| /* 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> |
| #include <bts.h> |
| #include <tbf.h> |
| |
| #include "pcu_utils.h" |
| |
| static uint32_t sched_poll(struct gprs_rlcmac_bts *bts, |
| uint8_t trx, uint8_t ts, uint32_t fn, uint8_t block_nr, |
| struct gprs_rlcmac_tbf **poll_tbf, |
| struct gprs_rlcmac_tbf **ul_ass_tbf, |
| struct gprs_rlcmac_tbf **dl_ass_tbf, |
| struct gprs_rlcmac_ul_tbf **ul_ack_tbf) |
| { |
| struct gprs_rlcmac_ul_tbf *ul_tbf; |
| struct gprs_rlcmac_dl_tbf *dl_tbf; |
| struct llist_pods *lpods; |
| uint32_t poll_fn; |
| |
| /* check special TBF for events */ |
| poll_fn = fn + 4; |
| if ((block_nr % 3) == 2) |
| poll_fn ++; |
| poll_fn = poll_fn % 2715648; |
| llist_pods_for_each_entry(ul_tbf, &bts->ul_tbfs, list, lpods) { |
| /* this trx, this ts */ |
| if (ul_tbf->trx->trx_no != trx || ul_tbf->control_ts != ts) |
| continue; |
| /* polling for next uplink block */ |
| if (ul_tbf->poll_state == GPRS_RLCMAC_POLL_SCHED |
| && ul_tbf->poll_fn == poll_fn) |
| *poll_tbf = ul_tbf; |
| if (ul_tbf->ul_ack_state == GPRS_RLCMAC_UL_ACK_SEND_ACK) |
| *ul_ack_tbf = ul_tbf; |
| if (ul_tbf->dl_ass_state == GPRS_RLCMAC_DL_ASS_SEND_ASS) |
| *dl_ass_tbf = ul_tbf; |
| if (ul_tbf->ul_ass_state == GPRS_RLCMAC_UL_ASS_SEND_ASS) |
| *ul_ass_tbf = ul_tbf; |
| #warning "Is this supposed to be fair? The last TBF for each wins? Maybe use llist_add_tail and skip once we have all states?" |
| } |
| llist_pods_for_each_entry(dl_tbf, &bts->dl_tbfs, list, lpods) { |
| /* this trx, this ts */ |
| if (dl_tbf->trx->trx_no != trx || dl_tbf->control_ts != ts) |
| continue; |
| /* polling for next uplink block */ |
| if (dl_tbf->poll_state == GPRS_RLCMAC_POLL_SCHED |
| && dl_tbf->poll_fn == poll_fn) |
| *poll_tbf = dl_tbf; |
| if (dl_tbf->dl_ass_state == GPRS_RLCMAC_DL_ASS_SEND_ASS) |
| *dl_ass_tbf = dl_tbf; |
| if (dl_tbf->ul_ass_state == GPRS_RLCMAC_UL_ASS_SEND_ASS) |
| *ul_ass_tbf = dl_tbf; |
| } |
| |
| return poll_fn; |
| } |
| |
| static uint8_t sched_select_uplink(uint8_t trx, uint8_t ts, uint32_t fn, |
| uint8_t block_nr, struct gprs_rlcmac_pdch *pdch) |
| { |
| struct gprs_rlcmac_ul_tbf *tbf; |
| uint8_t usf = 0x07; |
| uint8_t i, tfi; |
| |
| /* select uplink resource */ |
| for (i = 0, tfi = pdch->next_ul_tfi; i < 32; |
| i++, tfi = (tfi + 1) & 31) { |
| tbf = pdch->ul_tbf_by_tfi(tfi); |
| /* no TBF for this tfi, go next */ |
| if (!tbf) |
| continue; |
| /* no UL resources needed, go next */ |
| /* we don't need to give resources in FINISHED state, |
| * because we have received all blocks and only poll |
| * for packet control ack. */ |
| if (tbf->state_is_not(GPRS_RLCMAC_FLOW)) |
| continue; |
| |
| /* use this USF */ |
| usf = tbf->m_usf[ts]; |
| LOGP(DRLCMACSCHED, LOGL_DEBUG, "Received RTS for PDCH: TRX=%d " |
| "TS=%d FN=%d block_nr=%d scheduling USF=%d for " |
| "required uplink resource of UL TFI=%d\n", trx, ts, fn, |
| block_nr, usf, tfi); |
| /* next TBF to handle resource is the next one */ |
| pdch->next_ul_tfi = (tfi + 1) & 31; |
| break; |
| } |
| |
| return usf; |
| } |
| |
| static struct msgb *sched_select_ctrl_msg( |
| uint8_t trx, uint8_t ts, uint32_t fn, |
| uint8_t block_nr, struct gprs_rlcmac_pdch *pdch, |
| struct gprs_rlcmac_tbf *ul_ass_tbf, |
| struct gprs_rlcmac_tbf *dl_ass_tbf, |
| struct gprs_rlcmac_ul_tbf *ul_ack_tbf) |
| { |
| struct msgb *msg = NULL; |
| struct gprs_rlcmac_tbf *tbf = NULL; |
| struct gprs_rlcmac_tbf *next_list[3] = { ul_ass_tbf, dl_ass_tbf, ul_ack_tbf }; |
| |
| for (size_t i = 0; i < ARRAY_SIZE(next_list); ++i) { |
| tbf = next_list[(pdch->next_ctrl_prio + i) % 3]; |
| if (!tbf) |
| continue; |
| |
| if (tbf == ul_ass_tbf) |
| msg = ul_ass_tbf->create_ul_ass(fn); |
| else if (tbf == dl_ass_tbf) |
| msg = dl_ass_tbf->create_dl_ass(fn); |
| else if (tbf == ul_ack_tbf) |
| msg = ul_ack_tbf->create_ul_ack(fn); |
| else |
| abort(); |
| |
| if (!msg) { |
| tbf = NULL; |
| continue; |
| } |
| |
| pdch->next_ctrl_prio += i + 1; |
| pdch->next_ctrl_prio %= 3; |
| break; |
| } |
| |
| /* any message */ |
| if (msg) { |
| tbf->rotate_in_list(); |
| LOGP(DRLCMACSCHED, LOGL_DEBUG, "Scheduling control " |
| "message at RTS for %s (TRX=%d, TS=%d)\n", |
| tbf_name(tbf), trx, ts); |
| return msg; |
| } |
| /* schedule PACKET PAGING REQUEST */ |
| msg = pdch->packet_paging_request(); |
| if (msg) { |
| LOGP(DRLCMACSCHED, LOGL_DEBUG, "Scheduling paging request " |
| "message at RTS for (TRX=%d, TS=%d)\n", trx, ts); |
| return msg; |
| } |
| |
| return NULL; |
| } |
| |
| static struct msgb *sched_select_downlink(struct gprs_rlcmac_bts *bts, |
| uint8_t trx, uint8_t ts, uint32_t fn, |
| uint8_t block_nr, struct gprs_rlcmac_pdch *pdch) |
| { |
| struct msgb *msg = NULL; |
| struct gprs_rlcmac_dl_tbf *tbf, *prio_tbf = NULL; |
| enum { |
| DL_PRIO_NONE, |
| DL_PRIO_SENT_DATA, /* the data has been sent and not (yet) nacked */ |
| DL_PRIO_LOW_AGE, /* the age has reached the first threshold */ |
| DL_PRIO_NEW_DATA, /* the data has not been sent yet or nacked */ |
| DL_PRIO_HIGH_AGE, /* the age has reached the second threshold */ |
| DL_PRIO_CONTROL, /* a control block needs to be sent */ |
| } prio, max_prio = DL_PRIO_NONE; |
| |
| uint8_t i, tfi, prio_tfi; |
| int age; |
| const int age_thresh1 = msecs_to_frames(200); |
| const int high_prio_msecs = |
| OSMO_MIN(BTS::TIMER_T3190_MSEC/2, bts->dl_tbf_idle_msec); |
| const int age_thresh2 = msecs_to_frames(high_prio_msecs); |
| |
| /* select downlink resource */ |
| for (i = 0, tfi = pdch->next_dl_tfi; i < 32; |
| i++, tfi = (tfi + 1) & 31) { |
| tbf = pdch->dl_tbf_by_tfi(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 resources needed, go next */ |
| if (tbf->state_is_not(GPRS_RLCMAC_FLOW) |
| && tbf->state_is_not(GPRS_RLCMAC_FINISHED)) |
| continue; |
| |
| /* waiting for CCCH IMM.ASS confirm */ |
| if (tbf->m_wait_confirm) |
| continue; |
| |
| age = tbf->frames_since_last_poll(fn); |
| |
| /* compute priority */ |
| if (tbf->is_control_ts(ts) && tbf->need_control_ts()) |
| prio = DL_PRIO_CONTROL; |
| else if (tbf->is_control_ts(ts) && |
| age > age_thresh2 && age_thresh2 > 0) |
| prio = DL_PRIO_HIGH_AGE; |
| else if ((tbf->state_is(GPRS_RLCMAC_FLOW) && tbf->have_data()) || |
| tbf->m_window.resend_needed() >= 0) |
| prio = DL_PRIO_NEW_DATA; |
| else if (tbf->is_control_ts(ts) && |
| age > age_thresh1 && tbf->keep_open(fn)) |
| prio = DL_PRIO_LOW_AGE; |
| else if (!tbf->m_window.window_empty()) |
| prio = DL_PRIO_SENT_DATA; |
| else |
| continue; |
| |
| /* get the TBF with the highest priority */ |
| if (prio > max_prio) { |
| prio_tfi = tfi; |
| prio_tbf = tbf; |
| max_prio = prio; |
| } |
| } |
| |
| if (prio_tbf) { |
| LOGP(DRLCMACSCHED, LOGL_DEBUG, "Scheduling data message at " |
| "RTS for DL TFI=%d (TRX=%d, TS=%d) prio=%d\n", |
| prio_tfi, trx, ts, max_prio); |
| /* next TBF to handle resource is the next one */ |
| pdch->next_dl_tfi = (prio_tfi + 1) & 31; |
| /* generate DL data block */ |
| msg = prio_tbf->create_dl_acked_block(fn, ts); |
| } |
| |
| return msg; |
| } |
| |
| static const 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 |
| }; |
| |
| static struct msgb *sched_dummy(void) |
| { |
| struct msgb *msg; |
| |
| msg = msgb_alloc(23, "rlcmac_dl_idle"); |
| if (!msg) |
| return NULL; |
| memcpy(msgb_put(msg, 23), rlcmac_dl_idle, 23); |
| |
| return msg; |
| } |
| |
| int gprs_rlcmac_rcv_rts_block(struct gprs_rlcmac_bts *bts, |
| uint8_t trx, uint8_t ts, uint16_t arfcn, |
| uint32_t fn, uint8_t block_nr) |
| { |
| struct gprs_rlcmac_pdch *pdch; |
| struct gprs_rlcmac_tbf *poll_tbf = NULL, *dl_ass_tbf = NULL, |
| *ul_ass_tbf = NULL; |
| struct gprs_rlcmac_ul_tbf *ul_ack_tbf = NULL; |
| uint8_t usf = 0x7; |
| struct msgb *msg = NULL; |
| uint32_t poll_fn, sba_fn; |
| |
| #warning "ARFCN... it is already in the TRX..... is it consistent with it?" |
| |
| if (trx >= 8 || ts >= 8) |
| return -EINVAL; |
| pdch = &bts->trx[trx].pdch[ts]; |
| |
| if (!pdch->is_enabled()) { |
| 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; |
| |
| poll_fn = sched_poll(bts, trx, ts, fn, block_nr, &poll_tbf, &ul_ass_tbf, |
| &dl_ass_tbf, &ul_ack_tbf); |
| /* check uplink resource for polling */ |
| if (poll_tbf) |
| 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 %s\n", trx, ts, fn, |
| block_nr, poll_fn, |
| tbf_name(poll_tbf)); |
| /* use free USF */ |
| /* else. check for sba */ |
| else if ((sba_fn = bts->bts->sba()->sched(trx, ts, fn, block_nr) != 0xffffffff)) |
| LOGP(DRLCMACSCHED, LOGL_DEBUG, "Received RTS for PDCH: TRX=%d " |
| "TS=%d FN=%d block_nr=%d scheduling free USF for " |
| "single block allocation at FN=%d\n", trx, ts, fn, |
| block_nr, sba_fn); |
| /* use free USF */ |
| /* else, we search for uplink resource */ |
| else |
| usf = sched_select_uplink(trx, ts, fn, block_nr, pdch); |
| |
| /* Prio 1: select control message */ |
| msg = sched_select_ctrl_msg(trx, ts, fn, block_nr, pdch, ul_ass_tbf, |
| dl_ass_tbf, ul_ack_tbf); |
| |
| /* Prio 2: select data message for downlink */ |
| if (!msg) |
| msg = sched_select_downlink(bts, trx, ts, fn, block_nr, pdch); |
| |
| /* Prio 3: send dummy contol message */ |
| if (!msg) |
| msg = sched_dummy(); |
| |
| if (!msg) |
| return -ENOMEM; |
| /* msg is now available */ |
| |
| /* set USF */ |
| msg->data[0] = (msg->data[0] & 0xf8) | usf; |
| |
| /* Used to measure the leak rate, count all blocks */ |
| gprs_bssgp_update_frames_sent(); |
| |
| /* send PDTCH/PACCH to L1 */ |
| pcu_l1if_tx_pdtch(msg, trx, ts, arfcn, fn, block_nr); |
| |
| return 0; |
| } |