1 /* $NetBSD: athrate-onoe.c,v 1.11 2007/11/26 20:45:01 dyoung Exp $ */ 2 3 /*- 4 * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer, 12 * without modification. 13 * 2. Redistributions in binary form must reproduce at minimum a disclaimer 14 * similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any 15 * redistribution must be conditioned upon including a substantially 16 * similar Disclaimer requirement for further binary redistribution. 17 * 3. Neither the names of the above-listed copyright holders nor the names 18 * of any contributors may be used to endorse or promote products derived 19 * from this software without specific prior written permission. 20 * 21 * Alternatively, this software may be distributed under the terms of the 22 * GNU General Public License ("GPL") version 2 as published by the Free 23 * Software Foundation. 24 * 25 * NO WARRANTY 26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 28 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY 29 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 30 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, 31 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER 34 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 36 * THE POSSIBILITY OF SUCH DAMAGES. 37 */ 38 39 #include <sys/cdefs.h> 40 #ifdef __FreeBSD__ 41 __FBSDID("$FreeBSD: src/sys/dev/ath/ath_rate/onoe/onoe.c,v 1.10 2005/08/09 10:19:43 rwatson Exp $"); 42 #endif 43 #ifdef __NetBSD__ 44 __KERNEL_RCSID(0, "$NetBSD: athrate-onoe.c,v 1.11 2007/11/26 20:45:01 dyoung Exp $"); 45 #endif 46 47 /* 48 * Atsushi Onoe's rate control algorithm. 49 */ 50 #include "opt_inet.h" 51 52 #include <sys/param.h> 53 #include <sys/systm.h> 54 #include <sys/sysctl.h> 55 #include <sys/kernel.h> 56 #include <sys/lock.h> 57 #include <sys/errno.h> 58 #include <sys/device.h> 59 60 #include <sys/bus.h> 61 62 #include <sys/socket.h> 63 64 #include <net/if.h> 65 #include <net/if_media.h> 66 #include <net/if_arp.h> 67 #include <net/if_ether.h> /* XXX for ether_sprintf */ 68 69 #include <net80211/ieee80211_var.h> 70 71 #include <net/bpf.h> 72 73 #ifdef INET 74 #include <netinet/in.h> 75 #endif 76 77 #include <dev/ic/ath_netbsd.h> 78 #include <dev/ic/athvar.h> 79 #include <dev/ic/athrate-onoe.h> 80 #include <contrib/dev/ath/ah_desc.h> 81 82 #define ONOE_DEBUG 83 #ifdef ONOE_DEBUG 84 enum { 85 ATH_DEBUG_RATE = 0x00000010, /* rate control */ 86 }; 87 #define DPRINTF(sc, _fmt, ...) do { \ 88 if (sc->sc_debug & ATH_DEBUG_RATE) \ 89 printf(_fmt, __VA_ARGS__); \ 90 } while (0) 91 #else 92 #define DPRINTF(sc, _fmt, ...) 93 #endif 94 95 /* 96 * Default parameters for the rate control algorithm. These are 97 * all tunable with sysctls. The rate controller runs periodically 98 * (each ath_rateinterval ms) analyzing transmit statistics for each 99 * neighbor/station (when operating in station mode this is only the AP). 100 * If transmits look to be working well over a sampling period then 101 * it gives a "raise rate credit". If transmits look to not be working 102 * well than it deducts a credit. If the credits cross a threshold then 103 * the transmit rate is raised. Various error conditions force the 104 * the transmit rate to be dropped. 105 * 106 * The decision to issue/deduct a credit is based on the errors and 107 * retries accumulated over the sampling period. ath_rate_raise defines 108 * the percent of retransmits for which a credit is issued/deducted. 109 * ath_rate_raise_threshold defines the threshold on credits at which 110 * the transmit rate is increased. 111 * 112 * XXX this algorithm is flawed. 113 */ 114 static int ath_rateinterval = 1000; /* rate ctl interval (ms) */ 115 static int ath_rate_raise = 10; /* add credit threshold */ 116 static int ath_rate_raise_threshold = 10; /* rate ctl raise threshold */ 117 118 static void ath_ratectl(void *); 119 static void ath_rate_update(struct ath_softc *, struct ieee80211_node *, 120 int rate); 121 static void ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *); 122 static void ath_rate_ctl(void *, struct ieee80211_node *); 123 124 void 125 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an) 126 { 127 /* NB: assumed to be zero'd by caller */ 128 ath_rate_update(sc, &an->an_node, 0); 129 } 130 131 void 132 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an) 133 { 134 } 135 136 void 137 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an, 138 int shortPreamble, size_t frameLen, 139 u_int8_t *rix, int *try0, u_int8_t *txrate) 140 { 141 struct onoe_node *on = ATH_NODE_ONOE(an); 142 143 *rix = on->on_tx_rix0; 144 *try0 = on->on_tx_try0; 145 if (shortPreamble) 146 *txrate = on->on_tx_rate0sp; 147 else 148 *txrate = on->on_tx_rate0; 149 } 150 151 void 152 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an, 153 struct ath_desc *ds, int shortPreamble, u_int8_t rix) 154 { 155 struct onoe_node *on = ATH_NODE_ONOE(an); 156 157 ath_hal_setupxtxdesc(sc->sc_ah, ds 158 , on->on_tx_rate1sp, 2 /* series 1 */ 159 , on->on_tx_rate2sp, 2 /* series 2 */ 160 , on->on_tx_rate3sp, 2 /* series 3 */ 161 ); 162 } 163 164 void 165 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an, 166 const struct ath_desc *ds, const struct ath_desc *ds0) 167 { 168 struct onoe_node *on = ATH_NODE_ONOE(an); 169 170 if (ds->ds_txstat.ts_status == 0) 171 on->on_tx_ok++; 172 else 173 on->on_tx_err++; 174 on->on_tx_retr += ds->ds_txstat.ts_shortretry 175 + ds->ds_txstat.ts_longretry; 176 } 177 178 void 179 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew) 180 { 181 if (isnew) 182 ath_rate_ctl_start(sc, &an->an_node); 183 } 184 185 static void 186 ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate) 187 { 188 struct ath_node *an = ATH_NODE(ni); 189 struct onoe_node *on = ATH_NODE_ONOE(an); 190 const HAL_RATE_TABLE *rt = sc->sc_currates; 191 u_int8_t rix; 192 193 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode)); 194 195 DPRINTF(sc, "%s: set xmit rate for %s to %dM\n", 196 __func__, ether_sprintf(ni->ni_macaddr), 197 ni->ni_rates.rs_nrates > 0 ? 198 (ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0); 199 200 ni->ni_txrate = rate; 201 /* 202 * Before associating a node has no rate set setup 203 * so we can't calculate any transmit codes to use. 204 * This is ok since we should never be sending anything 205 * but management frames and those always go at the 206 * lowest hardware rate. 207 */ 208 if (ni->ni_rates.rs_nrates == 0) 209 goto done; 210 on->on_tx_rix0 = sc->sc_rixmap[ 211 ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL]; 212 on->on_tx_rate0 = rt->info[on->on_tx_rix0].rateCode; 213 214 on->on_tx_rate0sp = on->on_tx_rate0 | 215 rt->info[on->on_tx_rix0].shortPreamble; 216 if (sc->sc_mrretry) { 217 /* 218 * Hardware supports multi-rate retry; setup two 219 * step-down retry rates and make the lowest rate 220 * be the ``last chance''. We use 4, 2, 2, 2 tries 221 * respectively (4 is set here, the rest are fixed 222 * in the xmit routine). 223 */ 224 on->on_tx_try0 = 1 + 3; /* 4 tries at rate 0 */ 225 if (--rate >= 0) { 226 rix = sc->sc_rixmap[ 227 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL]; 228 on->on_tx_rate1 = rt->info[rix].rateCode; 229 on->on_tx_rate1sp = on->on_tx_rate1 | 230 rt->info[rix].shortPreamble; 231 } else { 232 on->on_tx_rate1 = on->on_tx_rate1sp = 0; 233 } 234 if (--rate >= 0) { 235 rix = sc->sc_rixmap[ 236 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL]; 237 on->on_tx_rate2 = rt->info[rix].rateCode; 238 on->on_tx_rate2sp = on->on_tx_rate2 | 239 rt->info[rix].shortPreamble; 240 } else { 241 on->on_tx_rate2 = on->on_tx_rate2sp = 0; 242 } 243 if (rate > 0) { 244 /* NB: only do this if we didn't already do it above */ 245 on->on_tx_rate3 = rt->info[0].rateCode; 246 on->on_tx_rate3sp = 247 on->on_tx_rate3 | rt->info[0].shortPreamble; 248 } else { 249 on->on_tx_rate3 = on->on_tx_rate3sp = 0; 250 } 251 } else { 252 on->on_tx_try0 = ATH_TXMAXTRY; /* max tries at rate 0 */ 253 on->on_tx_rate1 = on->on_tx_rate1sp = 0; 254 on->on_tx_rate2 = on->on_tx_rate2sp = 0; 255 on->on_tx_rate3 = on->on_tx_rate3sp = 0; 256 } 257 done: 258 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = on->on_tx_upper = 0; 259 } 260 261 /* 262 * Set the starting transmit rate for a node. 263 */ 264 static void 265 ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni) 266 { 267 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL) 268 struct ieee80211com *ic = &sc->sc_ic; 269 int srate; 270 271 KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates")); 272 if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE) { 273 /* 274 * No fixed rate is requested. For 11b start with 275 * the highest negotiated rate; otherwise, for 11g 276 * and 11a, we start "in the middle" at 24Mb or 36Mb. 277 */ 278 srate = ni->ni_rates.rs_nrates - 1; 279 if (sc->sc_curmode != IEEE80211_MODE_11B) { 280 /* 281 * Scan the negotiated rate set to find the 282 * closest rate. 283 */ 284 /* NB: the rate set is assumed sorted */ 285 for (; srate >= 0 && RATE(srate) > 72; srate--) 286 ; 287 KASSERT(srate >= 0, ("bogus rate set")); 288 } 289 } else { 290 /* 291 * A fixed rate is to be used; ic_fixed_rate is an 292 * index into the supported rate set. Convert this 293 * to the index into the negotiated rate set for 294 * the node. We know the rate is there because the 295 * rate set is checked when the station associates. 296 */ 297 const struct ieee80211_rateset *rs = 298 &ic->ic_sup_rates[ic->ic_curmode]; 299 int r = rs->rs_rates[ic->ic_fixed_rate] & IEEE80211_RATE_VAL; 300 /* NB: the rate set is assumed sorted */ 301 srate = ni->ni_rates.rs_nrates - 1; 302 for (; srate >= 0 && RATE(srate) != r; srate--) 303 ; 304 KASSERT(srate >= 0, 305 ("fixed rate %d not in rate set", ic->ic_fixed_rate)); 306 } 307 ath_rate_update(sc, ni, srate); 308 #undef RATE 309 } 310 311 static void 312 ath_rate_cb(void *arg, struct ieee80211_node *ni) 313 { 314 struct ath_softc *sc = arg; 315 316 ath_rate_update(sc, ni, 0); 317 } 318 319 /* 320 * Reset the rate control state for each 802.11 state transition. 321 */ 322 void 323 ath_rate_newstate(struct ath_softc *sc, enum ieee80211_state state) 324 { 325 struct onoe_softc *osc = (struct onoe_softc *) sc->sc_rc; 326 struct ieee80211com *ic = &sc->sc_ic; 327 struct ieee80211_node *ni; 328 329 if (state == IEEE80211_S_INIT) { 330 callout_stop(&osc->timer); 331 return; 332 } 333 if (ic->ic_opmode == IEEE80211_M_STA) { 334 /* 335 * Reset local xmit state; this is really only 336 * meaningful when operating in station mode. 337 */ 338 ni = ic->ic_bss; 339 if (state == IEEE80211_S_RUN) { 340 ath_rate_ctl_start(sc, ni); 341 } else { 342 ath_rate_update(sc, ni, 0); 343 } 344 } else { 345 /* 346 * When operating as a station the node table holds 347 * the AP's that were discovered during scanning. 348 * For any other operating mode we want to reset the 349 * tx rate state of each node. 350 */ 351 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_cb, sc); 352 ath_rate_update(sc, ic->ic_bss, 0); 353 } 354 if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE && 355 state == IEEE80211_S_RUN) { 356 int interval; 357 /* 358 * Start the background rate control thread if we 359 * are not configured to use a fixed xmit rate. 360 */ 361 interval = ath_rateinterval; 362 if (ic->ic_opmode == IEEE80211_M_STA) 363 interval /= 2; 364 callout_reset(&osc->timer, (interval * hz) / 1000, 365 ath_ratectl, &sc->sc_if); 366 } 367 } 368 369 /* 370 * Examine and potentially adjust the transmit rate. 371 */ 372 static void 373 ath_rate_ctl(void *arg, struct ieee80211_node *ni) 374 { 375 struct ath_softc *sc = arg; 376 struct onoe_node *on = ATH_NODE_ONOE(ATH_NODE(ni)); 377 struct ieee80211_rateset *rs = &ni->ni_rates; 378 int dir = 0, nrate, enough; 379 380 /* 381 * Rate control 382 * XXX: very primitive version. 383 */ 384 enough = (on->on_tx_ok + on->on_tx_err >= 10); 385 386 /* no packet reached -> down */ 387 if (on->on_tx_err > 0 && on->on_tx_ok == 0) 388 dir = -1; 389 390 /* all packets needs retry in average -> down */ 391 if (enough && on->on_tx_ok < on->on_tx_retr) 392 dir = -1; 393 394 /* no error and less than rate_raise% of packets need retry -> up */ 395 if (enough && on->on_tx_err == 0 && 396 on->on_tx_retr < (on->on_tx_ok * ath_rate_raise) / 100) 397 dir = 1; 398 399 DPRINTF(sc, "%s: ok %d err %d retr %d upper %d dir %d\n", 400 ether_sprintf(ni->ni_macaddr), 401 on->on_tx_ok, on->on_tx_err, on->on_tx_retr, 402 on->on_tx_upper, dir); 403 404 nrate = ni->ni_txrate; 405 switch (dir) { 406 case 0: 407 if (enough && on->on_tx_upper > 0) 408 on->on_tx_upper--; 409 break; 410 case -1: 411 if (nrate > 0) { 412 nrate--; 413 sc->sc_stats.ast_rate_drop++; 414 } 415 on->on_tx_upper = 0; 416 break; 417 case 1: 418 /* raise rate if we hit rate_raise_threshold */ 419 if (++on->on_tx_upper < ath_rate_raise_threshold) 420 break; 421 on->on_tx_upper = 0; 422 if (nrate + 1 < rs->rs_nrates) { 423 nrate++; 424 sc->sc_stats.ast_rate_raise++; 425 } 426 break; 427 } 428 429 if (nrate != ni->ni_txrate) { 430 DPRINTF(sc, "%s: %dM -> %dM (%d ok, %d err, %d retr)\n", 431 __func__, 432 (rs->rs_rates[ni->ni_txrate] & IEEE80211_RATE_VAL) / 2, 433 (rs->rs_rates[nrate] & IEEE80211_RATE_VAL) / 2, 434 on->on_tx_ok, on->on_tx_err, on->on_tx_retr); 435 ath_rate_update(sc, ni, nrate); 436 } else if (enough) 437 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = 0; 438 } 439 440 static void 441 ath_ratectl(void *arg) 442 { 443 struct ifnet *ifp = arg; 444 struct ath_softc *sc = ifp->if_softc; 445 struct onoe_softc *osc = (struct onoe_softc *) sc->sc_rc; 446 struct ieee80211com *ic = &sc->sc_ic; 447 int interval; 448 449 if (ifp->if_flags & IFF_RUNNING) { 450 sc->sc_stats.ast_rate_calls++; 451 452 if (ic->ic_opmode == IEEE80211_M_STA) 453 ath_rate_ctl(sc, ic->ic_bss); /* NB: no reference */ 454 else 455 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_ctl, sc); 456 } 457 interval = ath_rateinterval; 458 if (ic->ic_opmode == IEEE80211_M_STA) 459 interval /= 2; 460 callout_reset(&osc->timer, (interval * hz) / 1000, 461 ath_ratectl, &sc->sc_if); 462 } 463 464 static void 465 ath_rate_sysctlattach(struct ath_softc *sc) 466 { 467 struct sysctllog **clog = &sc->sc_sysctllog; 468 const struct sysctlnode *cnode, *rnode; 469 470 if ((rnode = ath_sysctl_treetop(NULL)) == NULL) 471 return; 472 473 SYSCTL_GLOBAL_INT(CTLFLAG_READWRITE, "rate_interval", 474 "rate control: operation interval (ms)", rateinterval); 475 /* XXX bounds check values */ 476 SYSCTL_GLOBAL_INT(CTLFLAG_READWRITE, "rate_raise", 477 "rate control: retry threshold to credit rate raise (%%)", 478 rate_raise); 479 SYSCTL_GLOBAL_INT(CTLFLAG_READWRITE, "rate_raise_threshold", 480 "rate control: # good periods before raising rate", 481 rate_raise_threshold); 482 } 483 484 struct ath_ratectrl * 485 ath_rate_attach(struct ath_softc *sc) 486 { 487 struct onoe_softc *osc; 488 489 osc = malloc(sizeof(struct onoe_softc), M_DEVBUF, M_NOWAIT|M_ZERO); 490 if (osc == NULL) 491 return NULL; 492 osc->arc.arc_space = sizeof(struct onoe_node); 493 callout_init(&osc->timer, 0); 494 ath_rate_sysctlattach(sc); 495 496 return &osc->arc; 497 } 498 499 void 500 ath_rate_detach(struct ath_ratectrl *arc) 501 { 502 struct onoe_softc *osc = (struct onoe_softc *) arc; 503 504 callout_stop(&osc->timer); 505 free(osc, M_DEVBUF); 506 } 507