Do not allocate CCE in nr_configure_pdcch()

nr_configure_pdcch() allocates the CCE, but this is not wanted, e.g., in
multi-user scheduling, since it might not be possible to allocate the
CCEs for these UEs. This commit makes the following changes:

- remove CCE allocation in nr_configure_pdcch()
- remove coreset search in nr_configure_pdcch()
- add functions get_coreset() and get_searchspace() to retrieve coresets
  and search spaces easily
- in nr_fill_nfapi_dl_pdu(), add extra parameters for aggregation level
  and CCE indices and the searchspace and coreset of a UE, which might
  be different for each UE
- allocate CCEs manually in phytest, RA, and DLSCH schedulers

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_RA.c

@@ -681,7 +681,31 @@ void nr_generate_Msg2(module_id_t module_idP,
 	  dci_pdu_rel15[0].mcs,
 	  dci_pdu_rel15[0].tb_scaling);
 
-    nr_configure_pdcch(nr_mac, pdcch_pdu_rel15, RA_rnti, 0, ss, scc, bwp);
+    uint8_t nr_of_candidates, aggregation_level;
+    find_aggregation_candidates(&aggregation_level, &nr_of_candidates, ss);
+    NR_ControlResourceSet_t *coreset = get_coreset(bwp, ss, 0 /* common */);
+    int CCEIndex = allocate_nr_CCEs(
+        nr_mac,
+        bwp,
+        coreset,
+        aggregation_level,
+        ss->searchSpaceType->present - 1, // 0 common, 1 ue-specific
+        UE_id,
+        0); // m
+
+    if (CCEIndex < 0) {
+      LOG_E(MAC, "%s(): cannot find free CCE for UE %d!\n", __func__, UE_id);
+      return;
+    }
+    nr_configure_pdcch(nr_mac,
+                       pdcch_pdu_rel15,
+                       RA_rnti,
+                       ss,
+                       coreset,
+                       scc,
+                       bwp,
+                       aggregation_level,
+                       CCEIndex);
 
     LOG_I(MAC, "Frame %d: Subframe %d : Adding common DL DCI for RA_RNTI %x\n", frameP, slotP, RA_rnti);
 

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c

@@ -447,18 +447,37 @@ void nr_schedule_ue_spec(module_id_t module_id,
         rlc_status.bytes_in_buffer);
 
   /* PREPROCESSOR */
-  /* Find PUCCH occasion */
-  int pucch_sched;
-  nr_update_pucch_scheduling(module_id, UE_id, frame, slot, num_slots_per_tdd, &pucch_sched);
-  NR_sched_pucch *pucch = &UE_list->UE_sched_ctrl[UE_id].sched_pucch[pucch_sched];
-
-  /* BWP and following: for MCS calculation, possibly based on CQI and RLC ind */
+  /* BWP */
   const int bwp_id = 1;
   NR_CellGroupConfig_t *secondaryCellGroup = UE_list->secondaryCellGroup[UE_id];
   AssertFatal(secondaryCellGroup->spCellConfig->spCellConfigDedicated->downlinkBWP_ToAddModList->list.count == 1,
               "downlinkBWP_ToAddModList has %d BWP!\n",
               secondaryCellGroup->spCellConfig->spCellConfigDedicated->downlinkBWP_ToAddModList->list.count);
   NR_BWP_Downlink_t *bwp = secondaryCellGroup->spCellConfig->spCellConfigDedicated->downlinkBWP_ToAddModList->list.array[bwp_id - 1];
+
+  const int target_ss = NR_SearchSpace__searchSpaceType_PR_ue_Specific;
+  NR_SearchSpace_t *ss = get_searchspace(bwp, target_ss);
+
+  /* Find a free CCE */
+  uint8_t nr_of_candidates, aggregation_level;
+  find_aggregation_candidates(&aggregation_level, &nr_of_candidates, ss);
+  NR_ControlResourceSet_t *coreset = get_coreset(bwp, ss, 1 /* dedicated */);
+  int CCEIndex = allocate_nr_CCEs(gNB_mac,
+                                  bwp,
+                                  coreset,
+                                  aggregation_level,
+                                  ss->searchSpaceType->present - 1,
+                                  UE_id,
+                                  0); // m
+  if (CCEIndex < 0) {
+    LOG_E(MAC, "%s(): could not find CCE for UE %d\n", __func__, UE_id);
+    return;
+  }
+  /* Find PUCCH occasion */
+  int pucch_sched;
+  nr_update_pucch_scheduling(module_id, UE_id, frame, slot, num_slots_per_tdd, &pucch_sched);
+  NR_sched_pucch *pucch = &UE_list->UE_sched_ctrl[UE_id].sched_pucch[pucch_sched];
+
   const uint16_t bwpSize = NRRIV2BW(bwp->bwp_Common->genericParameters.locationAndBandwidth,275);
 
   const uint8_t mcs = 9;
@@ -601,6 +620,8 @@ void nr_schedule_ue_spec(module_id_t module_id,
   nr_fill_nfapi_dl_pdu(module_id,
                        UE_id,
                        bwp_id,
+                       ss,
+                       coreset,
                        dl_req,
                        pucch,
                        nrOfLayers,
@@ -615,7 +636,9 @@ void nr_schedule_ue_spec(module_id_t module_id,
                        TBS,
                        time_domain_assignment,
                        startSymbolIndex,
-                       nrOfSymbols);
+                       nrOfSymbols,
+                       aggregation_level,
+                       CCEIndex);
 
   nfapi_nr_pdu_t *tx_req = &gNB_mac->TX_req[CC_id].pdu_list[gNB_mac->TX_req[CC_id].Number_of_PDUs];
   configure_fapi_dl_Tx(module_id,

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_phytest.c

@@ -414,18 +414,31 @@ int configure_fapi_dl_pdu_phytest(int Mod_idP,
   }
   AssertFatal(found==1,"Couldn't find an adequate searchspace\n");
 
-  int ret = nr_configure_pdcch(nr_mac,
-                               pdcch_pdu_rel15,
-                               UE_list->rnti[UE_id],
-		               1, // ue-specific
-		               ss,
-		               scc,
-		               bwp);
-  if (ret < 0) {
-   LOG_I(MAC,"CCE list not empty, couldn't schedule PDSCH\n");
-   free(dci_pdu_rel15);
-   return (0);
+  uint8_t nr_of_candidates, aggregation_level;
+  find_aggregation_candidates(&aggregation_level, &nr_of_candidates, ss);
+  NR_ControlResourceSet_t *coreset = get_coreset(bwp, ss, 1 /* dedicated */);
+  int CCEIndex = allocate_nr_CCEs(
+      nr_mac,
+      bwp,
+      coreset,
+      aggregation_level,
+      ss->searchSpaceType->present - 1, // 0 common, 1 ue-specific
+      UE_id,
+      0); // m
+  if (CCEIndex < 0) {
+    LOG_E(MAC, "%s(): CCE list not empty, couldn't schedule PDSCH\n", __func__);
+    free(dci_pdu_rel15);
+    return 0;
   }
+  nr_configure_pdcch(nr_mac,
+                     pdcch_pdu_rel15,
+                     UE_list->rnti[UE_id],
+                     ss,
+                     coreset,
+                     scc,
+                     bwp,
+                     aggregation_level,
+                     CCEIndex);
 
   int dci_formats[2];
   int rnti_types[2];
@@ -1083,20 +1096,33 @@ void schedule_fapi_ul_pdu(int Mod_idP,
     rnti_types[0]   = NR_RNTI_C;
     LOG_D(MAC,"Configuring ULDCI/PDCCH in %d.%d\n", frameP,slotP);
 
-    int ret = nr_configure_pdcch(nr_mac,
-                                 pdcch_pdu_rel15,
-                                 UE_list->rnti[UE_id],
-                                 1, // ue-specific,
-                                 ss,
-		                 scc,
-		                 bwp);
-
-    if (ret < 0) {
-      LOG_I(MAC,"CCE list not empty, couldn't schedule PUSCH\n");
+    uint8_t nr_of_candidates, aggregation_level;
+    find_aggregation_candidates(&aggregation_level, &nr_of_candidates, ss);
+    NR_ControlResourceSet_t *coreset = get_coreset(bwp, ss, 1 /* dedicated */);
+    int CCEIndex = allocate_nr_CCEs(
+        nr_mac,
+        bwp,
+        coreset,
+        aggregation_level,
+        ss->searchSpaceType->present - 1, // 0 common, 1 ue-specific
+        UE_id,
+        0); // m
+    if (CCEIndex < 0) {
+      LOG_E(MAC, "%s(): CCE list not empty, couldn't schedule PUSCH\n", __func__);
       pusch_sched->active = false;
       return;
     }
     else {
+      nr_configure_pdcch(nr_mac,
+                         pdcch_pdu_rel15,
+                         UE_list->rnti[UE_id],
+                         ss,
+                         coreset,
+                         scc,
+                         bwp,
+                         aggregation_level,
+                         CCEIndex);
+
       dci_pdu_rel15_t *dci_pdu_rel15 = calloc(MAX_DCI_CORESET,sizeof(dci_pdu_rel15_t));
       config_uldci(ubwp,pusch_pdu,pdcch_pdu_rel15,&dci_pdu_rel15[0],dci_formats,rnti_types,time_domain_assignment,UE_list->UE_sched_ctrl[UE_id].tpc0,n_ubwp,bwp_id);
       fill_dci_pdu_rel15(scc,secondaryCellGroup,pdcch_pdu_rel15,dci_pdu_rel15,dci_formats,rnti_types,pusch_pdu->bwp_size,bwp_id);

openair2/LAYER2/NR_MAC_gNB/mac_proto.h

@@ -132,6 +132,8 @@ void nr_schedule_css_dlsch_phytest(module_id_t   module_idP,
 void nr_fill_nfapi_dl_pdu(int Mod_id,
                           int UE_id,
                           int bwp_id,
+                          NR_SearchSpace_t *ss,
+                          NR_ControlResourceSet_t *coreset,
                           nfapi_nr_dl_tti_request_body_t *dl_req,
                           NR_sched_pucch *pucch_sched,
                           int nrOfLayers,
@@ -146,7 +148,9 @@ void nr_fill_nfapi_dl_pdu(int Mod_id,
                           uint32_t tbs,
                           int time_domain_assignment,
                           int StartSymbolIndex,
-                          int NrOfSymbols);
+                          int NrOfSymbols,
+                          uint8_t aggregation_level,
+                          int CCEIndex);
 
 int configure_fapi_dl_pdu_phytest(int Mod_id,
                                   nfapi_nr_dl_tti_request_body_t *dl_req,
@@ -233,13 +237,15 @@ void find_search_space(int ss_type,
                        NR_BWP_Downlink_t *bwp,
                        NR_SearchSpace_t *ss);
 
-int nr_configure_pdcch(gNB_MAC_INST *nr_mac,
-                       nfapi_nr_dl_tti_pdcch_pdu_rel15_t* pdcch_pdu,
-                       uint16_t rnti,
-                       int ss_type,
-                       NR_SearchSpace_t *ss,
-                       NR_ServingCellConfigCommon_t *scc,
-                       NR_BWP_Downlink_t *bwp);
+void nr_configure_pdcch(gNB_MAC_INST *nr_mac,
+                        nfapi_nr_dl_tti_pdcch_pdu_rel15_t *pdcch_pdu,
+                        uint16_t rnti,
+                        NR_SearchSpace_t *ss,
+                        NR_ControlResourceSet_t *coreset,
+                        NR_ServingCellConfigCommon_t *scc,
+                        NR_BWP_Downlink_t *bwp,
+                        uint8_t aggregation_level,
+                        int CCEIndex);
 
 void fill_dci_pdu_rel15(NR_ServingCellConfigCommon_t *scc,
                         NR_CellGroupConfig_t *secondaryCellGroup,
@@ -255,6 +261,16 @@ void prepare_dci(NR_CellGroupConfig_t *secondaryCellGroup,
                  nr_dci_format_t format,
                  int bwp_id);
 
+/* find coreset within the search space */
+NR_ControlResourceSet_t *get_coreset(NR_BWP_Downlink_t *bwp,
+                                     NR_SearchSpace_t *ss,
+                                     int ss_type);
+
+/* find a search space within a BWP */
+NR_SearchSpace_t *get_searchspace(
+    NR_BWP_Downlink_t *bwp,
+    NR_SearchSpace__searchSpaceType_PR target_ss);
+
 void find_aggregation_candidates(uint8_t *aggregation_level,
                                  uint8_t *nr_of_candidates,
                                  NR_SearchSpace_t *ss);
@@ -288,13 +304,12 @@ int find_nr_UE_id(module_id_t mod_idP, rnti_t rntiP);
 int add_new_nr_ue(module_id_t mod_idP, rnti_t rntiP);
 
 int allocate_nr_CCEs(gNB_MAC_INST *nr_mac,
-                     int bwp_id,
-                     int coreset_id,
+                     NR_BWP_Downlink_t *bwp,
+                     NR_ControlResourceSet_t *coreset,
                      int aggregation,
                      int search_space, // 0 common, 1 ue-specific
                      int UE_id,
-                     int m
-                     );
+                     int m);
 
 int get_dlscs(nfapi_nr_config_request_t *cfg);