1 /*- 2 * Copyright (c) 2002-2007 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 * 16 * NO WARRANTY 17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 19 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY 20 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 21 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, 22 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER 25 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 27 * THE POSSIBILITY OF SUCH DAMAGES. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 /* 34 * Atsushi Onoe's rate control algorithm. 35 */ 36 #include "opt_inet.h" 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/sysctl.h> 41 #include <sys/module.h> 42 #include <sys/kernel.h> 43 #include <sys/lock.h> 44 #include <sys/mutex.h> 45 #include <sys/errno.h> 46 47 #include <machine/bus.h> 48 #include <machine/resource.h> 49 #include <sys/bus.h> 50 51 #include <sys/socket.h> 52 53 #include <net/if.h> 54 #include <net/if_media.h> 55 #include <net/if_arp.h> 56 #include <net/ethernet.h> /* XXX for ether_sprintf */ 57 58 #include <net80211/ieee80211_var.h> 59 60 #include <net/bpf.h> 61 62 #ifdef INET 63 #include <netinet/in.h> 64 #include <netinet/if_ether.h> 65 #endif 66 67 #include <dev/ath/if_athvar.h> 68 #include <dev/ath/ath_rate/onoe/onoe.h> 69 #include <contrib/dev/ath/ah_desc.h> 70 71 #define ONOE_DEBUG 72 #ifdef ONOE_DEBUG 73 enum { 74 ATH_DEBUG_RATE = 0x00000010, /* rate control */ 75 }; 76 #define DPRINTF(sc, _fmt, ...) do { \ 77 if (sc->sc_debug & ATH_DEBUG_RATE) \ 78 printf(_fmt, __VA_ARGS__); \ 79 } while (0) 80 #else 81 #define DPRINTF(sc, _fmt, ...) 82 #endif 83 84 /* 85 * Default parameters for the rate control algorithm. These are 86 * all tunable with sysctls. The rate controller runs periodically 87 * (each ath_rateinterval ms) analyzing transmit statistics for each 88 * neighbor/station (when operating in station mode this is only the AP). 89 * If transmits look to be working well over a sampling period then 90 * it gives a "raise rate credit". If transmits look to not be working 91 * well than it deducts a credit. If the credits cross a threshold then 92 * the transmit rate is raised. Various error conditions force the 93 * the transmit rate to be dropped. 94 * 95 * The decision to issue/deduct a credit is based on the errors and 96 * retries accumulated over the sampling period. ath_rate_raise defines 97 * the percent of retransmits for which a credit is issued/deducted. 98 * ath_rate_raise_threshold defines the threshold on credits at which 99 * the transmit rate is increased. 100 * 101 * XXX this algorithm is flawed. 102 */ 103 static int ath_rateinterval = 1000; /* rate ctl interval (ms) */ 104 static int ath_rate_raise = 10; /* add credit threshold */ 105 static int ath_rate_raise_threshold = 10; /* rate ctl raise threshold */ 106 107 static void ath_ratectl(void *); 108 static void ath_rate_update(struct ath_softc *, struct ieee80211_node *, 109 int rate); 110 static void ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *); 111 static void ath_rate_ctl(void *, struct ieee80211_node *); 112 113 void 114 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an) 115 { 116 /* NB: assumed to be zero'd by caller */ 117 ath_rate_update(sc, &an->an_node, 0); 118 } 119 120 void 121 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an) 122 { 123 } 124 125 void 126 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an, 127 int shortPreamble, size_t frameLen, 128 u_int8_t *rix, int *try0, u_int8_t *txrate) 129 { 130 struct onoe_node *on = ATH_NODE_ONOE(an); 131 132 *rix = on->on_tx_rix0; 133 *try0 = on->on_tx_try0; 134 if (shortPreamble) 135 *txrate = on->on_tx_rate0sp; 136 else 137 *txrate = on->on_tx_rate0; 138 } 139 140 void 141 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an, 142 struct ath_desc *ds, int shortPreamble, u_int8_t rix) 143 { 144 struct onoe_node *on = ATH_NODE_ONOE(an); 145 146 ath_hal_setupxtxdesc(sc->sc_ah, ds 147 , on->on_tx_rate1sp, 2 /* series 1 */ 148 , on->on_tx_rate2sp, 2 /* series 2 */ 149 , on->on_tx_rate3sp, 2 /* series 3 */ 150 ); 151 } 152 153 void 154 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an, 155 const struct ath_buf *bf) 156 { 157 struct onoe_node *on = ATH_NODE_ONOE(an); 158 const struct ath_tx_status *ts = &bf->bf_status.ds_txstat; 159 160 if (ts->ts_status == 0) 161 on->on_tx_ok++; 162 else 163 on->on_tx_err++; 164 on->on_tx_retr += ts->ts_shortretry 165 + ts->ts_longretry; 166 } 167 168 void 169 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew) 170 { 171 if (isnew) 172 ath_rate_ctl_start(sc, &an->an_node); 173 } 174 175 static void 176 ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate) 177 { 178 struct ath_node *an = ATH_NODE(ni); 179 struct onoe_node *on = ATH_NODE_ONOE(an); 180 const HAL_RATE_TABLE *rt = sc->sc_currates; 181 u_int8_t rix; 182 183 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode)); 184 185 DPRINTF(sc, "%s: set xmit rate for %s to %dM\n", 186 __func__, ether_sprintf(ni->ni_macaddr), 187 ni->ni_rates.rs_nrates > 0 ? 188 (ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0); 189 190 ni->ni_txrate = rate; 191 /* 192 * Before associating a node has no rate set setup 193 * so we can't calculate any transmit codes to use. 194 * This is ok since we should never be sending anything 195 * but management frames and those always go at the 196 * lowest hardware rate. 197 */ 198 if (ni->ni_rates.rs_nrates == 0) 199 goto done; 200 on->on_tx_rix0 = sc->sc_rixmap[ 201 ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL]; 202 on->on_tx_rate0 = rt->info[on->on_tx_rix0].rateCode; 203 204 on->on_tx_rate0sp = on->on_tx_rate0 | 205 rt->info[on->on_tx_rix0].shortPreamble; 206 if (sc->sc_mrretry) { 207 /* 208 * Hardware supports multi-rate retry; setup two 209 * step-down retry rates and make the lowest rate 210 * be the ``last chance''. We use 4, 2, 2, 2 tries 211 * respectively (4 is set here, the rest are fixed 212 * in the xmit routine). 213 */ 214 on->on_tx_try0 = 1 + 3; /* 4 tries at rate 0 */ 215 if (--rate >= 0) { 216 rix = sc->sc_rixmap[ 217 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL]; 218 on->on_tx_rate1 = rt->info[rix].rateCode; 219 on->on_tx_rate1sp = on->on_tx_rate1 | 220 rt->info[rix].shortPreamble; 221 } else { 222 on->on_tx_rate1 = on->on_tx_rate1sp = 0; 223 } 224 if (--rate >= 0) { 225 rix = sc->sc_rixmap[ 226 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL]; 227 on->on_tx_rate2 = rt->info[rix].rateCode; 228 on->on_tx_rate2sp = on->on_tx_rate2 | 229 rt->info[rix].shortPreamble; 230 } else { 231 on->on_tx_rate2 = on->on_tx_rate2sp = 0; 232 } 233 if (rate > 0) { 234 /* NB: only do this if we didn't already do it above */ 235 on->on_tx_rate3 = rt->info[0].rateCode; 236 on->on_tx_rate3sp = 237 on->on_tx_rate3 | rt->info[0].shortPreamble; 238 } else { 239 on->on_tx_rate3 = on->on_tx_rate3sp = 0; 240 } 241 } else { 242 on->on_tx_try0 = ATH_TXMAXTRY; /* max tries at rate 0 */ 243 on->on_tx_rate1 = on->on_tx_rate1sp = 0; 244 on->on_tx_rate2 = on->on_tx_rate2sp = 0; 245 on->on_tx_rate3 = on->on_tx_rate3sp = 0; 246 } 247 done: 248 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = on->on_tx_upper = 0; 249 } 250 251 /* 252 * Set the starting transmit rate for a node. 253 */ 254 static void 255 ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni) 256 { 257 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL) 258 struct ieee80211com *ic = &sc->sc_ic; 259 int srate; 260 261 KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates")); 262 if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE) { 263 /* 264 * No fixed rate is requested. For 11b start with 265 * the highest negotiated rate; otherwise, for 11g 266 * and 11a, we start "in the middle" at 24Mb or 36Mb. 267 */ 268 srate = ni->ni_rates.rs_nrates - 1; 269 if (sc->sc_curmode != IEEE80211_MODE_11B) { 270 /* 271 * Scan the negotiated rate set to find the 272 * closest rate. 273 */ 274 /* NB: the rate set is assumed sorted */ 275 for (; srate >= 0 && RATE(srate) > 72; srate--) 276 ; 277 } 278 } else { 279 /* 280 * A fixed rate is to be used; ic_fixed_rate is the 281 * IEEE code for this rate (sans basic bit). Convert this 282 * to the index into the negotiated rate set for 283 * the node. We know the rate is there because the 284 * rate set is checked when the station associates. 285 */ 286 /* NB: the rate set is assumed sorted */ 287 srate = ni->ni_rates.rs_nrates - 1; 288 for (; srate >= 0 && RATE(srate) != ic->ic_fixed_rate; srate--) 289 ; 290 } 291 /* 292 * The selected rate may not be available due to races 293 * and mode settings. Also orphaned nodes created in 294 * adhoc mode may not have any rate set so this lookup 295 * can fail. This is not fatal. 296 */ 297 ath_rate_update(sc, ni, srate < 0 ? 0 : srate); 298 #undef RATE 299 } 300 301 static void 302 ath_rate_cb(void *arg, struct ieee80211_node *ni) 303 { 304 struct ath_softc *sc = arg; 305 306 ath_rate_update(sc, ni, 0); 307 } 308 309 /* 310 * Reset the rate control state for each 802.11 state transition. 311 */ 312 void 313 ath_rate_newstate(struct ath_softc *sc, enum ieee80211_state state) 314 { 315 struct onoe_softc *osc = (struct onoe_softc *) sc->sc_rc; 316 struct ieee80211com *ic = &sc->sc_ic; 317 struct ieee80211_node *ni; 318 319 if (state == IEEE80211_S_INIT) { 320 callout_stop(&osc->timer); 321 return; 322 } 323 if (ic->ic_opmode == IEEE80211_M_STA) { 324 /* 325 * Reset local xmit state; this is really only 326 * meaningful when operating in station mode. 327 */ 328 ni = ic->ic_bss; 329 if (state == IEEE80211_S_RUN) { 330 ath_rate_ctl_start(sc, ni); 331 } else { 332 ath_rate_update(sc, ni, 0); 333 } 334 } else { 335 /* 336 * When operating as a station the node table holds 337 * the AP's that were discovered during scanning. 338 * For any other operating mode we want to reset the 339 * tx rate state of each node. 340 */ 341 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_cb, sc); 342 ath_rate_update(sc, ic->ic_bss, 0); 343 } 344 if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE && 345 state == IEEE80211_S_RUN) { 346 int interval; 347 /* 348 * Start the background rate control thread if we 349 * are not configured to use a fixed xmit rate. 350 */ 351 interval = ath_rateinterval; 352 if (ic->ic_opmode == IEEE80211_M_STA) 353 interval /= 2; 354 callout_reset(&osc->timer, (interval * hz) / 1000, 355 ath_ratectl, sc->sc_ifp); 356 } 357 } 358 359 /* 360 * Examine and potentially adjust the transmit rate. 361 */ 362 static void 363 ath_rate_ctl(void *arg, struct ieee80211_node *ni) 364 { 365 struct ath_softc *sc = arg; 366 struct onoe_node *on = ATH_NODE_ONOE(ATH_NODE(ni)); 367 struct ieee80211_rateset *rs = &ni->ni_rates; 368 int dir = 0, nrate, enough; 369 370 /* 371 * Rate control 372 * XXX: very primitive version. 373 */ 374 enough = (on->on_tx_ok + on->on_tx_err >= 10); 375 376 /* no packet reached -> down */ 377 if (on->on_tx_err > 0 && on->on_tx_ok == 0) 378 dir = -1; 379 380 /* all packets needs retry in average -> down */ 381 if (enough && on->on_tx_ok < on->on_tx_retr) 382 dir = -1; 383 384 /* no error and less than rate_raise% of packets need retry -> up */ 385 if (enough && on->on_tx_err == 0 && 386 on->on_tx_retr < (on->on_tx_ok * ath_rate_raise) / 100) 387 dir = 1; 388 389 DPRINTF(sc, "%s: ok %d err %d retr %d upper %d dir %d\n", 390 ether_sprintf(ni->ni_macaddr), 391 on->on_tx_ok, on->on_tx_err, on->on_tx_retr, 392 on->on_tx_upper, dir); 393 394 nrate = ni->ni_txrate; 395 switch (dir) { 396 case 0: 397 if (enough && on->on_tx_upper > 0) 398 on->on_tx_upper--; 399 break; 400 case -1: 401 if (nrate > 0) { 402 nrate--; 403 sc->sc_stats.ast_rate_drop++; 404 } 405 on->on_tx_upper = 0; 406 break; 407 case 1: 408 /* raise rate if we hit rate_raise_threshold */ 409 if (++on->on_tx_upper < ath_rate_raise_threshold) 410 break; 411 on->on_tx_upper = 0; 412 if (nrate + 1 < rs->rs_nrates) { 413 nrate++; 414 sc->sc_stats.ast_rate_raise++; 415 } 416 break; 417 } 418 419 if (nrate != ni->ni_txrate) { 420 DPRINTF(sc, "%s: %dM -> %dM (%d ok, %d err, %d retr)\n", 421 __func__, 422 (rs->rs_rates[ni->ni_txrate] & IEEE80211_RATE_VAL) / 2, 423 (rs->rs_rates[nrate] & IEEE80211_RATE_VAL) / 2, 424 on->on_tx_ok, on->on_tx_err, on->on_tx_retr); 425 ath_rate_update(sc, ni, nrate); 426 } else if (enough) 427 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = 0; 428 } 429 430 static void 431 ath_ratectl(void *arg) 432 { 433 struct ifnet *ifp = arg; 434 struct ath_softc *sc = ifp->if_softc; 435 struct onoe_softc *osc = (struct onoe_softc *) sc->sc_rc; 436 struct ieee80211com *ic = &sc->sc_ic; 437 int interval; 438 439 if (ifp->if_drv_flags & IFF_DRV_RUNNING) { 440 sc->sc_stats.ast_rate_calls++; 441 442 if (ic->ic_opmode == IEEE80211_M_STA) 443 ath_rate_ctl(sc, ic->ic_bss); /* NB: no reference */ 444 else 445 ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_ctl, sc); 446 } 447 interval = ath_rateinterval; 448 if (ic->ic_opmode == IEEE80211_M_STA) 449 interval /= 2; 450 callout_reset(&osc->timer, (interval * hz) / 1000, 451 ath_ratectl, sc->sc_ifp); 452 } 453 454 static void 455 ath_rate_sysctlattach(struct ath_softc *sc) 456 { 457 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev); 458 struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev); 459 460 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 461 "rate_interval", CTLFLAG_RW, &ath_rateinterval, 0, 462 "rate control: operation interval (ms)"); 463 /* XXX bounds check values */ 464 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 465 "rate_raise", CTLFLAG_RW, &ath_rate_raise, 0, 466 "rate control: retry threshold to credit rate raise (%%)"); 467 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 468 "rate_raise_threshold", CTLFLAG_RW, &ath_rate_raise_threshold,0, 469 "rate control: # good periods before raising rate"); 470 } 471 472 struct ath_ratectrl * 473 ath_rate_attach(struct ath_softc *sc) 474 { 475 struct onoe_softc *osc; 476 477 osc = malloc(sizeof(struct onoe_softc), M_DEVBUF, M_NOWAIT|M_ZERO); 478 if (osc == NULL) 479 return NULL; 480 osc->arc.arc_space = sizeof(struct onoe_node); 481 callout_init(&osc->timer, CALLOUT_MPSAFE); 482 ath_rate_sysctlattach(sc); 483 484 return &osc->arc; 485 } 486 487 void 488 ath_rate_detach(struct ath_ratectrl *arc) 489 { 490 struct onoe_softc *osc = (struct onoe_softc *) arc; 491 492 callout_drain(&osc->timer); 493 free(osc, M_DEVBUF); 494 } 495 496 /* 497 * Module glue. 498 */ 499 static int 500 onoe_modevent(module_t mod, int type, void *unused) 501 { 502 switch (type) { 503 case MOD_LOAD: 504 if (bootverbose) 505 printf("ath_rate: <Atsushi Onoe's rate control algorithm>\n"); 506 return 0; 507 case MOD_UNLOAD: 508 return 0; 509 } 510 return EINVAL; 511 } 512 513 static moduledata_t onoe_mod = { 514 "ath_rate", 515 onoe_modevent, 516 0 517 }; 518 DECLARE_MODULE(ath_rate, onoe_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST); 519 MODULE_VERSION(ath_rate, 1); 520 MODULE_DEPEND(ath_rate, wlan, 1, 1, 1); 521