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 static 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
 115 /**
 116  * iwl_scan_cancel - Cancel any currently executing HW scan
 117  *
 118  * NOTE: priv->mutex is not required before calling this function
 119  */
 120 int iwl_scan_cancel(struct iwl_priv *priv)
 121 {
 122         if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
 123                 clear_bit(STATUS_SCANNING, &priv->status);
 124                 return 0;
 125         }
 126
 127         if (test_bit(STATUS_SCANNING, &priv->status)) {
 128                 if (!test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 129                         IWL_DEBUG_SCAN("Queuing scan abort.\n");
 130                         set_bit(STATUS_SCAN_ABORTING, &priv->status);
 131                         queue_work(priv->workqueue, &priv->abort_scan);
 132
 133                 } else
 134                         IWL_DEBUG_SCAN("Scan abort already in progress.\n");
 135
 136                 return test_bit(STATUS_SCANNING, &priv->status);
 137         }
 138
 139         return 0;
 140 }
 141 EXPORT_SYMBOL(iwl_scan_cancel);
 142 /**
 143  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
 144  * @ms: amount of time to wait (in milliseconds) for scan to abort
 145  *
 146  * NOTE: priv->mutex must be held before calling this function
 147  */
 148 int iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
 149 {
 150         unsigned long now = jiffies;
 151         int ret;
 152
 153         ret = iwl_scan_cancel(priv);
 154         if (ret && ms) {
 155                 mutex_unlock(&priv->mutex);
 156                 while (!time_after(jiffies, now + msecs_to_jiffies(ms)) &&
 157                                 test_bit(STATUS_SCANNING, &priv->status))
 158                         msleep(1);
 159                 mutex_lock(&priv->mutex);
 160
 161                 return test_bit(STATUS_SCANNING, &priv->status);
 162         }
 163
 164         return ret;
 165 }
 166 EXPORT_SYMBOL(iwl_scan_cancel_timeout);
 167
 168 static int iwl_send_scan_abort(struct iwl_priv *priv)
 169 {
 170         int ret = 0;
 171         struct iwl_rx_packet *res;
 172         struct iwl_host_cmd cmd = {
 173                 .id = REPLY_SCAN_ABORT_CMD,
 174                 .meta.flags = CMD_WANT_SKB,
 175         };
 176
 177         /* If there isn't a scan actively going on in the hardware
 178          * then we are in between scan bands and not actually
 179          * actively scanning, so don't send the abort command */
 180         if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
 181                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 182                 return 0;
 183         }
 184
 185         ret = iwl_send_cmd_sync(priv, &cmd);
 186         if (ret) {
 187                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 188                 return ret;
 189         }
 190
 191         res = (struct iwl_rx_packet *)cmd.meta.u.skb->data;
 192         if (res->u.status != CAN_ABORT_STATUS) {
 193                 /* The scan abort will return 1 for success or
 194                  * 2 for "failure".  A failure condition can be
 195                  * due to simply not being in an active scan which
 196                  * can occur if we send the scan abort before we
 197                  * the microcode has notified us that a scan is
 198                  * completed. */
 199                 IWL_DEBUG_INFO("SCAN_ABORT returned %d.\n", res->u.status);
 200                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 201                 clear_bit(STATUS_SCAN_HW, &priv->status);
 202         }
 203
 204         priv->alloc_rxb_skb--;
 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 #ifdef CONFIG_IWLWIFI_DEBUG
 274         struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
 275         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
 276
 277         IWL_DEBUG_SCAN("Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 278                        scan_notif->scanned_channels,
 279                        scan_notif->tsf_low,
 280                        scan_notif->tsf_high, scan_notif->status);
 281 #endif
 282
 283         /* The HW is no longer scanning */
 284         clear_bit(STATUS_SCAN_HW, &priv->status);
 285
 286         /* The scan completion notification came in, so kill that timer... */
 287         cancel_delayed_work(&priv->scan_check);
 288
 289         IWL_DEBUG_INFO("Scan pass on %sGHz took %dms\n",
 290                        (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) ?
 291                                                 "2.4" : "5.2",
 292                        jiffies_to_msecs(elapsed_jiffies
 293                                         (priv->scan_pass_start, jiffies)));
 294
 295         /* Remove this scanned band from the list of pending
 296          * bands to scan, band G precedes A in order of scanning
 297          * as seen in iwl_bg_request_scan */
 298         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ))
 299                 priv->scan_bands &= ~BIT(IEEE80211_BAND_2GHZ);
 300         else if (priv->scan_bands &  BIT(IEEE80211_BAND_5GHZ))
 301                 priv->scan_bands &= ~BIT(IEEE80211_BAND_5GHZ);
 302
 303         /* If a request to abort was given, or the scan did not succeed
 304          * then we reset the scan state machine and terminate,
 305          * re-queuing another scan if one has been requested */
 306         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 307                 IWL_DEBUG_INFO("Aborted scan completed.\n");
 308                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 309         } else {
 310                 /* If there are more bands on this scan pass reschedule */
 311                 if (priv->scan_bands)
 312                         goto reschedule;
 313         }
 314
 315         priv->last_scan_jiffies = jiffies;
 316         priv->next_scan_jiffies = 0;
 317         IWL_DEBUG_INFO("Setting scan to off\n");
 318
 319         clear_bit(STATUS_SCANNING, &priv->status);
 320
 321         IWL_DEBUG_INFO("Scan took %dms\n",
 322                 jiffies_to_msecs(elapsed_jiffies(priv->scan_start, jiffies)));
 323
 324         queue_work(priv->workqueue, &priv->scan_completed);
 325
 326         return;
 327
 328 reschedule:
 329         priv->scan_pass_start = jiffies;
 330         queue_work(priv->workqueue, &priv->request_scan);
 331 }
 332
 333 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 334 {
 335         /* scan handlers */
 336         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 337         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 338         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 339                                         iwl_rx_scan_results_notif;
 340         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 341                                         iwl_rx_scan_complete_notif;
 342 }
 343 EXPORT_SYMBOL(iwl_setup_rx_scan_handlers);
 344
 345 static inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 346                                             enum ieee80211_band band,
 347                                             u8 n_probes)
 348 {
 349         if (band == IEEE80211_BAND_5GHZ)
 350                 return IWL_ACTIVE_DWELL_TIME_52 +
 351                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 352         else
 353                 return IWL_ACTIVE_DWELL_TIME_24 +
 354                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 355 }
 356
 357 static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 358                                       enum ieee80211_band band)
 359 {
 360         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
 361             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 362             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 363
 364         if (iwl_is_associated(priv)) {
 365                 /* If we're associated, we clamp the maximum passive
 366                  * dwell time to be 98% of the beacon interval (minus
 367                  * 2 * channel tune time) */
 368                 passive = priv->beacon_int;
 369                 if ((passive > IWL_PASSIVE_DWELL_BASE) || !passive)
 370                         passive = IWL_PASSIVE_DWELL_BASE;
 371                 passive = (passive * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 372         }
 373
 374         return passive;
 375 }
 376
 377 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 378                                      enum ieee80211_band band,
 379                                      u8 is_active, u8 n_probes,
 380                                      struct iwl_scan_channel *scan_ch)
 381 {
 382         const struct ieee80211_channel *channels = NULL;
 383         const struct ieee80211_supported_band *sband;
 384         const struct iwl_channel_info *ch_info;
 385         u16 passive_dwell = 0;
 386         u16 active_dwell = 0;
 387         int added, i;
 388         u16 channel;
 389
 390         sband = iwl_get_hw_mode(priv, band);
 391         if (!sband)
 392                 return 0;
 393
 394         channels = sband->channels;
 395
 396         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 397         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 398
 399         if (passive_dwell <= active_dwell)
 400                 passive_dwell = active_dwell + 1;
 401
 402         for (i = 0, added = 0; i < sband->n_channels; i++) {
 403                 if (channels[i].flags & IEEE80211_CHAN_DISABLED)
 404                         continue;
 405
 406                 channel =
 407                         ieee80211_frequency_to_channel(channels[i].center_freq);
 408                 scan_ch->channel = cpu_to_le16(channel);
 409
 410                 ch_info = iwl_get_channel_info(priv, band, channel);
 411                 if (!is_channel_valid(ch_info)) {
 412                         IWL_DEBUG_SCAN("Channel %d is INVALID for this band.\n",
 413                                         channel);
 414                         continue;
 415                 }
 416
 417                 if (!is_active || is_channel_passive(ch_info) ||
 418                     (channels[i].flags & IEEE80211_CHAN_PASSIVE_SCAN))
 419                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 420                 else
 421                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 422
 423                 if (n_probes)
 424                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 425
 426                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 427                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 428
 429                 /* Set txpower levels to defaults */
 430                 scan_ch->dsp_atten = 110;
 431
 432                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 433                  * power level:
 434                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 435                  */
 436                 if (band == IEEE80211_BAND_5GHZ)
 437                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 438                 else
 439                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 440
 441                 IWL_DEBUG_SCAN("Scanning ch=%d prob=0x%X [%s %d]\n",
 442                                channel, le32_to_cpu(scan_ch->type),
 443                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 444                                 "ACTIVE" : "PASSIVE",
 445                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 446                                active_dwell : passive_dwell);
 447
 448                 scan_ch++;
 449                 added++;
 450         }
 451
 452         IWL_DEBUG_SCAN("total channels to scan %d \n", added);
 453         return added;
 454 }
 455
 456 void iwl_init_scan_params(struct iwl_priv *priv)
 457 {
 458         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
 459                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = RATE_MCS_ANT_INIT_IND;
 460         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
 461                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = RATE_MCS_ANT_INIT_IND;
 462 }
 463
 464 int iwl_scan_initiate(struct iwl_priv *priv)
 465 {
 466         if (!iwl_is_ready_rf(priv)) {
 467                 IWL_DEBUG_SCAN("Aborting scan due to not ready.\n");
 468                 return -EIO;
 469         }
 470
 471         if (test_bit(STATUS_SCANNING, &priv->status)) {
 472                 IWL_DEBUG_SCAN("Scan already in progress.\n");
 473                 return -EAGAIN;
 474         }
 475
 476         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 477                 IWL_DEBUG_SCAN("Scan request while abort pending\n");
 478                 return -EAGAIN;
 479         }
 480
 481         IWL_DEBUG_INFO("Starting scan...\n");
 482         if (priv->cfg->sku & IWL_SKU_G)
 483                 priv->scan_bands |= BIT(IEEE80211_BAND_2GHZ);
 484         if (priv->cfg->sku & IWL_SKU_A)
 485                 priv->scan_bands |= BIT(IEEE80211_BAND_5GHZ);
 486         set_bit(STATUS_SCANNING, &priv->status);
 487         priv->scan_start = jiffies;
 488         priv->scan_pass_start = priv->scan_start;
 489
 490         queue_work(priv->workqueue, &priv->request_scan);
 491
 492         return 0;
 493 }
 494 EXPORT_SYMBOL(iwl_scan_initiate);
 495
 496 #define IWL_SCAN_CHECK_WATCHDOG (7 * HZ)
 497
 498 static void iwl_bg_scan_check(struct work_struct *data)
 499 {
 500         struct iwl_priv *priv =
 501             container_of(data, struct iwl_priv, scan_check.work);
 502
 503         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 504                 return;
 505
 506         mutex_lock(&priv->mutex);
 507         if (test_bit(STATUS_SCANNING, &priv->status) ||
 508             test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 509                 IWL_DEBUG(IWL_DL_SCAN, "Scan completion watchdog resetting "
 510                         "adapter (%dms)\n",
 511                         jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG));
 512
 513                 if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
 514                         iwl_send_scan_abort(priv);
 515         }
 516         mutex_unlock(&priv->mutex);
 517 }
 518 /**
 519  * iwl_supported_rate_to_ie - fill in the supported rate in IE field
 520  *
 521  * return : set the bit for each supported rate insert in ie
 522  */
 523 static u16 iwl_supported_rate_to_ie(u8 *ie, u16 supported_rate,
 524                                     u16 basic_rate, int *left)
 525 {
 526         u16 ret_rates = 0, bit;
 527         int i;
 528         u8 *cnt = ie;
 529         u8 *rates = ie + 1;
 530
 531         for (bit = 1, i = 0; i < IWL_RATE_COUNT; i++, bit <<= 1) {
 532                 if (bit & supported_rate) {
 533                         ret_rates |= bit;
 534                         rates[*cnt] = iwl_rates[i].ieee |
 535                                 ((bit & basic_rate) ? 0x80 : 0x00);
 536                         (*cnt)++;
 537                         (*left)--;
 538                         if ((*left <= 0) ||
 539                             (*cnt >= IWL_SUPPORTED_RATES_IE_LEN))
 540                                 break;
 541                 }
 542         }
 543
 544         return ret_rates;
 545 }
 546
 547
 548 static void iwl_ht_cap_to_ie(const struct ieee80211_supported_band *sband,
 549                              u8 *pos, int *left)
 550 {
 551         struct ieee80211_ht_cap *ht_cap;
 552
 553         if (!sband || !sband->ht_info.ht_supported)
 554                 return;
 555
 556         if (*left < sizeof(struct ieee80211_ht_cap))
 557                 return;
 558
 559         *pos++ = sizeof(struct ieee80211_ht_cap);
 560         ht_cap = (struct ieee80211_ht_cap *) pos;
 561
 562         ht_cap->cap_info = cpu_to_le16(sband->ht_info.cap);
 563         memcpy(ht_cap->supp_mcs_set, sband->ht_info.supp_mcs_set, 16);
 564         ht_cap->ampdu_params_info =
 565                 (sband->ht_info.ampdu_factor & IEEE80211_HT_CAP_AMPDU_FACTOR) |
 566                 ((sband->ht_info.ampdu_density << 2) &
 567                         IEEE80211_HT_CAP_AMPDU_DENSITY);
 568         *left -= sizeof(struct ieee80211_ht_cap);
 569 }
 570
 571 /**
 572  * iwl_fill_probe_req - fill in all required fields and IE for probe request
 573  */
 574
 575 static u16 iwl_fill_probe_req(struct iwl_priv *priv,
 576                                   enum ieee80211_band band,
 577                                   struct ieee80211_mgmt *frame,
 578                                   int left)
 579 {
 580         int len = 0;
 581         u8 *pos = NULL;
 582         u16 active_rates, ret_rates, cck_rates, active_rate_basic;
 583         const struct ieee80211_supported_band *sband =
 584                                                 iwl_get_hw_mode(priv, band);
 585
 586
 587         /* Make sure there is enough space for the probe request,
 588          * two mandatory IEs and the data */
 589         left -= 24;
 590         if (left < 0)
 591                 return 0;
 592
 593         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 594         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
 595         memcpy(frame->sa, priv->mac_addr, ETH_ALEN);
 596         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
 597         frame->seq_ctrl = 0;
 598
 599         len += 24;
 600
 601         /* ...next IE... */
 602         pos = &frame->u.probe_req.variable[0];
 603
 604         /* fill in our indirect SSID IE */
 605         left -= 2;
 606         if (left < 0)
 607                 return 0;
 608         *pos++ = WLAN_EID_SSID;
 609         *pos++ = 0;
 610
 611         len += 2;
 612
 613         /* fill in supported rate */
 614         left -= 2;
 615         if (left < 0)
 616                 return 0;
 617
 618         *pos++ = WLAN_EID_SUPP_RATES;
 619         *pos = 0;
 620
 621         /* exclude 60M rate */
 622         active_rates = priv->rates_mask;
 623         active_rates &= ~IWL_RATE_60M_MASK;
 624
 625         active_rate_basic = active_rates & IWL_BASIC_RATES_MASK;
 626
 627         cck_rates = IWL_CCK_RATES_MASK & active_rates;
 628         ret_rates = iwl_supported_rate_to_ie(pos, cck_rates,
 629                                              active_rate_basic, &left);
 630         active_rates &= ~ret_rates;
 631
 632         ret_rates = iwl_supported_rate_to_ie(pos, active_rates,
 633                                              active_rate_basic, &left);
 634         active_rates &= ~ret_rates;
 635
 636         len += 2 + *pos;
 637         pos += (*pos) + 1;
 638
 639         if (active_rates == 0)
 640                 goto fill_end;
 641
 642         /* fill in supported extended rate */
 643         /* ...next IE... */
 644         left -= 2;
 645         if (left < 0)
 646                 return 0;
 647         /* ... fill it in... */
 648         *pos++ = WLAN_EID_EXT_SUPP_RATES;
 649         *pos = 0;
 650         iwl_supported_rate_to_ie(pos, active_rates, active_rate_basic, &left);
 651         if (*pos > 0) {
 652                 len += 2 + *pos;
 653                 pos += (*pos) + 1;
 654         } else {
 655                 pos--;
 656         }
 657
 658  fill_end:
 659
 660         left -= 2;
 661         if (left < 0)
 662                 return 0;
 663
 664         *pos++ = WLAN_EID_HT_CAPABILITY;
 665         *pos = 0;
 666         iwl_ht_cap_to_ie(sband, pos, &left);
 667         if (*pos > 0)
 668                 len += 2 + *pos;
 669
 670         return (u16)len;
 671 }
 672
 673 static u32 iwl_scan_tx_ant(struct iwl_priv *priv, enum ieee80211_band band)
 674 {
 675         int i, ind;
 676
 677         ind = priv->scan_tx_ant[band];
 678         for (i = 0; i < priv->hw_params.tx_chains_num; i++) {
 679                 ind = (ind+1) >= priv->hw_params.tx_chains_num ? 0 : ind+1;
 680                 if (priv->hw_params.valid_tx_ant & (1 << ind)) {
 681                         priv->scan_tx_ant[band] = ind;
 682                         break;
 683                 }
 684         }
 685         IWL_DEBUG_SCAN("select TX ANT = %c\n", 'A' + ind);
 686         return scan_tx_ant[ind];
 687 }
 688
 689
 690 static void iwl_bg_request_scan(struct work_struct *data)
 691 {
 692         struct iwl_priv *priv =
 693             container_of(data, struct iwl_priv, request_scan);
 694         struct iwl_host_cmd cmd = {
 695                 .id = REPLY_SCAN_CMD,
 696                 .len = sizeof(struct iwl_scan_cmd),
 697                 .meta.flags = CMD_SIZE_HUGE,
 698         };
 699         struct iwl_scan_cmd *scan;
 700         struct ieee80211_conf *conf = NULL;
 701         int ret = 0;
 702         u32 tx_ant;
 703         u16 cmd_len;
 704         enum ieee80211_band band;
 705         u8 n_probes = 2;
 706         u8 rx_chain = priv->hw_params.valid_rx_ant;
 707
 708         conf = ieee80211_get_hw_conf(priv->hw);
 709
 710         mutex_lock(&priv->mutex);
 711
 712         if (!iwl_is_ready(priv)) {
 713                 IWL_WARNING("request scan called when driver not ready.\n");
 714                 goto done;
 715         }
 716
 717         /* Make sure the scan wasn't cancelled before this queued work
 718          * was given the chance to run... */
 719         if (!test_bit(STATUS_SCANNING, &priv->status))
 720                 goto done;
 721
 722         /* This should never be called or scheduled if there is currently
 723          * a scan active in the hardware. */
 724         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
 725                 IWL_DEBUG_INFO("Multiple concurrent scan requests in parallel. "
 726                                "Ignoring second request.\n");
 727                 ret = -EIO;
 728                 goto done;
 729         }
 730
 731         if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
 732                 IWL_DEBUG_SCAN("Aborting scan due to device shutdown\n");
 733                 goto done;
 734         }
 735
 736         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 737                 IWL_DEBUG_HC("Scan request while abort pending.  Queuing.\n");
 738                 goto done;
 739         }
 740
 741         if (iwl_is_rfkill(priv)) {
 742                 IWL_DEBUG_HC("Aborting scan due to RF Kill activation\n");
 743                 goto done;
 744         }
 745
 746         if (!test_bit(STATUS_READY, &priv->status)) {
 747                 IWL_DEBUG_HC("Scan request while uninitialized.  Queuing.\n");
 748                 goto done;
 749         }
 750
 751         if (!priv->scan_bands) {
 752                 IWL_DEBUG_HC("Aborting scan due to no requested bands\n");
 753                 goto done;
 754         }
 755
 756         if (!priv->scan) {
 757                 priv->scan = kmalloc(sizeof(struct iwl_scan_cmd) +
 758                                      IWL_MAX_SCAN_SIZE, GFP_KERNEL);
 759                 if (!priv->scan) {
 760                         ret = -ENOMEM;
 761                         goto done;
 762                 }
 763         }
 764         scan = priv->scan;
 765         memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
 766
 767         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
 768         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
 769
 770         if (iwl_is_associated(priv)) {
 771                 u16 interval = 0;
 772                 u32 extra;
 773                 u32 suspend_time = 100;
 774                 u32 scan_suspend_time = 100;
 775                 unsigned long flags;
 776
 777                 IWL_DEBUG_INFO("Scanning while associated...\n");
 778
 779                 spin_lock_irqsave(&priv->lock, flags);
 780                 interval = priv->beacon_int;
 781                 spin_unlock_irqrestore(&priv->lock, flags);
 782
 783                 scan->suspend_time = 0;
 784                 scan->max_out_time = cpu_to_le32(200 * 1024);
 785                 if (!interval)
 786                         interval = suspend_time;
 787
 788                 extra = (suspend_time / interval) << 22;
 789                 scan_suspend_time = (extra |
 790                     ((suspend_time % interval) * 1024));
 791                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
 792                 IWL_DEBUG_SCAN("suspend_time 0x%X beacon interval %d\n",
 793                                scan_suspend_time, interval);
 794         }
 795
 796         /* We should add the ability for user to lock to PASSIVE ONLY */
 797         if (priv->one_direct_scan) {
 798                 IWL_DEBUG_SCAN("Start direct scan for '%s'\n",
 799                                 iwl_escape_essid(priv->direct_ssid,
 800                                 priv->direct_ssid_len));
 801                 scan->direct_scan[0].id = WLAN_EID_SSID;
 802                 scan->direct_scan[0].len = priv->direct_ssid_len;
 803                 memcpy(scan->direct_scan[0].ssid,
 804                        priv->direct_ssid, priv->direct_ssid_len);
 805                 n_probes++;
 806         } else if (!iwl_is_associated(priv) && priv->essid_len) {
 807                 IWL_DEBUG_SCAN("Start direct scan for '%s' (not associated)\n",
 808                                 iwl_escape_essid(priv->essid, priv->essid_len));
 809                 scan->direct_scan[0].id = WLAN_EID_SSID;
 810                 scan->direct_scan[0].len = priv->essid_len;
 811                 memcpy(scan->direct_scan[0].ssid, priv->essid, priv->essid_len);
 812                 n_probes++;
 813         } else {
 814                 IWL_DEBUG_SCAN("Start indirect scan.\n");
 815         }
 816
 817         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
 818         scan->tx_cmd.sta_id = priv->hw_params.bcast_sta_id;
 819         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
 820
 821
 822         if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) {
 823                 band = IEEE80211_BAND_2GHZ;
 824                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
 825                 tx_ant = iwl_scan_tx_ant(priv, band);
 826                 if (priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_PURE_40_MSK)
 827                         scan->tx_cmd.rate_n_flags =
 828                                 iwl_hw_set_rate_n_flags(IWL_RATE_6M_PLCP,
 829                                                         tx_ant);
 830                 else
 831                         scan->tx_cmd.rate_n_flags =
 832                                 iwl_hw_set_rate_n_flags(IWL_RATE_1M_PLCP,
 833                                                         tx_ant |
 834                                                         RATE_MCS_CCK_MSK);
 835                 scan->good_CRC_th = 0;
 836         } else if (priv->scan_bands & BIT(IEEE80211_BAND_5GHZ)) {
 837                 band = IEEE80211_BAND_5GHZ;
 838                 tx_ant = iwl_scan_tx_ant(priv, band);
 839                 scan->tx_cmd.rate_n_flags =
 840                                 iwl_hw_set_rate_n_flags(IWL_RATE_6M_PLCP,
 841                                                         tx_ant);
 842                 scan->good_CRC_th = IWL_GOOD_CRC_TH;
 843
 844                 /* Force use of chains B and C (0x6) for scan Rx for 4965
 845                  * Avoid A (0x1) because of its off-channel reception on A-band.
 846                  */
 847                 if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) == CSR_HW_REV_TYPE_4965)
 848                         rx_chain = 0x6;
 849         } else {
 850                 IWL_WARNING("Invalid scan band count\n");
 851                 goto done;
 852         }
 853
 854         /* MIMO is not used here, but value is required */
 855         scan->rx_chain = RXON_RX_CHAIN_DRIVER_FORCE_MSK |
 856                                 cpu_to_le16((0x7 << RXON_RX_CHAIN_VALID_POS) |
 857                                 (rx_chain << RXON_RX_CHAIN_FORCE_SEL_POS) |
 858                                 (0x7 << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS));
 859
 860         cmd_len = iwl_fill_probe_req(priv, band,
 861                                      (struct ieee80211_mgmt *)scan->data,
 862                                      IWL_MAX_SCAN_SIZE - sizeof(*scan));
 863
 864         scan->tx_cmd.len = cpu_to_le16(cmd_len);
 865
 866         if (priv->iw_mode == NL80211_IFTYPE_MONITOR)
 867                 scan->filter_flags = RXON_FILTER_PROMISC_MSK;
 868
 869         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 870                                RXON_FILTER_BCON_AWARE_MSK);
 871
 872         scan->channel_count =
 873                 iwl_get_channels_for_scan(priv, band, 1, /* active */
 874                         n_probes,
 875                         (void *)&scan->data[le16_to_cpu(scan->tx_cmd.len)]);
 876
 877         if (scan->channel_count == 0) {
 878                 IWL_DEBUG_SCAN("channel count %d\n", scan->channel_count);
 879                 goto done;
 880         }
 881
 882         cmd.len += le16_to_cpu(scan->tx_cmd.len) +
 883             scan->channel_count * sizeof(struct iwl_scan_channel);
 884         cmd.data = scan;
 885         scan->len = cpu_to_le16(cmd.len);
 886
 887         set_bit(STATUS_SCAN_HW, &priv->status);
 888         ret = iwl_send_cmd_sync(priv, &cmd);
 889         if (ret)
 890                 goto done;
 891
 892         queue_delayed_work(priv->workqueue, &priv->scan_check,
 893                            IWL_SCAN_CHECK_WATCHDOG);
 894
 895         mutex_unlock(&priv->mutex);
 896         return;
 897
 898  done:
 899         /* Cannot perform scan. Make sure we clear scanning
 900         * bits from status so next scan request can be performed.
 901         * If we don't clear scanning status bit here all next scan
 902         * will fail
 903         */
 904         clear_bit(STATUS_SCAN_HW, &priv->status);
 905         clear_bit(STATUS_SCANNING, &priv->status);
 906         /* inform mac80211 scan aborted */
 907         queue_work(priv->workqueue, &priv->scan_completed);
 908         mutex_unlock(&priv->mutex);
 909 }
 910
 911 static void iwl_bg_abort_scan(struct work_struct *work)
 912 {
 913         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
 914
 915         if (!iwl_is_ready(priv))
 916                 return;
 917
 918         mutex_lock(&priv->mutex);
 919
 920         set_bit(STATUS_SCAN_ABORTING, &priv->status);
 921         iwl_send_scan_abort(priv);
 922
 923         mutex_unlock(&priv->mutex);
 924 }
 925
 926 static void iwl_bg_scan_completed(struct work_struct *work)
 927 {
 928         struct iwl_priv *priv =
 929             container_of(work, struct iwl_priv, scan_completed);
 930
 931         IWL_DEBUG_SCAN("SCAN complete scan\n");
 932
 933         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 934                 return;
 935
 936         ieee80211_scan_completed(priv->hw);
 937
 938         /* Since setting the TXPOWER may have been deferred while
 939          * performing the scan, fire one off */
 940         mutex_lock(&priv->mutex);
 941         iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);
 942         mutex_unlock(&priv->mutex);
 943 }
 944
 945
 946 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
 947 {
 948         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
 949         INIT_WORK(&priv->request_scan, iwl_bg_request_scan);
 950         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
 951         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
 952 }
 953 EXPORT_SYMBOL(iwl_setup_scan_deferred_work);
 954