Refactoring of is_xlsch_in_slot usage in MAC

* Remove the ulsch_slot_bitmap and dlsch_slot_bitmap from nrmac
* Adopt the new is_dl_slot/is_ul_slot functions in the stack
  to replace is_xlsch_in_slot: these functions are getting
  the DL and UL slots as they are set in the TDD configuration
  stored in tdd_slot_bitmap (frame_structure_t)
* Keep is_xlsch_in_slot in openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_phytest.c:
  this is necessary because the phy-test pre-processors are using the bitmaps
  dlsch_slot_bitmap and ulsch_slot_bitmap to check which DL/UL slots to use
  for transmission among those set in the TDD configuration
Co-authored-by: Guido Casati <guido.casati@firecell.io>

openair2/E2AP/RAN_FUNCTION/CUSTOMIZED/ran_func_mac.c

@@ -60,11 +60,11 @@ bool read_mac_sm(void* data)
     rd->dl_aggr_tbs = UE->mac_stats.dl.total_bytes;
     rd->ul_aggr_tbs = UE->mac_stats.ul.total_bytes;
 
-    if (is_xlsch_in_slot(RC.nrmac[mod_id]->dlsch_slot_bitmap[rd->slot / 64], rd->slot)) {
+    if (is_dl_slot(rd->slot, &RC.nrmac[mod_id]->frame_structure)) {
       rd->dl_curr_tbs = UE->mac_stats.dl.current_bytes;
       rd->dl_sched_rb = UE->mac_stats.dl.current_rbs;
     }
-    if (is_xlsch_in_slot(RC.nrmac[mod_id]->ulsch_slot_bitmap[rd->slot / 64], rd->slot)) {
+    if (is_ul_slot(rd->slot, &RC.nrmac[mod_id]->frame_structure)) {
       rd->ul_curr_tbs = UE->mac_stats.ul.current_bytes;
       rd->ul_sched_rb = sched_ctrl->sched_pusch.rbSize;
     }

openair2/LAYER2/NR_MAC_gNB/config.c

@@ -921,31 +921,6 @@ void nr_mac_config_scc(gNB_MAC_INST *nrmac, NR_ServingCellConfigCommon_t *scc, c
 
   find_SSB_and_RO_available(nrmac);
 
-  const NR_TDD_UL_DL_Pattern_t *tdd = scc->tdd_UL_DL_ConfigurationCommon ? &scc->tdd_UL_DL_ConfigurationCommon->pattern1 : NULL;
-
-  int nr_slots_period = n;
-  int nr_dl_slots = n;
-  int nr_ulstart_slot = 0;
-  if (tdd) {
-    nr_dl_slots = tdd->nrofDownlinkSlots + (tdd->nrofDownlinkSymbols != 0);
-    nr_ulstart_slot = get_first_ul_slot(&nrmac->frame_structure, true);
-    nr_slots_period /= get_nb_periods_per_frame(tdd->dl_UL_TransmissionPeriodicity);
-  } else {
-    // if TDD configuration is not present and the band is not FDD, it means it is a dynamic TDD configuration
-    AssertFatal(nrmac->common_channels[0].frame_type == FDD,"Dynamic TDD not handled yet\n");
-  }
-
-  for (int slot = 0; slot < n; ++slot) {
-    nrmac->dlsch_slot_bitmap[slot / 64] |= (uint64_t)((slot % nr_slots_period) < nr_dl_slots) << (slot % 64);
-    nrmac->ulsch_slot_bitmap[slot / 64] |= (uint64_t)((slot % nr_slots_period) >= nr_ulstart_slot) << (slot % 64);
-
-    LOG_D(NR_MAC,
-          "slot %d DL %d UL %d\n",
-          slot,
-          (nrmac->dlsch_slot_bitmap[slot / 64] & ((uint64_t)1 << (slot % 64))) != 0,
-          (nrmac->ulsch_slot_bitmap[slot / 64] & ((uint64_t)1 << (slot % 64))) != 0);
-  }
-
   NR_COMMON_channels_t *cc = &nrmac->common_channels[0];
   NR_SCHED_LOCK(&nrmac->sched_lock);
   for (int n = 0; n < NR_NB_RA_PROC_MAX; n++) {

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler.c

@@ -122,10 +122,6 @@ void clear_beam_information(NR_beam_info_t *beam_info, int frame, int slot, int
   }
 }
 
-bool is_xlsch_in_slot(uint64_t bitmap, sub_frame_t slot) {
-  return (bitmap >> (slot % 64)) & 0x01;
-}
-
 /**
  * @brief Returns true for:
  *        (1) FDD

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_RA.c

@@ -278,7 +278,7 @@ static void schedule_nr_MsgA_pusch(NR_UplinkConfigCommon_t *uplinkConfigCommon,
 
   UL_tti_req->SFN = msgA_pusch_frame;
   UL_tti_req->Slot = msgA_pusch_slot;
-  AssertFatal(is_xlsch_in_slot(nr_mac->ulsch_slot_bitmap[msgA_pusch_slot / 64], msgA_pusch_slot),
+  AssertFatal(is_ul_slot(msgA_pusch_slot, &nr_mac->frame_structure),
               "Slot %d is not an Uplink slot, invalid msgA_PUSCH_TimeDomainOffset_r16 %ld\n",
               msgA_pusch_slot,
               msgA_PUSCH_Resource->msgA_PUSCH_TimeDomainOffset_r16);
@@ -376,7 +376,7 @@ void schedule_nr_prach(module_id_t module_idP, frame_t frameP, sub_frame_t slotP
   nfapi_nr_ul_tti_request_t *UL_tti_req = &RC.nrmac[module_idP]->UL_tti_req_ahead[0][index];
   nfapi_nr_config_request_scf_t *cfg = &RC.nrmac[module_idP]->config[0];
 
-  if (is_nr_UL_slot(scc->tdd_UL_DL_ConfigurationCommon, slotP, cc->frame_type)) {
+  if (is_ul_slot(slotP, &RC.nrmac[module_idP]->frame_structure)) {
     const NR_RACH_ConfigGeneric_t *rach_ConfigGeneric = &rach_ConfigCommon->rach_ConfigGeneric;
     uint8_t config_index = rach_ConfigGeneric->prach_ConfigurationIndex;
     uint8_t N_dur, N_t_slot, start_symbol = 0, N_RA_slot;
@@ -787,7 +787,7 @@ static void nr_generate_Msg3_retransmission(module_id_t module_idP,
   const int sched_frame = (frame + (slot + K2) / nr_slots_per_frame[mu]) % MAX_FRAME_NUMBER;
   const int sched_slot = (slot + K2) % nr_slots_per_frame[mu];
 
-  if (is_xlsch_in_slot(nr_mac->ulsch_slot_bitmap[sched_slot / 64], sched_slot)) {
+  if (is_ul_slot(sched_slot, &nr_mac->frame_structure)) {
     const int n_slots_frame = nr_slots_per_frame[mu];
     NR_beam_alloc_t beam_ul = beam_allocation_procedure(&nr_mac->beam_info, sched_frame, sched_slot, ra->beam_id, n_slots_frame);
     if (beam_ul.idx < 0)
@@ -957,7 +957,6 @@ static void nr_generate_Msg3_retransmission(module_id_t module_idP,
 
 static bool get_feasible_msg3_tda(const NR_ServingCellConfigCommon_t *scc,
                                   int mu_delta,
-                                  uint64_t ulsch_slot_bitmap[3],
                                   const NR_PUSCH_TimeDomainResourceAllocationList_t *tda_list,
                                   int frame,
                                   int slot,
@@ -976,7 +975,7 @@ static bool get_feasible_msg3_tda(const NR_ServingCellConfigCommon_t *scc,
     int abs_slot = slot + k2 + mu_delta;
     int temp_frame = (frame + (abs_slot / slots_per_frame)) & 1023;
     int temp_slot = abs_slot % slots_per_frame; // msg3 slot according to 8.3 in 38.213
-    if (fs->is_tdd && !is_xlsch_in_slot(ulsch_slot_bitmap[temp_slot / 64], temp_slot))
+    if (fs->is_tdd && !is_ul_slot(temp_slot, fs))
       continue;
 
     const tdd_bitmap_t *tdd_slot_bitmap = fs->period_cfg.tdd_slot_bitmap;
@@ -1385,7 +1384,7 @@ static void nr_generate_Msg2(module_id_t module_idP,
   gNB_MAC_INST *nr_mac = RC.nrmac[module_idP];
 
   // no DL -> cannot send Msg2
-  if (!is_xlsch_in_slot(nr_mac->dlsch_slot_bitmap[slotP / 64], slotP)) {
+  if (!is_dl_slot(slotP, &nr_mac->frame_structure)) {
     return;
   }
 
@@ -1415,7 +1414,6 @@ static void nr_generate_Msg2(module_id_t module_idP,
   const NR_UE_UL_BWP_t *ul_bwp = &ra->UL_BWP;
   bool ret = get_feasible_msg3_tda(scc,
                                    DELTA[ul_bwp->scs],
-                                   nr_mac->ulsch_slot_bitmap,
                                    ul_bwp->tdaList_Common,
                                    frameP,
                                    slotP,
@@ -1946,8 +1944,8 @@ static void nr_generate_Msg4_MsgB(module_id_t module_idP,
   NR_COMMON_channels_t *cc = &nr_mac->common_channels[CC_id];
   NR_UE_DL_BWP_t *dl_bwp = &ra->DL_BWP;
 
-   // if it is a DL slot, if the RA is in MSG4 state
-  if (is_xlsch_in_slot(nr_mac->dlsch_slot_bitmap[slotP / 64], slotP)) {
+  // if it is a DL slot, if the RA is in MSG4 state
+  if (is_dl_slot(slotP, &nr_mac->frame_structure)) {
     NR_ServingCellConfigCommon_t *scc = cc->ServingCellConfigCommon;
     NR_SearchSpace_t *ss = ra->ra_ss;
     const char *ra_type_str = ra->ra_type == RA_2_STEP ? "MsgB" : "Msg4";

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c

@@ -957,7 +957,7 @@ void nr_schedule_ue_spec(module_id_t module_id,
   AssertFatal(pthread_mutex_trylock(&gNB_mac->sched_lock) == EBUSY,
               "this function should be called with the scheduler mutex locked\n");
 
-  if (!is_xlsch_in_slot(gNB_mac->dlsch_slot_bitmap[slot / 64], slot))
+  if (!is_dl_slot(slot, &gNB_mac->frame_structure))
     return;
 
   /* PREPROCESSOR */

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_phytest.c

@@ -42,6 +42,14 @@ extern RAN_CONTEXT_t RC;
 
 //#define ENABLE_MAC_PAYLOAD_DEBUG 1
 
+/* This function checks whether the given Dl/UL slot is set
+   in the input bitmap, which is a mask indicating in which
+   slot to transmit (among those available in the TDD configuration) */
+static bool is_xlsch_in_slot(uint64_t bitmap, sub_frame_t slot)
+{
+  return (bitmap >> (slot % 64)) & 0x01;
+}
+
 uint32_t target_dl_mcs = 9;
 uint32_t target_dl_Nl = 1;
 uint32_t target_dl_bw = 50;

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_uci.c

@@ -138,7 +138,6 @@ static const int diff_rsrp_ssb_csi_meas_10_1_6_1_2[16] = {
 
 static int get_pucch_index(int frame, int slot, const frame_structure_t *fs, int sched_pucch_size)
 {
-  gNB_MAC_INST *nrmac = RC.nrmac[0];
   // PUCCH structures are indexed by slot in the PUCCH period determined by sched_pucch_size number of UL slots
   // this functions return the index to the structure for slot passed to the function
   const int n_ul_slots_period = get_ul_slots_per_period(fs);
@@ -150,7 +149,7 @@ static int get_pucch_index(int frame, int slot, const frame_structure_t *fs, int
   // ((slot % nr_slots_period) - first_ul_slot_period) gives the progressive number of the slot in this TDD period
   int ul_period_slot = -1;
   for (int i = 0; i <= slot % fs->numb_slots_period; i++) {
-    if (is_xlsch_in_slot(nrmac->ulsch_slot_bitmap[i / 64], i)) {
+    if (is_ul_slot(i, fs)) {
       ul_period_slot++;
     }
   }
@@ -173,7 +172,7 @@ void nr_schedule_pucch(gNB_MAC_INST *nrmac, frame_t frameP, sub_frame_t slotP)
   /* already mutex protected: held in gNB_dlsch_ulsch_scheduler() */
   NR_SCHED_ENSURE_LOCKED(&nrmac->sched_lock);
 
-  if (!is_xlsch_in_slot(nrmac->ulsch_slot_bitmap[slotP / 64], slotP))
+  if (!is_ul_slot(slotP, &nrmac->frame_structure))
     return;
 
   UE_iterator(nrmac->UE_info.list, UE) {
@@ -247,7 +246,7 @@ void nr_csi_meas_reporting(int Mod_idP,frame_t frame, sub_frame_t slot)
       if ((sched_frame * n_slots_frame + sched_slot - offset) % period != 0)
         continue;
 
-      AssertFatal(is_xlsch_in_slot(nrmac->ulsch_slot_bitmap[sched_slot / 64], sched_slot), "CSI reporting slot %d is not set for an uplink slot\n", sched_slot);
+      AssertFatal(is_ul_slot(sched_slot, &nrmac->frame_structure), "CSI reporting slot %d is not set for an uplink slot\n", sched_slot);
       LOG_D(NR_MAC, "CSI reporting in frame %d slot %d CSI report ID %ld\n", sched_frame, sched_slot, csirep->reportConfigId);
 
       const NR_PUCCH_ResourceSet_t *pucchresset = pucch_Config->resourceSetToAddModList->list.array[1]; // set with formats >1
@@ -1030,7 +1029,7 @@ int nr_acknack_scheduling(gNB_MAC_INST *mac,
     // check if the slot is UL
     if (fs->is_tdd) {
       int mod_slot = pucch_slot % fs->numb_slots_period;
-      if (!is_xlsch_in_slot(mac->ulsch_slot_bitmap[mod_slot / 64], mod_slot))
+      if (!is_ul_slot(mod_slot, fs))
         continue;
     }
     const int pucch_frame = (frame + ((slot + pdsch_to_harq_feedback[f] + NTN_gNB_Koffset) / n_slots_frame)) % MAX_FRAME_NUMBER;
@@ -1134,7 +1133,7 @@ void nr_sr_reporting(gNB_MAC_INST *nrmac, frame_t SFN, sub_frame_t slot)
   /* already mutex protected: held in gNB_dlsch_ulsch_scheduler() */
   NR_SCHED_ENSURE_LOCKED(&nrmac->sched_lock);
 
-  if (!is_xlsch_in_slot(nrmac->ulsch_slot_bitmap[slot / 64], slot))
+  if (!is_ul_slot(slot, &nrmac->frame_structure))
     return;
   const int CC_id = 0;
   UE_iterator(nrmac->UE_info.list, UE) {

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c

@@ -2221,7 +2221,7 @@ static bool nr_ulsch_preprocessor(module_id_t module_id, frame_t frame, sub_fram
   const int K2 = nr_mac->radio_config.minRXTXTIME + get_NTN_Koffset(scc);
   const int sched_frame = (frame + (slot + K2) / slots_frame) % MAX_FRAME_NUMBER;
   const int sched_slot = (slot + K2) % slots_frame;
-  if (!is_xlsch_in_slot(nr_mac->ulsch_slot_bitmap[sched_slot / 64], sched_slot))
+  if (!is_ul_slot(sched_slot, &nr_mac->frame_structure))
     return false;
 
   int num_beams = nr_mac->beam_info.beam_allocation ? nr_mac->beam_info.beams_per_period : 1;
@@ -2280,7 +2280,7 @@ void nr_schedule_ulsch(module_id_t module_id, frame_t frame, sub_frame_t slot, n
 
   /* Uplink data ONLY can be scheduled when the current slot is downlink slot,
    * because we have to schedule the DCI0 first before schedule uplink data */
-  if (!is_xlsch_in_slot(nr_mac->dlsch_slot_bitmap[slot / 64], slot)) {
+  if (!is_dl_slot(slot, &nr_mac->frame_structure)) {
     LOG_D(NR_MAC, "Current slot %d is NOT DL slot, cannot schedule DCI0 for UL data\n", slot);
     return;
   }

openair2/LAYER2/NR_MAC_gNB/mac_proto.h

@@ -352,7 +352,6 @@ int nr_write_ce_dlsch_pdu(module_id_t module_idP,
 
 int binomial(int n, int k);
 
-bool is_xlsch_in_slot(uint64_t bitmap, sub_frame_t slot);
 bool is_ul_slot(const slot_t slot, const frame_structure_t *fs);
 bool is_dl_slot(const slot_t slot, const frame_structure_t *fs);
 bool is_mixed_slot(const slot_t slot, const frame_structure_t *fs);

openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h

@@ -905,11 +905,6 @@ typedef struct gNB_MAC_INST_s {
 
   NR_beam_info_t beam_info;
 
-  /// bitmap of DLSCH slots, can hold up to 160 slots
-  uint64_t dlsch_slot_bitmap[3];
-  /// bitmap of ULSCH slots, can hold up to 160 slots
-  uint64_t ulsch_slot_bitmap[3];
-
   /// maximum number of slots before a UE will be scheduled ULSCH automatically
   uint32_t ulsch_max_frame_inactivity;
   /// instance of the frame structure configuration