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 enum data_queue_qid {
  59         QID_AC_BE = 0,
  60         QID_AC_BK = 1,
  61         QID_AC_VI = 2,
  62         QID_AC_VO = 3,
  63         QID_HCCA = 4,
  64         QID_MGMT = 13,
  65         QID_RX = 14,
  66         QID_OTHER = 15,
  67 };
  68
  69 /**
  70  * enum rt2x00_bcn_queue: Beacon queue index
  71  *
  72  * Start counting with a high offset, this because this enumeration
  73  * supplements &enum ieee80211_tx_queue and we should prevent value
  74  * conflicts.
  75  *
  76  * @RT2X00_BCN_QUEUE_BEACON: Beacon queue
  77  * @RT2X00_BCN_QUEUE_ATIM: Atim queue (sends frame after beacon)
  78  */
  79 enum rt2x00_bcn_queue {
  80         RT2X00_BCN_QUEUE_BEACON = 100,
  81         RT2X00_BCN_QUEUE_ATIM = 101,
  82 };
  83
  84 /**
  85  * enum skb_frame_desc_flags: Flags for &struct skb_frame_desc
  86  *
  87  * @FRAME_DESC_DRIVER_GENERATED: Frame was generated inside driver
  88  *      and should not be reported back to mac80211 during txdone.
  89  */
  90 enum skb_frame_desc_flags {
  91         FRAME_DESC_DRIVER_GENERATED = 1 << 0,
  92 };
  93
  94 /**
  95  * struct skb_frame_desc: Descriptor information for the skb buffer
  96  *
  97  * This structure is placed over the skb->cb array, this means that
  98  * this structure should not exceed the size of that array (48 bytes).
  99  *
 100  * @flags: Frame flags, see &enum skb_frame_desc_flags.
 101  * @frame_type: Frame type, see &enum rt2x00_dump_type.
 102  * @data: Pointer to data part of frame (Start of ieee80211 header).
 103  * @desc: Pointer to descriptor part of the frame.
 104  *      Note that this pointer could point to something outside
 105  *      of the scope of the skb->data pointer.
 106  * @data_len: Length of the frame data.
 107  * @desc_len: Length of the frame descriptor.
 108
 109  * @entry: The entry to which this sk buffer belongs.
 110  */
 111 struct skb_frame_desc {
 112         unsigned int flags;
 113
 114         unsigned int frame_type;
 115
 116         void *data;
 117         void *desc;
 118
 119         unsigned int data_len;
 120         unsigned int desc_len;
 121
 122         struct queue_entry *entry;
 123 };
 124
 125 static inline struct skb_frame_desc* get_skb_frame_desc(struct sk_buff *skb)
 126 {
 127         BUILD_BUG_ON(sizeof(struct skb_frame_desc) > sizeof(skb->cb));
 128         return (struct skb_frame_desc *)&skb->cb[0];
 129 }
 130
 131 /**
 132  * enum rxdone_entry_desc_flags: Flags for &struct rxdone_entry_desc
 133  *
 134  * @RXDONE_SIGNAL_PLCP: Does the signal field contain the plcp value,
 135  *      or does it contain the bitrate itself.
 136  * @RXDONE_MY_BSS: Does this frame originate from device's BSS.
 137  */
 138 enum rxdone_entry_desc_flags {
 139         RXDONE_SIGNAL_PLCP = 1 << 0,
 140         RXDONE_MY_BSS = 1 << 1,
 141 };
 142
 143 /**
 144  * struct rxdone_entry_desc: RX Entry descriptor
 145  *
 146  * Summary of information that has been read from the RX frame descriptor.
 147  *
 148  * @signal: Signal of the received frame.
 149  * @rssi: RSSI of the received frame.
 150  * @size: Data size of the received frame.
 151  * @flags: MAC80211 receive flags (See &enum mac80211_rx_flags).
 152  * @dev_flags: Ralink receive flags (See &enum rxdone_entry_desc_flags).
 153
 154  */
 155 struct rxdone_entry_desc {
 156         int signal;
 157         int rssi;
 158         int size;
 159         int flags;
 160         int dev_flags;
 161 };
 162
 163 /**
 164  * struct txdone_entry_desc: TX done entry descriptor
 165  *
 166  * Summary of information that has been read from the TX frame descriptor
 167  * after the device is done with transmission.
 168  *
 169  * @control: Control structure which was used to transmit the frame.
 170  * @status: TX status (See &enum tx_status).
 171  * @retry: Retry count.
 172  */
 173 struct txdone_entry_desc {
 174         struct ieee80211_tx_control *control;
 175         int status;
 176         int retry;
 177 };
 178
 179 /**
 180  * enum txentry_desc_flags: Status flags for TX entry descriptor
 181  *
 182  * @ENTRY_TXD_RTS_FRAME: This frame is a RTS frame.
 183  * @ENTRY_TXD_OFDM_RATE: This frame is send out with an OFDM rate.
 184  * @ENTRY_TXD_MORE_FRAG: This frame is followed by another fragment.
 185  * @ENTRY_TXD_REQ_TIMESTAMP: Require timestamp to be inserted.
 186  * @ENTRY_TXD_BURST: This frame belongs to the same burst event.
 187  * @ENTRY_TXD_ACK: An ACK is required for this frame.
 188  */
 189 enum txentry_desc_flags {
 190         ENTRY_TXD_RTS_FRAME,
 191         ENTRY_TXD_OFDM_RATE,
 192         ENTRY_TXD_MORE_FRAG,
 193         ENTRY_TXD_REQ_TIMESTAMP,
 194         ENTRY_TXD_BURST,
 195         ENTRY_TXD_ACK,
 196 };
 197
 198 /**
 199  * struct txentry_desc: TX Entry descriptor
 200  *
 201  * Summary of information for the frame descriptor before sending a TX frame.
 202  *
 203  * @flags: Descriptor flags (See &enum queue_entry_flags).
 204  * @queue: Queue identification (See &enum data_queue_qid).
 205  * @length_high: PLCP length high word.
 206  * @length_low: PLCP length low word.
 207  * @signal: PLCP signal.
 208  * @service: PLCP service.
 209  * @aifs: AIFS value.
 210  * @ifs: IFS value.
 211  * @cw_min: cwmin value.
 212  * @cw_max: cwmax value.
 213  */
 214 struct txentry_desc {
 215         unsigned long flags;
 216
 217         enum data_queue_qid queue;
 218
 219         u16 length_high;
 220         u16 length_low;
 221         u16 signal;
 222         u16 service;
 223
 224         int aifs;
 225         int ifs;
 226         int cw_min;
 227         int cw_max;
 228 };
 229
 230 /**
 231  * enum queue_entry_flags: Status flags for queue entry
 232  *
 233  * @ENTRY_BCN_ASSIGNED: This entry has been assigned to an interface.
 234  *      As long as this bit is set, this entry may only be touched
 235  *      through the interface structure.
 236  * @ENTRY_OWNER_DEVICE_DATA: This entry is owned by the device for data
 237  *      transfer (either TX or RX depending on the queue). The entry should
 238  *      only be touched after the device has signaled it is done with it.
 239  * @ENTRY_OWNER_DEVICE_CRYPTO: This entry is owned by the device for data
 240  *      encryption or decryption. The entry should only be touched after
 241  *      the device has signaled it is done with it.
 242  */
 243
 244 enum queue_entry_flags {
 245         ENTRY_BCN_ASSIGNED,
 246         ENTRY_OWNER_DEVICE_DATA,
 247         ENTRY_OWNER_DEVICE_CRYPTO,
 248 };
 249
 250 /**
 251  * struct queue_entry: Entry inside the &struct data_queue
 252  *
 253  * @flags: Entry flags, see &enum queue_entry_flags.
 254  * @queue: The data queue (&struct data_queue) to which this entry belongs.
 255  * @skb: The buffer which is currently being transmitted (for TX queue),
 256  *      or used to directly recieve data in (for RX queue).
 257  * @entry_idx: The entry index number.
 258  * @priv_data: Private data belonging to this queue entry. The pointer
 259  *      points to data specific to a particular driver and queue type.
 260  */
 261 struct queue_entry {
 262         unsigned long flags;
 263
 264         struct data_queue *queue;
 265
 266         struct sk_buff *skb;
 267
 268         unsigned int entry_idx;
 269
 270         void *priv_data;
 271 };
 272
 273 /**
 274  * enum queue_index: Queue index type
 275  *
 276  * @Q_INDEX: Index pointer to the current entry in the queue, if this entry is
 277  *      owned by the hardware then the queue is considered to be full.
 278  * @Q_INDEX_DONE: Index pointer to the next entry which will be completed by
 279  *      the hardware and for which we need to run the txdone handler. If this
 280  *      entry is not owned by the hardware the queue is considered to be empty.
 281  * @Q_INDEX_CRYPTO: Index pointer to the next entry which encryption/decription
 282  *      will be completed by the hardware next.
 283  * @Q_INDEX_MAX: Keep last, used in &struct data_queue to determine the size
 284  *      of the index array.
 285  */
 286 enum queue_index {
 287         Q_INDEX,
 288         Q_INDEX_DONE,
 289         Q_INDEX_CRYPTO,
 290         Q_INDEX_MAX,
 291 };
 292
 293 /**
 294  * struct data_queue: Data queue
 295  *
 296  * @rt2x00dev: Pointer to main &struct rt2x00dev where this queue belongs to.
 297  * @entries: Base address of the &struct queue_entry which are
 298  *      part of this queue.
 299  * @qid: The queue identification, see &enum data_queue_qid.
 300  * @lock: Spinlock to protect index handling. Whenever @index, @index_done or
 301  *      @index_crypt needs to be changed this lock should be grabbed to prevent
 302  *      index corruption due to concurrency.
 303  * @count: Number of frames handled in the queue.
 304  * @limit: Maximum number of entries in the queue.
 305  * @length: Number of frames in queue.
 306  * @index: Index pointers to entry positions in the queue,
 307  *      use &enum queue_index to get a specific index field.
 308  * @aifs: The aifs value for outgoing frames (field ignored in RX queue).
 309  * @cw_min: The cw min value for outgoing frames (field ignored in RX queue).
 310  * @cw_max: The cw max value for outgoing frames (field ignored in RX queue).
 311  * @data_size: Maximum data size for the frames in this queue.
 312  * @desc_size: Hardware descriptor size for the data in this queue.
 313  */
 314 struct data_queue {
 315         struct rt2x00_dev *rt2x00dev;
 316         struct queue_entry *entries;
 317
 318         enum data_queue_qid qid;
 319
 320         spinlock_t lock;
 321         unsigned int count;
 322         unsigned short limit;
 323         unsigned short length;
 324         unsigned short index[Q_INDEX_MAX];
 325
 326         unsigned short aifs;
 327         unsigned short cw_min;
 328         unsigned short cw_max;
 329
 330         unsigned short data_size;
 331         unsigned short desc_size;
 332 };
 333
 334 /**
 335  * struct data_queue_desc: Data queue description
 336  *
 337  * The information in this structure is used by drivers
 338  * to inform rt2x00lib about the creation of the data queue.
 339  *
 340  * @entry_num: Maximum number of entries for a queue.
 341  * @data_size: Maximum data size for the frames in this queue.
 342  * @desc_size: Hardware descriptor size for the data in this queue.
 343  * @priv_size: Size of per-queue_entry private data.
 344  */
 345 struct data_queue_desc {
 346         unsigned short entry_num;
 347         unsigned short data_size;
 348         unsigned short desc_size;
 349         unsigned short priv_size;
 350 };
 351
 352 /**
 353  * queue_end - Return pointer to the last queue (HELPER MACRO).
 354  * @__dev: Pointer to &struct rt2x00_dev
 355  *
 356  * Using the base rx pointer and the maximum number of available queues,
 357  * this macro will return the address of 1 position beyond  the end of the
 358  * queues array.
 359  */
 360 #define queue_end(__dev) \
 361         &(__dev)->rx[(__dev)->data_queues]
 362
 363 /**
 364  * tx_queue_end - Return pointer to the last TX queue (HELPER MACRO).
 365  * @__dev: Pointer to &struct rt2x00_dev
 366  *
 367  * Using the base tx pointer and the maximum number of available TX
 368  * queues, this macro will return the address of 1 position beyond
 369  * the end of the TX queue array.
 370  */
 371 #define tx_queue_end(__dev) \
 372         &(__dev)->tx[(__dev)->hw->queues]
 373
 374 /**
 375  * queue_loop - Loop through the queues within a specific range (HELPER MACRO).
 376  * @__entry: Pointer where the current queue entry will be stored in.
 377  * @__start: Start queue pointer.
 378  * @__end: End queue pointer.
 379  *
 380  * This macro will loop through all queues between &__start and &__end.
 381  */
 382 #define queue_loop(__entry, __start, __end)                     \
 383         for ((__entry) = (__start);                             \
 384              prefetch(&(__entry)[1]), (__entry) != (__end);     \
 385              (__entry) = &(__entry)[1])
 386
 387 /**
 388  * queue_for_each - Loop through all queues
 389  * @__dev: Pointer to &struct rt2x00_dev
 390  * @__entry: Pointer where the current queue entry will be stored in.
 391  *
 392  * This macro will loop through all available queues.
 393  */
 394 #define queue_for_each(__dev, __entry) \
 395         queue_loop(__entry, (__dev)->rx, queue_end(__dev))
 396
 397 /**
 398  * tx_queue_for_each - Loop through the TX queues
 399  * @__dev: Pointer to &struct rt2x00_dev
 400  * @__entry: Pointer where the current queue entry will be stored in.
 401  *
 402  * This macro will loop through all TX related queues excluding
 403  * the Beacon and Atim queues.
 404  */
 405 #define tx_queue_for_each(__dev, __entry) \
 406         queue_loop(__entry, (__dev)->tx, tx_queue_end(__dev))
 407
 408 /**
 409  * txall_queue_for_each - Loop through all TX related queues
 410  * @__dev: Pointer to &struct rt2x00_dev
 411  * @__entry: Pointer where the current queue entry will be stored in.
 412  *
 413  * This macro will loop through all TX related queues including
 414  * the Beacon and Atim queues.
 415  */
 416 #define txall_queue_for_each(__dev, __entry) \
 417         queue_loop(__entry, (__dev)->tx, queue_end(__dev))
 418
 419 /**
 420  * rt2x00queue_empty - Check if the queue is empty.
 421  * @queue: Queue to check if empty.
 422  */
 423 static inline int rt2x00queue_empty(struct data_queue *queue)
 424 {
 425         return queue->length == 0;
 426 }
 427
 428 /**
 429  * rt2x00queue_full - Check if the queue is full.
 430  * @queue: Queue to check if full.
 431  */
 432 static inline int rt2x00queue_full(struct data_queue *queue)
 433 {
 434         return queue->length == queue->limit;
 435 }
 436
 437 /**
 438  * rt2x00queue_free - Check the number of available entries in queue.
 439  * @queue: Queue to check.
 440  */
 441 static inline int rt2x00queue_available(struct data_queue *queue)
 442 {
 443         return queue->limit - queue->length;
 444 }
 445
 446 /**
 447  * rt2x00_desc_read - Read a word from the hardware descriptor.
 448  * @desc: Base descriptor address
 449  * @word: Word index from where the descriptor should be read.
 450  * @value: Address where the descriptor value should be written into.
 451  */
 452 static inline void rt2x00_desc_read(__le32 *desc, const u8 word, u32 *value)
 453 {
 454         *value = le32_to_cpu(desc[word]);
 455 }
 456
 457 /**
 458  * rt2x00_desc_write - wrote a word to the hardware descriptor.
 459  * @desc: Base descriptor address
 460  * @word: Word index from where the descriptor should be written.
 461  * @value: Value that should be written into the descriptor.
 462  */
 463 static inline void rt2x00_desc_write(__le32 *desc, const u8 word, u32 value)
 464 {
 465         desc[word] = cpu_to_le32(value);
 466 }
 467
 468 #endif /* RT2X00QUEUE_H */