xref: /openbmc/linux/net/mac80211/rate.c (revision 1edd0337)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2002-2005, Instant802 Networks, Inc.
4  * Copyright 2005-2006, Devicescape Software, Inc.
5  * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
6  * Copyright 2017	Intel Deutschland GmbH
7  * Copyright (C) 2022 Intel Corporation
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/rtnetlink.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include "rate.h"
15 #include "ieee80211_i.h"
16 #include "debugfs.h"
17 
18 struct rate_control_alg {
19 	struct list_head list;
20 	const struct rate_control_ops *ops;
21 };
22 
23 static LIST_HEAD(rate_ctrl_algs);
24 static DEFINE_MUTEX(rate_ctrl_mutex);
25 
26 static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
27 module_param(ieee80211_default_rc_algo, charp, 0644);
28 MODULE_PARM_DESC(ieee80211_default_rc_algo,
29 		 "Default rate control algorithm for mac80211 to use");
30 
31 void rate_control_rate_init(struct sta_info *sta)
32 {
33 	struct ieee80211_local *local = sta->sdata->local;
34 	struct rate_control_ref *ref = sta->rate_ctrl;
35 	struct ieee80211_sta *ista = &sta->sta;
36 	void *priv_sta = sta->rate_ctrl_priv;
37 	struct ieee80211_supported_band *sband;
38 	struct ieee80211_chanctx_conf *chanctx_conf;
39 
40 	ieee80211_sta_set_rx_nss(&sta->deflink);
41 
42 	if (!ref)
43 		return;
44 
45 	rcu_read_lock();
46 
47 	chanctx_conf = rcu_dereference(sta->sdata->vif.bss_conf.chanctx_conf);
48 	if (WARN_ON(!chanctx_conf)) {
49 		rcu_read_unlock();
50 		return;
51 	}
52 
53 	sband = local->hw.wiphy->bands[chanctx_conf->def.chan->band];
54 
55 	/* TODO: check for minstrel_s1g ? */
56 	if (sband->band == NL80211_BAND_S1GHZ) {
57 		ieee80211_s1g_sta_rate_init(sta);
58 		rcu_read_unlock();
59 		return;
60 	}
61 
62 	spin_lock_bh(&sta->rate_ctrl_lock);
63 	ref->ops->rate_init(ref->priv, sband, &chanctx_conf->def, ista,
64 			    priv_sta);
65 	spin_unlock_bh(&sta->rate_ctrl_lock);
66 	rcu_read_unlock();
67 	set_sta_flag(sta, WLAN_STA_RATE_CONTROL);
68 }
69 
70 void rate_control_tx_status(struct ieee80211_local *local,
71 			    struct ieee80211_tx_status *st)
72 {
73 	struct rate_control_ref *ref = local->rate_ctrl;
74 	struct sta_info *sta = container_of(st->sta, struct sta_info, sta);
75 	void *priv_sta = sta->rate_ctrl_priv;
76 	struct ieee80211_supported_band *sband;
77 
78 	if (!ref || !test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
79 		return;
80 
81 	sband = local->hw.wiphy->bands[st->info->band];
82 
83 	spin_lock_bh(&sta->rate_ctrl_lock);
84 	if (ref->ops->tx_status_ext)
85 		ref->ops->tx_status_ext(ref->priv, sband, priv_sta, st);
86 	else if (st->skb)
87 		ref->ops->tx_status(ref->priv, sband, st->sta, priv_sta, st->skb);
88 	else
89 		WARN_ON_ONCE(1);
90 
91 	spin_unlock_bh(&sta->rate_ctrl_lock);
92 }
93 
94 void rate_control_rate_update(struct ieee80211_local *local,
95 			      struct ieee80211_supported_band *sband,
96 			      struct sta_info *sta, unsigned int link_id,
97 			      u32 changed)
98 {
99 	struct rate_control_ref *ref = local->rate_ctrl;
100 	struct ieee80211_sta *ista = &sta->sta;
101 	void *priv_sta = sta->rate_ctrl_priv;
102 	struct ieee80211_chanctx_conf *chanctx_conf;
103 
104 	WARN_ON(link_id != 0);
105 
106 	if (ref && ref->ops->rate_update) {
107 		rcu_read_lock();
108 
109 		chanctx_conf = rcu_dereference(sta->sdata->vif.bss_conf.chanctx_conf);
110 		if (WARN_ON(!chanctx_conf)) {
111 			rcu_read_unlock();
112 			return;
113 		}
114 
115 		spin_lock_bh(&sta->rate_ctrl_lock);
116 		ref->ops->rate_update(ref->priv, sband, &chanctx_conf->def,
117 				      ista, priv_sta, changed);
118 		spin_unlock_bh(&sta->rate_ctrl_lock);
119 		rcu_read_unlock();
120 	}
121 
122 	drv_sta_rc_update(local, sta->sdata, &sta->sta, changed);
123 }
124 
125 int ieee80211_rate_control_register(const struct rate_control_ops *ops)
126 {
127 	struct rate_control_alg *alg;
128 
129 	if (!ops->name)
130 		return -EINVAL;
131 
132 	mutex_lock(&rate_ctrl_mutex);
133 	list_for_each_entry(alg, &rate_ctrl_algs, list) {
134 		if (!strcmp(alg->ops->name, ops->name)) {
135 			/* don't register an algorithm twice */
136 			WARN_ON(1);
137 			mutex_unlock(&rate_ctrl_mutex);
138 			return -EALREADY;
139 		}
140 	}
141 
142 	alg = kzalloc(sizeof(*alg), GFP_KERNEL);
143 	if (alg == NULL) {
144 		mutex_unlock(&rate_ctrl_mutex);
145 		return -ENOMEM;
146 	}
147 	alg->ops = ops;
148 
149 	list_add_tail(&alg->list, &rate_ctrl_algs);
150 	mutex_unlock(&rate_ctrl_mutex);
151 
152 	return 0;
153 }
154 EXPORT_SYMBOL(ieee80211_rate_control_register);
155 
156 void ieee80211_rate_control_unregister(const struct rate_control_ops *ops)
157 {
158 	struct rate_control_alg *alg;
159 
160 	mutex_lock(&rate_ctrl_mutex);
161 	list_for_each_entry(alg, &rate_ctrl_algs, list) {
162 		if (alg->ops == ops) {
163 			list_del(&alg->list);
164 			kfree(alg);
165 			break;
166 		}
167 	}
168 	mutex_unlock(&rate_ctrl_mutex);
169 }
170 EXPORT_SYMBOL(ieee80211_rate_control_unregister);
171 
172 static const struct rate_control_ops *
173 ieee80211_try_rate_control_ops_get(const char *name)
174 {
175 	struct rate_control_alg *alg;
176 	const struct rate_control_ops *ops = NULL;
177 
178 	if (!name)
179 		return NULL;
180 
181 	mutex_lock(&rate_ctrl_mutex);
182 	list_for_each_entry(alg, &rate_ctrl_algs, list) {
183 		if (!strcmp(alg->ops->name, name)) {
184 			ops = alg->ops;
185 			break;
186 		}
187 	}
188 	mutex_unlock(&rate_ctrl_mutex);
189 	return ops;
190 }
191 
192 /* Get the rate control algorithm. */
193 static const struct rate_control_ops *
194 ieee80211_rate_control_ops_get(const char *name)
195 {
196 	const struct rate_control_ops *ops;
197 	const char *alg_name;
198 
199 	kernel_param_lock(THIS_MODULE);
200 	if (!name)
201 		alg_name = ieee80211_default_rc_algo;
202 	else
203 		alg_name = name;
204 
205 	ops = ieee80211_try_rate_control_ops_get(alg_name);
206 	if (!ops && name)
207 		/* try default if specific alg requested but not found */
208 		ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
209 
210 	/* Note: check for > 0 is intentional to avoid clang warning */
211 	if (!ops && (strlen(CONFIG_MAC80211_RC_DEFAULT) > 0))
212 		/* try built-in one if specific alg requested but not found */
213 		ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
214 
215 	kernel_param_unlock(THIS_MODULE);
216 
217 	return ops;
218 }
219 
220 #ifdef CONFIG_MAC80211_DEBUGFS
221 static ssize_t rcname_read(struct file *file, char __user *userbuf,
222 			   size_t count, loff_t *ppos)
223 {
224 	struct rate_control_ref *ref = file->private_data;
225 	int len = strlen(ref->ops->name);
226 
227 	return simple_read_from_buffer(userbuf, count, ppos,
228 				       ref->ops->name, len);
229 }
230 
231 const struct file_operations rcname_ops = {
232 	.read = rcname_read,
233 	.open = simple_open,
234 	.llseek = default_llseek,
235 };
236 #endif
237 
238 static struct rate_control_ref *
239 rate_control_alloc(const char *name, struct ieee80211_local *local)
240 {
241 	struct rate_control_ref *ref;
242 
243 	ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
244 	if (!ref)
245 		return NULL;
246 	ref->ops = ieee80211_rate_control_ops_get(name);
247 	if (!ref->ops)
248 		goto free;
249 
250 	ref->priv = ref->ops->alloc(&local->hw);
251 	if (!ref->priv)
252 		goto free;
253 	return ref;
254 
255 free:
256 	kfree(ref);
257 	return NULL;
258 }
259 
260 static void rate_control_free(struct ieee80211_local *local,
261 			      struct rate_control_ref *ctrl_ref)
262 {
263 	ctrl_ref->ops->free(ctrl_ref->priv);
264 
265 #ifdef CONFIG_MAC80211_DEBUGFS
266 	debugfs_remove_recursive(local->debugfs.rcdir);
267 	local->debugfs.rcdir = NULL;
268 #endif
269 
270 	kfree(ctrl_ref);
271 }
272 
273 void ieee80211_check_rate_mask(struct ieee80211_link_data *link)
274 {
275 	struct ieee80211_sub_if_data *sdata = link->sdata;
276 	struct ieee80211_local *local = sdata->local;
277 	struct ieee80211_supported_band *sband;
278 	u32 user_mask, basic_rates = link->conf->basic_rates;
279 	enum nl80211_band band;
280 
281 	if (WARN_ON(!link->conf->chandef.chan))
282 		return;
283 
284 	band = link->conf->chandef.chan->band;
285 	if (band == NL80211_BAND_S1GHZ) {
286 		/* TODO */
287 		return;
288 	}
289 
290 	if (WARN_ON_ONCE(!basic_rates))
291 		return;
292 
293 	user_mask = sdata->rc_rateidx_mask[band];
294 	sband = local->hw.wiphy->bands[band];
295 
296 	if (user_mask & basic_rates)
297 		return;
298 
299 	sdata_dbg(sdata,
300 		  "no overlap between basic rates (0x%x) and user mask (0x%x on band %d) - clearing the latter",
301 		  basic_rates, user_mask, band);
302 	sdata->rc_rateidx_mask[band] = (1 << sband->n_bitrates) - 1;
303 }
304 
305 static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
306 {
307 	struct sk_buff *skb = txrc->skb;
308 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
309 
310 	return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
311 			       IEEE80211_TX_CTL_USE_MINRATE)) ||
312 		!ieee80211_is_tx_data(skb);
313 }
314 
315 static void rc_send_low_basicrate(struct ieee80211_tx_rate *rate,
316 				  u32 basic_rates,
317 				  struct ieee80211_supported_band *sband)
318 {
319 	u8 i;
320 
321 	if (sband->band == NL80211_BAND_S1GHZ) {
322 		/* TODO */
323 		rate->flags |= IEEE80211_TX_RC_S1G_MCS;
324 		rate->idx = 0;
325 		return;
326 	}
327 
328 	if (basic_rates == 0)
329 		return; /* assume basic rates unknown and accept rate */
330 	if (rate->idx < 0)
331 		return;
332 	if (basic_rates & (1 << rate->idx))
333 		return; /* selected rate is a basic rate */
334 
335 	for (i = rate->idx + 1; i <= sband->n_bitrates; i++) {
336 		if (basic_rates & (1 << i)) {
337 			rate->idx = i;
338 			return;
339 		}
340 	}
341 
342 	/* could not find a basic rate; use original selection */
343 }
344 
345 static void __rate_control_send_low(struct ieee80211_hw *hw,
346 				    struct ieee80211_supported_band *sband,
347 				    struct ieee80211_sta *sta,
348 				    struct ieee80211_tx_info *info,
349 				    u32 rate_mask)
350 {
351 	int i;
352 	u32 rate_flags =
353 		ieee80211_chandef_rate_flags(&hw->conf.chandef);
354 
355 	if (sband->band == NL80211_BAND_S1GHZ) {
356 		info->control.rates[0].flags |= IEEE80211_TX_RC_S1G_MCS;
357 		info->control.rates[0].idx = 0;
358 		return;
359 	}
360 
361 	if ((sband->band == NL80211_BAND_2GHZ) &&
362 	    (info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
363 		rate_flags |= IEEE80211_RATE_ERP_G;
364 
365 	info->control.rates[0].idx = 0;
366 	for (i = 0; i < sband->n_bitrates; i++) {
367 		if (!(rate_mask & BIT(i)))
368 			continue;
369 
370 		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
371 			continue;
372 
373 		if (!rate_supported(sta, sband->band, i))
374 			continue;
375 
376 		info->control.rates[0].idx = i;
377 		break;
378 	}
379 	WARN_ONCE(i == sband->n_bitrates,
380 		  "no supported rates for sta %pM (0x%x, band %d) in rate_mask 0x%x with flags 0x%x\n",
381 		  sta ? sta->addr : NULL,
382 		  sta ? sta->deflink.supp_rates[sband->band] : -1,
383 		  sband->band,
384 		  rate_mask, rate_flags);
385 
386 	info->control.rates[0].count =
387 		(info->flags & IEEE80211_TX_CTL_NO_ACK) ?
388 		1 : hw->max_rate_tries;
389 
390 	info->control.skip_table = 1;
391 }
392 
393 
394 static bool rate_control_send_low(struct ieee80211_sta *pubsta,
395 				  struct ieee80211_tx_rate_control *txrc)
396 {
397 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
398 	struct ieee80211_supported_band *sband = txrc->sband;
399 	struct sta_info *sta;
400 	int mcast_rate;
401 	bool use_basicrate = false;
402 
403 	if (!pubsta || rc_no_data_or_no_ack_use_min(txrc)) {
404 		__rate_control_send_low(txrc->hw, sband, pubsta, info,
405 					txrc->rate_idx_mask);
406 
407 		if (!pubsta && txrc->bss) {
408 			mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
409 			if (mcast_rate > 0) {
410 				info->control.rates[0].idx = mcast_rate - 1;
411 				return true;
412 			}
413 			use_basicrate = true;
414 		} else if (pubsta) {
415 			sta = container_of(pubsta, struct sta_info, sta);
416 			if (ieee80211_vif_is_mesh(&sta->sdata->vif))
417 				use_basicrate = true;
418 		}
419 
420 		if (use_basicrate)
421 			rc_send_low_basicrate(&info->control.rates[0],
422 					      txrc->bss_conf->basic_rates,
423 					      sband);
424 
425 		return true;
426 	}
427 	return false;
428 }
429 
430 static bool rate_idx_match_legacy_mask(s8 *rate_idx, int n_bitrates, u32 mask)
431 {
432 	int j;
433 
434 	/* See whether the selected rate or anything below it is allowed. */
435 	for (j = *rate_idx; j >= 0; j--) {
436 		if (mask & (1 << j)) {
437 			/* Okay, found a suitable rate. Use it. */
438 			*rate_idx = j;
439 			return true;
440 		}
441 	}
442 
443 	/* Try to find a higher rate that would be allowed */
444 	for (j = *rate_idx + 1; j < n_bitrates; j++) {
445 		if (mask & (1 << j)) {
446 			/* Okay, found a suitable rate. Use it. */
447 			*rate_idx = j;
448 			return true;
449 		}
450 	}
451 	return false;
452 }
453 
454 static bool rate_idx_match_mcs_mask(s8 *rate_idx, u8 *mcs_mask)
455 {
456 	int i, j;
457 	int ridx, rbit;
458 
459 	ridx = *rate_idx / 8;
460 	rbit = *rate_idx % 8;
461 
462 	/* sanity check */
463 	if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
464 		return false;
465 
466 	/* See whether the selected rate or anything below it is allowed. */
467 	for (i = ridx; i >= 0; i--) {
468 		for (j = rbit; j >= 0; j--)
469 			if (mcs_mask[i] & BIT(j)) {
470 				*rate_idx = i * 8 + j;
471 				return true;
472 			}
473 		rbit = 7;
474 	}
475 
476 	/* Try to find a higher rate that would be allowed */
477 	ridx = (*rate_idx + 1) / 8;
478 	rbit = (*rate_idx + 1) % 8;
479 
480 	for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
481 		for (j = rbit; j < 8; j++)
482 			if (mcs_mask[i] & BIT(j)) {
483 				*rate_idx = i * 8 + j;
484 				return true;
485 			}
486 		rbit = 0;
487 	}
488 	return false;
489 }
490 
491 static bool rate_idx_match_vht_mcs_mask(s8 *rate_idx, u16 *vht_mask)
492 {
493 	int i, j;
494 	int ridx, rbit;
495 
496 	ridx = *rate_idx >> 4;
497 	rbit = *rate_idx & 0xf;
498 
499 	if (ridx < 0 || ridx >= NL80211_VHT_NSS_MAX)
500 		return false;
501 
502 	/* See whether the selected rate or anything below it is allowed. */
503 	for (i = ridx; i >= 0; i--) {
504 		for (j = rbit; j >= 0; j--) {
505 			if (vht_mask[i] & BIT(j)) {
506 				*rate_idx = (i << 4) | j;
507 				return true;
508 			}
509 		}
510 		rbit = 15;
511 	}
512 
513 	/* Try to find a higher rate that would be allowed */
514 	ridx = (*rate_idx + 1) >> 4;
515 	rbit = (*rate_idx + 1) & 0xf;
516 
517 	for (i = ridx; i < NL80211_VHT_NSS_MAX; i++) {
518 		for (j = rbit; j < 16; j++) {
519 			if (vht_mask[i] & BIT(j)) {
520 				*rate_idx = (i << 4) | j;
521 				return true;
522 			}
523 		}
524 		rbit = 0;
525 	}
526 	return false;
527 }
528 
529 static void rate_idx_match_mask(s8 *rate_idx, u16 *rate_flags,
530 				struct ieee80211_supported_band *sband,
531 				enum nl80211_chan_width chan_width,
532 				u32 mask,
533 				u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
534 				u16 vht_mask[NL80211_VHT_NSS_MAX])
535 {
536 	if (*rate_flags & IEEE80211_TX_RC_VHT_MCS) {
537 		/* handle VHT rates */
538 		if (rate_idx_match_vht_mcs_mask(rate_idx, vht_mask))
539 			return;
540 
541 		*rate_idx = 0;
542 		/* keep protection flags */
543 		*rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
544 				IEEE80211_TX_RC_USE_CTS_PROTECT |
545 				IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
546 
547 		*rate_flags |= IEEE80211_TX_RC_MCS;
548 		if (chan_width == NL80211_CHAN_WIDTH_40)
549 			*rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
550 
551 		if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
552 			return;
553 
554 		/* also try the legacy rates. */
555 		*rate_flags &= ~(IEEE80211_TX_RC_MCS |
556 				 IEEE80211_TX_RC_40_MHZ_WIDTH);
557 		if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
558 					       mask))
559 			return;
560 	} else if (*rate_flags & IEEE80211_TX_RC_MCS) {
561 		/* handle HT rates */
562 		if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
563 			return;
564 
565 		/* also try the legacy rates. */
566 		*rate_idx = 0;
567 		/* keep protection flags */
568 		*rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
569 				IEEE80211_TX_RC_USE_CTS_PROTECT |
570 				IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
571 		if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
572 					       mask))
573 			return;
574 	} else {
575 		/* handle legacy rates */
576 		if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
577 					       mask))
578 			return;
579 
580 		/* if HT BSS, and we handle a data frame, also try HT rates */
581 		switch (chan_width) {
582 		case NL80211_CHAN_WIDTH_20_NOHT:
583 		case NL80211_CHAN_WIDTH_5:
584 		case NL80211_CHAN_WIDTH_10:
585 			return;
586 		default:
587 			break;
588 		}
589 
590 		*rate_idx = 0;
591 		/* keep protection flags */
592 		*rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
593 				IEEE80211_TX_RC_USE_CTS_PROTECT |
594 				IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
595 
596 		*rate_flags |= IEEE80211_TX_RC_MCS;
597 
598 		if (chan_width == NL80211_CHAN_WIDTH_40)
599 			*rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
600 
601 		if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
602 			return;
603 	}
604 
605 	/*
606 	 * Uh.. No suitable rate exists. This should not really happen with
607 	 * sane TX rate mask configurations. However, should someone manage to
608 	 * configure supported rates and TX rate mask in incompatible way,
609 	 * allow the frame to be transmitted with whatever the rate control
610 	 * selected.
611 	 */
612 }
613 
614 static void rate_fixup_ratelist(struct ieee80211_vif *vif,
615 				struct ieee80211_supported_band *sband,
616 				struct ieee80211_tx_info *info,
617 				struct ieee80211_tx_rate *rates,
618 				int max_rates)
619 {
620 	struct ieee80211_rate *rate;
621 	bool inval = false;
622 	int i;
623 
624 	/*
625 	 * Set up the RTS/CTS rate as the fastest basic rate
626 	 * that is not faster than the data rate unless there
627 	 * is no basic rate slower than the data rate, in which
628 	 * case we pick the slowest basic rate
629 	 *
630 	 * XXX: Should this check all retry rates?
631 	 */
632 	if (!(rates[0].flags &
633 	      (IEEE80211_TX_RC_MCS | IEEE80211_TX_RC_VHT_MCS))) {
634 		u32 basic_rates = vif->bss_conf.basic_rates;
635 		s8 baserate = basic_rates ? ffs(basic_rates) - 1 : 0;
636 
637 		rate = &sband->bitrates[rates[0].idx];
638 
639 		for (i = 0; i < sband->n_bitrates; i++) {
640 			/* must be a basic rate */
641 			if (!(basic_rates & BIT(i)))
642 				continue;
643 			/* must not be faster than the data rate */
644 			if (sband->bitrates[i].bitrate > rate->bitrate)
645 				continue;
646 			/* maximum */
647 			if (sband->bitrates[baserate].bitrate <
648 			     sband->bitrates[i].bitrate)
649 				baserate = i;
650 		}
651 
652 		info->control.rts_cts_rate_idx = baserate;
653 	}
654 
655 	for (i = 0; i < max_rates; i++) {
656 		/*
657 		 * make sure there's no valid rate following
658 		 * an invalid one, just in case drivers don't
659 		 * take the API seriously to stop at -1.
660 		 */
661 		if (inval) {
662 			rates[i].idx = -1;
663 			continue;
664 		}
665 		if (rates[i].idx < 0) {
666 			inval = true;
667 			continue;
668 		}
669 
670 		/*
671 		 * For now assume MCS is already set up correctly, this
672 		 * needs to be fixed.
673 		 */
674 		if (rates[i].flags & IEEE80211_TX_RC_MCS) {
675 			WARN_ON(rates[i].idx > 76);
676 
677 			if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
678 			    info->control.use_cts_prot)
679 				rates[i].flags |=
680 					IEEE80211_TX_RC_USE_CTS_PROTECT;
681 			continue;
682 		}
683 
684 		if (rates[i].flags & IEEE80211_TX_RC_VHT_MCS) {
685 			WARN_ON(ieee80211_rate_get_vht_mcs(&rates[i]) > 9);
686 			continue;
687 		}
688 
689 		/* set up RTS protection if desired */
690 		if (info->control.use_rts) {
691 			rates[i].flags |= IEEE80211_TX_RC_USE_RTS_CTS;
692 			info->control.use_cts_prot = false;
693 		}
694 
695 		/* RC is busted */
696 		if (WARN_ON_ONCE(rates[i].idx >= sband->n_bitrates)) {
697 			rates[i].idx = -1;
698 			continue;
699 		}
700 
701 		rate = &sband->bitrates[rates[i].idx];
702 
703 		/* set up short preamble */
704 		if (info->control.short_preamble &&
705 		    rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
706 			rates[i].flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
707 
708 		/* set up G protection */
709 		if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
710 		    info->control.use_cts_prot &&
711 		    rate->flags & IEEE80211_RATE_ERP_G)
712 			rates[i].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT;
713 	}
714 }
715 
716 
717 static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
718 					struct ieee80211_tx_info *info,
719 					struct ieee80211_tx_rate *rates,
720 					int max_rates)
721 {
722 	struct ieee80211_sta_rates *ratetbl = NULL;
723 	int i;
724 
725 	if (sta && !info->control.skip_table)
726 		ratetbl = rcu_dereference(sta->rates);
727 
728 	/* Fill remaining rate slots with data from the sta rate table. */
729 	max_rates = min_t(int, max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
730 	for (i = 0; i < max_rates; i++) {
731 		if (i < ARRAY_SIZE(info->control.rates) &&
732 		    info->control.rates[i].idx >= 0 &&
733 		    info->control.rates[i].count) {
734 			if (rates != info->control.rates)
735 				rates[i] = info->control.rates[i];
736 		} else if (ratetbl) {
737 			rates[i].idx = ratetbl->rate[i].idx;
738 			rates[i].flags = ratetbl->rate[i].flags;
739 			if (info->control.use_rts)
740 				rates[i].count = ratetbl->rate[i].count_rts;
741 			else if (info->control.use_cts_prot)
742 				rates[i].count = ratetbl->rate[i].count_cts;
743 			else
744 				rates[i].count = ratetbl->rate[i].count;
745 		} else {
746 			rates[i].idx = -1;
747 			rates[i].count = 0;
748 		}
749 
750 		if (rates[i].idx < 0 || !rates[i].count)
751 			break;
752 	}
753 }
754 
755 static bool rate_control_cap_mask(struct ieee80211_sub_if_data *sdata,
756 				  struct ieee80211_supported_band *sband,
757 				  struct ieee80211_sta *sta, u32 *mask,
758 				  u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
759 				  u16 vht_mask[NL80211_VHT_NSS_MAX])
760 {
761 	u32 i, flags;
762 
763 	*mask = sdata->rc_rateidx_mask[sband->band];
764 	flags = ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chandef);
765 	for (i = 0; i < sband->n_bitrates; i++) {
766 		if ((flags & sband->bitrates[i].flags) != flags)
767 			*mask &= ~BIT(i);
768 	}
769 
770 	if (*mask == (1 << sband->n_bitrates) - 1 &&
771 	    !sdata->rc_has_mcs_mask[sband->band] &&
772 	    !sdata->rc_has_vht_mcs_mask[sband->band])
773 		return false;
774 
775 	if (sdata->rc_has_mcs_mask[sband->band])
776 		memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[sband->band],
777 		       IEEE80211_HT_MCS_MASK_LEN);
778 	else
779 		memset(mcs_mask, 0xff, IEEE80211_HT_MCS_MASK_LEN);
780 
781 	if (sdata->rc_has_vht_mcs_mask[sband->band])
782 		memcpy(vht_mask, sdata->rc_rateidx_vht_mcs_mask[sband->band],
783 		       sizeof(u16) * NL80211_VHT_NSS_MAX);
784 	else
785 		memset(vht_mask, 0xff, sizeof(u16) * NL80211_VHT_NSS_MAX);
786 
787 	if (sta) {
788 		__le16 sta_vht_cap;
789 		u16 sta_vht_mask[NL80211_VHT_NSS_MAX];
790 
791 		/* Filter out rates that the STA does not support */
792 		*mask &= sta->deflink.supp_rates[sband->band];
793 		for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++)
794 			mcs_mask[i] &= sta->deflink.ht_cap.mcs.rx_mask[i];
795 
796 		sta_vht_cap = sta->deflink.vht_cap.vht_mcs.rx_mcs_map;
797 		ieee80211_get_vht_mask_from_cap(sta_vht_cap, sta_vht_mask);
798 		for (i = 0; i < NL80211_VHT_NSS_MAX; i++)
799 			vht_mask[i] &= sta_vht_mask[i];
800 	}
801 
802 	return true;
803 }
804 
805 static void
806 rate_control_apply_mask_ratetbl(struct sta_info *sta,
807 				struct ieee80211_supported_band *sband,
808 				struct ieee80211_sta_rates *rates)
809 {
810 	int i;
811 	u32 mask;
812 	u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
813 	u16 vht_mask[NL80211_VHT_NSS_MAX];
814 	enum nl80211_chan_width chan_width;
815 
816 	if (!rate_control_cap_mask(sta->sdata, sband, &sta->sta, &mask,
817 				   mcs_mask, vht_mask))
818 		return;
819 
820 	chan_width = sta->sdata->vif.bss_conf.chandef.width;
821 	for (i = 0; i < IEEE80211_TX_RATE_TABLE_SIZE; i++) {
822 		if (rates->rate[i].idx < 0)
823 			break;
824 
825 		rate_idx_match_mask(&rates->rate[i].idx, &rates->rate[i].flags,
826 				    sband, chan_width, mask, mcs_mask,
827 				    vht_mask);
828 	}
829 }
830 
831 static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
832 				    struct ieee80211_sta *sta,
833 				    struct ieee80211_supported_band *sband,
834 				    struct ieee80211_tx_rate *rates,
835 				    int max_rates)
836 {
837 	enum nl80211_chan_width chan_width;
838 	u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
839 	u32 mask;
840 	u16 rate_flags, vht_mask[NL80211_VHT_NSS_MAX];
841 	int i;
842 
843 	/*
844 	 * Try to enforce the rateidx mask the user wanted. skip this if the
845 	 * default mask (allow all rates) is used to save some processing for
846 	 * the common case.
847 	 */
848 	if (!rate_control_cap_mask(sdata, sband, sta, &mask, mcs_mask,
849 				   vht_mask))
850 		return;
851 
852 	/*
853 	 * Make sure the rate index selected for each TX rate is
854 	 * included in the configured mask and change the rate indexes
855 	 * if needed.
856 	 */
857 	chan_width = sdata->vif.bss_conf.chandef.width;
858 	for (i = 0; i < max_rates; i++) {
859 		/* Skip invalid rates */
860 		if (rates[i].idx < 0)
861 			break;
862 
863 		rate_flags = rates[i].flags;
864 		rate_idx_match_mask(&rates[i].idx, &rate_flags, sband,
865 				    chan_width, mask, mcs_mask, vht_mask);
866 		rates[i].flags = rate_flags;
867 	}
868 }
869 
870 void ieee80211_get_tx_rates(struct ieee80211_vif *vif,
871 			    struct ieee80211_sta *sta,
872 			    struct sk_buff *skb,
873 			    struct ieee80211_tx_rate *dest,
874 			    int max_rates)
875 {
876 	struct ieee80211_sub_if_data *sdata;
877 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
878 	struct ieee80211_supported_band *sband;
879 
880 	rate_control_fill_sta_table(sta, info, dest, max_rates);
881 
882 	if (!vif)
883 		return;
884 
885 	sdata = vif_to_sdata(vif);
886 	sband = sdata->local->hw.wiphy->bands[info->band];
887 
888 	if (ieee80211_is_tx_data(skb))
889 		rate_control_apply_mask(sdata, sta, sband, dest, max_rates);
890 
891 	if (dest[0].idx < 0)
892 		__rate_control_send_low(&sdata->local->hw, sband, sta, info,
893 					sdata->rc_rateidx_mask[info->band]);
894 
895 	if (sta)
896 		rate_fixup_ratelist(vif, sband, info, dest, max_rates);
897 }
898 EXPORT_SYMBOL(ieee80211_get_tx_rates);
899 
900 void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
901 			   struct sta_info *sta,
902 			   struct ieee80211_tx_rate_control *txrc)
903 {
904 	struct rate_control_ref *ref = sdata->local->rate_ctrl;
905 	void *priv_sta = NULL;
906 	struct ieee80211_sta *ista = NULL;
907 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
908 	int i;
909 
910 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
911 		info->control.rates[i].idx = -1;
912 		info->control.rates[i].flags = 0;
913 		info->control.rates[i].count = 0;
914 	}
915 
916 	if (rate_control_send_low(sta ? &sta->sta : NULL, txrc))
917 		return;
918 
919 	if (ieee80211_hw_check(&sdata->local->hw, HAS_RATE_CONTROL))
920 		return;
921 
922 	if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
923 		ista = &sta->sta;
924 		priv_sta = sta->rate_ctrl_priv;
925 	}
926 
927 	if (ista) {
928 		spin_lock_bh(&sta->rate_ctrl_lock);
929 		ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
930 		spin_unlock_bh(&sta->rate_ctrl_lock);
931 	} else {
932 		rate_control_send_low(NULL, txrc);
933 	}
934 
935 	if (ieee80211_hw_check(&sdata->local->hw, SUPPORTS_RC_TABLE))
936 		return;
937 
938 	ieee80211_get_tx_rates(&sdata->vif, ista, txrc->skb,
939 			       info->control.rates,
940 			       ARRAY_SIZE(info->control.rates));
941 }
942 
943 int rate_control_set_rates(struct ieee80211_hw *hw,
944 			   struct ieee80211_sta *pubsta,
945 			   struct ieee80211_sta_rates *rates)
946 {
947 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
948 	struct ieee80211_sta_rates *old;
949 	struct ieee80211_supported_band *sband;
950 
951 	sband = ieee80211_get_sband(sta->sdata);
952 	if (!sband)
953 		return -EINVAL;
954 	rate_control_apply_mask_ratetbl(sta, sband, rates);
955 	/*
956 	 * mac80211 guarantees that this function will not be called
957 	 * concurrently, so the following RCU access is safe, even without
958 	 * extra locking. This can not be checked easily, so we just set
959 	 * the condition to true.
960 	 */
961 	old = rcu_dereference_protected(pubsta->rates, true);
962 	rcu_assign_pointer(pubsta->rates, rates);
963 	if (old)
964 		kfree_rcu(old, rcu_head);
965 
966 	if (sta->uploaded)
967 		drv_sta_rate_tbl_update(hw_to_local(hw), sta->sdata, pubsta);
968 
969 	ieee80211_sta_set_expected_throughput(pubsta, sta_get_expected_throughput(sta));
970 
971 	return 0;
972 }
973 EXPORT_SYMBOL(rate_control_set_rates);
974 
975 int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
976 				 const char *name)
977 {
978 	struct rate_control_ref *ref;
979 
980 	ASSERT_RTNL();
981 
982 	if (local->open_count)
983 		return -EBUSY;
984 
985 	if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL)) {
986 		if (WARN_ON(!local->ops->set_rts_threshold))
987 			return -EINVAL;
988 		return 0;
989 	}
990 
991 	ref = rate_control_alloc(name, local);
992 	if (!ref) {
993 		wiphy_warn(local->hw.wiphy,
994 			   "Failed to select rate control algorithm\n");
995 		return -ENOENT;
996 	}
997 
998 	WARN_ON(local->rate_ctrl);
999 	local->rate_ctrl = ref;
1000 
1001 	wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
1002 		    ref->ops->name);
1003 
1004 	return 0;
1005 }
1006 
1007 void rate_control_deinitialize(struct ieee80211_local *local)
1008 {
1009 	struct rate_control_ref *ref;
1010 
1011 	ref = local->rate_ctrl;
1012 
1013 	if (!ref)
1014 		return;
1015 
1016 	local->rate_ctrl = NULL;
1017 	rate_control_free(local, ref);
1018 }
1019