Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
[deliverable/linux.git] / 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 */
39 #define DATA_FRAME_SIZE 2432
40 #define MGMT_FRAME_SIZE 256
41
42 /**
43 * DOC: Number of entries per queue
44 *
45 * Under normal load without fragmentation 12 entries are sufficient
46 * without the queue being filled up to the maximum. When using fragmentation
47 * and the queue threshold code we need to add some additional margins to
48 * make sure the queue will never (or only under extreme load) fill up
49 * completely.
50 * Since we don't use preallocated DMA having a large number of queue entries
51 * will have only minimal impact on the memory requirements for the queue.
52 */
53 #define RX_ENTRIES 24
54 #define TX_ENTRIES 24
55 #define BEACON_ENTRIES 1
56 #define ATIM_ENTRIES 8
57
58 /**
59 * enum data_queue_qid: Queue identification
60 *
61 * @QID_AC_BE: AC BE queue
62 * @QID_AC_BK: AC BK queue
63 * @QID_AC_VI: AC VI queue
64 * @QID_AC_VO: AC VO queue
65 * @QID_HCCA: HCCA queue
66 * @QID_MGMT: MGMT queue (prio queue)
67 * @QID_RX: RX queue
68 * @QID_OTHER: None of the above (don't use, only present for completeness)
69 * @QID_BEACON: Beacon queue (value unspecified, don't send it to device)
70 * @QID_ATIM: Atim queue (value unspeficied, don't send it to device)
71 */
72 enum data_queue_qid {
73 QID_AC_BE = 0,
74 QID_AC_BK = 1,
75 QID_AC_VI = 2,
76 QID_AC_VO = 3,
77 QID_HCCA = 4,
78 QID_MGMT = 13,
79 QID_RX = 14,
80 QID_OTHER = 15,
81 QID_BEACON,
82 QID_ATIM,
83 };
84
85 /**
86 * enum skb_frame_desc_flags: Flags for &struct skb_frame_desc
87 *
88 * @SKBDESC_DMA_MAPPED_RX: &skb_dma field has been mapped for RX
89 * @SKBDESC_DMA_MAPPED_TX: &skb_dma field has been mapped for TX
90 * @FRAME_DESC_IV_STRIPPED: Frame contained a IV/EIV provided by
91 * mac80211 but was stripped for processing by the driver.
92 */
93 enum skb_frame_desc_flags {
94 SKBDESC_DMA_MAPPED_RX = 1 << 0,
95 SKBDESC_DMA_MAPPED_TX = 1 << 1,
96 FRAME_DESC_IV_STRIPPED = 1 << 2,
97 };
98
99 /**
100 * struct skb_frame_desc: Descriptor information for the skb buffer
101 *
102 * This structure is placed over the driver_data array, this means that
103 * this structure should not exceed the size of that array (40 bytes).
104 *
105 * @flags: Frame flags, see &enum skb_frame_desc_flags.
106 * @desc_len: Length of the frame descriptor.
107 * @tx_rate_idx: the index of the TX rate, used for TX status reporting
108 * @tx_rate_flags: the TX rate flags, used for TX status reporting
109 * @desc: Pointer to descriptor part of the frame.
110 * Note that this pointer could point to something outside
111 * of the scope of the skb->data pointer.
112 * @iv: IV/EIV data used during encryption/decryption.
113 * @skb_dma: (PCI-only) the DMA address associated with the sk buffer.
114 * @entry: The entry to which this sk buffer belongs.
115 */
116 struct skb_frame_desc {
117 u8 flags;
118
119 u8 desc_len;
120 u8 tx_rate_idx;
121 u8 tx_rate_flags;
122
123 void *desc;
124
125 __le32 iv[2];
126
127 dma_addr_t skb_dma;
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: Signal field contains the plcp value.
147 * @RXDONE_SIGNAL_BITRATE: Signal field contains the bitrate value.
148 * @RXDONE_MY_BSS: Does this frame originate from device's BSS.
149 * @RXDONE_CRYPTO_IV: Driver provided IV/EIV data.
150 * @RXDONE_CRYPTO_ICV: Driver provided ICV data.
151 */
152 enum rxdone_entry_desc_flags {
153 RXDONE_SIGNAL_PLCP = 1 << 0,
154 RXDONE_SIGNAL_BITRATE = 1 << 1,
155 RXDONE_MY_BSS = 1 << 2,
156 RXDONE_CRYPTO_IV = 1 << 3,
157 RXDONE_CRYPTO_ICV = 1 << 4,
158 };
159
160 /**
161 * RXDONE_SIGNAL_MASK - Define to mask off all &rxdone_entry_desc_flags flags
162 * except for the RXDONE_SIGNAL_* flags. This is useful to convert the dev_flags
163 * from &rxdone_entry_desc to a signal value type.
164 */
165 #define RXDONE_SIGNAL_MASK \
166 ( RXDONE_SIGNAL_PLCP | RXDONE_SIGNAL_BITRATE )
167
168 /**
169 * struct rxdone_entry_desc: RX Entry descriptor
170 *
171 * Summary of information that has been read from the RX frame descriptor.
172 *
173 * @timestamp: RX Timestamp
174 * @signal: Signal of the received frame.
175 * @rssi: RSSI of the received frame.
176 * @noise: Measured noise during frame reception.
177 * @size: Data size of the received frame.
178 * @flags: MAC80211 receive flags (See &enum mac80211_rx_flags).
179 * @dev_flags: Ralink receive flags (See &enum rxdone_entry_desc_flags).
180 * @cipher: Cipher type used during decryption.
181 * @cipher_status: Decryption status.
182 * @iv: IV/EIV data used during decryption.
183 * @icv: ICV data used during decryption.
184 */
185 struct rxdone_entry_desc {
186 u64 timestamp;
187 int signal;
188 int rssi;
189 int noise;
190 int size;
191 int flags;
192 int dev_flags;
193 u8 cipher;
194 u8 cipher_status;
195
196 __le32 iv[2];
197 __le32 icv;
198 };
199
200 /**
201 * enum txdone_entry_desc_flags: Flags for &struct txdone_entry_desc
202 *
203 * @TXDONE_UNKNOWN: Hardware could not determine success of transmission.
204 * @TXDONE_SUCCESS: Frame was successfully send
205 * @TXDONE_FAILURE: Frame was not successfully send
206 * @TXDONE_EXCESSIVE_RETRY: In addition to &TXDONE_FAILURE, the
207 * frame transmission failed due to excessive retries.
208 */
209 enum txdone_entry_desc_flags {
210 TXDONE_UNKNOWN,
211 TXDONE_SUCCESS,
212 TXDONE_FAILURE,
213 TXDONE_EXCESSIVE_RETRY,
214 };
215
216 /**
217 * struct txdone_entry_desc: TX done entry descriptor
218 *
219 * Summary of information that has been read from the TX frame descriptor
220 * after the device is done with transmission.
221 *
222 * @flags: TX done flags (See &enum txdone_entry_desc_flags).
223 * @retry: Retry count.
224 */
225 struct txdone_entry_desc {
226 unsigned long flags;
227 int retry;
228 };
229
230 /**
231 * enum txentry_desc_flags: Status flags for TX entry descriptor
232 *
233 * @ENTRY_TXD_RTS_FRAME: This frame is a RTS frame.
234 * @ENTRY_TXD_CTS_FRAME: This frame is a CTS-to-self frame.
235 * @ENTRY_TXD_GENERATE_SEQ: This frame requires sequence counter.
236 * @ENTRY_TXD_FIRST_FRAGMENT: This is the first frame.
237 * @ENTRY_TXD_MORE_FRAG: This frame is followed by another fragment.
238 * @ENTRY_TXD_REQ_TIMESTAMP: Require timestamp to be inserted.
239 * @ENTRY_TXD_BURST: This frame belongs to the same burst event.
240 * @ENTRY_TXD_ACK: An ACK is required for this frame.
241 * @ENTRY_TXD_RETRY_MODE: When set, the long retry count is used.
242 * @ENTRY_TXD_ENCRYPT: This frame should be encrypted.
243 * @ENTRY_TXD_ENCRYPT_PAIRWISE: Use pairwise key table (instead of shared).
244 * @ENTRY_TXD_ENCRYPT_IV: Generate IV/EIV in hardware.
245 * @ENTRY_TXD_ENCRYPT_MMIC: Generate MIC in hardware.
246 */
247 enum txentry_desc_flags {
248 ENTRY_TXD_RTS_FRAME,
249 ENTRY_TXD_CTS_FRAME,
250 ENTRY_TXD_GENERATE_SEQ,
251 ENTRY_TXD_FIRST_FRAGMENT,
252 ENTRY_TXD_MORE_FRAG,
253 ENTRY_TXD_REQ_TIMESTAMP,
254 ENTRY_TXD_BURST,
255 ENTRY_TXD_ACK,
256 ENTRY_TXD_RETRY_MODE,
257 ENTRY_TXD_ENCRYPT,
258 ENTRY_TXD_ENCRYPT_PAIRWISE,
259 ENTRY_TXD_ENCRYPT_IV,
260 ENTRY_TXD_ENCRYPT_MMIC,
261 };
262
263 /**
264 * struct txentry_desc: TX Entry descriptor
265 *
266 * Summary of information for the frame descriptor before sending a TX frame.
267 *
268 * @flags: Descriptor flags (See &enum queue_entry_flags).
269 * @queue: Queue identification (See &enum data_queue_qid).
270 * @length_high: PLCP length high word.
271 * @length_low: PLCP length low word.
272 * @signal: PLCP signal.
273 * @service: PLCP service.
274 * @rate_mode: Rate mode (See @enum rate_modulation).
275 * @retry_limit: Max number of retries.
276 * @aifs: AIFS value.
277 * @ifs: IFS value.
278 * @cw_min: cwmin value.
279 * @cw_max: cwmax value.
280 * @cipher: Cipher type used for encryption.
281 * @key_idx: Key index used for encryption.
282 * @iv_offset: Position where IV should be inserted by hardware.
283 */
284 struct txentry_desc {
285 unsigned long flags;
286
287 enum data_queue_qid queue;
288
289 u16 length_high;
290 u16 length_low;
291 u16 signal;
292 u16 service;
293
294 u16 rate_mode;
295
296 short retry_limit;
297 short aifs;
298 short ifs;
299 short cw_min;
300 short cw_max;
301
302 enum cipher cipher;
303 u16 key_idx;
304 u16 iv_offset;
305 };
306
307 /**
308 * enum queue_entry_flags: Status flags for queue entry
309 *
310 * @ENTRY_BCN_ASSIGNED: This entry has been assigned to an interface.
311 * As long as this bit is set, this entry may only be touched
312 * through the interface structure.
313 * @ENTRY_OWNER_DEVICE_DATA: This entry is owned by the device for data
314 * transfer (either TX or RX depending on the queue). The entry should
315 * only be touched after the device has signaled it is done with it.
316 * @ENTRY_OWNER_DEVICE_CRYPTO: This entry is owned by the device for data
317 * encryption or decryption. The entry should only be touched after
318 * the device has signaled it is done with it.
319 * @ENTRY_DATA_PENDING: This entry contains a valid frame and is waiting
320 * for the signal to start sending.
321 */
322 enum queue_entry_flags {
323 ENTRY_BCN_ASSIGNED,
324 ENTRY_OWNER_DEVICE_DATA,
325 ENTRY_OWNER_DEVICE_CRYPTO,
326 ENTRY_DATA_PENDING,
327 };
328
329 /**
330 * struct queue_entry: Entry inside the &struct data_queue
331 *
332 * @flags: Entry flags, see &enum queue_entry_flags.
333 * @queue: The data queue (&struct data_queue) to which this entry belongs.
334 * @skb: The buffer which is currently being transmitted (for TX queue),
335 * or used to directly recieve data in (for RX queue).
336 * @entry_idx: The entry index number.
337 * @priv_data: Private data belonging to this queue entry. The pointer
338 * points to data specific to a particular driver and queue type.
339 */
340 struct queue_entry {
341 unsigned long flags;
342
343 struct data_queue *queue;
344
345 struct sk_buff *skb;
346
347 unsigned int entry_idx;
348
349 void *priv_data;
350 };
351
352 /**
353 * enum queue_index: Queue index type
354 *
355 * @Q_INDEX: Index pointer to the current entry in the queue, if this entry is
356 * owned by the hardware then the queue is considered to be full.
357 * @Q_INDEX_DONE: Index pointer to the next entry which will be completed by
358 * the hardware and for which we need to run the txdone handler. If this
359 * entry is not owned by the hardware the queue is considered to be empty.
360 * @Q_INDEX_CRYPTO: Index pointer to the next entry which encryption/decription
361 * will be completed by the hardware next.
362 * @Q_INDEX_MAX: Keep last, used in &struct data_queue to determine the size
363 * of the index array.
364 */
365 enum queue_index {
366 Q_INDEX,
367 Q_INDEX_DONE,
368 Q_INDEX_CRYPTO,
369 Q_INDEX_MAX,
370 };
371
372 /**
373 * struct data_queue: Data queue
374 *
375 * @rt2x00dev: Pointer to main &struct rt2x00dev where this queue belongs to.
376 * @entries: Base address of the &struct queue_entry which are
377 * part of this queue.
378 * @qid: The queue identification, see &enum data_queue_qid.
379 * @lock: Spinlock to protect index handling. Whenever @index, @index_done or
380 * @index_crypt needs to be changed this lock should be grabbed to prevent
381 * index corruption due to concurrency.
382 * @count: Number of frames handled in the queue.
383 * @limit: Maximum number of entries in the queue.
384 * @threshold: Minimum number of free entries before queue is kicked by force.
385 * @length: Number of frames in queue.
386 * @index: Index pointers to entry positions in the queue,
387 * use &enum queue_index to get a specific index field.
388 * @txop: maximum burst time.
389 * @aifs: The aifs value for outgoing frames (field ignored in RX queue).
390 * @cw_min: The cw min value for outgoing frames (field ignored in RX queue).
391 * @cw_max: The cw max value for outgoing frames (field ignored in RX queue).
392 * @data_size: Maximum data size for the frames in this queue.
393 * @desc_size: Hardware descriptor size for the data in this queue.
394 * @usb_endpoint: Device endpoint used for communication (USB only)
395 * @usb_maxpacket: Max packet size for given endpoint (USB only)
396 */
397 struct data_queue {
398 struct rt2x00_dev *rt2x00dev;
399 struct queue_entry *entries;
400
401 enum data_queue_qid qid;
402
403 spinlock_t lock;
404 unsigned int count;
405 unsigned short limit;
406 unsigned short threshold;
407 unsigned short length;
408 unsigned short index[Q_INDEX_MAX];
409
410 unsigned short txop;
411 unsigned short aifs;
412 unsigned short cw_min;
413 unsigned short cw_max;
414
415 unsigned short data_size;
416 unsigned short desc_size;
417
418 unsigned short usb_endpoint;
419 unsigned short usb_maxpacket;
420 };
421
422 /**
423 * struct data_queue_desc: Data queue description
424 *
425 * The information in this structure is used by drivers
426 * to inform rt2x00lib about the creation of the data queue.
427 *
428 * @entry_num: Maximum number of entries for a queue.
429 * @data_size: Maximum data size for the frames in this queue.
430 * @desc_size: Hardware descriptor size for the data in this queue.
431 * @priv_size: Size of per-queue_entry private data.
432 */
433 struct data_queue_desc {
434 unsigned short entry_num;
435 unsigned short data_size;
436 unsigned short desc_size;
437 unsigned short priv_size;
438 };
439
440 /**
441 * queue_end - Return pointer to the last queue (HELPER MACRO).
442 * @__dev: Pointer to &struct rt2x00_dev
443 *
444 * Using the base rx pointer and the maximum number of available queues,
445 * this macro will return the address of 1 position beyond the end of the
446 * queues array.
447 */
448 #define queue_end(__dev) \
449 &(__dev)->rx[(__dev)->data_queues]
450
451 /**
452 * tx_queue_end - Return pointer to the last TX queue (HELPER MACRO).
453 * @__dev: Pointer to &struct rt2x00_dev
454 *
455 * Using the base tx pointer and the maximum number of available TX
456 * queues, this macro will return the address of 1 position beyond
457 * the end of the TX queue array.
458 */
459 #define tx_queue_end(__dev) \
460 &(__dev)->tx[(__dev)->ops->tx_queues]
461
462 /**
463 * queue_next - Return pointer to next queue in list (HELPER MACRO).
464 * @__queue: Current queue for which we need the next queue
465 *
466 * Using the current queue address we take the address directly
467 * after the queue to take the next queue. Note that this macro
468 * should be used carefully since it does not protect against
469 * moving past the end of the list. (See macros &queue_end and
470 * &tx_queue_end for determining the end of the queue).
471 */
472 #define queue_next(__queue) \
473 &(__queue)[1]
474
475 /**
476 * queue_loop - Loop through the queues within a specific range (HELPER MACRO).
477 * @__entry: Pointer where the current queue entry will be stored in.
478 * @__start: Start queue pointer.
479 * @__end: End queue pointer.
480 *
481 * This macro will loop through all queues between &__start and &__end.
482 */
483 #define queue_loop(__entry, __start, __end) \
484 for ((__entry) = (__start); \
485 prefetch(queue_next(__entry)), (__entry) != (__end);\
486 (__entry) = queue_next(__entry))
487
488 /**
489 * queue_for_each - Loop through all queues
490 * @__dev: Pointer to &struct rt2x00_dev
491 * @__entry: Pointer where the current queue entry will be stored in.
492 *
493 * This macro will loop through all available queues.
494 */
495 #define queue_for_each(__dev, __entry) \
496 queue_loop(__entry, (__dev)->rx, queue_end(__dev))
497
498 /**
499 * tx_queue_for_each - Loop through the TX queues
500 * @__dev: Pointer to &struct rt2x00_dev
501 * @__entry: Pointer where the current queue entry will be stored in.
502 *
503 * This macro will loop through all TX related queues excluding
504 * the Beacon and Atim queues.
505 */
506 #define tx_queue_for_each(__dev, __entry) \
507 queue_loop(__entry, (__dev)->tx, tx_queue_end(__dev))
508
509 /**
510 * txall_queue_for_each - Loop through all TX related queues
511 * @__dev: Pointer to &struct rt2x00_dev
512 * @__entry: Pointer where the current queue entry will be stored in.
513 *
514 * This macro will loop through all TX related queues including
515 * the Beacon and Atim queues.
516 */
517 #define txall_queue_for_each(__dev, __entry) \
518 queue_loop(__entry, (__dev)->tx, queue_end(__dev))
519
520 /**
521 * rt2x00queue_empty - Check if the queue is empty.
522 * @queue: Queue to check if empty.
523 */
524 static inline int rt2x00queue_empty(struct data_queue *queue)
525 {
526 return queue->length == 0;
527 }
528
529 /**
530 * rt2x00queue_full - Check if the queue is full.
531 * @queue: Queue to check if full.
532 */
533 static inline int rt2x00queue_full(struct data_queue *queue)
534 {
535 return queue->length == queue->limit;
536 }
537
538 /**
539 * rt2x00queue_free - Check the number of available entries in queue.
540 * @queue: Queue to check.
541 */
542 static inline int rt2x00queue_available(struct data_queue *queue)
543 {
544 return queue->limit - queue->length;
545 }
546
547 /**
548 * rt2x00queue_threshold - Check if the queue is below threshold
549 * @queue: Queue to check.
550 */
551 static inline int rt2x00queue_threshold(struct data_queue *queue)
552 {
553 return rt2x00queue_available(queue) < queue->threshold;
554 }
555
556 /**
557 * _rt2x00_desc_read - Read a word from the hardware descriptor.
558 * @desc: Base descriptor address
559 * @word: Word index from where the descriptor should be read.
560 * @value: Address where the descriptor value should be written into.
561 */
562 static inline void _rt2x00_desc_read(__le32 *desc, const u8 word, __le32 *value)
563 {
564 *value = desc[word];
565 }
566
567 /**
568 * rt2x00_desc_read - Read a word from the hardware descriptor, this
569 * function will take care of the byte ordering.
570 * @desc: Base descriptor address
571 * @word: Word index from where the descriptor should be read.
572 * @value: Address where the descriptor value should be written into.
573 */
574 static inline void rt2x00_desc_read(__le32 *desc, const u8 word, u32 *value)
575 {
576 __le32 tmp;
577 _rt2x00_desc_read(desc, word, &tmp);
578 *value = le32_to_cpu(tmp);
579 }
580
581 /**
582 * rt2x00_desc_write - write a word to the hardware descriptor, this
583 * function will take care of the byte ordering.
584 * @desc: Base descriptor address
585 * @word: Word index from where the descriptor should be written.
586 * @value: Value that should be written into the descriptor.
587 */
588 static inline void _rt2x00_desc_write(__le32 *desc, const u8 word, __le32 value)
589 {
590 desc[word] = value;
591 }
592
593 /**
594 * rt2x00_desc_write - write a word to the hardware descriptor.
595 * @desc: Base descriptor address
596 * @word: Word index from where the descriptor should be written.
597 * @value: Value that should be written into the descriptor.
598 */
599 static inline void rt2x00_desc_write(__le32 *desc, const u8 word, u32 value)
600 {
601 _rt2x00_desc_write(desc, word, cpu_to_le32(value));
602 }
603
604 #endif /* RT2X00QUEUE_H */
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