move datapath control signals into control unit

because that's where control signals go

rocket/src/main/scala/ctrl.scala

@@ -41,6 +41,7 @@ class ioCtrlDpath extends Bundle()
   val ex_wen   = Bool(OUTPUT);
   val mem_wen  = Bool(OUTPUT);
   val wb_wen   = Bool(OUTPUT);
+  val wb_valid = Bool(OUTPUT)
   val flush_inst = Bool(OUTPUT);
   val ex_mem_type = UFix(3,OUTPUT)
   // enable/disable interrupts
@@ -70,7 +71,6 @@ class ioCtrlDpath extends Bundle()
   val sboard_clra = UFix(5, INPUT);
   val fp_sboard_clr  = Bool(INPUT);
   val fp_sboard_clra = UFix(5, INPUT);
-  val mem_valid = Bool(INPUT); // high if there's a valid (not flushed) instruction in mem stage
   val irq_timer = Bool(INPUT);
   val irq_ipi   = Bool(INPUT);
 }
@@ -300,6 +300,7 @@ class rocketCtrl extends Component
   val wb_reg_div_mul_val = Reg(resetVal = Bool(false))
   val wb_reg_dcache_miss = Reg(io.dmem.resp_miss, resetVal = Bool(false));
 
+  val id_reg_valid        = Reg(resetVal = Bool(false));
   val id_reg_btb_hit      = Reg(resetVal = Bool(false));
   val id_reg_xcpt_itlb    = Reg(resetVal = Bool(false));
   val id_reg_xcpt_ma_inst = Reg(resetVal = Bool(false));
@@ -314,6 +315,8 @@ class rocketCtrl extends Component
   val ex_reg_mem_val     = Reg(){Bool()};
   val ex_reg_mem_cmd     = Reg(){UFix(width = 4)};
   val ex_reg_mem_type    = Reg(){UFix(width = 3)};
+  val ex_reg_valid       = Reg(resetVal = Bool(false));
+  val ex_reg_wen_pcr     = Reg(resetVal = Bool(false));
   val ex_reg_wen         = Reg(resetVal = Bool(false));
   val ex_reg_fp_wen      = Reg(resetVal = Bool(false));
   val ex_reg_eret        = Reg(resetVal = Bool(false));
@@ -333,6 +336,8 @@ class rocketCtrl extends Component
   val ex_reg_load_use        = Reg(resetVal = Bool(false));
   val ex_reg_ext_mem_val     = Reg(resetVal = Bool(false))
 
+  val mem_reg_valid           = Reg(resetVal = Bool(false));
+  val mem_reg_wen_pcr         = Reg(resetVal = Bool(false));
   val mem_reg_wen             = Reg(resetVal = Bool(false));
   val mem_reg_fp_wen          = Reg(resetVal = Bool(false));
   val mem_reg_replay_next     = Reg(resetVal = Bool(false));
@@ -352,6 +357,8 @@ class rocketCtrl extends Component
   val mem_reg_ext_mem_val     = Reg(resetVal = Bool(false))
   val mem_reg_fp_sboard_set   = Reg(resetVal = Bool(false));
 
+  val wb_reg_valid           = Reg(resetVal = Bool(false));
+  val wb_reg_wen_pcr         = Reg(resetVal = Bool(false));
   val wb_reg_wen             = Reg(resetVal = Bool(false));
   val wb_reg_fp_wen          = Reg(resetVal = Bool(false));
   val wb_reg_replay_next     = Reg(resetVal = Bool(false));
@@ -369,11 +376,13 @@ class rocketCtrl extends Component
 
   when (!io.dpath.stalld) {
     when (io.dpath.killf) {
+      id_reg_valid := Bool(false)
       id_reg_btb_hit := Bool(false);
       id_reg_xcpt_ma_inst := Bool(false);   
       id_reg_xcpt_itlb := Bool(false);
     } 
     .otherwise{
+      id_reg_valid := Bool(true)
       id_reg_btb_hit := io.dpath.btb_hit;
       id_reg_xcpt_ma_inst := if_reg_xcpt_ma_inst;
       id_reg_xcpt_itlb := io.xcpt_itlb;
@@ -393,6 +402,8 @@ class rocketCtrl extends Component
     ex_reg_div_val := Bool(false);
     ex_reg_mul_val := Bool(false);
     ex_reg_mem_val     := Bool(false);
+    ex_reg_valid       := Bool(false);
+    ex_reg_wen_pcr     := Bool(false)
     ex_reg_wen         := Bool(false);
     ex_reg_fp_wen      := Bool(false);
     ex_reg_eret        := Bool(false);
@@ -417,6 +428,8 @@ class rocketCtrl extends Component
     ex_reg_div_val     := id_div_val.toBool && id_waddr != UFix(0);
     ex_reg_mul_val     := id_mul_val.toBool && id_waddr != UFix(0);
     ex_reg_mem_val     := id_mem_val.toBool;
+    ex_reg_valid       := id_reg_valid
+    ex_reg_wen_pcr     := id_wen_pcr
     ex_reg_wen         := id_wen.toBool && id_waddr != UFix(0);
     ex_reg_fp_wen      := io.fpu.dec.wen;
     ex_reg_eret        := id_eret.toBool;
@@ -463,6 +476,8 @@ class rocketCtrl extends Component
   val mem_reg_mem_type    = Reg(){UFix(width = 3)};
 
   when (reset.toBool || io.dpath.killx) {
+    mem_reg_valid       := Bool(false);
+    mem_reg_wen_pcr     := Bool(false)
     mem_reg_div_mul_val := Bool(false);
     mem_reg_wen         := Bool(false);
     mem_reg_fp_wen      := Bool(false);
@@ -483,6 +498,8 @@ class rocketCtrl extends Component
     mem_reg_fp_sboard_set    := Bool(false)
   }
   .otherwise {
+    mem_reg_valid       := ex_reg_valid
+    mem_reg_wen_pcr     := ex_reg_wen_pcr
     mem_reg_div_mul_val := ex_reg_div_val || ex_reg_mul_val;
     mem_reg_wen         := ex_reg_wen;
     mem_reg_fp_wen      := ex_reg_fp_wen;
@@ -507,6 +524,8 @@ class rocketCtrl extends Component
   mem_reg_mem_type    := ex_reg_mem_type;
 
   when (io.dpath.killm) {
+    wb_reg_valid       := Bool(false)
+    wb_reg_wen_pcr     := Bool(false)
     wb_reg_wen         := Bool(false);
     wb_reg_fp_wen      := Bool(false);
     wb_reg_eret        := Bool(false);
@@ -519,6 +538,8 @@ class rocketCtrl extends Component
     wb_reg_fp_sboard_set := Bool(false)
   }
   .otherwise {
+    wb_reg_valid       := mem_reg_valid
+    wb_reg_wen_pcr     := mem_reg_wen_pcr
     wb_reg_wen         := mem_reg_wen;
     wb_reg_fp_wen      := mem_reg_fp_wen;
     wb_reg_eret        := mem_reg_eret;
@@ -609,7 +630,7 @@ class rocketCtrl extends Component
   val p_irq_timer = (io.dpath.status(15).toBool && io.dpath.irq_timer);
   val p_irq_ipi   = (io.dpath.status(13).toBool && io.dpath.irq_ipi);
   val interrupt = 
-    io.dpath.status(SR_ET).toBool && io.dpath.mem_valid && 
+    io.dpath.status(SR_ET).toBool && mem_reg_valid && 
     ((io.dpath.status(15).toBool && io.dpath.irq_timer) ||
      (io.dpath.status(13).toBool && io.dpath.irq_ipi));
      
@@ -659,7 +680,7 @@ class rocketCtrl extends Component
 
   // replay mem stage PC on a DTLB miss or a long-latency writeback
   val mem_ll_wb = io.dpath.mem_wb || io.dpath.mul_result_val || io.dpath.div_result_val
-  val dmem_kill_mem = io.dpath.mem_valid && (io.dtlb_miss || io.dmem.resp_nack)
+  val dmem_kill_mem = mem_reg_valid && (io.dtlb_miss || io.dmem.resp_nack)
   val replay_mem  = dmem_kill_mem || mem_reg_wen && mem_ll_wb || mem_reg_replay
   val kill_mem    = dmem_kill_mem || mem_reg_wen && mem_ll_wb || take_pc_wb || mem_exception || mem_reg_kill
   val kill_dcache = io.dtlb_miss  || mem_reg_wen && mem_ll_wb || take_pc_wb || mem_exception || mem_reg_kill || Reg(io.ext_mem.resp_nack)
@@ -787,10 +808,11 @@ class rocketCtrl extends Component
   io.dpath.ex_wen   := ex_reg_wen;
   io.dpath.mem_wen  := mem_reg_wen;
   io.dpath.wb_wen   := wb_reg_wen;
+  io.dpath.wb_valid := wb_reg_valid;
   io.dpath.sel_wa   := id_sel_wa.toBool;
   io.dpath.sel_wb   := id_sel_wb;
   io.dpath.ren_pcr  := id_ren_pcr.toBool;
-  io.dpath.wen_pcr  := id_wen_pcr.toBool;
+  io.dpath.wen_pcr  := wb_reg_wen_pcr
   io.dpath.id_eret  := id_eret.toBool;
   io.dpath.wb_eret  := wb_reg_eret;  
   io.dpath.irq_disable := wb_reg_inst_di;

rocket/src/main/scala/dpath.scala

@@ -73,12 +73,10 @@ class rocketDpath extends Component
   val if_reg_pc         = Reg(resetVal = UFix(START_ADDR,VADDR_BITS+1));
 
   // instruction decode definitions
-  val id_reg_valid     = Reg(resetVal = Bool(false));
   val id_reg_inst      = Reg(resetVal = NOP);
   val id_reg_pc        = Reg() { UFix(width = VADDR_BITS+1) };
 
   // execute definitions
-  val ex_reg_valid          = Reg(resetVal = Bool(false));
   val ex_reg_pc             = Reg() { UFix() };
   val ex_reg_inst           = Reg() { Bits() };
   val ex_reg_raddr1         = Reg() { UFix() };
@@ -96,12 +94,10 @@ class rocketDpath extends Component
   val ex_reg_ctrl_div_fn    = Reg() { UFix() };
   val ex_reg_ctrl_sel_wb    = Reg() { UFix() };
   val ex_reg_ctrl_ren_pcr   = Reg(resetVal = Bool(false));
-  val ex_reg_ctrl_wen_pcr   = Reg(resetVal = Bool(false));
   val ex_reg_ext_mem_tag    = Reg() { Bits() };
  	val ex_wdata						  = Wire() { Bits() }; 	
 
   // memory definitions
-  val mem_reg_valid          = Reg(resetVal = Bool(false));
   val mem_reg_pc             = Reg() { UFix() };
   val mem_reg_inst           = Reg() { Bits() };
   val mem_reg_rs2            = Reg() { Bits() };
@@ -109,11 +105,9 @@ class rocketDpath extends Component
   val mem_reg_wdata          = Reg() { Bits() };
   val mem_reg_raddr1         = Reg() { UFix() };
   val mem_reg_raddr2         = Reg() { UFix() };
-  val mem_reg_ctrl_wen_pcr   = Reg(resetVal = Bool(false));
   val mem_wdata              = Wire() { Bits() }; 	
   
   // writeback definitions
-  val wb_reg_valid          = Reg(resetVal = Bool(false));
   val wb_reg_pc             = Reg() { UFix() };
   val wb_reg_inst           = Reg() { Bits() };
   val wb_reg_rs2            = Reg() { Bits() };
@@ -121,7 +115,6 @@ class rocketDpath extends Component
   val wb_reg_wdata          = Reg() { Bits() };
   val wb_reg_raddr1         = Reg() { UFix() };
   val wb_reg_raddr2         = Reg() { UFix() };
-  val wb_reg_ctrl_wen_pcr   = Reg(resetVal = Bool(false));
   val wb_reg_ll_wb          = Reg(resetVal = Bool(false));
   val wb_wdata              = Wire() { Bits() }; 	
 
@@ -170,14 +163,7 @@ class rocketDpath extends Component
   // instruction decode stage
   when (!io.ctrl.stalld) {
     id_reg_pc := if_reg_pc;
-    when(io.ctrl.killf) {
+    id_reg_inst := Mux(io.ctrl.killf, NOP, io.imem.resp_data)
-      id_reg_inst  := NOP;
-      id_reg_valid := Bool(false);
-    }
-    .otherwise {
-      id_reg_inst  := io.imem.resp_data;
-      id_reg_valid := Bool(true);
-    }
   }
 
   val id_raddr1 = id_reg_inst(26,22).toUFix;
@@ -251,17 +237,13 @@ class rocketDpath extends Component
   ex_reg_ext_mem_tag    := io.ext_mem.req_tag
 
   when(io.ctrl.killd) {
-    ex_reg_valid          := Bool(false);
     ex_reg_ctrl_div_val 	:= Bool(false);
     ex_reg_ctrl_mul_val   := Bool(false);
-    ex_reg_ctrl_wen_pcr 	:= Bool(false);
     ex_reg_ctrl_eret			:= Bool(false);
   } 
   .otherwise {
-    ex_reg_valid          := id_reg_valid;
     ex_reg_ctrl_div_val 	:= io.ctrl.div_val;
   	ex_reg_ctrl_mul_val   := io.ctrl.mul_val;
-    ex_reg_ctrl_wen_pcr		:= io.ctrl.wen_pcr;
     ex_reg_ctrl_eret			:= io.ctrl.id_eret;
   }
 
@@ -333,7 +315,7 @@ class rocketDpath extends Component
   tsc_reg := tsc_reg + UFix(1);
   // instructions retired counter
   val irt_reg = Reg(resetVal = UFix(0,64));
-  when (wb_reg_valid) { irt_reg := irt_reg + UFix(1); }
+  when (io.ctrl.wb_valid) { irt_reg := irt_reg + UFix(1); }
   
 	// writeback select mux
   ex_wdata :=
@@ -356,19 +338,9 @@ class rocketDpath extends Component
   mem_reg_wdata             := ex_wdata;
   mem_reg_raddr1            := ex_reg_raddr1
   mem_reg_raddr2            := ex_reg_raddr2;
-
-  when (io.ctrl.killx) {
-    mem_reg_valid          := Bool(false);
-    mem_reg_ctrl_wen_pcr 	 := Bool(false);
-  }
-  .otherwise {
-    mem_reg_valid          := ex_reg_valid;
-    mem_reg_ctrl_wen_pcr 	 := ex_reg_ctrl_wen_pcr;
-  }
   
   // for load/use hazard detection (load byte/halfword)
   io.ctrl.mem_waddr := mem_reg_waddr;
-  io.ctrl.mem_valid := mem_reg_valid;
 
   mem_wdata := Mux(io.ctrl.mem_load, io.dmem.resp_data, mem_reg_wdata)
 
@@ -410,17 +382,8 @@ class rocketDpath extends Component
   wb_reg_raddr1         := mem_reg_raddr1
   wb_reg_raddr2         := mem_reg_raddr2;
 
-  when (io.ctrl.killm) {
-    wb_reg_valid          := Bool(false);
-    wb_reg_ctrl_wen_pcr 	:= Bool(false);
-  }
-  .otherwise {
-    wb_reg_valid          := mem_reg_valid;
-    wb_reg_ctrl_wen_pcr 	:= mem_reg_ctrl_wen_pcr;
-  }
-
   // regfile write
-  val wb_src_dmem = Reg(io.ctrl.mem_load) && wb_reg_valid || r_dmem_resp_replay
+  val wb_src_dmem = Reg(io.ctrl.mem_load) && io.ctrl.wb_valid || r_dmem_resp_replay
 
   if (HAVE_VEC)
   {
@@ -430,7 +393,7 @@ class rocketDpath extends Component
     vec.io.ctrl <> io.vec_ctrl
     io.vec_iface <> vec.io.iface 
 
-    vec.io.valid := wb_reg_valid
+    vec.io.valid := io.ctrl.wb_valid
     vec.io.inst := wb_reg_inst
     vec.io.waddr := wb_reg_waddr
     vec.io.raddr1 := wb_reg_raddr1
@@ -471,7 +434,7 @@ class rocketDpath extends Component
 
 	// processor control regfile write
   pcr.io.w.addr := wb_reg_raddr2;
-  pcr.io.w.en   := wb_reg_ctrl_wen_pcr;
+  pcr.io.w.en   := io.ctrl.wen_pcr
   pcr.io.w.data := wb_reg_wdata;
 
   pcr.io.di           := io.ctrl.irq_disable;