Migrate the TDMA management functions out of if_ath.c into if_ath_tdma.c.

There's some TX path TDMA code in if_ath_tx.c which should be migrated
out, but first I should likely try and verify/fix/repair the TDMA support
in 9.x and -HEAD.

1 files changed, 476 insertions, 0 deletions

diff --git a/sys/dev/ath/if_ath_tdma.c b/sys/dev/ath/if_ath_tdma.c
new file mode 100644
index 000000000000..1d04ccd91c36
--- /dev/null
+++ b/sys/dev/ath/if_ath_tdma.c
@@ -0,0 +1,476 @@
+/*-
+ * Copyright (c) 2002-2009 Sam Leffler, Errno Consulting
+ * 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.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+/*
+ * Driver for the Atheros Wireless LAN controller.
+ *
+ * This software is derived from work of Atsushi Onoe; his contribution
+ * is greatly appreciated.
+ */
+
+#include "opt_inet.h"
+#include "opt_ath.h"
+/*
+ * This is needed for register operations which are performed
+ * by the driver - eg, calls to ath_hal_gettsf32().
+ *
+ * It's also required for any AH_DEBUG checks in here, eg the
+ * module dependencies.
+ */
+#include "opt_ah.h"
+#include "opt_wlan.h"
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/sysctl.h>
+#include <sys/mbuf.h>
+#include <sys/malloc.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
+#include <sys/kernel.h>
+#include <sys/socket.h>
+#include <sys/sockio.h>
+#include <sys/errno.h>
+#include <sys/callout.h>
+#include <sys/bus.h>
+#include <sys/endian.h>
+#include <sys/kthread.h>
+#include <sys/taskqueue.h>
+#include <sys/priv.h>
+#include <sys/module.h>
+#include <sys/ktr.h>
+#include <sys/smp.h>	/* for mp_ncpus */
+
+#include <machine/bus.h>
+
+#include <net/if.h>
+#include <net/if_dl.h>
+#include <net/if_media.h>
+#include <net/if_types.h>
+#include <net/if_arp.h>
+#include <net/ethernet.h>
+#include <net/if_llc.h>
+
+#include <net80211/ieee80211_var.h>
+#include <net80211/ieee80211_regdomain.h>
+#ifdef IEEE80211_SUPPORT_SUPERG
+#include <net80211/ieee80211_superg.h>
+#endif
+#ifdef IEEE80211_SUPPORT_TDMA
+#include <net80211/ieee80211_tdma.h>
+#endif
+
+#include <net/bpf.h>
+
+#ifdef INET
+#include <netinet/in.h>
+#include <netinet/if_ether.h>
+#endif
+
+#include <dev/ath/if_athvar.h>
+#include <dev/ath/ath_hal/ah_devid.h>		/* XXX for softled */
+#include <dev/ath/ath_hal/ah_diagcodes.h>
+
+#include <dev/ath/if_ath_debug.h>
+#include <dev/ath/if_ath_misc.h>
+#include <dev/ath/if_ath_tsf.h>
+#include <dev/ath/if_ath_tx.h>
+#include <dev/ath/if_ath_sysctl.h>
+#include <dev/ath/if_ath_led.h>
+#include <dev/ath/if_ath_keycache.h>
+#include <dev/ath/if_ath_rx.h>
+#include <dev/ath/if_ath_beacon.h>
+#include <dev/ath/if_athdfs.h>
+
+#ifdef ATH_TX99_DIAG
+#include <dev/ath/ath_tx99/ath_tx99.h>
+#endif
+
+#ifdef IEEE80211_SUPPORT_TDMA
+#include <dev/ath/if_ath_tdma.h>
+
+static void	ath_tdma_settimers(struct ath_softc *sc, u_int32_t nexttbtt,
+		    u_int32_t bintval);
+static void	ath_tdma_bintvalsetup(struct ath_softc *sc,
+		    const struct ieee80211_tdma_state *tdma);
+#endif /* IEEE80211_SUPPORT_TDMA */
+
+#ifdef IEEE80211_SUPPORT_TDMA
+static void
+ath_tdma_settimers(struct ath_softc *sc, u_int32_t nexttbtt, u_int32_t bintval)
+{
+	struct ath_hal *ah = sc->sc_ah;
+	HAL_BEACON_TIMERS bt;
+
+	bt.bt_intval = bintval | HAL_BEACON_ENA;
+	bt.bt_nexttbtt = nexttbtt;
+	bt.bt_nextdba = (nexttbtt<<3) - sc->sc_tdmadbaprep;
+	bt.bt_nextswba = (nexttbtt<<3) - sc->sc_tdmaswbaprep;
+	bt.bt_nextatim = nexttbtt+1;
+	/* Enables TBTT, DBA, SWBA timers by default */
+	bt.bt_flags = 0;
+	ath_hal_beaconsettimers(ah, &bt);
+}
+
+/*
+ * Calculate the beacon interval.  This is periodic in the
+ * superframe for the bss.  We assume each station is configured
+ * identically wrt transmit rate so the guard time we calculate
+ * above will be the same on all stations.  Note we need to
+ * factor in the xmit time because the hardware will schedule
+ * a frame for transmit if the start of the frame is within
+ * the burst time.  When we get hardware that properly kills
+ * frames in the PCU we can reduce/eliminate the guard time.
+ *
+ * Roundup to 1024 is so we have 1 TU buffer in the guard time
+ * to deal with the granularity of the nexttbtt timer.  11n MAC's
+ * with 1us timer granularity should allow us to reduce/eliminate
+ * this.
+ */
+static void
+ath_tdma_bintvalsetup(struct ath_softc *sc,
+	const struct ieee80211_tdma_state *tdma)
+{
+	/* copy from vap state (XXX check all vaps have same value?) */
+	sc->sc_tdmaslotlen = tdma->tdma_slotlen;
+
+	sc->sc_tdmabintval = roundup((sc->sc_tdmaslotlen+sc->sc_tdmaguard) *
+		tdma->tdma_slotcnt, 1024);
+	sc->sc_tdmabintval >>= 10;		/* TSF -> TU */
+	if (sc->sc_tdmabintval & 1)
+		sc->sc_tdmabintval++;
+
+	if (tdma->tdma_slot == 0) {
+		/*
+		 * Only slot 0 beacons; other slots respond.
+		 */
+		sc->sc_imask |= HAL_INT_SWBA;
+		sc->sc_tdmaswba = 0;		/* beacon immediately */
+	} else {
+		/* XXX all vaps must be slot 0 or slot !0 */
+		sc->sc_imask &= ~HAL_INT_SWBA;
+	}
+}
+
+/*
+ * Max 802.11 overhead.  This assumes no 4-address frames and
+ * the encapsulation done by ieee80211_encap (llc).  We also
+ * include potential crypto overhead.
+ */
+#define	IEEE80211_MAXOVERHEAD \
+	(sizeof(struct ieee80211_qosframe) \
+	 + sizeof(struct llc) \
+	 + IEEE80211_ADDR_LEN \
+	 + IEEE80211_WEP_IVLEN \
+	 + IEEE80211_WEP_KIDLEN \
+	 + IEEE80211_WEP_CRCLEN \
+	 + IEEE80211_WEP_MICLEN \
+	 + IEEE80211_CRC_LEN)
+
+/*
+ * Setup initially for tdma operation.  Start the beacon
+ * timers and enable SWBA if we are slot 0.  Otherwise
+ * we wait for slot 0 to arrive so we can sync up before
+ * starting to transmit.
+ */
+void
+ath_tdma_config(struct ath_softc *sc, struct ieee80211vap *vap)
+{
+	struct ath_hal *ah = sc->sc_ah;
+	struct ifnet *ifp = sc->sc_ifp;
+	struct ieee80211com *ic = ifp->if_l2com;
+	const struct ieee80211_txparam *tp;
+	const struct ieee80211_tdma_state *tdma = NULL;
+	int rix;
+
+	if (vap == NULL) {
+		vap = TAILQ_FIRST(&ic->ic_vaps);   /* XXX */
+		if (vap == NULL) {
+			if_printf(ifp, "%s: no vaps?\n", __func__);
+			return;
+		}
+	}
+	/* XXX should take a locked ref to iv_bss */
+	tp = vap->iv_bss->ni_txparms;
+	/*
+	 * Calculate the guard time for each slot.  This is the
+	 * time to send a maximal-size frame according to the
+	 * fixed/lowest transmit rate.  Note that the interface
+	 * mtu does not include the 802.11 overhead so we must
+	 * tack that on (ath_hal_computetxtime includes the
+	 * preamble and plcp in it's calculation).
+	 */
+	tdma = vap->iv_tdma;
+	if (tp->ucastrate != IEEE80211_FIXED_RATE_NONE)
+		rix = ath_tx_findrix(sc, tp->ucastrate);
+	else
+		rix = ath_tx_findrix(sc, tp->mcastrate);
+	/* XXX short preamble assumed */
+	sc->sc_tdmaguard = ath_hal_computetxtime(ah, sc->sc_currates,
+		ifp->if_mtu + IEEE80211_MAXOVERHEAD, rix, AH_TRUE);
+
+	ath_hal_intrset(ah, 0);
+
+	ath_beaconq_config(sc);			/* setup h/w beacon q */
+	if (sc->sc_setcca)
+		ath_hal_setcca(ah, AH_FALSE);	/* disable CCA */
+	ath_tdma_bintvalsetup(sc, tdma);	/* calculate beacon interval */
+	ath_tdma_settimers(sc, sc->sc_tdmabintval,
+		sc->sc_tdmabintval | HAL_BEACON_RESET_TSF);
+	sc->sc_syncbeacon = 0;
+
+	sc->sc_avgtsfdeltap = TDMA_DUMMY_MARKER;
+	sc->sc_avgtsfdeltam = TDMA_DUMMY_MARKER;
+
+	ath_hal_intrset(ah, sc->sc_imask);
+
+	DPRINTF(sc, ATH_DEBUG_TDMA, "%s: slot %u len %uus cnt %u "
+	    "bsched %u guard %uus bintval %u TU dba prep %u\n", __func__,
+	    tdma->tdma_slot, tdma->tdma_slotlen, tdma->tdma_slotcnt,
+	    tdma->tdma_bintval, sc->sc_tdmaguard, sc->sc_tdmabintval,
+	    sc->sc_tdmadbaprep);
+}
+
+/*
+ * Update tdma operation.  Called from the 802.11 layer
+ * when a beacon is received from the TDMA station operating
+ * in the slot immediately preceding us in the bss.  Use
+ * the rx timestamp for the beacon frame to update our
+ * beacon timers so we follow their schedule.  Note that
+ * by using the rx timestamp we implicitly include the
+ * propagation delay in our schedule.
+ */
+void
+ath_tdma_update(struct ieee80211_node *ni,
+	const struct ieee80211_tdma_param *tdma, int changed)
+{
+#define	TSF_TO_TU(_h,_l) \
+	((((u_int32_t)(_h)) << 22) | (((u_int32_t)(_l)) >> 10))
+#define	TU_TO_TSF(_tu)	(((u_int64_t)(_tu)) << 10)
+	struct ieee80211vap *vap = ni->ni_vap;
+	struct ieee80211com *ic = ni->ni_ic;
+	struct ath_softc *sc = ic->ic_ifp->if_softc;
+	struct ath_hal *ah = sc->sc_ah;
+	const HAL_RATE_TABLE *rt = sc->sc_currates;
+	u_int64_t tsf, rstamp, nextslot, nexttbtt;
+	u_int32_t txtime, nextslottu;
+	int32_t tudelta, tsfdelta;
+	const struct ath_rx_status *rs;
+	int rix;
+
+	sc->sc_stats.ast_tdma_update++;
+
+	/*
+	 * Check for and adopt configuration changes.
+	 */
+	if (changed != 0) {
+		const struct ieee80211_tdma_state *ts = vap->iv_tdma;
+
+		ath_tdma_bintvalsetup(sc, ts);
+		if (changed & TDMA_UPDATE_SLOTLEN)
+			ath_wme_update(ic);
+
+		DPRINTF(sc, ATH_DEBUG_TDMA,
+		    "%s: adopt slot %u slotcnt %u slotlen %u us "
+		    "bintval %u TU\n", __func__,
+		    ts->tdma_slot, ts->tdma_slotcnt, ts->tdma_slotlen,
+		    sc->sc_tdmabintval);
+
+		/* XXX right? */
+		ath_hal_intrset(ah, sc->sc_imask);
+		/* NB: beacon timers programmed below */
+	}
+
+	/* extend rx timestamp to 64 bits */
+	rs = sc->sc_lastrs;
+	tsf = ath_hal_gettsf64(ah);
+	rstamp = ath_extend_tsf(sc, rs->rs_tstamp, tsf);
+	/*
+	 * The rx timestamp is set by the hardware on completing
+	 * reception (at the point where the rx descriptor is DMA'd
+	 * to the host).  To find the start of our next slot we
+	 * must adjust this time by the time required to send
+	 * the packet just received.
+	 */
+	rix = rt->rateCodeToIndex[rs->rs_rate];
+	txtime = ath_hal_computetxtime(ah, rt, rs->rs_datalen, rix,
+	    rt->info[rix].shortPreamble);
+	/* NB: << 9 is to cvt to TU and /2 */
+	nextslot = (rstamp - txtime) + (sc->sc_tdmabintval << 9);
+	nextslottu = TSF_TO_TU(nextslot>>32, nextslot) & HAL_BEACON_PERIOD;
+
+	/*
+	 * Retrieve the hardware NextTBTT in usecs
+	 * and calculate the difference between what the
+	 * other station thinks and what we have programmed.  This
+	 * lets us figure how to adjust our timers to match.  The
+	 * adjustments are done by pulling the TSF forward and possibly
+	 * rewriting the beacon timers.
+	 */
+	nexttbtt = ath_hal_getnexttbtt(ah);
+	tsfdelta = (int32_t)((nextslot % TU_TO_TSF(HAL_BEACON_PERIOD + 1)) - nexttbtt);
+
+	DPRINTF(sc, ATH_DEBUG_TDMA_TIMER,
+	    "tsfdelta %d avg +%d/-%d\n", tsfdelta,
+	    TDMA_AVG(sc->sc_avgtsfdeltap), TDMA_AVG(sc->sc_avgtsfdeltam));
+
+	if (tsfdelta < 0) {
+		TDMA_SAMPLE(sc->sc_avgtsfdeltap, 0);
+		TDMA_SAMPLE(sc->sc_avgtsfdeltam, -tsfdelta);
+		tsfdelta = -tsfdelta % 1024;
+		nextslottu++;
+	} else if (tsfdelta > 0) {
+		TDMA_SAMPLE(sc->sc_avgtsfdeltap, tsfdelta);
+		TDMA_SAMPLE(sc->sc_avgtsfdeltam, 0);
+		tsfdelta = 1024 - (tsfdelta % 1024);
+		nextslottu++;
+	} else {
+		TDMA_SAMPLE(sc->sc_avgtsfdeltap, 0);
+		TDMA_SAMPLE(sc->sc_avgtsfdeltam, 0);
+	}
+	tudelta = nextslottu - TSF_TO_TU(nexttbtt >> 32, nexttbtt);
+
+	/*
+	 * Copy sender's timetstamp into tdma ie so they can
+	 * calculate roundtrip time.  We submit a beacon frame
+	 * below after any timer adjustment.  The frame goes out
+	 * at the next TBTT so the sender can calculate the
+	 * roundtrip by inspecting the tdma ie in our beacon frame.
+	 *
+	 * NB: This tstamp is subtlely preserved when
+	 *     IEEE80211_BEACON_TDMA is marked (e.g. when the
+	 *     slot position changes) because ieee80211_add_tdma
+	 *     skips over the data.
+	 */
+	memcpy(ATH_VAP(vap)->av_boff.bo_tdma +
+		__offsetof(struct ieee80211_tdma_param, tdma_tstamp),
+		&ni->ni_tstamp.data, 8);
+#if 0
+	DPRINTF(sc, ATH_DEBUG_TDMA_TIMER,
+	    "tsf %llu nextslot %llu (%d, %d) nextslottu %u nexttbtt %llu (%d)\n",
+	    (unsigned long long) tsf, (unsigned long long) nextslot,
+	    (int)(nextslot - tsf), tsfdelta, nextslottu, nexttbtt, tudelta);
+#endif
+	/*
+	 * Adjust the beacon timers only when pulling them forward
+	 * or when going back by less than the beacon interval.
+	 * Negative jumps larger than the beacon interval seem to
+	 * cause the timers to stop and generally cause instability.
+	 * This basically filters out jumps due to missed beacons.
+	 */
+	if (tudelta != 0 && (tudelta > 0 || -tudelta < sc->sc_tdmabintval)) {
+		ath_tdma_settimers(sc, nextslottu, sc->sc_tdmabintval);
+		sc->sc_stats.ast_tdma_timers++;
+	}
+	if (tsfdelta > 0) {
+		ath_hal_adjusttsf(ah, tsfdelta);
+		sc->sc_stats.ast_tdma_tsf++;
+	}
+	ath_tdma_beacon_send(sc, vap);		/* prepare response */
+#undef TU_TO_TSF
+#undef TSF_TO_TU
+}
+
+/*
+ * Transmit a beacon frame at SWBA.  Dynamic updates
+ * to the frame contents are done as needed.
+ */
+void
+ath_tdma_beacon_send(struct ath_softc *sc, struct ieee80211vap *vap)
+{
+	struct ath_hal *ah = sc->sc_ah;
+	struct ath_buf *bf;
+	int otherant;
+
+	/*
+	 * Check if the previous beacon has gone out.  If
+	 * not don't try to post another, skip this period
+	 * and wait for the next.  Missed beacons indicate
+	 * a problem and should not occur.  If we miss too
+	 * many consecutive beacons reset the device.
+	 */
+	if (ath_hal_numtxpending(ah, sc->sc_bhalq) != 0) {
+		sc->sc_bmisscount++;
+		DPRINTF(sc, ATH_DEBUG_BEACON,
+			"%s: missed %u consecutive beacons\n",
+			__func__, sc->sc_bmisscount);
+		if (sc->sc_bmisscount >= ath_bstuck_threshold)
+			taskqueue_enqueue(sc->sc_tq, &sc->sc_bstucktask);
+		return;
+	}
+	if (sc->sc_bmisscount != 0) {
+		DPRINTF(sc, ATH_DEBUG_BEACON,
+			"%s: resume beacon xmit after %u misses\n",
+			__func__, sc->sc_bmisscount);
+		sc->sc_bmisscount = 0;
+	}
+
+	/*
+	 * Check recent per-antenna transmit statistics and flip
+	 * the default antenna if noticeably more frames went out
+	 * on the non-default antenna.
+	 * XXX assumes 2 anntenae
+	 */
+	if (!sc->sc_diversity) {
+		otherant = sc->sc_defant & 1 ? 2 : 1;
+		if (sc->sc_ant_tx[otherant] > sc->sc_ant_tx[sc->sc_defant] + 2)
+			ath_setdefantenna(sc, otherant);
+		sc->sc_ant_tx[1] = sc->sc_ant_tx[2] = 0;
+	}
+
+	bf = ath_beacon_generate(sc, vap);
+	if (bf != NULL) {
+		/*
+		 * Stop any current dma and put the new frame on the queue.
+		 * This should never fail since we check above that no frames
+		 * are still pending on the queue.
+		 */
+		if (!ath_hal_stoptxdma(ah, sc->sc_bhalq)) {
+			DPRINTF(sc, ATH_DEBUG_ANY,
+				"%s: beacon queue %u did not stop?\n",
+				__func__, sc->sc_bhalq);
+			/* NB: the HAL still stops DMA, so proceed */
+		}
+		ath_hal_puttxbuf(ah, sc->sc_bhalq, bf->bf_daddr);
+		ath_hal_txstart(ah, sc->sc_bhalq);
+
+		sc->sc_stats.ast_be_xmit++;		/* XXX per-vap? */
+
+		/*
+		 * Record local TSF for our last send for use
+		 * in arbitrating slot collisions.
+		 */
+		/* XXX should take a locked ref to iv_bss */
+		vap->iv_bss->ni_tstamp.tsf = ath_hal_gettsf64(ah);
+	}
+}
+#endif /* IEEE80211_SUPPORT_TDMA */