1 /*
2 * Copyright (C) 2015 Jakub Kicinski <kubakici@wp.pl>
3 * Copyright (C) 2018 Stanislaw Gruszka <stf_xl@wp.pl>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2
7 * as published by the Free Software Foundation
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 */
14
15 #include "mt76x0.h"
16 #include "dma.h"
17 #include "usb.h"
18 #include "trace.h"
19
20 static int mt76x0_submit_rx_buf(struct mt76x0_dev *dev,
21 struct mt76x0_dma_buf_rx *e, gfp_t gfp);
22
ieee80211_get_hdrlen_from_buf(const u8 * data,unsigned len)23 static unsigned int ieee80211_get_hdrlen_from_buf(const u8 *data, unsigned len)
24 {
25 const struct ieee80211_hdr *hdr = (const struct ieee80211_hdr *)data;
26 unsigned int hdrlen;
27
28 if (unlikely(len < 10))
29 return 0;
30 hdrlen = ieee80211_hdrlen(hdr->frame_control);
31 if (unlikely(hdrlen > len))
32 return 0;
33 return hdrlen;
34 }
35
36 static struct sk_buff *
mt76x0_rx_skb_from_seg(struct mt76x0_dev * dev,struct mt76x0_rxwi * rxwi,void * data,u32 seg_len,u32 truesize,struct page * p)37 mt76x0_rx_skb_from_seg(struct mt76x0_dev *dev, struct mt76x0_rxwi *rxwi,
38 void *data, u32 seg_len, u32 truesize, struct page *p)
39 {
40 struct sk_buff *skb;
41 u32 true_len, hdr_len = 0, copy, frag;
42
43 skb = alloc_skb(p ? 128 : seg_len, GFP_ATOMIC);
44 if (!skb)
45 return NULL;
46
47 true_len = mt76x0_mac_process_rx(dev, skb, data, rxwi);
48 if (!true_len || true_len > seg_len)
49 goto bad_frame;
50
51 hdr_len = ieee80211_get_hdrlen_from_buf(data, true_len);
52 if (!hdr_len)
53 goto bad_frame;
54
55 if (rxwi->rxinfo & cpu_to_le32(MT_RXINFO_L2PAD)) {
56 memcpy(skb_put(skb, hdr_len), data, hdr_len);
57
58 data += hdr_len + 2;
59 true_len -= hdr_len;
60 hdr_len = 0;
61 }
62
63 /* If not doing paged RX allocated skb will always have enough space */
64 copy = (true_len <= skb_tailroom(skb)) ? true_len : hdr_len + 8;
65 frag = true_len - copy;
66
67 memcpy(skb_put(skb, copy), data, copy);
68 data += copy;
69
70 if (frag) {
71 skb_add_rx_frag(skb, 0, p, data - page_address(p),
72 frag, truesize);
73 get_page(p);
74 }
75
76 return skb;
77
78 bad_frame:
79 dev_err_ratelimited(dev->mt76.dev, "Error: incorrect frame len:%u hdr:%u\n",
80 true_len, hdr_len);
81 dev_kfree_skb(skb);
82 return NULL;
83 }
84
mt76x0_rx_process_seg(struct mt76x0_dev * dev,u8 * data,u32 seg_len,struct page * p)85 static void mt76x0_rx_process_seg(struct mt76x0_dev *dev, u8 *data,
86 u32 seg_len, struct page *p)
87 {
88 struct sk_buff *skb;
89 struct mt76x0_rxwi *rxwi;
90 u32 fce_info, truesize = seg_len;
91
92 /* DMA_INFO field at the beginning of the segment contains only some of
93 * the information, we need to read the FCE descriptor from the end.
94 */
95 fce_info = get_unaligned_le32(data + seg_len - MT_FCE_INFO_LEN);
96 seg_len -= MT_FCE_INFO_LEN;
97
98 data += MT_DMA_HDR_LEN;
99 seg_len -= MT_DMA_HDR_LEN;
100
101 rxwi = (struct mt76x0_rxwi *) data;
102 data += sizeof(struct mt76x0_rxwi);
103 seg_len -= sizeof(struct mt76x0_rxwi);
104
105 if (unlikely(FIELD_GET(MT_RXD_INFO_TYPE, fce_info)))
106 dev_err_once(dev->mt76.dev, "Error: RX path seen a non-pkt urb\n");
107
108 trace_mt76x0_rx(&dev->mt76, rxwi, fce_info);
109
110 skb = mt76x0_rx_skb_from_seg(dev, rxwi, data, seg_len, truesize, p);
111 if (!skb)
112 return;
113
114 spin_lock(&dev->mac_lock);
115 ieee80211_rx(dev->mt76.hw, skb);
116 spin_unlock(&dev->mac_lock);
117 }
118
mt76x0_rx_next_seg_len(u8 * data,u32 data_len)119 static u16 mt76x0_rx_next_seg_len(u8 *data, u32 data_len)
120 {
121 u32 min_seg_len = MT_DMA_HDR_LEN + MT_RX_INFO_LEN +
122 sizeof(struct mt76x0_rxwi) + MT_FCE_INFO_LEN;
123 u16 dma_len = get_unaligned_le16(data);
124
125 if (data_len < min_seg_len ||
126 WARN_ON(!dma_len) ||
127 WARN_ON(dma_len + MT_DMA_HDRS > data_len) ||
128 WARN_ON(dma_len & 0x3))
129 return 0;
130
131 return MT_DMA_HDRS + dma_len;
132 }
133
134 static void
mt76x0_rx_process_entry(struct mt76x0_dev * dev,struct mt76x0_dma_buf_rx * e)135 mt76x0_rx_process_entry(struct mt76x0_dev *dev, struct mt76x0_dma_buf_rx *e)
136 {
137 u32 seg_len, data_len = e->urb->actual_length;
138 u8 *data = page_address(e->p);
139 struct page *new_p = NULL;
140 int cnt = 0;
141
142 if (!test_bit(MT76_STATE_INITIALIZED, &dev->mt76.state))
143 return;
144
145 /* Copy if there is very little data in the buffer. */
146 if (data_len > 512)
147 new_p = dev_alloc_pages(MT_RX_ORDER);
148
149 while ((seg_len = mt76x0_rx_next_seg_len(data, data_len))) {
150 mt76x0_rx_process_seg(dev, data, seg_len, new_p ? e->p : NULL);
151
152 data_len -= seg_len;
153 data += seg_len;
154 cnt++;
155 }
156
157 if (cnt > 1)
158 trace_mt76x0_rx_dma_aggr(&dev->mt76, cnt, !!new_p);
159
160 if (new_p) {
161 /* we have one extra ref from the allocator */
162 __free_pages(e->p, MT_RX_ORDER);
163
164 e->p = new_p;
165 }
166 }
167
168 static struct mt76x0_dma_buf_rx *
mt76x0_rx_get_pending_entry(struct mt76x0_dev * dev)169 mt76x0_rx_get_pending_entry(struct mt76x0_dev *dev)
170 {
171 struct mt76x0_rx_queue *q = &dev->rx_q;
172 struct mt76x0_dma_buf_rx *buf = NULL;
173 unsigned long flags;
174
175 spin_lock_irqsave(&dev->rx_lock, flags);
176
177 if (!q->pending)
178 goto out;
179
180 buf = &q->e[q->start];
181 q->pending--;
182 q->start = (q->start + 1) % q->entries;
183 out:
184 spin_unlock_irqrestore(&dev->rx_lock, flags);
185
186 return buf;
187 }
188
mt76x0_complete_rx(struct urb * urb)189 static void mt76x0_complete_rx(struct urb *urb)
190 {
191 struct mt76x0_dev *dev = urb->context;
192 struct mt76x0_rx_queue *q = &dev->rx_q;
193 unsigned long flags;
194
195 spin_lock_irqsave(&dev->rx_lock, flags);
196
197 if (mt76x0_urb_has_error(urb))
198 dev_err(dev->mt76.dev, "Error: RX urb failed:%d\n", urb->status);
199 if (WARN_ONCE(q->e[q->end].urb != urb, "RX urb mismatch"))
200 goto out;
201
202 q->end = (q->end + 1) % q->entries;
203 q->pending++;
204 tasklet_schedule(&dev->rx_tasklet);
205 out:
206 spin_unlock_irqrestore(&dev->rx_lock, flags);
207 }
208
mt76x0_rx_tasklet(unsigned long data)209 static void mt76x0_rx_tasklet(unsigned long data)
210 {
211 struct mt76x0_dev *dev = (struct mt76x0_dev *) data;
212 struct mt76x0_dma_buf_rx *e;
213
214 while ((e = mt76x0_rx_get_pending_entry(dev))) {
215 if (e->urb->status)
216 continue;
217
218 mt76x0_rx_process_entry(dev, e);
219 mt76x0_submit_rx_buf(dev, e, GFP_ATOMIC);
220 }
221 }
222
mt76x0_complete_tx(struct urb * urb)223 static void mt76x0_complete_tx(struct urb *urb)
224 {
225 struct mt76x0_tx_queue *q = urb->context;
226 struct mt76x0_dev *dev = q->dev;
227 struct sk_buff *skb;
228 unsigned long flags;
229
230 spin_lock_irqsave(&dev->tx_lock, flags);
231
232 if (mt76x0_urb_has_error(urb))
233 dev_err(dev->mt76.dev, "Error: TX urb failed:%d\n", urb->status);
234 if (WARN_ONCE(q->e[q->start].urb != urb, "TX urb mismatch"))
235 goto out;
236
237 skb = q->e[q->start].skb;
238 trace_mt76x0_tx_dma_done(&dev->mt76, skb);
239
240 __skb_queue_tail(&dev->tx_skb_done, skb);
241 tasklet_schedule(&dev->tx_tasklet);
242
243 if (q->used == q->entries - q->entries / 8)
244 ieee80211_wake_queue(dev->mt76.hw, skb_get_queue_mapping(skb));
245
246 q->start = (q->start + 1) % q->entries;
247 q->used--;
248 out:
249 spin_unlock_irqrestore(&dev->tx_lock, flags);
250 }
251
mt76x0_tx_tasklet(unsigned long data)252 static void mt76x0_tx_tasklet(unsigned long data)
253 {
254 struct mt76x0_dev *dev = (struct mt76x0_dev *) data;
255 struct sk_buff_head skbs;
256 unsigned long flags;
257
258 __skb_queue_head_init(&skbs);
259
260 spin_lock_irqsave(&dev->tx_lock, flags);
261
262 set_bit(MT76_MORE_STATS, &dev->mt76.state);
263 if (!test_and_set_bit(MT76_READING_STATS, &dev->mt76.state))
264 queue_delayed_work(dev->stat_wq, &dev->stat_work,
265 msecs_to_jiffies(10));
266
267 skb_queue_splice_init(&dev->tx_skb_done, &skbs);
268
269 spin_unlock_irqrestore(&dev->tx_lock, flags);
270
271 while (!skb_queue_empty(&skbs)) {
272 struct sk_buff *skb = __skb_dequeue(&skbs);
273
274 mt76x0_tx_status(dev, skb);
275 }
276 }
277
mt76x0_dma_submit_tx(struct mt76x0_dev * dev,struct sk_buff * skb,u8 ep)278 static int mt76x0_dma_submit_tx(struct mt76x0_dev *dev,
279 struct sk_buff *skb, u8 ep)
280 {
281 struct usb_device *usb_dev = mt76x0_to_usb_dev(dev);
282 unsigned snd_pipe = usb_sndbulkpipe(usb_dev, dev->out_ep[ep]);
283 struct mt76x0_dma_buf_tx *e;
284 struct mt76x0_tx_queue *q = &dev->tx_q[ep];
285 unsigned long flags;
286 int ret;
287
288 spin_lock_irqsave(&dev->tx_lock, flags);
289
290 if (WARN_ON_ONCE(q->entries <= q->used)) {
291 ret = -ENOSPC;
292 goto out;
293 }
294
295 e = &q->e[q->end];
296 e->skb = skb;
297 usb_fill_bulk_urb(e->urb, usb_dev, snd_pipe, skb->data, skb->len,
298 mt76x0_complete_tx, q);
299 ret = usb_submit_urb(e->urb, GFP_ATOMIC);
300 if (ret) {
301 /* Special-handle ENODEV from TX urb submission because it will
302 * often be the first ENODEV we see after device is removed.
303 */
304 if (ret == -ENODEV)
305 set_bit(MT76_REMOVED, &dev->mt76.state);
306 else
307 dev_err(dev->mt76.dev, "Error: TX urb submit failed:%d\n",
308 ret);
309 goto out;
310 }
311
312 q->end = (q->end + 1) % q->entries;
313 q->used++;
314
315 if (q->used >= q->entries)
316 ieee80211_stop_queue(dev->mt76.hw, skb_get_queue_mapping(skb));
317 out:
318 spin_unlock_irqrestore(&dev->tx_lock, flags);
319
320 return ret;
321 }
322
323 /* Map USB endpoint number to Q id in the DMA engine */
ep2dmaq(u8 ep)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
mt76x0_dma_enqueue_tx(struct mt76x0_dev * dev,struct sk_buff * skb,struct mt76_wcid * wcid,int hw_q)331 int mt76x0_dma_enqueue_tx(struct mt76x0_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 = mt76x0_dma_skb_wrap_pkt(skb, ep2dmaq(ep), dma_flags);
343 if (ret)
344 return ret;
345
346 ret = mt76x0_dma_submit_tx(dev, skb, ep);
347
348 if (ret) {
349 ieee80211_free_txskb(dev->mt76.hw, skb);
350 return ret;
351 }
352
353 return 0;
354 }
355
mt76x0_kill_rx(struct mt76x0_dev * dev)356 static void mt76x0_kill_rx(struct mt76x0_dev *dev)
357 {
358 int i;
359 unsigned long flags;
360
361 spin_lock_irqsave(&dev->rx_lock, flags);
362
363 for (i = 0; i < dev->rx_q.entries; i++) {
364 int next = dev->rx_q.end;
365
366 spin_unlock_irqrestore(&dev->rx_lock, flags);
367 usb_poison_urb(dev->rx_q.e[next].urb);
368 spin_lock_irqsave(&dev->rx_lock, flags);
369 }
370
371 spin_unlock_irqrestore(&dev->rx_lock, flags);
372 }
373
mt76x0_submit_rx_buf(struct mt76x0_dev * dev,struct mt76x0_dma_buf_rx * e,gfp_t gfp)374 static int mt76x0_submit_rx_buf(struct mt76x0_dev *dev,
375 struct mt76x0_dma_buf_rx *e, gfp_t gfp)
376 {
377 struct usb_device *usb_dev = mt76x0_to_usb_dev(dev);
378 u8 *buf = page_address(e->p);
379 unsigned pipe;
380 int ret;
381
382 pipe = usb_rcvbulkpipe(usb_dev, dev->in_ep[MT_EP_IN_PKT_RX]);
383
384 usb_fill_bulk_urb(e->urb, usb_dev, pipe, buf, MT_RX_URB_SIZE,
385 mt76x0_complete_rx, dev);
386
387 trace_mt76x0_submit_urb(&dev->mt76, e->urb);
388 ret = usb_submit_urb(e->urb, gfp);
389 if (ret)
390 dev_err(dev->mt76.dev, "Error: submit RX URB failed:%d\n", ret);
391
392 return ret;
393 }
394
mt76x0_submit_rx(struct mt76x0_dev * dev)395 static int mt76x0_submit_rx(struct mt76x0_dev *dev)
396 {
397 int i, ret;
398
399 for (i = 0; i < dev->rx_q.entries; i++) {
400 ret = mt76x0_submit_rx_buf(dev, &dev->rx_q.e[i], GFP_KERNEL);
401 if (ret)
402 return ret;
403 }
404
405 return 0;
406 }
407
mt76x0_free_rx(struct mt76x0_dev * dev)408 static void mt76x0_free_rx(struct mt76x0_dev *dev)
409 {
410 int i;
411
412 for (i = 0; i < dev->rx_q.entries; i++) {
413 __free_pages(dev->rx_q.e[i].p, MT_RX_ORDER);
414 usb_free_urb(dev->rx_q.e[i].urb);
415 }
416 }
417
mt76x0_alloc_rx(struct mt76x0_dev * dev)418 static int mt76x0_alloc_rx(struct mt76x0_dev *dev)
419 {
420 int i;
421
422 memset(&dev->rx_q, 0, sizeof(dev->rx_q));
423 dev->rx_q.dev = dev;
424 dev->rx_q.entries = N_RX_ENTRIES;
425
426 for (i = 0; i < N_RX_ENTRIES; i++) {
427 dev->rx_q.e[i].urb = usb_alloc_urb(0, GFP_KERNEL);
428 dev->rx_q.e[i].p = dev_alloc_pages(MT_RX_ORDER);
429
430 if (!dev->rx_q.e[i].urb || !dev->rx_q.e[i].p)
431 return -ENOMEM;
432 }
433
434 return 0;
435 }
436
mt76x0_free_tx_queue(struct mt76x0_tx_queue * q)437 static void mt76x0_free_tx_queue(struct mt76x0_tx_queue *q)
438 {
439 int i;
440
441 WARN_ON(q->used);
442
443 for (i = 0; i < q->entries; i++) {
444 usb_poison_urb(q->e[i].urb);
445 usb_free_urb(q->e[i].urb);
446 }
447 }
448
mt76x0_free_tx(struct mt76x0_dev * dev)449 static void mt76x0_free_tx(struct mt76x0_dev *dev)
450 {
451 int i;
452
453 for (i = 0; i < __MT_EP_OUT_MAX; i++)
454 mt76x0_free_tx_queue(&dev->tx_q[i]);
455 }
456
mt76x0_alloc_tx_queue(struct mt76x0_dev * dev,struct mt76x0_tx_queue * q)457 static int mt76x0_alloc_tx_queue(struct mt76x0_dev *dev,
458 struct mt76x0_tx_queue *q)
459 {
460 int i;
461
462 q->dev = dev;
463 q->entries = N_TX_ENTRIES;
464
465 for (i = 0; i < N_TX_ENTRIES; i++) {
466 q->e[i].urb = usb_alloc_urb(0, GFP_KERNEL);
467 if (!q->e[i].urb)
468 return -ENOMEM;
469 }
470
471 return 0;
472 }
473
mt76x0_alloc_tx(struct mt76x0_dev * dev)474 static int mt76x0_alloc_tx(struct mt76x0_dev *dev)
475 {
476 int i;
477
478 dev->tx_q = devm_kcalloc(dev->mt76.dev, __MT_EP_OUT_MAX,
479 sizeof(*dev->tx_q), GFP_KERNEL);
480
481 for (i = 0; i < __MT_EP_OUT_MAX; i++)
482 if (mt76x0_alloc_tx_queue(dev, &dev->tx_q[i]))
483 return -ENOMEM;
484
485 return 0;
486 }
487
mt76x0_dma_init(struct mt76x0_dev * dev)488 int mt76x0_dma_init(struct mt76x0_dev *dev)
489 {
490 int ret = -ENOMEM;
491
492 tasklet_init(&dev->tx_tasklet, mt76x0_tx_tasklet, (unsigned long) dev);
493 tasklet_init(&dev->rx_tasklet, mt76x0_rx_tasklet, (unsigned long) dev);
494
495 ret = mt76x0_alloc_tx(dev);
496 if (ret)
497 goto err;
498 ret = mt76x0_alloc_rx(dev);
499 if (ret)
500 goto err;
501
502 ret = mt76x0_submit_rx(dev);
503 if (ret)
504 goto err;
505
506 return 0;
507 err:
508 mt76x0_dma_cleanup(dev);
509 return ret;
510 }
511
mt76x0_dma_cleanup(struct mt76x0_dev * dev)512 void mt76x0_dma_cleanup(struct mt76x0_dev *dev)
513 {
514 mt76x0_kill_rx(dev);
515
516 tasklet_kill(&dev->rx_tasklet);
517
518 mt76x0_free_rx(dev);
519 mt76x0_free_tx(dev);
520
521 tasklet_kill(&dev->tx_tasklet);
522 }
523
