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RVFI - Better minstret csr sampling
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Yoann Pruvost committed Jan 5, 2024
1 parent 17b972f commit a5061c7
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Showing 2 changed files with 13 additions and 31 deletions.
40 changes: 9 additions & 31 deletions bhv/cv32e40p_rvfi.sv
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1272,7 +1272,6 @@ insn_trace_t trace_if, trace_id, trace_ex, trace_ex_next, trace_wb;
bit s_id_done;
function void if_to_id();
if (trace_id.m_valid) begin
minstret_to_id();
`CSR_FROM_PIPE(id, misa)
`CSR_FROM_PIPE(id, tdata1)
`CSR_FROM_PIPE(id, tdata2)
Expand All @@ -1287,7 +1286,6 @@ insn_trace_t trace_if, trace_id, trace_ex, trace_ex_next, trace_wb;
s_is_irq_start = 1'b0;
trace_if.m_valid = 1'b0;
s_id_done = 1'b0;
// `CSR_FROM_PIPE(id, dpc)
endfunction

function logic [31:0] be_to_mask(logic [3:0] be);
Expand Down Expand Up @@ -1369,8 +1367,6 @@ insn_trace_t trace_if, trace_id, trace_ex, trace_ex_next, trace_wb;

if (r_pipe_freeze_trace.ctrl_fsm_cs == DBG_TAKEN_ID && r_pipe_freeze_trace.ebrk_insn_dec) begin
if (trace_id.m_valid) begin

minstret_to_id();
`CSR_FROM_PIPE(id, misa)
`CSR_FROM_PIPE(id, tdata1)
`CSR_FROM_PIPE(id, tdata2)
Expand Down Expand Up @@ -1484,10 +1480,11 @@ insn_trace_t trace_if, trace_id, trace_ex, trace_ex_next, trace_wb;
end

if (trace_ex.m_valid) begin

if (!trace_ex.m_csr.got_minstret) begin
if(trace_ex.m_instret_smaple_trigger == 1) begin //time to sample instret
minstret_to_ex();
end
trace_ex.m_instret_smaple_trigger = trace_ex.m_instret_smaple_trigger + 1;

`CSR_FROM_PIPE(ex, misa)
`CSR_FROM_PIPE(ex, tdata1)
`CSR_FROM_PIPE(ex, tdata2)
Expand All @@ -1514,9 +1511,6 @@ insn_trace_t trace_if, trace_id, trace_ex, trace_ex_next, trace_wb;
trace_ex.m_valid = 1'b0;
->e_send_rvfi_trace_ex_2;
end else begin
if (!s_ex_valid_adjusted & !trace_ex.m_csr.got_minstret) begin
minstret_to_ex();
end

if (s_rf_we_wb_adjusted) begin
->e_dev_commit_rf_to_ex_1;
Expand Down Expand Up @@ -1551,9 +1545,6 @@ insn_trace_t trace_if, trace_id, trace_ex, trace_ex_next, trace_wb;
->e_ex_to_wb_1;
trace_wb.move_down_pipe(trace_ex);
end else begin
if (!trace_ex.m_csr.got_minstret) begin
minstret_to_ex();
end
send_rvfi(trace_ex);
->e_send_rvfi_trace_ex_6;
end
Expand All @@ -1578,18 +1569,13 @@ insn_trace_t trace_if, trace_id, trace_ex, trace_ex_next, trace_wb;
// If mret, we need to keep the instruction in Id during flush_ex because mstatus update happens at that time
s_ex_valid_adjusted = (r_pipe_freeze_trace.ex_valid && r_pipe_freeze_trace.ex_ready) && (s_core_is_decoding || (r_pipe_freeze_trace.ctrl_fsm_cs == DBG_TAKEN_IF) || (r_pipe_freeze_trace.ctrl_fsm_cs == DBG_TAKEN_ID) || (r_pipe_freeze_trace.ctrl_fsm_cs == DBG_FLUSH) || ((r_pipe_freeze_trace.ctrl_fsm_cs == FLUSH_EX) && !r_pipe_freeze_trace.mret_insn_dec));
//EX_STAGE
// if(trace_id.m_valid && r_pipe_freeze_trace.ctrl_fsm_cs == XRET_JUMP) begin //xret done, we send it to rvfi
// `CSR_FROM_PIPE(id, mip)
// `CSR_FROM_PIPE(id, misa)
// `CSR_FROM_PIPE(id, mstatus)
// `CSR_FROM_PIPE(id, mstatus_fs)
// tinfo_to_id();

// send_rvfi(trace_id);
// trace_id.m_valid = 1'b0;
// end

if (trace_id.m_valid) begin
if(trace_id.m_instret_smaple_trigger == 1) begin //time to sample instret
minstret_to_id();
end
trace_id.m_instret_smaple_trigger = trace_id.m_instret_smaple_trigger + 1;

if(trace_id.m_sample_csr_write_in_ex && !csr_is_irq && !s_is_irq_start) begin //First cycle after id_ready, csr write is asserted in this cycle
`CSR_FROM_PIPE(id, mstatus)
`CSR_FROM_PIPE(id, mstatus_fs)
Expand Down Expand Up @@ -1617,10 +1603,6 @@ insn_trace_t trace_if, trace_id, trace_ex, trace_ex_next, trace_wb;
`CSR_FROM_PIPE(id, frm)
`CSR_FROM_PIPE(id, fcsr)

// if (r_pipe_freeze_trace.csr.we) begin
// `CSR_FROM_PIPE(id, dpc)
// end

if (r_pipe_freeze_trace.csr.dcsr_we) begin
dcsr_to_id();
end
Expand All @@ -1641,9 +1623,8 @@ insn_trace_t trace_if, trace_id, trace_ex, trace_ex_next, trace_wb;
trace_ex.m_csr.frm_wmask = '0;
trace_ex.m_csr.fcsr_wmask = '0;

if(r_pipe_freeze_trace.ctrl_fsm_cs == XRET_JUMP) begin
if(r_pipe_freeze_trace.ctrl_fsm_cs == XRET_JUMP) begin //xret exit pipeline
tinfo_to_id();
minstret_to_id();
`CSR_FROM_PIPE(id, tdata1)
`CSR_FROM_PIPE(id, tdata2)
send_rvfi(trace_id);
Expand Down Expand Up @@ -1737,9 +1718,6 @@ insn_trace_t trace_if, trace_id, trace_ex, trace_ex_next, trace_wb;
if (s_new_valid_insn) begin // There is a new valid instruction
if (trace_id.m_valid) begin
if (trace_ex.m_valid) begin
if (!trace_ex.m_csr.got_minstret) begin
minstret_to_ex();
end
if (trace_wb.m_valid) begin
send_rvfi(trace_ex);
->e_send_rvfi_trace_ex_4;
Expand Down
4 changes: 4 additions & 0 deletions bhv/insn_trace.sv
View file
Original file line number Diff line number Diff line change
Expand Up @@ -65,6 +65,7 @@
bit m_move_down_pipe;

int m_instret_cnt;
int m_instret_smaple_trigger; //We need to sample minstret from csr 2 cycle after id is doen

bit m_sample_csr_write_in_ex;

Expand Down Expand Up @@ -173,6 +174,7 @@
this.m_frm_we_non_apu = 1'b0;
this.m_fcsr_we_non_apu = 1'b0;
this.m_instret_cnt = 0;
this.m_instret_smaple_trigger = 0;
this.m_sample_csr_write_in_ex = 1'b1;
endfunction

Expand Down Expand Up @@ -896,6 +898,7 @@
this.m_got_regs_write = 1'b0;
this.m_move_down_pipe = 1'b0;
this.m_instret_cnt = 0;
this.m_instret_smaple_trigger = 0;
this.m_sample_csr_write_in_ex = 1'b1;
this.m_rd_addr[0] = '0;
this.m_rd_addr[1] = '0;
Expand Down Expand Up @@ -970,6 +973,7 @@
this.m_is_illegal = m_source.m_is_illegal;
this.m_is_irq = m_source.m_is_irq;
this.m_instret_cnt = m_source.m_instret_cnt;
this.m_instret_smaple_trigger = m_source.m_instret_smaple_trigger;
this.m_sample_csr_write_in_ex = m_source.m_sample_csr_write_in_ex;
this.m_rs1_addr = m_source.m_rs1_addr;
this.m_rs2_addr = m_source.m_rs2_addr;
Expand Down

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