CSR ops: wait until oldest

core/gc_unit.sv

@@ -78,7 +78,11 @@ module gc_unit(
 
         output logic [31:0] gc_fetch_pc,
 
+        //Ordering support
         input logic ls_is_idle,
+        input logic [LOG2_MAX_IDS:0] post_issue_count,
+
+        //WB
         unit_writeback_interface.unit wb
     );
 
@@ -358,7 +362,7 @@ module gc_unit(
       .result(processing_csr)
     );
 
-    assign csr_ready_to_complete = processing_csr & ls_is_idle;
+    assign csr_ready_to_complete = processing_csr & (post_issue_count == 1);
     always_ff @(posedge clk) begin
         csr_ready_to_complete_r <= csr_ready_to_complete;
         csr_id <= instruction_id;

core/instruction_metadata_and_id_management.sv

@@ -71,6 +71,8 @@ module instruction_metadata_and_id_management
         output id_t retire_ids [RETIRE_PORTS],
         output logic retire_ids_retired [RETIRE_PORTS],
 
+        //CSR
+        output logic [LOG2_MAX_IDS:0] post_issue_count,
         //Exception
         input id_t exception_id,
         output logic [31:0] exception_pc
@@ -88,12 +90,11 @@ module instruction_metadata_and_id_management
     logic [$bits(branch_metadata_t)-1:0] branch_metadata_table [MAX_IDS];
     logic [$bits(fetch_metadata_t)-1:0] fetch_metadata_table [MAX_IDS];
 
-    localparam LOG2_MAX_IDS = $clog2(MAX_IDS);
     id_t decode_id;
 
     logic [LOG2_MAX_IDS:0] fetched_count; //MSB used as valid for decode stage
     logic [LOG2_MAX_IDS:0] pre_issue_count;
-    logic [LOG2_MAX_IDS:0] post_issue_count;
+    //logic [LOG2_MAX_IDS:0] post_issue_count;
     logic [LOG2_MAX_IDS:0] inflight_count;
 
     genvar i;

core/taiga.sv

@@ -130,6 +130,7 @@ module taiga (
     logic gc_tlb_flush;
     logic [31:0] gc_fetch_pc;
     logic ls_is_idle;
+    logic [LOG2_MAX_IDS:0] post_issue_count;
 
     //Decode Unit and Fetch Unit
     logic illegal_instruction;
@@ -230,7 +231,8 @@ module taiga (
         .retire (retire),
         .retire_ids (retire_ids),
         .retire_ids_retired(retire_ids_retired),
-         .exception_id (exception_id),
+        .post_issue_count(post_issue_count),
+        .exception_id (exception_id),
         .exception_pc (exception_pc)
     );
 
@@ -501,6 +503,7 @@ module taiga (
         .gc_tlb_flush (gc_tlb_flush),
         .gc_fetch_pc (gc_fetch_pc),
         .ls_is_idle (ls_is_idle),
+        .post_issue_count (post_issue_count),
         .wb (unit_wb[GC_UNIT_ID])
     );