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path: root/src/mem/Bridge.py
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2012-08-22Bridge: Remove NACKs in the bridge and unify with packet queueAndreas Hansson
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.
2012-02-13MEM: Introduce the master/slave port roles in the Python classesAndreas Hansson
This patch classifies all ports in Python as either Master or Slave and enforces a binding of master to slave. Conceptually, a master (such as a CPU or DMA port) issues requests, and receives responses, and conversely, a slave (such as a memory or a PIO device) receives requests and sends back responses. Currently there is no differentiation between coherent and non-coherent masters and slaves. The classification as master/slave also involves splitting the dual role port of the bus into a master and slave port and updating all the system assembly scripts to use the appropriate port. Similarly, the interrupt devices have to have their int_port split into a master and slave port. The intdev and its children have minimal changes to facilitate the extra port. Note that this patch does not enforce any port typing in the C++ world, it merely ensures that the Python objects have a notion of the port roles and are connected in an appropriate manner. This check is carried when two ports are connected, e.g. bus.master = memory.port. The following patches will make use of the classifications and specialise the C++ ports into masters and slaves.
2012-01-17MEM: Make the bus bridge unidirectional and fixed address rangeAndreas Hansson
This patch makes the bus bridge uni-directional and specialises the bus ports to be a master port and a slave port. This greatly simplifies the assumptions on both sides as either port only has to deal with requests or responses. The following patches introduce the notion of master and slave ports, and would not be possible without this split of responsibilities. In making the bridge unidirectional, the address range mechanism of the bridge is also changed. For the cases where communication is taking place both ways, an additional bridge is needed. This causes issues with the existing mechanism, as the busses cannot determine when to stop iterating the address updates from the two bridges. To avoid this issue, and also greatly simplify the specification, the bridge now has a fixed set of address ranges, specified at creation time.
2007-08-10DMA: Add IOCache and fix bus bridge to optionally only send requests oneAli Saidi
way so a cache can handle partial block requests for i/o devices. --HG-- extra : convert_revision : a68b5ae826731bc87ed93eb7ef326a2393053964
2007-05-27Move SimObject python files alongside the C++ and fixNathan Binkert
the SConscript files so that only the objects that are actually available in a given build are compiled in. Remove a bunch of files that aren't used anymore. --HG-- rename : src/python/m5/objects/AlphaTLB.py => src/arch/alpha/AlphaTLB.py rename : src/python/m5/objects/SparcTLB.py => src/arch/sparc/SparcTLB.py rename : src/python/m5/objects/BaseCPU.py => src/cpu/BaseCPU.py rename : src/python/m5/objects/FuncUnit.py => src/cpu/FuncUnit.py rename : src/python/m5/objects/IntrControl.py => src/cpu/IntrControl.py rename : src/python/m5/objects/MemTest.py => src/cpu/memtest/MemTest.py rename : src/python/m5/objects/FUPool.py => src/cpu/o3/FUPool.py rename : src/python/m5/objects/FuncUnitConfig.py => src/cpu/o3/FuncUnitConfig.py rename : src/python/m5/objects/O3CPU.py => src/cpu/o3/O3CPU.py rename : src/python/m5/objects/OzoneCPU.py => src/cpu/ozone/OzoneCPU.py rename : src/python/m5/objects/SimpleOzoneCPU.py => src/cpu/ozone/SimpleOzoneCPU.py rename : src/python/m5/objects/BadDevice.py => src/dev/BadDevice.py rename : src/python/m5/objects/Device.py => src/dev/Device.py rename : src/python/m5/objects/DiskImage.py => src/dev/DiskImage.py rename : src/python/m5/objects/Ethernet.py => src/dev/Ethernet.py rename : src/python/m5/objects/Ide.py => src/dev/Ide.py rename : src/python/m5/objects/Pci.py => src/dev/Pci.py rename : src/python/m5/objects/Platform.py => src/dev/Platform.py rename : src/python/m5/objects/SimConsole.py => src/dev/SimConsole.py rename : src/python/m5/objects/SimpleDisk.py => src/dev/SimpleDisk.py rename : src/python/m5/objects/Uart.py => src/dev/Uart.py rename : src/python/m5/objects/AlphaConsole.py => src/dev/alpha/AlphaConsole.py rename : src/python/m5/objects/Tsunami.py => src/dev/alpha/Tsunami.py rename : src/python/m5/objects/T1000.py => src/dev/sparc/T1000.py rename : src/python/m5/objects/Bridge.py => src/mem/Bridge.py rename : src/python/m5/objects/Bus.py => src/mem/Bus.py rename : src/python/m5/objects/MemObject.py => src/mem/MemObject.py rename : src/python/m5/objects/PhysicalMemory.py => src/mem/PhysicalMemory.py rename : src/python/m5/objects/BaseCache.py => src/mem/cache/BaseCache.py rename : src/python/m5/objects/CoherenceProtocol.py => src/mem/cache/coherence/CoherenceProtocol.py rename : src/python/m5/objects/Repl.py => src/mem/cache/tags/Repl.py rename : src/python/m5/objects/Process.py => src/sim/Process.py rename : src/python/m5/objects/Root.py => src/sim/Root.py rename : src/python/m5/objects/System.py => src/sim/System.py extra : convert_revision : 173f8764bafa8ef899198438fa5573874e407321