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 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * version 2 as published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
19 * 02110-1301 USA
20 *
21 */
22
23#include <linux/kernel.h>
24#include <linux/module.h>
25
26#include "wl1251.h"
27#include "reg.h"
28#include "tx.h"
29#include "ps.h"
30#include "io.h"
31#include "event.h"
32
33static bool wl1251_tx_double_buffer_busy(struct wl1251 *wl, u32 data_out_count)
34{
35	int used, data_in_count;
36
37	data_in_count = wl->data_in_count;
38
39	if (data_in_count < data_out_count)
40		/* data_in_count has wrapped */
41		data_in_count += TX_STATUS_DATA_OUT_COUNT_MASK + 1;
42
43	used = data_in_count - data_out_count;
44
45	WARN_ON(used < 0);
46	WARN_ON(used > DP_TX_PACKET_RING_CHUNK_NUM);
47
48	if (used >= DP_TX_PACKET_RING_CHUNK_NUM)
49		return true;
50	else
51		return false;
52}
53
54static int wl1251_tx_path_status(struct wl1251 *wl)
55{
56	u32 status, addr, data_out_count;
57	bool busy;
58
59	addr = wl->data_path->tx_control_addr;
60	status = wl1251_mem_read32(wl, addr);
61	data_out_count = status & TX_STATUS_DATA_OUT_COUNT_MASK;
62	busy = wl1251_tx_double_buffer_busy(wl, data_out_count);
63
64	if (busy)
65		return -EBUSY;
66
67	return 0;
68}
69
70static int wl1251_tx_id(struct wl1251 *wl, struct sk_buff *skb)
71{
72	int i;
73
74	for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
75		if (wl->tx_frames[i] == NULL) {
76			wl->tx_frames[i] = skb;
77			return i;
78		}
79
80	return -EBUSY;
81}
82
83static void wl1251_tx_control(struct tx_double_buffer_desc *tx_hdr,
84			      struct ieee80211_tx_info *control, u16 fc)
85{
86	*(u16 *)&tx_hdr->control = 0;
87
88	tx_hdr->control.rate_policy = 0;
89
90	/* 802.11 packets */
91	tx_hdr->control.packet_type = 0;
92
93	/* Also disable retry and ACK policy for injected packets */
94	if ((control->flags & IEEE80211_TX_CTL_NO_ACK) ||
95	    (control->flags & IEEE80211_TX_CTL_INJECTED)) {
96		tx_hdr->control.rate_policy = 1;
97		tx_hdr->control.ack_policy = 1;
98	}
99
100	tx_hdr->control.tx_complete = 1;
101
102	if ((fc & IEEE80211_FTYPE_DATA) &&
103	    ((fc & IEEE80211_STYPE_QOS_DATA) ||
104	     (fc & IEEE80211_STYPE_QOS_NULLFUNC)))
105		tx_hdr->control.qos = 1;
106}
107
108/* RSN + MIC = 8 + 8 = 16 bytes (worst case - AES). */
109#define MAX_MSDU_SECURITY_LENGTH      16
110#define MAX_MPDU_SECURITY_LENGTH      16
111#define WLAN_QOS_HDR_LEN              26
112#define MAX_MPDU_HEADER_AND_SECURITY  (MAX_MPDU_SECURITY_LENGTH + \
113				       WLAN_QOS_HDR_LEN)
114#define HW_BLOCK_SIZE                 252
115static void wl1251_tx_frag_block_num(struct tx_double_buffer_desc *tx_hdr)
116{
117	u16 payload_len, frag_threshold, mem_blocks;
118	u16 num_mpdus, mem_blocks_per_frag;
119
120	frag_threshold = IEEE80211_MAX_FRAG_THRESHOLD;
121	tx_hdr->frag_threshold = cpu_to_le16(frag_threshold);
122
123	payload_len = le16_to_cpu(tx_hdr->length) + MAX_MSDU_SECURITY_LENGTH;
124
125	if (payload_len > frag_threshold) {
126		mem_blocks_per_frag =
127			((frag_threshold + MAX_MPDU_HEADER_AND_SECURITY) /
128			 HW_BLOCK_SIZE) + 1;
129		num_mpdus = payload_len / frag_threshold;
130		mem_blocks = num_mpdus * mem_blocks_per_frag;
131		payload_len -= num_mpdus * frag_threshold;
132		num_mpdus++;
133
134	} else {
135		mem_blocks_per_frag = 0;
136		mem_blocks = 0;
137		num_mpdus = 1;
138	}
139
140	mem_blocks += (payload_len / HW_BLOCK_SIZE) + 1;
141
142	if (num_mpdus > 1)
143		mem_blocks += min(num_mpdus, mem_blocks_per_frag);
144
145	tx_hdr->num_mem_blocks = mem_blocks;
146}
147
148static int wl1251_tx_fill_hdr(struct wl1251 *wl, struct sk_buff *skb,
149			      struct ieee80211_tx_info *control)
150{
151	struct tx_double_buffer_desc *tx_hdr;
152	struct ieee80211_rate *rate;
153	int id;
154	u16 fc;
155
156	if (!skb)
157		return -EINVAL;
158
159	id = wl1251_tx_id(wl, skb);
160	if (id < 0)
161		return id;
162
163	fc = *(u16 *)skb->data;
164	tx_hdr = (struct tx_double_buffer_desc *) skb_push(skb,
165							   sizeof(*tx_hdr));
166
167	tx_hdr->length = cpu_to_le16(skb->len - sizeof(*tx_hdr));
168	rate = ieee80211_get_tx_rate(wl->hw, control);
169	tx_hdr->rate = cpu_to_le16(rate->hw_value);
170	tx_hdr->expiry_time = cpu_to_le32(1 << 16);
171	tx_hdr->id = id;
172
173	tx_hdr->xmit_queue = wl1251_tx_get_queue(skb_get_queue_mapping(skb));
174
175	wl1251_tx_control(tx_hdr, control, fc);
176	wl1251_tx_frag_block_num(tx_hdr);
177
178	return 0;
179}
180
181/* We copy the packet to the target */
182static int wl1251_tx_send_packet(struct wl1251 *wl, struct sk_buff *skb,
183				 struct ieee80211_tx_info *control)
184{
185	struct tx_double_buffer_desc *tx_hdr;
186	int len;
187	u32 addr;
188
189	if (!skb)
190		return -EINVAL;
191
192	tx_hdr = (struct tx_double_buffer_desc *) skb->data;
193
194	if (control->control.hw_key &&
195	    control->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
196		int hdrlen;
197		__le16 fc;
198		u16 length;
199		u8 *pos;
200
201		fc = *(__le16 *)(skb->data + sizeof(*tx_hdr));
202		length = le16_to_cpu(tx_hdr->length) + WL1251_TKIP_IV_SPACE;
203		tx_hdr->length = cpu_to_le16(length);
204
205		hdrlen = ieee80211_hdrlen(fc);
206
207		pos = skb_push(skb, WL1251_TKIP_IV_SPACE);
208		memmove(pos, pos + WL1251_TKIP_IV_SPACE,
209			sizeof(*tx_hdr) + hdrlen);
210	}
211
212	/* Revisit. This is a workaround for getting non-aligned packets.
213	   This happens at least with EAPOL packets from the user space.
214	   Our DMA requires packets to be aligned on a 4-byte boundary.
215	*/
216	if (unlikely((long)skb->data & 0x03)) {
217		int offset = (4 - (long)skb->data) & 0x03;
218		wl1251_debug(DEBUG_TX, "skb offset %d", offset);
219
220		/* check whether the current skb can be used */
221		if (skb_cloned(skb) || (skb_tailroom(skb) < offset)) {
222			struct sk_buff *newskb = skb_copy_expand(skb, 0, 3,
223								 GFP_KERNEL);
224
225			if (unlikely(newskb == NULL)) {
226				wl1251_error("Can't allocate skb!");
227				return -EINVAL;
228			}
229
230			tx_hdr = (struct tx_double_buffer_desc *) newskb->data;
231
232			dev_kfree_skb_any(skb);
233			wl->tx_frames[tx_hdr->id] = skb = newskb;
234
235			offset = (4 - (long)skb->data) & 0x03;
236			wl1251_debug(DEBUG_TX, "new skb offset %d", offset);
237		}
238
239		/* align the buffer on a 4-byte boundary */
240		if (offset) {
241			unsigned char *src = skb->data;
242			skb_reserve(skb, offset);
243			memmove(skb->data, src, skb->len);
244			tx_hdr = (struct tx_double_buffer_desc *) skb->data;
245		}
246	}
247
248	/* Our skb->data at this point includes the HW header */
249	len = WL1251_TX_ALIGN(skb->len);
250
251	if (wl->data_in_count & 0x1)
252		addr = wl->data_path->tx_packet_ring_addr +
253			wl->data_path->tx_packet_ring_chunk_size;
254	else
255		addr = wl->data_path->tx_packet_ring_addr;
256
257	wl1251_mem_write(wl, addr, skb->data, len);
258
259	wl1251_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u rate 0x%x "
260		     "queue %d", tx_hdr->id, skb, tx_hdr->length,
261		     tx_hdr->rate, tx_hdr->xmit_queue);
262
263	return 0;
264}
265
266static void wl1251_tx_trigger(struct wl1251 *wl)
267{
268	u32 data, addr;
269
270	if (wl->data_in_count & 0x1) {
271		addr = ACX_REG_INTERRUPT_TRIG_H;
272		data = INTR_TRIG_TX_PROC1;
273	} else {
274		addr = ACX_REG_INTERRUPT_TRIG;
275		data = INTR_TRIG_TX_PROC0;
276	}
277
278	wl1251_reg_write32(wl, addr, data);
279
280	/* Bumping data in */
281	wl->data_in_count = (wl->data_in_count + 1) &
282		TX_STATUS_DATA_OUT_COUNT_MASK;
283}
284
285static void enable_tx_for_packet_injection(struct wl1251 *wl)
286{
287	int ret;
288
289	ret = wl1251_cmd_join(wl, BSS_TYPE_STA_BSS, wl->channel,
290			      wl->beacon_int, wl->dtim_period);
291	if (ret < 0) {
292		wl1251_warning("join failed");
293		return;
294	}
295
296	ret = wl1251_event_wait(wl, JOIN_EVENT_COMPLETE_ID, 100);
297	if (ret < 0) {
298		wl1251_warning("join timeout");
299		return;
300	}
301
302	wl->joined = true;
303}
304
305/* caller must hold wl->mutex */
306static int wl1251_tx_frame(struct wl1251 *wl, struct sk_buff *skb)
307{
308	struct ieee80211_tx_info *info;
309	int ret = 0;
310	u8 idx;
311
312	info = IEEE80211_SKB_CB(skb);
313
314	if (info->control.hw_key) {
315		if (unlikely(wl->monitor_present))
316			return -EINVAL;
317
318		idx = info->control.hw_key->hw_key_idx;
319		if (unlikely(wl->default_key != idx)) {
320			ret = wl1251_acx_default_key(wl, idx);
321			if (ret < 0)
322				return ret;
323		}
324	}
325
326	/* Enable tx path in monitor mode for packet injection */
327	if ((wl->vif == NULL) && !wl->joined)
328		enable_tx_for_packet_injection(wl);
329
330	ret = wl1251_tx_path_status(wl);
331	if (ret < 0)
332		return ret;
333
334	ret = wl1251_tx_fill_hdr(wl, skb, info);
335	if (ret < 0)
336		return ret;
337
338	ret = wl1251_tx_send_packet(wl, skb, info);
339	if (ret < 0)
340		return ret;
341
342	wl1251_tx_trigger(wl);
343
344	return ret;
345}
346
347void wl1251_tx_work(struct work_struct *work)
348{
349	struct wl1251 *wl = container_of(work, struct wl1251, tx_work);
350	struct sk_buff *skb;
351	bool woken_up = false;
352	int ret;
353
354	mutex_lock(&wl->mutex);
355
356	if (unlikely(wl->state == WL1251_STATE_OFF))
357		goto out;
358
359	while ((skb = skb_dequeue(&wl->tx_queue))) {
360		if (!woken_up) {
361			ret = wl1251_ps_elp_wakeup(wl);
362			if (ret < 0)
363				goto out;
364			woken_up = true;
365		}
366
367		ret = wl1251_tx_frame(wl, skb);
368		if (ret == -EBUSY) {
369			skb_queue_head(&wl->tx_queue, skb);
370			goto out;
371		} else if (ret < 0) {
372			dev_kfree_skb(skb);
373			goto out;
374		}
375	}
376
377out:
378	if (woken_up)
379		wl1251_ps_elp_sleep(wl);
380
381	mutex_unlock(&wl->mutex);
382}
383
384static const char *wl1251_tx_parse_status(u8 status)
385{
386	/* 8 bit status field, one character per bit plus null */
387	static char buf[9];
388	int i = 0;
389
390	memset(buf, 0, sizeof(buf));
391
392	if (status & TX_DMA_ERROR)
393		buf[i++] = 'm';
394	if (status & TX_DISABLED)
395		buf[i++] = 'd';
396	if (status & TX_RETRY_EXCEEDED)
397		buf[i++] = 'r';
398	if (status & TX_TIMEOUT)
399		buf[i++] = 't';
400	if (status & TX_KEY_NOT_FOUND)
401		buf[i++] = 'k';
402	if (status & TX_ENCRYPT_FAIL)
403		buf[i++] = 'e';
404	if (status & TX_UNAVAILABLE_PRIORITY)
405		buf[i++] = 'p';
406
407	/* bit 0 is unused apparently */
408
409	return buf;
410}
411
412static void wl1251_tx_packet_cb(struct wl1251 *wl,
413				struct tx_result *result)
414{
415	struct ieee80211_tx_info *info;
416	struct sk_buff *skb;
417	int hdrlen;
418	u8 *frame;
419
420	skb = wl->tx_frames[result->id];
421	if (skb == NULL) {
422		wl1251_error("SKB for packet %d is NULL", result->id);
423		return;
424	}
425
426	info = IEEE80211_SKB_CB(skb);
427
428	if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
429	    !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
430	    (result->status == TX_SUCCESS))
431		info->flags |= IEEE80211_TX_STAT_ACK;
432
433	info->status.rates[0].count = result->ack_failures + 1;
434	wl->stats.retry_count += result->ack_failures;
435
436	/*
437	 * We have to remove our private TX header before pushing
438	 * the skb back to mac80211.
439	 */
440	frame = skb_pull(skb, sizeof(struct tx_double_buffer_desc));
441	if (info->control.hw_key &&
442	    info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
443		hdrlen = ieee80211_get_hdrlen_from_skb(skb);
444		memmove(frame + WL1251_TKIP_IV_SPACE, frame, hdrlen);
445		skb_pull(skb, WL1251_TKIP_IV_SPACE);
446	}
447
448	wl1251_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
449		     " status 0x%x (%s)",
450		     result->id, skb, result->ack_failures, result->rate,
451		     result->status, wl1251_tx_parse_status(result->status));
452
453
454	ieee80211_tx_status(wl->hw, skb);
455
456	wl->tx_frames[result->id] = NULL;
457}
458
459/* Called upon reception of a TX complete interrupt */
460void wl1251_tx_complete(struct wl1251 *wl)
461{
462	int i, result_index, num_complete = 0, queue_len;
463	struct tx_result result[FW_TX_CMPLT_BLOCK_SIZE], *result_ptr;
464	unsigned long flags;
465
466	if (unlikely(wl->state != WL1251_STATE_ON))
467		return;
468
469	/* First we read the result */
470	wl1251_mem_read(wl, wl->data_path->tx_complete_addr,
471			    result, sizeof(result));
472
473	result_index = wl->next_tx_complete;
474
475	for (i = 0; i < ARRAY_SIZE(result); i++) {
476		result_ptr = &result[result_index];
477
478		if (result_ptr->done_1 == 1 &&
479		    result_ptr->done_2 == 1) {
480			wl1251_tx_packet_cb(wl, result_ptr);
481
482			result_ptr->done_1 = 0;
483			result_ptr->done_2 = 0;
484
485			result_index = (result_index + 1) &
486				(FW_TX_CMPLT_BLOCK_SIZE - 1);
487			num_complete++;
488		} else {
489			break;
490		}
491	}
492
493	queue_len = skb_queue_len(&wl->tx_queue);
494
495	if ((num_complete > 0) && (queue_len > 0)) {
496		/* firmware buffer has space, reschedule tx_work */
497		wl1251_debug(DEBUG_TX, "tx_complete: reschedule tx_work");
498		ieee80211_queue_work(wl->hw, &wl->tx_work);
499	}
500
501	if (wl->tx_queue_stopped &&
502	    queue_len <= WL1251_TX_QUEUE_LOW_WATERMARK) {
503		/* tx_queue has space, restart queues */
504		wl1251_debug(DEBUG_TX, "tx_complete: waking queues");
505		spin_lock_irqsave(&wl->wl_lock, flags);
506		ieee80211_wake_queues(wl->hw);
507		wl->tx_queue_stopped = false;
508		spin_unlock_irqrestore(&wl->wl_lock, flags);
509	}
510
511	/* Every completed frame needs to be acknowledged */
512	if (num_complete) {
513		/*
514		 * If we've wrapped, we have to clear
515		 * the results in 2 steps.
516		 */
517		if (result_index > wl->next_tx_complete) {
518			/* Only 1 write is needed */
519			wl1251_mem_write(wl,
520					 wl->data_path->tx_complete_addr +
521					 (wl->next_tx_complete *
522					  sizeof(struct tx_result)),
523					 &result[wl->next_tx_complete],
524					 num_complete *
525					 sizeof(struct tx_result));
526
527
528		} else if (result_index < wl->next_tx_complete) {
529			/* 2 writes are needed */
530			wl1251_mem_write(wl,
531					 wl->data_path->tx_complete_addr +
532					 (wl->next_tx_complete *
533					  sizeof(struct tx_result)),
534					 &result[wl->next_tx_complete],
535					 (FW_TX_CMPLT_BLOCK_SIZE -
536					  wl->next_tx_complete) *
537					 sizeof(struct tx_result));
538
539			wl1251_mem_write(wl,
540					 wl->data_path->tx_complete_addr,
541					 result,
542					 (num_complete -
543					  FW_TX_CMPLT_BLOCK_SIZE +
544					  wl->next_tx_complete) *
545					 sizeof(struct tx_result));
546
547		} else {
548			/* We have to write the whole array */
549			wl1251_mem_write(wl,
550					 wl->data_path->tx_complete_addr,
551					 result,
552					 FW_TX_CMPLT_BLOCK_SIZE *
553					 sizeof(struct tx_result));
554		}
555
556	}
557
558	wl->next_tx_complete = result_index;
559}
560
561/* caller must hold wl->mutex */
562void wl1251_tx_flush(struct wl1251 *wl)
563{
564	int i;
565	struct sk_buff *skb;
566	struct ieee80211_tx_info *info;
567
568	/* TX failure */
569/* 	control->flags = 0; FIXME */
570
571	while ((skb = skb_dequeue(&wl->tx_queue))) {
572		info = IEEE80211_SKB_CB(skb);
573
574		wl1251_debug(DEBUG_TX, "flushing skb 0x%p", skb);
575
576		if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
577				continue;
578
579		ieee80211_tx_status(wl->hw, skb);
580	}
581
582	for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
583		if (wl->tx_frames[i] != NULL) {
584			skb = wl->tx_frames[i];
585			info = IEEE80211_SKB_CB(skb);
586
587			if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
588				continue;
589
590			ieee80211_tx_status(wl->hw, skb);
591			wl->tx_frames[i] = NULL;
592		}
593}
594