gem5/configs/example/fs.py
Andreas Hansson a6074016e2 Bridge: Remove NACKs in the bridge and unify with packet queue
This patch removes the NACKing in the bridge, as the split
request/response busses now ensure that protocol deadlocks do not
occur, i.e. the message-dependency chain is broken by always allowing
responses to make progress without being stalled by requests. The
NACKs had limited support in the system with most components ignoring
their use (with a suitable call to panic), and as the NACKs are no
longer needed to avoid protocol deadlocks, the cleanest way is to
simply remove them.

The bridge is the starting point as this is the only place where the
NACKs are created. A follow-up patch will remove the code that deals
with NACKs in the endpoints, e.g. the X86 table walker and DMA
port. Ultimately the type of packet can be complete removed (until
someone sees a need for modelling more complex protocols, which can
now be done in parts of the system since the port and interface is
split).

As a consequence of the NACK removal, the bridge now has to send a
retry to a master if the request or response queue was full on the
first attempt. This change also makes the bridge ports very similar to
QueuedPorts, and a later patch will change the bridge to use these. A
first step in this direction is taken by aligning the name of the
member functions, as done by this patch.

A bit of tidying up has also been done as part of the simplifications.

Surprisingly, this patch has no impact on any of the
regressions. Hence, there was never any NACKs issued. In a follow-up
patch I would suggest changing the size of the bridge buffers set in
FSConfig.py to also test the situation where the bridge fills up.
2012-08-22 11:39:58 -04:00

185 lines
6.7 KiB
Python

# Copyright (c) 2010-2012 ARM Limited
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# terms below provided that you ensure that this notice is replicated
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# modified or unmodified, in source code or in binary form.
#
# Copyright (c) 2006-2007 The Regents of The University of Michigan
# All rights reserved.
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# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met: redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer;
# redistributions in binary form must reproduce the above copyright
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# documentation and/or other materials provided with the distribution;
# neither the name of the copyright holders nor the names of its
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# this software without specific prior written permission.
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# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# Authors: Ali Saidi
import optparse
import sys
import m5
from m5.defines import buildEnv
from m5.objects import *
from m5.util import addToPath, fatal
addToPath('../common')
from FSConfig import *
from SysPaths import *
from Benchmarks import *
import Simulation
import CacheConfig
from Caches import *
import Options
parser = optparse.OptionParser()
Options.addCommonOptions(parser)
Options.addFSOptions(parser)
(options, args) = parser.parse_args()
if args:
print "Error: script doesn't take any positional arguments"
sys.exit(1)
# driver system CPU is always simple... note this is an assignment of
# a class, not an instance.
DriveCPUClass = AtomicSimpleCPU
drive_mem_mode = 'atomic'
# system under test can be any CPU
(TestCPUClass, test_mem_mode, FutureClass) = Simulation.setCPUClass(options)
TestCPUClass.clock = options.clock
DriveCPUClass.clock = options.clock
if options.benchmark:
try:
bm = Benchmarks[options.benchmark]
except KeyError:
print "Error benchmark %s has not been defined." % options.benchmark
print "Valid benchmarks are: %s" % DefinedBenchmarks
sys.exit(1)
else:
if options.dual:
bm = [SysConfig(disk=options.disk_image, mem=options.mem_size), SysConfig(disk=options.disk_image, mem=options.mem_size)]
else:
bm = [SysConfig(disk=options.disk_image, mem=options.mem_size)]
np = options.num_cpus
if buildEnv['TARGET_ISA'] == "alpha":
test_sys = makeLinuxAlphaSystem(test_mem_mode, bm[0])
elif buildEnv['TARGET_ISA'] == "mips":
test_sys = makeLinuxMipsSystem(test_mem_mode, bm[0])
elif buildEnv['TARGET_ISA'] == "sparc":
test_sys = makeSparcSystem(test_mem_mode, bm[0])
elif buildEnv['TARGET_ISA'] == "x86":
test_sys = makeLinuxX86System(test_mem_mode, options.num_cpus, bm[0])
elif buildEnv['TARGET_ISA'] == "arm":
test_sys = makeArmSystem(test_mem_mode,
options.machine_type, bm[0],
bare_metal=options.bare_metal)
else:
fatal("Incapable of building %s full system!", buildEnv['TARGET_ISA'])
if options.kernel is not None:
test_sys.kernel = binary(options.kernel)
if options.script is not None:
test_sys.readfile = options.script
test_sys.init_param = options.init_param
test_sys.cpu = [TestCPUClass(cpu_id=i) for i in xrange(np)]
if bm[0]:
mem_size = bm[0].mem()
else:
mem_size = SysConfig().mem()
if options.caches or options.l2cache:
test_sys.iocache = IOCache(addr_ranges=[test_sys.physmem.range])
test_sys.iocache.cpu_side = test_sys.iobus.master
test_sys.iocache.mem_side = test_sys.membus.slave
else:
test_sys.iobridge = Bridge(delay='50ns', ranges = [test_sys.physmem.range])
test_sys.iobridge.slave = test_sys.iobus.master
test_sys.iobridge.master = test_sys.membus.slave
# Sanity check
if options.fastmem and (options.caches or options.l2cache):
fatal("You cannot use fastmem in combination with caches!")
for i in xrange(np):
if options.fastmem:
test_sys.cpu[i].fastmem = True
if options.checker:
test_sys.cpu[i].addCheckerCpu()
CacheConfig.config_cache(options, test_sys)
if len(bm) == 2:
if buildEnv['TARGET_ISA'] == 'alpha':
drive_sys = makeLinuxAlphaSystem(drive_mem_mode, bm[1])
elif buildEnv['TARGET_ISA'] == 'mips':
drive_sys = makeLinuxMipsSystem(drive_mem_mode, bm[1])
elif buildEnv['TARGET_ISA'] == 'sparc':
drive_sys = makeSparcSystem(drive_mem_mode, bm[1])
elif buildEnv['TARGET_ISA'] == 'x86':
drive_sys = makeX86System(drive_mem_mode, np, bm[1])
elif buildEnv['TARGET_ISA'] == 'arm':
drive_sys = makeArmSystem(drive_mem_mode, options.machine_type, bm[1])
drive_sys.cpu = DriveCPUClass(cpu_id=0)
drive_sys.cpu.createInterruptController()
drive_sys.cpu.connectAllPorts(drive_sys.membus)
if options.fastmem:
drive_sys.cpu.fastmem = True
if options.kernel is not None:
drive_sys.kernel = binary(options.kernel)
drive_sys.iobridge = Bridge(delay='50ns',
ranges = [drive_sys.physmem.range])
drive_sys.iobridge.slave = drive_sys.iobus.master
drive_sys.iobridge.master = drive_sys.membus.slave
drive_sys.init_param = options.init_param
root = makeDualRoot(True, test_sys, drive_sys, options.etherdump)
elif len(bm) == 1:
root = Root(full_system=True, system=test_sys)
else:
print "Error I don't know how to create more than 2 systems."
sys.exit(1)
if options.timesync:
root.time_sync_enable = True
if options.frame_capture:
VncServer.frame_capture = True
Simulation.setWorkCountOptions(test_sys, options)
Simulation.run(options, root, test_sys, FutureClass)