1/*
2	Copyright (C) 2010 Willow Garage <http://www.willowgarage.com>
3	Copyright (C) 2004 - 2010 Ivo van Doorn <IvDoorn@gmail.com>
4	Copyright (C) 2004 - 2009 Gertjan van Wingerde <gwingerde@gmail.com>
5	<http://rt2x00.serialmonkey.com>
6
7	This program is free software; you can redistribute it and/or modify
8	it under the terms of the GNU General Public License as published by
9	the Free Software Foundation; either version 2 of the License, or
10	(at your option) any later version.
11
12	This program is distributed in the hope that it will be useful,
13	but WITHOUT ANY WARRANTY; without even the implied warranty of
14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15	GNU General Public License for more details.
16
17	You should have received a copy of the GNU General Public License
18	along with this program; if not, see <http://www.gnu.org/licenses/>.
19 */
20
21/*
22	Module: rt2x00lib
23	Abstract: rt2x00 queue specific routines.
24 */
25
26#include <linux/slab.h>
27#include <linux/kernel.h>
28#include <linux/module.h>
29#include <linux/dma-mapping.h>
30
31#include "rt2x00.h"
32#include "rt2x00lib.h"
33
34struct sk_buff *rt2x00queue_alloc_rxskb(struct queue_entry *entry, gfp_t gfp)
35{
36	struct data_queue *queue = entry->queue;
37	struct rt2x00_dev *rt2x00dev = queue->rt2x00dev;
38	struct sk_buff *skb;
39	struct skb_frame_desc *skbdesc;
40	unsigned int frame_size;
41	unsigned int head_size = 0;
42	unsigned int tail_size = 0;
43
44	/*
45	 * The frame size includes descriptor size, because the
46	 * hardware directly receive the frame into the skbuffer.
47	 */
48	frame_size = queue->data_size + queue->desc_size + queue->winfo_size;
49
50	/*
51	 * The payload should be aligned to a 4-byte boundary,
52	 * this means we need at least 3 bytes for moving the frame
53	 * into the correct offset.
54	 */
55	head_size = 4;
56
57	/*
58	 * For IV/EIV/ICV assembly we must make sure there is
59	 * at least 8 bytes bytes available in headroom for IV/EIV
60	 * and 8 bytes for ICV data as tailroon.
61	 */
62	if (rt2x00_has_cap_hw_crypto(rt2x00dev)) {
63		head_size += 8;
64		tail_size += 8;
65	}
66
67	/*
68	 * Allocate skbuffer.
69	 */
70	skb = __dev_alloc_skb(frame_size + head_size + tail_size, gfp);
71	if (!skb)
72		return NULL;
73
74	/*
75	 * Make sure we not have a frame with the requested bytes
76	 * available in the head and tail.
77	 */
78	skb_reserve(skb, head_size);
79	skb_put(skb, frame_size);
80
81	/*
82	 * Populate skbdesc.
83	 */
84	skbdesc = get_skb_frame_desc(skb);
85	memset(skbdesc, 0, sizeof(*skbdesc));
86	skbdesc->entry = entry;
87
88	if (rt2x00_has_cap_flag(rt2x00dev, REQUIRE_DMA)) {
89		dma_addr_t skb_dma;
90
91		skb_dma = dma_map_single(rt2x00dev->dev, skb->data, skb->len,
92					 DMA_FROM_DEVICE);
93		if (unlikely(dma_mapping_error(rt2x00dev->dev, skb_dma))) {
94			dev_kfree_skb_any(skb);
95			return NULL;
96		}
97
98		skbdesc->skb_dma = skb_dma;
99		skbdesc->flags |= SKBDESC_DMA_MAPPED_RX;
100	}
101
102	return skb;
103}
104
105int rt2x00queue_map_txskb(struct queue_entry *entry)
106{
107	struct device *dev = entry->queue->rt2x00dev->dev;
108	struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
109
110	skbdesc->skb_dma =
111	    dma_map_single(dev, entry->skb->data, entry->skb->len, DMA_TO_DEVICE);
112
113	if (unlikely(dma_mapping_error(dev, skbdesc->skb_dma)))
114		return -ENOMEM;
115
116	skbdesc->flags |= SKBDESC_DMA_MAPPED_TX;
117	return 0;
118}
119EXPORT_SYMBOL_GPL(rt2x00queue_map_txskb);
120
121void rt2x00queue_unmap_skb(struct queue_entry *entry)
122{
123	struct device *dev = entry->queue->rt2x00dev->dev;
124	struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
125
126	if (skbdesc->flags & SKBDESC_DMA_MAPPED_RX) {
127		dma_unmap_single(dev, skbdesc->skb_dma, entry->skb->len,
128				 DMA_FROM_DEVICE);
129		skbdesc->flags &= ~SKBDESC_DMA_MAPPED_RX;
130	} else if (skbdesc->flags & SKBDESC_DMA_MAPPED_TX) {
131		dma_unmap_single(dev, skbdesc->skb_dma, entry->skb->len,
132				 DMA_TO_DEVICE);
133		skbdesc->flags &= ~SKBDESC_DMA_MAPPED_TX;
134	}
135}
136EXPORT_SYMBOL_GPL(rt2x00queue_unmap_skb);
137
138void rt2x00queue_free_skb(struct queue_entry *entry)
139{
140	if (!entry->skb)
141		return;
142
143	rt2x00queue_unmap_skb(entry);
144	dev_kfree_skb_any(entry->skb);
145	entry->skb = NULL;
146}
147
148void rt2x00queue_align_frame(struct sk_buff *skb)
149{
150	unsigned int frame_length = skb->len;
151	unsigned int align = ALIGN_SIZE(skb, 0);
152
153	if (!align)
154		return;
155
156	skb_push(skb, align);
157	memmove(skb->data, skb->data + align, frame_length);
158	skb_trim(skb, frame_length);
159}
160
161/*
162 * H/W needs L2 padding between the header and the paylod if header size
163 * is not 4 bytes aligned.
164 */
165void rt2x00queue_insert_l2pad(struct sk_buff *skb, unsigned int hdr_len)
166{
167	unsigned int l2pad = (skb->len > hdr_len) ? L2PAD_SIZE(hdr_len) : 0;
168
169	if (!l2pad)
170		return;
171
172	skb_push(skb, l2pad);
173	memmove(skb->data, skb->data + l2pad, hdr_len);
174}
175
176void rt2x00queue_remove_l2pad(struct sk_buff *skb, unsigned int hdr_len)
177{
178	unsigned int l2pad = (skb->len > hdr_len) ? L2PAD_SIZE(hdr_len) : 0;
179
180	if (!l2pad)
181		return;
182
183	memmove(skb->data + l2pad, skb->data, hdr_len);
184	skb_pull(skb, l2pad);
185}
186
187static void rt2x00queue_create_tx_descriptor_seq(struct rt2x00_dev *rt2x00dev,
188						 struct sk_buff *skb,
189						 struct txentry_desc *txdesc)
190{
191	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
192	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
193	struct rt2x00_intf *intf = vif_to_intf(tx_info->control.vif);
194	u16 seqno;
195
196	if (!(tx_info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ))
197		return;
198
199	__set_bit(ENTRY_TXD_GENERATE_SEQ, &txdesc->flags);
200
201	if (!rt2x00_has_cap_flag(rt2x00dev, REQUIRE_SW_SEQNO)) {
202		/*
203		 * rt2800 has a H/W (or F/W) bug, device incorrectly increase
204		 * seqno on retransmited data (non-QOS) frames. To workaround
205		 * the problem let's generate seqno in software if QOS is
206		 * disabled.
207		 */
208		if (test_bit(CONFIG_QOS_DISABLED, &rt2x00dev->flags))
209			__clear_bit(ENTRY_TXD_GENERATE_SEQ, &txdesc->flags);
210		else
211			/* H/W will generate sequence number */
212			return;
213	}
214
215	/*
216	 * The hardware is not able to insert a sequence number. Assign a
217	 * software generated one here.
218	 *
219	 * This is wrong because beacons are not getting sequence
220	 * numbers assigned properly.
221	 *
222	 * A secondary problem exists for drivers that cannot toggle
223	 * sequence counting per-frame, since those will override the
224	 * sequence counter given by mac80211.
225	 */
226	if (test_bit(ENTRY_TXD_FIRST_FRAGMENT, &txdesc->flags))
227		seqno = atomic_add_return(0x10, &intf->seqno);
228	else
229		seqno = atomic_read(&intf->seqno);
230
231	hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG);
232	hdr->seq_ctrl |= cpu_to_le16(seqno);
233}
234
235static void rt2x00queue_create_tx_descriptor_plcp(struct rt2x00_dev *rt2x00dev,
236						  struct sk_buff *skb,
237						  struct txentry_desc *txdesc,
238						  const struct rt2x00_rate *hwrate)
239{
240	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
241	struct ieee80211_tx_rate *txrate = &tx_info->control.rates[0];
242	unsigned int data_length;
243	unsigned int duration;
244	unsigned int residual;
245
246	/*
247	 * Determine with what IFS priority this frame should be send.
248	 * Set ifs to IFS_SIFS when the this is not the first fragment,
249	 * or this fragment came after RTS/CTS.
250	 */
251	if (test_bit(ENTRY_TXD_FIRST_FRAGMENT, &txdesc->flags))
252		txdesc->u.plcp.ifs = IFS_BACKOFF;
253	else
254		txdesc->u.plcp.ifs = IFS_SIFS;
255
256	/* Data length + CRC + Crypto overhead (IV/EIV/ICV/MIC) */
257	data_length = skb->len + 4;
258	data_length += rt2x00crypto_tx_overhead(rt2x00dev, skb);
259
260	/*
261	 * PLCP setup
262	 * Length calculation depends on OFDM/CCK rate.
263	 */
264	txdesc->u.plcp.signal = hwrate->plcp;
265	txdesc->u.plcp.service = 0x04;
266
267	if (hwrate->flags & DEV_RATE_OFDM) {
268		txdesc->u.plcp.length_high = (data_length >> 6) & 0x3f;
269		txdesc->u.plcp.length_low = data_length & 0x3f;
270	} else {
271		/*
272		 * Convert length to microseconds.
273		 */
274		residual = GET_DURATION_RES(data_length, hwrate->bitrate);
275		duration = GET_DURATION(data_length, hwrate->bitrate);
276
277		if (residual != 0) {
278			duration++;
279
280			/*
281			 * Check if we need to set the Length Extension
282			 */
283			if (hwrate->bitrate == 110 && residual <= 30)
284				txdesc->u.plcp.service |= 0x80;
285		}
286
287		txdesc->u.plcp.length_high = (duration >> 8) & 0xff;
288		txdesc->u.plcp.length_low = duration & 0xff;
289
290		/*
291		 * When preamble is enabled we should set the
292		 * preamble bit for the signal.
293		 */
294		if (txrate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)
295			txdesc->u.plcp.signal |= 0x08;
296	}
297}
298
299static void rt2x00queue_create_tx_descriptor_ht(struct rt2x00_dev *rt2x00dev,
300						struct sk_buff *skb,
301						struct txentry_desc *txdesc,
302						struct ieee80211_sta *sta,
303						const struct rt2x00_rate *hwrate)
304{
305	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
306	struct ieee80211_tx_rate *txrate = &tx_info->control.rates[0];
307	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
308	struct rt2x00_sta *sta_priv = NULL;
309
310	if (sta) {
311		txdesc->u.ht.mpdu_density =
312		    sta->ht_cap.ampdu_density;
313
314		sta_priv = sta_to_rt2x00_sta(sta);
315		txdesc->u.ht.wcid = sta_priv->wcid;
316	}
317
318	/*
319	 * If IEEE80211_TX_RC_MCS is set txrate->idx just contains the
320	 * mcs rate to be used
321	 */
322	if (txrate->flags & IEEE80211_TX_RC_MCS) {
323		txdesc->u.ht.mcs = txrate->idx;
324
325		/*
326		 * MIMO PS should be set to 1 for STA's using dynamic SM PS
327		 * when using more then one tx stream (>MCS7).
328		 */
329		if (sta && txdesc->u.ht.mcs > 7 &&
330		    sta->smps_mode == IEEE80211_SMPS_DYNAMIC)
331			__set_bit(ENTRY_TXD_HT_MIMO_PS, &txdesc->flags);
332	} else {
333		txdesc->u.ht.mcs = rt2x00_get_rate_mcs(hwrate->mcs);
334		if (txrate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)
335			txdesc->u.ht.mcs |= 0x08;
336	}
337
338	if (test_bit(CONFIG_HT_DISABLED, &rt2x00dev->flags)) {
339		if (!(tx_info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT))
340			txdesc->u.ht.txop = TXOP_SIFS;
341		else
342			txdesc->u.ht.txop = TXOP_BACKOFF;
343
344		/* Left zero on all other settings. */
345		return;
346	}
347
348	txdesc->u.ht.ba_size = 7;	/* FIXME: What value is needed? */
349
350	/*
351	 * Only one STBC stream is supported for now.
352	 */
353	if (tx_info->flags & IEEE80211_TX_CTL_STBC)
354		txdesc->u.ht.stbc = 1;
355
356	/*
357	 * This frame is eligible for an AMPDU, however, don't aggregate
358	 * frames that are intended to probe a specific tx rate.
359	 */
360	if (tx_info->flags & IEEE80211_TX_CTL_AMPDU &&
361	    !(tx_info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE))
362		__set_bit(ENTRY_TXD_HT_AMPDU, &txdesc->flags);
363
364	/*
365	 * Set 40Mhz mode if necessary (for legacy rates this will
366	 * duplicate the frame to both channels).
367	 */
368	if (txrate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH ||
369	    txrate->flags & IEEE80211_TX_RC_DUP_DATA)
370		__set_bit(ENTRY_TXD_HT_BW_40, &txdesc->flags);
371	if (txrate->flags & IEEE80211_TX_RC_SHORT_GI)
372		__set_bit(ENTRY_TXD_HT_SHORT_GI, &txdesc->flags);
373
374	/*
375	 * Determine IFS values
376	 * - Use TXOP_BACKOFF for management frames except beacons
377	 * - Use TXOP_SIFS for fragment bursts
378	 * - Use TXOP_HTTXOP for everything else
379	 *
380	 * Note: rt2800 devices won't use CTS protection (if used)
381	 * for frames not transmitted with TXOP_HTTXOP
382	 */
383	if (ieee80211_is_mgmt(hdr->frame_control) &&
384	    !ieee80211_is_beacon(hdr->frame_control))
385		txdesc->u.ht.txop = TXOP_BACKOFF;
386	else if (!(tx_info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT))
387		txdesc->u.ht.txop = TXOP_SIFS;
388	else
389		txdesc->u.ht.txop = TXOP_HTTXOP;
390}
391
392static void rt2x00queue_create_tx_descriptor(struct rt2x00_dev *rt2x00dev,
393					     struct sk_buff *skb,
394					     struct txentry_desc *txdesc,
395					     struct ieee80211_sta *sta)
396{
397	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
398	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
399	struct ieee80211_tx_rate *txrate = &tx_info->control.rates[0];
400	struct ieee80211_rate *rate;
401	const struct rt2x00_rate *hwrate = NULL;
402
403	memset(txdesc, 0, sizeof(*txdesc));
404
405	/*
406	 * Header and frame information.
407	 */
408	txdesc->length = skb->len;
409	txdesc->header_length = ieee80211_get_hdrlen_from_skb(skb);
410
411	/*
412	 * Check whether this frame is to be acked.
413	 */
414	if (!(tx_info->flags & IEEE80211_TX_CTL_NO_ACK))
415		__set_bit(ENTRY_TXD_ACK, &txdesc->flags);
416
417	/*
418	 * Check if this is a RTS/CTS frame
419	 */
420	if (ieee80211_is_rts(hdr->frame_control) ||
421	    ieee80211_is_cts(hdr->frame_control)) {
422		__set_bit(ENTRY_TXD_BURST, &txdesc->flags);
423		if (ieee80211_is_rts(hdr->frame_control))
424			__set_bit(ENTRY_TXD_RTS_FRAME, &txdesc->flags);
425		else
426			__set_bit(ENTRY_TXD_CTS_FRAME, &txdesc->flags);
427		if (tx_info->control.rts_cts_rate_idx >= 0)
428			rate =
429			    ieee80211_get_rts_cts_rate(rt2x00dev->hw, tx_info);
430	}
431
432	/*
433	 * Determine retry information.
434	 */
435	txdesc->retry_limit = tx_info->control.rates[0].count - 1;
436	if (txdesc->retry_limit >= rt2x00dev->long_retry)
437		__set_bit(ENTRY_TXD_RETRY_MODE, &txdesc->flags);
438
439	/*
440	 * Check if more fragments are pending
441	 */
442	if (ieee80211_has_morefrags(hdr->frame_control)) {
443		__set_bit(ENTRY_TXD_BURST, &txdesc->flags);
444		__set_bit(ENTRY_TXD_MORE_FRAG, &txdesc->flags);
445	}
446
447	/*
448	 * Check if more frames (!= fragments) are pending
449	 */
450	if (tx_info->flags & IEEE80211_TX_CTL_MORE_FRAMES)
451		__set_bit(ENTRY_TXD_BURST, &txdesc->flags);
452
453	/*
454	 * Beacons and probe responses require the tsf timestamp
455	 * to be inserted into the frame.
456	 */
457	if (ieee80211_is_beacon(hdr->frame_control) ||
458	    ieee80211_is_probe_resp(hdr->frame_control))
459		__set_bit(ENTRY_TXD_REQ_TIMESTAMP, &txdesc->flags);
460
461	if ((tx_info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT) &&
462	    !test_bit(ENTRY_TXD_RTS_FRAME, &txdesc->flags))
463		__set_bit(ENTRY_TXD_FIRST_FRAGMENT, &txdesc->flags);
464
465	/*
466	 * Determine rate modulation.
467	 */
468	if (txrate->flags & IEEE80211_TX_RC_GREEN_FIELD)
469		txdesc->rate_mode = RATE_MODE_HT_GREENFIELD;
470	else if (txrate->flags & IEEE80211_TX_RC_MCS)
471		txdesc->rate_mode = RATE_MODE_HT_MIX;
472	else {
473		rate = ieee80211_get_tx_rate(rt2x00dev->hw, tx_info);
474		hwrate = rt2x00_get_rate(rate->hw_value);
475		if (hwrate->flags & DEV_RATE_OFDM)
476			txdesc->rate_mode = RATE_MODE_OFDM;
477		else
478			txdesc->rate_mode = RATE_MODE_CCK;
479	}
480
481	/*
482	 * Apply TX descriptor handling by components
483	 */
484	rt2x00crypto_create_tx_descriptor(rt2x00dev, skb, txdesc);
485	rt2x00queue_create_tx_descriptor_seq(rt2x00dev, skb, txdesc);
486
487	if (rt2x00_has_cap_flag(rt2x00dev, REQUIRE_HT_TX_DESC))
488		rt2x00queue_create_tx_descriptor_ht(rt2x00dev, skb, txdesc,
489						   sta, hwrate);
490	else
491		rt2x00queue_create_tx_descriptor_plcp(rt2x00dev, skb, txdesc,
492						      hwrate);
493}
494
495static int rt2x00queue_write_tx_data(struct queue_entry *entry,
496				     struct txentry_desc *txdesc)
497{
498	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
499
500	/*
501	 * This should not happen, we already checked the entry
502	 * was ours. When the hardware disagrees there has been
503	 * a queue corruption!
504	 */
505	if (unlikely(rt2x00dev->ops->lib->get_entry_state &&
506		     rt2x00dev->ops->lib->get_entry_state(entry))) {
507		rt2x00_err(rt2x00dev,
508			   "Corrupt queue %d, accessing entry which is not ours\n"
509			   "Please file bug report to %s\n",
510			   entry->queue->qid, DRV_PROJECT);
511		return -EINVAL;
512	}
513
514	/*
515	 * Add the requested extra tx headroom in front of the skb.
516	 */
517	skb_push(entry->skb, rt2x00dev->extra_tx_headroom);
518	memset(entry->skb->data, 0, rt2x00dev->extra_tx_headroom);
519
520	/*
521	 * Call the driver's write_tx_data function, if it exists.
522	 */
523	if (rt2x00dev->ops->lib->write_tx_data)
524		rt2x00dev->ops->lib->write_tx_data(entry, txdesc);
525
526	/*
527	 * Map the skb to DMA.
528	 */
529	if (rt2x00_has_cap_flag(rt2x00dev, REQUIRE_DMA) &&
530	    rt2x00queue_map_txskb(entry))
531		return -ENOMEM;
532
533	return 0;
534}
535
536static void rt2x00queue_write_tx_descriptor(struct queue_entry *entry,
537					    struct txentry_desc *txdesc)
538{
539	struct data_queue *queue = entry->queue;
540
541	queue->rt2x00dev->ops->lib->write_tx_desc(entry, txdesc);
542
543	/*
544	 * All processing on the frame has been completed, this means
545	 * it is now ready to be dumped to userspace through debugfs.
546	 */
547	rt2x00debug_dump_frame(queue->rt2x00dev, DUMP_FRAME_TX, entry->skb);
548}
549
550static void rt2x00queue_kick_tx_queue(struct data_queue *queue,
551				      struct txentry_desc *txdesc)
552{
553	/*
554	 * Check if we need to kick the queue, there are however a few rules
555	 *	1) Don't kick unless this is the last in frame in a burst.
556	 *	   When the burst flag is set, this frame is always followed
557	 *	   by another frame which in some way are related to eachother.
558	 *	   This is true for fragments, RTS or CTS-to-self frames.
559	 *	2) Rule 1 can be broken when the available entries
560	 *	   in the queue are less then a certain threshold.
561	 */
562	if (rt2x00queue_threshold(queue) ||
563	    !test_bit(ENTRY_TXD_BURST, &txdesc->flags))
564		queue->rt2x00dev->ops->lib->kick_queue(queue);
565}
566
567static void rt2x00queue_bar_check(struct queue_entry *entry)
568{
569	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
570	struct ieee80211_bar *bar = (void *) (entry->skb->data +
571				    rt2x00dev->extra_tx_headroom);
572	struct rt2x00_bar_list_entry *bar_entry;
573
574	if (likely(!ieee80211_is_back_req(bar->frame_control)))
575		return;
576
577	bar_entry = kmalloc(sizeof(*bar_entry), GFP_ATOMIC);
578
579	/*
580	 * If the alloc fails we still send the BAR out but just don't track
581	 * it in our bar list. And as a result we will report it to mac80211
582	 * back as failed.
583	 */
584	if (!bar_entry)
585		return;
586
587	bar_entry->entry = entry;
588	bar_entry->block_acked = 0;
589
590	/*
591	 * Copy the relevant parts of the 802.11 BAR into out check list
592	 * such that we can use RCU for less-overhead in the RX path since
593	 * sending BARs and processing the according BlockAck should be
594	 * the exception.
595	 */
596	memcpy(bar_entry->ra, bar->ra, sizeof(bar->ra));
597	memcpy(bar_entry->ta, bar->ta, sizeof(bar->ta));
598	bar_entry->control = bar->control;
599	bar_entry->start_seq_num = bar->start_seq_num;
600
601	/*
602	 * Insert BAR into our BAR check list.
603	 */
604	spin_lock_bh(&rt2x00dev->bar_list_lock);
605	list_add_tail_rcu(&bar_entry->list, &rt2x00dev->bar_list);
606	spin_unlock_bh(&rt2x00dev->bar_list_lock);
607}
608
609int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb,
610			       struct ieee80211_sta *sta, bool local)
611{
612	struct ieee80211_tx_info *tx_info;
613	struct queue_entry *entry;
614	struct txentry_desc txdesc;
615	struct skb_frame_desc *skbdesc;
616	u8 rate_idx, rate_flags;
617	int ret = 0;
618
619	/*
620	 * Copy all TX descriptor information into txdesc,
621	 * after that we are free to use the skb->cb array
622	 * for our information.
623	 */
624	rt2x00queue_create_tx_descriptor(queue->rt2x00dev, skb, &txdesc, sta);
625
626	/*
627	 * All information is retrieved from the skb->cb array,
628	 * now we should claim ownership of the driver part of that
629	 * array, preserving the bitrate index and flags.
630	 */
631	tx_info = IEEE80211_SKB_CB(skb);
632	rate_idx = tx_info->control.rates[0].idx;
633	rate_flags = tx_info->control.rates[0].flags;
634	skbdesc = get_skb_frame_desc(skb);
635	memset(skbdesc, 0, sizeof(*skbdesc));
636	skbdesc->tx_rate_idx = rate_idx;
637	skbdesc->tx_rate_flags = rate_flags;
638
639	if (local)
640		skbdesc->flags |= SKBDESC_NOT_MAC80211;
641
642	/*
643	 * When hardware encryption is supported, and this frame
644	 * is to be encrypted, we should strip the IV/EIV data from
645	 * the frame so we can provide it to the driver separately.
646	 */
647	if (test_bit(ENTRY_TXD_ENCRYPT, &txdesc.flags) &&
648	    !test_bit(ENTRY_TXD_ENCRYPT_IV, &txdesc.flags)) {
649		if (rt2x00_has_cap_flag(queue->rt2x00dev, REQUIRE_COPY_IV))
650			rt2x00crypto_tx_copy_iv(skb, &txdesc);
651		else
652			rt2x00crypto_tx_remove_iv(skb, &txdesc);
653	}
654
655	/*
656	 * When DMA allocation is required we should guarantee to the
657	 * driver that the DMA is aligned to a 4-byte boundary.
658	 * However some drivers require L2 padding to pad the payload
659	 * rather then the header. This could be a requirement for
660	 * PCI and USB devices, while header alignment only is valid
661	 * for PCI devices.
662	 */
663	if (rt2x00_has_cap_flag(queue->rt2x00dev, REQUIRE_L2PAD))
664		rt2x00queue_insert_l2pad(skb, txdesc.header_length);
665	else if (rt2x00_has_cap_flag(queue->rt2x00dev, REQUIRE_DMA))
666		rt2x00queue_align_frame(skb);
667
668	/*
669	 * That function must be called with bh disabled.
670	 */
671	spin_lock(&queue->tx_lock);
672
673	if (unlikely(rt2x00queue_full(queue))) {
674		rt2x00_err(queue->rt2x00dev, "Dropping frame due to full tx queue %d\n",
675			   queue->qid);
676		ret = -ENOBUFS;
677		goto out;
678	}
679
680	entry = rt2x00queue_get_entry(queue, Q_INDEX);
681
682	if (unlikely(test_and_set_bit(ENTRY_OWNER_DEVICE_DATA,
683				      &entry->flags))) {
684		rt2x00_err(queue->rt2x00dev,
685			   "Arrived at non-free entry in the non-full queue %d\n"
686			   "Please file bug report to %s\n",
687			   queue->qid, DRV_PROJECT);
688		ret = -EINVAL;
689		goto out;
690	}
691
692	skbdesc->entry = entry;
693	entry->skb = skb;
694
695	/*
696	 * It could be possible that the queue was corrupted and this
697	 * call failed. Since we always return NETDEV_TX_OK to mac80211,
698	 * this frame will simply be dropped.
699	 */
700	if (unlikely(rt2x00queue_write_tx_data(entry, &txdesc))) {
701		clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
702		entry->skb = NULL;
703		ret = -EIO;
704		goto out;
705	}
706
707	/*
708	 * Put BlockAckReqs into our check list for driver BA processing.
709	 */
710	rt2x00queue_bar_check(entry);
711
712	set_bit(ENTRY_DATA_PENDING, &entry->flags);
713
714	rt2x00queue_index_inc(entry, Q_INDEX);
715	rt2x00queue_write_tx_descriptor(entry, &txdesc);
716	rt2x00queue_kick_tx_queue(queue, &txdesc);
717
718out:
719	spin_unlock(&queue->tx_lock);
720	return ret;
721}
722
723int rt2x00queue_clear_beacon(struct rt2x00_dev *rt2x00dev,
724			     struct ieee80211_vif *vif)
725{
726	struct rt2x00_intf *intf = vif_to_intf(vif);
727
728	if (unlikely(!intf->beacon))
729		return -ENOBUFS;
730
731	/*
732	 * Clean up the beacon skb.
733	 */
734	rt2x00queue_free_skb(intf->beacon);
735
736	/*
737	 * Clear beacon (single bssid devices don't need to clear the beacon
738	 * since the beacon queue will get stopped anyway).
739	 */
740	if (rt2x00dev->ops->lib->clear_beacon)
741		rt2x00dev->ops->lib->clear_beacon(intf->beacon);
742
743	return 0;
744}
745
746int rt2x00queue_update_beacon(struct rt2x00_dev *rt2x00dev,
747			      struct ieee80211_vif *vif)
748{
749	struct rt2x00_intf *intf = vif_to_intf(vif);
750	struct skb_frame_desc *skbdesc;
751	struct txentry_desc txdesc;
752
753	if (unlikely(!intf->beacon))
754		return -ENOBUFS;
755
756	/*
757	 * Clean up the beacon skb.
758	 */
759	rt2x00queue_free_skb(intf->beacon);
760
761	intf->beacon->skb = ieee80211_beacon_get(rt2x00dev->hw, vif);
762	if (!intf->beacon->skb)
763		return -ENOMEM;
764
765	/*
766	 * Copy all TX descriptor information into txdesc,
767	 * after that we are free to use the skb->cb array
768	 * for our information.
769	 */
770	rt2x00queue_create_tx_descriptor(rt2x00dev, intf->beacon->skb, &txdesc, NULL);
771
772	/*
773	 * Fill in skb descriptor
774	 */
775	skbdesc = get_skb_frame_desc(intf->beacon->skb);
776	memset(skbdesc, 0, sizeof(*skbdesc));
777	skbdesc->entry = intf->beacon;
778
779	/*
780	 * Send beacon to hardware.
781	 */
782	rt2x00dev->ops->lib->write_beacon(intf->beacon, &txdesc);
783
784	return 0;
785
786}
787
788bool rt2x00queue_for_each_entry(struct data_queue *queue,
789				enum queue_index start,
790				enum queue_index end,
791				void *data,
792				bool (*fn)(struct queue_entry *entry,
793					   void *data))
794{
795	unsigned long irqflags;
796	unsigned int index_start;
797	unsigned int index_end;
798	unsigned int i;
799
800	if (unlikely(start >= Q_INDEX_MAX || end >= Q_INDEX_MAX)) {
801		rt2x00_err(queue->rt2x00dev,
802			   "Entry requested from invalid index range (%d - %d)\n",
803			   start, end);
804		return true;
805	}
806
807	/*
808	 * Only protect the range we are going to loop over,
809	 * if during our loop a extra entry is set to pending
810	 * it should not be kicked during this run, since it
811	 * is part of another TX operation.
812	 */
813	spin_lock_irqsave(&queue->index_lock, irqflags);
814	index_start = queue->index[start];
815	index_end = queue->index[end];
816	spin_unlock_irqrestore(&queue->index_lock, irqflags);
817
818	/*
819	 * Start from the TX done pointer, this guarantees that we will
820	 * send out all frames in the correct order.
821	 */
822	if (index_start < index_end) {
823		for (i = index_start; i < index_end; i++) {
824			if (fn(&queue->entries[i], data))
825				return true;
826		}
827	} else {
828		for (i = index_start; i < queue->limit; i++) {
829			if (fn(&queue->entries[i], data))
830				return true;
831		}
832
833		for (i = 0; i < index_end; i++) {
834			if (fn(&queue->entries[i], data))
835				return true;
836		}
837	}
838
839	return false;
840}
841EXPORT_SYMBOL_GPL(rt2x00queue_for_each_entry);
842
843struct queue_entry *rt2x00queue_get_entry(struct data_queue *queue,
844					  enum queue_index index)
845{
846	struct queue_entry *entry;
847	unsigned long irqflags;
848
849	if (unlikely(index >= Q_INDEX_MAX)) {
850		rt2x00_err(queue->rt2x00dev, "Entry requested from invalid index type (%d)\n",
851			   index);
852		return NULL;
853	}
854
855	spin_lock_irqsave(&queue->index_lock, irqflags);
856
857	entry = &queue->entries[queue->index[index]];
858
859	spin_unlock_irqrestore(&queue->index_lock, irqflags);
860
861	return entry;
862}
863EXPORT_SYMBOL_GPL(rt2x00queue_get_entry);
864
865void rt2x00queue_index_inc(struct queue_entry *entry, enum queue_index index)
866{
867	struct data_queue *queue = entry->queue;
868	unsigned long irqflags;
869
870	if (unlikely(index >= Q_INDEX_MAX)) {
871		rt2x00_err(queue->rt2x00dev,
872			   "Index change on invalid index type (%d)\n", index);
873		return;
874	}
875
876	spin_lock_irqsave(&queue->index_lock, irqflags);
877
878	queue->index[index]++;
879	if (queue->index[index] >= queue->limit)
880		queue->index[index] = 0;
881
882	entry->last_action = jiffies;
883
884	if (index == Q_INDEX) {
885		queue->length++;
886	} else if (index == Q_INDEX_DONE) {
887		queue->length--;
888		queue->count++;
889	}
890
891	spin_unlock_irqrestore(&queue->index_lock, irqflags);
892}
893
894static void rt2x00queue_pause_queue_nocheck(struct data_queue *queue)
895{
896	switch (queue->qid) {
897	case QID_AC_VO:
898	case QID_AC_VI:
899	case QID_AC_BE:
900	case QID_AC_BK:
901		/*
902		 * For TX queues, we have to disable the queue
903		 * inside mac80211.
904		 */
905		ieee80211_stop_queue(queue->rt2x00dev->hw, queue->qid);
906		break;
907	default:
908		break;
909	}
910}
911void rt2x00queue_pause_queue(struct data_queue *queue)
912{
913	if (!test_bit(DEVICE_STATE_PRESENT, &queue->rt2x00dev->flags) ||
914	    !test_bit(QUEUE_STARTED, &queue->flags) ||
915	    test_and_set_bit(QUEUE_PAUSED, &queue->flags))
916		return;
917
918	rt2x00queue_pause_queue_nocheck(queue);
919}
920EXPORT_SYMBOL_GPL(rt2x00queue_pause_queue);
921
922void rt2x00queue_unpause_queue(struct data_queue *queue)
923{
924	if (!test_bit(DEVICE_STATE_PRESENT, &queue->rt2x00dev->flags) ||
925	    !test_bit(QUEUE_STARTED, &queue->flags) ||
926	    !test_and_clear_bit(QUEUE_PAUSED, &queue->flags))
927		return;
928
929	switch (queue->qid) {
930	case QID_AC_VO:
931	case QID_AC_VI:
932	case QID_AC_BE:
933	case QID_AC_BK:
934		/*
935		 * For TX queues, we have to enable the queue
936		 * inside mac80211.
937		 */
938		ieee80211_wake_queue(queue->rt2x00dev->hw, queue->qid);
939		break;
940	case QID_RX:
941		/*
942		 * For RX we need to kick the queue now in order to
943		 * receive frames.
944		 */
945		queue->rt2x00dev->ops->lib->kick_queue(queue);
946	default:
947		break;
948	}
949}
950EXPORT_SYMBOL_GPL(rt2x00queue_unpause_queue);
951
952void rt2x00queue_start_queue(struct data_queue *queue)
953{
954	mutex_lock(&queue->status_lock);
955
956	if (!test_bit(DEVICE_STATE_PRESENT, &queue->rt2x00dev->flags) ||
957	    test_and_set_bit(QUEUE_STARTED, &queue->flags)) {
958		mutex_unlock(&queue->status_lock);
959		return;
960	}
961
962	set_bit(QUEUE_PAUSED, &queue->flags);
963
964	queue->rt2x00dev->ops->lib->start_queue(queue);
965
966	rt2x00queue_unpause_queue(queue);
967
968	mutex_unlock(&queue->status_lock);
969}
970EXPORT_SYMBOL_GPL(rt2x00queue_start_queue);
971
972void rt2x00queue_stop_queue(struct data_queue *queue)
973{
974	mutex_lock(&queue->status_lock);
975
976	if (!test_and_clear_bit(QUEUE_STARTED, &queue->flags)) {
977		mutex_unlock(&queue->status_lock);
978		return;
979	}
980
981	rt2x00queue_pause_queue_nocheck(queue);
982
983	queue->rt2x00dev->ops->lib->stop_queue(queue);
984
985	mutex_unlock(&queue->status_lock);
986}
987EXPORT_SYMBOL_GPL(rt2x00queue_stop_queue);
988
989void rt2x00queue_flush_queue(struct data_queue *queue, bool drop)
990{
991	bool tx_queue =
992		(queue->qid == QID_AC_VO) ||
993		(queue->qid == QID_AC_VI) ||
994		(queue->qid == QID_AC_BE) ||
995		(queue->qid == QID_AC_BK);
996
997
998	/*
999	 * If we are not supposed to drop any pending
1000	 * frames, this means we must force a start (=kick)
1001	 * to the queue to make sure the hardware will
1002	 * start transmitting.
1003	 */
1004	if (!drop && tx_queue)
1005		queue->rt2x00dev->ops->lib->kick_queue(queue);
1006
1007	/*
1008	 * Check if driver supports flushing, if that is the case we can
1009	 * defer the flushing to the driver. Otherwise we must use the
1010	 * alternative which just waits for the queue to become empty.
1011	 */
1012	if (likely(queue->rt2x00dev->ops->lib->flush_queue))
1013		queue->rt2x00dev->ops->lib->flush_queue(queue, drop);
1014
1015	/*
1016	 * The queue flush has failed...
1017	 */
1018	if (unlikely(!rt2x00queue_empty(queue)))
1019		rt2x00_warn(queue->rt2x00dev, "Queue %d failed to flush\n",
1020			    queue->qid);
1021}
1022EXPORT_SYMBOL_GPL(rt2x00queue_flush_queue);
1023
1024void rt2x00queue_start_queues(struct rt2x00_dev *rt2x00dev)
1025{
1026	struct data_queue *queue;
1027
1028	/*
1029	 * rt2x00queue_start_queue will call ieee80211_wake_queue
1030	 * for each queue after is has been properly initialized.
1031	 */
1032	tx_queue_for_each(rt2x00dev, queue)
1033		rt2x00queue_start_queue(queue);
1034
1035	rt2x00queue_start_queue(rt2x00dev->rx);
1036}
1037EXPORT_SYMBOL_GPL(rt2x00queue_start_queues);
1038
1039void rt2x00queue_stop_queues(struct rt2x00_dev *rt2x00dev)
1040{
1041	struct data_queue *queue;
1042
1043	/*
1044	 * rt2x00queue_stop_queue will call ieee80211_stop_queue
1045	 * as well, but we are completely shutting doing everything
1046	 * now, so it is much safer to stop all TX queues at once,
1047	 * and use rt2x00queue_stop_queue for cleaning up.
1048	 */
1049	ieee80211_stop_queues(rt2x00dev->hw);
1050
1051	tx_queue_for_each(rt2x00dev, queue)
1052		rt2x00queue_stop_queue(queue);
1053
1054	rt2x00queue_stop_queue(rt2x00dev->rx);
1055}
1056EXPORT_SYMBOL_GPL(rt2x00queue_stop_queues);
1057
1058void rt2x00queue_flush_queues(struct rt2x00_dev *rt2x00dev, bool drop)
1059{
1060	struct data_queue *queue;
1061
1062	tx_queue_for_each(rt2x00dev, queue)
1063		rt2x00queue_flush_queue(queue, drop);
1064
1065	rt2x00queue_flush_queue(rt2x00dev->rx, drop);
1066}
1067EXPORT_SYMBOL_GPL(rt2x00queue_flush_queues);
1068
1069static void rt2x00queue_reset(struct data_queue *queue)
1070{
1071	unsigned long irqflags;
1072	unsigned int i;
1073
1074	spin_lock_irqsave(&queue->index_lock, irqflags);
1075
1076	queue->count = 0;
1077	queue->length = 0;
1078
1079	for (i = 0; i < Q_INDEX_MAX; i++)
1080		queue->index[i] = 0;
1081
1082	spin_unlock_irqrestore(&queue->index_lock, irqflags);
1083}
1084
1085void rt2x00queue_init_queues(struct rt2x00_dev *rt2x00dev)
1086{
1087	struct data_queue *queue;
1088	unsigned int i;
1089
1090	queue_for_each(rt2x00dev, queue) {
1091		rt2x00queue_reset(queue);
1092
1093		for (i = 0; i < queue->limit; i++)
1094			rt2x00dev->ops->lib->clear_entry(&queue->entries[i]);
1095	}
1096}
1097
1098static int rt2x00queue_alloc_entries(struct data_queue *queue)
1099{
1100	struct queue_entry *entries;
1101	unsigned int entry_size;
1102	unsigned int i;
1103
1104	rt2x00queue_reset(queue);
1105
1106	/*
1107	 * Allocate all queue entries.
1108	 */
1109	entry_size = sizeof(*entries) + queue->priv_size;
1110	entries = kcalloc(queue->limit, entry_size, GFP_KERNEL);
1111	if (!entries)
1112		return -ENOMEM;
1113
1114#define QUEUE_ENTRY_PRIV_OFFSET(__base, __index, __limit, __esize, __psize) \
1115	(((char *)(__base)) + ((__limit) * (__esize)) + \
1116	    ((__index) * (__psize)))
1117
1118	for (i = 0; i < queue->limit; i++) {
1119		entries[i].flags = 0;
1120		entries[i].queue = queue;
1121		entries[i].skb = NULL;
1122		entries[i].entry_idx = i;
1123		entries[i].priv_data =
1124		    QUEUE_ENTRY_PRIV_OFFSET(entries, i, queue->limit,
1125					    sizeof(*entries), queue->priv_size);
1126	}
1127
1128#undef QUEUE_ENTRY_PRIV_OFFSET
1129
1130	queue->entries = entries;
1131
1132	return 0;
1133}
1134
1135static void rt2x00queue_free_skbs(struct data_queue *queue)
1136{
1137	unsigned int i;
1138
1139	if (!queue->entries)
1140		return;
1141
1142	for (i = 0; i < queue->limit; i++) {
1143		rt2x00queue_free_skb(&queue->entries[i]);
1144	}
1145}
1146
1147static int rt2x00queue_alloc_rxskbs(struct data_queue *queue)
1148{
1149	unsigned int i;
1150	struct sk_buff *skb;
1151
1152	for (i = 0; i < queue->limit; i++) {
1153		skb = rt2x00queue_alloc_rxskb(&queue->entries[i], GFP_KERNEL);
1154		if (!skb)
1155			return -ENOMEM;
1156		queue->entries[i].skb = skb;
1157	}
1158
1159	return 0;
1160}
1161
1162int rt2x00queue_initialize(struct rt2x00_dev *rt2x00dev)
1163{
1164	struct data_queue *queue;
1165	int status;
1166
1167	status = rt2x00queue_alloc_entries(rt2x00dev->rx);
1168	if (status)
1169		goto exit;
1170
1171	tx_queue_for_each(rt2x00dev, queue) {
1172		status = rt2x00queue_alloc_entries(queue);
1173		if (status)
1174			goto exit;
1175	}
1176
1177	status = rt2x00queue_alloc_entries(rt2x00dev->bcn);
1178	if (status)
1179		goto exit;
1180
1181	if (rt2x00_has_cap_flag(rt2x00dev, REQUIRE_ATIM_QUEUE)) {
1182		status = rt2x00queue_alloc_entries(rt2x00dev->atim);
1183		if (status)
1184			goto exit;
1185	}
1186
1187	status = rt2x00queue_alloc_rxskbs(rt2x00dev->rx);
1188	if (status)
1189		goto exit;
1190
1191	return 0;
1192
1193exit:
1194	rt2x00_err(rt2x00dev, "Queue entries allocation failed\n");
1195
1196	rt2x00queue_uninitialize(rt2x00dev);
1197
1198	return status;
1199}
1200
1201void rt2x00queue_uninitialize(struct rt2x00_dev *rt2x00dev)
1202{
1203	struct data_queue *queue;
1204
1205	rt2x00queue_free_skbs(rt2x00dev->rx);
1206
1207	queue_for_each(rt2x00dev, queue) {
1208		kfree(queue->entries);
1209		queue->entries = NULL;
1210	}
1211}
1212
1213static void rt2x00queue_init(struct rt2x00_dev *rt2x00dev,
1214			     struct data_queue *queue, enum data_queue_qid qid)
1215{
1216	mutex_init(&queue->status_lock);
1217	spin_lock_init(&queue->tx_lock);
1218	spin_lock_init(&queue->index_lock);
1219
1220	queue->rt2x00dev = rt2x00dev;
1221	queue->qid = qid;
1222	queue->txop = 0;
1223	queue->aifs = 2;
1224	queue->cw_min = 5;
1225	queue->cw_max = 10;
1226
1227	rt2x00dev->ops->queue_init(queue);
1228
1229	queue->threshold = DIV_ROUND_UP(queue->limit, 10);
1230}
1231
1232int rt2x00queue_allocate(struct rt2x00_dev *rt2x00dev)
1233{
1234	struct data_queue *queue;
1235	enum data_queue_qid qid;
1236	unsigned int req_atim =
1237	    rt2x00_has_cap_flag(rt2x00dev, REQUIRE_ATIM_QUEUE);
1238
1239	/*
1240	 * We need the following queues:
1241	 * RX: 1
1242	 * TX: ops->tx_queues
1243	 * Beacon: 1
1244	 * Atim: 1 (if required)
1245	 */
1246	rt2x00dev->data_queues = 2 + rt2x00dev->ops->tx_queues + req_atim;
1247
1248	queue = kcalloc(rt2x00dev->data_queues, sizeof(*queue), GFP_KERNEL);
1249	if (!queue) {
1250		rt2x00_err(rt2x00dev, "Queue allocation failed\n");
1251		return -ENOMEM;
1252	}
1253
1254	/*
1255	 * Initialize pointers
1256	 */
1257	rt2x00dev->rx = queue;
1258	rt2x00dev->tx = &queue[1];
1259	rt2x00dev->bcn = &queue[1 + rt2x00dev->ops->tx_queues];
1260	rt2x00dev->atim = req_atim ? &queue[2 + rt2x00dev->ops->tx_queues] : NULL;
1261
1262	/*
1263	 * Initialize queue parameters.
1264	 * RX: qid = QID_RX
1265	 * TX: qid = QID_AC_VO + index
1266	 * TX: cw_min: 2^5 = 32.
1267	 * TX: cw_max: 2^10 = 1024.
1268	 * BCN: qid = QID_BEACON
1269	 * ATIM: qid = QID_ATIM
1270	 */
1271	rt2x00queue_init(rt2x00dev, rt2x00dev->rx, QID_RX);
1272
1273	qid = QID_AC_VO;
1274	tx_queue_for_each(rt2x00dev, queue)
1275		rt2x00queue_init(rt2x00dev, queue, qid++);
1276
1277	rt2x00queue_init(rt2x00dev, rt2x00dev->bcn, QID_BEACON);
1278	if (req_atim)
1279		rt2x00queue_init(rt2x00dev, rt2x00dev->atim, QID_ATIM);
1280
1281	return 0;
1282}
1283
1284void rt2x00queue_free(struct rt2x00_dev *rt2x00dev)
1285{
1286	kfree(rt2x00dev->rx);
1287	rt2x00dev->rx = NULL;
1288	rt2x00dev->tx = NULL;
1289	rt2x00dev->bcn = NULL;
1290}
1291