drivers/net/wireless/rt2x00/rt2x00queue.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: 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 data_queue *queue = entry->queue;
 167         struct rt2x00_dev *rt2x00dev = queue->rt2x00dev;
 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          * Check if we need to kick the queue, there are however a few rules
 179          *      1) Don't kick beacon queue
 180          *      2) Don't kick unless this is the last in frame in a burst.
 181          *         When the burst flag is set, this frame is always followed
 182          *         by another frame which in some way are related to eachother.
 183          *         This is true for fragments, RTS or CTS-to-self frames.
 184          *      3) Rule 2 can be broken when the available entries
 185          *         in the queue are less then a certain threshold.
 186          */
 187         if (entry->queue->qid == QID_BEACON)
 188                 return;
 189
 190         if (rt2x00queue_threshold(queue) ||
 191             !test_bit(ENTRY_TXD_BURST, &txdesc->flags))
 192                 rt2x00dev->ops->lib->kick_tx_queue(rt2x00dev, queue->qid);
 193 }
 194 EXPORT_SYMBOL_GPL(rt2x00queue_write_tx_descriptor);
 195
 196 int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb)
 197 {
 198         struct queue_entry *entry = rt2x00queue_get_entry(queue, Q_INDEX);
 199         struct txentry_desc txdesc;
 200
 201         if (unlikely(rt2x00queue_full(queue)))
 202                 return -EINVAL;
 203
 204         if (__test_and_set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags)) {
 205                 ERROR(queue->rt2x00dev,
 206                       "Arrived at non-free entry in the non-full queue %d.\n"
 207                       "Please file bug report to %s.\n",
 208                       queue->qid, DRV_PROJECT);
 209                 return -EINVAL;
 210         }
 211
 212         /*
 213          * Copy all TX descriptor information into txdesc,
 214          * after that we are free to use the skb->cb array
 215          * for our information.
 216          */
 217         entry->skb = skb;
 218         rt2x00queue_create_tx_descriptor(entry, &txdesc);
 219
 220         if (unlikely(queue->rt2x00dev->ops->lib->write_tx_data(entry))) {
 221                 __clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
 222                 return -EIO;
 223         }
 224
 225         __set_bit(ENTRY_DATA_PENDING, &entry->flags);
 226
 227         rt2x00queue_index_inc(queue, Q_INDEX);
 228         rt2x00queue_write_tx_descriptor(entry, &txdesc);
 229
 230         return 0;
 231 }
 232
 233 struct data_queue *rt2x00queue_get_queue(struct rt2x00_dev *rt2x00dev,
 234                                          const enum data_queue_qid queue)
 235 {
 236         int atim = test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags);
 237
 238         if (queue < rt2x00dev->ops->tx_queues && rt2x00dev->tx)
 239                 return &rt2x00dev->tx[queue];
 240
 241         if (!rt2x00dev->bcn)
 242                 return NULL;
 243
 244         if (queue == QID_BEACON)
 245                 return &rt2x00dev->bcn[0];
 246         else if (queue == QID_ATIM && atim)
 247                 return &rt2x00dev->bcn[1];
 248
 249         return NULL;
 250 }
 251 EXPORT_SYMBOL_GPL(rt2x00queue_get_queue);
 252
 253 struct queue_entry *rt2x00queue_get_entry(struct data_queue *queue,
 254                                           enum queue_index index)
 255 {
 256         struct queue_entry *entry;
 257         unsigned long irqflags;
 258
 259         if (unlikely(index >= Q_INDEX_MAX)) {
 260                 ERROR(queue->rt2x00dev,
 261                       "Entry requested from invalid index type (%d)\n", index);
 262                 return NULL;
 263         }
 264
 265         spin_lock_irqsave(&queue->lock, irqflags);
 266
 267         entry = &queue->entries[queue->index[index]];
 268
 269         spin_unlock_irqrestore(&queue->lock, irqflags);
 270
 271         return entry;
 272 }
 273 EXPORT_SYMBOL_GPL(rt2x00queue_get_entry);
 274
 275 void rt2x00queue_index_inc(struct data_queue *queue, enum queue_index index)
 276 {
 277         unsigned long irqflags;
 278
 279         if (unlikely(index >= Q_INDEX_MAX)) {
 280                 ERROR(queue->rt2x00dev,
 281                       "Index change on invalid index type (%d)\n", index);
 282                 return;
 283         }
 284
 285         spin_lock_irqsave(&queue->lock, irqflags);
 286
 287         queue->index[index]++;
 288         if (queue->index[index] >= queue->limit)
 289                 queue->index[index] = 0;
 290
 291         if (index == Q_INDEX) {
 292                 queue->length++;
 293         } else if (index == Q_INDEX_DONE) {
 294                 queue->length--;
 295                 queue->count ++;
 296         }
 297
 298         spin_unlock_irqrestore(&queue->lock, irqflags);
 299 }
 300 EXPORT_SYMBOL_GPL(rt2x00queue_index_inc);
 301
 302 static void rt2x00queue_reset(struct data_queue *queue)
 303 {
 304         unsigned long irqflags;
 305
 306         spin_lock_irqsave(&queue->lock, irqflags);
 307
 308         queue->count = 0;
 309         queue->length = 0;
 310         memset(queue->index, 0, sizeof(queue->index));
 311
 312         spin_unlock_irqrestore(&queue->lock, irqflags);
 313 }
 314
 315 void rt2x00queue_init_rx(struct rt2x00_dev *rt2x00dev)
 316 {
 317         struct data_queue *queue = rt2x00dev->rx;
 318         unsigned int i;
 319
 320         rt2x00queue_reset(queue);
 321
 322         if (!rt2x00dev->ops->lib->init_rxentry)
 323                 return;
 324
 325         for (i = 0; i < queue->limit; i++)
 326                 rt2x00dev->ops->lib->init_rxentry(rt2x00dev,
 327                                                   &queue->entries[i]);
 328 }
 329
 330 void rt2x00queue_init_tx(struct rt2x00_dev *rt2x00dev)
 331 {
 332         struct data_queue *queue;
 333         unsigned int i;
 334
 335         txall_queue_for_each(rt2x00dev, queue) {
 336                 rt2x00queue_reset(queue);
 337
 338                 if (!rt2x00dev->ops->lib->init_txentry)
 339                         continue;
 340
 341                 for (i = 0; i < queue->limit; i++)
 342                         rt2x00dev->ops->lib->init_txentry(rt2x00dev,
 343                                                           &queue->entries[i]);
 344         }
 345 }
 346
 347 static int rt2x00queue_alloc_entries(struct data_queue *queue,
 348                                      const struct data_queue_desc *qdesc)
 349 {
 350         struct queue_entry *entries;
 351         unsigned int entry_size;
 352         unsigned int i;
 353
 354         rt2x00queue_reset(queue);
 355
 356         queue->limit = qdesc->entry_num;
 357         queue->threshold = DIV_ROUND_UP(qdesc->entry_num, 10);
 358         queue->data_size = qdesc->data_size;
 359         queue->desc_size = qdesc->desc_size;
 360
 361         /*
 362          * Allocate all queue entries.
 363          */
 364         entry_size = sizeof(*entries) + qdesc->priv_size;
 365         entries = kzalloc(queue->limit * entry_size, GFP_KERNEL);
 366         if (!entries)
 367                 return -ENOMEM;
 368
 369 #define QUEUE_ENTRY_PRIV_OFFSET(__base, __index, __limit, __esize, __psize) \
 370         ( ((char *)(__base)) + ((__limit) * (__esize)) + \
 371             ((__index) * (__psize)) )
 372
 373         for (i = 0; i < queue->limit; i++) {
 374                 entries[i].flags = 0;
 375                 entries[i].queue = queue;
 376                 entries[i].skb = NULL;
 377                 entries[i].entry_idx = i;
 378                 entries[i].priv_data =
 379                     QUEUE_ENTRY_PRIV_OFFSET(entries, i, queue->limit,
 380                                             sizeof(*entries), qdesc->priv_size);
 381         }
 382
 383 #undef QUEUE_ENTRY_PRIV_OFFSET
 384
 385         queue->entries = entries;
 386
 387         return 0;
 388 }
 389
 390 int rt2x00queue_initialize(struct rt2x00_dev *rt2x00dev)
 391 {
 392         struct data_queue *queue;
 393         int status;
 394
 395
 396         status = rt2x00queue_alloc_entries(rt2x00dev->rx, rt2x00dev->ops->rx);
 397         if (status)
 398                 goto exit;
 399
 400         tx_queue_for_each(rt2x00dev, queue) {
 401                 status = rt2x00queue_alloc_entries(queue, rt2x00dev->ops->tx);
 402                 if (status)
 403                         goto exit;
 404         }
 405
 406         status = rt2x00queue_alloc_entries(rt2x00dev->bcn, rt2x00dev->ops->bcn);
 407         if (status)
 408                 goto exit;
 409
 410         if (!test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags))
 411                 return 0;
 412
 413         status = rt2x00queue_alloc_entries(&rt2x00dev->bcn[1],
 414                                            rt2x00dev->ops->atim);
 415         if (status)
 416                 goto exit;
 417
 418         return 0;
 419
 420 exit:
 421         ERROR(rt2x00dev, "Queue entries allocation failed.\n");
 422
 423         rt2x00queue_uninitialize(rt2x00dev);
 424
 425         return status;
 426 }
 427
 428 void rt2x00queue_uninitialize(struct rt2x00_dev *rt2x00dev)
 429 {
 430         struct data_queue *queue;
 431
 432         queue_for_each(rt2x00dev, queue) {
 433                 kfree(queue->entries);
 434                 queue->entries = NULL;
 435         }
 436 }
 437
 438 static void rt2x00queue_init(struct rt2x00_dev *rt2x00dev,
 439                              struct data_queue *queue, enum data_queue_qid qid)
 440 {
 441         spin_lock_init(&queue->lock);
 442
 443         queue->rt2x00dev = rt2x00dev;
 444         queue->qid = qid;
 445         queue->aifs = 2;
 446         queue->cw_min = 5;
 447         queue->cw_max = 10;
 448 }
 449
 450 int rt2x00queue_allocate(struct rt2x00_dev *rt2x00dev)
 451 {
 452         struct data_queue *queue;
 453         enum data_queue_qid qid;
 454         unsigned int req_atim =
 455             !!test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags);
 456
 457         /*
 458          * We need the following queues:
 459          * RX: 1
 460          * TX: ops->tx_queues
 461          * Beacon: 1
 462          * Atim: 1 (if required)
 463          */
 464         rt2x00dev->data_queues = 2 + rt2x00dev->ops->tx_queues + req_atim;
 465
 466         queue = kzalloc(rt2x00dev->data_queues * sizeof(*queue), GFP_KERNEL);
 467         if (!queue) {
 468                 ERROR(rt2x00dev, "Queue allocation failed.\n");
 469                 return -ENOMEM;
 470         }
 471
 472         /*
 473          * Initialize pointers
 474          */
 475         rt2x00dev->rx = queue;
 476         rt2x00dev->tx = &queue[1];
 477         rt2x00dev->bcn = &queue[1 + rt2x00dev->ops->tx_queues];
 478
 479         /*
 480          * Initialize queue parameters.
 481          * RX: qid = QID_RX
 482          * TX: qid = QID_AC_BE + index
 483          * TX: cw_min: 2^5 = 32.
 484          * TX: cw_max: 2^10 = 1024.
 485          * BCN: qid = QID_BEACON
 486          * ATIM: qid = QID_ATIM
 487          */
 488         rt2x00queue_init(rt2x00dev, rt2x00dev->rx, QID_RX);
 489
 490         qid = QID_AC_BE;
 491         tx_queue_for_each(rt2x00dev, queue)
 492                 rt2x00queue_init(rt2x00dev, queue, qid++);
 493
 494         rt2x00queue_init(rt2x00dev, &rt2x00dev->bcn[0], QID_BEACON);
 495         if (req_atim)
 496                 rt2x00queue_init(rt2x00dev, &rt2x00dev->bcn[1], QID_ATIM);
 497
 498         return 0;
 499 }
 500
 501 void rt2x00queue_free(struct rt2x00_dev *rt2x00dev)
 502 {
 503         kfree(rt2x00dev->rx);
 504         rt2x00dev->rx = NULL;
 505         rt2x00dev->tx = NULL;
 506         rt2x00dev->bcn = NULL;
 507 }