drivers/net/wireless/st/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         frame.skb = ieee80211_probereq_get(hw, priv->vif->addr, NULL, 0,
  82                 req->ie_len);
  83         if (!frame.skb)
  84                 return -ENOMEM;
  85
  86         if (req->ie_len)
  87                 skb_put_data(frame.skb, req->ie, req->ie_len);
  88
  89         /* will be unlocked in cw1200_scan_work() */
  90         down(&priv->scan.lock);
  91         mutex_lock(&priv->conf_mutex);
  92
  93         ret = wsm_set_template_frame(priv, &frame);
  94         if (!ret) {
  95                 /* Host want to be the probe responder. */
  96                 ret = wsm_set_probe_responder(priv, true);
  97         }
  98         if (ret) {
  99                 mutex_unlock(&priv->conf_mutex);
 100                 up(&priv->scan.lock);
 101                 dev_kfree_skb(frame.skb);
 102                 return ret;
 103         }
 104
 105         wsm_lock_tx(priv);
 106
 107         BUG_ON(priv->scan.req);
 108         priv->scan.req = req;
 109         priv->scan.n_ssids = 0;
 110         priv->scan.status = 0;
 111         priv->scan.begin = &req->channels[0];
 112         priv->scan.curr = priv->scan.begin;
 113         priv->scan.end = &req->channels[req->n_channels];
 114         priv->scan.output_power = priv->output_power;
 115
 116         for (i = 0; i < req->n_ssids; ++i) {
 117                 struct wsm_ssid *dst = &priv->scan.ssids[priv->scan.n_ssids];
 118                 memcpy(&dst->ssid[0], req->ssids[i].ssid, sizeof(dst->ssid));
 119                 dst->length = req->ssids[i].ssid_len;
 120                 ++priv->scan.n_ssids;
 121         }
 122
 123         mutex_unlock(&priv->conf_mutex);
 124
 125         if (frame.skb)
 126                 dev_kfree_skb(frame.skb);
 127         queue_work(priv->workqueue, &priv->scan.work);
 128         return 0;
 129 }
 130
 131 void cw1200_scan_work(struct work_struct *work)
 132 {
 133         struct cw1200_common *priv = container_of(work, struct cw1200_common,
 134                                                         scan.work);
 135         struct ieee80211_channel **it;
 136         struct wsm_scan scan = {
 137                 .type = WSM_SCAN_TYPE_FOREGROUND,
 138                 .flags = WSM_SCAN_FLAG_SPLIT_METHOD,
 139         };
 140         bool first_run = (priv->scan.begin == priv->scan.curr &&
 141                           priv->scan.begin != priv->scan.end);
 142         int i;
 143
 144         if (first_run) {
 145                 /* Firmware gets crazy if scan request is sent
 146                  * when STA is joined but not yet associated.
 147                  * Force unjoin in this case.
 148                  */
 149                 if (cancel_delayed_work_sync(&priv->join_timeout) > 0)
 150                         cw1200_join_timeout(&priv->join_timeout.work);
 151         }
 152
 153         mutex_lock(&priv->conf_mutex);
 154
 155         if (first_run) {
 156                 if (priv->join_status == CW1200_JOIN_STATUS_STA &&
 157                     !(priv->powersave_mode.mode & WSM_PSM_PS)) {
 158                         struct wsm_set_pm pm = priv->powersave_mode;
 159                         pm.mode = WSM_PSM_PS;
 160                         cw1200_set_pm(priv, &pm);
 161                 } else if (priv->join_status == CW1200_JOIN_STATUS_MONITOR) {
 162                         /* FW bug: driver has to restart p2p-dev mode
 163                          * after scan
 164                          */
 165                         cw1200_disable_listening(priv);
 166                 }
 167         }
 168
 169         if (!priv->scan.req || (priv->scan.curr == priv->scan.end)) {
 170                 struct cfg80211_scan_info info = {
 171                         .aborted = priv->scan.status ? 1 : 0,
 172                 };
 173
 174                 if (priv->scan.output_power != priv->output_power)
 175                         wsm_set_output_power(priv, priv->output_power * 10);
 176                 if (priv->join_status == CW1200_JOIN_STATUS_STA &&
 177                     !(priv->powersave_mode.mode & WSM_PSM_PS))
 178                         cw1200_set_pm(priv, &priv->powersave_mode);
 179
 180                 if (priv->scan.status < 0)
 181                         wiphy_warn(priv->hw->wiphy,
 182                                    "[SCAN] Scan failed (%d).\n",
 183                                    priv->scan.status);
 184                 else if (priv->scan.req)
 185                         wiphy_dbg(priv->hw->wiphy,
 186                                   "[SCAN] Scan completed.\n");
 187                 else
 188                         wiphy_dbg(priv->hw->wiphy,
 189                                   "[SCAN] Scan canceled.\n");
 190
 191                 priv->scan.req = NULL;
 192                 cw1200_scan_restart_delayed(priv);
 193                 wsm_unlock_tx(priv);
 194                 mutex_unlock(&priv->conf_mutex);
 195                 ieee80211_scan_completed(priv->hw, &info);
 196                 up(&priv->scan.lock);
 197                 return;
 198         } else {
 199                 struct ieee80211_channel *first = *priv->scan.curr;
 200                 for (it = priv->scan.curr + 1, i = 1;
 201                      it != priv->scan.end && i < WSM_SCAN_MAX_NUM_OF_CHANNELS;
 202                      ++it, ++i) {
 203                         if ((*it)->band != first->band)
 204                                 break;
 205                         if (((*it)->flags ^ first->flags) &
 206                                         IEEE80211_CHAN_NO_IR)
 207                                 break;
 208                         if (!(first->flags & IEEE80211_CHAN_NO_IR) &&
 209                             (*it)->max_power != first->max_power)
 210                                 break;
 211                 }
 212                 scan.band = first->band;
 213
 214                 if (priv->scan.req->no_cck)
 215                         scan.max_tx_rate = WSM_TRANSMIT_RATE_6;
 216                 else
 217                         scan.max_tx_rate = WSM_TRANSMIT_RATE_1;
 218                 scan.num_probes =
 219                         (first->flags & IEEE80211_CHAN_NO_IR) ? 0 : 2;
 220                 scan.num_ssids = priv->scan.n_ssids;
 221                 scan.ssids = &priv->scan.ssids[0];
 222                 scan.num_channels = it - priv->scan.curr;
 223                 /* TODO: Is it optimal? */
 224                 scan.probe_delay = 100;
 225                 /* It is not stated in WSM specification, however
 226                  * FW team says that driver may not use FG scan
 227                  * when joined.
 228                  */
 229                 if (priv->join_status == CW1200_JOIN_STATUS_STA) {
 230                         scan.type = WSM_SCAN_TYPE_BACKGROUND;
 231                         scan.flags = WSM_SCAN_FLAG_FORCE_BACKGROUND;
 232                 }
 233                 scan.ch = kzalloc(
 234                         sizeof(struct wsm_scan_ch) * (it - priv->scan.curr),
 235                         GFP_KERNEL);
 236                 if (!scan.ch) {
 237                         priv->scan.status = -ENOMEM;
 238                         goto fail;
 239                 }
 240                 for (i = 0; i < scan.num_channels; ++i) {
 241                         scan.ch[i].number = priv->scan.curr[i]->hw_value;
 242                         if (priv->scan.curr[i]->flags & IEEE80211_CHAN_NO_IR) {
 243                                 scan.ch[i].min_chan_time = 50;
 244                                 scan.ch[i].max_chan_time = 100;
 245                         } else {
 246                                 scan.ch[i].min_chan_time = 10;
 247                                 scan.ch[i].max_chan_time = 25;
 248                         }
 249                 }
 250                 if (!(first->flags & IEEE80211_CHAN_NO_IR) &&
 251                     priv->scan.output_power != first->max_power) {
 252                         priv->scan.output_power = first->max_power;
 253                         wsm_set_output_power(priv,
 254                                              priv->scan.output_power * 10);
 255                 }
 256                 priv->scan.status = cw1200_scan_start(priv, &scan);
 257                 kfree(scan.ch);
 258                 if (priv->scan.status)
 259                         goto fail;
 260                 priv->scan.curr = it;
 261         }
 262         mutex_unlock(&priv->conf_mutex);
 263         return;
 264
 265 fail:
 266         priv->scan.curr = priv->scan.end;
 267         mutex_unlock(&priv->conf_mutex);
 268         queue_work(priv->workqueue, &priv->scan.work);
 269         return;
 270 }
 271
 272 static void cw1200_scan_restart_delayed(struct cw1200_common *priv)
 273 {
 274         /* FW bug: driver has to restart p2p-dev mode after scan. */
 275         if (priv->join_status == CW1200_JOIN_STATUS_MONITOR) {
 276                 cw1200_enable_listening(priv);
 277                 cw1200_update_filtering(priv);
 278         }
 279
 280         if (priv->delayed_unjoin) {
 281                 priv->delayed_unjoin = false;
 282                 if (queue_work(priv->workqueue, &priv->unjoin_work) <= 0)
 283                         wsm_unlock_tx(priv);
 284         } else if (priv->delayed_link_loss) {
 285                         wiphy_dbg(priv->hw->wiphy, "[CQM] Requeue BSS loss.\n");
 286                         priv->delayed_link_loss = 0;
 287                         cw1200_cqm_bssloss_sm(priv, 1, 0, 0);
 288         }
 289 }
 290
 291 static void cw1200_scan_complete(struct cw1200_common *priv)
 292 {
 293         queue_delayed_work(priv->workqueue, &priv->clear_recent_scan_work, HZ);
 294         if (priv->scan.direct_probe) {
 295                 wiphy_dbg(priv->hw->wiphy, "[SCAN] Direct probe complete.\n");
 296                 cw1200_scan_restart_delayed(priv);
 297                 priv->scan.direct_probe = 0;
 298                 up(&priv->scan.lock);
 299                 wsm_unlock_tx(priv);
 300         } else {
 301                 cw1200_scan_work(&priv->scan.work);
 302         }
 303 }
 304
 305 void cw1200_scan_failed_cb(struct cw1200_common *priv)
 306 {
 307         if (priv->mode == NL80211_IFTYPE_UNSPECIFIED)
 308                 /* STA is stopped. */
 309                 return;
 310
 311         if (cancel_delayed_work_sync(&priv->scan.timeout) > 0) {
 312                 priv->scan.status = -EIO;
 313                 queue_delayed_work(priv->workqueue, &priv->scan.timeout, 0);
 314         }
 315 }
 316
 317
 318 void cw1200_scan_complete_cb(struct cw1200_common *priv,
 319                                 struct wsm_scan_complete *arg)
 320 {
 321         if (priv->mode == NL80211_IFTYPE_UNSPECIFIED)
 322                 /* STA is stopped. */
 323                 return;
 324
 325         if (cancel_delayed_work_sync(&priv->scan.timeout) > 0) {
 326                 priv->scan.status = 1;
 327                 queue_delayed_work(priv->workqueue, &priv->scan.timeout, 0);
 328         }
 329 }
 330
 331 void cw1200_clear_recent_scan_work(struct work_struct *work)
 332 {
 333         struct cw1200_common *priv =
 334                 container_of(work, struct cw1200_common,
 335                              clear_recent_scan_work.work);
 336         atomic_xchg(&priv->recent_scan, 0);
 337 }
 338
 339 void cw1200_scan_timeout(struct work_struct *work)
 340 {
 341         struct cw1200_common *priv =
 342                 container_of(work, struct cw1200_common, scan.timeout.work);
 343         if (atomic_xchg(&priv->scan.in_progress, 0)) {
 344                 if (priv->scan.status > 0) {
 345                         priv->scan.status = 0;
 346                 } else if (!priv->scan.status) {
 347                         wiphy_warn(priv->hw->wiphy,
 348                                    "Timeout waiting for scan complete notification.\n");
 349                         priv->scan.status = -ETIMEDOUT;
 350                         priv->scan.curr = priv->scan.end;
 351                         wsm_stop_scan(priv);
 352                 }
 353                 cw1200_scan_complete(priv);
 354         }
 355 }
 356
 357 void cw1200_probe_work(struct work_struct *work)
 358 {
 359         struct cw1200_common *priv =
 360                 container_of(work, struct cw1200_common, scan.probe_work.work);
 361         u8 queue_id = cw1200_queue_get_queue_id(priv->pending_frame_id);
 362         struct cw1200_queue *queue = &priv->tx_queue[queue_id];
 363         const struct cw1200_txpriv *txpriv;
 364         struct wsm_tx *wsm;
 365         struct wsm_template_frame frame = {
 366                 .frame_type = WSM_FRAME_TYPE_PROBE_REQUEST,
 367         };
 368         struct wsm_ssid ssids[1] = {{
 369                 .length = 0,
 370         } };
 371         struct wsm_scan_ch ch[1] = {{
 372                 .min_chan_time = 0,
 373                 .max_chan_time = 10,
 374         } };
 375         struct wsm_scan scan = {
 376                 .type = WSM_SCAN_TYPE_FOREGROUND,
 377                 .num_probes = 1,
 378                 .probe_delay = 0,
 379                 .num_channels = 1,
 380                 .ssids = ssids,
 381                 .ch = ch,
 382         };
 383         u8 *ies;
 384         size_t ies_len;
 385         int ret;
 386
 387         wiphy_dbg(priv->hw->wiphy, "[SCAN] Direct probe work.\n");
 388
 389         mutex_lock(&priv->conf_mutex);
 390         if (down_trylock(&priv->scan.lock)) {
 391                 /* Scan is already in progress. Requeue self. */
 392                 schedule();
 393                 queue_delayed_work(priv->workqueue, &priv->scan.probe_work,
 394                                    msecs_to_jiffies(100));
 395                 mutex_unlock(&priv->conf_mutex);
 396                 return;
 397         }
 398
 399         /* Make sure we still have a pending probe req */
 400         if (cw1200_queue_get_skb(queue, priv->pending_frame_id,
 401                                  &frame.skb, &txpriv)) {
 402                 up(&priv->scan.lock);
 403                 mutex_unlock(&priv->conf_mutex);
 404                 wsm_unlock_tx(priv);
 405                 return;
 406         }
 407         wsm = (struct wsm_tx *)frame.skb->data;
 408         scan.max_tx_rate = wsm->max_tx_rate;
 409         scan.band = (priv->channel->band == NL80211_BAND_5GHZ) ?
 410                 WSM_PHY_BAND_5G : WSM_PHY_BAND_2_4G;
 411         if (priv->join_status == CW1200_JOIN_STATUS_STA ||
 412             priv->join_status == CW1200_JOIN_STATUS_IBSS) {
 413                 scan.type = WSM_SCAN_TYPE_BACKGROUND;
 414                 scan.flags = WSM_SCAN_FLAG_FORCE_BACKGROUND;
 415         }
 416         ch[0].number = priv->channel->hw_value;
 417
 418         skb_pull(frame.skb, txpriv->offset);
 419
 420         ies = &frame.skb->data[sizeof(struct ieee80211_hdr_3addr)];
 421         ies_len = frame.skb->len - sizeof(struct ieee80211_hdr_3addr);
 422
 423         if (ies_len) {
 424                 u8 *ssidie =
 425                         (u8 *)cfg80211_find_ie(WLAN_EID_SSID, ies, ies_len);
 426                 if (ssidie && ssidie[1] && ssidie[1] <= sizeof(ssids[0].ssid)) {
 427                         u8 *nextie = &ssidie[2 + ssidie[1]];
 428                         /* Remove SSID from the IE list. It has to be provided
 429                          * as a separate argument in cw1200_scan_start call
 430                          */
 431
 432                         /* Store SSID localy */
 433                         ssids[0].length = ssidie[1];
 434                         memcpy(ssids[0].ssid, &ssidie[2], ssids[0].length);
 435                         scan.num_ssids = 1;
 436
 437                         /* Remove SSID from IE list */
 438                         ssidie[1] = 0;
 439                         memmove(&ssidie[2], nextie, &ies[ies_len] - nextie);
 440                         skb_trim(frame.skb, frame.skb->len - ssids[0].length);
 441                 }
 442         }
 443
 444         /* FW bug: driver has to restart p2p-dev mode after scan */
 445         if (priv->join_status == CW1200_JOIN_STATUS_MONITOR)
 446                 cw1200_disable_listening(priv);
 447         ret = wsm_set_template_frame(priv, &frame);
 448         priv->scan.direct_probe = 1;
 449         if (!ret) {
 450                 wsm_flush_tx(priv);
 451                 ret = cw1200_scan_start(priv, &scan);
 452         }
 453         mutex_unlock(&priv->conf_mutex);
 454
 455         skb_push(frame.skb, txpriv->offset);
 456         if (!ret)
 457                 IEEE80211_SKB_CB(frame.skb)->flags |= IEEE80211_TX_STAT_ACK;
 458         BUG_ON(cw1200_queue_remove(queue, priv->pending_frame_id));
 459
 460         if (ret) {
 461                 priv->scan.direct_probe = 0;
 462                 up(&priv->scan.lock);
 463                 wsm_unlock_tx(priv);
 464         }
 465
 466         return;
 467 }