rlc: Make the RLC types only operate on the BSN

The code has an internal optimization to only use window_size
space. This means that the caller needed to know that only half
of the size was used. Change the API to work on the BSN and do
the mapping internally. The compiler should have plenty of
opportunity to propagate the constant(s) but this has not been
verified.

1 files changed, 12 insertions, 17 deletions

diff --git a/src/rlc.cpp b/src/rlc.cpp
index dc5cf8b0..915da87f 100644
--- a/src/rlc.cpp
+++ b/src/rlc.cpp
@@ -49,8 +49,7 @@ void gprs_rlc_v_b::reset()
 int gprs_rlc_v_b::resend_needed(const gprs_rlc_dl_window &w)
 {
 	for (uint16_t bsn = w.v_a(); bsn != w.v_s(); bsn = (bsn + 1) & w.mod_sns()) {
-		uint16_t index = bsn & w.mod_sns_half();
-		if (is_nacked(index) || is_resend(index))
+		if (is_nacked(bsn) || is_resend(bsn))
 			return bsn;
 	}
 
@@ -62,10 +61,9 @@ int gprs_rlc_v_b::mark_for_resend(const gprs_rlc_dl_window &w)
 	int resend = 0;
 
 	for (uint16_t bsn = w.v_a(); bsn != w.v_s(); bsn = (bsn + 1) & w.mod_sns()) {
-		uint16_t index = bsn & w.mod_sns_half();
-		if (is_unacked(index)) {
+		if (is_unacked(bsn)) {
 			/* mark to be re-send */
-			mark_resend(index);
+			mark_resend(bsn);
 			resend += 1;
 		}
 	}
@@ -79,8 +77,7 @@ int gprs_rlc_v_b::count_unacked(const gprs_rlc_dl_window &w)
 	uint16_t bsn;
 
 	for (bsn = w.v_a(); bsn != w.v_s(); bsn = (bsn + 1) & w.mod_sns()) {
-		uint16_t index = bsn & w.mod_sns_half();
-		if (!is_acked(index))
+		if (!is_acked(bsn))
 			unacked += 1;
 	}
 
@@ -101,12 +98,12 @@ void gprs_rlc_v_b::update(BTS *bts, char *show_rbb, uint8_t ssn,
 
 		if (show_rbb[i] == '1') {
 			LOGP(DRLCMACDL, LOGL_DEBUG, "- got ack for BSN=%d\n", bsn);
-			if (!is_acked(bsn & w.mod_sns_half()))
+			if (!is_acked(bsn))
 				*received += 1;
-			mark_acked(bsn & w.mod_sns_half());
+			mark_acked(bsn);
 		} else {
 			LOGP(DRLCMACDL, LOGL_DEBUG, "- got NACK for BSN=%d\n", bsn);
-			mark_nacked(bsn & w.mod_sns_half());
+			mark_nacked(bsn);
 			bts->rlc_nacked();
 			*lost += 1;
 		}
@@ -120,9 +117,8 @@ int gprs_rlc_v_b::move_window(const gprs_rlc_dl_window &w)
 	int moved = 0;
 
 	for (i = 0, bsn = w.v_a(); bsn != w.v_s(); i++, bsn = (bsn + 1) & w.mod_sns()) {
-		uint16_t index = bsn & w.mod_sns_half();
-		if (is_acked(index)) {
-			mark_invalid(index);
+		if (is_acked(bsn)) {
+			mark_invalid(bsn);
 			moved += 1;
 		} else
 			break;
@@ -137,7 +133,7 @@ void gprs_rlc_v_b::state(char *show_v_b, const gprs_rlc_dl_window &w)
 	uint16_t bsn;
 
 	for (i = 0, bsn = w.v_a(); bsn != w.v_s(); i++, bsn = (bsn + 1) & w.mod_sns()) {
-		uint16_t index = bsn & w.mod_sns_half();
+		uint16_t index = bsn & mod_sns_half();
 		show_v_b[i] = m_v_b[index];
 		if (show_v_b[i] == 0)
 			show_v_b[i] = ' ';
@@ -159,7 +155,7 @@ void gprs_rlc_ul_window::raise_v_r(const uint16_t bsn, gprs_rlc_v_n *v_n)
 	if (offset_v_r < (sns() >> 1)) {
 		while (offset_v_r--) {
 			if (offset_v_r) /* all except the received block */
-				v_n->mark_missing(v_r() & mod_sns_half());
+				v_n->mark_missing(v_r());
 			raise_v_r(1);
 		}
 		LOGP(DRLCMACUL, LOGL_DEBUG, "- Raising V(R) to %d\n", v_r());
@@ -175,8 +171,7 @@ uint16_t gprs_rlc_ul_window::raise_v_q(gprs_rlc_v_n *v_n)
 	uint16_t count = 0;
 
 	while (v_q() != v_r()) {
-		uint16_t index = v_q() & mod_sns_half();
-		if (!v_n->is_received(index))
+		if (!v_n->is_received(v_q()))
 			break;
 		LOGP(DRLCMACUL, LOGL_DEBUG, "- Taking block %d out, raising "
 			"V(Q) to %d\n", v_q(), (v_q() + 1) & mod_sns());