1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 	Copyright (C) 2004 - 2010 Ivo van Doorn <IvDoorn@gmail.com>
4 	<http://rt2x00.serialmonkey.com>
5 
6  */
7 
8 /*
9 	Module: rt2x00
10 	Abstract: rt2x00 queue datastructures and routines
11  */
12 
13 #ifndef RT2X00QUEUE_H
14 #define RT2X00QUEUE_H
15 
16 #include <linux/prefetch.h>
17 
18 /**
19  * DOC: Entry frame size
20  *
21  * Ralink PCI devices demand the Frame size to be a multiple of 128 bytes,
22  * for USB devices this restriction does not apply, but the value of
23  * 2432 makes sense since it is big enough to contain the maximum fragment
24  * size according to the ieee802.11 specs.
25  * The aggregation size depends on support from the driver, but should
26  * be something around 3840 bytes.
27  */
28 #define DATA_FRAME_SIZE		2432
29 #define MGMT_FRAME_SIZE		256
30 #define AGGREGATION_SIZE	3840
31 
32 /**
33  * enum data_queue_qid: Queue identification
34  *
35  * @QID_AC_VO: AC VO queue
36  * @QID_AC_VI: AC VI queue
37  * @QID_AC_BE: AC BE queue
38  * @QID_AC_BK: AC BK queue
39  * @QID_HCCA: HCCA queue
40  * @QID_MGMT: MGMT queue (prio queue)
41  * @QID_RX: RX queue
42  * @QID_OTHER: None of the above (don't use, only present for completeness)
43  * @QID_BEACON: Beacon queue (value unspecified, don't send it to device)
44  * @QID_ATIM: Atim queue (value unspecified, don't send it to device)
45  */
46 enum data_queue_qid {
47 	QID_AC_VO = 0,
48 	QID_AC_VI = 1,
49 	QID_AC_BE = 2,
50 	QID_AC_BK = 3,
51 	QID_HCCA = 4,
52 	QID_MGMT = 13,
53 	QID_RX = 14,
54 	QID_OTHER = 15,
55 	QID_BEACON,
56 	QID_ATIM,
57 };
58 
59 /**
60  * enum skb_frame_desc_flags: Flags for &struct skb_frame_desc
61  *
62  * @SKBDESC_DMA_MAPPED_RX: &skb_dma field has been mapped for RX
63  * @SKBDESC_DMA_MAPPED_TX: &skb_dma field has been mapped for TX
64  * @SKBDESC_IV_STRIPPED: Frame contained a IV/EIV provided by
65  *	mac80211 but was stripped for processing by the driver.
66  * @SKBDESC_NOT_MAC80211: Frame didn't originate from mac80211,
67  *	don't try to pass it back.
68  * @SKBDESC_DESC_IN_SKB: The descriptor is at the start of the
69  *	skb, instead of in the desc field.
70  */
71 enum skb_frame_desc_flags {
72 	SKBDESC_DMA_MAPPED_RX = 1 << 0,
73 	SKBDESC_DMA_MAPPED_TX = 1 << 1,
74 	SKBDESC_IV_STRIPPED = 1 << 2,
75 	SKBDESC_NOT_MAC80211 = 1 << 3,
76 	SKBDESC_DESC_IN_SKB = 1 << 4,
77 };
78 
79 /**
80  * struct skb_frame_desc: Descriptor information for the skb buffer
81  *
82  * This structure is placed over the driver_data array, this means that
83  * this structure should not exceed the size of that array (40 bytes).
84  *
85  * @flags: Frame flags, see &enum skb_frame_desc_flags.
86  * @desc_len: Length of the frame descriptor.
87  * @tx_rate_idx: the index of the TX rate, used for TX status reporting
88  * @tx_rate_flags: the TX rate flags, used for TX status reporting
89  * @desc: Pointer to descriptor part of the frame.
90  *	Note that this pointer could point to something outside
91  *	of the scope of the skb->data pointer.
92  * @iv: IV/EIV data used during encryption/decryption.
93  * @skb_dma: (PCI-only) the DMA address associated with the sk buffer.
94  * @sta: The station where sk buffer was sent.
95  */
96 struct skb_frame_desc {
97 	u8 flags;
98 
99 	u8 desc_len;
100 	u8 tx_rate_idx;
101 	u8 tx_rate_flags;
102 
103 	void *desc;
104 
105 	__le32 iv[2];
106 
107 	dma_addr_t skb_dma;
108 	struct ieee80211_sta *sta;
109 };
110 
111 /**
112  * get_skb_frame_desc - Obtain the rt2x00 frame descriptor from a sk_buff.
113  * @skb: &struct sk_buff from where we obtain the &struct skb_frame_desc
114  */
115 static inline struct skb_frame_desc* get_skb_frame_desc(struct sk_buff *skb)
116 {
117 	BUILD_BUG_ON(sizeof(struct skb_frame_desc) >
118 		     IEEE80211_TX_INFO_DRIVER_DATA_SIZE);
119 	return (struct skb_frame_desc *)&IEEE80211_SKB_CB(skb)->driver_data;
120 }
121 
122 /**
123  * enum rxdone_entry_desc_flags: Flags for &struct rxdone_entry_desc
124  *
125  * @RXDONE_SIGNAL_PLCP: Signal field contains the plcp value.
126  * @RXDONE_SIGNAL_BITRATE: Signal field contains the bitrate value.
127  * @RXDONE_SIGNAL_MCS: Signal field contains the mcs value.
128  * @RXDONE_MY_BSS: Does this frame originate from device's BSS.
129  * @RXDONE_CRYPTO_IV: Driver provided IV/EIV data.
130  * @RXDONE_CRYPTO_ICV: Driver provided ICV data.
131  * @RXDONE_L2PAD: 802.11 payload has been padded to 4-byte boundary.
132  */
133 enum rxdone_entry_desc_flags {
134 	RXDONE_SIGNAL_PLCP = BIT(0),
135 	RXDONE_SIGNAL_BITRATE = BIT(1),
136 	RXDONE_SIGNAL_MCS = BIT(2),
137 	RXDONE_MY_BSS = BIT(3),
138 	RXDONE_CRYPTO_IV = BIT(4),
139 	RXDONE_CRYPTO_ICV = BIT(5),
140 	RXDONE_L2PAD = BIT(6),
141 };
142 
143 /**
144  * RXDONE_SIGNAL_MASK - Define to mask off all &rxdone_entry_desc_flags flags
145  * except for the RXDONE_SIGNAL_* flags. This is useful to convert the dev_flags
146  * from &rxdone_entry_desc to a signal value type.
147  */
148 #define RXDONE_SIGNAL_MASK \
149 	( RXDONE_SIGNAL_PLCP | RXDONE_SIGNAL_BITRATE | RXDONE_SIGNAL_MCS )
150 
151 /**
152  * struct rxdone_entry_desc: RX Entry descriptor
153  *
154  * Summary of information that has been read from the RX frame descriptor.
155  *
156  * @timestamp: RX Timestamp
157  * @signal: Signal of the received frame.
158  * @rssi: RSSI of the received frame.
159  * @size: Data size of the received frame.
160  * @flags: MAC80211 receive flags (See &enum mac80211_rx_flags).
161  * @dev_flags: Ralink receive flags (See &enum rxdone_entry_desc_flags).
162  * @rate_mode: Rate mode (See @enum rate_modulation).
163  * @cipher: Cipher type used during decryption.
164  * @cipher_status: Decryption status.
165  * @iv: IV/EIV data used during decryption.
166  * @icv: ICV data used during decryption.
167  */
168 struct rxdone_entry_desc {
169 	u64 timestamp;
170 	int signal;
171 	int rssi;
172 	int size;
173 	int flags;
174 	int dev_flags;
175 	u16 rate_mode;
176 	u16 enc_flags;
177 	enum mac80211_rx_encoding encoding;
178 	enum rate_info_bw bw;
179 	u8 cipher;
180 	u8 cipher_status;
181 
182 	__le32 iv[2];
183 	__le32 icv;
184 };
185 
186 /**
187  * enum txdone_entry_desc_flags: Flags for &struct txdone_entry_desc
188  *
189  * Every txdone report has to contain the basic result of the
190  * transmission, either &TXDONE_UNKNOWN, &TXDONE_SUCCESS or
191  * &TXDONE_FAILURE. The flag &TXDONE_FALLBACK can be used in
192  * conjunction with all of these flags but should only be set
193  * if retires > 0. The flag &TXDONE_EXCESSIVE_RETRY can only be used
194  * in conjunction with &TXDONE_FAILURE.
195  *
196  * @TXDONE_UNKNOWN: Hardware could not determine success of transmission.
197  * @TXDONE_SUCCESS: Frame was successfully send
198  * @TXDONE_FALLBACK: Hardware used fallback rates for retries
199  * @TXDONE_FAILURE: Frame was not successfully send
200  * @TXDONE_EXCESSIVE_RETRY: In addition to &TXDONE_FAILURE, the
201  *	frame transmission failed due to excessive retries.
202  */
203 enum txdone_entry_desc_flags {
204 	TXDONE_UNKNOWN,
205 	TXDONE_SUCCESS,
206 	TXDONE_FALLBACK,
207 	TXDONE_FAILURE,
208 	TXDONE_EXCESSIVE_RETRY,
209 	TXDONE_AMPDU,
210 	TXDONE_NO_ACK_REQ,
211 };
212 
213 /**
214  * struct txdone_entry_desc: TX done entry descriptor
215  *
216  * Summary of information that has been read from the TX frame descriptor
217  * after the device is done with transmission.
218  *
219  * @flags: TX done flags (See &enum txdone_entry_desc_flags).
220  * @retry: Retry count.
221  */
222 struct txdone_entry_desc {
223 	unsigned long flags;
224 	int retry;
225 };
226 
227 /**
228  * enum txentry_desc_flags: Status flags for TX entry descriptor
229  *
230  * @ENTRY_TXD_RTS_FRAME: This frame is a RTS frame.
231  * @ENTRY_TXD_CTS_FRAME: This frame is a CTS-to-self frame.
232  * @ENTRY_TXD_GENERATE_SEQ: This frame requires sequence counter.
233  * @ENTRY_TXD_FIRST_FRAGMENT: This is the first frame.
234  * @ENTRY_TXD_MORE_FRAG: This frame is followed by another fragment.
235  * @ENTRY_TXD_REQ_TIMESTAMP: Require timestamp to be inserted.
236  * @ENTRY_TXD_BURST: This frame belongs to the same burst event.
237  * @ENTRY_TXD_ACK: An ACK is required for this frame.
238  * @ENTRY_TXD_RETRY_MODE: When set, the long retry count is used.
239  * @ENTRY_TXD_ENCRYPT: This frame should be encrypted.
240  * @ENTRY_TXD_ENCRYPT_PAIRWISE: Use pairwise key table (instead of shared).
241  * @ENTRY_TXD_ENCRYPT_IV: Generate IV/EIV in hardware.
242  * @ENTRY_TXD_ENCRYPT_MMIC: Generate MIC in hardware.
243  * @ENTRY_TXD_HT_AMPDU: This frame is part of an AMPDU.
244  * @ENTRY_TXD_HT_BW_40: Use 40MHz Bandwidth.
245  * @ENTRY_TXD_HT_SHORT_GI: Use short GI.
246  * @ENTRY_TXD_HT_MIMO_PS: The receiving STA is in dynamic SM PS mode.
247  */
248 enum txentry_desc_flags {
249 	ENTRY_TXD_RTS_FRAME,
250 	ENTRY_TXD_CTS_FRAME,
251 	ENTRY_TXD_GENERATE_SEQ,
252 	ENTRY_TXD_FIRST_FRAGMENT,
253 	ENTRY_TXD_MORE_FRAG,
254 	ENTRY_TXD_REQ_TIMESTAMP,
255 	ENTRY_TXD_BURST,
256 	ENTRY_TXD_ACK,
257 	ENTRY_TXD_RETRY_MODE,
258 	ENTRY_TXD_ENCRYPT,
259 	ENTRY_TXD_ENCRYPT_PAIRWISE,
260 	ENTRY_TXD_ENCRYPT_IV,
261 	ENTRY_TXD_ENCRYPT_MMIC,
262 	ENTRY_TXD_HT_AMPDU,
263 	ENTRY_TXD_HT_BW_40,
264 	ENTRY_TXD_HT_SHORT_GI,
265 	ENTRY_TXD_HT_MIMO_PS,
266 };
267 
268 /**
269  * struct txentry_desc: TX Entry descriptor
270  *
271  * Summary of information for the frame descriptor before sending a TX frame.
272  *
273  * @flags: Descriptor flags (See &enum queue_entry_flags).
274  * @length: Length of the entire frame.
275  * @header_length: Length of 802.11 header.
276  * @length_high: PLCP length high word.
277  * @length_low: PLCP length low word.
278  * @signal: PLCP signal.
279  * @service: PLCP service.
280  * @msc: MCS.
281  * @stbc: Use Space Time Block Coding (only available for MCS rates < 8).
282  * @ba_size: Size of the recepients RX reorder buffer - 1.
283  * @rate_mode: Rate mode (See @enum rate_modulation).
284  * @mpdu_density: MDPU density.
285  * @retry_limit: Max number of retries.
286  * @ifs: IFS value.
287  * @txop: IFS value for 11n capable chips.
288  * @cipher: Cipher type used for encryption.
289  * @key_idx: Key index used for encryption.
290  * @iv_offset: Position where IV should be inserted by hardware.
291  * @iv_len: Length of IV data.
292  */
293 struct txentry_desc {
294 	unsigned long flags;
295 
296 	u16 length;
297 	u16 header_length;
298 
299 	union {
300 		struct {
301 			u16 length_high;
302 			u16 length_low;
303 			u16 signal;
304 			u16 service;
305 			enum ifs ifs;
306 		} plcp;
307 
308 		struct {
309 			u16 mcs;
310 			u8 stbc;
311 			u8 ba_size;
312 			u8 mpdu_density;
313 			enum txop txop;
314 			int wcid;
315 		} ht;
316 	} u;
317 
318 	enum rate_modulation rate_mode;
319 
320 	short retry_limit;
321 
322 	enum cipher cipher;
323 	u16 key_idx;
324 	u16 iv_offset;
325 	u16 iv_len;
326 };
327 
328 /**
329  * enum queue_entry_flags: Status flags for queue entry
330  *
331  * @ENTRY_BCN_ASSIGNED: This entry has been assigned to an interface.
332  *	As long as this bit is set, this entry may only be touched
333  *	through the interface structure.
334  * @ENTRY_OWNER_DEVICE_DATA: This entry is owned by the device for data
335  *	transfer (either TX or RX depending on the queue). The entry should
336  *	only be touched after the device has signaled it is done with it.
337  * @ENTRY_DATA_PENDING: This entry contains a valid frame and is waiting
338  *	for the signal to start sending.
339  * @ENTRY_DATA_IO_FAILED: Hardware indicated that an IO error occurred
340  *	while transferring the data to the hardware. No TX status report will
341  *	be expected from the hardware.
342  * @ENTRY_DATA_STATUS_PENDING: The entry has been send to the device and
343  *	returned. It is now waiting for the status reporting before the
344  *	entry can be reused again.
345  */
346 enum queue_entry_flags {
347 	ENTRY_BCN_ASSIGNED,
348 	ENTRY_BCN_ENABLED,
349 	ENTRY_OWNER_DEVICE_DATA,
350 	ENTRY_DATA_PENDING,
351 	ENTRY_DATA_IO_FAILED,
352 	ENTRY_DATA_STATUS_PENDING,
353 };
354 
355 /**
356  * struct queue_entry: Entry inside the &struct data_queue
357  *
358  * @flags: Entry flags, see &enum queue_entry_flags.
359  * @last_action: Timestamp of last change.
360  * @queue: The data queue (&struct data_queue) to which this entry belongs.
361  * @skb: The buffer which is currently being transmitted (for TX queue),
362  *	or used to directly receive data in (for RX queue).
363  * @entry_idx: The entry index number.
364  * @priv_data: Private data belonging to this queue entry. The pointer
365  *	points to data specific to a particular driver and queue type.
366  * @status: Device specific status
367  */
368 struct queue_entry {
369 	unsigned long flags;
370 	unsigned long last_action;
371 
372 	struct data_queue *queue;
373 
374 	struct sk_buff *skb;
375 
376 	unsigned int entry_idx;
377 
378 	void *priv_data;
379 };
380 
381 /**
382  * enum queue_index: Queue index type
383  *
384  * @Q_INDEX: Index pointer to the current entry in the queue, if this entry is
385  *	owned by the hardware then the queue is considered to be full.
386  * @Q_INDEX_DMA_DONE: Index pointer for the next entry which will have been
387  *	transferred to the hardware.
388  * @Q_INDEX_DONE: Index pointer to the next entry which will be completed by
389  *	the hardware and for which we need to run the txdone handler. If this
390  *	entry is not owned by the hardware the queue is considered to be empty.
391  * @Q_INDEX_MAX: Keep last, used in &struct data_queue to determine the size
392  *	of the index array.
393  */
394 enum queue_index {
395 	Q_INDEX,
396 	Q_INDEX_DMA_DONE,
397 	Q_INDEX_DONE,
398 	Q_INDEX_MAX,
399 };
400 
401 /**
402  * enum data_queue_flags: Status flags for data queues
403  *
404  * @QUEUE_STARTED: The queue has been started. Fox RX queues this means the
405  *	device might be DMA'ing skbuffers. TX queues will accept skbuffers to
406  *	be transmitted and beacon queues will start beaconing the configured
407  *	beacons.
408  * @QUEUE_PAUSED: The queue has been started but is currently paused.
409  *	When this bit is set, the queue has been stopped in mac80211,
410  *	preventing new frames to be enqueued. However, a few frames
411  *	might still appear shortly after the pausing...
412  */
413 enum data_queue_flags {
414 	QUEUE_STARTED,
415 	QUEUE_PAUSED,
416 };
417 
418 /**
419  * struct data_queue: Data queue
420  *
421  * @rt2x00dev: Pointer to main &struct rt2x00dev where this queue belongs to.
422  * @entries: Base address of the &struct queue_entry which are
423  *	part of this queue.
424  * @qid: The queue identification, see &enum data_queue_qid.
425  * @flags: Entry flags, see &enum queue_entry_flags.
426  * @status_lock: The mutex for protecting the start/stop/flush
427  *	handling on this queue.
428  * @tx_lock: Spinlock to serialize tx operations on this queue.
429  * @index_lock: Spinlock to protect index handling. Whenever @index, @index_done or
430  *	@index_crypt needs to be changed this lock should be grabbed to prevent
431  *	index corruption due to concurrency.
432  * @count: Number of frames handled in the queue.
433  * @limit: Maximum number of entries in the queue.
434  * @threshold: Minimum number of free entries before queue is kicked by force.
435  * @length: Number of frames in queue.
436  * @index: Index pointers to entry positions in the queue,
437  *	use &enum queue_index to get a specific index field.
438  * @txop: maximum burst time.
439  * @aifs: The aifs value for outgoing frames (field ignored in RX queue).
440  * @cw_min: The cw min value for outgoing frames (field ignored in RX queue).
441  * @cw_max: The cw max value for outgoing frames (field ignored in RX queue).
442  * @data_size: Maximum data size for the frames in this queue.
443  * @desc_size: Hardware descriptor size for the data in this queue.
444  * @priv_size: Size of per-queue_entry private data.
445  * @usb_endpoint: Device endpoint used for communication (USB only)
446  * @usb_maxpacket: Max packet size for given endpoint (USB only)
447  */
448 struct data_queue {
449 	struct rt2x00_dev *rt2x00dev;
450 	struct queue_entry *entries;
451 
452 	enum data_queue_qid qid;
453 	unsigned long flags;
454 
455 	struct mutex status_lock;
456 	spinlock_t tx_lock;
457 	spinlock_t index_lock;
458 
459 	unsigned int count;
460 	unsigned short limit;
461 	unsigned short threshold;
462 	unsigned short length;
463 	unsigned short index[Q_INDEX_MAX];
464 
465 	unsigned short txop;
466 	unsigned short aifs;
467 	unsigned short cw_min;
468 	unsigned short cw_max;
469 
470 	unsigned short data_size;
471 	unsigned char  desc_size;
472 	unsigned char  winfo_size;
473 	unsigned short priv_size;
474 
475 	unsigned short usb_endpoint;
476 	unsigned short usb_maxpacket;
477 };
478 
479 /**
480  * queue_end - Return pointer to the last queue (HELPER MACRO).
481  * @__dev: Pointer to &struct rt2x00_dev
482  *
483  * Using the base rx pointer and the maximum number of available queues,
484  * this macro will return the address of 1 position beyond  the end of the
485  * queues array.
486  */
487 #define queue_end(__dev) \
488 	&(__dev)->rx[(__dev)->data_queues]
489 
490 /**
491  * tx_queue_end - Return pointer to the last TX queue (HELPER MACRO).
492  * @__dev: Pointer to &struct rt2x00_dev
493  *
494  * Using the base tx pointer and the maximum number of available TX
495  * queues, this macro will return the address of 1 position beyond
496  * the end of the TX queue array.
497  */
498 #define tx_queue_end(__dev) \
499 	&(__dev)->tx[(__dev)->ops->tx_queues]
500 
501 /**
502  * queue_next - Return pointer to next queue in list (HELPER MACRO).
503  * @__queue: Current queue for which we need the next queue
504  *
505  * Using the current queue address we take the address directly
506  * after the queue to take the next queue. Note that this macro
507  * should be used carefully since it does not protect against
508  * moving past the end of the list. (See macros &queue_end and
509  * &tx_queue_end for determining the end of the queue).
510  */
511 #define queue_next(__queue) \
512 	&(__queue)[1]
513 
514 /**
515  * queue_loop - Loop through the queues within a specific range (HELPER MACRO).
516  * @__entry: Pointer where the current queue entry will be stored in.
517  * @__start: Start queue pointer.
518  * @__end: End queue pointer.
519  *
520  * This macro will loop through all queues between &__start and &__end.
521  */
522 #define queue_loop(__entry, __start, __end)			\
523 	for ((__entry) = (__start);				\
524 	     prefetch(queue_next(__entry)), (__entry) != (__end);\
525 	     (__entry) = queue_next(__entry))
526 
527 /**
528  * queue_for_each - Loop through all queues
529  * @__dev: Pointer to &struct rt2x00_dev
530  * @__entry: Pointer where the current queue entry will be stored in.
531  *
532  * This macro will loop through all available queues.
533  */
534 #define queue_for_each(__dev, __entry) \
535 	queue_loop(__entry, (__dev)->rx, queue_end(__dev))
536 
537 /**
538  * tx_queue_for_each - Loop through the TX queues
539  * @__dev: Pointer to &struct rt2x00_dev
540  * @__entry: Pointer where the current queue entry will be stored in.
541  *
542  * This macro will loop through all TX related queues excluding
543  * the Beacon and Atim queues.
544  */
545 #define tx_queue_for_each(__dev, __entry) \
546 	queue_loop(__entry, (__dev)->tx, tx_queue_end(__dev))
547 
548 /**
549  * txall_queue_for_each - Loop through all TX related queues
550  * @__dev: Pointer to &struct rt2x00_dev
551  * @__entry: Pointer where the current queue entry will be stored in.
552  *
553  * This macro will loop through all TX related queues including
554  * the Beacon and Atim queues.
555  */
556 #define txall_queue_for_each(__dev, __entry) \
557 	queue_loop(__entry, (__dev)->tx, queue_end(__dev))
558 
559 /**
560  * rt2x00queue_for_each_entry - Loop through all entries in the queue
561  * @queue: Pointer to @data_queue
562  * @start: &enum queue_index Pointer to start index
563  * @end: &enum queue_index Pointer to end index
564  * @data: Data to pass to the callback function
565  * @fn: The function to call for each &struct queue_entry
566  *
567  * This will walk through all entries in the queue, in chronological
568  * order. This means it will start at the current @start pointer
569  * and will walk through the queue until it reaches the @end pointer.
570  *
571  * If fn returns true for an entry rt2x00queue_for_each_entry will stop
572  * processing and return true as well.
573  */
574 bool rt2x00queue_for_each_entry(struct data_queue *queue,
575 				enum queue_index start,
576 				enum queue_index end,
577 				void *data,
578 				bool (*fn)(struct queue_entry *entry,
579 					   void *data));
580 
581 /**
582  * rt2x00queue_empty - Check if the queue is empty.
583  * @queue: Queue to check if empty.
584  */
585 static inline int rt2x00queue_empty(struct data_queue *queue)
586 {
587 	return queue->length == 0;
588 }
589 
590 /**
591  * rt2x00queue_full - Check if the queue is full.
592  * @queue: Queue to check if full.
593  */
594 static inline int rt2x00queue_full(struct data_queue *queue)
595 {
596 	return queue->length == queue->limit;
597 }
598 
599 /**
600  * rt2x00queue_free - Check the number of available entries in queue.
601  * @queue: Queue to check.
602  */
603 static inline int rt2x00queue_available(struct data_queue *queue)
604 {
605 	return queue->limit - queue->length;
606 }
607 
608 /**
609  * rt2x00queue_threshold - Check if the queue is below threshold
610  * @queue: Queue to check.
611  */
612 static inline int rt2x00queue_threshold(struct data_queue *queue)
613 {
614 	return rt2x00queue_available(queue) < queue->threshold;
615 }
616 /**
617  * rt2x00queue_dma_timeout - Check if a timeout occurred for DMA transfers
618  * @entry: Queue entry to check.
619  */
620 static inline int rt2x00queue_dma_timeout(struct queue_entry *entry)
621 {
622 	if (!test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
623 		return false;
624 	return time_after(jiffies, entry->last_action + msecs_to_jiffies(100));
625 }
626 
627 /**
628  * _rt2x00_desc_read - Read a word from the hardware descriptor.
629  * @desc: Base descriptor address
630  * @word: Word index from where the descriptor should be read.
631  */
632 static inline __le32 _rt2x00_desc_read(__le32 *desc, const u8 word)
633 {
634 	return desc[word];
635 }
636 
637 /**
638  * rt2x00_desc_read - Read a word from the hardware descriptor, this
639  * function will take care of the byte ordering.
640  * @desc: Base descriptor address
641  * @word: Word index from where the descriptor should be read.
642  */
643 static inline u32 rt2x00_desc_read(__le32 *desc, const u8 word)
644 {
645 	return le32_to_cpu(_rt2x00_desc_read(desc, word));
646 }
647 
648 /**
649  * rt2x00_desc_write - write a word to the hardware descriptor, this
650  * function will take care of the byte ordering.
651  * @desc: Base descriptor address
652  * @word: Word index from where the descriptor should be written.
653  * @value: Value that should be written into the descriptor.
654  */
655 static inline void _rt2x00_desc_write(__le32 *desc, const u8 word, __le32 value)
656 {
657 	desc[word] = value;
658 }
659 
660 /**
661  * rt2x00_desc_write - write a word to the hardware descriptor.
662  * @desc: Base descriptor address
663  * @word: Word index from where the descriptor should be written.
664  * @value: Value that should be written into the descriptor.
665  */
666 static inline void rt2x00_desc_write(__le32 *desc, const u8 word, u32 value)
667 {
668 	_rt2x00_desc_write(desc, word, cpu_to_le32(value));
669 }
670 
671 #endif /* RT2X00QUEUE_H */
672