xref: /openbmc/linux/drivers/net/wireless/ti/wl1251/tx.c (revision e2c75e76)
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 = skb_push(skb, sizeof(*tx_hdr));
165 
166 	tx_hdr->length = cpu_to_le16(skb->len - sizeof(*tx_hdr));
167 	rate = ieee80211_get_tx_rate(wl->hw, control);
168 	tx_hdr->rate = cpu_to_le16(rate->hw_value);
169 	tx_hdr->expiry_time = cpu_to_le32(1 << 16);
170 	tx_hdr->id = id;
171 
172 	tx_hdr->xmit_queue = wl1251_tx_get_queue(skb_get_queue_mapping(skb));
173 
174 	wl1251_tx_control(tx_hdr, control, fc);
175 	wl1251_tx_frag_block_num(tx_hdr);
176 
177 	return 0;
178 }
179 
180 /* We copy the packet to the target */
181 static int wl1251_tx_send_packet(struct wl1251 *wl, struct sk_buff *skb,
182 				 struct ieee80211_tx_info *control)
183 {
184 	struct tx_double_buffer_desc *tx_hdr;
185 	int len;
186 	u32 addr;
187 
188 	if (!skb)
189 		return -EINVAL;
190 
191 	tx_hdr = (struct tx_double_buffer_desc *) skb->data;
192 
193 	if (control->control.hw_key &&
194 	    control->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
195 		int hdrlen;
196 		__le16 fc;
197 		u16 length;
198 		u8 *pos;
199 
200 		fc = *(__le16 *)(skb->data + sizeof(*tx_hdr));
201 		length = le16_to_cpu(tx_hdr->length) + WL1251_TKIP_IV_SPACE;
202 		tx_hdr->length = cpu_to_le16(length);
203 
204 		hdrlen = ieee80211_hdrlen(fc);
205 
206 		pos = skb_push(skb, WL1251_TKIP_IV_SPACE);
207 		memmove(pos, pos + WL1251_TKIP_IV_SPACE,
208 			sizeof(*tx_hdr) + hdrlen);
209 	}
210 
211 	/* Revisit. This is a workaround for getting non-aligned packets.
212 	   This happens at least with EAPOL packets from the user space.
213 	   Our DMA requires packets to be aligned on a 4-byte boundary.
214 	*/
215 	if (unlikely((long)skb->data & 0x03)) {
216 		int offset = (4 - (long)skb->data) & 0x03;
217 		wl1251_debug(DEBUG_TX, "skb offset %d", offset);
218 
219 		/* check whether the current skb can be used */
220 		if (skb_cloned(skb) || (skb_tailroom(skb) < offset)) {
221 			struct sk_buff *newskb = skb_copy_expand(skb, 0, 3,
222 								 GFP_KERNEL);
223 
224 			if (unlikely(newskb == NULL)) {
225 				wl1251_error("Can't allocate skb!");
226 				return -EINVAL;
227 			}
228 
229 			tx_hdr = (struct tx_double_buffer_desc *) newskb->data;
230 
231 			dev_kfree_skb_any(skb);
232 			wl->tx_frames[tx_hdr->id] = skb = newskb;
233 
234 			offset = (4 - (long)skb->data) & 0x03;
235 			wl1251_debug(DEBUG_TX, "new skb offset %d", offset);
236 		}
237 
238 		/* align the buffer on a 4-byte boundary */
239 		if (offset) {
240 			unsigned char *src = skb->data;
241 			skb_reserve(skb, offset);
242 			memmove(skb->data, src, skb->len);
243 			tx_hdr = (struct tx_double_buffer_desc *) skb->data;
244 		}
245 	}
246 
247 	/* Our skb->data at this point includes the HW header */
248 	len = WL1251_TX_ALIGN(skb->len);
249 
250 	if (wl->data_in_count & 0x1)
251 		addr = wl->data_path->tx_packet_ring_addr +
252 			wl->data_path->tx_packet_ring_chunk_size;
253 	else
254 		addr = wl->data_path->tx_packet_ring_addr;
255 
256 	wl1251_mem_write(wl, addr, skb->data, len);
257 
258 	wl1251_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u rate 0x%x "
259 		     "queue %d", tx_hdr->id, skb, tx_hdr->length,
260 		     tx_hdr->rate, tx_hdr->xmit_queue);
261 
262 	return 0;
263 }
264 
265 static void wl1251_tx_trigger(struct wl1251 *wl)
266 {
267 	u32 data, addr;
268 
269 	if (wl->data_in_count & 0x1) {
270 		addr = ACX_REG_INTERRUPT_TRIG_H;
271 		data = INTR_TRIG_TX_PROC1;
272 	} else {
273 		addr = ACX_REG_INTERRUPT_TRIG;
274 		data = INTR_TRIG_TX_PROC0;
275 	}
276 
277 	wl1251_reg_write32(wl, addr, data);
278 
279 	/* Bumping data in */
280 	wl->data_in_count = (wl->data_in_count + 1) &
281 		TX_STATUS_DATA_OUT_COUNT_MASK;
282 }
283 
284 static void enable_tx_for_packet_injection(struct wl1251 *wl)
285 {
286 	int ret;
287 
288 	ret = wl1251_cmd_join(wl, BSS_TYPE_STA_BSS, wl->channel,
289 			      wl->beacon_int, wl->dtim_period);
290 	if (ret < 0) {
291 		wl1251_warning("join failed");
292 		return;
293 	}
294 
295 	ret = wl1251_event_wait(wl, JOIN_EVENT_COMPLETE_ID, 100);
296 	if (ret < 0) {
297 		wl1251_warning("join timeout");
298 		return;
299 	}
300 
301 	wl->joined = true;
302 }
303 
304 /* caller must hold wl->mutex */
305 static int wl1251_tx_frame(struct wl1251 *wl, struct sk_buff *skb)
306 {
307 	struct ieee80211_tx_info *info;
308 	int ret = 0;
309 	u8 idx;
310 
311 	info = IEEE80211_SKB_CB(skb);
312 
313 	if (info->control.hw_key) {
314 		if (unlikely(wl->monitor_present))
315 			return -EINVAL;
316 
317 		idx = info->control.hw_key->hw_key_idx;
318 		if (unlikely(wl->default_key != idx)) {
319 			ret = wl1251_acx_default_key(wl, idx);
320 			if (ret < 0)
321 				return ret;
322 		}
323 	}
324 
325 	/* Enable tx path in monitor mode for packet injection */
326 	if ((wl->vif == NULL) && !wl->joined)
327 		enable_tx_for_packet_injection(wl);
328 
329 	ret = wl1251_tx_path_status(wl);
330 	if (ret < 0)
331 		return ret;
332 
333 	ret = wl1251_tx_fill_hdr(wl, skb, info);
334 	if (ret < 0)
335 		return ret;
336 
337 	ret = wl1251_tx_send_packet(wl, skb, info);
338 	if (ret < 0)
339 		return ret;
340 
341 	wl1251_tx_trigger(wl);
342 
343 	return ret;
344 }
345 
346 void wl1251_tx_work(struct work_struct *work)
347 {
348 	struct wl1251 *wl = container_of(work, struct wl1251, tx_work);
349 	struct sk_buff *skb;
350 	bool woken_up = false;
351 	int ret;
352 
353 	mutex_lock(&wl->mutex);
354 
355 	if (unlikely(wl->state == WL1251_STATE_OFF))
356 		goto out;
357 
358 	while ((skb = skb_dequeue(&wl->tx_queue))) {
359 		if (!woken_up) {
360 			ret = wl1251_ps_elp_wakeup(wl);
361 			if (ret < 0)
362 				goto out;
363 			woken_up = true;
364 		}
365 
366 		ret = wl1251_tx_frame(wl, skb);
367 		if (ret == -EBUSY) {
368 			skb_queue_head(&wl->tx_queue, skb);
369 			goto out;
370 		} else if (ret < 0) {
371 			dev_kfree_skb(skb);
372 			goto out;
373 		}
374 	}
375 
376 out:
377 	if (woken_up)
378 		wl1251_ps_elp_sleep(wl);
379 
380 	mutex_unlock(&wl->mutex);
381 }
382 
383 static const char *wl1251_tx_parse_status(u8 status)
384 {
385 	/* 8 bit status field, one character per bit plus null */
386 	static char buf[9];
387 	int i = 0;
388 
389 	memset(buf, 0, sizeof(buf));
390 
391 	if (status & TX_DMA_ERROR)
392 		buf[i++] = 'm';
393 	if (status & TX_DISABLED)
394 		buf[i++] = 'd';
395 	if (status & TX_RETRY_EXCEEDED)
396 		buf[i++] = 'r';
397 	if (status & TX_TIMEOUT)
398 		buf[i++] = 't';
399 	if (status & TX_KEY_NOT_FOUND)
400 		buf[i++] = 'k';
401 	if (status & TX_ENCRYPT_FAIL)
402 		buf[i++] = 'e';
403 	if (status & TX_UNAVAILABLE_PRIORITY)
404 		buf[i++] = 'p';
405 
406 	/* bit 0 is unused apparently */
407 
408 	return buf;
409 }
410 
411 static void wl1251_tx_packet_cb(struct wl1251 *wl,
412 				struct tx_result *result)
413 {
414 	struct ieee80211_tx_info *info;
415 	struct sk_buff *skb;
416 	int hdrlen;
417 	u8 *frame;
418 
419 	skb = wl->tx_frames[result->id];
420 	if (skb == NULL) {
421 		wl1251_error("SKB for packet %d is NULL", result->id);
422 		return;
423 	}
424 
425 	info = IEEE80211_SKB_CB(skb);
426 
427 	if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
428 	    !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
429 	    (result->status == TX_SUCCESS))
430 		info->flags |= IEEE80211_TX_STAT_ACK;
431 
432 	info->status.rates[0].count = result->ack_failures + 1;
433 	wl->stats.retry_count += result->ack_failures;
434 
435 	/*
436 	 * We have to remove our private TX header before pushing
437 	 * the skb back to mac80211.
438 	 */
439 	frame = skb_pull(skb, sizeof(struct tx_double_buffer_desc));
440 	if (info->control.hw_key &&
441 	    info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
442 		hdrlen = ieee80211_get_hdrlen_from_skb(skb);
443 		memmove(frame + WL1251_TKIP_IV_SPACE, frame, hdrlen);
444 		skb_pull(skb, WL1251_TKIP_IV_SPACE);
445 	}
446 
447 	wl1251_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
448 		     " status 0x%x (%s)",
449 		     result->id, skb, result->ack_failures, result->rate,
450 		     result->status, wl1251_tx_parse_status(result->status));
451 
452 
453 	ieee80211_tx_status(wl->hw, skb);
454 
455 	wl->tx_frames[result->id] = NULL;
456 }
457 
458 /* Called upon reception of a TX complete interrupt */
459 void wl1251_tx_complete(struct wl1251 *wl)
460 {
461 	int i, result_index, num_complete = 0, queue_len;
462 	struct tx_result result[FW_TX_CMPLT_BLOCK_SIZE], *result_ptr;
463 	unsigned long flags;
464 
465 	if (unlikely(wl->state != WL1251_STATE_ON))
466 		return;
467 
468 	/* First we read the result */
469 	wl1251_mem_read(wl, wl->data_path->tx_complete_addr,
470 			    result, sizeof(result));
471 
472 	result_index = wl->next_tx_complete;
473 
474 	for (i = 0; i < ARRAY_SIZE(result); i++) {
475 		result_ptr = &result[result_index];
476 
477 		if (result_ptr->done_1 == 1 &&
478 		    result_ptr->done_2 == 1) {
479 			wl1251_tx_packet_cb(wl, result_ptr);
480 
481 			result_ptr->done_1 = 0;
482 			result_ptr->done_2 = 0;
483 
484 			result_index = (result_index + 1) &
485 				(FW_TX_CMPLT_BLOCK_SIZE - 1);
486 			num_complete++;
487 		} else {
488 			break;
489 		}
490 	}
491 
492 	queue_len = skb_queue_len(&wl->tx_queue);
493 
494 	if ((num_complete > 0) && (queue_len > 0)) {
495 		/* firmware buffer has space, reschedule tx_work */
496 		wl1251_debug(DEBUG_TX, "tx_complete: reschedule tx_work");
497 		ieee80211_queue_work(wl->hw, &wl->tx_work);
498 	}
499 
500 	if (wl->tx_queue_stopped &&
501 	    queue_len <= WL1251_TX_QUEUE_LOW_WATERMARK) {
502 		/* tx_queue has space, restart queues */
503 		wl1251_debug(DEBUG_TX, "tx_complete: waking queues");
504 		spin_lock_irqsave(&wl->wl_lock, flags);
505 		ieee80211_wake_queues(wl->hw);
506 		wl->tx_queue_stopped = false;
507 		spin_unlock_irqrestore(&wl->wl_lock, flags);
508 	}
509 
510 	/* Every completed frame needs to be acknowledged */
511 	if (num_complete) {
512 		/*
513 		 * If we've wrapped, we have to clear
514 		 * the results in 2 steps.
515 		 */
516 		if (result_index > wl->next_tx_complete) {
517 			/* Only 1 write is needed */
518 			wl1251_mem_write(wl,
519 					 wl->data_path->tx_complete_addr +
520 					 (wl->next_tx_complete *
521 					  sizeof(struct tx_result)),
522 					 &result[wl->next_tx_complete],
523 					 num_complete *
524 					 sizeof(struct tx_result));
525 
526 
527 		} else if (result_index < wl->next_tx_complete) {
528 			/* 2 writes are needed */
529 			wl1251_mem_write(wl,
530 					 wl->data_path->tx_complete_addr +
531 					 (wl->next_tx_complete *
532 					  sizeof(struct tx_result)),
533 					 &result[wl->next_tx_complete],
534 					 (FW_TX_CMPLT_BLOCK_SIZE -
535 					  wl->next_tx_complete) *
536 					 sizeof(struct tx_result));
537 
538 			wl1251_mem_write(wl,
539 					 wl->data_path->tx_complete_addr,
540 					 result,
541 					 (num_complete -
542 					  FW_TX_CMPLT_BLOCK_SIZE +
543 					  wl->next_tx_complete) *
544 					 sizeof(struct tx_result));
545 
546 		} else {
547 			/* We have to write the whole array */
548 			wl1251_mem_write(wl,
549 					 wl->data_path->tx_complete_addr,
550 					 result,
551 					 FW_TX_CMPLT_BLOCK_SIZE *
552 					 sizeof(struct tx_result));
553 		}
554 
555 	}
556 
557 	wl->next_tx_complete = result_index;
558 }
559 
560 /* caller must hold wl->mutex */
561 void wl1251_tx_flush(struct wl1251 *wl)
562 {
563 	int i;
564 	struct sk_buff *skb;
565 	struct ieee80211_tx_info *info;
566 
567 	/* TX failure */
568 /* 	control->flags = 0; FIXME */
569 
570 	while ((skb = skb_dequeue(&wl->tx_queue))) {
571 		info = IEEE80211_SKB_CB(skb);
572 
573 		wl1251_debug(DEBUG_TX, "flushing skb 0x%p", skb);
574 
575 		if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
576 				continue;
577 
578 		ieee80211_tx_status(wl->hw, skb);
579 	}
580 
581 	for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
582 		if (wl->tx_frames[i] != NULL) {
583 			skb = wl->tx_frames[i];
584 			info = IEEE80211_SKB_CB(skb);
585 
586 			if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
587 				continue;
588 
589 			ieee80211_tx_status(wl->hw, skb);
590 			wl->tx_frames[i] = NULL;
591 		}
592 }
593