-""" LOAD / STORE Computation Unit.
+"""LOAD / STORE Computation Unit.
- This module covers POWER9-compliant Load and Store operations,
- with selection on each between immediate and indexed mode as
- options for the calculation of the Effective Address (EA),
- and also "update" mode which optionally stores that EA into
- an additional register.
+This module covers POWER9-compliant Load and Store operations,
+with selection on each between immediate and indexed mode as
+options for the calculation of the Effective Address (EA),
+and also "update" mode which optionally stores that EA into
+an additional register.
- ----
- Note: it took 15 attempts over several weeks to redraw the diagram
- needed to capture this FSM properly. To understand it fully, please
- take the time to review the links, video, and diagram.
- ----
+----
+Note: it took 15 attempts over several weeks to redraw the diagram
+needed to capture this FSM properly. To understand it fully, please
+take the time to review the links, video, and diagram.
+----
- Stores are activated when Go_Store is enabled, and use a sync'd "ADD" to
- compute the "Effective Address", and, when ready the operand (src3_i)
- is stored in the computed address (passed through to the PortInterface)
+Stores are activated when Go_Store is enabled, and use a sync'd "ADD" to
+compute the "Effective Address", and, when ready the operand (src3_i)
+is stored in the computed address (passed through to the PortInterface)
- Loads are activated when Go_Write[0] is enabled. The EA is computed,
- and (as long as there was no exception) the data comes out (at any
- time from the PortInterface), and is captured by the LDCompSTUnit.
+Loads are activated when Go_Write[0] is enabled. The EA is computed,
+and (as long as there was no exception) the data comes out (at any
+time from the PortInterface), and is captured by the LDCompSTUnit.
- Both LD and ST may request that the address be computed from summing
- operand1 (src[0]) with operand2 (src[1]) *or* by summing operand1 with
- the immediate (from the opcode).
+TODO: dcbz, yes, that's going to be complicated, has to be done
+ with great care, to detect the case when dcbz is set
+ and *not* expect to read any data, just the address.
+ so, wait for RA but not RB.
- Both LD and ST may also request "update" mode (op_is_update) which
- activates the use of Go_Write[1] to control storage of the EA into
- a *second* operand in the register file.
+Both LD and ST may request that the address be computed from summing
+operand1 (src[0]) with operand2 (src[1]) *or* by summing operand1 with
+the immediate (from the opcode).
- Thus this module has *TWO* write-requests to the register file and
- *THREE* read-requests to the register file (not all at the same time!)
- The regfile port usage is:
+Both LD and ST may also request "update" mode (op_is_update) which
+activates the use of Go_Write[1] to control storage of the EA into
+a *second* operand in the register file.
+
+Thus this module has *TWO* write-requests to the register file and
+*THREE* read-requests to the register file (not all at the same time!)
+The regfile port usage is:
* LD-imm 1R1W
* LD-imm-update 1R2W
* ST-idx 3R
* ST-idx-update 3R1W
- It's a multi-level Finite State Machine that (unfortunately) nmigen.FSM
- is not suited to (nmigen.FSM is clock-driven, and some aspects of
- the nested FSMs below are *combinatorial*).
+It's a multi-level Finite State Machine that (unfortunately) nmigen.FSM
+is not suited to (nmigen.FSM is clock-driven, and some aspects of
+the nested FSMs below are *combinatorial*).
* One FSM covers Operand collection and communication address-side
with the LD/ST PortInterface. its role ends when "RD_DONE" is asserted
* A third FSM activates to cover ST. it activates if op_is_st is true
+ * TODO document DCBZ (not complete yet)
+
* The "overall" (fourth) FSM coordinates the progression and completion
of the three other FSMs, firing "WR_RESET" which switches off "busy"
- Full diagram:
+Full diagram:
+
https://libre-soc.org/3d_gpu/ld_st_comp_unit.jpg
- Links including to walk-through videos:
+Links including to walk-through videos:
+
* https://libre-soc.org/3d_gpu/architecture/6600scoreboard/
+ * http://libre-soc.org/openpower/isa/fixedload
+ * http://libre-soc.org/openpower/isa/fixedstore
+
+Related Bugreports:
- Related Bugreports:
* https://bugs.libre-soc.org/show_bug.cgi?id=302
+ * https://bugs.libre-soc.org/show_bug.cgi?id=216
- Terminology:
+Terminology:
* EA - Effective Address
* LD - Load
from nmigen.compat.sim import run_simulation
from nmigen.cli import verilog, rtlil
-from nmigen import Module, Signal, Mux, Cat, Elaboratable, Array, Repl
+from nmigen import Module, Signal, Mux, Cat, Elaboratable, Array, Repl, C
from nmigen.hdl.rec import Record, Layout
from nmutil.latch import SRLatch, latchregister
+from nmutil.byterev import byte_reverse
+from nmutil.extend import exts
-from soc.experiment.compalu_multi import go_record
+from soc.experiment.compalu_multi import go_record, CompUnitRecord
from soc.experiment.l0_cache import PortInterface
-from soc.experiment.testmem import TestMemory
-from soc.decoder.power_enums import InternalOp
+from soc.experiment.pimem import LDSTException
+from soc.fu.regspec import RegSpecAPI
-from soc.decoder.power_enums import InternalOp, Function
+from openpower.decoder.power_enums import MicrOp, Function, LDSTMode
+from soc.fu.ldst.ldst_input_record import CompLDSTOpSubset
+from openpower.decoder.power_decoder2 import Data
+from openpower.consts import MSR
+from soc.config.test.test_loadstore import TestMemPspec
+# for debugging dcbz
+from nmutil.util import Display
-class CompLDSTOpSubset(Record):
- """CompLDSTOpSubset
- a copy of the relevant subset information from Decode2Execute1Type
- needed for LD/ST operations. use with eq_from_execute1 (below) to
- grab subsets.
- """
- def __init__(self, name=None):
- layout = (('insn_type', InternalOp),
- ('imm_data', Layout((("imm", 64), ("imm_ok", 1)))),
- ('is_32bit', 1),
- ('is_signed', 1),
- ('data_len', 4), # TODO: should be in separate CompLDSTSubset
- ('byte_reverse', 1),
- ('sign_extend', 1),
- ('update', 1))
-
- Record.__init__(self, Layout(layout), name=name)
-
- # grrr. Record does not have kwargs
- self.insn_type.reset_less = True
- self.is_32bit.reset_less = True
- self.is_signed.reset_less = True
- self.data_len.reset_less = True
- self.byte_reverse.reset_less = True
- self.sign_extend.reset_less = True
- self.update.reset_less = True
-
- def eq_from_execute1(self, other):
- """ use this to copy in from Decode2Execute1Type
- """
- res = []
- for fname, sig in self.fields.items():
- eqfrom = other.fields[fname]
- res.append(sig.eq(eqfrom))
- return res
+# TODO: LDSTInputData and LDSTOutputData really should be used
+# here, to make things more like the other CompUnits. currently,
+# also, RegSpecAPI is used explicitly here
- def ports(self):
- return [self.insn_type,
- self.is_32bit,
- self.is_signed,
- self.data_len,
- self.byte_reverse,
- self.sign_extend,
- self.update,
- ]
+class LDSTCompUnitRecord(CompUnitRecord):
+ def __init__(self, rwid, opsubset=CompLDSTOpSubset, name=None):
+ CompUnitRecord.__init__(self, opsubset, rwid,
+ n_src=3, n_dst=2, name=name)
+
+ self.ad = go_record(1, name="cu_ad") # address go in, req out
+ self.st = go_record(1, name="cu_st") # store go in, req out
+
+ self.exc_o = LDSTException("exc_o")
+
+ self.ld_o = Signal(reset_less=True) # operation is a LD
+ self.st_o = Signal(reset_less=True) # operation is a ST
+
+ # hmm... are these necessary?
+ self.load_mem_o = Signal(reset_less=True) # activate memory LOAD
+ self.stwd_mem_o = Signal(reset_less=True) # activate memory STORE
-class LDSTCompUnit(Elaboratable):
+
+class LDSTCompUnit(RegSpecAPI, Elaboratable):
"""LOAD / STORE Computation Unit
Inputs
Data (outputs)
--------------
- * :data_o: Dest out (LD) - managed by wr[0] go/req
- * :addr_o: Address out (LD or ST) - managed by wr[1] go/req
- * :addr_exc_o: Address/Data Exception occurred. LD/ST must terminate
+ * :o_data: Dest out (LD) - managed by wr[0] go/req
+ * :addr_o: Address out (LD or ST) - managed by wr[1] go/req
+ * :exc_o: Address/Data Exception occurred. LD/ST must terminate
- TODO: make addr_exc_o a data-type rather than a single-bit signal
+ TODO: make exc_o a data-type rather than a single-bit signal
(see bug #302)
Control Signals (In)
in a single cycle and the CompUnit set back to doing another op.
This means deasserting go_st_i, go_ad_i or go_wr_i as appropriate
depending on whether the operation is a ST or LD.
+
+ Note: LDSTCompUnit takes care of LE/BE normalisation:
+ * LD data is normalised after receipt from the PortInterface
+ * ST data is normalised *prior* to sending onto the PortInterface
+ TODO: use one module for the byte-reverse as it's quite expensive in gates
"""
- def __init__(self, pi, rwid=64, awid=48, debugtest=False):
- self.rwid = rwid
+ def __init__(self, pi=None, rwid=64, awid=64, opsubset=CompLDSTOpSubset,
+ debugtest=False, name=None):
+ super().__init__(rwid)
self.awid = awid
self.pi = pi
- self.debugtest = debugtest
+ self.cu = cu = LDSTCompUnitRecord(rwid, opsubset, name=name)
+ self.debugtest = debugtest # enable debug output for unit testing
# POWER-compliant LD/ST has index and update: *fixed* number of ports
self.n_src = n_src = 3 # RA, RB, RT/RS
- self.n_dst = n_dst = 2 # RA, RT/RS
+ self.n_dst = n_dst = 3 # RA, RT/RS, CR0
# set up array of src and dest signals
- src = []
for i in range(n_src):
- j = i + 1 # name numbering to match src1/src2
- src.append(Signal(rwid, name="src%d_i" % j, reset_less=True))
+ j = i + 1 # name numbering to match src1/src2
+ name = "src%d_i" % j
+ setattr(self, name, getattr(cu, name))
dst = []
for i in range(n_dst):
- j = i + 1 # name numbering to match dest1/2...
- dst.append(Signal(rwid, name="dest%d_o" % j, reset_less=True))
-
- # control (dual in/out)
- self.rd = go_record(n_src, name="rd") # read in, req out
- self.wr = go_record(n_dst, name="wr") # write in, req out
- self.ad = go_record(1, name="ad") # address go in, req out
- self.st = go_record(1, name="st") # store go in, req out
-
- self.go_rd_i = self.rd.go # temporary naming
- self.go_wr_i = self.wr.go # temporary naming
- self.rd_rel_o = self.rd.rel # temporary naming
- self.req_rel_o = self.wr.rel # temporary naming
-
- self.go_ad_i = self.ad.go # temp naming: go address in
- self.go_st_i = self.st.go # temp naming: go store in
-
- # control inputs
- self.issue_i = Signal(reset_less=True) # fn issue in
- self.shadown_i = Signal(reset=1) # shadow function, defaults to ON
- self.go_die_i = Signal() # go die (reset)
-
- # operation / data input
- self.oper_i = CompLDSTOpSubset() # operand
- self.src_i = Array(src)
- self.src1_i = src[0] # oper1 in: RA
- self.src2_i = src[1] # oper2 in: RB
- self.src3_i = src[2] # oper2 in: RC (RS)
-
- # outputs
- self.busy_o = Signal(reset_less=True) # fn busy out
- self.done_o = Signal(reset_less=True) # final release signal
- # TODO (see bug #302)
- self.addr_exc_o = Signal(reset_less=True) # address exception
- self.dest = Array(dst)
- self.data_o = dst[0] # Dest1 out: RT
- self.addr_o = dst[1] # Address out (LD or ST) - Update => RA
-
- self.adr_rel_o = self.ad.rel # request address (from mem)
- self.sto_rel_o = self.st.rel # request store (to mem)
-
- self.ld_o = Signal(reset_less=True) # operation is a LD
- self.st_o = Signal(reset_less=True) # operation is a ST
-
- # hmm... are these necessary?
- self.load_mem_o = Signal(reset_less=True) # activate memory LOAD
- self.stwd_mem_o = Signal(reset_less=True) # activate memory STORE
+ j = i + 1 # name numbering to match dest1/2...
+ name = "dest%d_o" % j
+ setattr(self, name, getattr(cu, name))
+
+ # convenience names
+ self.rd = cu.rd
+ self.wr = cu.wr
+ self.rdmaskn = cu.rdmaskn
+ self.wrmask = cu.wrmask
+ self.ad = cu.ad
+ self.st = cu.st
+ self.dest = cu._dest
+
+ # HACK: get data width from dest[0]. this is used across the board
+ # (it really shouldn't be)
+ self.data_wid = self.dest[0].shape()
+
+ self.go_rd_i = self.rd.go_i # temporary naming
+ self.go_wr_i = self.wr.go_i # temporary naming
+ self.go_ad_i = self.ad.go_i # temp naming: go address in
+ self.go_st_i = self.st.go_i # temp naming: go store in
+
+ self.rd_rel_o = self.rd.rel_o # temporary naming
+ self.req_rel_o = self.wr.rel_o # temporary naming
+ self.adr_rel_o = self.ad.rel_o # request address (from mem)
+ self.sto_rel_o = self.st.rel_o # request store (to mem)
+
+ self.issue_i = cu.issue_i
+ self.shadown_i = cu.shadown_i
+ self.go_die_i = cu.go_die_i
+
+ self.oper_i = cu.oper_i
+ self.src_i = cu._src_i
+
+ self.o_data = Data(self.data_wid, name="o") # Dest1 out: RT
+ self.addr_o = Data(self.data_wid, name="ea") # Addr out: Update => RA
+ self.cr_o = Data(4, name="cr0") # CR0 (for stdcx etc)
+ self.exc_o = cu.exc_o
+ self.done_o = cu.done_o
+ self.busy_o = cu.busy_o
+
+ self.ld_o = cu.ld_o
+ self.st_o = cu.st_o
+
+ self.load_mem_o = cu.load_mem_o
+ self.stwd_mem_o = cu.stwd_mem_o
def elaborate(self, platform):
m = Module()
m.submodules.sto_l = sto_l = SRLatch(sync=False, name="sto")
m.submodules.wri_l = wri_l = SRLatch(sync=False, name="wri")
m.submodules.upd_l = upd_l = SRLatch(sync=False, name="upd")
+ m.submodules.cr0_l = cr0_l = SRLatch(sync=False, name="cr0")
m.submodules.rst_l = rst_l = SRLatch(sync=False, name="rst")
+ m.submodules.lsd_l = lsd_l = SRLatch(sync=False, name="lsd") # done
####################
# signals
# opcode decode
op_is_ld = Signal(reset_less=True)
op_is_st = Signal(reset_less=True)
+ op_is_dcbz = Signal(reset_less=True)
+ op_is_st_or_dcbz = Signal(reset_less=True)
+ op_is_atomic = Signal(reset_less=True)
# ALU/LD data output control
- alu_valid = Signal(reset_less=True) # ALU operands are valid
+ alu_valid = Signal(reset_less=True) # ALU operands are valid
alu_ok = Signal(reset_less=True) # ALU out ok (1 clock delay valid)
addr_ok = Signal(reset_less=True) # addr ok (from PortInterface)
ld_ok = Signal(reset_less=True) # LD out ok from PortInterface
rda_any = Signal(reset_less=True) # any read for address ops
rd_done = Signal(reset_less=True) # all *necessary* operands read
wr_reset = Signal(reset_less=True) # final reset condition
+ canceln = Signal(reset_less=True) # cancel (active low)
+ store_done = Signal(reset_less=True) # store has been actioned
# LD and ALU out
- alu_o = Signal(self.rwid, reset_less=True)
- ldd_o = Signal(self.rwid, reset_less=True)
-
- # select immediate or src2 reg to add
- src2_or_imm = Signal(self.rwid, reset_less=True)
- src_sel = Signal(reset_less=True)
+ alu_o = Signal(self.data_wid, reset_less=True)
+ ldd_o = Signal(self.data_wid, reset_less=True)
##############################
# reset conditions for latches
reset_o = Signal(reset_less=True) # reset opcode
reset_w = Signal(reset_less=True) # reset write
reset_u = Signal(reset_less=True) # reset update
+ reset_c = Signal(reset_less=True) # reset cr0
reset_a = Signal(reset_less=True) # reset adr latch
reset_i = Signal(reset_less=True) # issue|die (use a lot)
- reset_r = Signal(self.n_src, reset_less=True) # reset src
+ reset_r = Signal(self.n_src, reset_less=True) # reset src
reset_s = Signal(reset_less=True) # reset store
- comb += reset_i.eq(issue_i | self.go_die_i) # various
- comb += reset_o.eq(wr_reset | self.go_die_i) # opcode reset
- comb += reset_w.eq(self.wr.go[0] | self.go_die_i) # write reg 1
- comb += reset_u.eq(self.wr.go[1] | self.go_die_i) # update (reg 2)
- comb += reset_s.eq(self.go_st_i | self.go_die_i) # store reset
- comb += reset_r.eq(self.rd.go | Repl(self.go_die_i, self.n_src))
- comb += reset_a.eq(self.go_ad_i | self.go_die_i)
+ # end execution when a terminating condition is detected:
+ # - go_die_i: a speculative operation was cancelled
+ # - exc_o.happened: an exception has occurred
+ terminate = Signal()
+ comb += terminate.eq(self.go_die_i | self.exc_o.happened)
+
+ comb += reset_i.eq(issue_i | terminate) # various
+ comb += reset_o.eq(self.done_o | terminate) # opcode reset
+ comb += reset_w.eq(self.wr.go_i[0] | terminate) # write reg 1
+ comb += reset_u.eq(self.wr.go_i[1] | terminate) # update (reg 2)
+ comb += reset_c.eq(self.wr.go_i[2] | terminate) # cr0 (reg 3)
+ comb += reset_s.eq(self.go_st_i | terminate) # store reset
+ comb += reset_r.eq(self.rd.go_i | Repl(terminate, self.n_src))
+ comb += reset_a.eq(self.go_ad_i | terminate)
+
+ p_st_go = Signal(reset_less=True)
+ sync += p_st_go.eq(self.st.go_i)
+
+ # decode bits of operand (latched)
+ oper_r = CompLDSTOpSubset(name="oper_r") # Dest register
+ comb += op_is_st.eq(oper_r.insn_type == MicrOp.OP_STORE) # ST
+ comb += op_is_ld.eq(oper_r.insn_type == MicrOp.OP_LOAD) # LD
+ comb += op_is_dcbz.eq(oper_r.insn_type == MicrOp.OP_DCBZ) # DCBZ
+ comb += op_is_atomic.eq(oper_r.reserve) # atomic LR/SC
+ comb += op_is_st_or_dcbz.eq(op_is_st | op_is_dcbz)
+ # dcbz is special case of store
+ #uncomment if needed
+ #comb += Display("compldst_multi: op_is_dcbz = %i",
+ # (oper_r.insn_type == MicrOp.OP_DCBZ))
+ op_is_update = oper_r.ldst_mode == LDSTMode.update # UPDATE
+ op_is_cix = oper_r.ldst_mode == LDSTMode.cix # cache-inhibit
+ comb += self.load_mem_o.eq(op_is_ld & self.go_ad_i)
+ comb += self.stwd_mem_o.eq(op_is_st & self.go_st_i)
+ comb += self.ld_o.eq(op_is_ld)
+ comb += self.st_o.eq(op_is_st)
##########################
# FSM implemented through sequence of latches. approximately this:
# - alu_l : looks after add of src1/2/imm (EA)
# - adr_l : waits for add (EA)
# - upd_l : waits for adr and Regfile (port 2)
+ # - cr0_l : waits for Rc=1 and CR0 Regfile (port 3)
# - src_l[2] : ST
# - lod_l : waits for adr (EA) and for LD Data
# - wri_l : waits for LD Data and Regfile (port 1)
sync += opc_l.r.eq(reset_o) # XXX NOTE: INVERTED FROM book!
# src operand latch
- sync += src_l.s.eq(Repl(issue_i, self.n_src))
+ sync += src_l.s.eq(Repl(issue_i, self.n_src) & ~self.rdmaskn)
sync += src_l.r.eq(reset_r)
+ #### sync += Display("reset_r = %i",reset_r)
# alu latch. use sync-delay between alu_ok and valid to generate pulse
comb += alu_l.s.eq(reset_i)
# dest operand latch
comb += wri_l.s.eq(issue_i)
- sync += wri_l.r.eq(reset_w)
+ sync += wri_l.r.eq(reset_w | Repl(wr_reset |
+ (~self.pi.busy_o & op_is_update),
+ #(self.pi.busy_o & op_is_update),
+ #self.done_o | (self.pi.busy_o & op_is_update),
+ self.n_dst))
+
+ # CR0 operand latch (CR0 written to reg 3 if Rc=1)
+ op_is_rc1 = self.oper_i.rc.rc & self.oper_i.rc.ok
+ comb += cr0_l.s.eq(issue_i & op_is_rc1)
+ sync += cr0_l.r.eq(reset_c)
# update-mode operand latch (EA written to reg 2)
sync += upd_l.s.eq(reset_i)
sync += upd_l.r.eq(reset_u)
# store latch
- comb += sto_l.s.eq(addr_ok & op_is_st)
- comb += sto_l.r.eq(reset_s)
+ comb += sto_l.s.eq(addr_ok & op_is_st_or_dcbz)
+ sync += sto_l.r.eq(reset_s | p_st_go)
+
+ # ld/st done. needed to stop LD/ST from activating repeatedly
+ comb += lsd_l.s.eq(issue_i)
+ sync += lsd_l.r.eq(reset_s | p_st_go | ld_ok)
# reset latch
- comb += rst_l.s.eq(addr_ok) # start when address is ready
+ comb += rst_l.s.eq(addr_ok) # start when address is ready
comb += rst_l.r.eq(issue_i)
# create a latch/register for the operand
- oper_r = CompLDSTOpSubset() # Dest register
- latchregister(m, self.oper_i, oper_r, self.issue_i, name="oper_r")
+ with m.If(self.issue_i):
+ sync += oper_r.eq(self.oper_i)
+ with m.If(self.done_o | terminate):
+ sync += oper_r.eq(0)
- # and for LD
- ldd_r = Signal(self.rwid, reset_less=True) # Dest register
+ # and for LD and store-done
+ ldd_r = Signal(self.data_wid, reset_less=True) # Dest register
latchregister(m, ldd_o, ldd_r, ld_ok, name="ldo_r")
+ # store actioned, communicate through CR0 (for atomic LR/SC)
+ latchregister(m, self.pi.store_done.data, store_done,
+ self.pi.store_done.ok,
+ name="std_r")
+
# and for each input from the incoming src operands
srl = []
for i in range(self.n_src):
name = "src_r%d" % i
- src_r = Signal(self.rwid, name=name, reset_less=True)
- latchregister(m, self.src_i[i], src_r, src_l.q[i], name)
+ src_r = Signal(self.data_wid, name=name, reset_less=True)
+ with m.If(self.rd.go_i[i]):
+ sync += src_r.eq(self.src_i[i])
+ with m.If(self.issue_i):
+ sync += src_r.eq(0)
srl.append(src_r)
# and one for the output from the ADD (for the EA)
- addr_r = Signal(self.rwid, reset_less=True) # Effective Address Latch
+ addr_r = Signal(self.data_wid, reset_less=True) # Effective Address
latchregister(m, alu_o, addr_r, alu_l.q, "ea_r")
+ # select either zero or src1 if opcode says so
+ op_is_z = oper_r.zero_a
+ src1_or_z = Signal(self.data_wid, reset_less=True)
+ m.d.comb += src1_or_z.eq(Mux(op_is_z, 0, srl[0]))
+
# select either immediate or src2 if opcode says so
- op_is_imm = oper_r.imm_data.imm_ok
- src2_or_imm = Signal(self.rwid, reset_less=True)
- m.d.comb += src2_or_imm.eq(Mux(op_is_imm, oper_r.imm_data.imm, srl[1]))
+ op_is_imm = oper_r.imm_data.ok
+ src2_or_imm = Signal(self.data_wid, reset_less=True)
+ m.d.comb += src2_or_imm.eq(Mux(op_is_imm, oper_r.imm_data.data, srl[1]))
# now do the ALU addr add: one cycle, and say "ready" (next cycle, too)
- sync += alu_o.eq(srl[0] + src2_or_imm) # actual EA
- sync += alu_ok.eq(alu_valid) # keep ack in sync with EA
-
- # decode bits of operand (latched)
- comb += op_is_st.eq(oper_r.insn_type == InternalOp.OP_STORE) # ST
- comb += op_is_ld.eq(oper_r.insn_type == InternalOp.OP_LOAD) # LD
- op_is_update = oper_r.update # UPDATE
- comb += self.load_mem_o.eq(op_is_ld & self.go_ad_i)
- comb += self.stwd_mem_o.eq(op_is_st & self.go_st_i)
- comb += self.ld_o.eq(op_is_ld)
- comb += self.st_o.eq(op_is_st)
+ comb += alu_o.eq(src1_or_z + src2_or_imm) # actual EA
+ m.d.sync += alu_ok.eq(alu_valid & canceln) # keep ack in sync with EA
############################
# Control Signal calculation
# busy signal
busy_o = self.busy_o
- comb += self.busy_o.eq(opc_l.q) # | self.pi.busy_o) # busy out
-
- # 1st operand read-request is simple: always need it
- comb += self.rd.rel[0].eq(src_l.q[0] & busy_o)
+ comb += self.busy_o.eq(opc_l.q) # | self.pi.busy_o) # busy out
+ # 1st operand read-request only when zero not active
# 2nd operand only needed when immediate is not active
- comb += self.rd.rel[1].eq(src_l.q[1] & busy_o & ~op_is_imm)
+ slg = Cat(op_is_z, op_is_imm) #is this correct ?
+ bro = Repl(self.busy_o, self.n_src)
+ comb += self.rd.rel_o.eq(src_l.q & bro & ~slg)
# note when the address-related read "go" signals are active
- comb += rda_any.eq(self.rd.go[0] | self.rd.go[1])
+ comb += rda_any.eq(self.rd.go_i[0] | self.rd.go_i[1])
# alu input valid when 1st and 2nd ops done (or imm not active)
- comb += alu_valid.eq(busy_o & ~(self.rd.rel[0] | self.rd.rel[1]))
+ comb += alu_valid.eq(busy_o & ~(self.rd.rel_o[0] | self.rd.rel_o[1]) &
+ canceln)
# 3rd operand only needed when operation is a store
- comb += self.rd.rel[2].eq(src_l.q[2] & busy_o & op_is_st)
+ comb += self.rd.rel_o[2].eq(src_l.q[2] & busy_o & op_is_st)
# all reads done when alu is valid and 3rd operand needed
- comb += rd_done.eq(alu_valid & ~self.rd.rel[2])
+ comb += rd_done.eq(alu_valid & ~self.rd.rel_o[2])
# address release only if addr ready, but Port must be idle
- comb += self.adr_rel_o.eq(adr_l.q & busy_o)
+ comb += self.adr_rel_o.eq(alu_valid & adr_l.q & busy_o)
+
+ # the write/store (etc) all must be cancelled if an exception occurs
+ # note: cancel is active low, like shadown_i,
+ # while exc_o.happpened is active high
+ comb += canceln.eq(~self.exc_o.happened & self.shadown_i)
# store release when st ready *and* all operands read (and no shadow)
- comb += self.st.rel.eq(sto_l.q & busy_o & rd_done & op_is_st &
- self.shadown_i)
+ # dcbz is special case of store -- TODO verify shadows
+ comb += self.st.rel_o.eq(sto_l.q & busy_o & rd_done & op_is_st_or_dcbz &
+ canceln)
# request write of LD result. waits until shadow is dropped.
- comb += self.wr.rel[0].eq(wri_l.q & busy_o & lod_l.qn & op_is_ld &
- self.shadown_i)
+ comb += self.wr.rel_o[0].eq(rd_done & wri_l.q & busy_o & lod_l.qn &
+ op_is_ld & canceln)
# request write of EA result only in update mode
- comb += self.wr.rel[1].eq(upd_l.q & busy_o & op_is_update &
- self.shadown_i)
+ comb += self.wr.rel_o[1].eq(upd_l.q & busy_o & op_is_update &
+ alu_valid & canceln)
+
+ # request write of CR0 result only in reserve and Rc=1
+ comb += self.wr.rel_o[2].eq(cr0_l.q & busy_o & op_is_atomic &
+ alu_valid & canceln)
# provide "done" signal: select req_rel for non-LD/ST, adr_rel for LD/ST
- comb += wr_any.eq(self.st.go | self.wr.go[0] | self.wr.go[1])
- comb += wr_reset.eq(rst_l.q & busy_o & self.shadown_i & wr_any &
- ~(self.st.rel | self.wr.rel[0] | self.wr.rel[1]) &
- (lod_l.qn | op_is_st))
- comb += self.done_o.eq(wr_reset)
+ comb += wr_any.eq(self.st.go_i | p_st_go |
+ self.wr.go_i.bool())
+ comb += wr_reset.eq(rst_l.q & busy_o & canceln &
+ ~(self.st.rel_o | self.wr.rel_o.bool()) &
+ (lod_l.qn | op_is_st_or_dcbz)
+ )
+ comb += self.done_o.eq(wr_reset & (~self.pi.busy_o | op_is_ld))
######################
# Data/Address outputs
# put the LD-output register directly onto the output bus on a go_write
- with m.If(self.wr.go[0]):
- comb += self.data_o.eq(ldd_r)
+ comb += self.o_data.data.eq(self.dest[0])
+ comb += self.o_data.ok.eq(self.wr.rel_o[0])
+ with m.If(self.wr.go_i[0]):
+ comb += self.dest[0].eq(ldd_r)
# "update" mode, put address out on 2nd go-write
- with m.If(op_is_update & self.wr.go[1]):
- comb += self.addr_o.eq(addr_r)
+ comb += self.addr_o.data.eq(self.dest[1])
+ comb += self.addr_o.ok.eq(self.wr.rel_o[1])
+ with m.If(op_is_update & self.wr.go_i[1]):
+ comb += self.dest[1].eq(addr_r)
+
+ # fun-fun-fun, calculate CR0 when Rc=1 requested.
+ cr0 = self.dest[2]
+ comb += self.cr_o.data.eq(cr0)
+ comb += self.cr_o.ok.eq(self.wr.rel_o[2])
+ with m.If(cr0_l.q):
+ comb += cr0.eq(Cat(C(0, 1), store_done, C(0, 2)))
+
+ # need to look like MultiCompUnit: put wrmask out.
+ # XXX may need to make this enable only when write active
+ comb += self.wrmask.eq(bro & Cat(op_is_ld, op_is_update, cr0_l.q))
###########################
# PortInterface connections
# connect to LD/ST PortInterface.
comb += pi.is_ld_i.eq(op_is_ld & busy_o) # decoded-LD
- comb += pi.is_st_i.eq(op_is_st & busy_o) # decoded-ST
- comb += pi.op.eq(self.oper_i) # op details (not all needed)
- # address
- comb += pi.addr.data.eq(addr_r) # EA from adder
- comb += pi.addr.ok.eq(alu_ok & lod_l.q) # "go do address stuff"
- comb += self.addr_exc_o.eq(pi.addr_exc_o) # exception occurred
+ comb += pi.is_nc.eq(op_is_cix & busy_o) # cache-inhibited
+ comb += pi.is_st_i.eq(op_is_st_or_dcbz & busy_o) # decoded-ST
+ comb += pi.is_dcbz_i.eq(op_is_dcbz & busy_o) # decoded-DCBZ
+ comb += pi.reserve.eq(oper_r.reserve & busy_o) # atomic LR/SC
+ comb += pi.data_len.eq(oper_r.data_len) # data_len
+ # address: use sync to avoid long latency
+ sync += pi.addr.data.eq(addr_r) # EA from adder
+ with m.If(op_is_dcbz):
+ sync += Display("LDSTCompUnit.DCBZ: EA from adder %x", addr_r)
+
+ sync += pi.addr.ok.eq(alu_ok & lsd_l.q) # "do address stuff" (once)
+ comb += self.exc_o.eq(pi.exc_o) # exception occurred
comb += addr_ok.eq(self.pi.addr_ok_o) # no exc, address fine
+ # connect MSR.PR etc. for priv/virt operation
+ comb += pi.priv_mode.eq(~oper_r.msr[MSR.PR])
+ comb += pi.virt_mode.eq(oper_r.msr[MSR.DR])
+ comb += pi.mode_32bit.eq(~oper_r.msr[MSR.SF])
+ with m.If(self.issue_i): # display this only once
+ sync += Display("LDSTCompUnit: oper_r.msr %x pr=%x dr=%x sf=%x",
+ oper_r.msr,
+ oper_r.msr[MSR.PR],
+ oper_r.msr[MSR.DR],
+ oper_r.msr[MSR.SF])
+
+ # byte-reverse on LD
+ revnorev = Signal(64, reset_less=True)
+ with m.If(oper_r.byte_reverse):
+ # byte-reverse the data based on ld/st width (turn it to LE)
+ data_len = oper_r.data_len
+ lddata_r = byte_reverse(m, 'lddata_r', pi.ld.data, data_len)
+ comb += revnorev.eq(lddata_r) # put reversed- data out
+ with m.Else():
+ comb += revnorev.eq(pi.ld.data) # put data out, straight (as BE)
+
+ # then check sign-extend
+ with m.If(oper_r.sign_extend):
+ # okok really should "if data_len == 4" and so on here
+ with m.If(oper_r.data_len == 2):
+ comb += ldd_o.eq(exts(revnorev, 16, 64)) # sign-extend hword
+ with m.Else():
+ comb += ldd_o.eq(exts(revnorev, 32, 64)) # sign-extend dword
+ with m.Else():
+ comb += ldd_o.eq(revnorev)
+
# ld - ld gets latched in via lod_l
- comb += ldd_o.eq(pi.ld.data) # ld data goes into ld reg (above)
- comb += ld_ok.eq(pi.ld.ok) # ld.ok *closes* (freezes) ld data
+ comb += ld_ok.eq(pi.ld.ok) # ld.ok *closes* (freezes) ld data
+
+ # byte-reverse on ST
+ op3 = srl[2] # 3rd operand latch
+ with m.If(oper_r.byte_reverse):
+ # byte-reverse the data based on width
+ data_len = oper_r.data_len
+ stdata_r = byte_reverse(m, 'stdata_r', op3, data_len)
+ comb += pi.st.data.eq(stdata_r)
+ with m.Else():
+ comb += pi.st.data.eq(op3)
+
# store - data goes in based on go_st
- comb += pi.st.data.eq(srl[2]) # 3rd operand latch
- comb += pi.st.ok.eq(self.st.go) # go store signals st data valid
+ comb += pi.st.ok.eq(self.st.go_i) # go store signals st data valid
return m
+ def get_out(self, i):
+ """make LDSTCompUnit look like RegSpecALUAPI. these correspond
+ to LDSTOutputData o and o1 respectively.
+ """
+ if i == 0:
+ return self.o_data # LDSTOutputData.regspec o
+ if i == 1:
+ return self.addr_o # LDSTOutputData.regspec o1
+ if i == 2:
+ return self.cr_o # LDSTOutputData.regspec cr_a
+ # return self.dest[i]
+
+ def get_fu_out(self, i):
+ return self.get_out(i)
+
def __iter__(self):
- yield self.rd.go
+ yield self.rd.go_i
yield self.go_ad_i
- yield self.wr.go
+ yield self.wr.go_i
yield self.go_st_i
yield self.issue_i
yield self.shadown_i
yield from self.oper_i.ports()
yield from self.src_i
yield self.busy_o
- yield self.rd.rel
+ yield self.rd.rel_o
yield self.adr_rel_o
yield self.sto_rel_o
- yield self.wr.rel
- yield self.data_o
- yield self.addr_o
+ yield self.wr.rel_o
+ yield from self.o_data.ports()
+ yield from self.addr_o.ports()
+ yield from self.cr_o.ports()
yield self.load_mem_o
yield self.stwd_mem_o
break
-def store(dut, src1, src2, src3, imm, imm_ok=True, update=False):
- print ("ST", src1, src2, src3, imm, imm_ok, update)
- yield dut.oper_i.insn_type.eq(InternalOp.OP_STORE)
+def store(dut, src1, src2, src3, imm, imm_ok=True, update=False,
+ byterev=True):
+ print("ST", src1, src2, src3, imm, imm_ok, update)
+ yield dut.oper_i.insn_type.eq(MicrOp.OP_STORE)
+ yield dut.oper_i.data_len.eq(2) # half-word
+ yield dut.oper_i.byte_reverse.eq(byterev)
yield dut.src1_i.eq(src1)
yield dut.src2_i.eq(src2)
yield dut.src3_i.eq(src3)
- yield dut.oper_i.imm_data.imm.eq(imm)
- yield dut.oper_i.imm_data.imm_ok.eq(imm_ok)
- yield dut.oper_i.update.eq(update)
+ yield dut.oper_i.imm_data.data.eq(imm)
+ yield dut.oper_i.imm_data.ok.eq(imm_ok)
+ #guess: this one was removed -- yield dut.oper_i.update.eq(update)
yield dut.issue_i.eq(1)
yield
yield dut.issue_i.eq(0)
- yield
+
if imm_ok:
- yield dut.rd.go.eq(0b101)
+ active_rel = 0b101
else:
- yield dut.rd.go.eq(0b111)
- yield from wait_for(dut.rd.rel)
- yield dut.rd.go.eq(0)
+ active_rel = 0b111
+ # wait for all active rel signals to come up
+ while True:
+ rel = yield dut.rd.rel_o
+ if rel == active_rel:
+ break
+ yield
+ yield dut.rd.go_i.eq(active_rel)
+ yield
+ yield dut.rd.go_i.eq(0)
yield from wait_for(dut.adr_rel_o, False, test1st=True)
- #yield from wait_for(dut.adr_rel_o)
- #yield dut.ad.go.eq(1)
- #yield
- #yield dut.ad.go.eq(0)
+ # yield from wait_for(dut.adr_rel_o)
+ # yield dut.ad.go.eq(1)
+ # yield
+ # yield dut.ad.go.eq(0)
if update:
- yield from wait_for(dut.wr.rel[1])
+ yield from wait_for(dut.wr.rel_o[1])
yield dut.wr.go.eq(0b10)
yield
addr = yield dut.addr_o
- print ("addr", addr)
+ print("addr", addr)
yield dut.wr.go.eq(0)
else:
addr = None
yield
yield dut.go_st_i.eq(0)
yield from wait_for(dut.busy_o, False)
- #wait_for(dut.stwd_mem_o)
+ # wait_for(dut.stwd_mem_o)
yield
return addr
-def load(dut, src1, src2, imm, imm_ok=True, update=False):
- print ("LD", src1, src2, imm, imm_ok, update)
- yield dut.oper_i.insn_type.eq(InternalOp.OP_LOAD)
+def load(dut, src1, src2, imm, imm_ok=True, update=False, zero_a=False,
+ byterev=True):
+ print("LD", src1, src2, imm, imm_ok, update)
+ yield dut.oper_i.insn_type.eq(MicrOp.OP_LOAD)
+ yield dut.oper_i.data_len.eq(2) # half-word
+ yield dut.oper_i.byte_reverse.eq(byterev)
yield dut.src1_i.eq(src1)
yield dut.src2_i.eq(src2)
- yield dut.oper_i.imm_data.imm.eq(imm)
- yield dut.oper_i.imm_data.imm_ok.eq(imm_ok)
+ yield dut.oper_i.zero_a.eq(zero_a)
+ yield dut.oper_i.imm_data.data.eq(imm)
+ yield dut.oper_i.imm_data.ok.eq(imm_ok)
yield dut.issue_i.eq(1)
yield
yield dut.issue_i.eq(0)
yield
- if imm_ok:
- yield dut.rd.go.eq(0b01)
- else:
- yield dut.rd.go.eq(0b11)
- yield from wait_for(dut.rd.rel)
- yield dut.rd.go.eq(0)
+
+ # set up read-operand flags
+ rd = 0b00
+ if not imm_ok: # no immediate means RB register needs to be read
+ rd |= 0b10
+ if not zero_a: # no zero-a means RA needs to be read
+ rd |= 0b01
+
+ # wait for the operands (RA, RB, or both)
+ if rd:
+ yield dut.rd.go_i.eq(rd)
+ yield from wait_for(dut.rd.rel_o)
+ yield dut.rd.go_i.eq(0)
yield from wait_for(dut.adr_rel_o, False, test1st=True)
- #yield dut.ad.go.eq(1)
- #yield
- #yield dut.ad.go.eq(0)
+ # yield dut.ad.go.eq(1)
+ # yield
+ # yield dut.ad.go.eq(0)
if update:
- yield from wait_for(dut.wr.rel[1])
- yield dut.wr.go.eq(0b10)
+ yield from wait_for(dut.wr.rel_o[1])
+ yield dut.wr.go_i.eq(0b10)
yield
addr = yield dut.addr_o
- print ("addr", addr)
- yield dut.wr.go.eq(0)
+ print("addr", addr)
+ yield dut.wr.go_i.eq(0)
else:
addr = None
- yield from wait_for(dut.wr.rel[0], test1st=True)
- yield dut.wr.go.eq(1)
+ yield from wait_for(dut.wr.rel_o[0], test1st=True)
+ yield dut.wr.go_i.eq(1)
yield
- data = yield dut.data_o
- print (data)
- yield dut.wr.go.eq(0)
+ data = yield dut.o_data.o
+ data_ok = yield dut.o_data.o_ok
+ yield dut.wr.go_i.eq(0)
yield from wait_for(dut.busy_o)
yield
# wait_for(dut.stwd_mem_o)
- return data, addr
+ return data, data_ok, addr
-def scoreboard_sim(dut):
+def ldst_sim(dut):
###################
# immediate version
# two LDs (deliberately LD from the 1st address then 2nd)
data, addr = yield from load(dut, 4, 0, 2)
assert data == 0x0003, "returned %x" % data
- data, addr = yield from load(dut, 2, 0, 2)
+ data, addr = yield from load(dut, 2, 0, 2)
assert data == 0x0009, "returned %x" % data
yield
# indexed version
- yield from store(dut, 4, 5, 3, 0, imm_ok=False)
- data, addr = yield from load(dut, 4, 5, 0, imm_ok=False)
+ yield from store(dut, 9, 5, 3, 0, imm_ok=False)
+ data, addr = yield from load(dut, 9, 5, 0, imm_ok=False)
assert data == 0x0003, "returned %x" % data
# update-immediate version
- addr = yield from store(dut, 4, 6, 3, 2, update=True)
- assert addr == 0x0006, "returned %x" % addr
+ addr = yield from store(dut, 9, 6, 3, 2, update=True)
+ assert addr == 0x000b, "returned %x" % addr
# update-indexed version
- data, addr = yield from load(dut, 4, 5, 0, imm_ok=False, update=True)
- assert addr == 0x0009, "returned %x" % addr
+ data, addr = yield from load(dut, 9, 5, 0, imm_ok=False, update=True)
+ assert data == 0x0003, "returned %x" % data
+ assert addr == 0x000e, "returned %x" % addr
+
+ # immediate *and* zero version
+ data, addr = yield from load(dut, 1, 4, 8, imm_ok=True, zero_a=True)
+ assert data == 0x0008, "returned %x" % data
+
class TestLDSTCompUnit(LDSTCompUnit):
- def __init__(self, rwid):
+ def __init__(self, rwid, pspec):
from soc.experiment.l0_cache import TstL0CacheBuffer
- self.l0 = l0 = TstL0CacheBuffer()
- pi = l0.l0.dports[0].pi
+ self.l0 = l0 = TstL0CacheBuffer(pspec)
+ pi = l0.l0.dports[0]
LDSTCompUnit.__init__(self, pi, rwid, 4)
def elaborate(self, platform):
m = LDSTCompUnit.elaborate(self, platform)
m.submodules.l0 = self.l0
- m.d.comb += self.ad.go.eq(self.ad.rel) # link addr-go direct to rel
+ # link addr-go direct to rel
+ m.d.comb += self.ad.go_i.eq(self.ad.rel_o)
return m
def test_scoreboard():
- dut = TestLDSTCompUnit(16)
+ units = {}
+ pspec = TestMemPspec(ldst_ifacetype='bare_wb',
+ imem_ifacetype='bare_wb',
+ addr_wid=64,
+ mask_wid=8,
+ reg_wid=64,
+ units=units)
+
+ dut = TestLDSTCompUnit(16,pspec)
+ vl = rtlil.convert(dut, ports=dut.ports())
+ with open("test_ldst_comp.il", "w") as f:
+ f.write(vl)
+
+ run_simulation(dut, ldst_sim(dut), vcd_name='test_ldst_comp.vcd')
+
+
+class TestLDSTCompUnitRegSpec(LDSTCompUnit):
+
+ def __init__(self, pspec):
+ from soc.experiment.l0_cache import TstL0CacheBuffer
+ from soc.fu.ldst.pipe_data import LDSTPipeSpec
+ regspec = LDSTPipeSpec.regspec
+ self.l0 = l0 = TstL0CacheBuffer(pspec)
+ pi = l0.l0.dports[0]
+ LDSTCompUnit.__init__(self, pi, regspec, 4)
+
+ def elaborate(self, platform):
+ m = LDSTCompUnit.elaborate(self, platform)
+ m.submodules.l0 = self.l0
+ # link addr-go direct to rel
+ m.d.comb += self.ad.go_i.eq(self.ad.rel_o)
+ return m
+
+
+def test_scoreboard_regspec():
+
+ units = {}
+ pspec = TestMemPspec(ldst_ifacetype='bare_wb',
+ imem_ifacetype='bare_wb',
+ addr_wid=64,
+ mask_wid=8,
+ reg_wid=64,
+ units=units)
+
+ dut = TestLDSTCompUnitRegSpec(pspec)
vl = rtlil.convert(dut, ports=dut.ports())
with open("test_ldst_comp.il", "w") as f:
f.write(vl)
- run_simulation(dut, scoreboard_sim(dut), vcd_name='test_ldst_comp.vcd')
+ run_simulation(dut, ldst_sim(dut), vcd_name='test_ldst_regspec.vcd')
if __name__ == '__main__':
+ test_scoreboard_regspec()
test_scoreboard()
projects / soc.git / blobdiff