+"""core of the python-based POWER9 simulator
+
+this is part of a cycle-accurate POWER9 simulator. its primary purpose is
+not speed, it is for both learning and educational purposes, as well as
+a method of verifying the HDL.
+"""
+
from functools import wraps
from soc.decoder.orderedset import OrderedSet
-from soc.decoder.selectable_int import SelectableInt, selectconcat
+from soc.decoder.selectable_int import (FieldSelectableInt, SelectableInt,
+ selectconcat)
+from soc.decoder.power_enums import spr_dict, XER_bits, insns, InternalOp
+from soc.decoder.helpers import exts
+from collections import namedtuple
+import math
+import sys
+
+instruction_info = namedtuple('instruction_info',
+ 'func read_regs uninit_regs write_regs ' + \
+ 'special_regs op_fields form asmregs')
+
+special_sprs = {
+ 'LR': 8,
+ 'CTR': 9,
+ 'TAR': 815,
+ 'XER': 1,
+ 'VRSAVE': 256}
+
+
+def swap_order(x, nbytes):
+ x = x.to_bytes(nbytes, byteorder='little')
+ x = int.from_bytes(x, byteorder='big', signed=False)
+ return x
+
def create_args(reglist, extra=None):
args = OrderedSet()
args = [extra] + args
return args
+
class Mem:
- def __init__(self):
- self.mem = []
- for i in range(128):
- self.mem.append(i)
+ def __init__(self, row_bytes=8, initial_mem=None):
+ self.mem = {}
+ self.bytes_per_word = row_bytes
+ self.word_log2 = math.ceil(math.log2(row_bytes))
+ print ("Sim-Mem", initial_mem, self.bytes_per_word, self.word_log2)
+ if not initial_mem:
+ return
+
+ # different types of memory data structures recognised (for convenience)
+ if isinstance(initial_mem, list):
+ initial_mem = (0, initial_mem)
+ if isinstance(initial_mem, tuple):
+ startaddr, mem = initial_mem
+ initial_mem = {}
+ for i, val in enumerate(mem):
+ initial_mem[startaddr + row_bytes*i] = (val, row_bytes)
+
+ for addr, (val, width) in initial_mem.items():
+ #val = swap_order(val, width)
+ self.st(addr, val, width, swap=False)
+
+ def _get_shifter_mask(self, wid, remainder):
+ shifter = ((self.bytes_per_word - wid) - remainder) * \
+ 8 # bits per byte
+ # XXX https://bugs.libre-soc.org/show_bug.cgi?id=377
+ # BE/LE mode?
+ shifter = remainder * 8
+ mask = (1 << (wid * 8)) - 1
+ print ("width,rem,shift,mask", wid, remainder, hex(shifter), hex(mask))
+ return shifter, mask
+
+ # TODO: Implement ld/st of lesser width
+ def ld(self, address, width=8, swap=True, check_in_mem=False):
+ print("ld from addr 0x{:x} width {:d}".format(address, width))
+ remainder = address & (self.bytes_per_word - 1)
+ address = address >> self.word_log2
+ assert remainder & (width - 1) == 0, "Unaligned access unsupported!"
+ if address in self.mem:
+ val = self.mem[address]
+ elif check_in_mem:
+ return None
+ else:
+ val = 0
+ print("mem @ 0x{:x} rem {:d} : 0x{:x}".format(address, remainder, val))
+
+ if width != self.bytes_per_word:
+ shifter, mask = self._get_shifter_mask(width, remainder)
+ print ("masking", hex(val), hex(mask<<shifter), shifter)
+ val = val & (mask << shifter)
+ val >>= shifter
+ if swap:
+ val = swap_order(val, width)
+ print("Read 0x{:x} from addr 0x{:x}".format(val, address))
+ return val
+
+ def st(self, addr, v, width=8, swap=True):
+ staddr = addr
+ remainder = addr & (self.bytes_per_word - 1)
+ addr = addr >> self.word_log2
+ print("Writing 0x{:x} to ST 0x{:x} memaddr 0x{:x}/{:x}".format(v,
+ staddr, addr, remainder, swap))
+ assert remainder & (width - 1) == 0, "Unaligned access unsupported!"
+ if swap:
+ v = swap_order(v, width)
+ if width != self.bytes_per_word:
+ if addr in self.mem:
+ val = self.mem[addr]
+ else:
+ val = 0
+ shifter, mask = self._get_shifter_mask(width, remainder)
+ val &= ~(mask << shifter)
+ val |= v << shifter
+ self.mem[addr] = val
+ else:
+ self.mem[addr] = v
+ print("mem @ 0x{:x}: 0x{:x}".format(addr, self.mem[addr]))
def __call__(self, addr, sz):
- res = []
- for s in range(sz): # TODO: big/little-end
- res.append(SelectableInt(self.mem[addr.value + s], 8))
- print ("memread", addr, sz, res)
- return selectconcat(*res)
+ val = self.ld(addr.value, sz)
+ print ("memread", addr, sz, val)
+ return SelectableInt(val, sz*8)
def memassign(self, addr, sz, val):
print ("memassign", addr, sz, val)
- for s in range(sz):
- byte = (val.value) >> (s*8) & 0xff # TODO: big/little-end
- self.mem[addr.value + s] = byte
+ self.st(addr.value, val.value, sz)
class GPR(dict):
s = ' '.join(s)
print("reg", "%2d" % i, s)
+class PC:
+ def __init__(self, pc_init=0):
+ self.CIA = SelectableInt(pc_init, 64)
+ self.NIA = self.CIA + SelectableInt(4, 64)
+
+ def update(self, namespace):
+ self.CIA = namespace['NIA'].narrow(64)
+ self.NIA = self.CIA + SelectableInt(4, 64)
+ namespace['CIA'] = self.CIA
+ namespace['NIA'] = self.NIA
+
+
+class SPR(dict):
+ def __init__(self, dec2, initial_sprs={}):
+ self.sd = dec2
+ dict.__init__(self)
+ self.update(initial_sprs)
+
+ def __getitem__(self, key):
+ # if key in special_sprs get the special spr, otherwise return key
+ if isinstance(key, SelectableInt):
+ key = key.value
+ key = special_sprs.get(key, key)
+ if key in self:
+ return dict.__getitem__(self, key)
+ else:
+ info = spr_dict[key]
+ dict.__setitem__(self, key, SelectableInt(0, info.length))
+ return dict.__getitem__(self, key)
+
+ def __setitem__(self, key, value):
+ if isinstance(key, SelectableInt):
+ key = key.value
+ key = special_sprs.get(key, key)
+ dict.__setitem__(self, key, value)
+
+ def __call__(self, ridx):
+ return self[ridx]
+
class ISACaller:
# decoder2 - an instance of power_decoder2
# regfile - a list of initial values for the registers
- def __init__(self, decoder2, regfile):
+ # initial_{etc} - initial values for SPRs, Condition Register, Mem, MSR
+ # respect_pc - tracks the program counter. requires initial_insns
+ def __init__(self, decoder2, regfile, initial_sprs=None, initial_cr=0,
+ initial_mem=None, initial_msr=0,
+ initial_insns=None, respect_pc=False,
+ disassembly=None):
+
+ self.respect_pc = respect_pc
+ if initial_sprs is None:
+ initial_sprs = {}
+ if initial_mem is None:
+ initial_mem = {}
+ if initial_insns is None:
+ initial_insns = {}
+ assert self.respect_pc == False, "instructions required to honor pc"
+
+ print ("ISACaller insns", respect_pc, initial_insns, disassembly)
+
+ # "fake program counter" mode (for unit testing)
+ self.fake_pc = 0
+ if not respect_pc:
+ if isinstance(initial_mem, tuple):
+ self.fake_pc = initial_mem[0]
+
+ # disassembly: we need this for now (not given from the decoder)
+ self.disassembly = {}
+ if disassembly:
+ for i, code in enumerate(disassembly):
+ self.disassembly[i*4 + self.fake_pc] = code
+
+ # set up registers, instruction memory, data memory, PC, SPRs, MSR
self.gpr = GPR(decoder2, regfile)
- self.mem = Mem()
+ self.mem = Mem(row_bytes=8, initial_mem=initial_mem)
+ self.imem = Mem(row_bytes=4, initial_mem=initial_insns)
+ self.pc = PC()
+ self.spr = SPR(decoder2, initial_sprs)
+ self.msr = SelectableInt(initial_msr, 64) # underlying reg
+
+ # TODO, needed here:
+ # FPR (same as GPR except for FP nums)
+ # 4.2.2 p124 FPSCR (definitely "separate" - not in SPR)
+ # note that mffs, mcrfs, mtfsf "manage" this FPSCR
+ # 2.3.1 CR (and sub-fields CR0..CR6 - CR0 SO comes from XER.SO)
+ # note that mfocrf, mfcr, mtcr, mtocrf, mcrxrx "manage" CRs
+ # -- Done
+ # 2.3.2 LR (actually SPR #8) -- Done
+ # 2.3.3 CTR (actually SPR #9) -- Done
+ # 2.3.4 TAR (actually SPR #815)
+ # 3.2.2 p45 XER (actually SPR #1) -- Done
+ # 3.2.3 p46 p232 VRSAVE (actually SPR #256)
+
+ # create CR then allow portions of it to be "selectable" (below)
+ self._cr = SelectableInt(initial_cr, 64) # underlying reg
+ self.cr = FieldSelectableInt(self._cr, list(range(32,64)))
+
+ # "undefined", just set to variable-bit-width int (use exts "max")
+ self.undefined = SelectableInt(0, 256) # TODO, not hard-code 256!
+
self.namespace = {'GPR': self.gpr,
'MEM': self.mem,
- 'memassign': self.memassign
+ 'SPR': self.spr,
+ 'memassign': self.memassign,
+ 'NIA': self.pc.NIA,
+ 'CIA': self.pc.CIA,
+ 'CR': self.cr,
+ 'MSR': self.msr,
+ 'undefined': self.undefined,
+ 'mode_is_64bit': True,
+ 'SO': XER_bits['SO']
}
- self.decoder = decoder2
+
+ # field-selectable versions of Condition Register TODO check bitranges?
+ self.crl = []
+ for i in range(8):
+ bits = tuple(range(i*4, (i+1)*4))# errr... maybe?
+ _cr = FieldSelectableInt(self.cr, bits)
+ self.crl.append(_cr)
+ self.namespace["CR%d" % i] = _cr
+
+ self.decoder = decoder2.dec
+ self.dec2 = decoder2
+
+ def TRAP(self, trap_addr=0x700):
+ print ("TRAP: TODO")
+ # store CIA(+4?) in SRR0, set NIA to 0x700
+ # store MSR in SRR1, set MSR to um errr something, have to check spec
def memassign(self, ea, sz, val):
self.mem.memassign(ea, sz, val)
- def prep_namespace(self):
- si = yield self.decoder.SI
- self.namespace['SI'] = SelectableInt(si, bits=16)
+ def prep_namespace(self, formname, op_fields):
+ # TODO: get field names from form in decoder*1* (not decoder2)
+ # decoder2 is hand-created, and decoder1.sigform is auto-generated
+ # from spec
+ # then "yield" fields only from op_fields rather than hard-coded
+ # list, here.
+ fields = self.decoder.sigforms[formname]
+ for name in op_fields:
+ if name == 'spr':
+ sig = getattr(fields, name.upper())
+ else:
+ sig = getattr(fields, name)
+ val = yield sig
+ if name in ['BF', 'BFA']:
+ self.namespace[name] = val
+ else:
+ self.namespace[name] = SelectableInt(val, sig.width)
+
+ self.namespace['XER'] = self.spr['XER']
+ self.namespace['CA'] = self.spr['XER'][XER_bits['CA']].value
+ self.namespace['CA32'] = self.spr['XER'][XER_bits['CA32']].value
+
+ def handle_carry_(self, inputs, outputs, already_done):
+ inv_a = yield self.dec2.e.invert_a
+ if inv_a:
+ inputs[0] = ~inputs[0]
+
+ imm_ok = yield self.dec2.e.imm_data.ok
+ if imm_ok:
+ imm = yield self.dec2.e.imm_data.data
+ inputs.append(SelectableInt(imm, 64))
+ assert len(outputs) >= 1
+ output = outputs[0]
+ gts = [(x > output) for x in inputs]
+ print(gts)
+ cy = 1 if any(gts) else 0
+ if not (1 & already_done):
+ self.spr['XER'][XER_bits['CA']] = cy
+
+ print ("inputs", inputs)
+ # 32 bit carry
+ gts = [(x[32:64] > output[32:64]) == SelectableInt(1, 1)
+ for x in inputs]
+ cy32 = 1 if any(gts) else 0
+ if not (2 & already_done):
+ self.spr['XER'][XER_bits['CA32']] = cy32
+
+ def handle_overflow(self, inputs, outputs):
+ inv_a = yield self.dec2.e.invert_a
+ if inv_a:
+ inputs[0] = ~inputs[0]
+
+ imm_ok = yield self.dec2.e.imm_data.ok
+ if imm_ok:
+ imm = yield self.dec2.e.imm_data.data
+ inputs.append(SelectableInt(imm, 64))
+ assert len(outputs) >= 1
+ print ("handle_overflow", inputs, outputs)
+ if len(inputs) >= 2:
+ output = outputs[0]
+
+ # OV (64-bit)
+ input_sgn = [exts(x.value, x.bits) < 0 for x in inputs]
+ output_sgn = exts(output.value, output.bits) < 0
+ ov = 1 if input_sgn[0] == input_sgn[1] and \
+ output_sgn != input_sgn[0] else 0
+
+ # OV (32-bit)
+ input32_sgn = [exts(x.value, 32) < 0 for x in inputs]
+ output32_sgn = exts(output.value, 32) < 0
+ ov32 = 1 if input32_sgn[0] == input32_sgn[1] and \
+ output32_sgn != input32_sgn[0] else 0
+
+ self.spr['XER'][XER_bits['OV']] = ov
+ self.spr['XER'][XER_bits['OV32']] = ov32
+ so = self.spr['XER'][XER_bits['SO']]
+ so = so | ov
+ self.spr['XER'][XER_bits['SO']] = so
+
+ def handle_comparison(self, outputs):
+ out = outputs[0]
+ out = exts(out.value, out.bits)
+ zero = SelectableInt(out == 0, 1)
+ positive = SelectableInt(out > 0, 1)
+ negative = SelectableInt(out < 0, 1)
+ SO = self.spr['XER'][XER_bits['SO']]
+ cr_field = selectconcat(negative, positive, zero, SO)
+ self.crl[0].eq(cr_field)
+
+ def set_pc(self, pc_val):
+ self.namespace['NIA'] = SelectableInt(pc_val, 64)
+ self.pc.update(self.namespace)
+
+ def setup_one(self):
+ """set up one instruction
+ """
+ if self.respect_pc:
+ pc = self.pc.CIA.value
+ else:
+ pc = self.fake_pc
+ self._pc = pc
+ ins = self.imem.ld(pc, 4, False, True)
+ if ins is None:
+ raise KeyError("no instruction at 0x%x" % pc)
+ print("setup: 0x%x 0x%x %s" % (pc, ins & 0xffffffff, bin(ins)))
+ print ("NIA, CIA", self.pc.CIA.value, self.pc.NIA.value)
+
+ yield self.dec2.dec.raw_opcode_in.eq(ins)
+ yield self.dec2.dec.bigendian.eq(0) # little / big?
+
+ def execute_one(self):
+ """execute one instruction
+ """
+ # get the disassembly code for this instruction
+ code = self.disassembly[self._pc]
+ print("sim-execute", hex(self._pc), code)
+ opname = code.split(' ')[0]
+ yield from self.call(opname)
+
+ if not self.respect_pc:
+ self.fake_pc += 4
+ print ("NIA, CIA", self.pc.CIA.value, self.pc.NIA.value)
def call(self, name):
- yield from self.prep_namespace()
+ # TODO, asmregs is from the spec, e.g. add RT,RA,RB
+ # see http://bugs.libre-riscv.org/show_bug.cgi?id=282
+ asmcode = yield self.dec2.dec.op.asmcode
+ asmop = insns.get(asmcode, None)
- function, read_regs, uninit_regs, write_regs = self.instrs[name]
- input_names = create_args(read_regs | uninit_regs)
+ # sigh reconstruct the assembly instruction name
+ ov_en = yield self.dec2.e.oe.oe
+ ov_ok = yield self.dec2.e.oe.ok
+ if ov_en & ov_ok:
+ asmop += "."
+ lk = yield self.dec2.e.lk
+ if lk:
+ asmop += "l"
+ int_op = yield self.dec2.dec.op.internal_op
+ print ("int_op", int_op)
+ if int_op in [InternalOp.OP_B.value, InternalOp.OP_BC.value]:
+ AA = yield self.dec2.dec.fields.FormI.AA[0:-1]
+ print ("AA", AA)
+ if AA:
+ asmop += "a"
+ if int_op == InternalOp.OP_MFCR.value:
+ dec_insn = yield self.dec2.e.insn
+ if dec_insn & (1<<20): # sigh
+ asmop = 'mfocrf'
+ else:
+ asmop = 'mfcr'
+ if int_op == InternalOp.OP_MTCRF.value:
+ dec_insn = yield self.dec2.e.insn
+ if dec_insn & (1<<20): # sigh
+ asmop = 'mtocrf'
+ else:
+ asmop = 'mtcrf'
+ print ("call", name, asmcode, asmop)
+ assert name == asmop, "name %s != %s" % (name, asmop)
+
+ info = self.instrs[name]
+ yield from self.prep_namespace(info.form, info.op_fields)
+
+ # preserve order of register names
+ input_names = create_args(list(info.read_regs) + list(info.uninit_regs))
print(input_names)
+ # main registers (RT, RA ...)
inputs = []
for name in input_names:
regnum = yield getattr(self.decoder, name)
+ regname = "_" + name
+ self.namespace[regname] = regnum
print('reading reg %d' % regnum)
inputs.append(self.gpr(regnum))
+
+ # "special" registers
+ for special in info.special_regs:
+ if special in special_sprs:
+ inputs.append(self.spr[special])
+ else:
+ inputs.append(self.namespace[special])
+
print(inputs)
- results = function(self, *inputs)
+ results = info.func(self, *inputs)
print(results)
- output_names = create_args(write_regs)
- for name, output in zip(output_names, results):
- regnum = yield getattr(self.decoder, name)
- print('writing reg %d' % regnum)
- self.gpr[regnum] = output.narrow(64)
+ # detect if CA/CA32 already in outputs (sra*, basically)
+ already_done = 0
+ if info.write_regs:
+ output_names = create_args(info.write_regs)
+ for name in output_names:
+ if name == 'CA':
+ already_done |= 1
+ if name == 'CA32':
+ already_done |= 2
+
+ print ("carry already done?", bin(already_done))
+ carry_en = yield self.dec2.e.output_carry
+ if carry_en:
+ yield from self.handle_carry_(inputs, results, already_done)
+ ov_en = yield self.dec2.e.oe.oe
+ ov_ok = yield self.dec2.e.oe.ok
+ if ov_en & ov_ok:
+ yield from self.handle_overflow(inputs, results)
+ rc_en = yield self.dec2.e.rc.data
+ if rc_en:
+ self.handle_comparison(results)
+
+ # any modified return results?
+ if info.write_regs:
+ for name, output in zip(output_names, results):
+ if isinstance(output, int):
+ output = SelectableInt(output, 256)
+ if name in ['CA', 'CA32']:
+ if carry_en:
+ print ("writing %s to XER" % name, output)
+ self.spr['XER'][XER_bits[name]] = output.value
+ else:
+ print ("NOT writing %s to XER" % name, output)
+ elif name in info.special_regs:
+ print('writing special %s' % name, output, special_sprs)
+ if name in special_sprs:
+ self.spr[name] = output
+ else:
+ self.namespace[name].eq(output)
+ else:
+ regnum = yield getattr(self.decoder, name)
+ print('writing reg %d %s' % (regnum, str(output)))
+ if output.bits > 64:
+ output = SelectableInt(output.value, 64)
+ self.gpr[regnum] = output
+
+ # update program counter
+ self.pc.update(self.namespace)
def inject():
- """ Decorator factory. """
+ """Decorator factory.
+
+ this decorator will "inject" variables into the function's namespace,
+ from the *dictionary* in self.namespace. it therefore becomes possible
+ to make it look like a whole stack of variables which would otherwise
+ need "self." inserted in front of them (*and* for those variables to be
+ added to the instance) "appear" in the function.
+
+ "self.namespace['SI']" for example becomes accessible as just "SI" but
+ *only* inside the function, when decorated.
+ """
def variable_injector(func):
@wraps(func)
def decorator(*args, **kwargs):
except AttributeError:
func_globals = func.func_globals # Earlier versions.
- context = args[0].namespace
+ context = args[0].namespace # variables to be injected
saved_values = func_globals.copy() # Shallow copy of dict.
func_globals.update(context)
-
result = func(*args, **kwargs)
+ args[0].namespace = func_globals
#exec (func.__code__, func_globals)
#finally:
projects / soc.git / blobdiff