paging: cosmetic: rename all IMM.ASS references to MAC block

The paging interface towards the PCU has a confusing API. In fact what
the PCU does when it wants to page or do an immediate assignment is
sending a ready formatted MAC block to the BTS. The BTS then puts this
MAC block in the paging queue and then eventually it justs sends it
without looking at the contents. For the code in paging.c it is not
imortant if the MAC block is an immediate assignment, it only cares if
the paging record contains a MAC block or paging parameters.

Related: OS#5927
Change-Id: Ifab37fdedaba98b160718113767e4ef6ee7d16ad

3 files changed, 60 insertions, 58 deletions

diff --git a/include/osmo-bts/paging.h b/include/osmo-bts/paging.h
index fb50323b..f1ae8e3f 100644
--- a/include/osmo-bts/paging.h
+++ b/include/osmo-bts/paging.h
@@ -35,9 +35,10 @@ int paging_si_update(struct paging_state *ps, struct gsm48_control_channel_descr
 int paging_add_identity(struct paging_state *ps, uint8_t paging_group,
 			const uint8_t *identity_lv, uint8_t chan_needed);
 
-/* Add an IMM.ASS message to the paging queue */
-int paging_add_imm_ass(struct paging_state *ps,
-		       const uint8_t *data, uint8_t len);
+/* Add a ready formatted MAC block message to the paging queue, this can be an IMMEDIATE ASSIGNMENT, or a
+ * PAGING COMMAND (from the PCU) */
+int paging_add_macblock(struct paging_state *ps,
+			const uint8_t *data, uint8_t len);
 
 /* generate paging message for given gsm time */
 int paging_gen_msg(struct paging_state *ps, uint8_t *out_buf, struct gsm_time *gt,
diff --git a/src/common/paging.c b/src/common/paging.c
index 26ba9b04..284b71c5 100644
--- a/src/common/paging.c
+++ b/src/common/paging.c
@@ -48,8 +48,8 @@
 #define MAX_BS_PA_MFRMS		9
 
 enum paging_record_type {
-	PAGING_RECORD_PAGING,
-	PAGING_RECORD_IMM_ASS
+	PAGING_RECORD_NORMAL,
+	PAGING_RECORD_MACBLOCK
 };
 
 struct paging_record {
@@ -60,10 +60,10 @@ struct paging_record {
 			time_t expiration_time;
 			uint8_t chan_needed;
 			uint8_t identity_lv[9];
-		} paging;
+		} normal;
 		struct {
 			uint8_t msg[GSM_MACBLOCK_LEN];
-		} imm_ass;
+		} macblock;
 	} u;
 };
 
@@ -88,9 +88,9 @@ struct paging_state {
 
 /* The prioritization of cs pagings is controlled by a hysteresis. When the
  * fill state of the paging queue exceeds the upper fill level
- * THRESHOLD_CONGESTED [%], then PS pagings (immediate assignments) will be
- * dropped until fill state of the paging queue drops under the lower fill
- * level THRESHOLD_CLEAR [%]. */
+ * THRESHOLD_CONGESTED [%], then PS pagings (immediate assignments and pagings
+ * from the PCU) will be dropped until fill state of the paging queue drops
+ * under the lower fill level THRESHOLD_CLEAR [%]. */
 #define THRESHOLD_CONGESTED 66 /* (percent of num_paging_max) */
 #define THRESHOLD_CLEAR 50 /* (percent of num_paging_max) */
 
@@ -230,13 +230,13 @@ int paging_add_identity(struct paging_state *ps, uint8_t paging_group,
 
 	/* Check if we already have this identity */
 	llist_for_each_entry(pr, group_q, list) {
-		if (pr->type != PAGING_RECORD_PAGING)
+		if (pr->type != PAGING_RECORD_NORMAL)
 			continue;
-		if (identity_lv[0] == pr->u.paging.identity_lv[0] &&
-		    !memcmp(identity_lv+1, pr->u.paging.identity_lv+1,
+		if (identity_lv[0] == pr->u.normal.identity_lv[0] &&
+		    !memcmp(identity_lv+1, pr->u.normal.identity_lv+1,
 							identity_lv[0])) {
 			LOGP(DPAG, LOGL_INFO, "Ignoring duplicate paging\n");
-			pr->u.paging.expiration_time =
+			pr->u.normal.expiration_time =
 					time(NULL) + ps->paging_lifetime;
 			return -EEXIST;
 		}
@@ -245,9 +245,9 @@ int paging_add_identity(struct paging_state *ps, uint8_t paging_group,
 	pr = talloc_zero(ps, struct paging_record);
 	if (!pr)
 		return -ENOMEM;
-	pr->type = PAGING_RECORD_PAGING;
+	pr->type = PAGING_RECORD_NORMAL;
 
-	if (*identity_lv + 1 > sizeof(pr->u.paging.identity_lv)) {
+	if (*identity_lv + 1 > sizeof(pr->u.normal.identity_lv)) {
 		talloc_free(pr);
 		return -E2BIG;
 	}
@@ -255,9 +255,9 @@ int paging_add_identity(struct paging_state *ps, uint8_t paging_group,
 	LOGP(DPAG, LOGL_INFO, "Add paging to queue (group=%u, queue_len=%u)\n",
 		paging_group, ps->num_paging+1);
 
-	pr->u.paging.expiration_time = time(NULL) + ps->paging_lifetime;
-	pr->u.paging.chan_needed = chan_needed;
-	memcpy(&pr->u.paging.identity_lv, identity_lv, identity_lv[0]+1);
+	pr->u.normal.expiration_time = time(NULL) + ps->paging_lifetime;
+	pr->u.normal.chan_needed = chan_needed;
+	memcpy(&pr->u.normal.identity_lv, identity_lv, identity_lv[0]+1);
 
 	/* enqueue the new identity to the HEAD of the queue,
 	 * to ensure it will be paged quickly at least once.  */
@@ -267,9 +267,10 @@ int paging_add_identity(struct paging_state *ps, uint8_t paging_group,
 	return 0;
 }
 
-/* Add an IMM.ASS message to the paging queue */
-int paging_add_imm_ass(struct paging_state *ps,
-		       const uint8_t *data, uint8_t len)
+/* Add a ready formatted MAC block message to the paging queue, this can be an IMMEDIATE ASSIGNMENT, or a
+ * PAGING COMMAND (from the PCU) */
+int paging_add_macblock(struct paging_state *ps,
+			const uint8_t *data, uint8_t len)
 {
 	struct llist_head *group_q;
 	struct paging_record *pr;
@@ -285,7 +286,7 @@ int paging_add_imm_ass(struct paging_state *ps,
 	}
 
 	if (len != GSM_MACBLOCK_LEN + 3) {
-		LOGP(DPAG, LOGL_ERROR, "IMM.ASS invalid length %d\n", len);
+		LOGP(DPAG, LOGL_ERROR, "MAC block with invalid length %d (GSM_MACBLOCK_LEN + 3)\n", len);
 		return -EINVAL;
 	}
 	len -= 3;
@@ -300,11 +301,11 @@ int paging_add_imm_ass(struct paging_state *ps,
 	pr = talloc_zero(ps, struct paging_record);
 	if (!pr)
 		return -ENOMEM;
-	pr->type = PAGING_RECORD_IMM_ASS;
+	pr->type = PAGING_RECORD_MACBLOCK;
 
-	LOGP(DPAG, LOGL_INFO, "Add IMM.ASS to queue (group=%u)\n",
+	LOGP(DPAG, LOGL_INFO, "Add MAC block to paging queue (group=%u)\n",
 		paging_group);
-	memcpy(pr->u.imm_ass.msg, data, GSM_MACBLOCK_LEN);
+	memcpy(pr->u.macblock.msg, data, GSM_MACBLOCK_LEN);
 
 	/* enqueue the new message to the HEAD of the queue */
 	llist_add(&pr->list, group_q);
@@ -509,7 +510,7 @@ static struct paging_record *dequeue_pr(struct llist_head *group_q)
 
 static int pr_is_imsi(struct paging_record *pr)
 {
-	if ((pr->u.paging.identity_lv[1] & 7) == GSM_MI_TYPE_IMSI)
+	if ((pr->u.normal.identity_lv[1] & 7) == GSM_MI_TYPE_IMSI)
 		return 1;
 	else
 		return 0;
@@ -599,7 +600,7 @@ int paging_gen_msg(struct paging_state *ps, uint8_t *out_buf, struct gsm_time *g
 		*is_empty = 1;
 	} else {
 		struct paging_record *pr[4];
-		unsigned int num_pr = 0, imm_ass = 0;
+		unsigned int num_pr = 0, macblock = 0;
 		time_t now = time(NULL);
 		unsigned int i, num_imsi = 0;
 
@@ -611,9 +612,9 @@ int paging_gen_msg(struct paging_state *ps, uint8_t *out_buf, struct gsm_time *g
 				break;
 			pr[i] = dequeue_pr(group_q);
 
-			/* check for IMM.ASS */
-			if (pr[i]->type == PAGING_RECORD_IMM_ASS) {
-				imm_ass = 1;
+			/* check for MAC block */
+			if (pr[i]->type == PAGING_RECORD_MACBLOCK) {
+				macblock = 1;
 				break;
 			}
 
@@ -624,16 +625,16 @@ int paging_gen_msg(struct paging_state *ps, uint8_t *out_buf, struct gsm_time *g
 				num_imsi++;
 		}
 
-		/* if we have an IMMEDIATE ASSIGNMENT */
-		if (imm_ass) {
-			/* re-add paging records */
+		/* if we have a MAC block (from the PCU), we send a conformation back */
+		if (macblock) {
+			/* re-add normal paging records */
 			for (i = 0; i < num_pr; i++)
 				llist_add(&pr[i]->list, group_q);
 
-			/* get message and free record */
-			memcpy(out_buf, pr[num_pr]->u.imm_ass.msg,
+			/* get MAC block message and free record */
+			memcpy(out_buf, pr[num_pr]->u.macblock.msg,
 							GSM_MACBLOCK_LEN);
-			pcu_tx_pch_data_cnf(gt->fn, pr[num_pr]->u.imm_ass.msg,
+			pcu_tx_pch_data_cnf(gt->fn, pr[num_pr]->u.macblock.msg,
 							GSM_MACBLOCK_LEN);
 			talloc_free(pr[num_pr]);
 			return GSM_MACBLOCK_LEN;
@@ -646,23 +647,23 @@ int paging_gen_msg(struct paging_state *ps, uint8_t *out_buf, struct gsm_time *g
 			/* No IMSI: easy case, can use TYPE 3 */
 			DEBUGP(DPAG, "Tx PAGING TYPE 3 (4 TMSI)\n");
 			len = fill_paging_type_3(out_buf,
-						 pr[0]->u.paging.identity_lv,
-						 pr[0]->u.paging.chan_needed,
-						 pr[1]->u.paging.identity_lv,
-						 pr[1]->u.paging.chan_needed,
-						 pr[2]->u.paging.identity_lv,
-						 pr[2]->u.paging.chan_needed,
-						 pr[3]->u.paging.identity_lv,
-						 pr[3]->u.paging.chan_needed);
+						 pr[0]->u.normal.identity_lv,
+						 pr[0]->u.normal.chan_needed,
+						 pr[1]->u.normal.identity_lv,
+						 pr[1]->u.normal.chan_needed,
+						 pr[2]->u.normal.identity_lv,
+						 pr[2]->u.normal.chan_needed,
+						 pr[3]->u.normal.identity_lv,
+						 pr[3]->u.normal.chan_needed);
 		} else if (num_pr >= 3 && num_imsi <= 1) {
 			/* 3 or 4, of which only up to 1 is IMSI */
 			DEBUGP(DPAG, "Tx PAGING TYPE 2 (2 TMSI,1 xMSI)\n");
 			len = fill_paging_type_2(out_buf,
-						 pr[0]->u.paging.identity_lv,
-						 pr[0]->u.paging.chan_needed,
-						 pr[1]->u.paging.identity_lv,
-						 pr[1]->u.paging.chan_needed,
-						 pr[2]->u.paging.identity_lv);
+						 pr[0]->u.normal.identity_lv,
+						 pr[0]->u.normal.chan_needed,
+						 pr[1]->u.normal.identity_lv,
+						 pr[1]->u.normal.chan_needed,
+						 pr[2]->u.normal.identity_lv);
 			if (num_pr == 4) {
 				/* re-add #4 for next time */
 				llist_add(&pr[3]->list, group_q);
@@ -671,18 +672,18 @@ int paging_gen_msg(struct paging_state *ps, uint8_t *out_buf, struct gsm_time *g
 		} else if (num_pr == 1) {
 			DEBUGP(DPAG, "Tx PAGING TYPE 1 (1 xMSI,1 empty)\n");
 			len = fill_paging_type_1(out_buf,
-						 pr[0]->u.paging.identity_lv,
-						 pr[0]->u.paging.chan_needed,
+						 pr[0]->u.normal.identity_lv,
+						 pr[0]->u.normal.chan_needed,
 						 NULL, 0, NULL);
 		} else {
 			/* 2 (any type) or
 			 * 3 or 4, of which only 2 will be sent */
 			DEBUGP(DPAG, "Tx PAGING TYPE 1 (2 xMSI)\n");
 			len = fill_paging_type_1(out_buf,
-						 pr[0]->u.paging.identity_lv,
-						 pr[0]->u.paging.chan_needed,
-						 pr[1]->u.paging.identity_lv,
-						 pr[1]->u.paging.chan_needed, NULL);
+						 pr[0]->u.normal.identity_lv,
+						 pr[0]->u.normal.chan_needed,
+						 pr[1]->u.normal.identity_lv,
+						 pr[1]->u.normal.chan_needed, NULL);
 			if (num_pr >= 3) {
 				/* re-add #4 for next time */
 				llist_add(&pr[2]->list, group_q);
@@ -702,7 +703,7 @@ int paging_gen_msg(struct paging_state *ps, uint8_t *out_buf, struct gsm_time *g
 			rate_ctr_inc2(bts->ctrs, BTS_CTR_PAGING_SENT);
 			/* check if we can expire the paging record,
 			 * or if we need to re-queue it */
-			if (pr[i]->u.paging.expiration_time <= now) {
+			if (pr[i]->u.normal.expiration_time <= now) {
 				talloc_free(pr[i]);
 				ps->num_paging--;
 				LOGP(DPAG, LOGL_INFO, "Removed paging record, queue_len=%u\n",
diff --git a/src/common/pcu_sock.c b/src/common/pcu_sock.c
index 2fb0524c..00debad1 100644
--- a/src/common/pcu_sock.c
+++ b/src/common/pcu_sock.c
@@ -675,7 +675,7 @@ static int pcu_rx_data_req(struct gsm_bts *bts, uint8_t msg_type,
 
 	switch (data_req->sapi) {
 	case PCU_IF_SAPI_PCH:
-		paging_add_imm_ass(bts->paging_state, data_req->data, data_req->len);
+		paging_add_macblock(bts->paging_state, data_req->data, data_req->len);
 		break;
 	case PCU_IF_SAPI_AGCH:
 		msg = msgb_alloc(data_req->len, "pcu_agch");