rate.c revision 0d528d85c519b755b6f4e1bafa3a39984370e1c1
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/slab.h> 14#include <linux/module.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 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(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(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 struct rate_control_ops * 80ieee80211_try_rate_control_ops_get(const char *name) 81{ 82 struct rate_control_alg *alg; 83 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 if (try_module_get(alg->ops->module)) { 92 ops = alg->ops; 93 break; 94 } 95 } 96 mutex_unlock(&rate_ctrl_mutex); 97 return ops; 98} 99 100/* Get the rate control algorithm. */ 101static struct rate_control_ops * 102ieee80211_rate_control_ops_get(const char *name) 103{ 104 struct rate_control_ops *ops; 105 const char *alg_name; 106 107 kparam_block_sysfs_write(ieee80211_default_rc_algo); 108 if (!name) 109 alg_name = ieee80211_default_rc_algo; 110 else 111 alg_name = name; 112 113 ops = ieee80211_try_rate_control_ops_get(alg_name); 114 if (!ops) { 115 request_module("rc80211_%s", alg_name); 116 ops = ieee80211_try_rate_control_ops_get(alg_name); 117 } 118 if (!ops && name) 119 /* try default if specific alg requested but not found */ 120 ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo); 121 122 /* try built-in one if specific alg requested but not found */ 123 if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT)) 124 ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT); 125 kparam_unblock_sysfs_write(ieee80211_default_rc_algo); 126 127 return ops; 128} 129 130static void ieee80211_rate_control_ops_put(struct rate_control_ops *ops) 131{ 132 module_put(ops->module); 133} 134 135#ifdef CONFIG_MAC80211_DEBUGFS 136static ssize_t rcname_read(struct file *file, char __user *userbuf, 137 size_t count, loff_t *ppos) 138{ 139 struct rate_control_ref *ref = file->private_data; 140 int len = strlen(ref->ops->name); 141 142 return simple_read_from_buffer(userbuf, count, ppos, 143 ref->ops->name, len); 144} 145 146static const struct file_operations rcname_ops = { 147 .read = rcname_read, 148 .open = simple_open, 149 .llseek = default_llseek, 150}; 151#endif 152 153static struct rate_control_ref *rate_control_alloc(const char *name, 154 struct ieee80211_local *local) 155{ 156 struct dentry *debugfsdir = NULL; 157 struct rate_control_ref *ref; 158 159 ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL); 160 if (!ref) 161 goto fail_ref; 162 ref->local = local; 163 ref->ops = ieee80211_rate_control_ops_get(name); 164 if (!ref->ops) 165 goto fail_ops; 166 167#ifdef CONFIG_MAC80211_DEBUGFS 168 debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir); 169 local->debugfs.rcdir = debugfsdir; 170 debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops); 171#endif 172 173 ref->priv = ref->ops->alloc(&local->hw, debugfsdir); 174 if (!ref->priv) 175 goto fail_priv; 176 return ref; 177 178fail_priv: 179 ieee80211_rate_control_ops_put(ref->ops); 180fail_ops: 181 kfree(ref); 182fail_ref: 183 return NULL; 184} 185 186static void rate_control_free(struct rate_control_ref *ctrl_ref) 187{ 188 ctrl_ref->ops->free(ctrl_ref->priv); 189 190#ifdef CONFIG_MAC80211_DEBUGFS 191 debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir); 192 ctrl_ref->local->debugfs.rcdir = NULL; 193#endif 194 195 ieee80211_rate_control_ops_put(ctrl_ref->ops); 196 kfree(ctrl_ref); 197} 198 199static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc) 200{ 201 struct sk_buff *skb = txrc->skb; 202 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 203 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 204 __le16 fc; 205 206 fc = hdr->frame_control; 207 208 return (info->flags & (IEEE80211_TX_CTL_NO_ACK | 209 IEEE80211_TX_CTL_USE_MINRATE)) || 210 !ieee80211_is_data(fc); 211} 212 213static void rc_send_low_broadcast(s8 *idx, u32 basic_rates, 214 struct ieee80211_supported_band *sband) 215{ 216 u8 i; 217 218 if (basic_rates == 0) 219 return; /* assume basic rates unknown and accept rate */ 220 if (*idx < 0) 221 return; 222 if (basic_rates & (1 << *idx)) 223 return; /* selected rate is a basic rate */ 224 225 for (i = *idx + 1; i <= sband->n_bitrates; i++) { 226 if (basic_rates & (1 << i)) { 227 *idx = i; 228 return; 229 } 230 } 231 232 /* could not find a basic rate; use original selection */ 233} 234 235static inline s8 236rate_lowest_non_cck_index(struct ieee80211_supported_band *sband, 237 struct ieee80211_sta *sta) 238{ 239 int i; 240 241 for (i = 0; i < sband->n_bitrates; i++) { 242 struct ieee80211_rate *srate = &sband->bitrates[i]; 243 if ((srate->bitrate == 10) || (srate->bitrate == 20) || 244 (srate->bitrate == 55) || (srate->bitrate == 110)) 245 continue; 246 247 if (rate_supported(sta, sband->band, i)) 248 return i; 249 } 250 251 /* No matching rate found */ 252 return 0; 253} 254 255static void __rate_control_send_low(struct ieee80211_hw *hw, 256 struct ieee80211_supported_band *sband, 257 struct ieee80211_sta *sta, 258 struct ieee80211_tx_info *info) 259{ 260 if ((sband->band != IEEE80211_BAND_2GHZ) || 261 !(info->flags & IEEE80211_TX_CTL_NO_CCK_RATE)) 262 info->control.rates[0].idx = rate_lowest_index(sband, sta); 263 else 264 info->control.rates[0].idx = 265 rate_lowest_non_cck_index(sband, sta); 266 267 info->control.rates[0].count = 268 (info->flags & IEEE80211_TX_CTL_NO_ACK) ? 269 1 : hw->max_rate_tries; 270 271 info->control.skip_table = 1; 272} 273 274 275bool rate_control_send_low(struct ieee80211_sta *sta, 276 void *priv_sta, 277 struct ieee80211_tx_rate_control *txrc) 278{ 279 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); 280 struct ieee80211_supported_band *sband = txrc->sband; 281 int mcast_rate; 282 283 if (!sta || !priv_sta || rc_no_data_or_no_ack_use_min(txrc)) { 284 __rate_control_send_low(txrc->hw, sband, sta, info); 285 286 if (!sta && txrc->bss) { 287 mcast_rate = txrc->bss_conf->mcast_rate[sband->band]; 288 if (mcast_rate > 0) { 289 info->control.rates[0].idx = mcast_rate - 1; 290 return true; 291 } 292 293 rc_send_low_broadcast(&info->control.rates[0].idx, 294 txrc->bss_conf->basic_rates, 295 sband); 296 } 297 return true; 298 } 299 return false; 300} 301EXPORT_SYMBOL(rate_control_send_low); 302 303static bool rate_idx_match_legacy_mask(struct ieee80211_tx_rate *rate, 304 int n_bitrates, u32 mask) 305{ 306 int j; 307 308 /* See whether the selected rate or anything below it is allowed. */ 309 for (j = rate->idx; j >= 0; j--) { 310 if (mask & (1 << j)) { 311 /* Okay, found a suitable rate. Use it. */ 312 rate->idx = j; 313 return true; 314 } 315 } 316 317 /* Try to find a higher rate that would be allowed */ 318 for (j = rate->idx + 1; j < n_bitrates; j++) { 319 if (mask & (1 << j)) { 320 /* Okay, found a suitable rate. Use it. */ 321 rate->idx = j; 322 return true; 323 } 324 } 325 return false; 326} 327 328static bool rate_idx_match_mcs_mask(struct ieee80211_tx_rate *rate, 329 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN]) 330{ 331 int i, j; 332 int ridx, rbit; 333 334 ridx = rate->idx / 8; 335 rbit = rate->idx % 8; 336 337 /* sanity check */ 338 if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN) 339 return false; 340 341 /* See whether the selected rate or anything below it is allowed. */ 342 for (i = ridx; i >= 0; i--) { 343 for (j = rbit; j >= 0; j--) 344 if (mcs_mask[i] & BIT(j)) { 345 rate->idx = i * 8 + j; 346 return true; 347 } 348 rbit = 7; 349 } 350 351 /* Try to find a higher rate that would be allowed */ 352 ridx = (rate->idx + 1) / 8; 353 rbit = (rate->idx + 1) % 8; 354 355 for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) { 356 for (j = rbit; j < 8; j++) 357 if (mcs_mask[i] & BIT(j)) { 358 rate->idx = i * 8 + j; 359 return true; 360 } 361 rbit = 0; 362 } 363 return false; 364} 365 366 367 368static void rate_idx_match_mask(struct ieee80211_tx_rate *rate, 369 struct ieee80211_supported_band *sband, 370 enum nl80211_chan_width chan_width, 371 u32 mask, 372 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN]) 373{ 374 struct ieee80211_tx_rate alt_rate; 375 376 /* handle HT rates */ 377 if (rate->flags & IEEE80211_TX_RC_MCS) { 378 if (rate_idx_match_mcs_mask(rate, mcs_mask)) 379 return; 380 381 /* also try the legacy rates. */ 382 alt_rate.idx = 0; 383 /* keep protection flags */ 384 alt_rate.flags = rate->flags & 385 (IEEE80211_TX_RC_USE_RTS_CTS | 386 IEEE80211_TX_RC_USE_CTS_PROTECT | 387 IEEE80211_TX_RC_USE_SHORT_PREAMBLE); 388 alt_rate.count = rate->count; 389 if (rate_idx_match_legacy_mask(&alt_rate, 390 sband->n_bitrates, mask)) { 391 *rate = alt_rate; 392 return; 393 } 394 } else { 395 /* handle legacy rates */ 396 if (rate_idx_match_legacy_mask(rate, sband->n_bitrates, mask)) 397 return; 398 399 /* if HT BSS, and we handle a data frame, also try HT rates */ 400 if (chan_width == NL80211_CHAN_WIDTH_20_NOHT) 401 return; 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 int i; 583 584 /* 585 * Try to enforce the rateidx mask the user wanted. skip this if the 586 * default mask (allow all rates) is used to save some processing for 587 * the common case. 588 */ 589 mask = sdata->rc_rateidx_mask[info->band]; 590 has_mcs_mask = sdata->rc_has_mcs_mask[info->band]; 591 if (mask == (1 << sband->n_bitrates) - 1 && !has_mcs_mask) 592 return; 593 594 if (has_mcs_mask) 595 memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[info->band], 596 sizeof(mcs_mask)); 597 else 598 memset(mcs_mask, 0xff, sizeof(mcs_mask)); 599 600 if (sta) { 601 /* Filter out rates that the STA does not support */ 602 mask &= sta->supp_rates[info->band]; 603 for (i = 0; i < sizeof(mcs_mask); i++) 604 mcs_mask[i] &= sta->ht_cap.mcs.rx_mask[i]; 605 } 606 607 /* 608 * Make sure the rate index selected for each TX rate is 609 * included in the configured mask and change the rate indexes 610 * if needed. 611 */ 612 chan_width = sdata->vif.bss_conf.chandef.width; 613 for (i = 0; i < max_rates; i++) { 614 /* Skip invalid rates */ 615 if (rates[i].idx < 0) 616 break; 617 618 rate_idx_match_mask(&rates[i], sband, mask, chan_width, 619 mcs_mask); 620 } 621} 622 623void ieee80211_get_tx_rates(struct ieee80211_vif *vif, 624 struct ieee80211_sta *sta, 625 struct sk_buff *skb, 626 struct ieee80211_tx_rate *dest, 627 int max_rates) 628{ 629 struct ieee80211_sub_if_data *sdata; 630 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 631 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 632 struct ieee80211_supported_band *sband; 633 634 rate_control_fill_sta_table(sta, info, dest, max_rates); 635 636 if (!vif) 637 return; 638 639 sdata = vif_to_sdata(vif); 640 sband = sdata->local->hw.wiphy->bands[info->band]; 641 642 if (ieee80211_is_data(hdr->frame_control)) 643 rate_control_apply_mask(sdata, sta, sband, info, dest, max_rates); 644 645 if (dest[0].idx < 0) 646 __rate_control_send_low(&sdata->local->hw, sband, sta, info); 647 648 if (sta) 649 rate_fixup_ratelist(vif, sband, info, dest, max_rates); 650} 651EXPORT_SYMBOL(ieee80211_get_tx_rates); 652 653void rate_control_get_rate(struct ieee80211_sub_if_data *sdata, 654 struct sta_info *sta, 655 struct ieee80211_tx_rate_control *txrc) 656{ 657 struct rate_control_ref *ref = sdata->local->rate_ctrl; 658 void *priv_sta = NULL; 659 struct ieee80211_sta *ista = NULL; 660 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); 661 int i; 662 663 if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) { 664 ista = &sta->sta; 665 priv_sta = sta->rate_ctrl_priv; 666 } 667 668 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { 669 info->control.rates[i].idx = -1; 670 info->control.rates[i].flags = 0; 671 info->control.rates[i].count = 0; 672 } 673 674 if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) 675 return; 676 677 ref->ops->get_rate(ref->priv, ista, priv_sta, txrc); 678 679 if (sdata->local->hw.flags & IEEE80211_HW_SUPPORTS_RC_TABLE) 680 return; 681 682 ieee80211_get_tx_rates(&sdata->vif, ista, txrc->skb, 683 info->control.rates, 684 ARRAY_SIZE(info->control.rates)); 685} 686 687int rate_control_set_rates(struct ieee80211_hw *hw, 688 struct ieee80211_sta *pubsta, 689 struct ieee80211_sta_rates *rates) 690{ 691 struct ieee80211_sta_rates *old = rcu_dereference(pubsta->rates); 692 693 rcu_assign_pointer(pubsta->rates, rates); 694 if (old) 695 kfree_rcu(old, rcu_head); 696 697 return 0; 698} 699EXPORT_SYMBOL(rate_control_set_rates); 700 701int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local, 702 const char *name) 703{ 704 struct rate_control_ref *ref; 705 706 ASSERT_RTNL(); 707 708 if (local->open_count) 709 return -EBUSY; 710 711 if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) { 712 if (WARN_ON(!local->ops->set_rts_threshold)) 713 return -EINVAL; 714 return 0; 715 } 716 717 ref = rate_control_alloc(name, local); 718 if (!ref) { 719 wiphy_warn(local->hw.wiphy, 720 "Failed to select rate control algorithm\n"); 721 return -ENOENT; 722 } 723 724 WARN_ON(local->rate_ctrl); 725 local->rate_ctrl = ref; 726 727 wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n", 728 ref->ops->name); 729 730 return 0; 731} 732 733void rate_control_deinitialize(struct ieee80211_local *local) 734{ 735 struct rate_control_ref *ref; 736 737 ref = local->rate_ctrl; 738 739 if (!ref) 740 return; 741 742 local->rate_ctrl = NULL; 743 rate_control_free(ref); 744} 745 746