From 3a02028a35b76ea3cbc9368e12edb54ff79d64ec Mon Sep 17 00:00:00 2001 From: Rimas Avizienis Date: Wed, 2 Nov 2011 13:32:32 -0700 Subject: [PATCH] fixes to exception and dcache miss/blocked handling --- rocket/src/main/scala/ctrl.scala | 62 ++++++++++-------------- rocket/src/main/scala/dpath.scala | 79 +++++++++++++++---------------- 2 files changed, 63 insertions(+), 78 deletions(-) diff --git a/rocket/src/main/scala/ctrl.scala b/rocket/src/main/scala/ctrl.scala index 4b1326b5..2b155dd8 100644 --- a/rocket/src/main/scala/ctrl.scala +++ b/rocket/src/main/scala/ctrl.scala @@ -56,8 +56,6 @@ class ioCtrlDpath extends Bundle() val wb_waddr = UFix(5,'input); // write addr from writeback stage val exception = Bool('input); val status = Bits(8, 'input); -// val sboard_set = Bool('input); -// val sboard_seta = UFix(5, 'input); val sboard_clr0 = Bool('input); val sboard_clr0a = UFix(5, 'input); val sboard_clr1 = Bool('input); @@ -214,9 +212,6 @@ class rocketCtrl extends Component sboard.io.raddra := id_raddr2.toUFix; sboard.io.raddrb := id_raddr1.toUFix; sboard.io.raddrc := id_waddr.toUFix; - -// sboard.io.set := io.dpath.sboard_set; -// sboard.io.seta := io.dpath.sboard_seta; // scoreboard set (for D$ misses, div, mul) sboard.io.set := wb_reg_div_mul_val | dcache_miss; @@ -298,21 +293,27 @@ class rocketCtrl extends Component io.dmem.req_type := ex_reg_mem_type; val mem_reg_div_mul_val = Reg(){Bool()}; + val mem_reg_eret = Reg(){Bool()}; val mem_reg_mem_val = Reg(){Bool()}; val mem_reg_mem_cmd = Reg(){UFix(width = 4)}; val mem_reg_mem_type = Reg(){UFix(width = 3)}; + val mem_reg_privileged = Reg(){Bool()}; when (reset.toBool || io.dpath.killx) { mem_reg_div_mul_val <== Bool(false); + mem_reg_eret <== Bool(false); mem_reg_mem_val <== Bool(false); mem_reg_mem_cmd <== UFix(0, 4); mem_reg_mem_type <== UFix(0, 3); + mem_reg_privileged <== Bool(false); } otherwise { mem_reg_div_mul_val <== ex_reg_div_mul_val; + mem_reg_eret <== ex_reg_eret; mem_reg_mem_val <== ex_reg_mem_val; mem_reg_mem_cmd <== ex_reg_mem_cmd; mem_reg_mem_type <== ex_reg_mem_type; + mem_reg_privileged <== ex_reg_privileged; } when (reset.toBool || io.dpath.killm) { @@ -327,8 +328,10 @@ class rocketCtrl extends Component // replay PC+4 on a D$ load miss val mem_cmd_load = mem_reg_mem_val && (mem_reg_mem_cmd === M_XRD); val replay_mem_pc_plus4 = mem_cmd_load && !io.dmem.resp_val; - val replay_mem = replay_mem_pc | replay_mem_pc_plus4; + val kill_ex = replay_mem_pc | replay_mem_pc_plus4 | mem_reg_privileged | io.dpath.exception; + val kill_mem = io.dpath.exception; + dcache_miss <== replay_mem_pc_plus4; io.dpath.mem_load := mem_cmd_load; @@ -336,10 +339,11 @@ class rocketCtrl extends Component io.dpath.sel_pc := Mux(replay_mem_pc, PC_MEM, - Mux(replay_mem_pc_plus4, PC_MEM4, - Mux(io.dpath.exception || ex_reg_eret, PC_PCR, + Mux(replay_mem_pc_plus4 || mem_reg_privileged, PC_MEM4, + Mux(io.dpath.exception || mem_reg_eret, PC_PCR, Mux(!ex_reg_btb_hit && br_taken, PC_BR, - Mux(ex_reg_btb_hit && !br_taken || ex_reg_privileged, PC_EX4, + Mux(ex_reg_btb_hit && !br_taken, PC_EX4, +// Mux(ex_reg_btb_hit && !br_taken || ex_reg_privileged, PC_EX4, Mux(jr_taken, PC_JR, Mux(j_taken, PC_J, Mux(io.dpath.btb_hit, PC_BTB, @@ -353,8 +357,8 @@ class rocketCtrl extends Component jr_taken | j_taken | io.dpath.exception | - ex_reg_privileged | - ex_reg_eret | + mem_reg_privileged | + mem_reg_eret | replay_mem_pc | replay_mem_pc_plus4; @@ -369,15 +373,10 @@ class rocketCtrl extends Component // check for loads in execute and mem stages to detect load/use hazards val ex_mem_cmd_load = ex_reg_mem_val && (ex_reg_mem_cmd === M_XRD); - val lu_stall_raddr1_ex = + val lu_stall_ex = ex_mem_cmd_load && - id_ren1.toBool && - (id_raddr1 === io.dpath.ex_waddr); - - val lu_stall_raddr2_ex = - ex_mem_cmd_load && - id_ren2.toBool && - (id_raddr2 === io.dpath.ex_waddr); + ((id_ren1.toBool && (id_raddr1 === io.dpath.ex_waddr)) || + (id_ren2.toBool && (id_raddr2 === io.dpath.ex_waddr))); val mem_mem_cmd_load_bh = mem_reg_mem_val && @@ -387,15 +386,12 @@ class rocketCtrl extends Component (mem_reg_mem_type === MT_H) || (mem_reg_mem_type === MT_HU)); - val lu_stall_raddr1_mem = + val lu_stall_mem = mem_mem_cmd_load_bh && - id_ren1.toBool && - (id_raddr1 === io.dpath.mem_waddr); + ((id_ren1.toBool && (id_raddr1 === io.dpath.mem_waddr)) || + (id_ren2.toBool && (id_raddr2 === io.dpath.mem_waddr))); - val lu_stall_raddr2_mem = - mem_mem_cmd_load_bh && - id_ren2.toBool && - (id_raddr2 === io.dpath.mem_waddr); + val lu_stall = lu_stall_ex || lu_stall_mem; // check for divide and multiply instructions in ex,mem,wb stages val dm_stall_ex = @@ -419,19 +415,13 @@ class rocketCtrl extends Component ~take_pc & ( dm_stall | - lu_stall_raddr1_ex | - lu_stall_raddr2_ex | - lu_stall_raddr1_mem | - lu_stall_raddr2_mem | + lu_stall | id_ren2 & id_stall_raddr2 | id_ren1 & id_stall_raddr1 | - (id_sel_wa === WA_RD) && id_stall_waddr | + (id_sel_wa === WA_RD) & id_stall_waddr | (id_sel_wa === WA_RA) & id_stall_ra | id_mem_val & ~io.dmem.req_rdy | id_sync & ~io.dmem.req_rdy | -// id_mem_val_masked & id_full_mrq | -// id_sync & (~id_empty_mrq | io.mem.dc_busy) | -// mem_xstore_val & ~io.mem.xsdq_rdy | id_console_out_val & ~io.console.rdy | id_div_val & ~io.dpath.div_rdy | io.dpath.div_result_val | @@ -448,8 +438,8 @@ class rocketCtrl extends Component io.dpath.killf := take_pc | ~io.imem.resp_val; io.dpath.killd := ctrl_killd.toBool; - io.dpath.killx := replay_mem.toBool; - io.dpath.killm := replay_mem.toBool; + io.dpath.killx := kill_ex.toBool; + io.dpath.killm := kill_mem.toBool; io.dpath.ren2 := id_ren2.toBool; io.dpath.ren1 := id_ren1.toBool; diff --git a/rocket/src/main/scala/dpath.scala b/rocket/src/main/scala/dpath.scala index d53a257a..6383c4ec 100644 --- a/rocket/src/main/scala/dpath.scala +++ b/rocket/src/main/scala/dpath.scala @@ -76,23 +76,28 @@ class rocketDpath extends Component val ex_wdata = Wire() { Bits() }; // memory definitions - val mem_reg_pc = Reg(resetVal = UFix(0,32)); - val mem_reg_pc_plus4 = Reg(resetVal = UFix(0,32)); - val mem_reg_waddr = Reg(resetVal = UFix(0,5)); - val mem_reg_wdata = Reg(resetVal = Bits(0,64)); - val mem_reg_raddr2 = Reg(resetVal = UFix(0,5)); - val mem_reg_ctrl_ll_wb = Reg(resetVal = Bool(false)); + val mem_reg_pc = Reg(resetVal = UFix(0,32)); + val mem_reg_pc_plus4 = Reg(resetVal = UFix(0,32)); + val mem_reg_waddr = Reg(resetVal = UFix(0,5)); + val mem_reg_wdata = Reg(resetVal = Bits(0,64)); + val mem_reg_raddr2 = Reg(resetVal = UFix(0,5)); + val mem_reg_pcr = Reg(resetVal = Bits(0,64)); + val mem_reg_ctrl_cause = Reg(resetVal = UFix(0,5)); + val mem_reg_ctrl_eret = Reg(resetVal = Bool(false)); + val mem_reg_ctrl_exception = Reg(resetVal = Bool(false)); + val mem_reg_ctrl_ll_wb = Reg(resetVal = Bool(false)); val mem_reg_ctrl_wen = Reg(resetVal = Bool(false)); val mem_reg_ctrl_wen_pcr = Reg(resetVal = Bool(false)); - val mem_reg_ctrl_exception = Reg(resetVal = Bool(false)); // writeback definitions val wb_reg_pc = Reg(resetVal = UFix(0,32)); - val wb_reg_pc_plus4 = Reg(resetVal = UFix(0,32)); val wb_reg_waddr = Reg(resetVal = UFix(0,5)); val wb_reg_wdata = Reg(resetVal = Bits(0,64)); val wb_reg_ctrl_ll_wb = Reg(resetVal = Bool(false)); val wb_reg_raddr2 = Reg(resetVal = UFix(0,5)); + val wb_reg_ctrl_cause = Reg(resetVal = UFix(0,5)); + val wb_reg_ctrl_eret = Reg(resetVal = Bool(false)); + val wb_reg_ctrl_exception = Reg(resetVal = Bool(false)); val wb_reg_ctrl_wen = Reg(resetVal = Bool(false)); val wb_reg_ctrl_wen_pcr = Reg(resetVal = Bool(false)); @@ -125,7 +130,7 @@ class rocketDpath extends Component Mux(io.ctrl.sel_pc === PC_BR, ex_branch_target, Mux(io.ctrl.sel_pc === PC_J, ex_branch_target, Mux(io.ctrl.sel_pc === PC_JR, ex_jr_target.toUFix, - Mux(io.ctrl.sel_pc === PC_PCR, ex_pcr(31,0).toUFix, + Mux(io.ctrl.sel_pc === PC_PCR, mem_reg_pcr(31,0).toUFix, Mux(io.ctrl.sel_pc === PC_MEM, mem_reg_pc, Mux(io.ctrl.sel_pc === PC_MEM4, mem_reg_pc_plus4, UFix(0, 32)))))))))); @@ -336,10 +341,10 @@ class rocketDpath extends Component pcr.io.host.from ^^ io.host.from; pcr.io.host.to ^^ io.host.to; - pcr.io.eret := ex_reg_ctrl_eret; - pcr.io.exception := ex_reg_ctrl_exception; - pcr.io.cause := ex_reg_ctrl_cause; - pcr.io.pc := ex_reg_pc; +// pcr.io.eret := ex_reg_ctrl_eret; +// pcr.io.exception := ex_reg_ctrl_exception; +// pcr.io.cause := ex_reg_ctrl_cause; +// pcr.io.pc := ex_reg_pc; io.ctrl.status := pcr.io.status; io.debug.error_mode := pcr.io.debug.error_mode; @@ -363,17 +368,21 @@ class rocketDpath extends Component // memory stage mem_reg_pc <== ex_reg_pc; mem_reg_pc_plus4 <== ex_reg_pc_plus4; + mem_reg_pcr <== ex_pcr; mem_reg_waddr <== ex_reg_waddr; mem_reg_wdata <== ex_wdata; mem_reg_ctrl_ll_wb <== ex_reg_ctrl_ll_wb; mem_reg_raddr2 <== ex_reg_raddr2; + mem_reg_ctrl_cause <== ex_reg_ctrl_cause; when (io.ctrl.killx) { + mem_reg_ctrl_eret <== Bool(false); mem_reg_ctrl_wen <== Bool(false); mem_reg_ctrl_wen_pcr <== Bool(false); mem_reg_ctrl_exception <== Bool(false); } otherwise { + mem_reg_ctrl_eret <== ex_reg_ctrl_eret; mem_reg_ctrl_wen <== ex_reg_ctrl_wen; mem_reg_ctrl_wen_pcr <== ex_reg_ctrl_wen_pcr; mem_reg_ctrl_exception <== ex_reg_ctrl_exception; @@ -384,14 +393,7 @@ class rocketDpath extends Component // for load/use hazard detection (load byte/halfword) io.ctrl.mem_waddr := mem_reg_waddr; - // moved to earlier in file -// val mem_dmem_resp_data_w = -// Mux(io.dmem.resp_pos(2).toBool, io.dmem.resp_data(63, 32), io.dmem.resp_data(31, 0)); -// -// val mem_dmem_resp_data = -// Mux(io.dmem.resp_type === MT_D, io.dmem.resp_data, -// Mux(io.dmem.resp_type === MT_W, Cat(Fill(32, mem_dmem_resp_data_w(31)), mem_dmem_resp_data_w)), -// Cat(UFix(0,32), mem_dmem_resp_data_w)); + // 32/64 bit load handling (moved to earlier in file) // writeback stage r_dmem_resp_val <== io.dmem.resp_val; @@ -400,12 +402,14 @@ class rocketDpath extends Component r_dmem_resp_type <== dmem_resp_type; r_dmem_resp_data <== mem_dmem_resp_data; - wb_reg_pc <== mem_reg_pc; - wb_reg_pc_plus4 <== mem_reg_pc_plus4; - wb_reg_waddr <== mem_reg_waddr; - wb_reg_wdata <== mem_reg_wdata; - wb_reg_ctrl_ll_wb <== mem_reg_ctrl_ll_wb; - wb_reg_raddr2 <== mem_reg_raddr2; + wb_reg_pc <== mem_reg_pc; + wb_reg_waddr <== mem_reg_waddr; + wb_reg_wdata <== mem_reg_wdata; + wb_reg_ctrl_ll_wb <== mem_reg_ctrl_ll_wb; + wb_reg_raddr2 <== mem_reg_raddr2; + wb_reg_ctrl_cause <== mem_reg_ctrl_cause; + wb_reg_ctrl_eret <== mem_reg_ctrl_eret; + wb_reg_ctrl_exception <== mem_reg_ctrl_exception; when (io.ctrl.killm) { wb_reg_ctrl_wen <== Bool(false); @@ -416,21 +420,7 @@ class rocketDpath extends Component wb_reg_ctrl_wen_pcr <== mem_reg_ctrl_wen_pcr; } - // crossbar/sign extension for 8/16 bit loads -// val dmem_resp_data_h = -// Mux(r_dmem_resp_pos(1).toBool, r_dmem_resp_data(31, 16), r_dmem_resp_data(15, 0)); -// val dmem_resp_data_b = -// Mux(r_dmem_resp_pos(0).toBool, dmem_resp_data_h(15, 8), dmem_resp_data_h(7, 0)); -// -// val dmem_resp_data_final = -// Mux(r_dmem_resp_type === MT_B, Cat(Fill(56, dmem_resp_data_b(7)), dmem_resp_data_b), -// Mux(r_dmem_resp_type === MT_BU, Cat(UFix(0, 56), dmem_resp_data_b), -// Mux(r_dmem_resp_type === MT_H, Cat(Fill(48, dmem_resp_data_h(15)), dmem_resp_data_h), -// Mux(r_dmem_resp_type === MT_HU, Cat(UFix(0, 48), dmem_resp_data_h), -// Mux((r_dmem_resp_type === MT_W) || -// (r_dmem_resp_type === MT_WU) || -// (r_dmem_resp_type === MT_D), r_dmem_resp_data, -// UFix(0,64)))))); + // crossbar/sign extension for 8/16 bit loads (moved to earlier in file) // regfile write rfile.io.w0.addr := wb_reg_waddr; @@ -454,6 +444,11 @@ class rocketDpath extends Component pcr.io.w.en := wb_reg_ctrl_wen_pcr; pcr.io.w.data := wb_reg_wdata; + pcr.io.eret := wb_reg_ctrl_eret; + pcr.io.exception := wb_reg_ctrl_exception; + pcr.io.cause := wb_reg_ctrl_cause; + pcr.io.pc := wb_reg_pc; + } }