl_priv *priv,
 157                               struct iwl_rx_mem_buffer *rxb)
 158 {
 159 #ifdef CONFIG_IWLWIFI_DEBUG
 160         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
 161         struct iwl_scanreq_notification *notif =
 162             (struct iwl_scanreq_notification *)pkt->u.raw;
 163
 164         IWL_DEBUG_RX(priv, "Scan request status = 0x%x\n", notif->status);
 165 #endif
 166 }
 167
 168 /* Service SCAN_START_NOTIFICATION (0x82) */
 169 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
 170                                     struct iwl_rx_mem_buffer *rxb)
 171 {
 172         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
 173         struct iwl_scanstart_notification *notif =
 174             (struct iwl_scanstart_notification *)pkt->u.raw;
 175         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 176         IWL_DEBUG_SCAN(priv, "Scan start: "
 177                        "%d [802.11%s] "
 178                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 179                        notif->channel,
 180                        notif->band ? "bg" : "a",
 181                        le32_to_cpu(notif->tsf_high),
 182                        le32_to_cpu(notif->tsf_low),
 183                        notif->status, notif->beacon_timer);
 184 }
 185
 186 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 187 static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
 188                                       struct iwl_rx_mem_buffer *rxb)
 189 {
 190 #ifdef CONFIG_IWLWIFI_DEBUG
 191         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
 192         struct iwl_scanresults_notification *notif =
 193             (struct iwl_scanresults_notification *)pkt->u.raw;
 194
 195         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
 196                        "%d [802.11%s] "
 197                        "(TSF: 0x%08X:%08X) - %d "
 198                        "elapsed=%lu usec (%dms since last)\n",
 199                        notif->channel,
 200                        notif->band ? "bg" : "a",
 201                        le32_to_cpu(notif->tsf_high),
 202                        le32_to_cpu(notif->tsf_low),
 203                        le32_to_cpu(notif->statistics[0]),
 204                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf,
 205                        jiffies_to_msecs(elapsed_jiffies
 206                                         (priv->last_scan_jiffies, jiffies)));
 207 #endif
 208
 209         priv->last_scan_jiffies = jiffies;
 210         priv->next_scan_jiffies = 0;
 211 }
 212
 213 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 214 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 215                                        struct iwl_rx_mem_buffer *rxb)
 216 {
 217 #ifdef CONFIG_IWLWIFI_DEBUG
 218         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
 219         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
 220
 221         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 222                        scan_notif->scanned_channels,
 223                        scan_notif->tsf_low,
 224                        scan_notif->tsf_high, scan_notif->status);
 225 #endif
 226
 227         /* The HW is no longer scanning */
 228         clear_bit(STATUS_SCAN_HW, &priv->status);
 229
 230         IWL_DEBUG_INFO(priv, "Scan pass on %sGHz took %dms\n",
 231                        (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) ?
 232                                                 "2.4" : "5.2",
 233                        jiffies_to_msecs(elapsed_jiffies
 234                                         (priv->scan_pass_start, jiffies)));
 235
 236         /* Remove this scanned band from the list of pending
 237          * bands to scan, band G precedes A in order of scanning
 238          * as seen in iwl_bg_request_scan */
 239         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ))
 240                 priv->scan_bands &= ~BIT(IEEE80211_BAND_2GHZ);
 241         else if (priv->scan_bands &  BIT(IEEE80211_BAND_5GHZ))
 242                 priv->scan_bands &= ~BIT(IEEE80211_BAND_5GHZ);
 243
 244         /* If a request to abort was given, or the scan did not succeed
 245          * then we reset the scan state machine and terminate,
 246          * re-queuing another scan if one has been requested */
 247         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 248                 IWL_DEBUG_INFO(priv, "Aborted scan completed.\n");
 249                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 250         } else {
 251                 /* If there are more bands on this scan pass reschedule */
 252                 if (priv->scan_bands)
 253                         goto reschedule;
 254         }
 255
 256         priv->last_scan_jiffies = jiffies;
 257         priv->next_scan_jiffies = 0;
 258         IWL_DEBUG_INFO(priv, "Setting scan to off\n");
 259
 260         clear_bit(STATUS_SCANNING, &priv->status);
 261
 262         IWL_DEBUG_INFO(priv, "Scan took %dms\n",
 263                 jiffies_to_msecs(elapsed_jiffies(priv->scan_start, jiffies)));
 264
 265         queue_work(priv->workqueue, &priv->scan_completed);
 266
 267         return;
 268
 269 reschedule:
 270         priv->scan_pass_start = jiffies;
 271         queue_work(priv->workqueue, &priv->request_scan);
 272 }
 273
 274 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 275 {
 276         /* scan handlers */
 277         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 278         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 279         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 280                                         iwl_rx_scan_results_notif;
 281         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 282                                         iwl_rx_scan_complete_notif;
 283 }
 284 EXPORT_SYMBOL(iwl_setup_rx_scan_handlers);
 285
 286 inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 287                                      enum ieee80211_band band,
 288                                      u8 n_probes)
 289 {
 290         if (band == IEEE80211_BAND_5GHZ)
 291                 return IWL_ACTIVE_DWELL_TIME_52 +
 292                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 293         else
 294                 return IWL_ACTIVE_DWELL_TIME_24 +
 295                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 296 }
 297 EXPORT_SYMBOL(iwl_get_active_dwell_time);
 298
 299 u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 300                                enum ieee80211_band band)
 301 {
 302         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
 303             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 304             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 305
 306         if (iwl_is_associated(priv)) {
 307                 /* If we're associated, we clamp the maximum passive
 308                  * dwell time to be 98% of the beacon interval (minus
 309                  * 2 * channel tune time) */
 310                 passive = priv->beacon_int;
 311                 if ((passive > IWL_PASSIVE_DWELL_BASE) || !passive)
 312                         passive = IWL_PASSIVE_DWELL_BASE;
 313                 passive = (passive * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 314         }
 315
 316         return passive;
 317 }
 318 EXPORT_SYMBOL(iwl_get_passive_dwell_time);
 319
 320 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 321                                      enum ieee80211_band band,
 322                                      u8 is_active, u8 n_probes,
 323                                      struct iwl_scan_channel *scan_ch)
 324 {
 325         const struct ieee80211_channel *channels = NULL;
 326         const struct ieee80211_supported_band *sband;
 327         const struct iwl_channel_info *ch_info;
 328         u16 passive_dwell = 0;
 329         u16 active_dwell = 0;
 330         int added, i;
 331         u16 channel;
 332
 333         sband = iwl_get_hw_mode(priv, band);
 334         if (!sband)
 335                 return 0;
 336
 337         channels = sband->channels;
 338
 339         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 340         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 341
 342         if (passive_dwell <= active_dwell)
 343                 passive_dwell = active_dwell + 1;
 344
 345         for (i = 0, added = 0; i < sband->n_channels; i++) {
 346                 if (channels[i].flags & IEEE80211_CHAN_DISABLED)
 347                         continue;
 348
 349                 channel =
 350                         ieee80211_frequency_to_channel(channels[i].center_freq);
 351                 scan_ch->channel = cpu_to_le16(channel);
 352
 353                 ch_info = iwl_get_channel_info(priv, band, channel);
 354                 if (!is_channel_valid(ch_info)) {
 355                         IWL_DEBUG_SCAN(priv, "Channel %d is INVALID for this band.\n",
 356                                         channel);
 357                         continue;
 358                 }
 359
 360                 if (!is_active || is_channel_passive(ch_info) ||
 361                     (channels[i].flags & IEEE80211_CHAN_PASSIVE_SCAN))
 362                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 363                 else
 364                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 365
 366                 if (n_probes)
 367                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 368
 369                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 370                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 371
 372                 /* Set txpower levels to defaults */
 373                 scan_ch->dsp_atten = 110;
 374
 375                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 376                  * power level:
 377                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 378                  */
 379                 if (band == IEEE80211_BAND_5GHZ)
 380                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 381                 else
 382                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 383
 384                 IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
 385                                channel, le32_to_cpu(scan_ch->type),
 386                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 387                                 "ACTIVE" : "PASSIVE",
 388                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 389                                active_dwell : passive_dwell);
 390
 391                 scan_ch++;
 392                 added++;
 393         }
 394
 395         IWL_DEBUG_SCAN(priv, "total channels to scan %d \n", added);
 396         return added;
 397 }
 398
 399 void iwl_init_scan_params(struct iwl_priv *priv)
 400 {
 401         u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
 402         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
 403                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
 404         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
 405                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
 406 }
 407
 408 int iwl_scan_initiate(struct iwl_priv *priv)
 409 {
 410         if (!iwl_is_ready_rf(priv)) {
 411                 IWL_DEBUG_SCAN(priv, "Aborting scan due to not ready.\n");
 412                 return -EIO;
 413         }
 414
 415         if (test_bit(STATUS_SCANNING, &priv->status)) {
 416                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
 417                 return -EAGAIN;
 418         }
 419
 420         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 421                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
 422                 return -EAGAIN;
 423         }
 424
 425         IWL_DEBUG_INFO(priv, "Starting scan...\n");
 426         if (priv->cfg->sku & IWL_SKU_G)
 427                 priv->scan_bands |= BIT(IEEE80211_BAND_2GHZ);
 428         if (priv->cfg->sku & IWL_SKU_A)
 429                 priv->scan_bands |= BIT(IEEE80211_BAND_5GHZ);
 430         set_bit(STATUS_SCANNING, &priv->status);
 431         priv->scan_start = jiffies;
 432         priv->scan_pass_start = priv->scan_start;
 433
 434         queue_work(priv->workqueue, &priv->request_scan);
 435
 436         return 0;
 437 }
 438 EXPORT_SYMBOL(iwl_scan_initiate);
 439
 440 #define IWL_DELAY_NEXT_SCAN (HZ*2)
 441
 442 int iwl_mac_hw_scan(struct ieee80211_hw *hw,
 443                      struct cfg80211_scan_request *req)
 444 {
 445         unsigned long flags;
 446         struct iwl_priv *priv = hw->priv;
 447         int ret;
 448         u8 *ssid = NULL;
 449         size_t ssid_len = 0;
 450
 451         if (req->n_ssids) {
 452                 ssid = req->ssids[0].ssid;
 453                 ssid_len = req->ssids[0].ssid_len;
 454         }
 455
 456         IWL_DEBUG_MAC80211(priv, "enter\n");
 457
 458         mutex_lock(&priv->mutex);
 459         spin_lock_irqsave(&priv->lock, flags);
 460
 461         if (!iwl_is_ready_rf(priv)) {
 462                 ret = -EIO;
 463                 IWL_DEBUG_MAC80211(priv, "leave - not ready or exit pending\n");
 464                 goto out_unlock;
 465         }
 466
 467         /* We don't schedule scan within next_scan_jiffies period.
 468          * Avoid scanning during possible EAPOL exchange, return
 469          * success immediately.
 470          */
 471         if (priv->next_scan_jiffies &&
 472             time_after(priv->next_scan_jiffies, jiffies)) {
 473                 IWL_DEBUG_SCAN(priv, "scan rejected: within next scan period\n");
 474                 queue_work(priv->workqueue, &priv->scan_completed);
 475                 ret = 0;
 476                 goto out_unlock;
 477         }
 478
 479         /* if we just finished scan ask for delay */
 480         if (iwl_is_associated(priv) && priv->last_scan_jiffies &&
 481             time_after(priv->last_scan_jiffies + IWL_DELAY_NEXT_SCAN, jiffies)) {
 482                 IWL_DEBUG_SCAN(priv, "scan rejected: within previous scan period\n");
 483                 queue_work(priv->workqueue, &priv->scan_completed);
 484                 ret = 0;
 485                 goto out_unlock;
 486         }
 487
 488         if (ssid_len) {
 489                 priv->one_direct_scan = 1;
 490                 priv->direct_ssid_len =  ssid_len;
 491                 memcpy(priv->direct_ssid, ssid, priv->direct_ssid_len);
 492         } else {
 493                 priv->one_direct_scan = 0;
 494         }
 495
 496         ret = iwl_scan_initiate(priv);
 497
 498         IWL_DEBUG_MAC80211(priv, "leave\n");
 499
 500 out_unlock:
 501         spin_unlock_irqrestore(&priv->lock, flags);
 502         mutex_unlock(&priv->mutex);
 503
 504         return ret;
 505 }
 506 EXPORT_SYMBOL(iwl_mac_hw_scan);
 507
 508 #define IWL_SCAN_CHECK_WATCHDOG (7 * HZ)
 509
 510 void iwl_bg_scan_check(struct work_struct *data)
 511 {
 512         struct iwl_priv *priv =
 513             container_of(data, struct iwl_priv, scan_check.work);
 514
 515         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 516                 return;
 517
 518         mutex_lock(&priv->mutex);
 519         if (test_bit(STATUS_SCANNING, &priv->status) ||
 520             test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 521                 IWL_DEBUG_SCAN(priv, "Scan completion watchdog resetting "
 522                         "adapter (%dms)\n",
 523                         jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG));
 524
 525                 if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
 526                         iwl_send_scan_abort(priv);
 527         }
 528         mutex_unlock(&priv->mutex);
 529 }
 530 EXPORT_SYMBOL(iwl_bg_scan_check);
 531
 532 /**
 533  * iwl_supported_rate_to_ie - fill in the supported rate in IE field
 534  *
 535  * return : set the bit for each supported rate insert in ie
 536  */
 537 static u16 iwl_supported_rate_to_ie(u8 *ie, u16 supported_rate,
 538                                     u16 basic_rate, int *left)
 539 {
 540         u16 ret_rates = 0, bit;
 541         int i;
 542         u8 *cnt = ie;
 543         u8 *rates = ie + 1;
 544
 545         for (bit = 1, i = 0; i < IWL_RATE_COUNT; i++, bit <<= 1) {
 546                 if (bit & supported_rate) {
 547                         ret_rates |= bit;
 548                         rates[*cnt] = iwl_rates[i].ieee |
 549                                 ((bit & basic_rate) ? 0x80 : 0x00);
 550                         (*cnt)++;
 551                         (*left)--;
 552                         if ((*left <= 0) ||
 553                             (*cnt >= IWL_SUPPORTED_RATES_IE_LEN))
 554                                 break;
 555                 }
 556         }
 557
 558         return ret_rates;
 559 }
 560
 561
 562 static void iwl_ht_cap_to_ie(const struct ieee80211_supported_band *sband,
 563                              u8 *pos, int *left)
 564 {
 565         struct ieee80211_ht_cap *ht_cap;
 566
 567         if (!sband || !sband->ht_cap.ht_supported)
 568                 return;
 569
 570         if (*left < sizeof(struct ieee80211_ht_cap))
 571                 return;
 572
 573         *pos++ = sizeof(struct ieee80211_ht_cap);
 574         ht_cap = (struct ieee80211_ht_cap *) pos;
 575
 576         ht_cap->cap_info = cpu_to_le16(sband->ht_cap.cap);
 577         memcpy(&ht_cap->mcs, &sband->ht_cap.mcs, 16);
 578         ht_cap->ampdu_params_info =
 579                 (sband->ht_cap.ampdu_factor & IEEE80211_HT_AMPDU_PARM_FACTOR) |
 580                 ((sband->ht_cap.ampdu_density << 2) &
 581                         IEEE80211_HT_AMPDU_PARM_DENSITY);
 582         *left -= sizeof(struct ieee80211_ht_cap);
 583 }
 584
 585 /**
 586  * iwl_fill_probe_req - fill in all required fields and IE for probe request
 587  */
 588
 589 u16 iwl_fill_probe_req(struct iwl_priv *priv,
 590                        enum ieee80211_band band,
 591                        struct ieee80211_mgmt *frame,
 592                        int left)
 593 {
 594         int len = 0;
 595         u8 *pos = NULL;
 596         u16 active_rates, ret_rates, cck_rates, active_rate_basic;
 597         const struct ieee80211_supported_band *sband =
 598                                                 iwl_get_hw_mode(priv, band);
 599
 600
 601         /* Make sure there is enough space for the probe request,
 602          * two mandatory IEs and the data */
 603         left -= 24;
 604         if (left < 0)
 605                 return 0;
 606
 607         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 608         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
 609         memcpy(frame->sa, priv->mac_addr, ETH_ALEN);
 610         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
 611         frame->seq_ctrl = 0;
 612
 613         len += 24;
 614
 615         /* ...next IE... */
 616         pos = &frame->u.probe_req.variable[0];
 617
 618         /* fill in our indirect SSID IE */
 619         left -= 2;
 620         if (left < 0)
 621                 return 0;
 622         *pos++ = WLAN_EID_SSID;
 623         *pos++ = 0;
 624
 625         len += 2;
 626
 627         /* fill in supported rate */
 628         left -= 2;
 629         if (left < 0)
 630                 return 0;
 631
 632         *pos++ = WLAN_EID_SUPP_RATES;
 633         *pos = 0;
 634
 635         /* exclude 60M rate */
 636         active_rates = priv->rates_mask;
 637         active_rates &= ~IWL_RATE_60M_MASK;
 638
 639         active_rate_basic = active_rates & IWL_BASIC_RATES_MASK;
 640
 641         cck_rates = IWL_CCK_RATES_MASK & active_rates;
 642         ret_rates = iwl_supported_rate_to_ie(pos, cck_rates,
 643                                              active_rate_basic, &left);
 644         active_rates &= ~ret_rates;
 645
 646         ret_rates = iwl_supported_rate_to_ie(pos, active_rates,
 647                                              active_rate_basic, &left);
 648         active_rates &= ~ret_rates;
 649
 650         len += 2 + *pos;
 651         pos += (*pos) + 1;
 652
 653         if (active_rates == 0)
 654                 goto fill_end;
 655
 656         /* fill in supported extended rate */
 657         /* ...next IE... */
 658         left -= 2;
 659         if (left < 0)
 660                 return 0;
 661         /* ... fill it in... */
 662         *pos++ = WLAN_EID_EXT_SUPP_RATES;
 663         *pos = 0;
 664         iwl_supported_rate_to_ie(pos, active_rates, active_rate_basic, &left);
 665         if (*pos > 0) {
 666                 len += 2 + *pos;
 667                 pos += (*pos) + 1;
 668         } else {
 669                 pos--;
 670         }
 671
 672  fill_end:
 673
 674         left -= 2;
 675         if (left < 0)
 676                 return 0;
 677
 678         *pos++ = WLAN_EID_HT_CAPABILITY;
 679         *pos = 0;
 680         iwl_ht_cap_to_ie(sband, pos, &left);
 681         if (*pos > 0)
 682                 len += 2 + *pos;
 683
 684         return (u16)len;
 685 }
 686 EXPORT_SYMBOL(iwl_fill_probe_req);
 687
 688 static void iwl_bg_request_scan(struct work_struct *data)
 689 {
 690         struct iwl_priv *priv =
 691             container_of(data, struct iwl_priv, request_scan);
 692         struct iwl_host_cmd cmd = {
 693                 .id = REPLY_SCAN_CMD,
 694                 .len = sizeof(struct iwl_scan_cmd),
 695                 .meta.flags = CMD_SIZE_HUGE,
 696         };
 697         struct iwl_scan_cmd *scan;
 698         struct ieee80211_conf *conf = NULL;
 699         int ret = 0;
 700         u32 rate_flags = 0;
 701         u16 cmd_len;
 702         enum ieee80211_band band;
 703         u8 n_probes = 2;
 704         u8 rx_chain = priv->hw_params.valid_rx_ant;
 705         u8 rate;
 706         DECLARE_SSID_BUF(ssid);
 707
 708         conf = ieee80211_get_hw_conf(priv->hw);
 709
 710         mutex_lock(&priv->mutex);
 711
 712         cancel_delayed_work(&priv->scan_check);
 713
 714         if (!iwl_is_ready(priv)) {
 715                 IWL_WARN(priv, "request scan called when driver not ready.\n");
 716                 goto done;
 717         }
 718
 719         /* Make sure the scan wasn't canceled before this queued work
 720          * was given the chance to run... */
 721         if (!test_bit(STATUS_SCANNING, &priv->status))
 722                 goto done;
 723
 724         /* This should never be called or scheduled if there is currently
 725          * a scan active in the hardware. */
 726         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
 727                 IWL_DEBUG_INFO(priv, "Multiple concurrent scan requests in parallel. "
 728                                "Ignoring second request.\n");
 729                 ret = -EIO;
 730                 goto done;
 731         }
 732
 733         if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
 734                 IWL_DEBUG_SCAN(priv, "Aborting scan due to device shutdown\n");
 735                 goto done;
 736         }
 737
 738         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 739                 IWL_DEBUG_HC(priv, "Scan request while abort pending.  Queuing.\n");
 740                 goto done;
 741         }
 742
 743         if (iwl_is_rfkill(priv)) {
 744                 IWL_DEBUG_HC(priv, "Aborting scan due to RF Kill activation\n");
 745                 goto done;
 746         }
 747
 748         if (!test_bit(STATUS_READY, &priv->status)) {
 749                 IWL_DEBUG_HC(priv, "Scan request while uninitialized.  Queuing.\n");
 750                 goto done;
 751         }
 752
 753         if (!priv->scan_bands) {
 754                 IWL_DEBUG_HC(priv, "Aborting scan due to no requested bands\n");
 755                 goto done;
 756         }
 757
 758         if (!priv->scan) {
 759                 priv->scan = kmalloc(sizeof(struct iwl_scan_cmd) +
 760                                      IWL_MAX_SCAN_SIZE, GFP_KERNEL);
 761                 if (!priv->scan) {
 762                         ret = -ENOMEM;
 763                         goto done;
 764                 }
 765         }
 766         scan = priv->scan;
 767         memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
 768
 769         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
 770         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
 771
 772         if (iwl_is_associated(priv)) {
 773                 u16 interval = 0;
 774                 u32 extra;
 775                 u32 suspend_time = 100;
 776                 u32 scan_suspend_time = 100;
 777                 unsigned long flags;
 778
 779                 IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
 780
 781                 spin_lock_irqsave(&priv->lock, flags);
 782                 interval = priv->beacon_int;
 783                 spin_unlock_irqrestore(&priv->lock, flags);
 784
 785                 scan->suspend_time = 0;
 786                 scan->max_out_time = cpu_to_le32(200 * 1024);
 787                 if (!interval)
 788                         interval = suspend_time;
 789
 790                 extra = (suspend_time / interval) << 22;
 791                 scan_suspend_time = (extra |
 792                     ((suspend_time % interval) * 1024));
 793                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
 794                 IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
 795                                scan_suspend_time, interval);
 796         }
 797
 798         /* We should add the ability for user to lock to PASSIVE ONLY */
 799         if (priv->one_direct_scan) {
 800                 IWL_DEBUG_SCAN(priv, "Start direct scan for '%s'\n",
 801                                 print_ssid(ssid, priv->direct_ssid,
 802                                            priv->direct_ssid_len));
 803                 scan->direct_scan[0].id = WLAN_EID_SSID;
 804                 scan->direct_scan[0].len = priv->direct_ssid_len;
 805                 memcpy(scan->direct_scan[0].ssid,
 806                        priv->direct_ssid, priv->direct_ssid_len);
 807                 n_probes++;
 808         } else {
 809                 IWL_DEBUG_SCAN(priv, "Start indirect scan.\n");
 810         }
 811
 812         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
 813         scan->tx_cmd.sta_id = priv->hw_params.bcast_sta_id;
 814         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
 815
 816
 817         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) {
 818                 band = IEEE80211_BAND_2GHZ;
 819                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
 820                 if (priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_PURE_40_MSK) {
 821                         rate = IWL_RATE_6M_PLCP;
 822                 } else {
 823                         rate = IWL_RATE_1M_PLCP;
 824                         rate_flags = RATE_MCS_CCK_MSK;
 825                 }
 826                 scan->good_CRC_th = 0;
 827         } else if (priv->scan_bands & BIT(IEEE80211_BAND_5GHZ)) {
 828                 band = IEEE80211_BAND_5GHZ;
 829                 rate = IWL_RATE_6M_PLCP;
 830                 scan->good_CRC_th = IWL_GOOD_CRC_TH;
 831
 832                 /* Force use of chains B and C (0x6) for scan Rx for 4965
 833                  * Avoid A (0x1) because of its off-channel reception on A-band.
 834                  */
 835                 if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) == CSR_HW_REV_TYPE_4965)
 836                         rx_chain = 0x6;
 837         } else {
 838                 IWL_WARN(priv, "Invalid scan band count\n");
 839                 goto done;
 840         }
 841
 842         priv->scan_tx_ant[band] =
 843                          iwl_toggle_tx_ant(priv, priv->scan_tx_ant[band]);
 844         rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
 845         scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
 846
 847         /* MIMO is not used here, but value is required */
 848         scan->rx_chain = RXON_RX_CHAIN_DRIVER_FORCE_MSK |
 849                                 cpu_to_le16((0x7 << RXON_RX_CHAIN_VALID_POS) |
 850                                 (rx_chain << RXON_RX_CHAIN_FORCE_SEL_POS) |
 851                                 (0x7 << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS));
 852
 853         cmd_len = iwl_fill_probe_req(priv, band,
 854                                      (struct ieee80211_mgmt *)scan->data,
 855                                      IWL_MAX_SCAN_SIZE - sizeof(*scan));
 856
 857         scan->tx_cmd.len = cpu_to_le16(cmd_len);
 858
 859         if (priv->iw_mode == NL80211_IFTYPE_MONITOR)
 860                 scan->filter_flags = RXON_FILTER_PROMISC_MSK;
 861
 862         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 863                                RXON_FILTER_BCON_AWARE_MSK);
 864
 865         scan->channel_count =
 866                 iwl_get_channels_for_scan(priv, band, 1, /* active */
 867                         n_probes,
 868                         (void *)&scan->data[le16_to_cpu(scan->tx_cmd.len)]);
 869
 870         if (scan->channel_count == 0) {
 871                 IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
 872                 goto done;
 873         }
 874
 875         cmd.len += le16_to_cpu(scan->tx_cmd.len) +
 876             scan->channel_count * sizeof(struct iwl_scan_channel);
 877         cmd.data = scan;
 878         scan->len = cpu_to_le16(cmd.len);
 879
 880         set_bit(STATUS_SCAN_HW, &priv->status);
 881         ret = iwl_send_cmd_sync(priv, &cmd);
 882         if (ret)
 883                 goto done;
 884
 885         queue_delayed_work(priv->workqueue, &priv->scan_check,
 886                            IWL_SCAN_CHECK_WATCHDOG);
 887
 888         mutex_unlock(&priv->mutex);
 889         return;
 890
 891  done:
 892         /* Cannot perform scan. Make sure we clear scanning
 893         * bits from status so next scan request can be performed.
 894         * If we don't clear scanning status bit here all next scan
 895         * will fail
 896         */
 897         clear_bit(STATUS_SCAN_HW, &priv->status);
 898         clear_bit(STATUS_SCANNING, &priv->status);
 899         /* inform mac80211 scan aborted */
 900         queue_work(priv->workqueue, &priv->scan_completed);
 901         mutex_unlock(&priv->mutex);
 902 }
 903
 904 void iwl_bg_abort_scan(struct work_struct *work)
 905 {
 906         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
 907
 908         if (!iwl_is_ready(priv))
 909                 return;
 910
 911         mutex_lock(&priv->mutex);
 912
 913         set_bit(STATUS_SCAN_ABORTING, &priv->status);
 914         iwl_send_scan_abort(priv);
 915
 916         mutex_unlock(&priv->mutex);
 917 }
 918 EXPORT_SYMBOL(iwl_bg_abort_scan);
 919
 920 void iwl_bg_scan_completed(struct work_struct *work)
 921 {
 922         struct iwl_priv *priv =
 923             container_of(work, struct iwl_priv, scan_completed);
 924
 925         IWL_DEBUG_SCAN(priv, "SCAN complete scan\n");
 926
 927         cancel_delayed_work(&priv->scan_check);
 928
 929         ieee80211_scan_completed(priv->hw, false);
 930
 931         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 932                 return;
 933
 934         /* Since setting the TXPOWER may have been deferred while
 935          * performing the scan, fire one off */
 936         mutex_lock(&priv->mutex);
 937         iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);
 938         mutex_unlock(&priv->mutex);
 939 }
 940 EXPORT_SYMBOL(iwl_bg_scan_completed);
 941
 942 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
 943 {
 944         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
 945         INIT_WORK(&priv->request_scan, iwl_bg_request_scan);
 946         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
 947         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
 948 }
 949 EXPORT_SYMBOL(iwl_setup_scan_deferred_work);
 950