| /* 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 <tbf_ul.h> |
| #include <pdch.h> |
| #include <gprs_ms.h> |
| #include <pcu_utils.h> |
| |
| #include <errno.h> |
| #include <values.h> |
| |
| extern "C" { |
| #include "mslot_class.h" |
| #include <osmocom/core/linuxlist.h> |
| #include <osmocom/core/logging.h> |
| #include <osmocom/core/utils.h> |
| } |
| |
| /* 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] trx Optional pointer to TRX 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 gprs_rlcmac_trx *trx, const GprsMs *ms, |
| enum gprs_rlcmac_tbf_direction dir, int8_t use_trx, uint8_t *trx_no_) |
| { |
| int tfi; |
| uint8_t trx_no; |
| |
| if (trx) { |
| 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; |
| } |
| |
| if (use_trx == -1 && ms_current_trx(ms)) |
| use_trx = ms_current_trx(ms)->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, §6.4.2.2 */ |
| 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] avail_count Number of reserved TS |
| */ |
| static void update_slot_counters(uint8_t slots, uint8_t reserved_slots, uint8_t *slotcount, uint8_t *avail_count) |
| { |
| (*slotcount) = pcu_bitcount(slots); |
| (*avail_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 avail_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); |
| trx = ms_current_trx(ms); |
| |
| /* Step 2a: Find usable TRX and TFI */ |
| tfi = tfi_find_free(bts, trx, 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 */ |
| if (!trx) |
| 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; |
| update_slot_counters(dl_slots, reserved_dl_slots, &slotcount, &avail_count); |
| } else { |
| rc = allocate_usf(trx, rc, dl_slots, usf); |
| if (rc < 0) |
| return rc; |
| |
| ul_slots = rc; |
| reserved_ul_slots = ul_slots; |
| |
| update_slot_counters(ul_slots, reserved_ul_slots, &slotcount, &avail_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 = (avail_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; |
| } |