1012 lines
29 KiB
C++
1012 lines
29 KiB
C++
/* gprs_rlcmac.cpp
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*
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* Copyright (C) 2012 Ivan Klyuchnikov
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* Copyright (C) 2012 Andreas Eversberg <jolly@eversberg.eu>
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* Copyright (C) 2013 by Holger Hans Peter Freyther
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#include <gprs_rlcmac.h>
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#include <gprs_debug.h>
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#include <bts.h>
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#include <tbf.h>
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#include <pdch.h>
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#include <gprs_ms.h>
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#include <pcu_utils.h>
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#include <errno.h>
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#include <values.h>
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extern "C" {
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#include "mslot_class.h"
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#include <osmocom/core/linuxlist.h>
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#include <osmocom/core/logging.h>
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#include <osmocom/core/utils.h>
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}
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/* Consider a PDCH as idle if has at most this number of TBFs assigned to it */
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#define PDCH_IDLE_TBF_THRESH 1
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#define LOGPSL(tbf, level, fmt, args...) LOGP(DRLCMAC, level, "[%s] " fmt, \
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(tbf->direction == GPRS_RLCMAC_DL_TBF) ? "DL" : "UL", ## args)
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#define LOGPAL(tbf, kind, single, trx_n, level, fmt, args...) LOGPSL(tbf, level, \
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"algo %s <%s> (suggested TRX: %d): " fmt, \
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kind, single ? "single" : "multi", trx_n, ## args)
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static char *set_flag_chars(char *buf, uint8_t val, char set_char, char unset_char = 0)
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{
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int i;
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for (i = 0; i < 8; i += 1, val = val >> 1) {
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if (val & 1)
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buf[i] = set_char;
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else if (unset_char)
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buf[i] = unset_char;
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}
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return buf;
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}
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static uint8_t find_possible_pdchs(const struct gprs_rlcmac_trx *trx, uint8_t max_slots, uint8_t mask,
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const char *mask_reason = NULL)
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{
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unsigned ts;
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uint8_t valid_ts_set = 0;
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int8_t last_tsc = -1; /* must be signed */
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for (ts = 0; ts < ARRAY_SIZE(trx->pdch); ts++) {
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const struct gprs_rlcmac_pdch *pdch;
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pdch = &trx->pdch[ts];
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if (!pdch->is_enabled()) {
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LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, because "
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"not enabled\n", ts);
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continue;
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}
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if (((1 << ts) & mask) == 0) {
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if (mask_reason)
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LOGP(DRLCMAC, LOGL_DEBUG,
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"- Skipping TS %d, because %s\n",
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ts, mask_reason);
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continue;
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}
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if (max_slots > 1) {
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/* check if TSC changes, see TS 45.002, 6.4.2 */
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if (last_tsc < 0)
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last_tsc = pdch->tsc;
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else if (last_tsc != pdch->tsc) {
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LOGP(DRLCMAC, LOGL_ERROR,
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"Skipping TS %d of TRX=%d, because it "
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"has different TSC than lower TS of TRX. "
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"In order to allow multislot, all "
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"slots must be configured with the same "
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"TSC!\n", ts, trx->trx_no);
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continue;
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}
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}
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valid_ts_set |= 1 << ts;
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}
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return valid_ts_set;
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}
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static int compute_usage_by_num_tbfs(const struct gprs_rlcmac_pdch *pdch, enum gprs_rlcmac_tbf_direction dir)
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{
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return pdch->num_tbfs(dir);
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}
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static int compute_usage_by_reservation(const struct gprs_rlcmac_pdch *pdch, enum gprs_rlcmac_tbf_direction)
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{
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return
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pdch->num_reserved(GPRS_RLCMAC_DL_TBF) +
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pdch->num_reserved(GPRS_RLCMAC_UL_TBF);
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}
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static int compute_usage_for_algo_a(const struct gprs_rlcmac_pdch *pdch, enum gprs_rlcmac_tbf_direction dir)
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{
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int usage =
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pdch->num_tbfs(GPRS_RLCMAC_DL_TBF) +
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pdch->num_tbfs(GPRS_RLCMAC_UL_TBF) +
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compute_usage_by_reservation(pdch, dir);
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if (pdch->assigned_tfi(reverse(dir)) == NO_FREE_TFI)
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/* No TFI in the opposite direction, avoid it */
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usage += 32;
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return usage;
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}
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/*! Return the TS which corresponds to least busy PDCH
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*
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* \param[in] trx Pointer to TRX object
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* \param[in] dir TBF direction
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* \param[in] mask set of available timeslots
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* \param[in] fn Function pointer to function which computes number of associated TBFs
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* \param[out] free_tfi Free TFI
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* \param[out] free_usf Free USF
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* \returns TS number or -1 if unable to find
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*/
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static int find_least_busy_pdch(const struct gprs_rlcmac_trx *trx, enum gprs_rlcmac_tbf_direction dir, uint8_t mask,
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int (*fn)(const struct gprs_rlcmac_pdch *, enum gprs_rlcmac_tbf_direction dir),
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int *free_tfi = 0, int *free_usf = 0)
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{
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unsigned ts;
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int min_used = INT_MAX;
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int min_ts = -1;
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int min_tfi = -1;
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int min_usf = -1;
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for (ts = 0; ts < ARRAY_SIZE(trx->pdch); ts++) {
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const struct gprs_rlcmac_pdch *pdch = &trx->pdch[ts];
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int num_tbfs;
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int usf = -1; /* must be signed */
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int tfi = -1;
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if (((1 << ts) & mask) == 0)
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continue;
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num_tbfs = fn(pdch, dir);
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if (num_tbfs < min_used) {
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/* We have found a candidate */
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/* Make sure that a TFI is available */
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if (free_tfi) {
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tfi = find_free_tfi(pdch->assigned_tfi(dir));
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if (tfi < 0) {
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LOGP(DRLCMAC, LOGL_DEBUG,
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"- Skipping TS %d, because "
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"no TFI available\n", ts);
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continue;
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}
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}
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/* Make sure that an USF is available */
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if (dir == GPRS_RLCMAC_UL_TBF) {
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usf = find_free_usf(pdch->assigned_usf());
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if (usf < 0) {
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LOGP(DRLCMAC, LOGL_DEBUG,
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"- Skipping TS %d, because "
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"no USF available\n", ts);
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continue;
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}
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}
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if (min_ts >= 0)
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LOGP(DRLCMAC, LOGL_DEBUG,
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"- Skipping TS %d, because "
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"num TBFs %d > %d\n",
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min_ts, min_used, num_tbfs);
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min_used = num_tbfs;
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min_ts = ts;
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min_tfi = tfi;
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min_usf = usf;
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} else {
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LOGP(DRLCMAC, LOGL_DEBUG,
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"- Skipping TS %d, because "
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"num TBFs %d >= %d\n",
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ts, num_tbfs, min_used);
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}
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}
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if (min_ts < 0)
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return -1;
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if (free_tfi)
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*free_tfi = min_tfi;
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if (free_usf)
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*free_usf = min_usf;
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return min_ts;
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}
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static void attach_tbf_to_pdch(struct gprs_rlcmac_pdch *pdch,
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struct gprs_rlcmac_tbf *tbf)
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{
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if (tbf->pdch[pdch->ts_no])
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tbf->pdch[pdch->ts_no]->detach_tbf(tbf);
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tbf->pdch[pdch->ts_no] = pdch;
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pdch->attach_tbf(tbf);
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}
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static void assign_uplink_tbf_usf(struct gprs_rlcmac_pdch *pdch, struct gprs_rlcmac_ul_tbf *tbf, uint8_t tfi, int8_t usf)
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{
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tbf->m_tfi = tfi;
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tbf->m_usf[pdch->ts_no] = usf;
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attach_tbf_to_pdch(pdch, tbf);
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}
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static void assign_dlink_tbf(struct gprs_rlcmac_pdch *pdch, struct gprs_rlcmac_dl_tbf *tbf, uint8_t tfi)
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{
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tbf->m_tfi = tfi;
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attach_tbf_to_pdch(pdch, tbf);
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}
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static int find_trx(const struct gprs_rlcmac_bts *bts_data, const GprsMs *ms, int8_t use_trx)
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{
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unsigned trx_no;
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unsigned ts;
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/* We must use the TRX currently actively used by an MS */
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if (ms && ms->current_trx())
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return ms->current_trx()->trx_no;
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if (use_trx >= 0 && use_trx < 8)
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return use_trx;
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/* Find the first TRX that has a PDCH with a free UL and DL TFI */
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for (trx_no = 0; trx_no < ARRAY_SIZE(bts_data->trx); trx_no += 1) {
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const struct gprs_rlcmac_trx *trx = &bts_data->trx[trx_no];
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for (ts = 0; ts < ARRAY_SIZE(trx->pdch); ts++) {
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const struct gprs_rlcmac_pdch *pdch = &trx->pdch[ts];
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if (!pdch->is_enabled())
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continue;
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if (pdch->assigned_tfi(GPRS_RLCMAC_UL_TBF) == NO_FREE_TFI)
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continue;
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if (pdch->assigned_tfi(GPRS_RLCMAC_DL_TBF) == NO_FREE_TFI)
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continue;
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return trx_no;
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}
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}
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return -EBUSY;
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}
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static bool idle_pdch_avail(const struct gprs_rlcmac_bts *bts_data)
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{
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unsigned trx_no;
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unsigned ts;
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/* Find the first PDCH with an unused DL TS */
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for (trx_no = 0; trx_no < ARRAY_SIZE(bts_data->trx); trx_no += 1) {
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const struct gprs_rlcmac_trx *trx = &bts_data->trx[trx_no];
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for (ts = 0; ts < ARRAY_SIZE(trx->pdch); ts++) {
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const struct gprs_rlcmac_pdch *pdch = &trx->pdch[ts];
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if (!pdch->is_enabled())
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continue;
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if (pdch->num_tbfs(GPRS_RLCMAC_DL_TBF) > PDCH_IDLE_TBF_THRESH)
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continue;
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return true;
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}
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}
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return false;
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}
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/*! Return free TFI
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*
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* \param[in] bts Pointer to BTS struct
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* \param[in] trx Optional pointer to TRX struct
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* \param[in] ms Pointer to MS object
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* \param[in] dir DL or UL direction
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* \param[in] use_trx which TRX to use or -1 if it should be selected based on what MS uses
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* \param[out] trx_no_ TRX number on which TFI was found
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* \returns negative error code or 0 on success
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*/
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static int tfi_find_free(const BTS *bts, const gprs_rlcmac_trx *trx, const GprsMs *ms,
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enum gprs_rlcmac_tbf_direction dir, int8_t use_trx, uint8_t *trx_no_)
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{
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int tfi;
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uint8_t trx_no;
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if (trx) {
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if (use_trx >= 0 && use_trx != trx->trx_no) {
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LOGP(DRLCMAC, LOGL_ERROR, "- Requested incompatible TRX %d (current is %d)\n",
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use_trx, trx->trx_no);
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return -EINVAL;
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}
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use_trx = trx->trx_no;
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}
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if (use_trx == -1 && ms->current_trx())
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use_trx = ms->current_trx()->trx_no;
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tfi = bts->tfi_find_free(dir, &trx_no, use_trx);
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if (tfi < 0)
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return -EBUSY;
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if (trx_no_)
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*trx_no_ = trx_no;
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return tfi;
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}
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/*! Slot Allocation: Algorithm A
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*
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* Assign single slot for uplink and downlink
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*
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* \param[in,out] bts Pointer to BTS struct
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* \param[in,out] ms_ Pointer to MS object
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* \param[in,out] tbf_ Pointer to TBF struct
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* \param[in] single flag indicating if we should force single-slot allocation
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* \param[in] use_trx which TRX to use or -1 if it should be selected during allocation
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* \returns negative error code or 0 on success
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*/
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int alloc_algorithm_a(struct gprs_rlcmac_bts *bts, GprsMs *ms_, struct gprs_rlcmac_tbf *tbf_, bool single,
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int8_t use_trx)
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{
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struct gprs_rlcmac_pdch *pdch;
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int ts = -1;
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uint8_t ul_slots, dl_slots;
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int trx_no;
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int tfi = -1;
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int usf = -1;
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uint8_t mask = 0xff;
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const char *mask_reason = NULL;
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const GprsMs *ms = ms_;
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const gprs_rlcmac_tbf *tbf = tbf_;
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gprs_rlcmac_trx *trx = ms->current_trx();
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LOGPSL(tbf, LOGL_DEBUG, "Slot Allocation (Algorithm A) for class %d\n", tbf->ms_class());
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trx_no = find_trx(bts, ms, use_trx);
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if (trx_no < 0) {
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LOGPAL(tbf, "A", single ? "single" : "multi", use_trx, LOGL_NOTICE,
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"failed to find a usable TRX (TFI exhausted)\n");
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return trx_no;
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}
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if (!trx)
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trx = &bts->trx[trx_no];
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dl_slots = ms->reserved_dl_slots();
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ul_slots = ms->reserved_ul_slots();
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ts = ms->first_common_ts();
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if (ts >= 0) {
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mask_reason = "need to reuse TS";
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mask = 1 << ts;
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} else if (dl_slots || ul_slots) {
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mask_reason = "need to use a reserved common TS";
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mask = dl_slots & ul_slots;
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}
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mask = find_possible_pdchs(trx, 1, mask, mask_reason);
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if (!mask)
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return -EINVAL;
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ts = find_least_busy_pdch(trx, tbf->direction, mask,
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compute_usage_for_algo_a,
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&tfi, &usf);
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if (tbf->direction == GPRS_RLCMAC_UL_TBF && usf < 0) {
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LOGPAL(tbf, "A", single ? "single" : "multi", use_trx, LOGL_NOTICE,
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"failed to allocate a TS, no USF available\n");
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return -EBUSY;
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}
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if (ts < 0) {
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LOGPAL(tbf, "A", single ? "single" : "multi", use_trx, LOGL_NOTICE,
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"failed to allocate a TS, no TFI available\n");
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return -EBUSY;
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}
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pdch = &trx->pdch[ts];
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/* The allocation will be successful, so the system state and tbf_/ms_
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* may be modified from now on. */
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if (tbf->direction == GPRS_RLCMAC_UL_TBF) {
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struct gprs_rlcmac_ul_tbf *ul_tbf = as_ul_tbf(tbf_);
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LOGPSL(tbf, LOGL_DEBUG, "Assign uplink TS=%d TFI=%d USF=%d\n", ts, tfi, usf);
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assign_uplink_tbf_usf(pdch, ul_tbf, tfi, usf);
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} else {
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struct gprs_rlcmac_dl_tbf *dl_tbf = as_dl_tbf(tbf_);
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LOGPSL(tbf, LOGL_DEBUG, "Assign downlink TS=%d TFI=%d\n", ts, tfi);
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assign_dlink_tbf(pdch, dl_tbf, tfi);
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}
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tbf_->trx = trx;
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/* the only one TS is the common TS */
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tbf_->first_ts = tbf_->first_common_ts = ts;
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ms_->set_reserved_slots(trx, 1 << ts, 1 << ts);
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tbf_->upgrade_to_multislot = 0;
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bts->bts->tbf_alloc_algo_a();
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return 0;
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}
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/*! Compute capacity of a given TRX
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*
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* \param[in] trx Pointer to TRX object
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* \param[in] rx_window Receive window
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* \param[in] tx_window Transmit window
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* \returns non-negative capacity
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*/
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static inline unsigned compute_capacity(const struct gprs_rlcmac_trx *trx, int rx_window, int tx_window)
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{
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const struct gprs_rlcmac_pdch *pdch;
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unsigned ts, capacity = 0;
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for (ts = 0; ts < ARRAY_SIZE(trx->pdch); ts++) {
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pdch = &trx->pdch[ts];
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if (rx_window & (1 << ts))
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capacity += OSMO_MAX(32 - pdch->num_reserved(GPRS_RLCMAC_DL_TBF), 1);
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/* Only consider common slots for UL */
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if (tx_window & rx_window & (1 << ts)) {
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if (find_free_usf(pdch->assigned_usf()) >= 0)
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capacity += OSMO_MAX(32 - pdch->num_reserved(GPRS_RLCMAC_UL_TBF), 1);
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}
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}
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return capacity;
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}
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|
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/*! Decide if a given slot should be skipped by multislot allocator
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*
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* \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)
|
|
{
|
|
uint8_t 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 */
|
|
max_slots, 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(mslot_class_get_rx(mslot_class), 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 <= mslot_class_get_tx(mslot_class); 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);
|
|
|
|
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;
|
|
|
|
rx_valid_win = (1 << OSMO_MIN(mslot_class_get_rx(mslot_class), Sum - num_tx)) - 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;
|
|
|
|
/* 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");
|
|
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)
|
|
{
|
|
uint8_t sl = tbf->direction != GPRS_RLCMAC_DL_TBF ? 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",
|
|
tbf->direction != GPRS_RLCMAC_DL_TBF ? "uplink" : "downlink");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (tbf->direction != GPRS_RLCMAC_DL_TBF) {
|
|
snprintf(slot_info, 9, OSMO_BIT_SPEC, OSMO_BIT_PRINT_EX(reserved_ul_slots, 'u'));
|
|
masked_override_with(slot_info, sl, 'U');
|
|
LOGPC(DRLCMAC, LOGL_DEBUG, "- Selected UL");
|
|
} 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 DL");
|
|
}
|
|
|
|
LOGPC(DRLCMAC, LOGL_DEBUG, " slots: (TS=0)\"%s\"(TS=7), %s\n", slot_info, single ? "single" : "multi");
|
|
|
|
return sl;
|
|
}
|
|
|
|
/*! Allocate USF according to a given UL TS mapping
|
|
*
|
|
* N. B: this is legacy implementation which ignores given selected_ul_slots
|
|
* \param[in] trx Pointer to TRX object
|
|
* \param[in] tbf Pointer to TBF object
|
|
* \param[in] first_common_ts First TS which is common to both UL and DL
|
|
* \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 or negative on error
|
|
*/
|
|
static int allocate_usf(const gprs_rlcmac_trx *trx, int8_t first_common_ts, uint8_t selected_ul_slots, uint8_t dl_slots,
|
|
int *usf)
|
|
{
|
|
int free_usf = -1, ts;
|
|
uint8_t ul_slots = selected_ul_slots;
|
|
|
|
if (first_common_ts >= 0)
|
|
ul_slots = 1 << first_common_ts;
|
|
else
|
|
ul_slots = ul_slots & dl_slots;
|
|
|
|
ts = find_least_busy_pdch(trx, GPRS_RLCMAC_UL_TBF, ul_slots, compute_usage_by_num_tbfs, NULL, &free_usf);
|
|
|
|
if (free_usf < 0 || ts < 0) {
|
|
LOGP(DRLCMAC, LOGL_NOTICE, "No USF available\n");
|
|
return -EBUSY;
|
|
}
|
|
|
|
OSMO_ASSERT(ts >= 0 && ts <= 8);
|
|
|
|
/* We will stick to that single UL slot, unreserve the others */
|
|
ul_slots = 1 << ts;
|
|
usf[ts] = free_usf;
|
|
|
|
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() && res_dl_slots == ms->reserved_dl_slots())
|
|
return;
|
|
|
|
/* The reserved slots have changed, update the MS */
|
|
ms->set_reserved_slots(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] ms_ Pointer to MS object
|
|
* \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, GprsMs *ms_, 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;
|
|
const GprsMs *ms = ms_;
|
|
const gprs_rlcmac_tbf *tbf = tbf_;
|
|
gprs_rlcmac_trx *trx;
|
|
|
|
/* Step 1: Get current state from the MS object */
|
|
|
|
if (!ms) {
|
|
LOGP(DRLCMAC, LOGL_ERROR, "MS not set\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
dl_slots = ms->reserved_dl_slots();
|
|
ul_slots = ms->reserved_ul_slots();
|
|
first_common_ts = ms->first_common_ts();
|
|
trx = ms->current_trx();
|
|
|
|
/* Step 2a: Find usable TRX and TFI */
|
|
tfi = tfi_find_free(bts->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 (!dl_slots || !ul_slots) {
|
|
rc = find_multi_slots(trx, ms->ms_class(), &ul_slots, &dl_slots);
|
|
if (rc < 0)
|
|
return rc;
|
|
}
|
|
|
|
reserved_dl_slots = dl_slots;
|
|
reserved_ul_slots = 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;
|
|
|
|
first_ts = ffs(rc) - 1;
|
|
|
|
/* 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, first_common_ts, rc, dl_slots, usf);
|
|
if (rc < 0)
|
|
return rc;
|
|
|
|
/* We will stick to that single UL slot, unreserve the others */
|
|
ul_slots = rc;
|
|
reserved_ul_slots = ul_slots;
|
|
|
|
update_slot_counters(ul_slots, reserved_ul_slots, &slotcount, &avail_count);
|
|
}
|
|
|
|
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 = 0;
|
|
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->bts->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] ms_ Pointer to MS object
|
|
* \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, GprsMs *ms_, 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, ms_, 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, ms_, 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 (bts->alloc_algorithm == alloc_algorithm_a)
|
|
return 1;
|
|
|
|
if (bts->multislot_disabled)
|
|
return 1;
|
|
|
|
return rx;
|
|
}
|