1 /*
2  * Copyright (c) 2014-2017 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 /* process BAR frame, called in NAPI context */
209 void wil_rx_bar(struct wil6210_priv *wil, u8 cid, u8 tid, u16 seq)
210 {
211 	struct wil_sta_info *sta = &wil->sta[cid];
212 	struct wil_tid_ampdu_rx *r;
213 
214 	spin_lock(&sta->tid_rx_lock);
215 
216 	r = sta->tid_rx[tid];
217 	if (!r) {
218 		wil_err(wil, "BAR for non-existing CID %d TID %d\n", cid, tid);
219 		goto out;
220 	}
221 	if (seq_less(seq, r->head_seq_num)) {
222 		wil_err(wil, "BAR Seq 0x%03x preceding head 0x%03x\n",
223 			seq, r->head_seq_num);
224 		goto out;
225 	}
226 	wil_dbg_txrx(wil, "BAR: CID %d TID %d Seq 0x%03x head 0x%03x\n",
227 		     cid, tid, seq, r->head_seq_num);
228 	wil_release_reorder_frames(wil, r, seq);
229 
230 out:
231 	spin_unlock(&sta->tid_rx_lock);
232 }
233 
234 struct wil_tid_ampdu_rx *wil_tid_ampdu_rx_alloc(struct wil6210_priv *wil,
235 						int size, u16 ssn)
236 {
237 	struct wil_tid_ampdu_rx *r = kzalloc(sizeof(*r), GFP_KERNEL);
238 
239 	if (!r)
240 		return NULL;
241 
242 	r->reorder_buf =
243 		kcalloc(size, sizeof(struct sk_buff *), GFP_KERNEL);
244 	r->reorder_time =
245 		kcalloc(size, sizeof(unsigned long), GFP_KERNEL);
246 	if (!r->reorder_buf || !r->reorder_time) {
247 		kfree(r->reorder_buf);
248 		kfree(r->reorder_time);
249 		kfree(r);
250 		return NULL;
251 	}
252 
253 	r->ssn = ssn;
254 	r->head_seq_num = ssn;
255 	r->buf_size = size;
256 	r->stored_mpdu_num = 0;
257 	r->first_time = true;
258 	return r;
259 }
260 
261 void wil_tid_ampdu_rx_free(struct wil6210_priv *wil,
262 			   struct wil_tid_ampdu_rx *r)
263 {
264 	int i;
265 
266 	if (!r)
267 		return;
268 
269 	/* Do not pass remaining frames to the network stack - it may be
270 	 * not expecting to get any more Rx. Rx from here may lead to
271 	 * kernel OOPS since some per-socket accounting info was already
272 	 * released.
273 	 */
274 	for (i = 0; i < r->buf_size; i++)
275 		kfree_skb(r->reorder_buf[i]);
276 
277 	kfree(r->reorder_buf);
278 	kfree(r->reorder_time);
279 	kfree(r);
280 }
281 
282 /* ADDBA processing */
283 static u16 wil_agg_size(struct wil6210_priv *wil, u16 req_agg_wsize)
284 {
285 	u16 max_agg_size = min_t(u16, WIL_MAX_AGG_WSIZE, WIL_MAX_AMPDU_SIZE /
286 				 (mtu_max + WIL_MAX_MPDU_OVERHEAD));
287 
288 	if (!req_agg_wsize)
289 		return max_agg_size;
290 
291 	return min(max_agg_size, req_agg_wsize);
292 }
293 
294 /* Block Ack - Rx side (recipient) */
295 int wil_addba_rx_request(struct wil6210_priv *wil, u8 cidxtid,
296 			 u8 dialog_token, __le16 ba_param_set,
297 			 __le16 ba_timeout, __le16 ba_seq_ctrl)
298 __acquires(&sta->tid_rx_lock) __releases(&sta->tid_rx_lock)
299 {
300 	u16 param_set = le16_to_cpu(ba_param_set);
301 	u16 agg_timeout = le16_to_cpu(ba_timeout);
302 	u16 seq_ctrl = le16_to_cpu(ba_seq_ctrl);
303 	struct wil_sta_info *sta;
304 	u8 cid, tid;
305 	u16 agg_wsize = 0;
306 	/* bit 0: A-MSDU supported
307 	 * bit 1: policy (should be 0 for us)
308 	 * bits 2..5: TID
309 	 * bits 6..15: buffer size
310 	 */
311 	u16 req_agg_wsize = WIL_GET_BITS(param_set, 6, 15);
312 	bool agg_amsdu = !!(param_set & BIT(0));
313 	int ba_policy = param_set & BIT(1);
314 	u16 status = WLAN_STATUS_SUCCESS;
315 	u16 ssn = seq_ctrl >> 4;
316 	struct wil_tid_ampdu_rx *r;
317 	int rc = 0;
318 
319 	might_sleep();
320 	parse_cidxtid(cidxtid, &cid, &tid);
321 
322 	/* sanity checks */
323 	if (cid >= WIL6210_MAX_CID) {
324 		wil_err(wil, "BACK: invalid CID %d\n", cid);
325 		rc = -EINVAL;
326 		goto out;
327 	}
328 
329 	sta = &wil->sta[cid];
330 	if (sta->status != wil_sta_connected) {
331 		wil_err(wil, "BACK: CID %d not connected\n", cid);
332 		rc = -EINVAL;
333 		goto out;
334 	}
335 
336 	wil_dbg_wmi(wil,
337 		    "ADDBA request for CID %d %pM TID %d size %d timeout %d AMSDU%s policy %d token %d SSN 0x%03x\n",
338 		    cid, sta->addr, tid, req_agg_wsize, agg_timeout,
339 		    agg_amsdu ? "+" : "-", !!ba_policy, dialog_token, ssn);
340 
341 	/* apply policies */
342 	if (ba_policy) {
343 		wil_err(wil, "BACK requested unsupported ba_policy == 1\n");
344 		status = WLAN_STATUS_INVALID_QOS_PARAM;
345 	}
346 	if (status == WLAN_STATUS_SUCCESS) {
347 		if (req_agg_wsize == 0) {
348 			wil_dbg_misc(wil, "Suggest BACK wsize %d\n",
349 				     WIL_MAX_AGG_WSIZE);
350 			agg_wsize = WIL_MAX_AGG_WSIZE;
351 		} else {
352 			agg_wsize = min_t(u16,
353 					  WIL_MAX_AGG_WSIZE, req_agg_wsize);
354 		}
355 	}
356 
357 	rc = wmi_addba_rx_resp(wil, cid, tid, dialog_token, status,
358 			       agg_amsdu, agg_wsize, agg_timeout);
359 	if (rc || (status != WLAN_STATUS_SUCCESS)) {
360 		wil_err(wil, "do not apply ba, rc(%d), status(%d)\n", rc,
361 			status);
362 		goto out;
363 	}
364 
365 	/* apply */
366 	r = wil_tid_ampdu_rx_alloc(wil, agg_wsize, ssn);
367 	spin_lock_bh(&sta->tid_rx_lock);
368 	wil_tid_ampdu_rx_free(wil, sta->tid_rx[tid]);
369 	sta->tid_rx[tid] = r;
370 	spin_unlock_bh(&sta->tid_rx_lock);
371 
372 out:
373 	return rc;
374 }
375 
376 /* BACK - Tx side (originator) */
377 int wil_addba_tx_request(struct wil6210_priv *wil, u8 ringid, u16 wsize)
378 {
379 	u8 agg_wsize = wil_agg_size(wil, wsize);
380 	u16 agg_timeout = 0;
381 	struct vring_tx_data *txdata = &wil->vring_tx_data[ringid];
382 	int rc = 0;
383 
384 	if (txdata->addba_in_progress) {
385 		wil_dbg_misc(wil, "ADDBA for vring[%d] already in progress\n",
386 			     ringid);
387 		goto out;
388 	}
389 	if (txdata->agg_wsize) {
390 		wil_dbg_misc(wil,
391 			     "ADDBA for vring[%d] already done for wsize %d\n",
392 			     ringid, txdata->agg_wsize);
393 		goto out;
394 	}
395 	txdata->addba_in_progress = true;
396 	rc = wmi_addba(wil, ringid, agg_wsize, agg_timeout);
397 	if (rc) {
398 		wil_err(wil, "wmi_addba failed, rc (%d)", rc);
399 		txdata->addba_in_progress = false;
400 	}
401 
402 out:
403 	return rc;
404 }
405