diff options
Diffstat (limited to 'src/gprs_rlcmac_ts_alloc.cpp')
| -rw-r--r-- | src/gprs_rlcmac_ts_alloc.cpp | 681 |
1 files changed, 681 insertions, 0 deletions
diff --git a/src/gprs_rlcmac_ts_alloc.cpp b/src/gprs_rlcmac_ts_alloc.cpp new file mode 100644 index 00000000..366732c2 --- /dev/null +++ b/src/gprs_rlcmac_ts_alloc.cpp @@ -0,0 +1,681 @@ +/* gprs_rlcmac.cpp + * + * Copyright (C) 2012 Ivan Klyuchnikov + * Copyright (C) 2012 Andreas Eversberg <jolly@eversberg.eu> + * Copyright (C) 2013 by Holger Hans Peter Freyther + * + * 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_rlcmac.h> +#include <gprs_debug.h> +#include <bts.h> +#include <tbf.h> + +#include <errno.h> + +/* 3GPP TS 05.02 Annex B.1 */ + +#define MS_NA 255 /* N/A */ +#define MS_A 254 /* 1 with hopping, 0 without */ +#define MS_B 253 /* 1 with hopping, 0 without (change Rx to Tx)*/ +#define MS_C 252 /* 1 with hopping, 0 without (change Tx to Rx)*/ + +struct gprs_ms_multislot_class { + uint8_t rx, tx, sum; /* Maximum Number of Slots: RX, Tx, Sum Rx+Tx */ + uint8_t ta, tb, ra, rb; /* Minimum Number of Slots */ + uint8_t type; /* Type of Mobile */ +}; + +static const struct gprs_ms_multislot_class gprs_ms_multislot_class[32] = { +/* M-S Class Rx Tx Sum Tta Ttb Tra Trb Type */ +/* N/A */ { MS_NA,MS_NA, MS_NA, MS_NA, MS_NA, MS_NA, MS_NA, MS_NA }, +/* 1 */ { 1, 1, 2, 3, 2, 4, 2, 1 }, +/* 2 */ { 2, 1, 3, 3, 2, 3, 1, 1 }, +/* 3 */ { 2, 2, 3, 3, 2, 3, 1, 1 }, +/* 4 */ { 3, 1, 4, 3, 1, 3, 1, 1 }, +/* 5 */ { 2, 2, 4, 3, 1, 3, 1, 1 }, +/* 6 */ { 3, 2, 4, 3, 1, 3, 1, 1 }, +/* 7 */ { 3, 3, 4, 3, 1, 3, 1, 1 }, +/* 8 */ { 4, 1, 5, 3, 1, 2, 1, 1 }, +/* 9 */ { 3, 2, 5, 3, 1, 2, 1, 1 }, +/* 10 */ { 4, 2, 5, 3, 1, 2, 1, 1 }, +/* 11 */ { 4, 3, 5, 3, 1, 2, 1, 1 }, +/* 12 */ { 4, 4, 5, 2, 1, 2, 1, 1 }, +/* 13 */ { 3, 3, MS_NA, MS_NA, MS_A, 3, MS_A, 2 }, +/* 14 */ { 4, 4, MS_NA, MS_NA, MS_A, 3, MS_A, 2 }, +/* 15 */ { 5, 5, MS_NA, MS_NA, MS_A, 3, MS_A, 2 }, +/* 16 */ { 6, 6, MS_NA, MS_NA, MS_A, 2, MS_A, 2 }, +/* 17 */ { 7, 7, MS_NA, MS_NA, MS_A, 1, 0, 2 }, +/* 18 */ { 8, 8, MS_NA, MS_NA, 0, 0, 0, 2 }, +/* 19 */ { 6, 2, MS_NA, 3, MS_B, 2, MS_C, 1 }, +/* 20 */ { 6, 3, MS_NA, 3, MS_B, 2, MS_C, 1 }, +/* 21 */ { 6, 4, MS_NA, 3, MS_B, 2, MS_C, 1 }, +/* 22 */ { 6, 4, MS_NA, 2, MS_B, 2, MS_C, 1 }, +/* 23 */ { 6, 6, MS_NA, 2, MS_B, 2, MS_C, 1 }, +/* 24 */ { 8, 2, MS_NA, 3, MS_B, 2, MS_C, 1 }, +/* 25 */ { 8, 3, MS_NA, 3, MS_B, 2, MS_C, 1 }, +/* 26 */ { 8, 4, MS_NA, 3, MS_B, 2, MS_C, 1 }, +/* 27 */ { 8, 4, MS_NA, 2, MS_B, 2, MS_C, 1 }, +/* 28 */ { 8, 6, MS_NA, 2, MS_B, 2, MS_C, 1 }, +/* 29 */ { 8, 8, MS_NA, 2, MS_B, 2, MS_C, 1 }, +/* N/A */ { MS_NA,MS_NA, MS_NA, MS_NA, MS_NA, MS_NA, MS_NA, MS_NA }, +/* N/A */ { MS_NA,MS_NA, MS_NA, MS_NA, MS_NA, MS_NA, MS_NA, MS_NA }, +}; + +static inline int8_t find_free_usf(struct gprs_rlcmac_pdch *pdch) +{ + struct gprs_rlcmac_tbf *tbf; + uint8_t usf_map = 0; + uint8_t tfi, usf; + + /* make map of used USF */ + for (tfi = 0; tfi < 32; tfi++) { + tbf = pdch->ul_tbf[tfi]; + if (!tbf) + continue; + usf_map |= (1 << tbf->dir.ul.usf[pdch->ts_no]); + } + + /* look for USF, don't use USF=7 */ + for (usf = 0; usf < 7; usf++) { + if (!(usf_map & (1 << usf))) + return usf; + } + + return -1; +} + +static int find_enabled_pdch(struct gprs_rlcmac_trx *trx, const uint8_t start_ts) +{ + int ts; + for (ts = start_ts; ts < 8; ts++) { + struct gprs_rlcmac_pdch *pdch; + + pdch = &trx->pdch[ts]; + if (!pdch->is_enabled()) { + LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, because " + "not enabled\n", ts); + continue; + } + return ts; + } + + return 8; +} + +static void assign_uplink_tbf_usf( + struct gprs_rlcmac_pdch *pdch, + struct gprs_rlcmac_tbf *tbf, int8_t usf) +{ + tbf->trx->ul_tbf[tbf->tfi()] = tbf; + pdch->ul_tbf[tbf->tfi()] = tbf; + tbf->pdch[pdch->ts_no] = pdch; + tbf->dir.ul.usf[pdch->ts_no] = usf; +} + +static void assign_dlink_tbf( + struct gprs_rlcmac_pdch *pdch, + struct gprs_rlcmac_tbf *tbf) +{ + tbf->trx->dl_tbf[tbf->tfi()] = tbf; + pdch->dl_tbf[tbf->tfi()] = tbf; + tbf->pdch[pdch->ts_no] = pdch; +} + + +/* Slot Allocation: Algorithm A + * + * Assign single slot for uplink and downlink + */ +int alloc_algorithm_a(struct gprs_rlcmac_bts *bts, + struct gprs_rlcmac_tbf *old_tbf, + struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single) +{ + struct gprs_rlcmac_pdch *pdch; + uint8_t ts; + + LOGP(DRLCMAC, LOGL_DEBUG, "Slot Allocation (Algorithm A) for class " + "%d\n", tbf->ms_class); + + ts = find_enabled_pdch(tbf->trx, 0); + if (ts == 8) + return -EINVAL; + + pdch = &tbf->trx->pdch[ts]; + if (tbf->direction == GPRS_RLCMAC_UL_TBF) { + int8_t usf; /* must be signed */ + + /* if USF available */ + usf = find_free_usf(pdch); + if (usf < 0) { + LOGP(DRLCMAC, LOGL_NOTICE, "- Failed " + "allocating TS=%d, no USF available\n", ts); + return -EBUSY; + } + LOGP(DRLCMAC, LOGL_DEBUG, "- Assign uplink " + "TS=%d USF=%d\n", ts, usf); + assign_uplink_tbf_usf(pdch, tbf, usf); + } else { + LOGP(DRLCMAC, LOGL_DEBUG, "- Assign downlink TS=%d\n", ts); + assign_dlink_tbf(pdch, tbf); + } + /* the only one TS is the common TS */ + tbf->first_ts = tbf->first_common_ts = ts; + + return 0; +} + +/* + * Select a window of Rx slots if available. + * The maximum allowed slots depend on RX or the window of available + * slots. This must be done for uplink TBF also, because it is the basis + * for calculating control slot and uplink slot(s). + */ +static uint8_t select_dl_slots(struct gprs_rlcmac_trx *trx, + const int ms_type, const int ms_max_rxslots, + uint8_t *out_rx_win_min, uint8_t *out_rx_win_max) + +{ + uint8_t rx_window = 0; + int rx_window_size = 0; + int8_t last_tsc = -1; /* must be signed */ + uint8_t rx_win_min = 0, rx_win_max = 0; + + for (int ts_no = 0; ts_no < 8; ts_no++) { + struct gprs_rlcmac_pdch *pdch; + pdch = &trx->pdch[ts_no]; + + /* check if enabled */ + if (!pdch->is_enabled()) { + LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, because " + "not enabled\n", ts_no); + if (ms_type == 1 && rx_window) + goto inc_window; + continue; + } + /* check if TSC changes */ + if (last_tsc < 0) + last_tsc = pdch->tsc; + else if (last_tsc != pdch->tsc) { + LOGP(DRLCMAC, LOGL_ERROR, "Skipping TS %d of TRX=%d, " + "because it has different TSC than lower TS " + "of TRX. In order to allow multislot, all " + "slots must be configured with the same " + "TSC!\n", ts_no, trx->trx_no); + if (ms_type == 1 && rx_window) + goto inc_window; + continue; + } + + if (!rx_window) + rx_win_min = ts_no; + + rx_window |= (1 << ts_no); + LOGP(DRLCMAC, LOGL_DEBUG, "- Selected DL TS %d\n", ts_no); + + /* range of window (required for Type 1) */ + rx_win_max = ts_no; + +inc_window: + if (++rx_window_size == ms_max_rxslots) { + LOGP(DRLCMAC, LOGL_DEBUG, "- Done, because slots / " + "window reached maximum alowed Rx size\n"); + break; + } + if (ms_type == 1 && rx_window_size == 5) { + LOGP(DRLCMAC, LOGL_DEBUG, "- Done, because slots / " + "window reached maximum supported Rx size of " + "this algorithm\n"); + break; + } + } + + LOGP(DRLCMAC, LOGL_DEBUG, "- Selected slots for RX: " + "(TS=0)\"%c%c%c%c%c%c%c%c\"(TS=7)\n", + ((rx_window & 0x01)) ? 'D' : '.', + ((rx_window & 0x02)) ? 'D' : '.', + ((rx_window & 0x04)) ? 'D' : '.', + ((rx_window & 0x08)) ? 'D' : '.', + ((rx_window & 0x10)) ? 'D' : '.', + ((rx_window & 0x20)) ? 'D' : '.', + ((rx_window & 0x40)) ? 'D' : '.', + ((rx_window & 0x80)) ? 'D' : '.'); + + *out_rx_win_min = rx_win_min; + *out_rx_win_max = rx_win_max; + return rx_window; +} + +static int reduce_rx_window(const int ms_type, const struct gprs_rlcmac_tbf *old_tbf, + const int Tt, const int Tr, + int *rx_window, + uint8_t *rx_win_min, uint8_t *rx_win_max) +{ + if (ms_type != 1) + return 0; + if (!old_tbf) + return 0; + if (old_tbf->direction != GPRS_RLCMAC_UL_TBF) + return 0; + + uint8_t collide = 0, ul_usage = 0; + + /* calculate mask of colliding slots */ + for (uint8_t ts_no = 0; ts_no < 8; ts_no++) { + int j; + if (!old_tbf->pdch[ts_no]) + continue; + + ul_usage |= (1 << ts_no); + /* mark bits from TS-t .. TS+r */ + for (j = ts_no - Tt; j != ((ts_no + Tr + 1) & 7); j = (j + 1) & 7) + collide |= (1 << j); + } + + LOGP(DRLCMAC, LOGL_DEBUG, "- Not allowed slots due to existing " + "UL allocation: (TS=0)\"%c%c%c%c%c%c%c%c\"(TS=7) " + " D=downlink x=not usable\n", + ((ul_usage & 0x01)) ? 'D' : ((collide & 0x01))?'x':'.', + ((ul_usage & 0x02)) ? 'D' : ((collide & 0x02))?'x':'.', + ((ul_usage & 0x04)) ? 'D' : ((collide & 0x04))?'x':'.', + ((ul_usage & 0x08)) ? 'D' : ((collide & 0x08))?'x':'.', + ((ul_usage & 0x10)) ? 'D' : ((collide & 0x10))?'x':'.', + ((ul_usage & 0x20)) ? 'D' : ((collide & 0x20))?'x':'.', + ((ul_usage & 0x40)) ? 'D' : ((collide & 0x40))?'x':'.', + ((ul_usage & 0x80)) ? 'D' : ((collide & 0x80))?'x':'.'); + + /* + * Uplink/Downlink in GSM is shifted by three timeslots. Make + * sure they don't collide. + */ + *rx_window &= ~(collide << 3); + *rx_window &= ~(collide >> 5); + LOGP(DRLCMAC, LOGL_DEBUG, "- Remaining slots for RX: " + "(TS=0)\"%c%c%c%c%c%c%c%c\"(TS=7)\n", + ((*rx_window & 0x01)) ? 'D' : '.', + ((*rx_window & 0x02)) ? 'D' : '.', + ((*rx_window & 0x04)) ? 'D' : '.', + ((*rx_window & 0x08)) ? 'D' : '.', + ((*rx_window & 0x10)) ? 'D' : '.', + ((*rx_window & 0x20)) ? 'D' : '.', + ((*rx_window & 0x40)) ? 'D' : '.', + ((*rx_window & 0x80)) ? 'D' : '.'); + + if (!*rx_window) { + LOGP(DRLCMAC, LOGL_NOTICE, "No suitable downlink slots " + "available with current uplink assignment\n"); + return -EBUSY; + } + + return 0; +} + +/* shrink range of rx_win_min and rx_win_max */ +static void shrink_rx_window(uint8_t *rx_win_min, uint8_t *rx_win_max, int rx_window) +{ + /* calculate new min/max */ + for (uint8_t ts_no = *rx_win_min; ts_no <= *rx_win_max; ts_no++) { + if ((rx_window & (1 << ts_no))) + break; + *rx_win_min = ts_no + 1; + LOGP(DRLCMAC, LOGL_DEBUG, "- TS is unused, so " + "raising start of DL window to %d\n", + *rx_win_min); + } + for (uint8_t ts_no = *rx_win_max; ts_no >= *rx_win_min; ts_no--) { + if ((rx_window & (1 << ts_no))) + break; + *rx_win_max = ts_no - 1; + LOGP(DRLCMAC, LOGL_DEBUG, "- TS is unused, so " + "lowering end of DL window to %d\n", + *rx_win_max); + } +} + +/* + * reduce window, to allow at least one uplink TX slot + * this is only required for Type 1 + */ +static uint8_t update_rx_win_max(const int ms_type, const int Tt, + const int Tr, uint8_t rx_win_min, uint8_t rx_win_max) +{ + if (ms_type != 1) + return rx_win_max; + + if (rx_win_max - rx_win_min + 1 + Tt + 1 + Tr > 8) { + rx_win_max = rx_win_min + 7 - Tt - 1 - Tr; + LOGP(DRLCMAC, LOGL_DEBUG, "- Reduce RX window due to time " + "contraints to %d slots\n", rx_win_max - rx_win_min + 1); + } + + return rx_win_max; +} + +static void tx_win_from_rx(const int ms_type, + uint8_t rx_win_min, uint8_t rx_win_max, + int Tt, int Tr, + uint8_t *tx_win_min, uint8_t *tx_win_max, + uint8_t *tx_range) +{ + if (ms_type == 1) { + /* calculate TX window (shifted by 3 timeslots) + * it uses the space between tx_win_max and tx_win_min */ + *tx_win_min = (rx_win_max - 2 + Tt) & 7; + *tx_win_max = (rx_win_min + 4 - Tr) & 7; + } else { + /* TX and RX simultaniously */ + *tx_win_min = rx_win_min; + *tx_win_max = 7; + } + + *tx_range = (*tx_win_max - *tx_win_min + 1) & 7; + /* if TX window fills complete range */ + if (*tx_range == 0) + *tx_range = 8; + LOGP(DRLCMAC, LOGL_DEBUG, "- TX-Window is: %d..%d\n", *tx_win_min, + *tx_win_max); +} + +/* + * Select a window of Tx slots if available. + * The maximum allowed slots depend on TX or the window of available + * slots. + */ +static int select_ul_slots(gprs_rlcmac_trx *trx, + const int ms_type, const int ms_max_txslots, + uint8_t tx_win_min, uint8_t tx_range, + int8_t *usf, int8_t *first_common_ts, uint8_t rx_window) +{ + int tsc = -1; + uint8_t tx_window = 0; + int i; + uint8_t ts_no; + + for (ts_no = tx_win_min, i = 0; i < tx_range; ts_no = (ts_no + 1) & 7, i++) { + gprs_rlcmac_pdch *pdch = &trx->pdch[ts_no]; + + /* check if enabled */ + if (!pdch->is_enabled()) { + LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, " + "because not enabled\n", ts_no); + if (ms_type == 1 && tx_window) + goto inc_window; + continue; + } + /* check if used as downlink */ + if (!(rx_window & (1 << ts_no))) { + LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, " + "because not a downlink slot\n", ts_no); + if (ms_type == 1 && tx_window) + goto inc_window; + continue; + } + /* check if TSC changes */ + if (tsc < 0) + tsc = pdch->tsc; + else if (tsc != pdch->tsc) { + LOGP(DRLCMAC, LOGL_ERROR, "Skipping TS %d of " + "TRX=%d, because it has different TSC " + "than lower TS of TRX. In order to " + "allow multislot, all slots must be " + "configured with the same TSC!\n", + ts_no, trx->trx_no); + if (ms_type == 1) + goto inc_window; + continue; + } + /* check for free usf */ + usf[ts_no] = find_free_usf(pdch); + if (usf[ts_no] < 0) { + LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, " + "because no USF available\n", ts_no); + if (ms_type == 1) + goto inc_window; + continue; + } + + if (!tx_window) + *first_common_ts = ts_no; + + tx_window |= (1 << ts_no); + LOGP(DRLCMAC, LOGL_DEBUG, "- Selected UL TS %d\n", ts_no); + +inc_window: + if (1 && ms_type == 1) { /* FIXME: multislot UL assignment */ + LOGP(DRLCMAC, LOGL_DEBUG, "- Done, because " + "1 slot assigned\n"); + break; + } + if (i+1 == ms_max_txslots) { + LOGP(DRLCMAC, LOGL_DEBUG, "- Done, because " + "slots / window reached maximum " + "allowed Tx size\n"); + break; + } + } + + LOGP(DRLCMAC, LOGL_DEBUG, "- Selected TX window: " + "(TS=0)\"%c%c%c%c%c%c%c%c\"(TS=7)\n", + ((tx_window & 0x01)) ? 'U' : '.', + ((tx_window & 0x02)) ? 'U' : '.', + ((tx_window & 0x04)) ? 'U' : '.', + ((tx_window & 0x08)) ? 'U' : '.', + ((tx_window & 0x10)) ? 'U' : '.', + ((tx_window & 0x20)) ? 'U' : '.', + ((tx_window & 0x40)) ? 'U' : '.', + ((tx_window & 0x80)) ? 'U' : '.'); + + if (!tx_window) { + LOGP(DRLCMAC, LOGL_NOTICE, "No suitable uplink slots " + "available\n"); + return -EBUSY; + } + + return tx_window; +} + +/* + * Assign the first common ts, which is used for control or + * single slot. + */ +static int select_first_ts(gprs_rlcmac_trx *trx, uint8_t tx_win_min, + uint8_t tx_range, uint8_t rx_window) +{ + uint8_t ts_no; + int i; + for (ts_no = tx_win_min, i = 0; i < tx_range; ts_no = (ts_no + 1) & 7, i++) { + gprs_rlcmac_pdch *pdch = &trx->pdch[ts_no]; + /* check if enabled */ + if (!pdch->is_enabled()) { + LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, " + "because not enabled\n", ts_no); + continue; + } + /* check if used as downlink */ + if (!(rx_window & (1 << ts_no))) { + LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, " + "because not a downlink slot\n", ts_no); + continue; + } + return ts_no; + } + + return -1; +} + +/* Slot Allocation: Algorithm B + * + * Assign as many downlink slots as possible. + * Assign one uplink slot. (With free USF) + * + */ +int alloc_algorithm_b(struct gprs_rlcmac_bts *bts, + struct gprs_rlcmac_tbf *old_tbf, + struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single) +{ + const struct gprs_ms_multislot_class *ms_class; + uint8_t Tx, Sum; /* Maximum Number of Slots: RX, Tx, Sum Rx+Tx */ + uint8_t Tta, Ttb, Tra, Trb, Tt, Tr; /* Minimum Number of Slots */ + uint8_t Type; /* Type of Mobile */ + int rx_window; + static const char *digit[10] = { "0","1","2","3","4","5","6","7","8","9" }; + int8_t usf[8] = { -1, -1, -1, -1, -1, -1, -1, -1 }; /* must be signed */ + int8_t first_common_ts = -1; + uint8_t ts; + uint8_t slotcount = 0; + + + if (tbf->ms_class >= 32) { + LOGP(DRLCMAC, LOGL_ERROR, "Multislot class %d out of range.\n", + tbf->ms_class); + return -EINVAL; + } + + if (tbf->ms_class) { + ms_class = &gprs_ms_multislot_class[tbf->ms_class]; + LOGP(DRLCMAC, LOGL_DEBUG, "Slot Allocation (Algorithm B) for " + "class %d\n", tbf->ms_class); + } else { + ms_class = &gprs_ms_multislot_class[12]; + LOGP(DRLCMAC, LOGL_DEBUG, "Slot Allocation (Algorithm B) for " + "unknow class (assuming 12)\n"); + } + + if (ms_class->tx == MS_NA) { + LOGP(DRLCMAC, LOGL_NOTICE, "Multislot class %d not " + "applicable.\n", tbf->ms_class); + return -EINVAL; + } + + Tx = ms_class->tx; + Sum = ms_class->sum; + Tta = ms_class->ta; + Ttb = ms_class->tb; + Tra = ms_class->ra; + Trb = ms_class->rb; + Type = ms_class->type; + + /* Tta and Ttb may depend on hopping or frequency change */ + if (Ttb == MS_A || Ttb == MS_B) + Ttb = 0; + if (Trb == MS_A || Trb == MS_C) + Trb = 0; + + LOGP(DRLCMAC, LOGL_DEBUG, "- Rx=%d Tx=%d Sum Rx+Tx=%s Tta=%s Ttb=%d " + " Tra=%d Trb=%d Type=%d\n", ms_class->rx, Tx, + (Sum == MS_NA) ? "N/A" : digit[Sum], + (Tta == MS_NA) ? "N/A" : digit[Tta], Ttb, Tra, Trb, Type); + + /* select the values for time contraints */ + /* applicable to type 1 and type 2 */ + Tt = Ttb; + Tr = Trb; + + uint8_t rx_win_min, rx_win_max; + rx_window = select_dl_slots(tbf->trx, ms_class->type, ms_class->rx, + &rx_win_min, &rx_win_max); + + + /* reduce window, if existing uplink slots collide RX window */ + int rc = reduce_rx_window(ms_class->type, old_tbf, Tt, Tr, + &rx_window, &rx_win_min, &rx_win_max); + if (rc < 0) + return rc; + shrink_rx_window(&rx_win_min, &rx_win_max, rx_window); + rx_win_max = update_rx_win_max(ms_class->type, Tt, Tr, + rx_win_min, rx_win_max); + shrink_rx_window(&rx_win_min, &rx_win_max, rx_window); + LOGP(DRLCMAC, LOGL_DEBUG, "- RX-Window is: %d..%d\n", rx_win_min, + rx_win_max); + + /* calculate TX window */ + uint8_t tx_win_min, tx_win_max, tx_range; + tx_win_from_rx(ms_class->type, rx_win_min, rx_win_max, Tt, Tr, + &tx_win_min, &tx_win_max, &tx_range); + + /* select UL slots but in both cases assign first_common_ts */ + uint8_t tx_window = 0; + if (tbf->direction == GPRS_RLCMAC_UL_TBF) { + rc = select_ul_slots(tbf->trx, ms_class->type, ms_class->tx, + tx_win_min, tx_range, usf, + &first_common_ts, rx_window); + if (rc < 0) + return rc; + tx_window = rc; + } else { + first_common_ts = select_first_ts(tbf->trx, tx_win_min, + tx_range, rx_window); + } + #warning "first_common_ts might be different if there was no free USF for the new uplink assignment" + + if (first_common_ts < 0) { + LOGP(DRLCMAC, LOGL_NOTICE, "No first common slots available\n"); + return -EINVAL; + } + + if (tbf->direction == GPRS_RLCMAC_DL_TBF) { + /* assign downlink */ + if (rx_window == 0) { + LOGP(DRLCMAC, LOGL_NOTICE, "No downlink slots " + "available\n"); + return -EINVAL; + } + for (ts = 0; ts < 8; ts++) { + if ((rx_window & (1 << ts))) { + /* be sure to select a single downlink slots + * that can be used for uplink, if multiple + * slots are assigned later. */ + if (single && first_common_ts != ts) + continue; + LOGP(DRLCMAC, LOGL_DEBUG, "- Assigning DL TS " + "%d\n", ts); + assign_dlink_tbf(&tbf->trx->pdch[ts], tbf); + slotcount++; + if (slotcount == 1) + tbf->first_ts = ts; + if (single) + break; + } + } + } else { + for (ts = 0; ts < 8; ts++) { + if ((tx_window & (1 << ts))) { + LOGP(DRLCMAC, LOGL_DEBUG, "- Assigning UL TS " + "%d\n", ts); + assign_uplink_tbf_usf(&tbf->trx->pdch[ts], tbf, usf[ts]); + slotcount++; + if (slotcount == 1) + tbf->first_ts = ts; + if (single) + break; + } + } + } + if (single && slotcount) { + LOGP(DRLCMAC, LOGL_INFO, "Using single slot at TS %d for %s\n", + tbf->first_ts, + (tbf->direction == GPRS_RLCMAC_DL_TBF) ? "DL" : "UL"); + } else { + LOGP(DRLCMAC, LOGL_INFO, "Using %d slots for %s\n", slotcount, + (tbf->direction == GPRS_RLCMAC_DL_TBF) ? "DL" : "UL"); + } + if (slotcount == 0) + return -EBUSY; + + tbf->first_common_ts = first_common_ts; + + return 0; +} |