Use libosmocore's TDMA frame number API (constatns & arithmetic)

Depends: (libosmocore) Ic291fd3644f34964374227a191c7045d79d77e0d
Change-Id: I61c97a62bd5dbbb4a984921ebdfc10ad6ed00f2a

6 files changed, 31 insertions, 52 deletions

diff --git a/include/osmo-bts/gsm_data.h b/include/osmo-bts/gsm_data.h
index 416864fb..255c871d 100644
--- a/include/osmo-bts/gsm_data.h
+++ b/include/osmo-bts/gsm_data.h
@@ -12,6 +12,7 @@
 #include <osmocom/codec/ecu.h>
 #include <osmocom/gsm/lapdm.h>
 #include <osmocom/gsm/gsm23003.h>
+#include <osmocom/gsm/gsm0502.h>
 #include <osmocom/gsm/gsm_utils.h>
 #include <osmocom/gsm/tlv.h>
 #include <osmocom/gsm/rxlev_stat.h>
@@ -35,9 +36,6 @@
 #define GSM_HR_BYTES	14	/* TS 101318 Chapter 5.2: 112 bits, no sig */
 #define GSM_EFR_BYTES	31	/* TS 101318 Chapter 5.3: 244 bits + 4bit sig */
 
-#define GSM_SUPERFRAME	(26*51)			/* 1326 TDMA frames */
-#define GSM_HYPERFRAME	(2048*GSM_SUPERFRAME)	/* GSM_HYPERFRAME frames */
-
 #define GSM_BTS_AGCH_QUEUE_THRESH_LEVEL_DEFAULT 41
 #define GSM_BTS_AGCH_QUEUE_THRESH_LEVEL_DISABLE 999999
 #define GSM_BTS_AGCH_QUEUE_LOW_LEVEL_DEFAULT 41
diff --git a/src/common/l1sap.c b/src/common/l1sap.c
index dad1b494..17a6c5d4 100644
--- a/src/common/l1sap.c
+++ b/src/common/l1sap.c
@@ -621,7 +621,7 @@ static int l1sap_info_time_ind(struct gsm_bts *bts,
 	/* increment number of RACH slots that have passed by since the
 	 * last time indication */
 	for (i = 0; i < frames_expired; i++) {
-		uint32_t fn = (info_time_ind->fn + GSM_HYPERFRAME - i) % GSM_HYPERFRAME;
+		uint32_t fn = GSM_TDMA_FN_SUB(info_time_ind->fn, i);
 		bts->load.rach.total += calc_exprd_rach_frames(bts, fn);
 	}
 
@@ -891,7 +891,7 @@ int32_t bts_get_avg_fn_advance(struct gsm_bts *bts)
 
 static void l1sap_update_fnstats(struct gsm_bts *bts, uint32_t rts_fn)
 {
-	int32_t delta = (rts_fn + GSM_HYPERFRAME - bts->gsm_time.fn) % GSM_HYPERFRAME;
+	int32_t delta = GSM_TDMA_FN_SUB(rts_fn, bts->gsm_time.fn);
 
 	if (delta < bts->fn_stats.min)
 		bts->fn_stats.min = delta;
diff --git a/src/common/scheduler.c b/src/common/scheduler.c
index 01edc69c..62efed41 100644
--- a/src/common/scheduler.c
+++ b/src/common/scheduler.c
@@ -684,7 +684,7 @@ struct msgb *_sched_dequeue_prim(struct l1sched_trx *l1t, int8_t tn, uint32_t fn
 			LOGL1S(DL1P, LOGL_ERROR, l1t, tn, chan, fn, "Prim has wrong type.\n");
 			goto free_msg;
 		}
-		prim_fn = ((l1sap_fn + GSM_HYPERFRAME - fn) % GSM_HYPERFRAME);
+		prim_fn = GSM_TDMA_FN_SUB(l1sap_fn, fn);
 		if (prim_fn > 100) { /* l1sap_fn < fn */
 			LOGL1S(DL1P, LOGL_NOTICE, l1t, tn, chan, fn,
 			     "Prim %u is out of range (%u vs exp %u), or channel %s with "
@@ -1248,12 +1248,6 @@ no_data:
 	}
 }
 
-#define TDMA_FN_SUM(a, b) \
-	((a + GSM_HYPERFRAME + b) % GSM_HYPERFRAME)
-
-#define TDMA_FN_SUB(a, b) \
-	((a + GSM_HYPERFRAME - b) % GSM_HYPERFRAME)
-
 static int trx_sched_calc_frame_loss(struct l1sched_trx *l1t,
 	struct l1sched_chan_state *l1cs, uint8_t tn, uint32_t fn)
 {
@@ -1291,7 +1285,7 @@ static int trx_sched_calc_frame_loss(struct l1sched_trx *l1t,
 	}
 
 	/* How many frames elapsed since the last one? */
-	elapsed_fs = TDMA_FN_SUB(fn, l1cs->last_tdma_fn);
+	elapsed_fs = GSM_TDMA_FN_SUB(fn, l1cs->last_tdma_fn);
 	if (elapsed_fs > l1ts->mf_period) { /* Too many! */
 		LOGL1S(DL1P, LOGL_ERROR, l1t, tn, frame_head->ul_chan, fn,
 			"Too many (>%u) contiguous TDMA frames=%u elapsed "
@@ -1310,7 +1304,7 @@ static int trx_sched_calc_frame_loss(struct l1sched_trx *l1t,
 	 * Start counting from the last_fn + 1.
 	 */
 	for (i = 1; i < elapsed_fs; i++) {
-		fn_i = TDMA_FN_SUM(l1cs->last_tdma_fn, i);
+		fn_i = GSM_TDMA_FN_SUM(l1cs->last_tdma_fn, i);
 		offset = fn_i % l1ts->mf_period;
 		frame = l1ts->mf_frames + offset;
 
@@ -1343,7 +1337,7 @@ static int trx_sched_calc_frame_loss(struct l1sched_trx *l1t,
 		};
 
 		for (i = 1; i < elapsed_fs; i++) {
-			fn_i = TDMA_FN_SUM(l1cs->last_tdma_fn, i);
+			fn_i = GSM_TDMA_FN_SUM(l1cs->last_tdma_fn, i);
 			offset = fn_i % l1ts->mf_period;
 			frame = l1ts->mf_frames + offset;
 			func = trx_chan_desc[frame->ul_chan].ul_fn;
diff --git a/src/osmo-bts-trx/scheduler_trx.c b/src/osmo-bts-trx/scheduler_trx.c
index d4a38b61..3936124c 100644
--- a/src/osmo-bts-trx/scheduler_trx.c
+++ b/src/osmo-bts-trx/scheduler_trx.c
@@ -74,7 +74,7 @@ static int trx_sched_fn(struct gsm_bts *bts, uint32_t fn)
 
 		/* advance frame number, so the transceiver has more
 		 * time until it must be transmitted. */
-		fn = (fn + plink->u.osmotrx.clock_advance) % GSM_HYPERFRAME;
+		fn = GSM_TDMA_FN_SUM(fn, plink->u.osmotrx.clock_advance);
 
 		/* we don't schedule, if power is off */
 		if (!trx_if_powered(l1h))
@@ -83,8 +83,7 @@ static int trx_sched_fn(struct gsm_bts *bts, uint32_t fn)
 		/* process every TS of TRX */
 		for (tn = 0; tn < ARRAY_SIZE(l1t->ts); tn++) {
 			/* ready-to-send */
-			_sched_rts(l1t, tn,
-				(fn + plink->u.osmotrx.rts_advance) % GSM_HYPERFRAME);
+			_sched_rts(l1t, tn, GSM_TDMA_FN_SUM(fn, plink->u.osmotrx.rts_advance));
 
 			/* All other parameters to be set by _sched_dl_burst() */
 			br = (struct trx_dl_burst_req) {
@@ -105,10 +104,6 @@ static int trx_sched_fn(struct gsm_bts *bts, uint32_t fn)
 	return 0;
 }
 
-/*! duration of a GSM frame in nano-seconds. (120ms/26) */
-#define FRAME_DURATION_nS	4615384
-/*! duration of a GSM frame in micro-seconds (120s/26) */
-#define FRAME_DURATION_uS	(FRAME_DURATION_nS/1000)
 /*! maximum number of 'missed' frame periods we can tolerate of OS doesn't schedule us*/
 #define MAX_FN_SKEW		50
 /*! maximum number of frame periods we can tolerate without TRX Clock Indication*/
@@ -126,9 +121,9 @@ static inline int64_t compute_elapsed_us(const struct timespec *last, const stru
 /*! compute the number of frame number intervals elapsed between \a last and \a now */
 static inline int compute_elapsed_fn(const uint32_t last, const uint32_t now)
 {
-	int elapsed_fn = (now + GSM_HYPERFRAME - last) % GSM_HYPERFRAME;
+	int elapsed_fn = GSM_TDMA_FN_SUB(now, last);
 	if (elapsed_fn >= 135774)
-		elapsed_fn -= GSM_HYPERFRAME;
+		elapsed_fn -= GSM_TDMA_HYPERFRAME;
 	return elapsed_fn;
 }
 
@@ -139,9 +134,6 @@ static inline void normalize_timespec(struct timespec *ts)
 	ts->tv_nsec = ts->tv_nsec % 1000000000;
 }
 
-/*! Increment a GSM frame number modulo GSM_HYPERFRAME */
-#define INCREMENT_FN(fn)	(fn) = (((fn) + 1) % GSM_HYPERFRAME)
-
 extern int quit;
 
 /*! this is the timerfd-callback firing for every FN to be processed */
@@ -178,7 +170,7 @@ static int trx_fn_timer_cb(struct osmo_fd *ofd, unsigned int what)
 	/* compute actual elapsed time and resulting OS scheduling error */
 	clock_gettime(CLOCK_MONOTONIC, &tv_now);
 	elapsed_us = compute_elapsed_us(&tcs->last_fn_timer.tv, &tv_now);
-	error_us = elapsed_us - FRAME_DURATION_uS;
+	error_us = elapsed_us - GSM_TDMA_FN_DURATION_uS;
 #ifdef DEBUG_CLOCK
 	printf("%s(): %09ld, elapsed_us=%05" PRId64 ", error_us=%-d: fn=%d\n", __func__,
 		tv_now.tv_nsec, elapsed_us, error_us, tcs->last_fn_timer.fn+1);
@@ -186,17 +178,15 @@ static int trx_fn_timer_cb(struct osmo_fd *ofd, unsigned int what)
 	tcs->last_fn_timer.tv = tv_now;
 
 	/* if someone played with clock, or if the process stalled */
-	if (elapsed_us > FRAME_DURATION_uS * MAX_FN_SKEW || elapsed_us < 0) {
+	if (elapsed_us > GSM_TDMA_FN_DURATION_uS * MAX_FN_SKEW || elapsed_us < 0) {
 		LOGP(DL1C, LOGL_ERROR, "PC clock skew: elapsed_us=%" PRId64 ", error_us=%" PRId64 "\n",
 			elapsed_us, error_us);
 		goto no_clock;
 	}
 
 	/* call trx_sched_fn() for all expired FN */
-	for (i = 0; i < expire_count; i++) {
-		INCREMENT_FN(tcs->last_fn_timer.fn);
-		trx_sched_fn(bts, tcs->last_fn_timer.fn);
-	}
+	for (i = 0; i < expire_count; i++)
+		trx_sched_fn(bts, GSM_TDMA_FN_INC(tcs->last_fn_timer.fn));
 
 	return 0;
 
@@ -281,7 +271,7 @@ int trx_sched_clock(struct gsm_bts *bts, uint32_t fn)
 	int elapsed_fn;
 	int64_t elapsed_us, elapsed_us_since_clk, elapsed_fn_since_clk, error_us_since_clk;
 	unsigned int fn_caught_up = 0;
-	const struct timespec interval = { .tv_sec = 0, .tv_nsec = FRAME_DURATION_nS };
+	const struct timespec interval = { .tv_sec = 0, .tv_nsec = GSM_TDMA_FN_DURATION_nS };
 
 	if (quit)
 		return 0;
@@ -307,7 +297,7 @@ int trx_sched_clock(struct gsm_bts *bts, uint32_t fn)
 	elapsed_us_since_clk = compute_elapsed_us(&tcs->last_clk_ind.tv, &tv_now);
 	elapsed_fn_since_clk = compute_elapsed_fn(tcs->last_clk_ind.fn, fn);
 	/* error (delta) between local clock since last CLK and CLK based on FN clock at TRX */
-	error_us_since_clk = elapsed_us_since_clk - (FRAME_DURATION_uS * elapsed_fn_since_clk);
+	error_us_since_clk = elapsed_us_since_clk - (GSM_TDMA_FN_DURATION_uS * elapsed_fn_since_clk);
 	LOGP(DL1C, LOGL_INFO, "TRX Clock Ind: elapsed_us=%7"PRId64", "
 		"elapsed_fn=%3"PRId64", error_us=%+5"PRId64"\n",
 		elapsed_us_since_clk, elapsed_fn_since_clk, error_us_since_clk);
@@ -328,14 +318,14 @@ int trx_sched_clock(struct gsm_bts *bts, uint32_t fn)
 	}
 
 	LOGP(DL1C, LOGL_INFO, "GSM clock jitter: %" PRId64 "us (elapsed_fn=%d)\n",
-		elapsed_fn * FRAME_DURATION_uS - elapsed_us, elapsed_fn);
+		elapsed_fn * GSM_TDMA_FN_DURATION_uS - elapsed_us, elapsed_fn);
 
 	/* too many frames have been processed already */
 	if (elapsed_fn < 0) {
 		struct timespec first = interval;
 		/* set clock to the time or last FN should have been
 		 * transmitted. */
-		first.tv_nsec += (0 - elapsed_fn) * FRAME_DURATION_nS;
+		first.tv_nsec += (0 - elapsed_fn) * GSM_TDMA_FN_DURATION_nS;
 		normalize_timespec(&first);
 		LOGP(DL1C, LOGL_NOTICE, "We were %d FN faster than TRX, compensating\n", -elapsed_fn);
 		/* set time to the time our next FN has to be transmitted */
@@ -345,8 +335,7 @@ int trx_sched_clock(struct gsm_bts *bts, uint32_t fn)
 
 	/* transmit what we still need to transmit */
 	while (fn != tcs->last_fn_timer.fn) {
-		INCREMENT_FN(tcs->last_fn_timer.fn);
-		trx_sched_fn(bts, tcs->last_fn_timer.fn);
+		trx_sched_fn(bts, GSM_TDMA_FN_INC(tcs->last_fn_timer.fn));
 		fn_caught_up++;
 	}
 
diff --git a/src/osmo-bts-trx/trx_if.c b/src/osmo-bts-trx/trx_if.c
index 6fe0ecd6..58f74553 100644
--- a/src/osmo-bts-trx/trx_if.c
+++ b/src/osmo-bts-trx/trx_if.c
@@ -121,8 +121,8 @@ static int trx_clk_read_cb(struct osmo_fd *ofd, unsigned int what)
 
 	LOGPPHI(pinst, DTRX, LOGL_INFO, "Clock indication: fn=%u\n", fn);
 
-	if (fn >= GSM_HYPERFRAME) {
-		fn %= GSM_HYPERFRAME;
+	if (fn >= GSM_TDMA_HYPERFRAME) {
+		fn %= GSM_TDMA_HYPERFRAME;
 		LOGPPHI(pinst, DTRX, LOGL_ERROR, "Indicated clock's FN is not "
 			"wrapping correctly, correcting to fn=%u\n", fn);
 	}
@@ -737,7 +737,7 @@ static int trx_data_handle_hdr_v0(struct trx_l1h *l1h,
 	bi->rssi = -(int8_t)buf[5];
 	bi->toa256 = (int16_t) osmo_load16be(buf + 6);
 
-	if (bi->fn >= GSM_HYPERFRAME) {
+	if (bi->fn >= GSM_TDMA_HYPERFRAME) {
 		LOGPPHI(l1h->phy_inst, DTRX, LOGL_ERROR,
 			"Illegal TDMA fn=%u\n", bi->fn);
 		return -EINVAL;
diff --git a/src/osmo-bts-virtual/scheduler_virtbts.c b/src/osmo-bts-virtual/scheduler_virtbts.c
index d3fdf1ab..1c2b057e 100644
--- a/src/osmo-bts-virtual/scheduler_virtbts.c
+++ b/src/osmo-bts-virtual/scheduler_virtbts.c
@@ -532,7 +532,6 @@ void _sched_act_rach_det(struct l1sched_trx *l1t, uint8_t tn, uint8_t ss, int ac
  ***********************************************************************/
 
 #define RTS_ADVANCE		5	/* about 20ms */
-#define FRAME_DURATION_uS	4615
 
 static int vbts_sched_fn(struct gsm_bts *bts, uint32_t fn)
 {
@@ -558,7 +557,7 @@ static int vbts_sched_fn(struct gsm_bts *bts, uint32_t fn)
 			 *    --> Handle and process non-transparent RSL-Messages (activate channel, )
 			 *    --> Forward transparent RSL-DATA-Messages to the ms by appending them to
 			 *        the l1-dl-queue */
-			_sched_rts(l1t, br.tn, (fn + RTS_ADVANCE) % GSM_HYPERFRAME);
+			_sched_rts(l1t, br.tn, GSM_TDMA_FN_SUM(fn, RTS_ADVANCE));
 			/* schedule transmit backend functions */
 			/* Process data in the l1-dlqueue and forward it
 			 * to MS */
@@ -587,28 +586,27 @@ static void vbts_fn_timer_cb(void *data)
 	                + (tv_now.tv_usec - tv_clock->tv_usec);
 
 	/* not so good somehow a lot of time passed between two timer callbacks */
-	if (elapsed_us > 2 *FRAME_DURATION_uS)
+	if (elapsed_us > 2 *GSM_TDMA_FN_DURATION_uS)
 		LOGP(DL1P, LOGL_NOTICE, "vbts_fn_timer_cb after %d us\n", elapsed_us);
 
 	/* schedule the current frame/s (fn = frame number)
 	 * this loop will be called at least once, but can also be executed
 	 * multiple times if more than one frame duration (4615us) passed till the last callback */
-	while (elapsed_us > FRAME_DURATION_uS / 2) {
+	while (elapsed_us > GSM_TDMA_FN_DURATION_uS / 2) {
 		const struct timeval tv_frame = {
 			.tv_sec = 0,
-			.tv_usec = FRAME_DURATION_uS,
+			.tv_usec = GSM_TDMA_FN_DURATION_uS,
 		};
 		timeradd(tv_clock, &tv_frame, tv_clock);
 		/* increment the frame number in the BTS model instance */
-		bts_virt->last_fn = (bts_virt->last_fn + 1) % GSM_HYPERFRAME;
-		vbts_sched_fn(bts, bts_virt->last_fn);
-		elapsed_us -= FRAME_DURATION_uS;
+		vbts_sched_fn(bts, GSM_TDMA_FN_INC(bts_virt->last_fn));
+		elapsed_us -= GSM_TDMA_FN_DURATION_uS;
 	}
 
 	/* re-schedule the timer */
 	/* timer is set to frame duration - elapsed time to guarantee that this cb method will be
 	 * periodically executed every 4.615ms */
-	osmo_timer_schedule(&bts_virt->fn_timer, 0, FRAME_DURATION_uS - elapsed_us);
+	osmo_timer_schedule(&bts_virt->fn_timer, 0, GSM_TDMA_FN_DURATION_uS - elapsed_us);
 }
 
 int vbts_sched_start(struct gsm_bts *bts)
@@ -622,7 +620,7 @@ int vbts_sched_start(struct gsm_bts *bts)
 
 	gettimeofday(&bts_virt->tv_clock, NULL);
 	/* trigger the first timer after 4615us (a frame duration) */
-	osmo_timer_schedule(&bts_virt->fn_timer, 0, FRAME_DURATION_uS);
+	osmo_timer_schedule(&bts_virt->fn_timer, 0, GSM_TDMA_FN_DURATION_uS);
 
 	return 0;
 }