git.oblomov.eu Git - linux-2.6/blob - drivers/net/wireless/iwlwifi/iwl-scan.c

   1 /******************************************************************************
   2  *
   3  * GPL LICENSE SUMMARY
   4  *
   5  * Copyright(c) 2008 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  * Tomas Winkler <tomas.winkler@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 faster active scanning, scan will move to the next channel if fewer than
  50  * PLCP_QUIET_THRESH packets are heard on this channel within
  51  * ACTIVE_QUIET_TIME after sending probe request.  This shortens the dwell
  52  * time if it's a quiet channel (nothing responded to our probe, and there's
  53  * no other traffic).
  54  * Disable "quiet" feature by setting PLCP_QUIET_THRESH to 0. */
  55 #define IWL_PLCP_QUIET_THRESH       __constant_cpu_to_le16(1)  /* packets */
  56 #define IWL_ACTIVE_QUIET_TIME       __constant_cpu_to_le16(10)  /* msec */
  57
  58 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
  59  * Must be set longer than active dwell time.
  60  * For the most reliable scan, set > AP beacon interval (typically 100msec). */
  61 #define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
  62 #define IWL_PASSIVE_DWELL_TIME_52   (10)
  63 #define IWL_PASSIVE_DWELL_BASE      (100)
  64 #define IWL_CHANNEL_TUNE_TIME       5
  65
  66 #define IWL_SCAN_PROBE_MASK(n)  cpu_to_le32((BIT(n) | (BIT(n) - BIT(1))))
  67
  68
  69 /**
  70  * iwl_scan_cancel - Cancel any currently executing HW scan
  71  *
  72  * NOTE: priv->mutex is not required before calling this function
  73  */
  74 int iwl_scan_cancel(struct iwl_priv *priv)
  75 {
  76         if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
  77                 clear_bit(STATUS_SCANNING, &priv->status);
  78                 return 0;
  79         }
  80
  81         if (test_bit(STATUS_SCANNING, &priv->status)) {
  82                 if (!test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
  83                         IWL_DEBUG_SCAN("Queuing scan abort.\n");
  84                         set_bit(STATUS_SCAN_ABORTING, &priv->status);
  85                         queue_work(priv->workqueue, &priv->abort_scan);
  86
  87                 } else
  88                         IWL_DEBUG_SCAN("Scan abort already in progress.\n");
  89
  90                 return test_bit(STATUS_SCANNING, &priv->status);
  91         }
  92
  93         return 0;
  94 }
  95 EXPORT_SYMBOL(iwl_scan_cancel);
  96 /**
  97  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
  98  * @ms: amount of time to wait (in milliseconds) for scan to abort
  99  *
 100  * NOTE: priv->mutex must be held before calling this function
 101  */
 102 int iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
 103 {
 104         unsigned long now = jiffies;
 105         int ret;
 106
 107         ret = iwl_scan_cancel(priv);
 108         if (ret && ms) {
 109                 mutex_unlock(&priv->mutex);
 110                 while (!time_after(jiffies, now + msecs_to_jiffies(ms)) &&
 111                                 test_bit(STATUS_SCANNING, &priv->status))
 112                         msleep(1);
 113                 mutex_lock(&priv->mutex);
 114
 115                 return test_bit(STATUS_SCANNING, &priv->status);
 116         }
 117
 118         return ret;
 119 }
 120 EXPORT_SYMBOL(iwl_scan_cancel_timeout);
 121
 122 static int iwl_send_scan_abort(struct iwl_priv *priv)
 123 {
 124         int ret = 0;
 125         struct iwl_rx_packet *res;
 126         struct iwl_host_cmd cmd = {
 127                 .id = REPLY_SCAN_ABORT_CMD,
 128                 .meta.flags = CMD_WANT_SKB,
 129         };
 130
 131         /* If there isn't a scan actively going on in the hardware
 132          * then we are in between scan bands and not actually
 133          * actively scanning, so don't send the abort command */
 134         if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
 135                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 136                 return 0;
 137         }
 138
 139         ret = iwl_send_cmd_sync(priv, &cmd);
 140         if (ret) {
 141                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 142                 return ret;
 143         }
 144
 145         res = (struct iwl_rx_packet *)cmd.meta.u.skb->data;
 146         if (res->u.status != CAN_ABORT_STATUS) {
 147                 /* The scan abort will return 1 for success or
 148                  * 2 for "failure".  A failure condition can be
 149                  * due to simply not being in an active scan which
 150                  * can occur if we send the scan abort before we
 151                  * the microcode has notified us that a scan is
 152                  * completed. */
 153                 IWL_DEBUG_INFO("SCAN_ABORT returned %d.\n", res->u.status);
 154                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 155                 clear_bit(STATUS_SCAN_HW, &priv->status);
 156         }
 157
 158         priv->alloc_rxb_skb--;
 159         dev_kfree_skb_any(cmd.meta.u.skb);
 160
 161         return ret;
 162 }
 163
 164
 165 /* Service response to REPLY_SCAN_CMD (0x80) */
 166 static void iwl_rx_reply_scan(struct iwl_priv *priv,
 167                               struct iwl_rx_mem_buffer *rxb)
 168 {
 169 #ifdef CONFIG_IWLWIFI_DEBUG
 170         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
 171         struct iwl_scanreq_notification *notif =
 172             (struct iwl_scanreq_notification *)pkt->u.raw;
 173
 174         IWL_DEBUG_RX("Scan request status = 0x%x\n", notif->status);
 175 #endif
 176 }
 177
 178 /* Service SCAN_START_NOTIFICATION (0x82) */
 179 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
 180                                     struct iwl_rx_mem_buffer *rxb)
 181 {
 182         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
 183         struct iwl_scanstart_notification *notif =
 184             (struct iwl_scanstart_notification *)pkt->u.raw;
 185         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 186         IWL_DEBUG_SCAN("Scan start: "
 187                        "%d [802.11%s] "
 188                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 189                        notif->channel,
 190                        notif->band ? "bg" : "a",
 191                        le32_to_cpu(notif->tsf_high),
 192                        le32_to_cpu(notif->tsf_low),
 193                        notif->status, notif->beacon_timer);
 194 }
 195
 196 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 197 static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
 198                                       struct iwl_rx_mem_buffer *rxb)
 199 {
 200 #ifdef CONFIG_IWLWIFI_DEBUG
 201         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
 202         struct iwl_scanresults_notification *notif =
 203             (struct iwl_scanresults_notification *)pkt->u.raw;
 204
 205         IWL_DEBUG_SCAN("Scan ch.res: "
 206                        "%d [802.11%s] "
 207                        "(TSF: 0x%08X:%08X) - %d "
 208                        "elapsed=%lu usec (%dms since last)\n",
 209                        notif->channel,
 210                        notif->band ? "bg" : "a",
 211                        le32_to_cpu(notif->tsf_high),
 212                        le32_to_cpu(notif->tsf_low),
 213                        le32_to_cpu(notif->statistics[0]),
 214                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf,
 215                        jiffies_to_msecs(elapsed_jiffies
 216                                         (priv->last_scan_jiffies, jiffies)));
 217 #endif
 218
 219         priv->last_scan_jiffies = jiffies;
 220         priv->next_scan_jiffies = 0;
 221 }
 222
 223 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 224 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 225                                        struct iwl_rx_mem_buffer *rxb)
 226 {
 227 #ifdef CONFIG_IWLWIFI_DEBUG
 228         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
 229         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
 230
 231         IWL_DEBUG_SCAN("Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 232                        scan_notif->scanned_channels,
 233                        scan_notif->tsf_low,
 234                        scan_notif->tsf_high, scan_notif->status);
 235 #endif
 236
 237         /* The HW is no longer scanning */
 238         clear_bit(STATUS_SCAN_HW, &priv->status);
 239
 240         /* The scan completion notification came in, so kill that timer... */
 241         cancel_delayed_work(&priv->scan_check);
 242
 243         IWL_DEBUG_INFO("Scan pass on %sGHz took %dms\n",
 244                        (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) ?
 245                                                 "2.4" : "5.2",
 246                        jiffies_to_msecs(elapsed_jiffies
 247                                         (priv->scan_pass_start, jiffies)));
 248
 249         /* Remove this scanned band from the list of pending
 250          * bands to scan, band G precedes A in order of scanning
 251          * as seen in iwl_bg_request_scan */
 252         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ))
 253                 priv->scan_bands &= ~BIT(IEEE80211_BAND_2GHZ);
 254         else if (priv->scan_bands &  BIT(IEEE80211_BAND_5GHZ))
 255                 priv->scan_bands &= ~BIT(IEEE80211_BAND_5GHZ);
 256
 257         /* If a request to abort was given, or the scan did not succeed
 258          * then we reset the scan state machine and terminate,
 259          * re-queuing another scan if one has been requested */
 260         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 261                 IWL_DEBUG_INFO("Aborted scan completed.\n");
 262                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 263         } else {
 264                 /* If there are more bands on this scan pass reschedule */
 265                 if (priv->scan_bands)
 266                         goto reschedule;
 267         }
 268
 269         priv->last_scan_jiffies = jiffies;
 270         priv->next_scan_jiffies = 0;
 271         IWL_DEBUG_INFO("Setting scan to off\n");
 272
 273         clear_bit(STATUS_SCANNING, &priv->status);
 274
 275         IWL_DEBUG_INFO("Scan took %dms\n",
 276                 jiffies_to_msecs(elapsed_jiffies(priv->scan_start, jiffies)));
 277
 278         queue_work(priv->workqueue, &priv->scan_completed);
 279
 280         return;
 281
 282 reschedule:
 283         priv->scan_pass_start = jiffies;
 284         queue_work(priv->workqueue, &priv->request_scan);
 285 }
 286
 287 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 288 {
 289         /* scan handlers */
 290         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 291         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 292         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 293                                         iwl_rx_scan_results_notif;
 294         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 295                                         iwl_rx_scan_complete_notif;
 296 }
 297 EXPORT_SYMBOL(iwl_setup_rx_scan_handlers);
 298
 299 static inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 300                                             enum ieee80211_band band,
 301                                             u8 n_probes)
 302 {
 303         if (band == IEEE80211_BAND_5GHZ)
 304                 return IWL_ACTIVE_DWELL_TIME_52 +
 305                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 306         else
 307                 return IWL_ACTIVE_DWELL_TIME_24 +
 308                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 309 }
 310
 311 static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 312                                       enum ieee80211_band band)
 313 {
 314         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
 315             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 316             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 317
 318         if (iwl_is_associated(priv)) {
 319                 /* If we're associated, we clamp the maximum passive
 320                  * dwell time to be 98% of the beacon interval (minus
 321                  * 2 * channel tune time) */
 322                 passive = priv->beacon_int;
 323                 if ((passive > IWL_PASSIVE_DWELL_BASE) || !passive)
 324                         passive = IWL_PASSIVE_DWELL_BASE;
 325                 passive = (passive * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 326         }
 327
 328         return passive;
 329 }
 330
 331 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 332                                      enum ieee80211_band band,
 333                                      u8 is_active, u8 n_probes,
 334                                      struct iwl_scan_channel *scan_ch)
 335 {
 336         const struct ieee80211_channel *channels = NULL;
 337         const struct ieee80211_supported_band *sband;
 338         const struct iwl_channel_info *ch_info;
 339         u16 passive_dwell = 0;
 340         u16 active_dwell = 0;
 341         int added, i;
 342         u16 channel;
 343
 344         sband = iwl_get_hw_mode(priv, band);
 345         if (!sband)
 346                 return 0;
 347
 348         channels = sband->channels;
 349
 350         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 351         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 352
 353         if (passive_dwell <= active_dwell)
 354                 passive_dwell = active_dwell + 1;
 355
 356         for (i = 0, added = 0; i < sband->n_channels; i++) {
 357                 if (channels[i].flags & IEEE80211_CHAN_DISABLED)
 358                         continue;
 359
 360                 channel =
 361                         ieee80211_frequency_to_channel(channels[i].center_freq);
 362                 scan_ch->channel = cpu_to_le16(channel);
 363
 364                 ch_info = iwl_get_channel_info(priv, band, channel);
 365                 if (!is_channel_valid(ch_info)) {
 366                         IWL_DEBUG_SCAN("Channel %d is INVALID for this band.\n",
 367                                         channel);
 368                         continue;
 369                 }
 370
 371                 if (!is_active || is_channel_passive(ch_info) ||
 372                     (channels[i].flags & IEEE80211_CHAN_PASSIVE_SCAN))
 373                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 374                 else
 375                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 376
 377                 if (n_probes)
 378                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 379
 380                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 381                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 382
 383                 /* Set txpower levels to defaults */
 384                 scan_ch->dsp_atten = 110;
 385
 386                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 387                  * power level:
 388                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 389                  */
 390                 if (band == IEEE80211_BAND_5GHZ)
 391                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 392                 else
 393                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 394
 395                 IWL_DEBUG_SCAN("Scanning ch=%d prob=0x%X [%s %d]\n",
 396                                channel, le32_to_cpu(scan_ch->type),
 397                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 398                                 "ACTIVE" : "PASSIVE",
 399                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 400                                active_dwell : passive_dwell);
 401
 402                 scan_ch++;
 403                 added++;
 404         }
 405
 406         IWL_DEBUG_SCAN("total channels to scan %d \n", added);
 407         return added;
 408 }
 409
 410 void iwl_init_scan_params(struct iwl_priv *priv)
 411 {
 412         u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
 413         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
 414                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
 415         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
 416                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
 417 }
 418
 419 int iwl_scan_initiate(struct iwl_priv *priv)
 420 {
 421         if (!iwl_is_ready_rf(priv)) {
 422                 IWL_DEBUG_SCAN("Aborting scan due to not ready.\n");
 423                 return -EIO;
 424         }
 425
 426         if (test_bit(STATUS_SCANNING, &priv->status)) {
 427                 IWL_DEBUG_SCAN("Scan already in progress.\n");
 428                 return -EAGAIN;
 429         }
 430
 431         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 432                 IWL_DEBUG_SCAN("Scan request while abort pending\n");
 433                 return -EAGAIN;
 434         }
 435
 436         IWL_DEBUG_INFO("Starting scan...\n");
 437         if (priv->cfg->sku & IWL_SKU_G)
 438                 priv->scan_bands |= BIT(IEEE80211_BAND_2GHZ);
 439         if (priv->cfg->sku & IWL_SKU_A)
 440                 priv->scan_bands |= BIT(IEEE80211_BAND_5GHZ);
 441         set_bit(STATUS_SCANNING, &priv->status);
 442         priv->scan_start = jiffies;
 443         priv->scan_pass_start = priv->scan_start;
 444
 445         queue_work(priv->workqueue, &priv->request_scan);
 446
 447         return 0;
 448 }
 449 EXPORT_SYMBOL(iwl_scan_initiate);
 450
 451 #define IWL_SCAN_CHECK_WATCHDOG (7 * HZ)
 452
 453 static void iwl_bg_scan_check(struct work_struct *data)
 454 {
 455         struct iwl_priv *priv =
 456             container_of(data, struct iwl_priv, scan_check.work);
 457
 458         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 459                 return;
 460
 461         mutex_lock(&priv->mutex);
 462         if (test_bit(STATUS_SCANNING, &priv->status) ||
 463             test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 464                 IWL_DEBUG(IWL_DL_SCAN, "Scan completion watchdog resetting "
 465                         "adapter (%dms)\n",
 466                         jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG));
 467
 468                 if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
 469                         iwl_send_scan_abort(priv);
 470         }
 471         mutex_unlock(&priv->mutex);
 472 }
 473 /**
 474  * iwl_supported_rate_to_ie - fill in the supported rate in IE field
 475  *
 476  * return : set the bit for each supported rate insert in ie
 477  */
 478 static u16 iwl_supported_rate_to_ie(u8 *ie, u16 supported_rate,
 479                                     u16 basic_rate, int *left)
 480 {
 481         u16 ret_rates = 0, bit;
 482         int i;
 483         u8 *cnt = ie;
 484         u8 *rates = ie + 1;
 485
 486         for (bit = 1, i = 0; i < IWL_RATE_COUNT; i++, bit <<= 1) {
 487                 if (bit & supported_rate) {
 488                         ret_rates |= bit;
 489                         rates[*cnt] = iwl_rates[i].ieee |
 490                                 ((bit & basic_rate) ? 0x80 : 0x00);
 491                         (*cnt)++;
 492                         (*left)--;
 493                         if ((*left <= 0) ||
 494                             (*cnt >= IWL_SUPPORTED_RATES_IE_LEN))
 495                                 break;
 496                 }
 497         }
 498
 499         return ret_rates;
 500 }
 501
 502
 503 static void iwl_ht_cap_to_ie(const struct ieee80211_supported_band *sband,
 504                              u8 *pos, int *left)
 505 {
 506         struct ieee80211_ht_cap *ht_cap;
 507
 508         if (!sband || !sband->ht_cap.ht_supported)
 509                 return;
 510
 511         if (*left < sizeof(struct ieee80211_ht_cap))
 512                 return;
 513
 514         *pos++ = sizeof(struct ieee80211_ht_cap);
 515         ht_cap = (struct ieee80211_ht_cap *) pos;
 516
 517         ht_cap->cap_info = cpu_to_le16(sband->ht_cap.cap);
 518         memcpy(&ht_cap->mcs, &sband->ht_cap.mcs, 16);
 519         ht_cap->ampdu_params_info =
 520                 (sband->ht_cap.ampdu_factor & IEEE80211_HT_AMPDU_PARM_FACTOR) |
 521                 ((sband->ht_cap.ampdu_density << 2) &
 522                         IEEE80211_HT_AMPDU_PARM_DENSITY);
 523         *left -= sizeof(struct ieee80211_ht_cap);
 524 }
 525
 526 /**
 527  * iwl_fill_probe_req - fill in all required fields and IE for probe request
 528  */
 529
 530 static u16 iwl_fill_probe_req(struct iwl_priv *priv,
 531                                   enum ieee80211_band band,
 532                                   struct ieee80211_mgmt *frame,
 533                                   int left)
 534 {
 535         int len = 0;
 536         u8 *pos = NULL;
 537         u16 active_rates, ret_rates, cck_rates, active_rate_basic;
 538         const struct ieee80211_supported_band *sband =
 539                                                 iwl_get_hw_mode(priv, band);
 540
 541
 542         /* Make sure there is enough space for the probe request,
 543          * two mandatory IEs and the data */
 544         left -= 24;
 545         if (left < 0)
 546                 return 0;
 547
 548         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 549         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
 550         memcpy(frame->sa, priv->mac_addr, ETH_ALEN);
 551         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
 552         frame->seq_ctrl = 0;
 553
 554         len += 24;
 555
 556         /* ...next IE... */
 557         pos = &frame->u.probe_req.variable[0];
 558
 559         /* fill in our indirect SSID IE */
 560         left -= 2;
 561         if (left < 0)
 562                 return 0;
 563         *pos++ = WLAN_EID_SSID;
 564         *pos++ = 0;
 565
 566         len += 2;
 567
 568         /* fill in supported rate */
 569         left -= 2;
 570         if (left < 0)
 571                 return 0;
 572
 573         *pos++ = WLAN_EID_SUPP_RATES;
 574         *pos = 0;
 575
 576         /* exclude 60M rate */
 577         active_rates = priv->rates_mask;
 578         active_rates &= ~IWL_RATE_60M_MASK;
 579
 580         active_rate_basic = active_rates & IWL_BASIC_RATES_MASK;
 581
 582         cck_rates = IWL_CCK_RATES_MASK & active_rates;
 583         ret_rates = iwl_supported_rate_to_ie(pos, cck_rates,
 584                                              active_rate_basic, &left);
 585         active_rates &= ~ret_rates;
 586
 587         ret_rates = iwl_supported_rate_to_ie(pos, active_rates,
 588                                              active_rate_basic, &left);
 589         active_rates &= ~ret_rates;
 590
 591         len += 2 + *pos;
 592         pos += (*pos) + 1;
 593
 594         if (active_rates == 0)
 595                 goto fill_end;
 596
 597         /* fill in supported extended rate */
 598         /* ...next IE... */
 599         left -= 2;
 600         if (left < 0)
 601                 return 0;
 602         /* ... fill it in... */
 603         *pos++ = WLAN_EID_EXT_SUPP_RATES;
 604         *pos = 0;
 605         iwl_supported_rate_to_ie(pos, active_rates, active_rate_basic, &left);
 606         if (*pos > 0) {
 607                 len += 2 + *pos;
 608                 pos += (*pos) + 1;
 609         } else {
 610                 pos--;
 611         }
 612
 613  fill_end:
 614
 615         left -= 2;
 616         if (left < 0)
 617                 return 0;
 618
 619         *pos++ = WLAN_EID_HT_CAPABILITY;
 620         *pos = 0;
 621         iwl_ht_cap_to_ie(sband, pos, &left);
 622         if (*pos > 0)
 623                 len += 2 + *pos;
 624
 625         return (u16)len;
 626 }
 627
 628 static void iwl_bg_request_scan(struct work_struct *data)
 629 {
 630         struct iwl_priv *priv =
 631             container_of(data, struct iwl_priv, request_scan);
 632         struct iwl_host_cmd cmd = {
 633                 .id = REPLY_SCAN_CMD,
 634                 .len = sizeof(struct iwl_scan_cmd),
 635                 .meta.flags = CMD_SIZE_HUGE,
 636         };
 637         struct iwl_scan_cmd *scan;
 638         struct ieee80211_conf *conf = NULL;
 639         int ret = 0;
 640         u32 rate_flags = 0;
 641         u16 cmd_len;
 642         enum ieee80211_band band;
 643         u8 n_probes = 2;
 644         u8 rx_chain = priv->hw_params.valid_rx_ant;
 645         u8 rate;
 646         DECLARE_SSID_BUF(ssid);
 647
 648         conf = ieee80211_get_hw_conf(priv->hw);
 649
 650         mutex_lock(&priv->mutex);
 651
 652         if (!iwl_is_ready(priv)) {
 653                 IWL_WARNING("request scan called when driver not ready.\n");
 654                 goto done;
 655         }
 656
 657         /* Make sure the scan wasn't canceled before this queued work
 658          * was given the chance to run... */
 659         if (!test_bit(STATUS_SCANNING, &priv->status))
 660                 goto done;
 661
 662         /* This should never be called or scheduled if there is currently
 663          * a scan active in the hardware. */
 664         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
 665                 IWL_DEBUG_INFO("Multiple concurrent scan requests in parallel. "
 666                                "Ignoring second request.\n");
 667                 ret = -EIO;
 668                 goto done;
 669         }
 670
 671         if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
 672                 IWL_DEBUG_SCAN("Aborting scan due to device shutdown\n");
 673                 goto done;
 674         }
 675
 676         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 677                 IWL_DEBUG_HC("Scan request while abort pending.  Queuing.\n");
 678                 goto done;
 679         }
 680
 681         if (iwl_is_rfkill(priv)) {
 682                 IWL_DEBUG_HC("Aborting scan due to RF Kill activation\n");
 683                 goto done;
 684         }
 685
 686         if (!test_bit(STATUS_READY, &priv->status)) {
 687                 IWL_DEBUG_HC("Scan request while uninitialized.  Queuing.\n");
 688                 goto done;
 689         }
 690
 691         if (!priv->scan_bands) {
 692                 IWL_DEBUG_HC("Aborting scan due to no requested bands\n");
 693                 goto done;
 694         }
 695
 696         if (!priv->scan) {
 697                 priv->scan = kmalloc(sizeof(struct iwl_scan_cmd) +
 698                                      IWL_MAX_SCAN_SIZE, GFP_KERNEL);
 699                 if (!priv->scan) {
 700                         ret = -ENOMEM;
 701                         goto done;
 702                 }
 703         }
 704         scan = priv->scan;
 705         memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
 706
 707         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
 708         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
 709
 710         if (iwl_is_associated(priv)) {
 711                 u16 interval = 0;
 712                 u32 extra;
 713                 u32 suspend_time = 100;
 714                 u32 scan_suspend_time = 100;
 715                 unsigned long flags;
 716
 717                 IWL_DEBUG_INFO("Scanning while associated...\n");
 718
 719                 spin_lock_irqsave(&priv->lock, flags);
 720                 interval = priv->beacon_int;
 721                 spin_unlock_irqrestore(&priv->lock, flags);
 722
 723                 scan->suspend_time = 0;
 724                 scan->max_out_time = cpu_to_le32(200 * 1024);
 725                 if (!interval)
 726                         interval = suspend_time;
 727
 728                 extra = (suspend_time / interval) << 22;
 729                 scan_suspend_time = (extra |
 730                     ((suspend_time % interval) * 1024));
 731                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
 732                 IWL_DEBUG_SCAN("suspend_time 0x%X beacon interval %d\n",
 733                                scan_suspend_time, interval);
 734         }
 735
 736         /* We should add the ability for user to lock to PASSIVE ONLY */
 737         if (priv->one_direct_scan) {
 738                 IWL_DEBUG_SCAN("Start direct scan for '%s'\n",
 739                                 print_ssid(ssid, priv->direct_ssid,
 740                                            priv->direct_ssid_len));
 741                 scan->direct_scan[0].id = WLAN_EID_SSID;
 742                 scan->direct_scan[0].len = priv->direct_ssid_len;
 743                 memcpy(scan->direct_scan[0].ssid,
 744                        priv->direct_ssid, priv->direct_ssid_len);
 745                 n_probes++;
 746         } else {
 747                 IWL_DEBUG_SCAN("Start indirect scan.\n");
 748         }
 749
 750         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
 751         scan->tx_cmd.sta_id = priv->hw_params.bcast_sta_id;
 752         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
 753
 754
 755         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) {
 756                 band = IEEE80211_BAND_2GHZ;
 757                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
 758                 if (priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_PURE_40_MSK) {
 759                         rate = IWL_RATE_6M_PLCP;
 760                 } else {
 761                         rate = IWL_RATE_1M_PLCP;
 762                         rate_flags = RATE_MCS_CCK_MSK;
 763                 }
 764                 scan->good_CRC_th = 0;
 765         } else if (priv->scan_bands & BIT(IEEE80211_BAND_5GHZ)) {
 766                 band = IEEE80211_BAND_5GHZ;
 767                 rate = IWL_RATE_6M_PLCP;
 768                 scan->good_CRC_th = IWL_GOOD_CRC_TH;
 769
 770                 /* Force use of chains B and C (0x6) for scan Rx for 4965
 771                  * Avoid A (0x1) because of its off-channel reception on A-band.
 772                  */
 773                 if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) == CSR_HW_REV_TYPE_4965)
 774                         rx_chain = 0x6;
 775         } else {
 776                 IWL_WARNING("Invalid scan band count\n");
 777                 goto done;
 778         }
 779
 780         priv->scan_tx_ant[band] =
 781                          iwl_toggle_tx_ant(priv, priv->scan_tx_ant[band]);
 782         rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
 783         scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
 784
 785         /* MIMO is not used here, but value is required */
 786         scan->rx_chain = RXON_RX_CHAIN_DRIVER_FORCE_MSK |
 787                                 cpu_to_le16((0x7 << RXON_RX_CHAIN_VALID_POS) |
 788                                 (rx_chain << RXON_RX_CHAIN_FORCE_SEL_POS) |
 789                                 (0x7 << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS));
 790
 791         cmd_len = iwl_fill_probe_req(priv, band,
 792                                      (struct ieee80211_mgmt *)scan->data,
 793                                      IWL_MAX_SCAN_SIZE - sizeof(*scan));
 794
 795         scan->tx_cmd.len = cpu_to_le16(cmd_len);
 796
 797         if (priv->iw_mode == NL80211_IFTYPE_MONITOR)
 798                 scan->filter_flags = RXON_FILTER_PROMISC_MSK;
 799
 800         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 801                                RXON_FILTER_BCON_AWARE_MSK);
 802
 803         scan->channel_count =
 804                 iwl_get_channels_for_scan(priv, band, 1, /* active */
 805                         n_probes,
 806                         (void *)&scan->data[le16_to_cpu(scan->tx_cmd.len)]);
 807
 808         if (scan->channel_count == 0) {
 809                 IWL_DEBUG_SCAN("channel count %d\n", scan->channel_count);
 810                 goto done;
 811         }
 812
 813         cmd.len += le16_to_cpu(scan->tx_cmd.len) +
 814             scan->channel_count * sizeof(struct iwl_scan_channel);
 815         cmd.data = scan;
 816         scan->len = cpu_to_le16(cmd.len);
 817
 818         set_bit(STATUS_SCAN_HW, &priv->status);
 819         ret = iwl_send_cmd_sync(priv, &cmd);
 820         if (ret)
 821                 goto done;
 822
 823         queue_delayed_work(priv->workqueue, &priv->scan_check,
 824                            IWL_SCAN_CHECK_WATCHDOG);
 825
 826         mutex_unlock(&priv->mutex);
 827         return;
 828
 829  done:
 830         /* Cannot perform scan. Make sure we clear scanning
 831         * bits from status so next scan request can be performed.
 832         * If we don't clear scanning status bit here all next scan
 833         * will fail
 834         */
 835         clear_bit(STATUS_SCAN_HW, &priv->status);
 836         clear_bit(STATUS_SCANNING, &priv->status);
 837         /* inform mac80211 scan aborted */
 838         queue_work(priv->workqueue, &priv->scan_completed);
 839         mutex_unlock(&priv->mutex);
 840 }
 841
 842 static void iwl_bg_abort_scan(struct work_struct *work)
 843 {
 844         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
 845
 846         if (!iwl_is_ready(priv))
 847                 return;
 848
 849         mutex_lock(&priv->mutex);
 850
 851         set_bit(STATUS_SCAN_ABORTING, &priv->status);
 852         iwl_send_scan_abort(priv);
 853
 854         mutex_unlock(&priv->mutex);
 855 }
 856
 857 static void iwl_bg_scan_completed(struct work_struct *work)
 858 {
 859         struct iwl_priv *priv =
 860             container_of(work, struct iwl_priv, scan_completed);
 861
 862         IWL_DEBUG_SCAN("SCAN complete scan\n");
 863
 864         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 865                 return;
 866
 867         ieee80211_scan_completed(priv->hw);
 868
 869         /* Since setting the TXPOWER may have been deferred while
 870          * performing the scan, fire one off */
 871         mutex_lock(&priv->mutex);
 872         iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);
 873         mutex_unlock(&priv->mutex);
 874 }
 875
 876
 877 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
 878 {
 879         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
 880         INIT_WORK(&priv->request_scan, iwl_bg_request_scan);
 881         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
 882         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
 883 }
 884 EXPORT_SYMBOL(iwl_setup_scan_deferred_work);
 885