rate.c revision c7abf25af0f41be4b50d44c5b185d52eea360cb8
1/* 2 * Copyright 2002-2005, Instant802 Networks, Inc. 3 * Copyright 2005-2006, Devicescape Software, Inc. 4 * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 11#include <linux/kernel.h> 12#include <linux/rtnetlink.h> 13#include <linux/module.h> 14#include <linux/slab.h> 15#include "rate.h" 16#include "ieee80211_i.h" 17#include "debugfs.h" 18 19struct rate_control_alg { 20 struct list_head list; 21 const struct rate_control_ops *ops; 22}; 23 24static LIST_HEAD(rate_ctrl_algs); 25static DEFINE_MUTEX(rate_ctrl_mutex); 26 27static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT; 28module_param(ieee80211_default_rc_algo, charp, 0644); 29MODULE_PARM_DESC(ieee80211_default_rc_algo, 30 "Default rate control algorithm for mac80211 to use"); 31 32int ieee80211_rate_control_register(const struct rate_control_ops *ops) 33{ 34 struct rate_control_alg *alg; 35 36 if (!ops->name) 37 return -EINVAL; 38 39 mutex_lock(&rate_ctrl_mutex); 40 list_for_each_entry(alg, &rate_ctrl_algs, list) { 41 if (!strcmp(alg->ops->name, ops->name)) { 42 /* don't register an algorithm twice */ 43 WARN_ON(1); 44 mutex_unlock(&rate_ctrl_mutex); 45 return -EALREADY; 46 } 47 } 48 49 alg = kzalloc(sizeof(*alg), GFP_KERNEL); 50 if (alg == NULL) { 51 mutex_unlock(&rate_ctrl_mutex); 52 return -ENOMEM; 53 } 54 alg->ops = ops; 55 56 list_add_tail(&alg->list, &rate_ctrl_algs); 57 mutex_unlock(&rate_ctrl_mutex); 58 59 return 0; 60} 61EXPORT_SYMBOL(ieee80211_rate_control_register); 62 63void ieee80211_rate_control_unregister(const struct rate_control_ops *ops) 64{ 65 struct rate_control_alg *alg; 66 67 mutex_lock(&rate_ctrl_mutex); 68 list_for_each_entry(alg, &rate_ctrl_algs, list) { 69 if (alg->ops == ops) { 70 list_del(&alg->list); 71 kfree(alg); 72 break; 73 } 74 } 75 mutex_unlock(&rate_ctrl_mutex); 76} 77EXPORT_SYMBOL(ieee80211_rate_control_unregister); 78 79static const struct rate_control_ops * 80ieee80211_try_rate_control_ops_get(const char *name) 81{ 82 struct rate_control_alg *alg; 83 const struct rate_control_ops *ops = NULL; 84 85 if (!name) 86 return NULL; 87 88 mutex_lock(&rate_ctrl_mutex); 89 list_for_each_entry(alg, &rate_ctrl_algs, list) { 90 if (!strcmp(alg->ops->name, name)) { 91 ops = alg->ops; 92 break; 93 } 94 } 95 mutex_unlock(&rate_ctrl_mutex); 96 return ops; 97} 98 99/* Get the rate control algorithm. */ 100static const struct rate_control_ops * 101ieee80211_rate_control_ops_get(const char *name) 102{ 103 const struct rate_control_ops *ops; 104 const char *alg_name; 105 106 kparam_block_sysfs_write(ieee80211_default_rc_algo); 107 if (!name) 108 alg_name = ieee80211_default_rc_algo; 109 else 110 alg_name = name; 111 112 ops = ieee80211_try_rate_control_ops_get(alg_name); 113 if (!ops && name) 114 /* try default if specific alg requested but not found */ 115 ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo); 116 117 /* try built-in one if specific alg requested but not found */ 118 if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT)) 119 ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT); 120 kparam_unblock_sysfs_write(ieee80211_default_rc_algo); 121 122 return ops; 123} 124 125#ifdef CONFIG_MAC80211_DEBUGFS 126static ssize_t rcname_read(struct file *file, char __user *userbuf, 127 size_t count, loff_t *ppos) 128{ 129 struct rate_control_ref *ref = file->private_data; 130 int len = strlen(ref->ops->name); 131 132 return simple_read_from_buffer(userbuf, count, ppos, 133 ref->ops->name, len); 134} 135 136static const struct file_operations rcname_ops = { 137 .read = rcname_read, 138 .open = simple_open, 139 .llseek = default_llseek, 140}; 141#endif 142 143static struct rate_control_ref *rate_control_alloc(const char *name, 144 struct ieee80211_local *local) 145{ 146 struct dentry *debugfsdir = NULL; 147 struct rate_control_ref *ref; 148 149 ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL); 150 if (!ref) 151 return NULL; 152 ref->local = local; 153 ref->ops = ieee80211_rate_control_ops_get(name); 154 if (!ref->ops) 155 goto free; 156 157#ifdef CONFIG_MAC80211_DEBUGFS 158 debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir); 159 local->debugfs.rcdir = debugfsdir; 160 debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops); 161#endif 162 163 ref->priv = ref->ops->alloc(&local->hw, debugfsdir); 164 if (!ref->priv) 165 goto free; 166 return ref; 167 168free: 169 kfree(ref); 170 return NULL; 171} 172 173static void rate_control_free(struct rate_control_ref *ctrl_ref) 174{ 175 ctrl_ref->ops->free(ctrl_ref->priv); 176 177#ifdef CONFIG_MAC80211_DEBUGFS 178 debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir); 179 ctrl_ref->local->debugfs.rcdir = NULL; 180#endif 181 182 kfree(ctrl_ref); 183} 184 185static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc) 186{ 187 struct sk_buff *skb = txrc->skb; 188 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 189 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 190 __le16 fc; 191 192 fc = hdr->frame_control; 193 194 return (info->flags & (IEEE80211_TX_CTL_NO_ACK | 195 IEEE80211_TX_CTL_USE_MINRATE)) || 196 !ieee80211_is_data(fc); 197} 198 199static void rc_send_low_basicrate(s8 *idx, u32 basic_rates, 200 struct ieee80211_supported_band *sband) 201{ 202 u8 i; 203 204 if (basic_rates == 0) 205 return; /* assume basic rates unknown and accept rate */ 206 if (*idx < 0) 207 return; 208 if (basic_rates & (1 << *idx)) 209 return; /* selected rate is a basic rate */ 210 211 for (i = *idx + 1; i <= sband->n_bitrates; i++) { 212 if (basic_rates & (1 << i)) { 213 *idx = i; 214 return; 215 } 216 } 217 218 /* could not find a basic rate; use original selection */ 219} 220 221static void __rate_control_send_low(struct ieee80211_hw *hw, 222 struct ieee80211_supported_band *sband, 223 struct ieee80211_sta *sta, 224 struct ieee80211_tx_info *info, 225 u32 rate_mask) 226{ 227 int i; 228 u32 rate_flags = 229 ieee80211_chandef_rate_flags(&hw->conf.chandef); 230 231 if ((sband->band == IEEE80211_BAND_2GHZ) && 232 (info->flags & IEEE80211_TX_CTL_NO_CCK_RATE)) 233 rate_flags |= IEEE80211_RATE_ERP_G; 234 235 info->control.rates[0].idx = 0; 236 for (i = 0; i < sband->n_bitrates; i++) { 237 if (!(rate_mask & BIT(i))) 238 continue; 239 240 if ((rate_flags & sband->bitrates[i].flags) != rate_flags) 241 continue; 242 243 if (!rate_supported(sta, sband->band, i)) 244 continue; 245 246 info->control.rates[0].idx = i; 247 break; 248 } 249 WARN_ON_ONCE(i == sband->n_bitrates); 250 251 info->control.rates[0].count = 252 (info->flags & IEEE80211_TX_CTL_NO_ACK) ? 253 1 : hw->max_rate_tries; 254 255 info->control.skip_table = 1; 256} 257 258 259bool rate_control_send_low(struct ieee80211_sta *pubsta, 260 void *priv_sta, 261 struct ieee80211_tx_rate_control *txrc) 262{ 263 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); 264 struct ieee80211_supported_band *sband = txrc->sband; 265 struct sta_info *sta; 266 int mcast_rate; 267 bool use_basicrate = false; 268 269 if (!pubsta || !priv_sta || rc_no_data_or_no_ack_use_min(txrc)) { 270 __rate_control_send_low(txrc->hw, sband, pubsta, info, 271 txrc->rate_idx_mask); 272 273 if (!pubsta && txrc->bss) { 274 mcast_rate = txrc->bss_conf->mcast_rate[sband->band]; 275 if (mcast_rate > 0) { 276 info->control.rates[0].idx = mcast_rate - 1; 277 return true; 278 } 279 use_basicrate = true; 280 } else if (pubsta) { 281 sta = container_of(pubsta, struct sta_info, sta); 282 if (ieee80211_vif_is_mesh(&sta->sdata->vif)) 283 use_basicrate = true; 284 } 285 286 if (use_basicrate) 287 rc_send_low_basicrate(&info->control.rates[0].idx, 288 txrc->bss_conf->basic_rates, 289 sband); 290 291 return true; 292 } 293 return false; 294} 295EXPORT_SYMBOL(rate_control_send_low); 296 297static bool rate_idx_match_legacy_mask(struct ieee80211_tx_rate *rate, 298 int n_bitrates, u32 mask) 299{ 300 int j; 301 302 /* See whether the selected rate or anything below it is allowed. */ 303 for (j = rate->idx; j >= 0; j--) { 304 if (mask & (1 << j)) { 305 /* Okay, found a suitable rate. Use it. */ 306 rate->idx = j; 307 return true; 308 } 309 } 310 311 /* Try to find a higher rate that would be allowed */ 312 for (j = rate->idx + 1; j < n_bitrates; j++) { 313 if (mask & (1 << j)) { 314 /* Okay, found a suitable rate. Use it. */ 315 rate->idx = j; 316 return true; 317 } 318 } 319 return false; 320} 321 322static bool rate_idx_match_mcs_mask(struct ieee80211_tx_rate *rate, 323 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN]) 324{ 325 int i, j; 326 int ridx, rbit; 327 328 ridx = rate->idx / 8; 329 rbit = rate->idx % 8; 330 331 /* sanity check */ 332 if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN) 333 return false; 334 335 /* See whether the selected rate or anything below it is allowed. */ 336 for (i = ridx; i >= 0; i--) { 337 for (j = rbit; j >= 0; j--) 338 if (mcs_mask[i] & BIT(j)) { 339 rate->idx = i * 8 + j; 340 return true; 341 } 342 rbit = 7; 343 } 344 345 /* Try to find a higher rate that would be allowed */ 346 ridx = (rate->idx + 1) / 8; 347 rbit = (rate->idx + 1) % 8; 348 349 for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) { 350 for (j = rbit; j < 8; j++) 351 if (mcs_mask[i] & BIT(j)) { 352 rate->idx = i * 8 + j; 353 return true; 354 } 355 rbit = 0; 356 } 357 return false; 358} 359 360 361 362static void rate_idx_match_mask(struct ieee80211_tx_rate *rate, 363 struct ieee80211_supported_band *sband, 364 enum nl80211_chan_width chan_width, 365 u32 mask, 366 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN]) 367{ 368 struct ieee80211_tx_rate alt_rate; 369 370 /* handle HT rates */ 371 if (rate->flags & IEEE80211_TX_RC_MCS) { 372 if (rate_idx_match_mcs_mask(rate, mcs_mask)) 373 return; 374 375 /* also try the legacy rates. */ 376 alt_rate.idx = 0; 377 /* keep protection flags */ 378 alt_rate.flags = rate->flags & 379 (IEEE80211_TX_RC_USE_RTS_CTS | 380 IEEE80211_TX_RC_USE_CTS_PROTECT | 381 IEEE80211_TX_RC_USE_SHORT_PREAMBLE); 382 alt_rate.count = rate->count; 383 if (rate_idx_match_legacy_mask(&alt_rate, 384 sband->n_bitrates, mask)) { 385 *rate = alt_rate; 386 return; 387 } 388 } else { 389 /* handle legacy rates */ 390 if (rate_idx_match_legacy_mask(rate, sband->n_bitrates, mask)) 391 return; 392 393 /* if HT BSS, and we handle a data frame, also try HT rates */ 394 switch (chan_width) { 395 case NL80211_CHAN_WIDTH_20_NOHT: 396 case NL80211_CHAN_WIDTH_5: 397 case NL80211_CHAN_WIDTH_10: 398 return; 399 default: 400 break; 401 } 402 403 alt_rate.idx = 0; 404 /* keep protection flags */ 405 alt_rate.flags = rate->flags & 406 (IEEE80211_TX_RC_USE_RTS_CTS | 407 IEEE80211_TX_RC_USE_CTS_PROTECT | 408 IEEE80211_TX_RC_USE_SHORT_PREAMBLE); 409 alt_rate.count = rate->count; 410 411 alt_rate.flags |= IEEE80211_TX_RC_MCS; 412 413 if (chan_width == NL80211_CHAN_WIDTH_40) 414 alt_rate.flags |= IEEE80211_TX_RC_40_MHZ_WIDTH; 415 416 if (rate_idx_match_mcs_mask(&alt_rate, mcs_mask)) { 417 *rate = alt_rate; 418 return; 419 } 420 } 421 422 /* 423 * Uh.. No suitable rate exists. This should not really happen with 424 * sane TX rate mask configurations. However, should someone manage to 425 * configure supported rates and TX rate mask in incompatible way, 426 * allow the frame to be transmitted with whatever the rate control 427 * selected. 428 */ 429} 430 431static void rate_fixup_ratelist(struct ieee80211_vif *vif, 432 struct ieee80211_supported_band *sband, 433 struct ieee80211_tx_info *info, 434 struct ieee80211_tx_rate *rates, 435 int max_rates) 436{ 437 struct ieee80211_rate *rate; 438 bool inval = false; 439 int i; 440 441 /* 442 * Set up the RTS/CTS rate as the fastest basic rate 443 * that is not faster than the data rate unless there 444 * is no basic rate slower than the data rate, in which 445 * case we pick the slowest basic rate 446 * 447 * XXX: Should this check all retry rates? 448 */ 449 if (!(rates[0].flags & IEEE80211_TX_RC_MCS)) { 450 u32 basic_rates = vif->bss_conf.basic_rates; 451 s8 baserate = basic_rates ? ffs(basic_rates) - 1 : 0; 452 453 rate = &sband->bitrates[rates[0].idx]; 454 455 for (i = 0; i < sband->n_bitrates; i++) { 456 /* must be a basic rate */ 457 if (!(basic_rates & BIT(i))) 458 continue; 459 /* must not be faster than the data rate */ 460 if (sband->bitrates[i].bitrate > rate->bitrate) 461 continue; 462 /* maximum */ 463 if (sband->bitrates[baserate].bitrate < 464 sband->bitrates[i].bitrate) 465 baserate = i; 466 } 467 468 info->control.rts_cts_rate_idx = baserate; 469 } 470 471 for (i = 0; i < max_rates; i++) { 472 /* 473 * make sure there's no valid rate following 474 * an invalid one, just in case drivers don't 475 * take the API seriously to stop at -1. 476 */ 477 if (inval) { 478 rates[i].idx = -1; 479 continue; 480 } 481 if (rates[i].idx < 0) { 482 inval = true; 483 continue; 484 } 485 486 /* 487 * For now assume MCS is already set up correctly, this 488 * needs to be fixed. 489 */ 490 if (rates[i].flags & IEEE80211_TX_RC_MCS) { 491 WARN_ON(rates[i].idx > 76); 492 493 if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) && 494 info->control.use_cts_prot) 495 rates[i].flags |= 496 IEEE80211_TX_RC_USE_CTS_PROTECT; 497 continue; 498 } 499 500 if (rates[i].flags & IEEE80211_TX_RC_VHT_MCS) { 501 WARN_ON(ieee80211_rate_get_vht_mcs(&rates[i]) > 9); 502 continue; 503 } 504 505 /* set up RTS protection if desired */ 506 if (info->control.use_rts) { 507 rates[i].flags |= IEEE80211_TX_RC_USE_RTS_CTS; 508 info->control.use_cts_prot = false; 509 } 510 511 /* RC is busted */ 512 if (WARN_ON_ONCE(rates[i].idx >= sband->n_bitrates)) { 513 rates[i].idx = -1; 514 continue; 515 } 516 517 rate = &sband->bitrates[rates[i].idx]; 518 519 /* set up short preamble */ 520 if (info->control.short_preamble && 521 rate->flags & IEEE80211_RATE_SHORT_PREAMBLE) 522 rates[i].flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE; 523 524 /* set up G protection */ 525 if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) && 526 info->control.use_cts_prot && 527 rate->flags & IEEE80211_RATE_ERP_G) 528 rates[i].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT; 529 } 530} 531 532 533static void rate_control_fill_sta_table(struct ieee80211_sta *sta, 534 struct ieee80211_tx_info *info, 535 struct ieee80211_tx_rate *rates, 536 int max_rates) 537{ 538 struct ieee80211_sta_rates *ratetbl = NULL; 539 int i; 540 541 if (sta && !info->control.skip_table) 542 ratetbl = rcu_dereference(sta->rates); 543 544 /* Fill remaining rate slots with data from the sta rate table. */ 545 max_rates = min_t(int, max_rates, IEEE80211_TX_RATE_TABLE_SIZE); 546 for (i = 0; i < max_rates; i++) { 547 if (i < ARRAY_SIZE(info->control.rates) && 548 info->control.rates[i].idx >= 0 && 549 info->control.rates[i].count) { 550 if (rates != info->control.rates) 551 rates[i] = info->control.rates[i]; 552 } else if (ratetbl) { 553 rates[i].idx = ratetbl->rate[i].idx; 554 rates[i].flags = ratetbl->rate[i].flags; 555 if (info->control.use_rts) 556 rates[i].count = ratetbl->rate[i].count_rts; 557 else if (info->control.use_cts_prot) 558 rates[i].count = ratetbl->rate[i].count_cts; 559 else 560 rates[i].count = ratetbl->rate[i].count; 561 } else { 562 rates[i].idx = -1; 563 rates[i].count = 0; 564 } 565 566 if (rates[i].idx < 0 || !rates[i].count) 567 break; 568 } 569} 570 571static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata, 572 struct ieee80211_sta *sta, 573 struct ieee80211_supported_band *sband, 574 struct ieee80211_tx_info *info, 575 struct ieee80211_tx_rate *rates, 576 int max_rates) 577{ 578 enum nl80211_chan_width chan_width; 579 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN]; 580 bool has_mcs_mask; 581 u32 mask; 582 u32 rate_flags; 583 int i; 584 585 /* 586 * Try to enforce the rateidx mask the user wanted. skip this if the 587 * default mask (allow all rates) is used to save some processing for 588 * the common case. 589 */ 590 mask = sdata->rc_rateidx_mask[info->band]; 591 has_mcs_mask = sdata->rc_has_mcs_mask[info->band]; 592 rate_flags = 593 ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chandef); 594 for (i = 0; i < sband->n_bitrates; i++) 595 if ((rate_flags & sband->bitrates[i].flags) != rate_flags) 596 mask &= ~BIT(i); 597 598 if (mask == (1 << sband->n_bitrates) - 1 && !has_mcs_mask) 599 return; 600 601 if (has_mcs_mask) 602 memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[info->band], 603 sizeof(mcs_mask)); 604 else 605 memset(mcs_mask, 0xff, sizeof(mcs_mask)); 606 607 if (sta) { 608 /* Filter out rates that the STA does not support */ 609 mask &= sta->supp_rates[info->band]; 610 for (i = 0; i < sizeof(mcs_mask); i++) 611 mcs_mask[i] &= sta->ht_cap.mcs.rx_mask[i]; 612 } 613 614 /* 615 * Make sure the rate index selected for each TX rate is 616 * included in the configured mask and change the rate indexes 617 * if needed. 618 */ 619 chan_width = sdata->vif.bss_conf.chandef.width; 620 for (i = 0; i < max_rates; i++) { 621 /* Skip invalid rates */ 622 if (rates[i].idx < 0) 623 break; 624 625 rate_idx_match_mask(&rates[i], sband, chan_width, mask, 626 mcs_mask); 627 } 628} 629 630void ieee80211_get_tx_rates(struct ieee80211_vif *vif, 631 struct ieee80211_sta *sta, 632 struct sk_buff *skb, 633 struct ieee80211_tx_rate *dest, 634 int max_rates) 635{ 636 struct ieee80211_sub_if_data *sdata; 637 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 638 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 639 struct ieee80211_supported_band *sband; 640 641 rate_control_fill_sta_table(sta, info, dest, max_rates); 642 643 if (!vif) 644 return; 645 646 sdata = vif_to_sdata(vif); 647 sband = sdata->local->hw.wiphy->bands[info->band]; 648 649 if (ieee80211_is_data(hdr->frame_control)) 650 rate_control_apply_mask(sdata, sta, sband, info, dest, max_rates); 651 652 if (dest[0].idx < 0) 653 __rate_control_send_low(&sdata->local->hw, sband, sta, info, 654 sdata->rc_rateidx_mask[info->band]); 655 656 if (sta) 657 rate_fixup_ratelist(vif, sband, info, dest, max_rates); 658} 659EXPORT_SYMBOL(ieee80211_get_tx_rates); 660 661void rate_control_get_rate(struct ieee80211_sub_if_data *sdata, 662 struct sta_info *sta, 663 struct ieee80211_tx_rate_control *txrc) 664{ 665 struct rate_control_ref *ref = sdata->local->rate_ctrl; 666 void *priv_sta = NULL; 667 struct ieee80211_sta *ista = NULL; 668 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); 669 int i; 670 671 if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) { 672 ista = &sta->sta; 673 priv_sta = sta->rate_ctrl_priv; 674 } 675 676 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { 677 info->control.rates[i].idx = -1; 678 info->control.rates[i].flags = 0; 679 info->control.rates[i].count = 0; 680 } 681 682 if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) 683 return; 684 685 ref->ops->get_rate(ref->priv, ista, priv_sta, txrc); 686 687 if (sdata->local->hw.flags & IEEE80211_HW_SUPPORTS_RC_TABLE) 688 return; 689 690 ieee80211_get_tx_rates(&sdata->vif, ista, txrc->skb, 691 info->control.rates, 692 ARRAY_SIZE(info->control.rates)); 693} 694 695int rate_control_set_rates(struct ieee80211_hw *hw, 696 struct ieee80211_sta *pubsta, 697 struct ieee80211_sta_rates *rates) 698{ 699 struct ieee80211_sta_rates *old; 700 701 /* 702 * mac80211 guarantees that this function will not be called 703 * concurrently, so the following RCU access is safe, even without 704 * extra locking. This can not be checked easily, so we just set 705 * the condition to true. 706 */ 707 old = rcu_dereference_protected(pubsta->rates, true); 708 rcu_assign_pointer(pubsta->rates, rates); 709 if (old) 710 kfree_rcu(old, rcu_head); 711 712 return 0; 713} 714EXPORT_SYMBOL(rate_control_set_rates); 715 716int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local, 717 const char *name) 718{ 719 struct rate_control_ref *ref; 720 721 ASSERT_RTNL(); 722 723 if (local->open_count) 724 return -EBUSY; 725 726 if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) { 727 if (WARN_ON(!local->ops->set_rts_threshold)) 728 return -EINVAL; 729 return 0; 730 } 731 732 ref = rate_control_alloc(name, local); 733 if (!ref) { 734 wiphy_warn(local->hw.wiphy, 735 "Failed to select rate control algorithm\n"); 736 return -ENOENT; 737 } 738 739 WARN_ON(local->rate_ctrl); 740 local->rate_ctrl = ref; 741 742 wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n", 743 ref->ops->name); 744 745 return 0; 746} 747 748void rate_control_deinitialize(struct ieee80211_local *local) 749{ 750 struct rate_control_ref *ref; 751 752 ref = local->rate_ctrl; 753 754 if (!ref) 755 return; 756 757 local->rate_ctrl = NULL; 758 rate_control_free(ref); 759} 760 761