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/mutex.h> 46 #include <sys/errno.h> 47 48 #include <machine/bus.h> 49 #include <machine/resource.h> 50 #include <sys/bus.h> 51 52 #include <sys/socket.h> 53 54 #include <net/if.h> 55 #include <net/if_media.h> 56 #include <net/if_arp.h> 57 #include <net/ethernet.h> /* XXX for ether_sprintf */ 58 59 #include <net80211/ieee80211_var.h> 60 61 #include <net/bpf.h> 62 63 #ifdef INET 64 #include <netinet/in.h> 65 #include <netinet/if_ether.h> 66 #endif 67 68 #include <dev/ath/if_athvar.h> 69 #include <dev/ath/ath_rate/onoe/onoe.h> 70 #include <dev/ath/ath_hal/ah_desc.h> 71 72 /* 73 * Default parameters for the rate control algorithm. These are 74 * all tunable with sysctls. The rate controller runs periodically 75 * (each ath_rateinterval ms) analyzing transmit statistics for each 76 * neighbor/station (when operating in station mode this is only the AP). 77 * If transmits look to be working well over a sampling period then 78 * it gives a "raise rate credit". If transmits look to not be working 79 * well than it deducts a credit. If the credits cross a threshold then 80 * the transmit rate is raised. Various error conditions force the 81 * the transmit rate to be dropped. 82 * 83 * The decision to issue/deduct a credit is based on the errors and 84 * retries accumulated over the sampling period. ath_rate_raise defines 85 * the percent of retransmits for which a credit is issued/deducted. 86 * ath_rate_raise_threshold defines the threshold on credits at which 87 * the transmit rate is increased. 88 * 89 * XXX this algorithm is flawed. 90 */ 91 static int ath_rateinterval = 1000; /* rate ctl interval (ms) */ 92 static int ath_rate_raise = 10; /* add credit threshold */ 93 static int ath_rate_raise_threshold = 10; /* rate ctl raise threshold */ 94 95 static void ath_rate_update(struct ath_softc *, struct ieee80211_node *, 96 int rate); 97 static void ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *); 98 static void ath_rate_ctl(void *, struct ieee80211_node *); 99 100 void 101 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an) 102 { 103 /* NB: assumed to be zero'd by caller */ 104 } 105 106 void 107 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an) 108 { 109 } 110 111 void 112 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an, 113 int shortPreamble, size_t frameLen, 114 u_int8_t *rix, int *try0, u_int8_t *txrate) 115 { 116 struct onoe_node *on = ATH_NODE_ONOE(an); 117 118 *rix = on->on_tx_rix0; 119 *try0 = on->on_tx_try0; 120 if (shortPreamble) 121 *txrate = on->on_tx_rate0sp; 122 else 123 *txrate = on->on_tx_rate0; 124 } 125 126 /* 127 * Get the TX rates. 128 * 129 * The short preamble bits aren't set here; the caller should augment 130 * the returned rate with the relevant preamble rate flag. 131 */ 132 void 133 ath_rate_getxtxrates(struct ath_softc *sc, struct ath_node *an, 134 uint8_t rix0, struct ath_rc_series *rc) 135 { 136 struct onoe_node *on = ATH_NODE_ONOE(an); 137 138 rc[0].flags = rc[1].flags = rc[2].flags = rc[3].flags = 0; 139 140 rc[0].rix = on->on_tx_rate0; 141 rc[1].rix = on->on_tx_rate1; 142 rc[2].rix = on->on_tx_rate2; 143 rc[3].rix = on->on_tx_rate3; 144 145 rc[0].tries = on->on_tx_try0; 146 rc[1].tries = 2; 147 rc[2].tries = 2; 148 rc[3].tries = 2; 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_rc_series *rc, const struct ath_tx_status *ts, 167 int frame_size, int nframes, int nbad) 168 { 169 struct onoe_node *on = ATH_NODE_ONOE(an); 170 171 if (ts->ts_status == 0) 172 on->on_tx_ok++; 173 else 174 on->on_tx_err++; 175 on->on_tx_retr += ts->ts_shortretry 176 + ts->ts_longretry; 177 if (on->on_interval != 0 && ticks - on->on_ticks > on->on_interval) { 178 ath_rate_ctl(sc, &an->an_node); 179 on->on_ticks = ticks; 180 } 181 } 182 183 void 184 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew) 185 { 186 if (isnew) 187 ath_rate_ctl_start(sc, &an->an_node); 188 } 189 190 static void 191 ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate) 192 { 193 struct ath_node *an = ATH_NODE(ni); 194 struct onoe_node *on = ATH_NODE_ONOE(an); 195 struct ieee80211vap *vap = ni->ni_vap; 196 const HAL_RATE_TABLE *rt = sc->sc_currates; 197 u_int8_t rix; 198 199 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode)); 200 201 IEEE80211_NOTE(vap, IEEE80211_MSG_RATECTL, ni, 202 "%s: set xmit rate to %dM", __func__, 203 ni->ni_rates.rs_nrates > 0 ? 204 (ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0); 205 206 /* 207 * Before associating a node has no rate set setup 208 * so we can't calculate any transmit codes to use. 209 * This is ok since we should never be sending anything 210 * but management frames and those always go at the 211 * lowest hardware rate. 212 */ 213 if (ni->ni_rates.rs_nrates == 0) 214 goto done; 215 on->on_rix = rate; 216 ni->ni_txrate = ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL; 217 on->on_tx_rix0 = sc->sc_rixmap[ni->ni_txrate]; 218 on->on_tx_rate0 = rt->info[on->on_tx_rix0].rateCode; 219 220 on->on_tx_rate0sp = on->on_tx_rate0 | 221 rt->info[on->on_tx_rix0].shortPreamble; 222 if (sc->sc_mrretry) { 223 /* 224 * Hardware supports multi-rate retry; setup two 225 * step-down retry rates and make the lowest rate 226 * be the ``last chance''. We use 4, 2, 2, 2 tries 227 * respectively (4 is set here, the rest are fixed 228 * in the xmit routine). 229 */ 230 on->on_tx_try0 = 1 + 3; /* 4 tries at rate 0 */ 231 if (--rate >= 0) { 232 rix = sc->sc_rixmap[ 233 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL]; 234 on->on_tx_rate1 = rt->info[rix].rateCode; 235 on->on_tx_rate1sp = on->on_tx_rate1 | 236 rt->info[rix].shortPreamble; 237 } else { 238 on->on_tx_rate1 = on->on_tx_rate1sp = 0; 239 } 240 if (--rate >= 0) { 241 rix = sc->sc_rixmap[ 242 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL]; 243 on->on_tx_rate2 = rt->info[rix].rateCode; 244 on->on_tx_rate2sp = on->on_tx_rate2 | 245 rt->info[rix].shortPreamble; 246 } else { 247 on->on_tx_rate2 = on->on_tx_rate2sp = 0; 248 } 249 if (rate > 0) { 250 /* NB: only do this if we didn't already do it above */ 251 on->on_tx_rate3 = rt->info[0].rateCode; 252 on->on_tx_rate3sp = 253 on->on_tx_rate3 | rt->info[0].shortPreamble; 254 } else { 255 on->on_tx_rate3 = on->on_tx_rate3sp = 0; 256 } 257 } else { 258 on->on_tx_try0 = ATH_TXMAXTRY; /* max tries at rate 0 */ 259 on->on_tx_rate1 = on->on_tx_rate1sp = 0; 260 on->on_tx_rate2 = on->on_tx_rate2sp = 0; 261 on->on_tx_rate3 = on->on_tx_rate3sp = 0; 262 } 263 done: 264 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = on->on_tx_upper = 0; 265 266 on->on_interval = ath_rateinterval; 267 if (vap->iv_opmode == IEEE80211_M_STA) 268 on->on_interval /= 2; 269 on->on_interval = (on->on_interval * hz) / 1000; 270 } 271 272 /* 273 * Set the starting transmit rate for a node. 274 */ 275 static void 276 ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni) 277 { 278 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL) 279 const struct ieee80211_txparam *tp = ni->ni_txparms; 280 int srate; 281 282 KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates")); 283 if (tp == NULL || tp->ucastrate == IEEE80211_FIXED_RATE_NONE) { 284 /* 285 * No fixed rate is requested. For 11b start with 286 * the highest negotiated rate; otherwise, for 11g 287 * and 11a, we start "in the middle" at 24Mb or 36Mb. 288 */ 289 srate = ni->ni_rates.rs_nrates - 1; 290 if (sc->sc_curmode != IEEE80211_MODE_11B) { 291 /* 292 * Scan the negotiated rate set to find the 293 * closest rate. 294 */ 295 /* NB: the rate set is assumed sorted */ 296 for (; srate >= 0 && RATE(srate) > 72; srate--) 297 ; 298 } 299 } else { 300 /* 301 * A fixed rate is to be used; ic_fixed_rate is the 302 * IEEE code for this rate (sans basic bit). Convert this 303 * to the index into the negotiated rate set for 304 * the node. We know the rate is there because the 305 * rate set is checked when the station associates. 306 */ 307 /* NB: the rate set is assumed sorted */ 308 srate = ni->ni_rates.rs_nrates - 1; 309 for (; srate >= 0 && RATE(srate) != tp->ucastrate; srate--) 310 ; 311 } 312 /* 313 * The selected rate may not be available due to races 314 * and mode settings. Also orphaned nodes created in 315 * adhoc mode may not have any rate set so this lookup 316 * can fail. This is not fatal. 317 */ 318 ath_rate_update(sc, ni, srate < 0 ? 0 : srate); 319 #undef RATE 320 } 321 322 /* 323 * Examine and potentially adjust the transmit rate. 324 */ 325 static void 326 ath_rate_ctl(void *arg, struct ieee80211_node *ni) 327 { 328 struct ath_softc *sc = arg; 329 struct onoe_node *on = ATH_NODE_ONOE(ATH_NODE(ni)); 330 struct ieee80211_rateset *rs = &ni->ni_rates; 331 int dir = 0, nrate, enough; 332 333 /* 334 * Rate control 335 * XXX: very primitive version. 336 */ 337 enough = (on->on_tx_ok + on->on_tx_err >= 10); 338 339 /* no packet reached -> down */ 340 if (on->on_tx_err > 0 && on->on_tx_ok == 0) 341 dir = -1; 342 343 /* all packets needs retry in average -> down */ 344 if (enough && on->on_tx_ok < on->on_tx_retr) 345 dir = -1; 346 347 /* no error and less than rate_raise% of packets need retry -> up */ 348 if (enough && on->on_tx_err == 0 && 349 on->on_tx_retr < (on->on_tx_ok * ath_rate_raise) / 100) 350 dir = 1; 351 352 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 353 "ok %d err %d retr %d upper %d dir %d", 354 on->on_tx_ok, on->on_tx_err, on->on_tx_retr, on->on_tx_upper, dir); 355 356 nrate = on->on_rix; 357 switch (dir) { 358 case 0: 359 if (enough && on->on_tx_upper > 0) 360 on->on_tx_upper--; 361 break; 362 case -1: 363 if (nrate > 0) { 364 nrate--; 365 sc->sc_stats.ast_rate_drop++; 366 } 367 on->on_tx_upper = 0; 368 break; 369 case 1: 370 /* raise rate if we hit rate_raise_threshold */ 371 if (++on->on_tx_upper < ath_rate_raise_threshold) 372 break; 373 on->on_tx_upper = 0; 374 if (nrate + 1 < rs->rs_nrates) { 375 nrate++; 376 sc->sc_stats.ast_rate_raise++; 377 } 378 break; 379 } 380 381 if (nrate != on->on_rix) { 382 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 383 "%s: %dM -> %dM (%d ok, %d err, %d retr)", __func__, 384 ni->ni_txrate / 2, 385 (rs->rs_rates[nrate] & IEEE80211_RATE_VAL) / 2, 386 on->on_tx_ok, on->on_tx_err, on->on_tx_retr); 387 ath_rate_update(sc, ni, nrate); 388 } else if (enough) 389 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = 0; 390 } 391 392 static void 393 ath_rate_sysctlattach(struct ath_softc *sc) 394 { 395 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev); 396 struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev); 397 398 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 399 "rate_interval", CTLFLAG_RW, &ath_rateinterval, 0, 400 "rate control: operation interval (ms)"); 401 /* XXX bounds check values */ 402 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 403 "rate_raise", CTLFLAG_RW, &ath_rate_raise, 0, 404 "rate control: retry threshold to credit rate raise (%%)"); 405 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 406 "rate_raise_threshold", CTLFLAG_RW, &ath_rate_raise_threshold,0, 407 "rate control: # good periods before raising rate"); 408 } 409 410 static int 411 ath_rate_fetch_node_stats(struct ath_softc *sc, struct ath_node *an, 412 struct ath_rateioctl *re) 413 { 414 415 return (EINVAL); 416 } 417 418 struct ath_ratectrl * 419 ath_rate_attach(struct ath_softc *sc) 420 { 421 struct onoe_softc *osc; 422 423 osc = malloc(sizeof(struct onoe_softc), M_DEVBUF, M_NOWAIT|M_ZERO); 424 if (osc == NULL) 425 return NULL; 426 osc->arc.arc_space = sizeof(struct onoe_node); 427 ath_rate_sysctlattach(sc); 428 429 return &osc->arc; 430 } 431 432 void 433 ath_rate_detach(struct ath_ratectrl *arc) 434 { 435 struct onoe_softc *osc = (struct onoe_softc *) arc; 436 437 free(osc, M_DEVBUF); 438 } 439