aboutsummaryrefslogtreecommitdiff
path: root/drivers/net/wireless/rt2x00/rt2x00queue.c
blob: 19c10629c767513ca510e66c82732ce5e91584da (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
/*
	Copyright (C) 2004 - 2008 rt2x00 SourceForge Project
	<http://rt2x00.serialmonkey.com>

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to the
	Free Software Foundation, Inc.,
	59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/*
	Module: rt2x00lib
	Abstract: rt2x00 queue specific routines.
 */

#include <linux/kernel.h>
#include <linux/module.h>

#include "rt2x00.h"
#include "rt2x00lib.h"

void rt2x00queue_create_tx_descriptor(struct queue_entry *entry,
				      struct txentry_desc *txdesc,
				      struct ieee80211_tx_control *control)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)entry->skb->data;
	struct ieee80211_rate *rate = control->tx_rate;
	const struct rt2x00_rate *hwrate;
	unsigned int data_length;
	unsigned int duration;
	unsigned int residual;
	u16 frame_control;

	memset(txdesc, 0, sizeof(*txdesc));

	/*
	 * Initialize information from queue
	 */
	txdesc->queue = entry->queue->qid;
	txdesc->cw_min = entry->queue->cw_min;
	txdesc->cw_max = entry->queue->cw_max;
	txdesc->aifs = entry->queue->aifs;

	/* Data length should be extended with 4 bytes for CRC */
	data_length = entry->skb->len + 4;

	/*
	 * Read required fields from ieee80211 header.
	 */
	frame_control = le16_to_cpu(hdr->frame_control);

	/*
	 * Check whether this frame is to be acked.
	 */
	if (!(control->flags & IEEE80211_TXCTL_NO_ACK))
		__set_bit(ENTRY_TXD_ACK, &txdesc->flags);

	/*
	 * Check if this is a RTS/CTS frame
	 */
	if (is_rts_frame(frame_control) || is_cts_frame(frame_control)) {
		__set_bit(ENTRY_TXD_BURST, &txdesc->flags);
		if (is_rts_frame(frame_control)) {
			__set_bit(ENTRY_TXD_RTS_FRAME, &txdesc->flags);
			__set_bit(ENTRY_TXD_ACK, &txdesc->flags);
		} else {
			__set_bit(ENTRY_TXD_CTS_FRAME, &txdesc->flags);
			__clear_bit(ENTRY_TXD_ACK, &txdesc->flags);
		}
		if (control->rts_cts_rate)
			rate = control->rts_cts_rate;
	}

	/*
	 * Determine retry information.
	 */
	txdesc->retry_limit = control->retry_limit;
	if (control->flags & IEEE80211_TXCTL_LONG_RETRY_LIMIT)
		__set_bit(ENTRY_TXD_RETRY_MODE, &txdesc->flags);

	/*
	 * Check if more fragments are pending
	 */
	if (ieee80211_get_morefrag(hdr)) {
		__set_bit(ENTRY_TXD_BURST, &txdesc->flags);
		__set_bit(ENTRY_TXD_MORE_FRAG, &txdesc->flags);
	}

	/*
	 * Beacons and probe responses require the tsf timestamp
	 * to be inserted into the frame.
	 */
	if (txdesc->queue == QID_BEACON || is_probe_resp(frame_control))
		__set_bit(ENTRY_TXD_REQ_TIMESTAMP, &txdesc->flags);

	/*
	 * Determine with what IFS priority this frame should be send.
	 * Set ifs to IFS_SIFS when the this is not the first fragment,
	 * or this fragment came after RTS/CTS.
	 */
	if (test_bit(ENTRY_TXD_RTS_FRAME, &txdesc->flags)) {
		txdesc->ifs = IFS_SIFS;
	} else if (control->flags & IEEE80211_TXCTL_FIRST_FRAGMENT) {
		__set_bit(ENTRY_TXD_FIRST_FRAGMENT, &txdesc->flags);
		txdesc->ifs = IFS_BACKOFF;
	} else {
		txdesc->ifs = IFS_SIFS;
	}

	/*
	 * PLCP setup
	 * Length calculation depends on OFDM/CCK rate.
	 */
	hwrate = rt2x00_get_rate(rate->hw_value);
	txdesc->signal = hwrate->plcp;
	txdesc->service = 0x04;

	if (hwrate->flags & DEV_RATE_OFDM) {
		__set_bit(ENTRY_TXD_OFDM_RATE, &txdesc->flags);

		txdesc->length_high = (data_length >> 6) & 0x3f;
		txdesc->length_low = data_length & 0x3f;
	} else {
		/*
		 * Convert length to microseconds.
		 */
		residual = get_duration_res(data_length, hwrate->bitrate);
		duration = get_duration(data_length, hwrate->bitrate);

		if (residual != 0) {
			duration++;

			/*
			 * Check if we need to set the Length Extension
			 */
			if (hwrate->bitrate == 110 && residual <= 30)
				txdesc->service |= 0x80;
		}

		txdesc->length_high = (duration >> 8) & 0xff;
		txdesc->length_low = duration & 0xff;

		/*
		 * When preamble is enabled we should set the
		 * preamble bit for the signal.
		 */
		if (rt2x00_get_rate_preamble(rate->hw_value))
			txdesc->signal |= 0x08;
	}
}
EXPORT_SYMBOL_GPL(rt2x00queue_create_tx_descriptor);

void rt2x00queue_write_tx_descriptor(struct queue_entry *entry,
				     struct txentry_desc *txdesc)
{
	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
	struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);

	rt2x00dev->ops->lib->write_tx_desc(rt2x00dev, entry->skb, txdesc);

	/*
	 * All processing on the frame has been completed, this means
	 * it is now ready to be dumped to userspace through debugfs.
	 */
	rt2x00debug_dump_frame(rt2x00dev, DUMP_FRAME_TX, entry->skb);

	/*
	 * We are done writing the frame to the queue entry,
	 * if this entry is a RTS of CTS-to-self frame we are done,
	 * otherwise we need to kick the queue.
	 */
	if (rt2x00dev->ops->lib->kick_tx_queue &&
	    !(skbdesc->flags & FRAME_DESC_DRIVER_GENERATED))
		rt2x00dev->ops->lib->kick_tx_queue(rt2x00dev,
						   entry->queue->qid);
}
EXPORT_SYMBOL_GPL(rt2x00queue_write_tx_descriptor);

struct data_queue *rt2x00queue_get_queue(struct rt2x00_dev *rt2x00dev,
					 const enum data_queue_qid queue)
{
	int atim = test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags);

	if (queue < rt2x00dev->ops->tx_queues && rt2x00dev->tx)
		return &rt2x00dev->tx[queue];

	if (!rt2x00dev->bcn)
		return NULL;

	if (queue == QID_BEACON)
		return &rt2x00dev->bcn[0];
	else if (queue == QID_ATIM && atim)
		return &rt2x00dev->bcn[1];

	return NULL;
}
EXPORT_SYMBOL_GPL(rt2x00queue_get_queue);

struct queue_entry *rt2x00queue_get_entry(struct data_queue *queue,
					  enum queue_index index)
{
	struct queue_entry *entry;
	unsigned long irqflags;

	if (unlikely(index >= Q_INDEX_MAX)) {
		ERROR(queue->rt2x00dev,
		      "Entry requested from invalid index type (%d)\n", index);
		return NULL;
	}

	spin_lock_irqsave(&queue->lock, irqflags);

	entry = &queue->entries[queue->index[index]];

	spin_unlock_irqrestore(&queue->lock, irqflags);

	return entry;
}
EXPORT_SYMBOL_GPL(rt2x00queue_get_entry);

void rt2x00queue_index_inc(struct data_queue *queue, enum queue_index index)
{
	unsigned long irqflags;

	if (unlikely(index >= Q_INDEX_MAX)) {
		ERROR(queue->rt2x00dev,
		      "Index change on invalid index type (%d)\n", index);
		return;
	}

	spin_lock_irqsave(&queue->lock, irqflags);

	queue->index[index]++;
	if (queue->index[index] >= queue->limit)
		queue->index[index] = 0;

	if (index == Q_INDEX) {
		queue->length++;
	} else if (index == Q_INDEX_DONE) {
		queue->length--;
		queue->count ++;
	}

	spin_unlock_irqrestore(&queue->lock, irqflags);
}
EXPORT_SYMBOL_GPL(rt2x00queue_index_inc);

static void rt2x00queue_reset(struct data_queue *queue)
{
	unsigned long irqflags;

	spin_lock_irqsave(&queue->lock, irqflags);

	queue->count = 0;
	queue->length = 0;
	memset(queue->index, 0, sizeof(queue->index));

	spin_unlock_irqrestore(&queue->lock, irqflags);
}

void rt2x00queue_init_rx(struct rt2x00_dev *rt2x00dev)
{
	struct data_queue *queue = rt2x00dev->rx;
	unsigned int i;

	rt2x00queue_reset(queue);

	if (!rt2x00dev->ops->lib->init_rxentry)
		return;

	for (i = 0; i < queue->limit; i++)
		rt2x00dev->ops->lib->init_rxentry(rt2x00dev,
						  &queue->entries[i]);
}

void rt2x00queue_init_tx(struct rt2x00_dev *rt2x00dev)
{
	struct data_queue *queue;
	unsigned int i;

	txall_queue_for_each(rt2x00dev, queue) {
		rt2x00queue_reset(queue);

		if (!rt2x00dev->ops->lib->init_txentry)
			continue;

		for (i = 0; i < queue->limit; i++)
			rt2x00dev->ops->lib->init_txentry(rt2x00dev,
							  &queue->entries[i]);
	}
}

static int rt2x00queue_alloc_entries(struct data_queue *queue,
				     const struct data_queue_desc *qdesc)
{
	struct queue_entry *entries;
	unsigned int entry_size;
	unsigned int i;

	rt2x00queue_reset(queue);

	queue->limit = qdesc->entry_num;
	queue->data_size = qdesc->data_size;
	queue->desc_size = qdesc->desc_size;

	/*
	 * Allocate all queue entries.
	 */
	entry_size = sizeof(*entries) + qdesc->priv_size;
	entries = kzalloc(queue->limit * entry_size, GFP_KERNEL);
	if (!entries)
		return -ENOMEM;

#define QUEUE_ENTRY_PRIV_OFFSET(__base, __index, __limit, __esize, __psize) \
	( ((char *)(__base)) + ((__limit) * (__esize)) + \
	    ((__index) * (__psize)) )

	for (i = 0; i < queue->limit; i++) {
		entries[i].flags = 0;
		entries[i].queue = queue;
		entries[i].skb = NULL;
		entries[i].entry_idx = i;
		entries[i].priv_data =
		    QUEUE_ENTRY_PRIV_OFFSET(entries, i, queue->limit,
					    sizeof(*entries), qdesc->priv_size);
	}

#undef QUEUE_ENTRY_PRIV_OFFSET

	queue->entries = entries;

	return 0;
}

int rt2x00queue_initialize(struct rt2x00_dev *rt2x00dev)
{
	struct data_queue *queue;
	int status;


	status = rt2x00queue_alloc_entries(rt2x00dev->rx, rt2x00dev->ops->rx);
	if (status)
		goto exit;

	tx_queue_for_each(rt2x00dev, queue) {
		status = rt2x00queue_alloc_entries(queue, rt2x00dev->ops->tx);
		if (status)
			goto exit;
	}

	status = rt2x00queue_alloc_entries(rt2x00dev->bcn, rt2x00dev->ops->bcn);
	if (status)
		goto exit;

	if (!test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags))
		return 0;

	status = rt2x00queue_alloc_entries(&rt2x00dev->bcn[1],
					   rt2x00dev->ops->atim);
	if (status)
		goto exit;

	return 0;

exit:
	ERROR(rt2x00dev, "Queue entries allocation failed.\n");

	rt2x00queue_uninitialize(rt2x00dev);

	return status;
}

void rt2x00queue_uninitialize(struct rt2x00_dev *rt2x00dev)
{
	struct data_queue *queue;

	queue_for_each(rt2x00dev, queue) {
		kfree(queue->entries);
		queue->entries = NULL;
	}
}

static void rt2x00queue_init(struct rt2x00_dev *rt2x00dev,
			     struct data_queue *queue, enum data_queue_qid qid)
{
	spin_lock_init(&queue->lock);

	queue->rt2x00dev = rt2x00dev;
	queue->qid = qid;
	queue->aifs = 2;
	queue->cw_min = 5;
	queue->cw_max = 10;
}

int rt2x00queue_allocate(struct rt2x00_dev *rt2x00dev)
{
	struct data_queue *queue;
	enum data_queue_qid qid;
	unsigned int req_atim =
	    !!test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags);

	/*
	 * We need the following queues:
	 * RX: 1
	 * TX: ops->tx_queues
	 * Beacon: 1
	 * Atim: 1 (if required)
	 */
	rt2x00dev->data_queues = 2 + rt2x00dev->ops->tx_queues + req_atim;

	queue = kzalloc(rt2x00dev->data_queues * sizeof(*queue), GFP_KERNEL);
	if (!queue) {
		ERROR(rt2x00dev, "Queue allocation failed.\n");
		return -ENOMEM;
	}

	/*
	 * Initialize pointers
	 */
	rt2x00dev->rx = queue;
	rt2x00dev->tx = &queue[1];
	rt2x00dev->bcn = &queue[1 + rt2x00dev->ops->tx_queues];

	/*
	 * Initialize queue parameters.
	 * RX: qid = QID_RX
	 * TX: qid = QID_AC_BE + index
	 * TX: cw_min: 2^5 = 32.
	 * TX: cw_max: 2^10 = 1024.
	 * BCN & Atim: qid = QID_MGMT
	 */
	rt2x00queue_init(rt2x00dev, rt2x00dev->rx, QID_RX);

	qid = QID_AC_BE;
	tx_queue_for_each(rt2x00dev, queue)
		rt2x00queue_init(rt2x00dev, queue, qid++);

	rt2x00queue_init(rt2x00dev, &rt2x00dev->bcn[0], QID_MGMT);
	if (req_atim)
		rt2x00queue_init(rt2x00dev, &rt2x00dev->bcn[1], QID_MGMT);

	return 0;
}

void rt2x00queue_free(struct rt2x00_dev *rt2x00dev)
{
	kfree(rt2x00dev->rx);
	rt2x00dev->rx = NULL;
	rt2x00dev->tx = NULL;
	rt2x00dev->bcn = NULL;
}