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2014-09-19arch: Pass faults by const reference where possibleAndreas Hansson
This patch changes how faults are passed between methods in an attempt to copy as few reference-counting pointer instances as possible. This should avoid unecessary copies being created, contributing to the increment/decrement of the reference counters.
2014-05-13mem: Refactor assignment of Packet typesCurtis Dunham
Put the packet type swizzling (that is currently done in a lot of places) into a refineCommand() member function.
2014-09-03arch, cpu: Factor out the ExecContext into a proper base classAndreas Sandberg
We currently generate and compile one version of the ISA code per CPU model. This is obviously wasting a lot of resources at compile time. This changeset factors out the interface into a separate ExecContext class, which also serves as documentation for the interface between CPUs and the ISA code. While doing so, this changeset also fixes up interface inconsistencies between the different CPU models. The main argument for using one set of ISA code per CPU model has always been performance as this avoid indirect branches in the generated code. However, this argument does not hold water. Booting Linux on a simulated ARM system running in atomic mode (opt/10.linux-boot/realview-simple-atomic) is actually 2% faster (compiled using clang 3.4) after applying this patch. Additionally, compilation time is decreased by 35%.
2014-05-31style: eliminate equality tests with true and falseSteve Reinhardt
Using '== true' in a boolean expression is totally redundant, and using '== false' is pretty verbose (and arguably less readable in most cases) compared to '!'. It's somewhat of a pet peeve, perhaps, but I had some time waiting for some tests to run and decided to clean these up. Unfortunately, SLICC appears not to have the '!' operator, so I had to leave the '== false' tests in the SLICC code.
2014-05-09cpu, arm: Allow the specification of a socket fieldAkash Bagdia
Allow the specification of a socket ID for every core that is reflected in the MPIDR field in ARM systems. This allows studying multi-socket / cluster systems with ARM CPUs.
2014-03-07cpu: Make CPU and ThreadContext getters constAndreas Hansson
This patch merely tidies up the CPU and ThreadContext getters by making them const where appropriate.
2014-03-01cpu: Enable fast-forwarding for MIPS InOrderCPU and O3CPUChristopher Torng
A copyRegs() function is added to MIPS utilities to copy architectural state from the old CPU to the new CPU during fast-forwarding. This addition alone enables fast-forwarding for the o3 cpu model running MIPS. The patch also adds takeOverFrom() and drainResume() functions to the InOrderCPU to enable it to take over from another CPU. This change enables fast-forwarding for the inorder cpu model running MIPS, but not for Alpha. Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2014-01-24arch, cpu: Add support for flattening misc register indexes.Ali Saidi
With ARMv8 support the same misc register id results in accessing different registers depending on the current mode of the processor. This patch adds the same orthogonality to the misc register file as the others (int, float, cc). For all the othre ISAs this is currently a null-implementation. Additionally, a system variable is added to all the ISA objects.
2014-01-24cpu: Add CPU support for generatig wake up events when LLSC adresses are ↵Ali Saidi
snooped. This patch add support for generating wake-up events in the CPU when an address that is currently in the exclusive state is hit by a snoop. This mechanism is required for ARMv8 multi-processor support.
2013-10-15cpu: add a condition-code register classYasuko Eckert
Add a third register class for condition codes, in parallel with the integer and FP classes. No ISAs use the CC class at this point though.
2013-10-15cpu: rename *_DepTag constants to *_Reg_BaseSteve Reinhardt
Make these names more meaningful. Specifically, made these substitutions: s/FP_Base_DepTag/FP_Reg_Base/g; s/Ctrl_Base_DepTag/Misc_Reg_Base/g; s/Max_DepTag/Max_Reg_Index/g;
2013-10-15cpu/inorder: merge register class enumsSteve Reinhardt
The previous patch introduced a RegClass enum to clean up register classification. The inorder model already had an equivalent enum (RegType) that was used internally. This patch replaces RegType with RegClass to get rid of the now-redundant code.
2013-10-15cpu: clean up architectural register classificationSteve Reinhardt
Move from a poorly documented scheme where the mapping of unified architectural register indices to register classes is hardcoded all over to one where there's an enum for the register classes and a function that encapsulates the mapping.
2013-09-04cpu: Move the branch predictor out of the BaseCPUAndreas Hansson
The branch predictor is guarded by having either the in-order or out-of-order CPU as one of the available CPU models and therefore should not be used in the BaseCPU. This patch moves the parameter to the relevant CPU classes.
2013-07-18mem: Set the cache line size on a system levelAndreas Hansson
This patch removes the notion of a peer block size and instead sets the cache line size on the system level. Previously the size was set per cache, and communicated through the interconnect. There were plenty checks to ensure that everyone had the same size specified, and these checks are now removed. Another benefit that is not yet harnessed is that the cache line size is now known at construction time, rather than after the port binding. Hence, the block size can be locally stored and does not have to be queried every time it is used. A follow-on patch updates the configuration scripts accordingly.
2013-04-22sim: separate nextCycle() and clockEdge() in clockedObjectsDam Sunwoo
Previously, nextCycle() could return the *current* cycle if the current tick was already aligned with the clock edge. This behavior is not only confusing (not quite what the function name implies), but also caused problems in the drainResume() function. When exiting/re-entering the sim loop (e.g., to take checkpoints), the CPUs will drain and resume. Due to the previous behavior of nextCycle(), the CPU tick events were being rescheduled in the same ticks that were already processed before draining. This caused divergence from runs that did not exit/re-entered the sim loop. (Initially a cycle difference, but a significant impact later on.) This patch separates out the two behaviors (nextCycle() and clockEdge()), uses nextCycle() in drainResume, and uses clockEdge() everywhere else. Nothing (other than name) should change except for the drainResume timing.
2013-03-26cpu: Remove CpuPort and use MasterPort in the CPU classesAndreas Hansson
This patch changes the port in the CPU classes to use MasterPort instead of the derived CpuPort. The functions of the CpuPort are now distributed across the relevant subclasses. The port accessor functions (getInstPort and getDataPort) now return a MasterPort instead of a CpuPort. This simplifies creating derivative CPUs that do not use the CpuPort.
2013-03-20cpu: Avoid including inorder TLBUnit to avoid gcc LTO bugAndreas Hansson
This patch comments out the inclusion of the inorder TLBUnit which is only used in the 9-stage pipeline. With the TLBUnit present, gcc >= 4.6 in combination with LTO ends up throwing away the definition of the TLBUnit destructor, and consequently fail to link. See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53808 for more details about the bug, and http://gcc.gnu.org/ml/gcc/2012-06/msg00397.html for the discussion thread that also touches on similar issues seen with clang.
2013-02-15sim: Add a system-global option to bypass cachesAndreas Sandberg
Virtualized CPUs and the fastmem mode of the atomic CPU require direct access to physical memory. We currently require caches to be disabled when using them to prevent chaos. This is not ideal when switching between hardware virutalized CPUs and other CPU models as it would require a configuration change on each switch. This changeset introduces a new version of the atomic memory mode, 'atomic_noncaching', where memory accesses are inserted into the memory system as atomic accesses, but bypass caches. To make memory mode tests cleaner, the following methods are added to the System class: * isAtomicMode() -- True if the memory mode is 'atomic' or 'direct'. * isTimingMode() -- True if the memory mode is 'timing'. * bypassCaches() -- True if caches should be bypassed. The old getMemoryMode() and setMemoryMode() methods should never be used from the C++ world anymore.
2013-02-15cpu: Refactor memory system checksAndreas Sandberg
CPUs need to test that the memory system is in the right mode in two places, when the CPU is initialized (unless it's switched out) and on a drainResume(). This led to some code duplication in the CPU models. This changeset introduces the verifyMemoryMode() method which is called by BaseCPU::init() if the CPU isn't switched out. The individual CPU models are responsible for calling this method when resuming from a drain as this code is CPU model specific.
2013-02-15cpu: Add CPU metadata om the Python classesAndreas Sandberg
The configuration scripts currently hard-code the requirements of each CPU. This is clearly not optimal as it makes writing new configuration scripts painful and adding new CPU models requires existing scripts to be updated. This patch adds the following class methods to the base CPU and all relevant CPUs: * memory_mode -- Return a string describing the current memory mode (invalid/atomic/timing). * require_caches -- Does the CPU model require caches? * support_take_over -- Does the CPU support CPU handover?
2013-01-24branch predictor: move out of o3 and inorder cpusNilay Vaish ext:(%2C%20Timothy%20Jones%20%3Ctimothy.jones%40cl.cam.ac.uk%3E)
This patch moves the branch predictor files in the o3 and inorder directories to src/cpu/pred. This allows sharing the branch predictor across different cpu models. This patch was originally posted by Timothy Jones in July 2010 but never made it to the repository. --HG-- rename : src/cpu/o3/bpred_unit.cc => src/cpu/pred/bpred_unit.cc rename : src/cpu/o3/bpred_unit.hh => src/cpu/pred/bpred_unit.hh rename : src/cpu/o3/bpred_unit_impl.hh => src/cpu/pred/bpred_unit_impl.hh rename : src/cpu/o3/sat_counter.hh => src/cpu/pred/sat_counter.hh
2013-01-07cpu: Fix broken thread context handoverAndreas Sandberg
The thread context handover code used to break when multiple handovers were performed during the same quiesce period. Previously, the thread contexts would assign the TC pointer in the old quiesce event to the new TC. This obviously broke in cases where multiple switches were performed within the same quiesce period, in which case the TC pointer in the quiesce event would point to an old CPU. The new implementation deschedules pending quiesce events in the old TC and schedules a new quiesce event in the new TC. The code has been refactored to remove most of the code duplication.
2013-01-07cpu: Rename defer_registration->switched_outAndreas Sandberg
The defer_registration parameter is used to prevent a CPU from initializing at startup, leaving it in the "switched out" mode. The name of this parameter (and the help string) is confusing. This patch renames it to switched_out, which should be more descriptive.
2013-01-07cpu: Remove unused params.hh header file in inorder CPUAndreas Sandberg
2013-01-07cpu: Unify SimpleCPU and O3 CPU serialization codeAndreas Sandberg
The O3 CPU used to copy its thread context to a SimpleThread in order to do serialization. This was a bit of a hack involving two static SimpleThread instances and a magic constructor that was only used by the O3 CPU. This patch moves the ThreadContext serialization code into two global procedures that, in addition to the normal serialization parameters, take a ThreadContext reference as a parameter. This allows us to reuse the serialization code in all ThreadContext implementations.
2013-01-07cpu: Implement a flat register interface in thread contextsAndreas Sandberg
Some architectures map registers differently depending on their mode of operations. There is currently no architecture independent way of accessing all registers. This patch introduces a flat register interface to the ThreadContext class. This interface is useful, for example, when serializing or copying thread contexts.
2013-01-07cpu: Check that the memory system is in the correct modeAndreas Sandberg
This patch adds checks to all CPU models to make sure that the memory system is in the correct mode at startup and when resuming after a drain. Previously, we only checked that the memory system was in the right mode when resuming. This is inadequate since this is a configuration error that should be detected at startup as well as when resuming. Additionally, since the check was done using an assert, it wasn't performed when NDEBUG was set (e.g., the fast target).
2013-01-07arch: Make the ISA class inherit from SimObjectAndreas Sandberg
The ISA class on stores the contents of ID registers on many architectures. In order to make reset values of such registers configurable, we make the class inherit from SimObject, which allows us to use the normal generated parameter headers. This patch introduces a Python helper method, BaseCPU.createThreads(), which creates a set of ISAs for each of the threads in an SMT system. Although it is currently only needed when creating multi-threaded CPUs, it should always be called before instantiating the system as this is an obvious place to configure ID registers identifying a thread/CPU.
2013-01-07cpu: rename the misleading inSyscall to noSquashFromTCAli Saidi
isSyscall was originally created because during handling of a syscall in SE mode the threadcontext had to be updated. However, in many places this is used in FS mode (e.g. fault handlers) and the name doesn't make much sense. The boolean actually stops gem5 from squashing speculative and non-committed state when a write to a threadcontext happens, so re-name the variable to something more appropriate
2013-01-04Decoder: Remove the thread context get/set from the decoder.Gabe Black
This interface is no longer used, and getting rid of it simplifies the decoders and code that sets up the decoders. The thread context had been used to read architectural state which was used to contextualize the instruction memory as it came in. That was changed so that the state is now sent to the decoders to keep locally if/when it changes. That's significantly more efficient. Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2012-12-06TournamentBP: Fix some bugs with table sizes and countersErik Tomusk
globalHistoryBits, globalPredictorSize, and choicePredictorSize are decoupled. globalHistoryBits controls how much history is kept, global and choice predictor sizes control how much of that history is used when accessing predictor tables. This way, global and choice predictors can actually be different sizes, and it is no longer possible to walk off the predictor arrays and cause a seg fault. There are now individual thresholds for choice, global, and local saturating counters, so that taken/not taken decisions are correct even when the predictors' counters' sizes are different. The interface for localPredictorSize has been removed from TournamentBP because the value can be calculated from localHistoryBits. Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2012-12-06inorder cpu: add missing DPRINTF argumentMalek Musleh
Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2012-11-02sim: Include object header files in SWIG interfacesAndreas Sandberg
When casting objects in the generated SWIG interfaces, SWIG uses classical C-style casts ( (Foo *)bar; ). In some cases, this can degenerate into the equivalent of a reinterpret_cast (mainly if only a forward declaration of the type is available). This usually works for most compilers, but it is known to break if multiple inheritance is used anywhere in the object hierarchy. This patch introduces the cxx_header attribute to Python SimObject definitions, which should be used to specify a header to include in the SWIG interface. The header should include the declaration of the wrapped object. We currently don't enforce header the use of the header attribute, but a warning will be generated for objects that do not use it.
2012-09-07Param: Transition to Cycles for relevant parametersAndreas Hansson
This patch is a first step to using Cycles as a parameter type. The main affected modules are the CPUs and the Ruby caches. There are definitely plenty more places that are affected, but this patch serves as a starting point to making the transition. An important part of this patch is to actually enable parameters to be specified as Param.Cycles which involves some changes to params.py.
2012-08-28Clock: Add a Cycles wrapper class and use where applicableAndreas Hansson
This patch addresses the comments and feedback on the preceding patch that reworks the clocks and now more clearly shows where cycles (relative cycle counts) are used to express time. Instead of bumping the existing patch I chose to make this a separate patch, merely to try and focus the discussion around a smaller set of changes. The two patches will be pushed together though. This changes done as part of this patch are mostly following directly from the introduction of the wrapper class, and change enough code to make things compile and run again. There are definitely more places where int/uint/Tick is still used to represent cycles, and it will take some time to chase them all down. Similarly, a lot of parameters should be changed from Param.Tick and Param.Unsigned to Param.Cycles. In addition, the use of curTick is questionable as there should not be an absolute cycle. Potential solutions can be built on top of this patch. There is a similar situation in the o3 CPU where lastRunningCycle is currently counting in Cycles, and is still an absolute time. More discussion to be had in other words. An additional change that would be appropriate in the future is to perform a similar wrapping of Tick and probably also introduce a Ticks class along with suitable operators for all these classes.
2012-08-28Clock: Rework clocks to avoid tick-to-cycle transformationsAndreas Hansson
This patch introduces the notion of a clock update function that aims to avoid costly divisions when turning the current tick into a cycle. Each clocked object advances a private (hidden) cycle member and a tick member and uses these to implement functions for getting the tick of the next cycle, or the tick of a cycle some time in the future. In the different modules using the clocks, changes are made to avoid counting in ticks only to later translate to cycles. There are a few oddities in how the O3 and inorder CPU count idle cycles, as seen by a few locations where a cycle is subtracted in the calculation. This is done such that the regression does not change any stats, but should be revisited in a future patch. Another, much needed, change that is not done as part of this patch is to introduce a new typedef uint64_t Cycle to be able to at least hint at the unit of the variables counting Ticks vs Cycles. This will be done as a follow-up patch. As an additional follow up, the thread context still uses ticks for the book keeping of last activate and last suspend and this should probably also be changed into cycles as well.
2012-08-21CPU: Remove overloaded function_trace_start parameterAndreas Hansson
This patch removes the overloading of the parameter, which seems both redundant, and possibly incorrect. The inorder CPU is particularly interesting as it uses a different name for the parameter, and never make any use of it internally.
2012-08-06process: add progName() virtual functionSteve Reinhardt
This replaces a (potentially uninitialized) string field with a virtual function so that we can have a safe interface without requiring changes to the eio code.
2012-07-09Port: Align port names in C++ and PythonAndreas Hansson
This patch is a first step to align the port names used in the Python world and the C++ world. Ultimately it serves to make the use of config.json together with output from the simulation easier, including post-processing of statistics. Most notably, the CPU, cache, and bus is addressed in this patch, and there might be other ports that should be updated accordingly. The dash name separator has also been replaced with a "." which is what is used to concatenate the names in python, and a separation is made between the master and slave port in the bus.
2012-06-05cpu: Don't init simple and inorder CPUs if they are defered.Anthony Gutierrez
initCPU() will be called to initialize switched out CPUs for the simple and inorder CPU models. this patch prevents those CPUs from being initialized because they should get their state from the active CPU when it is switched out.
2012-06-05sim: Remove FastAllocAli Saidi
While FastAlloc provides a small performance increase (~1.5%) over regular malloc it isn't thread safe. After removing FastAlloc and using tcmalloc I've seen a performance increase of 12% over libc malloc when running twolf for ARM.
2012-05-26CPU: Merge the predecoder and decoder.Gabe Black
These classes are always used together, and merging them will give the ISAs more flexibility in how they cache things and manage the process. --HG-- rename : src/arch/x86/predecoder_tables.cc => src/arch/x86/decoder_tables.cc
2012-05-25Decode: Make the Decoder class defined per ISA.Gabe Black
--HG-- rename : src/cpu/decode.cc => src/arch/generic/decoder.cc rename : src/cpu/decode.hh => src/arch/generic/decoder.hh
2012-05-01MEM: Separate requests and responses for timing accessesAndreas Hansson
This patch moves send/recvTiming and send/recvTimingSnoop from the Port base class to the MasterPort and SlavePort, and also splits them into separate member functions for requests and responses: send/recvTimingReq, send/recvTimingResp, and send/recvTimingSnoopReq, send/recvTimingSnoopResp. A master port sends requests and receives responses, and also receives snoop requests and sends snoop responses. A slave port has the reciprocal behaviour as it receives requests and sends responses, and sends snoop requests and receives snoop responses. For all MemObjects that have only master ports or slave ports (but not both), e.g. a CPU, or a PIO device, this patch merely adds more clarity to what kind of access is taking place. For example, a CPU port used to call sendTiming, and will now call sendTimingReq. Similarly, a response previously came back through recvTiming, which is now recvTimingResp. For the modules that have both master and slave ports, e.g. the bus, the behaviour was previously relying on branches based on pkt->isRequest(), and this is now replaced with a direct call to the apprioriate member function depending on the type of access. Please note that send/recvRetry is still shared by all the timing accessors and remains in the Port base class for now (to maintain the current bus functionality and avoid changing the statistics of all regressions). The packet queue is split into a MasterPort and SlavePort version to facilitate the use of the new timing accessors. All uses of the PacketQueue are updated accordingly. With this patch, the type of packet (request or response) is now well defined for each type of access, and asserts on pkt->isRequest() and pkt->isResponse() are now moved to the appropriate send member functions. It is also worth noting that sendTimingSnoopReq no longer returns a boolean, as the semantics do not alow snoop requests to be rejected or stalled. All these assumptions are now excplicitly part of the port interface itself.
2012-04-14MEM: Remove the Broadcast destination from the packetAndreas Hansson
This patch simplifies the packet by removing the broadcast flag and instead more firmly relying on (and enforcing) the semantics of transactions in the classic memory system, i.e. request packets are routed from a master to a slave based on the address, and when they are created they have neither a valid source, nor destination. On their way to the slave, the request packet is updated with a source field for all modules that multiplex packets from multiple master (e.g. a bus). When a request packet is turned into a response packet (at the final slave), it moves the potentially populated source field to the destination field, and the response packet is routed through any multiplexing components back to the master based on the destination field. Modules that connect multiplexing components, such as caches and bridges store any existing source and destination field in the sender state as a stack (just as before). The packet constructor is simplified in that there is no longer a need to pass the Packet::Broadcast as the destination (this was always the case for the classic memory system). In the case of Ruby, rather than using the parameter to the constructor we now rely on setDest, as there is already another three-argument constructor in the packet class. In many places where the packet information was printed as part of DPRINTFs, request packets would be printed with a numeric "dest" that would always be -1 (Broadcast) and that field is now removed from the printing.
2012-04-14MEM: Separate snoops and normal memory requests/responsesAndreas Hansson
This patch introduces port access methods that separates snoop request/responses from normal memory request/responses. The differentiation is made for functional, atomic and timing accesses and builds on the introduction of master and slave ports. Before the introduction of this patch, the packets belonging to the different phases of the protocol (request -> [forwarded snoop request -> snoop response]* -> response) all use the same port access functions, even though the snoop packets flow in the opposite direction to the normal packet. That is, a coherent master sends normal request and receives responses, but receives snoop requests and sends snoop responses (vice versa for the slave). These two distinct phases now use different access functions, as described below. Starting with the functional access, a master sends a request to a slave through sendFunctional, and the request packet is turned into a response before the call returns. In a system without cache coherence, this is all that is needed from the functional interface. For the cache-coherent scenario, a slave also sends snoop requests to coherent masters through sendFunctionalSnoop, with responses returned within the same packet pointer. This is currently used by the bus and caches, and the LSQ of the O3 CPU. The send/recvFunctional and send/recvFunctionalSnoop are moved from the Port super class to the appropriate subclass. Atomic accesses follow the same flow as functional accesses, with request being sent from master to slave through sendAtomic. In the case of cache-coherent ports, a slave can send snoop requests to a master through sendAtomicSnoop. Just as for the functional access methods, the atomic send and receive member functions are moved to the appropriate subclasses. The timing access methods are different from the functional and atomic in that requests and responses are separated in time and send/recvTiming are used for both directions. Hence, a master uses sendTiming to send a request to a slave, and a slave uses sendTiming to send a response back to a master, at a later point in time. Snoop requests and responses travel in the opposite direction, similar to what happens in functional and atomic accesses. With the introduction of this patch, it is possible to determine the direction of packets in the bus, and no longer necessary to look for both a master and a slave port with the requested port id. In contrast to the normal recvFunctional, recvAtomic and recvTiming that are pure virtual functions, the recvFunctionalSnoop, recvAtomicSnoop and recvTimingSnoop have a default implementation that calls panic. This is to allow non-coherent master and slave ports to not implement these functions.
2012-04-14clang/gcc: Fix compilation issues with clang 3.0 and gcc 4.6Andreas Hansson
This patch addresses a number of minor issues that cause problems when compiling with clang >= 3.0 and gcc >= 4.6. Most importantly, it avoids using the deprecated ext/hash_map and instead uses unordered_map (and similarly so for the hash_set). To make use of the new STL containers, g++ and clang has to be invoked with "-std=c++0x", and this is now added for all gcc versions >= 4.6, and for clang >= 3.0. For gcc >= 4.3 and <= 4.5 and clang <= 3.0 we use the tr1 unordered_map to avoid the deprecation warning. The addition of c++0x in turn causes a few problems, as the compiler is more stringent and adds a number of new warnings. Below, the most important issues are enumerated: 1) the use of namespaces is more strict, e.g. for isnan, and all headers opening the entire namespace std are now fixed. 2) another other issue caused by the more stringent compiler is the narrowing of the embedded python, which used to be a char array, and is now unsigned char since there were values larger than 128. 3) a particularly odd issue that arose with the new c++0x behaviour is found in range.hh, where the operator< causes gcc to complain about the template type parsing (the "<" is interpreted as the beginning of a template argument), and the problem seems to be related to the begin/end members introduced for the range-type iteration, which is a new feature in c++11. As a minor update, this patch also fixes the build flags for the clang debug target that used to be shared with gcc and incorrectly use "-ggdb".
2012-04-06MEM: Enable multiple distributed generalized memoriesAndreas Hansson
This patch removes the assumption on having on single instance of PhysicalMemory, and enables a distributed memory where the individual memories in the system are each responsible for a single contiguous address range. All memories inherit from an AbstractMemory that encompasses the basic behaviuor of a random access memory, and provides untimed access methods. What was previously called PhysicalMemory is now SimpleMemory, and a subclass of AbstractMemory. All future types of memory controllers should inherit from AbstractMemory. To enable e.g. the atomic CPU and RubyPort to access the now distributed memory, the system has a wrapper class, called PhysicalMemory that is aware of all the memories in the system and their associated address ranges. This class thus acts as an infinitely-fast bus and performs address decoding for these "shortcut" accesses. Each memory can specify that it should not be part of the global address map (used e.g. by the functional memories by some testers). Moreover, each memory can be configured to be reported to the OS configuration table, useful for populating ATAG structures, and any potential ACPI tables. Checkpointing support currently assumes that all memories have the same size and organisation when creating and resuming from the checkpoint. A future patch will enable a more flexible re-organisation. --HG-- rename : src/mem/PhysicalMemory.py => src/mem/AbstractMemory.py rename : src/mem/PhysicalMemory.py => src/mem/SimpleMemory.py rename : src/mem/physical.cc => src/mem/abstract_mem.cc rename : src/mem/physical.hh => src/mem/abstract_mem.hh rename : src/mem/physical.cc => src/mem/simple_mem.cc rename : src/mem/physical.hh => src/mem/simple_mem.hh
2012-03-30MEM: Introduce the master/slave port sub-classes in C++William Wang
This patch introduces the notion of a master and slave port in the C++ code, thus bringing the previous classification from the Python classes into the corresponding simulation objects and memory objects. The patch enables us to classify behaviours into the two bins and add assumptions and enfore compliance, also simplifying the two interfaces. As a starting point, isSnooping is confined to a master port, and getAddrRanges to slave ports. More of these specilisations are to come in later patches. The getPort function is not getMasterPort and getSlavePort, and returns a port reference rather than a pointer as NULL would never be a valid return value. The default implementation of these two functions is placed in MemObject, and calls fatal. The one drawback with this specific patch is that it requires some code duplication, e.g. QueuedPort becomes QueuedMasterPort and QueuedSlavePort, and BusPort becomes BusMasterPort and BusSlavePort (avoiding multiple inheritance). With the later introduction of the port interfaces, moving the functionality outside the port itself, a lot of the duplicated code will disappear again.