xref: /linux/drivers/net/wireless/mediatek/mt76/usb.c (revision 44f57d78)
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 			usb->in_max_packet = usb_endpoint_maxp(ep_desc);
271 			in_ep++;
272 		} else if (usb_endpoint_is_bulk_out(ep_desc) &&
273 			   out_ep < __MT_EP_OUT_MAX) {
274 			usb->out_ep[out_ep] = usb_endpoint_num(ep_desc);
275 			usb->out_max_packet = usb_endpoint_maxp(ep_desc);
276 			out_ep++;
277 		}
278 	}
279 
280 	if (in_ep != __MT_EP_IN_MAX || out_ep != __MT_EP_OUT_MAX)
281 		return -EINVAL;
282 	return 0;
283 }
284 
285 static int
286 mt76u_fill_rx_sg(struct mt76_dev *dev, struct mt76_queue *q, struct urb *urb,
287 		 int nsgs, gfp_t gfp)
288 {
289 	int i;
290 
291 	for (i = 0; i < nsgs; i++) {
292 		struct page *page;
293 		void *data;
294 		int offset;
295 
296 		data = page_frag_alloc(&q->rx_page, q->buf_size, gfp);
297 		if (!data)
298 			break;
299 
300 		page = virt_to_head_page(data);
301 		offset = data - page_address(page);
302 		sg_set_page(&urb->sg[i], page, q->buf_size, offset);
303 	}
304 
305 	if (i < nsgs) {
306 		int j;
307 
308 		for (j = nsgs; j < urb->num_sgs; j++)
309 			skb_free_frag(sg_virt(&urb->sg[j]));
310 		urb->num_sgs = i;
311 	}
312 
313 	urb->num_sgs = max_t(int, i, urb->num_sgs);
314 	urb->transfer_buffer_length = urb->num_sgs * q->buf_size,
315 	sg_init_marker(urb->sg, urb->num_sgs);
316 
317 	return i ? : -ENOMEM;
318 }
319 
320 static int
321 mt76u_refill_rx(struct mt76_dev *dev, struct urb *urb, int nsgs, gfp_t gfp)
322 {
323 	struct mt76_queue *q = &dev->q_rx[MT_RXQ_MAIN];
324 
325 	if (dev->usb.sg_en) {
326 		return mt76u_fill_rx_sg(dev, q, urb, nsgs, gfp);
327 	} else {
328 		urb->transfer_buffer_length = q->buf_size;
329 		urb->transfer_buffer = page_frag_alloc(&q->rx_page,
330 						       q->buf_size, gfp);
331 		return urb->transfer_buffer ? 0 : -ENOMEM;
332 	}
333 }
334 
335 static int
336 mt76u_urb_alloc(struct mt76_dev *dev, struct mt76_queue_entry *e)
337 {
338 	unsigned int size = sizeof(struct urb);
339 
340 	if (dev->usb.sg_en)
341 		size += MT_SG_MAX_SIZE * sizeof(struct scatterlist);
342 
343 	e->urb = kzalloc(size, GFP_KERNEL);
344 	if (!e->urb)
345 		return -ENOMEM;
346 
347 	usb_init_urb(e->urb);
348 
349 	if (dev->usb.sg_en)
350 		e->urb->sg = (struct scatterlist *)(e->urb + 1);
351 
352 	return 0;
353 }
354 
355 static int
356 mt76u_rx_urb_alloc(struct mt76_dev *dev, struct mt76_queue_entry *e)
357 {
358 	int err;
359 
360 	err = mt76u_urb_alloc(dev, e);
361 	if (err)
362 		return err;
363 
364 	return mt76u_refill_rx(dev, e->urb, MT_SG_MAX_SIZE, 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->buf_size = dev->usb.sg_en ? MT_RX_BUF_SIZE : PAGE_SIZE;
581 	q->ndesc = MT_NUM_RX_ENTRIES;
582 	for (i = 0; i < q->ndesc; i++) {
583 		err = mt76u_rx_urb_alloc(dev, &q->entry[i]);
584 		if (err < 0)
585 			return err;
586 	}
587 
588 	return mt76u_submit_rx_buffers(dev);
589 }
590 
591 static void mt76u_free_rx(struct mt76_dev *dev)
592 {
593 	struct mt76_queue *q = &dev->q_rx[MT_RXQ_MAIN];
594 	struct page *page;
595 	int i;
596 
597 	for (i = 0; i < q->ndesc; i++)
598 		mt76u_urb_free(q->entry[i].urb);
599 
600 	if (!q->rx_page.va)
601 		return;
602 
603 	page = virt_to_page(q->rx_page.va);
604 	__page_frag_cache_drain(page, q->rx_page.pagecnt_bias);
605 	memset(&q->rx_page, 0, sizeof(q->rx_page));
606 }
607 
608 void mt76u_stop_rx(struct mt76_dev *dev)
609 {
610 	struct mt76_queue *q = &dev->q_rx[MT_RXQ_MAIN];
611 	int i;
612 
613 	for (i = 0; i < q->ndesc; i++)
614 		usb_poison_urb(q->entry[i].urb);
615 
616 	tasklet_kill(&dev->usb.rx_tasklet);
617 }
618 EXPORT_SYMBOL_GPL(mt76u_stop_rx);
619 
620 int mt76u_resume_rx(struct mt76_dev *dev)
621 {
622 	struct mt76_queue *q = &dev->q_rx[MT_RXQ_MAIN];
623 	int i;
624 
625 	for (i = 0; i < q->ndesc; i++)
626 		usb_unpoison_urb(q->entry[i].urb);
627 
628 	return mt76u_submit_rx_buffers(dev);
629 }
630 EXPORT_SYMBOL_GPL(mt76u_resume_rx);
631 
632 static void mt76u_tx_tasklet(unsigned long data)
633 {
634 	struct mt76_dev *dev = (struct mt76_dev *)data;
635 	struct mt76_queue_entry entry;
636 	struct mt76_sw_queue *sq;
637 	struct mt76_queue *q;
638 	bool wake;
639 	int i;
640 
641 	for (i = 0; i < IEEE80211_NUM_ACS; i++) {
642 		u32 n_dequeued = 0, n_sw_dequeued = 0;
643 
644 		sq = &dev->q_tx[i];
645 		q = sq->q;
646 
647 		while (q->queued > n_dequeued) {
648 			if (!q->entry[q->head].done)
649 				break;
650 
651 			if (q->entry[q->head].schedule) {
652 				q->entry[q->head].schedule = false;
653 				n_sw_dequeued++;
654 			}
655 
656 			entry = q->entry[q->head];
657 			q->entry[q->head].done = false;
658 			q->head = (q->head + 1) % q->ndesc;
659 			n_dequeued++;
660 
661 			dev->drv->tx_complete_skb(dev, i, &entry);
662 		}
663 
664 		spin_lock_bh(&q->lock);
665 
666 		sq->swq_queued -= n_sw_dequeued;
667 		q->queued -= n_dequeued;
668 
669 		wake = q->stopped && q->queued < q->ndesc - 8;
670 		if (wake)
671 			q->stopped = false;
672 
673 		if (!q->queued)
674 			wake_up(&dev->tx_wait);
675 
676 		spin_unlock_bh(&q->lock);
677 
678 		mt76_txq_schedule(dev, i);
679 
680 		if (!test_and_set_bit(MT76_READING_STATS, &dev->state))
681 			ieee80211_queue_delayed_work(dev->hw,
682 						     &dev->usb.stat_work,
683 						     msecs_to_jiffies(10));
684 
685 		if (wake)
686 			ieee80211_wake_queue(dev->hw, i);
687 	}
688 }
689 
690 static void mt76u_tx_status_data(struct work_struct *work)
691 {
692 	struct mt76_usb *usb;
693 	struct mt76_dev *dev;
694 	u8 update = 1;
695 	u16 count = 0;
696 
697 	usb = container_of(work, struct mt76_usb, stat_work.work);
698 	dev = container_of(usb, struct mt76_dev, usb);
699 
700 	while (true) {
701 		if (test_bit(MT76_REMOVED, &dev->state))
702 			break;
703 
704 		if (!dev->drv->tx_status_data(dev, &update))
705 			break;
706 		count++;
707 	}
708 
709 	if (count && test_bit(MT76_STATE_RUNNING, &dev->state))
710 		ieee80211_queue_delayed_work(dev->hw, &usb->stat_work,
711 					     msecs_to_jiffies(10));
712 	else
713 		clear_bit(MT76_READING_STATS, &dev->state);
714 }
715 
716 static void mt76u_complete_tx(struct urb *urb)
717 {
718 	struct mt76_dev *dev = dev_get_drvdata(&urb->dev->dev);
719 	struct mt76_queue_entry *e = urb->context;
720 
721 	if (mt76u_urb_error(urb))
722 		dev_err(dev->dev, "tx urb failed: %d\n", urb->status);
723 	e->done = true;
724 
725 	tasklet_schedule(&dev->tx_tasklet);
726 }
727 
728 static int
729 mt76u_tx_setup_buffers(struct mt76_dev *dev, struct sk_buff *skb,
730 		       struct urb *urb)
731 {
732 	urb->transfer_buffer_length = skb->len;
733 
734 	if (!dev->usb.sg_en) {
735 		urb->transfer_buffer = skb->data;
736 		return 0;
737 	} else {
738 		sg_init_table(urb->sg, MT_SG_MAX_SIZE);
739 		urb->num_sgs = skb_to_sgvec(skb, urb->sg, 0, skb->len);
740 		if (urb->num_sgs == 0)
741 			return -ENOMEM;
742 		return urb->num_sgs;
743 	}
744 }
745 
746 static int
747 mt76u_tx_queue_skb(struct mt76_dev *dev, enum mt76_txq_id qid,
748 		   struct sk_buff *skb, struct mt76_wcid *wcid,
749 		   struct ieee80211_sta *sta)
750 {
751 	struct mt76_queue *q = dev->q_tx[qid].q;
752 	struct mt76_tx_info tx_info = {
753 		.skb = skb,
754 	};
755 	u16 idx = q->tail;
756 	int err;
757 
758 	if (q->queued == q->ndesc)
759 		return -ENOSPC;
760 
761 	skb->prev = skb->next = NULL;
762 	err = dev->drv->tx_prepare_skb(dev, NULL, qid, wcid, sta, &tx_info);
763 	if (err < 0)
764 		return err;
765 
766 	err = mt76u_tx_setup_buffers(dev, tx_info.skb, q->entry[idx].urb);
767 	if (err < 0)
768 		return err;
769 
770 	mt76u_fill_bulk_urb(dev, USB_DIR_OUT, q2ep(q->hw_idx),
771 			    q->entry[idx].urb, mt76u_complete_tx,
772 			    &q->entry[idx]);
773 
774 	q->tail = (q->tail + 1) % q->ndesc;
775 	q->entry[idx].skb = tx_info.skb;
776 	q->queued++;
777 
778 	return idx;
779 }
780 
781 static void mt76u_tx_kick(struct mt76_dev *dev, struct mt76_queue *q)
782 {
783 	struct urb *urb;
784 	int err;
785 
786 	while (q->first != q->tail) {
787 		urb = q->entry[q->first].urb;
788 
789 		trace_submit_urb(dev, urb);
790 		err = usb_submit_urb(urb, GFP_ATOMIC);
791 		if (err < 0) {
792 			if (err == -ENODEV)
793 				set_bit(MT76_REMOVED, &dev->state);
794 			else
795 				dev_err(dev->dev, "tx urb submit failed:%d\n",
796 					err);
797 			break;
798 		}
799 		q->first = (q->first + 1) % q->ndesc;
800 	}
801 }
802 
803 static int mt76u_alloc_tx(struct mt76_dev *dev)
804 {
805 	struct mt76_queue *q;
806 	int i, j, err;
807 
808 	for (i = 0; i <= MT_TXQ_PSD; i++) {
809 		INIT_LIST_HEAD(&dev->q_tx[i].swq);
810 
811 		if (i >= IEEE80211_NUM_ACS) {
812 			dev->q_tx[i].q = dev->q_tx[0].q;
813 			continue;
814 		}
815 
816 		q = devm_kzalloc(dev->dev, sizeof(*q), GFP_KERNEL);
817 		if (!q)
818 			return -ENOMEM;
819 
820 		spin_lock_init(&q->lock);
821 		q->hw_idx = mt76_ac_to_hwq(i);
822 		dev->q_tx[i].q = q;
823 
824 		q->entry = devm_kcalloc(dev->dev,
825 					MT_NUM_TX_ENTRIES, sizeof(*q->entry),
826 					GFP_KERNEL);
827 		if (!q->entry)
828 			return -ENOMEM;
829 
830 		q->ndesc = MT_NUM_TX_ENTRIES;
831 		for (j = 0; j < q->ndesc; j++) {
832 			err = mt76u_urb_alloc(dev, &q->entry[j]);
833 			if (err < 0)
834 				return err;
835 		}
836 	}
837 	return 0;
838 }
839 
840 static void mt76u_free_tx(struct mt76_dev *dev)
841 {
842 	struct mt76_queue *q;
843 	int i, j;
844 
845 	for (i = 0; i < IEEE80211_NUM_ACS; i++) {
846 		q = dev->q_tx[i].q;
847 		for (j = 0; j < q->ndesc; j++)
848 			usb_free_urb(q->entry[j].urb);
849 	}
850 }
851 
852 void mt76u_stop_tx(struct mt76_dev *dev)
853 {
854 	struct mt76_queue_entry entry;
855 	struct mt76_queue *q;
856 	int i, j, ret;
857 
858 	ret = wait_event_timeout(dev->tx_wait, !mt76_has_tx_pending(dev), HZ/5);
859 	if (!ret) {
860 		dev_err(dev->dev, "timed out waiting for pending tx\n");
861 
862 		for (i = 0; i < IEEE80211_NUM_ACS; i++) {
863 			q = dev->q_tx[i].q;
864 			for (j = 0; j < q->ndesc; j++)
865 				usb_kill_urb(q->entry[j].urb);
866 		}
867 
868 		tasklet_kill(&dev->tx_tasklet);
869 
870 		/* On device removal we maight queue skb's, but mt76u_tx_kick()
871 		 * will fail to submit urb, cleanup those skb's manually.
872 		 */
873 		for (i = 0; i < IEEE80211_NUM_ACS; i++) {
874 			q = dev->q_tx[i].q;
875 
876 			/* Assure we are in sync with killed tasklet. */
877 			spin_lock_bh(&q->lock);
878 			while (q->queued) {
879 				entry = q->entry[q->head];
880 				q->head = (q->head + 1) % q->ndesc;
881 				q->queued--;
882 
883 				dev->drv->tx_complete_skb(dev, i, &entry);
884 			}
885 			spin_unlock_bh(&q->lock);
886 		}
887 	}
888 
889 	cancel_delayed_work_sync(&dev->usb.stat_work);
890 	clear_bit(MT76_READING_STATS, &dev->state);
891 
892 	mt76_tx_status_check(dev, NULL, true);
893 }
894 EXPORT_SYMBOL_GPL(mt76u_stop_tx);
895 
896 void mt76u_queues_deinit(struct mt76_dev *dev)
897 {
898 	mt76u_stop_rx(dev);
899 	mt76u_stop_tx(dev);
900 
901 	mt76u_free_rx(dev);
902 	mt76u_free_tx(dev);
903 }
904 EXPORT_SYMBOL_GPL(mt76u_queues_deinit);
905 
906 int mt76u_alloc_queues(struct mt76_dev *dev)
907 {
908 	int err;
909 
910 	err = mt76u_alloc_rx(dev);
911 	if (err < 0)
912 		return err;
913 
914 	return mt76u_alloc_tx(dev);
915 }
916 EXPORT_SYMBOL_GPL(mt76u_alloc_queues);
917 
918 static const struct mt76_queue_ops usb_queue_ops = {
919 	.tx_queue_skb = mt76u_tx_queue_skb,
920 	.kick = mt76u_tx_kick,
921 };
922 
923 int mt76u_init(struct mt76_dev *dev,
924 	       struct usb_interface *intf)
925 {
926 	static const struct mt76_bus_ops mt76u_ops = {
927 		.rr = mt76u_rr,
928 		.wr = mt76u_wr,
929 		.rmw = mt76u_rmw,
930 		.copy = mt76u_copy,
931 		.wr_rp = mt76u_wr_rp,
932 		.rd_rp = mt76u_rd_rp,
933 		.type = MT76_BUS_USB,
934 	};
935 	struct mt76_usb *usb = &dev->usb;
936 
937 	tasklet_init(&usb->rx_tasklet, mt76u_rx_tasklet, (unsigned long)dev);
938 	tasklet_init(&dev->tx_tasklet, mt76u_tx_tasklet, (unsigned long)dev);
939 	INIT_DELAYED_WORK(&usb->stat_work, mt76u_tx_status_data);
940 	skb_queue_head_init(&dev->rx_skb[MT_RXQ_MAIN]);
941 
942 	mutex_init(&usb->mcu.mutex);
943 
944 	mutex_init(&usb->usb_ctrl_mtx);
945 	dev->bus = &mt76u_ops;
946 	dev->queue_ops = &usb_queue_ops;
947 
948 	usb->sg_en = mt76u_check_sg(dev);
949 
950 	return mt76u_set_endpoints(intf, usb);
951 }
952 EXPORT_SYMBOL_GPL(mt76u_init);
953 
954 MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>");
955 MODULE_LICENSE("Dual BSD/GPL");
956