[sim] add ability to clear IPIs

diff --git a/riscv/insns/mfpcr.h b/riscv/insns/mfpcr.h
index b72b850416fb3b115917bba3dd071276315c974f..b151150f421c5ce05109a29f807ae606ff0d9abd 100644 (file)
--- a/riscv/insns/mfpcr.h
+++ b/riscv/insns/mfpcr.h
@@ -25,6 +25,9 @@ switch(insn.rtype.rs2)
   case 6:
     val = cause;
     break;
+  case 7:
+    cause &= ~(1 << (IPI_IRQ+CAUSE_IP_SHIFT));
+    break;
 
   case 8:
     val = MEMSIZE >> PGSHIFT;