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_dbg(priv->hw->wiphy, "[SCAN] Scan failed (%d).\n",
 177                                   priv->scan.status);
 178                 else if (priv->scan.req)
 179                         wiphy_dbg(priv->hw->wiphy,
 180                                   "[SCAN] Scan completed.\n");
 181                 else
 182                         wiphy_dbg(priv->hw->wiphy,
 183                                   "[SCAN] Scan canceled.\n");
 184
 185                 priv->scan.req = NULL;
 186                 cw1200_scan_restart_delayed(priv);
 187                 wsm_unlock_tx(priv);
 188                 mutex_unlock(&priv->conf_mutex);
 189                 ieee80211_scan_completed(priv->hw, priv->scan.status ? 1 : 0);
 190                 up(&priv->scan.lock);
 191                 return;
 192         } else {
 193                 struct ieee80211_channel *first = *priv->scan.curr;
 194                 for (it = priv->scan.curr + 1, i = 1;
 195                      it != priv->scan.end && i < WSM_SCAN_MAX_NUM_OF_CHANNELS;
 196                      ++it, ++i) {
 197                         if ((*it)->band != first->band)
 198                                 break;
 199                         if (((*it)->flags ^ first->flags) &
 200                                         IEEE80211_CHAN_PASSIVE_SCAN)
 201                                 break;
 202                         if (!(first->flags & IEEE80211_CHAN_PASSIVE_SCAN) &&
 203                             (*it)->max_power != first->max_power)
 204                                 break;
 205                 }
 206                 scan.band = first->band;
 207
 208                 if (priv->scan.req->no_cck)
 209                         scan.max_tx_rate = WSM_TRANSMIT_RATE_6;
 210                 else
 211                         scan.max_tx_rate = WSM_TRANSMIT_RATE_1;
 212                 scan.num_probes =
 213                         (first->flags & IEEE80211_CHAN_PASSIVE_SCAN) ? 0 : 2;
 214                 scan.num_ssids = priv->scan.n_ssids;
 215                 scan.ssids = &priv->scan.ssids[0];
 216                 scan.num_channels = it - priv->scan.curr;
 217                 /* TODO: Is it optimal? */
 218                 scan.probe_delay = 100;
 219                 /* It is not stated in WSM specification, however
 220                  * FW team says that driver may not use FG scan
 221                  * when joined.
 222                  */
 223                 if (priv->join_status == CW1200_JOIN_STATUS_STA) {
 224                         scan.type = WSM_SCAN_TYPE_BACKGROUND;
 225                         scan.flags = WSM_SCAN_FLAG_FORCE_BACKGROUND;
 226                 }
 227                 scan.ch = kzalloc(
 228                         sizeof(struct wsm_scan_ch) * (it - priv->scan.curr),
 229                         GFP_KERNEL);
 230                 if (!scan.ch) {
 231                         priv->scan.status = -ENOMEM;
 232                         goto fail;
 233                 }
 234                 for (i = 0; i < scan.num_channels; ++i) {
 235                         scan.ch[i].number = priv->scan.curr[i]->hw_value;
 236                         if (priv->scan.curr[i]->flags & IEEE80211_CHAN_PASSIVE_SCAN) {
 237                                 scan.ch[i].min_chan_time = 50;
 238                                 scan.ch[i].max_chan_time = 100;
 239                         } else {
 240                                 scan.ch[i].min_chan_time = 10;
 241                                 scan.ch[i].max_chan_time = 25;
 242                         }
 243                 }
 244                 if (!(first->flags & IEEE80211_CHAN_PASSIVE_SCAN) &&
 245                     priv->scan.output_power != first->max_power) {
 246                         priv->scan.output_power = first->max_power;
 247                         wsm_set_output_power(priv,
 248                                              priv->scan.output_power * 10);
 249                 }
 250                 priv->scan.status = cw1200_scan_start(priv, &scan);
 251                 kfree(scan.ch);
 252                 if (priv->scan.status)
 253                         goto fail;
 254                 priv->scan.curr = it;
 255         }
 256         mutex_unlock(&priv->conf_mutex);
 257         return;
 258
 259 fail:
 260         priv->scan.curr = priv->scan.end;
 261         mutex_unlock(&priv->conf_mutex);
 262         queue_work(priv->workqueue, &priv->scan.work);
 263         return;
 264 }
 265
 266 static void cw1200_scan_restart_delayed(struct cw1200_common *priv)
 267 {
 268         /* FW bug: driver has to restart p2p-dev mode after scan. */
 269         if (priv->join_status == CW1200_JOIN_STATUS_MONITOR) {
 270                 cw1200_enable_listening(priv);
 271                 cw1200_update_filtering(priv);
 272         }
 273
 274         if (priv->delayed_unjoin) {
 275                 priv->delayed_unjoin = false;
 276                 if (queue_work(priv->workqueue, &priv->unjoin_work) <= 0)
 277                         wsm_unlock_tx(priv);
 278         } else if (priv->delayed_link_loss) {
 279                         wiphy_dbg(priv->hw->wiphy, "[CQM] Requeue BSS loss.\n");
 280                         priv->delayed_link_loss = 0;
 281                         cw1200_cqm_bssloss_sm(priv, 1, 0, 0);
 282         }
 283 }
 284
 285 static void cw1200_scan_complete(struct cw1200_common *priv)
 286 {
 287         queue_delayed_work(priv->workqueue, &priv->clear_recent_scan_work, HZ);
 288         if (priv->scan.direct_probe) {
 289                 wiphy_dbg(priv->hw->wiphy, "[SCAN] Direct probe complete.\n");
 290                 cw1200_scan_restart_delayed(priv);
 291                 priv->scan.direct_probe = 0;
 292                 up(&priv->scan.lock);
 293                 wsm_unlock_tx(priv);
 294         } else {
 295                 cw1200_scan_work(&priv->scan.work);
 296         }
 297 }
 298
 299 void cw1200_scan_failed_cb(struct cw1200_common *priv)
 300 {
 301         if (priv->mode == NL80211_IFTYPE_UNSPECIFIED)
 302                 /* STA is stopped. */
 303                 return;
 304
 305         if (cancel_delayed_work_sync(&priv->scan.timeout) > 0) {
 306                 priv->scan.status = -EIO;
 307                 queue_delayed_work(priv->workqueue, &priv->scan.timeout, 0);
 308         }
 309 }
 310
 311
 312 void cw1200_scan_complete_cb(struct cw1200_common *priv,
 313                                 struct wsm_scan_complete *arg)
 314 {
 315         if (priv->mode == NL80211_IFTYPE_UNSPECIFIED)
 316                 /* STA is stopped. */
 317                 return;
 318
 319         if (cancel_delayed_work_sync(&priv->scan.timeout) > 0) {
 320                 priv->scan.status = 1;
 321                 queue_delayed_work(priv->workqueue, &priv->scan.timeout, 0);
 322         }
 323 }
 324
 325 void cw1200_clear_recent_scan_work(struct work_struct *work)
 326 {
 327         struct cw1200_common *priv =
 328                 container_of(work, struct cw1200_common,
 329                              clear_recent_scan_work.work);
 330         atomic_xchg(&priv->recent_scan, 0);
 331 }
 332
 333 void cw1200_scan_timeout(struct work_struct *work)
 334 {
 335         struct cw1200_common *priv =
 336                 container_of(work, struct cw1200_common, scan.timeout.work);
 337         if (atomic_xchg(&priv->scan.in_progress, 0)) {
 338                 if (priv->scan.status > 0) {
 339                         priv->scan.status = 0;
 340                 } else if (!priv->scan.status) {
 341                         wiphy_warn(priv->hw->wiphy,
 342                                    "Timeout waiting for scan complete notification.\n");
 343                         priv->scan.status = -ETIMEDOUT;
 344                         priv->scan.curr = priv->scan.end;
 345                         wsm_stop_scan(priv);
 346                 }
 347                 cw1200_scan_complete(priv);
 348         }
 349 }
 350
 351 void cw1200_probe_work(struct work_struct *work)
 352 {
 353         struct cw1200_common *priv =
 354                 container_of(work, struct cw1200_common, scan.probe_work.work);
 355         u8 queue_id = cw1200_queue_get_queue_id(priv->pending_frame_id);
 356         struct cw1200_queue *queue = &priv->tx_queue[queue_id];
 357         const struct cw1200_txpriv *txpriv;
 358         struct wsm_tx *wsm;
 359         struct wsm_template_frame frame = {
 360                 .frame_type = WSM_FRAME_TYPE_PROBE_REQUEST,
 361         };
 362         struct wsm_ssid ssids[1] = {{
 363                 .length = 0,
 364         } };
 365         struct wsm_scan_ch ch[1] = {{
 366                 .min_chan_time = 0,
 367                 .max_chan_time = 10,
 368         } };
 369         struct wsm_scan scan = {
 370                 .type = WSM_SCAN_TYPE_FOREGROUND,
 371                 .num_probes = 1,
 372                 .probe_delay = 0,
 373                 .num_channels = 1,
 374                 .ssids = ssids,
 375                 .ch = ch,
 376         };
 377         u8 *ies;
 378         size_t ies_len;
 379         int ret;
 380
 381         wiphy_dbg(priv->hw->wiphy, "[SCAN] Direct probe work.\n");
 382
 383         mutex_lock(&priv->conf_mutex);
 384         if (down_trylock(&priv->scan.lock)) {
 385                 /* Scan is already in progress. Requeue self. */
 386                 schedule();
 387                 queue_delayed_work(priv->workqueue,
 388                                    &priv->scan.probe_work, HZ / 10);
 389                 mutex_unlock(&priv->conf_mutex);
 390                 return;
 391         }
 392
 393         /* Make sure we still have a pending probe req */
 394         if (cw1200_queue_get_skb(queue, priv->pending_frame_id,
 395                                  &frame.skb, &txpriv)) {
 396                 up(&priv->scan.lock);
 397                 mutex_unlock(&priv->conf_mutex);
 398                 wsm_unlock_tx(priv);
 399                 return;
 400         }
 401         wsm = (struct wsm_tx *)frame.skb->data;
 402         scan.max_tx_rate = wsm->max_tx_rate;
 403         scan.band = (priv->channel->band == IEEE80211_BAND_5GHZ) ?
 404                 WSM_PHY_BAND_5G : WSM_PHY_BAND_2_4G;
 405         if (priv->join_status == CW1200_JOIN_STATUS_STA ||
 406             priv->join_status == CW1200_JOIN_STATUS_IBSS) {
 407                 scan.type = WSM_SCAN_TYPE_BACKGROUND;
 408                 scan.flags = WSM_SCAN_FLAG_FORCE_BACKGROUND;
 409         }
 410         ch[0].number = priv->channel->hw_value;
 411
 412         skb_pull(frame.skb, txpriv->offset);
 413
 414         ies = &frame.skb->data[sizeof(struct ieee80211_hdr_3addr)];
 415         ies_len = frame.skb->len - sizeof(struct ieee80211_hdr_3addr);
 416
 417         if (ies_len) {
 418                 u8 *ssidie =
 419                         (u8 *)cfg80211_find_ie(WLAN_EID_SSID, ies, ies_len);
 420                 if (ssidie && ssidie[1] && ssidie[1] <= sizeof(ssids[0].ssid)) {
 421                         u8 *nextie = &ssidie[2 + ssidie[1]];
 422                         /* Remove SSID from the IE list. It has to be provided
 423                          * as a separate argument in cw1200_scan_start call
 424                          */
 425
 426                         /* Store SSID localy */
 427                         ssids[0].length = ssidie[1];
 428                         memcpy(ssids[0].ssid, &ssidie[2], ssids[0].length);
 429                         scan.num_ssids = 1;
 430
 431                         /* Remove SSID from IE list */
 432                         ssidie[1] = 0;
 433                         memmove(&ssidie[2], nextie, &ies[ies_len] - nextie);
 434                         skb_trim(frame.skb, frame.skb->len - ssids[0].length);
 435                 }
 436         }
 437
 438         /* FW bug: driver has to restart p2p-dev mode after scan */
 439         if (priv->join_status == CW1200_JOIN_STATUS_MONITOR)
 440                 cw1200_disable_listening(priv);
 441         ret = wsm_set_template_frame(priv, &frame);
 442         priv->scan.direct_probe = 1;
 443         if (!ret) {
 444                 wsm_flush_tx(priv);
 445                 ret = cw1200_scan_start(priv, &scan);
 446         }
 447         mutex_unlock(&priv->conf_mutex);
 448
 449         skb_push(frame.skb, txpriv->offset);
 450         if (!ret)
 451                 IEEE80211_SKB_CB(frame.skb)->flags |= IEEE80211_TX_STAT_ACK;
 452         BUG_ON(cw1200_queue_remove(queue, priv->pending_frame_id));
 453
 454         if (ret) {
 455                 priv->scan.direct_probe = 0;
 456                 up(&priv->scan.lock);
 457                 wsm_unlock_tx(priv);
 458         }
 459
 460         return;
 461 }