/* gprs_rlcmac.cpp * * Copyright (C) 2012 Ivan Klyuchnikov * Copyright (C) 2012 Andreas Eversberg * 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 #include #include #include #include #include #include #include #include #include extern "C" { #include "mslot_class.h" #include #include #include } /* Consider a PDCH as idle if has at most this number of TBFs assigned to it */ #define PDCH_IDLE_TBF_THRESH 1 #define LOGPSL(tbf, level, fmt, args...) LOGP(DRLCMAC, level, "[%s] " fmt, \ (tbf->direction == GPRS_RLCMAC_DL_TBF) ? "DL" : "UL", ## args) #define LOGPAL(tbf, kind, single, trx_n, level, fmt, args...) LOGPSL(tbf, level, \ "algo %s <%s> (suggested TRX: %d): " fmt, \ kind, single ? "single" : "multi", trx_n, ## args) static char *set_flag_chars(char *buf, uint8_t val, char set_char, char unset_char = 0) { int i; for (i = 0; i < 8; i += 1, val = val >> 1) { if (val & 1) buf[i] = set_char; else if (unset_char) buf[i] = unset_char; } return buf; } static uint8_t find_possible_pdchs(const struct gprs_rlcmac_trx *trx, uint8_t max_slots, uint8_t mask, const char *mask_reason = NULL) { unsigned ts; uint8_t valid_ts_set = 0; int8_t last_tsc = -1; /* must be signed */ for (ts = 0; ts < ARRAY_SIZE(trx->pdch); ts++) { const 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; } if (((1 << ts) & mask) == 0) { if (mask_reason) LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, because %s\n", ts, mask_reason); continue; } if (max_slots > 1) { /* check if TSC changes, see TS 45.002, 6.4.2 */ 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, trx->trx_no); continue; } } valid_ts_set |= 1 << ts; } return valid_ts_set; } static int compute_usage_by_num_tbfs(const struct gprs_rlcmac_pdch *pdch, enum gprs_rlcmac_tbf_direction dir) { return pdch->num_tbfs(dir); } static int compute_usage_by_reservation(const struct gprs_rlcmac_pdch *pdch, enum gprs_rlcmac_tbf_direction) { return pdch->num_reserved(GPRS_RLCMAC_DL_TBF) + pdch->num_reserved(GPRS_RLCMAC_UL_TBF); } static int compute_usage_for_algo_a(const struct gprs_rlcmac_pdch *pdch, enum gprs_rlcmac_tbf_direction dir) { int usage = pdch->num_tbfs(GPRS_RLCMAC_DL_TBF) + pdch->num_tbfs(GPRS_RLCMAC_UL_TBF) + compute_usage_by_reservation(pdch, dir); if (pdch->assigned_tfi(reverse(dir)) == NO_FREE_TFI) /* No TFI in the opposite direction, avoid it */ usage += 32; return usage; } /*! Return the TS which corresponds to least busy PDCH * * \param[in] trx Pointer to TRX object * \param[in] dir TBF direction * \param[in] mask set of available timeslots * \param[in] fn Function pointer to function which computes number of associated TBFs * \param[out] free_tfi Free TFI * \param[out] free_usf Free USF * \returns TS number or -1 if unable to find */ static int find_least_busy_pdch(const struct gprs_rlcmac_trx *trx, enum gprs_rlcmac_tbf_direction dir, uint8_t mask, int (*fn)(const struct gprs_rlcmac_pdch *, enum gprs_rlcmac_tbf_direction dir), int *free_tfi = NULL, int *free_usf = NULL) { unsigned ts; int min_used = INT_MAX; int min_ts = -1; int min_tfi = -1; int min_usf = -1; for (ts = 0; ts < ARRAY_SIZE(trx->pdch); ts++) { const struct gprs_rlcmac_pdch *pdch = &trx->pdch[ts]; int num_tbfs; int usf = -1; /* must be signed */ int tfi = -1; if (((1 << ts) & mask) == 0) continue; num_tbfs = fn(pdch, dir); if (num_tbfs < min_used) { /* We have found a candidate */ /* Make sure that a TFI is available */ if (free_tfi) { tfi = find_free_tfi(pdch->assigned_tfi(dir)); if (tfi < 0) { LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, because " "no TFI available\n", ts); continue; } } /* Make sure that an USF is available */ if (dir == GPRS_RLCMAC_UL_TBF) { usf = find_free_usf(pdch->assigned_usf()); if (usf < 0) { LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, because " "no USF available\n", ts); continue; } } if (min_ts >= 0) LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, because " "num TBFs %d > %d\n", min_ts, min_used, num_tbfs); min_used = num_tbfs; min_ts = ts; min_tfi = tfi; min_usf = usf; } else { LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, because " "num TBFs %d >= %d\n", ts, num_tbfs, min_used); } } if (min_ts < 0) return -1; if (free_tfi) *free_tfi = min_tfi; if (free_usf) *free_usf = min_usf; return min_ts; } static void attach_tbf_to_pdch(struct gprs_rlcmac_pdch *pdch, struct gprs_rlcmac_tbf *tbf) { if (tbf->pdch[pdch->ts_no]) tbf->pdch[pdch->ts_no]->detach_tbf(tbf); tbf->pdch[pdch->ts_no] = pdch; pdch->attach_tbf(tbf); } static void assign_uplink_tbf_usf(struct gprs_rlcmac_pdch *pdch, struct gprs_rlcmac_ul_tbf *tbf, uint8_t tfi, int8_t usf) { tbf->m_tfi = tfi; tbf->m_usf[pdch->ts_no] = usf; attach_tbf_to_pdch(pdch, tbf); } static void assign_dlink_tbf(struct gprs_rlcmac_pdch *pdch, struct gprs_rlcmac_dl_tbf *tbf, uint8_t tfi) { tbf->m_tfi = tfi; attach_tbf_to_pdch(pdch, tbf); } static int find_trx(const struct gprs_rlcmac_bts *bts, const GprsMs *ms, int8_t use_trx) { unsigned trx_no; unsigned ts; /* We must use the TRX currently actively used by an MS */ if (ms && ms_current_trx(ms)) return ms_current_trx(ms)->trx_no; if (use_trx >= 0 && use_trx < 8) return use_trx; /* Find the first TRX that has a PDCH with a free UL and DL TFI */ for (trx_no = 0; trx_no < ARRAY_SIZE(bts->trx); trx_no += 1) { const struct gprs_rlcmac_trx *trx = &bts->trx[trx_no]; for (ts = 0; ts < ARRAY_SIZE(trx->pdch); ts++) { const struct gprs_rlcmac_pdch *pdch = &trx->pdch[ts]; if (!pdch->is_enabled()) continue; if (pdch->assigned_tfi(GPRS_RLCMAC_UL_TBF) == NO_FREE_TFI) continue; if (pdch->assigned_tfi(GPRS_RLCMAC_DL_TBF) == NO_FREE_TFI) continue; return trx_no; } } return -EBUSY; } static bool idle_pdch_avail(const struct gprs_rlcmac_bts *bts) { unsigned trx_no; unsigned ts; /* Find the first PDCH with an unused DL TS */ for (trx_no = 0; trx_no < ARRAY_SIZE(bts->trx); trx_no += 1) { const struct gprs_rlcmac_trx *trx = &bts->trx[trx_no]; for (ts = 0; ts < ARRAY_SIZE(trx->pdch); ts++) { const struct gprs_rlcmac_pdch *pdch = &trx->pdch[ts]; if (!pdch->is_enabled()) continue; if (pdch->num_tbfs(GPRS_RLCMAC_DL_TBF) > PDCH_IDLE_TBF_THRESH) continue; return true; } } return false; } /*! Return free TFI * * \param[in] bts Pointer to BTS struct * \param[in] ms Pointer to MS object * \param[in] dir DL or UL direction * \param[in] use_trx which TRX to use or -1 if it should be selected based on what MS uses * \param[out] trx_no_ TRX number on which TFI was found * \returns negative error code or 0 on success */ static int tfi_find_free(const struct gprs_rlcmac_bts *bts, const GprsMs *ms, enum gprs_rlcmac_tbf_direction dir, int8_t use_trx, uint8_t *trx_no_) { const struct gprs_rlcmac_trx *trx; int tfi; uint8_t trx_no; /* If MS is already doing stuff on a TRX, set use_trx to it: */ if ((trx = ms_current_trx(ms))) { if (use_trx >= 0 && use_trx != trx->trx_no) { LOGP(DRLCMAC, LOGL_ERROR, "- Requested incompatible TRX %d (current is %d)\n", use_trx, trx->trx_no); return -EINVAL; } use_trx = trx->trx_no; } tfi = bts_tfi_find_free(bts, dir, &trx_no, use_trx); if (tfi < 0) return -EBUSY; if (trx_no_) *trx_no_ = trx_no; return tfi; } /*! Slot Allocation: Algorithm A * * Assign single slot for uplink and downlink * * \param[in,out] bts Pointer to BTS struct * \param[in,out] tbf Pointer to TBF struct * \param[in] single flag indicating if we should force single-slot allocation * \param[in] use_trx which TRX to use or -1 if it should be selected during allocation * \returns negative error code or 0 on success */ int alloc_algorithm_a(struct gprs_rlcmac_bts *bts, struct gprs_rlcmac_tbf *tbf, bool single, int8_t use_trx) { struct gprs_rlcmac_pdch *pdch; int ts = -1; uint8_t ul_slots, dl_slots; int trx_no; int tfi = -1; int usf = -1; uint8_t mask = 0xff; const char *mask_reason = NULL; struct GprsMs *ms = tbf->ms(); gprs_rlcmac_trx *trx = ms_current_trx(ms); LOGPAL(tbf, "A", single, use_trx, LOGL_DEBUG, "Alloc start\n"); trx_no = find_trx(bts, ms, use_trx); if (trx_no < 0) { LOGPAL(tbf, "A", single, use_trx, LOGL_NOTICE, "failed to find a usable TRX (TFI exhausted)\n"); return trx_no; } if (!trx) trx = &bts->trx[trx_no]; dl_slots = ms_reserved_dl_slots(ms); ul_slots = ms_reserved_ul_slots(ms); ts = ms_first_common_ts(ms); if (ts >= 0) { mask_reason = "need to reuse TS"; mask = 1 << ts; } else if (dl_slots || ul_slots) { mask_reason = "need to use a reserved common TS"; mask = dl_slots & ul_slots; } mask = find_possible_pdchs(trx, 1, mask, mask_reason); if (!mask) return -EINVAL; ts = find_least_busy_pdch(trx, tbf->direction, mask, compute_usage_for_algo_a, &tfi, &usf); if (tbf->direction == GPRS_RLCMAC_UL_TBF && usf < 0) { LOGPAL(tbf, "A", single, use_trx, LOGL_NOTICE, "failed to allocate a TS, no USF available\n"); return -EBUSY; } if (ts < 0) { LOGPAL(tbf, "A", single, use_trx, LOGL_NOTICE, "failed to allocate a TS, no TFI available\n"); return -EBUSY; } pdch = &trx->pdch[ts]; /* The allocation will be successful, so the system state and tbf/ms * may be modified from now on. */ if (tbf->direction == GPRS_RLCMAC_UL_TBF) { struct gprs_rlcmac_ul_tbf *ul_tbf = as_ul_tbf(tbf); LOGPSL(tbf, LOGL_DEBUG, "Assign uplink TS=%d TFI=%d USF=%d\n", ts, tfi, usf); assign_uplink_tbf_usf(pdch, ul_tbf, tfi, usf); } else { struct gprs_rlcmac_dl_tbf *dl_tbf = as_dl_tbf(tbf); LOGPSL(tbf, LOGL_DEBUG, "Assign downlink TS=%d TFI=%d\n", ts, tfi); assign_dlink_tbf(pdch, dl_tbf, tfi); } tbf->trx = trx; /* the only one TS is the common TS */ tbf->first_ts = tbf->first_common_ts = ts; ms_set_reserved_slots(ms, trx, 1 << ts, 1 << ts); tbf->upgrade_to_multislot = false; bts_do_rate_ctr_inc(bts, CTR_TBF_ALLOC_ALGO_A); return 0; } /*! Compute capacity of a given TRX * * \param[in] trx Pointer to TRX object * \param[in] rx_window Receive window * \param[in] tx_window Transmit window * \returns non-negative capacity */ static inline unsigned compute_capacity(const struct gprs_rlcmac_trx *trx, int rx_window, int tx_window) { const struct gprs_rlcmac_pdch *pdch; unsigned ts, capacity = 0; for (ts = 0; ts < ARRAY_SIZE(trx->pdch); ts++) { pdch = &trx->pdch[ts]; if (rx_window & (1 << ts)) capacity += OSMO_MAX(32 - pdch->num_reserved(GPRS_RLCMAC_DL_TBF), 1); /* Only consider common slots for UL */ if (tx_window & rx_window & (1 << ts)) { if (find_free_usf(pdch->assigned_usf()) >= 0) capacity += OSMO_MAX(32 - pdch->num_reserved(GPRS_RLCMAC_UL_TBF), 1); } } return capacity; } /*! Decide if a given slot should be skipped by multislot allocator * * \param[in] ms_class Pointer to MS Class object * \param[in] check_tr Flag indicating whether we should check for Tra or Tta parameters for a given MS class * \param[in] rx_window Receive window * \param[in] tx_window Transmit window * \param[in,out] checked_rx array with already checked RX timeslots * \returns true if the slot should be skipped, false otherwise */ static bool skip_slot(uint8_t mslot_class, bool check_tr, int16_t rx_window, int16_t tx_window, uint32_t *checked_rx) { uint8_t common_slot_count, req_common_slots, rx_slot_count = pcu_bitcount(rx_window), tx_slot_count = pcu_bitcount(tx_window); /* Check compliance with TS 45.002, table 6.4.2.2.1 */ /* Whether to skip this round doesn not only depend on the bit * sets but also on check_tr. Therefore this check must be done * before doing the mslot_test_and_set_bit shortcut. */ if (mslot_class_get_type(mslot_class) == 1) { uint16_t slot_sum = rx_slot_count + tx_slot_count; /* Assume down + up / dynamic. * TODO: For ext-dynamic, down only, up only add more cases. */ if (slot_sum <= 6 && tx_slot_count < 3) { if (!check_tr) return true; /* Skip Tta */ } else if (slot_sum > 6 && tx_slot_count < 3) { if (check_tr) return true; /* Skip Tra */ } else return true; /* No supported row in TS 45.002, table 6.4.2.2.1. */ } /* Avoid repeated RX combination check */ if (mslot_test_and_set_bit(checked_rx, rx_window)) return true; /* Check number of common slots according to TS 45.002, ยง6.4.2.2 */ common_slot_count = pcu_bitcount(tx_window & rx_window); req_common_slots = OSMO_MIN(tx_slot_count, rx_slot_count); if (mslot_class_get_type(mslot_class) == 1) req_common_slots = OSMO_MIN(req_common_slots, 2); if (req_common_slots != common_slot_count) return true; return false; } /*! Find set of slots available for allocation while taking MS class into account * * \param[in] trx Pointer to TRX object * \param[in] mslot_class The multislot class * \param[in,out] ul_slots set of UL timeslots * \param[in,out] dl_slots set of DL timeslots * \returns negative error code or 0 on success */ int find_multi_slots(struct gprs_rlcmac_trx *trx, uint8_t mslot_class, uint8_t *ul_slots, uint8_t *dl_slots) { const uint8_t Rx = mslot_class_get_rx(mslot_class), /* Max number of Rx slots */ Tx = mslot_class_get_tx(mslot_class), /* Max number of Tx slots */ Sum = mslot_class_get_sum(mslot_class), /* Max number of Tx + Rx slots */ Type = mslot_class_get_type(mslot_class); uint8_t max_slots, num_rx, num_tx, mask_sel, pdch_slots, ul_ts, dl_ts; int16_t rx_window, tx_window; char slot_info[9] = {0}; int max_capacity = -1; uint8_t max_ul_slots = 0, max_dl_slots = 0; if (mslot_class) LOGP(DRLCMAC, LOGL_DEBUG, "Slot Allocation (Algorithm B) for class %d\n", mslot_class); if (Tx == MS_NA) { LOGP(DRLCMAC, LOGL_NOTICE, "Multislot class %d not applicable.\n", mslot_class); return -EINVAL; } max_slots = OSMO_MAX(Rx, Tx); if (*dl_slots == 0) *dl_slots = 0xff; if (*ul_slots == 0) *ul_slots = 0xff; pdch_slots = find_possible_pdchs(trx, max_slots, 0xff); *dl_slots &= pdch_slots; *ul_slots &= pdch_slots; LOGP(DRLCMAC, LOGL_DEBUG, "- Possible DL/UL slots: (TS=0)\"%s\"(TS=7)\n", set_flag_chars(set_flag_chars(set_flag_chars(slot_info, *dl_slots, 'D', '.'), *ul_slots, 'U'), *ul_slots & *dl_slots, 'C')); /* Check for each UL (TX) slot */ /* Iterate through possible numbers of TX slots */ for (num_tx = 1; num_tx <= Tx; num_tx += 1) { uint16_t tx_valid_win = (1 << num_tx) - 1; uint8_t rx_mask[MASK_TR + 1]; mslot_fill_rx_mask(mslot_class, num_tx, rx_mask); /* Rotate group of TX slots: UUU-----, -UUU----, ..., UU-----U */ for (ul_ts = 0; ul_ts < 8; ul_ts += 1, tx_valid_win <<= 1) { uint16_t rx_valid_win; uint32_t checked_rx[256/32] = {0}; /* Wrap valid window */ tx_valid_win = mslot_wrap_window(tx_valid_win); /* for multislot type 1: don't split the window to wrap around. * E.g. 'UU-----U' is invalid for a 4 TN window. Except 8 TN window. * See 45.002 B.1 */ if (Type == 1 && num_tx < 8 && tx_valid_win & (1 << 0) && tx_valid_win & (1 << 7)) continue; tx_window = tx_valid_win; /* Filter out unavailable slots */ tx_window &= *ul_slots; /* Skip if the the first TS (ul_ts) is not in the set */ if ((tx_window & (1 << ul_ts)) == 0) continue; /* Skip if the the last TS (ul_ts+num_tx-1) is not in the set */ if ((tx_window & (1 << ((ul_ts+num_tx-1) % 8))) == 0) continue; num_rx = OSMO_MIN(Rx, Sum - num_tx); rx_valid_win = (1 << num_rx) - 1; /* Rotate group of RX slots: DDD-----, -DDD----, ..., DD-----D */ for (dl_ts = 0; dl_ts < 8; dl_ts += 1, rx_valid_win <<= 1) { /* Wrap valid window */ rx_valid_win = (rx_valid_win | rx_valid_win >> 8) & 0xff; /* for multislot type 1: don't split the window to wrap around. * E.g. 'DD-----D' is invalid for a 4 TN window. Except 8 TN window. * See 45.002 B.1 */ if (Type == 1 && num_rx < 8 && (rx_valid_win & (1 << 0)) && (rx_valid_win & (1 << 7))) continue; /* Validate with both Tta/Ttb/Trb and Ttb/Tra/Trb */ for (mask_sel = MASK_TT; mask_sel <= MASK_TR; mask_sel += 1) { int capacity; rx_window = mslot_filter_bad(rx_mask[mask_sel], ul_ts, *dl_slots, rx_valid_win); if (rx_window < 0) continue; if (skip_slot(mslot_class, mask_sel != MASK_TT, rx_window, tx_window, checked_rx)) continue; /* Compute capacity */ capacity = compute_capacity(trx, rx_window, tx_window); #ifdef ENABLE_TS_ALLOC_DEBUG LOGP(DRLCMAC, LOGL_DEBUG, "- Considering DL/UL slots: (TS=0)\"%s\"(TS=7), " "capacity = %d\n", set_flag_chars(set_flag_chars(set_flag_chars(set_flag_chars( slot_info, rx_bad, 'x', '.'), rx_window, 'D'), tx_window, 'U'), rx_window & tx_window, 'C'), capacity); #endif if (capacity <= max_capacity) continue; max_capacity = capacity; max_ul_slots = tx_window; max_dl_slots = rx_window; } } } } if (!max_ul_slots || !max_dl_slots) { LOGP(DRLCMAC, LOGL_NOTICE, "No valid UL/DL slot combination found\n"); bts_do_rate_ctr_inc(trx->bts, CTR_TBF_ALLOC_FAIL_NO_SLOT_COMBI); return -EINVAL; } *ul_slots = max_ul_slots; *dl_slots = max_dl_slots; return 0; } /*! Count used bits in slots and reserved_slots bitmasks * * \param[in] slots Timeslots in use * \param[in] reserved_slots Reserved timeslots * \param[out] slotcount Number of TS in use * \param[out] reserve_count Number of reserved TS */ static void count_slots(uint8_t slots, uint8_t reserved_slots, uint8_t *slotcount, uint8_t *reserve_count) { (*slotcount) = pcu_bitcount(slots); (*reserve_count) = pcu_bitcount(reserved_slots); } /*! Return slot mask with single TS from a given UL/DL set according to TBF's direction, ts pointer is set to that TS * number or to negative value on error * * \param[in] trx Pointer to TRX object * \param[in] tbf Pointer to TBF object * \param[in] dl_slots set of DL timeslots * \param[in] ul_slots set of UL timeslots * \param[in] ts corresponding TS or -1 for autoselection * \returns slot mask with single UL or DL timeslot number if possible */ static uint8_t get_single_ts(const gprs_rlcmac_trx *trx, const gprs_rlcmac_tbf *tbf, uint8_t dl_slots, uint8_t ul_slots, int ts) { uint8_t ret = dl_slots & ul_slots; /* Make sure to consider the first common slot only */ if (ts < 0) ts = find_least_busy_pdch(trx, tbf->direction, ret, compute_usage_by_num_tbfs, NULL, NULL); if (ts < 0) return ffs(ret); return ret & (1 << ts); } /*! Find set of timeslots available for allocation * * \param[in] trx Pointer to TRX object * \param[in] tbf Pointer to TBF object * \param[in] single Flag to force the single TS allocation * \param[in] ul_slots set of UL timeslots * \param[in] dl_slots set of DL timeslots * \param[in] reserved_ul_slots set of reserved UL timeslots * \param[in] reserved_dl_slots set of reserved DL timeslots * \param[in] first_common_ts First TS common for both UL and DL or -1 if unknown * \returns negative error code or selected TS on success */ static int tbf_select_slot_set(const gprs_rlcmac_tbf *tbf, const gprs_rlcmac_trx *trx, bool single, uint8_t ul_slots, uint8_t dl_slots, uint8_t reserved_ul_slots, uint8_t reserved_dl_slots, int8_t first_common_ts) { bool is_ul = tbf->direction == GPRS_RLCMAC_UL_TBF; uint8_t sl = is_ul ? ul_slots : dl_slots; char slot_info[9] = { 0 }; if (single) sl = get_single_ts(trx, tbf, dl_slots, ul_slots, first_common_ts); if (!sl) { LOGP(DRLCMAC, LOGL_NOTICE, "No %s slots available\n", is_ul ? "uplink" : "downlink"); bts_do_rate_ctr_inc(trx->bts, CTR_TBF_ALLOC_FAIL_NO_SLOT_AVAIL); return -EINVAL; } if (is_ul) { snprintf(slot_info, 9, OSMO_BIT_SPEC, OSMO_BIT_PRINT_EX(reserved_ul_slots, 'u')); masked_override_with(slot_info, sl, 'U'); } else { snprintf(slot_info, 9, OSMO_BIT_SPEC, OSMO_BIT_PRINT_EX(reserved_dl_slots, 'd')); masked_override_with(slot_info, sl, 'D'); } LOGPC(DRLCMAC, LOGL_DEBUG, "Selected %s slots: (TS=0)\"%s\"(TS=7), %s\n", is_ul ? "UL" : "DL", slot_info, single ? "single" : "multi"); return sl; } /*! Allocate USF according to a given UL TS mapping * * \param[in] trx Pointer to TRX object * \param[in] selected_ul_slots set of UL timeslots selected for allocation * \param[in] dl_slots set of DL timeslots * \param[out] usf array for allocated USF * \returns updated UL TS mask or negative on error */ static int allocate_usf(const gprs_rlcmac_trx *trx, uint8_t selected_ul_slots, uint8_t dl_slots, int *usf_list) { uint8_t ul_slots = selected_ul_slots & dl_slots; unsigned int ts; for (ts = 0; ts < ARRAY_SIZE(trx->pdch); ts++) { const struct gprs_rlcmac_pdch *pdch = &trx->pdch[ts]; int8_t free_usf; if (((1 << ts) & ul_slots) == 0) continue; free_usf = find_free_usf(pdch->assigned_usf()); if (free_usf < 0) { LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, because " "no USF available\n", ts); ul_slots &= (~(1 << ts)) & 0xff; continue; } usf_list[ts] = free_usf; } if (!ul_slots) { LOGP(DRLCMAC, LOGL_NOTICE, "No USF available\n"); bts_do_rate_ctr_inc(trx->bts, CTR_TBF_ALLOC_FAIL_NO_USF); return -EBUSY; } return ul_slots; } /*! Update MS' reserved timeslots * * \param[in,out] trx Pointer to TRX struct * \param[in,out] ms_ Pointer to MS object * \param[in] tbf_ Pointer to TBF struct * \param[in] res_ul_slots Newly reserved UL slots * \param[in] res_dl_slots Newly reserved DL slots * \param[in] ul_slots available UL slots (for logging only) * \param[in] dl_slots available DL slots (for logging only) */ static void update_ms_reserved_slots(gprs_rlcmac_trx *trx, GprsMs *ms, uint8_t res_ul_slots, uint8_t res_dl_slots, uint8_t ul_slots, uint8_t dl_slots) { char slot_info[9] = { 0 }; if (res_ul_slots == ms_reserved_ul_slots(ms) && res_dl_slots == ms_reserved_dl_slots(ms)) return; /* The reserved slots have changed, update the MS */ ms_set_reserved_slots(ms, trx, res_ul_slots, res_dl_slots); ts_format(slot_info, dl_slots, ul_slots); LOGP(DRLCMAC, LOGL_DEBUG, "- Reserved DL/UL slots: (TS=0)\"%s\"(TS=7)\n", slot_info); } /*! Assign given UL timeslots to UL TBF * * \param[in,out] ul_tbf Pointer to UL TBF struct * \param[in,out] trx Pointer to TRX object * \param[in] ul_slots Set of slots to be assigned * \param[in] tfi selected TFI * \param[in] usf selected USF */ static void assign_ul_tbf_slots(struct gprs_rlcmac_ul_tbf *ul_tbf, gprs_rlcmac_trx *trx, uint8_t ul_slots, int tfi, int *usf) { uint8_t ts; for (ts = 0; ts < 8; ts++) { if (!(ul_slots & (1 << ts))) continue; OSMO_ASSERT(usf[ts] >= 0); LOGP(DRLCMAC, LOGL_DEBUG, "- Assigning UL TS %u\n", ts); assign_uplink_tbf_usf(&trx->pdch[ts], ul_tbf, tfi, usf[ts]); } } /*! Assign given DL timeslots to DL TBF * * \param[in,out] dl_tbf Pointer to DL TBF struct * \param[in,out] trx Pointer to TRX object * \param[in] ul_slots Set of slots to be assigned * \param[in] tfi selected TFI */ static void assign_dl_tbf_slots(struct gprs_rlcmac_dl_tbf *dl_tbf, gprs_rlcmac_trx *trx, uint8_t dl_slots, int tfi) { uint8_t ts; for (ts = 0; ts < 8; ts++) { if (!(dl_slots & (1 << ts))) continue; LOGP(DRLCMAC, LOGL_DEBUG, "- Assigning DL TS %u\n", ts); assign_dlink_tbf(&trx->pdch[ts], dl_tbf, tfi); } } /*! Slot Allocation: Algorithm B * * Assign as many downlink slots as possible. * Assign one uplink slot. (With free USF) * * \param[in,out] bts Pointer to BTS struct * \param[in,out] tbf Pointer to TBF struct * \param[in] single flag indicating if we should force single-slot allocation * \param[in] use_trx which TRX to use or -1 if it should be selected during allocation * \returns negative error code or 0 on success */ int alloc_algorithm_b(struct gprs_rlcmac_bts *bts, struct gprs_rlcmac_tbf *tbf, bool single, int8_t use_trx) { uint8_t dl_slots; uint8_t ul_slots; uint8_t reserved_dl_slots; uint8_t reserved_ul_slots; int8_t first_common_ts; uint8_t slotcount = 0; uint8_t reserve_count = 0, trx_no; int first_ts = -1; int usf[8] = {-1, -1, -1, -1, -1, -1, -1, -1}; int rc; int tfi; struct GprsMs *ms = tbf->ms(); gprs_rlcmac_trx *trx; LOGPAL(tbf, "B", single, use_trx, LOGL_DEBUG, "Alloc start\n"); /* Step 1: Get current state from the MS object */ reserved_dl_slots = ms_reserved_dl_slots(ms); reserved_ul_slots = ms_reserved_ul_slots(ms); first_common_ts = ms_first_common_ts(ms); /* Step 2a: Find usable TRX and TFI */ tfi = tfi_find_free(bts, ms, tbf->direction, use_trx, &trx_no); if (tfi < 0) { LOGPAL(tbf, "B", single, use_trx, LOGL_NOTICE, "failed to allocate a TFI\n"); return tfi; } /* Step 2b: Reserve slots on the TRX for the MS */ trx = &bts->trx[trx_no]; if (!reserved_dl_slots || !reserved_ul_slots) { rc = find_multi_slots(trx, ms_ms_class(ms), &reserved_ul_slots, &reserved_dl_slots); if (rc < 0) return rc; } dl_slots = reserved_dl_slots; ul_slots = reserved_ul_slots; /* Step 3a: Derive the slot set for the current TBF */ rc = tbf_select_slot_set(tbf, trx, single, ul_slots, dl_slots, reserved_ul_slots, reserved_dl_slots, first_common_ts); if (rc < 0) return -EINVAL; /* Step 3b: Derive the slot set for a given direction */ if (tbf->direction == GPRS_RLCMAC_DL_TBF) { dl_slots = rc; count_slots(dl_slots, reserved_dl_slots, &slotcount, &reserve_count); } else { rc = allocate_usf(trx, rc, dl_slots, usf); if (rc < 0) return rc; ul_slots = rc; reserved_ul_slots = ul_slots; count_slots(ul_slots, reserved_ul_slots, &slotcount, &reserve_count); } first_ts = ffs(rc) - 1; first_common_ts = ffs(dl_slots & ul_slots) - 1; if (first_common_ts < 0) { LOGPAL(tbf, "B", single, use_trx, LOGL_NOTICE, "first common slot unavailable\n"); return -EINVAL; } if (first_ts < 0) { LOGPAL(tbf, "B", single, use_trx, LOGL_NOTICE, "first slot unavailable\n"); return -EINVAL; } if (single && slotcount) { tbf->upgrade_to_multislot = (reserve_count > slotcount); LOGPAL(tbf, "B", single, use_trx, LOGL_INFO, "using single slot at TS %d\n", first_ts); } else { tbf->upgrade_to_multislot = false; LOGPAL(tbf, "B", single, use_trx, LOGL_INFO, "using %d slots\n", slotcount); } /* The allocation will be successful, so the system state and tbf/ms * may be modified from now on. */ /* Step 4: Update MS and TBF and really allocate the resources */ update_ms_reserved_slots(trx, ms, reserved_ul_slots, reserved_dl_slots, ul_slots, dl_slots); tbf->trx = trx; tbf->first_common_ts = first_common_ts; tbf->first_ts = first_ts; if (tbf->direction == GPRS_RLCMAC_DL_TBF) assign_dl_tbf_slots(as_dl_tbf(tbf), trx, dl_slots, tfi); else assign_ul_tbf_slots(as_ul_tbf(tbf), trx, ul_slots, tfi, usf); bts_do_rate_ctr_inc(bts, CTR_TBF_ALLOC_ALGO_B); return 0; } /*! Slot Allocation: Algorithm dynamic * * This meta algorithm automatically selects on of the other algorithms based * on the current system state. * * The goal is to support as many MS and TBF as possible. On low usage, the * goal is to provide the highest possible bandwidth per MS. * * \param[in,out] bts Pointer to BTS struct * \param[in,out] tbf Pointer to TBF struct * \param[in] single flag indicating if we should force single-slot allocation * \param[in] use_trx which TRX to use or -1 if it should be selected during allocation * \returns negative error code or 0 on success */ int alloc_algorithm_dynamic(struct gprs_rlcmac_bts *bts, struct gprs_rlcmac_tbf *tbf, bool single, int8_t use_trx) { int rc; /* Reset load_is_high if there is at least one idle PDCH */ if (bts->multislot_disabled) { bts->multislot_disabled = !idle_pdch_avail(bts); if (!bts->multislot_disabled) LOGP(DRLCMAC, LOGL_DEBUG, "Enabling algorithm B\n"); } if (!bts->multislot_disabled) { rc = alloc_algorithm_b(bts, tbf, single, use_trx); if (rc >= 0) return rc; if (!bts->multislot_disabled) LOGP(DRLCMAC, LOGL_DEBUG, "Disabling algorithm B\n"); bts->multislot_disabled = 1; } return alloc_algorithm_a(bts, tbf, single, use_trx); } int gprs_alloc_max_dl_slots_per_ms(const struct gprs_rlcmac_bts *bts, uint8_t ms_class) { int rx = mslot_class_get_rx(ms_class); if (rx == MS_NA) rx = 4; if (the_pcu->alloc_algorithm == alloc_algorithm_a) return 1; if (bts->multislot_disabled) return 1; return rx; }