/* * 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; }