tbf: Move TFI selection into alloc_algorithm

Currently the TFI and the TRX have to be determined before the actual TBF
allocation function is called, passing TFI and TRX number as
parameters. This does fit to TFI reuse for different slots, since
this were tightly coupled with the slot selection.

This commit just moves the TFI selection into the alloc_algorithm
functions. The tfi parameter is removed from the the TFI alloc
functions. The trx parameter is changed into use_trx to optionally
limit the trx selection (same semantics like in tfi_find_free).

Sponsored-by: On-Waves ehf

7 files changed, 71 insertions, 60 deletions

diff --git a/src/bts.cpp b/src/bts.cpp
index bd1e025e..712954ea 100644
--- a/src/bts.cpp
+++ b/src/bts.cpp
@@ -392,7 +392,6 @@ int BTS::rcv_rach(uint8_t ra, uint32_t Fn, int16_t qta)
 {
 	struct gprs_rlcmac_ul_tbf *tbf = NULL;
 	uint8_t trx_no, ts_no = 0;
-	int8_t tfi; /* must be signed */
 	uint8_t sb = 0;
 	uint32_t sb_fn = 0;
 	int rc;
@@ -429,14 +428,8 @@ int BTS::rcv_rach(uint8_t ra, uint32_t Fn, int16_t qta)
 	} else {
 		// Create new TBF
 		#warning "Copy and pate with other routines.."
-		tfi = tfi_find_free(GPRS_RLCMAC_UL_TBF, &trx_no, -1);
-		if (tfi < 0) {
-			LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH resource\n");
-			/* FIXME: send reject */
-			return -EBUSY;
-		}
 		/* set class to 0, since we don't know the multislot class yet */
-		tbf = tbf_alloc_ul_tbf(&m_bts, NULL, tfi, trx_no, 0, 1);
+		tbf = tbf_alloc_ul_tbf(&m_bts, NULL, -1, 0, 1);
 		if (!tbf) {
 			LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH resource\n");
 			/* FIXME: send reject */
diff --git a/src/bts.h b/src/bts.h
index b0e88f59..8784f4d5 100644
--- a/src/bts.h
+++ b/src/bts.h
@@ -162,7 +162,8 @@ struct gprs_rlcmac_bts {
 	struct gprs_rlcmac_trx trx[8];
 	int (*alloc_algorithm)(struct gprs_rlcmac_bts *bts,
 		struct GprsMs *ms,
-		struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single);
+		struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single,
+		int use_tbf);
 	uint32_t alloc_algorithm_curst; /* options to customize algorithm */
 	uint8_t force_two_phase;
 	uint8_t alpha, gamma;
diff --git a/src/gprs_rlcmac.h b/src/gprs_rlcmac.h
index dab3338f..3fc95e69 100644
--- a/src/gprs_rlcmac.h
+++ b/src/gprs_rlcmac.h
@@ -97,11 +97,13 @@ extern "C" {
 #endif
 int alloc_algorithm_a(struct gprs_rlcmac_bts *bts,
 	struct GprsMs *ms,
-	struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single);
+	struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single,
+	int use_trx);
 
 int alloc_algorithm_b(struct gprs_rlcmac_bts *bts,
 	struct GprsMs *ms,
-	struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single);
+	struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single,
+	int use_trx);
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/gprs_rlcmac_ts_alloc.cpp b/src/gprs_rlcmac_ts_alloc.cpp
index ec228d1a..33814365 100644
--- a/src/gprs_rlcmac_ts_alloc.cpp
+++ b/src/gprs_rlcmac_ts_alloc.cpp
@@ -277,6 +277,24 @@ static void assign_dlink_tbf(
 	attach_tbf_to_pdch(pdch, tbf);
 }
 
+static int tfi_find_free(BTS *bts, GprsMs *ms, enum gprs_rlcmac_tbf_direction dir,
+	int use_trx, int *trx_no_)
+{
+	int tfi;
+	uint8_t trx_no;
+
+	if (use_trx == -1 && ms->current_trx())
+		use_trx = ms->current_trx()->trx_no;
+
+	tfi = bts->tfi_find_free(dir, &trx_no, use_trx);
+	if (tfi < 0)
+		return -EBUSY;
+
+	if (trx_no_)
+		*trx_no_ = trx_no;
+
+	return tfi;
+}
 
 /* Slot Allocation: Algorithm A
  *
@@ -284,11 +302,14 @@ static void assign_dlink_tbf(
  */
 int alloc_algorithm_a(struct gprs_rlcmac_bts *bts,
 	GprsMs *ms,
-	struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single)
+	struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single,
+	int use_trx)
 {
 	struct gprs_rlcmac_pdch *pdch;
 	int ts = -1;
 	uint8_t ul_slots, dl_slots;
+	int trx_no;
+	int rc;
 	int usf = -1;
 	int mask = 0xff;
 	const char *mask_reason = NULL;
@@ -296,6 +317,14 @@ int alloc_algorithm_a(struct gprs_rlcmac_bts *bts,
 	LOGP(DRLCMAC, LOGL_DEBUG, "Slot Allocation (Algorithm A) for class "
 		"%d\n", tbf->ms_class());
 
+	rc = tfi_find_free(bts->bts, ms, tbf->direction, use_trx, &trx_no);
+	if (rc < 0) {
+		LOGP(DRLCMAC, LOGL_NOTICE, "- Failed to allocate a TFI\n");
+		return rc;
+	}
+	tbf->m_tfi = rc;
+	tbf->trx = &bts->trx[trx_no];
+
 	dl_slots = ms->reserved_dl_slots();
 	ul_slots = ms->reserved_ul_slots();
 
@@ -348,7 +377,6 @@ int alloc_algorithm_a(struct gprs_rlcmac_bts *bts,
 	ms->set_reserved_slots(tbf->trx, 1 << ts, 1 << ts);
 
 	tbf->upgrade_to_multislot = 0;
-
 	return 0;
 }
 
@@ -669,7 +697,7 @@ static int find_multi_slots(struct gprs_rlcmac_bts *bts,
  */
 int alloc_algorithm_b(struct gprs_rlcmac_bts *bts,
 	GprsMs *ms,
-	struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single)
+	struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single, int use_trx)
 {
 	uint8_t dl_slots = 0;
 	uint8_t ul_slots = 0;
@@ -679,6 +707,15 @@ int alloc_algorithm_b(struct gprs_rlcmac_bts *bts,
 	char slot_info[9] = {0};
 	int ts;
 	int rc;
+	int trx_no;
+
+	rc = tfi_find_free(bts->bts, ms, tbf->direction, use_trx, &trx_no);
+	if (rc < 0) {
+		LOGP(DRLCMAC, LOGL_NOTICE, "- Failed to allocate a TFI\n");
+		return rc;
+	}
+	tbf->m_tfi = rc;
+	tbf->trx = &bts->trx[trx_no];
 
 	if (!ms) {
 		LOGP(DRLCMAC, LOGL_ERROR, "MS not set\n");
diff --git a/src/tbf.cpp b/src/tbf.cpp
index 4a8fd337..70483e35 100644
--- a/src/tbf.cpp
+++ b/src/tbf.cpp
@@ -174,20 +174,12 @@ gprs_rlcmac_ul_tbf *tbf_alloc_ul(struct gprs_rlcmac_bts *bts,
 	int8_t use_trx, uint8_t ms_class,
 	uint32_t tlli, uint8_t ta, GprsMs *ms)
 {
-	uint8_t trx;
 	struct gprs_rlcmac_ul_tbf *tbf;
-	int8_t tfi; /* must be signed */
 
 #warning "Copy and paste with tbf_new_dl_assignment"
 	/* create new TBF, use same TRX as DL TBF */
-	tfi = bts->bts->tfi_find_free(GPRS_RLCMAC_UL_TBF, &trx, use_trx);
-	if (tfi < 0) {
-		LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH resource\n");
-		/* FIXME: send reject */
-		return NULL;
-	}
 	/* use multislot class of downlink TBF */
-	tbf = tbf_alloc_ul_tbf(bts, ms, tfi, trx, ms_class, 0);
+	tbf = tbf_alloc_ul_tbf(bts, ms, use_trx, ms_class, 0);
 	if (!tbf) {
 		LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH resource\n");
 		/* FIXME: send reject */
@@ -274,7 +266,8 @@ int gprs_rlcmac_tbf::update()
 		return -EINVAL;
 
 	tbf_unlink_pdch(this);
-	rc = bts_data->alloc_algorithm(bts_data, ms(), this, bts_data->alloc_algorithm_curst, 0);
+	rc = bts_data->alloc_algorithm(bts_data, ms(), this,
+		bts_data->alloc_algorithm_curst, 0, -1);
 	/* if no resource */
 	if (rc < 0) {
 		LOGP(DRLCMAC, LOGL_ERROR, "No resource after update???\n");
@@ -445,14 +438,11 @@ void gprs_rlcmac_tbf::poll_timeout()
 }
 
 static int setup_tbf(struct gprs_rlcmac_tbf *tbf, struct gprs_rlcmac_bts *bts,
-	GprsMs *ms, uint8_t tfi, uint8_t trx,
+	GprsMs *ms, int8_t use_trx,
 	uint8_t ms_class, uint8_t single_slot)
 {
 	int rc;
 
-	if (trx >= 8 || tfi >= 32)
-		return -1;
-
 	if (!tbf)
 		return -1;
 
@@ -461,12 +451,10 @@ static int setup_tbf(struct gprs_rlcmac_tbf *tbf, struct gprs_rlcmac_bts *bts,
 
 	tbf->m_created_ts = time(NULL);
 	tbf->bts = bts->bts;
-	tbf->m_tfi = tfi;
-	tbf->trx = &bts->trx[trx];
 	tbf->set_ms_class(ms_class);
 	/* select algorithm */
 	rc = bts->alloc_algorithm(bts, ms, tbf, bts->alloc_algorithm_curst,
-		single_slot);
+		single_slot, use_trx);
 	/* if no resource */
 	if (rc < 0) {
 		return -1;
@@ -485,23 +473,24 @@ static int setup_tbf(struct gprs_rlcmac_tbf *tbf, struct gprs_rlcmac_bts *bts,
 	tbf->m_llc.init();
 	tbf->set_ms(ms);
 
+	LOGP(DRLCMAC, LOGL_INFO,
+		"Allocated %s: trx = %d, ul_slots = %02x, dl_slots = %02x\n",
+		tbf->name(), tbf->trx->trx_no, tbf->ul_slots(), tbf->dl_slots());
+
 	return 0;
 }
 
 
 struct gprs_rlcmac_ul_tbf *tbf_alloc_ul_tbf(struct gprs_rlcmac_bts *bts,
-	GprsMs *ms, uint8_t tfi, uint8_t trx,
+	GprsMs *ms, int8_t use_trx,
 	uint8_t ms_class, uint8_t single_slot)
 {
 	struct gprs_rlcmac_ul_tbf *tbf;
 	int rc;
 
 	LOGP(DRLCMAC, LOGL_DEBUG, "********** TBF starts here **********\n");
-	LOGP(DRLCMAC, LOGL_INFO, "Allocating %s TBF: TFI=%d TRX=%d "
-		"MS_CLASS=%d\n", "UL", tfi, trx, ms_class);
-
-	if (trx >= 8 || tfi >= 32)
-		return NULL;
+	LOGP(DRLCMAC, LOGL_INFO, "Allocating %s TBF: MS_CLASS=%d\n",
+		"UL", ms_class);
 
 	tbf = talloc_zero(tall_pcu_ctx, struct gprs_rlcmac_ul_tbf);
 
@@ -513,7 +502,7 @@ struct gprs_rlcmac_ul_tbf *tbf_alloc_ul_tbf(struct gprs_rlcmac_bts *bts,
 	if (!ms)
 		ms = bts->bts->ms_alloc(ms_class);
 
-	rc = setup_tbf(tbf, bts, ms, tfi, trx, ms_class, single_slot);
+	rc = setup_tbf(tbf, bts, ms, use_trx, ms_class, single_slot);
 	/* if no resource */
 	if (rc < 0) {
 		talloc_free(tbf);
@@ -527,18 +516,15 @@ struct gprs_rlcmac_ul_tbf *tbf_alloc_ul_tbf(struct gprs_rlcmac_bts *bts,
 }
 
 struct gprs_rlcmac_dl_tbf *tbf_alloc_dl_tbf(struct gprs_rlcmac_bts *bts,
-	GprsMs *ms, uint8_t tfi, uint8_t trx,
+	GprsMs *ms, int8_t use_trx,
 	uint8_t ms_class, uint8_t single_slot)
 {
 	struct gprs_rlcmac_dl_tbf *tbf;
 	int rc;
 
 	LOGP(DRLCMAC, LOGL_DEBUG, "********** TBF starts here **********\n");
-	LOGP(DRLCMAC, LOGL_INFO, "Allocating %s TBF: TFI=%d TRX=%d "
-		"MS_CLASS=%d\n", "DL", tfi, trx, ms_class);
-
-	if (trx >= 8 || tfi >= 32)
-		return NULL;
+	LOGP(DRLCMAC, LOGL_INFO, "Allocating %s TBF: MS_CLASS=%d\n",
+		"DL", ms_class);
 
 	tbf = talloc_zero(tall_pcu_ctx, struct gprs_rlcmac_dl_tbf);
 
@@ -550,7 +536,7 @@ struct gprs_rlcmac_dl_tbf *tbf_alloc_dl_tbf(struct gprs_rlcmac_bts *bts,
 	if (!ms)
 		ms = bts->bts->ms_alloc(ms_class);
 
-	rc = setup_tbf(tbf, bts, ms, tfi, trx, ms_class, single_slot);
+	rc = setup_tbf(tbf, bts, ms, use_trx, ms_class, single_slot);
 	/* if no resource */
 	if (rc < 0) {
 		talloc_free(tbf);
diff --git a/src/tbf.h b/src/tbf.h
index 7f1dd765..5c198d3e 100644
--- a/src/tbf.h
+++ b/src/tbf.h
@@ -245,12 +245,11 @@ struct gprs_rlcmac_ul_tbf *tbf_alloc_ul(struct gprs_rlcmac_bts *bts,
 	uint32_t tlli, uint8_t ta, GprsMs *ms);
 
 struct gprs_rlcmac_ul_tbf *tbf_alloc_ul_tbf(struct gprs_rlcmac_bts *bts,
-	GprsMs *ms,
-	uint8_t tfi, uint8_t trx,
+	GprsMs *ms, int8_t use_trx,
 	uint8_t ms_class, uint8_t single_slot);
 
 struct gprs_rlcmac_dl_tbf *tbf_alloc_dl_tbf(struct gprs_rlcmac_bts *bts,
-	GprsMs *ms, uint8_t tfi, uint8_t trx,
+	GprsMs *ms, int8_t use_trx,
 	uint8_t ms_class, uint8_t single_slot);
 
 void tbf_free(struct gprs_rlcmac_tbf *tbf);
diff --git a/src/tbf_dl.cpp b/src/tbf_dl.cpp
index cf03d331..cdd02bae 100644
--- a/src/tbf_dl.cpp
+++ b/src/tbf_dl.cpp
@@ -139,12 +139,11 @@ static int tbf_new_dl_assignment(struct gprs_rlcmac_bts *bts,
 				const uint8_t ms_class,
 				struct gprs_rlcmac_dl_tbf **tbf)
 {
-	uint8_t trx, ss;
+	uint8_t ss;
 	int8_t use_trx;
 	uint16_t ta = 0;
 	struct gprs_rlcmac_ul_tbf *ul_tbf = NULL, *old_ul_tbf;
 	struct gprs_rlcmac_dl_tbf *dl_tbf = NULL;
-	int8_t tfi; /* must be signed */
 	GprsMs *ms;
 
 	/* check for uplink data, so we copy our informations */
@@ -170,10 +169,8 @@ static int tbf_new_dl_assignment(struct gprs_rlcmac_bts *bts,
 
 	// Create new TBF (any TRX)
 #warning "Copy and paste with alloc_ul_tbf"
-	tfi = bts->bts->tfi_find_free(GPRS_RLCMAC_DL_TBF, &trx, use_trx);
-	if (tfi >= 0)
-		/* set number of downlink slots according to multislot class */
-		dl_tbf = tbf_alloc_dl_tbf(bts, ms, tfi, trx, ms_class, ss);
+	/* set number of downlink slots according to multislot class */
+	dl_tbf = tbf_alloc_dl_tbf(bts, ms, use_trx, ms_class, ss);
 
 	if (!dl_tbf) {
 		LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH resource\n");
@@ -842,16 +839,12 @@ int gprs_rlcmac_dl_tbf::rcvd_dl_ack(uint8_t final_ack, uint8_t ssn, uint8_t *rbb
 
 void gprs_rlcmac_dl_tbf::reuse_tbf()
 {
-	uint8_t trx;
 	struct gprs_rlcmac_dl_tbf *new_tbf = NULL;
-	int8_t tfi; /* must be signed */
 
 	bts->tbf_reused();
 
-	tfi = bts->tfi_find_free(GPRS_RLCMAC_DL_TBF, &trx, this->trx->trx_no);
-	if (tfi >= 0)
-		new_tbf = tbf_alloc_dl_tbf(bts->bts_data(), ms(), tfi, trx,
-			ms_class(), 0);
+	new_tbf = tbf_alloc_dl_tbf(bts->bts_data(), ms(),
+		this->trx->trx_no, ms_class(), 0);
 
 	if (!new_tbf) {
 		LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH resource\n");