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path: root/src/mem/coherent_bus.hh
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2012-07-09Bus: Split the bus into separate request/response layersAndreas Hansson
This patch splits the existing buses into multiple layers. The non-coherent bus is split into a request and a response layer, and the coherent bus adds an additional layer for the snoop responses. The layer is modified to be templatised on the port type, such that the different layers can have retryLists with either master or slave ports. This patch also removes the dynamic cast from the retry, as previously promised when moving the recvRetry from the port base class to the master/slave port respectively. Overall, the split bus more closely reflects any modern on-chip bus and should be at step in the right direction. From this point, it would be reasonable straight forward to add separate layers (and thus contention points and arbitration) for each port and thus create a true crossbar. The regressions all produce the correct output, but have varying degrees of changes to their statistics. A separate patch will be pushed with the updates to the reference statistics.
2012-07-09Bus: Add a notion of layers to the busesAndreas Hansson
This patch moves all flow control, arbitration and state information into a bus layer. The layer is thus responsible for all the state transitions, and for keeping hold of the retry list. Consequently the layer is also responsible for the draining. With this change, the non-coherent and coherent bus are given a single layer to avoid changing any temporal behaviour, but the patch opens up for adding more layers.
2012-07-09Port: Make getAddrRanges constAndreas Hansson
This patch makes getAddrRanges const throughout the code base. There is no reason why it should not be, and making it const prevents adding any unintentional side-effects.
2012-06-29Bus: enable non/coherent buses sub-classesUri Wiener
This patch merely changes several methods to be virtual in order to enable non/coherent buses sub-classes.
2012-05-31Bus: Split the bus into a non-coherent and coherent busAndreas Hansson
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