xref: /openbmc/linux/drivers/net/wireless/ti/wl1251/tx.c (revision 7f6964c5)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * This file is part of wl1251
4  *
5  * Copyright (c) 1998-2007 Texas Instruments Incorporated
6  * Copyright (C) 2008 Nokia Corporation
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 
12 #include "wl1251.h"
13 #include "reg.h"
14 #include "tx.h"
15 #include "ps.h"
16 #include "io.h"
17 #include "event.h"
18 
19 static bool wl1251_tx_double_buffer_busy(struct wl1251 *wl, u32 data_out_count)
20 {
21 	int used, data_in_count;
22 
23 	data_in_count = wl->data_in_count;
24 
25 	if (data_in_count < data_out_count)
26 		/* data_in_count has wrapped */
27 		data_in_count += TX_STATUS_DATA_OUT_COUNT_MASK + 1;
28 
29 	used = data_in_count - data_out_count;
30 
31 	WARN_ON(used < 0);
32 	WARN_ON(used > DP_TX_PACKET_RING_CHUNK_NUM);
33 
34 	if (used >= DP_TX_PACKET_RING_CHUNK_NUM)
35 		return true;
36 	else
37 		return false;
38 }
39 
40 static int wl1251_tx_path_status(struct wl1251 *wl)
41 {
42 	u32 status, addr, data_out_count;
43 	bool busy;
44 
45 	addr = wl->data_path->tx_control_addr;
46 	status = wl1251_mem_read32(wl, addr);
47 	data_out_count = status & TX_STATUS_DATA_OUT_COUNT_MASK;
48 	busy = wl1251_tx_double_buffer_busy(wl, data_out_count);
49 
50 	if (busy)
51 		return -EBUSY;
52 
53 	return 0;
54 }
55 
56 static int wl1251_tx_id(struct wl1251 *wl, struct sk_buff *skb)
57 {
58 	int i;
59 
60 	for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
61 		if (wl->tx_frames[i] == NULL) {
62 			wl->tx_frames[i] = skb;
63 			return i;
64 		}
65 
66 	return -EBUSY;
67 }
68 
69 static void wl1251_tx_control(struct tx_double_buffer_desc *tx_hdr,
70 			      struct ieee80211_tx_info *control, u16 fc)
71 {
72 	*(u16 *)&tx_hdr->control = 0;
73 
74 	tx_hdr->control.rate_policy = 0;
75 
76 	/* 802.11 packets */
77 	tx_hdr->control.packet_type = 0;
78 
79 	/* Also disable retry and ACK policy for injected packets */
80 	if ((control->flags & IEEE80211_TX_CTL_NO_ACK) ||
81 	    (control->flags & IEEE80211_TX_CTL_INJECTED)) {
82 		tx_hdr->control.rate_policy = 1;
83 		tx_hdr->control.ack_policy = 1;
84 	}
85 
86 	tx_hdr->control.tx_complete = 1;
87 
88 	if ((fc & IEEE80211_FTYPE_DATA) &&
89 	    ((fc & IEEE80211_STYPE_QOS_DATA) ||
90 	     (fc & IEEE80211_STYPE_QOS_NULLFUNC)))
91 		tx_hdr->control.qos = 1;
92 }
93 
94 /* RSN + MIC = 8 + 8 = 16 bytes (worst case - AES). */
95 #define MAX_MSDU_SECURITY_LENGTH      16
96 #define MAX_MPDU_SECURITY_LENGTH      16
97 #define WLAN_QOS_HDR_LEN              26
98 #define MAX_MPDU_HEADER_AND_SECURITY  (MAX_MPDU_SECURITY_LENGTH + \
99 				       WLAN_QOS_HDR_LEN)
100 #define HW_BLOCK_SIZE                 252
101 static void wl1251_tx_frag_block_num(struct tx_double_buffer_desc *tx_hdr)
102 {
103 	u16 payload_len, frag_threshold, mem_blocks;
104 	u16 num_mpdus, mem_blocks_per_frag;
105 
106 	frag_threshold = IEEE80211_MAX_FRAG_THRESHOLD;
107 	tx_hdr->frag_threshold = cpu_to_le16(frag_threshold);
108 
109 	payload_len = le16_to_cpu(tx_hdr->length) + MAX_MSDU_SECURITY_LENGTH;
110 
111 	if (payload_len > frag_threshold) {
112 		mem_blocks_per_frag =
113 			((frag_threshold + MAX_MPDU_HEADER_AND_SECURITY) /
114 			 HW_BLOCK_SIZE) + 1;
115 		num_mpdus = payload_len / frag_threshold;
116 		mem_blocks = num_mpdus * mem_blocks_per_frag;
117 		payload_len -= num_mpdus * frag_threshold;
118 		num_mpdus++;
119 
120 	} else {
121 		mem_blocks_per_frag = 0;
122 		mem_blocks = 0;
123 		num_mpdus = 1;
124 	}
125 
126 	mem_blocks += (payload_len / HW_BLOCK_SIZE) + 1;
127 
128 	if (num_mpdus > 1)
129 		mem_blocks += min(num_mpdus, mem_blocks_per_frag);
130 
131 	tx_hdr->num_mem_blocks = mem_blocks;
132 }
133 
134 static int wl1251_tx_fill_hdr(struct wl1251 *wl, struct sk_buff *skb,
135 			      struct ieee80211_tx_info *control)
136 {
137 	struct tx_double_buffer_desc *tx_hdr;
138 	struct ieee80211_rate *rate;
139 	int id;
140 	u16 fc;
141 
142 	if (!skb)
143 		return -EINVAL;
144 
145 	id = wl1251_tx_id(wl, skb);
146 	if (id < 0)
147 		return id;
148 
149 	fc = *(u16 *)skb->data;
150 	tx_hdr = skb_push(skb, sizeof(*tx_hdr));
151 
152 	tx_hdr->length = cpu_to_le16(skb->len - sizeof(*tx_hdr));
153 	rate = ieee80211_get_tx_rate(wl->hw, control);
154 	tx_hdr->rate = cpu_to_le16(rate->hw_value);
155 	tx_hdr->expiry_time = cpu_to_le32(1 << 16);
156 	tx_hdr->id = id;
157 
158 	tx_hdr->xmit_queue = wl1251_tx_get_queue(skb_get_queue_mapping(skb));
159 
160 	wl1251_tx_control(tx_hdr, control, fc);
161 	wl1251_tx_frag_block_num(tx_hdr);
162 
163 	return 0;
164 }
165 
166 /* We copy the packet to the target */
167 static int wl1251_tx_send_packet(struct wl1251 *wl, struct sk_buff *skb,
168 				 struct ieee80211_tx_info *control)
169 {
170 	struct tx_double_buffer_desc *tx_hdr;
171 	int len;
172 	u32 addr;
173 
174 	if (!skb)
175 		return -EINVAL;
176 
177 	tx_hdr = (struct tx_double_buffer_desc *) skb->data;
178 
179 	if (control->control.hw_key &&
180 	    control->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
181 		int hdrlen;
182 		__le16 fc;
183 		u16 length;
184 		u8 *pos;
185 
186 		fc = *(__le16 *)(skb->data + sizeof(*tx_hdr));
187 		length = le16_to_cpu(tx_hdr->length) + WL1251_TKIP_IV_SPACE;
188 		tx_hdr->length = cpu_to_le16(length);
189 
190 		hdrlen = ieee80211_hdrlen(fc);
191 
192 		pos = skb_push(skb, WL1251_TKIP_IV_SPACE);
193 		memmove(pos, pos + WL1251_TKIP_IV_SPACE,
194 			sizeof(*tx_hdr) + hdrlen);
195 	}
196 
197 	/* Revisit. This is a workaround for getting non-aligned packets.
198 	   This happens at least with EAPOL packets from the user space.
199 	   Our DMA requires packets to be aligned on a 4-byte boundary.
200 	*/
201 	if (unlikely((long)skb->data & 0x03)) {
202 		int offset = (4 - (long)skb->data) & 0x03;
203 		wl1251_debug(DEBUG_TX, "skb offset %d", offset);
204 
205 		/* check whether the current skb can be used */
206 		if (skb_cloned(skb) || (skb_tailroom(skb) < offset)) {
207 			struct sk_buff *newskb = skb_copy_expand(skb, 0, 3,
208 								 GFP_KERNEL);
209 
210 			if (unlikely(newskb == NULL))
211 				return -EINVAL;
212 
213 			tx_hdr = (struct tx_double_buffer_desc *) newskb->data;
214 
215 			dev_kfree_skb_any(skb);
216 			wl->tx_frames[tx_hdr->id] = skb = newskb;
217 
218 			offset = (4 - (long)skb->data) & 0x03;
219 			wl1251_debug(DEBUG_TX, "new skb offset %d", offset);
220 		}
221 
222 		/* align the buffer on a 4-byte boundary */
223 		if (offset) {
224 			unsigned char *src = skb->data;
225 			skb_reserve(skb, offset);
226 			memmove(skb->data, src, skb->len);
227 			tx_hdr = (struct tx_double_buffer_desc *) skb->data;
228 		}
229 	}
230 
231 	/* Our skb->data at this point includes the HW header */
232 	len = WL1251_TX_ALIGN(skb->len);
233 
234 	if (wl->data_in_count & 0x1)
235 		addr = wl->data_path->tx_packet_ring_addr +
236 			wl->data_path->tx_packet_ring_chunk_size;
237 	else
238 		addr = wl->data_path->tx_packet_ring_addr;
239 
240 	wl1251_mem_write(wl, addr, skb->data, len);
241 
242 	wl1251_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u rate 0x%x "
243 		     "queue %d", tx_hdr->id, skb, tx_hdr->length,
244 		     tx_hdr->rate, tx_hdr->xmit_queue);
245 
246 	return 0;
247 }
248 
249 static void wl1251_tx_trigger(struct wl1251 *wl)
250 {
251 	u32 data, addr;
252 
253 	if (wl->data_in_count & 0x1) {
254 		addr = ACX_REG_INTERRUPT_TRIG_H;
255 		data = INTR_TRIG_TX_PROC1;
256 	} else {
257 		addr = ACX_REG_INTERRUPT_TRIG;
258 		data = INTR_TRIG_TX_PROC0;
259 	}
260 
261 	wl1251_reg_write32(wl, addr, data);
262 
263 	/* Bumping data in */
264 	wl->data_in_count = (wl->data_in_count + 1) &
265 		TX_STATUS_DATA_OUT_COUNT_MASK;
266 }
267 
268 static void enable_tx_for_packet_injection(struct wl1251 *wl)
269 {
270 	int ret;
271 
272 	ret = wl1251_cmd_join(wl, BSS_TYPE_STA_BSS, wl->channel,
273 			      wl->beacon_int, wl->dtim_period);
274 	if (ret < 0) {
275 		wl1251_warning("join failed");
276 		return;
277 	}
278 
279 	ret = wl1251_event_wait(wl, JOIN_EVENT_COMPLETE_ID, 100);
280 	if (ret < 0) {
281 		wl1251_warning("join timeout");
282 		return;
283 	}
284 
285 	wl->joined = true;
286 }
287 
288 /* caller must hold wl->mutex */
289 static int wl1251_tx_frame(struct wl1251 *wl, struct sk_buff *skb)
290 {
291 	struct ieee80211_tx_info *info;
292 	int ret = 0;
293 	u8 idx;
294 
295 	info = IEEE80211_SKB_CB(skb);
296 
297 	if (info->control.hw_key) {
298 		if (unlikely(wl->monitor_present))
299 			return -EINVAL;
300 
301 		idx = info->control.hw_key->hw_key_idx;
302 		if (unlikely(wl->default_key != idx)) {
303 			ret = wl1251_acx_default_key(wl, idx);
304 			if (ret < 0)
305 				return ret;
306 		}
307 	}
308 
309 	/* Enable tx path in monitor mode for packet injection */
310 	if ((wl->vif == NULL) && !wl->joined)
311 		enable_tx_for_packet_injection(wl);
312 
313 	ret = wl1251_tx_path_status(wl);
314 	if (ret < 0)
315 		return ret;
316 
317 	ret = wl1251_tx_fill_hdr(wl, skb, info);
318 	if (ret < 0)
319 		return ret;
320 
321 	ret = wl1251_tx_send_packet(wl, skb, info);
322 	if (ret < 0)
323 		return ret;
324 
325 	wl1251_tx_trigger(wl);
326 
327 	return ret;
328 }
329 
330 void wl1251_tx_work(struct work_struct *work)
331 {
332 	struct wl1251 *wl = container_of(work, struct wl1251, tx_work);
333 	struct sk_buff *skb;
334 	bool woken_up = false;
335 	int ret;
336 
337 	mutex_lock(&wl->mutex);
338 
339 	if (unlikely(wl->state == WL1251_STATE_OFF))
340 		goto out;
341 
342 	while ((skb = skb_dequeue(&wl->tx_queue))) {
343 		if (!woken_up) {
344 			ret = wl1251_ps_elp_wakeup(wl);
345 			if (ret < 0)
346 				goto out;
347 			woken_up = true;
348 		}
349 
350 		ret = wl1251_tx_frame(wl, skb);
351 		if (ret == -EBUSY) {
352 			skb_queue_head(&wl->tx_queue, skb);
353 			goto out;
354 		} else if (ret < 0) {
355 			dev_kfree_skb(skb);
356 			goto out;
357 		}
358 	}
359 
360 out:
361 	if (woken_up)
362 		wl1251_ps_elp_sleep(wl);
363 
364 	mutex_unlock(&wl->mutex);
365 }
366 
367 static const char *wl1251_tx_parse_status(u8 status)
368 {
369 	/* 8 bit status field, one character per bit plus null */
370 	static char buf[9];
371 	int i = 0;
372 
373 	memset(buf, 0, sizeof(buf));
374 
375 	if (status & TX_DMA_ERROR)
376 		buf[i++] = 'm';
377 	if (status & TX_DISABLED)
378 		buf[i++] = 'd';
379 	if (status & TX_RETRY_EXCEEDED)
380 		buf[i++] = 'r';
381 	if (status & TX_TIMEOUT)
382 		buf[i++] = 't';
383 	if (status & TX_KEY_NOT_FOUND)
384 		buf[i++] = 'k';
385 	if (status & TX_ENCRYPT_FAIL)
386 		buf[i++] = 'e';
387 	if (status & TX_UNAVAILABLE_PRIORITY)
388 		buf[i++] = 'p';
389 
390 	/* bit 0 is unused apparently */
391 
392 	return buf;
393 }
394 
395 static void wl1251_tx_packet_cb(struct wl1251 *wl,
396 				struct tx_result *result)
397 {
398 	struct ieee80211_tx_info *info;
399 	struct sk_buff *skb;
400 	int hdrlen;
401 	u8 *frame;
402 
403 	skb = wl->tx_frames[result->id];
404 	if (skb == NULL) {
405 		wl1251_error("SKB for packet %d is NULL", result->id);
406 		return;
407 	}
408 
409 	info = IEEE80211_SKB_CB(skb);
410 
411 	if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
412 	    !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
413 	    (result->status == TX_SUCCESS))
414 		info->flags |= IEEE80211_TX_STAT_ACK;
415 
416 	info->status.rates[0].count = result->ack_failures + 1;
417 	wl->stats.retry_count += result->ack_failures;
418 
419 	/*
420 	 * We have to remove our private TX header before pushing
421 	 * the skb back to mac80211.
422 	 */
423 	frame = skb_pull(skb, sizeof(struct tx_double_buffer_desc));
424 	if (info->control.hw_key &&
425 	    info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
426 		hdrlen = ieee80211_get_hdrlen_from_skb(skb);
427 		memmove(frame + WL1251_TKIP_IV_SPACE, frame, hdrlen);
428 		skb_pull(skb, WL1251_TKIP_IV_SPACE);
429 	}
430 
431 	wl1251_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
432 		     " status 0x%x (%s)",
433 		     result->id, skb, result->ack_failures, result->rate,
434 		     result->status, wl1251_tx_parse_status(result->status));
435 
436 
437 	ieee80211_tx_status(wl->hw, skb);
438 
439 	wl->tx_frames[result->id] = NULL;
440 }
441 
442 /* Called upon reception of a TX complete interrupt */
443 void wl1251_tx_complete(struct wl1251 *wl)
444 {
445 	int i, result_index, num_complete = 0, queue_len;
446 	struct tx_result result[FW_TX_CMPLT_BLOCK_SIZE], *result_ptr;
447 	unsigned long flags;
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 	queue_len = skb_queue_len(&wl->tx_queue);
477 
478 	if ((num_complete > 0) && (queue_len > 0)) {
479 		/* firmware buffer has space, reschedule tx_work */
480 		wl1251_debug(DEBUG_TX, "tx_complete: reschedule tx_work");
481 		ieee80211_queue_work(wl->hw, &wl->tx_work);
482 	}
483 
484 	if (wl->tx_queue_stopped &&
485 	    queue_len <= WL1251_TX_QUEUE_LOW_WATERMARK) {
486 		/* tx_queue has space, restart queues */
487 		wl1251_debug(DEBUG_TX, "tx_complete: waking queues");
488 		spin_lock_irqsave(&wl->wl_lock, flags);
489 		ieee80211_wake_queues(wl->hw);
490 		wl->tx_queue_stopped = false;
491 		spin_unlock_irqrestore(&wl->wl_lock, flags);
492 	}
493 
494 	/* Every completed frame needs to be acknowledged */
495 	if (num_complete) {
496 		/*
497 		 * If we've wrapped, we have to clear
498 		 * the results in 2 steps.
499 		 */
500 		if (result_index > wl->next_tx_complete) {
501 			/* Only 1 write is needed */
502 			wl1251_mem_write(wl,
503 					 wl->data_path->tx_complete_addr +
504 					 (wl->next_tx_complete *
505 					  sizeof(struct tx_result)),
506 					 &result[wl->next_tx_complete],
507 					 num_complete *
508 					 sizeof(struct tx_result));
509 
510 
511 		} else if (result_index < wl->next_tx_complete) {
512 			/* 2 writes are needed */
513 			wl1251_mem_write(wl,
514 					 wl->data_path->tx_complete_addr +
515 					 (wl->next_tx_complete *
516 					  sizeof(struct tx_result)),
517 					 &result[wl->next_tx_complete],
518 					 (FW_TX_CMPLT_BLOCK_SIZE -
519 					  wl->next_tx_complete) *
520 					 sizeof(struct tx_result));
521 
522 			wl1251_mem_write(wl,
523 					 wl->data_path->tx_complete_addr,
524 					 result,
525 					 (num_complete -
526 					  FW_TX_CMPLT_BLOCK_SIZE +
527 					  wl->next_tx_complete) *
528 					 sizeof(struct tx_result));
529 
530 		} else {
531 			/* We have to write the whole array */
532 			wl1251_mem_write(wl,
533 					 wl->data_path->tx_complete_addr,
534 					 result,
535 					 FW_TX_CMPLT_BLOCK_SIZE *
536 					 sizeof(struct tx_result));
537 		}
538 
539 	}
540 
541 	wl->next_tx_complete = result_index;
542 }
543 
544 /* caller must hold wl->mutex */
545 void wl1251_tx_flush(struct wl1251 *wl)
546 {
547 	int i;
548 	struct sk_buff *skb;
549 	struct ieee80211_tx_info *info;
550 
551 	/* TX failure */
552 /* 	control->flags = 0; FIXME */
553 
554 	while ((skb = skb_dequeue(&wl->tx_queue))) {
555 		info = IEEE80211_SKB_CB(skb);
556 
557 		wl1251_debug(DEBUG_TX, "flushing skb 0x%p", skb);
558 
559 		if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
560 				continue;
561 
562 		ieee80211_tx_status(wl->hw, skb);
563 	}
564 
565 	for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
566 		if (wl->tx_frames[i] != NULL) {
567 			skb = wl->tx_frames[i];
568 			info = IEEE80211_SKB_CB(skb);
569 
570 			if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
571 				continue;
572 
573 			ieee80211_tx_status(wl->hw, skb);
574 			wl->tx_frames[i] = NULL;
575 		}
576 }
577