Get it working more

sim/application_wrapper/cache/application_wrapper_cache_miss_handler_test.py

@@ -122,6 +122,8 @@ async def test_sanity(dut):
     cocotb.start_soon(Clock(dut.i_clk, CLK_PERIOD, unit="ns").start())
     cocotb.start_soon(handle_cache_arrays(dut))
 
+    dut.i_cpu_we.value = 0
+
     dut.i_rst.value = Immediate(1)
     for _ in range(10):
         await RisingEdge(dut.i_clk)
@@ -158,6 +160,8 @@ async def test_clean_eviction(dut):
     cocotb.start_soon(handle_writeback(dut))
     cocotb.start_soon(handle_bus_interface(dut))
 
+    dut.i_cpu_we.value = 0
+
     dut.i_rst.value = Immediate(1)
     for _ in range(10):
         await RisingEdge(dut.i_clk)
@@ -198,6 +202,8 @@ async def test_eviction(dut):
     cocotb.start_soon(handle_writeback(dut))
     cocotb.start_soon(handle_bus_interface(dut))
 
+    dut.i_cpu_we.value = 0
+
     dut.i_rst.value = Immediate(1)
     for _ in range(10):
         await RisingEdge(dut.i_clk)
@@ -238,6 +244,8 @@ async def test_request_ownership(dut):
     cocotb.start_soon(handle_writeback(dut))
     cocotb.start_soon(handle_bus_interface(dut))
 
+    dut.i_cpu_we.value = 0
+
     dut.i_rst.value = Immediate(1)
     for _ in range(10):
         await RisingEdge(dut.i_clk)
@@ -280,6 +288,7 @@ async def test_way_read_thrash(dut):
     cocotb.start_soon(handle_writeback(dut))
     cocotb.start_soon(handle_bus_interface(dut))
 
+    dut.i_cpu_we.value = 0
     dut.i_rst.value = Immediate(1)
     for _ in range(10):
         await RisingEdge(dut.i_clk)
@@ -297,3 +306,97 @@ async def test_way_read_thrash(dut):
             await RisingEdge(dut.i_clk)
 
     await Timer(1, "us")
+
+
+@cocotb.test
+async def test_write_waw(dut):
+    cocotb.start_soon(Clock(dut.i_clk, CLK_PERIOD, unit="ns").start())
+    cocotb.start_soon(handle_cache_arrays(dut))
+    cocotb.start_soon(handle_lru_arrays(dut))
+    cocotb.start_soon(handle_writeback(dut))
+    cocotb.start_soon(handle_bus_interface(dut))
+
+    dut.i_rst.value = Immediate(1)
+    for _ in range(10):
+        await RisingEdge(dut.i_clk)
+    dut.i_rst.value = 0
+
+    await RisingEdge(dut.o_rdy)
+
+    INDEX = 7
+    TAG = 0xabcd
+
+
+    # unused tag
+    dut.i_cpu_tag.value = 0xffff
+    dut.i_rdy.value = 1
+
+    dut.i_cpu_we.value = 1
+    dut.i_cpu_index.value = INDEX
+    dut.i_cpu_offset.value = 1
+    dut.i_cpu_data.value = 0xaa
+    await RisingEdge(dut.i_clk)
+    dut.i_cpu_tag.value = TAG
+
+    while not dut.o_rdy.value:
+        await RisingEdge(dut.i_clk)
+
+    dut.i_cpu_we.value = 1
+    dut.i_cpu_index.value = INDEX
+    dut.i_cpu_offset.value = 2
+    dut.i_cpu_data.value = 0x55
+    await RisingEdge(dut.i_clk)
+    dut.i_cpu_tag.value = TAG
+
+    while not dut.o_rdy.value:
+        await RisingEdge(dut.i_clk)
+
+    dut.i_cpu_we.value = 0
+
+    await Timer(1, "us")
+
+@cocotb.test
+async def test_write_raw(dut):
+    cocotb.start_soon(Clock(dut.i_clk, CLK_PERIOD, unit="ns").start())
+    cocotb.start_soon(handle_cache_arrays(dut))
+    cocotb.start_soon(handle_lru_arrays(dut))
+    cocotb.start_soon(handle_writeback(dut))
+    cocotb.start_soon(handle_bus_interface(dut))
+
+    dut.i_rst.value = Immediate(1)
+    for _ in range(10):
+        await RisingEdge(dut.i_clk)
+    dut.i_rst.value = 0
+
+    await RisingEdge(dut.o_rdy)
+
+    INDEX = 7
+    TAG = 0xabcd
+
+
+    # unused tag
+    dut.i_cpu_tag.value = 0xffff
+    dut.i_rdy.value = 1
+
+    dut.i_cpu_we.value = 1
+    dut.i_cpu_index.value = INDEX
+    dut.i_cpu_offset.value = 1
+    dut.i_cpu_data.value = 0x41
+    await RisingEdge(dut.i_clk)
+    dut.i_cpu_tag.value = TAG
+
+    while not dut.o_rdy.value:
+        await RisingEdge(dut.i_clk)
+
+    dut.i_cpu_we.value = 0
+    dut.i_cpu_index.value = INDEX
+    dut.i_cpu_offset.value = 1
+    await RisingEdge(dut.i_clk)
+    dut.i_cpu_tag.value = TAG
+
+    while not dut.o_rdy.value:
+        await RisingEdge(dut.i_clk)
+
+    dut.i_cpu_we.value = 0
+
+    await Timer(1, "us")

src/application_wrapper/cache/application_wrapper_cache_miss_handler.sv

@@ -90,6 +90,7 @@ logic [INDEX_W-1:0] cpu_index_new, cpu_index_new_next;
 logic [OFFSET_W-1:0] cpu_offset_new, cpu_offset_new_next;
 logic [$clog2(NUM_WAYS)-1:0] cpu_way_new, cpu_way_new_next;
 logic [7:0] cpu_data_new, cpu_data_new_next;
+logic cpu_we_new, cpu_we_new_next;
 
 logic previous_was_valid, previous_was_valid_next;
 
@@ -117,6 +118,7 @@ always_ff @(posedge i_clk) begin
     cpu_tag_new <= cpu_tag_new_next;
     cpu_way_new <= cpu_way_new_next;
     cpu_data_new <= cpu_data_new_next;
+    cpu_we_new <= cpu_we_new_next;
 
     clear_index <= clear_index_next;
     cpu_we_d1 <= i_cpu_we;
@@ -165,6 +167,7 @@ always_comb begin
     cpu_tag_new_next = cpu_tag_new;
     cpu_way_new_next = cpu_way_new;
     cpu_data_new_next = cpu_data_new;
+    cpu_we_new_next = cpu_we_new;
 
     read_req_addr_next = read_req_addr;
 
@@ -284,6 +287,9 @@ always_comb begin
                 end else begin
                     o_rdy = '0;
                     state_next = CHECK_VICTIM;
+
+                    cpu_data_new_next = cpu_i_data_d1;
+                    cpu_we_new_next = cpu_we_d1;
                 end
 
             end
@@ -391,26 +397,33 @@ always_comb begin
             // This state can be put into WAIT_WRITEBACK_ACK and CHECK_VICTIM
             o_memory_addr = read_req_addr;
             o_memory_valid = '1;
-            // if the cache hit was a write, we should read unique, so we can be
-            // sure that we are given EXCLUSIVE and can set it to MODIFIED right away
-            o_memory_cmd = CACHE_CMD_READ;
+
+            if (cpu_we_new) begin
+                o_memory_cmd = CACHE_CMD_READ_UNIQUE;
+            end else begin
+                o_memory_cmd = CACHE_CMD_READ;
+            end
             state_next = WAIT_MEMORY;
         end
 
         WAIT_MEMORY: begin
-            // need to handle if this was a write miss
             if (i_memory_done) begin
                 o_write_valid = (1 << cpu_way_new);
                 o_write_data = i_memory_data;
                 o_write_index = cpu_index_new;
-                if (i_memory_resp == CACHE_RSP_SHARED) begin
-                    o_write_meta = {MESI_SHARED, cpu_tag_new};
-                end else if (i_memory_resp == CACHE_RSP_EXCLUSIVE) begin
-                    o_write_meta = {MESI_EXCLUSIVE, cpu_tag_new};
+                if (cpu_we_new) begin
+                    o_write_data[cpu_offset_new*8 +: CPU_W] = cpu_data_new;
+                    o_write_meta = {MESI_MODIFIED, cpu_tag_new};
+                end else begin
+                    if (i_memory_resp == CACHE_RSP_SHARED) begin
+                        o_write_meta = {MESI_SHARED, cpu_tag_new};
+                    end else if (i_memory_resp == CACHE_RSP_EXCLUSIVE) begin
+                        o_write_meta = {MESI_EXCLUSIVE, cpu_tag_new};
+                    end
+                    o_cpu_data = i_memory_data[cpu_offset_new*8 +: CPU_W];
                 end
 
                 o_rdy = '1;
-                o_cpu_data = i_memory_data[cpu_offset_new*8 +: CPU_W];
 
                 // update lru
                 // start by copying the read data, then change the bits

src/application_wrapper/cache/application_wrapper_cache_pkg.sv

@@ -13,7 +13,7 @@ package application_wrapper_cache_pkg;
     typedef enum logic [2:0] {
         CACHE_CMD_NONE,
         CACHE_CMD_READ,
-        CAHCE_CMD_READ_UNIQUE,
+        CACHE_CMD_READ_UNIQUE,
         CACHE_CMD_WRITE,
         CACHE_CMD_CLEAN_UNIQUE,
         CACHE_CMD_EVICT