host/trxcon/scheduler: implement management functions

This change introduces some new functions to configure
TDMA scheduler. They can be grouped as follows:

  - Scheduler management functions
    - sched_trx_init()
    - sched_trx_reset()
    - sched_trx_shutdown()

  - Timeslot management functions
    - sched_trx_add_ts()
    - sched_trx_find_ts()
    - sched_trx_del_ts()
    - sched_trx_reset_ts()
    - sched_trx_configure_ts()

  - Logical channel management functions
    - sched_trx_activate_lchan()
    - sched_trx_deactivate_lchan()
    - sched_trx_find_lchan()

Change-Id: I6d0f437a68f0eb4e22bf635bf899b08673571085

5 files changed, 360 insertions, 0 deletions

diff --git a/src/host/trxcon/Makefile.am b/src/host/trxcon/Makefile.am
index a5008e6f..f832651f 100644
--- a/src/host/trxcon/Makefile.am
+++ b/src/host/trxcon/Makefile.am
@@ -33,6 +33,7 @@ trxcon_SOURCES += \
 	sched_lchan_desc.c \
 	sched_mframe.c \
 	sched_clck.c \
+	sched_trx.c \
 	$(NULL)
 
 trxcon_LDADD = \
diff --git a/src/host/trxcon/sched_trx.c b/src/host/trxcon/sched_trx.c
new file mode 100644
index 00000000..a0a2ed5f
--- /dev/null
+++ b/src/host/trxcon/sched_trx.c
@@ -0,0 +1,328 @@
+/*
+ * OsmocomBB <-> SDR connection bridge
+ * TDMA scheduler: GSM PHY routines
+ *
+ * (C) 2017 by Vadim Yanitskiy <axilirator@gmail.com>
+ *
+ * All Rights Reserved
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <error.h>
+#include <errno.h>
+#include <string.h>
+#include <talloc.h>
+
+#include <osmocom/core/bits.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/linuxlist.h>
+
+#include "scheduler.h"
+#include "sched_trx.h"
+#include "trx_if.h"
+#include "logging.h"
+
+static void msgb_queue_flush(struct llist_head *list)
+{
+	struct msgb *msg, *msg2;
+
+	llist_for_each_entry_safe(msg, msg2, list, list)
+		msgb_free(msg);
+}
+
+static void sched_frame_clck_cb(struct trx_sched *sched)
+{
+	struct trx_instance *trx = (struct trx_instance *) sched->data;
+
+	/* If we have no active timeslots, nothing to do */
+	if (llist_empty(&trx->ts_list))
+		return;
+
+	/* Do nothing for now */
+}
+
+int sched_trx_init(struct trx_instance *trx)
+{
+	struct trx_sched *sched;
+
+	if (!trx)
+		return -EINVAL;
+
+	LOGP(DSCH, LOGL_NOTICE, "Init scheduler\n");
+
+	/* Obtain a scheduler instance from TRX */
+	sched = &trx->sched;
+
+	/* Register frame clock callback */
+	sched->clock_cb = sched_frame_clck_cb;
+
+	/* Set pointers */
+	sched = &trx->sched;
+	sched->data = trx;
+
+	INIT_LLIST_HEAD(&trx->ts_list);
+
+	return 0;
+}
+
+int sched_trx_shutdown(struct trx_instance *trx)
+{
+	int i;
+
+	if (!trx)
+		return -EINVAL;
+
+	LOGP(DSCH, LOGL_NOTICE, "Shutdown scheduler\n");
+
+	/* Free all potentially allocated timeslots */
+	for (i = 0; i < TRX_TS_COUNT; i++)
+		sched_trx_del_ts(trx, i);
+
+	return 0;
+}
+
+int sched_trx_reset(struct trx_instance *trx)
+{
+	struct trx_sched *sched;
+	int i;
+
+	if (!trx)
+		return -EINVAL;
+
+	LOGP(DSCH, LOGL_NOTICE, "Reset scheduler\n");
+
+	/* Free all potentially allocated timeslots */
+	for (i = 0; i < TRX_TS_COUNT; i++)
+		sched_trx_del_ts(trx, i);
+
+	INIT_LLIST_HEAD(&trx->ts_list);
+
+	/* Obtain a scheduler instance from TRX */
+	sched = &trx->sched;
+
+	/* Reset clock counter */
+	osmo_timer_del(&sched->clock_timer);
+	sched->fn_counter_proc = 0;
+	sched->fn_counter_lost = 0;
+
+	return 0;
+}
+
+struct trx_ts *sched_trx_add_ts(struct trx_instance *trx, int ts_num)
+{
+	struct trx_ts *ts;
+
+	LOGP(DSCH, LOGL_INFO, "Add a new TDMA timeslot #%u\n", ts_num);
+
+	ts = talloc_zero(trx, struct trx_ts);
+	if (!ts)
+		return NULL;
+
+	llist_add_tail(&ts->list, &trx->ts_list);
+
+	return ts;
+}
+
+struct trx_ts *sched_trx_find_ts(struct trx_instance *trx, int ts_num)
+{
+	struct trx_ts *ts;
+
+	if (llist_empty(&trx->ts_list))
+		return NULL;
+
+	llist_for_each_entry(ts, &trx->ts_list, list) {
+		if (ts->index == ts_num)
+			return ts;
+	}
+
+	return NULL;
+}
+
+void sched_trx_del_ts(struct trx_instance *trx, int ts_num)
+{
+	struct trx_ts *ts;
+
+	/* Find ts in list */
+	ts = sched_trx_find_ts(trx, ts_num);
+	if (ts == NULL)
+		return;
+
+	LOGP(DSCH, LOGL_INFO, "Delete TDMA timeslot #%u\n", ts_num);
+
+	/* Flush queue primitives for TX */
+	msgb_queue_flush(&ts->tx_prims);
+
+	/* Remove ts from list */
+	llist_del(&ts->list);
+	talloc_free(ts);
+}
+
+int sched_trx_configure_ts(struct trx_instance *trx, int ts_num,
+	enum gsm_phys_chan_config config)
+{
+	int i, type, lchan_cnt = 0;
+	struct trx_ts *ts;
+
+	/* Try to find specified ts */
+	ts = sched_trx_find_ts(trx, ts_num);
+	if (ts != NULL) {
+		/* Reconfiguration of existing one */
+		sched_trx_reset_ts(trx, ts_num);
+	} else {
+		/* Allocate a new one if doesn't exist */
+		ts = sched_trx_add_ts(trx, ts_num);
+		if (ts == NULL)
+			return -ENOMEM;
+	}
+
+	/* Init queue primitives for TX */
+	INIT_LLIST_HEAD(&ts->tx_prims);
+
+	/* Choose proper multiframe layout */
+	ts->mf_layout = sched_mframe_layout(config, ts_num);
+	if (ts->mf_layout->chan_config != config)
+		return -EINVAL;
+
+	LOGP(DSCH, LOGL_INFO, "(Re)configure TDMA timeslot #%u as %s\n",
+		ts_num, ts->mf_layout->name);
+
+	/* Count channel states */
+	for (type = 0; type < _TRX_CHAN_MAX; type++)
+		if (ts->mf_layout->lchan_mask & ((uint64_t) 0x01 << type))
+			lchan_cnt++;
+
+	if (!lchan_cnt)
+		return 0;
+
+	/* Allocate channel states */
+	ts->lchans = talloc_zero_array(ts, struct trx_lchan_state, lchan_cnt);
+	if (ts->lchans == NULL)
+		return -ENOMEM;
+
+	/* Init channel states */
+	for (type = 0, i = 0; type < _TRX_CHAN_MAX; type++) {
+		if (ts->mf_layout->lchan_mask & ((uint64_t) 0x01 << type)) {
+			/* Set proper channel type */
+			ts->lchans[i++].type = type;
+
+			/* Enable channel automatically if required */
+			if (trx_lchan_desc[type].flags & TRX_CH_FLAG_AUTO)
+				sched_trx_activate_lchan(ts, type);
+		}
+	}
+
+	return 0;
+}
+
+int sched_trx_reset_ts(struct trx_instance *trx, int ts_num)
+{
+	struct trx_ts *ts;
+
+	/* Try to find specified ts */
+	ts = sched_trx_find_ts(trx, ts_num);
+	if (ts == NULL)
+		return -EINVAL;
+
+	/* FIXME: where do we need it? */
+	ts->mf_last_fn = 0;
+
+	/* Undefine multiframe layout */
+	ts->mf_layout = NULL;
+
+	/* Flush queue primitives for TX */
+	msgb_queue_flush(&ts->tx_prims);
+
+	/* Free channel states */
+	talloc_free(ts->lchans);
+
+	return 0;
+}
+
+struct trx_lchan_state *sched_trx_find_lchan(struct trx_ts *ts,
+	enum trx_lchan_type chan)
+{
+	int i, len;
+
+	len = talloc_array_length(ts->lchans);
+	for (i = 0; i < len; i++)
+		if (ts->lchans[i].type == chan)
+			return ts->lchans + i;
+
+	return NULL;
+}
+
+int sched_trx_activate_lchan(struct trx_ts *ts, enum trx_lchan_type chan)
+{
+	const struct trx_lchan_desc *lchan_desc = &trx_lchan_desc[chan];
+	struct trx_lchan_state *lchan;
+
+	/* Try to find requested logical channel */
+	lchan = sched_trx_find_lchan(ts, chan);
+	if (lchan == NULL)
+		return -EINVAL;
+
+	if (lchan->active) {
+		LOGP(DSCH, LOGL_ERROR, "Logical channel %s already activated "
+			"on ts=%d\n", trx_lchan_desc[chan].name, ts->index);
+		return -EINVAL;
+	}
+
+	/* Conditionally allocate memory for bursts */
+	if (lchan_desc->rx_fn && lchan_desc->burst_buf_size > 0) {
+		lchan->rx_bursts = talloc_zero_size(ts->lchans,
+			lchan_desc->burst_buf_size);
+		if (lchan->rx_bursts == NULL)
+			return -ENOMEM;
+	}
+
+	if (lchan_desc->tx_fn && lchan_desc->burst_buf_size > 0) {
+		lchan->tx_bursts = talloc_zero_size(ts->lchans,
+			lchan_desc->burst_buf_size);
+		if (lchan->tx_bursts == NULL)
+			return -ENOMEM;
+	}
+
+	/* Finally, update channel status */
+	lchan->active = 1;
+
+	return 0;
+}
+
+int sched_trx_deactivate_lchan(struct trx_ts *ts, enum trx_lchan_type chan)
+{
+	struct trx_lchan_state *lchan;
+
+	/* Try to find requested logical channel */
+	lchan = sched_trx_find_lchan(ts, chan);
+	if (lchan == NULL)
+		return -EINVAL;
+
+	if (lchan->active) {
+		LOGP(DSCH, LOGL_ERROR, "Logical channel %s already deactivated "
+			"on ts=%d", trx_lchan_desc[chan].name, ts->index);
+		return -EINVAL;
+	}
+
+	/* Free memory */
+	talloc_free(lchan->rx_bursts);
+	talloc_free(lchan->tx_bursts);
+
+	lchan->active = 0;
+
+	return 0;
+}
diff --git a/src/host/trxcon/sched_trx.h b/src/host/trxcon/sched_trx.h
index 1abd5156..bcb4df99 100644
--- a/src/host/trxcon/sched_trx.h
+++ b/src/host/trxcon/sched_trx.h
@@ -233,3 +233,22 @@ struct trx_ts {
 extern const struct trx_lchan_desc trx_lchan_desc[_TRX_CHAN_MAX];
 const struct trx_multiframe *sched_mframe_layout(
 	enum gsm_phys_chan_config config, int ts_num);
+
+/* Scheduler management functions */
+int sched_trx_init(struct trx_instance *trx);
+int sched_trx_reset(struct trx_instance *trx);
+int sched_trx_shutdown(struct trx_instance *trx);
+
+/* Timeslot management functions */
+struct trx_ts *sched_trx_add_ts(struct trx_instance *trx, int ts_num);
+struct trx_ts *sched_trx_find_ts(struct trx_instance *trx, int ts_num);
+void sched_trx_del_ts(struct trx_instance *trx, int ts_num);
+int sched_trx_reset_ts(struct trx_instance *trx, int ts_num);
+int sched_trx_configure_ts(struct trx_instance *trx, int ts_num,
+	enum gsm_phys_chan_config config);
+
+/* Logical channel management functions */
+int sched_trx_activate_lchan(struct trx_ts *ts, enum trx_lchan_type chan);
+int sched_trx_deactivate_lchan(struct trx_ts *ts, enum trx_lchan_type chan);
+struct trx_lchan_state *sched_trx_find_lchan(struct trx_ts *ts,
+	enum trx_lchan_type chan);
diff --git a/src/host/trxcon/trx_if.h b/src/host/trxcon/trx_if.h
index e41d506b..1241fd5a 100644
--- a/src/host/trxcon/trx_if.h
+++ b/src/host/trxcon/trx_if.h
@@ -6,6 +6,7 @@
 #include <osmocom/core/fsm.h>
 
 #include "scheduler.h"
+#include "sched_trx.h"
 
 enum trx_fsm_states {
 	TRX_STATE_OFFLINE = 0,
@@ -26,6 +27,7 @@ struct trx_instance {
 
 	/* Scheduler stuff */
 	struct trx_sched sched;
+	struct llist_head ts_list;
 };
 
 struct trx_ctrl_msg {
diff --git a/src/host/trxcon/trxcon.c b/src/host/trxcon/trxcon.c
index ace2f79a..791bd25d 100644
--- a/src/host/trxcon/trxcon.c
+++ b/src/host/trxcon/trxcon.c
@@ -42,6 +42,8 @@
 #include "l1ctl.h"
 #include "l1ctl_link.h"
 #include "l1ctl_proto.h"
+#include "scheduler.h"
+#include "sched_trx.h"
 
 #define COPYRIGHT \
 	"Copyright (C) 2016-2017 by Vadim Yanitskiy <axilirator@gmail.com>\n" \
@@ -90,7 +92,9 @@ static void trxcon_fsm_managed_action(struct osmo_fsm_inst *fi,
 		}
 		break;
 	case L1CTL_EVENT_RESET_REQ:
+		trx_if_cmd_poweroff(app_data.trx);
 		trx_if_cmd_echo(app_data.trx);
+		sched_trx_reset(app_data.trx);
 		break;
 	case TRX_EVENT_RESET_IND:
 		/* TODO: send proper reset type */
@@ -270,6 +274,11 @@ int main(int argc, char **argv)
 	if (rc)
 		goto exit;
 
+	/* Init scheduler */
+	rc = sched_trx_init(app_data.trx);
+	if (rc)
+		goto exit;
+
 	LOGP(DAPP, LOGL_NOTICE, "Init complete\n");
 
 	if (app_data.daemonize) {
@@ -286,6 +295,7 @@ int main(int argc, char **argv)
 exit:
 	/* Close active connections */
 	l1ctl_link_shutdown(app_data.l1l);
+	sched_trx_shutdown(app_data.trx);
 	trx_if_close(app_data.trx);
 
 	/* Shutdown main state machine */