xref: /openbmc/linux/drivers/net/wireless/ti/wl1251/tx.c (revision f3539c12)
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 
33 static 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 
54 static 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 
70 static 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 
83 static 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
115 static 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 
148 static 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 */
182 static 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 
266 static 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 
285 static 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 */
306 static 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 
347 void 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 
377 out:
378 	if (woken_up)
379 		wl1251_ps_elp_sleep(wl);
380 
381 	mutex_unlock(&wl->mutex);
382 }
383 
384 static 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 
412 static 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 */
460 void 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 */
562 void 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