xref: /openbmc/linux/drivers/net/wireless/mediatek/mt7601u/dma.c (revision bbde9fc1824aab58bc78c084163007dd6c03fe5b)
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 	ieee80211_rx_ni(dev->hw, skb);
116 }
117 
118 static u16 mt7601u_rx_next_seg_len(u8 *data, u32 data_len)
119 {
120 	u32 min_seg_len = MT_DMA_HDR_LEN + MT_RX_INFO_LEN +
121 		sizeof(struct mt7601u_rxwi) + MT_FCE_INFO_LEN;
122 	u16 dma_len = get_unaligned_le16(data);
123 
124 	if (data_len < min_seg_len ||
125 	    WARN_ON(!dma_len) ||
126 	    WARN_ON(dma_len + MT_DMA_HDRS > data_len) ||
127 	    WARN_ON(dma_len & 0x3))
128 		return 0;
129 
130 	return MT_DMA_HDRS + dma_len;
131 }
132 
133 static void
134 mt7601u_rx_process_entry(struct mt7601u_dev *dev, struct mt7601u_dma_buf_rx *e)
135 {
136 	u32 seg_len, data_len = e->urb->actual_length;
137 	u8 *data = page_address(e->p);
138 	struct page *new_p = NULL;
139 	int cnt = 0;
140 
141 	if (!test_bit(MT7601U_STATE_INITIALIZED, &dev->state))
142 		return;
143 
144 	/* Copy if there is very little data in the buffer. */
145 	if (data_len > 512)
146 		new_p = dev_alloc_pages(MT_RX_ORDER);
147 
148 	while ((seg_len = mt7601u_rx_next_seg_len(data, data_len))) {
149 		mt7601u_rx_process_seg(dev, data, seg_len, new_p ? e->p : NULL);
150 
151 		data_len -= seg_len;
152 		data += seg_len;
153 		cnt++;
154 	}
155 
156 	if (cnt > 1)
157 		trace_mt_rx_dma_aggr(dev, cnt, !!new_p);
158 
159 	if (new_p) {
160 		/* we have one extra ref from the allocator */
161 		__free_pages(e->p, MT_RX_ORDER);
162 
163 		e->p = new_p;
164 	}
165 }
166 
167 static struct mt7601u_dma_buf_rx *
168 mt7601u_rx_get_pending_entry(struct mt7601u_dev *dev)
169 {
170 	struct mt7601u_rx_queue *q = &dev->rx_q;
171 	struct mt7601u_dma_buf_rx *buf = NULL;
172 	unsigned long flags;
173 
174 	spin_lock_irqsave(&dev->rx_lock, flags);
175 
176 	if (!q->pending)
177 		goto out;
178 
179 	buf = &q->e[q->start];
180 	q->pending--;
181 	q->start = (q->start + 1) % q->entries;
182 out:
183 	spin_unlock_irqrestore(&dev->rx_lock, flags);
184 
185 	return buf;
186 }
187 
188 static void mt7601u_complete_rx(struct urb *urb)
189 {
190 	struct mt7601u_dev *dev = urb->context;
191 	struct mt7601u_rx_queue *q = &dev->rx_q;
192 	unsigned long flags;
193 
194 	spin_lock_irqsave(&dev->rx_lock, flags);
195 
196 	if (mt7601u_urb_has_error(urb))
197 		dev_err(dev->dev, "Error: RX urb failed:%d\n", urb->status);
198 	if (WARN_ONCE(q->e[q->end].urb != urb, "RX urb mismatch"))
199 		goto out;
200 
201 	q->end = (q->end + 1) % q->entries;
202 	q->pending++;
203 	tasklet_schedule(&dev->rx_tasklet);
204 out:
205 	spin_unlock_irqrestore(&dev->rx_lock, flags);
206 }
207 
208 static void mt7601u_rx_tasklet(unsigned long data)
209 {
210 	struct mt7601u_dev *dev = (struct mt7601u_dev *) data;
211 	struct mt7601u_dma_buf_rx *e;
212 
213 	while ((e = mt7601u_rx_get_pending_entry(dev))) {
214 		if (e->urb->status)
215 			continue;
216 
217 		mt7601u_rx_process_entry(dev, e);
218 		mt7601u_submit_rx_buf(dev, e, GFP_ATOMIC);
219 	}
220 }
221 
222 static void mt7601u_complete_tx(struct urb *urb)
223 {
224 	struct mt7601u_tx_queue *q = urb->context;
225 	struct mt7601u_dev *dev = q->dev;
226 	struct sk_buff *skb;
227 	unsigned long flags;
228 
229 	spin_lock_irqsave(&dev->tx_lock, flags);
230 
231 	if (mt7601u_urb_has_error(urb))
232 		dev_err(dev->dev, "Error: TX urb failed:%d\n", urb->status);
233 	if (WARN_ONCE(q->e[q->start].urb != urb, "TX urb mismatch"))
234 		goto out;
235 
236 	skb = q->e[q->start].skb;
237 	trace_mt_tx_dma_done(dev, skb);
238 
239 	mt7601u_tx_status(dev, skb);
240 
241 	if (q->used == q->entries - q->entries / 8)
242 		ieee80211_wake_queue(dev->hw, skb_get_queue_mapping(skb));
243 
244 	q->start = (q->start + 1) % q->entries;
245 	q->used--;
246 
247 	if (urb->status)
248 		goto out;
249 
250 	set_bit(MT7601U_STATE_MORE_STATS, &dev->state);
251 	if (!test_and_set_bit(MT7601U_STATE_READING_STATS, &dev->state))
252 		queue_delayed_work(dev->stat_wq, &dev->stat_work,
253 				   msecs_to_jiffies(10));
254 out:
255 	spin_unlock_irqrestore(&dev->tx_lock, flags);
256 }
257 
258 static int mt7601u_dma_submit_tx(struct mt7601u_dev *dev,
259 				 struct sk_buff *skb, u8 ep)
260 {
261 	struct usb_device *usb_dev = mt7601u_to_usb_dev(dev);
262 	unsigned snd_pipe = usb_sndbulkpipe(usb_dev, dev->out_eps[ep]);
263 	struct mt7601u_dma_buf_tx *e;
264 	struct mt7601u_tx_queue *q = &dev->tx_q[ep];
265 	unsigned long flags;
266 	int ret;
267 
268 	spin_lock_irqsave(&dev->tx_lock, flags);
269 
270 	if (WARN_ON(q->entries <= q->used)) {
271 		ret = -ENOSPC;
272 		goto out;
273 	}
274 
275 	e = &q->e[q->end];
276 	e->skb = skb;
277 	usb_fill_bulk_urb(e->urb, usb_dev, snd_pipe, skb->data, skb->len,
278 			  mt7601u_complete_tx, q);
279 	ret = usb_submit_urb(e->urb, GFP_ATOMIC);
280 	if (ret) {
281 		/* Special-handle ENODEV from TX urb submission because it will
282 		 * often be the first ENODEV we see after device is removed.
283 		 */
284 		if (ret == -ENODEV)
285 			set_bit(MT7601U_STATE_REMOVED, &dev->state);
286 		else
287 			dev_err(dev->dev, "Error: TX urb submit failed:%d\n",
288 				ret);
289 		goto out;
290 	}
291 
292 	q->end = (q->end + 1) % q->entries;
293 	q->used++;
294 
295 	if (q->used >= q->entries)
296 		ieee80211_stop_queue(dev->hw, skb_get_queue_mapping(skb));
297 out:
298 	spin_unlock_irqrestore(&dev->tx_lock, flags);
299 
300 	return ret;
301 }
302 
303 /* Map hardware Q to USB endpoint number */
304 static u8 q2ep(u8 qid)
305 {
306 	/* TODO: take management packets to queue 5 */
307 	return qid + 1;
308 }
309 
310 /* Map USB endpoint number to Q id in the DMA engine */
311 static enum mt76_qsel ep2dmaq(u8 ep)
312 {
313 	if (ep == 5)
314 		return MT_QSEL_MGMT;
315 	return MT_QSEL_EDCA;
316 }
317 
318 int mt7601u_dma_enqueue_tx(struct mt7601u_dev *dev, struct sk_buff *skb,
319 			   struct mt76_wcid *wcid, int hw_q)
320 {
321 	u8 ep = q2ep(hw_q);
322 	u32 dma_flags;
323 	int ret;
324 
325 	dma_flags = MT_TXD_PKT_INFO_80211;
326 	if (wcid->hw_key_idx == 0xff)
327 		dma_flags |= MT_TXD_PKT_INFO_WIV;
328 
329 	ret = mt7601u_dma_skb_wrap_pkt(skb, ep2dmaq(ep), dma_flags);
330 	if (ret)
331 		return ret;
332 
333 	ret = mt7601u_dma_submit_tx(dev, skb, ep);
334 	if (ret) {
335 		ieee80211_free_txskb(dev->hw, skb);
336 		return ret;
337 	}
338 
339 	return 0;
340 }
341 
342 static void mt7601u_kill_rx(struct mt7601u_dev *dev)
343 {
344 	int i;
345 	unsigned long flags;
346 
347 	spin_lock_irqsave(&dev->rx_lock, flags);
348 
349 	for (i = 0; i < dev->rx_q.entries; i++) {
350 		int next = dev->rx_q.end;
351 
352 		spin_unlock_irqrestore(&dev->rx_lock, flags);
353 		usb_poison_urb(dev->rx_q.e[next].urb);
354 		spin_lock_irqsave(&dev->rx_lock, flags);
355 	}
356 
357 	spin_unlock_irqrestore(&dev->rx_lock, flags);
358 }
359 
360 static int mt7601u_submit_rx_buf(struct mt7601u_dev *dev,
361 				 struct mt7601u_dma_buf_rx *e, gfp_t gfp)
362 {
363 	struct usb_device *usb_dev = mt7601u_to_usb_dev(dev);
364 	u8 *buf = page_address(e->p);
365 	unsigned pipe;
366 	int ret;
367 
368 	pipe = usb_rcvbulkpipe(usb_dev, dev->in_eps[MT_EP_IN_PKT_RX]);
369 
370 	usb_fill_bulk_urb(e->urb, usb_dev, pipe, buf, MT_RX_URB_SIZE,
371 			  mt7601u_complete_rx, dev);
372 
373 	trace_mt_submit_urb(dev, e->urb);
374 	ret = usb_submit_urb(e->urb, gfp);
375 	if (ret)
376 		dev_err(dev->dev, "Error: submit RX URB failed:%d\n", ret);
377 
378 	return ret;
379 }
380 
381 static int mt7601u_submit_rx(struct mt7601u_dev *dev)
382 {
383 	int i, ret;
384 
385 	for (i = 0; i < dev->rx_q.entries; i++) {
386 		ret = mt7601u_submit_rx_buf(dev, &dev->rx_q.e[i], GFP_KERNEL);
387 		if (ret)
388 			return ret;
389 	}
390 
391 	return 0;
392 }
393 
394 static void mt7601u_free_rx(struct mt7601u_dev *dev)
395 {
396 	int i;
397 
398 	for (i = 0; i < dev->rx_q.entries; i++) {
399 		__free_pages(dev->rx_q.e[i].p, MT_RX_ORDER);
400 		usb_free_urb(dev->rx_q.e[i].urb);
401 	}
402 }
403 
404 static int mt7601u_alloc_rx(struct mt7601u_dev *dev)
405 {
406 	int i;
407 
408 	memset(&dev->rx_q, 0, sizeof(dev->rx_q));
409 	dev->rx_q.dev = dev;
410 	dev->rx_q.entries = N_RX_ENTRIES;
411 
412 	for (i = 0; i < N_RX_ENTRIES; i++) {
413 		dev->rx_q.e[i].urb = usb_alloc_urb(0, GFP_KERNEL);
414 		dev->rx_q.e[i].p = dev_alloc_pages(MT_RX_ORDER);
415 
416 		if (!dev->rx_q.e[i].urb || !dev->rx_q.e[i].p)
417 			return -ENOMEM;
418 	}
419 
420 	return 0;
421 }
422 
423 static void mt7601u_free_tx_queue(struct mt7601u_tx_queue *q)
424 {
425 	int i;
426 
427 	WARN_ON(q->used);
428 
429 	for (i = 0; i < q->entries; i++)  {
430 		usb_poison_urb(q->e[i].urb);
431 		usb_free_urb(q->e[i].urb);
432 	}
433 }
434 
435 static void mt7601u_free_tx(struct mt7601u_dev *dev)
436 {
437 	int i;
438 
439 	for (i = 0; i < __MT_EP_OUT_MAX; i++)
440 		mt7601u_free_tx_queue(&dev->tx_q[i]);
441 }
442 
443 static int mt7601u_alloc_tx_queue(struct mt7601u_dev *dev,
444 				  struct mt7601u_tx_queue *q)
445 {
446 	int i;
447 
448 	q->dev = dev;
449 	q->entries = N_TX_ENTRIES;
450 
451 	for (i = 0; i < N_TX_ENTRIES; i++) {
452 		q->e[i].urb = usb_alloc_urb(0, GFP_KERNEL);
453 		if (!q->e[i].urb)
454 			return -ENOMEM;
455 	}
456 
457 	return 0;
458 }
459 
460 static int mt7601u_alloc_tx(struct mt7601u_dev *dev)
461 {
462 	int i;
463 
464 	dev->tx_q = devm_kcalloc(dev->dev, __MT_EP_OUT_MAX,
465 				 sizeof(*dev->tx_q), GFP_KERNEL);
466 
467 	for (i = 0; i < __MT_EP_OUT_MAX; i++)
468 		if (mt7601u_alloc_tx_queue(dev, &dev->tx_q[i]))
469 			return -ENOMEM;
470 
471 	return 0;
472 }
473 
474 int mt7601u_dma_init(struct mt7601u_dev *dev)
475 {
476 	int ret = -ENOMEM;
477 
478 	tasklet_init(&dev->rx_tasklet, mt7601u_rx_tasklet, (unsigned long) dev);
479 
480 	ret = mt7601u_alloc_tx(dev);
481 	if (ret)
482 		goto err;
483 	ret = mt7601u_alloc_rx(dev);
484 	if (ret)
485 		goto err;
486 
487 	ret = mt7601u_submit_rx(dev);
488 	if (ret)
489 		goto err;
490 
491 	return 0;
492 err:
493 	mt7601u_dma_cleanup(dev);
494 	return ret;
495 }
496 
497 void mt7601u_dma_cleanup(struct mt7601u_dev *dev)
498 {
499 	mt7601u_kill_rx(dev);
500 
501 	tasklet_kill(&dev->rx_tasklet);
502 
503 	mt7601u_free_rx(dev);
504 	mt7601u_free_tx(dev);
505 }
506