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, msecs_to_jiffies(tmo));
  43         queue_delayed_work(priv->workqueue, &priv->scan.timeout,
  44                            msecs_to_jiffies(tmo));
  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 ieee80211_scan_request *hw_req)
  57 {
  58         struct cw1200_common *priv = hw->priv;
  59         struct cfg80211_scan_request *req = &hw_req->req;
  60         struct wsm_template_frame frame = {
  61                 .frame_type = WSM_FRAME_TYPE_PROBE_REQUEST,
  62         };
  63         int i, ret;
  64
  65         if (!priv->vif)
  66                 return -EINVAL;
  67
  68         /* Scan when P2P_GO corrupt firmware MiniAP mode */
  69         if (priv->join_status == CW1200_JOIN_STATUS_AP)
  70                 return -EOPNOTSUPP;
  71
  72         if (req->n_ssids == 1 && !req->ssids[0].ssid_len)
  73                 req->n_ssids = 0;
  74
  75         wiphy_dbg(hw->wiphy, "[SCAN] Scan request for %d SSIDs.\n",
  76                   req->n_ssids);
  77
  78         if (req->n_ssids > WSM_SCAN_MAX_NUM_OF_SSIDS)
  79                 return -EINVAL;
  80
  81         /* will be unlocked in cw1200_scan_work() */
  82         down(&priv->scan.lock);
  83         mutex_lock(&priv->conf_mutex);
  84
  85         frame.skb = ieee80211_probereq_get(hw, priv->vif->addr, NULL, 0,
  86                 req->ie_len);
  87         if (!frame.skb) {
  88                 mutex_unlock(&priv->conf_mutex);
  89                 up(&priv->scan.lock);
  90                 return -ENOMEM;
  91         }
  92
  93         if (req->ie_len)
  94                 memcpy(skb_put(frame.skb, req->ie_len), req->ie, req->ie_len);
  95
  96         ret = wsm_set_template_frame(priv, &frame);
  97         if (!ret) {
  98                 /* Host want to be the probe responder. */
  99                 ret = wsm_set_probe_responder(priv, true);
 100         }
 101         if (ret) {
 102                 dev_kfree_skb(frame.skb);
 103                 mutex_unlock(&priv->conf_mutex);
 104                 up(&priv->scan.lock);
 105                 return ret;
 106         }
 107
 108         wsm_lock_tx(priv);
 109
 110         BUG_ON(priv->scan.req);
 111         priv->scan.req = req;
 112         priv->scan.n_ssids = 0;
 113         priv->scan.status = 0;
 114         priv->scan.begin = &req->channels[0];
 115         priv->scan.curr = priv->scan.begin;
 116         priv->scan.end = &req->channels[req->n_channels];
 117         priv->scan.output_power = priv->output_power;
 118
 119         for (i = 0; i < req->n_ssids; ++i) {
 120                 struct wsm_ssid *dst = &priv->scan.ssids[priv->scan.n_ssids];
 121                 memcpy(&dst->ssid[0], req->ssids[i].ssid, sizeof(dst->ssid));
 122                 dst->length = req->ssids[i].ssid_len;
 123                 ++priv->scan.n_ssids;
 124         }
 125
 126         if (frame.skb)
 127                 dev_kfree_skb(frame.skb);
 128         mutex_unlock(&priv->conf_mutex);
 129         queue_work(priv->workqueue, &priv->scan.work);
 130         return 0;
 131 }
 132
 133 void cw1200_scan_work(struct work_struct *work)
 134 {
 135         struct cw1200_common *priv = container_of(work, struct cw1200_common,
 136                                                         scan.work);
 137         struct ieee80211_channel **it;
 138         struct wsm_scan scan = {
 139                 .type = WSM_SCAN_TYPE_FOREGROUND,
 140                 .flags = WSM_SCAN_FLAG_SPLIT_METHOD,
 141         };
 142         bool first_run = (priv->scan.begin == priv->scan.curr &&
 143                           priv->scan.begin != priv->scan.end);
 144         int i;
 145
 146         if (first_run) {
 147                 /* Firmware gets crazy if scan request is sent
 148                  * when STA is joined but not yet associated.
 149                  * Force unjoin in this case.
 150                  */
 151                 if (cancel_delayed_work_sync(&priv->join_timeout) > 0)
 152                         cw1200_join_timeout(&priv->join_timeout.work);
 153         }
 154
 155         mutex_lock(&priv->conf_mutex);
 156
 157         if (first_run) {
 158                 if (priv->join_status == CW1200_JOIN_STATUS_STA &&
 159                     !(priv->powersave_mode.mode & WSM_PSM_PS)) {
 160                         struct wsm_set_pm pm = priv->powersave_mode;
 161                         pm.mode = WSM_PSM_PS;
 162                         cw1200_set_pm(priv, &pm);
 163                 } else if (priv->join_status == CW1200_JOIN_STATUS_MONITOR) {
 164                         /* FW bug: driver has to restart p2p-dev mode
 165                          * after scan
 166                          */
 167                         cw1200_disable_listening(priv);
 168                 }
 169         }
 170
 171         if (!priv->scan.req || (priv->scan.curr == priv->scan.end)) {
 172                 if (priv->scan.output_power != priv->output_power)
 173                         wsm_set_output_power(priv, priv->output_power * 10);
 174                 if (priv->join_status == CW1200_JOIN_STATUS_STA &&
 175                     !(priv->powersave_mode.mode & WSM_PSM_PS))
 176                         cw1200_set_pm(priv, &priv->powersave_mode);
 177
 178                 if (priv->scan.status < 0)
 179                         wiphy_warn(priv->hw->wiphy,
 180                                    "[SCAN] Scan failed (%d).\n",
 181                                    priv->scan.status);
 182                 else if (priv->scan.req)
 183                         wiphy_dbg(priv->hw->wiphy,
 184                                   "[SCAN] Scan completed.\n");
 185                 else
 186                         wiphy_dbg(priv->hw->wiphy,
 187                                   "[SCAN] Scan canceled.\n");
 188
 189                 priv->scan.req = NULL;
 190                 cw1200_scan_restart_delayed(priv);
 191                 wsm_unlock_tx(priv);
 192                 mutex_unlock(&priv->conf_mutex);
 193                 ieee80211_scan_completed(priv->hw, priv->scan.status ? 1 : 0);
 194                 up(&priv->scan.lock);
 195                 return;
 196         } else {
 197                 struct ieee80211_channel *first = *priv->scan.curr;
 198                 for (it = priv->scan.curr + 1, i = 1;
 199                      it != priv->scan.end && i < WSM_SCAN_MAX_NUM_OF_CHANNELS;
 200                      ++it, ++i) {
 201                         if ((*it)->band != first->band)
 202                                 break;
 203                         if (((*it)->flags ^ first->flags) &
 204                                         IEEE80211_CHAN_NO_IR)
 205                                 break;
 206                         if (!(first->flags & IEEE80211_CHAN_NO_IR) &&
 207                             (*it)->max_power != first->max_power)
 208                                 break;
 209                 }
 210                 scan.band = first->band;
 211
 212                 if (priv->scan.req->no_cck)
 213                         scan.max_tx_rate = WSM_TRANSMIT_RATE_6;
 214                 else
 215                         scan.max_tx_rate = WSM_TRANSMIT_RATE_1;
 216                 scan.num_probes =
 217                         (first->flags & IEEE80211_CHAN_NO_IR) ? 0 : 2;
 218                 scan.num_ssids = priv->scan.n_ssids;
 219                 scan.ssids = &priv->scan.ssids[0];
 220                 scan.num_channels = it - priv->scan.curr;
 221                 /* TODO: Is it optimal? */
 222                 scan.probe_delay = 100;
 223                 /* It is not stated in WSM specification, however
 224                  * FW team says that driver may not use FG scan
 225                  * when joined.
 226                  */
 227                 if (priv->join_status == CW1200_JOIN_STATUS_STA) {
 228                         scan.type = WSM_SCAN_TYPE_BACKGROUND;
 229                         scan.flags = WSM_SCAN_FLAG_FORCE_BACKGROUND;
 230                 }
 231                 scan.ch = kzalloc(
 232                         sizeof(struct wsm_scan_ch) * (it - priv->scan.curr),
 233                         GFP_KERNEL);
 234                 if (!scan.ch) {
 235                         priv->scan.status = -ENOMEM;
 236                         goto fail;
 237                 }
 238                 for (i = 0; i < scan.num_channels; ++i) {
 239                         scan.ch[i].number = priv->scan.curr[i]->hw_value;
 240                         if (priv->scan.curr[i]->flags & IEEE80211_CHAN_NO_IR) {
 241                                 scan.ch[i].min_chan_time = 50;
 242                                 scan.ch[i].max_chan_time = 100;
 243                         } else {
 244                                 scan.ch[i].min_chan_time = 10;
 245                                 scan.ch[i].max_chan_time = 25;
 246                         }
 247                 }
 248                 if (!(first->flags & IEEE80211_CHAN_NO_IR) &&
 249                     priv->scan.output_power != first->max_power) {
 250                         priv->scan.output_power = first->max_power;
 251                         wsm_set_output_power(priv,
 252                                              priv->scan.output_power * 10);
 253                 }
 254                 priv->scan.status = cw1200_scan_start(priv, &scan);
 255                 kfree(scan.ch);
 256                 if (priv->scan.status)
 257                         goto fail;
 258                 priv->scan.curr = it;
 259         }
 260         mutex_unlock(&priv->conf_mutex);
 261         return;
 262
 263 fail:
 264         priv->scan.curr = priv->scan.end;
 265         mutex_unlock(&priv->conf_mutex);
 266         queue_work(priv->workqueue, &priv->scan.work);
 267         return;
 268 }
 269
 270 static void cw1200_scan_restart_delayed(struct cw1200_common *priv)
 271 {
 272         /* FW bug: driver has to restart p2p-dev mode after scan. */
 273         if (priv->join_status == CW1200_JOIN_STATUS_MONITOR) {
 274                 cw1200_enable_listening(priv);
 275                 cw1200_update_filtering(priv);
 276         }
 277
 278         if (priv->delayed_unjoin) {
 279                 priv->delayed_unjoin = false;
 280                 if (queue_work(priv->workqueue, &priv->unjoin_work) <= 0)
 281                         wsm_unlock_tx(priv);
 282         } else if (priv->delayed_link_loss) {
 283                         wiphy_dbg(priv->hw->wiphy, "[CQM] Requeue BSS loss.\n");
 284                         priv->delayed_link_loss = 0;
 285                         cw1200_cqm_bssloss_sm(priv, 1, 0, 0);
 286         }
 287 }
 288
 289 static void cw1200_scan_complete(struct cw1200_common *priv)
 290 {
 291         queue_delayed_work(priv->workqueue, &priv->clear_recent_scan_work, HZ);
 292         if (priv->scan.direct_probe) {
 293                 wiphy_dbg(priv->hw->wiphy, "[SCAN] Direct probe complete.\n");
 294                 cw1200_scan_restart_delayed(priv);
 295                 priv->scan.direct_probe = 0;
 296                 up(&priv->scan.lock);
 297                 wsm_unlock_tx(priv);
 298         } else {
 299                 cw1200_scan_work(&priv->scan.work);
 300         }
 301 }
 302
 303 void cw1200_scan_failed_cb(struct cw1200_common *priv)
 304 {
 305         if (priv->mode == NL80211_IFTYPE_UNSPECIFIED)
 306                 /* STA is stopped. */
 307                 return;
 308
 309         if (cancel_delayed_work_sync(&priv->scan.timeout) > 0) {
 310                 priv->scan.status = -EIO;
 311                 queue_delayed_work(priv->workqueue, &priv->scan.timeout, 0);
 312         }
 313 }
 314
 315
 316 void cw1200_scan_complete_cb(struct cw1200_common *priv,
 317                                 struct wsm_scan_complete *arg)
 318 {
 319         if (priv->mode == NL80211_IFTYPE_UNSPECIFIED)
 320                 /* STA is stopped. */
 321                 return;
 322
 323         if (cancel_delayed_work_sync(&priv->scan.timeout) > 0) {
 324                 priv->scan.status = 1;
 325                 queue_delayed_work(priv->workqueue, &priv->scan.timeout, 0);
 326         }
 327 }
 328
 329 void cw1200_clear_recent_scan_work(struct work_struct *work)
 330 {
 331         struct cw1200_common *priv =
 332                 container_of(work, struct cw1200_common,
 333                              clear_recent_scan_work.work);
 334         atomic_xchg(&priv->recent_scan, 0);
 335 }
 336
 337 void cw1200_scan_timeout(struct work_struct *work)
 338 {
 339         struct cw1200_common *priv =
 340                 container_of(work, struct cw1200_common, scan.timeout.work);
 341         if (atomic_xchg(&priv->scan.in_progress, 0)) {
 342                 if (priv->scan.status > 0) {
 343                         priv->scan.status = 0;
 344                 } else if (!priv->scan.status) {
 345                         wiphy_warn(priv->hw->wiphy,
 346                                    "Timeout waiting for scan complete notification.\n");
 347                         priv->scan.status = -ETIMEDOUT;
 348                         priv->scan.curr = priv->scan.end;
 349                         wsm_stop_scan(priv);
 350                 }
 351                 cw1200_scan_complete(priv);
 352         }
 353 }
 354
 355 void cw1200_probe_work(struct work_struct *work)
 356 {
 357         struct cw1200_common *priv =
 358                 container_of(work, struct cw1200_common, scan.probe_work.work);
 359         u8 queue_id = cw1200_queue_get_queue_id(priv->pending_frame_id);
 360         struct cw1200_queue *queue = &priv->tx_queue[queue_id];
 361         const struct cw1200_txpriv *txpriv;
 362         struct wsm_tx *wsm;
 363         struct wsm_template_frame frame = {
 364                 .frame_type = WSM_FRAME_TYPE_PROBE_REQUEST,
 365         };
 366         struct wsm_ssid ssids[1] = {{
 367                 .length = 0,
 368         } };
 369         struct wsm_scan_ch ch[1] = {{
 370                 .min_chan_time = 0,
 371                 .max_chan_time = 10,
 372         } };
 373         struct wsm_scan scan = {
 374                 .type = WSM_SCAN_TYPE_FOREGROUND,
 375                 .num_probes = 1,
 376                 .probe_delay = 0,
 377                 .num_channels = 1,
 378                 .ssids = ssids,
 379                 .ch = ch,
 380         };
 381         u8 *ies;
 382         size_t ies_len;
 383         int ret;
 384
 385         wiphy_dbg(priv->hw->wiphy, "[SCAN] Direct probe work.\n");
 386
 387         mutex_lock(&priv->conf_mutex);
 388         if (down_trylock(&priv->scan.lock)) {
 389                 /* Scan is already in progress. Requeue self. */
 390                 schedule();
 391                 queue_delayed_work(priv->workqueue, &priv->scan.probe_work,
 392                                    msecs_to_jiffies(100));
 393                 mutex_unlock(&priv->conf_mutex);
 394                 return;
 395         }
 396
 397         /* Make sure we still have a pending probe req */
 398         if (cw1200_queue_get_skb(queue, priv->pending_frame_id,
 399                                  &frame.skb, &txpriv)) {
 400                 up(&priv->scan.lock);
 401                 mutex_unlock(&priv->conf_mutex);
 402                 wsm_unlock_tx(priv);
 403                 return;
 404         }
 405         wsm = (struct wsm_tx *)frame.skb->data;
 406         scan.max_tx_rate = wsm->max_tx_rate;
 407         scan.band = (priv->channel->band == IEEE80211_BAND_5GHZ) ?
 408                 WSM_PHY_BAND_5G : WSM_PHY_BAND_2_4G;
 409         if (priv->join_status == CW1200_JOIN_STATUS_STA ||
 410             priv->join_status == CW1200_JOIN_STATUS_IBSS) {
 411                 scan.type = WSM_SCAN_TYPE_BACKGROUND;
 412                 scan.flags = WSM_SCAN_FLAG_FORCE_BACKGROUND;
 413         }
 414         ch[0].number = priv->channel->hw_value;
 415
 416         skb_pull(frame.skb, txpriv->offset);
 417
 418         ies = &frame.skb->data[sizeof(struct ieee80211_hdr_3addr)];
 419         ies_len = frame.skb->len - sizeof(struct ieee80211_hdr_3addr);
 420
 421         if (ies_len) {
 422                 u8 *ssidie =
 423                         (u8 *)cfg80211_find_ie(WLAN_EID_SSID, ies, ies_len);
 424                 if (ssidie && ssidie[1] && ssidie[1] <= sizeof(ssids[0].ssid)) {
 425                         u8 *nextie = &ssidie[2 + ssidie[1]];
 426                         /* Remove SSID from the IE list. It has to be provided
 427                          * as a separate argument in cw1200_scan_start call
 428                          */
 429
 430                         /* Store SSID localy */
 431                         ssids[0].length = ssidie[1];
 432                         memcpy(ssids[0].ssid, &ssidie[2], ssids[0].length);
 433                         scan.num_ssids = 1;
 434
 435                         /* Remove SSID from IE list */
 436                         ssidie[1] = 0;
 437                         memmove(&ssidie[2], nextie, &ies[ies_len] - nextie);
 438                         skb_trim(frame.skb, frame.skb->len - ssids[0].length);
 439                 }
 440         }
 441
 442         /* FW bug: driver has to restart p2p-dev mode after scan */
 443         if (priv->join_status == CW1200_JOIN_STATUS_MONITOR)
 444                 cw1200_disable_listening(priv);
 445         ret = wsm_set_template_frame(priv, &frame);
 446         priv->scan.direct_probe = 1;
 447         if (!ret) {
 448                 wsm_flush_tx(priv);
 449                 ret = cw1200_scan_start(priv, &scan);
 450         }
 451         mutex_unlock(&priv->conf_mutex);
 452
 453         skb_push(frame.skb, txpriv->offset);
 454         if (!ret)
 455                 IEEE80211_SKB_CB(frame.skb)->flags |= IEEE80211_TX_STAT_ACK;
 456         BUG_ON(cw1200_queue_remove(queue, priv->pending_frame_id));
 457
 458         if (ret) {
 459                 priv->scan.direct_probe = 0;
 460                 up(&priv->scan.lock);
 461                 wsm_unlock_tx(priv);
 462         }
 463
 464         return;
 465 }