"""
Links:
* https://bugs.libre-soc.org/show_bug.cgi?id=421
+* https://libre-soc.org/openpower/isa/fixedtrap/
+* https://libre-soc.org/openpower/isa/sprset/
+* https://libre-soc.org/openpower/isa/system/
"""
import unittest
-from nmigen import Cat, Const, Elaboratable, Module
+from nmigen import Cat, Const, Elaboratable, Module, Signal, signed
from nmigen.asserts import Assert, AnyConst
from nmigen.cli import rtlil
+from nmutil.extend import exts
from nmutil.formaltest import FHDLTestCase
+from soc.consts import MSR, MSRb, PI, TT, field
+
from soc.decoder.power_enums import MicrOp
from soc.fu.trap.main_stage import TrapMainStage
from soc.fu.trap.trap_input_record import CompTrapOpSubset
-def is_ok(sig, value):
- """
- Answers with a list of assertions that checks for valid data on
- a pipeline stage output. sig.data must have the anticipated value,
- and sig.ok must be asserted. The `value` is constrained to the width
- of the sig.data field it's verified against, so it's safe to add, etc.
- offsets to Nmigen signals without having to worry about inequalities from
- differing signal widths.
- """
- return [
- Assert(sig.data == value[0:len(sig.data)]),
- Assert(sig.ok),
- ]
-
-
-def full_function_bits(msr):
- """
- Answers with a numeric constant signal with all "full functional"
- bits filled in, but all partial functional bits zeroed out.
-
- See src/soc/fu/trap/main_stage.py:msr_copy commentary for details.
- """
- zeros16_21 = Const(0, (22 - 16))
- zeros27_30 = Const(0, (31 - 27))
- return Cat(msr[0:16], zeros16_21, msr[22:27], zeros27_30, msr[31:64])
-
-
-def is_full_function_ok(out, inp):
- """
- Answers with a list of assertions that ONLY covers the full function
- MSR bits. It ignores the remaining bits.
- """
- return [
- Assert(out.data[0:16] == inp[0:16]),
-# Assert(out.data[22:27] == inp[22:27]),
-# Assert(out.data[31:64] == inp[31:64]),
- Assert(out.ok),
- ]
-
-
class Driver(Elaboratable):
"""
"""
# frequently used aliases
op = dut.i.ctx.op
+ msr_o, msr_i = dut.o.msr, op.msr
+ srr0_o, srr0_i = dut.o.srr0, dut.i.srr0
+ srr1_o, srr1_i = dut.o.srr1, dut.i.srr1
+ nia_o = dut.o.nia
comb += op.eq(rec)
+ d_fields = dut.fields.FormD
+ sc_fields = dut.fields.FormSC
+
# start of properties
with m.Switch(op.insn_type):
+
+ ###############
+ # TDI/TWI/TD/TW. v3.0B p90-91
+ ###############
+ with m.Case(MicrOp.OP_TRAP):
+ to = Signal(len(d_fields.TO))
+ comb += to.eq(d_fields.TO[0:-1])
+
+ a_i = Signal(64)
+ b_i = Signal(64)
+ comb += a_i.eq(dut.i.a)
+ comb += b_i.eq(dut.i.b)
+
+ a_s = Signal(signed(64), reset_less=True)
+ b_s = Signal(signed(64), reset_less=True)
+ a = Signal(64, reset_less=True)
+ b = Signal(64, reset_less=True)
+
+ with m.If(op.is_32bit):
+ comb += a_s.eq(exts(a_i, 32, 64))
+ comb += b_s.eq(exts(b_i, 32, 64))
+ comb += a.eq(a_i[0:32])
+ comb += b.eq(b_i[0:32])
+ with m.Else():
+ comb += a_s.eq(a_i)
+ comb += b_s.eq(b_i)
+ comb += a.eq(a_i)
+ comb += b.eq(b_i)
+
+ lt_s = Signal(reset_less=True)
+ gt_s = Signal(reset_less=True)
+ lt_u = Signal(reset_less=True)
+ gt_u = Signal(reset_less=True)
+ equal = Signal(reset_less=True)
+
+ comb += lt_s.eq(a_s < b_s)
+ comb += gt_s.eq(a_s > b_s)
+ comb += lt_u.eq(a < b)
+ comb += gt_u.eq(a > b)
+ comb += equal.eq(a == b)
+
+ trapbits = Signal(5, reset_less=True)
+ comb += trapbits.eq(Cat(gt_u, lt_u, equal, gt_s, lt_s))
+
+ take_trap = Signal()
+ traptype = op.traptype
+ comb += take_trap.eq(traptype.any() | (trapbits & to).any())
+
+ with m.If(take_trap):
+ expected_msr = Signal(len(msr_o.data))
+ comb += expected_msr.eq(op.msr)
+
+ comb += field(expected_msr, MSRb.IR).eq(0)
+ comb += field(expected_msr, MSRb.DR).eq(0)
+ comb += field(expected_msr, MSRb.FE0).eq(0)
+ comb += field(expected_msr, MSRb.FE1).eq(0)
+ comb += field(expected_msr, MSRb.EE).eq(0)
+ comb += field(expected_msr, MSRb.RI).eq(0)
+ comb += field(expected_msr, MSRb.SF).eq(1)
+ comb += field(expected_msr, MSRb.TM).eq(0)
+ comb += field(expected_msr, MSRb.VEC).eq(0)
+ comb += field(expected_msr, MSRb.VSX).eq(0)
+ comb += field(expected_msr, MSRb.PR).eq(0)
+ comb += field(expected_msr, MSRb.FP).eq(0)
+ comb += field(expected_msr, MSRb.PMM).eq(0)
+
+ # still wrong.
+ # see https://bugs.libre-soc.org/show_bug.cgi?id=325#c120
+ #
+ # saf2: no it's not. Proof by substitution:
+ #
+ # field(R,MSRb.TEs,MSRb.TEe).eq(0)
+ # == field(R,53,54).eq(0)
+ # == R[field_slice(53,54)].eq(0)
+ # == R[slice(63-54, (63-53)+1)].eq(0)
+ # == R[slice(9, 11)].eq(0)
+ # == R[9:11].eq(0)
+ #
+ # Also put proof in py-doc for field().
+
+ comb += field(expected_msr, MSRb.TEs, MSRb.TEe).eq(0)
+
+ comb += field(expected_msr, MSRb.UND).eq(0)
+ comb += field(expected_msr, MSRb.LE).eq(1)
+
+ expected_srr1 = Signal(len(srr1_o.data))
+ comb += expected_srr1.eq(op.msr)
+
+ # Per V3.0B, page 1075
+ comb += field(expected_srr1, 33, 36).eq(0)
+ comb += field(expected_srr1, 42).eq(0) # TM_BAD_THING
+ comb += field(expected_srr1, 43).eq(traptype[0]) # FP
+ comb += field(expected_srr1, 44).eq(traptype[4]) # ILLEG
+ comb += field(expected_srr1, 45).eq(traptype[1]) # PRIV
+ comb += field(expected_srr1, 46).eq(traptype == 0) # TRAP
+ comb += field(expected_srr1, 47).eq(traptype[3]) # ADDR
+
+ comb += [
+ Assert(msr_o.ok),
+ Assert(msr_o.data == expected_msr),
+ Assert(srr0_o.ok),
+ Assert(srr0_o.data == op.cia),
+ Assert(srr1_o.ok),
+ Assert(srr1_o.data == expected_srr1),
+ Assert(nia_o.ok),
+ Assert(nia_o.data == op.trapaddr << 4),
+ ]
+
+ #################
+ # SC. v3.0B p952
+ #################
with m.Case(MicrOp.OP_SC):
+ expected_msr = Signal(len(msr_o.data))
+ comb += expected_msr.eq(op.msr)
+ # Unless otherwise documented, these exceptions to the MSR bits
+ # are documented in Power ISA V3.0B, page 1063 or 1064.
+ # We are not supporting hypervisor or transactional semantics,
+ # so we skip enforcing those fields' properties.
+ comb += field(expected_msr, MSRb.IR).eq(0)
+ comb += field(expected_msr, MSRb.DR).eq(0)
+ comb += field(expected_msr, MSRb.FE0).eq(0)
+ comb += field(expected_msr, MSRb.FE1).eq(0)
+ comb += field(expected_msr, MSRb.EE).eq(0)
+ comb += field(expected_msr, MSRb.RI).eq(0)
+ comb += field(expected_msr, MSRb.SF).eq(1)
+ comb += field(expected_msr, MSRb.TM).eq(0)
+ comb += field(expected_msr, MSRb.VEC).eq(0)
+ comb += field(expected_msr, MSRb.VSX).eq(0)
+ comb += field(expected_msr, MSRb.PR).eq(0)
+ comb += field(expected_msr, MSRb.FP).eq(0)
+ comb += field(expected_msr, MSRb.PMM).eq(0)
+ comb += field(expected_msr, MSRb.TEs, MSRb.TEe).eq(0)
+ comb += field(expected_msr, MSRb.UND).eq(0)
+ comb += field(expected_msr, MSRb.LE).eq(1)
+
comb += [
- is_ok(dut.o.nia, Const(0xC00)),
- is_ok(dut.o.srr0, dut.i.cia + 4),
- is_ok(dut.o.srr1, full_function_bits(dut.i.msr)),
+ Assert(dut.o.srr0.ok),
+ Assert(srr1_o.ok),
+ Assert(msr_o.ok),
+
+ Assert(dut.o.srr0.data == (op.cia + 4)[0:64]),
+ Assert(field(srr1_o, 33, 36) == 0),
+ Assert(field(srr1_o, 42, 47) == 0),
+ Assert(field(srr1_o, 0, 32) == field(msr_i, 0, 32)),
+ Assert(field(srr1_o, 37, 41) == field(msr_i, 37, 41)),
+ Assert(field(srr1_o, 48, 63) == field(msr_i, 48, 63)),
+
+ Assert(msr_o.data == expected_msr),
]
+
+ ###################
+ # RFID. v3.0B p955
+ ###################
with m.Case(MicrOp.OP_RFID):
comb += [
- is_ok(dut.o.nia, Cat(Const(0, 2), dut.i.srr0[2:])),
- is_full_function_ok(dut.o.msr, dut.i.srr1),
+ Assert(msr_o.ok),
+ Assert(nia_o.ok),
]
+ # Note: going through the spec pseudo-code, line-by-line,
+ # in order, with these assertions. idea is: compare
+ # *directly* against the pseudo-code. therefore, leave
+ # numbering in (from pseudo-code) and add *comments* about
+ # which field it is (3 == HV etc.)
+
+ # spec: MSR[51] <- (MSR[3] & SRR1[51]) | ((¬MSR[3] & MSR[51]))
+ with m.If(field(msr_i, 3)): # HV
+ comb += Assert(field(msr_o, 51) == field(srr1_i, 51)) # ME
+ with m.Else():
+ comb += Assert(field(msr_o, 51) == field(msr_i, 51)) # ME
+
+ # if (MSR[29:31] != 0b010) | (SRR1[29:31] != 0b000) then
+ # MSR[29:31] <- SRR1[29:31]
+ with m.If((field(msr_i , 29, 31) != 0b010) |
+ (field(srr1_i, 29, 31) != 0b000)):
+ comb += Assert(field(msr_o.data, 29, 31) ==
+ field(srr1_i, 29, 31))
+ with m.Else():
+ comb += Assert(field(msr_o.data, 29, 31) ==
+ field(msr_i, 29, 31))
+
+ # check EE (48) IR (58), DR (59): PR (49) will over-ride
+ comb += [
+ Assert(
+ field(msr_o, 48) ==
+ field(srr1_i, 48) | field(srr1_i, 49)
+ ),
+ Assert(
+ field(msr_o, 58) ==
+ field(srr1_i, 58) | field(srr1_i, 49)
+ ),
+ Assert(
+ field(msr_o, 59) ==
+ field(srr1_i, 59) | field(srr1_i, 49)
+ ),
+ ]
+
+ # remaining bits: straight copy. don't know what these are:
+ # just trust the v3.0B spec is correct.
+ comb += [
+ Assert(field(msr_o, 0, 2) == field(srr1_i, 0, 2)),
+ Assert(field(msr_o, 4, 28) == field(srr1_i, 4, 28)),
+ Assert(field(msr_o, 32) == field(srr1_i, 32)),
+ Assert(field(msr_o, 37, 41) == field(srr1_i, 37, 41)),
+ Assert(field(msr_o, 49, 50) == field(srr1_i, 49, 50)),
+ Assert(field(msr_o, 52, 57) == field(srr1_i, 52, 57)),
+ Assert(field(msr_o, 60, 63) == field(srr1_i, 60, 63)),
+ ]
+
+ # check NIA against SRR0. 2 LSBs are set to zero (word-align)
+ comb += Assert(nia_o.data == Cat(Const(0, 2), dut.i.srr0[2:]))
+
comb += dut.i.ctx.matches(dut.o.ctx)
return m
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