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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
2013-01-22o3 cpu: fix zero reg problemAndrea Pellegrini
There was an issue w/ the rename logic, which would assign a previous physical register to the ZeroReg architectural register in x86. This issue was giving problems for instructions squashed in threads w/ ID different from 0, sometimes allowing non-mispredicted instructions to obtain a value different from zero when reading the zeroReg.
2013-01-22x86, cpu: corrects 270c9a75e91f, take over decoder on cpu switchNilay Vaish
The changes made by the changeset 270c9a75e91f do not work well with switching of cpus. The problem is that decoder for the old thread context holds state that is not taken over by the new decoder. This patch adds a takeOverFrom() function to Decoder class in each ISA. Except for x86, functions in other ISAs are blank. For x86, the function copies state from the old decoder to the new decoder.
2013-01-19O3 IEW: Make incrWb and decrWb clearerJoel Hestness
Move the increment/decrement of wbOutstanding outside of the comparison in incrWb and decrWb in the IEW. This also fixes a compiler bug with gcc 4.4.7, which incorrectly optimizes "-- ==" as "-=".
2013-01-17ruby: remove calls to g_system_ptr->getTime()Nilay Vaish
This patch further removes calls to g_system_ptr->getTime() where ever other clocked objects are available for providing current time.
2013-01-15x86 cpuid: enable clflushNilay Vaish
Note that clflush is only being enabled. It is not implemented in actual. A warning is printed if the cpu encounters a clflush instruction. We need to enable this instruction in cpuid since JRE 1.7 tests for it.
2013-01-15x86: implements fsin, fcos instructionsNilay Vaish
2013-01-15x86: implements emms instructionNilay Vaish
2013-01-15x86: implement fabs, fchs instructionsNilay Vaish
2013-01-14ruby sequencer: converts cycles to ticks in deadlock panic()Malek Musleh
This patch converts the panic() print outs in the Sequencer::wakeup() call from ruby cycles to Ticks(). This makes it easier to debug deadlocks with the ProtocolTrace flag so the issue time indicated in the panic message can be quickly searched for. Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2013-01-14Ruby: remove reference to g_system_ptr from class MessageNilay Vaish
This patch was initiated so as to remove reference to g_system_ptr, the pointer to Ruby System that is used for getting the current time. That simple change actual requires changing a lot many things in slicc and garnet. All these changes are related to how time is handled. In most of the places, g_system_ptr has been replaced by another clock object. The changes have been done under the assumption that all the components in the memory system are on the same clock frequency, but the actual clocks might be distributed.
2013-01-14Ruby: use ClockedObject in Consumer classNilay Vaish
Many Ruby structures inherit from the Consumer, which is used for scheduling events. The Consumer used to relay on an Event Manager for scheduling events and on g_system_ptr for time. With this patch, the Consumer will now use a ClockedObject to schedule events and to query for current time. This resulted in several structures being converted from SimObjects to ClockedObjects. Also, the MessageBuffer class now requires a pointer to a ClockedObject so as to query for time.
2013-01-14scons: Address clang 3.2 compilation errorAndreas Hansson
This patch fixes a compilation error encountered using clang 3.2 on OSX.
2013-01-12base simple cpu: removes commented out code about cache opsNilay Vaish
2013-01-12x86: Changes to decoder, corrects 9376Nilay Vaish
The changes made by the changeset 9376 were not quite correct. The patch made changes to the code which resulted in decoder not getting initialized correctly when the state was restored from a checkpoint. This patch adds a startup function to each ISA object. For x86, this function sets the required state in the decoder. For other ISAs, the function is empty right now.
2013-01-08util: add m5_fail op.LluĂ­s Vilanova
Used as a command in full-system scripts helps the user ensure the benchmarks have finished successfully. For example, one can use: /path/to/benchmark args || /sbin/m5 fail 1 and thus ensure gem5 will exit with an error if the benchmark fails.
2013-01-08sim: Fix early termination in multi-core simulation under SE mode.Tao Zhang
When "-I" (maximum instruction number) and "-F" (fastforward instruction number) are applied together, gem5 immediately exits after the cpu switching. The reason is that multiple exit events may be generated in the same cycle by Atomic CPU and inserted to mainEventQueue. However, mainEventQueue can only serve one exit event in one cycle. Therefore, the rest exit events are left in mainEventQueue without being descheduled or deleted, which causes gem5 exits immediately after the system resumes by cpu switching.
2013-01-08arm: add access syscall for ARM SE modeMitch Hayenga
This patch adds the "access" syscall for ARM SE as required by some spec2006 benchmarks.
2013-01-08mem: Make LL/SC locks fine grainedMitch Hayenga
The current implementation in gem5 just keeps a list of locks per cacheline. Due to this, a store to a non-overlapping portion of the cacheline can cause an LL/SC pair to fail. This patch simply adds an address range to the lock structure, so that the lock is only invalidated if the store overlaps the lock range.
2013-01-08mem: Fix use-after-free bugMitch Hayenga
Running with valgrind I noticed a use after free originating from simple_mem.cc. It looks like this is a known issue and this additional call site was missed in an earlier patch.
2013-01-07dev: Fix infinite recursion in DMA devicesAndreas Sandberg
The DMA device sometimes calls the process() method on a completion event directly instead of scheduling it on the current tick. This breaks some devices that assume that the completion handler won't be called until the current event handler has returned. Specifically, it causes infinite recursion in the IdeDisk component because it does not advance its chunk generator until after a dmaRead()/dmaWrite() has returned. This changeset removes this mico-optimization and schedules the event in the current tick instead. This way the semantics event handling stay the same even when the delay is 0.
2013-01-07stats: Fix swig wrapping for Tick in statsSascha Bischoff
Tick was not correctly wrapped for the stats system, and therefore it was not possible to configure the stats dumping from the python scripts without defining Ticks as long long. This patch fixes the wrapping of Tick by copying the typemap of uint64_t to Tick.
2013-01-07cpu: Unify the serialization code for all of the CPU modelsAndreas Sandberg
Cleanup the serialization code for the simple CPUs and the O3 CPU. The CPU-specific code has been replaced with a (un)serializeThread that serializes the thread state / context of a specific thread. Assuming that the thread state class uses the CPU-specific thread state uses the base thread state serialization code, this allows us to restore a checkpoint with any of the CPU models.
2013-01-07cpu: Flush TLBs on switchOut()Andreas Sandberg
This changeset inserts a TLB flush in BaseCPU::switchOut to prevent stale translations when doing repeated switching. Additionally, the TLB flushing functionality is exported to the Python to make debugging of switching/checkpointing easier. A simulation script will typically use the TLB flushing functionality to generate a reference trace. The following sequence can be used to simulate a handover (this depends on how drain is implemented, but is generally the case) between identically configured CPU models: m5.drain(test_sys) [ cpu.flushTLBs() for cpu in test_sys.cpu ] m5.resume(test_sys) The generated trace should normally be identical to a trace generated when switching between identically configured CPU models or checkpointing and resuming.
2013-01-07mem: Fix guest corruption when caches handle uncacheable accessesAndreas Sandberg
When the classic gem5 cache sees an uncacheable memory access, it used to ignore it or silently drop the cache line in case of a write. Normally, there shouldn't be any data in the cache belonging to an uncacheable address range. However, since some architecture models don't implement cache maintenance instructions, there might be some dirty data in the cache that is discarded when this happens. The reason it has mostly worked before is because such cache lines were most likely evicted by normal memory activity before a TLB flush was requested by the OS. Previously, the cache model would invalidate cache lines when they were accessed by an uncacheable write. This changeset alters this behavior so all uncacheable memory accesses cause a cache flush with an associated writeback if necessary. This is implemented by reusing the cache flushing machinery used when draining the cache, which implies that writebacks are performed using functional accesses.
2013-01-07cpu: Rewrite O3 draining to avoid stopping in microcodeAndreas Sandberg
Previously, the O3 CPU could stop in the middle of a microcode sequence. This patch makes sure that the pipeline stops when it has committed a normal instruction or exited from a microcode sequence. Additionally, it makes sure that the pipeline has no instructions in flight when it is drained, which should make draining more robust. Draining is controlled in the commit stage, which checks if the next PC after a committed instruction is in microcode. If this isn't the case, it requests a squash of all instructions after that the instruction that just committed and immediately signals a drain stall to the fetch stage. The CPU then continues to execute until the pipeline and all associated buffers are empty.
2013-01-07cpu: Make sure that a drained atomic CPU isn't executing ucodeAndreas Sandberg
Currently, the atomic CPU can be in the middle of a microcode sequence when it is drained. This leads to two problems: * When switching to a hardware virtualized CPU, we obviously can't execute gem5 microcode. * Since curMacroStaticInst is populated when executing microcode, repeated switching between CPUs executing microcode leads to incorrect execution. After applying this patch, the CPU will be on a proper instruction boundary, which means that it is safe to switch to any CPU model (including hardware virtualized ones). This changeset fixes a bug where the multiple switches to the same atomic CPU sometimes corrupts the target state because of dangling pointers to the currently executing microinstruction. Note: This changeset moves tick event descheduling from switchOut() to drain(), which makes timing consistent between just draining a system and draining /and/ switching between two atomic CPUs. This makes debugging quite a lot easier (execution traces get the same timing), but the latency of the last instruction before a drain will not be accounted for correctly (it will always be 1 cycle). Note 2: This changeset removes so_state variable, the locked variable, and the tickEvent from checkpoints since none of them contain state that needs to be preserved across checkpoints. The so_state is made redundant because we don't use the drain state variable anymore, the lock variable should never be set when the system is drained, and the tick event isn't scheduled.
2013-01-07cpu: Make sure that a drained timing CPU isn't executing ucodeAndreas Sandberg
Currently, the timing CPU can be in the middle of a microcode sequence or multicycle (stayAtPC is true) instruction when it is drained. This leads to two problems: * When switching to a hardware virtualized CPU, we obviously can't execute gem5 microcode. * If stayAtPC is true we might execute half of an instruction twice when restoring a checkpoint or switching CPUs, which leads to an incorrect execution. After applying this patch, the CPU will be on a proper instruction boundary, which means that it is safe to switch to any CPU model (including hardware virtualized ones). This changeset also fixes a bug where the timing CPU sometimes switches out with while stayAtPC is true, which corrupts the target state after a CPU switch or checkpoint. Note: This changeset removes the so_state variable from checkpoints since the drain state isn't used anymore.
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: Fix O3 LSQ debug dumping constness and formattingAndreas Sandberg
2013-01-07arm: Invalidate cached TLB configuration in drainResumeAndreas Sandberg
Currently, we invalidate the cached miscregs in TLB::unserialize(). The intended use of the drainResume() method is to invalidate cached state and prepare the system to resume after a CPU handover or (un)serialization. This patch moves the TLB miscregs invalidation code to the drainResume() method to avoid surprising behavior.
2013-01-07arm: Fix draining of the pagetable walker when squashingAndreas Sandberg
Since the page table walker only checks if a drain has completed in doL1DescriptorWrapper() and doL2DescriptorWrapper(), it sometimes looses track of a drain request if there is a squash. This changeset adds a completeDrain() call after squashing requests in the pending queue, which fixes this issue.
2013-01-07cpu: Fix broken squashAfter implementation in O3 CPUAndreas Sandberg
Commit can currently both commit and squash in the same cycle. This confuses other stages since the signals coming from the commit stage can only signal either a squash or a commit in a cycle. This changeset changes the behavior of squashAfter so that it commits all instructions, including the instruction that requested the squash, in the first cycle and then starts to squash in the next cycle.
2013-01-07o3 cpu: Remove unused variablesAndreas Sandberg
2013-01-07sim: Remove unused variablesAndreas Sandberg
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
2013-01-07arm: Remove the register mapping hack used when copying TCsAndreas Sandberg
In order to see all registers independent of the current CPU mode, the ARM architecture model uses the magic MISCREG_CPSR_MODE register to change the register mappings without actually updating the CPU mode. This hack is no longer needed since the thread context now provides a flat interface to the register file. This patch replaces the CPSR_MODE hack with the flat register interface.
2013-01-07cpu: Introduce sanity checks when switching between CPUsAndreas Sandberg
This patch introduces the following sanity checks when switching between CPUs: * Check that the set of new and old CPUs do not overlap. Having an overlap between the set of new CPUs and the set of old CPUs is currently not supported. Doing such a switch used to result in the following assertion error: BaseCPU::takeOverFrom(BaseCPU*): \ Assertion `!new_itb_port->isConnected()' failed. * Check that all new CPUs are in the switched out state. * Check that all old CPUs are in the switched in state.
2013-01-07cpu: Correctly call parent on switchOut() and takeOverFrom()Andreas Sandberg
This patch cleans up the CPU switching functionality by making sure that CPU models consistently call the parent on switchOut() and takeOverFrom(). This has the following implications that might alter current functionality: * The call to BaseCPU::switchout() in the O3 CPU is moved from signalDrained() (!) to switchOut(). * A call to BaseSimpleCPU::switchOut() is introduced in the simple CPUs.
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: Initialize the O3 pipeline from startup()Andreas Sandberg
The entire O3 pipeline used to be initialized from init(), which is called before initState() or unserialize(). This causes the pipeline to be initialized from an incorrect thread context. This doesn't currently lead to correctness problems as instructions fetched from the incorrect start PC will be squashed a few cycles after initialization. This patch will affect the regressions since the O3 CPU now issues its first instruction fetch to the correct PC instead of 0x0.
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.
2013-01-07arch: Move the ISA object to a separate sectionAndreas Sandberg
After making the ISA an independent SimObject, it is serialized automatically by the Python world. Previously, this just resulted in an empty ISA section. This patch moves the contents of the ISA to that section and removes the explicit ISA serialization from the thread contexts, which makes it behave like a normal SimObject during serialization. Note: This patch breaks checkpoint backwards compatibility! Use the cpt_upgrader.py utility to upgrade old checkpoints to the new format.
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: Add support for invalidating TLBs when drainingAndreas Sandberg
This patch adds support for the memInvalidate() drain method. TLB flushing is requested by calling the virtual flushAll() method on the TLB. Note: This patch renames invalidateAll() to flushAll() on x86 and SPARC to make the interface consistent across all supported architectures.
2013-01-07mem: Remove the IIC replacement policyAndreas Sandberg
The IIC replacement policy seems to be unused and has probably gathered too much bit rot to be useful. This patch removes the IIC and its associated cache parameters.
2013-01-07dev: Do not serialize timer parametersAndreas Hansson
This patch removes the intNum and clock from the serialized scalars as these are set by the Python parameters and should not be part of the checkpoint.
2013-01-07scons: Enforce gcc >= 4.4 or clang >= 2.9 and c++0x supportAndreas Hansson
This patch checks that the compiler in use is either gcc >= 4.4 or clang >= 2.9. and enables building with --std=c++0x in all cases. As a consequence, we can tidy up the hashmap and always have static_assert available. If anyone wants to use alternative compilers, icc for example supports c++0x to a similar level and could be added if needed. This patch opens up for a more elaborate use of c++0x features that are present in gcc 4.4 and clang 2.9, e.g. auto typed variables, variadic templates, rvalues and move semantics, and strongly typed enums. There will be no going back on this one...
2013-01-07scons: Remove stale compiler optionsAndreas Hansson
This patch simply prunes the SUNCC and ICC compiler options as they are both sufficiently stale that they would have to be re-written from scratch anyhow. The patch serves to clean things up before shifting to a build environment that enforces basic c++11 compliance as done in the following patch.