drivers/net/wireless/rt2x00/rt2x00queue.c

   1 /*
   2         Copyright (C) 2010 Willow Garage <http://www.willowgarage.com>
   3         Copyright (C) 2004 - 2010 Ivo van Doorn <IvDoorn@gmail.com>
   4         Copyright (C) 2004 - 2009 Gertjan van Wingerde <gwingerde@gmail.com>
   5         <http://rt2x00.serialmonkey.com>
   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 as published by
   9         the Free Software Foundation; either version 2 of the License, or
  10         (at your option) any later version.
  11
  12         This program is distributed in the hope that it will be useful,
  13         but WITHOUT ANY WARRANTY; without even the implied warranty of
  14         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15         GNU General Public License for more details.
  16
  17         You should have received a copy of the GNU General Public License
  18         along with this program; if not, write to the
  19         Free Software Foundation, Inc.,
  20         59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  21  */
  22
  23 /*
  24         Module: rt2x00lib
  25         Abstract: rt2x00 queue specific routines.
  26  */
  27
  28 #include <linux/slab.h>
  29 #include <linux/kernel.h>
  30 #include <linux/module.h>
  31 #include <linux/dma-mapping.h>
  32
  33 #include "rt2x00.h"
  34 #include "rt2x00lib.h"
  35
  36 struct sk_buff *rt2x00queue_alloc_rxskb(struct queue_entry *entry)
  37 {
  38         struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
  39         struct sk_buff *skb;
  40         struct skb_frame_desc *skbdesc;
  41         unsigned int frame_size;
  42         unsigned int head_size = 0;
  43         unsigned int tail_size = 0;
  44
  45         /*
  46          * The frame size includes descriptor size, because the
  47          * hardware directly receive the frame into the skbuffer.
  48          */
  49         frame_size = entry->queue->data_size + entry->queue->desc_size;
  50
  51         /*
  52          * The payload should be aligned to a 4-byte boundary,
  53          * this means we need at least 3 bytes for moving the frame
  54          * into the correct offset.
  55          */
  56         head_size = 4;
  57
  58         /*
  59          * For IV/EIV/ICV assembly we must make sure there is
  60          * at least 8 bytes bytes available in headroom for IV/EIV
  61          * and 8 bytes for ICV data as tailroon.
  62          */
  63         if (test_bit(CAPABILITY_HW_CRYPTO, &rt2x00dev->cap_flags)) {
  64                 head_size += 8;
  65                 tail_size += 8;
  66         }
  67
  68         /*
  69          * Allocate skbuffer.
  70          */
  71         skb = dev_alloc_skb(frame_size + head_size + tail_size);
  72         if (!skb)
  73                 return NULL;
  74
  75         /*
  76          * Make sure we not have a frame with the requested bytes
  77          * available in the head and tail.
  78          */
  79         skb_reserve(skb, head_size);
  80         skb_put(skb, frame_size);
  81
  82         /*
  83          * Populate skbdesc.
  84          */
  85         skbdesc = get_skb_frame_desc(skb);
  86         memset(skbdesc, 0, sizeof(*skbdesc));
  87         skbdesc->entry = entry;
  88
  89         if (test_bit(REQUIRE_DMA, &rt2x00dev->cap_flags)) {
  90                 skbdesc->skb_dma = dma_map_single(rt2x00dev->dev,
  91                                                   skb->data,
  92                                                   skb->len,
  93                                                   DMA_FROM_DEVICE);
  94                 skbdesc->flags |= SKBDESC_DMA_MAPPED_RX;
  95         }
  96
  97         return skb;
  98 }
  99
 100 void rt2x00queue_map_txskb(struct queue_entry *entry)
 101 {
 102         struct device *dev = entry->queue->rt2x00dev->dev;
 103         struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
 104
 105         skbdesc->skb_dma =
 106             dma_map_single(dev, entry->skb->data, entry->skb->len, DMA_TO_DEVICE);
 107         skbdesc->flags |= SKBDESC_DMA_MAPPED_TX;
 108 }
 109 EXPORT_SYMBOL_GPL(rt2x00queue_map_txskb);
 110
 111 void rt2x00queue_unmap_skb(struct queue_entry *entry)
 112 {
 113         struct device *dev = entry->queue->rt2x00dev->dev;
 114         struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
 115
 116         if (skbdesc->flags & SKBDESC_DMA_MAPPED_RX) {
 117                 dma_unmap_single(dev, skbdesc->skb_dma, entry->skb->len,
 118                                  DMA_FROM_DEVICE);
 119                 skbdesc->flags &= ~SKBDESC_DMA_MAPPED_RX;
 120         } else if (skbdesc->flags & SKBDESC_DMA_MAPPED_TX) {
 121                 dma_unmap_single(dev, skbdesc->skb_dma, entry->skb->len,
 122                                  DMA_TO_DEVICE);
 123                 skbdesc->flags &= ~SKBDESC_DMA_MAPPED_TX;
 124         }
 125 }
 126 EXPORT_SYMBOL_GPL(rt2x00queue_unmap_skb);
 127
 128 void rt2x00queue_free_skb(struct queue_entry *entry)
 129 {
 130         if (!entry->skb)
 131                 return;
 132
 133         rt2x00queue_unmap_skb(entry);
 134         dev_kfree_skb_any(entry->skb);
 135         entry->skb = NULL;
 136 }
 137
 138 void rt2x00queue_align_frame(struct sk_buff *skb)
 139 {
 140         unsigned int frame_length = skb->len;
 141         unsigned int align = ALIGN_SIZE(skb, 0);
 142
 143         if (!align)
 144                 return;
 145
 146         skb_push(skb, align);
 147         memmove(skb->data, skb->data + align, frame_length);
 148         skb_trim(skb, frame_length);
 149 }
 150
 151 void rt2x00queue_insert_l2pad(struct sk_buff *skb, unsigned int header_length)
 152 {
 153         unsigned int payload_length = skb->len - header_length;
 154         unsigned int header_align = ALIGN_SIZE(skb, 0);
 155         unsigned int payload_align = ALIGN_SIZE(skb, header_length);
 156         unsigned int l2pad = payload_length ? L2PAD_SIZE(header_length) : 0;
 157
 158         /*
 159          * Adjust the header alignment if the payload needs to be moved more
 160          * than the header.
 161          */
 162         if (payload_align > header_align)
 163                 header_align += 4;
 164
 165         /* There is nothing to do if no alignment is needed */
 166         if (!header_align)
 167                 return;
 168
 169         /* Reserve the amount of space needed in front of the frame */
 170         skb_push(skb, header_align);
 171
 172         /*
 173          * Move the header.
 174          */
 175         memmove(skb->data, skb->data + header_align, header_length);
 176
 177         /* Move the payload, if present and if required */
 178         if (payload_length && payload_align)
 179                 memmove(skb->data + header_length + l2pad,
 180                         skb->data + header_length + l2pad + payload_align,
 181                         payload_length);
 182
 183         /* Trim the skb to the correct size */
 184         skb_trim(skb, header_length + l2pad + payload_length);
 185 }
 186
 187 void rt2x00queue_remove_l2pad(struct sk_buff *skb, unsigned int header_length)
 188 {
 189         /*
 190          * L2 padding is only present if the skb contains more than just the
 191          * IEEE 802.11 header.
 192          */
 193         unsigned int l2pad = (skb->len > header_length) ?
 194                                 L2PAD_SIZE(header_length) : 0;
 195
 196         if (!l2pad)
 197                 return;
 198
 199         memmove(skb->data + l2pad, skb->data, header_length);
 200         skb_pull(skb, l2pad);
 201 }
 202
 203 static void rt2x00queue_create_tx_descriptor_seq(struct queue_entry *entry,
 204                                                  struct txentry_desc *txdesc)
 205 {
 206         struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(entry->skb);
 207         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)entry->skb->data;
 208         struct rt2x00_intf *intf = vif_to_intf(tx_info->control.vif);
 209         unsigned long irqflags;
 210
 211         if (!(tx_info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ))
 212                 return;
 213
 214         __set_bit(ENTRY_TXD_GENERATE_SEQ, &txdesc->flags);
 215
 216         if (!test_bit(REQUIRE_SW_SEQNO, &entry->queue->rt2x00dev->cap_flags))
 217                 return;
 218
 219         /*
 220          * The hardware is not able to insert a sequence number. Assign a
 221          * software generated one here.
 222          *
 223          * This is wrong because beacons are not getting sequence
 224          * numbers assigned properly.
 225          *
 226          * A secondary problem exists for drivers that cannot toggle
 227          * sequence counting per-frame, since those will override the
 228          * sequence counter given by mac80211.
 229          */
 230         spin_lock_irqsave(&intf->seqlock, irqflags);
 231
 232         if (test_bit(ENTRY_TXD_FIRST_FRAGMENT, &txdesc->flags))
 233                 intf->seqno += 0x10;
 234         hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG);
 235         hdr->seq_ctrl |= cpu_to_le16(intf->seqno);
 236
 237         spin_unlock_irqrestore(&intf->seqlock, irqflags);
 238
 239 }
 240
 241 static void rt2x00queue_create_tx_descriptor_plcp(struct queue_entry *entry,
 242                                                   struct txentry_desc *txdesc,
 243                                                   const struct rt2x00_rate *hwrate)
 244 {
 245         struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
 246         struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(entry->skb);
 247         struct ieee80211_tx_rate *txrate = &tx_info->control.rates[0];
 248         unsigned int data_length;
 249         unsigned int duration;
 250         unsigned int residual;
 251
 252         /*
 253          * Determine with what IFS priority this frame should be send.
 254          * Set ifs to IFS_SIFS when the this is not the first fragment,
 255          * or this fragment came after RTS/CTS.
 256          */
 257         if (test_bit(ENTRY_TXD_FIRST_FRAGMENT, &txdesc->flags))
 258                 txdesc->u.plcp.ifs = IFS_BACKOFF;
 259         else
 260                 txdesc->u.plcp.ifs = IFS_SIFS;
 261
 262         /* Data length + CRC + Crypto overhead (IV/EIV/ICV/MIC) */
 263         data_length = entry->skb->len + 4;
 264         data_length += rt2x00crypto_tx_overhead(rt2x00dev, entry->skb);
 265
 266         /*
 267          * PLCP setup
 268          * Length calculation depends on OFDM/CCK rate.
 269          */
 270         txdesc->u.plcp.signal = hwrate->plcp;
 271         txdesc->u.plcp.service = 0x04;
 272
 273         if (hwrate->flags & DEV_RATE_OFDM) {
 274                 txdesc->u.plcp.length_high = (data_length >> 6) & 0x3f;
 275                 txdesc->u.plcp.length_low = data_length & 0x3f;
 276         } else {
 277                 /*
 278                  * Convert length to microseconds.
 279                  */
 280                 residual = GET_DURATION_RES(data_length, hwrate->bitrate);
 281                 duration = GET_DURATION(data_length, hwrate->bitrate);
 282
 283                 if (residual != 0) {
 284                         duration++;
 285
 286                         /*
 287                          * Check if we need to set the Length Extension
 288                          */
 289                         if (hwrate->bitrate == 110 && residual <= 30)
 290                                 txdesc->u.plcp.service |= 0x80;
 291                 }
 292
 293                 txdesc->u.plcp.length_high = (duration >> 8) & 0xff;
 294                 txdesc->u.plcp.length_low = duration & 0xff;
 295
 296                 /*
 297                  * When preamble is enabled we should set the
 298                  * preamble bit for the signal.
 299                  */
 300                 if (txrate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)
 301                         txdesc->u.plcp.signal |= 0x08;
 302         }
 303 }
 304
 305 static void rt2x00queue_create_tx_descriptor(struct queue_entry *entry,
 306                                              struct txentry_desc *txdesc)
 307 {
 308         struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
 309         struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(entry->skb);
 310         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)entry->skb->data;
 311         struct ieee80211_tx_rate *txrate = &tx_info->control.rates[0];
 312         struct ieee80211_rate *rate;
 313         const struct rt2x00_rate *hwrate = NULL;
 314
 315         memset(txdesc, 0, sizeof(*txdesc));
 316
 317         /*
 318          * Header and frame information.
 319          */
 320         txdesc->length = entry->skb->len;
 321         txdesc->header_length = ieee80211_get_hdrlen_from_skb(entry->skb);
 322
 323         /*
 324          * Check whether this frame is to be acked.
 325          */
 326         if (!(tx_info->flags & IEEE80211_TX_CTL_NO_ACK))
 327                 __set_bit(ENTRY_TXD_ACK, &txdesc->flags);
 328
 329         /*
 330          * Check if this is a RTS/CTS frame
 331          */
 332         if (ieee80211_is_rts(hdr->frame_control) ||
 333             ieee80211_is_cts(hdr->frame_control)) {
 334                 __set_bit(ENTRY_TXD_BURST, &txdesc->flags);
 335                 if (ieee80211_is_rts(hdr->frame_control))
 336                         __set_bit(ENTRY_TXD_RTS_FRAME, &txdesc->flags);
 337                 else
 338                         __set_bit(ENTRY_TXD_CTS_FRAME, &txdesc->flags);
 339                 if (tx_info->control.rts_cts_rate_idx >= 0)
 340                         rate =
 341                             ieee80211_get_rts_cts_rate(rt2x00dev->hw, tx_info);
 342         }
 343
 344         /*
 345          * Determine retry information.
 346          */
 347         txdesc->retry_limit = tx_info->control.rates[0].count - 1;
 348         if (txdesc->retry_limit >= rt2x00dev->long_retry)
 349                 __set_bit(ENTRY_TXD_RETRY_MODE, &txdesc->flags);
 350
 351         /*
 352          * Check if more fragments are pending
 353          */
 354         if (ieee80211_has_morefrags(hdr->frame_control)) {
 355                 __set_bit(ENTRY_TXD_BURST, &txdesc->flags);
 356                 __set_bit(ENTRY_TXD_MORE_FRAG, &txdesc->flags);
 357         }
 358
 359         /*
 360          * Check if more frames (!= fragments) are pending
 361          */
 362         if (tx_info->flags & IEEE80211_TX_CTL_MORE_FRAMES)
 363                 __set_bit(ENTRY_TXD_BURST, &txdesc->flags);
 364
 365         /*
 366          * Beacons and probe responses require the tsf timestamp
 367          * to be inserted into the frame.
 368          */
 369         if (ieee80211_is_beacon(hdr->frame_control) ||
 370             ieee80211_is_probe_resp(hdr->frame_control))
 371                 __set_bit(ENTRY_TXD_REQ_TIMESTAMP, &txdesc->flags);
 372
 373         if ((tx_info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT) &&
 374             !test_bit(ENTRY_TXD_RTS_FRAME, &txdesc->flags))
 375                 __set_bit(ENTRY_TXD_FIRST_FRAGMENT, &txdesc->flags);
 376
 377         /*
 378          * Determine rate modulation.
 379          */
 380         if (txrate->flags & IEEE80211_TX_RC_GREEN_FIELD)
 381                 txdesc->rate_mode = RATE_MODE_HT_GREENFIELD;
 382         else if (txrate->flags & IEEE80211_TX_RC_MCS)
 383                 txdesc->rate_mode = RATE_MODE_HT_MIX;
 384         else {
 385                 rate = ieee80211_get_tx_rate(rt2x00dev->hw, tx_info);
 386                 hwrate = rt2x00_get_rate(rate->hw_value);
 387                 if (hwrate->flags & DEV_RATE_OFDM)
 388                         txdesc->rate_mode = RATE_MODE_OFDM;
 389                 else
 390                         txdesc->rate_mode = RATE_MODE_CCK;
 391         }
 392
 393         /*
 394          * Apply TX descriptor handling by components
 395          */
 396         rt2x00crypto_create_tx_descriptor(entry, txdesc);
 397         rt2x00queue_create_tx_descriptor_seq(entry, txdesc);
 398
 399         if (test_bit(REQUIRE_HT_TX_DESC, &rt2x00dev->cap_flags))
 400                 rt2x00ht_create_tx_descriptor(entry, txdesc, hwrate);
 401         else
 402                 rt2x00queue_create_tx_descriptor_plcp(entry, txdesc, hwrate);
 403 }
 404
 405 static int rt2x00queue_write_tx_data(struct queue_entry *entry,
 406                                      struct txentry_desc *txdesc)
 407 {
 408         struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
 409
 410         /*
 411          * This should not happen, we already checked the entry
 412          * was ours. When the hardware disagrees there has been
 413          * a queue corruption!
 414          */
 415         if (unlikely(rt2x00dev->ops->lib->get_entry_state &&
 416                      rt2x00dev->ops->lib->get_entry_state(entry))) {
 417                 ERROR(rt2x00dev,
 418                       "Corrupt queue %d, accessing entry which is not ours.\n"
 419                       "Please file bug report to %s.\n",
 420                       entry->queue->qid, DRV_PROJECT);
 421                 return -EINVAL;
 422         }
 423
 424         /*
 425          * Add the requested extra tx headroom in front of the skb.
 426          */
 427         skb_push(entry->skb, rt2x00dev->ops->extra_tx_headroom);
 428         memset(entry->skb->data, 0, rt2x00dev->ops->extra_tx_headroom);
 429
 430         /*
 431          * Call the driver's write_tx_data function, if it exists.
 432          */
 433         if (rt2x00dev->ops->lib->write_tx_data)
 434                 rt2x00dev->ops->lib->write_tx_data(entry, txdesc);
 435
 436         /*
 437          * Map the skb to DMA.
 438          */
 439         if (test_bit(REQUIRE_DMA, &rt2x00dev->cap_flags))
 440                 rt2x00queue_map_txskb(entry);
 441
 442         return 0;
 443 }
 444
 445 static void rt2x00queue_write_tx_descriptor(struct queue_entry *entry,
 446                                             struct txentry_desc *txdesc)
 447 {
 448         struct data_queue *queue = entry->queue;
 449
 450         queue->rt2x00dev->ops->lib->write_tx_desc(entry, txdesc);
 451
 452         /*
 453          * All processing on the frame has been completed, this means
 454          * it is now ready to be dumped to userspace through debugfs.
 455          */
 456         rt2x00debug_dump_frame(queue->rt2x00dev, DUMP_FRAME_TX, entry->skb);
 457 }
 458
 459 static void rt2x00queue_kick_tx_queue(struct data_queue *queue,
 460                                       struct txentry_desc *txdesc)
 461 {
 462         /*
 463          * Check if we need to kick the queue, there are however a few rules
 464          *      1) Don't kick unless this is the last in frame in a burst.
 465          *         When the burst flag is set, this frame is always followed
 466          *         by another frame which in some way are related to eachother.
 467          *         This is true for fragments, RTS or CTS-to-self frames.
 468          *      2) Rule 1 can be broken when the available entries
 469          *         in the queue are less then a certain threshold.
 470          */
 471         if (rt2x00queue_threshold(queue) ||
 472             !test_bit(ENTRY_TXD_BURST, &txdesc->flags))
 473                 queue->rt2x00dev->ops->lib->kick_queue(queue);
 474 }
 475
 476 int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb,
 477                                bool local)
 478 {
 479         struct ieee80211_tx_info *tx_info;
 480         struct queue_entry *entry = rt2x00queue_get_entry(queue, Q_INDEX);
 481         struct txentry_desc txdesc;
 482         struct skb_frame_desc *skbdesc;
 483         u8 rate_idx, rate_flags;
 484
 485         if (unlikely(rt2x00queue_full(queue))) {
 486                 ERROR(queue->rt2x00dev,
 487                       "Dropping frame due to full tx queue %d.\n", queue->qid);
 488                 return -ENOBUFS;
 489         }
 490
 491         if (unlikely(test_and_set_bit(ENTRY_OWNER_DEVICE_DATA,
 492                                       &entry->flags))) {
 493                 ERROR(queue->rt2x00dev,
 494                       "Arrived at non-free entry in the non-full queue %d.\n"
 495                       "Please file bug report to %s.\n",
 496                       queue->qid, DRV_PROJECT);
 497                 return -EINVAL;
 498         }
 499
 500         /*
 501          * Copy all TX descriptor information into txdesc,
 502          * after that we are free to use the skb->cb array
 503          * for our information.
 504          */
 505         entry->skb = skb;
 506         rt2x00queue_create_tx_descriptor(entry, &txdesc);
 507
 508         /*
 509          * All information is retrieved from the skb->cb array,
 510          * now we should claim ownership of the driver part of that
 511          * array, preserving the bitrate index and flags.
 512          */
 513         tx_info = IEEE80211_SKB_CB(skb);
 514         rate_idx = tx_info->control.rates[0].idx;
 515         rate_flags = tx_info->control.rates[0].flags;
 516         skbdesc = get_skb_frame_desc(skb);
 517         memset(skbdesc, 0, sizeof(*skbdesc));
 518         skbdesc->entry = entry;
 519         skbdesc->tx_rate_idx = rate_idx;
 520         skbdesc->tx_rate_flags = rate_flags;
 521
 522         if (local)
 523                 skbdesc->flags |= SKBDESC_NOT_MAC80211;
 524
 525         /*
 526          * When hardware encryption is supported, and this frame
 527          * is to be encrypted, we should strip the IV/EIV data from
 528          * the frame so we can provide it to the driver separately.
 529          */
 530         if (test_bit(ENTRY_TXD_ENCRYPT, &txdesc.flags) &&
 531             !test_bit(ENTRY_TXD_ENCRYPT_IV, &txdesc.flags)) {
 532                 if (test_bit(REQUIRE_COPY_IV, &queue->rt2x00dev->cap_flags))
 533                         rt2x00crypto_tx_copy_iv(skb, &txdesc);
 534                 else
 535                         rt2x00crypto_tx_remove_iv(skb, &txdesc);
 536         }
 537
 538         /*
 539          * When DMA allocation is required we should guarentee to the
 540          * driver that the DMA is aligned to a 4-byte boundary.
 541          * However some drivers require L2 padding to pad the payload
 542          * rather then the header. This could be a requirement for
 543          * PCI and USB devices, while header alignment only is valid
 544          * for PCI devices.
 545          */
 546         if (test_bit(REQUIRE_L2PAD, &queue->rt2x00dev->cap_flags))
 547                 rt2x00queue_insert_l2pad(entry->skb, txdesc.header_length);
 548         else if (test_bit(REQUIRE_DMA, &queue->rt2x00dev->cap_flags))
 549                 rt2x00queue_align_frame(entry->skb);
 550
 551         /*
 552          * It could be possible that the queue was corrupted and this
 553          * call failed. Since we always return NETDEV_TX_OK to mac80211,
 554          * this frame will simply be dropped.
 555          */
 556         if (unlikely(rt2x00queue_write_tx_data(entry, &txdesc))) {
 557                 clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
 558                 entry->skb = NULL;
 559                 return -EIO;
 560         }
 561
 562         set_bit(ENTRY_DATA_PENDING, &entry->flags);
 563
 564         rt2x00queue_index_inc(entry, Q_INDEX);
 565         rt2x00queue_write_tx_descriptor(entry, &txdesc);
 566         rt2x00queue_kick_tx_queue(queue, &txdesc);
 567
 568         return 0;
 569 }
 570
 571 int rt2x00queue_clear_beacon(struct rt2x00_dev *rt2x00dev,
 572                              struct ieee80211_vif *vif)
 573 {
 574         struct rt2x00_intf *intf = vif_to_intf(vif);
 575
 576         if (unlikely(!intf->beacon))
 577                 return -ENOBUFS;
 578
 579         mutex_lock(&intf->beacon_skb_mutex);
 580
 581         /*
 582          * Clean up the beacon skb.
 583          */
 584         rt2x00queue_free_skb(intf->beacon);
 585
 586         /*
 587          * Clear beacon (single bssid devices don't need to clear the beacon
 588          * since the beacon queue will get stopped anyway).
 589          */
 590         if (rt2x00dev->ops->lib->clear_beacon)
 591                 rt2x00dev->ops->lib->clear_beacon(intf->beacon);
 592
 593         mutex_unlock(&intf->beacon_skb_mutex);
 594
 595         return 0;
 596 }
 597
 598 int rt2x00queue_update_beacon_locked(struct rt2x00_dev *rt2x00dev,
 599                                      struct ieee80211_vif *vif)
 600 {
 601         struct rt2x00_intf *intf = vif_to_intf(vif);
 602         struct skb_frame_desc *skbdesc;
 603         struct txentry_desc txdesc;
 604
 605         if (unlikely(!intf->beacon))
 606                 return -ENOBUFS;
 607
 608         /*
 609          * Clean up the beacon skb.
 610          */
 611         rt2x00queue_free_skb(intf->beacon);
 612
 613         intf->beacon->skb = ieee80211_beacon_get(rt2x00dev->hw, vif);
 614         if (!intf->beacon->skb)
 615                 return -ENOMEM;
 616
 617         /*
 618          * Copy all TX descriptor information into txdesc,
 619          * after that we are free to use the skb->cb array
 620          * for our information.
 621          */
 622         rt2x00queue_create_tx_descriptor(intf->beacon, &txdesc);
 623
 624         /*
 625          * Fill in skb descriptor
 626          */
 627         skbdesc = get_skb_frame_desc(intf->beacon->skb);
 628         memset(skbdesc, 0, sizeof(*skbdesc));
 629         skbdesc->entry = intf->beacon;
 630
 631         /*
 632          * Send beacon to hardware.
 633          */
 634         rt2x00dev->ops->lib->write_beacon(intf->beacon, &txdesc);
 635
 636         return 0;
 637
 638 }
 639
 640 int rt2x00queue_update_beacon(struct rt2x00_dev *rt2x00dev,
 641                               struct ieee80211_vif *vif)
 642 {
 643         struct rt2x00_intf *intf = vif_to_intf(vif);
 644         int ret;
 645
 646         mutex_lock(&intf->beacon_skb_mutex);
 647         ret = rt2x00queue_update_beacon_locked(rt2x00dev, vif);
 648         mutex_unlock(&intf->beacon_skb_mutex);
 649
 650         return ret;
 651 }
 652
 653 bool rt2x00queue_for_each_entry(struct data_queue *queue,
 654                                 enum queue_index start,
 655                                 enum queue_index end,
 656                                 void *data,
 657                                 bool (*fn)(struct queue_entry *entry,
 658                                            void *data))
 659 {
 660         unsigned long irqflags;
 661         unsigned int index_start;
 662         unsigned int index_end;
 663         unsigned int i;
 664
 665         if (unlikely(start >= Q_INDEX_MAX || end >= Q_INDEX_MAX)) {
 666                 ERROR(queue->rt2x00dev,
 667                       "Entry requested from invalid index range (%d - %d)\n",
 668                       start, end);
 669                 return true;
 670         }
 671
 672         /*
 673          * Only protect the range we are going to loop over,
 674          * if during our loop a extra entry is set to pending
 675          * it should not be kicked during this run, since it
 676          * is part of another TX operation.
 677          */
 678         spin_lock_irqsave(&queue->index_lock, irqflags);
 679         index_start = queue->index[start];
 680         index_end = queue->index[end];
 681         spin_unlock_irqrestore(&queue->index_lock, irqflags);
 682
 683         /*
 684          * Start from the TX done pointer, this guarentees that we will
 685          * send out all frames in the correct order.
 686          */
 687         if (index_start < index_end) {
 688                 for (i = index_start; i < index_end; i++) {
 689                         if (fn(&queue->entries[i], data))
 690                                 return true;
 691                 }
 692         } else {
 693                 for (i = index_start; i < queue->limit; i++) {
 694                         if (fn(&queue->entries[i], data))
 695                                 return true;
 696                 }
 697
 698                 for (i = 0; i < index_end; i++) {
 699                         if (fn(&queue->entries[i], data))
 700                                 return true;
 701                 }
 702         }
 703
 704         return false;
 705 }
 706 EXPORT_SYMBOL_GPL(rt2x00queue_for_each_entry);
 707
 708 struct queue_entry *rt2x00queue_get_entry(struct data_queue *queue,
 709                                           enum queue_index index)
 710 {
 711         struct queue_entry *entry;
 712         unsigned long irqflags;
 713
 714         if (unlikely(index >= Q_INDEX_MAX)) {
 715                 ERROR(queue->rt2x00dev,
 716                       "Entry requested from invalid index type (%d)\n", index);
 717                 return NULL;
 718         }
 719
 720         spin_lock_irqsave(&queue->index_lock, irqflags);
 721
 722         entry = &queue->entries[queue->index[index]];
 723
 724         spin_unlock_irqrestore(&queue->index_lock, irqflags);
 725
 726         return entry;
 727 }
 728 EXPORT_SYMBOL_GPL(rt2x00queue_get_entry);
 729
 730 void rt2x00queue_index_inc(struct queue_entry *entry, enum queue_index index)
 731 {
 732         struct data_queue *queue = entry->queue;
 733         unsigned long irqflags;
 734
 735         if (unlikely(index >= Q_INDEX_MAX)) {
 736                 ERROR(queue->rt2x00dev,
 737                       "Index change on invalid index type (%d)\n", index);
 738                 return;
 739         }
 740
 741         spin_lock_irqsave(&queue->index_lock, irqflags);
 742
 743         queue->index[index]++;
 744         if (queue->index[index] >= queue->limit)
 745                 queue->index[index] = 0;
 746
 747         entry->last_action = jiffies;
 748
 749         if (index == Q_INDEX) {
 750                 queue->length++;
 751         } else if (index == Q_INDEX_DONE) {
 752                 queue->length--;
 753                 queue->count++;
 754         }
 755
 756         spin_unlock_irqrestore(&queue->index_lock, irqflags);
 757 }
 758
 759 void rt2x00queue_pause_queue(struct data_queue *queue)
 760 {
 761         if (!test_bit(DEVICE_STATE_PRESENT, &queue->rt2x00dev->flags) ||
 762             !test_bit(QUEUE_STARTED, &queue->flags) ||
 763             test_and_set_bit(QUEUE_PAUSED, &queue->flags))
 764                 return;
 765
 766         switch (queue->qid) {
 767         case QID_AC_VO:
 768         case QID_AC_VI:
 769         case QID_AC_BE:
 770         case QID_AC_BK:
 771                 /*
 772                  * For TX queues, we have to disable the queue
 773                  * inside mac80211.
 774                  */
 775                 ieee80211_stop_queue(queue->rt2x00dev->hw, queue->qid);
 776                 break;
 777         default:
 778                 break;
 779         }
 780 }
 781 EXPORT_SYMBOL_GPL(rt2x00queue_pause_queue);
 782
 783 void rt2x00queue_unpause_queue(struct data_queue *queue)
 784 {
 785         if (!test_bit(DEVICE_STATE_PRESENT, &queue->rt2x00dev->flags) ||
 786             !test_bit(QUEUE_STARTED, &queue->flags) ||
 787             !test_and_clear_bit(QUEUE_PAUSED, &queue->flags))
 788                 return;
 789
 790         switch (queue->qid) {
 791         case QID_AC_VO:
 792         case QID_AC_VI:
 793         case QID_AC_BE:
 794         case QID_AC_BK:
 795                 /*
 796                  * For TX queues, we have to enable the queue
 797                  * inside mac80211.
 798                  */
 799                 ieee80211_wake_queue(queue->rt2x00dev->hw, queue->qid);
 800                 break;
 801         case QID_RX:
 802                 /*
 803                  * For RX we need to kick the queue now in order to
 804                  * receive frames.
 805                  */
 806                 queue->rt2x00dev->ops->lib->kick_queue(queue);
 807         default:
 808                 break;
 809         }
 810 }
 811 EXPORT_SYMBOL_GPL(rt2x00queue_unpause_queue);
 812
 813 void rt2x00queue_start_queue(struct data_queue *queue)
 814 {
 815         mutex_lock(&queue->status_lock);
 816
 817         if (!test_bit(DEVICE_STATE_PRESENT, &queue->rt2x00dev->flags) ||
 818             test_and_set_bit(QUEUE_STARTED, &queue->flags)) {
 819                 mutex_unlock(&queue->status_lock);
 820                 return;
 821         }
 822
 823         set_bit(QUEUE_PAUSED, &queue->flags);
 824
 825         queue->rt2x00dev->ops->lib->start_queue(queue);
 826
 827         rt2x00queue_unpause_queue(queue);
 828
 829         mutex_unlock(&queue->status_lock);
 830 }
 831 EXPORT_SYMBOL_GPL(rt2x00queue_start_queue);
 832
 833 void rt2x00queue_stop_queue(struct data_queue *queue)
 834 {
 835         mutex_lock(&queue->status_lock);
 836
 837         if (!test_and_clear_bit(QUEUE_STARTED, &queue->flags)) {
 838                 mutex_unlock(&queue->status_lock);
 839                 return;
 840         }
 841
 842         rt2x00queue_pause_queue(queue);
 843
 844         queue->rt2x00dev->ops->lib->stop_queue(queue);
 845
 846         mutex_unlock(&queue->status_lock);
 847 }
 848 EXPORT_SYMBOL_GPL(rt2x00queue_stop_queue);
 849
 850 void rt2x00queue_flush_queue(struct data_queue *queue, bool drop)
 851 {
 852         bool started;
 853         bool tx_queue =
 854                 (queue->qid == QID_AC_VO) ||
 855                 (queue->qid == QID_AC_VI) ||
 856                 (queue->qid == QID_AC_BE) ||
 857                 (queue->qid == QID_AC_BK);
 858
 859         mutex_lock(&queue->status_lock);
 860
 861         /*
 862          * If the queue has been started, we must stop it temporarily
 863          * to prevent any new frames to be queued on the device. If
 864          * we are not dropping the pending frames, the queue must
 865          * only be stopped in the software and not the hardware,
 866          * otherwise the queue will never become empty on its own.
 867          */
 868         started = test_bit(QUEUE_STARTED, &queue->flags);
 869         if (started) {
 870                 /*
 871                  * Pause the queue
 872                  */
 873                 rt2x00queue_pause_queue(queue);
 874
 875                 /*
 876                  * If we are not supposed to drop any pending
 877                  * frames, this means we must force a start (=kick)
 878                  * to the queue to make sure the hardware will
 879                  * start transmitting.
 880                  */
 881                 if (!drop && tx_queue)
 882                         queue->rt2x00dev->ops->lib->kick_queue(queue);
 883         }
 884
 885         /*
 886          * Check if driver supports flushing, if that is the case we can
 887          * defer the flushing to the driver. Otherwise we must use the
 888          * alternative which just waits for the queue to become empty.
 889          */
 890         if (likely(queue->rt2x00dev->ops->lib->flush_queue))
 891                 queue->rt2x00dev->ops->lib->flush_queue(queue, drop);
 892
 893         /*
 894          * The queue flush has failed...
 895          */
 896         if (unlikely(!rt2x00queue_empty(queue)))
 897                 WARNING(queue->rt2x00dev, "Queue %d failed to flush\n", queue->qid);
 898
 899         /*
 900          * Restore the queue to the previous status
 901          */
 902         if (started)
 903                 rt2x00queue_unpause_queue(queue);
 904
 905         mutex_unlock(&queue->status_lock);
 906 }
 907 EXPORT_SYMBOL_GPL(rt2x00queue_flush_queue);
 908
 909 void rt2x00queue_start_queues(struct rt2x00_dev *rt2x00dev)
 910 {
 911         struct data_queue *queue;
 912
 913         /*
 914          * rt2x00queue_start_queue will call ieee80211_wake_queue
 915          * for each queue after is has been properly initialized.
 916          */
 917         tx_queue_for_each(rt2x00dev, queue)
 918                 rt2x00queue_start_queue(queue);
 919
 920         rt2x00queue_start_queue(rt2x00dev->rx);
 921 }
 922 EXPORT_SYMBOL_GPL(rt2x00queue_start_queues);
 923
 924 void rt2x00queue_stop_queues(struct rt2x00_dev *rt2x00dev)
 925 {
 926         struct data_queue *queue;
 927
 928         /*
 929          * rt2x00queue_stop_queue will call ieee80211_stop_queue
 930          * as well, but we are completely shutting doing everything
 931          * now, so it is much safer to stop all TX queues at once,
 932          * and use rt2x00queue_stop_queue for cleaning up.
 933          */
 934         ieee80211_stop_queues(rt2x00dev->hw);
 935
 936         tx_queue_for_each(rt2x00dev, queue)
 937                 rt2x00queue_stop_queue(queue);
 938
 939         rt2x00queue_stop_queue(rt2x00dev->rx);
 940 }
 941 EXPORT_SYMBOL_GPL(rt2x00queue_stop_queues);
 942
 943 void rt2x00queue_flush_queues(struct rt2x00_dev *rt2x00dev, bool drop)
 944 {
 945         struct data_queue *queue;
 946
 947         tx_queue_for_each(rt2x00dev, queue)
 948                 rt2x00queue_flush_queue(queue, drop);
 949
 950         rt2x00queue_flush_queue(rt2x00dev->rx, drop);
 951 }
 952 EXPORT_SYMBOL_GPL(rt2x00queue_flush_queues);
 953
 954 static void rt2x00queue_reset(struct data_queue *queue)
 955 {
 956         unsigned long irqflags;
 957         unsigned int i;
 958
 959         spin_lock_irqsave(&queue->index_lock, irqflags);
 960
 961         queue->count = 0;
 962         queue->length = 0;
 963
 964         for (i = 0; i < Q_INDEX_MAX; i++)
 965                 queue->index[i] = 0;
 966
 967         spin_unlock_irqrestore(&queue->index_lock, irqflags);
 968 }
 969
 970 void rt2x00queue_init_queues(struct rt2x00_dev *rt2x00dev)
 971 {
 972         struct data_queue *queue;
 973         unsigned int i;
 974
 975         queue_for_each(rt2x00dev, queue) {
 976                 rt2x00queue_reset(queue);
 977
 978                 for (i = 0; i < queue->limit; i++)
 979                         rt2x00dev->ops->lib->clear_entry(&queue->entries[i]);
 980         }
 981 }
 982
 983 static int rt2x00queue_alloc_entries(struct data_queue *queue,
 984                                      const struct data_queue_desc *qdesc)
 985 {
 986         struct queue_entry *entries;
 987         unsigned int entry_size;
 988         unsigned int i;
 989
 990         rt2x00queue_reset(queue);
 991
 992         queue->limit = qdesc->entry_num;
 993         queue->threshold = DIV_ROUND_UP(qdesc->entry_num, 10);
 994         queue->data_size = qdesc->data_size;
 995         queue->desc_size = qdesc->desc_size;
 996
 997         /*
 998          * Allocate all queue entries.
 999          */
1000         entry_size = sizeof(*entries) + qdesc->priv_size;
1001         entries = kcalloc(queue->limit, entry_size, GFP_KERNEL);
1002         if (!entries)
1003                 return -ENOMEM;
1004
1005 #define QUEUE_ENTRY_PRIV_OFFSET(__base, __index, __limit, __esize, __psize) \
1006         (((char *)(__base)) + ((__limit) * (__esize)) + \
1007             ((__index) * (__psize)))
1008
1009         for (i = 0; i < queue->limit; i++) {
1010                 entries[i].flags = 0;
1011                 entries[i].queue = queue;
1012                 entries[i].skb = NULL;
1013                 entries[i].entry_idx = i;
1014                 entries[i].priv_data =
1015                     QUEUE_ENTRY_PRIV_OFFSET(entries, i, queue->limit,
1016                                             sizeof(*entries), qdesc->priv_size);
1017         }
1018
1019 #undef QUEUE_ENTRY_PRIV_OFFSET
1020
1021         queue->entries = entries;
1022
1023         return 0;
1024 }
1025
1026 static void rt2x00queue_free_skbs(struct data_queue *queue)
1027 {
1028         unsigned int i;
1029
1030         if (!queue->entries)
1031                 return;
1032
1033         for (i = 0; i < queue->limit; i++) {
1034                 rt2x00queue_free_skb(&queue->entries[i]);
1035         }
1036 }
1037
1038 static int rt2x00queue_alloc_rxskbs(struct data_queue *queue)
1039 {
1040         unsigned int i;
1041         struct sk_buff *skb;
1042
1043         for (i = 0; i < queue->limit; i++) {
1044                 skb = rt2x00queue_alloc_rxskb(&queue->entries[i]);
1045                 if (!skb)
1046                         return -ENOMEM;
1047                 queue->entries[i].skb = skb;
1048         }
1049
1050         return 0;
1051 }
1052
1053 int rt2x00queue_initialize(struct rt2x00_dev *rt2x00dev)
1054 {
1055         struct data_queue *queue;
1056         int status;
1057
1058         status = rt2x00queue_alloc_entries(rt2x00dev->rx, rt2x00dev->ops->rx);
1059         if (status)
1060                 goto exit;
1061
1062         tx_queue_for_each(rt2x00dev, queue) {
1063                 status = rt2x00queue_alloc_entries(queue, rt2x00dev->ops->tx);
1064                 if (status)
1065                         goto exit;
1066         }
1067
1068         status = rt2x00queue_alloc_entries(rt2x00dev->bcn, rt2x00dev->ops->bcn);
1069         if (status)
1070                 goto exit;
1071
1072         if (test_bit(REQUIRE_ATIM_QUEUE, &rt2x00dev->cap_flags)) {
1073                 status = rt2x00queue_alloc_entries(rt2x00dev->atim,
1074                                                    rt2x00dev->ops->atim);
1075                 if (status)
1076                         goto exit;
1077         }
1078
1079         status = rt2x00queue_alloc_rxskbs(rt2x00dev->rx);
1080         if (status)
1081                 goto exit;
1082
1083         return 0;
1084
1085 exit:
1086         ERROR(rt2x00dev, "Queue entries allocation failed.\n");
1087
1088         rt2x00queue_uninitialize(rt2x00dev);
1089
1090         return status;
1091 }
1092
1093 void rt2x00queue_uninitialize(struct rt2x00_dev *rt2x00dev)
1094 {
1095         struct data_queue *queue;
1096
1097         rt2x00queue_free_skbs(rt2x00dev->rx);
1098
1099         queue_for_each(rt2x00dev, queue) {
1100                 kfree(queue->entries);
1101                 queue->entries = NULL;
1102         }
1103 }
1104
1105 static void rt2x00queue_init(struct rt2x00_dev *rt2x00dev,
1106                              struct data_queue *queue, enum data_queue_qid qid)
1107 {
1108         mutex_init(&queue->status_lock);
1109         spin_lock_init(&queue->index_lock);
1110
1111         queue->rt2x00dev = rt2x00dev;
1112         queue->qid = qid;
1113         queue->txop = 0;
1114         queue->aifs = 2;
1115         queue->cw_min = 5;
1116         queue->cw_max = 10;
1117 }
1118
1119 int rt2x00queue_allocate(struct rt2x00_dev *rt2x00dev)
1120 {
1121         struct data_queue *queue;
1122         enum data_queue_qid qid;
1123         unsigned int req_atim =
1124             !!test_bit(REQUIRE_ATIM_QUEUE, &rt2x00dev->cap_flags);
1125
1126         /*
1127          * We need the following queues:
1128          * RX: 1
1129          * TX: ops->tx_queues
1130          * Beacon: 1
1131          * Atim: 1 (if required)
1132          */
1133         rt2x00dev->data_queues = 2 + rt2x00dev->ops->tx_queues + req_atim;
1134
1135         queue = kcalloc(rt2x00dev->data_queues, sizeof(*queue), GFP_KERNEL);
1136         if (!queue) {
1137                 ERROR(rt2x00dev, "Queue allocation failed.\n");
1138                 return -ENOMEM;
1139         }
1140
1141         /*
1142          * Initialize pointers
1143          */
1144         rt2x00dev->rx = queue;
1145         rt2x00dev->tx = &queue[1];
1146         rt2x00dev->bcn = &queue[1 + rt2x00dev->ops->tx_queues];
1147         rt2x00dev->atim = req_atim ? &queue[2 + rt2x00dev->ops->tx_queues] : NULL;
1148
1149         /*
1150          * Initialize queue parameters.
1151          * RX: qid = QID_RX
1152          * TX: qid = QID_AC_VO + index
1153          * TX: cw_min: 2^5 = 32.
1154          * TX: cw_max: 2^10 = 1024.
1155          * BCN: qid = QID_BEACON
1156          * ATIM: qid = QID_ATIM
1157          */
1158         rt2x00queue_init(rt2x00dev, rt2x00dev->rx, QID_RX);
1159
1160         qid = QID_AC_VO;
1161         tx_queue_for_each(rt2x00dev, queue)
1162                 rt2x00queue_init(rt2x00dev, queue, qid++);
1163
1164         rt2x00queue_init(rt2x00dev, rt2x00dev->bcn, QID_BEACON);
1165         if (req_atim)
1166                 rt2x00queue_init(rt2x00dev, rt2x00dev->atim, QID_ATIM);
1167
1168         return 0;
1169 }
1170
1171 void rt2x00queue_free(struct rt2x00_dev *rt2x00dev)
1172 {
1173         kfree(rt2x00dev->rx);
1174         rt2x00dev->rx = NULL;
1175         rt2x00dev->tx = NULL;
1176         rt2x00dev->bcn = NULL;
1177 }