rate.c

   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) 2019, 2022-2025 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
  18struct rate_control_alg {
  19	struct list_head list;
  20	const struct rate_control_ops *ops;
  21};
  22
  23static LIST_HEAD(rate_ctrl_algs);
  24static DEFINE_MUTEX(rate_ctrl_mutex);
  25
  26static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
  27module_param(ieee80211_default_rc_algo, charp, 0644);
  28MODULE_PARM_DESC(ieee80211_default_rc_algo,
  29		 "Default rate control algorithm for mac80211 to use");
  30
  31void rate_control_rate_init(struct link_sta_info *link_sta)
  32{
  33	struct sta_info *sta = link_sta->sta;
  34	struct ieee80211_local *local = sta->sdata->local;
  35	struct rate_control_ref *ref = sta->rate_ctrl;
  36	struct ieee80211_sta *ista = &sta->sta;
  37	void *priv_sta = sta->rate_ctrl_priv;
  38	struct ieee80211_supported_band *sband;
  39	struct ieee80211_chanctx_conf *chanctx_conf;
  40
  41	ieee80211_sta_init_nss(link_sta);
  42
  43	if (!ref)
  44		return;
  45
  46	/* SW rate control isn't supported with MLO right now */
  47	if (WARN_ON(ieee80211_vif_is_mld(&sta->sdata->vif)))
  48		return;
  49
  50	rcu_read_lock();
  51
  52	chanctx_conf = rcu_dereference(sta->sdata->vif.bss_conf.chanctx_conf);
  53	if (WARN_ON(!chanctx_conf)) {
  54		rcu_read_unlock();
  55		return;
  56	}
  57
  58	sband = local->hw.wiphy->bands[chanctx_conf->def.chan->band];
  59
  60	/* TODO: check for minstrel_s1g ? */
  61	if (sband->band == NL80211_BAND_S1GHZ) {
  62		ieee80211_s1g_sta_rate_init(sta);
  63		rcu_read_unlock();
  64		return;
  65	}
  66
  67	spin_lock_bh(&sta->rate_ctrl_lock);
  68	ref->ops->rate_init(ref->priv, sband, &chanctx_conf->def, ista,
  69			    priv_sta);
  70	spin_unlock_bh(&sta->rate_ctrl_lock);
  71	rcu_read_unlock();
  72	set_sta_flag(sta, WLAN_STA_RATE_CONTROL);
  73}
  74
  75void rate_control_rate_init_all_links(struct sta_info *sta)
  76{
  77	int link_id;
  78
  79	for (link_id = 0; link_id < ARRAY_SIZE(sta->link); link_id++) {
  80		struct link_sta_info *link_sta;
  81
  82		link_sta = sdata_dereference(sta->link[link_id], sta->sdata);
  83		if (!link_sta)
  84			continue;
  85
  86		rate_control_rate_init(link_sta);
  87	}
  88}
  89
  90void rate_control_tx_status(struct ieee80211_local *local,
  91			    struct ieee80211_tx_status *st)
  92{
  93	struct rate_control_ref *ref = local->rate_ctrl;
  94	struct sta_info *sta = container_of(st->sta, struct sta_info, sta);
  95	void *priv_sta = sta->rate_ctrl_priv;
  96	struct ieee80211_supported_band *sband;
  97
  98	if (!ref || !test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
  99		return;
 100
 101	if (st->info->band >= NUM_NL80211_BANDS)
 102		return;
 103
 104	sband = local->hw.wiphy->bands[st->info->band];
 105
 106	spin_lock_bh(&sta->rate_ctrl_lock);
 107	if (ref->ops->tx_status_ext)
 108		ref->ops->tx_status_ext(ref->priv, sband, priv_sta, st);
 109	else if (st->skb)
 110		ref->ops->tx_status(ref->priv, sband, st->sta, priv_sta, st->skb);
 111	else
 112		WARN_ON_ONCE(1);
 113
 114	spin_unlock_bh(&sta->rate_ctrl_lock);
 115}
 116
 117void rate_control_rate_update(struct ieee80211_local *local,
 118			      struct ieee80211_supported_band *sband,
 119			      struct link_sta_info *link_sta,
 120			      u32 changed)
 121{
 122	struct rate_control_ref *ref = local->rate_ctrl;
 123	struct sta_info *sta = link_sta->sta;
 124	struct ieee80211_sta *ista = &sta->sta;
 125	void *priv_sta = sta->rate_ctrl_priv;
 126	struct ieee80211_chanctx_conf *chanctx_conf;
 127
 128	if (ref && ref->ops->rate_update) {
 129		rcu_read_lock();
 130
 131		chanctx_conf = rcu_dereference(sta->sdata->vif.bss_conf.chanctx_conf);
 132		if (WARN_ON(!chanctx_conf)) {
 133			rcu_read_unlock();
 134			return;
 135		}
 136
 137		spin_lock_bh(&sta->rate_ctrl_lock);
 138		ref->ops->rate_update(ref->priv, sband, &chanctx_conf->def,
 139				      ista, priv_sta, changed);
 140		spin_unlock_bh(&sta->rate_ctrl_lock);
 141		rcu_read_unlock();
 142	}
 143
 144	if (sta->uploaded)
 145		drv_link_sta_rc_update(local, sta->sdata, link_sta->pub,
 146				       changed);
 147}
 148
 149int ieee80211_rate_control_register(const struct rate_control_ops *ops)
 150{
 151	struct rate_control_alg *alg;
 152
 153	if (!ops->name)
 154		return -EINVAL;
 155
 156	mutex_lock(&rate_ctrl_mutex);
 157	list_for_each_entry(alg, &rate_ctrl_algs, list) {
 158		if (!strcmp(alg->ops->name, ops->name)) {
 159			/* don't register an algorithm twice */
 160			WARN_ON(1);
 161			mutex_unlock(&rate_ctrl_mutex);
 162			return -EALREADY;
 163		}
 164	}
 165
 166	alg = kzalloc(sizeof(*alg), GFP_KERNEL);
 167	if (alg == NULL) {
 168		mutex_unlock(&rate_ctrl_mutex);
 169		return -ENOMEM;
 170	}
 171	alg->ops = ops;
 172
 173	list_add_tail(&alg->list, &rate_ctrl_algs);
 174	mutex_unlock(&rate_ctrl_mutex);
 175
 176	return 0;
 177}
 178EXPORT_SYMBOL(ieee80211_rate_control_register);
 179
 180void ieee80211_rate_control_unregister(const struct rate_control_ops *ops)
 181{
 182	struct rate_control_alg *alg;
 183
 184	mutex_lock(&rate_ctrl_mutex);
 185	list_for_each_entry(alg, &rate_ctrl_algs, list) {
 186		if (alg->ops == ops) {
 187			list_del(&alg->list);
 188			kfree(alg);
 189			break;
 190		}
 191	}
 192	mutex_unlock(&rate_ctrl_mutex);
 193}
 194EXPORT_SYMBOL(ieee80211_rate_control_unregister);
 195
 196static const struct rate_control_ops *
 197ieee80211_try_rate_control_ops_get(const char *name)
 198{
 199	struct rate_control_alg *alg;
 200	const struct rate_control_ops *ops = NULL;
 201
 202	if (!name)
 203		return NULL;
 204
 205	mutex_lock(&rate_ctrl_mutex);
 206	list_for_each_entry(alg, &rate_ctrl_algs, list) {
 207		if (!strcmp(alg->ops->name, name)) {
 208			ops = alg->ops;
 209			break;
 210		}
 211	}
 212	mutex_unlock(&rate_ctrl_mutex);
 213	return ops;
 214}
 215
 216/* Get the rate control algorithm. */
 217static const struct rate_control_ops *
 218ieee80211_rate_control_ops_get(const char *name)
 219{
 220	const struct rate_control_ops *ops;
 221	const char *alg_name;
 222
 223	kernel_param_lock(THIS_MODULE);
 224	if (!name)
 225		alg_name = ieee80211_default_rc_algo;
 226	else
 227		alg_name = name;
 228
 229	ops = ieee80211_try_rate_control_ops_get(alg_name);
 230	if (!ops && name)
 231		/* try default if specific alg requested but not found */
 232		ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
 233
 234	/* Note: check for > 0 is intentional to avoid clang warning */
 235	if (!ops && (strlen(CONFIG_MAC80211_RC_DEFAULT) > 0))
 236		/* try built-in one if specific alg requested but not found */
 237		ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
 238
 239	kernel_param_unlock(THIS_MODULE);
 240
 241	return ops;
 242}
 243
 244#ifdef CONFIG_MAC80211_DEBUGFS
 245static ssize_t rcname_read(struct file *file, char __user *userbuf,
 246			   size_t count, loff_t *ppos)
 247{
 248	struct rate_control_ref *ref = file->private_data;
 249	int len = strlen(ref->ops->name);
 250
 251	return simple_read_from_buffer(userbuf, count, ppos,
 252				       ref->ops->name, len);
 253}
 254
 255const struct debugfs_short_fops rcname_ops = {
 256	.read = rcname_read,
 257	.llseek = default_llseek,
 258};
 259#endif
 260
 261static struct rate_control_ref *
 262rate_control_alloc(const char *name, struct ieee80211_local *local)
 263{
 264	struct rate_control_ref *ref;
 265
 266	ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
 267	if (!ref)
 268		return NULL;
 269	ref->ops = ieee80211_rate_control_ops_get(name);
 270	if (!ref->ops)
 271		goto free;
 272
 273	ref->priv = ref->ops->alloc(&local->hw);
 274	if (!ref->priv)
 275		goto free;
 276	return ref;
 277
 278free:
 279	kfree(ref);
 280	return NULL;
 281}
 282
 283static void rate_control_free(struct ieee80211_local *local,
 284			      struct rate_control_ref *ctrl_ref)
 285{
 286	ctrl_ref->ops->free(ctrl_ref->priv);
 287
 288#ifdef CONFIG_MAC80211_DEBUGFS
 289	debugfs_remove_recursive(local->debugfs.rcdir);
 290	local->debugfs.rcdir = NULL;
 291#endif
 292
 293	kfree(ctrl_ref);
 294}
 295
 296void ieee80211_check_rate_mask(struct ieee80211_link_data *link)
 297{
 298	struct ieee80211_sub_if_data *sdata = link->sdata;
 299	struct ieee80211_local *local = sdata->local;
 300	struct ieee80211_supported_band *sband;
 301	u32 user_mask, basic_rates = link->conf->basic_rates;
 302	enum nl80211_band band;
 303
 304	if (WARN_ON(!link->conf->chanreq.oper.chan))
 305		return;
 306
 307	band = link->conf->chanreq.oper.chan->band;
 308	if (band == NL80211_BAND_S1GHZ) {
 309		/* TODO */
 310		return;
 311	}
 312
 313	if (WARN_ON_ONCE(!basic_rates))
 314		return;
 315
 316	user_mask = sdata->rc_rateidx_mask[band];
 317	sband = local->hw.wiphy->bands[band];
 318
 319	if (user_mask & basic_rates)
 320		return;
 321
 322	sdata_dbg(sdata,
 323		  "no overlap between basic rates (0x%x) and user mask (0x%x on band %d) - clearing the latter",
 324		  basic_rates, user_mask, band);
 325	sdata->rc_rateidx_mask[band] = (1 << sband->n_bitrates) - 1;
 326}
 327
 328static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
 329{
 330	struct sk_buff *skb = txrc->skb;
 331	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 332
 333	return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
 334			       IEEE80211_TX_CTL_USE_MINRATE)) ||
 335		!ieee80211_is_tx_data(skb);
 336}
 337
 338static void rc_send_low_basicrate(struct ieee80211_tx_rate *rate,
 339				  u32 basic_rates,
 340				  struct ieee80211_supported_band *sband)
 341{
 342	u8 i;
 343
 344	if (sband->band == NL80211_BAND_S1GHZ) {
 345		/* TODO */
 346		rate->flags |= IEEE80211_TX_RC_S1G_MCS;
 347		rate->idx = 0;
 348		return;
 349	}
 350
 351	if (basic_rates == 0)
 352		return; /* assume basic rates unknown and accept rate */
 353	if (rate->idx < 0)
 354		return;
 355	if (basic_rates & (1 << rate->idx))
 356		return; /* selected rate is a basic rate */
 357
 358	for (i = rate->idx + 1; i <= sband->n_bitrates; i++) {
 359		if (basic_rates & (1 << i)) {
 360			rate->idx = i;
 361			return;
 362		}
 363	}
 364
 365	/* could not find a basic rate; use original selection */
 366}
 367
 368static void __rate_control_send_low(struct ieee80211_hw *hw,
 369				    struct ieee80211_supported_band *sband,
 370				    struct ieee80211_sta *sta,
 371				    struct ieee80211_tx_info *info,
 372				    u32 rate_mask)
 373{
 374	u32 rate_flags = 0;
 375	int i;
 376
 377	if (sband->band == NL80211_BAND_S1GHZ) {
 378		info->control.rates[0].flags |= IEEE80211_TX_RC_S1G_MCS;
 379		info->control.rates[0].idx = 0;
 380		return;
 381	}
 382
 383	if ((sband->band == NL80211_BAND_2GHZ) &&
 384	    (info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
 385		rate_flags |= IEEE80211_RATE_ERP_G;
 386
 387	info->control.rates[0].idx = 0;
 388	for (i = 0; i < sband->n_bitrates; i++) {
 389		if (!(rate_mask & BIT(i)))
 390			continue;
 391
 392		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
 393			continue;
 394
 395		if (!rate_supported(sta, sband->band, i))
 396			continue;
 397
 398		info->control.rates[0].idx = i;
 399		break;
 400	}
 401	WARN_ONCE(i == sband->n_bitrates,
 402		  "no supported rates for sta %pM (0x%x, band %d) in rate_mask 0x%x with flags 0x%x\n",
 403		  sta ? sta->addr : NULL,
 404		  sta ? sta->deflink.supp_rates[sband->band] : -1,
 405		  sband->band,
 406		  rate_mask, rate_flags);
 407
 408	info->control.rates[0].count =
 409		(info->flags & IEEE80211_TX_CTL_NO_ACK) ?
 410		1 : hw->max_rate_tries;
 411
 412	info->control.skip_table = 1;
 413}
 414
 415
 416static bool rate_control_send_low(struct ieee80211_sta *pubsta,
 417				  struct ieee80211_tx_rate_control *txrc)
 418{
 419	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 420	struct ieee80211_supported_band *sband = txrc->sband;
 421	struct sta_info *sta;
 422	int mcast_rate;
 423	bool use_basicrate = false;
 424
 425	if (!sband)
 426		return false;
 427
 428	if (!pubsta || rc_no_data_or_no_ack_use_min(txrc)) {
 429		__rate_control_send_low(txrc->hw, sband, pubsta, info,
 430					txrc->rate_idx_mask);
 431
 432		if (!pubsta && txrc->bss) {
 433			mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
 434			if (mcast_rate > 0) {
 435				info->control.rates[0].idx = mcast_rate - 1;
 436				return true;
 437			}
 438			use_basicrate = true;
 439		} else if (pubsta) {
 440			sta = container_of(pubsta, struct sta_info, sta);
 441			if (ieee80211_vif_is_mesh(&sta->sdata->vif))
 442				use_basicrate = true;
 443		}
 444
 445		if (use_basicrate)
 446			rc_send_low_basicrate(&info->control.rates[0],
 447					      txrc->bss_conf->basic_rates,
 448					      sband);
 449
 450		return true;
 451	}
 452	return false;
 453}
 454
 455static bool rate_idx_match_legacy_mask(s8 *rate_idx, int n_bitrates, u32 mask)
 456{
 457	int j;
 458
 459	/* See whether the selected rate or anything below it is allowed. */
 460	for (j = *rate_idx; j >= 0; j--) {
 461		if (mask & (1 << j)) {
 462			/* Okay, found a suitable rate. Use it. */
 463			*rate_idx = j;
 464			return true;
 465		}
 466	}
 467
 468	/* Try to find a higher rate that would be allowed */
 469	for (j = *rate_idx + 1; j < n_bitrates; j++) {
 470		if (mask & (1 << j)) {
 471			/* Okay, found a suitable rate. Use it. */
 472			*rate_idx = j;
 473			return true;
 474		}
 475	}
 476	return false;
 477}
 478
 479static bool rate_idx_match_mcs_mask(s8 *rate_idx, u8 *mcs_mask)
 480{
 481	int i, j;
 482	int ridx, rbit;
 483
 484	ridx = *rate_idx / 8;
 485	rbit = *rate_idx % 8;
 486
 487	/* sanity check */
 488	if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
 489		return false;
 490
 491	/* See whether the selected rate or anything below it is allowed. */
 492	for (i = ridx; i >= 0; i--) {
 493		for (j = rbit; j >= 0; j--)
 494			if (mcs_mask[i] & BIT(j)) {
 495				*rate_idx = i * 8 + j;
 496				return true;
 497			}
 498		rbit = 7;
 499	}
 500
 501	/* Try to find a higher rate that would be allowed */
 502	ridx = (*rate_idx + 1) / 8;
 503	rbit = (*rate_idx + 1) % 8;
 504
 505	for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
 506		for (j = rbit; j < 8; j++)
 507			if (mcs_mask[i] & BIT(j)) {
 508				*rate_idx = i * 8 + j;
 509				return true;
 510			}
 511		rbit = 0;
 512	}
 513	return false;
 514}
 515
 516static bool rate_idx_match_vht_mcs_mask(s8 *rate_idx, u16 *vht_mask)
 517{
 518	int i, j;
 519	int ridx, rbit;
 520
 521	ridx = *rate_idx >> 4;
 522	rbit = *rate_idx & 0xf;
 523
 524	if (ridx < 0 || ridx >= NL80211_VHT_NSS_MAX)
 525		return false;
 526
 527	/* See whether the selected rate or anything below it is allowed. */
 528	for (i = ridx; i >= 0; i--) {
 529		for (j = rbit; j >= 0; j--) {
 530			if (vht_mask[i] & BIT(j)) {
 531				*rate_idx = (i << 4) | j;
 532				return true;
 533			}
 534		}
 535		rbit = 15;
 536	}
 537
 538	/* Try to find a higher rate that would be allowed */
 539	ridx = (*rate_idx + 1) >> 4;
 540	rbit = (*rate_idx + 1) & 0xf;
 541
 542	for (i = ridx; i < NL80211_VHT_NSS_MAX; i++) {
 543		for (j = rbit; j < 16; j++) {
 544			if (vht_mask[i] & BIT(j)) {
 545				*rate_idx = (i << 4) | j;
 546				return true;
 547			}
 548		}
 549		rbit = 0;
 550	}
 551	return false;
 552}
 553
 554static void rate_idx_match_mask(s8 *rate_idx, u16 *rate_flags,
 555				struct ieee80211_supported_band *sband,
 556				enum nl80211_chan_width chan_width,
 557				u32 mask,
 558				u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
 559				u16 vht_mask[NL80211_VHT_NSS_MAX])
 560{
 561	if (*rate_flags & IEEE80211_TX_RC_VHT_MCS) {
 562		/* handle VHT rates */
 563		if (rate_idx_match_vht_mcs_mask(rate_idx, vht_mask))
 564			return;
 565
 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
 572		*rate_flags |= IEEE80211_TX_RC_MCS;
 573		if (chan_width == NL80211_CHAN_WIDTH_40)
 574			*rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
 575
 576		if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 577			return;
 578
 579		/* also try the legacy rates. */
 580		*rate_flags &= ~(IEEE80211_TX_RC_MCS |
 581				 IEEE80211_TX_RC_40_MHZ_WIDTH);
 582		if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 583					       mask))
 584			return;
 585	} else if (*rate_flags & IEEE80211_TX_RC_MCS) {
 586		/* handle HT rates */
 587		if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 588			return;
 589
 590		/* also try the legacy rates. */
 591		*rate_idx = 0;
 592		/* keep protection flags */
 593		*rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 594				IEEE80211_TX_RC_USE_CTS_PROTECT |
 595				IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 596		if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 597					       mask))
 598			return;
 599	} else {
 600		/* handle legacy rates */
 601		if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 602					       mask))
 603			return;
 604
 605		/* if HT BSS, and we handle a data frame, also try HT rates */
 606		switch (chan_width) {
 607		case NL80211_CHAN_WIDTH_20_NOHT:
 608		case NL80211_CHAN_WIDTH_5:
 609		case NL80211_CHAN_WIDTH_10:
 610			return;
 611		default:
 612			break;
 613		}
 614
 615		*rate_idx = 0;
 616		/* keep protection flags */
 617		*rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 618				IEEE80211_TX_RC_USE_CTS_PROTECT |
 619				IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 620
 621		*rate_flags |= IEEE80211_TX_RC_MCS;
 622
 623		if (chan_width == NL80211_CHAN_WIDTH_40)
 624			*rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
 625
 626		if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 627			return;
 628	}
 629
 630	/*
 631	 * Uh.. No suitable rate exists. This should not really happen with
 632	 * sane TX rate mask configurations. However, should someone manage to
 633	 * configure supported rates and TX rate mask in incompatible way,
 634	 * allow the frame to be transmitted with whatever the rate control
 635	 * selected.
 636	 */
 637}
 638
 639static void rate_fixup_ratelist(struct ieee80211_vif *vif,
 640				struct ieee80211_supported_band *sband,
 641				struct ieee80211_tx_info *info,
 642				struct ieee80211_tx_rate *rates,
 643				int max_rates)
 644{
 645	struct ieee80211_rate *rate;
 646	bool inval = false;
 647	int i;
 648
 649	/*
 650	 * Set up the RTS/CTS rate as the fastest basic rate
 651	 * that is not faster than the data rate unless there
 652	 * is no basic rate slower than the data rate, in which
 653	 * case we pick the slowest basic rate
 654	 *
 655	 * XXX: Should this check all retry rates?
 656	 */
 657	if (!(rates[0].flags &
 658	      (IEEE80211_TX_RC_MCS | IEEE80211_TX_RC_VHT_MCS))) {
 659		u32 basic_rates = vif->bss_conf.basic_rates;
 660		s8 baserate = basic_rates ? ffs(basic_rates) - 1 : 0;
 661
 662		rate = &sband->bitrates[rates[0].idx];
 663
 664		for (i = 0; i < sband->n_bitrates; i++) {
 665			/* must be a basic rate */
 666			if (!(basic_rates & BIT(i)))
 667				continue;
 668			/* must not be faster than the data rate */
 669			if (sband->bitrates[i].bitrate > rate->bitrate)
 670				continue;
 671			/* maximum */
 672			if (sband->bitrates[baserate].bitrate <
 673			     sband->bitrates[i].bitrate)
 674				baserate = i;
 675		}
 676
 677		info->control.rts_cts_rate_idx = baserate;
 678	}
 679
 680	for (i = 0; i < max_rates; i++) {
 681		/*
 682		 * make sure there's no valid rate following
 683		 * an invalid one, just in case drivers don't
 684		 * take the API seriously to stop at -1.
 685		 */
 686		if (inval) {
 687			rates[i].idx = -1;
 688			continue;
 689		}
 690		if (rates[i].idx < 0) {
 691			inval = true;
 692			continue;
 693		}
 694
 695		/*
 696		 * For now assume MCS is already set up correctly, this
 697		 * needs to be fixed.
 698		 */
 699		if (rates[i].flags & IEEE80211_TX_RC_MCS) {
 700			WARN_ON(rates[i].idx > 76);
 701
 702			if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
 703			    info->control.use_cts_prot)
 704				rates[i].flags |=
 705					IEEE80211_TX_RC_USE_CTS_PROTECT;
 706			continue;
 707		}
 708
 709		if (rates[i].flags & IEEE80211_TX_RC_VHT_MCS) {
 710			WARN_ON(ieee80211_rate_get_vht_mcs(&rates[i]) > 9);
 711			continue;
 712		}
 713
 714		/* set up RTS protection if desired */
 715		if (info->control.use_rts) {
 716			rates[i].flags |= IEEE80211_TX_RC_USE_RTS_CTS;
 717			info->control.use_cts_prot = false;
 718		}
 719
 720		/* RC is busted */
 721		if (WARN_ON_ONCE(rates[i].idx >= sband->n_bitrates)) {
 722			rates[i].idx = -1;
 723			continue;
 724		}
 725
 726		rate = &sband->bitrates[rates[i].idx];
 727
 728		/* set up short preamble */
 729		if (info->control.short_preamble &&
 730		    rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
 731			rates[i].flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
 732
 733		/* set up G protection */
 734		if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
 735		    info->control.use_cts_prot &&
 736		    rate->flags & IEEE80211_RATE_ERP_G)
 737			rates[i].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT;
 738	}
 739}
 740
 741
 742static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
 743					struct ieee80211_tx_info *info,
 744					struct ieee80211_tx_rate *rates,
 745					int max_rates)
 746{
 747	struct ieee80211_sta_rates *ratetbl = NULL;
 748	int i;
 749
 750	if (sta && !info->control.skip_table)
 751		ratetbl = rcu_dereference(sta->rates);
 752
 753	/* Fill remaining rate slots with data from the sta rate table. */
 754	max_rates = min_t(int, max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
 755	for (i = 0; i < max_rates; i++) {
 756		if (i < ARRAY_SIZE(info->control.rates) &&
 757		    info->control.rates[i].idx >= 0 &&
 758		    info->control.rates[i].count) {
 759			if (rates != info->control.rates)
 760				rates[i] = info->control.rates[i];
 761		} else if (ratetbl) {
 762			rates[i].idx = ratetbl->rate[i].idx;
 763			rates[i].flags = ratetbl->rate[i].flags;
 764			if (info->control.use_rts)
 765				rates[i].count = ratetbl->rate[i].count_rts;
 766			else if (info->control.use_cts_prot)
 767				rates[i].count = ratetbl->rate[i].count_cts;
 768			else
 769				rates[i].count = ratetbl->rate[i].count;
 770		} else {
 771			rates[i].idx = -1;
 772			rates[i].count = 0;
 773		}
 774
 775		if (rates[i].idx < 0 || !rates[i].count)
 776			break;
 777	}
 778}
 779
 780static bool rate_control_cap_mask(struct ieee80211_sub_if_data *sdata,
 781				  struct ieee80211_supported_band *sband,
 782				  struct ieee80211_sta *sta, u32 *mask,
 783				  u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
 784				  u16 vht_mask[NL80211_VHT_NSS_MAX])
 785{
 786	u32 i;
 787
 788	*mask = sdata->rc_rateidx_mask[sband->band];
 789
 790	if (*mask == (1 << sband->n_bitrates) - 1 &&
 791	    !sdata->rc_has_mcs_mask[sband->band] &&
 792	    !sdata->rc_has_vht_mcs_mask[sband->band])
 793		return false;
 794
 795	if (sdata->rc_has_mcs_mask[sband->band])
 796		memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[sband->band],
 797		       IEEE80211_HT_MCS_MASK_LEN);
 798	else
 799		memset(mcs_mask, 0xff, IEEE80211_HT_MCS_MASK_LEN);
 800
 801	if (sdata->rc_has_vht_mcs_mask[sband->band])
 802		memcpy(vht_mask, sdata->rc_rateidx_vht_mcs_mask[sband->band],
 803		       sizeof(u16) * NL80211_VHT_NSS_MAX);
 804	else
 805		memset(vht_mask, 0xff, sizeof(u16) * NL80211_VHT_NSS_MAX);
 806
 807	if (sta) {
 808		__le16 sta_vht_cap;
 809		u16 sta_vht_mask[NL80211_VHT_NSS_MAX];
 810
 811		/* Filter out rates that the STA does not support */
 812		*mask &= sta->deflink.supp_rates[sband->band];
 813		for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++)
 814			mcs_mask[i] &= sta->deflink.ht_cap.mcs.rx_mask[i];
 815
 816		sta_vht_cap = sta->deflink.vht_cap.vht_mcs.rx_mcs_map;
 817		ieee80211_get_vht_mask_from_cap(sta_vht_cap, sta_vht_mask);
 818		for (i = 0; i < NL80211_VHT_NSS_MAX; i++)
 819			vht_mask[i] &= sta_vht_mask[i];
 820	}
 821
 822	return true;
 823}
 824
 825static void
 826rate_control_apply_mask_ratetbl(struct sta_info *sta,
 827				struct ieee80211_supported_band *sband,
 828				struct ieee80211_sta_rates *rates)
 829{
 830	int i;
 831	u32 mask;
 832	u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
 833	u16 vht_mask[NL80211_VHT_NSS_MAX];
 834	enum nl80211_chan_width chan_width;
 835
 836	if (!rate_control_cap_mask(sta->sdata, sband, &sta->sta, &mask,
 837				   mcs_mask, vht_mask))
 838		return;
 839
 840	chan_width = sta->sdata->vif.bss_conf.chanreq.oper.width;
 841	for (i = 0; i < IEEE80211_TX_RATE_TABLE_SIZE; i++) {
 842		if (rates->rate[i].idx < 0)
 843			break;
 844
 845		rate_idx_match_mask(&rates->rate[i].idx, &rates->rate[i].flags,
 846				    sband, chan_width, mask, mcs_mask,
 847				    vht_mask);
 848	}
 849}
 850
 851static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
 852				    struct ieee80211_sta *sta,
 853				    struct ieee80211_supported_band *sband,
 854				    struct ieee80211_tx_rate *rates,
 855				    int max_rates)
 856{
 857	enum nl80211_chan_width chan_width;
 858	u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
 859	u32 mask;
 860	u16 rate_flags, vht_mask[NL80211_VHT_NSS_MAX];
 861	int i;
 862
 863	/*
 864	 * Try to enforce the rateidx mask the user wanted. skip this if the
 865	 * default mask (allow all rates) is used to save some processing for
 866	 * the common case.
 867	 */
 868	if (!rate_control_cap_mask(sdata, sband, sta, &mask, mcs_mask,
 869				   vht_mask))
 870		return;
 871
 872	/*
 873	 * Make sure the rate index selected for each TX rate is
 874	 * included in the configured mask and change the rate indexes
 875	 * if needed.
 876	 */
 877	chan_width = sdata->vif.bss_conf.chanreq.oper.width;
 878	for (i = 0; i < max_rates; i++) {
 879		/* Skip invalid rates */
 880		if (rates[i].idx < 0)
 881			break;
 882
 883		rate_flags = rates[i].flags;
 884		rate_idx_match_mask(&rates[i].idx, &rate_flags, sband,
 885				    chan_width, mask, mcs_mask, vht_mask);
 886		rates[i].flags = rate_flags;
 887	}
 888}
 889
 890void ieee80211_get_tx_rates(struct ieee80211_vif *vif,
 891			    struct ieee80211_sta *sta,
 892			    struct sk_buff *skb,
 893			    struct ieee80211_tx_rate *dest,
 894			    int max_rates)
 895{
 896	struct ieee80211_sub_if_data *sdata;
 897	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 898	struct ieee80211_supported_band *sband;
 899	u32 mask = ~0;
 900
 901	rate_control_fill_sta_table(sta, info, dest, max_rates);
 902
 903	if (!vif)
 904		return;
 905
 906	sdata = vif_to_sdata(vif);
 907	if (info->band >= NUM_NL80211_BANDS)
 908		return;
 909
 910	sband = sdata->local->hw.wiphy->bands[info->band];
 911
 912	if (ieee80211_is_tx_data(skb))
 913		rate_control_apply_mask(sdata, sta, sband, dest, max_rates);
 914
 915	if (!(info->control.flags & IEEE80211_TX_CTRL_DONT_USE_RATE_MASK))
 916		mask = sdata->rc_rateidx_mask[info->band];
 917
 918	if (dest[0].idx < 0)
 919		__rate_control_send_low(&sdata->local->hw, sband, sta, info,
 920					mask);
 921
 922	if (sta)
 923		rate_fixup_ratelist(vif, sband, info, dest, max_rates);
 924}
 925EXPORT_SYMBOL(ieee80211_get_tx_rates);
 926
 927void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
 928			   struct sta_info *sta,
 929			   struct ieee80211_tx_rate_control *txrc)
 930{
 931	struct rate_control_ref *ref = sdata->local->rate_ctrl;
 932	void *priv_sta = NULL;
 933	struct ieee80211_sta *ista = NULL;
 934	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 935	int i;
 936
 937	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
 938		info->control.rates[i].idx = -1;
 939		info->control.rates[i].flags = 0;
 940		info->control.rates[i].count = 0;
 941	}
 942
 943	if (rate_control_send_low(sta ? &sta->sta : NULL, txrc))
 944		return;
 945
 946	if (ieee80211_hw_check(&sdata->local->hw, HAS_RATE_CONTROL))
 947		return;
 948
 949	if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
 950		ista = &sta->sta;
 951		priv_sta = sta->rate_ctrl_priv;
 952	}
 953
 954	if (ista) {
 955		spin_lock_bh(&sta->rate_ctrl_lock);
 956		ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
 957		spin_unlock_bh(&sta->rate_ctrl_lock);
 958	} else {
 959		rate_control_send_low(NULL, txrc);
 960	}
 961
 962	if (ieee80211_hw_check(&sdata->local->hw, SUPPORTS_RC_TABLE))
 963		return;
 964
 965	ieee80211_get_tx_rates(&sdata->vif, ista, txrc->skb,
 966			       info->control.rates,
 967			       ARRAY_SIZE(info->control.rates));
 968}
 969
 970int rate_control_set_rates(struct ieee80211_hw *hw,
 971			   struct ieee80211_sta *pubsta,
 972			   struct ieee80211_sta_rates *rates)
 973{
 974	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 975	struct ieee80211_sta_rates *old;
 976	struct ieee80211_supported_band *sband;
 977
 978	sband = ieee80211_get_sband(sta->sdata);
 979	if (!sband)
 980		return -EINVAL;
 981	rate_control_apply_mask_ratetbl(sta, sband, rates);
 982	/*
 983	 * mac80211 guarantees that this function will not be called
 984	 * concurrently, so the following RCU access is safe, even without
 985	 * extra locking. This can not be checked easily, so we just set
 986	 * the condition to true.
 987	 */
 988	old = rcu_dereference_protected(pubsta->rates, true);
 989	rcu_assign_pointer(pubsta->rates, rates);
 990	if (old)
 991		kfree_rcu(old, rcu_head);
 992
 993	if (sta->uploaded)
 994		drv_sta_rate_tbl_update(hw_to_local(hw), sta->sdata, pubsta);
 995
 996	return 0;
 997}
 998EXPORT_SYMBOL(rate_control_set_rates);
 999
1000int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
1001				 const char *name)
1002{
1003	struct rate_control_ref *ref;
1004
1005	ASSERT_RTNL();
1006
1007	if (local->open_count)
1008		return -EBUSY;
1009
1010	if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL)) {
1011		if (WARN_ON(!local->ops->set_rts_threshold))
1012			return -EINVAL;
1013		return 0;
1014	}
1015
1016	ref = rate_control_alloc(name, local);
1017	if (!ref) {
1018		wiphy_warn(local->hw.wiphy,
1019			   "Failed to select rate control algorithm\n");
1020		return -ENOENT;
1021	}
1022
1023	WARN_ON(local->rate_ctrl);
1024	local->rate_ctrl = ref;
1025
1026	wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
1027		    ref->ops->name);
1028
1029	return 0;
1030}
1031
1032void rate_control_deinitialize(struct ieee80211_local *local)
1033{
1034	struct rate_control_ref *ref;
1035
1036	ref = local->rate_ctrl;
1037
1038	if (!ref)
1039		return;
1040
1041	local->rate_ctrl = NULL;
1042	rate_control_free(local, ref);
1043}