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kernels/hw/rtl/core/VX_csr_unit.sv
2023-12-28 12:12:11 -08:00

180 lines
6.1 KiB
Systemverilog

// Copyright © 2019-2023
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
`include "VX_define.vh"
module VX_csr_unit import VX_gpu_pkg::*; #(
parameter CORE_ID = 0,
parameter NUM_LANES = 1
) (
input wire clk,
input wire reset,
input base_dcrs_t base_dcrs,
`ifdef PERF_ENABLE
VX_mem_perf_if.slave mem_perf_if,
VX_pipeline_perf_if.slave pipeline_perf_if,
`endif
`ifdef EXT_F_ENABLE
VX_fpu_to_csr_if.slave fpu_to_csr_if [`NUM_FPU_BLOCKS],
`endif
VX_commit_csr_if.slave commit_csr_if,
VX_sched_csr_if.slave sched_csr_if,
VX_execute_if.slave execute_if,
VX_commit_if.master commit_if
);
`UNUSED_PARAM (CORE_ID)
localparam PID_BITS = `CLOG2(`NUM_THREADS / NUM_LANES);
localparam PID_WIDTH = `UP(PID_BITS);
localparam DATAW = `UUID_WIDTH + `NW_WIDTH + NUM_LANES + `XLEN + `NR_BITS + 1 + NUM_LANES * 32 + PID_WIDTH + 1 + 1;
`UNUSED_VAR (execute_if.data.rs3_data)
reg [NUM_LANES-1:0][31:0] csr_read_data;
reg [31:0] csr_write_data;
wire [31:0] csr_read_data_ro, csr_read_data_rw;
wire [31:0] csr_req_data;
reg csr_rd_enable;
wire csr_wr_enable;
wire csr_req_ready;
// wait for all pending instructions to complete
assign sched_csr_if.alm_empty_wid = execute_if.data.wid;
wire no_pending_instr = sched_csr_if.alm_empty;
wire csr_req_valid = execute_if.valid && no_pending_instr;
assign execute_if.ready = csr_req_ready && no_pending_instr;
wire [`VX_CSR_ADDR_BITS-1:0] csr_addr = execute_if.data.imm[`VX_CSR_ADDR_BITS-1:0];
wire [`NRI_BITS-1:0] csr_imm = execute_if.data.imm[`VX_CSR_ADDR_BITS +: `NRI_BITS];
wire [NUM_LANES-1:0][31:0] rs1_data;
`UNUSED_VAR (rs1_data)
for (genvar i = 0; i < NUM_LANES; ++i) begin
assign rs1_data[i] = execute_if.data.rs1_data[i][31:0];
end
wire csr_write_enable = (execute_if.data.op_type == `INST_SFU_CSRRW);
VX_csr_data #(
.CORE_ID (CORE_ID)
) csr_data (
.clk (clk),
.reset (reset),
.base_dcrs (base_dcrs),
`ifdef PERF_ENABLE
.mem_perf_if (mem_perf_if),
.pipeline_perf_if(pipeline_perf_if),
`endif
.commit_csr_if (commit_csr_if),
.cycles (sched_csr_if.cycles),
.active_warps (sched_csr_if.active_warps),
.thread_masks (sched_csr_if.thread_masks),
`ifdef EXT_F_ENABLE
.fpu_to_csr_if (fpu_to_csr_if),
`endif
.read_enable (csr_req_valid && csr_rd_enable),
.read_uuid (execute_if.data.uuid),
.read_wid (execute_if.data.wid),
.read_addr (csr_addr),
.read_data_ro (csr_read_data_ro),
.read_data_rw (csr_read_data_rw),
.write_enable (csr_req_valid && csr_wr_enable),
.write_uuid (execute_if.data.uuid),
.write_wid (execute_if.data.wid),
.write_addr (csr_addr),
.write_data (csr_write_data)
);
// CSR read
wire [NUM_LANES-1:0][31:0] wtid, gtid;
for (genvar i = 0; i < NUM_LANES; ++i) begin
if (PID_BITS != 0) begin
assign wtid[i] = 32'(execute_if.data.pid * NUM_LANES + i);
end else begin
assign wtid[i] = 32'(i);
end
assign gtid[i] = (32'(CORE_ID) << (`NW_BITS + `NT_BITS)) + (32'(execute_if.data.wid) << `NT_BITS) + wtid[i];
end
always @(*) begin
csr_rd_enable = 0;
case (csr_addr)
`VX_CSR_THREAD_ID : csr_read_data = wtid;
`VX_CSR_MHARTID : csr_read_data = gtid;
default : begin
csr_read_data = {NUM_LANES{csr_read_data_ro | csr_read_data_rw}};
csr_rd_enable = 1;
end
endcase
end
// CSR write
assign csr_req_data = execute_if.data.use_imm ? 32'(csr_imm) : rs1_data[0];
assign csr_wr_enable = (csr_write_enable || (| csr_req_data));
always @(*) begin
case (execute_if.data.op_type)
`INST_SFU_CSRRW: begin
csr_write_data = csr_req_data;
end
`INST_SFU_CSRRS: begin
csr_write_data = csr_read_data_rw | csr_req_data;
end
//`INST_SFU_CSRRC
default: begin
csr_write_data = csr_read_data_rw & ~csr_req_data;
end
endcase
end
// unlock the warp
assign sched_csr_if.unlock_warp = csr_req_valid && csr_req_ready && execute_if.data.eop;
assign sched_csr_if.unlock_wid = execute_if.data.wid;
// send response
wire [NUM_LANES-1:0][31:0] csr_commit_data;
VX_elastic_buffer #(
.DATAW (DATAW),
.SIZE (2)
) rsp_buf (
.clk (clk),
.reset (reset),
.valid_in (csr_req_valid),
.ready_in (csr_req_ready),
.data_in ({execute_if.data.uuid, execute_if.data.wid, execute_if.data.tmask, execute_if.data.PC, execute_if.data.rd, execute_if.data.wb, csr_read_data, execute_if.data.pid, execute_if.data.sop, execute_if.data.eop}),
.data_out ({commit_if.data.uuid, commit_if.data.wid, commit_if.data.tmask, commit_if.data.PC, commit_if.data.rd, commit_if.data.wb, csr_commit_data, commit_if.data.pid, commit_if.data.sop, commit_if.data.eop}),
.valid_out (commit_if.valid),
.ready_out (commit_if.ready)
);
for (genvar i = 0; i < NUM_LANES; ++i) begin
assign commit_if.data.data[i] = `XLEN'(csr_commit_data[i]);
end
endmodule