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 skb->cb array, this means that
 109  * this structure should not exceed the size of that array (48 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 static inline struct skb_frame_desc* get_skb_frame_desc(struct sk_buff *skb)
 133 {
 134         BUILD_BUG_ON(sizeof(struct skb_frame_desc) > sizeof(skb->cb));
 135         return (struct skb_frame_desc *)&skb->cb[0];
 136 }
 137
 138 /**
 139  * enum rxdone_entry_desc_flags: Flags for &struct rxdone_entry_desc
 140  *
 141  * @RXDONE_SIGNAL_PLCP: Does the signal field contain the plcp value,
 142  *      or does it contain the bitrate itself.
 143  * @RXDONE_MY_BSS: Does this frame originate from device's BSS.
 144  */
 145 enum rxdone_entry_desc_flags {
 146         RXDONE_SIGNAL_PLCP = 1 << 0,
 147         RXDONE_MY_BSS = 1 << 1,
 148 };
 149
 150 /**
 151  * struct rxdone_entry_desc: RX Entry descriptor
 152  *
 153  * Summary of information that has been read from the RX frame descriptor.
 154  *
 155  * @signal: Signal of the received frame.
 156  * @rssi: RSSI of the received frame.
 157  * @size: Data size of the received frame.
 158  * @flags: MAC80211 receive flags (See &enum mac80211_rx_flags).
 159  * @dev_flags: Ralink receive flags (See &enum rxdone_entry_desc_flags).
 160
 161  */
 162 struct rxdone_entry_desc {
 163         int signal;
 164         int rssi;
 165         int size;
 166         int flags;
 167         int dev_flags;
 168 };
 169
 170 /**
 171  * enum txdone_entry_desc_flags: Flags for &struct txdone_entry_desc
 172  *
 173  * @TXDONE_UNKNOWN: Hardware could not determine success of transmission.
 174  * @TXDONE_SUCCESS: Frame was successfully send
 175  * @TXDONE_FAILURE: Frame was not successfully send
 176  * @TXDONE_EXCESSIVE_RETRY: In addition to &TXDONE_FAILURE, the
 177  *      frame transmission failed due to excessive retries.
 178  */
 179 enum txdone_entry_desc_flags {
 180         TXDONE_UNKNOWN = 1 << 0,
 181         TXDONE_SUCCESS = 1 << 1,
 182         TXDONE_FAILURE = 1 << 2,
 183         TXDONE_EXCESSIVE_RETRY = 1 << 3,
 184 };
 185
 186 /**
 187  * struct txdone_entry_desc: TX done entry descriptor
 188  *
 189  * Summary of information that has been read from the TX frame descriptor
 190  * after the device is done with transmission.
 191  *
 192  * @control: Control structure which was used to transmit the frame.
 193  * @flags: TX done flags (See &enum txdone_entry_desc_flags).
 194  * @retry: Retry count.
 195  */
 196 struct txdone_entry_desc {
 197         struct ieee80211_tx_control *control;
 198         unsigned long flags;
 199         int retry;
 200 };
 201
 202 /**
 203  * enum txentry_desc_flags: Status flags for TX entry descriptor
 204  *
 205  * @ENTRY_TXD_RTS_FRAME: This frame is a RTS frame.
 206  * @ENTRY_TXD_OFDM_RATE: This frame is send out with an OFDM rate.
 207  * @ENTRY_TXD_FIRST_FRAGMENT: This is the first frame.
 208  * @ENTRY_TXD_MORE_FRAG: This frame is followed by another fragment.
 209  * @ENTRY_TXD_REQ_TIMESTAMP: Require timestamp to be inserted.
 210  * @ENTRY_TXD_BURST: This frame belongs to the same burst event.
 211  * @ENTRY_TXD_ACK: An ACK is required for this frame.
 212  * @ENTRY_TXD_RETRY_MODE: When set, the long retry count is used.
 213  */
 214 enum txentry_desc_flags {
 215         ENTRY_TXD_RTS_FRAME,
 216         ENTRY_TXD_OFDM_RATE,
 217         ENTRY_TXD_FIRST_FRAGMENT,
 218         ENTRY_TXD_MORE_FRAG,
 219         ENTRY_TXD_REQ_TIMESTAMP,
 220         ENTRY_TXD_BURST,
 221         ENTRY_TXD_ACK,
 222         ENTRY_TXD_RETRY_MODE,
 223 };
 224
 225 /**
 226  * struct txentry_desc: TX Entry descriptor
 227  *
 228  * Summary of information for the frame descriptor before sending a TX frame.
 229  *
 230  * @flags: Descriptor flags (See &enum queue_entry_flags).
 231  * @queue: Queue identification (See &enum data_queue_qid).
 232  * @length_high: PLCP length high word.
 233  * @length_low: PLCP length low word.
 234  * @signal: PLCP signal.
 235  * @service: PLCP service.
 236  * @retry_limit: Max number of retries.
 237  * @aifs: AIFS value.
 238  * @ifs: IFS value.
 239  * @cw_min: cwmin value.
 240  * @cw_max: cwmax value.
 241  */
 242 struct txentry_desc {
 243         unsigned long flags;
 244
 245         enum data_queue_qid queue;
 246
 247         u16 length_high;
 248         u16 length_low;
 249         u16 signal;
 250         u16 service;
 251
 252         short retry_limit;
 253         short aifs;
 254         short ifs;
 255         short cw_min;
 256         short cw_max;
 257 };
 258
 259 /**
 260  * enum queue_entry_flags: Status flags for queue entry
 261  *
 262  * @ENTRY_BCN_ASSIGNED: This entry has been assigned to an interface.
 263  *      As long as this bit is set, this entry may only be touched
 264  *      through the interface structure.
 265  * @ENTRY_OWNER_DEVICE_DATA: This entry is owned by the device for data
 266  *      transfer (either TX or RX depending on the queue). The entry should
 267  *      only be touched after the device has signaled it is done with it.
 268  * @ENTRY_OWNER_DEVICE_CRYPTO: This entry is owned by the device for data
 269  *      encryption or decryption. The entry should only be touched after
 270  *      the device has signaled it is done with it.
 271  */
 272 enum queue_entry_flags {
 273         ENTRY_BCN_ASSIGNED,
 274         ENTRY_OWNER_DEVICE_DATA,
 275         ENTRY_OWNER_DEVICE_CRYPTO,
 276 };
 277
 278 /**
 279  * struct queue_entry: Entry inside the &struct data_queue
 280  *
 281  * @flags: Entry flags, see &enum queue_entry_flags.
 282  * @queue: The data queue (&struct data_queue) to which this entry belongs.
 283  * @skb: The buffer which is currently being transmitted (for TX queue),
 284  *      or used to directly recieve data in (for RX queue).
 285  * @entry_idx: The entry index number.
 286  * @priv_data: Private data belonging to this queue entry. The pointer
 287  *      points to data specific to a particular driver and queue type.
 288  */
 289 struct queue_entry {
 290         unsigned long flags;
 291
 292         struct data_queue *queue;
 293
 294         struct sk_buff *skb;
 295
 296         unsigned int entry_idx;
 297
 298         void *priv_data;
 299 };
 300
 301 /**
 302  * enum queue_index: Queue index type
 303  *
 304  * @Q_INDEX: Index pointer to the current entry in the queue, if this entry is
 305  *      owned by the hardware then the queue is considered to be full.
 306  * @Q_INDEX_DONE: Index pointer to the next entry which will be completed by
 307  *      the hardware and for which we need to run the txdone handler. If this
 308  *      entry is not owned by the hardware the queue is considered to be empty.
 309  * @Q_INDEX_CRYPTO: Index pointer to the next entry which encryption/decription
 310  *      will be completed by the hardware next.
 311  * @Q_INDEX_MAX: Keep last, used in &struct data_queue to determine the size
 312  *      of the index array.
 313  */
 314 enum queue_index {
 315         Q_INDEX,
 316         Q_INDEX_DONE,
 317         Q_INDEX_CRYPTO,
 318         Q_INDEX_MAX,
 319 };
 320
 321 /**
 322  * struct data_queue: Data queue
 323  *
 324  * @rt2x00dev: Pointer to main &struct rt2x00dev where this queue belongs to.
 325  * @entries: Base address of the &struct queue_entry which are
 326  *      part of this queue.
 327  * @qid: The queue identification, see &enum data_queue_qid.
 328  * @lock: Spinlock to protect index handling. Whenever @index, @index_done or
 329  *      @index_crypt needs to be changed this lock should be grabbed to prevent
 330  *      index corruption due to concurrency.
 331  * @count: Number of frames handled in the queue.
 332  * @limit: Maximum number of entries in the queue.
 333  * @length: Number of frames in queue.
 334  * @index: Index pointers to entry positions in the queue,
 335  *      use &enum queue_index to get a specific index field.
 336  * @aifs: The aifs value for outgoing frames (field ignored in RX queue).
 337  * @cw_min: The cw min value for outgoing frames (field ignored in RX queue).
 338  * @cw_max: The cw max value for outgoing frames (field ignored in RX queue).
 339  * @data_size: Maximum data size for the frames in this queue.
 340  * @desc_size: Hardware descriptor size for the data in this queue.
 341  */
 342 struct data_queue {
 343         struct rt2x00_dev *rt2x00dev;
 344         struct queue_entry *entries;
 345
 346         enum data_queue_qid qid;
 347
 348         spinlock_t lock;
 349         unsigned int count;
 350         unsigned short limit;
 351         unsigned short length;
 352         unsigned short index[Q_INDEX_MAX];
 353
 354         unsigned short aifs;
 355         unsigned short cw_min;
 356         unsigned short cw_max;
 357
 358         unsigned short data_size;
 359         unsigned short desc_size;
 360 };
 361
 362 /**
 363  * struct data_queue_desc: Data queue description
 364  *
 365  * The information in this structure is used by drivers
 366  * to inform rt2x00lib about the creation of the data queue.
 367  *
 368  * @entry_num: Maximum number of entries for a queue.
 369  * @data_size: Maximum data size for the frames in this queue.
 370  * @desc_size: Hardware descriptor size for the data in this queue.
 371  * @priv_size: Size of per-queue_entry private data.
 372  */
 373 struct data_queue_desc {
 374         unsigned short entry_num;
 375         unsigned short data_size;
 376         unsigned short desc_size;
 377         unsigned short priv_size;
 378 };
 379
 380 /**
 381  * queue_end - Return pointer to the last queue (HELPER MACRO).
 382  * @__dev: Pointer to &struct rt2x00_dev
 383  *
 384  * Using the base rx pointer and the maximum number of available queues,
 385  * this macro will return the address of 1 position beyond  the end of the
 386  * queues array.
 387  */
 388 #define queue_end(__dev) \
 389         &(__dev)->rx[(__dev)->data_queues]
 390
 391 /**
 392  * tx_queue_end - Return pointer to the last TX queue (HELPER MACRO).
 393  * @__dev: Pointer to &struct rt2x00_dev
 394  *
 395  * Using the base tx pointer and the maximum number of available TX
 396  * queues, this macro will return the address of 1 position beyond
 397  * the end of the TX queue array.
 398  */
 399 #define tx_queue_end(__dev) \
 400         &(__dev)->tx[(__dev)->hw->queues]
 401
 402 /**
 403  * queue_loop - Loop through the queues within a specific range (HELPER MACRO).
 404  * @__entry: Pointer where the current queue entry will be stored in.
 405  * @__start: Start queue pointer.
 406  * @__end: End queue pointer.
 407  *
 408  * This macro will loop through all queues between &__start and &__end.
 409  */
 410 #define queue_loop(__entry, __start, __end)                     \
 411         for ((__entry) = (__start);                             \
 412              prefetch(&(__entry)[1]), (__entry) != (__end);     \
 413              (__entry) = &(__entry)[1])
 414
 415 /**
 416  * queue_for_each - Loop through all queues
 417  * @__dev: Pointer to &struct rt2x00_dev
 418  * @__entry: Pointer where the current queue entry will be stored in.
 419  *
 420  * This macro will loop through all available queues.
 421  */
 422 #define queue_for_each(__dev, __entry) \
 423         queue_loop(__entry, (__dev)->rx, queue_end(__dev))
 424
 425 /**
 426  * tx_queue_for_each - Loop through the TX queues
 427  * @__dev: Pointer to &struct rt2x00_dev
 428  * @__entry: Pointer where the current queue entry will be stored in.
 429  *
 430  * This macro will loop through all TX related queues excluding
 431  * the Beacon and Atim queues.
 432  */
 433 #define tx_queue_for_each(__dev, __entry) \
 434         queue_loop(__entry, (__dev)->tx, tx_queue_end(__dev))
 435
 436 /**
 437  * txall_queue_for_each - Loop through all TX related queues
 438  * @__dev: Pointer to &struct rt2x00_dev
 439  * @__entry: Pointer where the current queue entry will be stored in.
 440  *
 441  * This macro will loop through all TX related queues including
 442  * the Beacon and Atim queues.
 443  */
 444 #define txall_queue_for_each(__dev, __entry) \
 445         queue_loop(__entry, (__dev)->tx, queue_end(__dev))
 446
 447 /**
 448  * rt2x00queue_empty - Check if the queue is empty.
 449  * @queue: Queue to check if empty.
 450  */
 451 static inline int rt2x00queue_empty(struct data_queue *queue)
 452 {
 453         return queue->length == 0;
 454 }
 455
 456 /**
 457  * rt2x00queue_full - Check if the queue is full.
 458  * @queue: Queue to check if full.
 459  */
 460 static inline int rt2x00queue_full(struct data_queue *queue)
 461 {
 462         return queue->length == queue->limit;
 463 }
 464
 465 /**
 466  * rt2x00queue_free - Check the number of available entries in queue.
 467  * @queue: Queue to check.
 468  */
 469 static inline int rt2x00queue_available(struct data_queue *queue)
 470 {
 471         return queue->limit - queue->length;
 472 }
 473
 474 /**
 475  * rt2x00_desc_read - Read a word from the hardware descriptor.
 476  * @desc: Base descriptor address
 477  * @word: Word index from where the descriptor should be read.
 478  * @value: Address where the descriptor value should be written into.
 479  */
 480 static inline void rt2x00_desc_read(__le32 *desc, const u8 word, u32 *value)
 481 {
 482         *value = le32_to_cpu(desc[word]);
 483 }
 484
 485 /**
 486  * rt2x00_desc_write - wrote a word to the hardware descriptor.
 487  * @desc: Base descriptor address
 488  * @word: Word index from where the descriptor should be written.
 489  * @value: Value that should be written into the descriptor.
 490  */
 491 static inline void rt2x00_desc_write(__le32 *desc, const u8 word, u32 value)
 492 {
 493         desc[word] = cpu_to_le32(value);
 494 }
 495
 496 #endif /* RT2X00QUEUE_H */