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