| /* 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 <tbf_ul.h> |
| #include <gprs_debug.h> |
| #include <gprs_ms.h> |
| #include <rlc.h> |
| #include <sba.h> |
| #include <pdch.h> |
| #include "pcu_utils.h" |
| |
| extern "C" { |
| #include <osmocom/core/gsmtap.h> |
| } |
| |
| static uint32_t sched_poll(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; |
| LListHead<gprs_rlcmac_tbf> *pos; |
| uint32_t poll_fn; |
| |
| /* check special TBF for events */ |
| poll_fn = fn + 4; |
| if ((block_nr % 3) == 2) |
| poll_fn ++; |
| poll_fn = poll_fn % GSM_MAX_FN; |
| llist_for_each(pos, &bts->ul_tbfs()) { |
| ul_tbf = as_ul_tbf(pos->entry()); |
| OSMO_ASSERT(ul_tbf); |
| /* this trx, this ts */ |
| if (ul_tbf->trx->trx_no != trx || !ul_tbf->is_control_ts(ts)) |
| continue; |
| /* polling for next uplink block */ |
| if (ul_tbf->poll_scheduled() && ul_tbf->poll_fn == poll_fn) |
| *poll_tbf = ul_tbf; |
| if (ul_tbf->ul_ack_state_is(GPRS_RLCMAC_UL_ACK_SEND_ACK)) |
| *ul_ack_tbf = ul_tbf; |
| if (ul_tbf->dl_ass_state_is(GPRS_RLCMAC_DL_ASS_SEND_ASS)) |
| *dl_ass_tbf = ul_tbf; |
| if (ul_tbf->ul_ass_state_is(GPRS_RLCMAC_UL_ASS_SEND_ASS) |
| || ul_tbf->ul_ass_state_is(GPRS_RLCMAC_UL_ASS_SEND_ASS_REJ)) |
| *ul_ass_tbf = ul_tbf; |
| /* FIXME: 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_for_each(pos, &bts->dl_tbfs()) { |
| dl_tbf = as_dl_tbf(pos->entry()); |
| OSMO_ASSERT(dl_tbf); |
| /* this trx, this ts */ |
| if (dl_tbf->trx->trx_no != trx || !dl_tbf->is_control_ts(ts)) |
| continue; |
| /* polling for next uplink block */ |
| if (dl_tbf->poll_scheduled() && dl_tbf->poll_fn == poll_fn) |
| *poll_tbf = dl_tbf; |
| if (dl_tbf->dl_ass_state_is(GPRS_RLCMAC_DL_ASS_SEND_ASS)) |
| *dl_ass_tbf = dl_tbf; |
| if (dl_tbf->ul_ass_state_is(GPRS_RLCMAC_UL_ASS_SEND_ASS) |
| || dl_tbf->ul_ass_state_is(GPRS_RLCMAC_UL_ASS_SEND_ASS_REJ)) |
| *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; |
| } |
| |
| struct msgb *sched_app_info(struct gprs_rlcmac_tbf *tbf) { |
| struct gprs_rlcmac_bts *bts_data; |
| struct msgb *msg = NULL; |
| |
| if (!tbf || !tbf->ms()->app_info_pending) |
| return NULL; |
| |
| bts_data = BTS::main_bts()->bts_data(); |
| |
| if (bts_data->app_info) { |
| LOGP(DRLCMACSCHED, LOGL_DEBUG, "Sending Packet Application Information message\n"); |
| msg = msgb_copy(bts_data->app_info, "app_info_msg_sched"); |
| } else |
| LOGP(DRLCMACSCHED, LOGL_ERROR, "MS has app_info_pending flag set, but no Packet Application Information" |
| " message stored in BTS!\n"); |
| |
| tbf->ms()->app_info_pending = false; |
| bts_data->app_info_pending--; |
| |
| if (!bts_data->app_info_pending) { |
| LOGP(DRLCMACSCHED, LOGL_DEBUG, "Packet Application Information successfully sent to all MS with active" |
| " TBF\n"); |
| msgb_free(bts_data->app_info); |
| bts_data->app_info = NULL; |
| } |
| return msg; |
| } |
| |
| 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 }; |
| |
| /* Send Packet Application Information first (ETWS primary notifications) */ |
| msg = sched_app_info(dl_ass_tbf); |
| |
| if (!msg) { |
| for (size_t i = 0; i < ARRAY_SIZE(next_list); ++i) { |
| tbf = next_list[(pdch->next_ctrl_prio + i) % 3]; |
| if (!tbf) |
| continue; |
| |
| /* |
| * Assignments for the same direction have lower precedence, |
| * because they may kill the TBF when the CONTROL ACK is |
| * received, thus preventing the others from being processed. |
| */ |
| if (tbf == ul_ass_tbf && tbf->ul_ass_state_is(GPRS_RLCMAC_UL_ASS_SEND_ASS_REJ)) |
| msg = ul_ass_tbf->create_packet_access_reject(); |
| else if (tbf == ul_ass_tbf && tbf->direction == |
| GPRS_RLCMAC_DL_TBF) |
| if (tbf->ul_ass_state_is(GPRS_RLCMAC_UL_ASS_SEND_ASS_REJ)) |
| msg = ul_ass_tbf->create_packet_access_reject(); |
| else |
| msg = ul_ass_tbf->create_ul_ass(fn, ts); |
| else if (tbf == dl_ass_tbf && tbf->direction == GPRS_RLCMAC_UL_TBF) |
| msg = dl_ass_tbf->create_dl_ass(fn, ts); |
| else if (tbf == ul_ack_tbf) |
| msg = ul_ack_tbf->create_ul_ack(fn, ts); |
| |
| if (!msg) { |
| tbf = NULL; |
| continue; |
| } |
| |
| pdch->next_ctrl_prio += 1; |
| pdch->next_ctrl_prio %= 3; |
| break; |
| } |
| } |
| |
| if (!msg) { |
| /* |
| * If one of these is left, the response (CONTROL ACK) from the |
| * MS will kill the current TBF, only one of them can be |
| * non-NULL |
| */ |
| if (dl_ass_tbf) { |
| tbf = dl_ass_tbf; |
| msg = dl_ass_tbf->create_dl_ass(fn, ts); |
| } else if (ul_ass_tbf) { |
| tbf = ul_ass_tbf; |
| msg = ul_ass_tbf->create_ul_ass(fn, ts); |
| } |
| } |
| |
| /* any message */ |
| if (msg) { |
| if (!tbf) { |
| LOGP(DRLCMACSCHED, LOGL_ERROR, |
| "Control message to be scheduled, but no TBF (TRX=%d, TS=%d)\n", trx, ts); |
| msgb_free(msg); |
| return NULL; |
| } |
| 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); |
| /* Updates the dl ctrl msg counter for ms */ |
| tbf->ms()->update_dl_ctrl_msg(); |
| return msg; |
| } |
| |
| /* schedule PACKET PAGING REQUEST, if any are pending */ |
| 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 inline enum tbf_dl_prio tbf_compute_priority(const struct gprs_rlcmac_bts *bts, struct gprs_rlcmac_dl_tbf *tbf, |
| uint8_t ts, uint32_t fn, int age) |
| { |
| const gprs_rlc_dl_window *w = tbf->window(); |
| unsigned long msecs_t3190 = osmo_tdef_get(bts->T_defs_pcu, 3190, OSMO_TDEF_MS, -1); |
| unsigned long dl_tbf_idle_msec = osmo_tdef_get(bts->T_defs_pcu, -2031, OSMO_TDEF_MS, -1); |
| int age_thresh1 = msecs_to_frames(200); |
| int age_thresh2 = msecs_to_frames(OSMO_MIN(msecs_t3190/2, dl_tbf_idle_msec)); |
| |
| if (tbf->is_control_ts(ts) && tbf->need_control_ts()) |
| return DL_PRIO_CONTROL; |
| |
| if (tbf->is_control_ts(ts) && age > age_thresh2 && age_thresh2 > 0) |
| return DL_PRIO_HIGH_AGE; |
| |
| if ((tbf->state_is(GPRS_RLCMAC_FLOW) && tbf->have_data()) || w->resend_needed() >= 0) |
| return DL_PRIO_NEW_DATA; |
| |
| if (tbf->is_control_ts(ts) && age > age_thresh1 && tbf->keep_open(fn)) |
| return DL_PRIO_LOW_AGE; |
| |
| if (!w->window_empty()) |
| return DL_PRIO_SENT_DATA; |
| |
| return DL_PRIO_NONE; |
| } |
| |
| 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 tbf_dl_prio prio, max_prio = DL_PRIO_NONE; |
| |
| uint8_t i, tfi, prio_tfi; |
| int age; |
| |
| /* 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 */ |
| prio = tbf_compute_priority(bts, tbf, ts, fn, age); |
| if (prio == DL_PRIO_NONE) |
| 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; |
| } |
| |
| static inline void tap_n_acc(const struct msgb *msg, const struct gprs_rlcmac_bts *bts, uint8_t trx, uint8_t ts, |
| uint32_t fn, enum pcu_gsmtap_category cat) |
| { |
| if (!msg) |
| return; |
| |
| switch(cat) { |
| case PCU_GSMTAP_C_DL_CTRL: |
| bts->bts->rlc_sent_control(); |
| bts->bts->send_gsmtap(PCU_GSMTAP_C_DL_CTRL, false, trx, ts, GSMTAP_CHANNEL_PACCH, fn, msg->data, |
| msg->len); |
| break; |
| case PCU_GSMTAP_C_DL_DATA_GPRS: |
| bts->bts->rlc_sent(); |
| /* FIXME: distinguish between GPRS and EGPRS */ |
| bts->bts->send_gsmtap(PCU_GSMTAP_C_DL_DATA_GPRS, false, trx, ts, GSMTAP_CHANNEL_PDTCH, fn, msg->data, |
| msg->len); |
| break; |
| case PCU_GSMTAP_C_DL_DUMMY: |
| bts->bts->rlc_sent_dummy(); |
| bts->bts->send_gsmtap(PCU_GSMTAP_C_DL_DUMMY, false, trx, ts, GSMTAP_CHANNEL_PACCH, fn, msg->data, |
| msg->len); |
| break; |
| default: |
| break; |
| } |
| } |
| |
| int gprs_rlcmac_rcv_rts_block(struct gprs_rlcmac_bts *bts, |
| uint8_t trx, uint8_t ts, |
| 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; |
| |
| 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->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); |
| tap_n_acc(msg, bts, trx, ts, fn, PCU_GSMTAP_C_DL_CTRL); |
| |
| /* Prio 2: select data message for downlink */ |
| if (!msg) { |
| msg = sched_select_downlink(bts, trx, ts, fn, block_nr, pdch); |
| tap_n_acc(msg, bts, trx, ts, fn, PCU_GSMTAP_C_DL_DATA_GPRS); |
| } |
| |
| /* Prio 3: send dummy contol message */ |
| if (!msg) { |
| /* increase counter */ |
| msg = sched_dummy(); |
| tap_n_acc(msg, bts, trx, ts, fn, PCU_GSMTAP_C_DL_DUMMY); |
| } |
| |
| if (!msg) |
| return -ENOMEM; |
| /* msg is now available */ |
| bts->bts->rlc_dl_bytes(msg->data_len); |
| |
| /* set USF */ |
| OSMO_ASSERT(msgb_length(msg) > 0); |
| 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, bts->trx[trx].arfcn, fn, block_nr); |
| |
| return 0; |
| } |