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: Entrie 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 only 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_FAILURE: Frame was not successfully send
 218  * @TXDONE_EXCESSIVE_RETRY: In addition to &TXDONE_FAILURE, the
 219  *      frame transmission failed due to excessive retries.
 220  */
 221 enum txdone_entry_desc_flags {
 222         TXDONE_UNKNOWN,
 223         TXDONE_SUCCESS,
 224         TXDONE_FAILURE,
 225         TXDONE_EXCESSIVE_RETRY,
 226 };
 227
 228 /**
 229  * struct txdone_entry_desc: TX done entry descriptor
 230  *
 231  * Summary of information that has been read from the TX frame descriptor
 232  * after the device is done with transmission.
 233  *
 234  * @flags: TX done flags (See &enum txdone_entry_desc_flags).
 235  * @retry: Retry count.
 236  */
 237 struct txdone_entry_desc {
 238         unsigned long flags;
 239         int retry;
 240 };
 241
 242 /**
 243  * enum txentry_desc_flags: Status flags for TX entry descriptor
 244  *
 245  * @ENTRY_TXD_RTS_FRAME: This frame is a RTS frame.
 246  * @ENTRY_TXD_CTS_FRAME: This frame is a CTS-to-self frame.
 247  * @ENTRY_TXD_GENERATE_SEQ: This frame requires sequence counter.
 248  * @ENTRY_TXD_FIRST_FRAGMENT: This is the first frame.
 249  * @ENTRY_TXD_MORE_FRAG: This frame is followed by another fragment.
 250  * @ENTRY_TXD_REQ_TIMESTAMP: Require timestamp to be inserted.
 251  * @ENTRY_TXD_BURST: This frame belongs to the same burst event.
 252  * @ENTRY_TXD_ACK: An ACK is required for this frame.
 253  * @ENTRY_TXD_RETRY_MODE: When set, the long retry count is used.
 254  * @ENTRY_TXD_ENCRYPT: This frame should be encrypted.
 255  * @ENTRY_TXD_ENCRYPT_PAIRWISE: Use pairwise key table (instead of shared).
 256  * @ENTRY_TXD_ENCRYPT_IV: Generate IV/EIV in hardware.
 257  * @ENTRY_TXD_ENCRYPT_MMIC: Generate MIC in hardware.
 258  * @ENTRY_TXD_HT_AMPDU: This frame is part of an AMPDU.
 259  * @ENTRY_TXD_HT_BW_40: Use 40MHz Bandwidth.
 260  * @ENTRY_TXD_HT_SHORT_GI: Use short GI.
 261  */
 262 enum txentry_desc_flags {
 263         ENTRY_TXD_RTS_FRAME,
 264         ENTRY_TXD_CTS_FRAME,
 265         ENTRY_TXD_GENERATE_SEQ,
 266         ENTRY_TXD_FIRST_FRAGMENT,
 267         ENTRY_TXD_MORE_FRAG,
 268         ENTRY_TXD_REQ_TIMESTAMP,
 269         ENTRY_TXD_BURST,
 270         ENTRY_TXD_ACK,
 271         ENTRY_TXD_RETRY_MODE,
 272         ENTRY_TXD_ENCRYPT,
 273         ENTRY_TXD_ENCRYPT_PAIRWISE,
 274         ENTRY_TXD_ENCRYPT_IV,
 275         ENTRY_TXD_ENCRYPT_MMIC,
 276         ENTRY_TXD_HT_AMPDU,
 277         ENTRY_TXD_HT_BW_40,
 278         ENTRY_TXD_HT_SHORT_GI,
 279 };
 280
 281 /**
 282  * struct txentry_desc: TX Entry descriptor
 283  *
 284  * Summary of information for the frame descriptor before sending a TX frame.
 285  *
 286  * @flags: Descriptor flags (See &enum queue_entry_flags).
 287  * @queue: Queue identification (See &enum data_queue_qid).
 288  * @header_length: Length of 802.11 header.
 289  * @l2pad: Amount of padding to align 802.11 payload to 4-byte boundrary.
 290  * @length_high: PLCP length high word.
 291  * @length_low: PLCP length low word.
 292  * @signal: PLCP signal.
 293  * @service: PLCP service.
 294  * @msc: MCS.
 295  * @stbc: STBC.
 296  * @ba_size: BA size.
 297  * @rate_mode: Rate mode (See @enum rate_modulation).
 298  * @mpdu_density: MDPU density.
 299  * @retry_limit: Max number of retries.
 300  * @aifs: AIFS value.
 301  * @ifs: IFS value.
 302  * @cw_min: cwmin value.
 303  * @cw_max: cwmax value.
 304  * @cipher: Cipher type used for encryption.
 305  * @key_idx: Key index used for encryption.
 306  * @iv_offset: Position where IV should be inserted by hardware.
 307  * @iv_len: Length of IV data.
 308  */
 309 struct txentry_desc {
 310         unsigned long flags;
 311
 312         enum data_queue_qid queue;
 313
 314         u16 header_length;
 315         u16 l2pad;
 316
 317         u16 length_high;
 318         u16 length_low;
 319         u16 signal;
 320         u16 service;
 321
 322         u16 mcs;
 323         u16 stbc;
 324         u16 ba_size;
 325         u16 rate_mode;
 326         u16 mpdu_density;
 327
 328         short retry_limit;
 329         short aifs;
 330         short ifs;
 331         short cw_min;
 332         short cw_max;
 333
 334         enum cipher cipher;
 335         u16 key_idx;
 336         u16 iv_offset;
 337         u16 iv_len;
 338 };
 339
 340 /**
 341  * enum queue_entry_flags: Status flags for queue entry
 342  *
 343  * @ENTRY_BCN_ASSIGNED: This entry has been assigned to an interface.
 344  *      As long as this bit is set, this entry may only be touched
 345  *      through the interface structure.
 346  * @ENTRY_OWNER_DEVICE_DATA: This entry is owned by the device for data
 347  *      transfer (either TX or RX depending on the queue). The entry should
 348  *      only be touched after the device has signaled it is done with it.
 349  * @ENTRY_OWNER_DEVICE_CRYPTO: This entry is owned by the device for data
 350  *      encryption or decryption. The entry should only be touched after
 351  *      the device has signaled it is done with it.
 352  * @ENTRY_DATA_PENDING: This entry contains a valid frame and is waiting
 353  *      for the signal to start sending.
 354  */
 355 enum queue_entry_flags {
 356         ENTRY_BCN_ASSIGNED,
 357         ENTRY_OWNER_DEVICE_DATA,
 358         ENTRY_OWNER_DEVICE_CRYPTO,
 359         ENTRY_DATA_PENDING,
 360 };
 361
 362 /**
 363  * struct queue_entry: Entry inside the &struct data_queue
 364  *
 365  * @flags: Entry flags, see &enum queue_entry_flags.
 366  * @queue: The data queue (&struct data_queue) to which this entry belongs.
 367  * @skb: The buffer which is currently being transmitted (for TX queue),
 368  *      or used to directly recieve data in (for RX queue).
 369  * @entry_idx: The entry index number.
 370  * @priv_data: Private data belonging to this queue entry. The pointer
 371  *      points to data specific to a particular driver and queue type.
 372  */
 373 struct queue_entry {
 374         unsigned long flags;
 375
 376         struct data_queue *queue;
 377
 378         struct sk_buff *skb;
 379
 380         unsigned int entry_idx;
 381
 382         void *priv_data;
 383 };
 384
 385 /**
 386  * enum queue_index: Queue index type
 387  *
 388  * @Q_INDEX: Index pointer to the current entry in the queue, if this entry is
 389  *      owned by the hardware then the queue is considered to be full.
 390  * @Q_INDEX_DONE: Index pointer to the next entry which will be completed by
 391  *      the hardware and for which we need to run the txdone handler. If this
 392  *      entry is not owned by the hardware the queue is considered to be empty.
 393  * @Q_INDEX_CRYPTO: Index pointer to the next entry which encryption/decription
 394  *      will be completed by the hardware next.
 395  * @Q_INDEX_MAX: Keep last, used in &struct data_queue to determine the size
 396  *      of the index array.
 397  */
 398 enum queue_index {
 399         Q_INDEX,
 400         Q_INDEX_DONE,
 401         Q_INDEX_CRYPTO,
 402         Q_INDEX_MAX,
 403 };
 404
 405 /**
 406  * struct data_queue: Data queue
 407  *
 408  * @rt2x00dev: Pointer to main &struct rt2x00dev where this queue belongs to.
 409  * @entries: Base address of the &struct queue_entry which are
 410  *      part of this queue.
 411  * @qid: The queue identification, see &enum data_queue_qid.
 412  * @lock: Spinlock to protect index handling. Whenever @index, @index_done or
 413  *      @index_crypt needs to be changed this lock should be grabbed to prevent
 414  *      index corruption due to concurrency.
 415  * @count: Number of frames handled in the queue.
 416  * @limit: Maximum number of entries in the queue.
 417  * @threshold: Minimum number of free entries before queue is kicked by force.
 418  * @length: Number of frames in queue.
 419  * @index: Index pointers to entry positions in the queue,
 420  *      use &enum queue_index to get a specific index field.
 421  * @txop: maximum burst time.
 422  * @aifs: The aifs value for outgoing frames (field ignored in RX queue).
 423  * @cw_min: The cw min value for outgoing frames (field ignored in RX queue).
 424  * @cw_max: The cw max value for outgoing frames (field ignored in RX queue).
 425  * @data_size: Maximum data size for the frames in this queue.
 426  * @desc_size: Hardware descriptor size for the data in this queue.
 427  * @usb_endpoint: Device endpoint used for communication (USB only)
 428  * @usb_maxpacket: Max packet size for given endpoint (USB only)
 429  */
 430 struct data_queue {
 431         struct rt2x00_dev *rt2x00dev;
 432         struct queue_entry *entries;
 433
 434         enum data_queue_qid qid;
 435
 436         spinlock_t lock;
 437         unsigned int count;
 438         unsigned short limit;
 439         unsigned short threshold;
 440         unsigned short length;
 441         unsigned short index[Q_INDEX_MAX];
 442
 443         unsigned short txop;
 444         unsigned short aifs;
 445         unsigned short cw_min;
 446         unsigned short cw_max;
 447
 448         unsigned short data_size;
 449         unsigned short desc_size;
 450
 451         unsigned short usb_endpoint;
 452         unsigned short usb_maxpacket;
 453 };
 454
 455 /**
 456  * struct data_queue_desc: Data queue description
 457  *
 458  * The information in this structure is used by drivers
 459  * to inform rt2x00lib about the creation of the data queue.
 460  *
 461  * @entry_num: Maximum number of entries for a queue.
 462  * @data_size: Maximum data size for the frames in this queue.
 463  * @desc_size: Hardware descriptor size for the data in this queue.
 464  * @priv_size: Size of per-queue_entry private data.
 465  */
 466 struct data_queue_desc {
 467         unsigned short entry_num;
 468         unsigned short data_size;
 469         unsigned short desc_size;
 470         unsigned short priv_size;
 471 };
 472
 473 /**
 474  * queue_end - Return pointer to the last queue (HELPER MACRO).
 475  * @__dev: Pointer to &struct rt2x00_dev
 476  *
 477  * Using the base rx pointer and the maximum number of available queues,
 478  * this macro will return the address of 1 position beyond  the end of the
 479  * queues array.
 480  */
 481 #define queue_end(__dev) \
 482         &(__dev)->rx[(__dev)->data_queues]
 483
 484 /**
 485  * tx_queue_end - Return pointer to the last TX queue (HELPER MACRO).
 486  * @__dev: Pointer to &struct rt2x00_dev
 487  *
 488  * Using the base tx pointer and the maximum number of available TX
 489  * queues, this macro will return the address of 1 position beyond
 490  * the end of the TX queue array.
 491  */
 492 #define tx_queue_end(__dev) \
 493         &(__dev)->tx[(__dev)->ops->tx_queues]
 494
 495 /**
 496  * queue_next - Return pointer to next queue in list (HELPER MACRO).
 497  * @__queue: Current queue for which we need the next queue
 498  *
 499  * Using the current queue address we take the address directly
 500  * after the queue to take the next queue. Note that this macro
 501  * should be used carefully since it does not protect against
 502  * moving past the end of the list. (See macros &queue_end and
 503  * &tx_queue_end for determining the end of the queue).
 504  */
 505 #define queue_next(__queue) \
 506         &(__queue)[1]
 507
 508 /**
 509  * queue_loop - Loop through the queues within a specific range (HELPER MACRO).
 510  * @__entry: Pointer where the current queue entry will be stored in.
 511  * @__start: Start queue pointer.
 512  * @__end: End queue pointer.
 513  *
 514  * This macro will loop through all queues between &__start and &__end.
 515  */
 516 #define queue_loop(__entry, __start, __end)                     \
 517         for ((__entry) = (__start);                             \
 518              prefetch(queue_next(__entry)), (__entry) != (__end);\
 519              (__entry) = queue_next(__entry))
 520
 521 /**
 522  * queue_for_each - Loop through all queues
 523  * @__dev: Pointer to &struct rt2x00_dev
 524  * @__entry: Pointer where the current queue entry will be stored in.
 525  *
 526  * This macro will loop through all available queues.
 527  */
 528 #define queue_for_each(__dev, __entry) \
 529         queue_loop(__entry, (__dev)->rx, queue_end(__dev))
 530
 531 /**
 532  * tx_queue_for_each - Loop through the TX queues
 533  * @__dev: Pointer to &struct rt2x00_dev
 534  * @__entry: Pointer where the current queue entry will be stored in.
 535  *
 536  * This macro will loop through all TX related queues excluding
 537  * the Beacon and Atim queues.
 538  */
 539 #define tx_queue_for_each(__dev, __entry) \
 540         queue_loop(__entry, (__dev)->tx, tx_queue_end(__dev))
 541
 542 /**
 543  * txall_queue_for_each - Loop through all TX related queues
 544  * @__dev: Pointer to &struct rt2x00_dev
 545  * @__entry: Pointer where the current queue entry will be stored in.
 546  *
 547  * This macro will loop through all TX related queues including
 548  * the Beacon and Atim queues.
 549  */
 550 #define txall_queue_for_each(__dev, __entry) \
 551         queue_loop(__entry, (__dev)->tx, queue_end(__dev))
 552
 553 /**
 554  * rt2x00queue_empty - Check if the queue is empty.
 555  * @queue: Queue to check if empty.
 556  */
 557 static inline int rt2x00queue_empty(struct data_queue *queue)
 558 {
 559         return queue->length == 0;
 560 }
 561
 562 /**
 563  * rt2x00queue_full - Check if the queue is full.
 564  * @queue: Queue to check if full.
 565  */
 566 static inline int rt2x00queue_full(struct data_queue *queue)
 567 {
 568         return queue->length == queue->limit;
 569 }
 570
 571 /**
 572  * rt2x00queue_free - Check the number of available entries in queue.
 573  * @queue: Queue to check.
 574  */
 575 static inline int rt2x00queue_available(struct data_queue *queue)
 576 {
 577         return queue->limit - queue->length;
 578 }
 579
 580 /**
 581  * rt2x00queue_threshold - Check if the queue is below threshold
 582  * @queue: Queue to check.
 583  */
 584 static inline int rt2x00queue_threshold(struct data_queue *queue)
 585 {
 586         return rt2x00queue_available(queue) < queue->threshold;
 587 }
 588
 589 /**
 590  * _rt2x00_desc_read - Read a word from the hardware descriptor.
 591  * @desc: Base descriptor address
 592  * @word: Word index from where the descriptor should be read.
 593  * @value: Address where the descriptor value should be written into.
 594  */
 595 static inline void _rt2x00_desc_read(__le32 *desc, const u8 word, __le32 *value)
 596 {
 597         *value = desc[word];
 598 }
 599
 600 /**
 601  * rt2x00_desc_read - Read a word from the hardware descriptor, this
 602  * function will take care of the byte ordering.
 603  * @desc: Base descriptor address
 604  * @word: Word index from where the descriptor should be read.
 605  * @value: Address where the descriptor value should be written into.
 606  */
 607 static inline void rt2x00_desc_read(__le32 *desc, const u8 word, u32 *value)
 608 {
 609         __le32 tmp;
 610         _rt2x00_desc_read(desc, word, &tmp);
 611         *value = le32_to_cpu(tmp);
 612 }
 613
 614 /**
 615  * rt2x00_desc_write - write a word to the hardware descriptor, this
 616  * function will take care of the byte ordering.
 617  * @desc: Base descriptor address
 618  * @word: Word index from where the descriptor should be written.
 619  * @value: Value that should be written into the descriptor.
 620  */
 621 static inline void _rt2x00_desc_write(__le32 *desc, const u8 word, __le32 value)
 622 {
 623         desc[word] = value;
 624 }
 625
 626 /**
 627  * rt2x00_desc_write - write a word to the hardware descriptor.
 628  * @desc: Base descriptor address
 629  * @word: Word index from where the descriptor should be written.
 630  * @value: Value that should be written into the descriptor.
 631  */
 632 static inline void rt2x00_desc_write(__le32 *desc, const u8 word, u32 value)
 633 {
 634         _rt2x00_desc_write(desc, word, cpu_to_le32(value));
 635 }
 636
 637 #endif /* RT2X00QUEUE_H */