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1/*
2 * This file is part of wl1251
3 *
4 * Copyright (c) 1998-2007 Texas Instruments Incorporated
5 * Copyright (C) 2008 Nokia Corporation
6 *
7 * Contact: Kalle Valo <kalle.valo@nokia.com>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * version 2 as published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
21 * 02110-1301 USA
22 *
23 */
24
25#include <linux/kernel.h>
26#include <linux/module.h>
27
28#include "wl1251.h"
29#include "wl1251_reg.h"
30#include "wl1251_tx.h"
31#include "wl1251_ps.h"
32#include "wl1251_io.h"
33
34static bool wl1251_tx_double_buffer_busy(struct wl1251 *wl, u32 data_out_count)
35{
36	int used, data_in_count;
37
38	data_in_count = wl->data_in_count;
39
40	if (data_in_count < data_out_count)
41		/* data_in_count has wrapped */
42		data_in_count += TX_STATUS_DATA_OUT_COUNT_MASK + 1;
43
44	used = data_in_count - data_out_count;
45
46	WARN_ON(used < 0);
47	WARN_ON(used > DP_TX_PACKET_RING_CHUNK_NUM);
48
49	if (used >= DP_TX_PACKET_RING_CHUNK_NUM)
50		return true;
51	else
52		return false;
53}
54
55static int wl1251_tx_path_status(struct wl1251 *wl)
56{
57	u32 status, addr, data_out_count;
58	bool busy;
59
60	addr = wl->data_path->tx_control_addr;
61	status = wl1251_mem_read32(wl, addr);
62	data_out_count = status & TX_STATUS_DATA_OUT_COUNT_MASK;
63	busy = wl1251_tx_double_buffer_busy(wl, data_out_count);
64
65	if (busy)
66		return -EBUSY;
67
68	return 0;
69}
70
71static int wl1251_tx_id(struct wl1251 *wl, struct sk_buff *skb)
72{
73	int i;
74
75	for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
76		if (wl->tx_frames[i] == NULL) {
77			wl->tx_frames[i] = skb;
78			return i;
79		}
80
81	return -EBUSY;
82}
83
84static void wl1251_tx_control(struct tx_double_buffer_desc *tx_hdr,
85			      struct ieee80211_tx_info *control, u16 fc)
86{
87	*(u16 *)&tx_hdr->control = 0;
88
89	tx_hdr->control.rate_policy = 0;
90
91	/* 802.11 packets */
92	tx_hdr->control.packet_type = 0;
93
94	if (control->flags & IEEE80211_TX_CTL_NO_ACK)
95		tx_hdr->control.ack_policy = 1;
96
97	tx_hdr->control.tx_complete = 1;
98
99	if ((fc & IEEE80211_FTYPE_DATA) &&
100	    ((fc & IEEE80211_STYPE_QOS_DATA) ||
101	     (fc & IEEE80211_STYPE_QOS_NULLFUNC)))
102		tx_hdr->control.qos = 1;
103}
104
105/* RSN + MIC = 8 + 8 = 16 bytes (worst case - AES). */
106#define MAX_MSDU_SECURITY_LENGTH      16
107#define MAX_MPDU_SECURITY_LENGTH      16
108#define WLAN_QOS_HDR_LEN              26
109#define MAX_MPDU_HEADER_AND_SECURITY  (MAX_MPDU_SECURITY_LENGTH + \
110				       WLAN_QOS_HDR_LEN)
111#define HW_BLOCK_SIZE                 252
112static void wl1251_tx_frag_block_num(struct tx_double_buffer_desc *tx_hdr)
113{
114	u16 payload_len, frag_threshold, mem_blocks;
115	u16 num_mpdus, mem_blocks_per_frag;
116
117	frag_threshold = IEEE80211_MAX_FRAG_THRESHOLD;
118	tx_hdr->frag_threshold = cpu_to_le16(frag_threshold);
119
120	payload_len = le16_to_cpu(tx_hdr->length) + MAX_MSDU_SECURITY_LENGTH;
121
122	if (payload_len > frag_threshold) {
123		mem_blocks_per_frag =
124			((frag_threshold + MAX_MPDU_HEADER_AND_SECURITY) /
125			 HW_BLOCK_SIZE) + 1;
126		num_mpdus = payload_len / frag_threshold;
127		mem_blocks = num_mpdus * mem_blocks_per_frag;
128		payload_len -= num_mpdus * frag_threshold;
129		num_mpdus++;
130
131	} else {
132		mem_blocks_per_frag = 0;
133		mem_blocks = 0;
134		num_mpdus = 1;
135	}
136
137	mem_blocks += (payload_len / HW_BLOCK_SIZE) + 1;
138
139	if (num_mpdus > 1)
140		mem_blocks += min(num_mpdus, mem_blocks_per_frag);
141
142	tx_hdr->num_mem_blocks = mem_blocks;
143}
144
145static int wl1251_tx_fill_hdr(struct wl1251 *wl, struct sk_buff *skb,
146			      struct ieee80211_tx_info *control)
147{
148	struct tx_double_buffer_desc *tx_hdr;
149	struct ieee80211_rate *rate;
150	int id;
151	u16 fc;
152
153	if (!skb)
154		return -EINVAL;
155
156	id = wl1251_tx_id(wl, skb);
157	if (id < 0)
158		return id;
159
160	fc = *(u16 *)skb->data;
161	tx_hdr = (struct tx_double_buffer_desc *) skb_push(skb,
162							   sizeof(*tx_hdr));
163
164	tx_hdr->length = cpu_to_le16(skb->len - sizeof(*tx_hdr));
165	rate = ieee80211_get_tx_rate(wl->hw, control);
166	tx_hdr->rate = cpu_to_le16(rate->hw_value);
167	tx_hdr->expiry_time = cpu_to_le32(1 << 16);
168	tx_hdr->id = id;
169
170	tx_hdr->xmit_queue = wl1251_tx_get_queue(skb_get_queue_mapping(skb));
171
172	wl1251_tx_control(tx_hdr, control, fc);
173	wl1251_tx_frag_block_num(tx_hdr);
174
175	return 0;
176}
177
178/* We copy the packet to the target */
179static int wl1251_tx_send_packet(struct wl1251 *wl, struct sk_buff *skb,
180				 struct ieee80211_tx_info *control)
181{
182	struct tx_double_buffer_desc *tx_hdr;
183	int len;
184	u32 addr;
185
186	if (!skb)
187		return -EINVAL;
188
189	tx_hdr = (struct tx_double_buffer_desc *) skb->data;
190
191	if (control->control.hw_key &&
192	    control->control.hw_key->alg == ALG_TKIP) {
193		int hdrlen;
194		__le16 fc;
195		u16 length;
196		u8 *pos;
197
198		fc = *(__le16 *)(skb->data + sizeof(*tx_hdr));
199		length = le16_to_cpu(tx_hdr->length) + WL1251_TKIP_IV_SPACE;
200		tx_hdr->length = cpu_to_le16(length);
201
202		hdrlen = ieee80211_hdrlen(fc);
203
204		pos = skb_push(skb, WL1251_TKIP_IV_SPACE);
205		memmove(pos, pos + WL1251_TKIP_IV_SPACE,
206			sizeof(*tx_hdr) + hdrlen);
207	}
208
209	if (unlikely((long)skb->data & 0x03)) {
210		int offset = (4 - (long)skb->data) & 0x03;
211		wl1251_debug(DEBUG_TX, "skb offset %d", offset);
212
213		/* check whether the current skb can be used */
214		if (!skb_cloned(skb) && (skb_tailroom(skb) >= offset)) {
215			unsigned char *src = skb->data;
216
217			/* align the buffer on a 4-byte boundary */
218			skb_reserve(skb, offset);
219			memmove(skb->data, src, skb->len);
220			tx_hdr = (struct tx_double_buffer_desc *) skb->data;
221		} else {
222			wl1251_info("No handler, fixme!");
223			return -EINVAL;
224		}
225	}
226
227	/* Our skb->data at this point includes the HW header */
228	len = WL1251_TX_ALIGN(skb->len);
229
230	if (wl->data_in_count & 0x1)
231		addr = wl->data_path->tx_packet_ring_addr +
232			wl->data_path->tx_packet_ring_chunk_size;
233	else
234		addr = wl->data_path->tx_packet_ring_addr;
235
236	wl1251_mem_write(wl, addr, skb->data, len);
237
238	wl1251_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u rate 0x%x "
239		     "queue %d", tx_hdr->id, skb, tx_hdr->length,
240		     tx_hdr->rate, tx_hdr->xmit_queue);
241
242	return 0;
243}
244
245static void wl1251_tx_trigger(struct wl1251 *wl)
246{
247	u32 data, addr;
248
249	if (wl->data_in_count & 0x1) {
250		addr = ACX_REG_INTERRUPT_TRIG_H;
251		data = INTR_TRIG_TX_PROC1;
252	} else {
253		addr = ACX_REG_INTERRUPT_TRIG;
254		data = INTR_TRIG_TX_PROC0;
255	}
256
257	wl1251_reg_write32(wl, addr, data);
258
259	/* Bumping data in */
260	wl->data_in_count = (wl->data_in_count + 1) &
261		TX_STATUS_DATA_OUT_COUNT_MASK;
262}
263
264/* caller must hold wl->mutex */
265static int wl1251_tx_frame(struct wl1251 *wl, struct sk_buff *skb)
266{
267	struct ieee80211_tx_info *info;
268	int ret = 0;
269	u8 idx;
270
271	info = IEEE80211_SKB_CB(skb);
272
273	if (info->control.hw_key) {
274		idx = info->control.hw_key->hw_key_idx;
275		if (unlikely(wl->default_key != idx)) {
276			ret = wl1251_acx_default_key(wl, idx);
277			if (ret < 0)
278				return ret;
279		}
280	}
281
282	ret = wl1251_tx_path_status(wl);
283	if (ret < 0)
284		return ret;
285
286	ret = wl1251_tx_fill_hdr(wl, skb, info);
287	if (ret < 0)
288		return ret;
289
290	ret = wl1251_tx_send_packet(wl, skb, info);
291	if (ret < 0)
292		return ret;
293
294	wl1251_tx_trigger(wl);
295
296	return ret;
297}
298
299void wl1251_tx_work(struct work_struct *work)
300{
301	struct wl1251 *wl = container_of(work, struct wl1251, tx_work);
302	struct sk_buff *skb;
303	bool woken_up = false;
304	int ret;
305
306	mutex_lock(&wl->mutex);
307
308	if (unlikely(wl->state == WL1251_STATE_OFF))
309		goto out;
310
311	while ((skb = skb_dequeue(&wl->tx_queue))) {
312		if (!woken_up) {
313			ret = wl1251_ps_elp_wakeup(wl);
314			if (ret < 0)
315				goto out;
316			woken_up = true;
317		}
318
319		ret = wl1251_tx_frame(wl, skb);
320		if (ret == -EBUSY) {
321			/* firmware buffer is full, stop queues */
322			wl1251_debug(DEBUG_TX, "tx_work: fw buffer full, "
323				     "stop queues");
324			ieee80211_stop_queues(wl->hw);
325			wl->tx_queue_stopped = true;
326			skb_queue_head(&wl->tx_queue, skb);
327			goto out;
328		} else if (ret < 0) {
329			dev_kfree_skb(skb);
330			goto out;
331		}
332	}
333
334out:
335	if (woken_up)
336		wl1251_ps_elp_sleep(wl);
337
338	mutex_unlock(&wl->mutex);
339}
340
341static const char *wl1251_tx_parse_status(u8 status)
342{
343	/* 8 bit status field, one character per bit plus null */
344	static char buf[9];
345	int i = 0;
346
347	memset(buf, 0, sizeof(buf));
348
349	if (status & TX_DMA_ERROR)
350		buf[i++] = 'm';
351	if (status & TX_DISABLED)
352		buf[i++] = 'd';
353	if (status & TX_RETRY_EXCEEDED)
354		buf[i++] = 'r';
355	if (status & TX_TIMEOUT)
356		buf[i++] = 't';
357	if (status & TX_KEY_NOT_FOUND)
358		buf[i++] = 'k';
359	if (status & TX_ENCRYPT_FAIL)
360		buf[i++] = 'e';
361	if (status & TX_UNAVAILABLE_PRIORITY)
362		buf[i++] = 'p';
363
364	/* bit 0 is unused apparently */
365
366	return buf;
367}
368
369static void wl1251_tx_packet_cb(struct wl1251 *wl,
370				struct tx_result *result)
371{
372	struct ieee80211_tx_info *info;
373	struct sk_buff *skb;
374	int hdrlen, ret;
375	u8 *frame;
376
377	skb = wl->tx_frames[result->id];
378	if (skb == NULL) {
379		wl1251_error("SKB for packet %d is NULL", result->id);
380		return;
381	}
382
383	info = IEEE80211_SKB_CB(skb);
384
385	if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
386	    (result->status == TX_SUCCESS))
387		info->flags |= IEEE80211_TX_STAT_ACK;
388
389	info->status.rates[0].count = result->ack_failures + 1;
390	wl->stats.retry_count += result->ack_failures;
391
392	/*
393	 * We have to remove our private TX header before pushing
394	 * the skb back to mac80211.
395	 */
396	frame = skb_pull(skb, sizeof(struct tx_double_buffer_desc));
397	if (info->control.hw_key &&
398	    info->control.hw_key->alg == ALG_TKIP) {
399		hdrlen = ieee80211_get_hdrlen_from_skb(skb);
400		memmove(frame + WL1251_TKIP_IV_SPACE, frame, hdrlen);
401		skb_pull(skb, WL1251_TKIP_IV_SPACE);
402	}
403
404	wl1251_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
405		     " status 0x%x (%s)",
406		     result->id, skb, result->ack_failures, result->rate,
407		     result->status, wl1251_tx_parse_status(result->status));
408
409
410	ieee80211_tx_status(wl->hw, skb);
411
412	wl->tx_frames[result->id] = NULL;
413
414	if (wl->tx_queue_stopped) {
415		wl1251_debug(DEBUG_TX, "cb: queue was stopped");
416
417		skb = skb_dequeue(&wl->tx_queue);
418
419		/* The skb can be NULL because tx_work might have been
420		   scheduled before the queue was stopped making the
421		   queue empty */
422
423		if (skb) {
424			ret = wl1251_tx_frame(wl, skb);
425			if (ret == -EBUSY) {
426				/* firmware buffer is still full */
427				wl1251_debug(DEBUG_TX, "cb: fw buffer "
428					     "still full");
429				skb_queue_head(&wl->tx_queue, skb);
430				return;
431			} else if (ret < 0) {
432				dev_kfree_skb(skb);
433				return;
434			}
435		}
436
437		wl1251_debug(DEBUG_TX, "cb: waking queues");
438		ieee80211_wake_queues(wl->hw);
439		wl->tx_queue_stopped = false;
440	}
441}
442
443/* Called upon reception of a TX complete interrupt */
444void wl1251_tx_complete(struct wl1251 *wl)
445{
446	int i, result_index, num_complete = 0;
447	struct tx_result result[FW_TX_CMPLT_BLOCK_SIZE], *result_ptr;
448
449	if (unlikely(wl->state != WL1251_STATE_ON))
450		return;
451
452	/* First we read the result */
453	wl1251_mem_read(wl, wl->data_path->tx_complete_addr,
454			    result, sizeof(result));
455
456	result_index = wl->next_tx_complete;
457
458	for (i = 0; i < ARRAY_SIZE(result); i++) {
459		result_ptr = &result[result_index];
460
461		if (result_ptr->done_1 == 1 &&
462		    result_ptr->done_2 == 1) {
463			wl1251_tx_packet_cb(wl, result_ptr);
464
465			result_ptr->done_1 = 0;
466			result_ptr->done_2 = 0;
467
468			result_index = (result_index + 1) &
469				(FW_TX_CMPLT_BLOCK_SIZE - 1);
470			num_complete++;
471		} else {
472			break;
473		}
474	}
475
476	/* Every completed frame needs to be acknowledged */
477	if (num_complete) {
478		/*
479		 * If we've wrapped, we have to clear
480		 * the results in 2 steps.
481		 */
482		if (result_index > wl->next_tx_complete) {
483			/* Only 1 write is needed */
484			wl1251_mem_write(wl,
485					 wl->data_path->tx_complete_addr +
486					 (wl->next_tx_complete *
487					  sizeof(struct tx_result)),
488					 &result[wl->next_tx_complete],
489					 num_complete *
490					 sizeof(struct tx_result));
491
492
493		} else if (result_index < wl->next_tx_complete) {
494			/* 2 writes are needed */
495			wl1251_mem_write(wl,
496					 wl->data_path->tx_complete_addr +
497					 (wl->next_tx_complete *
498					  sizeof(struct tx_result)),
499					 &result[wl->next_tx_complete],
500					 (FW_TX_CMPLT_BLOCK_SIZE -
501					  wl->next_tx_complete) *
502					 sizeof(struct tx_result));
503
504			wl1251_mem_write(wl,
505					 wl->data_path->tx_complete_addr,
506					 result,
507					 (num_complete -
508					  FW_TX_CMPLT_BLOCK_SIZE +
509					  wl->next_tx_complete) *
510					 sizeof(struct tx_result));
511
512		} else {
513			/* We have to write the whole array */
514			wl1251_mem_write(wl,
515					 wl->data_path->tx_complete_addr,
516					 result,
517					 FW_TX_CMPLT_BLOCK_SIZE *
518					 sizeof(struct tx_result));
519		}
520
521	}
522
523	wl->next_tx_complete = result_index;
524}
525
526/* caller must hold wl->mutex */
527void wl1251_tx_flush(struct wl1251 *wl)
528{
529	int i;
530	struct sk_buff *skb;
531	struct ieee80211_tx_info *info;
532
533	/* TX failure */
534
535	while ((skb = skb_dequeue(&wl->tx_queue))) {
536		info = IEEE80211_SKB_CB(skb);
537
538		wl1251_debug(DEBUG_TX, "flushing skb 0x%p", skb);
539
540		if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
541				continue;
542
543		ieee80211_tx_status(wl->hw, skb);
544	}
545
546	for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
547		if (wl->tx_frames[i] != NULL) {
548			skb = wl->tx_frames[i];
549			info = IEEE80211_SKB_CB(skb);
550
551			if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
552				continue;
553
554			ieee80211_tx_status(wl->hw, skb);
555			wl->tx_frames[i] = NULL;
556		}
557}
558