1 // SPDX-License-Identifier: ISC
2 /*
3  * Copyright (c) 2014-2017 Qualcomm Atheros, Inc.
4  * Copyright (c) 2018-2019, The Linux Foundation. All rights reserved.
5  */
6 
7 #include "wil6210.h"
8 #include "txrx.h"
9 
10 #define SEQ_MODULO 0x1000
11 #define SEQ_MASK   0xfff
12 
13 static inline int seq_less(u16 sq1, u16 sq2)
14 {
15 	return ((sq1 - sq2) & SEQ_MASK) > (SEQ_MODULO >> 1);
16 }
17 
18 static inline u16 seq_inc(u16 sq)
19 {
20 	return (sq + 1) & SEQ_MASK;
21 }
22 
23 static inline u16 seq_sub(u16 sq1, u16 sq2)
24 {
25 	return (sq1 - sq2) & SEQ_MASK;
26 }
27 
28 static inline int reorder_index(struct wil_tid_ampdu_rx *r, u16 seq)
29 {
30 	return seq_sub(seq, r->ssn) % r->buf_size;
31 }
32 
33 static void wil_release_reorder_frame(struct net_device *ndev,
34 				      struct wil_tid_ampdu_rx *r,
35 				      int index)
36 {
37 	struct sk_buff *skb = r->reorder_buf[index];
38 
39 	if (!skb)
40 		goto no_frame;
41 
42 	/* release the frame from the reorder ring buffer */
43 	r->stored_mpdu_num--;
44 	r->reorder_buf[index] = NULL;
45 	wil_netif_rx_any(skb, ndev);
46 
47 no_frame:
48 	r->head_seq_num = seq_inc(r->head_seq_num);
49 }
50 
51 static void wil_release_reorder_frames(struct net_device *ndev,
52 				       struct wil_tid_ampdu_rx *r,
53 				       u16 hseq)
54 {
55 	int index;
56 
57 	/* note: this function is never called with
58 	 * hseq preceding r->head_seq_num, i.e it is always true
59 	 * !seq_less(hseq, r->head_seq_num)
60 	 * and thus on loop exit it should be
61 	 * r->head_seq_num == hseq
62 	 */
63 	while (seq_less(r->head_seq_num, hseq) && r->stored_mpdu_num) {
64 		index = reorder_index(r, r->head_seq_num);
65 		wil_release_reorder_frame(ndev, r, index);
66 	}
67 	r->head_seq_num = hseq;
68 }
69 
70 static void wil_reorder_release(struct net_device *ndev,
71 				struct wil_tid_ampdu_rx *r)
72 {
73 	int index = reorder_index(r, r->head_seq_num);
74 
75 	while (r->reorder_buf[index]) {
76 		wil_release_reorder_frame(ndev, r, index);
77 		index = reorder_index(r, r->head_seq_num);
78 	}
79 }
80 
81 /* called in NAPI context */
82 void wil_rx_reorder(struct wil6210_priv *wil, struct sk_buff *skb)
83 __acquires(&sta->tid_rx_lock) __releases(&sta->tid_rx_lock)
84 {
85 	struct wil6210_vif *vif;
86 	struct net_device *ndev;
87 	int tid, cid, mid, mcast, retry;
88 	u16 seq;
89 	struct wil_sta_info *sta;
90 	struct wil_tid_ampdu_rx *r;
91 	u16 hseq;
92 	int index;
93 
94 	wil->txrx_ops.get_reorder_params(wil, skb, &tid, &cid, &mid, &seq,
95 					 &mcast, &retry);
96 	sta = &wil->sta[cid];
97 
98 	wil_dbg_txrx(wil, "MID %d CID %d TID %d Seq 0x%03x mcast %01x\n",
99 		     mid, cid, tid, seq, mcast);
100 
101 	vif = wil->vifs[mid];
102 	if (unlikely(!vif)) {
103 		wil_dbg_txrx(wil, "invalid VIF, mid %d\n", mid);
104 		dev_kfree_skb(skb);
105 		return;
106 	}
107 	ndev = vif_to_ndev(vif);
108 
109 	spin_lock(&sta->tid_rx_lock);
110 
111 	r = sta->tid_rx[tid];
112 	if (!r) {
113 		wil_netif_rx_any(skb, ndev);
114 		goto out;
115 	}
116 
117 	if (unlikely(mcast)) {
118 		if (retry && seq == r->mcast_last_seq) {
119 			r->drop_dup_mcast++;
120 			wil_dbg_txrx(wil, "Rx drop: dup mcast seq 0x%03x\n",
121 				     seq);
122 			dev_kfree_skb(skb);
123 			goto out;
124 		}
125 		r->mcast_last_seq = seq;
126 		wil_netif_rx_any(skb, ndev);
127 		goto out;
128 	}
129 
130 	r->total++;
131 	hseq = r->head_seq_num;
132 
133 	/** Due to the race between WMI events, where BACK establishment
134 	 * reported, and data Rx, few packets may be pass up before reorder
135 	 * buffer get allocated. Catch up by pretending SSN is what we
136 	 * see in the 1-st Rx packet
137 	 *
138 	 * Another scenario, Rx get delayed and we got packet from before
139 	 * BACK. Pass it to the stack and wait.
140 	 */
141 	if (r->first_time) {
142 		r->first_time = false;
143 		if (seq != r->head_seq_num) {
144 			if (seq_less(seq, r->head_seq_num)) {
145 				wil_err(wil,
146 					"Error: frame with early sequence 0x%03x, should be 0x%03x. Waiting...\n",
147 					seq, r->head_seq_num);
148 				r->first_time = true;
149 				wil_netif_rx_any(skb, ndev);
150 				goto out;
151 			}
152 			wil_err(wil,
153 				"Error: 1-st frame with wrong sequence 0x%03x, should be 0x%03x. Fixing...\n",
154 				seq, r->head_seq_num);
155 			r->head_seq_num = seq;
156 			r->ssn = seq;
157 		}
158 	}
159 
160 	/* frame with out of date sequence number */
161 	if (seq_less(seq, r->head_seq_num)) {
162 		r->ssn_last_drop = seq;
163 		r->drop_old++;
164 		wil_dbg_txrx(wil, "Rx drop: old seq 0x%03x head 0x%03x\n",
165 			     seq, r->head_seq_num);
166 		dev_kfree_skb(skb);
167 		goto out;
168 	}
169 
170 	/*
171 	 * If frame the sequence number exceeds our buffering window
172 	 * size release some previous frames to make room for this one.
173 	 */
174 	if (!seq_less(seq, r->head_seq_num + r->buf_size)) {
175 		hseq = seq_inc(seq_sub(seq, r->buf_size));
176 		/* release stored frames up to new head to stack */
177 		wil_release_reorder_frames(ndev, r, hseq);
178 	}
179 
180 	/* Now the new frame is always in the range of the reordering buffer */
181 
182 	index = reorder_index(r, seq);
183 
184 	/* check if we already stored this frame */
185 	if (r->reorder_buf[index]) {
186 		r->drop_dup++;
187 		wil_dbg_txrx(wil, "Rx drop: dup seq 0x%03x\n", seq);
188 		dev_kfree_skb(skb);
189 		goto out;
190 	}
191 
192 	/*
193 	 * If the current MPDU is in the right order and nothing else
194 	 * is stored we can process it directly, no need to buffer it.
195 	 * If it is first but there's something stored, we may be able
196 	 * to release frames after this one.
197 	 */
198 	if (seq == r->head_seq_num && r->stored_mpdu_num == 0) {
199 		r->head_seq_num = seq_inc(r->head_seq_num);
200 		wil_netif_rx_any(skb, ndev);
201 		goto out;
202 	}
203 
204 	/* put the frame in the reordering buffer */
205 	r->reorder_buf[index] = skb;
206 	r->stored_mpdu_num++;
207 	wil_reorder_release(ndev, r);
208 
209 out:
210 	spin_unlock(&sta->tid_rx_lock);
211 }
212 
213 /* process BAR frame, called in NAPI context */
214 void wil_rx_bar(struct wil6210_priv *wil, struct wil6210_vif *vif,
215 		u8 cid, u8 tid, u16 seq)
216 {
217 	struct wil_sta_info *sta = &wil->sta[cid];
218 	struct net_device *ndev = vif_to_ndev(vif);
219 	struct wil_tid_ampdu_rx *r;
220 
221 	spin_lock(&sta->tid_rx_lock);
222 
223 	r = sta->tid_rx[tid];
224 	if (!r) {
225 		wil_err(wil, "BAR for non-existing CID %d TID %d\n", cid, tid);
226 		goto out;
227 	}
228 	if (seq_less(seq, r->head_seq_num)) {
229 		wil_err(wil, "BAR Seq 0x%03x preceding head 0x%03x\n",
230 			seq, r->head_seq_num);
231 		goto out;
232 	}
233 	wil_dbg_txrx(wil, "BAR: CID %d MID %d TID %d Seq 0x%03x head 0x%03x\n",
234 		     cid, vif->mid, tid, seq, r->head_seq_num);
235 	wil_release_reorder_frames(ndev, r, seq);
236 
237 out:
238 	spin_unlock(&sta->tid_rx_lock);
239 }
240 
241 struct wil_tid_ampdu_rx *wil_tid_ampdu_rx_alloc(struct wil6210_priv *wil,
242 						int size, u16 ssn)
243 {
244 	struct wil_tid_ampdu_rx *r = kzalloc(sizeof(*r), GFP_KERNEL);
245 
246 	if (!r)
247 		return NULL;
248 
249 	r->reorder_buf =
250 		kcalloc(size, sizeof(struct sk_buff *), GFP_KERNEL);
251 	if (!r->reorder_buf) {
252 		kfree(r);
253 		return NULL;
254 	}
255 
256 	r->ssn = ssn;
257 	r->head_seq_num = ssn;
258 	r->buf_size = size;
259 	r->stored_mpdu_num = 0;
260 	r->first_time = true;
261 	r->mcast_last_seq = U16_MAX;
262 	return r;
263 }
264 
265 void wil_tid_ampdu_rx_free(struct wil6210_priv *wil,
266 			   struct wil_tid_ampdu_rx *r)
267 {
268 	int i;
269 
270 	if (!r)
271 		return;
272 
273 	/* Do not pass remaining frames to the network stack - it may be
274 	 * not expecting to get any more Rx. Rx from here may lead to
275 	 * kernel OOPS since some per-socket accounting info was already
276 	 * released.
277 	 */
278 	for (i = 0; i < r->buf_size; i++)
279 		kfree_skb(r->reorder_buf[i]);
280 
281 	kfree(r->reorder_buf);
282 	kfree(r);
283 }
284 
285 /* ADDBA processing */
286 static u16 wil_agg_size(struct wil6210_priv *wil, u16 req_agg_wsize)
287 {
288 	u16 max_agg_size = min_t(u16, wil->max_agg_wsize, wil->max_ampdu_size /
289 				 (mtu_max + WIL_MAX_MPDU_OVERHEAD));
290 
291 	if (!req_agg_wsize)
292 		return max_agg_size;
293 
294 	return min(max_agg_size, req_agg_wsize);
295 }
296 
297 /* Block Ack - Rx side (recipient) */
298 int wil_addba_rx_request(struct wil6210_priv *wil, u8 mid, u8 cid, u8 tid,
299 			 u8 dialog_token, __le16 ba_param_set,
300 			 __le16 ba_timeout, __le16 ba_seq_ctrl)
301 __acquires(&sta->tid_rx_lock) __releases(&sta->tid_rx_lock)
302 {
303 	u16 param_set = le16_to_cpu(ba_param_set);
304 	u16 agg_timeout = le16_to_cpu(ba_timeout);
305 	u16 seq_ctrl = le16_to_cpu(ba_seq_ctrl);
306 	struct wil_sta_info *sta;
307 	u16 agg_wsize;
308 	/* bit 0: A-MSDU supported
309 	 * bit 1: policy (should be 0 for us)
310 	 * bits 2..5: TID
311 	 * bits 6..15: buffer size
312 	 */
313 	u16 req_agg_wsize = WIL_GET_BITS(param_set, 6, 15);
314 	bool agg_amsdu = wil->use_enhanced_dma_hw &&
315 		wil->use_rx_hw_reordering &&
316 		test_bit(WMI_FW_CAPABILITY_AMSDU, wil->fw_capabilities) &&
317 		wil->amsdu_en && (param_set & BIT(0));
318 	int ba_policy = param_set & BIT(1);
319 	u16 ssn = seq_ctrl >> 4;
320 	struct wil_tid_ampdu_rx *r;
321 	int rc = 0;
322 
323 	might_sleep();
324 
325 	/* sanity checks */
326 	if (cid >= wil->max_assoc_sta) {
327 		wil_err(wil, "BACK: invalid CID %d\n", cid);
328 		rc = -EINVAL;
329 		goto out;
330 	}
331 
332 	sta = &wil->sta[cid];
333 	if (sta->status != wil_sta_connected) {
334 		wil_err(wil, "BACK: CID %d not connected\n", cid);
335 		rc = -EINVAL;
336 		goto out;
337 	}
338 
339 	wil_dbg_wmi(wil,
340 		    "ADDBA request for CID %d %pM TID %d size %d timeout %d AMSDU%s policy %d token %d SSN 0x%03x\n",
341 		    cid, sta->addr, tid, req_agg_wsize, agg_timeout,
342 		    agg_amsdu ? "+" : "-", !!ba_policy, dialog_token, ssn);
343 
344 	/* apply policies */
345 	if (req_agg_wsize == 0) {
346 		wil_dbg_misc(wil, "Suggest BACK wsize %d\n",
347 			     wil->max_agg_wsize);
348 		agg_wsize = wil->max_agg_wsize;
349 	} else {
350 		agg_wsize = min_t(u16, wil->max_agg_wsize, req_agg_wsize);
351 	}
352 
353 	rc = wil->txrx_ops.wmi_addba_rx_resp(wil, mid, cid, tid, dialog_token,
354 					     WLAN_STATUS_SUCCESS, agg_amsdu,
355 					     agg_wsize, agg_timeout);
356 	if (rc) {
357 		wil_err(wil, "do not apply ba, rc(%d)\n", rc);
358 		goto out;
359 	}
360 
361 	/* apply */
362 	if (!wil->use_rx_hw_reordering) {
363 		r = wil_tid_ampdu_rx_alloc(wil, agg_wsize, ssn);
364 		spin_lock_bh(&sta->tid_rx_lock);
365 		wil_tid_ampdu_rx_free(wil, sta->tid_rx[tid]);
366 		sta->tid_rx[tid] = r;
367 		spin_unlock_bh(&sta->tid_rx_lock);
368 	}
369 
370 out:
371 	return rc;
372 }
373 
374 /* BACK - Tx side (originator) */
375 int wil_addba_tx_request(struct wil6210_priv *wil, u8 ringid, u16 wsize)
376 {
377 	u8 agg_wsize = wil_agg_size(wil, wsize);
378 	u16 agg_timeout = 0;
379 	struct wil_ring_tx_data *txdata = &wil->ring_tx_data[ringid];
380 	int rc = 0;
381 
382 	if (txdata->addba_in_progress) {
383 		wil_dbg_misc(wil, "ADDBA for vring[%d] already in progress\n",
384 			     ringid);
385 		goto out;
386 	}
387 	if (txdata->agg_wsize) {
388 		wil_dbg_misc(wil,
389 			     "ADDBA for vring[%d] already done for wsize %d\n",
390 			     ringid, txdata->agg_wsize);
391 		goto out;
392 	}
393 	txdata->addba_in_progress = true;
394 	rc = wmi_addba(wil, txdata->mid, ringid, agg_wsize, agg_timeout);
395 	if (rc) {
396 		wil_err(wil, "wmi_addba failed, rc (%d)", rc);
397 		txdata->addba_in_progress = false;
398 	}
399 
400 out:
401 	return rc;
402 }
403