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 <net/mac80211.h>
  29 #include <linux/etherdevice.h>
  30
  31 #include "iwl-eeprom.h"
  32 #include "iwl-dev.h"
  33 #include "iwl-core.h"
  34 #include "iwl-sta.h"
  35 #include "iwl-io.h"
  36 #include "iwl-helpers.h"
  37
  38 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
  39  * sending probe req.  This should be set long enough to hear probe responses
  40  * from more than one AP.  */
  41 #define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
  42 #define IWL_ACTIVE_DWELL_TIME_52    (20)
  43
  44 #define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
  45 #define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
  46
  47 /* For faster active scanning, scan will move to the next channel if fewer than
  48  * PLCP_QUIET_THRESH packets are heard on this channel within
  49  * ACTIVE_QUIET_TIME after sending probe request.  This shortens the dwell
  50  * time if it's a quiet channel (nothing responded to our probe, and there's
  51  * no other traffic).
  52  * Disable "quiet" feature by setting PLCP_QUIET_THRESH to 0. */
  53 #define IWL_PLCP_QUIET_THRESH       __constant_cpu_to_le16(1)  /* packets */
  54 #define IWL_ACTIVE_QUIET_TIME       __constant_cpu_to_le16(10)  /* msec */
  55
  56 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
  57  * Must be set longer than active dwell time.
  58  * For the most reliable scan, set > AP beacon interval (typically 100msec). */
  59 #define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
  60 #define IWL_PASSIVE_DWELL_TIME_52   (10)
  61 #define IWL_PASSIVE_DWELL_BASE      (100)
  62 #define IWL_CHANNEL_TUNE_TIME       5
  63
  64 #define IWL_SCAN_PROBE_MASK(n)  cpu_to_le32((BIT(n) | (BIT(n) - BIT(1))))
  65
  66
  67 static int scan_tx_ant[3] = {
  68         RATE_MCS_ANT_A_MSK, RATE_MCS_ANT_B_MSK, RATE_MCS_ANT_C_MSK
  69 };
  70
  71
  72
  73 static int iwl_is_empty_essid(const char *essid, int essid_len)
  74 {
  75         /* Single white space is for Linksys APs */
  76         if (essid_len == 1 && essid[0] == ' ')
  77                 return 1;
  78
  79         /* Otherwise, if the entire essid is 0, we assume it is hidden */
  80         while (essid_len) {
  81                 essid_len--;
  82                 if (essid[essid_len] != '\0')
  83                         return 0;
  84         }
  85
  86         return 1;
  87 }
  88
  89
  90
  91 const char *iwl_escape_essid(const char *essid, u8 essid_len)
  92 {
  93         static char escaped[IW_ESSID_MAX_SIZE * 2 + 1];
  94         const char *s = essid;
  95         char *d = escaped;
  96
  97         if (iwl_is_empty_essid(essid, essid_len)) {
  98                 memcpy(escaped, "<hidden>", sizeof("<hidden>"));
  99                 return escaped;
 100         }
 101
 102         essid_len = min(essid_len, (u8) IW_ESSID_MAX_SIZE);
 103         while (essid_len--) {
 104                 if (*s == '\0') {
 105                         *d++ = '\\';
 106                         *d++ = '0';
 107                         s++;
 108                 } else
 109                         *d++ = *s++;
 110         }
 111         *d = '\0';
 112         return escaped;
 113 }
 114 EXPORT_SYMBOL(iwl_escape_essid);
 115
 116 /**
 117  * iwl_scan_cancel - Cancel any currently executing HW scan
 118  *
 119  * NOTE: priv->mutex is not required before calling this function
 120  */
 121 int iwl_scan_cancel(struct iwl_priv *priv)
 122 {
 123         if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
 124                 clear_bit(STATUS_SCANNING, &priv->status);
 125                 return 0;
 126         }
 127
 128         if (test_bit(STATUS_SCANNING, &priv->status)) {
 129                 if (!test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 130                         IWL_DEBUG_SCAN("Queuing scan abort.\n");
 131                         set_bit(STATUS_SCAN_ABORTING, &priv->status);
 132                         queue_work(priv->workqueue, &priv->abort_scan);
 133
 134                 } else
 135                         IWL_DEBUG_SCAN("Scan abort already in progress.\n");
 136
 137                 return test_bit(STATUS_SCANNING, &priv->status);
 138         }
 139
 140         return 0;
 141 }
 142 EXPORT_SYMBOL(iwl_scan_cancel);
 143 /**
 144  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
 145  * @ms: amount of time to wait (in milliseconds) for scan to abort
 146  *
 147  * NOTE: priv->mutex must be held before calling this function
 148  */
 149 int iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
 150 {
 151         unsigned long now = jiffies;
 152         int ret;
 153
 154         ret = iwl_scan_cancel(priv);
 155         if (ret && ms) {
 156                 mutex_unlock(&priv->mutex);
 157                 while (!time_after(jiffies, now + msecs_to_jiffies(ms)) &&
 158                                 test_bit(STATUS_SCANNING, &priv->status))
 159                         msleep(1);
 160                 mutex_lock(&priv->mutex);
 161
 162                 return test_bit(STATUS_SCANNING, &priv->status);
 163         }
 164
 165         return ret;
 166 }
 167 EXPORT_SYMBOL(iwl_scan_cancel_timeout);
 168
 169 static int iwl_send_scan_abort(struct iwl_priv *priv)
 170 {
 171         int ret = 0;
 172         struct iwl_rx_packet *res;
 173         struct iwl_host_cmd cmd = {
 174                 .id = REPLY_SCAN_ABORT_CMD,
 175                 .meta.flags = CMD_WANT_SKB,
 176         };
 177
 178         /* If there isn't a scan actively going on in the hardware
 179          * then we are in between scan bands and not actually
 180          * actively scanning, so don't send the abort command */
 181         if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
 182                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 183                 return 0;
 184         }
 185
 186         ret = iwl_send_cmd_sync(priv, &cmd);
 187         if (ret) {
 188                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 189                 return ret;
 190         }
 191
 192         res = (struct iwl_rx_packet *)cmd.meta.u.skb->data;
 193         if (res->u.status != CAN_ABORT_STATUS) {
 194                 /* The scan abort will return 1 for success or
 195                  * 2 for "failure".  A failure condition can be
 196                  * due to simply not being in an active scan which
 197                  * can occur if we send the scan abort before we
 198                  * the microcode has notified us that a scan is
 199                  * completed. */
 200                 IWL_DEBUG_INFO("SCAN_ABORT returned %d.\n", res->u.status);
 201                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 202                 clear_bit(STATUS_SCAN_HW, &priv->status);
 203         }
 204
 205         priv->alloc_rxb_skb--;
 206         dev_kfree_skb_any(cmd.meta.u.skb);
 207
 208         return ret;
 209 }
 210
 211
 212 /* Service response to REPLY_SCAN_CMD (0x80) */
 213 static void iwl_rx_reply_scan(struct iwl_priv *priv,
 214                               struct iwl_rx_mem_buffer *rxb)
 215 {
 216 #ifdef CONFIG_IWLWIFI_DEBUG
 217         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
 218         struct iwl_scanreq_notification *notif =
 219             (struct iwl_scanreq_notification *)pkt->u.raw;
 220
 221         IWL_DEBUG_RX("Scan request status = 0x%x\n", notif->status);
 222 #endif
 223 }
 224
 225 /* Service SCAN_START_NOTIFICATION (0x82) */
 226 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
 227                                     struct iwl_rx_mem_buffer *rxb)
 228 {
 229         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
 230         struct iwl_scanstart_notification *notif =
 231             (struct iwl_scanstart_notification *)pkt->u.raw;
 232         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 233         IWL_DEBUG_SCAN("Scan start: "
 234                        "%d [802.11%s] "
 235                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 236                        notif->channel,
 237                        notif->band ? "bg" : "a",
 238                        le32_to_cpu(notif->tsf_high),
 239                        le32_to_cpu(notif->tsf_low),
 240                        notif->status, notif->beacon_timer);
 241 }
 242
 243 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 244 static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
 245                                       struct iwl_rx_mem_buffer *rxb)
 246 {
 247 #ifdef CONFIG_IWLWIFI_DEBUG
 248         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
 249         struct iwl_scanresults_notification *notif =
 250             (struct iwl_scanresults_notification *)pkt->u.raw;
 251
 252         IWL_DEBUG_SCAN("Scan ch.res: "
 253                        "%d [802.11%s] "
 254                        "(TSF: 0x%08X:%08X) - %d "
 255                        "elapsed=%lu usec (%dms since last)\n",
 256                        notif->channel,
 257                        notif->band ? "bg" : "a",
 258                        le32_to_cpu(notif->tsf_high),
 259                        le32_to_cpu(notif->tsf_low),
 260                        le32_to_cpu(notif->statistics[0]),
 261                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf,
 262                        jiffies_to_msecs(elapsed_jiffies
 263                                         (priv->last_scan_jiffies, jiffies)));
 264 #endif
 265
 266         priv->last_scan_jiffies = jiffies;
 267         priv->next_scan_jiffies = 0;
 268 }
 269
 270 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 271 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 272                                        struct iwl_rx_mem_buffer *rxb)
 273 {
 274 #ifdef CONFIG_IWLWIFI_DEBUG
 275         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
 276         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
 277
 278         IWL_DEBUG_SCAN("Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 279                        scan_notif->scanned_channels,
 280                        scan_notif->tsf_low,
 281                        scan_notif->tsf_high, scan_notif->status);
 282 #endif
 283
 284         /* The HW is no longer scanning */
 285         clear_bit(STATUS_SCAN_HW, &priv->status);
 286
 287         /* The scan completion notification came in, so kill that timer... */
 288         cancel_delayed_work(&priv->scan_check);
 289
 290         IWL_DEBUG_INFO("Scan pass on %sGHz took %dms\n",
 291                        (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) ?
 292                                                 "2.4" : "5.2",
 293                        jiffies_to_msecs(elapsed_jiffies
 294                                         (priv->scan_pass_start, jiffies)));
 295
 296         /* Remove this scanned band from the list of pending
 297          * bands to scan, band G precedes A in order of scanning
 298          * as seen in iwl_bg_request_scan */
 299         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ))
 300                 priv->scan_bands &= ~BIT(IEEE80211_BAND_2GHZ);
 301         else if (priv->scan_bands &  BIT(IEEE80211_BAND_5GHZ))
 302                 priv->scan_bands &= ~BIT(IEEE80211_BAND_5GHZ);
 303
 304         /* If a request to abort was given, or the scan did not succeed
 305          * then we reset the scan state machine and terminate,
 306          * re-queuing another scan if one has been requested */
 307         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 308                 IWL_DEBUG_INFO("Aborted scan completed.\n");
 309                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 310         } else {
 311                 /* If there are more bands on this scan pass reschedule */
 312                 if (priv->scan_bands)
 313                         goto reschedule;
 314         }
 315
 316         priv->last_scan_jiffies = jiffies;
 317         priv->next_scan_jiffies = 0;
 318         IWL_DEBUG_INFO("Setting scan to off\n");
 319
 320         clear_bit(STATUS_SCANNING, &priv->status);
 321
 322         IWL_DEBUG_INFO("Scan took %dms\n",
 323                 jiffies_to_msecs(elapsed_jiffies(priv->scan_start, jiffies)));
 324
 325         queue_work(priv->workqueue, &priv->scan_completed);
 326
 327         return;
 328
 329 reschedule:
 330         priv->scan_pass_start = jiffies;
 331         queue_work(priv->workqueue, &priv->request_scan);
 332 }
 333
 334 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 335 {
 336         /* scan handlers */
 337         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 338         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 339         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 340                                         iwl_rx_scan_results_notif;
 341         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 342                                         iwl_rx_scan_complete_notif;
 343 }
 344 EXPORT_SYMBOL(iwl_setup_rx_scan_handlers);
 345
 346 static inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 347                                             enum ieee80211_band band,
 348                                             u8 n_probes)
 349 {
 350         if (band == IEEE80211_BAND_5GHZ)
 351                 return IWL_ACTIVE_DWELL_TIME_52 +
 352                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 353         else
 354                 return IWL_ACTIVE_DWELL_TIME_24 +
 355                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 356 }
 357
 358 static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 359                                       enum ieee80211_band band)
 360 {
 361         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
 362             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 363             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 364
 365         if (iwl_is_associated(priv)) {
 366                 /* If we're associated, we clamp the maximum passive
 367                  * dwell time to be 98% of the beacon interval (minus
 368                  * 2 * channel tune time) */
 369                 passive = priv->beacon_int;
 370                 if ((passive > IWL_PASSIVE_DWELL_BASE) || !passive)
 371                         passive = IWL_PASSIVE_DWELL_BASE;
 372                 passive = (passive * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 373         }
 374
 375         return passive;
 376 }
 377
 378 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 379                                      enum ieee80211_band band,
 380                                      u8 is_active, u8 n_probes,
 381                                      struct iwl_scan_channel *scan_ch)
 382 {
 383         const struct ieee80211_channel *channels = NULL;
 384         const struct ieee80211_supported_band *sband;
 385         const struct iwl_channel_info *ch_info;
 386         u16 passive_dwell = 0;
 387         u16 active_dwell = 0;
 388         int added, i;
 389         u16 channel;
 390
 391         sband = iwl_get_hw_mode(priv, band);
 392         if (!sband)
 393                 return 0;
 394
 395         channels = sband->channels;
 396
 397         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 398         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 399
 400         if (passive_dwell <= active_dwell)
 401                 passive_dwell = active_dwell + 1;
 402
 403         for (i = 0, added = 0; i < sband->n_channels; i++) {
 404                 if (channels[i].flags & IEEE80211_CHAN_DISABLED)
 405                         continue;
 406
 407                 channel =
 408                         ieee80211_frequency_to_channel(channels[i].center_freq);
 409                 scan_ch->channel = cpu_to_le16(channel);
 410
 411                 ch_info = iwl_get_channel_info(priv, band, channel);
 412                 if (!is_channel_valid(ch_info)) {
 413                         IWL_DEBUG_SCAN("Channel %d is INVALID for this band.\n",
 414                                         channel);
 415                         continue;
 416                 }
 417
 418                 if (!is_active || is_channel_passive(ch_info) ||
 419                     (channels[i].flags & IEEE80211_CHAN_PASSIVE_SCAN))
 420                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 421                 else
 422                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 423
 424                 if (n_probes)
 425                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 426
 427                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 428                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 429
 430                 /* Set txpower levels to defaults */
 431                 scan_ch->dsp_atten = 110;
 432
 433                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 434                  * power level:
 435                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 436                  */
 437                 if (band == IEEE80211_BAND_5GHZ)
 438                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 439                 else
 440                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 441
 442                 IWL_DEBUG_SCAN("Scanning ch=%d prob=0x%X [%s %d]\n",
 443                                channel, le32_to_cpu(scan_ch->type),
 444                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 445                                 "ACTIVE" : "PASSIVE",
 446                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 447                                active_dwell : passive_dwell);
 448
 449                 scan_ch++;
 450                 added++;
 451         }
 452
 453         IWL_DEBUG_SCAN("total channels to scan %d \n", added);
 454         return added;
 455 }
 456
 457 void iwl_init_scan_params(struct iwl_priv *priv)
 458 {
 459         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
 460                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = RATE_MCS_ANT_INIT_IND;
 461         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
 462                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = RATE_MCS_ANT_INIT_IND;
 463 }
 464
 465 int iwl_scan_initiate(struct iwl_priv *priv)
 466 {
 467         if (priv->iw_mode == IEEE80211_IF_TYPE_AP) {
 468                 IWL_ERROR("APs don't scan.\n");
 469                 return 0;
 470         }
 471
 472         if (!iwl_is_ready_rf(priv)) {
 473                 IWL_DEBUG_SCAN("Aborting scan due to not ready.\n");
 474                 return -EIO;
 475         }
 476
 477         if (test_bit(STATUS_SCANNING, &priv->status)) {
 478                 IWL_DEBUG_SCAN("Scan already in progress.\n");
 479                 return -EAGAIN;
 480         }
 481
 482         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 483                 IWL_DEBUG_SCAN("Scan request while abort pending.  "
 484                                "Queuing.\n");
 485                 return -EAGAIN;
 486         }
 487
 488         IWL_DEBUG_INFO("Starting scan...\n");
 489         if (priv->cfg->sku & IWL_SKU_G)
 490                 priv->scan_bands |= BIT(IEEE80211_BAND_2GHZ);
 491         if (priv->cfg->sku & IWL_SKU_A)
 492                 priv->scan_bands |= BIT(IEEE80211_BAND_5GHZ);
 493         set_bit(STATUS_SCANNING, &priv->status);
 494         priv->scan_start = jiffies;
 495         priv->scan_pass_start = priv->scan_start;
 496
 497         queue_work(priv->workqueue, &priv->request_scan);
 498
 499         return 0;
 500 }
 501 EXPORT_SYMBOL(iwl_scan_initiate);
 502
 503 #define IWL_SCAN_CHECK_WATCHDOG (7 * HZ)
 504
 505 static void iwl_bg_scan_check(struct work_struct *data)
 506 {
 507         struct iwl_priv *priv =
 508             container_of(data, struct iwl_priv, scan_check.work);
 509
 510         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 511                 return;
 512
 513         mutex_lock(&priv->mutex);
 514         if (test_bit(STATUS_SCANNING, &priv->status) ||
 515             test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 516                 IWL_DEBUG(IWL_DL_SCAN, "Scan completion watchdog resetting "
 517                         "adapter (%dms)\n",
 518                         jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG));
 519
 520                 if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
 521                         iwl_send_scan_abort(priv);
 522         }
 523         mutex_unlock(&priv->mutex);
 524 }
 525 /**
 526  * iwl_supported_rate_to_ie - fill in the supported rate in IE field
 527  *
 528  * return : set the bit for each supported rate insert in ie
 529  */
 530 static u16 iwl_supported_rate_to_ie(u8 *ie, u16 supported_rate,
 531                                     u16 basic_rate, int *left)
 532 {
 533         u16 ret_rates = 0, bit;
 534         int i;
 535         u8 *cnt = ie;
 536         u8 *rates = ie + 1;
 537
 538         for (bit = 1, i = 0; i < IWL_RATE_COUNT; i++, bit <<= 1) {
 539                 if (bit & supported_rate) {
 540                         ret_rates |= bit;
 541                         rates[*cnt] = iwl_rates[i].ieee |
 542                                 ((bit & basic_rate) ? 0x80 : 0x00);
 543                         (*cnt)++;
 544                         (*left)--;
 545                         if ((*left <= 0) ||
 546                             (*cnt >= IWL_SUPPORTED_RATES_IE_LEN))
 547                                 break;
 548                 }
 549         }
 550
 551         return ret_rates;
 552 }
 553
 554
 555 static void iwl_ht_cap_to_ie(const struct ieee80211_supported_band *sband,
 556                              u8 *pos, int *left)
 557 {
 558         struct ieee80211_ht_cap *ht_cap;
 559
 560         if (!sband || !sband->ht_info.ht_supported)
 561                 return;
 562
 563         if (*left < sizeof(struct ieee80211_ht_cap))
 564                 return;
 565
 566         *pos++ = sizeof(struct ieee80211_ht_cap);
 567         ht_cap = (struct ieee80211_ht_cap *) pos;
 568
 569         ht_cap->cap_info = cpu_to_le16(sband->ht_info.cap);
 570         memcpy(ht_cap->supp_mcs_set, sband->ht_info.supp_mcs_set, 16);
 571         ht_cap->ampdu_params_info =
 572                 (sband->ht_info.ampdu_factor & IEEE80211_HT_CAP_AMPDU_FACTOR) |
 573                 ((sband->ht_info.ampdu_density << 2) &
 574                         IEEE80211_HT_CAP_AMPDU_DENSITY);
 575         *left -= sizeof(struct ieee80211_ht_cap);
 576 }
 577
 578 /**
 579  * iwl_fill_probe_req - fill in all required fields and IE for probe request
 580  */
 581
 582 static u16 iwl_fill_probe_req(struct iwl_priv *priv,
 583                                   enum ieee80211_band band,
 584                                   struct ieee80211_mgmt *frame,
 585                                   int left)
 586 {
 587         int len = 0;
 588         u8 *pos = NULL;
 589         u16 active_rates, ret_rates, cck_rates, active_rate_basic;
 590         const struct ieee80211_supported_band *sband =
 591                                                 iwl_get_hw_mode(priv, band);
 592
 593
 594         /* Make sure there is enough space for the probe request,
 595          * two mandatory IEs and the data */
 596         left -= 24;
 597         if (left < 0)
 598                 return 0;
 599
 600         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 601         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
 602         memcpy(frame->sa, priv->mac_addr, ETH_ALEN);
 603         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
 604         frame->seq_ctrl = 0;
 605
 606         len += 24;
 607
 608         /* ...next IE... */
 609         pos = &frame->u.probe_req.variable[0];
 610
 611         /* fill in our indirect SSID IE */
 612         left -= 2;
 613         if (left < 0)
 614                 return 0;
 615         *pos++ = WLAN_EID_SSID;
 616         *pos++ = 0;
 617
 618         len += 2;
 619
 620         /* fill in supported rate */
 621         left -= 2;
 622         if (left < 0)
 623                 return 0;
 624
 625         *pos++ = WLAN_EID_SUPP_RATES;
 626         *pos = 0;
 627
 628         /* exclude 60M rate */
 629         active_rates = priv->rates_mask;
 630         active_rates &= ~IWL_RATE_60M_MASK;
 631
 632         active_rate_basic = active_rates & IWL_BASIC_RATES_MASK;
 633
 634         cck_rates = IWL_CCK_RATES_MASK & active_rates;
 635         ret_rates = iwl_supported_rate_to_ie(pos, cck_rates,
 636                                              active_rate_basic, &left);
 637         active_rates &= ~ret_rates;
 638
 639         ret_rates = iwl_supported_rate_to_ie(pos, active_rates,
 640                                              active_rate_basic, &left);
 641         active_rates &= ~ret_rates;
 642
 643         len += 2 + *pos;
 644         pos += (*pos) + 1;
 645
 646         if (active_rates == 0)
 647                 goto fill_end;
 648
 649         /* fill in supported extended rate */
 650         /* ...next IE... */
 651         left -= 2;
 652         if (left < 0)
 653                 return 0;
 654         /* ... fill it in... */
 655         *pos++ = WLAN_EID_EXT_SUPP_RATES;
 656         *pos = 0;
 657         iwl_supported_rate_to_ie(pos, active_rates, active_rate_basic, &left);
 658         if (*pos > 0) {
 659                 len += 2 + *pos;
 660                 pos += (*pos) + 1;
 661         } else {
 662                 pos--;
 663         }
 664
 665  fill_end:
 666
 667         left -= 2;
 668         if (left < 0)
 669                 return 0;
 670
 671         *pos++ = WLAN_EID_HT_CAPABILITY;
 672         *pos = 0;
 673         iwl_ht_cap_to_ie(sband, pos, &left);
 674         if (*pos > 0)
 675                 len += 2 + *pos;
 676
 677         return (u16)len;
 678 }
 679
 680 static u32 iwl_scan_tx_ant(struct iwl_priv *priv, enum ieee80211_band band)
 681 {
 682         int i, ind;
 683
 684         ind = priv->scan_tx_ant[band];
 685         for (i = 0; i < priv->hw_params.tx_chains_num; i++) {
 686                 ind = (ind+1) >= priv->hw_params.tx_chains_num ? 0 : ind+1;
 687                 if (priv->hw_params.valid_tx_ant & (1 << ind)) {
 688                         priv->scan_tx_ant[band] = ind;
 689                         break;
 690                 }
 691         }
 692         IWL_DEBUG_SCAN("select TX ANT = %c\n", 'A' + ind);
 693         return scan_tx_ant[ind];
 694 }
 695
 696
 697 static void iwl_bg_request_scan(struct work_struct *data)
 698 {
 699         struct iwl_priv *priv =
 700             container_of(data, struct iwl_priv, request_scan);
 701         struct iwl_host_cmd cmd = {
 702                 .id = REPLY_SCAN_CMD,
 703                 .len = sizeof(struct iwl_scan_cmd),
 704                 .meta.flags = CMD_SIZE_HUGE,
 705         };
 706         struct iwl_scan_cmd *scan;
 707         struct ieee80211_conf *conf = NULL;
 708         int ret = 0;
 709         u32 tx_ant;
 710         u16 cmd_len;
 711         enum ieee80211_band band;
 712         u8 n_probes = 2;
 713         u8 rx_chain = 0x7; /* bitmap: ABC chains */
 714
 715         conf = ieee80211_get_hw_conf(priv->hw);
 716
 717         mutex_lock(&priv->mutex);
 718
 719         if (!iwl_is_ready(priv)) {
 720                 IWL_WARNING("request scan called when driver not ready.\n");
 721                 goto done;
 722         }
 723
 724         /* Make sure the scan wasn't cancelled before this queued work
 725          * was given the chance to run... */
 726         if (!test_bit(STATUS_SCANNING, &priv->status))
 727                 goto done;
 728
 729         /* This should never be called or scheduled if there is currently
 730          * a scan active in the hardware. */
 731         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
 732                 IWL_DEBUG_INFO("Multiple concurrent scan requests in parallel. "
 733                                "Ignoring second request.\n");
 734                 ret = -EIO;
 735                 goto done;
 736         }
 737
 738         if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
 739                 IWL_DEBUG_SCAN("Aborting scan due to device shutdown\n");
 740                 goto done;
 741         }
 742
 743         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 744                 IWL_DEBUG_HC("Scan request while abort pending.  Queuing.\n");
 745                 goto done;
 746         }
 747
 748         if (iwl_is_rfkill(priv)) {
 749                 IWL_DEBUG_HC("Aborting scan due to RF Kill activation\n");
 750                 goto done;
 751         }
 752
 753         if (!test_bit(STATUS_READY, &priv->status)) {
 754                 IWL_DEBUG_HC("Scan request while uninitialized.  Queuing.\n");
 755                 goto done;
 756         }
 757
 758         if (!priv->scan_bands) {
 759                 IWL_DEBUG_HC("Aborting scan due to no requested bands\n");
 760                 goto done;
 761         }
 762
 763         if (!priv->scan) {
 764                 priv->scan = kmalloc(sizeof(struct iwl_scan_cmd) +
 765                                      IWL_MAX_SCAN_SIZE, GFP_KERNEL);
 766                 if (!priv->scan) {
 767                         ret = -ENOMEM;
 768                         goto done;
 769                 }
 770         }
 771         scan = priv->scan;
 772         memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
 773
 774         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
 775         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
 776
 777         if (iwl_is_associated(priv)) {
 778                 u16 interval = 0;
 779                 u32 extra;
 780                 u32 suspend_time = 100;
 781                 u32 scan_suspend_time = 100;
 782                 unsigned long flags;
 783
 784                 IWL_DEBUG_INFO("Scanning while associated...\n");
 785
 786                 spin_lock_irqsave(&priv->lock, flags);
 787                 interval = priv->beacon_int;
 788                 spin_unlock_irqrestore(&priv->lock, flags);
 789
 790                 scan->suspend_time = 0;
 791                 scan->max_out_time = cpu_to_le32(200 * 1024);
 792                 if (!interval)
 793                         interval = suspend_time;
 794
 795                 extra = (suspend_time / interval) << 22;
 796                 scan_suspend_time = (extra |
 797                     ((suspend_time % interval) * 1024));
 798                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
 799                 IWL_DEBUG_SCAN("suspend_time 0x%X beacon interval %d\n",
 800                                scan_suspend_time, interval);
 801         }
 802
 803         /* We should add the ability for user to lock to PASSIVE ONLY */
 804         if (priv->one_direct_scan) {
 805                 IWL_DEBUG_SCAN("Start direct scan for '%s'\n",
 806                                 iwl_escape_essid(priv->direct_ssid,
 807                                 priv->direct_ssid_len));
 808                 scan->direct_scan[0].id = WLAN_EID_SSID;
 809                 scan->direct_scan[0].len = priv->direct_ssid_len;
 810                 memcpy(scan->direct_scan[0].ssid,
 811                        priv->direct_ssid, priv->direct_ssid_len);
 812                 n_probes++;
 813         } else if (!iwl_is_associated(priv) && priv->essid_len) {
 814                 IWL_DEBUG_SCAN("Start direct scan for '%s' (not associated)\n",
 815                                 iwl_escape_essid(priv->essid, priv->essid_len));
 816                 scan->direct_scan[0].id = WLAN_EID_SSID;
 817                 scan->direct_scan[0].len = priv->essid_len;
 818                 memcpy(scan->direct_scan[0].ssid, priv->essid, priv->essid_len);
 819                 n_probes++;
 820         } else {
 821                 IWL_DEBUG_SCAN("Start indirect scan.\n");
 822         }
 823
 824         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
 825         scan->tx_cmd.sta_id = priv->hw_params.bcast_sta_id;
 826         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
 827
 828
 829         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) {
 830                 band = IEEE80211_BAND_2GHZ;
 831                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
 832                 tx_ant = iwl_scan_tx_ant(priv, band);
 833                 if (priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_PURE_40_MSK)
 834                         scan->tx_cmd.rate_n_flags =
 835                                 iwl_hw_set_rate_n_flags(IWL_RATE_6M_PLCP,
 836                                                         tx_ant);
 837                 else
 838                         scan->tx_cmd.rate_n_flags =
 839                                 iwl_hw_set_rate_n_flags(IWL_RATE_1M_PLCP,
 840                                                         tx_ant |
 841                                                         RATE_MCS_CCK_MSK);
 842                 scan->good_CRC_th = 0;
 843         } else if (priv->scan_bands & BIT(IEEE80211_BAND_5GHZ)) {
 844                 band = IEEE80211_BAND_5GHZ;
 845                 tx_ant = iwl_scan_tx_ant(priv, band);
 846                 scan->tx_cmd.rate_n_flags =
 847                                 iwl_hw_set_rate_n_flags(IWL_RATE_6M_PLCP,
 848                                                         tx_ant);
 849                 scan->good_CRC_th = IWL_GOOD_CRC_TH;
 850
 851                 /* Force use of chains B and C (0x6) for scan Rx for 4965
 852                  * Avoid A (0x1) because of its off-channel reception on A-band.
 853                  * MIMO is not used here, but value is required */
 854                 if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) == CSR_HW_REV_TYPE_4965)
 855                         rx_chain = 0x6;
 856         } else {
 857                 IWL_WARNING("Invalid scan band count\n");
 858                 goto done;
 859         }
 860
 861         scan->rx_chain = RXON_RX_CHAIN_DRIVER_FORCE_MSK |
 862                                 cpu_to_le16((0x7 << RXON_RX_CHAIN_VALID_POS) |
 863                                 (rx_chain << RXON_RX_CHAIN_FORCE_SEL_POS) |
 864                                 (0x7 << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS));
 865
 866         cmd_len = iwl_fill_probe_req(priv, band,
 867                                      (struct ieee80211_mgmt *)scan->data,
 868                                      IWL_MAX_SCAN_SIZE - sizeof(*scan));
 869
 870         scan->tx_cmd.len = cpu_to_le16(cmd_len);
 871
 872         if (priv->iw_mode == IEEE80211_IF_TYPE_MNTR)
 873                 scan->filter_flags = RXON_FILTER_PROMISC_MSK;
 874
 875         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 876                                RXON_FILTER_BCON_AWARE_MSK);
 877
 878         scan->channel_count =
 879                 iwl_get_channels_for_scan(priv, band, 1, /* active */
 880                         n_probes,
 881                         (void *)&scan->data[le16_to_cpu(scan->tx_cmd.len)]);
 882
 883         if (scan->channel_count == 0) {
 884                 IWL_DEBUG_SCAN("channel count %d\n", scan->channel_count);
 885                 goto done;
 886         }
 887
 888         cmd.len += le16_to_cpu(scan->tx_cmd.len) +
 889             scan->channel_count * sizeof(struct iwl_scan_channel);
 890         cmd.data = scan;
 891         scan->len = cpu_to_le16(cmd.len);
 892
 893         set_bit(STATUS_SCAN_HW, &priv->status);
 894         ret = iwl_send_cmd_sync(priv, &cmd);
 895         if (ret)
 896                 goto done;
 897
 898         queue_delayed_work(priv->workqueue, &priv->scan_check,
 899                            IWL_SCAN_CHECK_WATCHDOG);
 900
 901         mutex_unlock(&priv->mutex);
 902         return;
 903
 904  done:
 905         /* inform mac80211 scan aborted */
 906         queue_work(priv->workqueue, &priv->scan_completed);
 907         mutex_unlock(&priv->mutex);
 908 }
 909
 910 static void iwl_bg_abort_scan(struct work_struct *work)
 911 {
 912         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
 913
 914         if (!iwl_is_ready(priv))
 915                 return;
 916
 917         mutex_lock(&priv->mutex);
 918
 919         set_bit(STATUS_SCAN_ABORTING, &priv->status);
 920         iwl_send_scan_abort(priv);
 921
 922         mutex_unlock(&priv->mutex);
 923 }
 924
 925 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
 926 {
 927         /*  FIXME: move here when resolved PENDING
 928          *  INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed); */
 929         INIT_WORK(&priv->request_scan, iwl_bg_request_scan);
 930         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
 931         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
 932 }
 933 EXPORT_SYMBOL(iwl_setup_scan_deferred_work);
 934