gem5/configs/common/Caches.py
Andreas Hansson 554ddc7c07 arch, cpu: Do not forward snoops to table walker
This patch simplifies the overall CPU by changing the TLB caches such
that they do not forward snoops to the table walker port(s). Note that
only ARM and X86 are affected.

There is no reason for the ports to snoop as they do not actually take
any action, and from a performance point of view we are better of not
snooping more than we have to.

Should it at a later point be required to snoop for a particular TLB
design it is easy enough to add it back.
2015-05-05 03:22:27 -04:00

83 lines
3.1 KiB
Python

# Copyright (c) 2012 ARM Limited
# All rights reserved.
#
# The license below extends only to copyright in the software and shall
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# property including but not limited to intellectual property relating
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# unmodified and in its entirety in all distributions of the software,
# 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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# modification, are permitted provided that the following conditions are
# met: redistributions of source code must retain the above copyright
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# 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
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# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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#
# Authors: Lisa Hsu
from m5.objects import *
# Base implementations of L1, L2, IO and TLB-walker caches. There are
# used in the regressions and also as base components in the
# system-configuration scripts. The values are meant to serve as a
# starting point, and specific parameters can be overridden in the
# specific instantiations.
class L1Cache(BaseCache):
assoc = 2
hit_latency = 2
response_latency = 2
mshrs = 4
tgts_per_mshr = 20
is_top_level = True
class L2Cache(BaseCache):
assoc = 8
hit_latency = 20
response_latency = 20
mshrs = 20
tgts_per_mshr = 12
write_buffers = 8
class IOCache(BaseCache):
assoc = 8
hit_latency = 50
response_latency = 50
mshrs = 20
size = '1kB'
tgts_per_mshr = 12
forward_snoops = False
is_top_level = True
class PageTableWalkerCache(BaseCache):
assoc = 2
hit_latency = 2
response_latency = 2
mshrs = 10
size = '1kB'
tgts_per_mshr = 12
forward_snoops = False
is_top_level = True