xref: /openbmc/linux/drivers/net/wireless/ath/wil6210/rx_reorder.c (revision b240b419db5d624ce7a5a397d6f62a1a686009ec)
1 /*
2  * Copyright (c) 2014-2017 Qualcomm Atheros, Inc.
3  * Copyright (c) 2018, The Linux Foundation. All rights reserved.
4  *
5  * Permission to use, copy, modify, and/or distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #include "wil6210.h"
19 #include "txrx.h"
20 
21 #define SEQ_MODULO 0x1000
22 #define SEQ_MASK   0xfff
23 
24 static inline int seq_less(u16 sq1, u16 sq2)
25 {
26 	return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
27 }
28 
29 static inline u16 seq_inc(u16 sq)
30 {
31 	return (sq + 1) & SEQ_MASK;
32 }
33 
34 static inline u16 seq_sub(u16 sq1, u16 sq2)
35 {
36 	return (sq1 - sq2) & SEQ_MASK;
37 }
38 
39 static inline int reorder_index(struct wil_tid_ampdu_rx *r, u16 seq)
40 {
41 	return seq_sub(seq, r->ssn) % r->buf_size;
42 }
43 
44 static void wil_release_reorder_frame(struct net_device *ndev,
45 				      struct wil_tid_ampdu_rx *r,
46 				      int index)
47 {
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 net_device *ndev,
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(ndev, r, index);
77 	}
78 	r->head_seq_num = hseq;
79 }
80 
81 static void wil_reorder_release(struct net_device *ndev,
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(ndev, 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 wil6210_vif *vif;
97 	struct net_device *ndev;
98 	struct vring_rx_desc *d = wil_skb_rxdesc(skb);
99 	int tid = wil_rxdesc_tid(d);
100 	int cid = wil_rxdesc_cid(d);
101 	int mid = wil_rxdesc_mid(d);
102 	u16 seq = wil_rxdesc_seq(d);
103 	int mcast = wil_rxdesc_mcast(d);
104 	struct wil_sta_info *sta = &wil->sta[cid];
105 	struct wil_tid_ampdu_rx *r;
106 	u16 hseq;
107 	int index;
108 
109 	wil_dbg_txrx(wil, "MID %d CID %d TID %d Seq 0x%03x mcast %01x\n",
110 		     mid, cid, tid, seq, mcast);
111 
112 	vif = wil->vifs[mid];
113 	if (unlikely(!vif)) {
114 		wil_dbg_txrx(wil, "invalid VIF, mid %d\n", mid);
115 		dev_kfree_skb(skb);
116 		return;
117 	}
118 	ndev = vif_to_ndev(vif);
119 
120 	if (unlikely(mcast)) {
121 		wil_netif_rx_any(skb, ndev);
122 		return;
123 	}
124 
125 	spin_lock(&sta->tid_rx_lock);
126 
127 	r = sta->tid_rx[tid];
128 	if (!r) {
129 		wil_netif_rx_any(skb, ndev);
130 		goto out;
131 	}
132 
133 	r->total++;
134 	hseq = r->head_seq_num;
135 
136 	/** Due to the race between WMI events, where BACK establishment
137 	 * reported, and data Rx, few packets may be pass up before reorder
138 	 * buffer get allocated. Catch up by pretending SSN is what we
139 	 * see in the 1-st Rx packet
140 	 *
141 	 * Another scenario, Rx get delayed and we got packet from before
142 	 * BACK. Pass it to the stack and wait.
143 	 */
144 	if (r->first_time) {
145 		r->first_time = false;
146 		if (seq != r->head_seq_num) {
147 			if (seq_less(seq, r->head_seq_num)) {
148 				wil_err(wil,
149 					"Error: frame with early sequence 0x%03x, should be 0x%03x. Waiting...\n",
150 					seq, r->head_seq_num);
151 				r->first_time = true;
152 				wil_netif_rx_any(skb, ndev);
153 				goto out;
154 			}
155 			wil_err(wil,
156 				"Error: 1-st frame with wrong sequence 0x%03x, should be 0x%03x. Fixing...\n",
157 				seq, r->head_seq_num);
158 			r->head_seq_num = seq;
159 			r->ssn = seq;
160 		}
161 	}
162 
163 	/* frame with out of date sequence number */
164 	if (seq_less(seq, r->head_seq_num)) {
165 		r->ssn_last_drop = seq;
166 		r->drop_old++;
167 		wil_dbg_txrx(wil, "Rx drop: old seq 0x%03x head 0x%03x\n",
168 			     seq, r->head_seq_num);
169 		dev_kfree_skb(skb);
170 		goto out;
171 	}
172 
173 	/*
174 	 * If frame the sequence number exceeds our buffering window
175 	 * size release some previous frames to make room for this one.
176 	 */
177 	if (!seq_less(seq, r->head_seq_num + r->buf_size)) {
178 		hseq = seq_inc(seq_sub(seq, r->buf_size));
179 		/* release stored frames up to new head to stack */
180 		wil_release_reorder_frames(ndev, r, hseq);
181 	}
182 
183 	/* Now the new frame is always in the range of the reordering buffer */
184 
185 	index = reorder_index(r, seq);
186 
187 	/* check if we already stored this frame */
188 	if (r->reorder_buf[index]) {
189 		r->drop_dup++;
190 		wil_dbg_txrx(wil, "Rx drop: dup seq 0x%03x\n", seq);
191 		dev_kfree_skb(skb);
192 		goto out;
193 	}
194 
195 	/*
196 	 * If the current MPDU is in the right order and nothing else
197 	 * is stored we can process it directly, no need to buffer it.
198 	 * If it is first but there's something stored, we may be able
199 	 * to release frames after this one.
200 	 */
201 	if (seq == r->head_seq_num && r->stored_mpdu_num == 0) {
202 		r->head_seq_num = seq_inc(r->head_seq_num);
203 		wil_netif_rx_any(skb, ndev);
204 		goto out;
205 	}
206 
207 	/* put the frame in the reordering buffer */
208 	r->reorder_buf[index] = skb;
209 	r->reorder_time[index] = jiffies;
210 	r->stored_mpdu_num++;
211 	wil_reorder_release(ndev, r);
212 
213 out:
214 	spin_unlock(&sta->tid_rx_lock);
215 }
216 
217 /* process BAR frame, called in NAPI context */
218 void wil_rx_bar(struct wil6210_priv *wil, struct wil6210_vif *vif,
219 		u8 cid, u8 tid, u16 seq)
220 {
221 	struct wil_sta_info *sta = &wil->sta[cid];
222 	struct net_device *ndev = vif_to_ndev(vif);
223 	struct wil_tid_ampdu_rx *r;
224 
225 	spin_lock(&sta->tid_rx_lock);
226 
227 	r = sta->tid_rx[tid];
228 	if (!r) {
229 		wil_err(wil, "BAR for non-existing CID %d TID %d\n", cid, tid);
230 		goto out;
231 	}
232 	if (seq_less(seq, r->head_seq_num)) {
233 		wil_err(wil, "BAR Seq 0x%03x preceding head 0x%03x\n",
234 			seq, r->head_seq_num);
235 		goto out;
236 	}
237 	wil_dbg_txrx(wil, "BAR: CID %d MID %d TID %d Seq 0x%03x head 0x%03x\n",
238 		     cid, vif->mid, tid, seq, r->head_seq_num);
239 	wil_release_reorder_frames(ndev, r, seq);
240 
241 out:
242 	spin_unlock(&sta->tid_rx_lock);
243 }
244 
245 struct wil_tid_ampdu_rx *wil_tid_ampdu_rx_alloc(struct wil6210_priv *wil,
246 						int size, u16 ssn)
247 {
248 	struct wil_tid_ampdu_rx *r = kzalloc(sizeof(*r), GFP_KERNEL);
249 
250 	if (!r)
251 		return NULL;
252 
253 	r->reorder_buf =
254 		kcalloc(size, sizeof(struct sk_buff *), GFP_KERNEL);
255 	r->reorder_time =
256 		kcalloc(size, sizeof(unsigned long), GFP_KERNEL);
257 	if (!r->reorder_buf || !r->reorder_time) {
258 		kfree(r->reorder_buf);
259 		kfree(r->reorder_time);
260 		kfree(r);
261 		return NULL;
262 	}
263 
264 	r->ssn = ssn;
265 	r->head_seq_num = ssn;
266 	r->buf_size = size;
267 	r->stored_mpdu_num = 0;
268 	r->first_time = true;
269 	return r;
270 }
271 
272 void wil_tid_ampdu_rx_free(struct wil6210_priv *wil,
273 			   struct wil_tid_ampdu_rx *r)
274 {
275 	int i;
276 
277 	if (!r)
278 		return;
279 
280 	/* Do not pass remaining frames to the network stack - it may be
281 	 * not expecting to get any more Rx. Rx from here may lead to
282 	 * kernel OOPS since some per-socket accounting info was already
283 	 * released.
284 	 */
285 	for (i = 0; i < r->buf_size; i++)
286 		kfree_skb(r->reorder_buf[i]);
287 
288 	kfree(r->reorder_buf);
289 	kfree(r->reorder_time);
290 	kfree(r);
291 }
292 
293 /* ADDBA processing */
294 static u16 wil_agg_size(struct wil6210_priv *wil, u16 req_agg_wsize)
295 {
296 	u16 max_agg_size = min_t(u16, WIL_MAX_AGG_WSIZE, WIL_MAX_AMPDU_SIZE /
297 				 (mtu_max + WIL_MAX_MPDU_OVERHEAD));
298 
299 	if (!req_agg_wsize)
300 		return max_agg_size;
301 
302 	return min(max_agg_size, req_agg_wsize);
303 }
304 
305 /* Block Ack - Rx side (recipient) */
306 int wil_addba_rx_request(struct wil6210_priv *wil, u8 mid,
307 			 u8 cidxtid, u8 dialog_token, __le16 ba_param_set,
308 			 __le16 ba_timeout, __le16 ba_seq_ctrl)
309 __acquires(&sta->tid_rx_lock) __releases(&sta->tid_rx_lock)
310 {
311 	u16 param_set = le16_to_cpu(ba_param_set);
312 	u16 agg_timeout = le16_to_cpu(ba_timeout);
313 	u16 seq_ctrl = le16_to_cpu(ba_seq_ctrl);
314 	struct wil_sta_info *sta;
315 	u8 cid, tid;
316 	u16 agg_wsize = 0;
317 	/* bit 0: A-MSDU supported
318 	 * bit 1: policy (should be 0 for us)
319 	 * bits 2..5: TID
320 	 * bits 6..15: buffer size
321 	 */
322 	u16 req_agg_wsize = WIL_GET_BITS(param_set, 6, 15);
323 	bool agg_amsdu = !!(param_set & BIT(0));
324 	int ba_policy = param_set & BIT(1);
325 	u16 status = WLAN_STATUS_SUCCESS;
326 	u16 ssn = seq_ctrl >> 4;
327 	struct wil_tid_ampdu_rx *r;
328 	int rc = 0;
329 
330 	might_sleep();
331 	parse_cidxtid(cidxtid, &cid, &tid);
332 
333 	/* sanity checks */
334 	if (cid >= WIL6210_MAX_CID) {
335 		wil_err(wil, "BACK: invalid CID %d\n", cid);
336 		rc = -EINVAL;
337 		goto out;
338 	}
339 
340 	sta = &wil->sta[cid];
341 	if (sta->status != wil_sta_connected) {
342 		wil_err(wil, "BACK: CID %d not connected\n", cid);
343 		rc = -EINVAL;
344 		goto out;
345 	}
346 
347 	wil_dbg_wmi(wil,
348 		    "ADDBA request for CID %d %pM TID %d size %d timeout %d AMSDU%s policy %d token %d SSN 0x%03x\n",
349 		    cid, sta->addr, tid, req_agg_wsize, agg_timeout,
350 		    agg_amsdu ? "+" : "-", !!ba_policy, dialog_token, ssn);
351 
352 	/* apply policies */
353 	if (ba_policy) {
354 		wil_err(wil, "BACK requested unsupported ba_policy == 1\n");
355 		status = WLAN_STATUS_INVALID_QOS_PARAM;
356 	}
357 	if (status == WLAN_STATUS_SUCCESS) {
358 		if (req_agg_wsize == 0) {
359 			wil_dbg_misc(wil, "Suggest BACK wsize %d\n",
360 				     WIL_MAX_AGG_WSIZE);
361 			agg_wsize = WIL_MAX_AGG_WSIZE;
362 		} else {
363 			agg_wsize = min_t(u16,
364 					  WIL_MAX_AGG_WSIZE, req_agg_wsize);
365 		}
366 	}
367 
368 	rc = wmi_addba_rx_resp(wil, mid, cid, tid, dialog_token, status,
369 			       agg_amsdu, agg_wsize, agg_timeout);
370 	if (rc || (status != WLAN_STATUS_SUCCESS)) {
371 		wil_err(wil, "do not apply ba, rc(%d), status(%d)\n", rc,
372 			status);
373 		goto out;
374 	}
375 
376 	/* apply */
377 	r = wil_tid_ampdu_rx_alloc(wil, agg_wsize, ssn);
378 	spin_lock_bh(&sta->tid_rx_lock);
379 	wil_tid_ampdu_rx_free(wil, sta->tid_rx[tid]);
380 	sta->tid_rx[tid] = r;
381 	spin_unlock_bh(&sta->tid_rx_lock);
382 
383 out:
384 	return rc;
385 }
386 
387 /* BACK - Tx side (originator) */
388 int wil_addba_tx_request(struct wil6210_priv *wil, u8 ringid, u16 wsize)
389 {
390 	u8 agg_wsize = wil_agg_size(wil, wsize);
391 	u16 agg_timeout = 0;
392 	struct vring_tx_data *txdata = &wil->vring_tx_data[ringid];
393 	int rc = 0;
394 
395 	if (txdata->addba_in_progress) {
396 		wil_dbg_misc(wil, "ADDBA for vring[%d] already in progress\n",
397 			     ringid);
398 		goto out;
399 	}
400 	if (txdata->agg_wsize) {
401 		wil_dbg_misc(wil,
402 			     "ADDBA for vring[%d] already done for wsize %d\n",
403 			     ringid, txdata->agg_wsize);
404 		goto out;
405 	}
406 	txdata->addba_in_progress = true;
407 	rc = wmi_addba(wil, txdata->mid, ringid, agg_wsize, agg_timeout);
408 	if (rc) {
409 		wil_err(wil, "wmi_addba failed, rc (%d)", rc);
410 		txdata->addba_in_progress = false;
411 	}
412 
413 out:
414 	return rc;
415 }
416