nr,gnb,sched: implement helper methods to check available PRBs in BWP, taking into account common SearchSpace BW limitations

srsgnb/hdr/stack/mac/sched_nr_cfg.h

@@ -95,6 +95,20 @@ struct bwp_params_t {
   srsran::optional_vector<bwp_cce_pos_list> common_cce_list;
 
   bwp_params_t(const cell_cfg_t& cell, const sched_args_t& sched_cfg_, uint32_t cc, uint32_t bwp_id);
+
+  const prb_bitmap& used_prbs(uint32_t ss_id, srsran_dci_format_nr_t dci_fmt) const
+  {
+    if (used_common_prb_masks.contains(ss_id)) {
+      if (dci_fmt == srsran_dci_format_nr_1_0) {
+        return used_common_prb_masks[ss_id];
+      }
+    }
+    return cached_empty_prb_mask;
+  }
+
+private:
+  prb_bitmap                          cached_empty_prb_mask;
+  srsran::optional_vector<prb_bitmap> used_common_prb_masks;
 };
 
 /// Structure packing a single cell config params, and sched args

srsgnb/hdr/stack/mac/sched_nr_grant_allocator.h

@@ -62,6 +62,11 @@ struct bwp_slot_grid {
 
   bool is_dl() const { return cfg->slots[slot_idx].is_dl; }
   bool is_ul() const { return cfg->slots[slot_idx].is_ul; }
+
+  prb_bitmap used_prbs(uint32_t ss_id, srsran_dci_format_nr_t dci_fmt) const
+  {
+    return dl_prbs.prbs() | cfg->used_prbs(ss_id, dci_fmt);
+  }
 };
 
 struct bwp_res_grid {

srsgnb/src/stack/mac/sched_nr_bwp.cc

@@ -25,7 +25,8 @@ alloc_result
 ra_sched::allocate_pending_rar(bwp_slot_allocator& slot_grid, const pending_rar_t& rar, uint32_t& nof_grants_alloc)
 {
   const uint32_t rar_aggr_level = 2;
-  const prb_bitmap& prbs           = slot_grid.res_grid()[slot_grid.get_pdcch_tti()].dl_prbs.prbs();
+  prb_bitmap     prbs = slot_grid.res_grid()[slot_grid.get_pdcch_tti()].used_prbs(bwp_cfg->cfg.pdcch.ra_search_space.id,
+                                                                              srsran_dci_format_nr_1_0);
 
   alloc_result                            ret = alloc_result::other_cause;
   srsran::const_span<dl_sched_rar_info_t> msg3_grants{rar.msg3_grant};

srsgnb/src/stack/mac/sched_nr_cfg.cc

@@ -51,6 +51,7 @@ bwp_params_t::bwp_params_t(const cell_cfg_t& cell, const sched_args_t& sched_cfg
 
   P     = get_P(cfg.rb_width, cfg.pdsch.rbg_size_cfg_1);
   N_rbg = get_nof_rbgs(cfg.rb_width, cfg.start_rb, cfg.pdsch.rbg_size_cfg_1);
+  cached_empty_prb_mask.resize(cfg.rb_width);
 
   // Derive params of individual slots
   uint32_t nof_slots = SRSRAN_NSLOTS_PER_FRAME_NR(cfg.numerology_idx);
@@ -91,7 +92,9 @@ bwp_params_t::bwp_params_t(const cell_cfg_t& cell, const sched_args_t& sched_cfg
   }
 
   for (uint32_t ss_id = 0; ss_id < SRSRAN_UE_DL_NR_MAX_NOF_SEARCH_SPACE; ++ss_id) {
-    if (cell_cfg.bwps[0].pdcch.search_space_present[ss_id]) {
+    if (not cell_cfg.bwps[0].pdcch.search_space_present[ss_id]) {
+      continue;
+    }
     auto& ss      = cell_cfg.bwps[0].pdcch.search_space[ss_id];
     auto& coreset = cell_cfg.bwps[0].pdcch.coreset[ss.coreset_id];
     common_cce_list.emplace(ss_id);
@@ -105,6 +108,15 @@ bwp_params_t::bwp_params_t(const cell_cfg_t& cell, const sched_args_t& sched_cfg
         ss_cce_list[sl][agg_idx].resize(n);
       }
     }
+
+    if (SRSRAN_SEARCH_SPACE_IS_COMMON(ss.type)) {
+      used_common_prb_masks.emplace(ss_id, cached_empty_prb_mask);
+      uint32_t coreset_start = srsran_coreset_start_rb(&cfg.pdcch.coreset[ss.coreset_id]);
+      used_common_prb_masks[ss_id].fill(0, coreset_start, true);
+      if (ss.coreset_id == 0) {
+        uint32_t coreset0_bw = srsran_coreset_get_bw(&cfg.pdcch.coreset[0]);
+        used_common_prb_masks[ss_id].fill(coreset_start + coreset0_bw, cfg.rb_width, true);
+      }
     }
   }
 }

srsgnb/src/stack/mac/sched_nr_helpers.cc

@@ -84,6 +84,7 @@ void fill_dci_grant(const bwp_params_t& bwp_cfg, const prb_grant& grant, srsran_
     if (dci.ctx.coreset_id == 0 and SRSRAN_SEARCH_SPACE_IS_COMMON(dci.ctx.ss_type)) {
       nof_prb = dci.coreset0_bw;
     }
+    srsran_assert(grant.prbs().start() >= rb_start, "Invalid PRB index=%d < %d", grant.prbs().start(), rb_start);
     uint32_t grant_start      = grant.prbs().start() - rb_start;
     dci.freq_domain_assigment = srsran_ra_nr_type1_riv(nof_prb, grant_start, grant.prbs().length());
   }
@@ -233,9 +234,9 @@ void log_sched_bwp_result(srslog::basic_logger& logger,
       data_count++;
     } else if (pdcch.dci.ctx.rnti_type == srsran_rnti_type_ra) {
       const pdsch_t&           pdsch = bwp_slot.dl.phy.pdsch[std::distance(bwp_slot.dl.phy.pdcch_dl.data(), &pdcch)];
-      srsran::const_span<bool> prbs{pdsch.sch.grant.prb_idx, pdsch.sch.grant.prb_idx + pdsch.sch.grant.nof_prb};
+      srsran::const_span<bool> prbs{pdsch.sch.grant.prb_idx, pdsch.sch.grant.prb_idx + SRSRAN_MAX_PRB_NR};
       uint32_t                 start_idx = std::distance(prbs.begin(), std::find(prbs.begin(), prbs.end(), true));
-      uint32_t end_idx = std::distance(prbs.begin(), std::find(prbs.begin() + start_idx, prbs.end(), false));
+      uint32_t                 end_idx   = start_idx + pdsch.sch.grant.nof_prb;
       fmt::format_to(fmtbuf,
                      "SCHED: RAR, cc={}, ra-rnti=0x{:x}, prbs={}, pdsch_slot={}, msg3_slot={}, nof_grants={}",
                      res_grid.cfg->cc,
@@ -248,9 +249,9 @@ void log_sched_bwp_result(srslog::basic_logger& logger,
     } else if (pdcch.dci.ctx.rnti_type == srsran_rnti_type_si) {
       if (logger.debug.enabled()) {
         const pdsch_t&           pdsch = bwp_slot.dl.phy.pdsch[std::distance(bwp_slot.dl.phy.pdcch_dl.data(), &pdcch)];
-        srsran::const_span<bool> prbs{pdsch.sch.grant.prb_idx, pdsch.sch.grant.prb_idx + pdsch.sch.grant.nof_prb};
+        srsran::const_span<bool> prbs{pdsch.sch.grant.prb_idx, pdsch.sch.grant.prb_idx + SRSRAN_MAX_PRB_NR};
         uint32_t                 start_idx = std::distance(prbs.begin(), std::find(prbs.begin(), prbs.end(), true));
-        uint32_t end_idx = std::distance(prbs.begin(), std::find(prbs.begin() + start_idx, prbs.end(), false));
+        uint32_t                 end_idx   = start_idx + pdsch.sch.grant.nof_prb;
         fmt::format_to(fmtbuf,
                        "SCHED: SI{}, cc={}, prbs={}, pdsch_slot={}",
                        pdcch.dci.sii == 0 ? "B" : " message",