Move paging queue specific handling to signal callback outside RSL code

The signal is already there but not being used.
Let's further split generic paging code from RSL specificites.

Change-Id: Iabc1c29908a5136501d6dc6e60f8777dab511b86
---
M include/osmocom/bsc/paging.h
M src/osmo-bsc/abis_rsl.c
M src/osmo-bsc/paging.c
3 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/include/osmocom/bsc/paging.h b/include/osmocom/bsc/paging.h
index 15eb49e..054e5c7 100644
--- a/include/osmocom/bsc/paging.h
+++ b/include/osmocom/bsc/paging.h
@@ -150,9 +150,6 @@
 			struct gsm_bts *bts, struct bsc_subscr *bsub);
 void paging_request_cancel(struct bsc_subscr *bsub, enum bsc_paging_reason reasons);
 
-/* update paging load */
-void paging_update_buffer_space(struct gsm_bts *bts, uint16_t);
-
 /* pending paging requests */
 unsigned int paging_pending_requests_nr(const struct gsm_bts *bts);
 
diff --git a/src/osmo-bsc/abis_rsl.c b/src/osmo-bsc/abis_rsl.c
index 6a9712e..dfe7da9 100644
--- a/src/osmo-bsc/abis_rsl.c
+++ b/src/osmo-bsc/abis_rsl.c
@@ -2311,10 +2311,9 @@
 	switch (rslh->data[0]) {
 	case RSL_IE_PAGING_LOAD:
 		sd.pg_buf_space = rslh->data[1] << 8 | rslh->data[2];
-		if (is_ipaccess_bts(sign_link->trx->bts) && sd.pg_buf_space == UINT16_MAX) {
+		if (is_ipaccess_bts(sd.bts) && sd.pg_buf_space == UINT16_MAX) {
 			sd.pg_buf_space = paging_estimate_available_slots(sd.bts, sd.bts->ccch_load_ind_period);
 		}
-		paging_update_buffer_space(sign_link->trx->bts, sd.pg_buf_space);
 		osmo_signal_dispatch(SS_CCCH, S_CCCH_PAGING_LOAD, &sd);
 		break;
 	case RSL_IE_RACH_LOAD:
diff --git a/src/osmo-bsc/paging.c b/src/osmo-bsc/paging.c
index e6f6fe4..1cee164 100644
--- a/src/osmo-bsc/paging.c
+++ b/src/osmo-bsc/paging.c
@@ -684,7 +684,7 @@
 }
 
 /*! Update the BTS paging buffer slots on given BTS */
-void paging_update_buffer_space(struct gsm_bts *bts, uint16_t free_slots)
+static void paging_update_buffer_space(struct gsm_bts *bts, uint16_t free_slots)
 {
 	LOG_BTS(bts, DPAG, LOGL_DEBUG, "Rx CCCH Load Indication from BTS (available_slots %u -> %u)\n",
 		bts->paging.available_slots, free_slots);
@@ -841,8 +841,24 @@
 	return 0;
 }
 
+/* Callback function to be called every time we receive a signal from CCCH */
+static int ccch_sig_cb(unsigned int subsys, unsigned int signal,
+		       void *handler_data, void *signal_data)
+{
+	struct ccch_signal_data *sd;
+
+	if (signal != S_CCCH_PAGING_LOAD)
+		return 0;
+
+	sd = signal_data;
+
+	paging_update_buffer_space(sd->bts, sd->pg_buf_space);
+	return 0;
+}
+
 /* To be called once at startup of the process: */
 void paging_global_init(void)
 {
 	osmo_signal_register_handler(SS_NM, nm_sig_cb, NULL);
+	osmo_signal_register_handler(SS_CCCH, ccch_sig_cb, NULL);
 }

