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authorHolger Hans Peter Freyther <holger@moiji-mobile.com>2014-05-15 12:24:12 +0200
committerHolger Hans Peter Freyther <holger@moiji-mobile.com>2014-05-15 12:24:12 +0200
commit8f3520579a6d1b11c98176e1da1515b9d995a73f (patch)
tree3adeebda790f406b898d5b42ad4f2d28ad639313 /src/gprs_rlcmac_ts_alloc.cpp
parent6f0796a33adf989db18ba6aae5cb64806049c435 (diff)
parentf81e2f7621c9bc6866035cb47ac09adab4897b55 (diff)
Merge remote-tracking branch 'origin/sysmocom/master'
Diffstat (limited to 'src/gprs_rlcmac_ts_alloc.cpp')
-rw-r--r--src/gprs_rlcmac_ts_alloc.cpp681
1 files changed, 681 insertions, 0 deletions
diff --git a/src/gprs_rlcmac_ts_alloc.cpp b/src/gprs_rlcmac_ts_alloc.cpp
new file mode 100644
index 0000000..366732c
--- /dev/null
+++ b/src/gprs_rlcmac_ts_alloc.cpp
@@ -0,0 +1,681 @@
+/* gprs_rlcmac.cpp
+ *
+ * Copyright (C) 2012 Ivan Klyuchnikov
+ * Copyright (C) 2012 Andreas Eversberg <jolly@eversberg.eu>
+ * Copyright (C) 2013 by Holger Hans Peter Freyther
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <gprs_rlcmac.h>
+#include <gprs_debug.h>
+#include <bts.h>
+#include <tbf.h>
+
+#include <errno.h>
+
+/* 3GPP TS 05.02 Annex B.1 */
+
+#define MS_NA 255 /* N/A */
+#define MS_A 254 /* 1 with hopping, 0 without */
+#define MS_B 253 /* 1 with hopping, 0 without (change Rx to Tx)*/
+#define MS_C 252 /* 1 with hopping, 0 without (change Tx to Rx)*/
+
+struct gprs_ms_multislot_class {
+ uint8_t rx, tx, sum; /* Maximum Number of Slots: RX, Tx, Sum Rx+Tx */
+ uint8_t ta, tb, ra, rb; /* Minimum Number of Slots */
+ uint8_t type; /* Type of Mobile */
+};
+
+static const struct gprs_ms_multislot_class gprs_ms_multislot_class[32] = {
+/* M-S Class Rx Tx Sum Tta Ttb Tra Trb Type */
+/* N/A */ { MS_NA,MS_NA, MS_NA, MS_NA, MS_NA, MS_NA, MS_NA, MS_NA },
+/* 1 */ { 1, 1, 2, 3, 2, 4, 2, 1 },
+/* 2 */ { 2, 1, 3, 3, 2, 3, 1, 1 },
+/* 3 */ { 2, 2, 3, 3, 2, 3, 1, 1 },
+/* 4 */ { 3, 1, 4, 3, 1, 3, 1, 1 },
+/* 5 */ { 2, 2, 4, 3, 1, 3, 1, 1 },
+/* 6 */ { 3, 2, 4, 3, 1, 3, 1, 1 },
+/* 7 */ { 3, 3, 4, 3, 1, 3, 1, 1 },
+/* 8 */ { 4, 1, 5, 3, 1, 2, 1, 1 },
+/* 9 */ { 3, 2, 5, 3, 1, 2, 1, 1 },
+/* 10 */ { 4, 2, 5, 3, 1, 2, 1, 1 },
+/* 11 */ { 4, 3, 5, 3, 1, 2, 1, 1 },
+/* 12 */ { 4, 4, 5, 2, 1, 2, 1, 1 },
+/* 13 */ { 3, 3, MS_NA, MS_NA, MS_A, 3, MS_A, 2 },
+/* 14 */ { 4, 4, MS_NA, MS_NA, MS_A, 3, MS_A, 2 },
+/* 15 */ { 5, 5, MS_NA, MS_NA, MS_A, 3, MS_A, 2 },
+/* 16 */ { 6, 6, MS_NA, MS_NA, MS_A, 2, MS_A, 2 },
+/* 17 */ { 7, 7, MS_NA, MS_NA, MS_A, 1, 0, 2 },
+/* 18 */ { 8, 8, MS_NA, MS_NA, 0, 0, 0, 2 },
+/* 19 */ { 6, 2, MS_NA, 3, MS_B, 2, MS_C, 1 },
+/* 20 */ { 6, 3, MS_NA, 3, MS_B, 2, MS_C, 1 },
+/* 21 */ { 6, 4, MS_NA, 3, MS_B, 2, MS_C, 1 },
+/* 22 */ { 6, 4, MS_NA, 2, MS_B, 2, MS_C, 1 },
+/* 23 */ { 6, 6, MS_NA, 2, MS_B, 2, MS_C, 1 },
+/* 24 */ { 8, 2, MS_NA, 3, MS_B, 2, MS_C, 1 },
+/* 25 */ { 8, 3, MS_NA, 3, MS_B, 2, MS_C, 1 },
+/* 26 */ { 8, 4, MS_NA, 3, MS_B, 2, MS_C, 1 },
+/* 27 */ { 8, 4, MS_NA, 2, MS_B, 2, MS_C, 1 },
+/* 28 */ { 8, 6, MS_NA, 2, MS_B, 2, MS_C, 1 },
+/* 29 */ { 8, 8, MS_NA, 2, MS_B, 2, MS_C, 1 },
+/* N/A */ { MS_NA,MS_NA, MS_NA, MS_NA, MS_NA, MS_NA, MS_NA, MS_NA },
+/* N/A */ { MS_NA,MS_NA, MS_NA, MS_NA, MS_NA, MS_NA, MS_NA, MS_NA },
+};
+
+static inline int8_t find_free_usf(struct gprs_rlcmac_pdch *pdch)
+{
+ struct gprs_rlcmac_tbf *tbf;
+ uint8_t usf_map = 0;
+ uint8_t tfi, usf;
+
+ /* make map of used USF */
+ for (tfi = 0; tfi < 32; tfi++) {
+ tbf = pdch->ul_tbf[tfi];
+ if (!tbf)
+ continue;
+ usf_map |= (1 << tbf->dir.ul.usf[pdch->ts_no]);
+ }
+
+ /* look for USF, don't use USF=7 */
+ for (usf = 0; usf < 7; usf++) {
+ if (!(usf_map & (1 << usf)))
+ return usf;
+ }
+
+ return -1;
+}
+
+static int find_enabled_pdch(struct gprs_rlcmac_trx *trx, const uint8_t start_ts)
+{
+ int ts;
+ for (ts = start_ts; ts < 8; ts++) {
+ struct gprs_rlcmac_pdch *pdch;
+
+ pdch = &trx->pdch[ts];
+ if (!pdch->is_enabled()) {
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, because "
+ "not enabled\n", ts);
+ continue;
+ }
+ return ts;
+ }
+
+ return 8;
+}
+
+static void assign_uplink_tbf_usf(
+ struct gprs_rlcmac_pdch *pdch,
+ struct gprs_rlcmac_tbf *tbf, int8_t usf)
+{
+ tbf->trx->ul_tbf[tbf->tfi()] = tbf;
+ pdch->ul_tbf[tbf->tfi()] = tbf;
+ tbf->pdch[pdch->ts_no] = pdch;
+ tbf->dir.ul.usf[pdch->ts_no] = usf;
+}
+
+static void assign_dlink_tbf(
+ struct gprs_rlcmac_pdch *pdch,
+ struct gprs_rlcmac_tbf *tbf)
+{
+ tbf->trx->dl_tbf[tbf->tfi()] = tbf;
+ pdch->dl_tbf[tbf->tfi()] = tbf;
+ tbf->pdch[pdch->ts_no] = pdch;
+}
+
+
+/* Slot Allocation: Algorithm A
+ *
+ * Assign single slot for uplink and downlink
+ */
+int alloc_algorithm_a(struct gprs_rlcmac_bts *bts,
+ struct gprs_rlcmac_tbf *old_tbf,
+ struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single)
+{
+ struct gprs_rlcmac_pdch *pdch;
+ uint8_t ts;
+
+ LOGP(DRLCMAC, LOGL_DEBUG, "Slot Allocation (Algorithm A) for class "
+ "%d\n", tbf->ms_class);
+
+ ts = find_enabled_pdch(tbf->trx, 0);
+ if (ts == 8)
+ return -EINVAL;
+
+ pdch = &tbf->trx->pdch[ts];
+ if (tbf->direction == GPRS_RLCMAC_UL_TBF) {
+ int8_t usf; /* must be signed */
+
+ /* if USF available */
+ usf = find_free_usf(pdch);
+ if (usf < 0) {
+ LOGP(DRLCMAC, LOGL_NOTICE, "- Failed "
+ "allocating TS=%d, no USF available\n", ts);
+ return -EBUSY;
+ }
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Assign uplink "
+ "TS=%d USF=%d\n", ts, usf);
+ assign_uplink_tbf_usf(pdch, tbf, usf);
+ } else {
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Assign downlink TS=%d\n", ts);
+ assign_dlink_tbf(pdch, tbf);
+ }
+ /* the only one TS is the common TS */
+ tbf->first_ts = tbf->first_common_ts = ts;
+
+ return 0;
+}
+
+/*
+ * Select a window of Rx slots if available.
+ * The maximum allowed slots depend on RX or the window of available
+ * slots. This must be done for uplink TBF also, because it is the basis
+ * for calculating control slot and uplink slot(s).
+ */
+static uint8_t select_dl_slots(struct gprs_rlcmac_trx *trx,
+ const int ms_type, const int ms_max_rxslots,
+ uint8_t *out_rx_win_min, uint8_t *out_rx_win_max)
+
+{
+ uint8_t rx_window = 0;
+ int rx_window_size = 0;
+ int8_t last_tsc = -1; /* must be signed */
+ uint8_t rx_win_min = 0, rx_win_max = 0;
+
+ for (int ts_no = 0; ts_no < 8; ts_no++) {
+ struct gprs_rlcmac_pdch *pdch;
+ pdch = &trx->pdch[ts_no];
+
+ /* check if enabled */
+ if (!pdch->is_enabled()) {
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, because "
+ "not enabled\n", ts_no);
+ if (ms_type == 1 && rx_window)
+ goto inc_window;
+ continue;
+ }
+ /* check if TSC changes */
+ if (last_tsc < 0)
+ last_tsc = pdch->tsc;
+ else if (last_tsc != pdch->tsc) {
+ LOGP(DRLCMAC, LOGL_ERROR, "Skipping TS %d of TRX=%d, "
+ "because it has different TSC than lower TS "
+ "of TRX. In order to allow multislot, all "
+ "slots must be configured with the same "
+ "TSC!\n", ts_no, trx->trx_no);
+ if (ms_type == 1 && rx_window)
+ goto inc_window;
+ continue;
+ }
+
+ if (!rx_window)
+ rx_win_min = ts_no;
+
+ rx_window |= (1 << ts_no);
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Selected DL TS %d\n", ts_no);
+
+ /* range of window (required for Type 1) */
+ rx_win_max = ts_no;
+
+inc_window:
+ if (++rx_window_size == ms_max_rxslots) {
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Done, because slots / "
+ "window reached maximum alowed Rx size\n");
+ break;
+ }
+ if (ms_type == 1 && rx_window_size == 5) {
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Done, because slots / "
+ "window reached maximum supported Rx size of "
+ "this algorithm\n");
+ break;
+ }
+ }
+
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Selected slots for RX: "
+ "(TS=0)\"%c%c%c%c%c%c%c%c\"(TS=7)\n",
+ ((rx_window & 0x01)) ? 'D' : '.',
+ ((rx_window & 0x02)) ? 'D' : '.',
+ ((rx_window & 0x04)) ? 'D' : '.',
+ ((rx_window & 0x08)) ? 'D' : '.',
+ ((rx_window & 0x10)) ? 'D' : '.',
+ ((rx_window & 0x20)) ? 'D' : '.',
+ ((rx_window & 0x40)) ? 'D' : '.',
+ ((rx_window & 0x80)) ? 'D' : '.');
+
+ *out_rx_win_min = rx_win_min;
+ *out_rx_win_max = rx_win_max;
+ return rx_window;
+}
+
+static int reduce_rx_window(const int ms_type, const struct gprs_rlcmac_tbf *old_tbf,
+ const int Tt, const int Tr,
+ int *rx_window,
+ uint8_t *rx_win_min, uint8_t *rx_win_max)
+{
+ if (ms_type != 1)
+ return 0;
+ if (!old_tbf)
+ return 0;
+ if (old_tbf->direction != GPRS_RLCMAC_UL_TBF)
+ return 0;
+
+ uint8_t collide = 0, ul_usage = 0;
+
+ /* calculate mask of colliding slots */
+ for (uint8_t ts_no = 0; ts_no < 8; ts_no++) {
+ int j;
+ if (!old_tbf->pdch[ts_no])
+ continue;
+
+ ul_usage |= (1 << ts_no);
+ /* mark bits from TS-t .. TS+r */
+ for (j = ts_no - Tt; j != ((ts_no + Tr + 1) & 7); j = (j + 1) & 7)
+ collide |= (1 << j);
+ }
+
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Not allowed slots due to existing "
+ "UL allocation: (TS=0)\"%c%c%c%c%c%c%c%c\"(TS=7) "
+ " D=downlink x=not usable\n",
+ ((ul_usage & 0x01)) ? 'D' : ((collide & 0x01))?'x':'.',
+ ((ul_usage & 0x02)) ? 'D' : ((collide & 0x02))?'x':'.',
+ ((ul_usage & 0x04)) ? 'D' : ((collide & 0x04))?'x':'.',
+ ((ul_usage & 0x08)) ? 'D' : ((collide & 0x08))?'x':'.',
+ ((ul_usage & 0x10)) ? 'D' : ((collide & 0x10))?'x':'.',
+ ((ul_usage & 0x20)) ? 'D' : ((collide & 0x20))?'x':'.',
+ ((ul_usage & 0x40)) ? 'D' : ((collide & 0x40))?'x':'.',
+ ((ul_usage & 0x80)) ? 'D' : ((collide & 0x80))?'x':'.');
+
+ /*
+ * Uplink/Downlink in GSM is shifted by three timeslots. Make
+ * sure they don't collide.
+ */
+ *rx_window &= ~(collide << 3);
+ *rx_window &= ~(collide >> 5);
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Remaining slots for RX: "
+ "(TS=0)\"%c%c%c%c%c%c%c%c\"(TS=7)\n",
+ ((*rx_window & 0x01)) ? 'D' : '.',
+ ((*rx_window & 0x02)) ? 'D' : '.',
+ ((*rx_window & 0x04)) ? 'D' : '.',
+ ((*rx_window & 0x08)) ? 'D' : '.',
+ ((*rx_window & 0x10)) ? 'D' : '.',
+ ((*rx_window & 0x20)) ? 'D' : '.',
+ ((*rx_window & 0x40)) ? 'D' : '.',
+ ((*rx_window & 0x80)) ? 'D' : '.');
+
+ if (!*rx_window) {
+ LOGP(DRLCMAC, LOGL_NOTICE, "No suitable downlink slots "
+ "available with current uplink assignment\n");
+ return -EBUSY;
+ }
+
+ return 0;
+}
+
+/* shrink range of rx_win_min and rx_win_max */
+static void shrink_rx_window(uint8_t *rx_win_min, uint8_t *rx_win_max, int rx_window)
+{
+ /* calculate new min/max */
+ for (uint8_t ts_no = *rx_win_min; ts_no <= *rx_win_max; ts_no++) {
+ if ((rx_window & (1 << ts_no)))
+ break;
+ *rx_win_min = ts_no + 1;
+ LOGP(DRLCMAC, LOGL_DEBUG, "- TS is unused, so "
+ "raising start of DL window to %d\n",
+ *rx_win_min);
+ }
+ for (uint8_t ts_no = *rx_win_max; ts_no >= *rx_win_min; ts_no--) {
+ if ((rx_window & (1 << ts_no)))
+ break;
+ *rx_win_max = ts_no - 1;
+ LOGP(DRLCMAC, LOGL_DEBUG, "- TS is unused, so "
+ "lowering end of DL window to %d\n",
+ *rx_win_max);
+ }
+}
+
+/*
+ * reduce window, to allow at least one uplink TX slot
+ * this is only required for Type 1
+ */
+static uint8_t update_rx_win_max(const int ms_type, const int Tt,
+ const int Tr, uint8_t rx_win_min, uint8_t rx_win_max)
+{
+ if (ms_type != 1)
+ return rx_win_max;
+
+ if (rx_win_max - rx_win_min + 1 + Tt + 1 + Tr > 8) {
+ rx_win_max = rx_win_min + 7 - Tt - 1 - Tr;
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Reduce RX window due to time "
+ "contraints to %d slots\n", rx_win_max - rx_win_min + 1);
+ }
+
+ return rx_win_max;
+}
+
+static void tx_win_from_rx(const int ms_type,
+ uint8_t rx_win_min, uint8_t rx_win_max,
+ int Tt, int Tr,
+ uint8_t *tx_win_min, uint8_t *tx_win_max,
+ uint8_t *tx_range)
+{
+ if (ms_type == 1) {
+ /* calculate TX window (shifted by 3 timeslots)
+ * it uses the space between tx_win_max and tx_win_min */
+ *tx_win_min = (rx_win_max - 2 + Tt) & 7;
+ *tx_win_max = (rx_win_min + 4 - Tr) & 7;
+ } else {
+ /* TX and RX simultaniously */
+ *tx_win_min = rx_win_min;
+ *tx_win_max = 7;
+ }
+
+ *tx_range = (*tx_win_max - *tx_win_min + 1) & 7;
+ /* if TX window fills complete range */
+ if (*tx_range == 0)
+ *tx_range = 8;
+ LOGP(DRLCMAC, LOGL_DEBUG, "- TX-Window is: %d..%d\n", *tx_win_min,
+ *tx_win_max);
+}
+
+/*
+ * Select a window of Tx slots if available.
+ * The maximum allowed slots depend on TX or the window of available
+ * slots.
+ */
+static int select_ul_slots(gprs_rlcmac_trx *trx,
+ const int ms_type, const int ms_max_txslots,
+ uint8_t tx_win_min, uint8_t tx_range,
+ int8_t *usf, int8_t *first_common_ts, uint8_t rx_window)
+{
+ int tsc = -1;
+ uint8_t tx_window = 0;
+ int i;
+ uint8_t ts_no;
+
+ for (ts_no = tx_win_min, i = 0; i < tx_range; ts_no = (ts_no + 1) & 7, i++) {
+ gprs_rlcmac_pdch *pdch = &trx->pdch[ts_no];
+
+ /* check if enabled */
+ if (!pdch->is_enabled()) {
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, "
+ "because not enabled\n", ts_no);
+ if (ms_type == 1 && tx_window)
+ goto inc_window;
+ continue;
+ }
+ /* check if used as downlink */
+ if (!(rx_window & (1 << ts_no))) {
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, "
+ "because not a downlink slot\n", ts_no);
+ if (ms_type == 1 && tx_window)
+ goto inc_window;
+ continue;
+ }
+ /* check if TSC changes */
+ if (tsc < 0)
+ tsc = pdch->tsc;
+ else if (tsc != pdch->tsc) {
+ LOGP(DRLCMAC, LOGL_ERROR, "Skipping TS %d of "
+ "TRX=%d, because it has different TSC "
+ "than lower TS of TRX. In order to "
+ "allow multislot, all slots must be "
+ "configured with the same TSC!\n",
+ ts_no, trx->trx_no);
+ if (ms_type == 1)
+ goto inc_window;
+ continue;
+ }
+ /* check for free usf */
+ usf[ts_no] = find_free_usf(pdch);
+ if (usf[ts_no] < 0) {
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, "
+ "because no USF available\n", ts_no);
+ if (ms_type == 1)
+ goto inc_window;
+ continue;
+ }
+
+ if (!tx_window)
+ *first_common_ts = ts_no;
+
+ tx_window |= (1 << ts_no);
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Selected UL TS %d\n", ts_no);
+
+inc_window:
+ if (1 && ms_type == 1) { /* FIXME: multislot UL assignment */
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Done, because "
+ "1 slot assigned\n");
+ break;
+ }
+ if (i+1 == ms_max_txslots) {
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Done, because "
+ "slots / window reached maximum "
+ "allowed Tx size\n");
+ break;
+ }
+ }
+
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Selected TX window: "
+ "(TS=0)\"%c%c%c%c%c%c%c%c\"(TS=7)\n",
+ ((tx_window & 0x01)) ? 'U' : '.',
+ ((tx_window & 0x02)) ? 'U' : '.',
+ ((tx_window & 0x04)) ? 'U' : '.',
+ ((tx_window & 0x08)) ? 'U' : '.',
+ ((tx_window & 0x10)) ? 'U' : '.',
+ ((tx_window & 0x20)) ? 'U' : '.',
+ ((tx_window & 0x40)) ? 'U' : '.',
+ ((tx_window & 0x80)) ? 'U' : '.');
+
+ if (!tx_window) {
+ LOGP(DRLCMAC, LOGL_NOTICE, "No suitable uplink slots "
+ "available\n");
+ return -EBUSY;
+ }
+
+ return tx_window;
+}
+
+/*
+ * Assign the first common ts, which is used for control or
+ * single slot.
+ */
+static int select_first_ts(gprs_rlcmac_trx *trx, uint8_t tx_win_min,
+ uint8_t tx_range, uint8_t rx_window)
+{
+ uint8_t ts_no;
+ int i;
+ for (ts_no = tx_win_min, i = 0; i < tx_range; ts_no = (ts_no + 1) & 7, i++) {
+ gprs_rlcmac_pdch *pdch = &trx->pdch[ts_no];
+ /* check if enabled */
+ if (!pdch->is_enabled()) {
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, "
+ "because not enabled\n", ts_no);
+ continue;
+ }
+ /* check if used as downlink */
+ if (!(rx_window & (1 << ts_no))) {
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, "
+ "because not a downlink slot\n", ts_no);
+ continue;
+ }
+ return ts_no;
+ }
+
+ return -1;
+}
+
+/* Slot Allocation: Algorithm B
+ *
+ * Assign as many downlink slots as possible.
+ * Assign one uplink slot. (With free USF)
+ *
+ */
+int alloc_algorithm_b(struct gprs_rlcmac_bts *bts,
+ struct gprs_rlcmac_tbf *old_tbf,
+ struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single)
+{
+ const struct gprs_ms_multislot_class *ms_class;
+ uint8_t Tx, Sum; /* Maximum Number of Slots: RX, Tx, Sum Rx+Tx */
+ uint8_t Tta, Ttb, Tra, Trb, Tt, Tr; /* Minimum Number of Slots */
+ uint8_t Type; /* Type of Mobile */
+ int rx_window;
+ static const char *digit[10] = { "0","1","2","3","4","5","6","7","8","9" };
+ int8_t usf[8] = { -1, -1, -1, -1, -1, -1, -1, -1 }; /* must be signed */
+ int8_t first_common_ts = -1;
+ uint8_t ts;
+ uint8_t slotcount = 0;
+
+
+ if (tbf->ms_class >= 32) {
+ LOGP(DRLCMAC, LOGL_ERROR, "Multislot class %d out of range.\n",
+ tbf->ms_class);
+ return -EINVAL;
+ }
+
+ if (tbf->ms_class) {
+ ms_class = &gprs_ms_multislot_class[tbf->ms_class];
+ LOGP(DRLCMAC, LOGL_DEBUG, "Slot Allocation (Algorithm B) for "
+ "class %d\n", tbf->ms_class);
+ } else {
+ ms_class = &gprs_ms_multislot_class[12];
+ LOGP(DRLCMAC, LOGL_DEBUG, "Slot Allocation (Algorithm B) for "
+ "unknow class (assuming 12)\n");
+ }
+
+ if (ms_class->tx == MS_NA) {
+ LOGP(DRLCMAC, LOGL_NOTICE, "Multislot class %d not "
+ "applicable.\n", tbf->ms_class);
+ return -EINVAL;
+ }
+
+ Tx = ms_class->tx;
+ Sum = ms_class->sum;
+ Tta = ms_class->ta;
+ Ttb = ms_class->tb;
+ Tra = ms_class->ra;
+ Trb = ms_class->rb;
+ Type = ms_class->type;
+
+ /* Tta and Ttb may depend on hopping or frequency change */
+ if (Ttb == MS_A || Ttb == MS_B)
+ Ttb = 0;
+ if (Trb == MS_A || Trb == MS_C)
+ Trb = 0;
+
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Rx=%d Tx=%d Sum Rx+Tx=%s Tta=%s Ttb=%d "
+ " Tra=%d Trb=%d Type=%d\n", ms_class->rx, Tx,
+ (Sum == MS_NA) ? "N/A" : digit[Sum],
+ (Tta == MS_NA) ? "N/A" : digit[Tta], Ttb, Tra, Trb, Type);
+
+ /* select the values for time contraints */
+ /* applicable to type 1 and type 2 */
+ Tt = Ttb;
+ Tr = Trb;
+
+ uint8_t rx_win_min, rx_win_max;
+ rx_window = select_dl_slots(tbf->trx, ms_class->type, ms_class->rx,
+ &rx_win_min, &rx_win_max);
+
+
+ /* reduce window, if existing uplink slots collide RX window */
+ int rc = reduce_rx_window(ms_class->type, old_tbf, Tt, Tr,
+ &rx_window, &rx_win_min, &rx_win_max);
+ if (rc < 0)
+ return rc;
+ shrink_rx_window(&rx_win_min, &rx_win_max, rx_window);
+ rx_win_max = update_rx_win_max(ms_class->type, Tt, Tr,
+ rx_win_min, rx_win_max);
+ shrink_rx_window(&rx_win_min, &rx_win_max, rx_window);
+ LOGP(DRLCMAC, LOGL_DEBUG, "- RX-Window is: %d..%d\n", rx_win_min,
+ rx_win_max);
+
+ /* calculate TX window */
+ uint8_t tx_win_min, tx_win_max, tx_range;
+ tx_win_from_rx(ms_class->type, rx_win_min, rx_win_max, Tt, Tr,
+ &tx_win_min, &tx_win_max, &tx_range);
+
+ /* select UL slots but in both cases assign first_common_ts */
+ uint8_t tx_window = 0;
+ if (tbf->direction == GPRS_RLCMAC_UL_TBF) {
+ rc = select_ul_slots(tbf->trx, ms_class->type, ms_class->tx,
+ tx_win_min, tx_range, usf,
+ &first_common_ts, rx_window);
+ if (rc < 0)
+ return rc;
+ tx_window = rc;
+ } else {
+ first_common_ts = select_first_ts(tbf->trx, tx_win_min,
+ tx_range, rx_window);
+ }
+ #warning "first_common_ts might be different if there was no free USF for the new uplink assignment"
+
+ if (first_common_ts < 0) {
+ LOGP(DRLCMAC, LOGL_NOTICE, "No first common slots available\n");
+ return -EINVAL;
+ }
+
+ if (tbf->direction == GPRS_RLCMAC_DL_TBF) {
+ /* assign downlink */
+ if (rx_window == 0) {
+ LOGP(DRLCMAC, LOGL_NOTICE, "No downlink slots "
+ "available\n");
+ return -EINVAL;
+ }
+ for (ts = 0; ts < 8; ts++) {
+ if ((rx_window & (1 << ts))) {
+ /* be sure to select a single downlink slots
+ * that can be used for uplink, if multiple
+ * slots are assigned later. */
+ if (single && first_common_ts != ts)
+ continue;
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Assigning DL TS "
+ "%d\n", ts);
+ assign_dlink_tbf(&tbf->trx->pdch[ts], tbf);
+ slotcount++;
+ if (slotcount == 1)
+ tbf->first_ts = ts;
+ if (single)
+ break;
+ }
+ }
+ } else {
+ for (ts = 0; ts < 8; ts++) {
+ if ((tx_window & (1 << ts))) {
+ LOGP(DRLCMAC, LOGL_DEBUG, "- Assigning UL TS "
+ "%d\n", ts);
+ assign_uplink_tbf_usf(&tbf->trx->pdch[ts], tbf, usf[ts]);
+ slotcount++;
+ if (slotcount == 1)
+ tbf->first_ts = ts;
+ if (single)
+ break;
+ }
+ }
+ }
+ if (single && slotcount) {
+ LOGP(DRLCMAC, LOGL_INFO, "Using single slot at TS %d for %s\n",
+ tbf->first_ts,
+ (tbf->direction == GPRS_RLCMAC_DL_TBF) ? "DL" : "UL");
+ } else {
+ LOGP(DRLCMAC, LOGL_INFO, "Using %d slots for %s\n", slotcount,
+ (tbf->direction == GPRS_RLCMAC_DL_TBF) ? "DL" : "UL");
+ }
+ if (slotcount == 0)
+ return -EBUSY;
+
+ tbf->first_common_ts = first_common_ts;
+
+ return 0;
+}