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 #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 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 <dev/ath/ath_hal/ah_desc.h> 70 71 /* 72 * Default parameters for the rate control algorithm. These are 73 * all tunable with sysctls. The rate controller runs periodically 74 * (each ath_rateinterval ms) analyzing transmit statistics for each 75 * neighbor/station (when operating in station mode this is only the AP). 76 * If transmits look to be working well over a sampling period then 77 * it gives a "raise rate credit". If transmits look to not be working 78 * well than it deducts a credit. If the credits cross a threshold then 79 * the transmit rate is raised. Various error conditions force the 80 * the transmit rate to be dropped. 81 * 82 * The decision to issue/deduct a credit is based on the errors and 83 * retries accumulated over the sampling period. ath_rate_raise defines 84 * the percent of retransmits for which a credit is issued/deducted. 85 * ath_rate_raise_threshold defines the threshold on credits at which 86 * the transmit rate is increased. 87 * 88 * XXX this algorithm is flawed. 89 */ 90 static int ath_rateinterval = 1000; /* rate ctl interval (ms) */ 91 static int ath_rate_raise = 10; /* add credit threshold */ 92 static int ath_rate_raise_threshold = 10; /* rate ctl raise threshold */ 93 94 static void ath_rate_update(struct ath_softc *, struct ieee80211_node *, 95 int rate); 96 static void ath_rate_ctl_start(struct ath_softc *, struct ieee80211_node *); 97 static void ath_rate_ctl(void *, struct ieee80211_node *); 98 99 void 100 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an) 101 { 102 /* NB: assumed to be zero'd by caller */ 103 } 104 105 void 106 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an) 107 { 108 } 109 110 void 111 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an, 112 int shortPreamble, size_t frameLen, 113 u_int8_t *rix, int *try0, u_int8_t *txrate) 114 { 115 struct onoe_node *on = ATH_NODE_ONOE(an); 116 117 *rix = on->on_tx_rix0; 118 *try0 = on->on_tx_try0; 119 if (shortPreamble) 120 *txrate = on->on_tx_rate0sp; 121 else 122 *txrate = on->on_tx_rate0; 123 } 124 125 void 126 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an, 127 struct ath_desc *ds, int shortPreamble, u_int8_t rix) 128 { 129 struct onoe_node *on = ATH_NODE_ONOE(an); 130 131 ath_hal_setupxtxdesc(sc->sc_ah, ds 132 , on->on_tx_rate1sp, 2 /* series 1 */ 133 , on->on_tx_rate2sp, 2 /* series 2 */ 134 , on->on_tx_rate3sp, 2 /* series 3 */ 135 ); 136 } 137 138 void 139 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an, 140 const struct ath_buf *bf) 141 { 142 struct onoe_node *on = ATH_NODE_ONOE(an); 143 const struct ath_tx_status *ts = &bf->bf_status.ds_txstat; 144 145 if (ts->ts_status == 0) 146 on->on_tx_ok++; 147 else 148 on->on_tx_err++; 149 on->on_tx_retr += ts->ts_shortretry 150 + ts->ts_longretry; 151 if (on->on_interval != 0 && ticks - on->on_ticks > on->on_interval) { 152 ath_rate_ctl(sc, &an->an_node); 153 on->on_ticks = ticks; 154 } 155 } 156 157 void 158 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew) 159 { 160 if (isnew) 161 ath_rate_ctl_start(sc, &an->an_node); 162 } 163 164 static void 165 ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate) 166 { 167 struct ath_node *an = ATH_NODE(ni); 168 struct onoe_node *on = ATH_NODE_ONOE(an); 169 struct ieee80211vap *vap = ni->ni_vap; 170 const HAL_RATE_TABLE *rt = sc->sc_currates; 171 u_int8_t rix; 172 173 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode)); 174 175 IEEE80211_NOTE(vap, IEEE80211_MSG_RATECTL, ni, 176 "%s: set xmit rate to %dM", __func__, 177 ni->ni_rates.rs_nrates > 0 ? 178 (ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0); 179 180 /* 181 * Before associating a node has no rate set setup 182 * so we can't calculate any transmit codes to use. 183 * This is ok since we should never be sending anything 184 * but management frames and those always go at the 185 * lowest hardware rate. 186 */ 187 if (ni->ni_rates.rs_nrates == 0) 188 goto done; 189 on->on_rix = rate; 190 ni->ni_txrate = ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL; 191 on->on_tx_rix0 = sc->sc_rixmap[ni->ni_txrate]; 192 on->on_tx_rate0 = rt->info[on->on_tx_rix0].rateCode; 193 194 on->on_tx_rate0sp = on->on_tx_rate0 | 195 rt->info[on->on_tx_rix0].shortPreamble; 196 if (sc->sc_mrretry) { 197 /* 198 * Hardware supports multi-rate retry; setup two 199 * step-down retry rates and make the lowest rate 200 * be the ``last chance''. We use 4, 2, 2, 2 tries 201 * respectively (4 is set here, the rest are fixed 202 * in the xmit routine). 203 */ 204 on->on_tx_try0 = 1 + 3; /* 4 tries at rate 0 */ 205 if (--rate >= 0) { 206 rix = sc->sc_rixmap[ 207 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL]; 208 on->on_tx_rate1 = rt->info[rix].rateCode; 209 on->on_tx_rate1sp = on->on_tx_rate1 | 210 rt->info[rix].shortPreamble; 211 } else { 212 on->on_tx_rate1 = on->on_tx_rate1sp = 0; 213 } 214 if (--rate >= 0) { 215 rix = sc->sc_rixmap[ 216 ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL]; 217 on->on_tx_rate2 = rt->info[rix].rateCode; 218 on->on_tx_rate2sp = on->on_tx_rate2 | 219 rt->info[rix].shortPreamble; 220 } else { 221 on->on_tx_rate2 = on->on_tx_rate2sp = 0; 222 } 223 if (rate > 0) { 224 /* NB: only do this if we didn't already do it above */ 225 on->on_tx_rate3 = rt->info[0].rateCode; 226 on->on_tx_rate3sp = 227 on->on_tx_rate3 | rt->info[0].shortPreamble; 228 } else { 229 on->on_tx_rate3 = on->on_tx_rate3sp = 0; 230 } 231 } else { 232 on->on_tx_try0 = ATH_TXMAXTRY; /* max tries at rate 0 */ 233 on->on_tx_rate1 = on->on_tx_rate1sp = 0; 234 on->on_tx_rate2 = on->on_tx_rate2sp = 0; 235 on->on_tx_rate3 = on->on_tx_rate3sp = 0; 236 } 237 done: 238 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = on->on_tx_upper = 0; 239 240 on->on_interval = ath_rateinterval; 241 if (vap->iv_opmode == IEEE80211_M_STA) 242 on->on_interval /= 2; 243 on->on_interval = (on->on_interval * hz) / 1000; 244 } 245 246 /* 247 * Set the starting transmit rate for a node. 248 */ 249 static void 250 ath_rate_ctl_start(struct ath_softc *sc, struct ieee80211_node *ni) 251 { 252 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL) 253 const struct ieee80211_txparam *tp = ni->ni_txparms; 254 int srate; 255 256 KASSERT(ni->ni_rates.rs_nrates > 0, ("no rates")); 257 if (tp == NULL || tp->ucastrate == IEEE80211_FIXED_RATE_NONE) { 258 /* 259 * No fixed rate is requested. For 11b start with 260 * the highest negotiated rate; otherwise, for 11g 261 * and 11a, we start "in the middle" at 24Mb or 36Mb. 262 */ 263 srate = ni->ni_rates.rs_nrates - 1; 264 if (sc->sc_curmode != IEEE80211_MODE_11B) { 265 /* 266 * Scan the negotiated rate set to find the 267 * closest rate. 268 */ 269 /* NB: the rate set is assumed sorted */ 270 for (; srate >= 0 && RATE(srate) > 72; srate--) 271 ; 272 } 273 } else { 274 /* 275 * A fixed rate is to be used; ic_fixed_rate is the 276 * IEEE code for this rate (sans basic bit). Convert this 277 * to the index into the negotiated rate set for 278 * the node. We know the rate is there because the 279 * rate set is checked when the station associates. 280 */ 281 /* NB: the rate set is assumed sorted */ 282 srate = ni->ni_rates.rs_nrates - 1; 283 for (; srate >= 0 && RATE(srate) != tp->ucastrate; srate--) 284 ; 285 } 286 /* 287 * The selected rate may not be available due to races 288 * and mode settings. Also orphaned nodes created in 289 * adhoc mode may not have any rate set so this lookup 290 * can fail. This is not fatal. 291 */ 292 ath_rate_update(sc, ni, srate < 0 ? 0 : srate); 293 #undef RATE 294 } 295 296 /* 297 * Examine and potentially adjust the transmit rate. 298 */ 299 static void 300 ath_rate_ctl(void *arg, struct ieee80211_node *ni) 301 { 302 struct ath_softc *sc = arg; 303 struct onoe_node *on = ATH_NODE_ONOE(ATH_NODE(ni)); 304 struct ieee80211_rateset *rs = &ni->ni_rates; 305 int dir = 0, nrate, enough; 306 307 /* 308 * Rate control 309 * XXX: very primitive version. 310 */ 311 enough = (on->on_tx_ok + on->on_tx_err >= 10); 312 313 /* no packet reached -> down */ 314 if (on->on_tx_err > 0 && on->on_tx_ok == 0) 315 dir = -1; 316 317 /* all packets needs retry in average -> down */ 318 if (enough && on->on_tx_ok < on->on_tx_retr) 319 dir = -1; 320 321 /* no error and less than rate_raise% of packets need retry -> up */ 322 if (enough && on->on_tx_err == 0 && 323 on->on_tx_retr < (on->on_tx_ok * ath_rate_raise) / 100) 324 dir = 1; 325 326 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 327 "ok %d err %d retr %d upper %d dir %d", 328 on->on_tx_ok, on->on_tx_err, on->on_tx_retr, on->on_tx_upper, dir); 329 330 nrate = on->on_rix; 331 switch (dir) { 332 case 0: 333 if (enough && on->on_tx_upper > 0) 334 on->on_tx_upper--; 335 break; 336 case -1: 337 if (nrate > 0) { 338 nrate--; 339 sc->sc_stats.ast_rate_drop++; 340 } 341 on->on_tx_upper = 0; 342 break; 343 case 1: 344 /* raise rate if we hit rate_raise_threshold */ 345 if (++on->on_tx_upper < ath_rate_raise_threshold) 346 break; 347 on->on_tx_upper = 0; 348 if (nrate + 1 < rs->rs_nrates) { 349 nrate++; 350 sc->sc_stats.ast_rate_raise++; 351 } 352 break; 353 } 354 355 if (nrate != on->on_rix) { 356 IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, 357 "%s: %dM -> %dM (%d ok, %d err, %d retr)", __func__, 358 ni->ni_txrate / 2, 359 (rs->rs_rates[nrate] & IEEE80211_RATE_VAL) / 2, 360 on->on_tx_ok, on->on_tx_err, on->on_tx_retr); 361 ath_rate_update(sc, ni, nrate); 362 } else if (enough) 363 on->on_tx_ok = on->on_tx_err = on->on_tx_retr = 0; 364 } 365 366 static void 367 ath_rate_sysctlattach(struct ath_softc *sc) 368 { 369 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev); 370 struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev); 371 372 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 373 "rate_interval", CTLFLAG_RW, &ath_rateinterval, 0, 374 "rate control: operation interval (ms)"); 375 /* XXX bounds check values */ 376 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 377 "rate_raise", CTLFLAG_RW, &ath_rate_raise, 0, 378 "rate control: retry threshold to credit rate raise (%%)"); 379 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 380 "rate_raise_threshold", CTLFLAG_RW, &ath_rate_raise_threshold,0, 381 "rate control: # good periods before raising rate"); 382 } 383 384 struct ath_ratectrl * 385 ath_rate_attach(struct ath_softc *sc) 386 { 387 struct onoe_softc *osc; 388 389 osc = malloc(sizeof(struct onoe_softc), M_DEVBUF, M_NOWAIT|M_ZERO); 390 if (osc == NULL) 391 return NULL; 392 osc->arc.arc_space = sizeof(struct onoe_node); 393 ath_rate_sysctlattach(sc); 394 395 return &osc->arc; 396 } 397 398 void 399 ath_rate_detach(struct ath_ratectrl *arc) 400 { 401 struct onoe_softc *osc = (struct onoe_softc *) arc; 402 403 free(osc, M_DEVBUF); 404 } 405