From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Wed, 15 Jul 2020 14:20:59 +0000 (+0100)
Subject: move priv test to above illegal/trap test
X-Git-Tag: div_pipeline~23
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=8a0e6a5c59e4af9027685a45e8854e178544b4cb;p=soc.git

move priv test to above illegal/trap test
---

diff --git a/src/soc/decoder/power_decoder2.py b/src/soc/decoder/power_decoder2.py
index 8cc68f4f..5ae286e5 100644
--- a/src/soc/decoder/power_decoder2.py
+++ b/src/soc/decoder/power_decoder2.py
@@ -679,11 +679,16 @@ class PowerDecode2(Elaboratable):
         with m.If(op.internal_op == MicrOp.OP_TRAP):
             comb += do.trapaddr.eq(0x70)    # addr=0x700 (strip first nibble)
 
+        # TODO: get msr, then can do privileged instruction
+        with m.If(instr_is_priv(m, op.internal_op, e.do.insn) & msr[MSR.PR]):
+            # privileged instruction trap
+            self.trap(m, TT_PRIV, 0x700)
+
         # illegal instruction must redirect to trap. this is done by
         # *overwriting* the decoded instruction and starting again.
         # (note: the same goes for interrupts and for privileged operations,
         # just with different trapaddr and traptype)
-        with m.If(op.internal_op == MicrOp.OP_ILLEGAL):
+        with m.Elif(op.internal_op == MicrOp.OP_ILLEGAL):
             # illegal instruction trap
             self.trap(m, TT_ILLEG, 0x700)
 
@@ -707,11 +712,6 @@ class PowerDecode2(Elaboratable):
             comb += e.read_fast2.data.eq(FastRegs.SRR1) # constant: SRR1
             comb += e.read_fast2.ok.eq(1)
 
-        # TODO: get msr, then can do privileged instruction
-        with m.If(instr_is_priv(m, op.internal_op, e.do.insn) & msr[MSR.PR]):
-            # privileged instruction trap
-            self.trap(m, TT_PRIV, 0x700)
-
         return m
 
     def trap(self, m, traptype, trapaddr):