Files
kernels/hw/rtl/cache/VX_miss_resrv.v

205 lines
7.6 KiB
Verilog

`include "VX_cache_config.vh"
module VX_miss_resrv #(
parameter CACHE_ID = 0,
parameter BANK_ID = 0,
// Number of Word requests per cycle
parameter NUM_REQS = 1,
// Size of line inside a bank in bytes
parameter CACHE_LINE_SIZE = 1,
// Number of banks
parameter NUM_BANKS = 1,
// Number of ports per banks
parameter NUM_PORTS = 1,
// Size of a word in bytes
parameter WORD_SIZE = 1,
// Miss Reserv Queue Knob
parameter MSHR_SIZE = 1,
parameter ALM_FULL = (MSHR_SIZE-1),
// core request tag size
parameter CORE_TAG_WIDTH = 1
) (
input wire clk,
input wire reset,
`ifdef DBG_CACHE_REQ_INFO
`IGNORE_WARNINGS_BEGIN
input wire[31:0] deq_debug_pc,
input wire[`NW_BITS-1:0] deq_debug_wid,
input wire[31:0] enq_debug_pc,
input wire[`NW_BITS-1:0] enq_debug_wid,
`IGNORE_WARNINGS_END
`endif
// enqueue
input wire enqueue,
input wire [`LINE_ADDR_WIDTH-1:0] enqueue_addr,
input wire [`MSHR_DATA_WIDTH-1:0] enqueue_data,
input wire enqueue_is_mshr,
input wire enqueue_as_ready,
output wire enqueue_full,
output wire enqueue_almfull,
// lookup
input wire lookup_ready,
input wire [`LINE_ADDR_WIDTH-1:0] lookup_addr,
output wire lookup_match,
// schedule
input wire schedule,
output wire schedule_valid,
output wire [`LINE_ADDR_WIDTH-1:0] schedule_addr,
output wire [`MSHR_DATA_WIDTH-1:0] schedule_data,
// dequeue
input wire dequeue
);
`UNUSED_PARAM (CACHE_ID)
`UNUSED_PARAM (BANK_ID)
localparam ADDRW = $clog2(MSHR_SIZE);
reg [MSHR_SIZE-1:0][`LINE_ADDR_WIDTH-1:0] addr_table;
reg [MSHR_SIZE-1:0] valid_table;
reg [MSHR_SIZE-1:0] ready_table;
reg [ADDRW-1:0] head_ptr, tail_ptr;
reg [ADDRW-1:0] schedule_ptr, restore_ptr;
reg [ADDRW-1:0] used_r;
reg alm_full_r, full_r;
wire [MSHR_SIZE-1:0] valid_address_match;
for (genvar i = 0; i < MSHR_SIZE; i++) begin
assign valid_address_match[i] = valid_table[i] && (addr_table[i] == lookup_addr);
end
assign lookup_match = (| valid_address_match);
wire push_new = enqueue && !enqueue_is_mshr;
wire restore = enqueue && enqueue_is_mshr;
wire [`LOG2UP(MSHR_SIZE)-1:0] head_ptr_n = head_ptr + $bits(head_ptr)'(1);
always @(posedge clk) begin
if (reset) begin
valid_table <= 0;
ready_table <= 0;
head_ptr <= 0;
tail_ptr <= 0;
schedule_ptr <= 0;
restore_ptr <= 0;
used_r <= 0;
alm_full_r <= 0;
full_r <= 0;
end else begin
// WARNING: lookup should happen enqueue for ready_table's correct update
if (lookup_ready) begin
// unlock pending requests for scheduling
ready_table <= ready_table | valid_address_match;
end
if (push_new) begin
// push new entry
assert(!full_r);
valid_table[tail_ptr] <= 1;
ready_table[tail_ptr] <= enqueue_as_ready;
tail_ptr <= tail_ptr + $bits(tail_ptr)'(1);
end else if (restore) begin
assert(!schedule);
// restore schedule, returning missed mshr entry
valid_table[restore_ptr] <= 1;
ready_table[restore_ptr] <= enqueue_as_ready;
restore_ptr <= restore_ptr + $bits(restore_ptr)'(1);
schedule_ptr <= head_ptr;
end else if (dequeue) begin
// clear scheduled entry
assert(((head_ptr+$bits(head_ptr)'(1)) == schedule_ptr)
|| ((head_ptr+$bits(head_ptr)'(2)) == schedule_ptr)) else $error("schedule_ptr=%0d, head_ptr=%0d", schedule_ptr, head_ptr);
valid_table[head_ptr] <= 0;
head_ptr <= head_ptr_n;
restore_ptr <= head_ptr_n;
end
if (schedule) begin
// schedule next entry
assert(schedule_valid);
valid_table[schedule_ptr] <= 0;
ready_table[schedule_ptr] <= 0;
schedule_ptr <= schedule_ptr + $bits(schedule_ptr)'(1);
end
if (push_new) begin
if (!dequeue) begin
if (used_r == ADDRW'(ALM_FULL-1))
alm_full_r <= 1;
if (used_r == ADDRW'(MSHR_SIZE-1))
full_r <= 1;
end
end else if (dequeue) begin
if (used_r == ADDRW'(ALM_FULL))
alm_full_r <= 0;
full_r <= 0;
end
used_r <= used_r + ADDRW'($signed(2'(push_new) - 2'(dequeue)));
end
end
always @(posedge clk) begin
if (push_new) begin
addr_table[tail_ptr] <= enqueue_addr;
end
end
VX_dp_ram #(
.DATAW(`MSHR_DATA_WIDTH),
.SIZE(MSHR_SIZE),
.RWCHECK(1),
.FASTRAM(1)
) entries (
.clk(clk),
.waddr(tail_ptr),
.raddr(schedule_ptr),
.wren(push_new),
.byteen(1'b1),
.rden(1'b1),
.din(enqueue_data),
.dout(schedule_data)
);
assign schedule_valid = ready_table[schedule_ptr];
assign schedule_addr = addr_table[schedule_ptr];
assign enqueue_almfull = alm_full_r;
assign enqueue_full = full_r;
`ifdef DBG_PRINT_CACHE_MSHR
always @(posedge clk) begin
if (lookup_ready || schedule || enqueue || dequeue) begin
if (schedule)
$display("%t: cache%0d:%0d mshr-schedule: addr%0d=%0h, wid=%0d, PC=%0h", $time, CACHE_ID, BANK_ID, schedule_ptr, `LINE_TO_BYTE_ADDR(schedule_addr, BANK_ID), deq_debug_wid, deq_debug_pc);
if (enqueue) begin
if (enqueue_is_mshr)
$display("%t: cache%0d:%0d mshr-restore: addr%0d=%0h, ready=%b", $time, CACHE_ID, BANK_ID, restore_ptr, `LINE_TO_BYTE_ADDR(enqueue_addr, BANK_ID), enqueue_as_ready);
else
$display("%t: cache%0d:%0d mshr-enqueue: addr%0d=%0h, ready=%b, wid=%0d, PC=%0h", $time, CACHE_ID, BANK_ID, tail_ptr, `LINE_TO_BYTE_ADDR(enqueue_addr, BANK_ID), enqueue_as_ready, enq_debug_wid, enq_debug_pc);
end
if (dequeue)
$display("%t: cache%0d:%0d mshr-dequeue addr%0d, wid=%0d, PC=%0h", $time, CACHE_ID, BANK_ID, head_ptr, enq_debug_wid, enq_debug_pc);
$write("%t: cache%0d:%0d mshr-table", $time, CACHE_ID, BANK_ID);
for (integer j = 0; j < MSHR_SIZE; j++) begin
if (valid_table[j]) begin
$write(" ");
if (schedule_ptr == $bits(schedule_ptr)'(j)) $write("*");
if (~ready_table[j]) $write("!");
$write("addr%0d=%0h", j, `LINE_TO_BYTE_ADDR(addr_table[j], BANK_ID));
end
end
$write("\n");
end
end
`endif
endmodule