drivers/net/wireless/rt2x00/rt2x00mac.c

   1 /*
   2         Copyright (C) 2004 - 2008 rt2x00 SourceForge Project
   3         <http://rt2x00.serialmonkey.com>
   4
   5         This program is free software; you can redistribute it and/or modify
   6         it under the terms of the GNU General Public License as published by
   7         the Free Software Foundation; either version 2 of the License, or
   8         (at your option) any later version.
   9
  10         This program is distributed in the hope that it will be useful,
  11         but WITHOUT ANY WARRANTY; without even the implied warranty of
  12         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13         GNU General Public License for more details.
  14
  15         You should have received a copy of the GNU General Public License
  16         along with this program; if not, write to the
  17         Free Software Foundation, Inc.,
  18         59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19  */
  20
  21 /*
  22         Module: rt2x00mac
  23         Abstract: rt2x00 generic mac80211 routines.
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/module.h>
  28
  29 #include "rt2x00.h"
  30 #include "rt2x00lib.h"
  31
  32 static int rt2x00mac_tx_rts_cts(struct rt2x00_dev *rt2x00dev,
  33                                 struct data_queue *queue,
  34                                 struct sk_buff *frag_skb,
  35                                 struct ieee80211_tx_control *control)
  36 {
  37         struct sk_buff *skb;
  38         int size;
  39
  40         if (control->flags & IEEE80211_TXCTL_USE_CTS_PROTECT)
  41                 size = sizeof(struct ieee80211_cts);
  42         else
  43                 size = sizeof(struct ieee80211_rts);
  44
  45         skb = dev_alloc_skb(size + rt2x00dev->hw->extra_tx_headroom);
  46         if (!skb) {
  47                 WARNING(rt2x00dev, "Failed to create RTS/CTS frame.\n");
  48                 return NETDEV_TX_BUSY;
  49         }
  50
  51         skb_reserve(skb, rt2x00dev->hw->extra_tx_headroom);
  52         skb_put(skb, size);
  53
  54         if (control->flags & IEEE80211_TXCTL_USE_CTS_PROTECT)
  55                 ieee80211_ctstoself_get(rt2x00dev->hw, control->vif,
  56                                         frag_skb->data, frag_skb->len, control,
  57                                         (struct ieee80211_cts *)(skb->data));
  58         else
  59                 ieee80211_rts_get(rt2x00dev->hw, control->vif,
  60                                   frag_skb->data, frag_skb->len, control,
  61                                   (struct ieee80211_rts *)(skb->data));
  62
  63         if (rt2x00dev->ops->lib->write_tx_data(rt2x00dev, queue, skb, control)) {
  64                 WARNING(rt2x00dev, "Failed to send RTS/CTS frame.\n");
  65                 return NETDEV_TX_BUSY;
  66         }
  67
  68         return NETDEV_TX_OK;
  69 }
  70
  71 int rt2x00mac_tx(struct ieee80211_hw *hw, struct sk_buff *skb,
  72                  struct ieee80211_tx_control *control)
  73 {
  74         struct rt2x00_dev *rt2x00dev = hw->priv;
  75         struct ieee80211_hdr *ieee80211hdr = (struct ieee80211_hdr *)skb->data;
  76         struct data_queue *queue;
  77         u16 frame_control;
  78
  79         /*
  80          * Mac80211 might be calling this function while we are trying
  81          * to remove the device or perhaps suspending it.
  82          * Note that we can only stop the TX queues inside the TX path
  83          * due to possible race conditions in mac80211.
  84          */
  85         if (!test_bit(DEVICE_PRESENT, &rt2x00dev->flags)) {
  86                 ieee80211_stop_queues(hw);
  87                 return NETDEV_TX_OK;
  88         }
  89
  90         /*
  91          * Determine which queue to put packet on.
  92          */
  93         queue = rt2x00queue_get_queue(rt2x00dev, control->queue);
  94         if (unlikely(!queue)) {
  95                 ERROR(rt2x00dev,
  96                       "Attempt to send packet over invalid queue %d.\n"
  97                       "Please file bug report to %s.\n",
  98                       control->queue, DRV_PROJECT);
  99                 dev_kfree_skb_any(skb);
 100                 return NETDEV_TX_OK;
 101         }
 102
 103         /*
 104          * If CTS/RTS is required. and this frame is not CTS or RTS,
 105          * create and queue that frame first. But make sure we have
 106          * at least enough entries available to send this CTS/RTS
 107          * frame as well as the data frame.
 108          */
 109         frame_control = le16_to_cpu(ieee80211hdr->frame_control);
 110         if (!is_rts_frame(frame_control) && !is_cts_frame(frame_control) &&
 111             (control->flags & (IEEE80211_TXCTL_USE_RTS_CTS |
 112                                IEEE80211_TXCTL_USE_CTS_PROTECT))) {
 113                 if (rt2x00queue_available(queue) <= 1) {
 114                         ieee80211_stop_queue(rt2x00dev->hw, control->queue);
 115                         return NETDEV_TX_BUSY;
 116                 }
 117
 118                 if (rt2x00mac_tx_rts_cts(rt2x00dev, queue, skb, control)) {
 119                         ieee80211_stop_queue(rt2x00dev->hw, control->queue);
 120                         return NETDEV_TX_BUSY;
 121                 }
 122         }
 123
 124         if (rt2x00dev->ops->lib->write_tx_data(rt2x00dev, queue, skb, control)) {
 125                 ieee80211_stop_queue(rt2x00dev->hw, control->queue);
 126                 return NETDEV_TX_BUSY;
 127         }
 128
 129         if (rt2x00queue_full(queue))
 130                 ieee80211_stop_queue(rt2x00dev->hw, control->queue);
 131
 132         if (rt2x00dev->ops->lib->kick_tx_queue)
 133                 rt2x00dev->ops->lib->kick_tx_queue(rt2x00dev, control->queue);
 134
 135         return NETDEV_TX_OK;
 136 }
 137 EXPORT_SYMBOL_GPL(rt2x00mac_tx);
 138
 139 int rt2x00mac_start(struct ieee80211_hw *hw)
 140 {
 141         struct rt2x00_dev *rt2x00dev = hw->priv;
 142
 143         if (!test_bit(DEVICE_PRESENT, &rt2x00dev->flags))
 144                 return 0;
 145
 146         return rt2x00lib_start(rt2x00dev);
 147 }
 148 EXPORT_SYMBOL_GPL(rt2x00mac_start);
 149
 150 void rt2x00mac_stop(struct ieee80211_hw *hw)
 151 {
 152         struct rt2x00_dev *rt2x00dev = hw->priv;
 153
 154         if (!test_bit(DEVICE_PRESENT, &rt2x00dev->flags))
 155                 return;
 156
 157         rt2x00lib_stop(rt2x00dev);
 158 }
 159 EXPORT_SYMBOL_GPL(rt2x00mac_stop);
 160
 161 int rt2x00mac_add_interface(struct ieee80211_hw *hw,
 162                             struct ieee80211_if_init_conf *conf)
 163 {
 164         struct rt2x00_dev *rt2x00dev = hw->priv;
 165         struct rt2x00_intf *intf = vif_to_intf(conf->vif);
 166         struct data_queue *queue =
 167             rt2x00queue_get_queue(rt2x00dev, RT2X00_BCN_QUEUE_BEACON);
 168         struct queue_entry *entry = NULL;
 169         unsigned int i;
 170
 171         /*
 172          * Don't allow interfaces to be added
 173          * the device has disappeared.
 174          */
 175         if (!test_bit(DEVICE_PRESENT, &rt2x00dev->flags) ||
 176             !test_bit(DEVICE_STARTED, &rt2x00dev->flags))
 177                 return -ENODEV;
 178
 179         /*
 180          * When we don't support mixed interfaces (a combination
 181          * of sta and ap virtual interfaces) then we can only
 182          * add this interface when the rival interface count is 0.
 183          */
 184         if (!test_bit(DRIVER_SUPPORT_MIXED_INTERFACES, &rt2x00dev->flags) &&
 185             ((conf->type == IEEE80211_IF_TYPE_AP && rt2x00dev->intf_sta_count) ||
 186              (conf->type != IEEE80211_IF_TYPE_AP && rt2x00dev->intf_ap_count)))
 187                 return -ENOBUFS;
 188
 189         /*
 190          * Check if we exceeded the maximum amount of supported interfaces.
 191          */
 192         if ((conf->type == IEEE80211_IF_TYPE_AP &&
 193              rt2x00dev->intf_ap_count >= rt2x00dev->ops->max_ap_intf) ||
 194             (conf->type != IEEE80211_IF_TYPE_AP &&
 195              rt2x00dev->intf_sta_count >= rt2x00dev->ops->max_sta_intf))
 196                 return -ENOBUFS;
 197
 198         /*
 199          * Loop through all beacon queues to find a free
 200          * entry. Since there are as much beacon entries
 201          * as the maximum interfaces, this search shouldn't
 202          * fail.
 203          */
 204         for (i = 0; i < queue->limit; i++) {
 205                 entry = &queue->entries[i];
 206                 if (!__test_and_set_bit(ENTRY_BCN_ASSIGNED, &entry->flags))
 207                         break;
 208         }
 209
 210         if (unlikely(i == queue->limit))
 211                 return -ENOBUFS;
 212
 213         /*
 214          * We are now absolutely sure the interface can be created,
 215          * increase interface count and start initialization.
 216          */
 217
 218         if (conf->type == IEEE80211_IF_TYPE_AP)
 219                 rt2x00dev->intf_ap_count++;
 220         else
 221                 rt2x00dev->intf_sta_count++;
 222
 223         spin_lock_init(&intf->lock);
 224         intf->beacon = entry;
 225
 226         if (conf->type == IEEE80211_IF_TYPE_AP)
 227                 memcpy(&intf->bssid, conf->mac_addr, ETH_ALEN);
 228         memcpy(&intf->mac, conf->mac_addr, ETH_ALEN);
 229
 230         /*
 231          * The MAC adddress must be configured after the device
 232          * has been initialized. Otherwise the device can reset
 233          * the MAC registers.
 234          */
 235         rt2x00lib_config_intf(rt2x00dev, intf, conf->type, intf->mac, NULL);
 236
 237         return 0;
 238 }
 239 EXPORT_SYMBOL_GPL(rt2x00mac_add_interface);
 240
 241 void rt2x00mac_remove_interface(struct ieee80211_hw *hw,
 242                                 struct ieee80211_if_init_conf *conf)
 243 {
 244         struct rt2x00_dev *rt2x00dev = hw->priv;
 245         struct rt2x00_intf *intf = vif_to_intf(conf->vif);
 246
 247         /*
 248          * Don't allow interfaces to be remove while
 249          * either the device has disappeared or when
 250          * no interface is present.
 251          */
 252         if (!test_bit(DEVICE_PRESENT, &rt2x00dev->flags) ||
 253             (conf->type == IEEE80211_IF_TYPE_AP && !rt2x00dev->intf_ap_count) ||
 254             (conf->type != IEEE80211_IF_TYPE_AP && !rt2x00dev->intf_sta_count))
 255                 return;
 256
 257         if (conf->type == IEEE80211_IF_TYPE_AP)
 258                 rt2x00dev->intf_ap_count--;
 259         else
 260                 rt2x00dev->intf_sta_count--;
 261
 262         /*
 263          * Release beacon entry so it is available for
 264          * new interfaces again.
 265          */
 266         __clear_bit(ENTRY_BCN_ASSIGNED, &intf->beacon->flags);
 267
 268         /*
 269          * Make sure the bssid and mac address registers
 270          * are cleared to prevent false ACKing of frames.
 271          */
 272         rt2x00lib_config_intf(rt2x00dev, intf,
 273                               IEEE80211_IF_TYPE_INVALID, NULL, NULL);
 274 }
 275 EXPORT_SYMBOL_GPL(rt2x00mac_remove_interface);
 276
 277 int rt2x00mac_config(struct ieee80211_hw *hw, struct ieee80211_conf *conf)
 278 {
 279         struct rt2x00_dev *rt2x00dev = hw->priv;
 280
 281         /*
 282          * Mac80211 might be calling this function while we are trying
 283          * to remove the device or perhaps suspending it.
 284          */
 285         if (!test_bit(DEVICE_PRESENT, &rt2x00dev->flags))
 286                 return 0;
 287
 288         /*
 289          * Check if we need to disable the radio,
 290          * if this is not the case, at least the RX must be disabled.
 291          */
 292         if (test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags)) {
 293                 if (!conf->radio_enabled)
 294                         rt2x00lib_disable_radio(rt2x00dev);
 295                 else
 296                         rt2x00lib_toggle_rx(rt2x00dev, STATE_RADIO_RX_OFF);
 297         }
 298
 299         rt2x00lib_config(rt2x00dev, conf, 0);
 300
 301         /*
 302          * Reenable RX only if the radio should be on.
 303          */
 304         if (test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags))
 305                 rt2x00lib_toggle_rx(rt2x00dev, STATE_RADIO_RX_ON);
 306         else if (conf->radio_enabled)
 307                 return rt2x00lib_enable_radio(rt2x00dev);
 308
 309         return 0;
 310 }
 311 EXPORT_SYMBOL_GPL(rt2x00mac_config);
 312
 313 int rt2x00mac_config_interface(struct ieee80211_hw *hw,
 314                                struct ieee80211_vif *vif,
 315                                struct ieee80211_if_conf *conf)
 316 {
 317         struct rt2x00_dev *rt2x00dev = hw->priv;
 318         struct rt2x00_intf *intf = vif_to_intf(vif);
 319         int status;
 320
 321         /*
 322          * Mac80211 might be calling this function while we are trying
 323          * to remove the device or perhaps suspending it.
 324          */
 325         if (!test_bit(DEVICE_PRESENT, &rt2x00dev->flags))
 326                 return 0;
 327
 328         spin_lock(&intf->lock);
 329
 330         /*
 331          * If the interface does not work in master mode,
 332          * then the bssid value in the interface structure
 333          * should now be set.
 334          */
 335         if (conf->type != IEEE80211_IF_TYPE_AP)
 336                 memcpy(&intf->bssid, conf->bssid, ETH_ALEN);
 337
 338         spin_unlock(&intf->lock);
 339
 340         /*
 341          * Call rt2x00_config_intf() outside of the spinlock context since
 342          * the call will sleep for USB drivers. By using the ieee80211_if_conf
 343          * values as arguments we make keep access to rt2x00_intf thread safe
 344          * even without the lock.
 345          */
 346         rt2x00lib_config_intf(rt2x00dev, intf, conf->type, NULL, conf->bssid);
 347
 348         /*
 349          * We only need to initialize the beacon when master mode is enabled.
 350          */
 351         if (conf->type != IEEE80211_IF_TYPE_AP || !conf->beacon)
 352                 return 0;
 353
 354         status = rt2x00dev->ops->hw->beacon_update(rt2x00dev->hw,
 355                                                    conf->beacon,
 356                                                    conf->beacon_control);
 357         if (status)
 358                 dev_kfree_skb(conf->beacon);
 359
 360         return status;
 361 }
 362 EXPORT_SYMBOL_GPL(rt2x00mac_config_interface);
 363
 364 int rt2x00mac_get_stats(struct ieee80211_hw *hw,
 365                         struct ieee80211_low_level_stats *stats)
 366 {
 367         struct rt2x00_dev *rt2x00dev = hw->priv;
 368
 369         /*
 370          * The dot11ACKFailureCount, dot11RTSFailureCount and
 371          * dot11RTSSuccessCount are updated in interrupt time.
 372          * dot11FCSErrorCount is updated in the link tuner.
 373          */
 374         memcpy(stats, &rt2x00dev->low_level_stats, sizeof(*stats));
 375
 376         return 0;
 377 }
 378 EXPORT_SYMBOL_GPL(rt2x00mac_get_stats);
 379
 380 int rt2x00mac_get_tx_stats(struct ieee80211_hw *hw,
 381                            struct ieee80211_tx_queue_stats *stats)
 382 {
 383         struct rt2x00_dev *rt2x00dev = hw->priv;
 384         unsigned int i;
 385
 386         for (i = 0; i < hw->queues; i++) {
 387                 stats->data[i].len = rt2x00dev->tx[i].length;
 388                 stats->data[i].limit = rt2x00dev->tx[i].limit;
 389                 stats->data[i].count = rt2x00dev->tx[i].count;
 390         }
 391
 392         return 0;
 393 }
 394 EXPORT_SYMBOL_GPL(rt2x00mac_get_tx_stats);
 395
 396 void rt2x00mac_bss_info_changed(struct ieee80211_hw *hw,
 397                                 struct ieee80211_vif *vif,
 398                                 struct ieee80211_bss_conf *bss_conf,
 399                                 u32 changes)
 400 {
 401         struct rt2x00_dev *rt2x00dev = hw->priv;
 402         struct rt2x00_intf *intf = vif_to_intf(vif);
 403
 404         /*
 405          * When the association status has changed we must reset the link
 406          * tuner counter. This is because some drivers determine if they
 407          * should perform link tuning based on the number of seconds
 408          * while associated or not associated.
 409          */
 410         if (changes & BSS_CHANGED_ASSOC) {
 411                 rt2x00dev->link.count = 0;
 412
 413                 if (bss_conf->assoc)
 414                         rt2x00dev->intf_associated++;
 415                 else
 416                         rt2x00dev->intf_associated--;
 417         }
 418
 419         /*
 420          * When the preamble mode has changed, we should perform additional
 421          * configuration steps. For all other changes we are already done.
 422          */
 423         if (changes & BSS_CHANGED_ERP_PREAMBLE) {
 424                 rt2x00lib_config_preamble(rt2x00dev, intf,
 425                                           bss_conf->use_short_preamble);
 426
 427                 spin_lock(&intf->lock);
 428                 memcpy(&intf->conf, bss_conf, sizeof(*bss_conf));
 429                 spin_unlock(&intf->lock);
 430         }
 431 }
 432 EXPORT_SYMBOL_GPL(rt2x00mac_bss_info_changed);
 433
 434 int rt2x00mac_conf_tx(struct ieee80211_hw *hw, int queue_idx,
 435                       const struct ieee80211_tx_queue_params *params)
 436 {
 437         struct rt2x00_dev *rt2x00dev = hw->priv;
 438         struct data_queue *queue;
 439
 440         queue = rt2x00queue_get_queue(rt2x00dev, queue_idx);
 441         if (unlikely(!queue))
 442                 return -EINVAL;
 443
 444         /*
 445          * The passed variables are stored as real value ((2^n)-1).
 446          * Ralink registers require to know the bit number 'n'.
 447          */
 448         if (params->cw_min > 0)
 449                 queue->cw_min = fls(params->cw_min);
 450         else
 451                 queue->cw_min = 5; /* cw_min: 2^5 = 32. */
 452
 453         if (params->cw_max > 0)
 454                 queue->cw_max = fls(params->cw_max);
 455         else
 456                 queue->cw_max = 10; /* cw_min: 2^10 = 1024. */
 457
 458         if (params->aifs >= 0)
 459                 queue->aifs = params->aifs;
 460         else
 461                 queue->aifs = 2;
 462
 463         INFO(rt2x00dev,
 464              "Configured TX queue %d - CWmin: %d, CWmax: %d, Aifs: %d.\n",
 465              queue_idx, queue->cw_min, queue->cw_max, queue->aifs);
 466
 467         return 0;
 468 }
 469 EXPORT_SYMBOL_GPL(rt2x00mac_conf_tx);