onoe.c revision 144347
1/*- 2 * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer, 10 * without modification. 11 * 2. Redistributions in binary form must reproduce at minimum a disclaimer 12 * similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any 13 * redistribution must be conditioned upon including a substantially 14 * similar Disclaimer requirement for further binary redistribution. 15 * 3. Neither the names of the above-listed copyright holders nor the names 16 * of any contributors may be used to endorse or promote products derived 17 * from this software without specific prior written permission. 18 * 19 * Alternatively, this software may be distributed under the terms of the 20 * GNU General Public License ("GPL") version 2 as published by the Free 21 * Software Foundation. 22 * 23 * NO WARRANTY 24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 25 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 26 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY 27 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 28 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, 29 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER 32 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 34 * THE POSSIBILITY OF SUCH DAMAGES. 35 */ 36 37#include <sys/cdefs.h> 38__FBSDID("$FreeBSD: head/sys/dev/ath/ath_rate/onoe/onoe.c 144347 2005-03-30 20:17:18Z sam $"); 39 40/* 41 * Atsushi Onoe's rate control algorithm. 42 */ 43#include "opt_inet.h" 44 45#include <sys/param.h> 46#include <sys/systm.h> 47#include <sys/sysctl.h> 48#include <sys/module.h> 49#include <sys/kernel.h> 50#include <sys/lock.h> 51#include <sys/mutex.h> 52#include <sys/errno.h> 53 54#include <machine/bus.h> 55#include <machine/resource.h> 56#include <sys/bus.h> 57 58#include <sys/socket.h> 59 60#include <net/if.h> 61#include <net/if_media.h> 62#include <net/if_arp.h> 63#include <net/ethernet.h> /* XXX for ether_sprintf */ 64 65#include <net80211/ieee80211_var.h> 66 67#include <net/bpf.h> 68 69#ifdef INET 70#include <netinet/in.h> 71#include <netinet/if_ether.h> 72#endif 73 74#include <dev/ath/if_athvar.h> 75#include <dev/ath/ath_rate/onoe/onoe.h> 76#include <contrib/dev/ath/ah_desc.h> 77 78#define ONOE_DEBUG 79#ifdef ONOE_DEBUG 80enum { 81 ATH_DEBUG_RATE = 0x00000010, /* rate control */ 82}; 83#define DPRINTF(sc, _fmt, ...) do { \ 84 if (sc->sc_debug & ATH_DEBUG_RATE) \ 85 printf(_fmt, __VA_ARGS__); \ 86} while (0) 87#else 88#define DPRINTF(sc, _fmt, ...) 89#endif 90 91/* 92 * Default parameters for the rate control algorithm. These are 93 * all tunable with sysctls. The rate controller runs periodically 94 * (each ath_rateinterval ms) analyzing transmit statistics for each 95 * neighbor/station (when operating in station mode this is only the AP). 96 * If transmits look to be working well over a sampling period then 97 * it gives a "raise rate credit". If transmits look to not be working 98 * well than it deducts a credit. If the credits cross a threshold then 99 * the transmit rate is raised. Various error conditions force the 100 * the transmit rate to be dropped. 101 * 102 * The decision to issue/deduct a credit is based on the errors and 103 * retries accumulated over the sampling period. ath_rate_raise defines 104 * the percent of retransmits for which a credit is issued/deducted. 105 * ath_rate_raise_threshold defines the threshold on credits at which 106 * the transmit rate is increased. 107 * 108 * XXX this algorithm is flawed. 109 */ 110static int ath_rateinterval = 1000; /* rate ctl interval (ms) */ 111static int ath_rate_raise = 10; /* add credit threshold */ 112static int ath_rate_raise_threshold = 10; /* rate ctl raise threshold */ 113 114static void ath_ratectl(void *); 115static void ath_rate_update(struct ath_softc *, struct ieee80211_node *, 116 int rate); 117static void ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *); 118static void ath_rate_ctl(void *, struct ieee80211_node *); 119 120void 121ath_rate_node_init(struct ath_softc *sc, struct ath_node *an) 122{ 123 /* NB: assumed to be zero'd by caller */ 124 ath_rate_update(sc, &an->an_node, 0); 125} 126 127void 128ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an) 129{ 130} 131 132void 133ath_rate_findrate(struct ath_softc *sc, struct ath_node *an, 134 HAL_BOOL shortPreamble, size_t frameLen, 135 u_int8_t *rix, int *try0, u_int8_t *txrate) 136{ 137 struct onoe_node *on = ATH_NODE_ONOE(an); 138 139 *rix = on->on_tx_rix0; 140 *try0 = on->on_tx_try0; 141 if (shortPreamble) 142 *txrate = on->on_tx_rate0sp; 143 else 144 *txrate = on->on_tx_rate0; 145} 146 147void 148ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an, 149 struct ath_desc *ds, HAL_BOOL shortPreamble, u_int8_t rix) 150{ 151 struct onoe_node *on = ATH_NODE_ONOE(an); 152 153 ath_hal_setupxtxdesc(sc->sc_ah, ds 154 , on->on_tx_rate1sp, 2 /* series 1 */ 155 , on->on_tx_rate2sp, 2 /* series 2 */ 156 , on->on_tx_rate3sp, 2 /* series 3 */ 157 ); 158} 159 160void 161ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an, 162 const struct ath_desc *ds, const struct ath_desc *ds0) 163{ 164 struct onoe_node *on = ATH_NODE_ONOE(an); 165 166 if (ds->ds_txstat.ts_status == 0) 167 on->on_tx_ok++; 168 else 169 on->on_tx_err++; 170 on->on_tx_retr += ds->ds_txstat.ts_shortretry 171 + ds->ds_txstat.ts_longretry; 172} 173 174void 175ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew) 176{ 177 if (isnew) 178 ath_rate_ctl_start(sc, &an->an_node); 179} 180 181static void 182ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate) 183{ 184 struct ath_node *an = ATH_NODE(ni); 185 struct onoe_node *on = ATH_NODE_ONOE(an); 186 const HAL_RATE_TABLE *rt = sc->sc_currates; 187 u_int8_t rix; 188 189 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode)); 190 191 DPRINTF(sc, "%s: set xmit rate for %s to %dM\n", 192 __func__, ether_sprintf(ni->ni_macaddr), 193 ni->ni_rates.rs_nrates > 0 ? 194 (ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0); 195 196 ni->ni_txrate = rate; 197 /* XXX management/control frames always go at the lowest speed */ 198 an->an_tx_mgtrate = rt->info[0].rateCode; 199 an->an_tx_mgtratesp = an->an_tx_mgtrate | rt->info[0].shortPreamble; 200 /* 201 * Before associating a node has no rate set setup 202 * so we can't calculate any transmit codes to use. 203 * This is ok since we should never be sending anything 204 * but management frames and those always go at the 205 * lowest hardware rate. 206 */ 207 if (ni->ni_rates.rs_nrates == 0) 208 goto done; 209 on->on_tx_rix0 = sc->sc_rixmap[ 210 ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL]; 211 on->on_tx_rate0 = rt->info[on->on_tx_rix0].rateCode; 212 213 on->on_tx_rate0sp = on->on_tx_rate0 | 214 rt->info[on->on_tx_rix0].shortPreamble; 215 if (sc->sc_mrretry) { 216 /* 217 * Hardware supports multi-rate retry; setup two 218 * step-down retry rates and make the lowest rate 219 * be the ``last chance''. We use 4, 2, 2, 2 tries 220 * respectively (4 is set here, the rest are fixed 221 * in the xmit routine). 222 */ 223 on->on_tx_try0 = 1 + 3; /* 4 tries at rate 0 */ 224 if (--rate >= 0) { 225 rix = sc->sc_rixmap[ 226 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL]; 227 on->on_tx_rate1 = rt->info[rix].rateCode; 228 on->on_tx_rate1sp = on->on_tx_rate1 | 229 rt->info[rix].shortPreamble; 230 } else { 231 on->on_tx_rate1 = on->on_tx_rate1sp = 0; 232 } 233 if (--rate >= 0) { 234 rix = sc->sc_rixmap[ 235 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL]; 236 on->on_tx_rate2 = rt->info[rix].rateCode; 237 on->on_tx_rate2sp = on->on_tx_rate2 | 238 rt->info[rix].shortPreamble; 239 } else { 240 on->on_tx_rate2 = on->on_tx_rate2sp = 0; 241 } 242 if (rate > 0) { 243 /* NB: only do this if we didn't already do it above */ 244 on->on_tx_rate3 = rt->info[0].rateCode; 245 on->on_tx_rate3sp = 246 an->an_tx_mgtrate | rt->info[0].shortPreamble; 247 } else { 248 on->on_tx_rate3 = on->on_tx_rate3sp = 0; 249 } 250 } else { 251 on->on_tx_try0 = ATH_TXMAXTRY; /* max tries at rate 0 */ 252 on->on_tx_rate1 = on->on_tx_rate1sp = 0; 253 on->on_tx_rate2 = on->on_tx_rate2sp = 0; 254 on->on_tx_rate3 = on->on_tx_rate3sp = 0; 255 } 256done: 257 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = on->on_tx_upper = 0; 258} 259 260/* 261 * Set the starting transmit rate for a node. 262 */ 263static void 264ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni) 265{ 266#define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL) 267 struct ieee80211com *ic = &sc->sc_ic; 268 int srate; 269 270 KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates")); 271 if (ic->ic_fixed_rate == -1) { 272 /* 273 * No fixed rate is requested. For 11b start with 274 * the highest negotiated rate; otherwise, for 11g 275 * and 11a, we start "in the middle" at 24Mb or 36Mb. 276 */ 277 srate = ni->ni_rates.rs_nrates - 1; 278 if (sc->sc_curmode != IEEE80211_MODE_11B) { 279 /* 280 * Scan the negotiated rate set to find the 281 * closest rate. 282 */ 283 /* NB: the rate set is assumed sorted */ 284 for (; srate >= 0 && RATE(srate) > 72; srate--) 285 ; 286 KASSERT(srate >= 0, ("bogus rate set")); 287 } 288 } else { 289 /* 290 * A fixed rate is to be used; ic_fixed_rate is an 291 * index into the supported rate set. Convert this 292 * to the index into the negotiated rate set for 293 * the node. We know the rate is there because the 294 * rate set is checked when the station associates. 295 */ 296 const struct ieee80211_rateset *rs = 297 &ic->ic_sup_rates[ic->ic_curmode]; 298 int r = rs->rs_rates[ic->ic_fixed_rate] & IEEE80211_RATE_VAL; 299 /* NB: the rate set is assumed sorted */ 300 srate = ni->ni_rates.rs_nrates - 1; 301 for (; srate >= 0 && RATE(srate) != r; srate--) 302 ; 303 KASSERT(srate >= 0, 304 ("fixed rate %d not in rate set", ic->ic_fixed_rate)); 305 } 306 ath_rate_update(sc, ni, srate); 307#undef RATE 308} 309 310static void 311ath_rate_cb(void *arg, struct ieee80211_node *ni) 312{ 313 struct ath_softc *sc = arg; 314 315 ath_rate_update(sc, ni, 0); 316} 317 318/* 319 * Reset the rate control state for each 802.11 state transition. 320 */ 321void 322ath_rate_newstate(struct ath_softc *sc, enum ieee80211_state state) 323{ 324 struct onoe_softc *osc = (struct onoe_softc *) sc->sc_rc; 325 struct ieee80211com *ic = &sc->sc_ic; 326 struct ieee80211_node *ni; 327 328 if (state == IEEE80211_S_INIT) { 329 callout_stop(&osc->timer); 330 return; 331 } 332 if (ic->ic_opmode == IEEE80211_M_STA) { 333 /* 334 * Reset local xmit state; this is really only 335 * meaningful when operating in station mode. 336 */ 337 ni = ic->ic_bss; 338 if (state == IEEE80211_S_RUN) { 339 ath_rate_ctl_start(sc, ni); 340 } else { 341 ath_rate_update(sc, ni, 0); 342 } 343 } else { 344 /* 345 * When operating as a station the node table holds 346 * the AP's that were discovered during scanning. 347 * For any other operating mode we want to reset the 348 * tx rate state of each node. 349 */ 350 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_cb, sc); 351 ath_rate_update(sc, ic->ic_bss, 0); 352 } 353 if (ic->ic_fixed_rate == -1 && state == IEEE80211_S_RUN) { 354 int interval; 355 /* 356 * Start the background rate control thread if we 357 * are not configured to use a fixed xmit rate. 358 */ 359 interval = ath_rateinterval; 360 if (ic->ic_opmode == IEEE80211_M_STA) 361 interval /= 2; 362 callout_reset(&osc->timer, (interval * hz) / 1000, 363 ath_ratectl, &sc->sc_if); 364 } 365} 366 367/* 368 * Examine and potentially adjust the transmit rate. 369 */ 370static void 371ath_rate_ctl(void *arg, struct ieee80211_node *ni) 372{ 373 struct ath_softc *sc = arg; 374 struct onoe_node *on = ATH_NODE_ONOE(ATH_NODE(ni)); 375 struct ieee80211_rateset *rs = &ni->ni_rates; 376 int dir = 0, nrate, enough; 377 378 /* 379 * Rate control 380 * XXX: very primitive version. 381 */ 382 enough = (on->on_tx_ok + on->on_tx_err >= 10); 383 384 /* no packet reached -> down */ 385 if (on->on_tx_err > 0 && on->on_tx_ok == 0) 386 dir = -1; 387 388 /* all packets needs retry in average -> down */ 389 if (enough && on->on_tx_ok < on->on_tx_retr) 390 dir = -1; 391 392 /* no error and less than rate_raise% of packets need retry -> up */ 393 if (enough && on->on_tx_err == 0 && 394 on->on_tx_retr < (on->on_tx_ok * ath_rate_raise) / 100) 395 dir = 1; 396 397 DPRINTF(sc, "%s: ok %d err %d retr %d upper %d dir %d\n", 398 ether_sprintf(ni->ni_macaddr), 399 on->on_tx_ok, on->on_tx_err, on->on_tx_retr, 400 on->on_tx_upper, dir); 401 402 nrate = ni->ni_txrate; 403 switch (dir) { 404 case 0: 405 if (enough && on->on_tx_upper > 0) 406 on->on_tx_upper--; 407 break; 408 case -1: 409 if (nrate > 0) { 410 nrate--; 411 sc->sc_stats.ast_rate_drop++; 412 } 413 on->on_tx_upper = 0; 414 break; 415 case 1: 416 /* raise rate if we hit rate_raise_threshold */ 417 if (++on->on_tx_upper < ath_rate_raise_threshold) 418 break; 419 on->on_tx_upper = 0; 420 if (nrate + 1 < rs->rs_nrates) { 421 nrate++; 422 sc->sc_stats.ast_rate_raise++; 423 } 424 break; 425 } 426 427 if (nrate != ni->ni_txrate) { 428 DPRINTF(sc, "%s: %dM -> %dM (%d ok, %d err, %d retr)\n", 429 __func__, 430 (rs->rs_rates[ni->ni_txrate] & IEEE80211_RATE_VAL) / 2, 431 (rs->rs_rates[nrate] & IEEE80211_RATE_VAL) / 2, 432 on->on_tx_ok, on->on_tx_err, on->on_tx_retr); 433 ath_rate_update(sc, ni, nrate); 434 } else if (enough) 435 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = 0; 436} 437 438static void 439ath_ratectl(void *arg) 440{ 441 struct ifnet *ifp = arg; 442 struct ath_softc *sc = ifp->if_softc; 443 struct onoe_softc *osc = (struct onoe_softc *) sc->sc_rc; 444 struct ieee80211com *ic = &sc->sc_ic; 445 int interval; 446 447 if (ifp->if_flags & IFF_RUNNING) { 448 sc->sc_stats.ast_rate_calls++; 449 450 if (ic->ic_opmode == IEEE80211_M_STA) 451 ath_rate_ctl(sc, ic->ic_bss); /* NB: no reference */ 452 else 453 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_ctl, sc); 454 } 455 interval = ath_rateinterval; 456 if (ic->ic_opmode == IEEE80211_M_STA) 457 interval /= 2; 458 callout_reset(&osc->timer, (interval * hz) / 1000, 459 ath_ratectl, &sc->sc_if); 460} 461 462static void 463ath_rate_sysctlattach(struct ath_softc *sc) 464{ 465 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev); 466 struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev); 467 468 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 469 "rate_interval", CTLFLAG_RW, &ath_rateinterval, 0, 470 "rate control: operation interval (ms)"); 471 /* XXX bounds check values */ 472 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 473 "rate_raise", CTLFLAG_RW, &ath_rate_raise, 0, 474 "rate control: retry threshold to credit rate raise (%%)"); 475 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 476 "rate_raise_threshold", CTLFLAG_RW, &ath_rate_raise_threshold,0, 477 "rate control: # good periods before raising rate"); 478} 479 480struct ath_ratectrl * 481ath_rate_attach(struct ath_softc *sc) 482{ 483 struct onoe_softc *osc; 484 485 osc = malloc(sizeof(struct onoe_softc), M_DEVBUF, M_NOWAIT|M_ZERO); 486 if (osc == NULL) 487 return NULL; 488 osc->arc.arc_space = sizeof(struct onoe_node); 489 callout_init(&osc->timer, debug_mpsafenet ? CALLOUT_MPSAFE : 0); 490 ath_rate_sysctlattach(sc); 491 492 return &osc->arc; 493} 494 495void 496ath_rate_detach(struct ath_ratectrl *arc) 497{ 498 struct onoe_softc *osc = (struct onoe_softc *) arc; 499 500 callout_drain(&osc->timer); 501 free(osc, M_DEVBUF); 502} 503 504/* 505 * Module glue. 506 */ 507static int 508onoe_modevent(module_t mod, int type, void *unused) 509{ 510 switch (type) { 511 case MOD_LOAD: 512 if (bootverbose) 513 printf("ath_rate: <Atsushi Onoe's rate control algorithm>\n"); 514 return 0; 515 case MOD_UNLOAD: 516 return 0; 517 } 518 return EINVAL; 519} 520 521static moduledata_t onoe_mod = { 522 "ath_rate", 523 onoe_modevent, 524 0 525}; 526DECLARE_MODULE(ath_rate, onoe_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST); 527MODULE_VERSION(ath_rate, 1); 528MODULE_DEPEND(ath_rate, wlan, 1, 1, 1); 529