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freebsd-dev/sys/dev/ath/if_ath_beacon.c
Adrian Chadd 9be82a4209 Be (very) careful about how to add more TX DMA work. 
The list-based DMA engine has the following behaviour:

* When the DMA engine is in the init state, you can write the first
  descriptor address to the QCU TxDP register and it will work.

* Then when it hits the end of the list (ie, it either hits a NULL
  link pointer, OR it hits a descriptor with VEOL set) the QCU
  stops, and the TxDP points to the last descriptor that was transmitted.

* Then when you want to transmit a new frame, you can then either:
  + write the head of the new list into TxDP, or
  + you write the head of the new list into the link pointer of the
    last completed descriptor (ie, where TxDP points), then kick
    TxE to restart transmission on that QCU>

* The hardware then will re-read the descriptor to pick up the link
  pointer and then jump to that.

Now, the quirks:

* If you write a TxDP when there's been no previous TxDP (ie, it's 0),
  it works.

* If you write a TxDP in any other instance, the TxDP write may actually
  fail.  Thus, when you start transmission, it will re-read the last
  transmitted descriptor to get the link pointer, NOT just start a new
  transmission.

So the correct thing to do here is:

* ALWAYS use the holding descriptor (ie, the last transmitted descriptor
  that we've kept safe) and use the link pointer in _THAT_ to transmit
  the next frame.

* NEVER write to the TxDP after you've done the initial write.

* .. also, don't do this whilst you're also resetting the NIC.

With this in mind, the following patch does basically the above.

* Since this encapsulates Sam's issues with the QCU behaviour w/ TDMA,
  kill the TDMA special case and replace it with the above.

* Add a new TXQ flag - PUTRUNNING - which indicates that we've started
  DMA.

* Clear that flag when DMA has been shutdown.

* Ensure that we're not restarting DMA with PUTRUNNING enabled.

* Fix the link pointer logic during TXQ drain - we should always ensure
  the link pointer does point to something if there's a list of frames.
  Having it be NULL as an indication that DMA has finished or during
  a reset causes trouble.

Now, given all of this, i want to nuke axq_link from orbit.  There's now HAL
methods to get and set the link pointer of a descriptor, so what we
should do instead is to update the right link pointer.

* If there's a holding descriptor and an empty TXQ list, set the
  link pointer of said holding descriptor to the new frame.

* If there's a non-empty TXQ list, set the link pointer of the
  last descriptor in the list to the new frame.

* Nuke axq_link from orbit.

Note:

* The AR9380 doesn't need this.  FIFO TX writes are atomic.  As long as
  we don't append to a list of frames that we've already passed to the
  hardware, all of the above doesn't apply.  The holding descriptor stuff
  is still needed to ensure the hardware can re-read a completed
  descriptor to move onto the next one, but we restart DMA by pushing in
  a new FIFO entry into the TX QCU.  That doesn't require any real
  gymnastics.

Tested:

* AR5210, AR5211, AR5212, AR5416, AR9380 - STA mode.
2013-05-18 18:27:53 +00:00

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/*-
* 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
#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/if_ath_debug.h>
#include <dev/ath/if_ath_misc.h>
#include <dev/ath/if_ath_tx.h>
#include <dev/ath/if_ath_beacon.h>
#ifdef ATH_TX99_DIAG
#include <dev/ath/ath_tx99/ath_tx99.h>
#endif
/*
* Setup a h/w transmit queue for beacons.
*/
int
ath_beaconq_setup(struct ath_softc *sc)
{
struct ath_hal *ah = sc->sc_ah;
HAL_TXQ_INFO qi;
memset(&qi, 0, sizeof(qi));
qi.tqi_aifs = HAL_TXQ_USEDEFAULT;
qi.tqi_cwmin = HAL_TXQ_USEDEFAULT;
qi.tqi_cwmax = HAL_TXQ_USEDEFAULT;
/* NB: for dynamic turbo, don't enable any other interrupts */
qi.tqi_qflags = HAL_TXQ_TXDESCINT_ENABLE;
if (sc->sc_isedma)
qi.tqi_qflags |= HAL_TXQ_TXOKINT_ENABLE |
HAL_TXQ_TXERRINT_ENABLE;
return ath_hal_setuptxqueue(ah, HAL_TX_QUEUE_BEACON, &qi);
}
/*
* Setup the transmit queue parameters for the beacon queue.
*/
int
ath_beaconq_config(struct ath_softc *sc)
{
#define ATH_EXPONENT_TO_VALUE(v) ((1<<(v))-1)
struct ieee80211com *ic = sc->sc_ifp->if_l2com;
struct ath_hal *ah = sc->sc_ah;
HAL_TXQ_INFO qi;
ath_hal_gettxqueueprops(ah, sc->sc_bhalq, &qi);
if (ic->ic_opmode == IEEE80211_M_HOSTAP ||
ic->ic_opmode == IEEE80211_M_MBSS) {
/*
* Always burst out beacon and CAB traffic.
*/
qi.tqi_aifs = ATH_BEACON_AIFS_DEFAULT;
qi.tqi_cwmin = ATH_BEACON_CWMIN_DEFAULT;
qi.tqi_cwmax = ATH_BEACON_CWMAX_DEFAULT;
} else {
struct wmeParams *wmep =
&ic->ic_wme.wme_chanParams.cap_wmeParams[WME_AC_BE];
/*
* Adhoc mode; important thing is to use 2x cwmin.
*/
qi.tqi_aifs = wmep->wmep_aifsn;
qi.tqi_cwmin = 2*ATH_EXPONENT_TO_VALUE(wmep->wmep_logcwmin);
qi.tqi_cwmax = ATH_EXPONENT_TO_VALUE(wmep->wmep_logcwmax);
}
if (!ath_hal_settxqueueprops(ah, sc->sc_bhalq, &qi)) {
device_printf(sc->sc_dev, "unable to update parameters for "
"beacon hardware queue!\n");
return 0;
} else {
ath_hal_resettxqueue(ah, sc->sc_bhalq); /* push to h/w */
return 1;
}
#undef ATH_EXPONENT_TO_VALUE
}
/*
* Allocate and setup an initial beacon frame.
*/
int
ath_beacon_alloc(struct ath_softc *sc, struct ieee80211_node *ni)
{
struct ieee80211vap *vap = ni->ni_vap;
struct ath_vap *avp = ATH_VAP(vap);
struct ath_buf *bf;
struct mbuf *m;
int error;
bf = avp->av_bcbuf;
DPRINTF(sc, ATH_DEBUG_NODE, "%s: bf_m=%p, bf_node=%p\n",
__func__, bf->bf_m, bf->bf_node);
if (bf->bf_m != NULL) {
bus_dmamap_unload(sc->sc_dmat, bf->bf_dmamap);
m_freem(bf->bf_m);
bf->bf_m = NULL;
}
if (bf->bf_node != NULL) {
ieee80211_free_node(bf->bf_node);
bf->bf_node = NULL;
}
/*
* NB: the beacon data buffer must be 32-bit aligned;
* we assume the mbuf routines will return us something
* with this alignment (perhaps should assert).
*/
m = ieee80211_beacon_alloc(ni, &avp->av_boff);
if (m == NULL) {
device_printf(sc->sc_dev, "%s: cannot get mbuf\n", __func__);
sc->sc_stats.ast_be_nombuf++;
return ENOMEM;
}
error = bus_dmamap_load_mbuf_sg(sc->sc_dmat, bf->bf_dmamap, m,
bf->bf_segs, &bf->bf_nseg,
BUS_DMA_NOWAIT);
if (error != 0) {
device_printf(sc->sc_dev,
"%s: cannot map mbuf, bus_dmamap_load_mbuf_sg returns %d\n",
__func__, error);
m_freem(m);
return error;
}
/*
* Calculate a TSF adjustment factor required for staggered
* beacons. Note that we assume the format of the beacon
* frame leaves the tstamp field immediately following the
* header.
*/
if (sc->sc_stagbeacons && avp->av_bslot > 0) {
uint64_t tsfadjust;
struct ieee80211_frame *wh;
/*
* The beacon interval is in TU's; the TSF is in usecs.
* We figure out how many TU's to add to align the timestamp
* then convert to TSF units and handle byte swapping before
* inserting it in the frame. The hardware will then add this
* each time a beacon frame is sent. Note that we align vap's
* 1..N and leave vap 0 untouched. This means vap 0 has a
* timestamp in one beacon interval while the others get a
* timstamp aligned to the next interval.
*/
tsfadjust = ni->ni_intval *
(ATH_BCBUF - avp->av_bslot) / ATH_BCBUF;
tsfadjust = htole64(tsfadjust << 10); /* TU -> TSF */
DPRINTF(sc, ATH_DEBUG_BEACON,
"%s: %s beacons bslot %d intval %u tsfadjust %llu\n",
__func__, sc->sc_stagbeacons ? "stagger" : "burst",
avp->av_bslot, ni->ni_intval,
(long long unsigned) le64toh(tsfadjust));
wh = mtod(m, struct ieee80211_frame *);
memcpy(&wh[1], &tsfadjust, sizeof(tsfadjust));
}
bf->bf_m = m;
bf->bf_node = ieee80211_ref_node(ni);
return 0;
}
/*
* Setup the beacon frame for transmit.
*/
static void
ath_beacon_setup(struct ath_softc *sc, struct ath_buf *bf)
{
#define USE_SHPREAMBLE(_ic) \
(((_ic)->ic_flags & (IEEE80211_F_SHPREAMBLE | IEEE80211_F_USEBARKER))\
== IEEE80211_F_SHPREAMBLE)
struct ieee80211_node *ni = bf->bf_node;
struct ieee80211com *ic = ni->ni_ic;
struct mbuf *m = bf->bf_m;
struct ath_hal *ah = sc->sc_ah;
struct ath_desc *ds;
int flags, antenna;
const HAL_RATE_TABLE *rt;
u_int8_t rix, rate;
HAL_DMA_ADDR bufAddrList[4];
uint32_t segLenList[4];
HAL_11N_RATE_SERIES rc[4];
DPRINTF(sc, ATH_DEBUG_BEACON_PROC, "%s: m %p len %u\n",
__func__, m, m->m_len);
/* setup descriptors */
ds = bf->bf_desc;
bf->bf_last = bf;
bf->bf_lastds = ds;
flags = HAL_TXDESC_NOACK;
if (ic->ic_opmode == IEEE80211_M_IBSS && sc->sc_hasveol) {
/* self-linked descriptor */
ath_hal_settxdesclink(sc->sc_ah, ds, bf->bf_daddr);
flags |= HAL_TXDESC_VEOL;
/*
* Let hardware handle antenna switching.
*/
antenna = sc->sc_txantenna;
} else {
ath_hal_settxdesclink(sc->sc_ah, ds, 0);
/*
* Switch antenna every 4 beacons.
* XXX assumes two antenna
*/
if (sc->sc_txantenna != 0)
antenna = sc->sc_txantenna;
else if (sc->sc_stagbeacons && sc->sc_nbcnvaps != 0)
antenna = ((sc->sc_stats.ast_be_xmit / sc->sc_nbcnvaps) & 4 ? 2 : 1);
else
antenna = (sc->sc_stats.ast_be_xmit & 4 ? 2 : 1);
}
KASSERT(bf->bf_nseg == 1,
("multi-segment beacon frame; nseg %u", bf->bf_nseg));
/*
* Calculate rate code.
* XXX everything at min xmit rate
*/
rix = 0;
rt = sc->sc_currates;
rate = rt->info[rix].rateCode;
if (USE_SHPREAMBLE(ic))
rate |= rt->info[rix].shortPreamble;
ath_hal_setuptxdesc(ah, ds
, m->m_len + IEEE80211_CRC_LEN /* frame length */
, sizeof(struct ieee80211_frame)/* header length */
, HAL_PKT_TYPE_BEACON /* Atheros packet type */
, ieee80211_get_node_txpower(ni) /* txpower XXX */
, rate, 1 /* series 0 rate/tries */
, HAL_TXKEYIX_INVALID /* no encryption */
, antenna /* antenna mode */
, flags /* no ack, veol for beacons */
, 0 /* rts/cts rate */
, 0 /* rts/cts duration */
);
/*
* The EDMA HAL currently assumes that _all_ rate control
* settings are done in ath_hal_set11nratescenario(), rather
* than in ath_hal_setuptxdesc().
*/
if (sc->sc_isedma) {
memset(&rc, 0, sizeof(rc));
rc[0].ChSel = sc->sc_txchainmask;
rc[0].Tries = 1;
rc[0].Rate = rt->info[rix].rateCode;
rc[0].RateIndex = rix;
rc[0].tx_power_cap = 0x3f;
rc[0].PktDuration =
ath_hal_computetxtime(ah, rt, roundup(m->m_len, 4),
rix, 0);
ath_hal_set11nratescenario(ah, ds, 0, 0, rc, 4, flags);
}
/* NB: beacon's BufLen must be a multiple of 4 bytes */
segLenList[0] = roundup(m->m_len, 4);
segLenList[1] = segLenList[2] = segLenList[3] = 0;
bufAddrList[0] = bf->bf_segs[0].ds_addr;
bufAddrList[1] = bufAddrList[2] = bufAddrList[3] = 0;
ath_hal_filltxdesc(ah, ds
, bufAddrList
, segLenList
, 0 /* XXX desc id */
, sc->sc_bhalq /* hardware TXQ */
, AH_TRUE /* first segment */
, AH_TRUE /* last segment */
, ds /* first descriptor */
);
#if 0
ath_desc_swap(ds);
#endif
#undef USE_SHPREAMBLE
}
void
ath_beacon_update(struct ieee80211vap *vap, int item)
{
struct ieee80211_beacon_offsets *bo = &ATH_VAP(vap)->av_boff;
setbit(bo->bo_flags, item);
}
/*
* Handle a beacon miss.
*/
static void
ath_beacon_miss(struct ath_softc *sc)
{
HAL_SURVEY_SAMPLE hs;
HAL_BOOL ret;
uint32_t hangs;
bzero(&hs, sizeof(hs));
ret = ath_hal_get_mib_cycle_counts(sc->sc_ah, &hs);
if (ath_hal_gethangstate(sc->sc_ah, 0xffff, &hangs) && hangs != 0) {
DPRINTF(sc, ATH_DEBUG_BEACON,
"%s: hang=0x%08x\n",
__func__,
hangs);
}
#ifdef ATH_DEBUG_ALQ
if (if_ath_alq_checkdebug(&sc->sc_alq, ATH_ALQ_MISSED_BEACON))
if_ath_alq_post(&sc->sc_alq, ATH_ALQ_MISSED_BEACON, 0, NULL);
#endif
DPRINTF(sc, ATH_DEBUG_BEACON,
"%s: valid=%d, txbusy=%u, rxbusy=%u, chanbusy=%u, "
"extchanbusy=%u, cyclecount=%u\n",
__func__,
ret,
hs.tx_busy,
hs.rx_busy,
hs.chan_busy,
hs.ext_chan_busy,
hs.cycle_count);
}
/*
* Transmit a beacon frame at SWBA. Dynamic updates to the
* frame contents are done as needed and the slot time is
* also adjusted based on current state.
*/
void
ath_beacon_proc(void *arg, int pending)
{
struct ath_softc *sc = arg;
struct ath_hal *ah = sc->sc_ah;
struct ieee80211vap *vap;
struct ath_buf *bf;
int slot, otherant;
uint32_t bfaddr;
DPRINTF(sc, ATH_DEBUG_BEACON_PROC, "%s: pending %u\n",
__func__, pending);
/*
* 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++;
sc->sc_stats.ast_be_missed++;
ath_beacon_miss(sc);
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;
#ifdef ATH_DEBUG_ALQ
if (if_ath_alq_checkdebug(&sc->sc_alq, ATH_ALQ_RESUME_BEACON))
if_ath_alq_post(&sc->sc_alq, ATH_ALQ_RESUME_BEACON, 0, NULL);
#endif
}
if (sc->sc_stagbeacons) { /* staggered beacons */
struct ieee80211com *ic = sc->sc_ifp->if_l2com;
uint32_t tsftu;
tsftu = ath_hal_gettsf32(ah) >> 10;
/* XXX lintval */
slot = ((tsftu % ic->ic_lintval) * ATH_BCBUF) / ic->ic_lintval;
vap = sc->sc_bslot[(slot+1) % ATH_BCBUF];
bfaddr = 0;
if (vap != NULL && vap->iv_state >= IEEE80211_S_RUN) {
bf = ath_beacon_generate(sc, vap);
if (bf != NULL)
bfaddr = bf->bf_daddr;
}
} else { /* burst'd beacons */
uint32_t *bflink = &bfaddr;
for (slot = 0; slot < ATH_BCBUF; slot++) {
vap = sc->sc_bslot[slot];
if (vap != NULL && vap->iv_state >= IEEE80211_S_RUN) {
bf = ath_beacon_generate(sc, vap);
/*
* XXX TODO: this should use settxdesclinkptr()
* otherwise it won't work for EDMA chipsets!
*/
if (bf != NULL) {
/* XXX should do this using the ds */
*bflink = bf->bf_daddr;
ath_hal_gettxdesclinkptr(sc->sc_ah,
bf->bf_desc, &bflink);
}
}
}
/*
* XXX TODO: this should use settxdesclinkptr()
* otherwise it won't work for EDMA chipsets!
*/
*bflink = 0; /* terminate list */
}
/*
* Handle slot time change when a non-ERP station joins/leaves
* an 11g network. The 802.11 layer notifies us via callback,
* we mark updateslot, then wait one beacon before effecting
* the change. This gives associated stations at least one
* beacon interval to note the state change.
*/
/* XXX locking */
if (sc->sc_updateslot == UPDATE) {
sc->sc_updateslot = COMMIT; /* commit next beacon */
sc->sc_slotupdate = slot;
} else if (sc->sc_updateslot == COMMIT && sc->sc_slotupdate == slot)
ath_setslottime(sc); /* commit change to h/w */
/*
* 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 && (!sc->sc_stagbeacons || slot == 0)) {
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;
}
/* Program the CABQ with the contents of the CABQ txq and start it */
ATH_TXQ_LOCK(sc->sc_cabq);
ath_beacon_cabq_start(sc);
ATH_TXQ_UNLOCK(sc->sc_cabq);
/* Program the new beacon frame if we have one for this interval */
if (bfaddr != 0) {
/*
* 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 (! sc->sc_isedma) {
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: cabq traffic should already be queued and primed */
ath_hal_puttxbuf(ah, sc->sc_bhalq, bfaddr);
ath_hal_txstart(ah, sc->sc_bhalq);
sc->sc_stats.ast_be_xmit++;
}
}
static void
ath_beacon_cabq_start_edma(struct ath_softc *sc)
{
struct ath_buf *bf, *bf_last;
struct ath_txq *cabq = sc->sc_cabq;
#if 0
struct ath_buf *bfi;
int i = 0;
#endif
ATH_TXQ_LOCK_ASSERT(cabq);
if (TAILQ_EMPTY(&cabq->axq_q))
return;
bf = TAILQ_FIRST(&cabq->axq_q);
bf_last = TAILQ_LAST(&cabq->axq_q, axq_q_s);
/*
* This is a dirty, dirty hack to push the contents of
* the cabq staging queue into the FIFO.
*
* This ideally should live in the EDMA code file
* and only push things into the CABQ if there's a FIFO
* slot.
*
* We can't treat this like a normal TX queue because
* in the case of multi-VAP traffic, we may have to flush
* the CABQ each new (staggered) beacon that goes out.
* But for non-staggered beacons, we could in theory
* handle multicast traffic for all VAPs in one FIFO
* push. Just keep all of this in mind if you're wondering
* how to correctly/better handle multi-VAP CABQ traffic
* with EDMA.
*/
/*
* Is the CABQ FIFO free? If not, complain loudly and
* don't queue anything. Maybe we'll flush the CABQ
* traffic, maybe we won't. But that'll happen next
* beacon interval.
*/
if (cabq->axq_fifo_depth >= HAL_TXFIFO_DEPTH) {
device_printf(sc->sc_dev,
"%s: Q%d: CAB FIFO queue=%d?\n",
__func__,
cabq->axq_qnum,
cabq->axq_fifo_depth);
return;
}
/*
* Ok, so here's the gymnastics reqiured to make this
* all sensible.
*/
/*
* Tag the first/last buffer appropriately.
*/
bf->bf_flags |= ATH_BUF_FIFOPTR;
bf_last->bf_flags |= ATH_BUF_FIFOEND;
#if 0
i = 0;
TAILQ_FOREACH(bfi, &cabq->axq_q, bf_list) {
ath_printtxbuf(sc, bf, cabq->axq_qnum, i, 0);
i++;
}
#endif
/*
* We now need to push this set of frames onto the tail
* of the FIFO queue. We don't adjust the aggregate
* count, only the queue depth counter(s).
* We also need to blank the link pointer now.
*/
TAILQ_CONCAT(&cabq->fifo.axq_q, &cabq->axq_q, bf_list);
cabq->axq_link = NULL;
cabq->fifo.axq_depth += cabq->axq_depth;
cabq->axq_depth = 0;
/* Bump FIFO queue */
cabq->axq_fifo_depth++;
/* Push the first entry into the hardware */
ath_hal_puttxbuf(sc->sc_ah, cabq->axq_qnum, bf->bf_daddr);
cabq->axq_flags |= ATH_TXQ_PUTRUNNING;
/* NB: gated by beacon so safe to start here */
ath_hal_txstart(sc->sc_ah, cabq->axq_qnum);
}
static void
ath_beacon_cabq_start_legacy(struct ath_softc *sc)
{
struct ath_buf *bf;
struct ath_txq *cabq = sc->sc_cabq;
ATH_TXQ_LOCK_ASSERT(cabq);
if (TAILQ_EMPTY(&cabq->axq_q))
return;
bf = TAILQ_FIRST(&cabq->axq_q);
/* Push the first entry into the hardware */
ath_hal_puttxbuf(sc->sc_ah, cabq->axq_qnum, bf->bf_daddr);
cabq->axq_flags |= ATH_TXQ_PUTRUNNING;
/* NB: gated by beacon so safe to start here */
ath_hal_txstart(sc->sc_ah, cabq->axq_qnum);
}
/*
* Start CABQ transmission - this assumes that all frames are prepped
* and ready in the CABQ.
*/
void
ath_beacon_cabq_start(struct ath_softc *sc)
{
struct ath_txq *cabq = sc->sc_cabq;
ATH_TXQ_LOCK_ASSERT(cabq);
if (TAILQ_EMPTY(&cabq->axq_q))
return;
if (sc->sc_isedma)
ath_beacon_cabq_start_edma(sc);
else
ath_beacon_cabq_start_legacy(sc);
}
struct ath_buf *
ath_beacon_generate(struct ath_softc *sc, struct ieee80211vap *vap)
{
struct ath_vap *avp = ATH_VAP(vap);
struct ath_txq *cabq = sc->sc_cabq;
struct ath_buf *bf;
struct mbuf *m;
int nmcastq, error;
KASSERT(vap->iv_state >= IEEE80211_S_RUN,
("not running, state %d", vap->iv_state));
KASSERT(avp->av_bcbuf != NULL, ("no beacon buffer"));
/*
* Update dynamic beacon contents. If this returns
* non-zero then we need to remap the memory because
* the beacon frame changed size (probably because
* of the TIM bitmap).
*/
bf = avp->av_bcbuf;
m = bf->bf_m;
/* XXX lock mcastq? */
nmcastq = avp->av_mcastq.axq_depth;
if (ieee80211_beacon_update(bf->bf_node, &avp->av_boff, m, nmcastq)) {
/* XXX too conservative? */
bus_dmamap_unload(sc->sc_dmat, bf->bf_dmamap);
error = bus_dmamap_load_mbuf_sg(sc->sc_dmat, bf->bf_dmamap, m,
bf->bf_segs, &bf->bf_nseg,
BUS_DMA_NOWAIT);
if (error != 0) {
if_printf(vap->iv_ifp,
"%s: bus_dmamap_load_mbuf_sg failed, error %u\n",
__func__, error);
return NULL;
}
}
if ((avp->av_boff.bo_tim[4] & 1) && cabq->axq_depth) {
DPRINTF(sc, ATH_DEBUG_BEACON,
"%s: cabq did not drain, mcastq %u cabq %u\n",
__func__, nmcastq, cabq->axq_depth);
sc->sc_stats.ast_cabq_busy++;
if (sc->sc_nvaps > 1 && sc->sc_stagbeacons) {
/*
* CABQ traffic from a previous vap is still pending.
* We must drain the q before this beacon frame goes
* out as otherwise this vap's stations will get cab
* frames from a different vap.
* XXX could be slow causing us to miss DBA
*/
/*
* XXX TODO: this doesn't stop CABQ DMA - it assumes
* that since we're about to transmit a beacon, we've
* already stopped transmitting on the CABQ. But this
* doesn't at all mean that the CABQ DMA QCU will
* accept a new TXDP! So what, should we do a DMA
* stop? What if it fails?
*
* More thought is required here.
*/
ath_tx_draintxq(sc, cabq);
}
}
ath_beacon_setup(sc, bf);
bus_dmamap_sync(sc->sc_dmat, bf->bf_dmamap, BUS_DMASYNC_PREWRITE);
/*
* Enable the CAB queue before the beacon queue to
* insure cab frames are triggered by this beacon.
*/
if (avp->av_boff.bo_tim[4] & 1) {
/* NB: only at DTIM */
ATH_TXQ_LOCK(&avp->av_mcastq);
if (nmcastq) {
struct ath_buf *bfm, *bfc_last;
/*
* Move frames from the s/w mcast q to the h/w cab q.
*
* XXX TODO: if we chain together multiple VAPs
* worth of CABQ traffic, should we keep the
* MORE data bit set on the last frame of each
* intermediary VAP (ie, only clear the MORE
* bit of the last frame on the last vap?)
*/
bfm = TAILQ_FIRST(&avp->av_mcastq.axq_q);
ATH_TXQ_LOCK(cabq);
/*
* If there's already a frame on the CABQ, we
* need to link to the end of the last frame.
* We can't use axq_link here because
* EDMA descriptors require some recalculation
* (checksum) to occur.
*/
bfc_last = ATH_TXQ_LAST(cabq, axq_q_s);
if (bfc_last != NULL) {
ath_hal_settxdesclink(sc->sc_ah,
bfc_last->bf_lastds,
bfm->bf_daddr);
}
ath_txqmove(cabq, &avp->av_mcastq);
ATH_TXQ_UNLOCK(cabq);
/*
* XXX not entirely accurate, in case a mcast
* queue frame arrived before we grabbed the TX
* lock.
*/
sc->sc_stats.ast_cabq_xmit += nmcastq;
}
ATH_TXQ_UNLOCK(&avp->av_mcastq);
}
return bf;
}
void
ath_beacon_start_adhoc(struct ath_softc *sc, struct ieee80211vap *vap)
{
struct ath_vap *avp = ATH_VAP(vap);
struct ath_hal *ah = sc->sc_ah;
struct ath_buf *bf;
struct mbuf *m;
int error;
KASSERT(avp->av_bcbuf != NULL, ("no beacon buffer"));
/*
* Update dynamic beacon contents. If this returns
* non-zero then we need to remap the memory because
* the beacon frame changed size (probably because
* of the TIM bitmap).
*/
bf = avp->av_bcbuf;
m = bf->bf_m;
if (ieee80211_beacon_update(bf->bf_node, &avp->av_boff, m, 0)) {
/* XXX too conservative? */
bus_dmamap_unload(sc->sc_dmat, bf->bf_dmamap);
error = bus_dmamap_load_mbuf_sg(sc->sc_dmat, bf->bf_dmamap, m,
bf->bf_segs, &bf->bf_nseg,
BUS_DMA_NOWAIT);
if (error != 0) {
if_printf(vap->iv_ifp,
"%s: bus_dmamap_load_mbuf_sg failed, error %u\n",
__func__, error);
return;
}
}
ath_beacon_setup(sc, bf);
bus_dmamap_sync(sc->sc_dmat, bf->bf_dmamap, BUS_DMASYNC_PREWRITE);
/* NB: caller is known to have already stopped tx dma */
ath_hal_puttxbuf(ah, sc->sc_bhalq, bf->bf_daddr);
ath_hal_txstart(ah, sc->sc_bhalq);
}
/*
* Reclaim beacon resources and return buffer to the pool.
*/
void
ath_beacon_return(struct ath_softc *sc, struct ath_buf *bf)
{
DPRINTF(sc, ATH_DEBUG_NODE, "%s: free bf=%p, bf_m=%p, bf_node=%p\n",
__func__, bf, bf->bf_m, bf->bf_node);
if (bf->bf_m != NULL) {
bus_dmamap_unload(sc->sc_dmat, bf->bf_dmamap);
m_freem(bf->bf_m);
bf->bf_m = NULL;
}
if (bf->bf_node != NULL) {
ieee80211_free_node(bf->bf_node);
bf->bf_node = NULL;
}
TAILQ_INSERT_TAIL(&sc->sc_bbuf, bf, bf_list);
}
/*
* Reclaim beacon resources.
*/
void
ath_beacon_free(struct ath_softc *sc)
{
struct ath_buf *bf;
TAILQ_FOREACH(bf, &sc->sc_bbuf, bf_list) {
DPRINTF(sc, ATH_DEBUG_NODE,
"%s: free bf=%p, bf_m=%p, bf_node=%p\n",
__func__, bf, bf->bf_m, bf->bf_node);
if (bf->bf_m != NULL) {
bus_dmamap_unload(sc->sc_dmat, bf->bf_dmamap);
m_freem(bf->bf_m);
bf->bf_m = NULL;
}
if (bf->bf_node != NULL) {
ieee80211_free_node(bf->bf_node);
bf->bf_node = NULL;
}
}
}
/*
* Configure the beacon and sleep timers.
*
* When operating as an AP this resets the TSF and sets
* up the hardware to notify us when we need to issue beacons.
*
* When operating in station mode this sets up the beacon
* timers according to the timestamp of the last received
* beacon and the current TSF, configures PCF and DTIM
* handling, programs the sleep registers so the hardware
* will wakeup in time to receive beacons, and configures
* the beacon miss handling so we'll receive a BMISS
* interrupt when we stop seeing beacons from the AP
* we've associated with.
*/
void
ath_beacon_config(struct ath_softc *sc, struct ieee80211vap *vap)
{
#define TSF_TO_TU(_h,_l) \
((((u_int32_t)(_h)) << 22) | (((u_int32_t)(_l)) >> 10))
#define FUDGE 2
struct ath_hal *ah = sc->sc_ah;
struct ieee80211com *ic = sc->sc_ifp->if_l2com;
struct ieee80211_node *ni;
u_int32_t nexttbtt, intval, tsftu;
u_int32_t nexttbtt_u8, intval_u8;
u_int64_t tsf;
if (vap == NULL)
vap = TAILQ_FIRST(&ic->ic_vaps); /* XXX */
/*
* Just ensure that we aren't being called when the last
* VAP is destroyed.
*/
if (vap == NULL) {
device_printf(sc->sc_dev, "%s: called with no VAPs\n",
__func__);
return;
}
ni = ieee80211_ref_node(vap->iv_bss);
/* extract tstamp from last beacon and convert to TU */
nexttbtt = TSF_TO_TU(LE_READ_4(ni->ni_tstamp.data + 4),
LE_READ_4(ni->ni_tstamp.data));
if (ic->ic_opmode == IEEE80211_M_HOSTAP ||
ic->ic_opmode == IEEE80211_M_MBSS) {
/*
* For multi-bss ap/mesh support beacons are either staggered
* evenly over N slots or burst together. For the former
* arrange for the SWBA to be delivered for each slot.
* Slots that are not occupied will generate nothing.
*/
/* NB: the beacon interval is kept internally in TU's */
intval = ni->ni_intval & HAL_BEACON_PERIOD;
if (sc->sc_stagbeacons)
intval /= ATH_BCBUF;
} else {
/* NB: the beacon interval is kept internally in TU's */
intval = ni->ni_intval & HAL_BEACON_PERIOD;
}
if (nexttbtt == 0) /* e.g. for ap mode */
nexttbtt = intval;
else if (intval) /* NB: can be 0 for monitor mode */
nexttbtt = roundup(nexttbtt, intval);
DPRINTF(sc, ATH_DEBUG_BEACON, "%s: nexttbtt %u intval %u (%u)\n",
__func__, nexttbtt, intval, ni->ni_intval);
if (ic->ic_opmode == IEEE80211_M_STA && !sc->sc_swbmiss) {
HAL_BEACON_STATE bs;
int dtimperiod, dtimcount;
int cfpperiod, cfpcount;
/*
* Setup dtim and cfp parameters according to
* last beacon we received (which may be none).
*/
dtimperiod = ni->ni_dtim_period;
if (dtimperiod <= 0) /* NB: 0 if not known */
dtimperiod = 1;
dtimcount = ni->ni_dtim_count;
if (dtimcount >= dtimperiod) /* NB: sanity check */
dtimcount = 0; /* XXX? */
cfpperiod = 1; /* NB: no PCF support yet */
cfpcount = 0;
/*
* Pull nexttbtt forward to reflect the current
* TSF and calculate dtim+cfp state for the result.
*/
tsf = ath_hal_gettsf64(ah);
tsftu = TSF_TO_TU(tsf>>32, tsf) + FUDGE;
do {
nexttbtt += intval;
if (--dtimcount < 0) {
dtimcount = dtimperiod - 1;
if (--cfpcount < 0)
cfpcount = cfpperiod - 1;
}
} while (nexttbtt < tsftu);
memset(&bs, 0, sizeof(bs));
bs.bs_intval = intval;
bs.bs_nexttbtt = nexttbtt;
bs.bs_dtimperiod = dtimperiod*intval;
bs.bs_nextdtim = bs.bs_nexttbtt + dtimcount*intval;
bs.bs_cfpperiod = cfpperiod*bs.bs_dtimperiod;
bs.bs_cfpnext = bs.bs_nextdtim + cfpcount*bs.bs_dtimperiod;
bs.bs_cfpmaxduration = 0;
#if 0
/*
* The 802.11 layer records the offset to the DTIM
* bitmap while receiving beacons; use it here to
* enable h/w detection of our AID being marked in
* the bitmap vector (to indicate frames for us are
* pending at the AP).
* XXX do DTIM handling in s/w to WAR old h/w bugs
* XXX enable based on h/w rev for newer chips
*/
bs.bs_timoffset = ni->ni_timoff;
#endif
/*
* Calculate the number of consecutive beacons to miss
* before taking a BMISS interrupt.
* Note that we clamp the result to at most 10 beacons.
*/
bs.bs_bmissthreshold = vap->iv_bmissthreshold;
if (bs.bs_bmissthreshold > 10)
bs.bs_bmissthreshold = 10;
else if (bs.bs_bmissthreshold <= 0)
bs.bs_bmissthreshold = 1;
/*
* Calculate sleep duration. The configuration is
* given in ms. We insure a multiple of the beacon
* period is used. Also, if the sleep duration is
* greater than the DTIM period then it makes senses
* to make it a multiple of that.
*
* XXX fixed at 100ms
*/
bs.bs_sleepduration =
roundup(IEEE80211_MS_TO_TU(100), bs.bs_intval);
if (bs.bs_sleepduration > bs.bs_dtimperiod)
bs.bs_sleepduration = roundup(bs.bs_sleepduration, bs.bs_dtimperiod);
DPRINTF(sc, ATH_DEBUG_BEACON,
"%s: tsf %ju tsf:tu %u intval %u nexttbtt %u dtim %u nextdtim %u bmiss %u sleep %u cfp:period %u maxdur %u next %u timoffset %u\n"
, __func__
, tsf, tsftu
, bs.bs_intval
, bs.bs_nexttbtt
, bs.bs_dtimperiod
, bs.bs_nextdtim
, bs.bs_bmissthreshold
, bs.bs_sleepduration
, bs.bs_cfpperiod
, bs.bs_cfpmaxduration
, bs.bs_cfpnext
, bs.bs_timoffset
);
ath_hal_intrset(ah, 0);
ath_hal_beacontimers(ah, &bs);
sc->sc_imask |= HAL_INT_BMISS;
ath_hal_intrset(ah, sc->sc_imask);
} else {
ath_hal_intrset(ah, 0);
if (nexttbtt == intval)
intval |= HAL_BEACON_RESET_TSF;
if (ic->ic_opmode == IEEE80211_M_IBSS) {
/*
* In IBSS mode enable the beacon timers but only
* enable SWBA interrupts if we need to manually
* prepare beacon frames. Otherwise we use a
* self-linked tx descriptor and let the hardware
* deal with things.
*/
intval |= HAL_BEACON_ENA;
if (!sc->sc_hasveol)
sc->sc_imask |= HAL_INT_SWBA;
if ((intval & HAL_BEACON_RESET_TSF) == 0) {
/*
* Pull nexttbtt forward to reflect
* the current TSF.
*/
tsf = ath_hal_gettsf64(ah);
tsftu = TSF_TO_TU(tsf>>32, tsf) + FUDGE;
do {
nexttbtt += intval;
} while (nexttbtt < tsftu);
}
ath_beaconq_config(sc);
} else if (ic->ic_opmode == IEEE80211_M_HOSTAP ||
ic->ic_opmode == IEEE80211_M_MBSS) {
/*
* In AP/mesh mode we enable the beacon timers
* and SWBA interrupts to prepare beacon frames.
*/
intval |= HAL_BEACON_ENA;
sc->sc_imask |= HAL_INT_SWBA; /* beacon prepare */
ath_beaconq_config(sc);
}
/*
* Now dirty things because for now, the EDMA HAL has
* nexttbtt and intval is TU/8.
*/
if (sc->sc_isedma) {
nexttbtt_u8 = (nexttbtt << 3);
intval_u8 = (intval << 3);
if (intval & HAL_BEACON_ENA)
intval_u8 |= HAL_BEACON_ENA;
if (intval & HAL_BEACON_RESET_TSF)
intval_u8 |= HAL_BEACON_RESET_TSF;
ath_hal_beaconinit(ah, nexttbtt_u8, intval_u8);
} else
ath_hal_beaconinit(ah, nexttbtt, intval);
sc->sc_bmisscount = 0;
ath_hal_intrset(ah, sc->sc_imask);
/*
* When using a self-linked beacon descriptor in
* ibss mode load it once here.
*/
if (ic->ic_opmode == IEEE80211_M_IBSS && sc->sc_hasveol)
ath_beacon_start_adhoc(sc, vap);
}
sc->sc_syncbeacon = 0;
ieee80211_free_node(ni);
#undef FUDGE
#undef TSF_TO_TU
}
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