/*- * Copyright (c) 2005 John Bicket * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer, * without modification. * 2. Redistributions in binary form must reproduce at minimum a disclaimer * similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any * redistribution must be conditioned upon including a substantially * similar Disclaimer requirement for further binary redistribution. * 3. Neither the names of the above-listed copyright holders nor the names * of any contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * Alternatively, this software may be distributed under the terms of the * GNU General Public License ("GPL") version 2 as published by the Free * Software Foundation. * * NO WARRANTY * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF * THE POSSIBILITY OF SUCH DAMAGES. * * $Id$ */ /* * John Bicket's SampleRate control algorithm. */ #if !defined(AUTOCONF_INCLUDED) && !defined(CONFIG_LOCALVERSION) #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "if_athvar.h" #include "if_ath_hal.h" #include "ah_desc.h" #include "sample.h" #define SAMPLE_DEBUG #ifdef SAMPLE_DEBUG enum { ATH_DEBUG_RATE = 0x00000010, /* rate control */ ATH_DEBUG_ANY = 0xffffffff }; #define DPRINTF(sc, m, fmt, ...) do { \ if (sc->sc_debug & (m)) \ printk(fmt, __VA_ARGS__); \ } while (0) #else #define DPRINTF(sc, m, fmt, ...) do { \ (void) sc; \ } while (0) #endif /* * This file is an implementation of the SampleRate algorithm * in "Bit-rate Selection in Wireless Networks" * (http://www.pdos.lcs.mit.edu/papers/jbicket-ms.ps) * * SampleRate chooses the bit-rate it predicts will provide the most * throughput based on estimates of the expected per-packet * transmission time for each bit-rate. SampleRate periodically sends * packets at bit-rates other than the current one to estimate when * another bit-rate will provide better performance. SampleRate * switches to another bit-rate when its estimated per-packet * transmission time becomes smaller than the current bit-rate's. * SampleRate reduces the number of bit-rates it must sample by * eliminating those that could not perform better than the one * currently being used. SampleRate also stops probing at a bit-rate * if it experiences several successive losses. * * The difference between the algorithm in the thesis and the one in this * file is that the one in this file uses a ewma instead of a window. * * Also, this implementation tracks the average transmission time for * a few different packet sizes independently for each link. * */ #include "release.h" #if 0 static char *version = "1.2 (" RELEASE_VERSION ")"; #endif static char *dev_info = "ath_rate_sample"; #define STALE_FAILURE_TIMEOUT_MS 10000 #define MIN_SWITCH_MS 1000 #define ENABLE_MRR 1 static int ath_smoothing_rate = 95; /* ewma percentage (out of 100) */ static int ath_sample_rate = 10; /* use x% of transmission time * sending at a different bit-rate */ static int packet_size_bins[NUM_PACKET_SIZE_BINS] = {250, 1600, 3000}; static void ath_rate_ctl_reset(struct ath_softc *, struct ieee80211_node *); static __inline int size_to_bin(int size) { unsigned int x; for (x = 0; x < NUM_PACKET_SIZE_BINS; x++) if (size <= packet_size_bins[x]) return x; return NUM_PACKET_SIZE_BINS - 1; } static __inline int bin_to_size(int index) { return packet_size_bins[index]; } static __inline int rate_to_ndx(struct sample_node *sn, int rate) { unsigned int x; for (x = 0; x < sn->num_rates; x++) if (sn->rates[x].rate == rate) return x; return -1; } /* * Calculate the transmit duration of a frame. */ static unsigned calc_usecs_unicast_packet(struct ath_softc *sc, int length, int rix, int short_retries, int long_retries) { const HAL_RATE_TABLE *rt = sc->sc_currates; int rts, cts; unsigned t_slot; unsigned t_difs; unsigned t_sifs; struct ieee80211com *ic = &sc->sc_ic; unsigned int tt = 0; unsigned int x; unsigned int cw = ATH_DEFAULT_CWMIN; unsigned int cix = rt->info[rix].controlRate; KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode)); if (!rt->info[rix].rateKbps) { printk(KERN_WARNING "rix %u (%u) bad ratekbps %u mode %u\n", rix, rt->info[rix].dot11Rate, rt->info[rix].rateKbps, sc->sc_curmode); return 0; } cix = rt->info[rix].controlRate; /* * XXX getting mac/phy level timings should be fixed for turbo * rates, and there is probably a way to get this from the * hal... */ switch (rt->info[rix].phy) { case IEEE80211_T_OFDM: t_slot = 9; t_sifs = 16; t_difs = 28; /* fall through */ case IEEE80211_T_TURBO: t_slot = 9; t_sifs = 8; t_difs = 28; break; case IEEE80211_T_DS: /* fall through to default */ default: /* pg 205 ieee.802.11.pdf */ t_slot = 20; t_difs = 50; t_sifs = 10; } rts = cts = 0; if ((ic->ic_flags & IEEE80211_F_USEPROT) && rt->info[rix].phy == IEEE80211_T_OFDM) { if (ic->ic_protmode == IEEE80211_PROT_RTSCTS) rts = 1; else if (ic->ic_protmode == IEEE80211_PROT_CTSONLY) cts = 1; cix = rt->info[sc->sc_protrix].controlRate; } if (0 /*length > ic->ic_rtsthreshold */) rts = 1; if (rts || cts) { int ctsduration = 0; if (!rt->info[cix].rateKbps) { printk(KERN_WARNING "cix %u (%u) bad ratekbps %u mode %u\n", cix, rt->info[cix].dot11Rate, rt->info[cix].rateKbps, sc->sc_curmode); return 0; } if (rts) /* SIFS + CTS */ ctsduration += rt->info[cix].spAckDuration; ctsduration += ath_hal_computetxtime(sc->sc_ah, rt, length, rix, AH_TRUE); if (cts) /* SIFS + ACK */ ctsduration += rt->info[cix].spAckDuration; tt += (short_retries + 1) * ctsduration; } tt += t_difs; tt += (long_retries+1)*(t_sifs + rt->info[rix].spAckDuration); tt += (long_retries+1)*ath_hal_computetxtime(sc->sc_ah, rt, length, rix, AH_TRUE); for (x = 0; x <= short_retries + long_retries; x++) { cw = MIN(ATH_DEFAULT_CWMAX, (cw << 1) | 1); tt += (t_slot * cw / 2); } return tt; } static void ath_rate_node_init(struct ath_softc *sc, struct ath_node *an) { /* NB: assumed to be zero'd by caller */ ath_rate_ctl_reset(sc, &an->an_node); } static void ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an) { } #if 0 static void ath_rate_node_copy(struct ath_softc *sc, struct ath_node *dst, const struct ath_node *src) { struct sample_node *odst = ATH_NODE_SAMPLE(dst); const struct sample_node *osrc = (const struct sample_node *)&src[1]; memcpy(odst, osrc, sizeof(struct sample_node)); } #endif /* * returns the ndx with the lowest average_tx_time, * or -1 if all the average_tx_times are 0. */ static __inline int best_rate_ndx(struct sample_node *sn, int size_bin, int require_acked_before) { unsigned int x; unsigned int best_rate_tt = 0; unsigned int best_rate_ndx = -1; for (x = 0; x < sn->num_rates; x++) { unsigned int tt = sn->stats[size_bin][x].average_tx_time; if (tt <= 0 || (require_acked_before && !sn->stats[size_bin][x].packets_acked)) continue; /* 9 megabits never works better than 12 */ if (sn->rates[x].rate == 18) continue; /* don't use a bit-rate that has been failing */ if (sn->stats[size_bin][x].successive_failures > 3) continue; if (!best_rate_tt || best_rate_tt > tt) { best_rate_tt = tt; best_rate_ndx = x; } } return best_rate_ndx; } /* * pick a good "random" bit-rate to sample other than the current one */ static __inline int pick_sample_ndx(struct sample_node *sn, int size_bin) { unsigned int x; unsigned current_tt; int current_ndx; current_ndx = sn->current_rate[size_bin]; if (current_ndx < 0) { /* no successes yet, send at the lowest bit-rate */ return 0; } current_tt = sn->stats[size_bin][current_ndx].average_tx_time; for (x = 0; x < sn->num_rates; x++) { unsigned int ndx = (sn->last_sample_ndx[size_bin] + 1 + x) % sn->num_rates; /* don't sample the current bit-rate */ if (ndx == current_ndx) continue; /* this bit-rate is always worse than the current one */ if (sn->stats[size_bin][ndx].perfect_tx_time > current_tt) continue; /* rarely sample bit-rates that fail a lot */ if (time_before(jiffies, sn->stats[size_bin][ndx].last_tx + ((HZ * STALE_FAILURE_TIMEOUT_MS) / 1000)) && sn->stats[size_bin][ndx].successive_failures > 3) continue; /* don't sample more than 2 indexes higher * for rates higher than 11 megabits */ if (sn->rates[ndx].rate > 22 && ndx > current_ndx + 2) continue; /* 9 megabits never works better than 12 */ if (sn->rates[ndx].rate == 18) continue; /* if we're using 11 megabits, only sample up to 12 megabits */ if (sn->rates[current_ndx].rate == 22 && ndx > current_ndx + 1) continue; sn->last_sample_ndx[size_bin] = ndx; return ndx; } return current_ndx; } static void ath_rate_findrate(struct ath_softc *sc, struct ath_node *an, int shortPreamble, size_t frameLen, u_int8_t *rix, unsigned int *try0, u_int8_t *txrate) { struct sample_node *sn = ATH_NODE_SAMPLE(an); struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc); struct ieee80211com *ic = &sc->sc_ic; unsigned int size_bin, mrr, change_rates; int ndx, best_ndx; unsigned average_tx_time; if (sn->num_rates <= 0) { printk(KERN_WARNING "%s: no rates for " MAC_FMT "?\n", dev_info, MAC_ADDR(an->an_node.ni_macaddr)); return; } mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT) && ENABLE_MRR; size_bin = size_to_bin(frameLen); best_ndx = best_rate_ndx(sn, size_bin, !mrr); if (best_ndx >= 0) average_tx_time = sn->stats[size_bin][best_ndx].average_tx_time; else average_tx_time = 0; if (sn->static_rate_ndx != -1) { ndx = sn->static_rate_ndx; *try0 = ATH_TXMAXTRY; } else { *try0 = mrr ? 2 : ATH_TXMAXTRY; if (sn->sample_tt[size_bin] < average_tx_time * (sn->packets_since_sample[size_bin] * ssc->ath_sample_rate / 100)) { /* * we want to limit the time measuring the performance * of other bit-rates to ath_sample_rate% of the * total transmission time. */ ndx = pick_sample_ndx(sn, size_bin); if (ndx != sn->current_rate[size_bin]) sn->current_sample_ndx[size_bin] = ndx; else sn->current_sample_ndx[size_bin] = -1; sn->packets_since_sample[size_bin] = 0; } else { change_rates = 0; if (!sn->packets_sent[size_bin] || best_ndx == -1) { /* no packet has been sent successfully yet, so * pick an rssi-appropriate bit-rate. We know if * the rssi is very low that the really high * bit rates will not work. */ int initial_rate = 72; if (an->an_avgrssi > 50) { initial_rate = 108; /* 54 mbps */ } else if (an->an_avgrssi > 30) { initial_rate = 72; /* 36 mbps */ } else { initial_rate = 22; /* 11 mbps */ } for (ndx = sn->num_rates-1; ndx > 0; ndx--) { /* * pick the highest rate <= initial_rate/2 Mbps * that hasn't failed. */ if (sn->rates[ndx].rate <= initial_rate && sn->stats[size_bin][ndx].successive_failures == 0) break; } change_rates = 1; best_ndx = ndx; } else if (sn->packets_sent[size_bin] < 20) { /* let the bit-rate switch quickly during the first few packets */ change_rates = 1; } else if (time_after(jiffies, sn->jiffies_since_switch[size_bin] + ((HZ * MIN_SWITCH_MS) / 1000))) { /* 2 seconds have gone by */ change_rates = 1; } else if (average_tx_time * 2 < sn->stats[size_bin][sn->current_rate[size_bin]].average_tx_time) { /* the current bit-rate is twice as slow as the best one */ change_rates = 1; } sn->packets_since_sample[size_bin]++; if (change_rates) { if (best_ndx != sn->current_rate[size_bin]) { DPRINTF(sc, ATH_DEBUG_RATE, "%s: " MAC_FMT " size %u switch rate %u (%u/%u) -> %u (%u/%u) after %u packets mrr %u\n", dev_info, MAC_ADDR(an->an_node.ni_macaddr), packet_size_bins[size_bin], sn->rates[sn->current_rate[size_bin]].rate, sn->stats[size_bin][sn->current_rate[size_bin]].average_tx_time, sn->stats[size_bin][sn->current_rate[size_bin]].perfect_tx_time, sn->rates[best_ndx].rate, sn->stats[size_bin][best_ndx].average_tx_time, sn->stats[size_bin][best_ndx].perfect_tx_time, sn->packets_since_switch[size_bin], mrr); } sn->packets_since_switch[size_bin] = 0; sn->current_rate[size_bin] = best_ndx; sn->jiffies_since_switch[size_bin] = jiffies; } ndx = sn->current_rate[size_bin]; sn->packets_since_switch[size_bin]++; if (size_bin == 0) { /* * set the visible txrate for this node * to the rate of small packets */ an->an_node.ni_txrate = ndx; } } } KASSERT(ndx >= 0 && ndx < sn->num_rates, ("%s: bad ndx (%u/%u) for " MAC_FMT "?", dev_info, ndx, sn->num_rates, MAC_ADDR(an->an_node.ni_macaddr))); *rix = sn->rates[ndx].rix; if (shortPreamble) *txrate = sn->rates[ndx].shortPreambleRateCode; else *txrate = sn->rates[ndx].rateCode; sn->packets_sent[size_bin]++; } static void ath_rate_get_mrr(struct ath_softc *sc, struct ath_node *an, int shortPreamble, size_t frame_size, u_int8_t rix, struct ieee80211_mrr *mrr) { struct sample_node *sn = ATH_NODE_SAMPLE(an); unsigned int size_bin; int ndx; size_bin = size_to_bin(frame_size); ndx = sn->current_rate[size_bin]; /* retry at the current bit-rate */ if (!sn->stats[size_bin][ndx].packets_acked) ndx = 0; /* use the lowest bit-rate */ if (shortPreamble) mrr->rate1 = sn->rates[ndx].shortPreambleRateCode; else mrr->rate1 = sn->rates[ndx].rateCode; mrr->retries1 = 3; mrr->rate2 = sn->rates[0].rateCode; mrr->retries2 = 3; mrr->rate3 = 0; mrr->retries3 = 0; } static void update_stats(struct ath_softc *sc, struct ath_node *an, int frame_size, int ndx0, int tries0, int ndx1, int tries1, int ndx2, int tries2, int ndx3, int tries3, int short_tries, int tries, int status) { const HAL_RATE_TABLE *rt = sc->sc_currates; struct sample_node *sn = ATH_NODE_SAMPLE(an); struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc); unsigned int tt = 0; unsigned int tries_so_far = 0; unsigned int size_bin; unsigned int size; unsigned int rate; size_bin = size_to_bin(frame_size); size = bin_to_size(size_bin); if (!(0 <= ndx0 && ndx0 < sn->num_rates)) { printk("%s: bogus ndx0 %d, max %u, mode %u\n", __func__, ndx0, sn->num_rates, sc->sc_curmode); return; } rate = sn->rates[ndx0].rate; if (!rt->info[ndx0].rateKbps) { /* * sometimes we get feedback back for packets we didn't send. * just ignore these packets. */ return; } tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx0].rix, short_tries, MIN(tries0, tries) - 1); tries_so_far += tries0; if (tries1 && (tries0 < tries)) { if (!(0 <= ndx1 && ndx1 < sn->num_rates)) { printk("%s: bogus ndx1 %d, max %u, mode %u\n", __func__, ndx1, sn->num_rates, sc->sc_curmode); return; } tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx1].rix, short_tries, MIN(tries1 + tries_so_far, tries) - tries_so_far - 1); } tries_so_far += tries1; if (tries2 && ((tries0 + tries1) < tries)) { if (!(0 <= ndx2 && ndx2 < sn->num_rates)) { printk("%s: bogus ndx2 %d, max %u, mode %u\n", __func__, ndx2, sn->num_rates, sc->sc_curmode); return; } tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx2].rix, short_tries, MIN(tries2 + tries_so_far, tries) - tries_so_far - 1); } tries_so_far += tries2; if (tries3 && ((tries0 + tries1 + tries2) < tries)) { if (!(0 <= ndx3 && ndx3 < sn->num_rates)) { printk("%s: bogus ndx3 %d, max %u, mode %u\n", __func__, ndx3, sn->num_rates, sc->sc_curmode); return; } tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx3].rix, short_tries, MIN(tries3 + tries_so_far, tries) - tries_so_far - 1); } if (sn->stats[size_bin][ndx0].total_packets < (100 / (100 - ssc->ath_smoothing_rate))) { /* just average the first few packets */ unsigned int avg_tx = sn->stats[size_bin][ndx0].average_tx_time; unsigned int packets = sn->stats[size_bin][ndx0].total_packets; sn->stats[size_bin][ndx0].average_tx_time = (tt + (avg_tx * packets)) / (packets + 1); } else { /* use a ewma */ sn->stats[size_bin][ndx0].average_tx_time = ((sn->stats[size_bin][ndx0].average_tx_time * ssc->ath_smoothing_rate) + (tt * (100 - ssc->ath_smoothing_rate))) / 100; } if (status) { unsigned int y; sn->stats[size_bin][ndx0].successive_failures++; for (y = size_bin + 1; y < NUM_PACKET_SIZE_BINS; y++) { /* also say larger packets failed since we * assume if a small packet fails at a lower * bit-rate then a larger one will also. */ sn->stats[y][ndx0].successive_failures++; sn->stats[y][ndx0].last_tx = jiffies; sn->stats[y][ndx0].tries += tries; sn->stats[y][ndx0].total_packets++; } } else { sn->stats[size_bin][ndx0].packets_acked++; sn->stats[size_bin][ndx0].successive_failures = 0; } sn->stats[size_bin][ndx0].tries += tries; sn->stats[size_bin][ndx0].last_tx = jiffies; sn->stats[size_bin][ndx0].total_packets++; if (ndx0 == sn->current_sample_ndx[size_bin]) { DPRINTF(sc, ATH_DEBUG_RATE, "%s: " MAC_FMT " size %u sample rate %u tries (%u/%u) tt %u avg_tt (%u/%u) status %u\n", dev_info, MAC_ADDR(an->an_node.ni_macaddr), size, rate, short_tries, tries, tt, sn->stats[size_bin][ndx0].average_tx_time, sn->stats[size_bin][ndx0].perfect_tx_time, status); sn->sample_tt[size_bin] = tt; sn->current_sample_ndx[size_bin] = -1; } } static void ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an, const struct ath_buf *bf) { struct sample_node *sn = ATH_NODE_SAMPLE(an); struct ieee80211com *ic = &sc->sc_ic; const struct ath_tx_status *ts = &bf->bf_dsstatus.ds_txstat; const struct ath_desc *ds = &bf->bf_desc[0]; unsigned int final_rate; unsigned int short_tries; unsigned int long_tries; unsigned int frame_size; unsigned int mrr; final_rate = sc->sc_hwmap[ts->ts_rate &~ HAL_TXSTAT_ALTRATE].ieeerate; short_tries = ts->ts_shortretry + 1; long_tries = ts->ts_longretry + 1; frame_size = ds->ds_ctl0 & 0x0fff; /* low-order 12 bits of ds_ctl0 */ if (frame_size == 0) frame_size = 1500; if (sn->num_rates <= 0) { DPRINTF(sc, ATH_DEBUG_RATE, "%s: " MAC_FMT " %s no rates yet\n", dev_info, MAC_ADDR(an->an_node.ni_macaddr), __func__); return; } mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT) && ENABLE_MRR; if (!mrr || !(ts->ts_rate & HAL_TXSTAT_ALTRATE)) { /* only one rate was used */ int ndx = rate_to_ndx(sn, final_rate); if ((ndx >= 0) && (ndx < sn->num_rates)) { update_stats(sc, an, frame_size, ndx, long_tries, 0, 0, 0, 0, 0, 0, short_tries, long_tries, ts->ts_status); } } else { unsigned int rate[4], tries[4], hwrate[4]; int ndx[4]; int finalTSIdx = ts->ts_finaltsi; /* * Process intermediate rates that failed. */ if (sc->sc_ah->ah_magic != 0x20065416) { hwrate[0] = MS(ds->ds_ctl3, AR_XmitRate0); hwrate[1] = MS(ds->ds_ctl3, AR_XmitRate1); hwrate[2] = MS(ds->ds_ctl3, AR_XmitRate2); hwrate[3] = MS(ds->ds_ctl3, AR_XmitRate3); } else { hwrate[0] = MS(ds->ds_ctl3, AR5416_XmitRate0); hwrate[1] = MS(ds->ds_ctl3, AR5416_XmitRate1); hwrate[2] = MS(ds->ds_ctl3, AR5416_XmitRate2); hwrate[3] = MS(ds->ds_ctl3, AR5416_XmitRate3); } rate[0] = sc->sc_hwmap[hwrate[0]].ieeerate; tries[0] = MS(ds->ds_ctl2, AR_XmitDataTries0); ndx[0] = rate_to_ndx(sn, rate[0]); rate[1] = sc->sc_hwmap[hwrate[1]].ieeerate; tries[1] = MS(ds->ds_ctl2, AR_XmitDataTries1); ndx[1] = rate_to_ndx(sn, rate[1]); rate[2] = sc->sc_hwmap[hwrate[2]].ieeerate; tries[2] = MS(ds->ds_ctl2, AR_XmitDataTries2); ndx[2] = rate_to_ndx(sn, rate[2]); rate[3] = sc->sc_hwmap[hwrate[3]].ieeerate; tries[3] = MS(ds->ds_ctl2, AR_XmitDataTries3); ndx[3] = rate_to_ndx(sn, rate[3]); #if 0 DPRINTF(sc, "%s: " MAC_FMT " size %u finaltsidx %u tries %u status %u rate/try %u/%u %u/%u %u/%u %u/%u\n", dev_info, MAC_ADDR(an->an_node.ni_macaddr), bin_to_size(size_to_bin(frame_size)), finalTSIdx, long_tries, ts->ts_status, rate[0], tries[0], rate[1], tries[1], rate[2], tries[2], rate[3], tries[3]); #endif /* NB: series > 0 are not penalized for failure * based on the try counts under the assumption * that losses are often bursty and since we * sample higher rates 1 try at a time doing so * may unfairly penalize them. */ if (tries[0] && ndx[0] >= 0) { update_stats(sc, an, frame_size, ndx[0], tries[0], ndx[1], tries[1], ndx[2], tries[2], ndx[3], tries[3], short_tries, long_tries, long_tries > tries[0]); long_tries -= tries[0]; } if (tries[1] && ndx[1] >= 0 && finalTSIdx > 0) { update_stats(sc, an, frame_size, ndx[1], tries[1], ndx[2], tries[2], ndx[3], tries[3], 0, 0, short_tries, long_tries, ts->ts_status); long_tries -= tries[1]; } if (tries[2] && ndx[2] >= 0 && finalTSIdx > 1) { update_stats(sc, an, frame_size, ndx[2], tries[2], ndx[3], tries[3], 0, 0, 0, 0, short_tries, long_tries, ts->ts_status); long_tries -= tries[2]; } if (tries[3] && ndx[3] >= 0 && finalTSIdx > 2) { update_stats(sc, an, frame_size, ndx[3], tries[3], 0, 0, 0, 0, 0, 0, short_tries, long_tries, ts->ts_status); } } } static void ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew) { DPRINTF(sc, ATH_DEBUG_RATE, "%s: " MAC_FMT " %s isnew %d\n", dev_info, MAC_ADDR(an->an_node.ni_macaddr), __func__, isnew); if (isnew) ath_rate_ctl_reset(sc, &an->an_node); } /* * Initialize the tables for a node. */ static void ath_rate_ctl_reset(struct ath_softc *sc, struct ieee80211_node *ni) { struct ath_node *an = ATH_NODE(ni); struct sample_node *sn = ATH_NODE_SAMPLE(an); struct ieee80211vap *vap = ni->ni_vap; const HAL_RATE_TABLE *rt = sc->sc_currates; unsigned int x, y; sn->num_rates = 0; if (rt == NULL) { printk(KERN_WARNING "no rates yet! mode %u\n", sc->sc_curmode); return; } sn->static_rate_ndx = -1; sn->num_rates = ni->ni_rates.rs_nrates; for (x = 0; x < ni->ni_rates.rs_nrates; x++) { sn->rates[x].rate = ni->ni_rates.rs_rates[x] & IEEE80211_RATE_VAL; sn->rates[x].rix = sc->sc_rixmap[sn->rates[x].rate]; if (sn->rates[x].rix == 0xff) { DPRINTF(sc, ATH_DEBUG_RATE, "%s: %s ignore bogus rix at %u\n", dev_info, __func__, x); continue; } sn->rates[x].rateCode = rt->info[sn->rates[x].rix].rateCode; sn->rates[x].shortPreambleRateCode = rt->info[sn->rates[x].rix].rateCode | rt->info[sn->rates[x].rix].shortPreamble; } ni->ni_txrate = 0; sn->num_rates = ni->ni_rates.rs_nrates; if (sn->num_rates <= 0) { DPRINTF(sc, ATH_DEBUG_RATE,"%s: %s " MAC_FMT " no rates (fixed %u) \n", dev_info, __func__, MAC_ADDR(ni->ni_macaddr), vap->iv_fixed_rate); /* there are no rates yet we're done */ return; } if (vap->iv_fixed_rate != IEEE80211_FIXED_RATE_NONE) { int srate; /* * A fixed rate is to be used. Find the corresponding * index in the rate table. */ for (srate = 0; srate < sn->num_rates; srate++) if (vap->iv_fixed_rate == (ni->ni_rates.rs_rates[srate] & IEEE80211_RATE_VAL)) { sn->static_rate_ndx = srate; ni->ni_txrate = srate; return; } printk(KERN_WARNING "%s: %s: fixed rate %u%sMbps is not " "available and will be ignored\n", vap->iv_dev->name, dev_info, vap->iv_fixed_rate / 2, (vap->iv_fixed_rate & 1) ? ".5" : ""); } for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) { unsigned int size = bin_to_size(y); int ndx = 0; sn->packets_sent[y] = 0; sn->current_sample_ndx[y] = -1; sn->last_sample_ndx[y] = 0; for (x = 0; x < ni->ni_rates.rs_nrates; x++) { if (sn->rates[x].rix == 0xff) { DPRINTF(sc, ATH_DEBUG_RATE, "%s: %s ignore bogus rix at %u\n", dev_info, __func__, x); continue; } sn->stats[y][x].successive_failures = 0; sn->stats[y][x].tries = 0; sn->stats[y][x].total_packets = 0; sn->stats[y][x].packets_acked = 0; sn->stats[y][x].last_tx = 0; sn->stats[y][x].perfect_tx_time = calc_usecs_unicast_packet(sc, size, sn->rates[x].rix, 0, 0); sn->stats[y][x].average_tx_time = sn->stats[y][x].perfect_tx_time; } /* set the initial rate */ for (ndx = sn->num_rates - 1; ndx > 0; ndx--) if (sn->rates[ndx].rate <= 72) break; sn->current_rate[y] = ndx; } DPRINTF(sc, ATH_DEBUG_RATE, "%s: %s " MAC_FMT " %u rates %u%sMbps (%uus)- %u%sMbps (%uus)\n", dev_info, __func__, MAC_ADDR(ni->ni_macaddr), sn->num_rates, sn->rates[0].rate / 2, sn->rates[0].rate % 0x1 ? ".5" : "", sn->stats[1][0].perfect_tx_time, sn->rates[sn->num_rates-1].rate / 2, sn->rates[sn->num_rates-1].rate % 0x1 ? ".5" : "", sn->stats[1][sn->num_rates-1].perfect_tx_time); ni->ni_txrate = sn->current_rate[0]; } static void ath_rate_cb(void *arg, struct ieee80211_node *ni) { ath_rate_ctl_reset(netdev_priv(ni->ni_ic->ic_dev), ni); } /* * Reset the rate control state for each 802.11 state transition. */ static void ath_rate_newstate(struct ieee80211vap *vap, enum ieee80211_state newstate) { struct ieee80211com *ic = vap->iv_ic; if (newstate == IEEE80211_S_RUN) { if (ic->ic_opmode != IEEE80211_M_STA) { /* * Sync rates for associated stations and neighbors. */ ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_cb, NULL); } ath_rate_newassoc(netdev_priv(ic->ic_dev), ATH_NODE(vap->iv_bss), 1); } } static struct ath_ratectrl * ath_rate_attach(struct ath_softc *sc) { struct sample_softc *osc; DPRINTF(sc, ATH_DEBUG_ANY, "%s: %s\n", dev_info, __func__); _MOD_INC_USE(THIS_MODULE, return NULL); osc = kmalloc(sizeof(struct sample_softc), GFP_ATOMIC); if (osc == NULL) { _MOD_DEC_USE(THIS_MODULE); return NULL; } osc->arc.arc_space = sizeof(struct sample_node); osc->arc.arc_vap_space = 0; osc->ath_smoothing_rate = ath_smoothing_rate; osc->ath_sample_rate = ath_sample_rate; return &osc->arc; } static void ath_rate_detach(struct ath_ratectrl *arc) { struct sample_softc *osc = (struct sample_softc *)arc; kfree(osc); _MOD_DEC_USE(THIS_MODULE); } static int proc_read_nodes(struct ieee80211vap *vap, const int size, char *buf, int space) { char *p = buf; struct ieee80211_node *ni; struct ath_node *an; struct sample_node *sn; struct ieee80211_node_table *nt = (struct ieee80211_node_table *)&vap->iv_ic->ic_sta; unsigned int ndx; unsigned int size_bin; IEEE80211_NODE_TABLE_LOCK_IRQ(nt); TAILQ_FOREACH(ni, &nt->nt_node, ni_list) { /* Assume each node needs 500 bytes */ if (buf + space < p + 500) break; an = ATH_NODE(ni); sn = ATH_NODE_SAMPLE(an); /* Skip ourself */ if (memcmp(vap->iv_myaddr, ni->ni_macaddr, IEEE80211_ADDR_LEN)==0) { continue; } size_bin = size_to_bin(size); p += sprintf(p, MAC_FMT "\n", MAC_ADDR(ni->ni_macaddr)); p += sprintf(p, "rate\ttt\tperfect\tfailed\tpkts\tavg_tries\tlast_tx\n"); for (ndx = 0; ndx < sn->num_rates; ndx++) { unsigned int a = 1; unsigned int t = 1; p += sprintf(p, "%s", (ndx == sn->current_rate[size_bin]) ? "*" : " "); p += sprintf(p, "%3u%s", sn->rates[ndx].rate / 2, (sn->rates[ndx].rate & 0x1) ? ".5" : ".0"); p += sprintf(p, "\t%4u\t%4u\t%2u\t%6u", sn->stats[size_bin][ndx].average_tx_time, sn->stats[size_bin][ndx].perfect_tx_time, sn->stats[size_bin][ndx].successive_failures, sn->stats[size_bin][ndx].total_packets); if (sn->stats[size_bin][ndx].total_packets) { a = sn->stats[size_bin][ndx].total_packets; t = sn->stats[size_bin][ndx].tries; } p += sprintf(p, "\t%u.%02u\t\t", t / a, (t * 100 / a) % 100); if (sn->stats[size_bin][ndx].last_tx) { unsigned long d = jiffies - sn->stats[size_bin][ndx].last_tx; p += sprintf(p, "%lu.%02lu", d / HZ, d % HZ); } else { p += sprintf(p, "-"); } p += sprintf(p, "\n"); } } IEEE80211_NODE_TABLE_UNLOCK_IRQ(nt); return (p - buf); } static int proc_ratesample_open(struct inode *inode, struct file *file) { struct proc_ieee80211_priv *pv; struct ieee80211vap *vap = PDE_DATA(inode); unsigned long size; /* Determine what size packets to get stats for based on proc filename */ size = simple_strtoul(file->f_dentry->d_name.name + strlen("ratestats_"), NULL, 0); if (size < 250 || size > 3000) return -ENOENT; if (!(file->private_data = kzalloc(sizeof(struct proc_ieee80211_priv), GFP_KERNEL))) return -ENOMEM; /* initially allocate both read and write buffers */ pv = (struct proc_ieee80211_priv *)file->private_data; pv->rbuf = vmalloc(MAX_PROC_IEEE80211_SIZE); if (!pv->rbuf) { kfree(pv); return -ENOMEM; } pv->wbuf = vmalloc(MAX_PROC_IEEE80211_SIZE); if (!pv->wbuf) { vfree(pv->rbuf); kfree(pv); return -ENOMEM; } memset(pv->wbuf, 0, MAX_PROC_IEEE80211_SIZE); memset(pv->rbuf, 0, MAX_PROC_IEEE80211_SIZE); pv->max_wlen = MAX_PROC_IEEE80211_SIZE; pv->max_rlen = MAX_PROC_IEEE80211_SIZE; /* now read the data into the buffer */ pv->rlen = proc_read_nodes(vap, size, pv->rbuf, MAX_PROC_IEEE80211_SIZE); return 0; } static struct file_operations proc_ratesample_ops = { .read = NULL, .write = NULL, .open = proc_ratesample_open, .release = NULL, }; static void ath_rate_dynamic_proc_register(struct ieee80211vap *vap) { /* Create proc entries for the rate control algorithm */ ieee80211_proc_vcreate(vap, &proc_ratesample_ops, "ratestats_250"); ieee80211_proc_vcreate(vap, &proc_ratesample_ops, "ratestats_1600"); ieee80211_proc_vcreate(vap, &proc_ratesample_ops, "ratestats_3000"); } static struct ieee80211_rate_ops ath_rate_ops = { .ratectl_id = IEEE80211_RATE_SAMPLE, .node_init = ath_rate_node_init, .node_cleanup = ath_rate_node_cleanup, .findrate = ath_rate_findrate, .get_mrr = ath_rate_get_mrr, .tx_complete = ath_rate_tx_complete, .newassoc = ath_rate_newassoc, .newstate = ath_rate_newstate, .attach = ath_rate_attach, .detach = ath_rate_detach, .dynamic_proc_register = ath_rate_dynamic_proc_register, }; MODULE_AUTHOR("John Bicket"); MODULE_DESCRIPTION("SampleRate bit-rate selection algorithm for Atheros devices"); #ifdef MODULE_VERSION MODULE_VERSION(RELEASE_VERSION); #endif #ifdef MODULE_LICENSE MODULE_LICENSE("Dual BSD/GPL"); #endif static int __init init_ath_rate_sample(void) { return ieee80211_rate_register(&ath_rate_ops); } module_init(init_ath_rate_sample); static void __exit exit_ath_rate_sample(void) { ieee80211_rate_unregister(&ath_rate_ops); } module_exit(exit_ath_rate_sample);