1 /*- 2 * Copyright (c) 2005 John Bicket 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 * 3. Neither the names of the above-listed copyright holders nor the names 16 * of any contributors may be used to endorse or promote products derived 17 * from this software without specific prior written permission. 18 * 19 * Alternatively, this software may be distributed under the terms of the 20 * GNU General Public License ("GPL") version 2 as published by the Free 21 * Software Foundation. 22 * 23 * NO WARRANTY 24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 25 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 26 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY 27 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 28 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, 29 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER 32 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 34 * THE POSSIBILITY OF SUCH DAMAGES. 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 /* 41 * John Bicket's SampleRate control algorithm. 42 */ 43 #include "opt_inet.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/sysctl.h> 48 #include <sys/module.h> 49 #include <sys/kernel.h> 50 #include <sys/lock.h> 51 #include <sys/mutex.h> 52 #include <sys/errno.h> 53 54 #include <machine/bus.h> 55 #include <machine/resource.h> 56 #include <sys/bus.h> 57 58 #include <sys/socket.h> 59 60 #include <net/if.h> 61 #include <net/if_media.h> 62 #include <net/if_arp.h> 63 #include <net/ethernet.h> /* XXX for ether_sprintf */ 64 65 #include <net80211/ieee80211_var.h> 66 67 #include <net/bpf.h> 68 69 #ifdef INET 70 #include <netinet/in.h> 71 #include <netinet/if_ether.h> 72 #endif 73 74 #include <dev/ath/if_athvar.h> 75 #include <dev/ath/ath_rate/sample/sample.h> 76 #include <contrib/dev/ath/ah_desc.h> 77 78 #define SAMPLE_DEBUG 79 #ifdef SAMPLE_DEBUG 80 enum { 81 ATH_DEBUG_NODE = 0x00080000, /* node management */ 82 ATH_DEBUG_RATE = 0x00000010, /* rate control */ 83 ATH_DEBUG_ANY = 0xffffffff 84 }; 85 #define DPRINTF(sc, m, fmt, ...) do { \ 86 if (sc->sc_debug & (m)) \ 87 printf(fmt, __VA_ARGS__); \ 88 } while (0) 89 #else 90 #define DPRINTF(sc, m, fmt, ...) do { \ 91 (void) sc; \ 92 } while (0) 93 #endif 94 95 /* 96 * This file is an implementation of the SampleRate algorithm 97 * in "Bit-rate Selection in Wireless Networks" 98 * (http://www.pdos.lcs.mit.edu/papers/jbicket-ms.ps) 99 * 100 * SampleRate chooses the bit-rate it predicts will provide the most 101 * throughput based on estimates of the expected per-packet 102 * transmission time for each bit-rate. SampleRate periodically sends 103 * packets at bit-rates other than the current one to estimate when 104 * another bit-rate will provide better performance. SampleRate 105 * switches to another bit-rate when its estimated per-packet 106 * transmission time becomes smaller than the current bit-rate's. 107 * SampleRate reduces the number of bit-rates it must sample by 108 * eliminating those that could not perform better than the one 109 * currently being used. SampleRate also stops probing at a bit-rate 110 * if it experiences several successive losses. 111 * 112 * The difference between the algorithm in the thesis and the one in this 113 * file is that the one in this file uses a ewma instead of a window. 114 * 115 * Also, this implementation tracks the average transmission time for 116 * a few different packet sizes independently for each link. 117 */ 118 119 #define STALE_FAILURE_TIMEOUT_MS 10000 120 #define MIN_SWITCH_MS 1000 121 122 static void ath_rate_ctl_reset(struct ath_softc *, struct ieee80211_node *); 123 124 static __inline int 125 size_to_bin(int size) 126 { 127 int x = 0; 128 for (x = 0; x < NUM_PACKET_SIZE_BINS; x++) { 129 if (size <= packet_size_bins[x]) { 130 return x; 131 } 132 } 133 return NUM_PACKET_SIZE_BINS-1; 134 } 135 static __inline int 136 bin_to_size(int index) { 137 return packet_size_bins[index]; 138 } 139 140 static __inline int 141 rate_to_ndx(struct sample_node *sn, int rate) { 142 int x = 0; 143 for (x = 0; x < sn->num_rates; x++) { 144 if (sn->rates[x].rate == rate) { 145 return x; 146 } 147 } 148 return -1; 149 } 150 151 void 152 ath_rate_node_init(struct ath_softc *sc, struct ath_node *an) 153 { 154 DPRINTF(sc, ATH_DEBUG_NODE, "%s:\n", __func__); 155 /* NB: assumed to be zero'd by caller */ 156 } 157 158 void 159 ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an) 160 { 161 DPRINTF(sc, ATH_DEBUG_NODE, "%s:\n", __func__); 162 } 163 164 165 /* 166 * returns the ndx with the lowest average_tx_time, 167 * or -1 if all the average_tx_times are 0. 168 */ 169 static __inline int best_rate_ndx(struct sample_node *sn, int size_bin, 170 int require_acked_before) 171 { 172 int x = 0; 173 int best_rate_ndx = 0; 174 int best_rate_tt = 0; 175 for (x = 0; x < sn->num_rates; x++) { 176 int tt = sn->stats[size_bin][x].average_tx_time; 177 if (tt <= 0 || (require_acked_before && 178 !sn->stats[size_bin][x].packets_acked)) { 179 continue; 180 } 181 182 /* 9 megabits never works better than 12 */ 183 if (sn->rates[x].rate == 18) 184 continue; 185 186 /* don't use a bit-rate that has been failing */ 187 if (sn->stats[size_bin][x].successive_failures > 3) 188 continue; 189 190 if (!best_rate_tt || best_rate_tt > tt) { 191 best_rate_tt = tt; 192 best_rate_ndx = x; 193 } 194 } 195 return (best_rate_tt) ? best_rate_ndx : -1; 196 } 197 198 /* 199 * pick a good "random" bit-rate to sample other than the current one 200 */ 201 static __inline int 202 pick_sample_ndx(struct sample_node *sn, int size_bin) 203 { 204 int x = 0; 205 int current_ndx = 0; 206 unsigned current_tt = 0; 207 208 current_ndx = sn->current_rate[size_bin]; 209 if (current_ndx < 0) { 210 /* no successes yet, send at the lowest bit-rate */ 211 return 0; 212 } 213 214 current_tt = sn->stats[size_bin][current_ndx].average_tx_time; 215 216 for (x = 0; x < sn->num_rates; x++) { 217 int ndx = (sn->last_sample_ndx[size_bin]+1+x) % sn->num_rates; 218 219 /* don't sample the current bit-rate */ 220 if (ndx == current_ndx) 221 continue; 222 223 /* this bit-rate is always worse than the current one */ 224 if (sn->stats[size_bin][ndx].perfect_tx_time > current_tt) 225 continue; 226 227 /* rarely sample bit-rates that fail a lot */ 228 if (ticks - sn->stats[size_bin][ndx].last_tx < ((hz * STALE_FAILURE_TIMEOUT_MS)/1000) && 229 sn->stats[size_bin][ndx].successive_failures > 3) 230 continue; 231 232 /* don't sample more than 2 indexes higher 233 * for rates higher than 11 megabits 234 */ 235 if (sn->rates[ndx].rate > 22 && ndx > current_ndx + 2) 236 continue; 237 238 /* 9 megabits never works better than 12 */ 239 if (sn->rates[ndx].rate == 18) 240 continue; 241 242 /* if we're using 11 megabits, only sample up to 12 megabits 243 */ 244 if (sn->rates[current_ndx].rate == 22 && ndx > current_ndx + 1) 245 continue; 246 247 sn->last_sample_ndx[size_bin] = ndx; 248 return ndx; 249 } 250 return current_ndx; 251 } 252 253 void 254 ath_rate_findrate(struct ath_softc *sc, struct ath_node *an, 255 int shortPreamble, size_t frameLen, 256 u_int8_t *rix, int *try0, u_int8_t *txrate) 257 { 258 struct sample_node *sn = ATH_NODE_SAMPLE(an); 259 struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc); 260 struct ieee80211com *ic = &sc->sc_ic; 261 int ndx, size_bin, mrr, best_ndx, change_rates; 262 unsigned average_tx_time; 263 264 mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT); 265 size_bin = size_to_bin(frameLen); 266 best_ndx = best_rate_ndx(sn, size_bin, !mrr); 267 268 if (best_ndx >= 0) { 269 average_tx_time = sn->stats[size_bin][best_ndx].average_tx_time; 270 } else { 271 average_tx_time = 0; 272 } 273 274 if (sn->static_rate_ndx != -1) { 275 ndx = sn->static_rate_ndx; 276 *try0 = ATH_TXMAXTRY; 277 } else { 278 *try0 = mrr ? 2 : ATH_TXMAXTRY; 279 280 if (sn->sample_tt[size_bin] < average_tx_time * (sn->packets_since_sample[size_bin]*ssc->ath_sample_rate/100)) { 281 /* 282 * we want to limit the time measuring the performance 283 * of other bit-rates to ath_sample_rate% of the 284 * total transmission time. 285 */ 286 ndx = pick_sample_ndx(sn, size_bin); 287 if (ndx != sn->current_rate[size_bin]) { 288 sn->current_sample_ndx[size_bin] = ndx; 289 } else { 290 sn->current_sample_ndx[size_bin] = -1; 291 } 292 sn->packets_since_sample[size_bin] = 0; 293 294 } else { 295 change_rates = 0; 296 if (!sn->packets_sent[size_bin] || best_ndx == -1) { 297 /* no packet has been sent successfully yet */ 298 for (ndx = sn->num_rates-1; ndx > 0; ndx--) { 299 /* 300 * pick the highest rate <= 36 Mbps 301 * that hasn't failed. 302 */ 303 if (sn->rates[ndx].rate <= 72 && 304 sn->stats[size_bin][ndx].successive_failures == 0) { 305 break; 306 } 307 } 308 change_rates = 1; 309 best_ndx = ndx; 310 } else if (sn->packets_sent[size_bin] < 20) { 311 /* let the bit-rate switch quickly during the first few packets */ 312 change_rates = 1; 313 } else if (ticks - ((hz*MIN_SWITCH_MS)/1000) > sn->ticks_since_switch[size_bin]) { 314 /* 2 seconds have gone by */ 315 change_rates = 1; 316 } else if (average_tx_time * 2 < sn->stats[size_bin][sn->current_rate[size_bin]].average_tx_time) { 317 /* the current bit-rate is twice as slow as the best one */ 318 change_rates = 1; 319 } 320 321 sn->packets_since_sample[size_bin]++; 322 323 if (change_rates) { 324 if (best_ndx != sn->current_rate[size_bin]) { 325 DPRINTF(sc, ATH_DEBUG_RATE, 326 "%s: %s size %d switch rate %d (%d/%d) -> %d (%d/%d) after %d packets mrr %d\n", 327 __func__, 328 ether_sprintf(an->an_node.ni_macaddr), 329 packet_size_bins[size_bin], 330 sn->rates[sn->current_rate[size_bin]].rate, 331 sn->stats[size_bin][sn->current_rate[size_bin]].average_tx_time, 332 sn->stats[size_bin][sn->current_rate[size_bin]].perfect_tx_time, 333 sn->rates[best_ndx].rate, 334 sn->stats[size_bin][best_ndx].average_tx_time, 335 sn->stats[size_bin][best_ndx].perfect_tx_time, 336 sn->packets_since_switch[size_bin], 337 mrr); 338 } 339 sn->packets_since_switch[size_bin] = 0; 340 sn->current_rate[size_bin] = best_ndx; 341 sn->ticks_since_switch[size_bin] = ticks; 342 } 343 ndx = sn->current_rate[size_bin]; 344 sn->packets_since_switch[size_bin]++; 345 if (size_bin == 0) { 346 /* 347 * set the visible txrate for this node 348 * to the rate of small packets 349 */ 350 an->an_node.ni_txrate = ndx; 351 } 352 } 353 } 354 355 KASSERT(ndx >= 0 && ndx < sn->num_rates, ("ndx is %d", ndx)); 356 357 *rix = sn->rates[ndx].rix; 358 if (shortPreamble) { 359 *txrate = sn->rates[ndx].shortPreambleRateCode; 360 } else { 361 *txrate = sn->rates[ndx].rateCode; 362 } 363 sn->packets_sent[size_bin]++; 364 } 365 366 void 367 ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an, 368 struct ath_desc *ds, int shortPreamble, u_int8_t rix) 369 { 370 struct sample_node *sn = ATH_NODE_SAMPLE(an); 371 int rateCode = -1; 372 int frame_size = 0; 373 int size_bin = 0; 374 int ndx = 0; 375 376 size_bin = size_to_bin(frame_size); // TODO: it's correct that frame_size alway 0 ? 377 ndx = sn->current_rate[size_bin]; /* retry at the current bit-rate */ 378 379 if (!sn->stats[size_bin][ndx].packets_acked) { 380 ndx = 0; /* use the lowest bit-rate */ 381 } 382 383 if (shortPreamble) { 384 rateCode = sn->rates[ndx].shortPreambleRateCode; 385 } else { 386 rateCode = sn->rates[ndx].rateCode; 387 } 388 ath_hal_setupxtxdesc(sc->sc_ah, ds 389 , rateCode, 3 /* series 1 */ 390 , sn->rates[0].rateCode, 3 /* series 2 */ 391 , 0, 0 /* series 3 */ 392 ); 393 } 394 395 static void 396 update_stats(struct ath_softc *sc, struct ath_node *an, 397 int frame_size, 398 int ndx0, int tries0, 399 int ndx1, int tries1, 400 int ndx2, int tries2, 401 int ndx3, int tries3, 402 int short_tries, int tries, int status) 403 { 404 struct sample_node *sn = ATH_NODE_SAMPLE(an); 405 struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc); 406 int tt = 0; 407 int tries_so_far = 0; 408 int size_bin = 0; 409 int size = 0; 410 int rate = 0; 411 412 size_bin = size_to_bin(frame_size); 413 size = bin_to_size(size_bin); 414 415 if (!(0 <= ndx0 && ndx0 < sn->num_rates)) { 416 printf("%s: bogus ndx0 %d, max %u, mode %u\n", 417 __func__, ndx0, sn->num_rates, sc->sc_curmode); 418 return; 419 } 420 rate = sn->rates[ndx0].rate; 421 422 tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx0].rix, 423 short_tries, 424 MIN(tries0, tries) - 1); 425 tries_so_far += tries0; 426 if (tries1 && tries0 < tries) { 427 if (!(0 <= ndx1 && ndx1 < sn->num_rates)) { 428 printf("%s: bogus ndx1 %d, max %u, mode %u\n", 429 __func__, ndx1, sn->num_rates, sc->sc_curmode); 430 return; 431 } 432 tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx1].rix, 433 short_tries, 434 MIN(tries1 + tries_so_far, tries) - tries_so_far - 1); 435 } 436 tries_so_far += tries1; 437 438 if (tries2 && tries0 + tries1 < tries) { 439 if (!(0 <= ndx2 && ndx2 < sn->num_rates)) { 440 printf("%s: bogus ndx2 %d, max %u, mode %u\n", 441 __func__, ndx2, sn->num_rates, sc->sc_curmode); 442 return; 443 } 444 tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx2].rix, 445 short_tries, 446 MIN(tries2 + tries_so_far, tries) - tries_so_far - 1); 447 } 448 449 tries_so_far += tries2; 450 451 if (tries3 && tries0 + tries1 + tries2 < tries) { 452 if (!(0 <= ndx3 && ndx3 < sn->num_rates)) { 453 printf("%s: bogus ndx3 %d, max %u, mode %u\n", 454 __func__, ndx3, sn->num_rates, sc->sc_curmode); 455 return; 456 } 457 tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx3].rix, 458 short_tries, 459 MIN(tries3 + tries_so_far, tries) - tries_so_far - 1); 460 } 461 if (sn->stats[size_bin][ndx0].total_packets < (100 / (100 - ssc->ath_smoothing_rate))) { 462 /* just average the first few packets */ 463 int avg_tx = sn->stats[size_bin][ndx0].average_tx_time; 464 int packets = sn->stats[size_bin][ndx0].total_packets; 465 sn->stats[size_bin][ndx0].average_tx_time = (tt+(avg_tx*packets))/(packets+1); 466 } else { 467 /* use a ewma */ 468 sn->stats[size_bin][ndx0].average_tx_time = 469 ((sn->stats[size_bin][ndx0].average_tx_time * ssc->ath_smoothing_rate) + 470 (tt * (100 - ssc->ath_smoothing_rate))) / 100; 471 } 472 473 if (status) { 474 int y; 475 sn->stats[size_bin][ndx0].successive_failures++; 476 for (y = size_bin+1; y < NUM_PACKET_SIZE_BINS; y++) { 477 /* also say larger packets failed since we 478 * assume if a small packet fails at a lower 479 * bit-rate then a larger one will also. 480 */ 481 sn->stats[y][ndx0].successive_failures++; 482 sn->stats[y][ndx0].last_tx = ticks; 483 sn->stats[y][ndx0].tries += tries; 484 sn->stats[y][ndx0].total_packets++; 485 } 486 } else { 487 sn->stats[size_bin][ndx0].packets_acked++; 488 sn->stats[size_bin][ndx0].successive_failures = 0; 489 } 490 sn->stats[size_bin][ndx0].tries += tries; 491 sn->stats[size_bin][ndx0].last_tx = ticks; 492 sn->stats[size_bin][ndx0].total_packets++; 493 494 495 if (ndx0 == sn->current_sample_ndx[size_bin]) { 496 DPRINTF(sc, ATH_DEBUG_RATE, 497 "%s: %s size %d %s sample rate %d tries (%d/%d) tt %d avg_tt (%d/%d)\n", 498 __func__, ether_sprintf(an->an_node.ni_macaddr), 499 size, 500 status ? "FAIL" : "OK", 501 rate, short_tries, tries, tt, 502 sn->stats[size_bin][ndx0].average_tx_time, 503 sn->stats[size_bin][ndx0].perfect_tx_time); 504 sn->sample_tt[size_bin] = tt; 505 sn->current_sample_ndx[size_bin] = -1; 506 } 507 } 508 509 void 510 ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an, 511 const struct ath_buf *bf) 512 { 513 struct ieee80211com *ic = &sc->sc_ic; 514 struct sample_node *sn = ATH_NODE_SAMPLE(an); 515 const struct ath_tx_status *ts = &bf->bf_status.ds_txstat; 516 const struct ath_desc *ds0 = &bf->bf_desc[0]; 517 int final_rate, short_tries, long_tries, frame_size; 518 int mrr; 519 520 final_rate = sc->sc_hwmap[ts->ts_rate &~ HAL_TXSTAT_ALTRATE].ieeerate; 521 short_tries = ts->ts_shortretry; 522 long_tries = ts->ts_longretry + 1; 523 frame_size = ds0->ds_ctl0 & 0x0fff; /* low-order 12 bits of ds_ctl0 */ 524 if (frame_size == 0) /* NB: should not happen */ 525 frame_size = 1500; 526 527 if (sn->num_rates <= 0) { 528 DPRINTF(sc, ATH_DEBUG_RATE, 529 "%s: %s size %d %s rate/try %d/%d no rates yet\n", 530 __func__, ether_sprintf(an->an_node.ni_macaddr), 531 bin_to_size(size_to_bin(frame_size)), 532 ts->ts_status ? "FAIL" : "OK", 533 short_tries, long_tries); 534 return; 535 } 536 mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT); 537 if (!mrr || !(ts->ts_rate & HAL_TXSTAT_ALTRATE)) { 538 int ndx = rate_to_ndx(sn, final_rate); 539 540 /* 541 * Only one rate was used; optimize work. 542 */ 543 DPRINTF(sc, ATH_DEBUG_RATE, 544 "%s: %s size %d %s rate/try %d/%d/%d\n", 545 __func__, ether_sprintf(an->an_node.ni_macaddr), 546 bin_to_size(size_to_bin(frame_size)), 547 ts->ts_status ? "FAIL" : "OK", 548 final_rate, short_tries, long_tries); 549 update_stats(sc, an, frame_size, 550 ndx, long_tries, 551 0, 0, 552 0, 0, 553 0, 0, 554 short_tries, long_tries, ts->ts_status); 555 } else { 556 int hwrate0, rate0, tries0, ndx0; 557 int hwrate1, rate1, tries1, ndx1; 558 int hwrate2, rate2, tries2, ndx2; 559 int hwrate3, rate3, tries3, ndx3; 560 int finalTSIdx = ts->ts_finaltsi; 561 562 /* 563 * Process intermediate rates that failed. 564 */ 565 if (sc->sc_ah->ah_magic != 0x20065416) { 566 hwrate0 = MS(ds0->ds_ctl3, AR_XmitRate0); 567 hwrate1 = MS(ds0->ds_ctl3, AR_XmitRate1); 568 hwrate2 = MS(ds0->ds_ctl3, AR_XmitRate2); 569 hwrate3 = MS(ds0->ds_ctl3, AR_XmitRate3); 570 } else { 571 hwrate0 = MS(ds0->ds_ctl3, AR5416_XmitRate0); 572 hwrate1 = MS(ds0->ds_ctl3, AR5416_XmitRate1); 573 hwrate2 = MS(ds0->ds_ctl3, AR5416_XmitRate2); 574 hwrate3 = MS(ds0->ds_ctl3, AR5416_XmitRate3); 575 } 576 577 rate0 = sc->sc_hwmap[hwrate0].ieeerate; 578 tries0 = MS(ds0->ds_ctl2, AR_XmitDataTries0); 579 ndx0 = rate_to_ndx(sn, rate0); 580 581 rate1 = sc->sc_hwmap[hwrate1].ieeerate; 582 tries1 = MS(ds0->ds_ctl2, AR_XmitDataTries1); 583 ndx1 = rate_to_ndx(sn, rate1); 584 585 rate2 = sc->sc_hwmap[hwrate2].ieeerate; 586 tries2 = MS(ds0->ds_ctl2, AR_XmitDataTries2); 587 ndx2 = rate_to_ndx(sn, rate2); 588 589 rate3 = sc->sc_hwmap[hwrate3].ieeerate; 590 tries3 = MS(ds0->ds_ctl2, AR_XmitDataTries3); 591 ndx3 = rate_to_ndx(sn, rate3); 592 593 DPRINTF(sc, ATH_DEBUG_RATE, 594 "%s: %s size %d finaltsidx %d tries %d %s rate/try [%d/%d %d/%d %d/%d %d/%d]\n", 595 __func__, ether_sprintf(an->an_node.ni_macaddr), 596 bin_to_size(size_to_bin(frame_size)), 597 finalTSIdx, 598 long_tries, 599 ts->ts_status ? "FAIL" : "OK", 600 rate0, tries0, 601 rate1, tries1, 602 rate2, tries2, 603 rate3, tries3); 604 605 /* 606 * NB: series > 0 are not penalized for failure 607 * based on the try counts under the assumption 608 * that losses are often bursty and since we 609 * sample higher rates 1 try at a time doing so 610 * may unfairly penalize them. 611 */ 612 if (tries0) { 613 update_stats(sc, an, frame_size, 614 ndx0, tries0, 615 ndx1, tries1, 616 ndx2, tries2, 617 ndx3, tries3, 618 short_tries, long_tries, 619 long_tries > tries0); 620 long_tries -= tries0; 621 } 622 623 if (tries1 && finalTSIdx > 0) { 624 update_stats(sc, an, frame_size, 625 ndx1, tries1, 626 ndx2, tries2, 627 ndx3, tries3, 628 0, 0, 629 short_tries, long_tries, 630 ts->ts_status); 631 long_tries -= tries1; 632 } 633 634 if (tries2 && finalTSIdx > 1) { 635 update_stats(sc, an, frame_size, 636 ndx2, tries2, 637 ndx3, tries3, 638 0, 0, 639 0, 0, 640 short_tries, long_tries, 641 ts->ts_status); 642 long_tries -= tries2; 643 } 644 645 if (tries3 && finalTSIdx > 2) { 646 update_stats(sc, an, frame_size, 647 ndx3, tries3, 648 0, 0, 649 0, 0, 650 0, 0, 651 short_tries, long_tries, 652 ts->ts_status); 653 } 654 } 655 } 656 657 void 658 ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew) 659 { 660 DPRINTF(sc, ATH_DEBUG_NODE, "%s: %s isnew %d\n", __func__, 661 ether_sprintf(an->an_node.ni_macaddr), isnew); 662 if (isnew) 663 ath_rate_ctl_reset(sc, &an->an_node); 664 } 665 666 /* 667 * Initialize the tables for a node. 668 */ 669 static void 670 ath_rate_ctl_reset(struct ath_softc *sc, struct ieee80211_node *ni) 671 { 672 #define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL) 673 struct ieee80211com *ic = &sc->sc_ic; 674 struct ath_node *an = ATH_NODE(ni); 675 struct sample_node *sn = ATH_NODE_SAMPLE(an); 676 const HAL_RATE_TABLE *rt = sc->sc_currates; 677 int x, y, srate; 678 679 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode)); 680 sn->static_rate_ndx = -1; 681 if (ic->ic_fixed_rate != IEEE80211_FIXED_RATE_NONE) { 682 /* 683 * A fixed rate is to be used; ic_fixed_rate is an 684 * index into the supported rate set. Convert this 685 * to the index into the negotiated rate set for 686 * the node. 687 */ 688 const struct ieee80211_rateset *rs = 689 &ic->ic_sup_rates[ic->ic_curmode]; 690 int r = rs->rs_rates[ic->ic_fixed_rate] & IEEE80211_RATE_VAL; 691 /* NB: the rate set is assumed sorted */ 692 srate = ni->ni_rates.rs_nrates - 1; 693 for (; srate >= 0 && RATE(srate) != r; srate--) 694 ; 695 KASSERT(srate >= 0, 696 ("fixed rate %d not in rate set", ic->ic_fixed_rate)); 697 sn->static_rate_ndx = srate; 698 } 699 700 DPRINTF(sc, ATH_DEBUG_RATE, "%s: %s size 1600 rate/tt", 701 __func__, ether_sprintf(ni->ni_macaddr)); 702 703 sn->num_rates = ni->ni_rates.rs_nrates; 704 for (x = 0; x < ni->ni_rates.rs_nrates; x++) { 705 sn->rates[x].rate = ni->ni_rates.rs_rates[x] & IEEE80211_RATE_VAL; 706 sn->rates[x].rix = sc->sc_rixmap[sn->rates[x].rate]; 707 if (sn->rates[x].rix == 0xff) { 708 DPRINTF(sc, ATH_DEBUG_RATE, 709 "%s: ignore bogus rix at %d\n", __func__, x); 710 continue; 711 } 712 sn->rates[x].rateCode = rt->info[sn->rates[x].rix].rateCode; 713 sn->rates[x].shortPreambleRateCode = 714 rt->info[sn->rates[x].rix].rateCode | 715 rt->info[sn->rates[x].rix].shortPreamble; 716 717 DPRINTF(sc, ATH_DEBUG_RATE, " %d/%d", sn->rates[x].rate, 718 calc_usecs_unicast_packet(sc, 1600, sn->rates[x].rix, 0,0)); 719 } 720 DPRINTF(sc, ATH_DEBUG_RATE, "%s\n", ""); 721 722 /* set the visible bit-rate to the lowest one available */ 723 ni->ni_txrate = 0; 724 sn->num_rates = ni->ni_rates.rs_nrates; 725 726 for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) { 727 int size = bin_to_size(y); 728 int ndx = 0; 729 sn->packets_sent[y] = 0; 730 sn->current_sample_ndx[y] = -1; 731 sn->last_sample_ndx[y] = 0; 732 733 for (x = 0; x < ni->ni_rates.rs_nrates; x++) { 734 sn->stats[y][x].successive_failures = 0; 735 sn->stats[y][x].tries = 0; 736 sn->stats[y][x].total_packets = 0; 737 sn->stats[y][x].packets_acked = 0; 738 sn->stats[y][x].last_tx = 0; 739 740 sn->stats[y][x].perfect_tx_time = 741 calc_usecs_unicast_packet(sc, size, 742 sn->rates[x].rix, 743 0, 0); 744 sn->stats[y][x].average_tx_time = sn->stats[y][x].perfect_tx_time; 745 } 746 747 /* set the initial rate */ 748 for (ndx = sn->num_rates-1; ndx > 0; ndx--) { 749 if (sn->rates[ndx].rate <= 72) { 750 break; 751 } 752 } 753 sn->current_rate[y] = ndx; 754 } 755 756 DPRINTF(sc, ATH_DEBUG_RATE, 757 "%s: %s %d rates %d%sMbps (%dus)- %d%sMbps (%dus)\n", 758 __func__, ether_sprintf(ni->ni_macaddr), 759 sn->num_rates, 760 sn->rates[0].rate/2, sn->rates[0].rate % 0x1 ? ".5" : "", 761 sn->stats[1][0].perfect_tx_time, 762 sn->rates[sn->num_rates-1].rate/2, 763 sn->rates[sn->num_rates-1].rate % 0x1 ? ".5" : "", 764 sn->stats[1][sn->num_rates-1].perfect_tx_time 765 ); 766 767 if (sn->static_rate_ndx != -1) 768 ni->ni_txrate = sn->static_rate_ndx; 769 else 770 ni->ni_txrate = sn->current_rate[0]; 771 #undef RATE 772 } 773 774 static void 775 rate_cb(void *arg, struct ieee80211_node *ni) 776 { 777 struct ath_softc *sc = arg; 778 779 ath_rate_newassoc(sc, ATH_NODE(ni), 1); 780 } 781 782 /* 783 * Reset the rate control state for each 802.11 state transition. 784 */ 785 void 786 ath_rate_newstate(struct ath_softc *sc, enum ieee80211_state state) 787 { 788 struct ieee80211com *ic = &sc->sc_ic; 789 790 if (state == IEEE80211_S_RUN) { 791 if (ic->ic_opmode != IEEE80211_M_STA) { 792 /* 793 * Sync rates for associated stations and neighbors. 794 */ 795 ieee80211_iterate_nodes(&ic->ic_sta, rate_cb, sc); 796 } 797 ath_rate_newassoc(sc, ATH_NODE(ic->ic_bss), 1); 798 } 799 } 800 801 static void 802 ath_rate_sysctlattach(struct ath_softc *sc, struct sample_softc *osc) 803 { 804 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev); 805 struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev); 806 807 /* XXX bounds check [0..100] */ 808 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 809 "smoothing_rate", CTLFLAG_RW, &osc->ath_smoothing_rate, 0, 810 "rate control: retry threshold to credit rate raise (%%)"); 811 /* XXX bounds check [2..100] */ 812 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 813 "sample_rate", CTLFLAG_RW, &osc->ath_sample_rate,0, 814 "rate control: # good periods before raising rate"); 815 } 816 817 struct ath_ratectrl * 818 ath_rate_attach(struct ath_softc *sc) 819 { 820 struct sample_softc *osc; 821 822 DPRINTF(sc, ATH_DEBUG_ANY, "%s:\n", __func__); 823 osc = malloc(sizeof(struct sample_softc), M_DEVBUF, M_NOWAIT|M_ZERO); 824 if (osc == NULL) 825 return NULL; 826 osc->arc.arc_space = sizeof(struct sample_node); 827 osc->ath_smoothing_rate = 95; /* ewma percentage (out of 100) */ 828 osc->ath_sample_rate = 10; /* send a different bit-rate 1/X packets */ 829 ath_rate_sysctlattach(sc, osc); 830 return &osc->arc; 831 } 832 833 void 834 ath_rate_detach(struct ath_ratectrl *arc) 835 { 836 struct sample_softc *osc = (struct sample_softc *) arc; 837 838 free(osc, M_DEVBUF); 839 } 840 841 /* 842 * Module glue. 843 */ 844 static int 845 sample_modevent(module_t mod, int type, void *unused) 846 { 847 switch (type) { 848 case MOD_LOAD: 849 if (bootverbose) 850 printf("ath_rate: version 1.2 <SampleRate bit-rate selection algorithm>\n"); 851 return 0; 852 case MOD_UNLOAD: 853 return 0; 854 } 855 return EINVAL; 856 } 857 858 static moduledata_t sample_mod = { 859 "ath_rate", 860 sample_modevent, 861 0 862 }; 863 DECLARE_MODULE(ath_rate, sample_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST); 864 MODULE_VERSION(ath_rate, 1); 865 MODULE_DEPEND(ath_rate, ath_hal, 1, 1, 1); /* Atheros HAL */ 866 MODULE_DEPEND(ath_rate, wlan, 1, 1, 1); 867