xref: /linux/drivers/net/wireless/mediatek/mt76/usb.c (revision 31d166642c7c601c65eccf0ff2e0afe9a0538be2)
1 /*
2  * Copyright (C) 2018 Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
3  *
4  * Permission to use, copy, modify, and/or distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <linux/module.h>
18 #include "mt76.h"
19 #include "usb_trace.h"
20 #include "dma.h"
21 
22 #define MT_VEND_REQ_MAX_RETRY	10
23 #define MT_VEND_REQ_TOUT_MS	300
24 
25 static bool disable_usb_sg;
26 module_param_named(disable_usb_sg, disable_usb_sg, bool, 0644);
27 MODULE_PARM_DESC(disable_usb_sg, "Disable usb scatter-gather support");
28 
29 /* should be called with usb_ctrl_mtx locked */
30 static int __mt76u_vendor_request(struct mt76_dev *dev, u8 req,
31 				  u8 req_type, u16 val, u16 offset,
32 				  void *buf, size_t len)
33 {
34 	struct usb_device *udev = to_usb_device(dev->dev);
35 	unsigned int pipe;
36 	int i, ret;
37 
38 	pipe = (req_type & USB_DIR_IN) ? usb_rcvctrlpipe(udev, 0)
39 				       : usb_sndctrlpipe(udev, 0);
40 	for (i = 0; i < MT_VEND_REQ_MAX_RETRY; i++) {
41 		if (test_bit(MT76_REMOVED, &dev->state))
42 			return -EIO;
43 
44 		ret = usb_control_msg(udev, pipe, req, req_type, val,
45 				      offset, buf, len, MT_VEND_REQ_TOUT_MS);
46 		if (ret == -ENODEV)
47 			set_bit(MT76_REMOVED, &dev->state);
48 		if (ret >= 0 || ret == -ENODEV)
49 			return ret;
50 		usleep_range(5000, 10000);
51 	}
52 
53 	dev_err(dev->dev, "vendor request req:%02x off:%04x failed:%d\n",
54 		req, offset, ret);
55 	return ret;
56 }
57 
58 int mt76u_vendor_request(struct mt76_dev *dev, u8 req,
59 			 u8 req_type, u16 val, u16 offset,
60 			 void *buf, size_t len)
61 {
62 	int ret;
63 
64 	mutex_lock(&dev->usb.usb_ctrl_mtx);
65 	ret = __mt76u_vendor_request(dev, req, req_type,
66 				     val, offset, buf, len);
67 	trace_usb_reg_wr(dev, offset, val);
68 	mutex_unlock(&dev->usb.usb_ctrl_mtx);
69 
70 	return ret;
71 }
72 EXPORT_SYMBOL_GPL(mt76u_vendor_request);
73 
74 /* should be called with usb_ctrl_mtx locked */
75 static u32 __mt76u_rr(struct mt76_dev *dev, u32 addr)
76 {
77 	struct mt76_usb *usb = &dev->usb;
78 	u32 data = ~0;
79 	u16 offset;
80 	int ret;
81 	u8 req;
82 
83 	switch (addr & MT_VEND_TYPE_MASK) {
84 	case MT_VEND_TYPE_EEPROM:
85 		req = MT_VEND_READ_EEPROM;
86 		break;
87 	case MT_VEND_TYPE_CFG:
88 		req = MT_VEND_READ_CFG;
89 		break;
90 	default:
91 		req = MT_VEND_MULTI_READ;
92 		break;
93 	}
94 	offset = addr & ~MT_VEND_TYPE_MASK;
95 
96 	ret = __mt76u_vendor_request(dev, req,
97 				     USB_DIR_IN | USB_TYPE_VENDOR,
98 				     0, offset, usb->data, sizeof(__le32));
99 	if (ret == sizeof(__le32))
100 		data = get_unaligned_le32(usb->data);
101 	trace_usb_reg_rr(dev, addr, data);
102 
103 	return data;
104 }
105 
106 static u32 mt76u_rr(struct mt76_dev *dev, u32 addr)
107 {
108 	u32 ret;
109 
110 	mutex_lock(&dev->usb.usb_ctrl_mtx);
111 	ret = __mt76u_rr(dev, addr);
112 	mutex_unlock(&dev->usb.usb_ctrl_mtx);
113 
114 	return ret;
115 }
116 
117 /* should be called with usb_ctrl_mtx locked */
118 static void __mt76u_wr(struct mt76_dev *dev, u32 addr, u32 val)
119 {
120 	struct mt76_usb *usb = &dev->usb;
121 	u16 offset;
122 	u8 req;
123 
124 	switch (addr & MT_VEND_TYPE_MASK) {
125 	case MT_VEND_TYPE_CFG:
126 		req = MT_VEND_WRITE_CFG;
127 		break;
128 	default:
129 		req = MT_VEND_MULTI_WRITE;
130 		break;
131 	}
132 	offset = addr & ~MT_VEND_TYPE_MASK;
133 
134 	put_unaligned_le32(val, usb->data);
135 	__mt76u_vendor_request(dev, req,
136 			       USB_DIR_OUT | USB_TYPE_VENDOR, 0,
137 			       offset, usb->data, sizeof(__le32));
138 	trace_usb_reg_wr(dev, addr, val);
139 }
140 
141 static void mt76u_wr(struct mt76_dev *dev, u32 addr, u32 val)
142 {
143 	mutex_lock(&dev->usb.usb_ctrl_mtx);
144 	__mt76u_wr(dev, addr, val);
145 	mutex_unlock(&dev->usb.usb_ctrl_mtx);
146 }
147 
148 static u32 mt76u_rmw(struct mt76_dev *dev, u32 addr,
149 		     u32 mask, u32 val)
150 {
151 	mutex_lock(&dev->usb.usb_ctrl_mtx);
152 	val |= __mt76u_rr(dev, addr) & ~mask;
153 	__mt76u_wr(dev, addr, val);
154 	mutex_unlock(&dev->usb.usb_ctrl_mtx);
155 
156 	return val;
157 }
158 
159 static void mt76u_copy(struct mt76_dev *dev, u32 offset,
160 		       const void *data, int len)
161 {
162 	struct mt76_usb *usb = &dev->usb;
163 	const u32 *val = data;
164 	int i, ret;
165 
166 	mutex_lock(&usb->usb_ctrl_mtx);
167 	for (i = 0; i < (len / 4); i++) {
168 		put_unaligned_le32(val[i], usb->data);
169 		ret = __mt76u_vendor_request(dev, MT_VEND_MULTI_WRITE,
170 					     USB_DIR_OUT | USB_TYPE_VENDOR,
171 					     0, offset + i * 4, usb->data,
172 					     sizeof(__le32));
173 		if (ret < 0)
174 			break;
175 	}
176 	mutex_unlock(&usb->usb_ctrl_mtx);
177 }
178 
179 void mt76u_single_wr(struct mt76_dev *dev, const u8 req,
180 		     const u16 offset, const u32 val)
181 {
182 	mutex_lock(&dev->usb.usb_ctrl_mtx);
183 	__mt76u_vendor_request(dev, req,
184 			       USB_DIR_OUT | USB_TYPE_VENDOR,
185 			       val & 0xffff, offset, NULL, 0);
186 	__mt76u_vendor_request(dev, req,
187 			       USB_DIR_OUT | USB_TYPE_VENDOR,
188 			       val >> 16, offset + 2, NULL, 0);
189 	mutex_unlock(&dev->usb.usb_ctrl_mtx);
190 }
191 EXPORT_SYMBOL_GPL(mt76u_single_wr);
192 
193 static int
194 mt76u_req_wr_rp(struct mt76_dev *dev, u32 base,
195 		const struct mt76_reg_pair *data, int len)
196 {
197 	struct mt76_usb *usb = &dev->usb;
198 
199 	mutex_lock(&usb->usb_ctrl_mtx);
200 	while (len > 0) {
201 		__mt76u_wr(dev, base + data->reg, data->value);
202 		len--;
203 		data++;
204 	}
205 	mutex_unlock(&usb->usb_ctrl_mtx);
206 
207 	return 0;
208 }
209 
210 static int
211 mt76u_wr_rp(struct mt76_dev *dev, u32 base,
212 	    const struct mt76_reg_pair *data, int n)
213 {
214 	if (test_bit(MT76_STATE_MCU_RUNNING, &dev->state))
215 		return dev->mcu_ops->mcu_wr_rp(dev, base, data, n);
216 	else
217 		return mt76u_req_wr_rp(dev, base, data, n);
218 }
219 
220 static int
221 mt76u_req_rd_rp(struct mt76_dev *dev, u32 base, struct mt76_reg_pair *data,
222 		int len)
223 {
224 	struct mt76_usb *usb = &dev->usb;
225 
226 	mutex_lock(&usb->usb_ctrl_mtx);
227 	while (len > 0) {
228 		data->value = __mt76u_rr(dev, base + data->reg);
229 		len--;
230 		data++;
231 	}
232 	mutex_unlock(&usb->usb_ctrl_mtx);
233 
234 	return 0;
235 }
236 
237 static int
238 mt76u_rd_rp(struct mt76_dev *dev, u32 base,
239 	    struct mt76_reg_pair *data, int n)
240 {
241 	if (test_bit(MT76_STATE_MCU_RUNNING, &dev->state))
242 		return dev->mcu_ops->mcu_rd_rp(dev, base, data, n);
243 	else
244 		return mt76u_req_rd_rp(dev, base, data, n);
245 }
246 
247 static bool mt76u_check_sg(struct mt76_dev *dev)
248 {
249 	struct usb_device *udev = to_usb_device(dev->dev);
250 
251 	return (!disable_usb_sg && udev->bus->sg_tablesize > 0 &&
252 		(udev->bus->no_sg_constraint ||
253 		 udev->speed == USB_SPEED_WIRELESS));
254 }
255 
256 static int
257 mt76u_set_endpoints(struct usb_interface *intf,
258 		    struct mt76_usb *usb)
259 {
260 	struct usb_host_interface *intf_desc = intf->cur_altsetting;
261 	struct usb_endpoint_descriptor *ep_desc;
262 	int i, in_ep = 0, out_ep = 0;
263 
264 	for (i = 0; i < intf_desc->desc.bNumEndpoints; i++) {
265 		ep_desc = &intf_desc->endpoint[i].desc;
266 
267 		if (usb_endpoint_is_bulk_in(ep_desc) &&
268 		    in_ep < __MT_EP_IN_MAX) {
269 			usb->in_ep[in_ep] = usb_endpoint_num(ep_desc);
270 			in_ep++;
271 		} else if (usb_endpoint_is_bulk_out(ep_desc) &&
272 			   out_ep < __MT_EP_OUT_MAX) {
273 			usb->out_ep[out_ep] = usb_endpoint_num(ep_desc);
274 			out_ep++;
275 		}
276 	}
277 
278 	if (in_ep != __MT_EP_IN_MAX || out_ep != __MT_EP_OUT_MAX)
279 		return -EINVAL;
280 	return 0;
281 }
282 
283 static int
284 mt76u_fill_rx_sg(struct mt76_dev *dev, struct mt76_queue *q, struct urb *urb,
285 		 int nsgs, gfp_t gfp)
286 {
287 	int i;
288 
289 	for (i = 0; i < nsgs; i++) {
290 		struct page *page;
291 		void *data;
292 		int offset;
293 
294 		data = page_frag_alloc(&q->rx_page, q->buf_size, gfp);
295 		if (!data)
296 			break;
297 
298 		page = virt_to_head_page(data);
299 		offset = data - page_address(page);
300 		sg_set_page(&urb->sg[i], page, q->buf_size, offset);
301 	}
302 
303 	if (i < nsgs) {
304 		int j;
305 
306 		for (j = nsgs; j < urb->num_sgs; j++)
307 			skb_free_frag(sg_virt(&urb->sg[j]));
308 		urb->num_sgs = i;
309 	}
310 
311 	urb->num_sgs = max_t(int, i, urb->num_sgs);
312 	urb->transfer_buffer_length = urb->num_sgs * q->buf_size,
313 	sg_init_marker(urb->sg, urb->num_sgs);
314 
315 	return i ? : -ENOMEM;
316 }
317 
318 static int
319 mt76u_refill_rx(struct mt76_dev *dev, struct urb *urb, int nsgs, gfp_t gfp)
320 {
321 	struct mt76_queue *q = &dev->q_rx[MT_RXQ_MAIN];
322 
323 	if (dev->usb.sg_en) {
324 		return mt76u_fill_rx_sg(dev, q, urb, nsgs, gfp);
325 	} else {
326 		urb->transfer_buffer_length = q->buf_size;
327 		urb->transfer_buffer = page_frag_alloc(&q->rx_page,
328 						       q->buf_size, gfp);
329 		return urb->transfer_buffer ? 0 : -ENOMEM;
330 	}
331 }
332 
333 static int
334 mt76u_urb_alloc(struct mt76_dev *dev, struct mt76_queue_entry *e,
335 		int sg_max_size)
336 {
337 	unsigned int size = sizeof(struct urb);
338 
339 	if (dev->usb.sg_en)
340 		size += sg_max_size * sizeof(struct scatterlist);
341 
342 	e->urb = kzalloc(size, GFP_KERNEL);
343 	if (!e->urb)
344 		return -ENOMEM;
345 
346 	usb_init_urb(e->urb);
347 
348 	if (dev->usb.sg_en)
349 		e->urb->sg = (struct scatterlist *)(e->urb + 1);
350 
351 	return 0;
352 }
353 
354 static int
355 mt76u_rx_urb_alloc(struct mt76_dev *dev, struct mt76_queue_entry *e)
356 {
357 	int err;
358 
359 	err = mt76u_urb_alloc(dev, e, MT_RX_SG_MAX_SIZE);
360 	if (err)
361 		return err;
362 
363 	return mt76u_refill_rx(dev, e->urb, MT_RX_SG_MAX_SIZE,
364 			       GFP_KERNEL);
365 }
366 
367 static void mt76u_urb_free(struct urb *urb)
368 {
369 	int i;
370 
371 	for (i = 0; i < urb->num_sgs; i++)
372 		skb_free_frag(sg_virt(&urb->sg[i]));
373 
374 	if (urb->transfer_buffer)
375 		skb_free_frag(urb->transfer_buffer);
376 
377 	usb_free_urb(urb);
378 }
379 
380 static void
381 mt76u_fill_bulk_urb(struct mt76_dev *dev, int dir, int index,
382 		    struct urb *urb, usb_complete_t complete_fn,
383 		    void *context)
384 {
385 	struct usb_device *udev = to_usb_device(dev->dev);
386 	unsigned int pipe;
387 
388 	if (dir == USB_DIR_IN)
389 		pipe = usb_rcvbulkpipe(udev, dev->usb.in_ep[index]);
390 	else
391 		pipe = usb_sndbulkpipe(udev, dev->usb.out_ep[index]);
392 
393 	urb->dev = udev;
394 	urb->pipe = pipe;
395 	urb->complete = complete_fn;
396 	urb->context = context;
397 }
398 
399 static inline struct urb *
400 mt76u_get_next_rx_entry(struct mt76_dev *dev)
401 {
402 	struct mt76_queue *q = &dev->q_rx[MT_RXQ_MAIN];
403 	struct urb *urb = NULL;
404 	unsigned long flags;
405 
406 	spin_lock_irqsave(&q->lock, flags);
407 	if (q->queued > 0) {
408 		urb = q->entry[q->head].urb;
409 		q->head = (q->head + 1) % q->ndesc;
410 		q->queued--;
411 	}
412 	spin_unlock_irqrestore(&q->lock, flags);
413 
414 	return urb;
415 }
416 
417 static int mt76u_get_rx_entry_len(u8 *data, u32 data_len)
418 {
419 	u16 dma_len, min_len;
420 
421 	dma_len = get_unaligned_le16(data);
422 	min_len = MT_DMA_HDR_LEN + MT_RX_RXWI_LEN +
423 		  MT_FCE_INFO_LEN;
424 
425 	if (data_len < min_len || !dma_len ||
426 	    dma_len + MT_DMA_HDR_LEN > data_len ||
427 	    (dma_len & 0x3))
428 		return -EINVAL;
429 	return dma_len;
430 }
431 
432 static int
433 mt76u_process_rx_entry(struct mt76_dev *dev, struct urb *urb)
434 {
435 	struct mt76_queue *q = &dev->q_rx[MT_RXQ_MAIN];
436 	u8 *data = urb->num_sgs ? sg_virt(&urb->sg[0]) : urb->transfer_buffer;
437 	int data_len = urb->num_sgs ? urb->sg[0].length : urb->actual_length;
438 	int len, nsgs = 1;
439 	struct sk_buff *skb;
440 
441 	if (!test_bit(MT76_STATE_INITIALIZED, &dev->state))
442 		return 0;
443 
444 	len = mt76u_get_rx_entry_len(data, urb->actual_length);
445 	if (len < 0)
446 		return 0;
447 
448 	data_len = min_t(int, len, data_len - MT_DMA_HDR_LEN);
449 	if (MT_DMA_HDR_LEN + data_len > SKB_WITH_OVERHEAD(q->buf_size)) {
450 		dev_err_ratelimited(dev->dev, "rx data too big %d\n", data_len);
451 		return 0;
452 	}
453 
454 	skb = build_skb(data, q->buf_size);
455 	if (!skb)
456 		return 0;
457 
458 	skb_reserve(skb, MT_DMA_HDR_LEN);
459 	__skb_put(skb, data_len);
460 	len -= data_len;
461 
462 	while (len > 0 && nsgs < urb->num_sgs) {
463 		data_len = min_t(int, len, urb->sg[nsgs].length);
464 		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
465 				sg_page(&urb->sg[nsgs]),
466 				urb->sg[nsgs].offset,
467 				data_len, q->buf_size);
468 		len -= data_len;
469 		nsgs++;
470 	}
471 	dev->drv->rx_skb(dev, MT_RXQ_MAIN, skb);
472 
473 	return nsgs;
474 }
475 
476 static void mt76u_complete_rx(struct urb *urb)
477 {
478 	struct mt76_dev *dev = urb->context;
479 	struct mt76_queue *q = &dev->q_rx[MT_RXQ_MAIN];
480 	unsigned long flags;
481 
482 	trace_rx_urb(dev, urb);
483 
484 	switch (urb->status) {
485 	case -ECONNRESET:
486 	case -ESHUTDOWN:
487 	case -ENOENT:
488 		return;
489 	default:
490 		dev_err_ratelimited(dev->dev, "rx urb failed: %d\n",
491 				    urb->status);
492 		/* fall through */
493 	case 0:
494 		break;
495 	}
496 
497 	spin_lock_irqsave(&q->lock, flags);
498 	if (WARN_ONCE(q->entry[q->tail].urb != urb, "rx urb mismatch"))
499 		goto out;
500 
501 	q->tail = (q->tail + 1) % q->ndesc;
502 	q->queued++;
503 	tasklet_schedule(&dev->usb.rx_tasklet);
504 out:
505 	spin_unlock_irqrestore(&q->lock, flags);
506 }
507 
508 static int
509 mt76u_submit_rx_buf(struct mt76_dev *dev, struct urb *urb)
510 {
511 	mt76u_fill_bulk_urb(dev, USB_DIR_IN, MT_EP_IN_PKT_RX, urb,
512 			    mt76u_complete_rx, dev);
513 	trace_submit_urb(dev, urb);
514 
515 	return usb_submit_urb(urb, GFP_ATOMIC);
516 }
517 
518 static void mt76u_rx_tasklet(unsigned long data)
519 {
520 	struct mt76_dev *dev = (struct mt76_dev *)data;
521 	struct urb *urb;
522 	int err, count;
523 
524 	rcu_read_lock();
525 
526 	while (true) {
527 		urb = mt76u_get_next_rx_entry(dev);
528 		if (!urb)
529 			break;
530 
531 		count = mt76u_process_rx_entry(dev, urb);
532 		if (count > 0) {
533 			err = mt76u_refill_rx(dev, urb, count, GFP_ATOMIC);
534 			if (err < 0)
535 				break;
536 		}
537 		mt76u_submit_rx_buf(dev, urb);
538 	}
539 	mt76_rx_poll_complete(dev, MT_RXQ_MAIN, NULL);
540 
541 	rcu_read_unlock();
542 }
543 
544 static int mt76u_submit_rx_buffers(struct mt76_dev *dev)
545 {
546 	struct mt76_queue *q = &dev->q_rx[MT_RXQ_MAIN];
547 	unsigned long flags;
548 	int i, err = 0;
549 
550 	spin_lock_irqsave(&q->lock, flags);
551 	for (i = 0; i < q->ndesc; i++) {
552 		err = mt76u_submit_rx_buf(dev, q->entry[i].urb);
553 		if (err < 0)
554 			break;
555 	}
556 	q->head = q->tail = 0;
557 	q->queued = 0;
558 	spin_unlock_irqrestore(&q->lock, flags);
559 
560 	return err;
561 }
562 
563 static int mt76u_alloc_rx(struct mt76_dev *dev)
564 {
565 	struct mt76_usb *usb = &dev->usb;
566 	struct mt76_queue *q = &dev->q_rx[MT_RXQ_MAIN];
567 	int i, err;
568 
569 	usb->mcu.data = devm_kmalloc(dev->dev, MCU_RESP_URB_SIZE, GFP_KERNEL);
570 	if (!usb->mcu.data)
571 		return -ENOMEM;
572 
573 	spin_lock_init(&q->lock);
574 	q->entry = devm_kcalloc(dev->dev,
575 				MT_NUM_RX_ENTRIES, sizeof(*q->entry),
576 				GFP_KERNEL);
577 	if (!q->entry)
578 		return -ENOMEM;
579 
580 	q->ndesc = MT_NUM_RX_ENTRIES;
581 	q->buf_size = PAGE_SIZE;
582 
583 	for (i = 0; i < q->ndesc; i++) {
584 		err = mt76u_rx_urb_alloc(dev, &q->entry[i]);
585 		if (err < 0)
586 			return err;
587 	}
588 
589 	return mt76u_submit_rx_buffers(dev);
590 }
591 
592 static void mt76u_free_rx(struct mt76_dev *dev)
593 {
594 	struct mt76_queue *q = &dev->q_rx[MT_RXQ_MAIN];
595 	struct page *page;
596 	int i;
597 
598 	for (i = 0; i < q->ndesc; i++)
599 		mt76u_urb_free(q->entry[i].urb);
600 
601 	if (!q->rx_page.va)
602 		return;
603 
604 	page = virt_to_page(q->rx_page.va);
605 	__page_frag_cache_drain(page, q->rx_page.pagecnt_bias);
606 	memset(&q->rx_page, 0, sizeof(q->rx_page));
607 }
608 
609 void mt76u_stop_rx(struct mt76_dev *dev)
610 {
611 	struct mt76_queue *q = &dev->q_rx[MT_RXQ_MAIN];
612 	int i;
613 
614 	for (i = 0; i < q->ndesc; i++)
615 		usb_poison_urb(q->entry[i].urb);
616 
617 	tasklet_kill(&dev->usb.rx_tasklet);
618 }
619 EXPORT_SYMBOL_GPL(mt76u_stop_rx);
620 
621 int mt76u_resume_rx(struct mt76_dev *dev)
622 {
623 	struct mt76_queue *q = &dev->q_rx[MT_RXQ_MAIN];
624 	int i;
625 
626 	for (i = 0; i < q->ndesc; i++)
627 		usb_unpoison_urb(q->entry[i].urb);
628 
629 	return mt76u_submit_rx_buffers(dev);
630 }
631 EXPORT_SYMBOL_GPL(mt76u_resume_rx);
632 
633 static void mt76u_tx_tasklet(unsigned long data)
634 {
635 	struct mt76_dev *dev = (struct mt76_dev *)data;
636 	struct mt76_queue_entry entry;
637 	struct mt76_sw_queue *sq;
638 	struct mt76_queue *q;
639 	bool wake;
640 	int i;
641 
642 	for (i = 0; i < IEEE80211_NUM_ACS; i++) {
643 		u32 n_dequeued = 0, n_sw_dequeued = 0;
644 
645 		sq = &dev->q_tx[i];
646 		q = sq->q;
647 
648 		while (q->queued > n_dequeued) {
649 			if (!q->entry[q->head].done)
650 				break;
651 
652 			if (q->entry[q->head].schedule) {
653 				q->entry[q->head].schedule = false;
654 				n_sw_dequeued++;
655 			}
656 
657 			entry = q->entry[q->head];
658 			q->entry[q->head].done = false;
659 			q->head = (q->head + 1) % q->ndesc;
660 			n_dequeued++;
661 
662 			dev->drv->tx_complete_skb(dev, i, &entry);
663 		}
664 
665 		spin_lock_bh(&q->lock);
666 
667 		sq->swq_queued -= n_sw_dequeued;
668 		q->queued -= n_dequeued;
669 
670 		wake = q->stopped && q->queued < q->ndesc - 8;
671 		if (wake)
672 			q->stopped = false;
673 
674 		if (!q->queued)
675 			wake_up(&dev->tx_wait);
676 
677 		spin_unlock_bh(&q->lock);
678 
679 		mt76_txq_schedule(dev, i);
680 
681 		if (!test_and_set_bit(MT76_READING_STATS, &dev->state))
682 			ieee80211_queue_delayed_work(dev->hw,
683 						     &dev->usb.stat_work,
684 						     msecs_to_jiffies(10));
685 
686 		if (wake)
687 			ieee80211_wake_queue(dev->hw, i);
688 	}
689 }
690 
691 static void mt76u_tx_status_data(struct work_struct *work)
692 {
693 	struct mt76_usb *usb;
694 	struct mt76_dev *dev;
695 	u8 update = 1;
696 	u16 count = 0;
697 
698 	usb = container_of(work, struct mt76_usb, stat_work.work);
699 	dev = container_of(usb, struct mt76_dev, usb);
700 
701 	while (true) {
702 		if (test_bit(MT76_REMOVED, &dev->state))
703 			break;
704 
705 		if (!dev->drv->tx_status_data(dev, &update))
706 			break;
707 		count++;
708 	}
709 
710 	if (count && test_bit(MT76_STATE_RUNNING, &dev->state))
711 		ieee80211_queue_delayed_work(dev->hw, &usb->stat_work,
712 					     msecs_to_jiffies(10));
713 	else
714 		clear_bit(MT76_READING_STATS, &dev->state);
715 }
716 
717 static void mt76u_complete_tx(struct urb *urb)
718 {
719 	struct mt76_dev *dev = dev_get_drvdata(&urb->dev->dev);
720 	struct mt76_queue_entry *e = urb->context;
721 
722 	if (mt76u_urb_error(urb))
723 		dev_err(dev->dev, "tx urb failed: %d\n", urb->status);
724 	e->done = true;
725 
726 	tasklet_schedule(&dev->tx_tasklet);
727 }
728 
729 static int
730 mt76u_tx_setup_buffers(struct mt76_dev *dev, struct sk_buff *skb,
731 		       struct urb *urb)
732 {
733 	urb->transfer_buffer_length = skb->len;
734 
735 	if (!dev->usb.sg_en) {
736 		urb->transfer_buffer = skb->data;
737 		return 0;
738 	} else {
739 		sg_init_table(urb->sg, MT_TX_SG_MAX_SIZE);
740 		urb->num_sgs = skb_to_sgvec(skb, urb->sg, 0, skb->len);
741 		if (urb->num_sgs == 0)
742 			return -ENOMEM;
743 		return urb->num_sgs;
744 	}
745 }
746 
747 static int
748 mt76u_tx_queue_skb(struct mt76_dev *dev, enum mt76_txq_id qid,
749 		   struct sk_buff *skb, struct mt76_wcid *wcid,
750 		   struct ieee80211_sta *sta)
751 {
752 	struct mt76_queue *q = dev->q_tx[qid].q;
753 	struct mt76_tx_info tx_info = {
754 		.skb = skb,
755 	};
756 	u16 idx = q->tail;
757 	int err;
758 
759 	if (q->queued == q->ndesc)
760 		return -ENOSPC;
761 
762 	skb->prev = skb->next = NULL;
763 	err = dev->drv->tx_prepare_skb(dev, NULL, qid, wcid, sta, &tx_info);
764 	if (err < 0)
765 		return err;
766 
767 	err = mt76u_tx_setup_buffers(dev, tx_info.skb, q->entry[idx].urb);
768 	if (err < 0)
769 		return err;
770 
771 	mt76u_fill_bulk_urb(dev, USB_DIR_OUT, q2ep(q->hw_idx),
772 			    q->entry[idx].urb, mt76u_complete_tx,
773 			    &q->entry[idx]);
774 
775 	q->tail = (q->tail + 1) % q->ndesc;
776 	q->entry[idx].skb = tx_info.skb;
777 	q->queued++;
778 
779 	return idx;
780 }
781 
782 static void mt76u_tx_kick(struct mt76_dev *dev, struct mt76_queue *q)
783 {
784 	struct urb *urb;
785 	int err;
786 
787 	while (q->first != q->tail) {
788 		urb = q->entry[q->first].urb;
789 
790 		trace_submit_urb(dev, urb);
791 		err = usb_submit_urb(urb, GFP_ATOMIC);
792 		if (err < 0) {
793 			if (err == -ENODEV)
794 				set_bit(MT76_REMOVED, &dev->state);
795 			else
796 				dev_err(dev->dev, "tx urb submit failed:%d\n",
797 					err);
798 			break;
799 		}
800 		q->first = (q->first + 1) % q->ndesc;
801 	}
802 }
803 
804 static int mt76u_alloc_tx(struct mt76_dev *dev)
805 {
806 	struct mt76_queue *q;
807 	int i, j, err;
808 
809 	for (i = 0; i <= MT_TXQ_PSD; i++) {
810 		INIT_LIST_HEAD(&dev->q_tx[i].swq);
811 
812 		if (i >= IEEE80211_NUM_ACS) {
813 			dev->q_tx[i].q = dev->q_tx[0].q;
814 			continue;
815 		}
816 
817 		q = devm_kzalloc(dev->dev, sizeof(*q), GFP_KERNEL);
818 		if (!q)
819 			return -ENOMEM;
820 
821 		spin_lock_init(&q->lock);
822 		q->hw_idx = mt76_ac_to_hwq(i);
823 		dev->q_tx[i].q = q;
824 
825 		q->entry = devm_kcalloc(dev->dev,
826 					MT_NUM_TX_ENTRIES, sizeof(*q->entry),
827 					GFP_KERNEL);
828 		if (!q->entry)
829 			return -ENOMEM;
830 
831 		q->ndesc = MT_NUM_TX_ENTRIES;
832 		for (j = 0; j < q->ndesc; j++) {
833 			err = mt76u_urb_alloc(dev, &q->entry[j],
834 					      MT_TX_SG_MAX_SIZE);
835 			if (err < 0)
836 				return err;
837 		}
838 	}
839 	return 0;
840 }
841 
842 static void mt76u_free_tx(struct mt76_dev *dev)
843 {
844 	struct mt76_queue *q;
845 	int i, j;
846 
847 	for (i = 0; i < IEEE80211_NUM_ACS; i++) {
848 		q = dev->q_tx[i].q;
849 		for (j = 0; j < q->ndesc; j++)
850 			usb_free_urb(q->entry[j].urb);
851 	}
852 }
853 
854 void mt76u_stop_tx(struct mt76_dev *dev)
855 {
856 	struct mt76_queue_entry entry;
857 	struct mt76_queue *q;
858 	int i, j, ret;
859 
860 	ret = wait_event_timeout(dev->tx_wait, !mt76_has_tx_pending(dev), HZ/5);
861 	if (!ret) {
862 		dev_err(dev->dev, "timed out waiting for pending tx\n");
863 
864 		for (i = 0; i < IEEE80211_NUM_ACS; i++) {
865 			q = dev->q_tx[i].q;
866 			for (j = 0; j < q->ndesc; j++)
867 				usb_kill_urb(q->entry[j].urb);
868 		}
869 
870 		tasklet_kill(&dev->tx_tasklet);
871 
872 		/* On device removal we maight queue skb's, but mt76u_tx_kick()
873 		 * will fail to submit urb, cleanup those skb's manually.
874 		 */
875 		for (i = 0; i < IEEE80211_NUM_ACS; i++) {
876 			q = dev->q_tx[i].q;
877 
878 			/* Assure we are in sync with killed tasklet. */
879 			spin_lock_bh(&q->lock);
880 			while (q->queued) {
881 				entry = q->entry[q->head];
882 				q->head = (q->head + 1) % q->ndesc;
883 				q->queued--;
884 
885 				dev->drv->tx_complete_skb(dev, i, &entry);
886 			}
887 			spin_unlock_bh(&q->lock);
888 		}
889 	}
890 
891 	cancel_delayed_work_sync(&dev->usb.stat_work);
892 	clear_bit(MT76_READING_STATS, &dev->state);
893 
894 	mt76_tx_status_check(dev, NULL, true);
895 }
896 EXPORT_SYMBOL_GPL(mt76u_stop_tx);
897 
898 void mt76u_queues_deinit(struct mt76_dev *dev)
899 {
900 	mt76u_stop_rx(dev);
901 	mt76u_stop_tx(dev);
902 
903 	mt76u_free_rx(dev);
904 	mt76u_free_tx(dev);
905 }
906 EXPORT_SYMBOL_GPL(mt76u_queues_deinit);
907 
908 int mt76u_alloc_queues(struct mt76_dev *dev)
909 {
910 	int err;
911 
912 	err = mt76u_alloc_rx(dev);
913 	if (err < 0)
914 		return err;
915 
916 	return mt76u_alloc_tx(dev);
917 }
918 EXPORT_SYMBOL_GPL(mt76u_alloc_queues);
919 
920 static const struct mt76_queue_ops usb_queue_ops = {
921 	.tx_queue_skb = mt76u_tx_queue_skb,
922 	.kick = mt76u_tx_kick,
923 };
924 
925 int mt76u_init(struct mt76_dev *dev,
926 	       struct usb_interface *intf)
927 {
928 	static const struct mt76_bus_ops mt76u_ops = {
929 		.rr = mt76u_rr,
930 		.wr = mt76u_wr,
931 		.rmw = mt76u_rmw,
932 		.copy = mt76u_copy,
933 		.wr_rp = mt76u_wr_rp,
934 		.rd_rp = mt76u_rd_rp,
935 		.type = MT76_BUS_USB,
936 	};
937 	struct mt76_usb *usb = &dev->usb;
938 
939 	tasklet_init(&usb->rx_tasklet, mt76u_rx_tasklet, (unsigned long)dev);
940 	tasklet_init(&dev->tx_tasklet, mt76u_tx_tasklet, (unsigned long)dev);
941 	INIT_DELAYED_WORK(&usb->stat_work, mt76u_tx_status_data);
942 	skb_queue_head_init(&dev->rx_skb[MT_RXQ_MAIN]);
943 
944 	mutex_init(&usb->mcu.mutex);
945 
946 	mutex_init(&usb->usb_ctrl_mtx);
947 	dev->bus = &mt76u_ops;
948 	dev->queue_ops = &usb_queue_ops;
949 
950 	usb->sg_en = mt76u_check_sg(dev);
951 
952 	return mt76u_set_endpoints(intf, usb);
953 }
954 EXPORT_SYMBOL_GPL(mt76u_init);
955 
956 MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>");
957 MODULE_LICENSE("Dual BSD/GPL");
958