add msr exception bits setting function in hardware

[soc.git] / src / soc / decoder / isa / caller.py

diff --git a/src/soc/decoder/isa/caller.py b/src/soc/decoder/isa/caller.py
index e5fdfc5a526190764e71d00cb26fd0eda4b87390..5c8d6b6f06a12d0dadf43d9d5db114209f984e7e 100644 (file)
--- a/src/soc/decoder/isa/caller.py
+++ b/src/soc/decoder/isa/caller.py
@@ -10,6 +10,7 @@ related bugs:
 """
 
 from functools import wraps
+from copy import copy
 from soc.decoder.orderedset import OrderedSet
 from soc.decoder.selectable_int import (FieldSelectableInt, SelectableInt,
                                         selectconcat)
@@ -264,6 +265,7 @@ class ISACaller:
             assert self.respect_pc == False, "instructions required to honor pc"
 
         print ("ISACaller insns", respect_pc, initial_insns, disassembly)
+        print ("ISACaller initial_msr", initial_msr)
 
         # "fake program counter" mode (for unit testing)
         self.fake_pc = 0
@@ -342,10 +344,22 @@ class ISACaller:
         print ("TRAP:", hex(trap_addr))
         # store CIA(+4?) in SRR0, set NIA to 0x700
         # store MSR in SRR1, set MSR to um errr something, have to check spec
-        self.spr['SRR0'] = self.pc.CIA
-        self.spr['SRR1'] = self.namespace['MSR']
+        self.spr['SRR0'].value = self.pc.CIA.value
+        self.spr['SRR1'].value = self.namespace['MSR'].value
         self.trap_nia = SelectableInt(trap_addr, 64)
-        self.namespace['MSR'][63-trap_bit] = 1
+        self.spr['SRR1'][63-trap_bit] = 1 # change *copy* of MSR in SRR1
+
+        # set exception bits.  TODO: this should, based on the address
+        # in figure 66 p1065 V3.0B and the table figure 65 p1063 set these
+        # bits appropriately.  however it turns out that *for now* in all
+        # cases (all trap_addrs) the exact same thing is needed.
+        self.namespace['MSR'][63-MSR.SF] = 1
+        self.namespace['MSR'][63-MSR.EE] = 0
+        self.namespace['MSR'][63-MSR.PR] = 0
+        self.namespace['MSR'][63-MSR.IR] = 0
+        self.namespace['MSR'][63-MSR.DR] = 0
+        self.namespace['MSR'][63-MSR.RI] = 0
+        self.namespace['MSR'][63-MSR.LE] = 1
 
     def memassign(self, ea, sz, val):
         self.mem.memassign(ea, sz, val)
@@ -531,22 +545,25 @@ class ISACaller:
             print ("AA", AA)
             if AA:
                 asmop += "a"
+        spr_msb = yield from self.get_spr_msb()
         if int_op == MicrOp.OP_MFCR.value:
-            dec_insn = yield self.dec2.e.do.insn
-            if dec_insn & (1<<20) != 0: # sigh
+            if spr_msb:
                 asmop = 'mfocrf'
             else:
                 asmop = 'mfcr'
         # XXX TODO: for whatever weird reason this doesn't work
         # https://bugs.libre-soc.org/show_bug.cgi?id=390
         if int_op == MicrOp.OP_MTCRF.value:
-            dec_insn = yield self.dec2.e.do.insn
-            if dec_insn & (1<<20) != 0: # sigh
+            if spr_msb:
                 asmop = 'mtocrf'
             else:
                 asmop = 'mtcrf'
         return asmop
 
+    def get_spr_msb(self):
+        dec_insn = yield self.dec2.e.do.insn
+        return dec_insn & (1<<20) != 0 # sigh - XFF.spr[-1]?
+
     def call(self, name):
         name = name.strip() # remove spaces if not already done so
         if self.halted:
@@ -558,6 +575,31 @@ class ISACaller:
         asmop = yield from self.get_assembly_name()
         print  ("call", name, asmop)
 
+        # check privileged
+        int_op = yield self.dec2.dec.op.internal_op
+        spr_msb = yield from self.get_spr_msb()
+
+        instr_is_privileged = False
+        if int_op in [MicrOp.OP_ATTN.value,
+                      MicrOp.OP_MFMSR.value,
+                      MicrOp.OP_MTMSR.value,
+                      MicrOp.OP_MTMSRD.value,
+                      # TODO: OP_TLBIE
+                      MicrOp.OP_RFID.value]:
+            instr_is_privileged = True
+        if int_op in [MicrOp.OP_MFSPR.value,
+                      MicrOp.OP_MTSPR.value] and spr_msb:
+            instr_is_privileged = True
+
+        print ("is priv", instr_is_privileged, hex(self.msr.value),
+                          self.msr[63-MSR.PR])
+        # check MSR priv bit and whether op is privileged: if so, throw trap
+        if instr_is_privileged and self.msr[63-MSR.PR] == 1:
+            self.TRAP(0x700, PI.PRIV)
+            self.namespace['NIA'] = self.trap_nia
+            self.pc.update(self.namespace)
+            return
+
         # check halted condition
         if name == 'attn':
             self.halted = True
@@ -569,10 +611,11 @@ class ISACaller:
             illegal = name != asmop
 
         if illegal:
-            print ("name %s != %s - calling ILLEGAL trap" % (name, asmop))
             self.TRAP(0x700, PI.ILLEG)
             self.namespace['NIA'] = self.trap_nia
             self.pc.update(self.namespace)
+            print ("name %s != %s - calling ILLEGAL trap, PC: %x" % \
+                    (name, asmop, self.pc.CIA.value))
             return
 
         info = self.instrs[name]