drivers/net/wireless/rt2x00/rt2x00queue.h

   1 /*
   2         Copyright (C) 2004 - 2009 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: rt2x00
  23         Abstract: rt2x00 queue datastructures and routines
  24  */
  25
  26 #ifndef RT2X00QUEUE_H
  27 #define RT2X00QUEUE_H
  28
  29 #include <linux/prefetch.h>
  30
  31 /**
  32  * DOC: Entry frame size
  33  *
  34  * Ralink PCI devices demand the Frame size to be a multiple of 128 bytes,
  35  * for USB devices this restriction does not apply, but the value of
  36  * 2432 makes sense since it is big enough to contain the maximum fragment
  37  * size according to the ieee802.11 specs.
  38  * The aggregation size depends on support from the driver, but should
  39  * be something around 3840 bytes.
  40  */
  41 #define DATA_FRAME_SIZE         2432
  42 #define MGMT_FRAME_SIZE         256
  43 #define AGGREGATION_SIZE        3840
  44
  45 /**
  46  * DOC: Number of entries per queue
  47  *
  48  * Under normal load without fragmentation, 12 entries are sufficient
  49  * without the queue being filled up to the maximum. When using fragmentation
  50  * and the queue threshold code, we need to add some additional margins to
  51  * make sure the queue will never (or only under extreme load) fill up
  52  * completely.
  53  * Since we don't use preallocated DMA, having a large number of queue entries
  54  * will have minimal impact on the memory requirements for the queue.
  55  */
  56 #define RX_ENTRIES      24
  57 #define TX_ENTRIES      24
  58 #define BEACON_ENTRIES  1
  59 #define ATIM_ENTRIES    8
  60
  61 /**
  62  * enum data_queue_qid: Queue identification
  63  *
  64  * @QID_AC_BE: AC BE queue
  65  * @QID_AC_BK: AC BK queue
  66  * @QID_AC_VI: AC VI queue
  67  * @QID_AC_VO: AC VO queue
  68  * @QID_HCCA: HCCA queue
  69  * @QID_MGMT: MGMT queue (prio queue)
  70  * @QID_RX: RX queue
  71  * @QID_OTHER: None of the above (don't use, only present for completeness)
  72  * @QID_BEACON: Beacon queue (value unspecified, don't send it to device)
  73  * @QID_ATIM: Atim queue (value unspeficied, don't send it to device)
  74  */
  75 enum data_queue_qid {
  76         QID_AC_BE = 0,
  77         QID_AC_BK = 1,
  78         QID_AC_VI = 2,
  79         QID_AC_VO = 3,
  80         QID_HCCA = 4,
  81         QID_MGMT = 13,
  82         QID_RX = 14,
  83         QID_OTHER = 15,
  84         QID_BEACON,
  85         QID_ATIM,
  86 };
  87
  88 /**
  89  * enum skb_frame_desc_flags: Flags for &struct skb_frame_desc
  90  *
  91  * @SKBDESC_DMA_MAPPED_RX: &skb_dma field has been mapped for RX
  92  * @SKBDESC_DMA_MAPPED_TX: &skb_dma field has been mapped for TX
  93  * @SKBDESC_IV_STRIPPED: Frame contained a IV/EIV provided by
  94  *      mac80211 but was stripped for processing by the driver.
  95  * @SKBDESC_L2_PADDED: Payload has been padded for 4-byte alignment,
  96  *      the padded bytes are located between header and payload.
  97  */
  98 enum skb_frame_desc_flags {
  99         SKBDESC_DMA_MAPPED_RX = 1 << 0,
 100         SKBDESC_DMA_MAPPED_TX = 1 << 1,
 101         SKBDESC_IV_STRIPPED = 1 << 2,
 102         SKBDESC_L2_PADDED = 1 << 3
 103 };
 104
 105 /**
 106  * struct skb_frame_desc: Descriptor information for the skb buffer
 107  *
 108  * This structure is placed over the driver_data array, this means that
 109  * this structure should not exceed the size of that array (40 bytes).
 110  *
 111  * @flags: Frame flags, see &enum skb_frame_desc_flags.
 112  * @desc_len: Length of the frame descriptor.
 113  * @tx_rate_idx: the index of the TX rate, used for TX status reporting
 114  * @tx_rate_flags: the TX rate flags, used for TX status reporting
 115  * @desc: Pointer to descriptor part of the frame.
 116  *      Note that this pointer could point to something outside
 117  *      of the scope of the skb->data pointer.
 118  * @iv: IV/EIV data used during encryption/decryption.
 119  * @skb_dma: (PCI-only) the DMA address associated with the sk buffer.
 120  * @entry: The entry to which this sk buffer belongs.
 121  */
 122 struct skb_frame_desc {
 123         u8 flags;
 124
 125         u8 desc_len;
 126         u8 tx_rate_idx;
 127         u8 tx_rate_flags;
 128
 129         void *desc;
 130
 131         __le32 iv[2];
 132
 133         dma_addr_t skb_dma;
 134
 135         struct queue_entry *entry;
 136 };
 137
 138 /**
 139  * get_skb_frame_desc - Obtain the rt2x00 frame descriptor from a sk_buff.
 140  * @skb: &struct sk_buff from where we obtain the &struct skb_frame_desc
 141  */
 142 static inline struct skb_frame_desc* get_skb_frame_desc(struct sk_buff *skb)
 143 {
 144         BUILD_BUG_ON(sizeof(struct skb_frame_desc) >
 145                      IEEE80211_TX_INFO_DRIVER_DATA_SIZE);
 146         return (struct skb_frame_desc *)&IEEE80211_SKB_CB(skb)->driver_data;
 147 }
 148
 149 /**
 150  * enum rxdone_entry_desc_flags: Flags for &struct rxdone_entry_desc
 151  *
 152  * @RXDONE_SIGNAL_PLCP: Signal field contains the plcp value.
 153  * @RXDONE_SIGNAL_BITRATE: Signal field contains the bitrate value.
 154  * @RXDONE_SIGNAL_MCS: Signal field contains the mcs value.
 155  * @RXDONE_MY_BSS: Does this frame originate from device's BSS.
 156  * @RXDONE_CRYPTO_IV: Driver provided IV/EIV data.
 157  * @RXDONE_CRYPTO_ICV: Driver provided ICV data.
 158  * @RXDONE_L2PAD: 802.11 payload has been padded to 4-byte boundary.
 159  */
 160 enum rxdone_entry_desc_flags {
 161         RXDONE_SIGNAL_PLCP = BIT(0),
 162         RXDONE_SIGNAL_BITRATE = BIT(1),
 163         RXDONE_SIGNAL_MCS = BIT(2),
 164         RXDONE_MY_BSS = BIT(3),
 165         RXDONE_CRYPTO_IV = BIT(4),
 166         RXDONE_CRYPTO_ICV = BIT(5),
 167         RXDONE_L2PAD = BIT(6),
 168 };
 169
 170 /**
 171  * RXDONE_SIGNAL_MASK - Define to mask off all &rxdone_entry_desc_flags flags
 172  * except for the RXDONE_SIGNAL_* flags. This is useful to convert the dev_flags
 173  * from &rxdone_entry_desc to a signal value type.
 174  */
 175 #define RXDONE_SIGNAL_MASK \
 176         ( RXDONE_SIGNAL_PLCP | RXDONE_SIGNAL_BITRATE | RXDONE_SIGNAL_MCS )
 177
 178 /**
 179  * struct rxdone_entry_desc: RX Entry descriptor
 180  *
 181  * Summary of information that has been read from the RX frame descriptor.
 182  *
 183  * @timestamp: RX Timestamp
 184  * @signal: Signal of the received frame.
 185  * @rssi: RSSI of the received frame.
 186  * @noise: Measured noise during frame reception.
 187  * @size: Data size of the received frame.
 188  * @flags: MAC80211 receive flags (See &enum mac80211_rx_flags).
 189  * @dev_flags: Ralink receive flags (See &enum rxdone_entry_desc_flags).
 190  * @rate_mode: Rate mode (See @enum rate_modulation).
 191  * @cipher: Cipher type used during decryption.
 192  * @cipher_status: Decryption status.
 193  * @iv: IV/EIV data used during decryption.
 194  * @icv: ICV data used during decryption.
 195  */
 196 struct rxdone_entry_desc {
 197         u64 timestamp;
 198         int signal;
 199         int rssi;
 200         int noise;
 201         int size;
 202         int flags;
 203         int dev_flags;
 204         u16 rate_mode;
 205         u8 cipher;
 206         u8 cipher_status;
 207
 208         __le32 iv[2];
 209         __le32 icv;
 210 };
 211
 212 /**
 213  * enum txdone_entry_desc_flags: Flags for &struct txdone_entry_desc
 214  *
 215  * @TXDONE_UNKNOWN: Hardware could not determine success of transmission.
 216  * @TXDONE_SUCCESS: Frame was successfully send
 217  * @TXDONE_FALLBACK: Frame was successfully send using a fallback rate.
 218  * @TXDONE_FAILURE: Frame was not successfully send
 219  * @TXDONE_EXCESSIVE_RETRY: In addition to &TXDONE_FAILURE, the
 220  *      frame transmission failed due to excessive retries.
 221  */
 222 enum txdone_entry_desc_flags {
 223         TXDONE_UNKNOWN,
 224         TXDONE_SUCCESS,
 225         TXDONE_FALLBACK,
 226         TXDONE_FAILURE,
 227         TXDONE_EXCESSIVE_RETRY,
 228 };
 229
 230 /**
 231  * struct txdone_entry_desc: TX done entry descriptor
 232  *
 233  * Summary of information that has been read from the TX frame descriptor
 234  * after the device is done with transmission.
 235  *
 236  * @flags: TX done flags (See &enum txdone_entry_desc_flags).
 237  * @retry: Retry count.
 238  */
 239 struct txdone_entry_desc {
 240         unsigned long flags;
 241         int retry;
 242 };
 243
 244 /**
 245  * enum txentry_desc_flags: Status flags for TX entry descriptor
 246  *
 247  * @ENTRY_TXD_RTS_FRAME: This frame is a RTS frame.
 248  * @ENTRY_TXD_CTS_FRAME: This frame is a CTS-to-self frame.
 249  * @ENTRY_TXD_GENERATE_SEQ: This frame requires sequence counter.
 250  * @ENTRY_TXD_FIRST_FRAGMENT: This is the first frame.
 251  * @ENTRY_TXD_MORE_FRAG: This frame is followed by another fragment.
 252  * @ENTRY_TXD_REQ_TIMESTAMP: Require timestamp to be inserted.
 253  * @ENTRY_TXD_BURST: This frame belongs to the same burst event.
 254  * @ENTRY_TXD_ACK: An ACK is required for this frame.
 255  * @ENTRY_TXD_RETRY_MODE: When set, the long retry count is used.
 256  * @ENTRY_TXD_ENCRYPT: This frame should be encrypted.
 257  * @ENTRY_TXD_ENCRYPT_PAIRWISE: Use pairwise key table (instead of shared).
 258  * @ENTRY_TXD_ENCRYPT_IV: Generate IV/EIV in hardware.
 259  * @ENTRY_TXD_ENCRYPT_MMIC: Generate MIC in hardware.
 260  * @ENTRY_TXD_HT_AMPDU: This frame is part of an AMPDU.
 261  * @ENTRY_TXD_HT_BW_40: Use 40MHz Bandwidth.
 262  * @ENTRY_TXD_HT_SHORT_GI: Use short GI.
 263  */
 264 enum txentry_desc_flags {
 265         ENTRY_TXD_RTS_FRAME,
 266         ENTRY_TXD_CTS_FRAME,
 267         ENTRY_TXD_GENERATE_SEQ,
 268         ENTRY_TXD_FIRST_FRAGMENT,
 269         ENTRY_TXD_MORE_FRAG,
 270         ENTRY_TXD_REQ_TIMESTAMP,
 271         ENTRY_TXD_BURST,
 272         ENTRY_TXD_ACK,
 273         ENTRY_TXD_RETRY_MODE,
 274         ENTRY_TXD_ENCRYPT,
 275         ENTRY_TXD_ENCRYPT_PAIRWISE,
 276         ENTRY_TXD_ENCRYPT_IV,
 277         ENTRY_TXD_ENCRYPT_MMIC,
 278         ENTRY_TXD_HT_AMPDU,
 279         ENTRY_TXD_HT_BW_40,
 280         ENTRY_TXD_HT_SHORT_GI,
 281 };
 282
 283 /**
 284  * struct txentry_desc: TX Entry descriptor
 285  *
 286  * Summary of information for the frame descriptor before sending a TX frame.
 287  *
 288  * @flags: Descriptor flags (See &enum queue_entry_flags).
 289  * @queue: Queue identification (See &enum data_queue_qid).
 290  * @header_length: Length of 802.11 header.
 291  * @l2pad: Amount of padding to align 802.11 payload to 4-byte boundrary.
 292  * @length_high: PLCP length high word.
 293  * @length_low: PLCP length low word.
 294  * @signal: PLCP signal.
 295  * @service: PLCP service.
 296  * @msc: MCS.
 297  * @stbc: STBC.
 298  * @ba_size: BA size.
 299  * @rate_mode: Rate mode (See @enum rate_modulation).
 300  * @mpdu_density: MDPU density.
 301  * @retry_limit: Max number of retries.
 302  * @aifs: AIFS value.
 303  * @ifs: IFS value.
 304  * @cw_min: cwmin value.
 305  * @cw_max: cwmax value.
 306  * @cipher: Cipher type used for encryption.
 307  * @key_idx: Key index used for encryption.
 308  * @iv_offset: Position where IV should be inserted by hardware.
 309  * @iv_len: Length of IV data.
 310  */
 311 struct txentry_desc {
 312         unsigned long flags;
 313
 314         enum data_queue_qid queue;
 315
 316         u16 header_length;
 317         u16 l2pad;
 318
 319         u16 length_high;
 320         u16 length_low;
 321         u16 signal;
 322         u16 service;
 323
 324         u16 mcs;
 325         u16 stbc;
 326         u16 ba_size;
 327         u16 rate_mode;
 328         u16 mpdu_density;
 329
 330         short retry_limit;
 331         short aifs;
 332         short ifs;
 333         short cw_min;
 334         short cw_max;
 335
 336         enum cipher cipher;
 337         u16 key_idx;
 338         u16 iv_offset;
 339         u16 iv_len;
 340 };
 341
 342 /**
 343  * enum queue_entry_flags: Status flags for queue entry
 344  *
 345  * @ENTRY_BCN_ASSIGNED: This entry has been assigned to an interface.
 346  *      As long as this bit is set, this entry may only be touched
 347  *      through the interface structure.
 348  * @ENTRY_OWNER_DEVICE_DATA: This entry is owned by the device for data
 349  *      transfer (either TX or RX depending on the queue). The entry should
 350  *      only be touched after the device has signaled it is done with it.
 351  * @ENTRY_OWNER_DEVICE_CRYPTO: This entry is owned by the device for data
 352  *      encryption or decryption. The entry should only be touched after
 353  *      the device has signaled it is done with it.
 354  * @ENTRY_DATA_PENDING: This entry contains a valid frame and is waiting
 355  *      for the signal to start sending.
 356  */
 357 enum queue_entry_flags {
 358         ENTRY_BCN_ASSIGNED,
 359         ENTRY_OWNER_DEVICE_DATA,
 360         ENTRY_OWNER_DEVICE_CRYPTO,
 361         ENTRY_DATA_PENDING,
 362 };
 363
 364 /**
 365  * struct queue_entry: Entry inside the &struct data_queue
 366  *
 367  * @flags: Entry flags, see &enum queue_entry_flags.
 368  * @queue: The data queue (&struct data_queue) to which this entry belongs.
 369  * @skb: The buffer which is currently being transmitted (for TX queue),
 370  *      or used to directly recieve data in (for RX queue).
 371  * @entry_idx: The entry index number.
 372  * @priv_data: Private data belonging to this queue entry. The pointer
 373  *      points to data specific to a particular driver and queue type.
 374  */
 375 struct queue_entry {
 376         unsigned long flags;
 377
 378         struct data_queue *queue;
 379
 380         struct sk_buff *skb;
 381
 382         unsigned int entry_idx;
 383
 384         void *priv_data;
 385 };
 386
 387 /**
 388  * enum queue_index: Queue index type
 389  *
 390  * @Q_INDEX: Index pointer to the current entry in the queue, if this entry is
 391  *      owned by the hardware then the queue is considered to be full.
 392  * @Q_INDEX_DONE: Index pointer to the next entry which will be completed by
 393  *      the hardware and for which we need to run the txdone handler. If this
 394  *      entry is not owned by the hardware the queue is considered to be empty.
 395  * @Q_INDEX_CRYPTO: Index pointer to the next entry which encryption/decription
 396  *      will be completed by the hardware next.
 397  * @Q_INDEX_MAX: Keep last, used in &struct data_queue to determine the size
 398  *      of the index array.
 399  */
 400 enum queue_index {
 401         Q_INDEX,
 402         Q_INDEX_DONE,
 403         Q_INDEX_CRYPTO,
 404         Q_INDEX_MAX,
 405 };
 406
 407 /**
 408  * struct data_queue: Data queue
 409  *
 410  * @rt2x00dev: Pointer to main &struct rt2x00dev where this queue belongs to.
 411  * @entries: Base address of the &struct queue_entry which are
 412  *      part of this queue.
 413  * @qid: The queue identification, see &enum data_queue_qid.
 414  * @lock: Spinlock to protect index handling. Whenever @index, @index_done or
 415  *      @index_crypt needs to be changed this lock should be grabbed to prevent
 416  *      index corruption due to concurrency.
 417  * @count: Number of frames handled in the queue.
 418  * @limit: Maximum number of entries in the queue.
 419  * @threshold: Minimum number of free entries before queue is kicked by force.
 420  * @length: Number of frames in queue.
 421  * @index: Index pointers to entry positions in the queue,
 422  *      use &enum queue_index to get a specific index field.
 423  * @txop: maximum burst time.
 424  * @aifs: The aifs value for outgoing frames (field ignored in RX queue).
 425  * @cw_min: The cw min value for outgoing frames (field ignored in RX queue).
 426  * @cw_max: The cw max value for outgoing frames (field ignored in RX queue).
 427  * @data_size: Maximum data size for the frames in this queue.
 428  * @desc_size: Hardware descriptor size for the data in this queue.
 429  * @usb_endpoint: Device endpoint used for communication (USB only)
 430  * @usb_maxpacket: Max packet size for given endpoint (USB only)
 431  */
 432 struct data_queue {
 433         struct rt2x00_dev *rt2x00dev;
 434         struct queue_entry *entries;
 435
 436         enum data_queue_qid qid;
 437
 438         spinlock_t lock;
 439         unsigned int count;
 440         unsigned short limit;
 441         unsigned short threshold;
 442         unsigned short length;
 443         unsigned short index[Q_INDEX_MAX];
 444
 445         unsigned short txop;
 446         unsigned short aifs;
 447         unsigned short cw_min;
 448         unsigned short cw_max;
 449
 450         unsigned short data_size;
 451         unsigned short desc_size;
 452
 453         unsigned short usb_endpoint;
 454         unsigned short usb_maxpacket;
 455 };
 456
 457 /**
 458  * struct data_queue_desc: Data queue description
 459  *
 460  * The information in this structure is used by drivers
 461  * to inform rt2x00lib about the creation of the data queue.
 462  *
 463  * @entry_num: Maximum number of entries for a queue.
 464  * @data_size: Maximum data size for the frames in this queue.
 465  * @desc_size: Hardware descriptor size for the data in this queue.
 466  * @priv_size: Size of per-queue_entry private data.
 467  */
 468 struct data_queue_desc {
 469         unsigned short entry_num;
 470         unsigned short data_size;
 471         unsigned short desc_size;
 472         unsigned short priv_size;
 473 };
 474
 475 /**
 476  * queue_end - Return pointer to the last queue (HELPER MACRO).
 477  * @__dev: Pointer to &struct rt2x00_dev
 478  *
 479  * Using the base rx pointer and the maximum number of available queues,
 480  * this macro will return the address of 1 position beyond  the end of the
 481  * queues array.
 482  */
 483 #define queue_end(__dev) \
 484         &(__dev)->rx[(__dev)->data_queues]
 485
 486 /**
 487  * tx_queue_end - Return pointer to the last TX queue (HELPER MACRO).
 488  * @__dev: Pointer to &struct rt2x00_dev
 489  *
 490  * Using the base tx pointer and the maximum number of available TX
 491  * queues, this macro will return the address of 1 position beyond
 492  * the end of the TX queue array.
 493  */
 494 #define tx_queue_end(__dev) \
 495         &(__dev)->tx[(__dev)->ops->tx_queues]
 496
 497 /**
 498  * queue_next - Return pointer to next queue in list (HELPER MACRO).
 499  * @__queue: Current queue for which we need the next queue
 500  *
 501  * Using the current queue address we take the address directly
 502  * after the queue to take the next queue. Note that this macro
 503  * should be used carefully since it does not protect against
 504  * moving past the end of the list. (See macros &queue_end and
 505  * &tx_queue_end for determining the end of the queue).
 506  */
 507 #define queue_next(__queue) \
 508         &(__queue)[1]
 509
 510 /**
 511  * queue_loop - Loop through the queues within a specific range (HELPER MACRO).
 512  * @__entry: Pointer where the current queue entry will be stored in.
 513  * @__start: Start queue pointer.
 514  * @__end: End queue pointer.
 515  *
 516  * This macro will loop through all queues between &__start and &__end.
 517  */
 518 #define queue_loop(__entry, __start, __end)                     \
 519         for ((__entry) = (__start);                             \
 520              prefetch(queue_next(__entry)), (__entry) != (__end);\
 521              (__entry) = queue_next(__entry))
 522
 523 /**
 524  * queue_for_each - Loop through all queues
 525  * @__dev: Pointer to &struct rt2x00_dev
 526  * @__entry: Pointer where the current queue entry will be stored in.
 527  *
 528  * This macro will loop through all available queues.
 529  */
 530 #define queue_for_each(__dev, __entry) \
 531         queue_loop(__entry, (__dev)->rx, queue_end(__dev))
 532
 533 /**
 534  * tx_queue_for_each - Loop through the TX queues
 535  * @__dev: Pointer to &struct rt2x00_dev
 536  * @__entry: Pointer where the current queue entry will be stored in.
 537  *
 538  * This macro will loop through all TX related queues excluding
 539  * the Beacon and Atim queues.
 540  */
 541 #define tx_queue_for_each(__dev, __entry) \
 542         queue_loop(__entry, (__dev)->tx, tx_queue_end(__dev))
 543
 544 /**
 545  * txall_queue_for_each - Loop through all TX related queues
 546  * @__dev: Pointer to &struct rt2x00_dev
 547  * @__entry: Pointer where the current queue entry will be stored in.
 548  *
 549  * This macro will loop through all TX related queues including
 550  * the Beacon and Atim queues.
 551  */
 552 #define txall_queue_for_each(__dev, __entry) \
 553         queue_loop(__entry, (__dev)->tx, queue_end(__dev))
 554
 555 /**
 556  * rt2x00queue_empty - Check if the queue is empty.
 557  * @queue: Queue to check if empty.
 558  */
 559 static inline int rt2x00queue_empty(struct data_queue *queue)
 560 {
 561         return queue->length == 0;
 562 }
 563
 564 /**
 565  * rt2x00queue_full - Check if the queue is full.
 566  * @queue: Queue to check if full.
 567  */
 568 static inline int rt2x00queue_full(struct data_queue *queue)
 569 {
 570         return queue->length == queue->limit;
 571 }
 572
 573 /**
 574  * rt2x00queue_free - Check the number of available entries in queue.
 575  * @queue: Queue to check.
 576  */
 577 static inline int rt2x00queue_available(struct data_queue *queue)
 578 {
 579         return queue->limit - queue->length;
 580 }
 581
 582 /**
 583  * rt2x00queue_threshold - Check if the queue is below threshold
 584  * @queue: Queue to check.
 585  */
 586 static inline int rt2x00queue_threshold(struct data_queue *queue)
 587 {
 588         return rt2x00queue_available(queue) < queue->threshold;
 589 }
 590
 591 /**
 592  * _rt2x00_desc_read - Read a word from the hardware descriptor.
 593  * @desc: Base descriptor address
 594  * @word: Word index from where the descriptor should be read.
 595  * @value: Address where the descriptor value should be written into.
 596  */
 597 static inline void _rt2x00_desc_read(__le32 *desc, const u8 word, __le32 *value)
 598 {
 599         *value = desc[word];
 600 }
 601
 602 /**
 603  * rt2x00_desc_read - Read a word from the hardware descriptor, this
 604  * function will take care of the byte ordering.
 605  * @desc: Base descriptor address
 606  * @word: Word index from where the descriptor should be read.
 607  * @value: Address where the descriptor value should be written into.
 608  */
 609 static inline void rt2x00_desc_read(__le32 *desc, const u8 word, u32 *value)
 610 {
 611         __le32 tmp;
 612         _rt2x00_desc_read(desc, word, &tmp);
 613         *value = le32_to_cpu(tmp);
 614 }
 615
 616 /**
 617  * rt2x00_desc_write - write a word to the hardware descriptor, this
 618  * function will take care of the byte ordering.
 619  * @desc: Base descriptor address
 620  * @word: Word index from where the descriptor should be written.
 621  * @value: Value that should be written into the descriptor.
 622  */
 623 static inline void _rt2x00_desc_write(__le32 *desc, const u8 word, __le32 value)
 624 {
 625         desc[word] = value;
 626 }
 627
 628 /**
 629  * rt2x00_desc_write - write a word to the hardware descriptor.
 630  * @desc: Base descriptor address
 631  * @word: Word index from where the descriptor should be written.
 632  * @value: Value that should be written into the descriptor.
 633  */
 634 static inline void rt2x00_desc_write(__le32 *desc, const u8 word, u32 value)
 635 {
 636         _rt2x00_desc_write(desc, word, cpu_to_le32(value));
 637 }
 638
 639 #endif /* RT2X00QUEUE_H */