minstrel.c

最新之atheros芯片driver source code, 基于linux操作系统,內含atheros芯片HAL全部代码

					ndx = sn->max_tp_rate;				
			} else
				ndx = sn->max_tp_rate;
		 }

		if ((sn->static_rate_ndx != -1) || !mrr)
			    *try0 = ATH_TXMAXTRY;
		else
			    *try0 = sn->retry_adjusted_count[ndx];

		KASSERT((ndx < sn->num_rates),
			    ("%s: bad ndx (%d/%d) 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;
}


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 minstrel_node *sn = ATH_NODE_MINSTREL(an);
		/* Index into the rate table, so for example, it is  0..11. */
		int rc1, rc2, rc3;

		if (sn->num_rates <= 0) {
			DPRINTF(sc, "%s: no rates for " MAC_FMT "\n",
					dev_info,
					MAC_ADDR(an->an_node.ni_macaddr));
			memset(mrr, 0, sizeof(struct ieee80211_mrr));
			return;
		}

		if (sn->is_sampling) {
			sn->is_sampling = 0;
			if (sn->rs_sample_rate_slower)
				rc1 = sn->rs_sample_rate;
			else
				rc1 = sn->max_tp_rate;
		} else {
			rc1 = sn->max_tp_rate2;
		}

		rc2 = sn->max_prob_rate;
		rc3 = 0;

		KASSERT((rc1 >= 0) && (rc1 < sn->num_rates),
			    ("%s: bad rc1 (%d/%d) for " MAC_FMT "?",
			     dev_info, rc1, sn->num_rates,
			     MAC_ADDR(an->an_node.ni_macaddr)));

		KASSERT((rc2 >= 0) && (rc2 < sn->num_rates),
			    ("%s: bad rc2 (%d/%d) for " MAC_FMT "?",
			     dev_info, rc2, sn->num_rates,
			     MAC_ADDR(an->an_node.ni_macaddr)));

		KASSERT((rc3 >= 0) && (rc3 < sn->num_rates),
			    ("%s: bad rc3 (%d/%d) for " MAC_FMT "?",
			     dev_info, rc3, sn->num_rates,
			     MAC_ADDR(an->an_node.ni_macaddr)));

		if (shortPreamble) {
			mrr->rate1 = sn->rates[rc1].shortPreambleRateCode;
			mrr->rate2 = sn->rates[rc2].shortPreambleRateCode;
			mrr->rate3 = sn->rates[rc3].shortPreambleRateCode;
		} else {
			mrr->rate1 = sn->rates[rc1].rateCode;
			mrr->rate2 = sn->rates[rc2].rateCode;
			mrr->rate3 = sn->rates[rc3].rateCode;
		}

		mrr->retries1 = sn->retry_adjusted_count[rc1];
		mrr->retries2 = sn->retry_adjusted_count[rc2];
		mrr->retries3 = sn->retry_adjusted_count[rc3];
}

static void
ath_rate_tx_complete(struct ath_softc *sc,
		struct ath_node *an, const struct ath_buf *bf)
{
		struct minstrel_node *sn = ATH_NODE_MINSTREL(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];
		int final_rate = 0;
		int tries = 0;
		int mrr;
		int final_ndx;
		int rate0, tries0, ndx0;
		int rate1, tries1, ndx1;
		int rate2, tries2, ndx2;
		int rate3, tries3, ndx3;

		/* This is the index in the retry chain we finish at.
		 * With no retransmits, it is always 0.
		 * int finalTSIdx = ads->final_ts_index; */
		final_rate = sc->sc_hwmap[ts->ts_rate & ~HAL_TXSTAT_ALTRATE].ieeerate;
		final_ndx = rate_to_ndx(sn, final_rate);
		if (final_ndx >= sn->num_rates) {
			DPRINTF(sc, "%s: final ndx too high\n", __func__);
			final_ndx = 0;
		}
		if (final_ndx < 0) {
			DPRINTF(sc, "%s: final ndx too low\n", __func__);
			final_ndx = 0;
		}

		/* 'tries' is the total number of times we have endeavoured to
		 * send this packet, and is a sum of the #attempts at each
		 * level in the multi-rate retry chain. */
		tries = ts->ts_longretry + 1;

		if (sn->num_rates <= 0) {
			DPRINTF(sc, "%s: " MAC_FMT " %s no rates yet\n", dev_info,
				MAC_ADDR(an->an_node.ni_macaddr), __func__);
			return;
		}

		if (!ts->ts_status)  /* Success when sending a packet*/
			sn->rs_ratesuccess[final_ndx]++;

		mrr = sc->sc_mrretry &&
			!(ic->ic_flags & IEEE80211_F_USEPROT) &&
			ENABLE_MRR;

		if (!mrr) {
			if ((0 <= final_ndx) && (final_ndx < sn->num_rates)) {
				/* only one rate was used */
				sn->rs_rateattempts[final_ndx] += tries;
			}
			return;
		}

		/* Now, query the HAL/hardware to find out the contents of the
		 * multirate retry chain. If we have it set to 6, 3, 2, 2, this
		 * call will always return 6,3,2,2. For some packets, we can
		 * get a mrr of 0, -1, -1, -1, which indicates there is no
		 * chain installed for that packet */
		rate0 = sc->sc_hwmap[MS(ds->ds_ctl3, AR_XmitRate0)].ieeerate;
		tries0 = MS(ds->ds_ctl2, AR_XmitDataTries0);
		ndx0 = rate_to_ndx(sn, rate0);

		rate1 = sc->sc_hwmap[MS(ds->ds_ctl3, AR_XmitRate1)].ieeerate;
		tries1 = MS(ds->ds_ctl2, AR_XmitDataTries1);
		ndx1 = rate_to_ndx(sn, rate1);

		rate2 = sc->sc_hwmap[MS(ds->ds_ctl3, AR_XmitRate2)].ieeerate;
		tries2 = MS(ds->ds_ctl2, AR_XmitDataTries2);
		ndx2 = rate_to_ndx(sn, rate2);

		rate3 = sc->sc_hwmap[MS(ds->ds_ctl3, AR_XmitRate3)].ieeerate;
		tries3 = MS(ds->ds_ctl2, AR_XmitDataTries3);
		ndx3 = rate_to_ndx(sn, rate3);

		sn->rs_rateattempts[ndx0] += MIN(tries, tries0);
		if (tries <= tries0)
			return;

		if (tries1 < 0)
			return;
		tries = tries - tries0;
		sn->rs_rateattempts[ndx1] += MIN(tries, tries1);
		if (tries <= tries1)
			return;

		if  (tries2 < 0)
			return;
		tries = tries - tries1;
		sn->rs_rateattempts[ndx2] += MIN(tries, tries2);
		if (tries <= tries2)
			return;

		if  (tries3 < 0)
			return;
		tries = tries - tries2;
		sn->rs_rateattempts[ndx3] += MIN(tries, tries3);
}

static void
ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
{
		DPRINTF(sc, "%s: " MAC_FMT " %s\n", dev_info,
			MAC_ADDR(an->an_node.ni_macaddr), __func__);
		if (isnew)
			ath_rate_ctl_reset(sc, &an->an_node);
}

static void
ath_fill_sample_table(struct ath_softc *sc, struct minstrel_node *sn)
{
	unsigned int num_sample_rates = (sn->num_rates - 1);
	/* newIndex varies as 0 .. (num_rates - 2) 
	 * The highest index rate is the slowest and is ignored */
	unsigned int i, column_index, newIndex;
	u_int8_t random_bytes[8];

	/* This should be unnecessary if we are assuming storage is provided
	 * as zeroed */
	memset(sn->rs_sampleTable, 0, sizeof(sn->rs_sampleTable));

	sn->rs_sampleColumn = 0;
	sn->rs_sampleIndex = 0;

	/* Seed value to random number generator, which determines when we
	 * send a sample packet at some non-optimal rate
	 * FIXME: randomise? */
	sn->random_n = 1;
	sn->a = 1664525;
	sn->b = 1013904223;

	if (sn->num_rates > 1) {
		for (column_index = 0; column_index < MINSTREL_COLUMNS; column_index++) {
			for (i = 0; i < num_sample_rates; i++) {
				get_random_bytes(random_bytes, 8);
				newIndex = (i + random_bytes[i & 7]) % num_sample_rates;

				while (sn->rs_sampleTable[newIndex][column_index] != 0)
					newIndex = (newIndex + 1) % num_sample_rates;

				sn->rs_sampleTable[newIndex][column_index] = i + 1;
			}
		}
	}
	
	for (column_index = 0; column_index < MINSTREL_COLUMNS; column_index++) {
		for (i = 0; i < num_sample_rates && i < IEEE80211_RATE_MAXSIZE; i++) {
			DPRINTF(sc, "rs_sampleTable[%2u][%2u] = %2u\n",
				i, column_index, sn->rs_sampleTable[i][column_index]);
		}
	}
}

/* Initialize the tables for a node. */
static void
ath_rate_ctl_reset(struct ath_softc *sc, struct ieee80211_node *ni)
{
	struct minstrel_node *sn = ATH_NODE_MINSTREL(ATH_NODE(ni));
	struct ieee80211vap *vap = ni->ni_vap;
	const HAL_RATE_TABLE *rt = sc->sc_currates;
	unsigned int x;
	int retry_index, tx_time;
	int srate;
	int ndx = 0;

	sn->num_rates = 0;
	sn->max_tp_rate = 0;
	sn->max_tp_rate2 = 0;
	sn->max_prob_rate = 0;
	sn->packet_count = 0;
	sn->sample_count = 0;
	sn->is_sampling = 0;

	if (rt == NULL) {
		DPRINTF(sc, "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->rs_rateattempts 	[x] = 0;
		sn->rs_thisprob 	[x] = 0;
		sn->rs_ratesuccess 	[x] = 0;
		sn->rs_lastrateattempts [x] = 0;
		sn->rs_lastratesuccess	[x] = 0;
		sn->rs_probability	[x] = 0;
		sn->rs_succ_hist	[x] = 0;
		sn->rs_att_hist 	[x] = 0;
		sn->rs_this_tp 		[x] = 0;

		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, "%s: %s ignore bogus rix at %d\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;
	}
	
	ath_fill_sample_table(sc, sn);
	
	ni->ni_txrate = 0;

	if (sn->num_rates <= 0) {
		DPRINTF(sc, "%s: %s " MAC_FMT " no rates (fixed %d) \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) {
		srate = sn->num_rates - 1;

		/* A fixed rate is to be used; ic_fixed_rate is an
		 * index into the supported rate set.  Convert this
		 * to the index into the negotiated rate set for
		 * the node.  We know the rate is there because the
		 * rate set is checked when the station associates. */
		/* NB: the rate set is assumed to be sorted. */
		for (;
				(srate >= 0) &&
				(ni->ni_rates.rs_rates[srate] &
				 IEEE80211_RATE_VAL) != vap->iv_fixed_rate;
				srate--);

		KASSERT(srate >= 0,
			("fixed rate %d not in rate set", vap->iv_fixed_rate));

		sn->static_rate_ndx = srate;
		ni->ni_txrate = srate;
		DPRINTF(sc, "%s: %s " MAC_FMT " fixed rate %d%sMbps\n",
			dev_info, __func__, MAC_ADDR(ni->ni_macaddr),
			sn->rates[srate].rate / 2,
			(sn->rates[srate].rate % 2) ? ".5 " : " ");
		return;
	}

	for (x = 0; x < ni->ni_rates.rs_nrates; x++) {
		if (sn->rates[x].rix == 0xff) {
			DPRINTF(sc, "%s: %s ignore bogus rix at %d\n",
				dev_info, __func__, x);
			continue;
		}

		sn->rs_rateattempts	[x] = 0;
		sn->rs_thisprob		[x] = 0;
		sn->rs_ratesuccess 	[x] = 0;
		sn->rs_probability 	[x] = 0;
		sn->rs_lastrateattempts [x] = 0;
		sn->rs_lastratesuccess 	[x] = 0;
		sn->rs_succ_hist 	[x] = 0;
		sn->rs_att_hist 	[x] = 0;
		sn->perfect_tx_time 	[x] =
			calc_usecs_unicast_packet(sc, 1200,
						  sn->rates[x].rix,
						  0, 0);
		sn->retry_count 	[x] = 1;
		sn->retry_adjusted_count[x] = 1;

		for (retry_index = 2; retry_index < ATH_TXMAXTRY; retry_index++) {
			tx_time = calc_usecs_unicast_packet(sc, 1200,
					sn->rates[x].rix, 0, retry_index);
			if (tx_time > ath_segment_size)
				break;
			sn->retry_count[x] = retry_index;
			sn->retry_adjusted_count[x] = retry_index;
		}
	}

#if 0
	DPRINTF(sc, "%s: Retry table for this node\n", __func__);
	for (x = 0; x < ni->ni_rates.rs_nrates; x++)
		DPRINTF(sc, "%2d  %2d %6d  \n", x, sn->retry_count[x],
				sn->perfect_tx_time[x]);
#endif

	/* Set the initial rate */
	for (ndx = sn->num_rates - 1; ndx > 0; ndx--)
		if (sn->rates[ndx].rate <= 72)
			break;
	sn->current_rate = ndx;

	ni->ni_txrate = sn->current_rate;
}

static void
ath_rate_cb(void *arg, struct ieee80211_node *ni)