/*
* Form an aggregate packet list.
*
* This function enforces the aggregate restrictions/requirements.
*
* These are:
*
* + The aggregate size maximum (64k for AR9160 and later, 8K for
* AR5416 when doing RTS frame protection.)
* + Maximum number of sub-frames for an aggregate
* + The aggregate delimiter size, giving MACs time to do whatever is
* needed before each frame
* + Enforce the BAW limit
*
* Each descriptor queued should have the DMA setup.
* The rate series, descriptor setup, linking, etc is all done
* externally. This routine simply chains them together.
* ath_tx_setds_11n() will take care of configuring the per-
* descriptor setup, and ath_buf_set_rate() will configure the
* rate control.
*
* Note that the TID lock is only grabbed when dequeuing packets from
* the TID queue. If some code in another thread adds to the head of this
* list, very strange behaviour will occur. Since retransmission is the
* only reason this will occur, and this routine is designed to be called
* from within the scheduler task, it won't ever clash with the completion
* task.
*
* So if you want to call this from an upper layer context (eg, to direct-
* dispatch aggregate frames to the hardware), please keep this in mind.
*/
ATH_AGGR_STATUS
ath_tx_form_aggr(struct ath_softc *sc, struct ath_node *an, struct ath_tid *tid,
ath_bufhead *bf_q)
{
struct ieee80211_node *ni = &an->an_node;
struct ath_buf *bf, *bf_first = NULL, *bf_prev = NULL;
int nframes = 0;
uint16_t aggr_limit = 0, al = 0, bpad = 0, al_delta, h_baw;
struct ieee80211_tx_ampdu *tap;
int status = ATH_AGGR_DONE;
int prev_frames = 0; /* XXX for AR5416 burst, not done here */
int prev_al = 0; /* XXX also for AR5416 burst */
ATH_TXQ_LOCK_ASSERT(sc->sc_ac2q[tid->ac]);
tap = ath_tx_get_tx_tid(an, tid->tid);
if (tap == NULL) {
status = ATH_AGGR_ERROR;
goto finish;
}
h_baw = tap->txa_wnd / 2;
for (;;) {
bf = TAILQ_FIRST(&tid->axq_q);
if (bf_first == NULL)
bf_first = bf;
if (bf == NULL) {
status = ATH_AGGR_DONE;
break;
} else {
/*
* It's the first frame;
* set the aggregation limit based on the
* rate control decision that has been made.
*/
aggr_limit = ath_get_aggr_limit(sc, bf_first);
}
/* Set this early just so things don't get confused */
bf->bf_next = NULL;
/*
* Don't unlock the tid lock until we're sure we are going
* to queue this frame.
*/
/*
* If the frame doesn't have a sequence number that we're
* tracking in the BAW (eg NULL QOS data frame), we can't
* aggregate it. Stop the aggregation process; the sender
* can then TX what's in the list thus far and then
* TX the frame individually.
*/
if (! bf->bf_state.bfs_dobaw) {
status = ATH_AGGR_NONAGGR;
break;
}
/*
* If any of the rates are non-HT, this packet
* can't be aggregated.
* XXX TODO: add a bf_state flag which gets marked
* if any active rate is non-HT.
*/
/*
* do not exceed aggregation limit
*/
al_delta = ATH_AGGR_DELIM_SZ + bf->bf_state.bfs_pktlen;
if (nframes &&
(aggr_limit < (al + bpad + al_delta + prev_al))) {
status = ATH_AGGR_LIMITED;
break;
}
/*
* If RTS/CTS is set on the first frame, enforce
* the RTS aggregate limit.
*/
if (bf_first->bf_state.bfs_txflags &
(HAL_TXDESC_CTSENA | HAL_TXDESC_RTSENA)) {
if (nframes &&
(sc->sc_rts_aggr_limit <
(al + bpad + al_delta + prev_al))) {
status = ATH_AGGR_8K_LIMITED;
break;
}
}
/*
* Do not exceed subframe limit.
*/
if ((nframes + prev_frames) >= MIN((h_baw),
IEEE80211_AMPDU_SUBFRAME_DEFAULT)) {
status = ATH_AGGR_LIMITED;
break;
}
/*
* If the current frame has an RTS/CTS configuration
* that differs from the first frame, override the
* subsequent frame with this config.
*/
bf->bf_state.bfs_txflags &=
(HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA);
bf->bf_state.bfs_txflags |=
bf_first->bf_state.bfs_txflags &
(HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA);
/*
* TODO: If it's _before_ the BAW left edge, complain very
* loudly.
*
* This means something (else) has slid the left edge along
* before we got a chance to be TXed.
*/
/*
* Check if we have space in the BAW for this frame before
* we add it.
*
* see ath_tx_xmit_aggr() for more info.
*/
if (bf->bf_state.bfs_dobaw) {
ieee80211_seq seqno;
/*
* If the sequence number is allocated, use it.
* Otherwise, use the sequence number we WOULD
* allocate.
*/
if (bf->bf_state.bfs_seqno_assigned)
seqno = SEQNO(bf->bf_state.bfs_seqno);
else
seqno = ni->ni_txseqs[bf->bf_state.bfs_tid];
/*
* Check whether either the currently allocated
* sequence number _OR_ the to-be allocated
* sequence number is inside the BAW.
*/
if (! BAW_WITHIN(tap->txa_start, tap->txa_wnd,
seqno)) {
status = ATH_AGGR_BAW_CLOSED;
break;
}
/* XXX check for bfs_need_seqno? */
if (! bf->bf_state.bfs_seqno_assigned) {
int seqno;
seqno = ath_tx_tid_seqno_assign(sc, ni, bf, bf->bf_m);
if (seqno < 0) {
device_printf(sc->sc_dev,
"%s: bf=%p, huh, seqno=-1?\n",
__func__,
bf);
/* XXX what can we even do here? */
}
/* Flush seqno update to RAM */
/*
* XXX This is required because the dmasetup
* XXX is done early rather than at dispatch
* XXX time. Ew, we should fix this!
*/
bus_dmamap_sync(sc->sc_dmat, bf->bf_dmamap,
BUS_DMASYNC_PREWRITE);
}
}
/*
* If the packet has a sequence number, do not
* step outside of the block-ack window.
*/
if (! BAW_WITHIN(tap->txa_start, tap->txa_wnd,
SEQNO(bf->bf_state.bfs_seqno))) {
device_printf(sc->sc_dev,
"%s: bf=%p, seqno=%d, outside?!\n",
__func__, bf, SEQNO(bf->bf_state.bfs_seqno));
status = ATH_AGGR_BAW_CLOSED;
break;
}
/*
* this packet is part of an aggregate.
*/
ATH_TXQ_REMOVE(tid, bf, bf_list);
/* The TID lock is required for the BAW update */
ath_tx_addto_baw(sc, an, tid, bf);
bf->bf_state.bfs_addedbaw = 1;
/*
* XXX enforce ACK for aggregate frames (this needs to be
* XXX handled more gracefully?
*/
if (bf->bf_state.bfs_txflags & HAL_TXDESC_NOACK) {
device_printf(sc->sc_dev,
"%s: HAL_TXDESC_NOACK set for an aggregate frame?\n",
__func__);
bf->bf_state.bfs_txflags &= (~HAL_TXDESC_NOACK);
}
/*
* Add the now owned buffer (which isn't
* on the software TXQ any longer) to our
* aggregate frame list.
*/
TAILQ_INSERT_TAIL(bf_q, bf, bf_list);
nframes ++;
/* Completion handler */
bf->bf_comp = ath_tx_aggr_comp;
/*
* add padding for previous frame to aggregation length
*/
al += bpad + al_delta;
/*
* Calculate delimiters needed for the current frame
*/
bf->bf_state.bfs_ndelim =
ath_compute_num_delims(sc, bf_first,
bf->bf_state.bfs_pktlen);
/*
* Calculate the padding needed from this set of delimiters,
* used when calculating if the next frame will fit in
* the aggregate.
*/
bpad = PADBYTES(al_delta) + (bf->bf_state.bfs_ndelim << 2);
/*
* Chain the buffers together
*/
if (bf_prev)
bf_prev->bf_next = bf;
bf_prev = bf;
/*
* XXX TODO: if any sub-frames have RTS/CTS enabled;
* enable it for the entire aggregate.
*/
#if 0
/*
* terminate aggregation on a small packet boundary
*/
if (bf->bf_state.bfs_pktlen < ATH_AGGR_MINPLEN) {
status = ATH_AGGR_SHORTPKT;
break;
}
#endif
}
finish:
/*
* Just in case the list was empty when we tried to
* dequeue a packet ..
*/
if (bf_first) {
bf_first->bf_state.bfs_al = al;
bf_first->bf_state.bfs_nframes = nframes;
}
return status;
}
/*
* Form an aggregate packet list.
*
* This function enforces the aggregate restrictions/requirements.
*
* These are:
*
* + The aggregate size maximum (64k for AR9160 and later, 8K for
* AR5416 when doing RTS frame protection.)
* + Maximum number of sub-frames for an aggregate
* + The aggregate delimiter size, giving MACs time to do whatever is
* needed before each frame
* + Enforce the BAW limit
*
* Each descriptor queued should have the DMA setup.
* The rate series, descriptor setup, linking, etc is all done
* externally. This routine simply chains them together.
* ath_tx_setds_11n() will take care of configuring the per-
* descriptor setup, and ath_buf_set_rate() will configure the
* rate control.
*
* The TID lock is required for the entirety of this function.
*
* If some code in another thread adds to the head of this
* list, very strange behaviour will occur. Since retransmission is the
* only reason this will occur, and this routine is designed to be called
* from within the scheduler task, it won't ever clash with the completion
* task.
*
* So if you want to call this from an upper layer context (eg, to direct-
* dispatch aggregate frames to the hardware), please keep this in mind.
*/
ATH_AGGR_STATUS
ath_tx_form_aggr(struct ath_softc *sc, struct ath_node *an,
struct ath_tid *tid, ath_bufhead *bf_q)
{
//struct ieee80211_node *ni = &an->an_node;
struct ath_buf *bf, *bf_first = NULL, *bf_prev = NULL;
int nframes = 0;
uint16_t aggr_limit = 0, al = 0, bpad = 0, al_delta, h_baw;
struct ieee80211_tx_ampdu *tap;
int status = ATH_AGGR_DONE;
int prev_frames = 0; /* XXX for AR5416 burst, not done here */
int prev_al = 0; /* XXX also for AR5416 burst */
ATH_TX_LOCK_ASSERT(sc);
tap = ath_tx_get_tx_tid(an, tid->tid);
if (tap == NULL) {
status = ATH_AGGR_ERROR;
goto finish;
}
h_baw = tap->txa_wnd / 2;
for (;;) {
bf = ATH_TID_FIRST(tid);
if (bf_first == NULL)
bf_first = bf;
if (bf == NULL) {
status = ATH_AGGR_DONE;
break;
} else {
/*
* It's the first frame;
* set the aggregation limit based on the
* rate control decision that has been made.
*/
aggr_limit = ath_get_aggr_limit(sc, bf_first);
}
/* Set this early just so things don't get confused */
bf->bf_next = NULL;
/*
* If the frame doesn't have a sequence number that we're
* tracking in the BAW (eg NULL QOS data frame), we can't
* aggregate it. Stop the aggregation process; the sender
* can then TX what's in the list thus far and then
* TX the frame individually.
*/
if (! bf->bf_state.bfs_dobaw) {
status = ATH_AGGR_NONAGGR;
break;
}
/*
* If any of the rates are non-HT, this packet
* can't be aggregated.
* XXX TODO: add a bf_state flag which gets marked
* if any active rate is non-HT.
*/
/*
* do not exceed aggregation limit
*/
al_delta = ATH_AGGR_DELIM_SZ + bf->bf_state.bfs_pktlen;
if (nframes &&
(aggr_limit < (al + bpad + al_delta + prev_al))) {
status = ATH_AGGR_LIMITED;
break;
}
/*
* If RTS/CTS is set on the first frame, enforce
* the RTS aggregate limit.
*/
if (bf_first->bf_state.bfs_txflags &
(HAL_TXDESC_CTSENA | HAL_TXDESC_RTSENA)) {
if (nframes &&
(sc->sc_rts_aggr_limit <
(al + bpad + al_delta + prev_al))) {
status = ATH_AGGR_8K_LIMITED;
break;
}
}
/*
* Do not exceed subframe limit.
*/
if ((nframes + prev_frames) >= MIN((h_baw),
IEEE80211_AMPDU_SUBFRAME_DEFAULT)) {
status = ATH_AGGR_LIMITED;
break;
}
/*
* If the current frame has an RTS/CTS configuration
* that differs from the first frame, override the
* subsequent frame with this config.
*/
if (bf != bf_first) {
bf->bf_state.bfs_txflags &=
~ (HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA);
bf->bf_state.bfs_txflags |=
bf_first->bf_state.bfs_txflags &
(HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA);
}
/*
* If the packet has a sequence number, do not
* step outside of the block-ack window.
*/
if (! BAW_WITHIN(tap->txa_start, tap->txa_wnd,
SEQNO(bf->bf_state.bfs_seqno))) {
status = ATH_AGGR_BAW_CLOSED;
break;
}
/*
* this packet is part of an aggregate.
*/
ATH_TID_REMOVE(tid, bf, bf_list);
/* The TID lock is required for the BAW update */
ath_tx_addto_baw(sc, an, tid, bf);
bf->bf_state.bfs_addedbaw = 1;
/*
* XXX enforce ACK for aggregate frames (this needs to be
* XXX handled more gracefully?
*/
if (bf->bf_state.bfs_txflags & HAL_TXDESC_NOACK) {
device_printf(sc->sc_dev,
"%s: HAL_TXDESC_NOACK set for an aggregate frame?\n",
__func__);
bf->bf_state.bfs_txflags &= (~HAL_TXDESC_NOACK);
}
/*
* Add the now owned buffer (which isn't
* on the software TXQ any longer) to our
* aggregate frame list.
*/
TAILQ_INSERT_TAIL(bf_q, bf, bf_list);
nframes ++;
/* Completion handler */
bf->bf_comp = ath_tx_aggr_comp;
/*
* add padding for previous frame to aggregation length
*/
al += bpad + al_delta;
/*
* Calculate delimiters needed for the current frame
*/
bf->bf_state.bfs_ndelim =
ath_compute_num_delims(sc, bf_first,
bf->bf_state.bfs_pktlen);
/*
* Calculate the padding needed from this set of delimiters,
* used when calculating if the next frame will fit in
* the aggregate.
*/
bpad = PADBYTES(al_delta) + (bf->bf_state.bfs_ndelim << 2);
/*
* Chain the buffers together
*/
if (bf_prev)
bf_prev->bf_next = bf;
bf_prev = bf;
/*
* If we're leaking frames, just return at this point;
* we've queued a single frame and we don't want to add
* any more.
*/
if (tid->an->an_leak_count) {
status = ATH_AGGR_LEAK_CLOSED;
break;
}
#if 0
/*
* terminate aggregation on a small packet boundary
*/
if (bf->bf_state.bfs_pktlen < ATH_AGGR_MINPLEN) {
status = ATH_AGGR_SHORTPKT;
break;
}
#endif
}
finish:
/*
* Just in case the list was empty when we tried to
* dequeue a packet ..
*/
if (bf_first) {
bf_first->bf_state.bfs_al = al;
bf_first->bf_state.bfs_nframes = nframes;
}
return status;
}