1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2002-2007 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 * 18 * NO WARRANTY 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY 22 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 23 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, 24 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER 27 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 29 * THE POSSIBILITY OF SUCH DAMAGES. 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 /* 36 * Atsushi Onoe's rate control algorithm. 37 */ 38 #include "opt_ath.h" 39 #include "opt_inet.h" 40 #include "opt_wlan.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/sysctl.h> 45 #include <sys/kernel.h> 46 #include <sys/lock.h> 47 #include <sys/mutex.h> 48 #include <sys/errno.h> 49 50 #include <machine/bus.h> 51 #include <machine/resource.h> 52 #include <sys/bus.h> 53 54 #include <sys/socket.h> 55 56 #include <net/if.h> 57 #include <net/if_media.h> 58 #include <net/if_arp.h> 59 #include <net/ethernet.h> /* XXX for ether_sprintf */ 60 61 #include <net80211/ieee80211_var.h> 62 63 #include <net/bpf.h> 64 65 #ifdef INET 66 #include <netinet/in.h> 67 #include <netinet/if_ether.h> 68 #endif 69 70 #include <dev/ath/if_athvar.h> 71 #include <dev/ath/ath_rate/onoe/onoe.h> 72 #include <dev/ath/ath_hal/ah_desc.h> 73 74 /* 75 * Default parameters for the rate control algorithm. These are 76 * all tunable with sysctls. The rate controller runs periodically 77 * (each ath_rateinterval ms) analyzing transmit statistics for each 78 * neighbor/station (when operating in station mode this is only the AP). 79 * If transmits look to be working well over a sampling period then 80 * it gives a "raise rate credit". If transmits look to not be working 81 * well than it deducts a credit. If the credits cross a threshold then 82 * the transmit rate is raised. Various error conditions force the 83 * the transmit rate to be dropped. 84 * 85 * The decision to issue/deduct a credit is based on the errors and 86 * retries accumulated over the sampling period. ath_rate_raise defines 87 * the percent of retransmits for which a credit is issued/deducted. 88 * ath_rate_raise_threshold defines the threshold on credits at which 89 * the transmit rate is increased. 90 * 91 * XXX this algorithm is flawed. 92 */ 93 static int ath_rateinterval = 1000; /* rate ctl interval (ms) */ 94 static int ath_rate_raise = 10; /* add credit threshold */ 95 static int ath_rate_raise_threshold = 10; /* rate ctl raise threshold */ 96 97 static void ath_rate_update(struct ath_softc *, struct ieee80211_node *, 98 int rate); 99 static void ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *); 100 static void ath_rate_ctl(void *, struct ieee80211_node *); 101 102 void 103 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an) 104 { 105 /* NB: assumed to be zero'd by caller */ 106 } 107 108 void 109 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an) 110 { 111 } 112 113 void 114 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an, 115 int shortPreamble, size_t frameLen, 116 u_int8_t *rix, int *try0, u_int8_t *txrate) 117 { 118 struct onoe_node *on = ATH_NODE_ONOE(an); 119 120 *rix = on->on_tx_rix0; 121 *try0 = on->on_tx_try0; 122 if (shortPreamble) 123 *txrate = on->on_tx_rate0sp; 124 else 125 *txrate = on->on_tx_rate0; 126 } 127 128 /* 129 * Get the TX rates. 130 * 131 * The short preamble bits aren't set here; the caller should augment 132 * the returned rate with the relevant preamble rate flag. 133 */ 134 void 135 ath_rate_getxtxrates(struct ath_softc *sc, struct ath_node *an, 136 uint8_t rix0, struct ath_rc_series *rc) 137 { 138 struct onoe_node *on = ATH_NODE_ONOE(an); 139 140 rc[0].flags = rc[1].flags = rc[2].flags = rc[3].flags = 0; 141 142 rc[0].rix = on->on_tx_rate0; 143 rc[1].rix = on->on_tx_rate1; 144 rc[2].rix = on->on_tx_rate2; 145 rc[3].rix = on->on_tx_rate3; 146 147 rc[0].tries = on->on_tx_try0; 148 rc[1].tries = 2; 149 rc[2].tries = 2; 150 rc[3].tries = 2; 151 } 152 153 void 154 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an, 155 struct ath_desc *ds, int shortPreamble, u_int8_t rix) 156 { 157 struct onoe_node *on = ATH_NODE_ONOE(an); 158 159 ath_hal_setupxtxdesc(sc->sc_ah, ds 160 , on->on_tx_rate1sp, 2 /* series 1 */ 161 , on->on_tx_rate2sp, 2 /* series 2 */ 162 , on->on_tx_rate3sp, 2 /* series 3 */ 163 ); 164 } 165 166 void 167 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an, 168 const struct ath_rc_series *rc, const struct ath_tx_status *ts, 169 int frame_size, int nframes, int nbad) 170 { 171 struct onoe_node *on = ATH_NODE_ONOE(an); 172 173 if (ts->ts_status == 0) 174 on->on_tx_ok++; 175 else 176 on->on_tx_err++; 177 on->on_tx_retr += ts->ts_shortretry 178 + ts->ts_longretry; 179 if (on->on_interval != 0 && ticks - on->on_ticks > on->on_interval) { 180 ath_rate_ctl(sc, &an->an_node); 181 on->on_ticks = ticks; 182 } 183 } 184 185 void 186 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew) 187 { 188 if (isnew) 189 ath_rate_ctl_start(sc, &an->an_node); 190 } 191 192 static void 193 ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate) 194 { 195 struct ath_node *an = ATH_NODE(ni); 196 struct onoe_node *on = ATH_NODE_ONOE(an); 197 struct ieee80211vap *vap = ni->ni_vap; 198 const HAL_RATE_TABLE *rt = sc->sc_currates; 199 u_int8_t rix; 200 201 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode)); 202 203 IEEE80211_NOTE(vap, IEEE80211_MSG_RATECTL, ni, 204 "%s: set xmit rate to %dM", __func__, 205 ni->ni_rates.rs_nrates > 0 ? 206 (ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0); 207 208 /* 209 * Before associating a node has no rate set setup 210 * so we can't calculate any transmit codes to use. 211 * This is ok since we should never be sending anything 212 * but management frames and those always go at the 213 * lowest hardware rate. 214 */ 215 if (ni->ni_rates.rs_nrates == 0) 216 goto done; 217 on->on_rix = rate; 218 ni->ni_txrate = ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL; 219 on->on_tx_rix0 = sc->sc_rixmap[ni->ni_txrate]; 220 on->on_tx_rate0 = rt->info[on->on_tx_rix0].rateCode; 221 222 on->on_tx_rate0sp = on->on_tx_rate0 | 223 rt->info[on->on_tx_rix0].shortPreamble; 224 if (sc->sc_mrretry) { 225 /* 226 * Hardware supports multi-rate retry; setup two 227 * step-down retry rates and make the lowest rate 228 * be the ``last chance''. We use 4, 2, 2, 2 tries 229 * respectively (4 is set here, the rest are fixed 230 * in the xmit routine). 231 */ 232 on->on_tx_try0 = 1 + 3; /* 4 tries at rate 0 */ 233 if (--rate >= 0) { 234 rix = sc->sc_rixmap[ 235 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL]; 236 on->on_tx_rate1 = rt->info[rix].rateCode; 237 on->on_tx_rate1sp = on->on_tx_rate1 | 238 rt->info[rix].shortPreamble; 239 } else { 240 on->on_tx_rate1 = on->on_tx_rate1sp = 0; 241 } 242 if (--rate >= 0) { 243 rix = sc->sc_rixmap[ 244 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL]; 245 on->on_tx_rate2 = rt->info[rix].rateCode; 246 on->on_tx_rate2sp = on->on_tx_rate2 | 247 rt->info[rix].shortPreamble; 248 } else { 249 on->on_tx_rate2 = on->on_tx_rate2sp = 0; 250 } 251 if (rate > 0) { 252 /* NB: only do this if we didn't already do it above */ 253 on->on_tx_rate3 = rt->info[0].rateCode; 254 on->on_tx_rate3sp = 255 on->on_tx_rate3 | rt->info[0].shortPreamble; 256 } else { 257 on->on_tx_rate3 = on->on_tx_rate3sp = 0; 258 } 259 } else { 260 on->on_tx_try0 = ATH_TXMAXTRY; /* max tries at rate 0 */ 261 on->on_tx_rate1 = on->on_tx_rate1sp = 0; 262 on->on_tx_rate2 = on->on_tx_rate2sp = 0; 263 on->on_tx_rate3 = on->on_tx_rate3sp = 0; 264 } 265 done: 266 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = on->on_tx_upper = 0; 267 268 on->on_interval = ath_rateinterval; 269 if (vap->iv_opmode == IEEE80211_M_STA) 270 on->on_interval /= 2; 271 on->on_interval = (on->on_interval * hz) / 1000; 272 } 273 274 /* 275 * Set the starting transmit rate for a node. 276 */ 277 static void 278 ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni) 279 { 280 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL) 281 const struct ieee80211_txparam *tp = ni->ni_txparms; 282 int srate; 283 284 KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates")); 285 if (tp == NULL || tp->ucastrate == IEEE80211_FIXED_RATE_NONE) { 286 /* 287 * No fixed rate is requested. For 11b start with 288 * the highest negotiated rate; otherwise, for 11g 289 * and 11a, we start "in the middle" at 24Mb or 36Mb. 290 */ 291 srate = ni->ni_rates.rs_nrates - 1; 292 if (sc->sc_curmode != IEEE80211_MODE_11B) { 293 /* 294 * Scan the negotiated rate set to find the 295 * closest rate. 296 */ 297 /* NB: the rate set is assumed sorted */ 298 for (; srate >= 0 && RATE(srate) > 72; srate--) 299 ; 300 } 301 } else { 302 /* 303 * A fixed rate is to be used; ic_fixed_rate is the 304 * IEEE code for this rate (sans basic bit). Convert this 305 * to the index into the negotiated rate set for 306 * the node. We know the rate is there because the 307 * rate set is checked when the station associates. 308 */ 309 /* NB: the rate set is assumed sorted */ 310 srate = ni->ni_rates.rs_nrates - 1; 311 for (; srate >= 0 && RATE(srate) != tp->ucastrate; srate--) 312 ; 313 } 314 /* 315 * The selected rate may not be available due to races 316 * and mode settings. Also orphaned nodes created in 317 * adhoc mode may not have any rate set so this lookup 318 * can fail. This is not fatal. 319 */ 320 ath_rate_update(sc, ni, srate < 0 ? 0 : srate); 321 #undef RATE 322 } 323 324 /* 325 * Examine and potentially adjust the transmit rate. 326 */ 327 static void 328 ath_rate_ctl(void *arg, struct ieee80211_node *ni) 329 { 330 struct ath_softc *sc = arg; 331 struct onoe_node *on = ATH_NODE_ONOE(ATH_NODE(ni)); 332 struct ieee80211_rateset *rs = &ni->ni_rates; 333 int dir = 0, nrate, enough; 334 335 /* 336 * Rate control 337 * XXX: very primitive version. 338 */ 339 enough = (on->on_tx_ok + on->on_tx_err >= 10); 340 341 /* no packet reached -> down */ 342 if (on->on_tx_err > 0 && on->on_tx_ok == 0) 343 dir = -1; 344 345 /* all packets needs retry in average -> down */ 346 if (enough && on->on_tx_ok < on->on_tx_retr) 347 dir = -1; 348 349 /* no error and less than rate_raise% of packets need retry -> up */ 350 if (enough && on->on_tx_err == 0 && 351 on->on_tx_retr < (on->on_tx_ok * ath_rate_raise) / 100) 352 dir = 1; 353 354 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 355 "ok %d err %d retr %d upper %d dir %d", 356 on->on_tx_ok, on->on_tx_err, on->on_tx_retr, on->on_tx_upper, dir); 357 358 nrate = on->on_rix; 359 switch (dir) { 360 case 0: 361 if (enough && on->on_tx_upper > 0) 362 on->on_tx_upper--; 363 break; 364 case -1: 365 if (nrate > 0) { 366 nrate--; 367 sc->sc_stats.ast_rate_drop++; 368 } 369 on->on_tx_upper = 0; 370 break; 371 case 1: 372 /* raise rate if we hit rate_raise_threshold */ 373 if (++on->on_tx_upper < ath_rate_raise_threshold) 374 break; 375 on->on_tx_upper = 0; 376 if (nrate + 1 < rs->rs_nrates) { 377 nrate++; 378 sc->sc_stats.ast_rate_raise++; 379 } 380 break; 381 } 382 383 if (nrate != on->on_rix) { 384 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 385 "%s: %dM -> %dM (%d ok, %d err, %d retr)", __func__, 386 ni->ni_txrate / 2, 387 (rs->rs_rates[nrate] & IEEE80211_RATE_VAL) / 2, 388 on->on_tx_ok, on->on_tx_err, on->on_tx_retr); 389 ath_rate_update(sc, ni, nrate); 390 } else if (enough) 391 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = 0; 392 } 393 394 static void 395 ath_rate_sysctlattach(struct ath_softc *sc) 396 { 397 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev); 398 struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev); 399 400 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 401 "rate_interval", CTLFLAG_RW, &ath_rateinterval, 0, 402 "rate control: operation interval (ms)"); 403 /* XXX bounds check values */ 404 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 405 "rate_raise", CTLFLAG_RW, &ath_rate_raise, 0, 406 "rate control: retry threshold to credit rate raise (%%)"); 407 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 408 "rate_raise_threshold", CTLFLAG_RW, &ath_rate_raise_threshold,0, 409 "rate control: # good periods before raising rate"); 410 } 411 412 static int 413 ath_rate_fetch_node_stats(struct ath_softc *sc, struct ath_node *an, 414 struct ath_rateioctl *re) 415 { 416 417 return (EINVAL); 418 } 419 420 struct ath_ratectrl * 421 ath_rate_attach(struct ath_softc *sc) 422 { 423 struct onoe_softc *osc; 424 425 osc = malloc(sizeof(struct onoe_softc), M_DEVBUF, M_NOWAIT|M_ZERO); 426 if (osc == NULL) 427 return NULL; 428 osc->arc.arc_space = sizeof(struct onoe_node); 429 ath_rate_sysctlattach(sc); 430 431 return &osc->arc; 432 } 433 434 void 435 ath_rate_detach(struct ath_ratectrl *arc) 436 { 437 struct onoe_softc *osc = (struct onoe_softc *) arc; 438 439 free(osc, M_DEVBUF); 440 } 441