X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=src%2Fsoc%2Fdecoder%2Fpower_regspec_map.py;h=05ff4814e2504e3acbc5924b614031b460f8bd7c;hb=e653b5cb1e6e5a8c2070841a67f3c812d2a0f90c;hp=a88375d0dcc1d02ffec2df6b855a4eedc9b9fa94;hpb=f28cca6470be176d84d69f83950a46268e0f3a1c;p=soc.git

diff --git a/src/soc/decoder/power_regspec_map.py b/src/soc/decoder/power_regspec_map.py
index a88375d0..05ff4814 100644
--- a/src/soc/decoder/power_regspec_map.py
+++ b/src/soc/decoder/power_regspec_map.py
@@ -20,20 +20,22 @@ some point that 8-bit mask from the instruction could actually be passed
 directly through to full_cr (TODO).
 
 For the INT and CR numbering, these are expressed in binary in the
-instruction (note however that XFX in MTCR is unary-masked!)
+instruction and need to be converted to unary (1<<read_reg1.data).
+Note however that XFX in MTCR is unary-masked!
 
-XER is implicitly-encoded based on whether the operation has carry or
-overflow.
+XER regs are implicitly-encoded (hard-coded) based on whether the
+operation has carry or overflow.
 
 FAST regfile is, again, implicitly encoded, back in PowerDecode2, based
-on the type of operation (see DecodeB for an example).
+on the type of operation (see DecodeB for an example, where fast_out
+is set, then carried into read_fast2 in PowerDecode2).
 
 The SPR regfile on the other hand is *binary*-encoded, and, furthermore,
-has to be "remapped".
+has to be "remapped" to internal SPR Enum indices (see SPRMap in PowerDecode2)
 see https://libre-soc.org/3d_gpu/architecture/regfile/ section on regspecs
 """
 from nmigen import Const
-from soc.regfile.regfiles import XERRegs, FastRegs
+from soc.regfile.regfiles import XERRegs, FastRegs, StateRegs
 from soc.decoder.power_enums import CryIn
 
 
@@ -41,20 +43,23 @@ def regspec_decode_read(e, regfile, name):
     """regspec_decode_read
     """
 
+    # INT regfile
+
     if regfile == 'INT':
         # Int register numbering is *unary* encoded
         if name == 'ra': # RA
-            return e.read_reg1.ok, 1<<e.read_reg1.data
+            return e.read_reg1.ok, e.read_reg1.data
         if name == 'rb': # RB
-            return e.read_reg2.ok, 1<<e.read_reg2.data
+            return e.read_reg2.ok, e.read_reg2.data
         if name == 'rc': # RS
-            return e.read_reg3.ok, 1<<e.read_reg3.data
+            return e.read_reg3.ok, e.read_reg3.data
+
+    # CR regfile
 
     if regfile == 'CR':
         # CRRegs register numbering is *unary* encoded
-        # *sigh*.  numbering inverted on part-CRs.  because POWER.
-        if name == 'full_cr': # full CR
-            return e.read_cr_whole, 0b11111111
+        if name == 'full_cr': # full CR (from FXM field)
+            return e.do.read_cr_whole.ok, e.do.read_cr_whole.data
         if name == 'cr_a': # CR A
             return e.read_cr1.ok, 1<<(7-e.read_cr1.data)
         if name == 'cr_b': # CR B
@@ -62,39 +67,52 @@ def regspec_decode_read(e, regfile, name):
         if name == 'cr_c': # CR C
             return e.read_cr3.ok, 1<<(7-e.read_cr3.data)
 
+    # XER regfile
+
     if regfile == 'XER':
         # XERRegs register numbering is *unary* encoded
         SO = 1<<XERRegs.SO
         CA = 1<<XERRegs.CA
         OV = 1<<XERRegs.OV
         if name == 'xer_so':
-            return e.oe.oe[0] & e.oe.oe_ok, SO
+            # SO needs to be read for overflow *and* for creation
+            # of CR0 and also for MFSPR
+            return ((e.do.oe.oe[0] & e.do.oe.ok) | (e.xer_in & SO == SO)|
+                     (e.do.rc.rc & e.do.rc.ok)), SO
         if name == 'xer_ov':
-            return e.oe.oe[0] & e.oe.oe_ok, OV
+            return ((e.do.oe.oe[0] & e.do.oe.ok) |
+                    (e.xer_in & CA == CA)), OV
         if name == 'xer_ca':
-            return (e.input_carry == CryIn.CA.value), CA
+            return ((e.do.input_carry == CryIn.CA.value) |
+                    (e.xer_in & OV == OV)), CA
 
-    if regfile == 'FAST':
-        # FAST register numbering is *unary* encoded
-        PC = 1<<FastRegs.PC
-        MSR = 1<<FastRegs.MSR
-        CTR = 1<<FastRegs.CTR
-        LR = 1<<FastRegs.LR
-        TAR = 1<<FastRegs.TAR
-        SRR0 = 1<<FastRegs.SRR0
-        SRR1 = 1<<FastRegs.SRR1
+    # STATE regfile
+
+    if regfile == 'STATE':
+        # STATE register numbering is *unary* encoded
+        PC = 1<<StateRegs.PC
+        MSR = 1<<StateRegs.MSR
         if name in ['cia', 'nia']:
             return Const(1), PC # TODO: detect read-conditions
         if name == 'msr':
             return Const(1), MSR # TODO: detect read-conditions
-        # TODO: remap the SPR numbers to FAST regs
-        if name == 'spr1':
-            return e.read_fast1.ok, 1<<e.read_fast1.data
-        if name == 'spr2':
-            return e.read_fast2.ok, 1<<e.read_fast2.data
+
+    # FAST regfile
+
+    if regfile == 'FAST':
+        # FAST register numbering is *unary* encoded
+        if name == 'fast1':
+            return e.read_fast1.ok, e.read_fast1.data
+        if name == 'fast2':
+            return e.read_fast2.ok, e.read_fast2.data
+
+    # SPR regfile
 
     if regfile == 'SPR':
-        assert False, "regfile TODO %s %s" % (regfile, name)
+        # SPR register numbering is *binary* encoded
+        if name == 'spr1':
+            return e.read_spr1.ok, e.read_spr1.data
+
     assert False, "regspec not found %s %s" % (regfile, name)
 
 
@@ -102,53 +120,65 @@ def regspec_decode_write(e, regfile, name):
     """regspec_decode_write
     """
 
+    # INT regfile
+
     if regfile == 'INT':
         # Int register numbering is *unary* encoded
         if name == 'o': # RT
-            return e.write_reg, 1<<e.write_reg.data
+            return e.write_reg, e.write_reg.data
         if name == 'o1': # RA (update mode: LD/ST EA)
-            return e.write_ea, 1<<e.write_ea.data
+            return e.write_ea, e.write_ea.data
+
+    # CR regfile
 
     if regfile == 'CR':
         # CRRegs register numbering is *unary* encoded
         # *sigh*.  numbering inverted on part-CRs.  because POWER.
-        if name == 'full_cr': # full CR
-            return e.write_cr_whole, 0b11111111
+        if name == 'full_cr': # full CR (from FXM field)
+            return e.do.write_cr_whole.ok, e.do.write_cr_whole.data
         if name == 'cr_a': # CR A
             return e.write_cr, 1<<(7-e.write_cr.data)
 
+    # XER regfile
+
     if regfile == 'XER':
         # XERRegs register numbering is *unary* encoded
         SO = 1<<XERRegs.SO
         CA = 1<<XERRegs.CA
         OV = 1<<XERRegs.OV
         if name == 'xer_so':
-            return None, SO # hmmm
+            return e.xer_out, SO # hmmm
         if name == 'xer_ov':
-            return None, OV # hmmm
+            return e.xer_out, OV # hmmm
         if name == 'xer_ca':
-            return None, CA # hmmm
+            return e.xer_out, CA # hmmm
 
-    if regfile == 'FAST':
-        # FAST register numbering is *unary* encoded
-        PC = 1<<FastRegs.PC
-        MSR = 1<<FastRegs.MSR
-        CTR = 1<<FastRegs.CTR
-        LR = 1<<FastRegs.LR
-        TAR = 1<<FastRegs.TAR
-        SRR0 = 1<<FastRegs.SRR0
-        SRR1 = 1<<FastRegs.SRR1
+    # STATE regfile
+
+    if regfile == 'STATE':
+        # STATE register numbering is *unary* encoded
+        PC = 1<<StateRegs.PC
+        MSR = 1<<StateRegs.MSR
         if name in ['cia', 'nia']:
             return None, PC # hmmm
         if name == 'msr':
             return None, MSR # hmmm
-        # TODO: remap the SPR numbers to FAST regs
-        if name == 'spr1':
-            return e.write_fast1, 1<<e.write_fast1.data
-        if name == 'spr2':
-            return e.write_fast2, 1<<e.write_fast2.data
+
+    # FAST regfile
+
+    if regfile == 'FAST':
+        # FAST register numbering is *unary* encoded
+        if name == 'fast1':
+            return e.write_fast1, e.write_fast1.data
+        if name == 'fast2':
+            return e.write_fast2, e.write_fast2.data
+
+    # SPR regfile
 
     if regfile == 'SPR':
-        assert False, "regfile TODO %s %s" % (regfile, name)
+        # SPR register numbering is *binary* encoded
+        if name == 'spr1': # SPR1
+            return e.write_spr, e.write_spr.data
+
     assert False, "regspec not found %s %s" % (regfile, name)