xref: /linux/drivers/net/wireless/ath/wil6210/rx_reorder.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  * Copyright (c) 2014-2015 Qualcomm Atheros, Inc.
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 "wil6210.h"
18 #include "txrx.h"
19 
20 #define SEQ_MODULO 0x1000
21 #define SEQ_MASK   0xfff
22 
23 static inline int seq_less(u16 sq1, u16 sq2)
24 {
25 	return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
26 }
27 
28 static inline u16 seq_inc(u16 sq)
29 {
30 	return (sq + 1) & SEQ_MASK;
31 }
32 
33 static inline u16 seq_sub(u16 sq1, u16 sq2)
34 {
35 	return (sq1 - sq2) & SEQ_MASK;
36 }
37 
38 static inline int reorder_index(struct wil_tid_ampdu_rx *r, u16 seq)
39 {
40 	return seq_sub(seq, r->ssn) % r->buf_size;
41 }
42 
43 static void wil_release_reorder_frame(struct wil6210_priv *wil,
44 				      struct wil_tid_ampdu_rx *r,
45 				      int index)
46 {
47 	struct net_device *ndev = wil_to_ndev(wil);
48 	struct sk_buff *skb = r->reorder_buf[index];
49 
50 	if (!skb)
51 		goto no_frame;
52 
53 	/* release the frame from the reorder ring buffer */
54 	r->stored_mpdu_num--;
55 	r->reorder_buf[index] = NULL;
56 	wil_netif_rx_any(skb, ndev);
57 
58 no_frame:
59 	r->head_seq_num = seq_inc(r->head_seq_num);
60 }
61 
62 static void wil_release_reorder_frames(struct wil6210_priv *wil,
63 				       struct wil_tid_ampdu_rx *r,
64 				       u16 hseq)
65 {
66 	int index;
67 
68 	/* note: this function is never called with
69 	 * hseq preceding r->head_seq_num, i.e it is always true
70 	 * !seq_less(hseq, r->head_seq_num)
71 	 * and thus on loop exit it should be
72 	 * r->head_seq_num == hseq
73 	 */
74 	while (seq_less(r->head_seq_num, hseq) && r->stored_mpdu_num) {
75 		index = reorder_index(r, r->head_seq_num);
76 		wil_release_reorder_frame(wil, r, index);
77 	}
78 	r->head_seq_num = hseq;
79 }
80 
81 static void wil_reorder_release(struct wil6210_priv *wil,
82 				struct wil_tid_ampdu_rx *r)
83 {
84 	int index = reorder_index(r, r->head_seq_num);
85 
86 	while (r->reorder_buf[index]) {
87 		wil_release_reorder_frame(wil, r, index);
88 		index = reorder_index(r, r->head_seq_num);
89 	}
90 }
91 
92 /* called in NAPI context */
93 void wil_rx_reorder(struct wil6210_priv *wil, struct sk_buff *skb)
94 __acquires(&sta->tid_rx_lock) __releases(&sta->tid_rx_lock)
95 {
96 	struct net_device *ndev = wil_to_ndev(wil);
97 	struct vring_rx_desc *d = wil_skb_rxdesc(skb);
98 	int tid = wil_rxdesc_tid(d);
99 	int cid = wil_rxdesc_cid(d);
100 	int mid = wil_rxdesc_mid(d);
101 	u16 seq = wil_rxdesc_seq(d);
102 	int mcast = wil_rxdesc_mcast(d);
103 	struct wil_sta_info *sta = &wil->sta[cid];
104 	struct wil_tid_ampdu_rx *r;
105 	u16 hseq;
106 	int index;
107 
108 	wil_dbg_txrx(wil, "MID %d CID %d TID %d Seq 0x%03x mcast %01x\n",
109 		     mid, cid, tid, seq, mcast);
110 
111 	if (unlikely(mcast)) {
112 		wil_netif_rx_any(skb, ndev);
113 		return;
114 	}
115 
116 	spin_lock(&sta->tid_rx_lock);
117 
118 	r = sta->tid_rx[tid];
119 	if (!r) {
120 		wil_netif_rx_any(skb, ndev);
121 		goto out;
122 	}
123 
124 	r->total++;
125 	hseq = r->head_seq_num;
126 
127 	/** Due to the race between WMI events, where BACK establishment
128 	 * reported, and data Rx, few packets may be pass up before reorder
129 	 * buffer get allocated. Catch up by pretending SSN is what we
130 	 * see in the 1-st Rx packet
131 	 *
132 	 * Another scenario, Rx get delayed and we got packet from before
133 	 * BACK. Pass it to the stack and wait.
134 	 */
135 	if (r->first_time) {
136 		r->first_time = false;
137 		if (seq != r->head_seq_num) {
138 			if (seq_less(seq, r->head_seq_num)) {
139 				wil_err(wil,
140 					"Error: frame with early sequence 0x%03x, should be 0x%03x. Waiting...\n",
141 					seq, r->head_seq_num);
142 				r->first_time = true;
143 				wil_netif_rx_any(skb, ndev);
144 				goto out;
145 			}
146 			wil_err(wil,
147 				"Error: 1-st frame with wrong sequence 0x%03x, should be 0x%03x. Fixing...\n",
148 				seq, r->head_seq_num);
149 			r->head_seq_num = seq;
150 			r->ssn = seq;
151 		}
152 	}
153 
154 	/* frame with out of date sequence number */
155 	if (seq_less(seq, r->head_seq_num)) {
156 		r->ssn_last_drop = seq;
157 		r->drop_old++;
158 		wil_dbg_txrx(wil, "Rx drop: old seq 0x%03x head 0x%03x\n",
159 			     seq, r->head_seq_num);
160 		dev_kfree_skb(skb);
161 		goto out;
162 	}
163 
164 	/*
165 	 * If frame the sequence number exceeds our buffering window
166 	 * size release some previous frames to make room for this one.
167 	 */
168 	if (!seq_less(seq, r->head_seq_num + r->buf_size)) {
169 		hseq = seq_inc(seq_sub(seq, r->buf_size));
170 		/* release stored frames up to new head to stack */
171 		wil_release_reorder_frames(wil, r, hseq);
172 	}
173 
174 	/* Now the new frame is always in the range of the reordering buffer */
175 
176 	index = reorder_index(r, seq);
177 
178 	/* check if we already stored this frame */
179 	if (r->reorder_buf[index]) {
180 		r->drop_dup++;
181 		wil_dbg_txrx(wil, "Rx drop: dup seq 0x%03x\n", seq);
182 		dev_kfree_skb(skb);
183 		goto out;
184 	}
185 
186 	/*
187 	 * If the current MPDU is in the right order and nothing else
188 	 * is stored we can process it directly, no need to buffer it.
189 	 * If it is first but there's something stored, we may be able
190 	 * to release frames after this one.
191 	 */
192 	if (seq == r->head_seq_num && r->stored_mpdu_num == 0) {
193 		r->head_seq_num = seq_inc(r->head_seq_num);
194 		wil_netif_rx_any(skb, ndev);
195 		goto out;
196 	}
197 
198 	/* put the frame in the reordering buffer */
199 	r->reorder_buf[index] = skb;
200 	r->reorder_time[index] = jiffies;
201 	r->stored_mpdu_num++;
202 	wil_reorder_release(wil, r);
203 
204 out:
205 	spin_unlock(&sta->tid_rx_lock);
206 }
207 
208 struct wil_tid_ampdu_rx *wil_tid_ampdu_rx_alloc(struct wil6210_priv *wil,
209 						int size, u16 ssn)
210 {
211 	struct wil_tid_ampdu_rx *r = kzalloc(sizeof(*r), GFP_KERNEL);
212 
213 	if (!r)
214 		return NULL;
215 
216 	r->reorder_buf =
217 		kcalloc(size, sizeof(struct sk_buff *), GFP_KERNEL);
218 	r->reorder_time =
219 		kcalloc(size, sizeof(unsigned long), GFP_KERNEL);
220 	if (!r->reorder_buf || !r->reorder_time) {
221 		kfree(r->reorder_buf);
222 		kfree(r->reorder_time);
223 		kfree(r);
224 		return NULL;
225 	}
226 
227 	r->ssn = ssn;
228 	r->head_seq_num = ssn;
229 	r->buf_size = size;
230 	r->stored_mpdu_num = 0;
231 	r->first_time = true;
232 	return r;
233 }
234 
235 void wil_tid_ampdu_rx_free(struct wil6210_priv *wil,
236 			   struct wil_tid_ampdu_rx *r)
237 {
238 	if (!r)
239 		return;
240 	wil_release_reorder_frames(wil, r, r->head_seq_num + r->buf_size);
241 	kfree(r->reorder_buf);
242 	kfree(r->reorder_time);
243 	kfree(r);
244 }
245 
246 /* ADDBA processing */
247 static u16 wil_agg_size(struct wil6210_priv *wil, u16 req_agg_wsize)
248 {
249 	u16 max_agg_size = min_t(u16, WIL_MAX_AGG_WSIZE, WIL_MAX_AMPDU_SIZE /
250 				 (mtu_max + WIL_MAX_MPDU_OVERHEAD));
251 
252 	if (!req_agg_wsize)
253 		return max_agg_size;
254 
255 	return min(max_agg_size, req_agg_wsize);
256 }
257 
258 /* Block Ack - Rx side (recipient */
259 int wil_addba_rx_request(struct wil6210_priv *wil, u8 cidxtid,
260 			 u8 dialog_token, __le16 ba_param_set,
261 			 __le16 ba_timeout, __le16 ba_seq_ctrl)
262 {
263 	struct wil_back_rx *req = kzalloc(sizeof(*req), GFP_KERNEL);
264 
265 	if (!req)
266 		return -ENOMEM;
267 
268 	req->cidxtid = cidxtid;
269 	req->dialog_token = dialog_token;
270 	req->ba_param_set = le16_to_cpu(ba_param_set);
271 	req->ba_timeout = le16_to_cpu(ba_timeout);
272 	req->ba_seq_ctrl = le16_to_cpu(ba_seq_ctrl);
273 
274 	mutex_lock(&wil->back_rx_mutex);
275 	list_add_tail(&req->list, &wil->back_rx_pending);
276 	mutex_unlock(&wil->back_rx_mutex);
277 
278 	queue_work(wil->wq_service, &wil->back_rx_worker);
279 
280 	return 0;
281 }
282 
283 static void wil_back_rx_handle(struct wil6210_priv *wil,
284 			       struct wil_back_rx *req)
285 __acquires(&sta->tid_rx_lock) __releases(&sta->tid_rx_lock)
286 {
287 	struct wil_sta_info *sta;
288 	u8 cid, tid;
289 	u16 agg_wsize = 0;
290 	/* bit 0: A-MSDU supported
291 	 * bit 1: policy (should be 0 for us)
292 	 * bits 2..5: TID
293 	 * bits 6..15: buffer size
294 	 */
295 	u16 req_agg_wsize = WIL_GET_BITS(req->ba_param_set, 6, 15);
296 	bool agg_amsdu = !!(req->ba_param_set & BIT(0));
297 	int ba_policy = req->ba_param_set & BIT(1);
298 	u16 agg_timeout = req->ba_timeout;
299 	u16 status = WLAN_STATUS_SUCCESS;
300 	u16 ssn = req->ba_seq_ctrl >> 4;
301 	struct wil_tid_ampdu_rx *r;
302 	int rc;
303 
304 	might_sleep();
305 	parse_cidxtid(req->cidxtid, &cid, &tid);
306 
307 	/* sanity checks */
308 	if (cid >= WIL6210_MAX_CID) {
309 		wil_err(wil, "BACK: invalid CID %d\n", cid);
310 		return;
311 	}
312 
313 	sta = &wil->sta[cid];
314 	if (sta->status != wil_sta_connected) {
315 		wil_err(wil, "BACK: CID %d not connected\n", cid);
316 		return;
317 	}
318 
319 	wil_dbg_wmi(wil,
320 		    "ADDBA request for CID %d %pM TID %d size %d timeout %d AMSDU%s policy %d token %d SSN 0x%03x\n",
321 		    cid, sta->addr, tid, req_agg_wsize, req->ba_timeout,
322 		    agg_amsdu ? "+" : "-", !!ba_policy, req->dialog_token, ssn);
323 
324 	/* apply policies */
325 	if (ba_policy) {
326 		wil_err(wil, "BACK requested unsupported ba_policy == 1\n");
327 		status = WLAN_STATUS_INVALID_QOS_PARAM;
328 	}
329 	if (status == WLAN_STATUS_SUCCESS)
330 		agg_wsize = wil_agg_size(wil, req_agg_wsize);
331 
332 	rc = wmi_addba_rx_resp(wil, cid, tid, req->dialog_token, status,
333 			       agg_amsdu, agg_wsize, agg_timeout);
334 	if (rc || (status != WLAN_STATUS_SUCCESS))
335 		return;
336 
337 	/* apply */
338 	r = wil_tid_ampdu_rx_alloc(wil, agg_wsize, ssn);
339 	spin_lock_bh(&sta->tid_rx_lock);
340 	wil_tid_ampdu_rx_free(wil, sta->tid_rx[tid]);
341 	sta->tid_rx[tid] = r;
342 	spin_unlock_bh(&sta->tid_rx_lock);
343 }
344 
345 void wil_back_rx_flush(struct wil6210_priv *wil)
346 {
347 	struct wil_back_rx *evt, *t;
348 
349 	wil_dbg_misc(wil, "%s()\n", __func__);
350 
351 	mutex_lock(&wil->back_rx_mutex);
352 
353 	list_for_each_entry_safe(evt, t, &wil->back_rx_pending, list) {
354 		list_del(&evt->list);
355 		kfree(evt);
356 	}
357 
358 	mutex_unlock(&wil->back_rx_mutex);
359 }
360 
361 /* Retrieve next ADDBA request from the pending list */
362 static struct list_head *next_back_rx(struct wil6210_priv *wil)
363 {
364 	struct list_head *ret = NULL;
365 
366 	mutex_lock(&wil->back_rx_mutex);
367 
368 	if (!list_empty(&wil->back_rx_pending)) {
369 		ret = wil->back_rx_pending.next;
370 		list_del(ret);
371 	}
372 
373 	mutex_unlock(&wil->back_rx_mutex);
374 
375 	return ret;
376 }
377 
378 void wil_back_rx_worker(struct work_struct *work)
379 {
380 	struct wil6210_priv *wil = container_of(work, struct wil6210_priv,
381 						back_rx_worker);
382 	struct wil_back_rx *evt;
383 	struct list_head *lh;
384 
385 	while ((lh = next_back_rx(wil)) != NULL) {
386 		evt = list_entry(lh, struct wil_back_rx, list);
387 
388 		wil_back_rx_handle(wil, evt);
389 		kfree(evt);
390 	}
391 }
392 
393 /* BACK - Tx (originator) side */
394 static void wil_back_tx_handle(struct wil6210_priv *wil,
395 			       struct wil_back_tx *req)
396 {
397 	struct vring_tx_data *txdata = &wil->vring_tx_data[req->ringid];
398 	int rc;
399 
400 	if (txdata->addba_in_progress) {
401 		wil_dbg_misc(wil, "ADDBA for vring[%d] already in progress\n",
402 			     req->ringid);
403 		return;
404 	}
405 	if (txdata->agg_wsize) {
406 		wil_dbg_misc(wil,
407 			     "ADDBA for vring[%d] already established wsize %d\n",
408 			     req->ringid, txdata->agg_wsize);
409 		return;
410 	}
411 	txdata->addba_in_progress = true;
412 	rc = wmi_addba(wil, req->ringid, req->agg_wsize, req->agg_timeout);
413 	if (rc)
414 		txdata->addba_in_progress = false;
415 }
416 
417 static struct list_head *next_back_tx(struct wil6210_priv *wil)
418 {
419 	struct list_head *ret = NULL;
420 
421 	mutex_lock(&wil->back_tx_mutex);
422 
423 	if (!list_empty(&wil->back_tx_pending)) {
424 		ret = wil->back_tx_pending.next;
425 		list_del(ret);
426 	}
427 
428 	mutex_unlock(&wil->back_tx_mutex);
429 
430 	return ret;
431 }
432 
433 void wil_back_tx_worker(struct work_struct *work)
434 {
435 	struct wil6210_priv *wil = container_of(work, struct wil6210_priv,
436 						 back_tx_worker);
437 	struct wil_back_tx *evt;
438 	struct list_head *lh;
439 
440 	while ((lh = next_back_tx(wil)) != NULL) {
441 		evt = list_entry(lh, struct wil_back_tx, list);
442 
443 		wil_back_tx_handle(wil, evt);
444 		kfree(evt);
445 	}
446 }
447 
448 void wil_back_tx_flush(struct wil6210_priv *wil)
449 {
450 	struct wil_back_tx *evt, *t;
451 
452 	wil_dbg_misc(wil, "%s()\n", __func__);
453 
454 	mutex_lock(&wil->back_tx_mutex);
455 
456 	list_for_each_entry_safe(evt, t, &wil->back_tx_pending, list) {
457 		list_del(&evt->list);
458 		kfree(evt);
459 	}
460 
461 	mutex_unlock(&wil->back_tx_mutex);
462 }
463 
464 int wil_addba_tx_request(struct wil6210_priv *wil, u8 ringid, u16 wsize)
465 {
466 	struct wil_back_tx *req = kzalloc(sizeof(*req), GFP_KERNEL);
467 
468 	if (!req)
469 		return -ENOMEM;
470 
471 	req->ringid = ringid;
472 	req->agg_wsize = wil_agg_size(wil, wsize);
473 	req->agg_timeout = 0;
474 
475 	mutex_lock(&wil->back_tx_mutex);
476 	list_add_tail(&req->list, &wil->back_tx_pending);
477 	mutex_unlock(&wil->back_tx_mutex);
478 
479 	queue_work(wil->wq_service, &wil->back_tx_worker);
480 
481 	return 0;
482 }
483