fixed shared memory multi-tag requests bug

hw/rtl/cache/VX_shared_mem.v

@@ -4,25 +4,25 @@ module VX_shared_mem #(
     parameter CACHE_ID                      = 0,
 
     // Size of cache in bytes
-    parameter CACHE_SIZE                    = 16384, 
+    parameter CACHE_SIZE                    = (1024*16), 
     // Number of banks
-    parameter NUM_BANKS                     = 4, 
+    parameter NUM_BANKS                     = 2, 
     // Size of a word in bytes
     parameter WORD_SIZE                     = 4, 
     // Number of Word requests per cycle
-    parameter NUM_REQS                      = NUM_BANKS, 
+    parameter NUM_REQS                      = 4, 
 
     // Core Request Queue Size
-    parameter CREQ_SIZE                     = 4,
+    parameter CREQ_SIZE                     = 8,
-
-    // core request tag size
-    parameter CORE_TAG_WIDTH                = 1,
 
     // size of tag id in core request tag
-    parameter CORE_TAG_ID_BITS              = 0,
+    parameter CORE_TAG_ID_BITS              = 8,
+
+    // core request tag size
+    parameter CORE_TAG_WIDTH                = (2 + CORE_TAG_ID_BITS),
 
     // bank offset from beginning of index range
-    parameter BANK_ADDR_OFFSET              = 0    
+    parameter BANK_ADDR_OFFSET              = `CLOG2(256)    
  ) (    
     input wire clk,
     input wire reset,   
@@ -54,13 +54,6 @@ module VX_shared_mem #(
 
     localparam CACHE_LINE_SIZE = WORD_SIZE;
 
-`ifdef DBG_CACHE_REQ_INFO
-    /* verilator lint_off UNUSED */
-    wire [31:0]         debug_pc_st0;
-    wire [`NW_BITS-1:0] debug_wid_st0;
-    /* verilator lint_on UNUSED */
-`endif
-
     wire [NUM_BANKS-1:0]                    per_bank_core_req_valid_unqual; 
     wire [NUM_BANKS-1:0]                    per_bank_core_req_rw_unqual;  
     wire [NUM_BANKS-1:0][`LINE_ADDR_WIDTH-1:0] per_bank_core_req_addr_unqual;
@@ -109,20 +102,26 @@ module VX_shared_mem #(
     wire [NUM_BANKS-1:0][`LINE_SELECT_BITS-1:0] per_bank_core_req_addr;
     wire [NUM_BANKS-1:0][WORD_SIZE-1:0]     per_bank_core_req_byteen;
     wire [NUM_BANKS-1:0][`WORD_WIDTH-1:0]   per_bank_core_req_data;
-    wire [NUM_REQS-1:0][CORE_TAG_WIDTH-1:0] per_bank_core_req_tag;
+    wire [NUM_BANKS-1:0][CORE_TAG_WIDTH-1:0] per_bank_core_req_tag;
     wire [NUM_BANKS-1:0][`REQS_BITS-1:0]    per_bank_core_req_tid;
 
     wire creq_push, creq_pop, creq_empty, creq_full;
-    wire crsq_in_ready;
+    wire crsq_in_fire_last;
+
+    wire [NUM_BANKS-1:0] per_bank_rsp_valid = per_bank_core_req_valid & ~per_bank_core_req_rw;
+
+    wire core_req_has_read = (| per_bank_rsp_valid);
         
-    assign creq_push = (| core_req_valid) && !creq_full;
+    assign creq_push = (| core_req_valid) && ~creq_full;
-    assign creq_pop = ~creq_empty && crsq_in_ready;
+
+    assign creq_pop = (~creq_empty && ~core_req_has_read) 
+                   || crsq_in_fire_last;
     
     assign per_bank_core_req_ready_unqual = ~creq_full;
 
-    wire [NUM_REQS-1:0][`LINE_SELECT_BITS-1:0] per_bank_core_req_addr_qual;
+    wire [NUM_BANKS-1:0][`LINE_SELECT_BITS-1:0] per_bank_core_req_addr_qual;
     `UNUSED_VAR (per_bank_core_req_addr_unqual)
-    for (genvar i = 0; i < NUM_REQS; i++) begin
+    for (genvar i = 0; i < NUM_BANKS; i++) begin
         assign per_bank_core_req_addr_qual[i] = per_bank_core_req_addr_unqual[i][`LINE_SELECT_BITS-1:0];
     end
 
@@ -179,6 +178,34 @@ module VX_shared_mem #(
             .dout   (per_bank_core_rsp_data[i])
         );
     end  
+
+    // The core response bus handles a single tag at the time
+    // We first need to select the current tag to process,
+    // then send all bank responses for that tag as a batch
+
+    wire crsq_in_valid, crsq_in_ready;
+
+    reg [NUM_BANKS-1:0] bank_rsp_sel, bank_rsp_sel_r;
+
+    wire [NUM_BANKS-1:0] bank_rsp_sel_n = bank_rsp_sel | bank_rsp_sel_r;
+
+    wire crsq_in_fire = crsq_in_valid && crsq_in_ready;
+
+    assign crsq_in_fire_last = crsq_in_fire && (bank_rsp_sel_n == per_bank_rsp_valid);
+
+    always @(posedge clk) begin
+        if (reset) begin
+            bank_rsp_sel <= 0;
+        end else begin
+            if (crsq_in_fire) begin
+                if (bank_rsp_sel_n == per_bank_rsp_valid) begin
+                    bank_rsp_sel <= 0;
+                end else begin
+                    bank_rsp_sel <= bank_rsp_sel_n;
+                end
+            end
+        end
+    end
     
     reg [NUM_REQS-1:0] core_rsp_valids_in;
     reg [NUM_REQS-1:0][`WORD_WIDTH-1:0] core_rsp_data_in;
@@ -186,31 +213,30 @@ module VX_shared_mem #(
     
     always @(*) begin              
         core_rsp_valids_in = 0;
-        core_rsp_data_in   = 'x;        
+        core_rsp_data_in   = 'x;
         core_rsp_tag_in    = 'x;
-        for (integer i = 0; i < NUM_BANKS; i++) begin 
+        bank_rsp_sel_r     = 0;
-            if (per_bank_core_req_valid[i]) begin
+
-                core_rsp_valids_in[per_bank_core_req_tid[i]] = 1;
+        for (integer i = NUM_BANKS-1; i >= 0; --i) begin
-                core_rsp_data_in[per_bank_core_req_tid[i]] = per_bank_core_rsp_data[i];
+            if (per_bank_rsp_valid[i] && ~bank_rsp_sel[i]) begin
                 core_rsp_tag_in = per_bank_core_req_tag[i];
             end
         end
-    end    
+
-    
+        for (integer i = 0; i < NUM_BANKS; i++) begin 
-`ifdef DBG_CACHE_REQ_INFO
+            if (per_bank_core_req_valid[i] 
-    if (CORE_TAG_WIDTH != CORE_TAG_ID_BITS && CORE_TAG_ID_BITS != 0) begin
+             && (core_rsp_tag_in[CORE_TAG_ID_BITS-1:0] == per_bank_core_req_tag[i][CORE_TAG_ID_BITS-1:0])) begin
-        assign {debug_pc_st0, debug_wid_st0} = core_rsp_tag_in[CORE_TAG_WIDTH-1:CORE_TAG_ID_BITS];
+                core_rsp_valids_in[per_bank_core_req_tid[i]] = 1;
-    end else begin
+                core_rsp_data_in[per_bank_core_req_tid[i]] = per_bank_core_rsp_data[i];
-        assign {debug_pc_st0, debug_wid_st0} = 0;
+                bank_rsp_sel_r[i] = 1;
+            end
+        end
     end
-`endif
+
-    
     wire [NUM_REQS-1:0] core_rsp_valids_out;
     wire core_rsp_valid_out;
 
-    wire core_rsp_rw = | (per_bank_core_req_valid & per_bank_core_req_rw);
+    assign crsq_in_valid = ~creq_empty && core_req_has_read;
-
-    wire crsq_in_valid = ~creq_empty && ~core_rsp_rw;
 
     VX_skid_buffer #(
         .DATAW (NUM_BANKS * (1 + `WORD_WIDTH) + CORE_TAG_WIDTH)
@@ -227,25 +253,82 @@ module VX_shared_mem #(
 
     assign core_rsp_valid = core_rsp_valids_out & {NUM_REQS{core_rsp_valid_out}};
 
+`ifdef DBG_CACHE_REQ_INFO
+`IGNORE_WARNINGS_BEGIN
+    wire [NUM_BANKS-1:0][31:0]         debug_pc_st0, debug_pc_st1;
+    wire [NUM_BANKS-1:0][`NW_BITS-1:0] debug_wid_st0, debug_wid_st1;
+`IGNORE_WARNINGS_END
+
+    for (genvar i = 0; i < NUM_BANKS; ++i) begin
+        if (CORE_TAG_WIDTH != CORE_TAG_ID_BITS && CORE_TAG_ID_BITS != 0) begin        
+            assign {debug_pc_st0[i], debug_wid_st0[i]} = per_bank_core_req_tag_unqual[i][CORE_TAG_WIDTH-1:CORE_TAG_ID_BITS];
+            assign {debug_pc_st1[i], debug_wid_st1[i]} = per_bank_core_req_tag[i][CORE_TAG_WIDTH-1:CORE_TAG_ID_BITS];        
+        end else begin
+            assign {debug_pc_st0[i], debug_wid_st0[i]} = 0;
+            assign {debug_pc_st1[i], debug_wid_st1[i]} = 0;
+        end
+    end
+`endif
+
 `ifdef DBG_PRINT_CACHE_BANK
+    
+    reg is_multi_tag_req;
+`IGNORE_WARNINGS_BEGIN
+    reg [CORE_TAG_WIDTH-1:0] core_req_tag_sel;
+`IGNORE_WARNINGS_END
+
+    always @(*) begin                      
+        core_req_tag_sel ='x;
+        for (integer i = NUM_BANKS-1; i >= 0; --i) begin
+            if (per_bank_core_req_valid[i]) begin
+                core_req_tag_sel = per_bank_core_req_tag[i];
+            end
+        end
+        is_multi_tag_req = 0;
+        for (integer i = 0; i < NUM_BANKS; ++i) begin
+            if (per_bank_core_req_valid[i] 
+             && (core_req_tag_sel[CORE_TAG_ID_BITS-1:0] != per_bank_core_req_tag[i][CORE_TAG_ID_BITS-1:0])) begin
+                is_multi_tag_req = !creq_empty;
+            end
+        end
+    end
+
     always @(posedge clk) begin        
         if (!crsq_in_ready) begin
-            $display("%t: cache%0d pipeline-stall", $time, CACHE_ID);
+            $display("%t: *** cache%0d pipeline-stall", $time, CACHE_ID);        
+        end
+        if (is_multi_tag_req) begin
+            $display("%t: *** cache%0d multi-tag request!", $time, CACHE_ID);
+        end
+        if (creq_push) begin
+            for (integer i = 0; i < NUM_BANKS; ++i) begin
+                if (per_bank_core_req_valid_unqual[i]) begin
+                    if (per_bank_core_req_rw_unqual[i]) begin
+                        $display("%t: cache%0d:%0d core-wr-req: addr=%0h, tag=%0h, byteen=%b, data=%0h, wid=%0d, PC=%0h", 
+                            $time, CACHE_ID, i, per_bank_core_req_addr_unqual[i], per_bank_core_req_tag_unqual[i], per_bank_core_req_byteen_unqual[i], per_bank_core_req_data_unqual[i], 
+                            debug_wid_st0[i], debug_pc_st0[i]);
+                    end else begin
+                        $display("%t: cache%0d:%0d core-rd-req: addr=%0h, tag=%0h, byteen=%b, wid=%0d, PC=%0h", 
+                            $time, CACHE_ID, i, per_bank_core_req_addr_unqual[i], per_bank_core_req_tag_unqual[i], per_bank_core_req_byteen_unqual[i], 
+                            debug_wid_st0[i], debug_pc_st0[i]);
+                    end
+                end
+            end
         end
         if (creq_pop) begin
-            if (core_rsp_rw) begin
+            for (integer i = 0; i < NUM_BANKS; ++i) begin
-                $write("%t: cache%0d core-wr-req: tmask=%0b, addr=", $time, CACHE_ID, per_bank_core_req_valid);
+                if (per_bank_core_req_valid[i]) begin
-            end else begin
+                    if (per_bank_core_req_rw[i]) begin
-                $write("%t: cache%0d core-rd-req: tmask=%0b, addr=", $time, CACHE_ID, per_bank_core_req_valid);
+                        $display("%t: cache%0d:%0d core-wr-rsp: addr=%0h, tag=%0h, byteen=%b, data=%0h, wid=%0d, PC=%0h", 
+                            $time, CACHE_ID, i, per_bank_core_req_addr[i], per_bank_core_req_tag[i], per_bank_core_req_byteen[i], per_bank_core_req_data[i], 
+                            debug_wid_st1[i], debug_pc_st1[i]);
+                    end else begin
+                        $display("%t: cache%0d:%0d core-rd-rsp: addr=%0h, tag=%0h, byteen=%b, wid=%0d, PC=%0h", 
+                            $time, CACHE_ID, i, per_bank_core_req_addr[i], per_bank_core_req_tag[i], per_bank_core_req_byteen[i], 
+                            debug_wid_st1[i], debug_pc_st1[i]);
+                    end
+                end
             end
-            `PRINT_ARRAY1D(per_bank_core_req_addr, `NUM_THREADS);
-            $write(", tag=%0h, byteen=%b, data=", per_bank_core_req_tag, per_bank_core_req_byteen);
-            if (core_rsp_rw) begin
-                `PRINT_ARRAY1D(per_bank_core_req_data, `NUM_THREADS);
-            end else begin
-                `PRINT_ARRAY1D(per_bank_core_rsp_data, `NUM_THREADS);
-            end
-            $write(", wid=%0d, PC=%0h\n", debug_wid_st0, debug_pc_st0);
         end
     end    
 `endif