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 32 /* 33 * Atsushi Onoe's rate control algorithm. 34 */ 35 #include "opt_ath.h" 36 #include "opt_inet.h" 37 #include "opt_wlan.h" 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/sysctl.h> 42 #include <sys/kernel.h> 43 #include <sys/lock.h> 44 #include <sys/mutex.h> 45 #include <sys/errno.h> 46 #include <sys/bus.h> 47 #include <sys/socket.h> 48 49 #include <net/if.h> 50 #include <net/if_media.h> 51 #include <net/if_arp.h> 52 #include <net/ethernet.h> /* XXX for ether_sprintf */ 53 54 #include <netproto/802_11/ieee80211_var.h> 55 56 #include <net/bpf.h> 57 58 #ifdef INET 59 #include <netinet/in.h> 60 #include <netinet/if_ether.h> 61 #endif 62 63 #include <dev/netif/ath/ath/if_athvar.h> 64 #include <dev/netif/ath/ath_rate/onoe/onoe.h> 65 #include <dev/netif/ath/ath_hal/ah_desc.h> 66 67 /* 68 * Default parameters for the rate control algorithm. These are 69 * all tunable with sysctls. The rate controller runs periodically 70 * (each ath_rateinterval ms) analyzing transmit statistics for each 71 * neighbor/station (when operating in station mode this is only the AP). 72 * If transmits look to be working well over a sampling period then 73 * it gives a "raise rate credit". If transmits look to not be working 74 * well than it deducts a credit. If the credits cross a threshold then 75 * the transmit rate is raised. Various error conditions force the 76 * the transmit rate to be dropped. 77 * 78 * The decision to issue/deduct a credit is based on the errors and 79 * retries accumulated over the sampling period. ath_rate_raise defines 80 * the percent of retransmits for which a credit is issued/deducted. 81 * ath_rate_raise_threshold defines the threshold on credits at which 82 * the transmit rate is increased. 83 * 84 * XXX this algorithm is flawed. 85 */ 86 static int ath_rateinterval = 1000; /* rate ctl interval (ms) */ 87 static int ath_rate_raise = 10; /* add credit threshold */ 88 static int ath_rate_raise_threshold = 10; /* rate ctl raise threshold */ 89 90 static void ath_rate_update(struct ath_softc *, struct ieee80211_node *, 91 int rate); 92 static void ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *); 93 static void ath_rate_ctl(void *, struct ieee80211_node *); 94 95 void 96 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an) 97 { 98 /* NB: assumed to be zero'd by caller */ 99 } 100 101 void 102 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an) 103 { 104 } 105 106 void 107 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an, 108 int shortPreamble, size_t frameLen, 109 u_int8_t *rix, int *try0, u_int8_t *txrate) 110 { 111 struct onoe_node *on = ATH_NODE_ONOE(an); 112 113 *rix = on->on_tx_rix0; 114 *try0 = on->on_tx_try0; 115 if (shortPreamble) 116 *txrate = on->on_tx_rate0sp; 117 else 118 *txrate = on->on_tx_rate0; 119 } 120 121 /* 122 * Get the TX rates. 123 * 124 * The short preamble bits aren't set here; the caller should augment 125 * the returned rate with the relevant preamble rate flag. 126 */ 127 void 128 ath_rate_getxtxrates(struct ath_softc *sc, struct ath_node *an, 129 uint8_t rix0, struct ath_rc_series *rc) 130 { 131 struct onoe_node *on = ATH_NODE_ONOE(an); 132 133 rc[0].flags = rc[1].flags = rc[2].flags = rc[3].flags = 0; 134 135 rc[0].rix = on->on_tx_rate0; 136 rc[1].rix = on->on_tx_rate1; 137 rc[2].rix = on->on_tx_rate2; 138 rc[3].rix = on->on_tx_rate3; 139 140 rc[0].tries = on->on_tx_try0; 141 rc[1].tries = 2; 142 rc[2].tries = 2; 143 rc[3].tries = 2; 144 } 145 146 void 147 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an, 148 struct ath_desc *ds, int shortPreamble, u_int8_t rix) 149 { 150 struct onoe_node *on = ATH_NODE_ONOE(an); 151 152 ath_hal_setupxtxdesc(sc->sc_ah, ds 153 , on->on_tx_rate1sp, 2 /* series 1 */ 154 , on->on_tx_rate2sp, 2 /* series 2 */ 155 , on->on_tx_rate3sp, 2 /* series 3 */ 156 ); 157 } 158 159 void 160 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an, 161 const struct ath_rc_series *rc, const struct ath_tx_status *ts, 162 int frame_size, int nframes, int nbad) 163 { 164 struct onoe_node *on = ATH_NODE_ONOE(an); 165 166 if (ts->ts_status == 0) 167 on->on_tx_ok++; 168 else 169 on->on_tx_err++; 170 on->on_tx_retr += ts->ts_shortretry 171 + ts->ts_longretry; 172 if (on->on_interval != 0 && ticks - on->on_ticks > on->on_interval) { 173 ath_rate_ctl(sc, &an->an_node); 174 on->on_ticks = ticks; 175 } 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 struct ieee80211vap *vap = ni->ni_vap; 191 const HAL_RATE_TABLE *rt = sc->sc_currates; 192 u_int8_t rix; 193 194 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode)); 195 196 IEEE80211_NOTE(vap, IEEE80211_MSG_RATECTL, ni, 197 "%s: set xmit rate to %dM", __func__, 198 ni->ni_rates.rs_nrates > 0 ? 199 (ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0); 200 201 /* 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_rix = rate; 211 ni->ni_txrate = ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL; 212 on->on_tx_rix0 = sc->sc_rixmap[ni->ni_txrate]; 213 on->on_tx_rate0 = rt->info[on->on_tx_rix0].rateCode; 214 215 on->on_tx_rate0sp = on->on_tx_rate0 | 216 rt->info[on->on_tx_rix0].shortPreamble; 217 if (sc->sc_mrretry) { 218 /* 219 * Hardware supports multi-rate retry; setup two 220 * step-down retry rates and make the lowest rate 221 * be the ``last chance''. We use 4, 2, 2, 2 tries 222 * respectively (4 is set here, the rest are fixed 223 * in the xmit routine). 224 */ 225 on->on_tx_try0 = 1 + 3; /* 4 tries at rate 0 */ 226 if (--rate >= 0) { 227 rix = sc->sc_rixmap[ 228 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL]; 229 on->on_tx_rate1 = rt->info[rix].rateCode; 230 on->on_tx_rate1sp = on->on_tx_rate1 | 231 rt->info[rix].shortPreamble; 232 } else { 233 on->on_tx_rate1 = on->on_tx_rate1sp = 0; 234 } 235 if (--rate >= 0) { 236 rix = sc->sc_rixmap[ 237 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL]; 238 on->on_tx_rate2 = rt->info[rix].rateCode; 239 on->on_tx_rate2sp = on->on_tx_rate2 | 240 rt->info[rix].shortPreamble; 241 } else { 242 on->on_tx_rate2 = on->on_tx_rate2sp = 0; 243 } 244 if (rate > 0) { 245 /* NB: only do this if we didn't already do it above */ 246 on->on_tx_rate3 = rt->info[0].rateCode; 247 on->on_tx_rate3sp = 248 on->on_tx_rate3 | rt->info[0].shortPreamble; 249 } else { 250 on->on_tx_rate3 = on->on_tx_rate3sp = 0; 251 } 252 } else { 253 on->on_tx_try0 = ATH_TXMAXTRY; /* max tries at rate 0 */ 254 on->on_tx_rate1 = on->on_tx_rate1sp = 0; 255 on->on_tx_rate2 = on->on_tx_rate2sp = 0; 256 on->on_tx_rate3 = on->on_tx_rate3sp = 0; 257 } 258 done: 259 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = on->on_tx_upper = 0; 260 261 on->on_interval = ath_rateinterval; 262 if (vap->iv_opmode == IEEE80211_M_STA) 263 on->on_interval /= 2; 264 on->on_interval = (on->on_interval * hz) / 1000; 265 } 266 267 /* 268 * Set the starting transmit rate for a node. 269 */ 270 static void 271 ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni) 272 { 273 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL) 274 const struct ieee80211_txparam *tp = ni->ni_txparms; 275 int srate; 276 277 KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates")); 278 if (tp == NULL || tp->ucastrate == IEEE80211_FIXED_RATE_NONE) { 279 /* 280 * No fixed rate is requested. For 11b start with 281 * the highest negotiated rate; otherwise, for 11g 282 * and 11a, we start "in the middle" at 24Mb or 36Mb. 283 */ 284 srate = ni->ni_rates.rs_nrates - 1; 285 if (sc->sc_curmode != IEEE80211_MODE_11B) { 286 /* 287 * Scan the negotiated rate set to find the 288 * closest rate. 289 */ 290 /* NB: the rate set is assumed sorted */ 291 for (; srate >= 0 && RATE(srate) > 72; srate--) 292 ; 293 } 294 } else { 295 /* 296 * A fixed rate is to be used; ic_fixed_rate is the 297 * IEEE code for this rate (sans basic bit). Convert this 298 * to the index into the negotiated rate set for 299 * the node. We know the rate is there because the 300 * rate set is checked when the station associates. 301 */ 302 /* NB: the rate set is assumed sorted */ 303 srate = ni->ni_rates.rs_nrates - 1; 304 for (; srate >= 0 && RATE(srate) != tp->ucastrate; srate--) 305 ; 306 } 307 /* 308 * The selected rate may not be available due to races 309 * and mode settings. Also orphaned nodes created in 310 * adhoc mode may not have any rate set so this lookup 311 * can fail. This is not fatal. 312 */ 313 ath_rate_update(sc, ni, srate < 0 ? 0 : srate); 314 #undef RATE 315 } 316 317 /* 318 * Examine and potentially adjust the transmit rate. 319 */ 320 static void 321 ath_rate_ctl(void *arg, struct ieee80211_node *ni) 322 { 323 struct ath_softc *sc = arg; 324 struct onoe_node *on = ATH_NODE_ONOE(ATH_NODE(ni)); 325 struct ieee80211_rateset *rs = &ni->ni_rates; 326 int dir = 0, nrate, enough; 327 328 /* 329 * Rate control 330 * XXX: very primitive version. 331 */ 332 enough = (on->on_tx_ok + on->on_tx_err >= 10); 333 334 /* no packet reached -> down */ 335 if (on->on_tx_err > 0 && on->on_tx_ok == 0) 336 dir = -1; 337 338 /* all packets needs retry in average -> down */ 339 if (enough && on->on_tx_ok < on->on_tx_retr) 340 dir = -1; 341 342 /* no error and less than rate_raise% of packets need retry -> up */ 343 if (enough && on->on_tx_err == 0 && 344 on->on_tx_retr < (on->on_tx_ok * ath_rate_raise) / 100) 345 dir = 1; 346 347 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 348 "ok %d err %d retr %d upper %d dir %d", 349 on->on_tx_ok, on->on_tx_err, on->on_tx_retr, on->on_tx_upper, dir); 350 351 nrate = on->on_rix; 352 switch (dir) { 353 case 0: 354 if (enough && on->on_tx_upper > 0) 355 on->on_tx_upper--; 356 break; 357 case -1: 358 if (nrate > 0) { 359 nrate--; 360 sc->sc_stats.ast_rate_drop++; 361 } 362 on->on_tx_upper = 0; 363 break; 364 case 1: 365 /* raise rate if we hit rate_raise_threshold */ 366 if (++on->on_tx_upper < ath_rate_raise_threshold) 367 break; 368 on->on_tx_upper = 0; 369 if (nrate + 1 < rs->rs_nrates) { 370 nrate++; 371 sc->sc_stats.ast_rate_raise++; 372 } 373 break; 374 } 375 376 if (nrate != on->on_rix) { 377 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 378 "%s: %dM -> %dM (%d ok, %d err, %d retr)", __func__, 379 ni->ni_txrate / 2, 380 (rs->rs_rates[nrate] & IEEE80211_RATE_VAL) / 2, 381 on->on_tx_ok, on->on_tx_err, on->on_tx_retr); 382 ath_rate_update(sc, ni, nrate); 383 } else if (enough) 384 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = 0; 385 } 386 387 static void 388 ath_rate_sysctlattach(struct ath_softc *sc) 389 { 390 struct sysctl_ctx_list *ctx = &sc->sc_sysctl_ctx; 391 struct sysctl_oid *tree = sc->sc_sysctl_tree; 392 393 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 394 "rate_interval", CTLFLAG_RW, &ath_rateinterval, 0, 395 "rate control: operation interval (ms)"); 396 /* XXX bounds check values */ 397 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 398 "rate_raise", CTLFLAG_RW, &ath_rate_raise, 0, 399 "rate control: retry threshold to credit rate raise (%%)"); 400 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 401 "rate_raise_threshold", CTLFLAG_RW, &ath_rate_raise_threshold,0, 402 "rate control: # good periods before raising rate"); 403 } 404 405 static int 406 ath_rate_fetch_node_stats(struct ath_softc *sc, struct ath_node *an, 407 struct ath_rateioctl *re) 408 { 409 410 return (EINVAL); 411 } 412 413 struct ath_ratectrl * 414 ath_rate_attach(struct ath_softc *sc) 415 { 416 struct onoe_softc *osc; 417 418 osc = kmalloc(sizeof(struct onoe_softc), M_DEVBUF, M_INTWAIT|M_ZERO); 419 if (osc == NULL) 420 return NULL; 421 osc->arc.arc_space = sizeof(struct onoe_node); 422 ath_rate_sysctlattach(sc); 423 424 return &osc->arc; 425 } 426 427 void 428 ath_rate_detach(struct ath_ratectrl *arc) 429 { 430 struct onoe_softc *osc = (struct onoe_softc *) arc; 431 432 kfree(osc, M_DEVBUF); 433 } 434 435 /* 436 * Module glue. 437 */ 438 static int 439 onoe_modevent(module_t mod, int type, void *unused) 440 { 441 int error; 442 443 wlan_serialize_enter(); 444 445 switch (type) { 446 case MOD_LOAD: 447 if (bootverbose) { 448 kprintf("ath_rate: <Atsushi Onoe's rate " 449 "control algorithm>\n"); 450 } 451 error = 0; 452 break; 453 case MOD_UNLOAD: 454 error = 0; 455 break; 456 default: 457 error = EINVAL; 458 break; 459 } 460 wlan_serialize_exit(); 461 462 return error; 463 } 464 465 static moduledata_t onoe_mod = { 466 "ath_rate", 467 onoe_modevent, 468 0 469 }; 470 471 DECLARE_MODULE(ath_rate, onoe_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST); 472 MODULE_VERSION(ath_rate, 1); 473 MODULE_DEPEND(ath_rate, ath_hal, 1, 1, 1); 474 MODULE_DEPEND(ath_rate, wlan, 1, 1, 1); 475