fix(LSU, CSR): SPF/LPF now redirect correctly

When SPF/LPF was raised, LSU used to wait until its FSM go back to s_idle then commit.
However, CSR will modify mode/status immediately when it gets PF signal.
Here comes the problem: when a PF is raised, redirect may not happen because mode/status i not right.

src/main/scala/noop/fu/CSR.scala

@@ -564,7 +564,8 @@ class CSR(implicit val p: NOOPConfig) extends NOOPModule with HasCSRConst{
 
   Debug(){
     when(raiseExceptionIntr){
-      printf("[CSR] int/exc: pc %x int (%d):%x exc: (%d):%x\n",io.cfIn.pc, intrNO, io.cfIn.intrVec.asUInt, exceptionNO, io.cfIn.exceptionVec.asUInt)
+      printf("[CSR] int/exc: pc %x int (%d):%x exc: (%d):%x\n",io.cfIn.pc, intrNO, io.cfIn.intrVec.asUInt, exceptionNO, raiseExceptionVec.asUInt)
+      printf("[MST] time %d pc %x mstatus %x mideleg %x medeleg %x mode %x\n", GTimer(), io.cfIn.pc, mstatus, mideleg , medeleg, priviledgeMode)
     }
     when(io.redirect.valid){
       printf("[CSR] redirect to %x\n", io.redirect.target)

src/main/scala/noop/fu/LSU.scala

@@ -136,6 +136,14 @@ class LSU extends NOOPModule {
 
     val scInvalid = !(src1 === lrAddr) && scReq
 
+    // PF signal from TLB
+    val dtlbFinish = WireInit(false.B)
+    val dtlbPF = WireInit(false.B)
+    val dtlbEnable = WireInit(false.B)
+    BoringUtils.addSink(dtlbFinish, "DTLBFINISH")
+    BoringUtils.addSink(dtlbPF, "DTLBPF")
+    BoringUtils.addSink(dtlbEnable, "DTLBENABLE")
+
     // LSU control FSM state
     val s_idle :: s_load :: s_lr :: s_sc :: s_amo_l :: s_amo_a :: s_amo_s :: Nil = Enum(7)
 
@@ -292,6 +300,11 @@ class LSU extends NOOPModule {
         }
       }
     }
+    when(dtlbPF){
+      state := s_idle
+      io.out.valid := true.B
+      io.in.ready := true.B
+    }
 
     // controled by FSM 
     // io.in.ready := lsExecUnit.io.in.ready

src/test/csrc/uart.cpp

@@ -21,7 +21,7 @@ static int uart_dequeue(void) {
     f = (f + 1) % QUEUE_SIZE;
   } else {
     // generate a random key every 1s for pal
-    k = "uiojkl"[rand()% 6];
+    k = -1;//"uiojkl"[rand()% 6];
   }
   return k;
 }
@@ -32,10 +32,10 @@ extern "C" void uart_getc(uint8_t *ch) {
   uint32_t now = uptime();
 
   *ch = -1;
-  if (now - lasttime > 3000) {
-    lasttime = now;
+  // if (now - lasttime > 3000) {
+    // lasttime = now;
     *ch = uart_dequeue();
-  }
+  // }
 }
 
 void uart_putc(char c) {