tx.c

  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
 19static 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
 40static 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
 56static 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
 69static 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
101static 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
134static 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 */
167static 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
249static 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
268static 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 */
289static 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
330void 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				skb_queue_head(&wl->tx_queue, skb);
347				goto out;
348			}
349			woken_up = true;
350		}
351
352		ret = wl1251_tx_frame(wl, skb);
353		if (ret == -EBUSY) {
354			skb_queue_head(&wl->tx_queue, skb);
355			goto out;
356		} else if (ret < 0) {
357			dev_kfree_skb(skb);
358			goto out;
359		}
360	}
361
362out:
363	if (woken_up)
364		wl1251_ps_elp_sleep(wl);
365
366	mutex_unlock(&wl->mutex);
367}
368
369static const char *wl1251_tx_parse_status(u8 status)
370{
371	/* 8 bit status field, one character per bit plus null */
372	static char buf[9];
373	int i = 0;
374
375	memset(buf, 0, sizeof(buf));
376
377	if (status & TX_DMA_ERROR)
378		buf[i++] = 'm';
379	if (status & TX_DISABLED)
380		buf[i++] = 'd';
381	if (status & TX_RETRY_EXCEEDED)
382		buf[i++] = 'r';
383	if (status & TX_TIMEOUT)
384		buf[i++] = 't';
385	if (status & TX_KEY_NOT_FOUND)
386		buf[i++] = 'k';
387	if (status & TX_ENCRYPT_FAIL)
388		buf[i++] = 'e';
389	if (status & TX_UNAVAILABLE_PRIORITY)
390		buf[i++] = 'p';
391
392	/* bit 0 is unused apparently */
393
394	return buf;
395}
396
397static void wl1251_tx_packet_cb(struct wl1251 *wl,
398				struct tx_result *result)
399{
400	struct ieee80211_tx_info *info;
401	struct sk_buff *skb;
402	int hdrlen;
403	u8 *frame;
404
405	if (unlikely(result->id >= ARRAY_SIZE(wl->tx_frames) ||
406		     wl->tx_frames[result->id] == NULL)) {
407		wl1251_error("invalid packet id %u", result->id);
408		return;
409	}
410
411	skb = wl->tx_frames[result->id];
412
413	info = IEEE80211_SKB_CB(skb);
414
415	if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
416	    !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
417	    (result->status == TX_SUCCESS))
418		info->flags |= IEEE80211_TX_STAT_ACK;
419
420	info->status.rates[0].count = result->ack_failures + 1;
421	wl->stats.retry_count += result->ack_failures;
422
423	/*
424	 * We have to remove our private TX header before pushing
425	 * the skb back to mac80211.
426	 */
427	frame = skb_pull(skb, sizeof(struct tx_double_buffer_desc));
428	if (info->control.hw_key &&
429	    info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
430		hdrlen = ieee80211_get_hdrlen_from_skb(skb);
431		memmove(frame + WL1251_TKIP_IV_SPACE, frame, hdrlen);
432		skb_pull(skb, WL1251_TKIP_IV_SPACE);
433	}
434
435	wl1251_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
436		     " status 0x%x (%s)",
437		     result->id, skb, result->ack_failures, result->rate,
438		     result->status, wl1251_tx_parse_status(result->status));
439
440
441	ieee80211_tx_status_skb(wl->hw, skb);
442
443	wl->tx_frames[result->id] = NULL;
444}
445
446/* Called upon reception of a TX complete interrupt */
447void wl1251_tx_complete(struct wl1251 *wl)
448{
449	int i, result_index, num_complete = 0, queue_len;
450	struct tx_result *result, *result_ptr;
451	unsigned long flags;
452
453	if (unlikely(wl->state != WL1251_STATE_ON))
454		return;
455
456	result = kmalloc_array(FW_TX_CMPLT_BLOCK_SIZE, sizeof(*result), GFP_KERNEL);
457	if (!result) {
458		wl1251_error("can not allocate result buffer");
459		return;
460	}
461
462	/* First we read the result */
463	wl1251_mem_read(wl, wl->data_path->tx_complete_addr, result,
464			FW_TX_CMPLT_BLOCK_SIZE * sizeof(*result));
465
466	result_index = wl->next_tx_complete;
467
468	for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++) {
469		result_ptr = &result[result_index];
470
471		if (result_ptr->done_1 == 1 &&
472		    result_ptr->done_2 == 1) {
473			wl1251_tx_packet_cb(wl, result_ptr);
474
475			result_ptr->done_1 = 0;
476			result_ptr->done_2 = 0;
477
478			result_index = (result_index + 1) &
479				(FW_TX_CMPLT_BLOCK_SIZE - 1);
480			num_complete++;
481		} else {
482			break;
483		}
484	}
485
486	queue_len = skb_queue_len(&wl->tx_queue);
487
488	if ((num_complete > 0) && (queue_len > 0)) {
489		/* firmware buffer has space, reschedule tx_work */
490		wl1251_debug(DEBUG_TX, "tx_complete: reschedule tx_work");
491		ieee80211_queue_work(wl->hw, &wl->tx_work);
492	}
493
494	if (wl->tx_queue_stopped &&
495	    queue_len <= WL1251_TX_QUEUE_LOW_WATERMARK) {
496		/* tx_queue has space, restart queues */
497		wl1251_debug(DEBUG_TX, "tx_complete: waking queues");
498		spin_lock_irqsave(&wl->wl_lock, flags);
499		ieee80211_wake_queues(wl->hw);
500		wl->tx_queue_stopped = false;
501		spin_unlock_irqrestore(&wl->wl_lock, flags);
502	}
503
504	/* Every completed frame needs to be acknowledged */
505	if (num_complete) {
506		/*
507		 * If we've wrapped, we have to clear
508		 * the results in 2 steps.
509		 */
510		if (result_index > wl->next_tx_complete) {
511			/* Only 1 write is needed */
512			wl1251_mem_write(wl,
513					 wl->data_path->tx_complete_addr +
514					 (wl->next_tx_complete *
515					  sizeof(struct tx_result)),
516					 &result[wl->next_tx_complete],
517					 num_complete *
518					 sizeof(struct tx_result));
519
520
521		} else if (result_index < wl->next_tx_complete) {
522			/* 2 writes are needed */
523			wl1251_mem_write(wl,
524					 wl->data_path->tx_complete_addr +
525					 (wl->next_tx_complete *
526					  sizeof(struct tx_result)),
527					 &result[wl->next_tx_complete],
528					 (FW_TX_CMPLT_BLOCK_SIZE -
529					  wl->next_tx_complete) *
530					 sizeof(struct tx_result));
531
532			wl1251_mem_write(wl,
533					 wl->data_path->tx_complete_addr,
534					 result,
535					 (num_complete -
536					  FW_TX_CMPLT_BLOCK_SIZE +
537					  wl->next_tx_complete) *
538					 sizeof(struct tx_result));
539
540		} else {
541			/* We have to write the whole array */
542			wl1251_mem_write(wl,
543					 wl->data_path->tx_complete_addr,
544					 result,
545					 FW_TX_CMPLT_BLOCK_SIZE *
546					 sizeof(struct tx_result));
547		}
548
549	}
550
551	kfree(result);
552	wl->next_tx_complete = result_index;
553}
554
555/* caller must hold wl->mutex */
556void wl1251_tx_flush(struct wl1251 *wl)
557{
558	int i;
559	struct sk_buff *skb;
560	struct ieee80211_tx_info *info;
561
562	/* TX failure */
563/* 	control->flags = 0; FIXME */
564
565	while ((skb = skb_dequeue(&wl->tx_queue))) {
566		info = IEEE80211_SKB_CB(skb);
567
568		wl1251_debug(DEBUG_TX, "flushing skb 0x%p", skb);
569
570		if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
571				continue;
572
573		ieee80211_tx_status_skb(wl->hw, skb);
574	}
575
576	for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
577		if (wl->tx_frames[i] != NULL) {
578			skb = wl->tx_frames[i];
579			info = IEEE80211_SKB_CB(skb);
580
581			if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
582				continue;
583
584			ieee80211_tx_status_skb(wl->hw, skb);
585			wl->tx_frames[i] = NULL;
586		}
587}