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_ath.h" 37 #include "opt_inet.h" 38 #include "opt_wlan.h" 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/sysctl.h> 43 #include <sys/kernel.h> 44 #include <sys/lock.h> 45 #include <sys/errno.h> 46 47 #if defined(__DragonFly__) 48 /* empty */ 49 #else 50 #include <machine/bus.h> 51 #include <machine/resource.h> 52 #endif 53 #include <sys/bus.h> 54 55 #include <sys/socket.h> 56 57 #include <net/if.h> 58 #include <net/if_media.h> 59 #include <net/if_arp.h> 60 #include <net/ethernet.h> /* XXX for ether_sprintf */ 61 62 #include <netproto/802_11/ieee80211_var.h> 63 64 #include <net/bpf.h> 65 66 #ifdef INET 67 #include <netinet/in.h> 68 #include <netinet/if_ether.h> 69 #endif 70 71 #include <dev/netif/ath/ath/if_athvar.h> 72 #include <dev/netif/ath/ath_rate/onoe/onoe.h> 73 #include <dev/netif/ath/ath_hal/ah_desc.h> 74 75 /* 76 * Default parameters for the rate control algorithm. These are 77 * all tunable with sysctls. The rate controller runs periodically 78 * (each ath_rateinterval ms) analyzing transmit statistics for each 79 * neighbor/station (when operating in station mode this is only the AP). 80 * If transmits look to be working well over a sampling period then 81 * it gives a "raise rate credit". If transmits look to not be working 82 * well than it deducts a credit. If the credits cross a threshold then 83 * the transmit rate is raised. Various error conditions force the 84 * the transmit rate to be dropped. 85 * 86 * The decision to issue/deduct a credit is based on the errors and 87 * retries accumulated over the sampling period. ath_rate_raise defines 88 * the percent of retransmits for which a credit is issued/deducted. 89 * ath_rate_raise_threshold defines the threshold on credits at which 90 * the transmit rate is increased. 91 * 92 * XXX this algorithm is flawed. 93 */ 94 static int ath_rateinterval = 1000; /* rate ctl interval (ms) */ 95 static int ath_rate_raise = 10; /* add credit threshold */ 96 static int ath_rate_raise_threshold = 10; /* rate ctl raise threshold */ 97 98 static void ath_rate_update(struct ath_softc *, struct ieee80211_node *, 99 int rate); 100 static void ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *); 101 static void ath_rate_ctl(void *, struct ieee80211_node *); 102 103 void 104 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an) 105 { 106 /* NB: assumed to be zero'd by caller */ 107 } 108 109 void 110 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an) 111 { 112 } 113 114 void 115 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an, 116 int shortPreamble, size_t frameLen, 117 u_int8_t *rix, int *try0, u_int8_t *txrate) 118 { 119 struct onoe_node *on = ATH_NODE_ONOE(an); 120 121 *rix = on->on_tx_rix0; 122 *try0 = on->on_tx_try0; 123 if (shortPreamble) 124 *txrate = on->on_tx_rate0sp; 125 else 126 *txrate = on->on_tx_rate0; 127 } 128 129 /* 130 * Get the TX rates. 131 * 132 * The short preamble bits aren't set here; the caller should augment 133 * the returned rate with the relevant preamble rate flag. 134 */ 135 void 136 ath_rate_getxtxrates(struct ath_softc *sc, struct ath_node *an, 137 uint8_t rix0, struct ath_rc_series *rc) 138 { 139 struct onoe_node *on = ATH_NODE_ONOE(an); 140 141 rc[0].flags = rc[1].flags = rc[2].flags = rc[3].flags = 0; 142 143 rc[0].rix = on->on_tx_rate0; 144 rc[1].rix = on->on_tx_rate1; 145 rc[2].rix = on->on_tx_rate2; 146 rc[3].rix = on->on_tx_rate3; 147 148 rc[0].tries = on->on_tx_try0; 149 rc[1].tries = 2; 150 rc[2].tries = 2; 151 rc[3].tries = 2; 152 } 153 154 void 155 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an, 156 struct ath_desc *ds, int shortPreamble, u_int8_t rix) 157 { 158 struct onoe_node *on = ATH_NODE_ONOE(an); 159 160 ath_hal_setupxtxdesc(sc->sc_ah, ds 161 , on->on_tx_rate1sp, 2 /* series 1 */ 162 , on->on_tx_rate2sp, 2 /* series 2 */ 163 , on->on_tx_rate3sp, 2 /* series 3 */ 164 ); 165 } 166 167 void 168 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an, 169 const struct ath_rc_series *rc, const struct ath_tx_status *ts, 170 int frame_size, int nframes, int nbad) 171 { 172 struct onoe_node *on = ATH_NODE_ONOE(an); 173 174 if (ts->ts_status == 0) 175 on->on_tx_ok++; 176 else 177 on->on_tx_err++; 178 on->on_tx_retr += ts->ts_shortretry 179 + ts->ts_longretry; 180 if (on->on_interval != 0 && ticks - on->on_ticks > on->on_interval) { 181 ath_rate_ctl(sc, &an->an_node); 182 on->on_ticks = ticks; 183 } 184 } 185 186 void 187 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew) 188 { 189 if (isnew) 190 ath_rate_ctl_start(sc, &an->an_node); 191 } 192 193 static void 194 ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate) 195 { 196 struct ath_node *an = ATH_NODE(ni); 197 struct onoe_node *on = ATH_NODE_ONOE(an); 198 struct ieee80211vap *vap = ni->ni_vap; 199 const HAL_RATE_TABLE *rt = sc->sc_currates; 200 u_int8_t rix; 201 202 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode)); 203 204 IEEE80211_NOTE(vap, IEEE80211_MSG_RATECTL, ni, 205 "%s: set xmit rate to %dM", __func__, 206 ni->ni_rates.rs_nrates > 0 ? 207 (ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0); 208 209 /* 210 * Before associating a node has no rate set setup 211 * so we can't calculate any transmit codes to use. 212 * This is ok since we should never be sending anything 213 * but management frames and those always go at the 214 * lowest hardware rate. 215 */ 216 if (ni->ni_rates.rs_nrates == 0) 217 goto done; 218 on->on_rix = rate; 219 ni->ni_txrate = ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL; 220 on->on_tx_rix0 = sc->sc_rixmap[ni->ni_txrate]; 221 on->on_tx_rate0 = rt->info[on->on_tx_rix0].rateCode; 222 223 on->on_tx_rate0sp = on->on_tx_rate0 | 224 rt->info[on->on_tx_rix0].shortPreamble; 225 if (sc->sc_mrretry) { 226 /* 227 * Hardware supports multi-rate retry; setup two 228 * step-down retry rates and make the lowest rate 229 * be the ``last chance''. We use 4, 2, 2, 2 tries 230 * respectively (4 is set here, the rest are fixed 231 * in the xmit routine). 232 */ 233 on->on_tx_try0 = 1 + 3; /* 4 tries at rate 0 */ 234 if (--rate >= 0) { 235 rix = sc->sc_rixmap[ 236 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL]; 237 on->on_tx_rate1 = rt->info[rix].rateCode; 238 on->on_tx_rate1sp = on->on_tx_rate1 | 239 rt->info[rix].shortPreamble; 240 } else { 241 on->on_tx_rate1 = on->on_tx_rate1sp = 0; 242 } 243 if (--rate >= 0) { 244 rix = sc->sc_rixmap[ 245 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL]; 246 on->on_tx_rate2 = rt->info[rix].rateCode; 247 on->on_tx_rate2sp = on->on_tx_rate2 | 248 rt->info[rix].shortPreamble; 249 } else { 250 on->on_tx_rate2 = on->on_tx_rate2sp = 0; 251 } 252 if (rate > 0) { 253 /* NB: only do this if we didn't already do it above */ 254 on->on_tx_rate3 = rt->info[0].rateCode; 255 on->on_tx_rate3sp = 256 on->on_tx_rate3 | rt->info[0].shortPreamble; 257 } else { 258 on->on_tx_rate3 = on->on_tx_rate3sp = 0; 259 } 260 } else { 261 on->on_tx_try0 = ATH_TXMAXTRY; /* max tries at rate 0 */ 262 on->on_tx_rate1 = on->on_tx_rate1sp = 0; 263 on->on_tx_rate2 = on->on_tx_rate2sp = 0; 264 on->on_tx_rate3 = on->on_tx_rate3sp = 0; 265 } 266 done: 267 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = on->on_tx_upper = 0; 268 269 on->on_interval = ath_rateinterval; 270 if (vap->iv_opmode == IEEE80211_M_STA) 271 on->on_interval /= 2; 272 on->on_interval = (on->on_interval * hz) / 1000; 273 } 274 275 /* 276 * Set the starting transmit rate for a node. 277 */ 278 static void 279 ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni) 280 { 281 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL) 282 const struct ieee80211_txparam *tp = ni->ni_txparms; 283 int srate; 284 285 KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates")); 286 if (tp == NULL || tp->ucastrate == IEEE80211_FIXED_RATE_NONE) { 287 /* 288 * No fixed rate is requested. For 11b start with 289 * the highest negotiated rate; otherwise, for 11g 290 * and 11a, we start "in the middle" at 24Mb or 36Mb. 291 */ 292 srate = ni->ni_rates.rs_nrates - 1; 293 if (sc->sc_curmode != IEEE80211_MODE_11B) { 294 /* 295 * Scan the negotiated rate set to find the 296 * closest rate. 297 */ 298 /* NB: the rate set is assumed sorted */ 299 for (; srate >= 0 && RATE(srate) > 72; srate--) 300 ; 301 } 302 } else { 303 /* 304 * A fixed rate is to be used; ic_fixed_rate is the 305 * IEEE code for this rate (sans basic bit). Convert this 306 * to the index into the negotiated rate set for 307 * the node. We know the rate is there because the 308 * rate set is checked when the station associates. 309 */ 310 /* NB: the rate set is assumed sorted */ 311 srate = ni->ni_rates.rs_nrates - 1; 312 for (; srate >= 0 && RATE(srate) != tp->ucastrate; srate--) 313 ; 314 } 315 /* 316 * The selected rate may not be available due to races 317 * and mode settings. Also orphaned nodes created in 318 * adhoc mode may not have any rate set so this lookup 319 * can fail. This is not fatal. 320 */ 321 ath_rate_update(sc, ni, srate < 0 ? 0 : srate); 322 #undef RATE 323 } 324 325 /* 326 * Examine and potentially adjust the transmit rate. 327 */ 328 static void 329 ath_rate_ctl(void *arg, struct ieee80211_node *ni) 330 { 331 struct ath_softc *sc = arg; 332 struct onoe_node *on = ATH_NODE_ONOE(ATH_NODE(ni)); 333 struct ieee80211_rateset *rs = &ni->ni_rates; 334 int dir = 0, nrate, enough; 335 336 /* 337 * Rate control 338 * XXX: very primitive version. 339 */ 340 enough = (on->on_tx_ok + on->on_tx_err >= 10); 341 342 /* no packet reached -> down */ 343 if (on->on_tx_err > 0 && on->on_tx_ok == 0) 344 dir = -1; 345 346 /* all packets needs retry in average -> down */ 347 if (enough && on->on_tx_ok < on->on_tx_retr) 348 dir = -1; 349 350 /* no error and less than rate_raise% of packets need retry -> up */ 351 if (enough && on->on_tx_err == 0 && 352 on->on_tx_retr < (on->on_tx_ok * ath_rate_raise) / 100) 353 dir = 1; 354 355 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 356 "ok %d err %d retr %d upper %d dir %d", 357 on->on_tx_ok, on->on_tx_err, on->on_tx_retr, on->on_tx_upper, dir); 358 359 nrate = on->on_rix; 360 switch (dir) { 361 case 0: 362 if (enough && on->on_tx_upper > 0) 363 on->on_tx_upper--; 364 break; 365 case -1: 366 if (nrate > 0) { 367 nrate--; 368 sc->sc_stats.ast_rate_drop++; 369 } 370 on->on_tx_upper = 0; 371 break; 372 case 1: 373 /* raise rate if we hit rate_raise_threshold */ 374 if (++on->on_tx_upper < ath_rate_raise_threshold) 375 break; 376 on->on_tx_upper = 0; 377 if (nrate + 1 < rs->rs_nrates) { 378 nrate++; 379 sc->sc_stats.ast_rate_raise++; 380 } 381 break; 382 } 383 384 if (nrate != on->on_rix) { 385 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 386 "%s: %dM -> %dM (%d ok, %d err, %d retr)", __func__, 387 ni->ni_txrate / 2, 388 (rs->rs_rates[nrate] & IEEE80211_RATE_VAL) / 2, 389 on->on_tx_ok, on->on_tx_err, on->on_tx_retr); 390 ath_rate_update(sc, ni, nrate); 391 } else if (enough) 392 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = 0; 393 } 394 395 static void 396 ath_rate_sysctlattach(struct ath_softc *sc) 397 { 398 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev); 399 struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev); 400 401 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 402 "rate_interval", CTLFLAG_RW, &ath_rateinterval, 0, 403 "rate control: operation interval (ms)"); 404 /* XXX bounds check values */ 405 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 406 "rate_raise", CTLFLAG_RW, &ath_rate_raise, 0, 407 "rate control: retry threshold to credit rate raise (%%)"); 408 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 409 "rate_raise_threshold", CTLFLAG_RW, &ath_rate_raise_threshold,0, 410 "rate control: # good periods before raising rate"); 411 } 412 413 static int 414 ath_rate_fetch_node_stats(struct ath_softc *sc, struct ath_node *an, 415 struct ath_rateioctl *re) 416 { 417 418 return (EINVAL); 419 } 420 421 struct ath_ratectrl * 422 ath_rate_attach(struct ath_softc *sc) 423 { 424 struct onoe_softc *osc; 425 426 osc = kmalloc(sizeof(struct onoe_softc), M_DEVBUF, M_INTWAIT|M_ZERO); 427 if (osc == NULL) 428 return NULL; 429 osc->arc.arc_space = sizeof(struct onoe_node); 430 ath_rate_sysctlattach(sc); 431 432 return &osc->arc; 433 } 434 435 void 436 ath_rate_detach(struct ath_ratectrl *arc) 437 { 438 struct onoe_softc *osc = (struct onoe_softc *) arc; 439 440 kfree(osc, M_DEVBUF); 441 } 442 443 #if defined(__DragonFly__) 444 445 /* 446 * Module glue. 447 */ 448 static int 449 onoe_modevent(module_t mod, int type, void *unused) 450 { 451 int error; 452 453 wlan_serialize_enter(); 454 455 switch (type) { 456 case MOD_LOAD: 457 if (bootverbose) { 458 kprintf("ath_rate: <Atsushi Onoe's rate " 459 "control algorithm>\n"); 460 } 461 error = 0; 462 break; 463 case MOD_UNLOAD: 464 error = 0; 465 break; 466 default: 467 error = EINVAL; 468 break; 469 } 470 wlan_serialize_exit(); 471 472 return error; 473 } 474 475 static moduledata_t onoe_mod = { 476 "ath_rate", 477 onoe_modevent, 478 0 479 }; 480 481 DECLARE_MODULE(ath_rate, onoe_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST); 482 MODULE_VERSION(ath_rate, 1); 483 MODULE_DEPEND(ath_rate, ath_hal, 1, 1, 1); 484 MODULE_DEPEND(ath_rate, wlan, 1, 1, 1); 485 486 #endif 487