drivers/net/wireless/cw1200/scan.c

   1 /*
   2  * Scan implementation for ST-Ericsson CW1200 mac80211 drivers
   3  *
   4  * Copyright (c) 2010, ST-Ericsson
   5  * Author: Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/sched.h>
  13 #include "cw1200.h"
  14 #include "scan.h"
  15 #include "sta.h"
  16 #include "pm.h"
  17
  18 static void cw1200_scan_restart_delayed(struct cw1200_common *priv);
  19
  20 static int cw1200_scan_start(struct cw1200_common *priv, struct wsm_scan *scan)
  21 {
  22         int ret, i;
  23         int tmo = 2000;
  24
  25         switch (priv->join_status) {
  26         case CW1200_JOIN_STATUS_PRE_STA:
  27         case CW1200_JOIN_STATUS_JOINING:
  28                 return -EBUSY;
  29         default:
  30                 break;
  31         }
  32
  33         wiphy_dbg(priv->hw->wiphy, "[SCAN] hw req, type %d, %d channels, flags: 0x%x.\n",
  34                   scan->type, scan->num_channels, scan->flags);
  35
  36         for (i = 0; i < scan->num_channels; ++i)
  37                 tmo += scan->ch[i].max_chan_time + 10;
  38
  39         cancel_delayed_work_sync(&priv->clear_recent_scan_work);
  40         atomic_set(&priv->scan.in_progress, 1);
  41         atomic_set(&priv->recent_scan, 1);
  42         cw1200_pm_stay_awake(&priv->pm_state, tmo * HZ / 1000);
  43         queue_delayed_work(priv->workqueue, &priv->scan.timeout,
  44                            tmo * HZ / 1000);
  45         ret = wsm_scan(priv, scan);
  46         if (ret) {
  47                 atomic_set(&priv->scan.in_progress, 0);
  48                 cancel_delayed_work_sync(&priv->scan.timeout);
  49                 cw1200_scan_restart_delayed(priv);
  50         }
  51         return ret;
  52 }
  53
  54 int cw1200_hw_scan(struct ieee80211_hw *hw,
  55                    struct ieee80211_vif *vif,
  56                    struct cfg80211_scan_request *req)
  57 {
  58         struct cw1200_common *priv = hw->priv;
  59         struct wsm_template_frame frame = {
  60                 .frame_type = WSM_FRAME_TYPE_PROBE_REQUEST,
  61         };
  62         int i, ret;
  63
  64         if (!priv->vif)
  65                 return -EINVAL;
  66
  67         /* Scan when P2P_GO corrupt firmware MiniAP mode */
  68         if (priv->join_status == CW1200_JOIN_STATUS_AP)
  69                 return -EOPNOTSUPP;
  70
  71         if (req->n_ssids == 1 && !req->ssids[0].ssid_len)
  72                 req->n_ssids = 0;
  73
  74         wiphy_dbg(hw->wiphy, "[SCAN] Scan request for %d SSIDs.\n",
  75                   req->n_ssids);
  76
  77         if (req->n_ssids > WSM_SCAN_MAX_NUM_OF_SSIDS)
  78                 return -EINVAL;
  79
  80         frame.skb = ieee80211_probereq_get(hw, priv->vif, NULL, 0,
  81                 req->ie_len);
  82         if (!frame.skb)
  83                 return -ENOMEM;
  84
  85         if (req->ie_len)
  86                 memcpy(skb_put(frame.skb, req->ie_len), req->ie, req->ie_len);
  87
  88         /* will be unlocked in cw1200_scan_work() */
  89         down(&priv->scan.lock);
  90         mutex_lock(&priv->conf_mutex);
  91
  92         ret = wsm_set_template_frame(priv, &frame);
  93         if (!ret) {
  94                 /* Host want to be the probe responder. */
  95                 ret = wsm_set_probe_responder(priv, true);
  96         }
  97         if (ret) {
  98                 mutex_unlock(&priv->conf_mutex);
  99                 up(&priv->scan.lock);
 100                 dev_kfree_skb(frame.skb);
 101                 return ret;
 102         }
 103
 104         wsm_lock_tx(priv);
 105
 106         BUG_ON(priv->scan.req);
 107         priv->scan.req = req;
 108         priv->scan.n_ssids = 0;
 109         priv->scan.status = 0;
 110         priv->scan.begin = &req->channels[0];
 111         priv->scan.curr = priv->scan.begin;
 112         priv->scan.end = &req->channels[req->n_channels];
 113         priv->scan.output_power = priv->output_power;
 114
 115         for (i = 0; i < req->n_ssids; ++i) {
 116                 struct wsm_ssid *dst = &priv->scan.ssids[priv->scan.n_ssids];
 117                 memcpy(&dst->ssid[0], req->ssids[i].ssid, sizeof(dst->ssid));
 118                 dst->length = req->ssids[i].ssid_len;
 119                 ++priv->scan.n_ssids;
 120         }
 121
 122         mutex_unlock(&priv->conf_mutex);
 123
 124         if (frame.skb)
 125                 dev_kfree_skb(frame.skb);
 126         queue_work(priv->workqueue, &priv->scan.work);
 127         return 0;
 128 }
 129
 130 void cw1200_scan_work(struct work_struct *work)
 131 {
 132         struct cw1200_common *priv = container_of(work, struct cw1200_common,
 133                                                         scan.work);
 134         struct ieee80211_channel **it;
 135         struct wsm_scan scan = {
 136                 .type = WSM_SCAN_TYPE_FOREGROUND,
 137                 .flags = WSM_SCAN_FLAG_SPLIT_METHOD,
 138         };
 139         bool first_run = (priv->scan.begin == priv->scan.curr &&
 140                           priv->scan.begin != priv->scan.end);
 141         int i;
 142
 143         if (first_run) {
 144                 /* Firmware gets crazy if scan request is sent
 145                  * when STA is joined but not yet associated.
 146                  * Force unjoin in this case.
 147                  */
 148                 if (cancel_delayed_work_sync(&priv->join_timeout) > 0)
 149                         cw1200_join_timeout(&priv->join_timeout.work);
 150         }
 151
 152         mutex_lock(&priv->conf_mutex);
 153
 154         if (first_run) {
 155                 if (priv->join_status == CW1200_JOIN_STATUS_STA &&
 156                     !(priv->powersave_mode.mode & WSM_PSM_PS)) {
 157                         struct wsm_set_pm pm = priv->powersave_mode;
 158                         pm.mode = WSM_PSM_PS;
 159                         cw1200_set_pm(priv, &pm);
 160                 } else if (priv->join_status == CW1200_JOIN_STATUS_MONITOR) {
 161                         /* FW bug: driver has to restart p2p-dev mode
 162                          * after scan
 163                          */
 164                         cw1200_disable_listening(priv);
 165                 }
 166         }
 167
 168         if (!priv->scan.req || (priv->scan.curr == priv->scan.end)) {
 169                 if (priv->scan.output_power != priv->output_power)
 170                         wsm_set_output_power(priv, priv->output_power * 10);
 171                 if (priv->join_status == CW1200_JOIN_STATUS_STA &&
 172                     !(priv->powersave_mode.mode & WSM_PSM_PS))
 173                         cw1200_set_pm(priv, &priv->powersave_mode);
 174
 175                 if (priv->scan.status < 0)
 176                         wiphy_warn(priv->hw->wiphy,
 177                                    "[SCAN] Scan failed (%d).\n",
 178                                    priv->scan.status);
 179                 else if (priv->scan.req)
 180                         wiphy_dbg(priv->hw->wiphy,
 181                                   "[SCAN] Scan completed.\n");
 182                 else
 183                         wiphy_dbg(priv->hw->wiphy,
 184                                   "[SCAN] Scan canceled.\n");
 185
 186                 priv->scan.req = NULL;
 187                 cw1200_scan_restart_delayed(priv);
 188                 wsm_unlock_tx(priv);
 189                 mutex_unlock(&priv->conf_mutex);
 190                 ieee80211_scan_completed(priv->hw, priv->scan.status ? 1 : 0);
 191                 up(&priv->scan.lock);
 192                 return;
 193         } else {
 194                 struct ieee80211_channel *first = *priv->scan.curr;
 195                 for (it = priv->scan.curr + 1, i = 1;
 196                      it != priv->scan.end && i < WSM_SCAN_MAX_NUM_OF_CHANNELS;
 197                      ++it, ++i) {
 198                         if ((*it)->band != first->band)
 199                                 break;
 200                         if (((*it)->flags ^ first->flags) &
 201                                         IEEE80211_CHAN_NO_IR)
 202                                 break;
 203                         if (!(first->flags & IEEE80211_CHAN_NO_IR) &&
 204                             (*it)->max_power != first->max_power)
 205                                 break;
 206                 }
 207                 scan.band = first->band;
 208
 209                 if (priv->scan.req->no_cck)
 210                         scan.max_tx_rate = WSM_TRANSMIT_RATE_6;
 211                 else
 212                         scan.max_tx_rate = WSM_TRANSMIT_RATE_1;
 213                 scan.num_probes =
 214                         (first->flags & IEEE80211_CHAN_NO_IR) ? 0 : 2;
 215                 scan.num_ssids = priv->scan.n_ssids;
 216                 scan.ssids = &priv->scan.ssids[0];
 217                 scan.num_channels = it - priv->scan.curr;
 218                 /* TODO: Is it optimal? */
 219                 scan.probe_delay = 100;
 220                 /* It is not stated in WSM specification, however
 221                  * FW team says that driver may not use FG scan
 222                  * when joined.
 223                  */
 224                 if (priv->join_status == CW1200_JOIN_STATUS_STA) {
 225                         scan.type = WSM_SCAN_TYPE_BACKGROUND;
 226                         scan.flags = WSM_SCAN_FLAG_FORCE_BACKGROUND;
 227                 }
 228                 scan.ch = kzalloc(
 229                         sizeof(struct wsm_scan_ch) * (it - priv->scan.curr),
 230                         GFP_KERNEL);
 231                 if (!scan.ch) {
 232                         priv->scan.status = -ENOMEM;
 233                         goto fail;
 234                 }
 235                 for (i = 0; i < scan.num_channels; ++i) {
 236                         scan.ch[i].number = priv->scan.curr[i]->hw_value;
 237                         if (priv->scan.curr[i]->flags & IEEE80211_CHAN_NO_IR) {
 238                                 scan.ch[i].min_chan_time = 50;
 239                                 scan.ch[i].max_chan_time = 100;
 240                         } else {
 241                                 scan.ch[i].min_chan_time = 10;
 242                                 scan.ch[i].max_chan_time = 25;
 243                         }
 244                 }
 245                 if (!(first->flags & IEEE80211_CHAN_NO_IR) &&
 246                     priv->scan.output_power != first->max_power) {
 247                         priv->scan.output_power = first->max_power;
 248                         wsm_set_output_power(priv,
 249                                              priv->scan.output_power * 10);
 250                 }
 251                 priv->scan.status = cw1200_scan_start(priv, &scan);
 252                 kfree(scan.ch);
 253                 if (priv->scan.status)
 254                         goto fail;
 255                 priv->scan.curr = it;
 256         }
 257         mutex_unlock(&priv->conf_mutex);
 258         return;
 259
 260 fail:
 261         priv->scan.curr = priv->scan.end;
 262         mutex_unlock(&priv->conf_mutex);
 263         queue_work(priv->workqueue, &priv->scan.work);
 264         return;
 265 }
 266
 267 static void cw1200_scan_restart_delayed(struct cw1200_common *priv)
 268 {
 269         /* FW bug: driver has to restart p2p-dev mode after scan. */
 270         if (priv->join_status == CW1200_JOIN_STATUS_MONITOR) {
 271                 cw1200_enable_listening(priv);
 272                 cw1200_update_filtering(priv);
 273         }
 274
 275         if (priv->delayed_unjoin) {
 276                 priv->delayed_unjoin = false;
 277                 if (queue_work(priv->workqueue, &priv->unjoin_work) <= 0)
 278                         wsm_unlock_tx(priv);
 279         } else if (priv->delayed_link_loss) {
 280                         wiphy_dbg(priv->hw->wiphy, "[CQM] Requeue BSS loss.\n");
 281                         priv->delayed_link_loss = 0;
 282                         cw1200_cqm_bssloss_sm(priv, 1, 0, 0);
 283         }
 284 }
 285
 286 static void cw1200_scan_complete(struct cw1200_common *priv)
 287 {
 288         queue_delayed_work(priv->workqueue, &priv->clear_recent_scan_work, HZ);
 289         if (priv->scan.direct_probe) {
 290                 wiphy_dbg(priv->hw->wiphy, "[SCAN] Direct probe complete.\n");
 291                 cw1200_scan_restart_delayed(priv);
 292                 priv->scan.direct_probe = 0;
 293                 up(&priv->scan.lock);
 294                 wsm_unlock_tx(priv);
 295         } else {
 296                 cw1200_scan_work(&priv->scan.work);
 297         }
 298 }
 299
 300 void cw1200_scan_failed_cb(struct cw1200_common *priv)
 301 {
 302         if (priv->mode == NL80211_IFTYPE_UNSPECIFIED)
 303                 /* STA is stopped. */
 304                 return;
 305
 306         if (cancel_delayed_work_sync(&priv->scan.timeout) > 0) {
 307                 priv->scan.status = -EIO;
 308                 queue_delayed_work(priv->workqueue, &priv->scan.timeout, 0);
 309         }
 310 }
 311
 312
 313 void cw1200_scan_complete_cb(struct cw1200_common *priv,
 314                                 struct wsm_scan_complete *arg)
 315 {
 316         if (priv->mode == NL80211_IFTYPE_UNSPECIFIED)
 317                 /* STA is stopped. */
 318                 return;
 319
 320         if (cancel_delayed_work_sync(&priv->scan.timeout) > 0) {
 321                 priv->scan.status = 1;
 322                 queue_delayed_work(priv->workqueue, &priv->scan.timeout, 0);
 323         }
 324 }
 325
 326 void cw1200_clear_recent_scan_work(struct work_struct *work)
 327 {
 328         struct cw1200_common *priv =
 329                 container_of(work, struct cw1200_common,
 330                              clear_recent_scan_work.work);
 331         atomic_xchg(&priv->recent_scan, 0);
 332 }
 333
 334 void cw1200_scan_timeout(struct work_struct *work)
 335 {
 336         struct cw1200_common *priv =
 337                 container_of(work, struct cw1200_common, scan.timeout.work);
 338         if (atomic_xchg(&priv->scan.in_progress, 0)) {
 339                 if (priv->scan.status > 0) {
 340                         priv->scan.status = 0;
 341                 } else if (!priv->scan.status) {
 342                         wiphy_warn(priv->hw->wiphy,
 343                                    "Timeout waiting for scan complete notification.\n");
 344                         priv->scan.status = -ETIMEDOUT;
 345                         priv->scan.curr = priv->scan.end;
 346                         wsm_stop_scan(priv);
 347                 }
 348                 cw1200_scan_complete(priv);
 349         }
 350 }
 351
 352 void cw1200_probe_work(struct work_struct *work)
 353 {
 354         struct cw1200_common *priv =
 355                 container_of(work, struct cw1200_common, scan.probe_work.work);
 356         u8 queue_id = cw1200_queue_get_queue_id(priv->pending_frame_id);
 357         struct cw1200_queue *queue = &priv->tx_queue[queue_id];
 358         const struct cw1200_txpriv *txpriv;
 359         struct wsm_tx *wsm;
 360         struct wsm_template_frame frame = {
 361                 .frame_type = WSM_FRAME_TYPE_PROBE_REQUEST,
 362         };
 363         struct wsm_ssid ssids[1] = {{
 364                 .length = 0,
 365         } };
 366         struct wsm_scan_ch ch[1] = {{
 367                 .min_chan_time = 0,
 368                 .max_chan_time = 10,
 369         } };
 370         struct wsm_scan scan = {
 371                 .type = WSM_SCAN_TYPE_FOREGROUND,
 372                 .num_probes = 1,
 373                 .probe_delay = 0,
 374                 .num_channels = 1,
 375                 .ssids = ssids,
 376                 .ch = ch,
 377         };
 378         u8 *ies;
 379         size_t ies_len;
 380         int ret;
 381
 382         wiphy_dbg(priv->hw->wiphy, "[SCAN] Direct probe work.\n");
 383
 384         mutex_lock(&priv->conf_mutex);
 385         if (down_trylock(&priv->scan.lock)) {
 386                 /* Scan is already in progress. Requeue self. */
 387                 schedule();
 388                 queue_delayed_work(priv->workqueue,
 389                                    &priv->scan.probe_work, HZ / 10);
 390                 mutex_unlock(&priv->conf_mutex);
 391                 return;
 392         }
 393
 394         /* Make sure we still have a pending probe req */
 395         if (cw1200_queue_get_skb(queue, priv->pending_frame_id,
 396                                  &frame.skb, &txpriv)) {
 397                 up(&priv->scan.lock);
 398                 mutex_unlock(&priv->conf_mutex);
 399                 wsm_unlock_tx(priv);
 400                 return;
 401         }
 402         wsm = (struct wsm_tx *)frame.skb->data;
 403         scan.max_tx_rate = wsm->max_tx_rate;
 404         scan.band = (priv->channel->band == IEEE80211_BAND_5GHZ) ?
 405                 WSM_PHY_BAND_5G : WSM_PHY_BAND_2_4G;
 406         if (priv->join_status == CW1200_JOIN_STATUS_STA ||
 407             priv->join_status == CW1200_JOIN_STATUS_IBSS) {
 408                 scan.type = WSM_SCAN_TYPE_BACKGROUND;
 409                 scan.flags = WSM_SCAN_FLAG_FORCE_BACKGROUND;
 410         }
 411         ch[0].number = priv->channel->hw_value;
 412
 413         skb_pull(frame.skb, txpriv->offset);
 414
 415         ies = &frame.skb->data[sizeof(struct ieee80211_hdr_3addr)];
 416         ies_len = frame.skb->len - sizeof(struct ieee80211_hdr_3addr);
 417
 418         if (ies_len) {
 419                 u8 *ssidie =
 420                         (u8 *)cfg80211_find_ie(WLAN_EID_SSID, ies, ies_len);
 421                 if (ssidie && ssidie[1] && ssidie[1] <= sizeof(ssids[0].ssid)) {
 422                         u8 *nextie = &ssidie[2 + ssidie[1]];
 423                         /* Remove SSID from the IE list. It has to be provided
 424                          * as a separate argument in cw1200_scan_start call
 425                          */
 426
 427                         /* Store SSID localy */
 428                         ssids[0].length = ssidie[1];
 429                         memcpy(ssids[0].ssid, &ssidie[2], ssids[0].length);
 430                         scan.num_ssids = 1;
 431
 432                         /* Remove SSID from IE list */
 433                         ssidie[1] = 0;
 434                         memmove(&ssidie[2], nextie, &ies[ies_len] - nextie);
 435                         skb_trim(frame.skb, frame.skb->len - ssids[0].length);
 436                 }
 437         }
 438
 439         /* FW bug: driver has to restart p2p-dev mode after scan */
 440         if (priv->join_status == CW1200_JOIN_STATUS_MONITOR)
 441                 cw1200_disable_listening(priv);
 442         ret = wsm_set_template_frame(priv, &frame);
 443         priv->scan.direct_probe = 1;
 444         if (!ret) {
 445                 wsm_flush_tx(priv);
 446                 ret = cw1200_scan_start(priv, &scan);
 447         }
 448         mutex_unlock(&priv->conf_mutex);
 449
 450         skb_push(frame.skb, txpriv->offset);
 451         if (!ret)
 452                 IEEE80211_SKB_CB(frame.skb)->flags |= IEEE80211_TX_STAT_ACK;
 453         BUG_ON(cw1200_queue_remove(queue, priv->pending_frame_id));
 454
 455         if (ret) {
 456                 priv->scan.direct_probe = 0;
 457                 up(&priv->scan.lock);
 458                 wsm_unlock_tx(priv);
 459         }
 460
 461         return;
 462 }