tbf: Put the TFI->TBF mapping into the PDCH objects

Currently the TBFs are registered in a TFI indexed array within the TRX
objects. TBFs can be searched globally by TFI and TRX number. This
conflicts with the use of the same TFI for different TBF on different
PDCH. This use case requires the specification of the PDCH as
additional search dimension.

This commit moves the TFI index TBF arrays into the PDCH objects. The
related methods are updated accordingly.

Ticket: #1793
Sponsored-by: On-Waves ehf

1 files changed, 78 insertions, 52 deletions

diff --git a/src/bts.cpp b/src/bts.cpp
index 712954ea..412e0c03 100644
--- a/src/bts.cpp
+++ b/src/bts.cpp
@@ -257,48 +257,35 @@ gprs_rlcmac_ul_tbf *BTS::ul_tbf_by_poll_fn(uint32_t fn, uint8_t trx, uint8_t ts)
 }
 
 /* lookup downlink TBF Entity (by TFI) */
-gprs_rlcmac_dl_tbf *BTS::dl_tbf_by_tfi(uint8_t tfi, uint8_t trx)
+gprs_rlcmac_dl_tbf *BTS::dl_tbf_by_tfi(uint8_t tfi, uint8_t trx, uint8_t ts)
 {
-	return static_cast<gprs_rlcmac_dl_tbf *>(tbf_by_tfi(tfi, trx, GPRS_RLCMAC_DL_TBF));
-}
+	if (trx >= 8 || ts >= 8)
+		return NULL;
 
-/* lookup uplink TBF Entity (by TFI) */
-gprs_rlcmac_ul_tbf *BTS::ul_tbf_by_tfi(uint8_t tfi, uint8_t trx)
-{
-	return static_cast<gprs_rlcmac_ul_tbf *>(tbf_by_tfi(tfi, trx, GPRS_RLCMAC_UL_TBF));
+	return m_bts.trx[trx].pdch[ts].dl_tbf_by_tfi(tfi);
 }
 
-/* lookup TBF Entity (by TFI) */
-gprs_rlcmac_tbf *BTS::tbf_by_tfi(uint8_t tfi, uint8_t trx,
-				enum gprs_rlcmac_tbf_direction dir)
+/* lookup uplink TBF Entity (by TFI) */
+gprs_rlcmac_ul_tbf *BTS::ul_tbf_by_tfi(uint8_t tfi, uint8_t trx, uint8_t ts)
 {
-	struct gprs_rlcmac_tbf *tbf;
-
-	if (tfi >= 32 || trx >= 8)
-		return NULL;
-
-	if (dir == GPRS_RLCMAC_UL_TBF)
-		tbf = m_bts.trx[trx].ul_tbf[tfi];
-	else
-		tbf = m_bts.trx[trx].dl_tbf[tfi];
-	if (!tbf)
+	if (trx >= 8 || ts >= 8)
 		return NULL;
 
-	if (tbf->state_is_not(GPRS_RLCMAC_RELEASING)) {
-		return tbf;
-	}
-
-	return NULL;
+	return m_bts.trx[trx].pdch[ts].ul_tbf_by_tfi(tfi);
 }
 
-/* FIXME: spread resources over multiple TRX. Also add option to use same
- * TRX in case of existing TBF for TLLI in the other direction. */
-/* search for free TFI and return TFI, TRX */
+/*
+ * Search for free TFI and return TFI, TRX.
+ * This method returns the first TFI that is currently not used in any PDCH of
+ * a TRX. The first TRX that contains such an TFI is returned. Negative values
+ * indicate errors.
+ */
 int BTS::tfi_find_free(enum gprs_rlcmac_tbf_direction dir,
 		uint8_t *_trx, int8_t use_trx)
 {
 	struct gprs_rlcmac_pdch *pdch;
-	struct gprs_rlcmac_tbf **tbfp;
+	uint32_t free_tfis;
+	bool has_pdch = false;
 	uint8_t trx_from, trx_to, trx, ts, tfi;
 
 	if (use_trx >= 0 && use_trx < 8)
@@ -308,42 +295,50 @@ int BTS::tfi_find_free(enum gprs_rlcmac_tbf_direction dir,
 		trx_to = 7;
 	}
 
-	/* on TRX find first enabled TS */
+	/* find a TFI that is unused on all PDCH */
 	for (trx = trx_from; trx <= trx_to; trx++) {
+		bool trx_has_pdch = false;
+
+		free_tfis = 0xffffffff;
+
 		for (ts = 0; ts < 8; ts++) {
 			pdch = &m_bts.trx[trx].pdch[ts];
 			if (!pdch->is_enabled())
 				continue;
-			break;
+			free_tfis &= ~pdch->assigned_tfi(dir);
+			trx_has_pdch = true;
+			has_pdch = true;
 		}
-		if (ts < 8)
+		if (trx_has_pdch && free_tfis)
 			break;
+
+		free_tfis = 0;
 	}
-	if (trx > trx_to) {
+	if (!has_pdch) {
 		LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH available.\n");
 		return -EINVAL;
 	}
 
+	if (!free_tfis) {
+		LOGP(DRLCMAC, LOGL_NOTICE, "No TFI available.\n");
+		return -EBUSY;
+	}
 
-	LOGP(DRLCMAC, LOGL_DEBUG, "Searching for first unallocated TFI: "
-		"TRX=%d first TS=%d\n", trx, ts);
-	if (dir == GPRS_RLCMAC_UL_TBF)
-		tbfp = m_bts.trx[trx].ul_tbf;
-	else
-		tbfp = m_bts.trx[trx].dl_tbf;
+
+	LOGP(DRLCMAC, LOGL_DEBUG,
+		"Searching for first unallocated TFI: TRX=%d\n", trx);
+
+	/* find the first */
 	for (tfi = 0; tfi < 32; tfi++) {
-		if (!tbfp[tfi])
+		if (free_tfis & 1 << tfi)
 			break;
 	}
 
-	if (tfi < 32) {
-		LOGP(DRLCMAC, LOGL_DEBUG, " Found TFI=%d.\n", tfi);
-		*_trx = trx;
-		return tfi;
-	}
-	LOGP(DRLCMAC, LOGL_NOTICE, "No TFI available.\n");
+	OSMO_ASSERT(tfi < 32);
 
-	return -1;
+	LOGP(DRLCMAC, LOGL_DEBUG, " Found TFI=%d.\n", tfi);
+	*_trx = trx;
+	return tfi;
 }
 
 int BTS::rcv_imm_ass_cnf(const uint8_t *data, uint32_t fn)
@@ -693,7 +688,7 @@ int gprs_rlcmac_pdch::rcv_data_block_acknowledged(uint8_t *data, uint8_t len,
 	}
 
 	/* find TBF inst from given TFI */
-	tbf = bts()->ul_tbf_by_tfi(rh->tfi, trx_no());
+	tbf = ul_tbf_by_tfi(rh->tfi);
 	if (!tbf) {
 		LOGP(DRLCMACUL, LOGL_NOTICE, "UL DATA unknown TFI=%d\n",
 			rh->tfi);
@@ -990,7 +985,7 @@ void gprs_rlcmac_pdch::rcv_resource_request(Packet_Resource_Request_t *request,
 	if (request->ID.u.Global_TFI.UnionType) {
 		struct gprs_rlcmac_dl_tbf *dl_tbf;
 		int8_t tfi = request->ID.u.Global_TFI.u.DOWNLINK_TFI;
-		dl_tbf = bts()->dl_tbf_by_tfi(tfi, trx_no());
+		dl_tbf = bts()->dl_tbf_by_tfi(tfi, trx_no(), ts_no);
 		if (!dl_tbf) {
 			LOGP(DRLCMAC, LOGL_NOTICE, "PACKET RESSOURCE REQ unknown downlink TFI=%d\n", tfi);
 			return;
@@ -1001,7 +996,7 @@ void gprs_rlcmac_pdch::rcv_resource_request(Packet_Resource_Request_t *request,
 	} else {
 		struct gprs_rlcmac_ul_tbf *ul_tbf;
 		int8_t tfi = request->ID.u.Global_TFI.u.UPLINK_TFI;
-		ul_tbf = bts()->ul_tbf_by_tfi(tfi, trx_no());
+		ul_tbf = bts()->ul_tbf_by_tfi(tfi, trx_no(), ts_no);
 		if (!ul_tbf) {
 			LOGP(DRLCMAC, LOGL_NOTICE, "PACKET RESSOURCE REQ unknown uplink TFI=%d\n", tfi);
 			return;
@@ -1120,24 +1115,54 @@ gprs_rlcmac_tbf *gprs_rlcmac_pdch::tbf_from_list_by_tfi(struct llist_head *tbf_l
 
 gprs_rlcmac_ul_tbf *gprs_rlcmac_pdch::ul_tbf_by_tfi(uint8_t tfi)
 {
-	return static_cast<gprs_rlcmac_ul_tbf *>(tbf_from_list_by_tfi(&bts_data()->ul_tbfs, tfi, GPRS_RLCMAC_UL_TBF));
+	return static_cast<gprs_rlcmac_ul_tbf *>(
+		tbf_by_tfi(tfi, GPRS_RLCMAC_UL_TBF));
 }
 
 gprs_rlcmac_dl_tbf *gprs_rlcmac_pdch::dl_tbf_by_tfi(uint8_t tfi)
 {
-	return static_cast<gprs_rlcmac_dl_tbf *>(tbf_from_list_by_tfi(&bts_data()->dl_tbfs, tfi, GPRS_RLCMAC_DL_TBF));
+	return static_cast<gprs_rlcmac_dl_tbf *>(
+		tbf_by_tfi(tfi, GPRS_RLCMAC_DL_TBF));
+}
+
+/* lookup TBF Entity (by TFI) */
+gprs_rlcmac_tbf *gprs_rlcmac_pdch::tbf_by_tfi(uint8_t tfi,
+	enum gprs_rlcmac_tbf_direction dir)
+{
+	struct gprs_rlcmac_tbf *tbf;
+
+	if (tfi >= 32)
+		return NULL;
+
+	tbf = m_tbfs[dir][tfi];
+
+	if (!tbf)
+		return NULL;
+
+	if (tbf->state_is_not(GPRS_RLCMAC_RELEASING)) {
+		return tbf;
+	}
+
+	return NULL;
 }
 
 void gprs_rlcmac_pdch::attach_tbf(gprs_rlcmac_tbf *tbf)
 {
 	gprs_rlcmac_ul_tbf *ul_tbf;
 
+	if (m_tbfs[tbf->direction][tbf->tfi()])
+		LOGP(DRLCMAC, LOGL_ERROR, "PDCH(TS %d, TRX %d): "
+			"%s has not been detached, overwriting it\n",
+			ts_no, trx_no(),
+			m_tbfs[tbf->direction][tbf->tfi()]->name());
+
 	m_num_tbfs[tbf->direction] += 1;
 	if (tbf->direction == GPRS_RLCMAC_UL_TBF) {
 		ul_tbf = static_cast<gprs_rlcmac_ul_tbf *>(tbf);
 		m_assigned_usf |= 1 << ul_tbf->m_usf[ts_no];
 	}
 	m_assigned_tfi[tbf->direction] |= 1UL << tbf->tfi();
+	m_tbfs[tbf->direction][tbf->tfi()] = tbf;
 
 	LOGP(DRLCMAC, LOGL_INFO, "PDCH(TS %d, TRX %d): Attaching %s, %d TBFs, "
 		"USFs = %02x, TFIs = %08x.\n",
@@ -1157,6 +1182,7 @@ void gprs_rlcmac_pdch::detach_tbf(gprs_rlcmac_tbf *tbf)
 		m_assigned_usf &= ~(1 << ul_tbf->m_usf[ts_no]);
 	}
 	m_assigned_tfi[tbf->direction] &= ~(1UL << tbf->tfi());
+	m_tbfs[tbf->direction][tbf->tfi()] = NULL;
 
 	LOGP(DRLCMAC, LOGL_INFO, "PDCH(TS %d, TRX %d): Detaching %s, %d TBFs, "
 		"USFs = %02x, TFIs = %08x.\n",