"""
from nmigen import (Elaboratable, Module, Signal, ClockSignal, ResetSignal,
- ClockDomain, DomainRenamer, Mux, Const)
+ ClockDomain, DomainRenamer, Mux, Const, Repl, Cat)
from nmigen.cli import rtlil
from nmigen.cli import main
import sys
-from soc.decoder.power_decoder import create_pdecode
-from soc.decoder.power_decoder2 import PowerDecode2, SVP64PrefixDecoder
-from soc.decoder.decode2execute1 import IssuerDecode2ToOperand
-from soc.decoder.decode2execute1 import Data
-from soc.experiment.testmem import TestMemory # test only for instructions
+from nmutil.singlepipe import ControlBase
+from soc.simple.core_data import FetchOutput, FetchInput
+
+from nmigen.lib.coding import PriorityEncoder
+
+from openpower.decoder.power_decoder import create_pdecode
+from openpower.decoder.power_decoder2 import PowerDecode2, SVP64PrefixDecoder
+from openpower.decoder.decode2execute1 import IssuerDecode2ToOperand
+from openpower.decoder.decode2execute1 import Data
+from openpower.decoder.power_enums import (MicrOp, SVP64PredInt, SVP64PredCR,
+ SVP64PredMode)
+from openpower.state import CoreState
+from openpower.consts import (CR, SVP64CROffs, MSR)
+from soc.experiment.testmem import TestMemory # test only for instructions
from soc.regfile.regfiles import StateRegs, FastRegs
from soc.simple.core import NonProductionCore
from soc.config.test.test_loadstore import TestMemPspec
from soc.config.ifetch import ConfigFetchUnit
-from soc.decoder.power_enums import MicrOp
from soc.debug.dmi import CoreDebug, DMIInterface
from soc.debug.jtag import JTAG
from soc.config.pinouts import get_pinspecs
-from soc.config.state import CoreState
from soc.interrupts.xics import XICS_ICP, XICS_ICS
from soc.bus.simple_gpio import SimpleGPIO
from soc.bus.SPBlock512W64B8W import SPBlock512W64B8W
from soc.clock.select import ClockSelect
from soc.clock.dummypll import DummyPLL
-from soc.sv.svstate import SVSTATERec
-
+from openpower.sv.svstate import SVSTATERec
+from soc.experiment.icache import ICache
from nmutil.util import rising_edge
+
def get_insn(f_instr_o, pc):
if f_instr_o.width == 32:
return f_instr_o
return f_instr_o.word_select(pc[2], 32)
# gets state input or reads from state regfile
-def state_get(m, state_i, name, regfile, regnum):
+
+
+def state_get(m, res, core_rst, state_i, name, regfile, regnum):
comb = m.d.comb
sync = m.d.sync
- # read the PC
- res = Signal(64, reset_less=True, name=name)
+ # read the {insert state variable here}
res_ok_delay = Signal(name="%s_ok_delay" % name)
- sync += res_ok_delay.eq(~state_i.ok)
- with m.If(state_i.ok):
- # incoming override (start from pc_i)
- comb += res.eq(state_i.data)
- with m.Else():
- # otherwise read StateRegs regfile for PC...
- comb += regfile.ren.eq(1<<regnum)
- # ... but on a 1-clock delay
- with m.If(res_ok_delay):
- comb += res.eq(regfile.data_o)
- return res
-
-def get_predint(m, mask):
+ with m.If(~core_rst):
+ sync += res_ok_delay.eq(~state_i.ok)
+ with m.If(state_i.ok):
+ # incoming override (start from pc_i)
+ comb += res.eq(state_i.data)
+ with m.Else():
+ # otherwise read StateRegs regfile for {insert state here}...
+ comb += regfile.ren.eq(1 << regnum)
+ # ... but on a 1-clock delay
+ with m.If(res_ok_delay):
+ comb += res.eq(regfile.o_data)
+
+
+def get_predint(m, mask, name):
"""decode SVP64 predicate integer mask field to reg number and invert
this is identical to the equivalent function in ISACaller except that
it doesn't read the INT directly, it just decodes "what needs to be done"
i.e. which INT reg, whether it is shifted and whether it is bit-inverted.
+
+ * all1s is set to indicate that no mask is to be applied.
+ * regread indicates the GPR register number to be read
+ * invert is set to indicate that the register value is to be inverted
+ * unary indicates that the contents of the register is to be shifted 1<<r3
"""
- regread = Signal(5)
- invert = Signal()
- unary = Signal()
+ comb = m.d.comb
+ regread = Signal(5, name=name+"regread")
+ invert = Signal(name=name+"invert")
+ unary = Signal(name=name+"unary")
+ all1s = Signal(name=name+"all1s")
with m.Switch(mask):
with m.Case(SVP64PredInt.ALWAYS.value):
- comb += regread.eq(0)
- comb += invert.eq(1)
+ comb += all1s.eq(1) # use 0b1111 (all ones)
with m.Case(SVP64PredInt.R3_UNARY.value):
comb += regread.eq(3)
- comb += unary.eq(1)
+ comb += unary.eq(1) # 1<<r3 - shift r3 (single bit)
with m.Case(SVP64PredInt.R3.value):
comb += regread.eq(3)
with m.Case(SVP64PredInt.R3_N.value):
with m.Case(SVP64PredInt.R30_N.value):
comb += regread.eq(30)
comb += invert.eq(1)
- return regread, invert, unary
+ return regread, invert, unary, all1s
-def get_predcr(m, mask):
+
+def get_predcr(m, mask, name):
"""decode SVP64 predicate CR to reg number field and invert status
this is identical to _get_predcr in ISACaller
"""
- idx = Signal(2)
- invert = Signal()
+ comb = m.d.comb
+ idx = Signal(2, name=name+"idx")
+ invert = Signal(name=name+"crinvert")
with m.Switch(mask):
with m.Case(SVP64PredCR.LT.value):
- comb += idx.eq(0)
- comb += invert.eq(1)
- with m.Case(SVP64PredCR.GE.value):
- comb += idx.eq(0)
+ comb += idx.eq(CR.LT)
comb += invert.eq(0)
- with m.Case(SVP64PredCR.GT.value):
- comb += idx.eq(1)
+ with m.Case(SVP64PredCR.GE.value):
+ comb += idx.eq(CR.LT)
comb += invert.eq(1)
- with m.Case(SVP64PredCR.LE.value):
- comb += idx.eq(1)
+ with m.Case(SVP64PredCR.GT.value):
+ comb += idx.eq(CR.GT)
comb += invert.eq(0)
- with m.Case(SVP64PredCR.EQ.value):
- comb += idx.eq(2)
+ with m.Case(SVP64PredCR.LE.value):
+ comb += idx.eq(CR.GT)
comb += invert.eq(1)
- with m.Case(SVP64PredCR.NE.value):
- comb += idx.eq(1)
+ with m.Case(SVP64PredCR.EQ.value):
+ comb += idx.eq(CR.EQ)
comb += invert.eq(0)
- with m.Case(SVP64PredCR.SO.value):
- comb += idx.eq(3)
+ with m.Case(SVP64PredCR.NE.value):
+ comb += idx.eq(CR.EQ)
comb += invert.eq(1)
- with m.Case(SVP64PredCR.NS.value):
- comb += idx.eq(3)
+ with m.Case(SVP64PredCR.SO.value):
+ comb += idx.eq(CR.SO)
comb += invert.eq(0)
+ with m.Case(SVP64PredCR.NS.value):
+ comb += idx.eq(CR.SO)
+ comb += invert.eq(1)
return idx, invert
-class TestIssuerInternal(Elaboratable):
- """TestIssuer - reads instructions from TestMemory and issues them
+class TestIssuerBase(Elaboratable):
+ """TestIssuerBase - common base class for Issuers
- efficiency and speed is not the main goal here: functional correctness is.
+ takes care of power-on reset, peripherals, debug, DEC/TB,
+ and gets PC/MSR/SVSTATE from the State Regfile etc.
"""
+
def __init__(self, pspec):
# test is SVP64 is to be enabled
self.svp64_en = hasattr(pspec, "svp64") and (pspec.svp64 == True)
+ # and if regfiles are reduced
+ self.regreduce_en = (hasattr(pspec, "regreduce") and
+ (pspec.regreduce == True))
+
+ # and if overlap requested
+ self.allow_overlap = (hasattr(pspec, "allow_overlap") and
+ (pspec.allow_overlap == True))
+
+ # and get the core domain
+ self.core_domain = "coresync"
+ if (hasattr(pspec, "core_domain") and
+ isinstance(pspec.core_domain, str)):
+ self.core_domain = pspec.core_domain
+
# JTAG interface. add this right at the start because if it's
# added it *modifies* the pspec, by adding enable/disable signals
# for parts of the rest of the core
self.jtag_en = hasattr(pspec, "debug") and pspec.debug == 'jtag'
+ #self.dbg_domain = "sync" # sigh "dbgsunc" too problematic
+ self.dbg_domain = "dbgsync" # domain for DMI/JTAG clock
if self.jtag_en:
- subset = {'uart', 'mtwi', 'eint', 'gpio', 'mspi0', 'mspi1',
- 'pwm', 'sd0', 'sdr'}
- self.jtag = JTAG(get_pinspecs(subset=subset))
+ # XXX MUST keep this up-to-date with litex, and
+ # soc-cocotb-sim, and err.. all needs sorting out, argh
+ subset = ['uart',
+ 'mtwi',
+ 'eint', 'gpio', 'mspi0',
+ # 'mspi1', - disabled for now
+ # 'pwm', 'sd0', - disabled for now
+ 'sdr']
+ self.jtag = JTAG(get_pinspecs(subset=subset),
+ domain=self.dbg_domain)
# add signals to pspec to enable/disable icache and dcache
# (or data and intstruction wishbone if icache/dcache not included)
# https://bugs.libre-soc.org/show_bug.cgi?id=520
self.sram4k = []
for i in range(4):
self.sram4k.append(SPBlock512W64B8W(name="sram4k_%d" % i,
- features={'err'}))
+ # features={'err'}
+ ))
# add interrupt controller?
self.xics = hasattr(pspec, "xics") and pspec.xics == True
# main instruction core. suitable for prototyping / demo only
self.core = core = NonProductionCore(pspec)
+ self.core_rst = ResetSignal(self.core_domain)
# instruction decoder. goes into Trap Record
- pdecode = create_pdecode()
- self.cur_state = CoreState("cur") # current state (MSR/PC/SVSTATE)
- self.pdecode2 = PowerDecode2(pdecode, state=self.cur_state,
+ #pdecode = create_pdecode()
+ self.cur_state = CoreState("cur") # current state (MSR/PC/SVSTATE)
+ self.pdecode2 = PowerDecode2(None, state=self.cur_state,
opkls=IssuerDecode2ToOperand,
- svp64_en=self.svp64_en)
+ svp64_en=self.svp64_en,
+ regreduce_en=self.regreduce_en)
+ pdecode = self.pdecode2.dec
+
if self.svp64_en:
- self.svp64 = SVP64PrefixDecoder() # for decoding SVP64 prefix
+ self.svp64 = SVP64PrefixDecoder() # for decoding SVP64 prefix
+
+ self.update_svstate = Signal() # set this if updating svstate
+ self.new_svstate = new_svstate = SVSTATERec("new_svstate")
# Test Instruction memory
+ if hasattr(core, "icache"):
+ # XXX BLECH! use pspec to transfer the I-Cache to ConfigFetchUnit
+ # truly dreadful. needs a huge reorg.
+ pspec.icache = core.icache
self.imem = ConfigFetchUnit(pspec).fu
# DMI interface
self.dbg = CoreDebug()
+ self.dbg_rst_i = Signal(reset_less=True)
# instruction go/monitor
self.pc_o = Signal(64, reset_less=True)
- self.pc_i = Data(64, "pc_i") # set "ok" to indicate "please change me"
- self.svstate_i = Data(32, "svstate_i") # ditto
- self.core_bigendian_i = Signal() # TODO: set based on MSR.LE
+ self.pc_i = Data(64, "pc_i") # set "ok" to indicate "please change me"
+ self.msr_i = Data(64, "msr_i") # set "ok" to indicate "please change me"
+ self.svstate_i = Data(64, "svstate_i") # ditto
+ self.core_bigendian_i = Signal() # TODO: set based on MSR.LE
self.busy_o = Signal(reset_less=True)
self.memerr_o = Signal(reset_less=True)
# STATE regfile read /write ports for PC, MSR, SVSTATE
staterf = self.core.regs.rf['state']
- self.state_r_pc = staterf.r_ports['cia'] # PC rd
- self.state_w_pc = staterf.w_ports['d_wr1'] # PC wr
- self.state_r_msr = staterf.r_ports['msr'] # MSR rd
- self.state_r_sv = staterf.r_ports['sv'] # SVSTATE rd
- self.state_w_sv = staterf.w_ports['sv'] # SVSTATE wr
+ self.state_r_msr = staterf.r_ports['msr'] # MSR rd
+ self.state_r_pc = staterf.r_ports['cia'] # PC rd
+ self.state_r_sv = staterf.r_ports['sv'] # SVSTATE rd
+
+ self.state_w_msr = staterf.w_ports['msr'] # MSR wr
+ self.state_w_pc = staterf.w_ports['d_wr1'] # PC wr
+ self.state_w_sv = staterf.w_ports['sv'] # SVSTATE wr
# DMI interface access
intrf = self.core.regs.rf['int']
crrf = self.core.regs.rf['cr']
xerrf = self.core.regs.rf['xer']
- self.int_r = intrf.r_ports['dmi'] # INT read
- self.cr_r = crrf.r_ports['full_cr_dbg'] # CR read
- self.xer_r = xerrf.r_ports['full_xer'] # XER read
+ self.int_r = intrf.r_ports['dmi'] # INT read
+ self.cr_r = crrf.r_ports['full_cr_dbg'] # CR read
+ self.xer_r = xerrf.r_ports['full_xer'] # XER read
- # for predication
- self.int_pred = intrf.r_ports['pred'] # INT predicate read
- self.cr_pred = crrf.r_ports['cr_pred'] # CR predicate read
+ if self.svp64_en:
+ # for predication
+ self.int_pred = intrf.r_ports['pred'] # INT predicate read
+ self.cr_pred = crrf.r_ports['cr_pred'] # CR predicate read
# hack method of keeping an eye on whether branch/trap set the PC
self.state_nia = self.core.regs.rf['state'].w_ports['nia']
# pulse to synchronize the simulator at instruction end
self.insn_done = Signal()
+ # indicate any instruction still outstanding, in execution
+ self.any_busy = Signal()
+
if self.svp64_en:
# store copies of predicate masks
self.srcmask = Signal(64)
self.dstmask = Signal(64)
- def fetch_fsm(self, m, core, pc, svstate, nia, is_svp64_mode,
- fetch_pc_ready_o, fetch_pc_valid_i,
- fetch_insn_valid_o, fetch_insn_ready_i):
+ def setup_peripherals(self, m):
+ comb, sync = m.d.comb, m.d.sync
+
+ # okaaaay so the debug module must be in coresync clock domain
+ # but NOT its reset signal. to cope with this, set every single
+ # submodule explicitly in coresync domain, debug and JTAG
+ # in their own one but using *external* reset.
+ csd = DomainRenamer(self.core_domain)
+ dbd = DomainRenamer(self.dbg_domain)
+
+ m.submodules.core = core = csd(self.core)
+ # this _so_ needs sorting out. ICache is added down inside
+ # LoadStore1 and is already a submodule of LoadStore1
+ if not isinstance(self.imem, ICache):
+ m.submodules.imem = imem = csd(self.imem)
+ m.submodules.dbg = dbg = dbd(self.dbg)
+ if self.jtag_en:
+ m.submodules.jtag = jtag = dbd(self.jtag)
+ # TODO: UART2GDB mux, here, from external pin
+ # see https://bugs.libre-soc.org/show_bug.cgi?id=499
+ sync += dbg.dmi.connect_to(jtag.dmi)
+
+ cur_state = self.cur_state
+
+ # 4x 4k SRAM blocks. these simply "exist", they get routed in litex
+ if self.sram4x4k:
+ for i, sram in enumerate(self.sram4k):
+ m.submodules["sram4k_%d" % i] = csd(sram)
+ comb += sram.enable.eq(self.wb_sram_en)
+
+ # XICS interrupt handler
+ if self.xics:
+ m.submodules.xics_icp = icp = csd(self.xics_icp)
+ m.submodules.xics_ics = ics = csd(self.xics_ics)
+ comb += icp.ics_i.eq(ics.icp_o) # connect ICS to ICP
+ sync += cur_state.eint.eq(icp.core_irq_o) # connect ICP to core
+
+ # GPIO test peripheral
+ if self.gpio:
+ m.submodules.simple_gpio = simple_gpio = csd(self.simple_gpio)
+
+ # connect one GPIO output to ICS bit 15 (like in microwatt soc.vhdl)
+ # XXX causes litex ECP5 test to get wrong idea about input and output
+ # (but works with verilator sim *sigh*)
+ # if self.gpio and self.xics:
+ # comb += self.int_level_i[15].eq(simple_gpio.gpio_o[0])
+
+ # instruction decoder
+ pdecode = create_pdecode()
+ m.submodules.dec2 = pdecode2 = csd(self.pdecode2)
+ if self.svp64_en:
+ m.submodules.svp64 = svp64 = csd(self.svp64)
+
+ # convenience
+ dmi, d_reg, d_cr, d_xer, = dbg.dmi, dbg.d_gpr, dbg.d_cr, dbg.d_xer
+ intrf = self.core.regs.rf['int']
+
+ # clock delay power-on reset
+ cd_por = ClockDomain(reset_less=True)
+ cd_sync = ClockDomain()
+ m.domains += cd_por, cd_sync
+ core_sync = ClockDomain(self.core_domain)
+ if self.core_domain != "sync":
+ m.domains += core_sync
+ if self.dbg_domain != "sync":
+ dbg_sync = ClockDomain(self.dbg_domain)
+ m.domains += dbg_sync
+
+ ti_rst = Signal(reset_less=True)
+ delay = Signal(range(4), reset=3)
+ with m.If(delay != 0):
+ m.d.por += delay.eq(delay - 1)
+ comb += cd_por.clk.eq(ClockSignal())
+
+ # power-on reset delay
+ core_rst = ResetSignal(self.core_domain)
+ if self.core_domain != "sync":
+ comb += ti_rst.eq(delay != 0 | dbg.core_rst_o | ResetSignal())
+ comb += core_rst.eq(ti_rst)
+ else:
+ with m.If(delay != 0 | dbg.core_rst_o):
+ comb += core_rst.eq(1)
+
+ # connect external reset signal to DMI Reset
+ if self.dbg_domain != "sync":
+ dbg_rst = ResetSignal(self.dbg_domain)
+ comb += dbg_rst.eq(self.dbg_rst_i)
+
+ # busy/halted signals from core
+ core_busy_o = ~core.p.o_ready | core.n.o_data.busy_o # core is busy
+ comb += self.busy_o.eq(core_busy_o)
+ comb += pdecode2.dec.bigendian.eq(self.core_bigendian_i)
+
+ # temporary hack: says "go" immediately for both address gen and ST
+ l0 = core.l0
+ ldst = core.fus.fus['ldst0']
+ st_go_edge = rising_edge(m, ldst.st.rel_o)
+ # link addr-go direct to rel
+ m.d.comb += ldst.ad.go_i.eq(ldst.ad.rel_o)
+ m.d.comb += ldst.st.go_i.eq(st_go_edge) # link store-go to rising rel
+
+ def do_dmi(self, m, dbg):
+ """deals with DMI debug requests
+
+ currently only provides read requests for the INT regfile, CR and XER
+ it will later also deal with *writing* to these regfiles.
+ """
+ comb = m.d.comb
+ sync = m.d.sync
+ dmi, d_reg, d_cr, d_xer, = dbg.dmi, dbg.d_gpr, dbg.d_cr, dbg.d_xer
+ intrf = self.core.regs.rf['int']
+
+ with m.If(d_reg.req): # request for regfile access being made
+ # TODO: error-check this
+ # XXX should this be combinatorial? sync better?
+ if intrf.unary:
+ comb += self.int_r.ren.eq(1 << d_reg.addr)
+ else:
+ comb += self.int_r.addr.eq(d_reg.addr)
+ comb += self.int_r.ren.eq(1)
+ d_reg_delay = Signal()
+ sync += d_reg_delay.eq(d_reg.req)
+ with m.If(d_reg_delay):
+ # data arrives one clock later
+ comb += d_reg.data.eq(self.int_r.o_data)
+ comb += d_reg.ack.eq(1)
+
+ # sigh same thing for CR debug
+ with m.If(d_cr.req): # request for regfile access being made
+ comb += self.cr_r.ren.eq(0b11111111) # enable all
+ d_cr_delay = Signal()
+ sync += d_cr_delay.eq(d_cr.req)
+ with m.If(d_cr_delay):
+ # data arrives one clock later
+ comb += d_cr.data.eq(self.cr_r.o_data)
+ comb += d_cr.ack.eq(1)
+
+ # aaand XER...
+ with m.If(d_xer.req): # request for regfile access being made
+ comb += self.xer_r.ren.eq(0b111111) # enable all
+ d_xer_delay = Signal()
+ sync += d_xer_delay.eq(d_xer.req)
+ with m.If(d_xer_delay):
+ # data arrives one clock later
+ comb += d_xer.data.eq(self.xer_r.o_data)
+ comb += d_xer.ack.eq(1)
+
+ def tb_dec_fsm(self, m, spr_dec):
+ """tb_dec_fsm
+
+ this is a FSM for updating either dec or tb. it runs alternately
+ DEC, TB, DEC, TB. note that SPR pipeline could have written a new
+ value to DEC, however the regfile has "passthrough" on it so this
+ *should* be ok.
+
+ see v3.0B p1097-1099 for Timeer Resource and p1065 and p1076
+ """
+
+ comb, sync = m.d.comb, m.d.sync
+ fast_rf = self.core.regs.rf['fast']
+ fast_r_dectb = fast_rf.r_ports['issue'] # DEC/TB
+ fast_w_dectb = fast_rf.w_ports['issue'] # DEC/TB
+
+ with m.FSM() as fsm:
+
+ # initiates read of current DEC
+ with m.State("DEC_READ"):
+ comb += fast_r_dectb.addr.eq(FastRegs.DEC)
+ comb += fast_r_dectb.ren.eq(1)
+ m.next = "DEC_WRITE"
+
+ # waits for DEC read to arrive (1 cycle), updates with new value
+ with m.State("DEC_WRITE"):
+ new_dec = Signal(64)
+ # TODO: MSR.LPCR 32-bit decrement mode
+ comb += new_dec.eq(fast_r_dectb.o_data - 1)
+ comb += fast_w_dectb.addr.eq(FastRegs.DEC)
+ comb += fast_w_dectb.wen.eq(1)
+ comb += fast_w_dectb.i_data.eq(new_dec)
+ sync += spr_dec.eq(new_dec) # copy into cur_state for decoder
+ m.next = "TB_READ"
+
+ # initiates read of current TB
+ with m.State("TB_READ"):
+ comb += fast_r_dectb.addr.eq(FastRegs.TB)
+ comb += fast_r_dectb.ren.eq(1)
+ m.next = "TB_WRITE"
+
+ # waits for read TB to arrive, initiates write of current TB
+ with m.State("TB_WRITE"):
+ new_tb = Signal(64)
+ comb += new_tb.eq(fast_r_dectb.o_data + 1)
+ comb += fast_w_dectb.addr.eq(FastRegs.TB)
+ comb += fast_w_dectb.wen.eq(1)
+ comb += fast_w_dectb.i_data.eq(new_tb)
+ m.next = "DEC_READ"
+
+ return m
+
+ def elaborate(self, platform):
+ m = Module()
+ # convenience
+ comb, sync = m.d.comb, m.d.sync
+ cur_state = self.cur_state
+ pdecode2 = self.pdecode2
+ dbg = self.dbg
+
+ # set up peripherals and core
+ core_rst = self.core_rst
+ self.setup_peripherals(m)
+
+ # reset current state if core reset requested
+ with m.If(core_rst):
+ m.d.sync += self.cur_state.eq(0)
+
+ # check halted condition: requested PC to execute matches DMI stop addr
+ # and immediately stop. address of 0xffff_ffff_ffff_ffff can never
+ # match
+ halted = Signal()
+ comb += halted.eq(dbg.stop_addr_o == dbg.state.pc)
+ with m.If(halted):
+ comb += dbg.core_stopped_i.eq(1)
+ comb += dbg.terminate_i.eq(1)
+
+ # PC and instruction from I-Memory
+ comb += self.pc_o.eq(cur_state.pc)
+ self.pc_changed = Signal() # note write to PC
+ self.msr_changed = Signal() # note write to MSR
+ self.sv_changed = Signal() # note write to SVSTATE
+
+ # read state either from incoming override or from regfile
+ state = CoreState("get") # current state (MSR/PC/SVSTATE)
+ state_get(m, state.msr, core_rst, self.msr_i,
+ "msr", # read MSR
+ self.state_r_msr, StateRegs.MSR)
+ state_get(m, state.pc, core_rst, self.pc_i,
+ "pc", # read PC
+ self.state_r_pc, StateRegs.PC)
+ state_get(m, state.svstate, core_rst, self.svstate_i,
+ "svstate", # read SVSTATE
+ self.state_r_sv, StateRegs.SVSTATE)
+
+ # don't write pc every cycle
+ comb += self.state_w_pc.wen.eq(0)
+ comb += self.state_w_pc.i_data.eq(0)
+
+ # connect up debug state. note "combinatorially same" below,
+ # this is a bit naff, passing state over in the dbg class, but
+ # because it is combinatorial it achieves the desired goal
+ comb += dbg.state.eq(state)
+
+ # this bit doesn't have to be in the FSM: connect up to read
+ # regfiles on demand from DMI
+ self.do_dmi(m, dbg)
+
+ # DEC and TB inc/dec FSM. copy of DEC is put into CoreState,
+ # (which uses that in PowerDecoder2 to raise 0x900 exception)
+ self.tb_dec_fsm(m, cur_state.dec)
+
+ # while stopped, allow updating the MSR, PC and SVSTATE.
+ # these are mainly for debugging purposes (including DMI/JTAG)
+ with m.If(dbg.core_stopped_i):
+ with m.If(self.pc_i.ok):
+ comb += self.state_w_pc.wen.eq(1 << StateRegs.PC)
+ comb += self.state_w_pc.i_data.eq(self.pc_i.data)
+ sync += self.pc_changed.eq(1)
+ with m.If(self.msr_i.ok):
+ comb += self.state_w_msr.wen.eq(1 << StateRegs.MSR)
+ comb += self.state_w_msr.i_data.eq(self.msr_i.data)
+ sync += self.msr_changed.eq(1)
+ with m.If(self.svstate_i.ok | self.update_svstate):
+ with m.If(self.svstate_i.ok): # over-ride from external source
+ comb += self.new_svstate.eq(self.svstate_i.data)
+ comb += self.state_w_sv.wen.eq(1 << StateRegs.SVSTATE)
+ comb += self.state_w_sv.i_data.eq(self.new_svstate)
+ sync += self.sv_changed.eq(1)
+
+ return m
+
+ def __iter__(self):
+ yield from self.pc_i.ports()
+ yield from self.msr_i.ports()
+ yield self.pc_o
+ yield self.memerr_o
+ yield from self.core.ports()
+ yield from self.imem.ports()
+ yield self.core_bigendian_i
+ yield self.busy_o
+
+ def ports(self):
+ return list(self)
+
+ def external_ports(self):
+ ports = self.pc_i.ports()
+ ports = self.msr_i.ports()
+ ports += [self.pc_o, self.memerr_o, self.core_bigendian_i, self.busy_o,
+ ]
+
+ if self.jtag_en:
+ ports += list(self.jtag.external_ports())
+ else:
+ # don't add DMI if JTAG is enabled
+ ports += list(self.dbg.dmi.ports())
+
+ ports += list(self.imem.ibus.fields.values())
+ ports += list(self.core.l0.cmpi.wb_bus().fields.values())
+
+ if self.sram4x4k:
+ for sram in self.sram4k:
+ ports += list(sram.bus.fields.values())
+
+ if self.xics:
+ ports += list(self.xics_icp.bus.fields.values())
+ ports += list(self.xics_ics.bus.fields.values())
+ ports.append(self.int_level_i)
+
+ if self.gpio:
+ ports += list(self.simple_gpio.bus.fields.values())
+ ports.append(self.gpio_o)
+
+ return ports
+
+ def ports(self):
+ return list(self)
+
+
+
+# Fetch Finite State Machine.
+# WARNING: there are currently DriverConflicts but it's actually working.
+# TODO, here: everything that is global in nature, information from the
+# main TestIssuerInternal, needs to move to either ispec() or ospec().
+# not only that: TestIssuerInternal.imem can entirely move into here
+# because imem is only ever accessed inside the FetchFSM.
+class FetchFSM(ControlBase):
+ def __init__(self, allow_overlap, svp64_en, imem, core_rst,
+ pdecode2, cur_state,
+ dbg, core, svstate, nia, is_svp64_mode):
+ self.allow_overlap = allow_overlap
+ self.svp64_en = svp64_en
+ self.imem = imem
+ self.core_rst = core_rst
+ self.pdecode2 = pdecode2
+ self.cur_state = cur_state
+ self.dbg = dbg
+ self.core = core
+ self.svstate = svstate
+ self.nia = nia
+ self.is_svp64_mode = is_svp64_mode
+
+ # set up pipeline ControlBase and allocate i/o specs
+ # (unusual: normally done by the Pipeline API)
+ super().__init__(stage=self)
+ self.p.i_data, self.n.o_data = self.new_specs(None)
+ self.i, self.o = self.p.i_data, self.n.o_data
+
+ # next 3 functions are Stage API Compliance
+ def setup(self, m, i):
+ pass
+
+ def ispec(self):
+ return FetchInput()
+
+ def ospec(self):
+ return FetchOutput()
+
+ def elaborate(self, platform):
"""fetch FSM
+
this FSM performs fetch of raw instruction data, partial-decodes
it 32-bit at a time to detect SVP64 prefixes, and will optionally
read a 2nd 32-bit quantity if that occurs.
"""
+ m = super().elaborate(platform)
+
+ dbg = self.dbg
+ core = self.core
+ pc = self.i.pc
+ msr = self.i.msr
+ svstate = self.svstate
+ nia = self.nia
+ is_svp64_mode = self.is_svp64_mode
+ fetch_pc_o_ready = self.p.o_ready
+ fetch_pc_i_valid = self.p.i_valid
+ fetch_insn_o_valid = self.n.o_valid
+ fetch_insn_i_ready = self.n.i_ready
+
comb = m.d.comb
sync = m.d.sync
pdecode2 = self.pdecode2
cur_state = self.cur_state
- dec_opcode_i = pdecode2.dec.raw_opcode_in # raw opcode
+ dec_opcode_o = pdecode2.dec.raw_opcode_in # raw opcode
+
+ # also note instruction fetch failed
+ if hasattr(core, "icache"):
+ fetch_failed = core.icache.i_out.fetch_failed
+ flush_needed = True
+ else:
+ fetch_failed = Const(0, 1)
+ flush_needed = False
- msr_read = Signal(reset=1)
+ # set priv / virt mode on I-Cache, sigh
+ if isinstance(self.imem, ICache):
+ comb += self.imem.i_in.priv_mode.eq(~msr[MSR.PR])
+ comb += self.imem.i_in.virt_mode.eq(msr[MSR.IR]) # Instr. Redir (VM)
with m.FSM(name='fetch_fsm'):
# waiting (zzz)
with m.State("IDLE"):
- comb += fetch_pc_ready_o.eq(1)
- with m.If(fetch_pc_valid_i):
+ # fetch allowed if not failed and stopped but not stepping
+ # (see dmi.py for how core_stop_o is generated)
+ with m.If(~fetch_failed & ~dbg.core_stop_o):
+ comb += fetch_pc_o_ready.eq(1)
+ with m.If(fetch_pc_i_valid & ~pdecode2.instr_fault
+ & ~dbg.core_stop_o):
# instruction allowed to go: start by reading the PC
# capture the PC and also drop it into Insn Memory
# we have joined a pair of combinatorial memory
# lookups together. this is Generally Bad.
comb += self.imem.a_pc_i.eq(pc)
- comb += self.imem.a_valid_i.eq(1)
- comb += self.imem.f_valid_i.eq(1)
+ comb += self.imem.a_i_valid.eq(1)
+ comb += self.imem.f_i_valid.eq(1)
+ # transfer state to output
sync += cur_state.pc.eq(pc)
- sync += cur_state.svstate.eq(svstate) # and svstate
-
- # initiate read of MSR. arrives one clock later
- comb += self.state_r_msr.ren.eq(1 << StateRegs.MSR)
- sync += msr_read.eq(0)
+ sync += cur_state.svstate.eq(svstate) # and svstate
+ sync += cur_state.msr.eq(msr) # and msr
m.next = "INSN_READ" # move to "wait for bus" phase
# dummy pause to find out why simulation is not keeping up
with m.State("INSN_READ"):
- # one cycle later, msr/sv read arrives. valid only once.
- with m.If(~msr_read):
- sync += msr_read.eq(1) # yeah don't read it again
- sync += cur_state.msr.eq(self.state_r_msr.data_o)
- with m.If(self.imem.f_busy_o): # zzz...
- # busy: stay in wait-read
- comb += self.imem.a_valid_i.eq(1)
- comb += self.imem.f_valid_i.eq(1)
+ # when using "single-step" mode, checking dbg.stopping_o
+ # prevents progress. allow fetch to proceed once started
+ stopping = Const(0)
+ #if self.allow_overlap:
+ # stopping = dbg.stopping_o
+ with m.If(stopping):
+ # stopping: jump back to idle
+ m.next = "IDLE"
with m.Else():
- # not busy: instruction fetched
- insn = get_insn(self.imem.f_instr_o, cur_state.pc)
- if self.svp64_en:
- svp64 = self.svp64
- # decode the SVP64 prefix, if any
- comb += svp64.raw_opcode_in.eq(insn)
- comb += svp64.bigendian.eq(self.core_bigendian_i)
- # pass the decoded prefix (if any) to PowerDecoder2
- sync += pdecode2.sv_rm.eq(svp64.svp64_rm)
- # remember whether this is a prefixed instruction, so
- # the FSM can readily loop when VL==0
- sync += is_svp64_mode.eq(svp64.is_svp64_mode)
- # calculate the address of the following instruction
- insn_size = Mux(svp64.is_svp64_mode, 8, 4)
- sync += nia.eq(cur_state.pc + insn_size)
- with m.If(~svp64.is_svp64_mode):
- # with no prefix, store the instruction
- # and hand it directly to the next FSM
- sync += dec_opcode_i.eq(insn)
+ with m.If(self.imem.f_busy_o &
+ ~pdecode2.instr_fault): # zzz...
+ # busy but not fetch failed: stay in wait-read
+ comb += self.imem.a_pc_i.eq(pc)
+ comb += self.imem.a_i_valid.eq(1)
+ comb += self.imem.f_i_valid.eq(1)
+ with m.Else():
+ # not busy (or fetch failed!): instruction fetched
+ # when fetch failed, the instruction gets ignored
+ # by the decoder
+ if hasattr(core, "icache"):
+ # blech, icache returns actual instruction
+ insn = self.imem.f_instr_o
+ else:
+ # but these return raw memory
+ insn = get_insn(self.imem.f_instr_o, cur_state.pc)
+ if self.svp64_en:
+ svp64 = self.svp64
+ # decode the SVP64 prefix, if any
+ comb += svp64.raw_opcode_in.eq(insn)
+ comb += svp64.bigendian.eq(self.core_bigendian_i)
+ # pass the decoded prefix (if any) to PowerDecoder2
+ sync += pdecode2.sv_rm.eq(svp64.svp64_rm)
+ sync += pdecode2.is_svp64_mode.eq(is_svp64_mode)
+ # remember whether this is a prefixed instruction,
+ # so the FSM can readily loop when VL==0
+ sync += is_svp64_mode.eq(svp64.is_svp64_mode)
+ # calculate the address of the following instruction
+ insn_size = Mux(svp64.is_svp64_mode, 8, 4)
+ sync += nia.eq(cur_state.pc + insn_size)
+ with m.If(~svp64.is_svp64_mode):
+ # with no prefix, store the instruction
+ # and hand it directly to the next FSM
+ sync += dec_opcode_o.eq(insn)
+ m.next = "INSN_READY"
+ with m.Else():
+ # fetch the rest of the instruction from memory
+ comb += self.imem.a_pc_i.eq(cur_state.pc + 4)
+ comb += self.imem.a_i_valid.eq(1)
+ comb += self.imem.f_i_valid.eq(1)
+ m.next = "INSN_READ2"
+ else:
+ # not SVP64 - 32-bit only
+ sync += nia.eq(cur_state.pc + 4)
+ sync += dec_opcode_o.eq(insn)
m.next = "INSN_READY"
- with m.Else():
- # fetch the rest of the instruction from memory
- comb += self.imem.a_pc_i.eq(cur_state.pc + 4)
- comb += self.imem.a_valid_i.eq(1)
- comb += self.imem.f_valid_i.eq(1)
- m.next = "INSN_READ2"
- else:
- # not SVP64 - 32-bit only
- sync += nia.eq(cur_state.pc + 4)
- sync += dec_opcode_i.eq(insn)
- m.next = "INSN_READY"
with m.State("INSN_READ2"):
with m.If(self.imem.f_busy_o): # zzz...
# busy: stay in wait-read
- comb += self.imem.a_valid_i.eq(1)
- comb += self.imem.f_valid_i.eq(1)
+ comb += self.imem.a_i_valid.eq(1)
+ comb += self.imem.f_i_valid.eq(1)
with m.Else():
# not busy: instruction fetched
- insn = get_insn(self.imem.f_instr_o, cur_state.pc+4)
- sync += dec_opcode_i.eq(insn)
+ if hasattr(core, "icache"):
+ # blech, icache returns actual instruction
+ insn = self.imem.f_instr_o
+ else:
+ insn = get_insn(self.imem.f_instr_o, cur_state.pc+4)
+ sync += dec_opcode_o.eq(insn)
m.next = "INSN_READY"
# TODO: probably can start looking at pdecode2.rm_dec
- # here (or maybe even in INSN_READ state, if svp64_mode
+ # here or maybe even in INSN_READ state, if svp64_mode
# detected, in order to trigger - and wait for - the
# predicate reading.
- pmode = pdecode2.rm_dec.predmode
+ if self.svp64_en:
+ pmode = pdecode2.rm_dec.predmode
"""
if pmode != SVP64PredMode.ALWAYS.value:
fire predicate loading FSM and wait before
m.next = "INSN_READY"
"""
- with m.State("INSN_READY"):
- # hand over the instruction, to be decoded
- comb += fetch_insn_valid_o.eq(1)
- with m.If(fetch_insn_ready_i):
- m.next = "IDLE"
+ with m.State("INSN_READY"):
+ # hand over the instruction, to be decoded
+ comb += fetch_insn_o_valid.eq(1)
+ with m.If(fetch_insn_i_ready):
+ m.next = "IDLE"
+
+ # whatever was done above, over-ride it if core reset is held
+ with m.If(self.core_rst):
+ sync += nia.eq(0)
+
+ return m
+
+
+class TestIssuerInternal(TestIssuerBase):
+ """TestIssuer - reads instructions from TestMemory and issues them
+
+ efficiency and speed is not the main goal here: functional correctness
+ and code clarity is. optimisations (which almost 100% interfere with
+ easy understanding) come later.
+ """
def fetch_predicate_fsm(self, m,
- pred_insn_valid_i, pred_insn_ready_o,
- pred_mask_valid_o, pred_mask_ready_i):
+ pred_insn_i_valid, pred_insn_o_ready,
+ pred_mask_o_valid, pred_mask_i_ready):
"""fetch_predicate_fsm - obtains (constructs in the case of CR)
src/dest predicate masks
be done through multiple reads, extracting one relevant at a time.
later, a faster way would be to use the 32-bit-wide CR port but
this is more complex decoding, here. equivalent code used in
- ISACaller is "from soc.decoder.isa.caller import get_predcr"
+ ISACaller is "from openpower.decoder.isa.caller import get_predcr"
+
+ note: this ENTIRE FSM is not to be called when svp64 is disabled
"""
comb = m.d.comb
sync = m.d.sync
pdecode2 = self.pdecode2
- rm_dec = pdecode2.rm_dec # SVP64RMModeDecode
+ rm_dec = pdecode2.rm_dec # SVP64RMModeDecode
predmode = rm_dec.predmode
srcpred, dstpred = rm_dec.srcpred, rm_dec.dstpred
cr_pred, int_pred = self.cr_pred, self.int_pred # read regfiles
- # if predmode == INT:
- # INT-src sregread, sinvert, sunary = get_predint(m, srcpred)
- # INT-dst dregread, dinvert, dunary = get_predint(m, dstpred)
- # TODO read INT-src and INT-dst into self.srcmask+dstmask
- # elif predmode == CR:
- # CR-src sidx, sinvert = get_predcr(m, srcpred)
- # CR-dst didx, dinvert = get_predcr(m, dstpred)
- # TODO read CR-src and CR-dst into self.srcmask+dstmask with loop
- # else
- # sync += self.srcmask.eq(-1) # set to all 1s
- # sync += self.dstmask.eq(-1) # set to all 1s
+ # get src/dst step, so we can skip already used mask bits
+ cur_state = self.cur_state
+ srcstep = cur_state.svstate.srcstep
+ dststep = cur_state.svstate.dststep
+ cur_vl = cur_state.svstate.vl
+
+ # decode predicates
+ sregread, sinvert, sunary, sall1s = get_predint(m, srcpred, 's')
+ dregread, dinvert, dunary, dall1s = get_predint(m, dstpred, 'd')
+ sidx, scrinvert = get_predcr(m, srcpred, 's')
+ didx, dcrinvert = get_predcr(m, dstpred, 'd')
+
+ # store fetched masks, for either intpred or crpred
+ # when src/dst step is not zero, the skipped mask bits need to be
+ # shifted-out, before actually storing them in src/dest mask
+ new_srcmask = Signal(64, reset_less=True)
+ new_dstmask = Signal(64, reset_less=True)
+
with m.FSM(name="fetch_predicate"):
with m.State("FETCH_PRED_IDLE"):
- comb += pred_insn_ready_o.eq(1)
- with m.If(pred_insn_valid_i):
- sync += self.srcmask.eq(-1)
- sync += self.dstmask.eq(-1)
- m.next = "FETCH_PRED_DONE"
+ comb += pred_insn_o_ready.eq(1)
+ with m.If(pred_insn_i_valid):
+ with m.If(predmode == SVP64PredMode.INT):
+ # skip fetching destination mask register, when zero
+ with m.If(dall1s):
+ sync += new_dstmask.eq(-1)
+ # directly go to fetch source mask register
+ # guaranteed not to be zero (otherwise predmode
+ # would be SVP64PredMode.ALWAYS, not INT)
+ comb += int_pred.addr.eq(sregread)
+ comb += int_pred.ren.eq(1)
+ m.next = "INT_SRC_READ"
+ # fetch destination predicate register
+ with m.Else():
+ comb += int_pred.addr.eq(dregread)
+ comb += int_pred.ren.eq(1)
+ m.next = "INT_DST_READ"
+ with m.Elif(predmode == SVP64PredMode.CR):
+ # go fetch masks from the CR register file
+ sync += new_srcmask.eq(0)
+ sync += new_dstmask.eq(0)
+ m.next = "CR_READ"
+ with m.Else():
+ sync += self.srcmask.eq(-1)
+ sync += self.dstmask.eq(-1)
+ m.next = "FETCH_PRED_DONE"
+
+ with m.State("INT_DST_READ"):
+ # store destination mask
+ inv = Repl(dinvert, 64)
+ with m.If(dunary):
+ # set selected mask bit for 1<<r3 mode
+ dst_shift = Signal(range(64))
+ comb += dst_shift.eq(self.int_pred.o_data & 0b111111)
+ sync += new_dstmask.eq(1 << dst_shift)
+ with m.Else():
+ # invert mask if requested
+ sync += new_dstmask.eq(self.int_pred.o_data ^ inv)
+ # skip fetching source mask register, when zero
+ with m.If(sall1s):
+ sync += new_srcmask.eq(-1)
+ m.next = "FETCH_PRED_SHIFT_MASK"
+ # fetch source predicate register
+ with m.Else():
+ comb += int_pred.addr.eq(sregread)
+ comb += int_pred.ren.eq(1)
+ m.next = "INT_SRC_READ"
+
+ with m.State("INT_SRC_READ"):
+ # store source mask
+ inv = Repl(sinvert, 64)
+ with m.If(sunary):
+ # set selected mask bit for 1<<r3 mode
+ src_shift = Signal(range(64))
+ comb += src_shift.eq(self.int_pred.o_data & 0b111111)
+ sync += new_srcmask.eq(1 << src_shift)
+ with m.Else():
+ # invert mask if requested
+ sync += new_srcmask.eq(self.int_pred.o_data ^ inv)
+ m.next = "FETCH_PRED_SHIFT_MASK"
+
+ # fetch masks from the CR register file
+ # implements the following loop:
+ # idx, inv = get_predcr(mask)
+ # mask = 0
+ # for cr_idx in range(vl):
+ # cr = crl[cr_idx + SVP64CROffs.CRPred] # takes one cycle
+ # if cr[idx] ^ inv:
+ # mask |= 1 << cr_idx
+ # return mask
+ with m.State("CR_READ"):
+ # CR index to be read, which will be ready by the next cycle
+ cr_idx = Signal.like(cur_vl, reset_less=True)
+ # submit the read operation to the regfile
+ with m.If(cr_idx != cur_vl):
+ # the CR read port is unary ...
+ # ren = 1 << cr_idx
+ # ... in MSB0 convention ...
+ # ren = 1 << (7 - cr_idx)
+ # ... and with an offset:
+ # ren = 1 << (7 - off - cr_idx)
+ idx = SVP64CROffs.CRPred + cr_idx
+ comb += cr_pred.ren.eq(1 << (7 - idx))
+ # signal data valid in the next cycle
+ cr_read = Signal(reset_less=True)
+ sync += cr_read.eq(1)
+ # load the next index
+ sync += cr_idx.eq(cr_idx + 1)
+ with m.Else():
+ # exit on loop end
+ sync += cr_read.eq(0)
+ sync += cr_idx.eq(0)
+ m.next = "FETCH_PRED_SHIFT_MASK"
+ with m.If(cr_read):
+ # compensate for the one cycle delay on the regfile
+ cur_cr_idx = Signal.like(cur_vl)
+ comb += cur_cr_idx.eq(cr_idx - 1)
+ # read the CR field, select the appropriate bit
+ cr_field = Signal(4)
+ scr_bit = Signal()
+ dcr_bit = Signal()
+ comb += cr_field.eq(cr_pred.o_data)
+ comb += scr_bit.eq(cr_field.bit_select(sidx, 1)
+ ^ scrinvert)
+ comb += dcr_bit.eq(cr_field.bit_select(didx, 1)
+ ^ dcrinvert)
+ # set the corresponding mask bit
+ bit_to_set = Signal.like(self.srcmask)
+ comb += bit_to_set.eq(1 << cur_cr_idx)
+ with m.If(scr_bit):
+ sync += new_srcmask.eq(new_srcmask | bit_to_set)
+ with m.If(dcr_bit):
+ sync += new_dstmask.eq(new_dstmask | bit_to_set)
+
+ with m.State("FETCH_PRED_SHIFT_MASK"):
+ # shift-out skipped mask bits
+ sync += self.srcmask.eq(new_srcmask >> srcstep)
+ sync += self.dstmask.eq(new_dstmask >> dststep)
+ m.next = "FETCH_PRED_DONE"
with m.State("FETCH_PRED_DONE"):
- comb += pred_mask_valid_o.eq(1)
- with m.If(pred_mask_ready_i):
+ comb += pred_mask_o_valid.eq(1)
+ with m.If(pred_mask_i_ready):
m.next = "FETCH_PRED_IDLE"
- def issue_fsm(self, m, core, pc_changed, sv_changed, nia,
+ def issue_fsm(self, m, core, nia,
dbg, core_rst, is_svp64_mode,
- fetch_pc_ready_o, fetch_pc_valid_i,
- fetch_insn_valid_o, fetch_insn_ready_i,
- pred_insn_valid_i, pred_insn_ready_o,
- pred_mask_valid_o, pred_mask_ready_i,
- exec_insn_valid_i, exec_insn_ready_o,
- exec_pc_valid_o, exec_pc_ready_i):
+ fetch_pc_o_ready, fetch_pc_i_valid,
+ fetch_insn_o_valid, fetch_insn_i_ready,
+ pred_insn_i_valid, pred_insn_o_ready,
+ pred_mask_o_valid, pred_mask_i_ready,
+ exec_insn_i_valid, exec_insn_o_ready,
+ exec_pc_o_valid, exec_pc_i_ready):
"""issue FSM
decode / issue FSM. this interacts with the "fetch" FSM
sync = m.d.sync
pdecode2 = self.pdecode2
cur_state = self.cur_state
+ new_svstate = self.new_svstate
# temporaries
- dec_opcode_i = pdecode2.dec.raw_opcode_in # raw opcode
+ dec_opcode_i = pdecode2.dec.raw_opcode_in # raw opcode
# for updating svstate (things like srcstep etc.)
- update_svstate = Signal() # set this (below) if updating
- new_svstate = SVSTATERec("new_svstate")
comb += new_svstate.eq(cur_state.svstate)
# precalculate srcstep+1 and dststep+1
comb += next_srcstep.eq(cur_state.svstate.srcstep+1)
comb += next_dststep.eq(cur_state.svstate.dststep+1)
+ # note if an exception happened. in a pipelined or OoO design
+ # this needs to be accompanied by "shadowing" (or stalling)
+ exc_happened = self.core.o.exc_happened
+ # also note instruction fetch failed
+ if hasattr(core, "icache"):
+ fetch_failed = core.icache.i_out.fetch_failed
+ flush_needed = True
+ # set to fault in decoder
+ # update (highest priority) instruction fault
+ rising_fetch_failed = rising_edge(m, fetch_failed)
+ with m.If(rising_fetch_failed):
+ sync += pdecode2.instr_fault.eq(1)
+ else:
+ fetch_failed = Const(0, 1)
+ flush_needed = False
+
with m.FSM(name="issue_fsm"):
# sync with the "fetch" phase which is reading the instruction
# at this point, there is no instruction running, that
# could inadvertently update the PC.
with m.State("ISSUE_START"):
+ # reset instruction fault
+ sync += pdecode2.instr_fault.eq(0)
# wait on "core stop" release, before next fetch
# need to do this here, in case we are in a VL==0 loop
with m.If(~dbg.core_stop_o & ~core_rst):
- comb += fetch_pc_valid_i.eq(1) # tell fetch to start
- with m.If(fetch_pc_ready_o): # fetch acknowledged us
+ comb += fetch_pc_i_valid.eq(1) # tell fetch to start
+ with m.If(fetch_pc_o_ready): # fetch acknowledged us
m.next = "INSN_WAIT"
with m.Else():
# tell core it's stopped, and acknowledge debug handshake
- comb += core.core_stopped_i.eq(1)
comb += dbg.core_stopped_i.eq(1)
- # while stopped, allow updating the PC and SVSTATE
- with m.If(self.pc_i.ok):
- comb += self.state_w_pc.wen.eq(1 << StateRegs.PC)
- comb += self.state_w_pc.data_i.eq(self.pc_i.data)
- sync += pc_changed.eq(1)
+ # while stopped, allow updating SVSTATE
with m.If(self.svstate_i.ok):
comb += new_svstate.eq(self.svstate_i.data)
- comb += update_svstate.eq(1)
- sync += sv_changed.eq(1)
+ comb += self.update_svstate.eq(1)
+ sync += self.sv_changed.eq(1)
- # decode the instruction when it arrives
+ # wait for an instruction to arrive from Fetch
with m.State("INSN_WAIT"):
- comb += fetch_insn_ready_i.eq(1)
- with m.If(fetch_insn_valid_o):
- # decode the instruction
- sync += core.e.eq(pdecode2.e)
- sync += core.state.eq(cur_state)
- sync += core.raw_insn_i.eq(dec_opcode_i)
- sync += core.bigendian_i.eq(self.core_bigendian_i)
- # set RA_OR_ZERO detection in satellite decoders
- sync += core.sv_a_nz.eq(pdecode2.sv_a_nz)
- # loop into ISSUE_START if it's a SVP64 instruction
- # and VL == 0. this because VL==0 is a for-loop
- # from 0 to 0 i.e. always, always a NOP.
- cur_vl = cur_state.svstate.vl
- with m.If(is_svp64_mode & (cur_vl == 0)):
- # update the PC before fetching the next instruction
- # since we are in a VL==0 loop, no instruction was
- # executed that we could be overwriting
- comb += self.state_w_pc.wen.eq(1 << StateRegs.PC)
- comb += self.state_w_pc.data_i.eq(nia)
- comb += self.insn_done.eq(1)
- m.next = "ISSUE_START"
- with m.Else():
- m.next = "PRED_START" # start fetching the predicate
+ # when using "single-step" mode, checking dbg.stopping_o
+ # prevents progress. allow issue to proceed once started
+ stopping = Const(0)
+ #if self.allow_overlap:
+ # stopping = dbg.stopping_o
+ with m.If(stopping):
+ # stopping: jump back to idle
+ m.next = "ISSUE_START"
+ if flush_needed:
+ # request the icache to stop asserting "failed"
+ comb += core.icache.flush_in.eq(1)
+ # stop instruction fault
+ sync += pdecode2.instr_fault.eq(0)
+ with m.Else():
+ comb += fetch_insn_i_ready.eq(1)
+ with m.If(fetch_insn_o_valid):
+ # loop into ISSUE_START if it's a SVP64 instruction
+ # and VL == 0. this because VL==0 is a for-loop
+ # from 0 to 0 i.e. always, always a NOP.
+ cur_vl = cur_state.svstate.vl
+ with m.If(is_svp64_mode & (cur_vl == 0)):
+ # update the PC before fetching the next instruction
+ # since we are in a VL==0 loop, no instruction was
+ # executed that we could be overwriting
+ comb += self.state_w_pc.wen.eq(1 << StateRegs.PC)
+ comb += self.state_w_pc.i_data.eq(nia)
+ comb += self.insn_done.eq(1)
+ m.next = "ISSUE_START"
+ with m.Else():
+ if self.svp64_en:
+ m.next = "PRED_START" # fetching predicate
+ else:
+ m.next = "DECODE_SV" # skip predication
with m.State("PRED_START"):
- comb += pred_insn_valid_i.eq(1) # tell fetch_pred to start
- with m.If(pred_insn_ready_o): # fetch_pred acknowledged us
+ comb += pred_insn_i_valid.eq(1) # tell fetch_pred to start
+ with m.If(pred_insn_o_ready): # fetch_pred acknowledged us
m.next = "MASK_WAIT"
with m.State("MASK_WAIT"):
- comb += pred_mask_ready_i.eq(1) # ready to receive the masks
- with m.If(pred_mask_valid_o): # predication masks are ready
- m.next = "INSN_EXECUTE"
-
- # handshake with execution FSM, move to "wait" once acknowledged
- with m.State("INSN_EXECUTE"):
- # with m.If(is_svp64_mode):
- # TODO advance src/dst step to "skip" over predicated-out
- # from self.srcmask and self.dstmask
- # https://bugs.libre-soc.org/show_bug.cgi?id=617#c3
- # but still without exceeding VL in either case
- # IMPORTANT: when changing src/dest step, have to
- # jump to m.next = "DECODE_SV" to deal with the change in
- # SVSTATE
-
- with m.If(is_svp64_mode):
-
- pred_src_zero = pdecode2.rm_dec.pred_sz
- pred_dst_zero = pdecode2.rm_dec.pred_dz
+ comb += pred_mask_i_ready.eq(1) # ready to receive the masks
+ with m.If(pred_mask_o_valid): # predication masks are ready
+ m.next = "PRED_SKIP"
+
+ # skip zeros in predicate
+ with m.State("PRED_SKIP"):
+ with m.If(~is_svp64_mode):
+ m.next = "DECODE_SV" # nothing to do
+ with m.Else():
+ if self.svp64_en:
+ pred_src_zero = pdecode2.rm_dec.pred_sz
+ pred_dst_zero = pdecode2.rm_dec.pred_dz
+
+ # new srcstep, after skipping zeros
+ skip_srcstep = Signal.like(cur_srcstep)
+ # value to be added to the current srcstep
+ src_delta = Signal.like(cur_srcstep)
+ # add leading zeros to srcstep, if not in zero mode
+ with m.If(~pred_src_zero):
+ # priority encoder (count leading zeros)
+ # append guard bit, in case the mask is all zeros
+ pri_enc_src = PriorityEncoder(65)
+ m.submodules.pri_enc_src = pri_enc_src
+ comb += pri_enc_src.i.eq(Cat(self.srcmask,
+ Const(1, 1)))
+ comb += src_delta.eq(pri_enc_src.o)
+ # apply delta to srcstep
+ comb += skip_srcstep.eq(cur_srcstep + src_delta)
+ # shift-out all leading zeros from the mask
+ # plus the leading "one" bit
+ # TODO count leading zeros and shift-out the zero
+ # bits, in the same step, in hardware
+ sync += self.srcmask.eq(self.srcmask >> (src_delta+1))
+
+ # same as above, but for dststep
+ skip_dststep = Signal.like(cur_dststep)
+ dst_delta = Signal.like(cur_dststep)
+ with m.If(~pred_dst_zero):
+ pri_enc_dst = PriorityEncoder(65)
+ m.submodules.pri_enc_dst = pri_enc_dst
+ comb += pri_enc_dst.i.eq(Cat(self.dstmask,
+ Const(1, 1)))
+ comb += dst_delta.eq(pri_enc_dst.o)
+ comb += skip_dststep.eq(cur_dststep + dst_delta)
+ sync += self.dstmask.eq(self.dstmask >> (dst_delta+1))
+
+ # TODO: initialize mask[VL]=1 to avoid passing past VL
+ with m.If((skip_srcstep >= cur_vl) |
+ (skip_dststep >= cur_vl)):
+ # end of VL loop. Update PC and reset src/dst step
+ comb += self.state_w_pc.wen.eq(1 << StateRegs.PC)
+ comb += self.state_w_pc.i_data.eq(nia)
+ comb += new_svstate.srcstep.eq(0)
+ comb += new_svstate.dststep.eq(0)
+ comb += self.update_svstate.eq(1)
+ # synchronize with the simulator
+ comb += self.insn_done.eq(1)
+ # go back to Issue
+ m.next = "ISSUE_START"
+ with m.Else():
+ # update new src/dst step
+ comb += new_svstate.srcstep.eq(skip_srcstep)
+ comb += new_svstate.dststep.eq(skip_dststep)
+ comb += self.update_svstate.eq(1)
+ # proceed to Decode
+ m.next = "DECODE_SV"
- """
- if not pred_src_zero:
- if (((1<<cur_srcstep) & self.srcmask) == 0) and
- (cur_srcstep != vl):
- comb += update_svstate.eq(1)
- comb += new_svstate.srcstep.eq(next_srcstep)
- sync += sv_changed.eq(1)
+ # pass predicate mask bits through to satellite decoders
+ # TODO: for SIMD this will be *multiple* bits
+ sync += core.i.sv_pred_sm.eq(self.srcmask[0])
+ sync += core.i.sv_pred_dm.eq(self.dstmask[0])
- if not pred_dst_zero:
- if (((1<<cur_dststep) & self.dstmask) == 0) and
- (cur_dststep != vl):
- comb += new_svstate.dststep.eq(next_dststep)
- comb += update_svstate.eq(1)
- sync += sv_changed.eq(1)
+ # after src/dst step have been updated, we are ready
+ # to decode the instruction
+ with m.State("DECODE_SV"):
+ # decode the instruction
+ with m.If(~fetch_failed):
+ sync += pdecode2.instr_fault.eq(0)
+ sync += core.i.e.eq(pdecode2.e)
+ sync += core.i.state.eq(cur_state)
+ sync += core.i.raw_insn_i.eq(dec_opcode_i)
+ sync += core.i.bigendian_i.eq(self.core_bigendian_i)
+ if self.svp64_en:
+ sync += core.i.sv_rm.eq(pdecode2.sv_rm)
+ # set RA_OR_ZERO detection in satellite decoders
+ sync += core.i.sv_a_nz.eq(pdecode2.sv_a_nz)
+ # and svp64 detection
+ sync += core.i.is_svp64_mode.eq(is_svp64_mode)
+ # and svp64 bit-rev'd ldst mode
+ ldst_dec = pdecode2.use_svp64_ldst_dec
+ sync += core.i.use_svp64_ldst_dec.eq(ldst_dec)
+ # after decoding, reset any previous exception condition,
+ # allowing it to be set again during the next execution
+ sync += pdecode2.ldst_exc.eq(0)
- if update_svstate:
- m.next = "DECODE_SV"
- """
+ m.next = "INSN_EXECUTE" # move to "execute"
- comb += exec_insn_valid_i.eq(1) # trigger execute
- with m.If(exec_insn_ready_o): # execute acknowledged us
- m.next = "EXECUTE_WAIT"
+ # handshake with execution FSM, move to "wait" once acknowledged
+ with m.State("INSN_EXECUTE"):
+ # when using "single-step" mode, checking dbg.stopping_o
+ # prevents progress. allow execute to proceed once started
+ stopping = Const(0)
+ #if self.allow_overlap:
+ # stopping = dbg.stopping_o
+ with m.If(stopping):
+ # stopping: jump back to idle
+ m.next = "ISSUE_START"
+ if flush_needed:
+ # request the icache to stop asserting "failed"
+ comb += core.icache.flush_in.eq(1)
+ # stop instruction fault
+ sync += pdecode2.instr_fault.eq(0)
+ with m.Else():
+ comb += exec_insn_i_valid.eq(1) # trigger execute
+ with m.If(exec_insn_o_ready): # execute acknowledged us
+ m.next = "EXECUTE_WAIT"
with m.State("EXECUTE_WAIT"):
# wait on "core stop" release, at instruction end
# need to do this here, in case we are in a VL>1 loop
with m.If(~dbg.core_stop_o & ~core_rst):
- comb += exec_pc_ready_i.eq(1)
- with m.If(exec_pc_valid_o):
+ comb += exec_pc_i_ready.eq(1)
+ # see https://bugs.libre-soc.org/show_bug.cgi?id=636
+ # the exception info needs to be blatted into
+ # pdecode.ldst_exc, and the instruction "re-run".
+ # when ldst_exc.happened is set, the PowerDecoder2
+ # reacts very differently: it re-writes the instruction
+ # with a "trap" (calls PowerDecoder2.trap()) which
+ # will *overwrite* whatever was requested and jump the
+ # PC to the exception address, as well as alter MSR.
+ # nothing else needs to be done other than to note
+ # the change of PC and MSR (and, later, SVSTATE)
+ with m.If(exc_happened):
+ mmu = core.fus.get_exc("mmu0")
+ ldst = core.fus.get_exc("ldst0")
+ if mmu is not None:
+ with m.If(fetch_failed):
+ # instruction fetch: exception is from MMU
+ # reset instr_fault (highest priority)
+ sync += pdecode2.ldst_exc.eq(mmu)
+ sync += pdecode2.instr_fault.eq(0)
+ if flush_needed:
+ # request icache to stop asserting "failed"
+ comb += core.icache.flush_in.eq(1)
+ with m.If(~fetch_failed):
+ # otherwise assume it was a LDST exception
+ sync += pdecode2.ldst_exc.eq(ldst)
+
+ with m.If(exec_pc_o_valid):
# was this the last loop iteration?
is_last = Signal()
cur_vl = cur_state.svstate.vl
comb += is_last.eq(next_srcstep == cur_vl)
- # if either PC or SVSTATE were changed by the previous
+ with m.If(pdecode2.instr_fault):
+ # reset instruction fault, try again
+ sync += pdecode2.instr_fault.eq(0)
+ m.next = "ISSUE_START"
+
+ # return directly to Decode if Execute generated an
+ # exception.
+ with m.Elif(pdecode2.ldst_exc.happened):
+ m.next = "DECODE_SV"
+
+ # if MSR, PC or SVSTATE were changed by the previous
# instruction, go directly back to Fetch, without
- # updating either PC or SVSTATE
- with m.If(pc_changed | sv_changed):
+ # updating either MSR PC or SVSTATE
+ with m.Elif(self.msr_changed | self.pc_changed |
+ self.sv_changed):
m.next = "ISSUE_START"
# also return to Fetch, when no output was a vector
# TODO: this just blithely overwrites whatever
# pipeline updated the PC
comb += self.state_w_pc.wen.eq(1 << StateRegs.PC)
- comb += self.state_w_pc.data_i.eq(nia)
+ comb += self.state_w_pc.i_data.eq(nia)
# reset SRCSTEP before returning to Fetch
- with m.If(pdecode2.loop_continue):
+ if self.svp64_en:
+ with m.If(pdecode2.loop_continue):
+ comb += new_svstate.srcstep.eq(0)
+ comb += new_svstate.dststep.eq(0)
+ comb += self.update_svstate.eq(1)
+ else:
comb += new_svstate.srcstep.eq(0)
comb += new_svstate.dststep.eq(0)
- comb += update_svstate.eq(1)
+ comb += self.update_svstate.eq(1)
m.next = "ISSUE_START"
# returning to Execute? then, first update SRCSTEP
with m.Else():
comb += new_svstate.srcstep.eq(next_srcstep)
comb += new_svstate.dststep.eq(next_dststep)
- comb += update_svstate.eq(1)
- m.next = "DECODE_SV"
+ comb += self.update_svstate.eq(1)
+ # return to mask skip loop
+ m.next = "PRED_SKIP"
with m.Else():
- comb += core.core_stopped_i.eq(1)
comb += dbg.core_stopped_i.eq(1)
- # while stopped, allow updating the PC and SVSTATE
- with m.If(self.pc_i.ok):
- comb += self.state_w_pc.wen.eq(1 << StateRegs.PC)
- comb += self.state_w_pc.data_i.eq(self.pc_i.data)
- sync += pc_changed.eq(1)
- with m.If(self.svstate_i.ok):
- comb += new_svstate.eq(self.svstate_i.data)
- comb += update_svstate.eq(1)
- sync += sv_changed.eq(1)
-
- # need to decode the instruction again, after updating SRCSTEP
- # in the previous state.
- # mostly a copy of INSN_WAIT, but without the actual wait
- with m.State("DECODE_SV"):
- # decode the instruction
- sync += core.e.eq(pdecode2.e)
- sync += core.state.eq(cur_state)
- sync += core.bigendian_i.eq(self.core_bigendian_i)
- sync += core.sv_a_nz.eq(pdecode2.sv_a_nz)
- m.next = "INSN_EXECUTE" # move to "execute"
+ if flush_needed:
+ # request the icache to stop asserting "failed"
+ comb += core.icache.flush_in.eq(1)
+ # stop instruction fault
+ sync += pdecode2.instr_fault.eq(0)
+ # if terminated return to idle
+ with m.If(dbg.terminate_i):
+ m.next = "ISSUE_START"
# check if svstate needs updating: if so, write it to State Regfile
- with m.If(update_svstate):
- comb += self.state_w_sv.wen.eq(1<<StateRegs.SVSTATE)
- comb += self.state_w_sv.data_i.eq(new_svstate)
- sync += cur_state.svstate.eq(new_svstate) # for next clock
-
- def execute_fsm(self, m, core, pc_changed, sv_changed,
- exec_insn_valid_i, exec_insn_ready_o,
- exec_pc_valid_o, exec_pc_ready_i):
+ with m.If(self.update_svstate):
+ sync += cur_state.svstate.eq(self.new_svstate) # for next clock
+
+ def execute_fsm(self, m, core,
+ exec_insn_i_valid, exec_insn_o_ready,
+ exec_pc_o_valid, exec_pc_i_ready):
"""execute FSM
execute FSM. this interacts with the "issue" FSM
comb = m.d.comb
sync = m.d.sync
+ dbg = self.dbg
pdecode2 = self.pdecode2
# temporaries
- core_busy_o = core.busy_o # core is busy
- core_ivalid_i = core.ivalid_i # instruction is valid
- core_issue_i = core.issue_i # instruction is issued
- insn_type = core.e.do.insn_type # instruction MicroOp type
+ core_busy_o = core.n.o_data.busy_o # core is busy
+ core_ivalid_i = core.p.i_valid # instruction is valid
+
+ if hasattr(core, "icache"):
+ fetch_failed = core.icache.i_out.fetch_failed
+ else:
+ fetch_failed = Const(0, 1)
with m.FSM(name="exec_fsm"):
# waiting for instruction bus (stays there until not busy)
with m.State("INSN_START"):
- comb += exec_insn_ready_o.eq(1)
- with m.If(exec_insn_valid_i):
- comb += core_ivalid_i.eq(1) # instruction is valid
- comb += core_issue_i.eq(1) # and issued
- sync += sv_changed.eq(0)
- sync += pc_changed.eq(0)
- m.next = "INSN_ACTIVE" # move to "wait completion"
+ comb += exec_insn_o_ready.eq(1)
+ with m.If(exec_insn_i_valid):
+ comb += core_ivalid_i.eq(1) # instruction is valid/issued
+ sync += self.sv_changed.eq(0)
+ sync += self.pc_changed.eq(0)
+ sync += self.msr_changed.eq(0)
+ with m.If(core.p.o_ready): # only move if accepted
+ m.next = "INSN_ACTIVE" # move to "wait completion"
# instruction started: must wait till it finishes
with m.State("INSN_ACTIVE"):
- with m.If(insn_type != MicrOp.OP_NOP):
- comb += core_ivalid_i.eq(1) # instruction is valid
- # note changes to PC and SVSTATE
- with m.If(self.state_nia.wen & (1<<StateRegs.SVSTATE)):
- sync += sv_changed.eq(1)
- with m.If(self.state_nia.wen & (1<<StateRegs.PC)):
- sync += pc_changed.eq(1)
- with m.If(~core_busy_o): # instruction done!
- comb += exec_pc_valid_o.eq(1)
- with m.If(exec_pc_ready_i):
- comb += self.insn_done.eq(1)
+ # note changes to MSR, PC and SVSTATE
+ # XXX oops, really must monitor *all* State Regfile write
+ # ports looking for changes!
+ with m.If(self.state_nia.wen & (1 << StateRegs.SVSTATE)):
+ sync += self.sv_changed.eq(1)
+ with m.If(self.state_nia.wen & (1 << StateRegs.MSR)):
+ sync += self.msr_changed.eq(1)
+ with m.If(self.state_nia.wen & (1 << StateRegs.PC)):
+ sync += self.pc_changed.eq(1)
+ with m.If(~core_busy_o): # instruction done!
+ comb += exec_pc_o_valid.eq(1)
+ with m.If(exec_pc_i_ready):
+ # when finished, indicate "done".
+ # however, if there was an exception, the instruction
+ # is *not* yet done. this is an implementation
+ # detail: we choose to implement exceptions by
+ # taking the exception information from the LDST
+ # unit, putting that *back* into the PowerDecoder2,
+ # and *re-running the entire instruction*.
+ # if we erroneously indicate "done" here, it is as if
+ # there were *TWO* instructions:
+ # 1) the failed LDST 2) a TRAP.
+ with m.If(~pdecode2.ldst_exc.happened &
+ ~pdecode2.instr_fault):
+ comb += self.insn_done.eq(1)
m.next = "INSN_START" # back to fetch
-
- def setup_peripherals(self, m):
- comb, sync = m.d.comb, m.d.sync
-
- m.submodules.core = core = DomainRenamer("coresync")(self.core)
- m.submodules.imem = imem = self.imem
- m.submodules.dbg = dbg = self.dbg
- if self.jtag_en:
- m.submodules.jtag = jtag = self.jtag
- # TODO: UART2GDB mux, here, from external pin
- # see https://bugs.libre-soc.org/show_bug.cgi?id=499
- sync += dbg.dmi.connect_to(jtag.dmi)
-
- cur_state = self.cur_state
-
- # 4x 4k SRAM blocks. these simply "exist", they get routed in litex
- if self.sram4x4k:
- for i, sram in enumerate(self.sram4k):
- m.submodules["sram4k_%d" % i] = sram
- comb += sram.enable.eq(self.wb_sram_en)
-
- # XICS interrupt handler
- if self.xics:
- m.submodules.xics_icp = icp = self.xics_icp
- m.submodules.xics_ics = ics = self.xics_ics
- comb += icp.ics_i.eq(ics.icp_o) # connect ICS to ICP
- sync += cur_state.eint.eq(icp.core_irq_o) # connect ICP to core
-
- # GPIO test peripheral
- if self.gpio:
- m.submodules.simple_gpio = simple_gpio = self.simple_gpio
-
- # connect one GPIO output to ICS bit 15 (like in microwatt soc.vhdl)
- # XXX causes litex ECP5 test to get wrong idea about input and output
- # (but works with verilator sim *sigh*)
- #if self.gpio and self.xics:
- # comb += self.int_level_i[15].eq(simple_gpio.gpio_o[0])
-
- # instruction decoder
- pdecode = create_pdecode()
- m.submodules.dec2 = pdecode2 = self.pdecode2
- if self.svp64_en:
- m.submodules.svp64 = svp64 = self.svp64
-
- # convenience
- dmi, d_reg, d_cr, d_xer, = dbg.dmi, dbg.d_gpr, dbg.d_cr, dbg.d_xer
- intrf = self.core.regs.rf['int']
-
- # clock delay power-on reset
- cd_por = ClockDomain(reset_less=True)
- cd_sync = ClockDomain()
- core_sync = ClockDomain("coresync")
- m.domains += cd_por, cd_sync, core_sync
-
- ti_rst = Signal(reset_less=True)
- delay = Signal(range(4), reset=3)
- with m.If(delay != 0):
- m.d.por += delay.eq(delay - 1)
- comb += cd_por.clk.eq(ClockSignal())
-
- # power-on reset delay
- core_rst = ResetSignal("coresync")
- comb += ti_rst.eq(delay != 0 | dbg.core_rst_o | ResetSignal())
- comb += core_rst.eq(ti_rst)
-
- # busy/halted signals from core
- comb += self.busy_o.eq(core.busy_o)
- comb += pdecode2.dec.bigendian.eq(self.core_bigendian_i)
-
- # temporary hack: says "go" immediately for both address gen and ST
- l0 = core.l0
- ldst = core.fus.fus['ldst0']
- st_go_edge = rising_edge(m, ldst.st.rel_o)
- m.d.comb += ldst.ad.go_i.eq(ldst.ad.rel_o) # link addr-go direct to rel
- m.d.comb += ldst.st.go_i.eq(st_go_edge) # link store-go to rising rel
-
- return core_rst
+ # terminate returns directly to INSN_START
+ with m.If(dbg.terminate_i):
+ # comb += self.insn_done.eq(1) - no because it's not
+ m.next = "INSN_START" # back to fetch
def elaborate(self, platform):
- m = Module()
+ m = super().elaborate(platform)
# convenience
comb, sync = m.d.comb, m.d.sync
cur_state = self.cur_state
core = self.core
# set up peripherals and core
- core_rst = self.setup_peripherals(m)
-
- # PC and instruction from I-Memory
- comb += self.pc_o.eq(cur_state.pc)
- pc_changed = Signal() # note write to PC
- sv_changed = Signal() # note write to SVSTATE
-
- # read state either from incoming override or from regfile
- # TODO: really should be doing MSR in the same way
- pc = state_get(m, self.pc_i, "pc", # read PC
- self.state_r_pc, StateRegs.PC)
- svstate = state_get(m, self.svstate_i, "svstate", # read SVSTATE
- self.state_r_sv, StateRegs.SVSTATE)
-
- # don't write pc every cycle
- comb += self.state_w_pc.wen.eq(0)
- comb += self.state_w_pc.data_i.eq(0)
+ core_rst = self.core_rst
- # don't read msr every cycle
- comb += self.state_r_msr.ren.eq(0)
+ # indicate to outside world if any FU is still executing
+ comb += self.any_busy.eq(core.n.o_data.any_busy_o) # any FU executing
# address of the next instruction, in the absence of a branch
# depends on the instruction size
- nia = Signal(64, reset_less=True)
+ nia = Signal(64)
# connect up debug signals
- # TODO comb += core.icache_rst_i.eq(dbg.icache_rst_o)
- comb += dbg.terminate_i.eq(core.core_terminate_o)
- comb += dbg.state.pc.eq(pc)
- comb += dbg.state.svstate.eq(svstate)
- comb += dbg.state.msr.eq(cur_state.msr)
+ with m.If(core.o.core_terminate_o):
+ comb += dbg.terminate_i.eq(1)
# pass the prefix mode from Fetch to Issue, so the latter can loop
# on VL==0
is_svp64_mode = Signal()
- # there are *THREE* FSMs, fetch (32/64-bit) issue, decode/execute.
- # these are the handshake signals between fetch and decode/execute
+ # there are *THREE^WFOUR-if-SVP64-enabled* FSMs, fetch (32/64-bit)
+ # issue, decode/execute, now joined by "Predicate fetch/calculate".
+ # these are the handshake signals between each
# fetch FSM can run as soon as the PC is valid
- fetch_pc_valid_i = Signal() # Execute tells Fetch "start next read"
- fetch_pc_ready_o = Signal() # Fetch Tells SVSTATE "proceed"
+ fetch_pc_i_valid = Signal() # Execute tells Fetch "start next read"
+ fetch_pc_o_ready = Signal() # Fetch Tells SVSTATE "proceed"
# fetch FSM hands over the instruction to be decoded / issued
- fetch_insn_valid_o = Signal()
- fetch_insn_ready_i = Signal()
+ fetch_insn_o_valid = Signal()
+ fetch_insn_i_ready = Signal()
# predicate fetch FSM decodes and fetches the predicate
- pred_insn_valid_i = Signal()
- pred_insn_ready_o = Signal()
+ pred_insn_i_valid = Signal()
+ pred_insn_o_ready = Signal()
# predicate fetch FSM delivers the masks
- pred_mask_valid_o = Signal()
- pred_mask_ready_i = Signal()
+ pred_mask_o_valid = Signal()
+ pred_mask_i_ready = Signal()
# issue FSM delivers the instruction to the be executed
- exec_insn_valid_i = Signal()
- exec_insn_ready_o = Signal()
+ exec_insn_i_valid = Signal()
+ exec_insn_o_ready = Signal()
# execute FSM, hands over the PC/SVSTATE back to the issue FSM
- exec_pc_valid_o = Signal()
- exec_pc_ready_i = Signal()
+ exec_pc_o_valid = Signal()
+ exec_pc_i_ready = Signal()
# the FSMs here are perhaps unusual in that they detect conditions
# then "hold" information, combinatorially, for the core
# (as opposed to using sync - which would be on a clock's delay)
# this includes the actual opcode, valid flags and so on.
- # Fetch, then Issue, then Execute. Issue is where the VL for-loop
- # lives. the ready/valid signalling is used to communicate between
- # the three.
-
- self.fetch_fsm(m, core, pc, svstate, nia, is_svp64_mode,
- fetch_pc_ready_o, fetch_pc_valid_i,
- fetch_insn_valid_o, fetch_insn_ready_i)
-
- self.issue_fsm(m, core, pc_changed, sv_changed, nia,
+ # Fetch, then predicate fetch, then Issue, then Execute.
+ # Issue is where the VL for-loop # lives. the ready/valid
+ # signalling is used to communicate between the four.
+
+ # set up Fetch FSM
+ fetch = FetchFSM(self.allow_overlap, self.svp64_en,
+ self.imem, core_rst, pdecode2, cur_state,
+ dbg, core,
+ dbg.state.svstate, # combinatorially same
+ nia, is_svp64_mode)
+ m.submodules.fetch = fetch
+ # connect up in/out data to existing Signals
+ comb += fetch.p.i_data.pc.eq(dbg.state.pc) # combinatorially same
+ comb += fetch.p.i_data.msr.eq(dbg.state.msr) # combinatorially same
+ # and the ready/valid signalling
+ comb += fetch_pc_o_ready.eq(fetch.p.o_ready)
+ comb += fetch.p.i_valid.eq(fetch_pc_i_valid)
+ comb += fetch_insn_o_valid.eq(fetch.n.o_valid)
+ comb += fetch.n.i_ready.eq(fetch_insn_i_ready)
+
+ self.issue_fsm(m, core, nia,
dbg, core_rst, is_svp64_mode,
- fetch_pc_ready_o, fetch_pc_valid_i,
- fetch_insn_valid_o, fetch_insn_ready_i,
- pred_insn_valid_i, pred_insn_ready_o,
- pred_mask_valid_o, pred_mask_ready_i,
- exec_insn_valid_i, exec_insn_ready_o,
- exec_pc_valid_o, exec_pc_ready_i)
-
- self.fetch_predicate_fsm(m,
- pred_insn_valid_i, pred_insn_ready_o,
- pred_mask_valid_o, pred_mask_ready_i)
-
- self.execute_fsm(m, core, pc_changed, sv_changed,
- exec_insn_valid_i, exec_insn_ready_o,
- exec_pc_valid_o, exec_pc_ready_i)
-
- # this bit doesn't have to be in the FSM: connect up to read
- # regfiles on demand from DMI
- self.do_dmi(m, dbg)
-
- # DEC and TB inc/dec FSM. copy of DEC is put into CoreState,
- # (which uses that in PowerDecoder2 to raise 0x900 exception)
- self.tb_dec_fsm(m, cur_state.dec)
-
- return m
-
- def do_dmi(self, m, dbg):
- comb = m.d.comb
- sync = m.d.sync
- dmi, d_reg, d_cr, d_xer, = dbg.dmi, dbg.d_gpr, dbg.d_cr, dbg.d_xer
- intrf = self.core.regs.rf['int']
-
- with m.If(d_reg.req): # request for regfile access being made
- # TODO: error-check this
- # XXX should this be combinatorial? sync better?
- if intrf.unary:
- comb += self.int_r.ren.eq(1<<d_reg.addr)
- else:
- comb += self.int_r.addr.eq(d_reg.addr)
- comb += self.int_r.ren.eq(1)
- d_reg_delay = Signal()
- sync += d_reg_delay.eq(d_reg.req)
- with m.If(d_reg_delay):
- # data arrives one clock later
- comb += d_reg.data.eq(self.int_r.data_o)
- comb += d_reg.ack.eq(1)
-
- # sigh same thing for CR debug
- with m.If(d_cr.req): # request for regfile access being made
- comb += self.cr_r.ren.eq(0b11111111) # enable all
- d_cr_delay = Signal()
- sync += d_cr_delay.eq(d_cr.req)
- with m.If(d_cr_delay):
- # data arrives one clock later
- comb += d_cr.data.eq(self.cr_r.data_o)
- comb += d_cr.ack.eq(1)
-
- # aaand XER...
- with m.If(d_xer.req): # request for regfile access being made
- comb += self.xer_r.ren.eq(0b111111) # enable all
- d_xer_delay = Signal()
- sync += d_xer_delay.eq(d_xer.req)
- with m.If(d_xer_delay):
- # data arrives one clock later
- comb += d_xer.data.eq(self.xer_r.data_o)
- comb += d_xer.ack.eq(1)
-
- def tb_dec_fsm(self, m, spr_dec):
- """tb_dec_fsm
-
- this is a FSM for updating either dec or tb. it runs alternately
- DEC, TB, DEC, TB. note that SPR pipeline could have written a new
- value to DEC, however the regfile has "passthrough" on it so this
- *should* be ok.
-
- see v3.0B p1097-1099 for Timeer Resource and p1065 and p1076
- """
-
- comb, sync = m.d.comb, m.d.sync
- fast_rf = self.core.regs.rf['fast']
- fast_r_dectb = fast_rf.r_ports['issue'] # DEC/TB
- fast_w_dectb = fast_rf.w_ports['issue'] # DEC/TB
-
- with m.FSM() as fsm:
-
- # initiates read of current DEC
- with m.State("DEC_READ"):
- comb += fast_r_dectb.addr.eq(FastRegs.DEC)
- comb += fast_r_dectb.ren.eq(1)
- m.next = "DEC_WRITE"
-
- # waits for DEC read to arrive (1 cycle), updates with new value
- with m.State("DEC_WRITE"):
- new_dec = Signal(64)
- # TODO: MSR.LPCR 32-bit decrement mode
- comb += new_dec.eq(fast_r_dectb.data_o - 1)
- comb += fast_w_dectb.addr.eq(FastRegs.DEC)
- comb += fast_w_dectb.wen.eq(1)
- comb += fast_w_dectb.data_i.eq(new_dec)
- sync += spr_dec.eq(new_dec) # copy into cur_state for decoder
- m.next = "TB_READ"
+ fetch_pc_o_ready, fetch_pc_i_valid,
+ fetch_insn_o_valid, fetch_insn_i_ready,
+ pred_insn_i_valid, pred_insn_o_ready,
+ pred_mask_o_valid, pred_mask_i_ready,
+ exec_insn_i_valid, exec_insn_o_ready,
+ exec_pc_o_valid, exec_pc_i_ready)
- # initiates read of current TB
- with m.State("TB_READ"):
- comb += fast_r_dectb.addr.eq(FastRegs.TB)
- comb += fast_r_dectb.ren.eq(1)
- m.next = "TB_WRITE"
+ if self.svp64_en:
+ self.fetch_predicate_fsm(m,
+ pred_insn_i_valid, pred_insn_o_ready,
+ pred_mask_o_valid, pred_mask_i_ready)
- # waits for read TB to arrive, initiates write of current TB
- with m.State("TB_WRITE"):
- new_tb = Signal(64)
- comb += new_tb.eq(fast_r_dectb.data_o + 1)
- comb += fast_w_dectb.addr.eq(FastRegs.TB)
- comb += fast_w_dectb.wen.eq(1)
- comb += fast_w_dectb.data_i.eq(new_tb)
- m.next = "DEC_READ"
+ self.execute_fsm(m, core,
+ exec_insn_i_valid, exec_insn_o_ready,
+ exec_pc_o_valid, exec_pc_i_ready)
return m
- def __iter__(self):
- yield from self.pc_i.ports()
- yield self.pc_o
- yield self.memerr_o
- yield from self.core.ports()
- yield from self.imem.ports()
- yield self.core_bigendian_i
- yield self.busy_o
-
- def ports(self):
- return list(self)
-
- def external_ports(self):
- ports = self.pc_i.ports()
- ports += [self.pc_o, self.memerr_o, self.core_bigendian_i, self.busy_o,
- ]
-
- if self.jtag_en:
- ports += list(self.jtag.external_ports())
- else:
- # don't add DMI if JTAG is enabled
- ports += list(self.dbg.dmi.ports())
-
- ports += list(self.imem.ibus.fields.values())
- ports += list(self.core.l0.cmpi.lsmem.lsi.slavebus.fields.values())
-
- if self.sram4x4k:
- for sram in self.sram4k:
- ports += list(sram.bus.fields.values())
-
- if self.xics:
- ports += list(self.xics_icp.bus.fields.values())
- ports += list(self.xics_ics.bus.fields.values())
- ports.append(self.int_level_i)
-
- if self.gpio:
- ports += list(self.simple_gpio.bus.fields.values())
- ports.append(self.gpio_o)
-
- return ports
-
- def ports(self):
- return list(self)
-
class TestIssuer(Elaboratable):
def __init__(self, pspec):
self.ti = TestIssuerInternal(pspec)
+ # XXX TODO: make this a command-line selectable option from pspec
+ #from soc.simple.inorder import TestIssuerInternalInOrder
+ #self.ti = TestIssuerInternalInOrder(pspec)
+ self.pll = DummyPLL(instance=True)
- self.pll = DummyPLL()
+ self.dbg_rst_i = Signal(reset_less=True)
# PLL direct clock or not
self.pll_en = hasattr(pspec, "use_pll") and pspec.use_pll
if self.pll_en:
- self.pll_18_o = Signal(reset_less=True)
+ self.pll_test_o = Signal(reset_less=True)
+ self.pll_vco_o = Signal(reset_less=True)
+ self.clk_sel_i = Signal(2, reset_less=True)
+ self.ref_clk = ClockSignal() # can't rename it but that's ok
+ self.pllclk_clk = ClockSignal("pllclk")
def elaborate(self, platform):
m = Module()
comb = m.d.comb
- # TestIssuer runs at direct clock
+ # TestIssuer nominally runs at main clock, actually it is
+ # all combinatorial internally except for coresync'd components
m.submodules.ti = ti = self.ti
- cd_int = ClockDomain("coresync")
if self.pll_en:
# ClockSelect runs at PLL output internal clock rate
- m.submodules.pll = pll = self.pll
+ m.submodules.wrappll = pll = self.pll
# add clock domains from PLL
cd_pll = ClockDomain("pllclk")
# PLL clock established. has the side-effect of running clklsel
# at the PLL's speed (see DomainRenamer("pllclk") above)
- pllclk = ClockSignal("pllclk")
+ pllclk = self.pllclk_clk
comb += pllclk.eq(pll.clk_pll_o)
# wire up external 24mhz to PLL
- comb += pll.clk_24_i.eq(ClockSignal())
+ #comb += pll.clk_24_i.eq(self.ref_clk)
+ # output 18 mhz PLL test signal, and analog oscillator out
+ comb += self.pll_test_o.eq(pll.pll_test_o)
+ comb += self.pll_vco_o.eq(pll.pll_vco_o)
- # output 18 mhz PLL test signal
- comb += self.pll_18_o.eq(pll.pll_18_o)
+ # input to pll clock selection
+ comb += pll.clk_sel_i.eq(self.clk_sel_i)
# now wire up ResetSignals. don't mind them being in this domain
pll_rst = ResetSignal("pllclk")
# internal clock is set to selector clock-out. has the side-effect of
# running TestIssuer at this speed (see DomainRenamer("intclk") above)
- intclk = ClockSignal("coresync")
+ # debug clock runs at coresync internal clock
+ if self.ti.dbg_domain != 'sync':
+ cd_dbgsync = ClockDomain("dbgsync")
+ intclk = ClockSignal(self.ti.core_domain)
+ dbgclk = ClockSignal(self.ti.dbg_domain)
+ # XXX BYPASS PLL XXX
+ # XXX BYPASS PLL XXX
+ # XXX BYPASS PLL XXX
if self.pll_en:
- comb += intclk.eq(pll.clk_pll_o)
+ comb += intclk.eq(self.ref_clk)
+ assert self.ti.core_domain != 'sync', \
+ "cannot set core_domain to sync and use pll at the same time"
else:
- comb += intclk.eq(ClockSignal())
+ if self.ti.core_domain != 'sync':
+ comb += intclk.eq(ClockSignal())
+ if self.ti.dbg_domain != 'sync':
+ dbgclk = ClockSignal(self.ti.dbg_domain)
+ comb += dbgclk.eq(intclk)
+ comb += self.ti.dbg_rst_i.eq(self.dbg_rst_i)
return m
def ports(self):
return list(self.ti.ports()) + list(self.pll.ports()) + \
- [ClockSignal(), ResetSignal()]
+ [ClockSignal(), ResetSignal()]
def external_ports(self):
ports = self.ti.external_ports()
ports.append(ClockSignal())
ports.append(ResetSignal())
if self.pll_en:
- ports.append(self.pll.clk_sel_i)
- ports.append(self.pll_18_o)
- ports.append(self.pll.pll_lck_o)
+ ports.append(self.clk_sel_i)
+ ports.append(self.pll.clk_24_i)
+ ports.append(self.pll_test_o)
+ ports.append(self.pll_vco_o)
+ ports.append(self.pllclk_clk)
+ ports.append(self.ref_clk)
return ports
'div': 1,
'mul': 1,
'shiftrot': 1
- }
+ }
pspec = TestMemPspec(ldst_ifacetype='bare_wb',
imem_ifacetype='bare_wb',
addr_wid=48,
projects / soc.git / blobdiff