err.no Git - linux-2.6/blob - 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                                       struct ieee80211_tx_control *control)
  35 {
  36         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)entry->skb->data;
  37         struct ieee80211_rate *rate = control->tx_rate;
  38         const struct rt2x00_rate *hwrate;
  39         unsigned int data_length;
  40         unsigned int duration;
  41         unsigned int residual;
  42         u16 frame_control;
  43
  44         memset(txdesc, 0, sizeof(*txdesc));
  45
  46         /*
  47          * Initialize information from queue
  48          */
  49         txdesc->queue = entry->queue->qid;
  50         txdesc->cw_min = entry->queue->cw_min;
  51         txdesc->cw_max = entry->queue->cw_max;
  52         txdesc->aifs = entry->queue->aifs;
  53
  54         /* Data length should be extended with 4 bytes for CRC */
  55         data_length = entry->skb->len + 4;
  56
  57         /*
  58          * Read required fields from ieee80211 header.
  59          */
  60         frame_control = le16_to_cpu(hdr->frame_control);
  61
  62         /*
  63          * Check whether this frame is to be acked.
  64          */
  65         if (!(control->flags & IEEE80211_TXCTL_NO_ACK))
  66                 __set_bit(ENTRY_TXD_ACK, &txdesc->flags);
  67
  68         /*
  69          * Check if this is a RTS/CTS frame
  70          */
  71         if (is_rts_frame(frame_control) || is_cts_frame(frame_control)) {
  72                 __set_bit(ENTRY_TXD_BURST, &txdesc->flags);
  73                 if (is_rts_frame(frame_control)) {
  74                         __set_bit(ENTRY_TXD_RTS_FRAME, &txdesc->flags);
  75                         __set_bit(ENTRY_TXD_ACK, &txdesc->flags);
  76                 } else {
  77                         __set_bit(ENTRY_TXD_CTS_FRAME, &txdesc->flags);
  78                         __clear_bit(ENTRY_TXD_ACK, &txdesc->flags);
  79                 }
  80                 if (control->rts_cts_rate)
  81                         rate = control->rts_cts_rate;
  82         }
  83
  84         /*
  85          * Determine retry information.
  86          */
  87         txdesc->retry_limit = control->retry_limit;
  88         if (control->flags & IEEE80211_TXCTL_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 (control->flags & IEEE80211_TXCTL_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          * if this entry is a RTS of CTS-to-self frame we are done,
 180          * otherwise we need to kick the queue.
 181          */
 182         if (rt2x00dev->ops->lib->kick_tx_queue &&
 183             !(skbdesc->flags & FRAME_DESC_DRIVER_GENERATED))
 184                 rt2x00dev->ops->lib->kick_tx_queue(rt2x00dev,
 185                                                    entry->queue->qid);
 186 }
 187 EXPORT_SYMBOL_GPL(rt2x00queue_write_tx_descriptor);
 188
 189 struct data_queue *rt2x00queue_get_queue(struct rt2x00_dev *rt2x00dev,
 190                                          const enum data_queue_qid queue)
 191 {
 192         int atim = test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags);
 193
 194         if (queue < rt2x00dev->ops->tx_queues && rt2x00dev->tx)
 195                 return &rt2x00dev->tx[queue];
 196
 197         if (!rt2x00dev->bcn)
 198                 return NULL;
 199
 200         if (queue == QID_BEACON)
 201                 return &rt2x00dev->bcn[0];
 202         else if (queue == QID_ATIM && atim)
 203                 return &rt2x00dev->bcn[1];
 204
 205         return NULL;
 206 }
 207 EXPORT_SYMBOL_GPL(rt2x00queue_get_queue);
 208
 209 struct queue_entry *rt2x00queue_get_entry(struct data_queue *queue,
 210                                           enum queue_index index)
 211 {
 212         struct queue_entry *entry;
 213         unsigned long irqflags;
 214
 215         if (unlikely(index >= Q_INDEX_MAX)) {
 216                 ERROR(queue->rt2x00dev,
 217                       "Entry requested from invalid index type (%d)\n", index);
 218                 return NULL;
 219         }
 220
 221         spin_lock_irqsave(&queue->lock, irqflags);
 222
 223         entry = &queue->entries[queue->index[index]];
 224
 225         spin_unlock_irqrestore(&queue->lock, irqflags);
 226
 227         return entry;
 228 }
 229 EXPORT_SYMBOL_GPL(rt2x00queue_get_entry);
 230
 231 void rt2x00queue_index_inc(struct data_queue *queue, enum queue_index index)
 232 {
 233         unsigned long irqflags;
 234
 235         if (unlikely(index >= Q_INDEX_MAX)) {
 236                 ERROR(queue->rt2x00dev,
 237                       "Index change on invalid index type (%d)\n", index);
 238                 return;
 239         }
 240
 241         spin_lock_irqsave(&queue->lock, irqflags);
 242
 243         queue->index[index]++;
 244         if (queue->index[index] >= queue->limit)
 245                 queue->index[index] = 0;
 246
 247         if (index == Q_INDEX) {
 248                 queue->length++;
 249         } else if (index == Q_INDEX_DONE) {
 250                 queue->length--;
 251                 queue->count ++;
 252         }
 253
 254         spin_unlock_irqrestore(&queue->lock, irqflags);
 255 }
 256 EXPORT_SYMBOL_GPL(rt2x00queue_index_inc);
 257
 258 static void rt2x00queue_reset(struct data_queue *queue)
 259 {
 260         unsigned long irqflags;
 261
 262         spin_lock_irqsave(&queue->lock, irqflags);
 263
 264         queue->count = 0;
 265         queue->length = 0;
 266         memset(queue->index, 0, sizeof(queue->index));
 267
 268         spin_unlock_irqrestore(&queue->lock, irqflags);
 269 }
 270
 271 void rt2x00queue_init_rx(struct rt2x00_dev *rt2x00dev)
 272 {
 273         struct data_queue *queue = rt2x00dev->rx;
 274         unsigned int i;
 275
 276         rt2x00queue_reset(queue);
 277
 278         if (!rt2x00dev->ops->lib->init_rxentry)
 279                 return;
 280
 281         for (i = 0; i < queue->limit; i++)
 282                 rt2x00dev->ops->lib->init_rxentry(rt2x00dev,
 283                                                   &queue->entries[i]);
 284 }
 285
 286 void rt2x00queue_init_tx(struct rt2x00_dev *rt2x00dev)
 287 {
 288         struct data_queue *queue;
 289         unsigned int i;
 290
 291         txall_queue_for_each(rt2x00dev, queue) {
 292                 rt2x00queue_reset(queue);
 293
 294                 if (!rt2x00dev->ops->lib->init_txentry)
 295                         continue;
 296
 297                 for (i = 0; i < queue->limit; i++)
 298                         rt2x00dev->ops->lib->init_txentry(rt2x00dev,
 299                                                           &queue->entries[i]);
 300         }
 301 }
 302
 303 static int rt2x00queue_alloc_entries(struct data_queue *queue,
 304                                      const struct data_queue_desc *qdesc)
 305 {
 306         struct queue_entry *entries;
 307         unsigned int entry_size;
 308         unsigned int i;
 309
 310         rt2x00queue_reset(queue);
 311
 312         queue->limit = qdesc->entry_num;
 313         queue->data_size = qdesc->data_size;
 314         queue->desc_size = qdesc->desc_size;
 315
 316         /*
 317          * Allocate all queue entries.
 318          */
 319         entry_size = sizeof(*entries) + qdesc->priv_size;
 320         entries = kzalloc(queue->limit * entry_size, GFP_KERNEL);
 321         if (!entries)
 322                 return -ENOMEM;
 323
 324 #define QUEUE_ENTRY_PRIV_OFFSET(__base, __index, __limit, __esize, __psize) \
 325         ( ((char *)(__base)) + ((__limit) * (__esize)) + \
 326             ((__index) * (__psize)) )
 327
 328         for (i = 0; i < queue->limit; i++) {
 329                 entries[i].flags = 0;
 330                 entries[i].queue = queue;
 331                 entries[i].skb = NULL;
 332                 entries[i].entry_idx = i;
 333                 entries[i].priv_data =
 334                     QUEUE_ENTRY_PRIV_OFFSET(entries, i, queue->limit,
 335                                             sizeof(*entries), qdesc->priv_size);
 336         }
 337
 338 #undef QUEUE_ENTRY_PRIV_OFFSET
 339
 340         queue->entries = entries;
 341
 342         return 0;
 343 }
 344
 345 int rt2x00queue_initialize(struct rt2x00_dev *rt2x00dev)
 346 {
 347         struct data_queue *queue;
 348         int status;
 349
 350
 351         status = rt2x00queue_alloc_entries(rt2x00dev->rx, rt2x00dev->ops->rx);
 352         if (status)
 353                 goto exit;
 354
 355         tx_queue_for_each(rt2x00dev, queue) {
 356                 status = rt2x00queue_alloc_entries(queue, rt2x00dev->ops->tx);
 357                 if (status)
 358                         goto exit;
 359         }
 360
 361         status = rt2x00queue_alloc_entries(rt2x00dev->bcn, rt2x00dev->ops->bcn);
 362         if (status)
 363                 goto exit;
 364
 365         if (!test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags))
 366                 return 0;
 367
 368         status = rt2x00queue_alloc_entries(&rt2x00dev->bcn[1],
 369                                            rt2x00dev->ops->atim);
 370         if (status)
 371                 goto exit;
 372
 373         return 0;
 374
 375 exit:
 376         ERROR(rt2x00dev, "Queue entries allocation failed.\n");
 377
 378         rt2x00queue_uninitialize(rt2x00dev);
 379
 380         return status;
 381 }
 382
 383 void rt2x00queue_uninitialize(struct rt2x00_dev *rt2x00dev)
 384 {
 385         struct data_queue *queue;
 386
 387         queue_for_each(rt2x00dev, queue) {
 388                 kfree(queue->entries);
 389                 queue->entries = NULL;
 390         }
 391 }
 392
 393 static void rt2x00queue_init(struct rt2x00_dev *rt2x00dev,
 394                              struct data_queue *queue, enum data_queue_qid qid)
 395 {
 396         spin_lock_init(&queue->lock);
 397
 398         queue->rt2x00dev = rt2x00dev;
 399         queue->qid = qid;
 400         queue->aifs = 2;
 401         queue->cw_min = 5;
 402         queue->cw_max = 10;
 403 }
 404
 405 int rt2x00queue_allocate(struct rt2x00_dev *rt2x00dev)
 406 {
 407         struct data_queue *queue;
 408         enum data_queue_qid qid;
 409         unsigned int req_atim =
 410             !!test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags);
 411
 412         /*
 413          * We need the following queues:
 414          * RX: 1
 415          * TX: ops->tx_queues
 416          * Beacon: 1
 417          * Atim: 1 (if required)
 418          */
 419         rt2x00dev->data_queues = 2 + rt2x00dev->ops->tx_queues + req_atim;
 420
 421         queue = kzalloc(rt2x00dev->data_queues * sizeof(*queue), GFP_KERNEL);
 422         if (!queue) {
 423                 ERROR(rt2x00dev, "Queue allocation failed.\n");
 424                 return -ENOMEM;
 425         }
 426
 427         /*
 428          * Initialize pointers
 429          */
 430         rt2x00dev->rx = queue;
 431         rt2x00dev->tx = &queue[1];
 432         rt2x00dev->bcn = &queue[1 + rt2x00dev->ops->tx_queues];
 433
 434         /*
 435          * Initialize queue parameters.
 436          * RX: qid = QID_RX
 437          * TX: qid = QID_AC_BE + index
 438          * TX: cw_min: 2^5 = 32.
 439          * TX: cw_max: 2^10 = 1024.
 440          * BCN & Atim: qid = QID_MGMT
 441          */
 442         rt2x00queue_init(rt2x00dev, rt2x00dev->rx, QID_RX);
 443
 444         qid = QID_AC_BE;
 445         tx_queue_for_each(rt2x00dev, queue)
 446                 rt2x00queue_init(rt2x00dev, queue, qid++);
 447
 448         rt2x00queue_init(rt2x00dev, &rt2x00dev->bcn[0], QID_MGMT);
 449         if (req_atim)
 450                 rt2x00queue_init(rt2x00dev, &rt2x00dev->bcn[1], QID_MGMT);
 451
 452         return 0;
 453 }
 454
 455 void rt2x00queue_free(struct rt2x00_dev *rt2x00dev)
 456 {
 457         kfree(rt2x00dev->rx);
 458         rt2x00dev->rx = NULL;
 459         rt2x00dev->tx = NULL;
 460         rt2x00dev->bcn = NULL;
 461 }