onoe.c revision 155477
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 155477 2006-02-09 20:49:55Z 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 int 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, int 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 /* 198 * Before associating a node has no rate set setup 199 * so we can't calculate any transmit codes to use. 200 * This is ok since we should never be sending anything 201 * but management frames and those always go at the 202 * lowest hardware rate. 203 */ 204 if (ni->ni_rates.rs_nrates == 0) 205 goto done; 206 on->on_tx_rix0 = sc->sc_rixmap[ 207 ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL]; 208 on->on_tx_rate0 = rt->info[on->on_tx_rix0].rateCode; 209 210 on->on_tx_rate0sp = on->on_tx_rate0 | 211 rt->info[on->on_tx_rix0].shortPreamble; 212 if (sc->sc_mrretry) { 213 /* 214 * Hardware supports multi-rate retry; setup two 215 * step-down retry rates and make the lowest rate 216 * be the ``last chance''. We use 4, 2, 2, 2 tries 217 * respectively (4 is set here, the rest are fixed 218 * in the xmit routine). 219 */ 220 on->on_tx_try0 = 1 + 3; /* 4 tries at rate 0 */ 221 if (--rate >= 0) { 222 rix = sc->sc_rixmap[ 223 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL]; 224 on->on_tx_rate1 = rt->info[rix].rateCode; 225 on->on_tx_rate1sp = on->on_tx_rate1 | 226 rt->info[rix].shortPreamble; 227 } else { 228 on->on_tx_rate1 = on->on_tx_rate1sp = 0; 229 } 230 if (--rate >= 0) { 231 rix = sc->sc_rixmap[ 232 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL]; 233 on->on_tx_rate2 = rt->info[rix].rateCode; 234 on->on_tx_rate2sp = on->on_tx_rate2 | 235 rt->info[rix].shortPreamble; 236 } else { 237 on->on_tx_rate2 = on->on_tx_rate2sp = 0; 238 } 239 if (rate > 0) { 240 /* NB: only do this if we didn't already do it above */ 241 on->on_tx_rate3 = rt->info[0].rateCode; 242 on->on_tx_rate3sp = 243 on->on_tx_rate3 | rt->info[0].shortPreamble; 244 } else { 245 on->on_tx_rate3 = on->on_tx_rate3sp = 0; 246 } 247 } else { 248 on->on_tx_try0 = ATH_TXMAXTRY; /* max tries at rate 0 */ 249 on->on_tx_rate1 = on->on_tx_rate1sp = 0; 250 on->on_tx_rate2 = on->on_tx_rate2sp = 0; 251 on->on_tx_rate3 = on->on_tx_rate3sp = 0; 252 } 253done: 254 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = on->on_tx_upper = 0; 255} 256 257/* 258 * Set the starting transmit rate for a node. 259 */ 260static void 261ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni) 262{ 263#define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL) 264 struct ieee80211com *ic = &sc->sc_ic; 265 int srate; 266 267 KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates")); 268 if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE) { 269 /* 270 * No fixed rate is requested. For 11b start with 271 * the highest negotiated rate; otherwise, for 11g 272 * and 11a, we start "in the middle" at 24Mb or 36Mb. 273 */ 274 srate = ni->ni_rates.rs_nrates - 1; 275 if (sc->sc_curmode != IEEE80211_MODE_11B) { 276 /* 277 * Scan the negotiated rate set to find the 278 * closest rate. 279 */ 280 /* NB: the rate set is assumed sorted */ 281 for (; srate >= 0 && RATE(srate) > 72; srate--) 282 ; 283 KASSERT(srate >= 0, ("bogus rate set")); 284 } 285 } else { 286 /* 287 * A fixed rate is to be used; ic_fixed_rate is an 288 * index into the supported rate set. Convert this 289 * to the index into the negotiated rate set for 290 * the node. We know the rate is there because the 291 * rate set is checked when the station associates. 292 */ 293 const struct ieee80211_rateset *rs = 294 &ic->ic_sup_rates[ic->ic_curmode]; 295 int r = rs->rs_rates[ic->ic_fixed_rate] & IEEE80211_RATE_VAL; 296 /* NB: the rate set is assumed sorted */ 297 srate = ni->ni_rates.rs_nrates - 1; 298 for (; srate >= 0 && RATE(srate) != r; srate--) 299 ; 300 KASSERT(srate >= 0, 301 ("fixed rate %d not in rate set", ic->ic_fixed_rate)); 302 } 303 ath_rate_update(sc, ni, srate); 304#undef RATE 305} 306 307static void 308ath_rate_cb(void *arg, struct ieee80211_node *ni) 309{ 310 struct ath_softc *sc = arg; 311 312 ath_rate_update(sc, ni, 0); 313} 314 315/* 316 * Reset the rate control state for each 802.11 state transition. 317 */ 318void 319ath_rate_newstate(struct ath_softc *sc, enum ieee80211_state state) 320{ 321 struct onoe_softc *osc = (struct onoe_softc *) sc->sc_rc; 322 struct ieee80211com *ic = &sc->sc_ic; 323 struct ieee80211_node *ni; 324 325 if (state == IEEE80211_S_INIT) { 326 callout_stop(&osc->timer); 327 return; 328 } 329 if (ic->ic_opmode == IEEE80211_M_STA) { 330 /* 331 * Reset local xmit state; this is really only 332 * meaningful when operating in station mode. 333 */ 334 ni = ic->ic_bss; 335 if (state == IEEE80211_S_RUN) { 336 ath_rate_ctl_start(sc, ni); 337 } else { 338 ath_rate_update(sc, ni, 0); 339 } 340 } else { 341 /* 342 * When operating as a station the node table holds 343 * the AP's that were discovered during scanning. 344 * For any other operating mode we want to reset the 345 * tx rate state of each node. 346 */ 347 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_cb, sc); 348 ath_rate_update(sc, ic->ic_bss, 0); 349 } 350 if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE && 351 state == IEEE80211_S_RUN) { 352 int interval; 353 /* 354 * Start the background rate control thread if we 355 * are not configured to use a fixed xmit rate. 356 */ 357 interval = ath_rateinterval; 358 if (ic->ic_opmode == IEEE80211_M_STA) 359 interval /= 2; 360 callout_reset(&osc->timer, (interval * hz) / 1000, 361 ath_ratectl, sc->sc_ifp); 362 } 363} 364 365/* 366 * Examine and potentially adjust the transmit rate. 367 */ 368static void 369ath_rate_ctl(void *arg, struct ieee80211_node *ni) 370{ 371 struct ath_softc *sc = arg; 372 struct onoe_node *on = ATH_NODE_ONOE(ATH_NODE(ni)); 373 struct ieee80211_rateset *rs = &ni->ni_rates; 374 int dir = 0, nrate, enough; 375 376 /* 377 * Rate control 378 * XXX: very primitive version. 379 */ 380 enough = (on->on_tx_ok + on->on_tx_err >= 10); 381 382 /* no packet reached -> down */ 383 if (on->on_tx_err > 0 && on->on_tx_ok == 0) 384 dir = -1; 385 386 /* all packets needs retry in average -> down */ 387 if (enough && on->on_tx_ok < on->on_tx_retr) 388 dir = -1; 389 390 /* no error and less than rate_raise% of packets need retry -> up */ 391 if (enough && on->on_tx_err == 0 && 392 on->on_tx_retr < (on->on_tx_ok * ath_rate_raise) / 100) 393 dir = 1; 394 395 DPRINTF(sc, "%s: ok %d err %d retr %d upper %d dir %d\n", 396 ether_sprintf(ni->ni_macaddr), 397 on->on_tx_ok, on->on_tx_err, on->on_tx_retr, 398 on->on_tx_upper, dir); 399 400 nrate = ni->ni_txrate; 401 switch (dir) { 402 case 0: 403 if (enough && on->on_tx_upper > 0) 404 on->on_tx_upper--; 405 break; 406 case -1: 407 if (nrate > 0) { 408 nrate--; 409 sc->sc_stats.ast_rate_drop++; 410 } 411 on->on_tx_upper = 0; 412 break; 413 case 1: 414 /* raise rate if we hit rate_raise_threshold */ 415 if (++on->on_tx_upper < ath_rate_raise_threshold) 416 break; 417 on->on_tx_upper = 0; 418 if (nrate + 1 < rs->rs_nrates) { 419 nrate++; 420 sc->sc_stats.ast_rate_raise++; 421 } 422 break; 423 } 424 425 if (nrate != ni->ni_txrate) { 426 DPRINTF(sc, "%s: %dM -> %dM (%d ok, %d err, %d retr)\n", 427 __func__, 428 (rs->rs_rates[ni->ni_txrate] & IEEE80211_RATE_VAL) / 2, 429 (rs->rs_rates[nrate] & IEEE80211_RATE_VAL) / 2, 430 on->on_tx_ok, on->on_tx_err, on->on_tx_retr); 431 ath_rate_update(sc, ni, nrate); 432 } else if (enough) 433 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = 0; 434} 435 436static void 437ath_ratectl(void *arg) 438{ 439 struct ifnet *ifp = arg; 440 struct ath_softc *sc = ifp->if_softc; 441 struct onoe_softc *osc = (struct onoe_softc *) sc->sc_rc; 442 struct ieee80211com *ic = &sc->sc_ic; 443 int interval; 444 445 if (ifp->if_drv_flags & IFF_DRV_RUNNING) { 446 sc->sc_stats.ast_rate_calls++; 447 448 if (ic->ic_opmode == IEEE80211_M_STA) 449 ath_rate_ctl(sc, ic->ic_bss); /* NB: no reference */ 450 else 451 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_ctl, sc); 452 } 453 interval = ath_rateinterval; 454 if (ic->ic_opmode == IEEE80211_M_STA) 455 interval /= 2; 456 callout_reset(&osc->timer, (interval * hz) / 1000, 457 ath_ratectl, sc->sc_ifp); 458} 459 460static void 461ath_rate_sysctlattach(struct ath_softc *sc) 462{ 463 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev); 464 struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev); 465 466 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 467 "rate_interval", CTLFLAG_RW, &ath_rateinterval, 0, 468 "rate control: operation interval (ms)"); 469 /* XXX bounds check values */ 470 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 471 "rate_raise", CTLFLAG_RW, &ath_rate_raise, 0, 472 "rate control: retry threshold to credit rate raise (%%)"); 473 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 474 "rate_raise_threshold", CTLFLAG_RW, &ath_rate_raise_threshold,0, 475 "rate control: # good periods before raising rate"); 476} 477 478struct ath_ratectrl * 479ath_rate_attach(struct ath_softc *sc) 480{ 481 struct onoe_softc *osc; 482 483 osc = malloc(sizeof(struct onoe_softc), M_DEVBUF, M_NOWAIT|M_ZERO); 484 if (osc == NULL) 485 return NULL; 486 osc->arc.arc_space = sizeof(struct onoe_node); 487 callout_init(&osc->timer, debug_mpsafenet ? CALLOUT_MPSAFE : 0); 488 ath_rate_sysctlattach(sc); 489 490 return &osc->arc; 491} 492 493void 494ath_rate_detach(struct ath_ratectrl *arc) 495{ 496 struct onoe_softc *osc = (struct onoe_softc *) arc; 497 498 callout_drain(&osc->timer); 499 free(osc, M_DEVBUF); 500} 501 502/* 503 * Module glue. 504 */ 505static int 506onoe_modevent(module_t mod, int type, void *unused) 507{ 508 switch (type) { 509 case MOD_LOAD: 510 if (bootverbose) 511 printf("ath_rate: <Atsushi Onoe's rate control algorithm>\n"); 512 return 0; 513 case MOD_UNLOAD: 514 return 0; 515 } 516 return EINVAL; 517} 518 519static moduledata_t onoe_mod = { 520 "ath_rate", 521 onoe_modevent, 522 0 523}; 524DECLARE_MODULE(ath_rate, onoe_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST); 525MODULE_VERSION(ath_rate, 1); 526MODULE_DEPEND(ath_rate, wlan, 1, 1, 1); 527