Files
vortex/hw/rtl/VX_lsu_unit.v
2021-05-23 10:57:58 -07:00

323 lines
12 KiB
Verilog

`include "VX_define.vh"
module VX_lsu_unit #(
parameter CORE_ID = 0
) (
`SCOPE_IO_VX_lsu_unit
input wire clk,
input wire reset,
// Dcache interface
VX_dcache_core_req_if dcache_req_if,
VX_dcache_core_rsp_if dcache_rsp_if,
// inputs
VX_lsu_req_if lsu_req_if,
// outputs
VX_commit_if ld_commit_if,
VX_commit_if st_commit_if
);
`UNUSED_PARAM (CORE_ID)
wire req_valid;
wire [`NUM_THREADS-1:0] req_tmask;
wire [`NUM_THREADS-1:0][31:0] req_addr;
wire [`LSU_BITS-1:0] req_type;
wire [`NUM_THREADS-1:0][31:0] req_data;
wire [`NR_BITS-1:0] req_rd;
wire req_wb;
wire [`NW_BITS-1:0] req_wid;
wire [31:0] req_pc;
wire req_is_dup;
wire [`NUM_THREADS-1:0][31:0] full_address;
for (genvar i = 0; i < `NUM_THREADS; i++) begin
assign full_address[i] = lsu_req_if.base_addr[i] + lsu_req_if.offset;
end
wire [`NUM_THREADS-1:0] addr_matches;
for (genvar i = 0; i < `NUM_THREADS; i++) begin
assign addr_matches[i] = (full_address[0][31:2] == full_address[i][31:2]) || ~lsu_req_if.tmask[i];
end
wire is_dup_load = lsu_req_if.wb && lsu_req_if.tmask[0] && (& addr_matches);
wire ready_in;
wire stall_in = ~ready_in && req_valid;
VX_pipe_register #(
.DATAW (1 + 1 + `NW_BITS + `NUM_THREADS + 32 + (`NUM_THREADS * 32) + `LSU_BITS + `NR_BITS + 1 + (`NUM_THREADS * 32)),
.RESETW (1)
) req_pipe_reg (
.clk (clk),
.reset (reset),
.enable (!stall_in),
.data_in ({lsu_req_if.valid, is_dup_load, lsu_req_if.wid, lsu_req_if.tmask, lsu_req_if.PC, full_address, lsu_req_if.op_type, lsu_req_if.rd, lsu_req_if.wb, lsu_req_if.store_data}),
.data_out ({req_valid, req_is_dup, req_wid, req_tmask, req_pc, req_addr, req_type, req_rd, req_wb, req_data})
);
// Can accept new request?
assign lsu_req_if.ready = ~stall_in;
wire [`NW_BITS-1:0] rsp_wid;
wire [31:0] rsp_pc;
wire [`NR_BITS-1:0] rsp_rd;
wire rsp_wb;
wire [`LSU_BITS-1:0] rsp_type;
wire rsp_is_dup;
`UNUSED_VAR (rsp_type)
reg [`LSUQ_SIZE-1:0][`NUM_THREADS-1:0] rsp_rem_mask;
wire [`NUM_THREADS-1:0] rsp_rem_mask_n;
wire [`NUM_THREADS-1:0] rsp_tmask;
reg [`NUM_THREADS-1:0] req_sent_mask;
wire req_ready_all;
wire [`DCORE_TAG_ID_BITS-1:0] mbuf_waddr, mbuf_raddr;
wire mbuf_full;
wire [`NUM_THREADS-1:0][1:0] req_offset, rsp_offset;
for (genvar i = 0; i < `NUM_THREADS; i++) begin
assign req_offset[i] = req_addr[i][1:0];
end
wire [`NUM_THREADS-1:0] dcache_req_fire = dcache_req_if.valid & dcache_req_if.ready;
wire dcache_rsp_fire = (| dcache_rsp_if.valid) && dcache_rsp_if.ready;
wire mbuf_push = (| dcache_req_fire)
&& (0 == req_sent_mask) // first submission only
&& req_wb; // loads only
wire mbuf_pop = dcache_rsp_fire && (0 == rsp_rem_mask_n);
assign mbuf_raddr = dcache_rsp_if.tag[`DCORE_TAG_ID_BITS-1:0];
VX_index_buffer #(
.DATAW (`NW_BITS + 32 + `NUM_THREADS + `NR_BITS + 1 + `LSU_BITS + (`NUM_THREADS * 2) + 1),
.SIZE (`LSUQ_SIZE)
) req_metadata (
.clk (clk),
.reset (reset),
.write_addr (mbuf_waddr),
.acquire_slot (mbuf_push),
.read_addr (mbuf_raddr),
.write_data ({req_wid, req_pc, req_tmask, req_rd, req_wb, req_type, req_offset, req_is_dup}),
.read_data ({rsp_wid, rsp_pc, rsp_tmask, rsp_rd, rsp_wb, rsp_type, rsp_offset, rsp_is_dup}),
.release_addr (mbuf_raddr),
.release_slot (mbuf_pop),
.full (mbuf_full),
`UNUSED_PIN (empty)
);
assign req_ready_all = &(dcache_req_if.ready | req_sent_mask | ~req_tmask);
wire [`NUM_THREADS-1:0] req_sent_dup = {{(`NUM_THREADS-1){dcache_req_fire[0] && req_is_dup}}, 1'b0};
always @(posedge clk) begin
if (reset) begin
req_sent_mask <= 0;
end else begin
if (req_ready_all)
req_sent_mask <= 0;
else
req_sent_mask <= req_sent_mask | dcache_req_fire | req_sent_dup;
end
end
wire is_req_start = (0 == req_sent_mask);
// need to hold the acquired tag index until the full request is submitted
reg [`DCORE_TAG_ID_BITS-1:0] req_tag_hold;
wire [`DCORE_TAG_ID_BITS-1:0] req_tag = is_req_start ? mbuf_waddr : req_tag_hold;
always @(posedge clk) begin
if (mbuf_push) begin
req_tag_hold <= mbuf_waddr;
end
end
wire [`NUM_THREADS-1:0] req_tmask_dup = req_tmask & {{(`NUM_THREADS-1){~req_is_dup}}, 1'b1};
assign rsp_rem_mask_n = rsp_rem_mask[mbuf_raddr] & ~dcache_rsp_if.valid;
always @(posedge clk) begin
if (mbuf_push) begin
rsp_rem_mask[mbuf_waddr] <= req_tmask_dup;
end
if (dcache_rsp_fire) begin
rsp_rem_mask[mbuf_raddr] <= rsp_rem_mask_n;
end
end
// ensure all dependencies for the requests are resolved
wire req_dep_ready = (req_wb && (~mbuf_full || ~is_req_start))
|| (~req_wb && st_commit_if.ready);
// DCache Request
reg [`NUM_THREADS-1:0][29:0] mem_req_addr;
reg [`NUM_THREADS-1:0][3:0] mem_req_byteen;
reg [`NUM_THREADS-1:0][31:0] mem_req_data;
always @(*) begin
for (integer i = 0; i < `NUM_THREADS; i++) begin
mem_req_byteen[i] = {4{req_wb}};
case (`LSU_WSIZE(req_type))
0: mem_req_byteen[i][req_offset[i]] = 1;
1: begin
mem_req_byteen[i][req_offset[i]] = 1;
mem_req_byteen[i][{req_addr[i][1], 1'b1}] = 1;
end
default : mem_req_byteen[i] = {4{1'b1}};
endcase
mem_req_data[i] = 'x;
case (req_offset[i])
1: mem_req_data[i][31:8] = req_data[i][23:0];
2: mem_req_data[i][31:16] = req_data[i][15:0];
3: mem_req_data[i][31:24] = req_data[i][7:0];
default: mem_req_data[i] = req_data[i];
endcase
mem_req_addr[i] = req_addr[i][31:2];
end
end
assign dcache_req_if.valid = {`NUM_THREADS{req_valid && req_dep_ready}} & req_tmask_dup & ~req_sent_mask;
assign dcache_req_if.rw = {`NUM_THREADS{~req_wb}};
assign dcache_req_if.addr = mem_req_addr;
assign dcache_req_if.byteen = mem_req_byteen;
assign dcache_req_if.data = mem_req_data;
`ifdef DBG_CACHE_REQ_INFO
assign dcache_req_if.tag = {`NUM_THREADS{req_pc, req_wid, req_tag}};
`else
assign dcache_req_if.tag = {`NUM_THREADS{req_tag}};
`endif
assign ready_in = req_dep_ready && req_ready_all;
// send store commit
wire is_store_rsp = req_valid && ~req_wb && req_ready_all;
assign st_commit_if.valid = is_store_rsp;
assign st_commit_if.wid = req_wid;
assign st_commit_if.tmask = req_tmask;
assign st_commit_if.PC = req_pc;
assign st_commit_if.rd = 0;
assign st_commit_if.wb = 0;
assign st_commit_if.eop = 1'b1;
assign st_commit_if.data = 0;
// load response formatting
reg [`NUM_THREADS-1:0][31:0] rsp_data;
wire [`NUM_THREADS-1:0] rsp_tmask_qual;
for (genvar i = 0; i < `NUM_THREADS; i++) begin
wire [31:0] src_data = (i == 0 || rsp_is_dup) ? dcache_rsp_if.data[0] : dcache_rsp_if.data[i];
reg [31:0] rsp_data_shifted;
always @(*) begin
rsp_data_shifted[31:16] = src_data[31:16];
rsp_data_shifted[15:0] = rsp_offset[i][1] ? src_data[31:16] : src_data[15:0];
rsp_data_shifted[7:0] = rsp_offset[i][0] ? rsp_data_shifted[15:8] : rsp_data_shifted[7:0];
end
always @(*) begin
case (`LSU_FMT(rsp_type))
`FMT_B: rsp_data[i] = 32'(signed'(rsp_data_shifted[7:0]));
`FMT_H: rsp_data[i] = 32'(signed'(rsp_data_shifted[15:0]));
`FMT_BU: rsp_data[i] = 32'(unsigned'(rsp_data_shifted[7:0]));
`FMT_HU: rsp_data[i] = 32'(unsigned'(rsp_data_shifted[15:0]));
default: rsp_data[i] = rsp_data_shifted;
endcase
end
end
assign rsp_tmask_qual = rsp_is_dup ? rsp_tmask : dcache_rsp_if.valid;
// send load commit
wire load_rsp_stall = ~ld_commit_if.ready && ld_commit_if.valid;
VX_pipe_register #(
.DATAW (1 + `NW_BITS + `NUM_THREADS + 32 + `NR_BITS + 1 + (`NUM_THREADS * 32) + 1),
.RESETW (1)
) rsp_pipe_reg (
.clk (clk),
.reset (reset),
.enable (!load_rsp_stall),
.data_in ({(| dcache_rsp_if.valid), rsp_wid, rsp_tmask_qual, rsp_pc, rsp_rd, rsp_wb, rsp_data, mbuf_pop}),
.data_out ({ld_commit_if.valid, ld_commit_if.wid, ld_commit_if.tmask, ld_commit_if.PC, ld_commit_if.rd, ld_commit_if.wb, ld_commit_if.data, ld_commit_if.eop})
);
// Can accept new cache response?
assign dcache_rsp_if.ready = ~load_rsp_stall;
// scope registration
`SCOPE_ASSIGN (dcache_req_fire, dcache_req_fire);
`SCOPE_ASSIGN (dcache_req_wid, req_wid);
`SCOPE_ASSIGN (dcache_req_pc, req_pc);
`SCOPE_ASSIGN (dcache_req_addr, req_addr);
`SCOPE_ASSIGN (dcache_req_rw, ~req_wb);
`SCOPE_ASSIGN (dcache_req_byteen,dcache_req_if.byteen);
`SCOPE_ASSIGN (dcache_req_data, dcache_req_if.data);
`SCOPE_ASSIGN (dcache_req_tag, req_tag);
`SCOPE_ASSIGN (dcache_rsp_fire, dcache_rsp_if.valid & {`NUM_THREADS{dcache_rsp_if.ready}});
`SCOPE_ASSIGN (dcache_rsp_data, dcache_rsp_if.data);
`SCOPE_ASSIGN (dcache_rsp_tag, mbuf_raddr);
`ifdef DBG_PRINT_CORE_DCACHE
`IGNORE_WARNINGS_BEGIN
reg [`LSUQ_SIZE-1:0][`DCORE_TAG_WIDTH:0] pending_reqs;
`IGNORE_WARNINGS_END
always @(posedge clk) begin
if (reset) begin
pending_reqs <= '0;
end else if (mbuf_push) begin
pending_reqs[mbuf_waddr] <= {dcache_req_if.tag[0], 1'b1};
end else if (mbuf_pop) begin
pending_reqs[mbuf_raddr] <= '0;
end
end
always @(posedge clk) begin
if ((| dcache_req_fire)) begin
if (dcache_req_if.rw[0]) begin
$write("%t: D$%0d Wr Req: wid=%0d, PC=%0h, tmask=%b, addr=", $time, CORE_ID, req_wid, req_pc, dcache_req_fire);
`PRINT_ARRAY1D(req_addr, `NUM_THREADS);
$write(", tag=%0h, byteen=%0h, data=", dcache_req_if.tag[0], dcache_req_if.byteen);
`PRINT_ARRAY1D(dcache_req_if.data, `NUM_THREADS);
$write("\n");
end else begin
$write("%t: D$%0d Rd Req: wid=%0d, PC=%0h, tmask=%b, addr=", $time, CORE_ID, req_wid, req_pc, dcache_req_fire);
`PRINT_ARRAY1D(req_addr, `NUM_THREADS);
$write(", tag=%0h, byteen=%0h, rd=%0d, is_dup=%b\n", dcache_req_if.tag[0], dcache_req_if.byteen, req_rd, req_is_dup);
end
end
if (dcache_rsp_fire) begin
$write("%t: D$%0d Rsp: valid=%b, wid=%0d, PC=%0h, tag=%0h, rd=%0d, data=",
$time, CORE_ID, dcache_rsp_if.valid, rsp_wid, rsp_pc, dcache_rsp_if.tag, rsp_rd);
`PRINT_ARRAY1D(dcache_rsp_if.data, `NUM_THREADS);
$write(", is_dup=%b\n", rsp_is_dup);
end
if (mbuf_full) begin
$write("%t: *** D$%0d queue-full:", $time, CORE_ID);
for (integer j = 0; j < `LSUQ_SIZE; j++) begin
if (pending_reqs[j][0]) begin
$write(" %0d->%0h", j, pending_reqs[j][1 +: `DCORE_TAG_WIDTH]);
end
end
$write("\n");
end
end
`endif
endmodule