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-rw-r--r--src/gprs_rlcmac_sched.c265
1 files changed, 265 insertions, 0 deletions
diff --git a/src/gprs_rlcmac_sched.c b/src/gprs_rlcmac_sched.c
new file mode 100644
index 0000000..edc2937
--- /dev/null
+++ b/src/gprs_rlcmac_sched.c
@@ -0,0 +1,265 @@
+/* PDCH scheduler
+ *
+ * Copyright (C) 2012 Andreas Eversberg <jolly@eversberg.eu>
+ *
+ * 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_bssgp_pcu.h>
+#include <gprs_rlcmac.h>
+#include <gprs_rlcmac_ctrl.h>
+#include <pcu_l1_if.h>
+
+uint32_t sched_poll(uint8_t trx, uint8_t ts, uint32_t fn, uint8_t block_nr,
+ struct gprs_rlcmac_tbf **poll_tbf,
+ struct gprs_rlcmac_tbf **ul_ass_tbf,
+ struct gprs_rlcmac_tbf **dl_ass_tbf,
+ struct gprs_rlcmac_tbf **ul_ack_tbf)
+{
+ struct gprs_rlcmac_tbf *tbf;
+ uint32_t poll_fn;
+
+ /* check special TBF for events */
+ poll_fn = fn + 4;
+ if ((block_nr % 3) == 2)
+ poll_fn ++;
+ poll_fn = poll_fn % 2715648;
+ llist_for_each_entry(tbf, &gprs_rlcmac_ul_tbfs, list) {
+ /* this trx, this ts */
+ if (tbf->trx != trx || tbf->control_ts != ts)
+ continue;
+ /* polling for next uplink block */
+ if (tbf->poll_state == GPRS_RLCMAC_POLL_SCHED
+ && tbf->poll_fn == poll_fn)
+ *poll_tbf = tbf;
+ if (tbf->ul_ack_state == GPRS_RLCMAC_UL_ACK_SEND_ACK)
+ *ul_ack_tbf = tbf;
+ if (tbf->dl_ass_state == GPRS_RLCMAC_DL_ASS_SEND_ASS)
+ *dl_ass_tbf = tbf;
+ if (tbf->ul_ass_state == GPRS_RLCMAC_UL_ASS_SEND_ASS)
+ *ul_ass_tbf = tbf;
+ }
+ llist_for_each_entry(tbf, &gprs_rlcmac_dl_tbfs, list) {
+ /* this trx, this ts */
+ if (tbf->trx != trx || tbf->control_ts != ts)
+ continue;
+ /* polling for next uplink block */
+ if (tbf->poll_state == GPRS_RLCMAC_POLL_SCHED
+ && tbf->poll_fn == poll_fn)
+ *poll_tbf = tbf;
+ if (tbf->dl_ass_state == GPRS_RLCMAC_DL_ASS_SEND_ASS)
+ *dl_ass_tbf = tbf;
+ if (tbf->ul_ass_state == GPRS_RLCMAC_UL_ASS_SEND_ASS)
+ *ul_ass_tbf = tbf;
+ }
+
+ return poll_fn;
+}
+
+uint8_t sched_select_uplink(uint8_t trx, uint8_t ts, uint32_t fn,
+ uint8_t block_nr, struct gprs_rlcmac_pdch *pdch)
+{
+ struct gprs_rlcmac_tbf *tbf;
+ uint8_t usf = 0x07;
+ uint8_t i, tfi;
+
+ /* select uplink ressource */
+ for (i = 0, tfi = pdch->next_ul_tfi; i < 32;
+ i++, tfi = (tfi + 1) & 31) {
+ tbf = pdch->ul_tbf[tfi];
+ /* no TBF for this tfi, go next */
+ if (!tbf)
+ continue;
+ /* no UL ressources needed, go next */
+ /* we don't need to give ressources in FINISHED state,
+ * because we have received all blocks and only poll
+ * for packet control ack. */
+ if (tbf->state != GPRS_RLCMAC_FLOW)
+ continue;
+
+ /* use this USF */
+ usf = tbf->dir.ul.usf[ts];
+ LOGP(DRLCMACSCHED, LOGL_DEBUG, "Received RTS for PDCH: TRX=%d "
+ "TS=%d FN=%d block_nr=%d scheduling USF=%d for "
+ "required uplink ressource of UL TBF=%d\n", trx, ts, fn,
+ block_nr, usf, tfi);
+ /* next TBF to handle ressource is the next one */
+ pdch->next_ul_tfi = (tfi + 1) & 31;
+ break;
+ }
+
+ return usf;
+}
+
+struct msgb *sched_select_ctrl_msg(uint8_t trx, uint8_t ts, uint32_t fn,
+ uint8_t block_nr, struct gprs_rlcmac_pdch *pdch,
+ struct gprs_rlcmac_tbf *ul_ass_tbf,
+ struct gprs_rlcmac_tbf *dl_ass_tbf,
+ struct gprs_rlcmac_tbf *ul_ack_tbf)
+{
+ struct msgb *msg = NULL;
+ struct gprs_rlcmac_tbf *tbf = NULL;
+
+ /* schedule PACKET UPLINK ASSIGNMENT (1st priority) */
+ if (ul_ass_tbf) {
+ tbf = ul_ass_tbf;
+ msg = gprs_rlcmac_send_packet_uplink_assignment(tbf, fn);
+ }
+ /* schedule PACKET DOWNLINK ASSIGNMENT (2nd priotiry) */
+ if (!msg && dl_ass_tbf) {
+ tbf = dl_ass_tbf;
+ msg = gprs_rlcmac_send_packet_downlink_assignment(tbf, fn);
+ }
+ /* schedule PACKET UPLINK ACK (3rd priority) */
+ if (!msg && ul_ack_tbf) {
+ tbf = ul_ack_tbf;
+ msg = gprs_rlcmac_send_uplink_ack(tbf, fn);
+ }
+ /* any message */
+ if (msg) {
+ LOGP(DRLCMACSCHED, LOGL_DEBUG, "Scheduling control "
+ "message at RTS for %s TBF=%d (TRX=%d, TS=%d)\n",
+ (tbf->direction == GPRS_RLCMAC_UL_TBF)
+ ? "UL" : "DL", tbf->tfi, trx, ts);
+ return msg;
+ }
+ /* schedule PACKET PAGING REQUEST */
+ if (llist_empty(&pdch->paging_list))
+ return NULL;
+ msg = gprs_rlcmac_send_packet_paging_request(pdch);
+ if (msg)
+ LOGP(DRLCMACSCHED, LOGL_DEBUG, "Scheduling paging request "
+ "message at RTS for (TRX=%d, TS=%d)\n", trx, ts);
+
+ return msg;
+}
+
+struct msgb *sched_select_downlink(uint8_t trx, uint8_t ts, uint32_t fn,
+ uint8_t block_nr, struct gprs_rlcmac_pdch *pdch)
+{
+ struct msgb *msg = NULL;
+ struct gprs_rlcmac_tbf *tbf = NULL;
+ uint8_t i, tfi;
+
+ /* select downlink ressource */
+ for (i = 0, tfi = pdch->next_dl_tfi; i < 32;
+ i++, tfi = (tfi + 1) & 31) {
+ tbf = pdch->dl_tbf[tfi];
+ /* no TBF for this tfi, go next */
+ if (!tbf)
+ continue;
+ /* no DL TBF, go next */
+ if (tbf->direction != GPRS_RLCMAC_DL_TBF)
+ continue;
+ /* no DL ressources needed, go next */
+ if (tbf->state != GPRS_RLCMAC_FLOW
+ && tbf->state != GPRS_RLCMAC_FINISHED)
+ continue;
+
+ LOGP(DRLCMACSCHED, LOGL_DEBUG, "Scheduling data message at "
+ "RTS for DL TBF=%d (TRX=%d, TS=%d)\n", tfi, trx, ts);
+ /* next TBF to handle ressource is the next one */
+ pdch->next_dl_tfi = (tfi + 1) & 31;
+ /* generate DL data block */
+ msg = gprs_rlcmac_send_data_block_acknowledged(tbf, fn,
+ ts);
+ break;
+ }
+
+ return msg;
+}
+static uint8_t rlcmac_dl_idle[23] = {
+ 0x47, /* control without optional header octets, no polling, USF=111 */
+ 0x94, /* dummy downlink control message, paging mode 00 */
+ 0x2b, /* no persistance level, 7 bits spare pattern */
+ 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b,
+ 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b
+};
+
+struct msgb *sched_dummy(void)
+{
+ struct msgb *msg;
+
+ msg = msgb_alloc(23, "rlcmac_dl_idle");
+ if (!msg)
+ return NULL;
+ memcpy(msgb_put(msg, 23), rlcmac_dl_idle, 23);
+
+ return msg;
+}
+
+int gprs_rlcmac_rcv_rts_block(uint8_t trx, uint8_t ts, uint16_t arfcn,
+ uint32_t fn, uint8_t block_nr)
+{
+ struct gprs_rlcmac_bts *bts = gprs_rlcmac_bts;
+ struct gprs_rlcmac_pdch *pdch;
+ struct gprs_rlcmac_tbf *poll_tbf = NULL, *dl_ass_tbf = NULL,
+ *ul_ass_tbf = NULL, *ul_ack_tbf = NULL;
+ uint8_t usf = 0x7;
+ struct msgb *msg = NULL;
+ uint32_t poll_fn;
+
+ if (trx >= 8 || ts >= 8)
+ return -EINVAL;
+ pdch = &bts->trx[trx].pdch[ts];
+
+ if (!pdch->enable) {
+ LOGP(DRLCMACSCHED, LOGL_ERROR, "Received RTS on disabled PDCH: "
+ "TRX=%d TS=%d\n", trx, ts);
+ return -EIO;
+ }
+
+ /* store last frame number of RTS */
+ pdch->last_rts_fn = fn;
+
+ poll_fn = sched_poll(trx, ts, fn, block_nr, &poll_tbf, &ul_ass_tbf,
+ &dl_ass_tbf, &ul_ack_tbf);
+ /* check uplink ressource for polling */
+ if (poll_tbf)
+ LOGP(DRLCMACSCHED, LOGL_DEBUG, "Received RTS for PDCH: TRX=%d "
+ "TS=%d FN=%d block_nr=%d scheduling free USF for "
+ "polling at FN=%d of %s TFI=%d\n", trx, ts, fn,
+ block_nr, poll_fn,
+ (poll_tbf->direction == GPRS_RLCMAC_UL_TBF)
+ ? "UL" : "DL", poll_tbf->tfi);
+ /* use free USF */
+ /* else, we search for uplink ressource */
+ else
+ usf = sched_select_uplink(trx, ts, fn, block_nr, pdch);
+
+ /* Prio 1: select control message */
+ msg = sched_select_ctrl_msg(trx, ts, fn, block_nr, pdch, ul_ass_tbf,
+ dl_ass_tbf, ul_ack_tbf);
+
+ /* Prio 2: select data message for downlink */
+ if (!msg)
+ msg = sched_select_downlink(trx, ts, fn, block_nr, pdch);
+
+ /* Prio 3: send dummy contol message */
+ if (!msg)
+ msg = sched_dummy();
+
+ if (!msg)
+ return -ENOMEM;
+ /* msg is now available */
+
+ /* set USF */
+ msg->data[0] = (msg->data[0] & 0xf8) | usf;
+
+ /* send PDTCH/PACCH to L1 */
+ pcu_l1if_tx_pdtch(msg, trx, ts, arfcn, fn, block_nr);
+
+ return 0;
+}