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authorAndreas Hansson <andreas.hansson@arm.com>2012-05-31 13:30:04 -0400
committerAndreas Hansson <andreas.hansson@arm.com>2012-05-31 13:30:04 -0400
commit0d329407116921cd9aed6f02da551cc5a8ec5131 (patch)
tree6cc534a94543ed1e40c65d502cd428338eabb94d /src/cpu
parentfb9bfb9cfcb6ef5db6881b769c7011ff4907f219 (diff)
downloadgem5-0d329407116921cd9aed6f02da551cc5a8ec5131.tar.xz
Bus: Split the bus into a non-coherent and coherent bus
This patch introduces a class hierarchy of buses, a non-coherent one, and a coherent one, splitting the existing bus functionality. By doing so it also enables further specialisation of the two types of buses. A non-coherent bus connects a number of non-snooping masters and slaves, and routes the request and response packets based on the address. The request packets issued by the master connected to a non-coherent bus could still snoop in caches attached to a coherent bus, as is the case with the I/O bus and memory bus in most system configurations. No snoops will, however, reach any master on the non-coherent bus itself. The non-coherent bus can be used as a template for modelling PCI, PCIe, and non-coherent AMBA and OCP buses, and is typically used for the I/O buses. A coherent bus connects a number of (potentially) snooping masters and slaves, and routes the request and response packets based on the address, and also forwards all requests to the snoopers and deals with the snoop responses. The coherent bus can be used as a template for modelling QPI, HyperTransport, ACE and coherent OCP buses, and is typically used for the L1-to-L2 buses and as the main system interconnect. The configuration scripts are updated to use a NoncoherentBus for all peripheral and I/O buses. A bit of minor tidying up has also been done. --HG-- rename : src/mem/bus.cc => src/mem/coherent_bus.cc rename : src/mem/bus.hh => src/mem/coherent_bus.hh rename : src/mem/bus.cc => src/mem/noncoherent_bus.cc rename : src/mem/bus.hh => src/mem/noncoherent_bus.hh
Diffstat (limited to 'src/cpu')
-rw-r--r--src/cpu/BaseCPU.py4
1 files changed, 2 insertions, 2 deletions
diff --git a/src/cpu/BaseCPU.py b/src/cpu/BaseCPU.py
index 60d06b209..9ed2cb789 100644
--- a/src/cpu/BaseCPU.py
+++ b/src/cpu/BaseCPU.py
@@ -47,7 +47,7 @@ from m5.defines import buildEnv
from m5.params import *
from m5.proxy import *
-from Bus import Bus
+from Bus import CoherentBus
from InstTracer import InstTracer
from ExeTracer import ExeTracer
from MemObject import MemObject
@@ -223,7 +223,7 @@ class BaseCPU(MemObject):
def addTwoLevelCacheHierarchy(self, ic, dc, l2c, iwc = None, dwc = None):
self.addPrivateSplitL1Caches(ic, dc, iwc, dwc)
- self.toL2Bus = Bus()
+ self.toL2Bus = CoherentBus()
self.connectCachedPorts(self.toL2Bus)
self.l2cache = l2c
self.toL2Bus.master = self.l2cache.cpu_side