1 /*
2  * Copyright (C) 2015 Jakub Kicinski <kubakici@wp.pl>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2
6  * as published by the Free Software Foundation
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11  * GNU General Public License for more details.
12  */
13 
14 #include "mt7601u.h"
15 #include "dma.h"
16 #include "usb.h"
17 #include "trace.h"
18 
19 static int mt7601u_submit_rx_buf(struct mt7601u_dev *dev,
20 				 struct mt7601u_dma_buf_rx *e, gfp_t gfp);
21 
22 static unsigned int ieee80211_get_hdrlen_from_buf(const u8 *data, unsigned len)
23 {
24 	const struct ieee80211_hdr *hdr = (const struct ieee80211_hdr *)data;
25 	unsigned int hdrlen;
26 
27 	if (unlikely(len < 10))
28 		return 0;
29 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
30 	if (unlikely(hdrlen > len))
31 		return 0;
32 	return hdrlen;
33 }
34 
35 static struct sk_buff *
36 mt7601u_rx_skb_from_seg(struct mt7601u_dev *dev, struct mt7601u_rxwi *rxwi,
37 			void *data, u32 seg_len, u32 truesize, struct page *p)
38 {
39 	struct sk_buff *skb;
40 	u32 true_len, hdr_len = 0, copy, frag;
41 
42 	skb = alloc_skb(p ? 128 : seg_len, GFP_ATOMIC);
43 	if (!skb)
44 		return NULL;
45 
46 	true_len = mt76_mac_process_rx(dev, skb, data, rxwi);
47 	if (!true_len || true_len > seg_len)
48 		goto bad_frame;
49 
50 	hdr_len = ieee80211_get_hdrlen_from_buf(data, true_len);
51 	if (!hdr_len)
52 		goto bad_frame;
53 
54 	if (rxwi->rxinfo & cpu_to_le32(MT_RXINFO_L2PAD)) {
55 		memcpy(skb_put(skb, hdr_len), data, hdr_len);
56 
57 		data += hdr_len + 2;
58 		true_len -= hdr_len;
59 		hdr_len = 0;
60 	}
61 
62 	/* If not doing paged RX allocated skb will always have enough space */
63 	copy = (true_len <= skb_tailroom(skb)) ? true_len : hdr_len + 8;
64 	frag = true_len - copy;
65 
66 	memcpy(skb_put(skb, copy), data, copy);
67 	data += copy;
68 
69 	if (frag) {
70 		skb_add_rx_frag(skb, 0, p, data - page_address(p),
71 				frag, truesize);
72 		get_page(p);
73 	}
74 
75 	return skb;
76 
77 bad_frame:
78 	dev_err_ratelimited(dev->dev, "Error: incorrect frame len:%u hdr:%u\n",
79 			    true_len, hdr_len);
80 	dev_kfree_skb(skb);
81 	return NULL;
82 }
83 
84 static void mt7601u_rx_process_seg(struct mt7601u_dev *dev, u8 *data,
85 				   u32 seg_len, struct page *p)
86 {
87 	struct sk_buff *skb;
88 	struct mt7601u_rxwi *rxwi;
89 	u32 fce_info, truesize = seg_len;
90 
91 	/* DMA_INFO field at the beginning of the segment contains only some of
92 	 * the information, we need to read the FCE descriptor from the end.
93 	 */
94 	fce_info = get_unaligned_le32(data + seg_len - MT_FCE_INFO_LEN);
95 	seg_len -= MT_FCE_INFO_LEN;
96 
97 	data += MT_DMA_HDR_LEN;
98 	seg_len -= MT_DMA_HDR_LEN;
99 
100 	rxwi = (struct mt7601u_rxwi *) data;
101 	data += sizeof(struct mt7601u_rxwi);
102 	seg_len -= sizeof(struct mt7601u_rxwi);
103 
104 	if (unlikely(rxwi->zero[0] || rxwi->zero[1] || rxwi->zero[2]))
105 		dev_err_once(dev->dev, "Error: RXWI zero fields are set\n");
106 	if (unlikely(MT76_GET(MT_RXD_INFO_TYPE, fce_info)))
107 		dev_err_once(dev->dev, "Error: RX path seen a non-pkt urb\n");
108 
109 	trace_mt_rx(dev, rxwi, fce_info);
110 
111 	skb = mt7601u_rx_skb_from_seg(dev, rxwi, data, seg_len, truesize, p);
112 	if (!skb)
113 		return;
114 
115 	spin_lock(&dev->mac_lock);
116 	ieee80211_rx(dev->hw, skb);
117 	spin_unlock(&dev->mac_lock);
118 }
119 
120 static u16 mt7601u_rx_next_seg_len(u8 *data, u32 data_len)
121 {
122 	u32 min_seg_len = MT_DMA_HDR_LEN + MT_RX_INFO_LEN +
123 		sizeof(struct mt7601u_rxwi) + MT_FCE_INFO_LEN;
124 	u16 dma_len = get_unaligned_le16(data);
125 
126 	if (data_len < min_seg_len ||
127 	    WARN_ON(!dma_len) ||
128 	    WARN_ON(dma_len + MT_DMA_HDRS > data_len) ||
129 	    WARN_ON(dma_len & 0x3))
130 		return 0;
131 
132 	return MT_DMA_HDRS + dma_len;
133 }
134 
135 static void
136 mt7601u_rx_process_entry(struct mt7601u_dev *dev, struct mt7601u_dma_buf_rx *e)
137 {
138 	u32 seg_len, data_len = e->urb->actual_length;
139 	u8 *data = page_address(e->p);
140 	struct page *new_p = NULL;
141 	int cnt = 0;
142 
143 	if (!test_bit(MT7601U_STATE_INITIALIZED, &dev->state))
144 		return;
145 
146 	/* Copy if there is very little data in the buffer. */
147 	if (data_len > 512)
148 		new_p = dev_alloc_pages(MT_RX_ORDER);
149 
150 	while ((seg_len = mt7601u_rx_next_seg_len(data, data_len))) {
151 		mt7601u_rx_process_seg(dev, data, seg_len, new_p ? e->p : NULL);
152 
153 		data_len -= seg_len;
154 		data += seg_len;
155 		cnt++;
156 	}
157 
158 	if (cnt > 1)
159 		trace_mt_rx_dma_aggr(dev, cnt, !!new_p);
160 
161 	if (new_p) {
162 		/* we have one extra ref from the allocator */
163 		__free_pages(e->p, MT_RX_ORDER);
164 
165 		e->p = new_p;
166 	}
167 }
168 
169 static struct mt7601u_dma_buf_rx *
170 mt7601u_rx_get_pending_entry(struct mt7601u_dev *dev)
171 {
172 	struct mt7601u_rx_queue *q = &dev->rx_q;
173 	struct mt7601u_dma_buf_rx *buf = NULL;
174 	unsigned long flags;
175 
176 	spin_lock_irqsave(&dev->rx_lock, flags);
177 
178 	if (!q->pending)
179 		goto out;
180 
181 	buf = &q->e[q->start];
182 	q->pending--;
183 	q->start = (q->start + 1) % q->entries;
184 out:
185 	spin_unlock_irqrestore(&dev->rx_lock, flags);
186 
187 	return buf;
188 }
189 
190 static void mt7601u_complete_rx(struct urb *urb)
191 {
192 	struct mt7601u_dev *dev = urb->context;
193 	struct mt7601u_rx_queue *q = &dev->rx_q;
194 	unsigned long flags;
195 
196 	spin_lock_irqsave(&dev->rx_lock, flags);
197 
198 	if (mt7601u_urb_has_error(urb))
199 		dev_err(dev->dev, "Error: RX urb failed:%d\n", urb->status);
200 	if (WARN_ONCE(q->e[q->end].urb != urb, "RX urb mismatch"))
201 		goto out;
202 
203 	q->end = (q->end + 1) % q->entries;
204 	q->pending++;
205 	tasklet_schedule(&dev->rx_tasklet);
206 out:
207 	spin_unlock_irqrestore(&dev->rx_lock, flags);
208 }
209 
210 static void mt7601u_rx_tasklet(unsigned long data)
211 {
212 	struct mt7601u_dev *dev = (struct mt7601u_dev *) data;
213 	struct mt7601u_dma_buf_rx *e;
214 
215 	while ((e = mt7601u_rx_get_pending_entry(dev))) {
216 		if (e->urb->status)
217 			continue;
218 
219 		mt7601u_rx_process_entry(dev, e);
220 		mt7601u_submit_rx_buf(dev, e, GFP_ATOMIC);
221 	}
222 }
223 
224 static void mt7601u_complete_tx(struct urb *urb)
225 {
226 	struct mt7601u_tx_queue *q = urb->context;
227 	struct mt7601u_dev *dev = q->dev;
228 	struct sk_buff *skb;
229 	unsigned long flags;
230 
231 	spin_lock_irqsave(&dev->tx_lock, flags);
232 
233 	if (mt7601u_urb_has_error(urb))
234 		dev_err(dev->dev, "Error: TX urb failed:%d\n", urb->status);
235 	if (WARN_ONCE(q->e[q->start].urb != urb, "TX urb mismatch"))
236 		goto out;
237 
238 	skb = q->e[q->start].skb;
239 	trace_mt_tx_dma_done(dev, skb);
240 
241 	__skb_queue_tail(&dev->tx_skb_done, skb);
242 	tasklet_schedule(&dev->tx_tasklet);
243 
244 	if (q->used == q->entries - q->entries / 8)
245 		ieee80211_wake_queue(dev->hw, skb_get_queue_mapping(skb));
246 
247 	q->start = (q->start + 1) % q->entries;
248 	q->used--;
249 out:
250 	spin_unlock_irqrestore(&dev->tx_lock, flags);
251 }
252 
253 static void mt7601u_tx_tasklet(unsigned long data)
254 {
255 	struct mt7601u_dev *dev = (struct mt7601u_dev *) data;
256 	struct sk_buff_head skbs;
257 	unsigned long flags;
258 
259 	__skb_queue_head_init(&skbs);
260 
261 	spin_lock_irqsave(&dev->tx_lock, flags);
262 
263 	set_bit(MT7601U_STATE_MORE_STATS, &dev->state);
264 	if (!test_and_set_bit(MT7601U_STATE_READING_STATS, &dev->state))
265 		queue_delayed_work(dev->stat_wq, &dev->stat_work,
266 				   msecs_to_jiffies(10));
267 
268 	skb_queue_splice_init(&dev->tx_skb_done, &skbs);
269 
270 	spin_unlock_irqrestore(&dev->tx_lock, flags);
271 
272 	while (!skb_queue_empty(&skbs)) {
273 		struct sk_buff *skb = __skb_dequeue(&skbs);
274 
275 		mt7601u_tx_status(dev, skb);
276 	}
277 }
278 
279 static int mt7601u_dma_submit_tx(struct mt7601u_dev *dev,
280 				 struct sk_buff *skb, u8 ep)
281 {
282 	struct usb_device *usb_dev = mt7601u_to_usb_dev(dev);
283 	unsigned snd_pipe = usb_sndbulkpipe(usb_dev, dev->out_eps[ep]);
284 	struct mt7601u_dma_buf_tx *e;
285 	struct mt7601u_tx_queue *q = &dev->tx_q[ep];
286 	unsigned long flags;
287 	int ret;
288 
289 	spin_lock_irqsave(&dev->tx_lock, flags);
290 
291 	if (WARN_ON(q->entries <= q->used)) {
292 		ret = -ENOSPC;
293 		goto out;
294 	}
295 
296 	e = &q->e[q->end];
297 	e->skb = skb;
298 	usb_fill_bulk_urb(e->urb, usb_dev, snd_pipe, skb->data, skb->len,
299 			  mt7601u_complete_tx, q);
300 	ret = usb_submit_urb(e->urb, GFP_ATOMIC);
301 	if (ret) {
302 		/* Special-handle ENODEV from TX urb submission because it will
303 		 * often be the first ENODEV we see after device is removed.
304 		 */
305 		if (ret == -ENODEV)
306 			set_bit(MT7601U_STATE_REMOVED, &dev->state);
307 		else
308 			dev_err(dev->dev, "Error: TX urb submit failed:%d\n",
309 				ret);
310 		goto out;
311 	}
312 
313 	q->end = (q->end + 1) % q->entries;
314 	q->used++;
315 
316 	if (q->used >= q->entries)
317 		ieee80211_stop_queue(dev->hw, skb_get_queue_mapping(skb));
318 out:
319 	spin_unlock_irqrestore(&dev->tx_lock, flags);
320 
321 	return ret;
322 }
323 
324 /* Map hardware Q to USB endpoint number */
325 static u8 q2ep(u8 qid)
326 {
327 	/* TODO: take management packets to queue 5 */
328 	return qid + 1;
329 }
330 
331 /* Map USB endpoint number to Q id in the DMA engine */
332 static enum mt76_qsel ep2dmaq(u8 ep)
333 {
334 	if (ep == 5)
335 		return MT_QSEL_MGMT;
336 	return MT_QSEL_EDCA;
337 }
338 
339 int mt7601u_dma_enqueue_tx(struct mt7601u_dev *dev, struct sk_buff *skb,
340 			   struct mt76_wcid *wcid, int hw_q)
341 {
342 	u8 ep = q2ep(hw_q);
343 	u32 dma_flags;
344 	int ret;
345 
346 	dma_flags = MT_TXD_PKT_INFO_80211;
347 	if (wcid->hw_key_idx == 0xff)
348 		dma_flags |= MT_TXD_PKT_INFO_WIV;
349 
350 	ret = mt7601u_dma_skb_wrap_pkt(skb, ep2dmaq(ep), dma_flags);
351 	if (ret)
352 		return ret;
353 
354 	ret = mt7601u_dma_submit_tx(dev, skb, ep);
355 	if (ret) {
356 		ieee80211_free_txskb(dev->hw, skb);
357 		return ret;
358 	}
359 
360 	return 0;
361 }
362 
363 static void mt7601u_kill_rx(struct mt7601u_dev *dev)
364 {
365 	int i;
366 	unsigned long flags;
367 
368 	spin_lock_irqsave(&dev->rx_lock, flags);
369 
370 	for (i = 0; i < dev->rx_q.entries; i++) {
371 		int next = dev->rx_q.end;
372 
373 		spin_unlock_irqrestore(&dev->rx_lock, flags);
374 		usb_poison_urb(dev->rx_q.e[next].urb);
375 		spin_lock_irqsave(&dev->rx_lock, flags);
376 	}
377 
378 	spin_unlock_irqrestore(&dev->rx_lock, flags);
379 }
380 
381 static int mt7601u_submit_rx_buf(struct mt7601u_dev *dev,
382 				 struct mt7601u_dma_buf_rx *e, gfp_t gfp)
383 {
384 	struct usb_device *usb_dev = mt7601u_to_usb_dev(dev);
385 	u8 *buf = page_address(e->p);
386 	unsigned pipe;
387 	int ret;
388 
389 	pipe = usb_rcvbulkpipe(usb_dev, dev->in_eps[MT_EP_IN_PKT_RX]);
390 
391 	usb_fill_bulk_urb(e->urb, usb_dev, pipe, buf, MT_RX_URB_SIZE,
392 			  mt7601u_complete_rx, dev);
393 
394 	trace_mt_submit_urb(dev, e->urb);
395 	ret = usb_submit_urb(e->urb, gfp);
396 	if (ret)
397 		dev_err(dev->dev, "Error: submit RX URB failed:%d\n", ret);
398 
399 	return ret;
400 }
401 
402 static int mt7601u_submit_rx(struct mt7601u_dev *dev)
403 {
404 	int i, ret;
405 
406 	for (i = 0; i < dev->rx_q.entries; i++) {
407 		ret = mt7601u_submit_rx_buf(dev, &dev->rx_q.e[i], GFP_KERNEL);
408 		if (ret)
409 			return ret;
410 	}
411 
412 	return 0;
413 }
414 
415 static void mt7601u_free_rx(struct mt7601u_dev *dev)
416 {
417 	int i;
418 
419 	for (i = 0; i < dev->rx_q.entries; i++) {
420 		__free_pages(dev->rx_q.e[i].p, MT_RX_ORDER);
421 		usb_free_urb(dev->rx_q.e[i].urb);
422 	}
423 }
424 
425 static int mt7601u_alloc_rx(struct mt7601u_dev *dev)
426 {
427 	int i;
428 
429 	memset(&dev->rx_q, 0, sizeof(dev->rx_q));
430 	dev->rx_q.dev = dev;
431 	dev->rx_q.entries = N_RX_ENTRIES;
432 
433 	for (i = 0; i < N_RX_ENTRIES; i++) {
434 		dev->rx_q.e[i].urb = usb_alloc_urb(0, GFP_KERNEL);
435 		dev->rx_q.e[i].p = dev_alloc_pages(MT_RX_ORDER);
436 
437 		if (!dev->rx_q.e[i].urb || !dev->rx_q.e[i].p)
438 			return -ENOMEM;
439 	}
440 
441 	return 0;
442 }
443 
444 static void mt7601u_free_tx_queue(struct mt7601u_tx_queue *q)
445 {
446 	int i;
447 
448 	WARN_ON(q->used);
449 
450 	for (i = 0; i < q->entries; i++)  {
451 		usb_poison_urb(q->e[i].urb);
452 		usb_free_urb(q->e[i].urb);
453 	}
454 }
455 
456 static void mt7601u_free_tx(struct mt7601u_dev *dev)
457 {
458 	int i;
459 
460 	for (i = 0; i < __MT_EP_OUT_MAX; i++)
461 		mt7601u_free_tx_queue(&dev->tx_q[i]);
462 }
463 
464 static int mt7601u_alloc_tx_queue(struct mt7601u_dev *dev,
465 				  struct mt7601u_tx_queue *q)
466 {
467 	int i;
468 
469 	q->dev = dev;
470 	q->entries = N_TX_ENTRIES;
471 
472 	for (i = 0; i < N_TX_ENTRIES; i++) {
473 		q->e[i].urb = usb_alloc_urb(0, GFP_KERNEL);
474 		if (!q->e[i].urb)
475 			return -ENOMEM;
476 	}
477 
478 	return 0;
479 }
480 
481 static int mt7601u_alloc_tx(struct mt7601u_dev *dev)
482 {
483 	int i;
484 
485 	dev->tx_q = devm_kcalloc(dev->dev, __MT_EP_OUT_MAX,
486 				 sizeof(*dev->tx_q), GFP_KERNEL);
487 
488 	for (i = 0; i < __MT_EP_OUT_MAX; i++)
489 		if (mt7601u_alloc_tx_queue(dev, &dev->tx_q[i]))
490 			return -ENOMEM;
491 
492 	return 0;
493 }
494 
495 int mt7601u_dma_init(struct mt7601u_dev *dev)
496 {
497 	int ret = -ENOMEM;
498 
499 	tasklet_init(&dev->tx_tasklet, mt7601u_tx_tasklet, (unsigned long) dev);
500 	tasklet_init(&dev->rx_tasklet, mt7601u_rx_tasklet, (unsigned long) dev);
501 
502 	ret = mt7601u_alloc_tx(dev);
503 	if (ret)
504 		goto err;
505 	ret = mt7601u_alloc_rx(dev);
506 	if (ret)
507 		goto err;
508 
509 	ret = mt7601u_submit_rx(dev);
510 	if (ret)
511 		goto err;
512 
513 	return 0;
514 err:
515 	mt7601u_dma_cleanup(dev);
516 	return ret;
517 }
518 
519 void mt7601u_dma_cleanup(struct mt7601u_dev *dev)
520 {
521 	mt7601u_kill_rx(dev);
522 
523 	tasklet_kill(&dev->rx_tasklet);
524 
525 	mt7601u_free_rx(dev);
526 	mt7601u_free_tx(dev);
527 
528 	tasklet_kill(&dev->tx_tasklet);
529 }
530