drivers/net/wireless/rt2x00/rt2x00queue.h

   1 /*
   2         Copyright (C) 2004 - 2008 rt2x00 SourceForge Project
   3         <http://rt2x00.serialmonkey.com>
   4
   5         This program is free software; you can redistribute it and/or modify
   6         it under the terms of the GNU General Public License as published by
   7         the Free Software Foundation; either version 2 of the License, or
   8         (at your option) any later version.
   9
  10         This program is distributed in the hope that it will be useful,
  11         but WITHOUT ANY WARRANTY; without even the implied warranty of
  12         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13         GNU General Public License for more details.
  14
  15         You should have received a copy of the GNU General Public License
  16         along with this program; if not, write to the
  17         Free Software Foundation, Inc.,
  18         59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19  */
  20
  21 /*
  22         Module: 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  */
  39 #define DATA_FRAME_SIZE 2432
  40 #define MGMT_FRAME_SIZE 256
  41
  42 /**
  43  * DOC: Number of entries per queue
  44  *
  45  * After research it was concluded that 12 entries in a RX and TX
  46  * queue would be sufficient. Although this is almost one third of
  47  * the amount the legacy driver allocated, the queues aren't getting
  48  * filled to the maximum even when working with the maximum rate.
  49  */
  50 #define RX_ENTRIES      12
  51 #define TX_ENTRIES      12
  52 #define BEACON_ENTRIES  1
  53 #define ATIM_ENTRIES    1
  54
  55 /**
  56  * enum data_queue_qid: Queue identification
  57  *
  58  * @QID_AC_BE: AC BE queue
  59  * @QID_AC_BK: AC BK queue
  60  * @QID_AC_VI: AC VI queue
  61  * @QID_AC_VO: AC VO queue
  62  * @QID_HCCA: HCCA queue
  63  * @QID_MGMT: MGMT queue (prio queue)
  64  * @QID_RX: RX queue
  65  * @QID_OTHER: None of the above (don't use, only present for completeness)
  66  * @QID_BEACON: Beacon queue (value unspecified, don't send it to device)
  67  * @QID_ATIM: Atim queue (value unspeficied, don't send it to device)
  68  */
  69 enum data_queue_qid {
  70         QID_AC_BE = 0,
  71         QID_AC_BK = 1,
  72         QID_AC_VI = 2,
  73         QID_AC_VO = 3,
  74         QID_HCCA = 4,
  75         QID_MGMT = 13,
  76         QID_RX = 14,
  77         QID_OTHER = 15,
  78         QID_BEACON,
  79         QID_ATIM,
  80 };
  81
  82 /**
  83  * mac80211_queue_to_qid - Convert mac80211 queue to rt2x00 qid
  84  * @queue: mac80211 queue.
  85  */
  86 static inline enum data_queue_qid mac80211_queue_to_qid(unsigned int queue)
  87 {
  88         /* Regular TX queues are mapped directly */
  89         if (queue < 4)
  90                 return queue;
  91         WARN_ON(1);
  92         return QID_OTHER;
  93 }
  94
  95 /**
  96  * enum skb_frame_desc_flags: Flags for &struct skb_frame_desc
  97  *
  98  * @FRAME_DESC_DRIVER_GENERATED: Frame was generated inside driver
  99  *      and should not be reported back to mac80211 during txdone.
 100  */
 101 enum skb_frame_desc_flags {
 102         FRAME_DESC_DRIVER_GENERATED = 1 << 0,
 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  * @data: Pointer to data part of frame (Start of ieee80211 header).
 113  * @desc: Pointer to descriptor part of the frame.
 114  *      Note that this pointer could point to something outside
 115  *      of the scope of the skb->data pointer.
 116  * @data_len: Length of the frame data.
 117  * @desc_len: Length of the frame descriptor.
 118  * @entry: The entry to which this sk buffer belongs.
 119  */
 120 struct skb_frame_desc {
 121         unsigned int flags;
 122
 123         unsigned short data_len;
 124         unsigned short desc_len;
 125
 126         void *data;
 127         void *desc;
 128
 129         struct queue_entry *entry;
 130 };
 131
 132 /**
 133  * get_skb_frame_desc - Obtain the rt2x00 frame descriptor from a sk_buff.
 134  * @skb: &struct sk_buff from where we obtain the &struct skb_frame_desc
 135  */
 136 static inline struct skb_frame_desc* get_skb_frame_desc(struct sk_buff *skb)
 137 {
 138         BUILD_BUG_ON(sizeof(struct skb_frame_desc) >
 139                      IEEE80211_TX_INFO_DRIVER_DATA_SIZE);
 140         return (struct skb_frame_desc *)&IEEE80211_SKB_CB(skb)->driver_data;
 141 }
 142
 143 /**
 144  * enum rxdone_entry_desc_flags: Flags for &struct rxdone_entry_desc
 145  *
 146  * @RXDONE_SIGNAL_PLCP: Does the signal field contain the plcp value,
 147  *      or does it contain the bitrate itself.
 148  * @RXDONE_MY_BSS: Does this frame originate from device's BSS.
 149  */
 150 enum rxdone_entry_desc_flags {
 151         RXDONE_SIGNAL_PLCP = 1 << 0,
 152         RXDONE_MY_BSS = 1 << 1,
 153 };
 154
 155 /**
 156  * struct rxdone_entry_desc: RX Entry descriptor
 157  *
 158  * Summary of information that has been read from the RX frame descriptor.
 159  *
 160  * @signal: Signal of the received frame.
 161  * @rssi: RSSI of the received frame.
 162  * @size: Data size of the received frame.
 163  * @flags: MAC80211 receive flags (See &enum mac80211_rx_flags).
 164  * @dev_flags: Ralink receive flags (See &enum rxdone_entry_desc_flags).
 165
 166  */
 167 struct rxdone_entry_desc {
 168         int signal;
 169         int rssi;
 170         int size;
 171         int flags;
 172         int dev_flags;
 173 };
 174
 175 /**
 176  * enum txdone_entry_desc_flags: Flags for &struct txdone_entry_desc
 177  *
 178  * @TXDONE_UNKNOWN: Hardware could not determine success of transmission.
 179  * @TXDONE_SUCCESS: Frame was successfully send
 180  * @TXDONE_FAILURE: Frame was not successfully send
 181  * @TXDONE_EXCESSIVE_RETRY: In addition to &TXDONE_FAILURE, the
 182  *      frame transmission failed due to excessive retries.
 183  */
 184 enum txdone_entry_desc_flags {
 185         TXDONE_UNKNOWN = 1 << 0,
 186         TXDONE_SUCCESS = 1 << 1,
 187         TXDONE_FAILURE = 1 << 2,
 188         TXDONE_EXCESSIVE_RETRY = 1 << 3,
 189 };
 190
 191 /**
 192  * struct txdone_entry_desc: TX done entry descriptor
 193  *
 194  * Summary of information that has been read from the TX frame descriptor
 195  * after the device is done with transmission.
 196  *
 197  * @flags: TX done flags (See &enum txdone_entry_desc_flags).
 198  * @retry: Retry count.
 199  */
 200 struct txdone_entry_desc {
 201         unsigned long flags;
 202         int retry;
 203 };
 204
 205 /**
 206  * enum txentry_desc_flags: Status flags for TX entry descriptor
 207  *
 208  * @ENTRY_TXD_RTS_FRAME: This frame is a RTS frame.
 209  * @ENTRY_TXD_CTS_FRAME: This frame is a CTS-to-self frame.
 210  * @ENTRY_TXD_OFDM_RATE: This frame is send out with an OFDM rate.
 211  * @ENTRY_TXD_FIRST_FRAGMENT: This is the first frame.
 212  * @ENTRY_TXD_MORE_FRAG: This frame is followed by another fragment.
 213  * @ENTRY_TXD_REQ_TIMESTAMP: Require timestamp to be inserted.
 214  * @ENTRY_TXD_BURST: This frame belongs to the same burst event.
 215  * @ENTRY_TXD_ACK: An ACK is required for this frame.
 216  * @ENTRY_TXD_RETRY_MODE: When set, the long retry count is used.
 217  */
 218 enum txentry_desc_flags {
 219         ENTRY_TXD_RTS_FRAME,
 220         ENTRY_TXD_CTS_FRAME,
 221         ENTRY_TXD_OFDM_RATE,
 222         ENTRY_TXD_FIRST_FRAGMENT,
 223         ENTRY_TXD_MORE_FRAG,
 224         ENTRY_TXD_REQ_TIMESTAMP,
 225         ENTRY_TXD_BURST,
 226         ENTRY_TXD_ACK,
 227         ENTRY_TXD_RETRY_MODE,
 228 };
 229
 230 /**
 231  * struct txentry_desc: TX Entry descriptor
 232  *
 233  * Summary of information for the frame descriptor before sending a TX frame.
 234  *
 235  * @flags: Descriptor flags (See &enum queue_entry_flags).
 236  * @queue: Queue identification (See &enum data_queue_qid).
 237  * @length_high: PLCP length high word.
 238  * @length_low: PLCP length low word.
 239  * @signal: PLCP signal.
 240  * @service: PLCP service.
 241  * @retry_limit: Max number of retries.
 242  * @aifs: AIFS value.
 243  * @ifs: IFS value.
 244  * @cw_min: cwmin value.
 245  * @cw_max: cwmax value.
 246  */
 247 struct txentry_desc {
 248         unsigned long flags;
 249
 250         enum data_queue_qid queue;
 251
 252         u16 length_high;
 253         u16 length_low;
 254         u16 signal;
 255         u16 service;
 256
 257         short retry_limit;
 258         short aifs;
 259         short ifs;
 260         short cw_min;
 261         short cw_max;
 262 };
 263
 264 /**
 265  * enum queue_entry_flags: Status flags for queue entry
 266  *
 267  * @ENTRY_BCN_ASSIGNED: This entry has been assigned to an interface.
 268  *      As long as this bit is set, this entry may only be touched
 269  *      through the interface structure.
 270  * @ENTRY_OWNER_DEVICE_DATA: This entry is owned by the device for data
 271  *      transfer (either TX or RX depending on the queue). The entry should
 272  *      only be touched after the device has signaled it is done with it.
 273  * @ENTRY_OWNER_DEVICE_CRYPTO: This entry is owned by the device for data
 274  *      encryption or decryption. The entry should only be touched after
 275  *      the device has signaled it is done with it.
 276  */
 277 enum queue_entry_flags {
 278         ENTRY_BCN_ASSIGNED,
 279         ENTRY_OWNER_DEVICE_DATA,
 280         ENTRY_OWNER_DEVICE_CRYPTO,
 281 };
 282
 283 /**
 284  * struct queue_entry: Entry inside the &struct data_queue
 285  *
 286  * @flags: Entry flags, see &enum queue_entry_flags.
 287  * @queue: The data queue (&struct data_queue) to which this entry belongs.
 288  * @skb: The buffer which is currently being transmitted (for TX queue),
 289  *      or used to directly recieve data in (for RX queue).
 290  * @entry_idx: The entry index number.
 291  * @priv_data: Private data belonging to this queue entry. The pointer
 292  *      points to data specific to a particular driver and queue type.
 293  */
 294 struct queue_entry {
 295         unsigned long flags;
 296
 297         struct data_queue *queue;
 298
 299         struct sk_buff *skb;
 300
 301         unsigned int entry_idx;
 302
 303         void *priv_data;
 304 };
 305
 306 /**
 307  * enum queue_index: Queue index type
 308  *
 309  * @Q_INDEX: Index pointer to the current entry in the queue, if this entry is
 310  *      owned by the hardware then the queue is considered to be full.
 311  * @Q_INDEX_DONE: Index pointer to the next entry which will be completed by
 312  *      the hardware and for which we need to run the txdone handler. If this
 313  *      entry is not owned by the hardware the queue is considered to be empty.
 314  * @Q_INDEX_CRYPTO: Index pointer to the next entry which encryption/decription
 315  *      will be completed by the hardware next.
 316  * @Q_INDEX_MAX: Keep last, used in &struct data_queue to determine the size
 317  *      of the index array.
 318  */
 319 enum queue_index {
 320         Q_INDEX,
 321         Q_INDEX_DONE,
 322         Q_INDEX_CRYPTO,
 323         Q_INDEX_MAX,
 324 };
 325
 326 /**
 327  * struct data_queue: Data queue
 328  *
 329  * @rt2x00dev: Pointer to main &struct rt2x00dev where this queue belongs to.
 330  * @entries: Base address of the &struct queue_entry which are
 331  *      part of this queue.
 332  * @qid: The queue identification, see &enum data_queue_qid.
 333  * @lock: Spinlock to protect index handling. Whenever @index, @index_done or
 334  *      @index_crypt needs to be changed this lock should be grabbed to prevent
 335  *      index corruption due to concurrency.
 336  * @count: Number of frames handled in the queue.
 337  * @limit: Maximum number of entries in the queue.
 338  * @length: Number of frames in queue.
 339  * @index: Index pointers to entry positions in the queue,
 340  *      use &enum queue_index to get a specific index field.
 341  * @aifs: The aifs value for outgoing frames (field ignored in RX queue).
 342  * @cw_min: The cw min value for outgoing frames (field ignored in RX queue).
 343  * @cw_max: The cw max value for outgoing frames (field ignored in RX queue).
 344  * @data_size: Maximum data size for the frames in this queue.
 345  * @desc_size: Hardware descriptor size for the data in this queue.
 346  */
 347 struct data_queue {
 348         struct rt2x00_dev *rt2x00dev;
 349         struct queue_entry *entries;
 350
 351         enum data_queue_qid qid;
 352
 353         spinlock_t lock;
 354         unsigned int count;
 355         unsigned short limit;
 356         unsigned short length;
 357         unsigned short index[Q_INDEX_MAX];
 358
 359         unsigned short aifs;
 360         unsigned short cw_min;
 361         unsigned short cw_max;
 362
 363         unsigned short data_size;
 364         unsigned short desc_size;
 365 };
 366
 367 /**
 368  * struct data_queue_desc: Data queue description
 369  *
 370  * The information in this structure is used by drivers
 371  * to inform rt2x00lib about the creation of the data queue.
 372  *
 373  * @entry_num: Maximum number of entries for a queue.
 374  * @data_size: Maximum data size for the frames in this queue.
 375  * @desc_size: Hardware descriptor size for the data in this queue.
 376  * @priv_size: Size of per-queue_entry private data.
 377  */
 378 struct data_queue_desc {
 379         unsigned short entry_num;
 380         unsigned short data_size;
 381         unsigned short desc_size;
 382         unsigned short priv_size;
 383 };
 384
 385 /**
 386  * queue_end - Return pointer to the last queue (HELPER MACRO).
 387  * @__dev: Pointer to &struct rt2x00_dev
 388  *
 389  * Using the base rx pointer and the maximum number of available queues,
 390  * this macro will return the address of 1 position beyond  the end of the
 391  * queues array.
 392  */
 393 #define queue_end(__dev) \
 394         &(__dev)->rx[(__dev)->data_queues]
 395
 396 /**
 397  * tx_queue_end - Return pointer to the last TX queue (HELPER MACRO).
 398  * @__dev: Pointer to &struct rt2x00_dev
 399  *
 400  * Using the base tx pointer and the maximum number of available TX
 401  * queues, this macro will return the address of 1 position beyond
 402  * the end of the TX queue array.
 403  */
 404 #define tx_queue_end(__dev) \
 405         &(__dev)->tx[(__dev)->ops->tx_queues]
 406
 407 /**
 408  * queue_loop - Loop through the queues within a specific range (HELPER MACRO).
 409  * @__entry: Pointer where the current queue entry will be stored in.
 410  * @__start: Start queue pointer.
 411  * @__end: End queue pointer.
 412  *
 413  * This macro will loop through all queues between &__start and &__end.
 414  */
 415 #define queue_loop(__entry, __start, __end)                     \
 416         for ((__entry) = (__start);                             \
 417              prefetch(&(__entry)[1]), (__entry) != (__end);     \
 418              (__entry) = &(__entry)[1])
 419
 420 /**
 421  * queue_for_each - Loop through all queues
 422  * @__dev: Pointer to &struct rt2x00_dev
 423  * @__entry: Pointer where the current queue entry will be stored in.
 424  *
 425  * This macro will loop through all available queues.
 426  */
 427 #define queue_for_each(__dev, __entry) \
 428         queue_loop(__entry, (__dev)->rx, queue_end(__dev))
 429
 430 /**
 431  * tx_queue_for_each - Loop through the TX queues
 432  * @__dev: Pointer to &struct rt2x00_dev
 433  * @__entry: Pointer where the current queue entry will be stored in.
 434  *
 435  * This macro will loop through all TX related queues excluding
 436  * the Beacon and Atim queues.
 437  */
 438 #define tx_queue_for_each(__dev, __entry) \
 439         queue_loop(__entry, (__dev)->tx, tx_queue_end(__dev))
 440
 441 /**
 442  * txall_queue_for_each - Loop through all TX related queues
 443  * @__dev: Pointer to &struct rt2x00_dev
 444  * @__entry: Pointer where the current queue entry will be stored in.
 445  *
 446  * This macro will loop through all TX related queues including
 447  * the Beacon and Atim queues.
 448  */
 449 #define txall_queue_for_each(__dev, __entry) \
 450         queue_loop(__entry, (__dev)->tx, queue_end(__dev))
 451
 452 /**
 453  * rt2x00queue_empty - Check if the queue is empty.
 454  * @queue: Queue to check if empty.
 455  */
 456 static inline int rt2x00queue_empty(struct data_queue *queue)
 457 {
 458         return queue->length == 0;
 459 }
 460
 461 /**
 462  * rt2x00queue_full - Check if the queue is full.
 463  * @queue: Queue to check if full.
 464  */
 465 static inline int rt2x00queue_full(struct data_queue *queue)
 466 {
 467         return queue->length == queue->limit;
 468 }
 469
 470 /**
 471  * rt2x00queue_free - Check the number of available entries in queue.
 472  * @queue: Queue to check.
 473  */
 474 static inline int rt2x00queue_available(struct data_queue *queue)
 475 {
 476         return queue->limit - queue->length;
 477 }
 478
 479 /**
 480  * rt2x00_desc_read - Read a word from the hardware descriptor.
 481  * @desc: Base descriptor address
 482  * @word: Word index from where the descriptor should be read.
 483  * @value: Address where the descriptor value should be written into.
 484  */
 485 static inline void rt2x00_desc_read(__le32 *desc, const u8 word, u32 *value)
 486 {
 487         *value = le32_to_cpu(desc[word]);
 488 }
 489
 490 /**
 491  * rt2x00_desc_write - wrote a word to the hardware descriptor.
 492  * @desc: Base descriptor address
 493  * @word: Word index from where the descriptor should be written.
 494  * @value: Value that should be written into the descriptor.
 495  */
 496 static inline void rt2x00_desc_write(__le32 *desc, const u8 word, u32 value)
 497 {
 498         desc[word] = cpu_to_le32(value);
 499 }
 500
 501 #endif /* RT2X00QUEUE_H */