diff options
Diffstat (limited to 'src/gprs_rlcmac_sched.cpp')
| -rw-r--r-- | src/gprs_rlcmac_sched.cpp | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/src/gprs_rlcmac_sched.cpp b/src/gprs_rlcmac_sched.cpp new file mode 100644 index 00000000..4a4b85ca --- /dev/null +++ b/src/gprs_rlcmac_sched.cpp @@ -0,0 +1,184 @@ +/* PDCH scheduler + * + * Copyright (C) 2012 Andreas Eversberg <jolly@eversberg.eu> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#include <gprs_bssgp_pcu.h> +#include <gprs_rlcmac.h> +#include <pcu_l1_if.h> + +extern struct llist_head block_queue; + +static uint8_t rlcmac_dl_idle[23] = { + 0x47, /* control without optional header octets, no polling, USF=111 */ + 0x94, /* dummy downlink control message, paging mode 00 */ + 0x2b, /* no persistance level, 7 bits spare pattern */ + 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, + 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b +}; + +int gprs_rlcmac_rcv_rts_block(uint8_t trx, uint8_t ts, uint16_t arfcn, + uint32_t fn, uint8_t block_nr) +{ + struct gprs_rlcmac_bts *bts = gprs_rlcmac_bts; + struct gprs_rlcmac_pdch *pdch; + struct gprs_rlcmac_tbf *tbf; + uint8_t usf = 0x7; + struct msgb *msg = NULL; + uint32_t poll_fn; + uint8_t i, tfi; + + if (trx >= 8 || ts >= 8) + return -EINVAL; + pdch = &bts->trx[trx].pdch[ts]; + + if (!pdch->enable) { + LOGP(DRLCMACSCHED, LOGL_ERROR, "Received RTS on disabled PDCH: " + "TRX=%d TS=%d\n", trx, ts); + return -EIO; + } + + /* store last frame number of RTS */ + pdch->last_rts_fn = fn; + + /* check uplink ressource for polling */ + poll_fn = fn + 4; + if ((block_nr % 3) == 2) + poll_fn ++; + poll_fn = poll_fn % 2715648; + for (tfi = 0; tfi < 32; tfi++) { + tbf = pdch->tbf[tfi]; + /* no TBF for this tfi, go next */ + if (!tbf) + continue; + /* no polling */ + if (tbf->poll_state != GPRS_RLCMAC_POLL_SCHED) + continue; + /* polling for next uplink block */ + if (tbf->poll_fn == poll_fn) + break; + } + /* found uplink where a block is polled */ + if (tfi < 32) { + LOGP(DRLCMACSCHED, LOGL_DEBUG, "Received RTS for PDCH: TRX=%d " + "TS=%d FN=%d block_nr=%d scheduling free USF for " + "polling at FN=%d of TFI=%d\n", trx, ts, fn, block_nr, + poll_fn, tfi); + /* use free USF */ + /* else, we search for uplink ressource */ + } else { + /* select uplink ressource */ + for (i = 0, tfi = pdch->next_ul_tfi; i < 32; + i++, tfi = (tfi + 1) & 31) { + tbf = pdch->tbf[tfi]; + /* no TBF for this tfi, go next */ + if (!tbf) + continue; + /* no UL TBF, go next */ + if (tbf->direction != GPRS_RLCMAC_UL_TBF) + continue; + /* no UL ressources needed, go next */ + /* we don't need to give ressources in FINISHED state, + * because we have received all blocks and only poll + * for packet control ack. */ + if (tbf->state != GPRS_RLCMAC_FLOW) + continue; + + /* use this USF */ + usf = tbf->dir.ul.usf; + LOGP(DRLCMACSCHED, LOGL_DEBUG, "Received RTS for PDCH: " + "TRX=%d TS=%d FN=%d block_nr=%d scheduling " + "USF=%d for required uplink ressource of " + "TBF=%d\n", trx, ts, fn, block_nr, usf, tfi); + /* next TBF to handle ressource is the next one */ + pdch->next_ul_tfi = (tfi + 1) & 31; + break; + } + } + + /* Prio 1: select control message */ + for (tfi = 0; tfi < 32; tfi++) { + tbf = pdch->tbf[tfi]; + /* no TBF for this tfi, go next */ + if (!tbf) + continue; + /* schedule PACKET DOWNLINK ASSIGNMENT */ + if (tbf->dl_ass_state == GPRS_RLCMAC_DL_ASS_SEND_ASS) + msg = gprs_rlcmac_send_packet_downlink_assignment(tbf, + fn); + else + /* schedule PACKET UPLINK ASSIGNMENT */ + if (tbf->ul_ass_state == GPRS_RLCMAC_UL_ASS_SEND_ASS) + msg = gprs_rlcmac_send_packet_uplink_assignment(tbf, + fn); + else + /* schedule PACKET UPLINK ACK */ + if (tbf->ul_ack_state == GPRS_RLCMAC_UL_ACK_SEND_ACK) + msg = gprs_rlcmac_send_uplink_ack(tbf, fn); + if (msg) { + LOGP(DRLCMACSCHED, LOGL_DEBUG, "Scheduling control " + "message at RTS for TBF=%d\n", tfi); + break; + } + } + + /* Prio 2: select data message for downlink */ + if (!msg) { + /* select downlink ressource */ + for (i = 0, tfi = pdch->next_dl_tfi; i < 32; + i++, tfi = (tfi + 1) & 31) { + tbf = pdch->tbf[tfi]; + /* no TBF for this tfi, go next */ + if (!tbf) + continue; + /* no DL TBF, go next */ + if (tbf->direction != GPRS_RLCMAC_DL_TBF) + continue; + /* no DL ressources needed, go next */ + if (tbf->state != GPRS_RLCMAC_FLOW + && tbf->state != GPRS_RLCMAC_FINISHED) + continue; + + LOGP(DRLCMACSCHED, LOGL_DEBUG, "Scheduling data " + "message at RTS for TBF=%d\n", tfi); + /* next TBF to handle ressource is the next one */ + pdch->next_dl_tfi = (tfi + 1) & 31; + /* generate DL data block */ + msg = gprs_rlcmac_send_data_block_acknowledged(tbf, fn); + break; + } + } + + /* Prio 3: send dummy contol message */ + if (!msg) { + msg = msgb_alloc(23, "rlcmac_dl_idle"); + if (!msg) + return -ENOMEM; + memcpy(msgb_put(msg, 23), rlcmac_dl_idle, 23); + } + /* msg is now available */ + + /* set USF */ + msg->data[0] = (msg->data[0] & 0xf8) | usf; + +// printf("len=%d, date=%s\n", msg->len, osmo_hexdump(msg->data, msg->len)); + + /* send PDTCH/PACCH to L1 */ + pcu_l1if_tx_pdtch(msg, trx, ts, arfcn, fn, block_nr); + + return 0; +} |