1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2015 Jakub Kicinski <kubakici@wp.pl>
4  */
5 
6 #include "mt7601u.h"
7 #include "dma.h"
8 #include "usb.h"
9 #include "trace.h"
10 
11 static int mt7601u_submit_rx_buf(struct mt7601u_dev *dev,
12 				 struct mt7601u_dma_buf_rx *e, gfp_t gfp);
13 
14 static unsigned int ieee80211_get_hdrlen_from_buf(const u8 *data, unsigned len)
15 {
16 	const struct ieee80211_hdr *hdr = (const struct ieee80211_hdr *)data;
17 	unsigned int hdrlen;
18 
19 	if (unlikely(len < 10))
20 		return 0;
21 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
22 	if (unlikely(hdrlen > len))
23 		return 0;
24 	return hdrlen;
25 }
26 
27 static struct sk_buff *
28 mt7601u_rx_skb_from_seg(struct mt7601u_dev *dev, struct mt7601u_rxwi *rxwi,
29 			void *data, u32 seg_len, u32 truesize, struct page *p)
30 {
31 	struct sk_buff *skb;
32 	u32 true_len, hdr_len = 0, copy, frag;
33 
34 	skb = alloc_skb(p ? 128 : seg_len, GFP_ATOMIC);
35 	if (!skb)
36 		return NULL;
37 
38 	true_len = mt76_mac_process_rx(dev, skb, data, rxwi);
39 	if (!true_len || true_len > seg_len)
40 		goto bad_frame;
41 
42 	hdr_len = ieee80211_get_hdrlen_from_buf(data, true_len);
43 	if (!hdr_len)
44 		goto bad_frame;
45 
46 	if (rxwi->rxinfo & cpu_to_le32(MT_RXINFO_L2PAD)) {
47 		skb_put_data(skb, data, hdr_len);
48 
49 		data += hdr_len + 2;
50 		true_len -= hdr_len;
51 		hdr_len = 0;
52 	}
53 
54 	/* If not doing paged RX allocated skb will always have enough space */
55 	copy = (true_len <= skb_tailroom(skb)) ? true_len : hdr_len + 8;
56 	frag = true_len - copy;
57 
58 	skb_put_data(skb, data, copy);
59 	data += copy;
60 
61 	if (frag) {
62 		skb_add_rx_frag(skb, 0, p, data - page_address(p),
63 				frag, truesize);
64 		get_page(p);
65 	}
66 
67 	return skb;
68 
69 bad_frame:
70 	dev_err_ratelimited(dev->dev, "Error: incorrect frame len:%u hdr:%u\n",
71 			    true_len, hdr_len);
72 	dev_kfree_skb(skb);
73 	return NULL;
74 }
75 
76 static void mt7601u_rx_process_seg(struct mt7601u_dev *dev, u8 *data,
77 				   u32 seg_len, struct page *p)
78 {
79 	struct sk_buff *skb;
80 	struct mt7601u_rxwi *rxwi;
81 	u32 fce_info, truesize = seg_len;
82 
83 	/* DMA_INFO field at the beginning of the segment contains only some of
84 	 * the information, we need to read the FCE descriptor from the end.
85 	 */
86 	fce_info = get_unaligned_le32(data + seg_len - MT_FCE_INFO_LEN);
87 	seg_len -= MT_FCE_INFO_LEN;
88 
89 	data += MT_DMA_HDR_LEN;
90 	seg_len -= MT_DMA_HDR_LEN;
91 
92 	rxwi = (struct mt7601u_rxwi *) data;
93 	data += sizeof(struct mt7601u_rxwi);
94 	seg_len -= sizeof(struct mt7601u_rxwi);
95 
96 	if (unlikely(rxwi->zero[0] || rxwi->zero[1] || rxwi->zero[2]))
97 		dev_err_once(dev->dev, "Error: RXWI zero fields are set\n");
98 	if (unlikely(FIELD_GET(MT_RXD_INFO_TYPE, fce_info)))
99 		dev_err_once(dev->dev, "Error: RX path seen a non-pkt urb\n");
100 
101 	trace_mt_rx(dev, rxwi, fce_info);
102 
103 	skb = mt7601u_rx_skb_from_seg(dev, rxwi, data, seg_len, truesize, p);
104 	if (!skb)
105 		return;
106 
107 	spin_lock(&dev->mac_lock);
108 	ieee80211_rx(dev->hw, skb);
109 	spin_unlock(&dev->mac_lock);
110 }
111 
112 static u16 mt7601u_rx_next_seg_len(u8 *data, u32 data_len)
113 {
114 	u32 min_seg_len = MT_DMA_HDR_LEN + MT_RX_INFO_LEN +
115 		sizeof(struct mt7601u_rxwi) + MT_FCE_INFO_LEN;
116 	u16 dma_len = get_unaligned_le16(data);
117 
118 	if (data_len < min_seg_len ||
119 	    WARN_ON_ONCE(!dma_len) ||
120 	    WARN_ON_ONCE(dma_len + MT_DMA_HDRS > data_len) ||
121 	    WARN_ON_ONCE(dma_len & 0x3))
122 		return 0;
123 
124 	return MT_DMA_HDRS + dma_len;
125 }
126 
127 static void
128 mt7601u_rx_process_entry(struct mt7601u_dev *dev, struct mt7601u_dma_buf_rx *e)
129 {
130 	u32 seg_len, data_len = e->urb->actual_length;
131 	u8 *data = page_address(e->p);
132 	struct page *new_p = NULL;
133 	int cnt = 0;
134 
135 	if (!test_bit(MT7601U_STATE_INITIALIZED, &dev->state))
136 		return;
137 
138 	/* Copy if there is very little data in the buffer. */
139 	if (data_len > 512)
140 		new_p = dev_alloc_pages(MT_RX_ORDER);
141 
142 	while ((seg_len = mt7601u_rx_next_seg_len(data, data_len))) {
143 		mt7601u_rx_process_seg(dev, data, seg_len, new_p ? e->p : NULL);
144 
145 		data_len -= seg_len;
146 		data += seg_len;
147 		cnt++;
148 	}
149 
150 	if (cnt > 1)
151 		trace_mt_rx_dma_aggr(dev, cnt, !!new_p);
152 
153 	if (new_p) {
154 		/* we have one extra ref from the allocator */
155 		__free_pages(e->p, MT_RX_ORDER);
156 
157 		e->p = new_p;
158 	}
159 }
160 
161 static struct mt7601u_dma_buf_rx *
162 mt7601u_rx_get_pending_entry(struct mt7601u_dev *dev)
163 {
164 	struct mt7601u_rx_queue *q = &dev->rx_q;
165 	struct mt7601u_dma_buf_rx *buf = NULL;
166 	unsigned long flags;
167 
168 	spin_lock_irqsave(&dev->rx_lock, flags);
169 
170 	if (!q->pending)
171 		goto out;
172 
173 	buf = &q->e[q->start];
174 	q->pending--;
175 	q->start = (q->start + 1) % q->entries;
176 out:
177 	spin_unlock_irqrestore(&dev->rx_lock, flags);
178 
179 	return buf;
180 }
181 
182 static void mt7601u_complete_rx(struct urb *urb)
183 {
184 	struct mt7601u_dev *dev = urb->context;
185 	struct mt7601u_rx_queue *q = &dev->rx_q;
186 	unsigned long flags;
187 
188 	spin_lock_irqsave(&dev->rx_lock, flags);
189 
190 	if (mt7601u_urb_has_error(urb))
191 		dev_err(dev->dev, "Error: RX urb failed:%d\n", urb->status);
192 	if (WARN_ONCE(q->e[q->end].urb != urb, "RX urb mismatch"))
193 		goto out;
194 
195 	q->end = (q->end + 1) % q->entries;
196 	q->pending++;
197 	tasklet_schedule(&dev->rx_tasklet);
198 out:
199 	spin_unlock_irqrestore(&dev->rx_lock, flags);
200 }
201 
202 static void mt7601u_rx_tasklet(unsigned long data)
203 {
204 	struct mt7601u_dev *dev = (struct mt7601u_dev *) data;
205 	struct mt7601u_dma_buf_rx *e;
206 
207 	while ((e = mt7601u_rx_get_pending_entry(dev))) {
208 		if (e->urb->status)
209 			continue;
210 
211 		mt7601u_rx_process_entry(dev, e);
212 		mt7601u_submit_rx_buf(dev, e, GFP_ATOMIC);
213 	}
214 }
215 
216 static void mt7601u_complete_tx(struct urb *urb)
217 {
218 	struct mt7601u_tx_queue *q = urb->context;
219 	struct mt7601u_dev *dev = q->dev;
220 	struct sk_buff *skb;
221 	unsigned long flags;
222 
223 	spin_lock_irqsave(&dev->tx_lock, flags);
224 
225 	if (mt7601u_urb_has_error(urb))
226 		dev_err(dev->dev, "Error: TX urb failed:%d\n", urb->status);
227 	if (WARN_ONCE(q->e[q->start].urb != urb, "TX urb mismatch"))
228 		goto out;
229 
230 	skb = q->e[q->start].skb;
231 	trace_mt_tx_dma_done(dev, skb);
232 
233 	__skb_queue_tail(&dev->tx_skb_done, skb);
234 	tasklet_schedule(&dev->tx_tasklet);
235 
236 	if (q->used == q->entries - q->entries / 8)
237 		ieee80211_wake_queue(dev->hw, skb_get_queue_mapping(skb));
238 
239 	q->start = (q->start + 1) % q->entries;
240 	q->used--;
241 out:
242 	spin_unlock_irqrestore(&dev->tx_lock, flags);
243 }
244 
245 static void mt7601u_tx_tasklet(unsigned long data)
246 {
247 	struct mt7601u_dev *dev = (struct mt7601u_dev *) data;
248 	struct sk_buff_head skbs;
249 	unsigned long flags;
250 
251 	__skb_queue_head_init(&skbs);
252 
253 	spin_lock_irqsave(&dev->tx_lock, flags);
254 
255 	set_bit(MT7601U_STATE_MORE_STATS, &dev->state);
256 	if (!test_and_set_bit(MT7601U_STATE_READING_STATS, &dev->state))
257 		queue_delayed_work(dev->stat_wq, &dev->stat_work,
258 				   msecs_to_jiffies(10));
259 
260 	skb_queue_splice_init(&dev->tx_skb_done, &skbs);
261 
262 	spin_unlock_irqrestore(&dev->tx_lock, flags);
263 
264 	while (!skb_queue_empty(&skbs)) {
265 		struct sk_buff *skb = __skb_dequeue(&skbs);
266 
267 		mt7601u_tx_status(dev, skb);
268 	}
269 }
270 
271 static int mt7601u_dma_submit_tx(struct mt7601u_dev *dev,
272 				 struct sk_buff *skb, u8 ep)
273 {
274 	struct usb_device *usb_dev = mt7601u_to_usb_dev(dev);
275 	unsigned snd_pipe = usb_sndbulkpipe(usb_dev, dev->out_eps[ep]);
276 	struct mt7601u_dma_buf_tx *e;
277 	struct mt7601u_tx_queue *q = &dev->tx_q[ep];
278 	unsigned long flags;
279 	int ret;
280 
281 	spin_lock_irqsave(&dev->tx_lock, flags);
282 
283 	if (WARN_ON(q->entries <= q->used)) {
284 		ret = -ENOSPC;
285 		goto out;
286 	}
287 
288 	e = &q->e[q->end];
289 	e->skb = skb;
290 	usb_fill_bulk_urb(e->urb, usb_dev, snd_pipe, skb->data, skb->len,
291 			  mt7601u_complete_tx, q);
292 	ret = usb_submit_urb(e->urb, GFP_ATOMIC);
293 	if (ret) {
294 		/* Special-handle ENODEV from TX urb submission because it will
295 		 * often be the first ENODEV we see after device is removed.
296 		 */
297 		if (ret == -ENODEV)
298 			set_bit(MT7601U_STATE_REMOVED, &dev->state);
299 		else
300 			dev_err(dev->dev, "Error: TX urb submit failed:%d\n",
301 				ret);
302 		goto out;
303 	}
304 
305 	q->end = (q->end + 1) % q->entries;
306 	q->used++;
307 
308 	if (q->used >= q->entries)
309 		ieee80211_stop_queue(dev->hw, skb_get_queue_mapping(skb));
310 out:
311 	spin_unlock_irqrestore(&dev->tx_lock, flags);
312 
313 	return ret;
314 }
315 
316 /* Map hardware Q to USB endpoint number */
317 static u8 q2ep(u8 qid)
318 {
319 	/* TODO: take management packets to queue 5 */
320 	return qid + 1;
321 }
322 
323 /* Map USB endpoint number to Q id in the DMA engine */
324 static enum mt76_qsel ep2dmaq(u8 ep)
325 {
326 	if (ep == 5)
327 		return MT_QSEL_MGMT;
328 	return MT_QSEL_EDCA;
329 }
330 
331 int mt7601u_dma_enqueue_tx(struct mt7601u_dev *dev, struct sk_buff *skb,
332 			   struct mt76_wcid *wcid, int hw_q)
333 {
334 	u8 ep = q2ep(hw_q);
335 	u32 dma_flags;
336 	int ret;
337 
338 	dma_flags = MT_TXD_PKT_INFO_80211;
339 	if (wcid->hw_key_idx == 0xff)
340 		dma_flags |= MT_TXD_PKT_INFO_WIV;
341 
342 	ret = mt7601u_dma_skb_wrap_pkt(skb, ep2dmaq(ep), dma_flags);
343 	if (ret)
344 		return ret;
345 
346 	ret = mt7601u_dma_submit_tx(dev, skb, ep);
347 	if (ret) {
348 		ieee80211_free_txskb(dev->hw, skb);
349 		return ret;
350 	}
351 
352 	return 0;
353 }
354 
355 static void mt7601u_kill_rx(struct mt7601u_dev *dev)
356 {
357 	int i;
358 	unsigned long flags;
359 
360 	spin_lock_irqsave(&dev->rx_lock, flags);
361 
362 	for (i = 0; i < dev->rx_q.entries; i++) {
363 		int next = dev->rx_q.end;
364 
365 		spin_unlock_irqrestore(&dev->rx_lock, flags);
366 		usb_poison_urb(dev->rx_q.e[next].urb);
367 		spin_lock_irqsave(&dev->rx_lock, flags);
368 	}
369 
370 	spin_unlock_irqrestore(&dev->rx_lock, flags);
371 }
372 
373 static int mt7601u_submit_rx_buf(struct mt7601u_dev *dev,
374 				 struct mt7601u_dma_buf_rx *e, gfp_t gfp)
375 {
376 	struct usb_device *usb_dev = mt7601u_to_usb_dev(dev);
377 	u8 *buf = page_address(e->p);
378 	unsigned pipe;
379 	int ret;
380 
381 	pipe = usb_rcvbulkpipe(usb_dev, dev->in_eps[MT_EP_IN_PKT_RX]);
382 
383 	usb_fill_bulk_urb(e->urb, usb_dev, pipe, buf, MT_RX_URB_SIZE,
384 			  mt7601u_complete_rx, dev);
385 
386 	trace_mt_submit_urb(dev, e->urb);
387 	ret = usb_submit_urb(e->urb, gfp);
388 	if (ret)
389 		dev_err(dev->dev, "Error: submit RX URB failed:%d\n", ret);
390 
391 	return ret;
392 }
393 
394 static int mt7601u_submit_rx(struct mt7601u_dev *dev)
395 {
396 	int i, ret;
397 
398 	for (i = 0; i < dev->rx_q.entries; i++) {
399 		ret = mt7601u_submit_rx_buf(dev, &dev->rx_q.e[i], GFP_KERNEL);
400 		if (ret)
401 			return ret;
402 	}
403 
404 	return 0;
405 }
406 
407 static void mt7601u_free_rx(struct mt7601u_dev *dev)
408 {
409 	int i;
410 
411 	for (i = 0; i < dev->rx_q.entries; i++) {
412 		__free_pages(dev->rx_q.e[i].p, MT_RX_ORDER);
413 		usb_free_urb(dev->rx_q.e[i].urb);
414 	}
415 }
416 
417 static int mt7601u_alloc_rx(struct mt7601u_dev *dev)
418 {
419 	int i;
420 
421 	memset(&dev->rx_q, 0, sizeof(dev->rx_q));
422 	dev->rx_q.dev = dev;
423 	dev->rx_q.entries = N_RX_ENTRIES;
424 
425 	for (i = 0; i < N_RX_ENTRIES; i++) {
426 		dev->rx_q.e[i].urb = usb_alloc_urb(0, GFP_KERNEL);
427 		dev->rx_q.e[i].p = dev_alloc_pages(MT_RX_ORDER);
428 
429 		if (!dev->rx_q.e[i].urb || !dev->rx_q.e[i].p)
430 			return -ENOMEM;
431 	}
432 
433 	return 0;
434 }
435 
436 static void mt7601u_free_tx_queue(struct mt7601u_tx_queue *q)
437 {
438 	int i;
439 
440 	WARN_ON(q->used);
441 
442 	for (i = 0; i < q->entries; i++)  {
443 		usb_poison_urb(q->e[i].urb);
444 		usb_free_urb(q->e[i].urb);
445 	}
446 }
447 
448 static void mt7601u_free_tx(struct mt7601u_dev *dev)
449 {
450 	int i;
451 
452 	if (!dev->tx_q)
453 		return;
454 
455 	for (i = 0; i < __MT_EP_OUT_MAX; i++)
456 		mt7601u_free_tx_queue(&dev->tx_q[i]);
457 }
458 
459 static int mt7601u_alloc_tx_queue(struct mt7601u_dev *dev,
460 				  struct mt7601u_tx_queue *q)
461 {
462 	int i;
463 
464 	q->dev = dev;
465 	q->entries = N_TX_ENTRIES;
466 
467 	for (i = 0; i < N_TX_ENTRIES; i++) {
468 		q->e[i].urb = usb_alloc_urb(0, GFP_KERNEL);
469 		if (!q->e[i].urb)
470 			return -ENOMEM;
471 	}
472 
473 	return 0;
474 }
475 
476 static int mt7601u_alloc_tx(struct mt7601u_dev *dev)
477 {
478 	int i;
479 
480 	dev->tx_q = devm_kcalloc(dev->dev, __MT_EP_OUT_MAX,
481 				 sizeof(*dev->tx_q), GFP_KERNEL);
482 	if (!dev->tx_q)
483 		return -ENOMEM;
484 
485 	for (i = 0; i < __MT_EP_OUT_MAX; i++)
486 		if (mt7601u_alloc_tx_queue(dev, &dev->tx_q[i]))
487 			return -ENOMEM;
488 
489 	return 0;
490 }
491 
492 int mt7601u_dma_init(struct mt7601u_dev *dev)
493 {
494 	int ret = -ENOMEM;
495 
496 	tasklet_init(&dev->tx_tasklet, mt7601u_tx_tasklet, (unsigned long) dev);
497 	tasklet_init(&dev->rx_tasklet, mt7601u_rx_tasklet, (unsigned long) dev);
498 
499 	ret = mt7601u_alloc_tx(dev);
500 	if (ret)
501 		goto err;
502 	ret = mt7601u_alloc_rx(dev);
503 	if (ret)
504 		goto err;
505 
506 	ret = mt7601u_submit_rx(dev);
507 	if (ret)
508 		goto err;
509 
510 	return 0;
511 err:
512 	mt7601u_dma_cleanup(dev);
513 	return ret;
514 }
515 
516 void mt7601u_dma_cleanup(struct mt7601u_dev *dev)
517 {
518 	mt7601u_kill_rx(dev);
519 
520 	tasklet_kill(&dev->rx_tasklet);
521 
522 	mt7601u_free_rx(dev);
523 	mt7601u_free_tx(dev);
524 
525 	tasklet_kill(&dev->tx_tasklet);
526 }
527