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   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: rt2x00lib
  23         Abstract: rt2x00 queue specific routines.
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/module.h>
  28
  29 #include "rt2x00.h"
  30 #include "rt2x00lib.h"
  31
  32 void rt2x00queue_create_tx_descriptor(struct queue_entry *entry,
  33                                       struct txentry_desc *txdesc)
  34 {
  35         struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
  36         struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(entry->skb);
  37         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)entry->skb->data;
  38         struct ieee80211_rate *rate =
  39             ieee80211_get_tx_rate(rt2x00dev->hw, tx_info);
  40         const struct rt2x00_rate *hwrate;
  41         unsigned int data_length;
  42         unsigned int duration;
  43         unsigned int residual;
  44         u16 frame_control;
  45
  46         memset(txdesc, 0, sizeof(*txdesc));
  47
  48         /*
  49          * Initialize information from queue
  50          */
  51         txdesc->queue = entry->queue->qid;
  52         txdesc->cw_min = entry->queue->cw_min;
  53         txdesc->cw_max = entry->queue->cw_max;
  54         txdesc->aifs = entry->queue->aifs;
  55
  56         /* Data length should be extended with 4 bytes for CRC */
  57         data_length = entry->skb->len + 4;
  58
  59         /*
  60          * Read required fields from ieee80211 header.
  61          */
  62         frame_control = le16_to_cpu(hdr->frame_control);
  63
  64         /*
  65          * Check whether this frame is to be acked.
  66          */
  67         if (!(tx_info->flags & IEEE80211_TX_CTL_NO_ACK))
  68                 __set_bit(ENTRY_TXD_ACK, &txdesc->flags);
  69
  70         /*
  71          * Check if this is a RTS/CTS frame
  72          */
  73         if (is_rts_frame(frame_control) || is_cts_frame(frame_control)) {
  74                 __set_bit(ENTRY_TXD_BURST, &txdesc->flags);
  75                 if (is_rts_frame(frame_control))
  76                         __set_bit(ENTRY_TXD_RTS_FRAME, &txdesc->flags);
  77                 else
  78                         __set_bit(ENTRY_TXD_CTS_FRAME, &txdesc->flags);
  79                 if (tx_info->control.rts_cts_rate_idx >= 0)
  80                         rate =
  81                             ieee80211_get_rts_cts_rate(rt2x00dev->hw, tx_info);
  82         }
  83
  84         /*
  85          * Determine retry information.
  86          */
  87         txdesc->retry_limit = tx_info->control.retry_limit;
  88         if (tx_info->flags & IEEE80211_TX_CTL_LONG_RETRY_LIMIT)
  89                 __set_bit(ENTRY_TXD_RETRY_MODE, &txdesc->flags);
  90
  91         /*
  92          * Check if more fragments are pending
  93          */
  94         if (ieee80211_get_morefrag(hdr)) {
  95                 __set_bit(ENTRY_TXD_BURST, &txdesc->flags);
  96                 __set_bit(ENTRY_TXD_MORE_FRAG, &txdesc->flags);
  97         }
  98
  99         /*
 100          * Beacons and probe responses require the tsf timestamp
 101          * to be inserted into the frame.
 102          */
 103         if (txdesc->queue == QID_BEACON || is_probe_resp(frame_control))
 104                 __set_bit(ENTRY_TXD_REQ_TIMESTAMP, &txdesc->flags);
 105
 106         /*
 107          * Determine with what IFS priority this frame should be send.
 108          * Set ifs to IFS_SIFS when the this is not the first fragment,
 109          * or this fragment came after RTS/CTS.
 110          */
 111         if (test_bit(ENTRY_TXD_RTS_FRAME, &txdesc->flags)) {
 112                 txdesc->ifs = IFS_SIFS;
 113         } else if (tx_info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT) {
 114                 __set_bit(ENTRY_TXD_FIRST_FRAGMENT, &txdesc->flags);
 115                 txdesc->ifs = IFS_BACKOFF;
 116         } else {
 117                 txdesc->ifs = IFS_SIFS;
 118         }
 119
 120         /*
 121          * PLCP setup
 122          * Length calculation depends on OFDM/CCK rate.
 123          */
 124         hwrate = rt2x00_get_rate(rate->hw_value);
 125         txdesc->signal = hwrate->plcp;
 126         txdesc->service = 0x04;
 127
 128         if (hwrate->flags & DEV_RATE_OFDM) {
 129                 __set_bit(ENTRY_TXD_OFDM_RATE, &txdesc->flags);
 130
 131                 txdesc->length_high = (data_length >> 6) & 0x3f;
 132                 txdesc->length_low = data_length & 0x3f;
 133         } else {
 134                 /*
 135                  * Convert length to microseconds.
 136                  */
 137                 residual = get_duration_res(data_length, hwrate->bitrate);
 138                 duration = get_duration(data_length, hwrate->bitrate);
 139
 140                 if (residual != 0) {
 141                         duration++;
 142
 143                         /*
 144                          * Check if we need to set the Length Extension
 145                          */
 146                         if (hwrate->bitrate == 110 && residual <= 30)
 147                                 txdesc->service |= 0x80;
 148                 }
 149
 150                 txdesc->length_high = (duration >> 8) & 0xff;
 151                 txdesc->length_low = duration & 0xff;
 152
 153                 /*
 154                  * When preamble is enabled we should set the
 155                  * preamble bit for the signal.
 156                  */
 157                 if (rt2x00_get_rate_preamble(rate->hw_value))
 158                         txdesc->signal |= 0x08;
 159         }
 160 }
 161 EXPORT_SYMBOL_GPL(rt2x00queue_create_tx_descriptor);
 162
 163 void rt2x00queue_write_tx_descriptor(struct queue_entry *entry,
 164                                      struct txentry_desc *txdesc)
 165 {
 166         struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
 167         struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
 168
 169         rt2x00dev->ops->lib->write_tx_desc(rt2x00dev, entry->skb, txdesc);
 170
 171         /*
 172          * All processing on the frame has been completed, this means
 173          * it is now ready to be dumped to userspace through debugfs.
 174          */
 175         rt2x00debug_dump_frame(rt2x00dev, DUMP_FRAME_TX, entry->skb);
 176
 177         /*
 178          * We are done writing the frame to the queue entry,
 179          * also kick the queue in case the correct flags are set,
 180          * note that this will automatically filter beacons and
 181          * RTS/CTS frames since those frames don't have this flag
 182          * set.
 183          */
 184         if (rt2x00dev->ops->lib->kick_tx_queue &&
 185             !(skbdesc->flags & FRAME_DESC_DRIVER_GENERATED))
 186                 rt2x00dev->ops->lib->kick_tx_queue(rt2x00dev,
 187                                                    entry->queue->qid);
 188 }
 189 EXPORT_SYMBOL_GPL(rt2x00queue_write_tx_descriptor);
 190
 191 struct data_queue *rt2x00queue_get_queue(struct rt2x00_dev *rt2x00dev,
 192                                          const enum data_queue_qid queue)
 193 {
 194         int atim = test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags);
 195
 196         if (queue < rt2x00dev->ops->tx_queues && rt2x00dev->tx)
 197                 return &rt2x00dev->tx[queue];
 198
 199         if (!rt2x00dev->bcn)
 200                 return NULL;
 201
 202         if (queue == QID_BEACON)
 203                 return &rt2x00dev->bcn[0];
 204         else if (queue == QID_ATIM && atim)
 205                 return &rt2x00dev->bcn[1];
 206
 207         return NULL;
 208 }
 209 EXPORT_SYMBOL_GPL(rt2x00queue_get_queue);
 210
 211 struct queue_entry *rt2x00queue_get_entry(struct data_queue *queue,
 212                                           enum queue_index index)
 213 {
 214         struct queue_entry *entry;
 215         unsigned long irqflags;
 216
 217         if (unlikely(index >= Q_INDEX_MAX)) {
 218                 ERROR(queue->rt2x00dev,
 219                       "Entry requested from invalid index type (%d)\n", index);
 220                 return NULL;
 221         }
 222
 223         spin_lock_irqsave(&queue->lock, irqflags);
 224
 225         entry = &queue->entries[queue->index[index]];
 226
 227         spin_unlock_irqrestore(&queue->lock, irqflags);
 228
 229         return entry;
 230 }
 231 EXPORT_SYMBOL_GPL(rt2x00queue_get_entry);
 232
 233 void rt2x00queue_index_inc(struct data_queue *queue, enum queue_index index)
 234 {
 235         unsigned long irqflags;
 236
 237         if (unlikely(index >= Q_INDEX_MAX)) {
 238                 ERROR(queue->rt2x00dev,
 239                       "Index change on invalid index type (%d)\n", index);
 240                 return;
 241         }
 242
 243         spin_lock_irqsave(&queue->lock, irqflags);
 244
 245         queue->index[index]++;
 246         if (queue->index[index] >= queue->limit)
 247                 queue->index[index] = 0;
 248
 249         if (index == Q_INDEX) {
 250                 queue->length++;
 251         } else if (index == Q_INDEX_DONE) {
 252                 queue->length--;
 253                 queue->count ++;
 254         }
 255
 256         spin_unlock_irqrestore(&queue->lock, irqflags);
 257 }
 258 EXPORT_SYMBOL_GPL(rt2x00queue_index_inc);
 259
 260 static void rt2x00queue_reset(struct data_queue *queue)
 261 {
 262         unsigned long irqflags;
 263
 264         spin_lock_irqsave(&queue->lock, irqflags);
 265
 266         queue->count = 0;
 267         queue->length = 0;
 268         memset(queue->index, 0, sizeof(queue->index));
 269
 270         spin_unlock_irqrestore(&queue->lock, irqflags);
 271 }
 272
 273 void rt2x00queue_init_rx(struct rt2x00_dev *rt2x00dev)
 274 {
 275         struct data_queue *queue = rt2x00dev->rx;
 276         unsigned int i;
 277
 278         rt2x00queue_reset(queue);
 279
 280         if (!rt2x00dev->ops->lib->init_rxentry)
 281                 return;
 282
 283         for (i = 0; i < queue->limit; i++)
 284                 rt2x00dev->ops->lib->init_rxentry(rt2x00dev,
 285                                                   &queue->entries[i]);
 286 }
 287
 288 void rt2x00queue_init_tx(struct rt2x00_dev *rt2x00dev)
 289 {
 290         struct data_queue *queue;
 291         unsigned int i;
 292
 293         txall_queue_for_each(rt2x00dev, queue) {
 294                 rt2x00queue_reset(queue);
 295
 296                 if (!rt2x00dev->ops->lib->init_txentry)
 297                         continue;
 298
 299                 for (i = 0; i < queue->limit; i++)
 300                         rt2x00dev->ops->lib->init_txentry(rt2x00dev,
 301                                                           &queue->entries[i]);
 302         }
 303 }
 304
 305 static int rt2x00queue_alloc_entries(struct data_queue *queue,
 306                                      const struct data_queue_desc *qdesc)
 307 {
 308         struct queue_entry *entries;
 309         unsigned int entry_size;
 310         unsigned int i;
 311
 312         rt2x00queue_reset(queue);
 313
 314         queue->limit = qdesc->entry_num;
 315         queue->data_size = qdesc->data_size;
 316         queue->desc_size = qdesc->desc_size;
 317
 318         /*
 319          * Allocate all queue entries.
 320          */
 321         entry_size = sizeof(*entries) + qdesc->priv_size;
 322         entries = kzalloc(queue->limit * entry_size, GFP_KERNEL);
 323         if (!entries)
 324                 return -ENOMEM;
 325
 326 #define QUEUE_ENTRY_PRIV_OFFSET(__base, __index, __limit, __esize, __psize) \
 327         ( ((char *)(__base)) + ((__limit) * (__esize)) + \
 328             ((__index) * (__psize)) )
 329
 330         for (i = 0; i < queue->limit; i++) {
 331                 entries[i].flags = 0;
 332                 entries[i].queue = queue;
 333                 entries[i].skb = NULL;
 334                 entries[i].entry_idx = i;
 335                 entries[i].priv_data =
 336                     QUEUE_ENTRY_PRIV_OFFSET(entries, i, queue->limit,
 337                                             sizeof(*entries), qdesc->priv_size);
 338         }
 339
 340 #undef QUEUE_ENTRY_PRIV_OFFSET
 341
 342         queue->entries = entries;
 343
 344         return 0;
 345 }
 346
 347 int rt2x00queue_initialize(struct rt2x00_dev *rt2x00dev)
 348 {
 349         struct data_queue *queue;
 350         int status;
 351
 352
 353         status = rt2x00queue_alloc_entries(rt2x00dev->rx, rt2x00dev->ops->rx);
 354         if (status)
 355                 goto exit;
 356
 357         tx_queue_for_each(rt2x00dev, queue) {
 358                 status = rt2x00queue_alloc_entries(queue, rt2x00dev->ops->tx);
 359                 if (status)
 360                         goto exit;
 361         }
 362
 363         status = rt2x00queue_alloc_entries(rt2x00dev->bcn, rt2x00dev->ops->bcn);
 364         if (status)
 365                 goto exit;
 366
 367         if (!test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags))
 368                 return 0;
 369
 370         status = rt2x00queue_alloc_entries(&rt2x00dev->bcn[1],
 371                                            rt2x00dev->ops->atim);
 372         if (status)
 373                 goto exit;
 374
 375         return 0;
 376
 377 exit:
 378         ERROR(rt2x00dev, "Queue entries allocation failed.\n");
 379
 380         rt2x00queue_uninitialize(rt2x00dev);
 381
 382         return status;
 383 }
 384
 385 void rt2x00queue_uninitialize(struct rt2x00_dev *rt2x00dev)
 386 {
 387         struct data_queue *queue;
 388
 389         queue_for_each(rt2x00dev, queue) {
 390                 kfree(queue->entries);
 391                 queue->entries = NULL;
 392         }
 393 }
 394
 395 static void rt2x00queue_init(struct rt2x00_dev *rt2x00dev,
 396                              struct data_queue *queue, enum data_queue_qid qid)
 397 {
 398         spin_lock_init(&queue->lock);
 399
 400         queue->rt2x00dev = rt2x00dev;
 401         queue->qid = qid;
 402         queue->aifs = 2;
 403         queue->cw_min = 5;
 404         queue->cw_max = 10;
 405 }
 406
 407 int rt2x00queue_allocate(struct rt2x00_dev *rt2x00dev)
 408 {
 409         struct data_queue *queue;
 410         enum data_queue_qid qid;
 411         unsigned int req_atim =
 412             !!test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags);
 413
 414         /*
 415          * We need the following queues:
 416          * RX: 1
 417          * TX: ops->tx_queues
 418          * Beacon: 1
 419          * Atim: 1 (if required)
 420          */
 421         rt2x00dev->data_queues = 2 + rt2x00dev->ops->tx_queues + req_atim;
 422
 423         queue = kzalloc(rt2x00dev->data_queues * sizeof(*queue), GFP_KERNEL);
 424         if (!queue) {
 425                 ERROR(rt2x00dev, "Queue allocation failed.\n");
 426                 return -ENOMEM;
 427         }
 428
 429         /*
 430          * Initialize pointers
 431          */
 432         rt2x00dev->rx = queue;
 433         rt2x00dev->tx = &queue[1];
 434         rt2x00dev->bcn = &queue[1 + rt2x00dev->ops->tx_queues];
 435
 436         /*
 437          * Initialize queue parameters.
 438          * RX: qid = QID_RX
 439          * TX: qid = QID_AC_BE + index
 440          * TX: cw_min: 2^5 = 32.
 441          * TX: cw_max: 2^10 = 1024.
 442          * BCN & Atim: qid = QID_MGMT
 443          */
 444         rt2x00queue_init(rt2x00dev, rt2x00dev->rx, QID_RX);
 445
 446         qid = QID_AC_BE;
 447         tx_queue_for_each(rt2x00dev, queue)
 448                 rt2x00queue_init(rt2x00dev, queue, qid++);
 449
 450         rt2x00queue_init(rt2x00dev, &rt2x00dev->bcn[0], QID_MGMT);
 451         if (req_atim)
 452                 rt2x00queue_init(rt2x00dev, &rt2x00dev->bcn[1], QID_MGMT);
 453
 454         return 0;
 455 }
 456
 457 void rt2x00queue_free(struct rt2x00_dev *rt2x00dev)
 458 {
 459         kfree(rt2x00dev->rx);
 460         rt2x00dev->rx = NULL;
 461         rt2x00dev->tx = NULL;
 462         rt2x00dev->bcn = NULL;
 463 }