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2018-02-16arch-arm: Fix big endian support in do{Long,L1,L2}DescriptorChuan Zhu
do{Long,L1,L2}Descriptor was not able to load descriptors correctly for big-endian situations, causing recognised Descriptors. Added big-endian related data conversions to correct them. Change-Id: I0fdfbbdf56f94bbed19172acae1b6e4a0382b5a0 Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-on: https://gem5-review.googlesource.com/8144 Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
2018-02-07arch-arm: Change function name for banked miscregsGiacomo Travaglini
This commit changes the function's name used for retrieving the index of a security banked register given the flatten index. This will avoid confusion with flattenRegId, which has a different purpose. Change-Id: I470ffb55916cb7fc9f78e071a7f2e609c1829f1a Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com> Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com> Reviewed-on: https://gem5-review.googlesource.com/7982 Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
2017-12-22arch,cpu: "virtualize" the TLB interface.Gabe Black
CPUs have historically instantiated the architecture specific version of the TLBs to avoid a virtual function call, making them a little bit more dependent on what the current ISA is. Some simple performance measurement, the x86 twolf regression on the atomic CPU, shows that there isn't actually any performance benefit, and if anything the simulator goes slightly faster (although still within margin of error) when the TLB functions are virtual. This change switches everything outside of the architectures themselves to use the generic BaseTLB type, and then inside the ISA for them to cast that to their architecture specific type to call into architecture specific interfaces. The ARM TLB needed the most adjustment since it was using non-standard translation function signatures. Specifically, they all took an extra "type" parameter which defaulted to normal, and translateTiming returned a Fault. translateTiming actually doesn't need to return a Fault because everywhere that consumed it just stored it into a structure which it then deleted(?), and the fault is stored in the Translation object when the translation is done. A little more work is needed to fully obviate the arch/tlb.hh header, so the TheISA::TLB type is still visible outside of the ISAs. Specifically, the TlbEntry type is used in the generic PageTable which lives in src/mem. Change-Id: I51b68ee74411f9af778317eff222f9349d2ed575 Reviewed-on: https://gem5-review.googlesource.com/6921 Maintainer: Gabe Black <gabeblack@google.com> Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
2017-12-14misc: Updates for gcc7.2 for x86Jason Lowe-Power
GCC 7.2 is much stricter than previous GCC versions. The following changes are needed: * There is now a warning if there is an implicit fallthrough between two case statments. C++17 adds the [[fallthrough]]; declaration. However, to support non C++17 standards (i.e., C++11), we use M5_FALLTHROUGH. M5_FALLTHROUGH checks for [[fallthrough]] compliant C++17 compiler and if that doesn't exist, it defaults to nothing (no older compilers generate warnings). * The above resulted in a couple of bugs that were found. This is noted in the review request on gerrit. * throw() for dynamic exception specification is deprecated * There were a couple of new uninitialized variable warnings * Can no longer perform bitwise operations on a bool. * Must now include <functional> for std::function * Compiler bug for void* lambda. Changed to auto as work around. See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82878 Change-Id: I5d4c782a4e133fa4cdb119e35d9aff68c6e2958e Signed-off-by: Jason Lowe-Power <jason@lowepower.com> Reviewed-on: https://gem5-review.googlesource.com/5802 Reviewed-by: Gabe Black <gabeblack@google.com>
2017-06-20arm: Replace EventWrapper use with EventFunctionWrapperSean Wilson
Change-Id: I08de5f72513645d1fe92bde99fa205dde897e951 Signed-off-by: Sean Wilson <spwilson2@wisc.edu> Reviewed-on: https://gem5-review.googlesource.com/3747 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com> Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
2017-04-03arm: Treat Write-Through Normal memory as Non-CacheableNikos Nikoleris
A completed write to a memory location that is Write-Through Cacheable has to be visible to an external observer without the need of explicit cache maintenance. This change adds support for Write-Through Cacheable Normal memory and treats it as Non-cacheable. This incurs a small penalty as accesses to the memory do not fill in the cache but does not violate the properties of the memory type. Change-Id: Iee17ef9d952a550be9ad660b1e60e9f6c4ef2c2d Reviewed-by: Giacomo Gabrielli <giacomo.gabrielli@arm.com> Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-on: https://gem5-review.googlesource.com/2280 Maintainer: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
2016-08-02arm: refactor page table walkingCurtis Dunham
Introduce and use a lookup table. Using fetchDescriptor() rather than DMA cleanly handles nested paging. Change-Id: I69ec762f176bd752ba1040890e731826b58d15a6
2016-08-02arm: Fix stage 2 memory attribute checking in AArch64Dylan Johnson
Change-Id: I14c93a5460550051a12129e792a9a9bd522a145c
2016-08-02arm: Fix stage 2 determination in table walkerDylan Johnson
We recompute if we are doing a stage 2 walk inside of the table walker but we have already figured it out in the tlb. Pass the information in to the walk instead of recomputing it. Change-Id: I39637ce99309b2ddbc30344d45ac9ebf6a203401
2016-08-02arm: Refactor aarch64 table walk logic to remove redundancyDylan Johnson
The functional case is already handled within the fetchDescriptor() function. We can thus use that function for both atomic and functional mode when we start the table walk. Change-Id: Iacaed28cd9024d259fd37a58150efd00ff94d86e
2016-08-02arm: add stage2 translation supportDylan Johnson
Change-Id: I8f7c09c7ec3a97149ebebf4b21471b244e6cecc1
2016-08-02arm: enable EL2 supportCurtis Dunham
Change-Id: I59fa4fae98c33d9e5c2185382e1411911d27d341
2016-06-06sim: Call regStats of base-class as wellStephan Diestelhorst
We want to extend the stats of objects hierarchically and thus it is necessary to register the statistics of the base-class(es), as well. For now, these are empty, but generic stats will be added there. Patch originally provided by Akash Bagdia at ARM Ltd.
2016-06-02arm: refactor page table format determinationCurtis Dunham
In particular, when EL0 is in AArch32 but EL1 is AArch64, AArch64 memory translation must be used. This is essential for typical AArch64/32 interworking use cases.
2016-03-21arm: Refactor the TLB test interfaceAndreas Sandberg
Refactor the TLB and page table walker test interface to use a dynamic registration mechanism. Instead of patching a couple of empty methods to wire up a TLB tester, this change allows such testers to register themselves using the setTestInterface() method.
2015-10-29arm: Add secure flag to TableWalker request when neededNathanael Premillieu
2015-07-07sim: Refactor and simplify the drain APIAndreas Sandberg
The drain() call currently passes around a DrainManager pointer, which is now completely pointless since there is only ever one global DrainManager in the system. It also contains vestiges from the time when SimObjects had to keep track of their child objects that needed draining. This changeset moves all of the DrainState handling to the Drainable base class and changes the drain() and drainResume() calls to reflect this. Particularly, the drain() call has been updated to take no parameters (the DrainManager argument isn't needed) and return a DrainState instead of an unsigned integer (there is no point returning anything other than 0 or 1 any more). Drainable objects should return either DrainState::Draining (equivalent to returning 1 in the old system) if they need more time to drain or DrainState::Drained (equivalent to returning 0 in the old system) if they are already in a consistent state. Returning DrainState::Running is considered an error. Drain done signalling is now done through the signalDrainDone() method in the Drainable class instead of using the DrainManager directly. The new call checks if the state of the object is DrainState::Draining before notifying the drain manager. This means that it is safe to call signalDrainDone() without first checking if the simulator has requested draining. The intention here is to reduce the code needed to implement draining in simple objects.
2015-07-07sim: Make the drain state a global typed enumAndreas Sandberg
The drain state enum is currently a part of the Drainable interface. The same state machine will be used by the DrainManager to identify the global state of the simulator. Make the drain state a global typed enum to better cater for this usage scenario.
2015-06-21arm: Cleanup arch headers to remove dma_device.hh dependencyAndreas Sandberg
Break the dependency on dma_device.hh by forward-declaring DmaPort in the relevant header.
2015-05-15arm: Identify table-walker requestsAndreas Hansson
This patch ensures all page-table walks are flagged as such.
2015-03-02arm: Share a port for the two table walker objectsAndreas Hansson
This patch changes how the MMU and table walkers are created such that a single port is used to connect the MMU and the TLBs to the memory system. Previously two ports were needed as there are two table walker objects (stage one and stage two), and they both had a port. Now the port itself is moved to the Stage2MMU, and each TableWalker is simply using the port from the parent. By using the same port we also remove the need for having an additional crossbar joining the two ports before the walker cache or the L2. This simplifies the creation of the CPU cache topology in BaseCPU.py considerably. Moreover, for naming and symmetry reasons, the TLB walker port is connected through the stage-one table walker thus making the naming identical to x86. Along the same line, we use the stage-one table walker to generate the master id that is used by all TLB-related requests.
2014-12-23arm: Add stats to table walkerCurtis Dunham
This patch adds table walker stats for: - Walk events - Instruction vs Data - Page size histogram - Wait time and service time histograms - Pending requests histogram (per cycle) - measures dist. of L (p(1..) = how often busy, p(0) = how often idle) - Squashes, before starting and after completion
2014-12-02arm: Fix TLB ignoring faults when table walkingAndrew Bardsley
This patch fixes a case where the Minor CPU can deadlock due to the lack of a response to TLB request because of a bug in fault handling in the ARM table walker. TableWalker::processWalkWrapper is the scheduler-called wrapper which handles deferred walks which calls to TableWalker::wait cannot immediately process. The handling of faults generated by processWalk{AArch64,LPAE,} calls in those two functions is is different. processWalkWrapper ignores fault returns from processWalk... which can lead to ::finish not being called on a translation. This fix provides fault handling in processWalkWrapper similar to that found in the leaf functions which BaseTLB::Translation::finish.
2014-11-14arm: Fixes based on UBSan and static analysisAndreas Hansson
Another churn to clean up undefined behaviour, mostly ARM, but some parts also touching the generic part of the code base. Most of the fixes are simply ensuring that proper intialisation. One of the more subtle changes is the return type of the sign-extension, which is changed to uint64_t. This is to avoid shifting negative values (undefined behaviour) in the ISA code.
2014-10-29arm, mem: Fix drain bug and provide drain prints for more components.Ali Saidi
2014-10-16arch: Use shared_ptr for all FaultsAndreas Hansson
This patch takes quite a large step in transitioning from the ad-hoc RefCountingPtr to the c++11 shared_ptr by adopting its use for all Faults. There are no changes in behaviour, and the code modifications are mostly just replacing "new" with "make_shared".
2014-10-01arm: Use MiscRegIndex rather than int when flatteningAndreas Hansson
Some additional type checking to avoid future issues.
2014-09-12style: Fix line continuation, especially in debug messagesAndrew Bardsley
This patch closes a number of space gaps in debug messages caused by the incorrect use of line continuation within strings. (There's also one consistency change to a similar, but correct, use of line continuation)
2014-05-27arm: support 16kb vm granulesCurtis Dunham
2014-03-07arm: Handle functional TLB walks properlyGeoffrey Blake
The table walker code currently accounts for two types of walks, Atomic and Timing, and treats them differently. Atomic walks keep a single instance of WalkerState around for all walks to use in currState. Timing mode keeps a queue of in-flight WalkerStates and maintains currState as NULL between walks. If a functional walk is done during Timing mode, it is treated as an atomic walk and either creates a persistent WalkerState if in between Timing walks, or stomps an existing currState for an in-progress Timing walk. This patch distinguishes functional walks as being able to exist at any time and sets up a temporary WalkerState for its exclusive use and then cleans up when finished, leaving any in progress Atomic or Timing walks undisturbed.
2014-01-24arm: Add support for ARMv8 (AArch64 & AArch32)ARM gem5 Developers
Note: AArch64 and AArch32 interworking is not supported. If you use an AArch64 kernel you are restricted to AArch64 user-mode binaries. This will be addressed in a later patch. Note: Virtualization is only supported in AArch32 mode. This will also be fixed in a later patch. Contributors: Giacomo Gabrielli (TrustZone, LPAE, system-level AArch64, AArch64 NEON, validation) Thomas Grocutt (AArch32 Virtualization, AArch64 FP, validation) Mbou Eyole (AArch64 NEON, validation) Ali Saidi (AArch64 Linux support, code integration, validation) Edmund Grimley-Evans (AArch64 FP) William Wang (AArch64 Linux support) Rene De Jong (AArch64 Linux support, performance opt.) Matt Horsnell (AArch64 MP, validation) Matt Evans (device models, code integration, validation) Chris Adeniyi-Jones (AArch64 syscall-emulation) Prakash Ramrakhyani (validation) Dam Sunwoo (validation) Chander Sudanthi (validation) Stephan Diestelhorst (validation) Andreas Hansson (code integration, performance opt.) Eric Van Hensbergen (performance opt.) Gabe Black
2014-01-24mem: per-thread cache occupancy and per-block agesDam Sunwoo
This patch enables tracking of cache occupancy per thread along with ages (in buckets) per cache blocks. Cache occupancy stats are recalculated on each stat dump.
2013-02-15arm: fix a page table walker issue where a page could be translated multiple ↵Mrinmoy Ghosh
times If multiple memory operations to the same page are miss the TLB they are all inserted into the page table queue and before this change could result in multiple uncessesary walks as well as duplicate enteries being inserted into the TLB.
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.
2013-01-07arm: 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.
2012-11-02sim: Move the draining interface into a separate base classAndreas Sandberg
This patch moves the draining interface from SimObject to a separate class that can be used by any object needing draining. However, objects not visible to the Python code (i.e., objects not deriving from SimObject) still depend on their parents informing them when to drain. This patch also gets rid of the CountedDrainEvent (which isn't really an event) and replaces it with a DrainManager.
2012-10-25arm: Use table walker clock that is inherited from CPUAndreas Hansson
This patch simplifies the scheduling of the next walk for the ARM table walker. Previously it used the CPU clock, but as the table walker inherits the clock from the CPU, it is cleaner to simply use its own clock (which is the same).
2012-10-15Port: Add protocol-agnostic ports in the port hierarchyAndreas Hansson
This patch adds an additional level of ports in the inheritance hierarchy, separating out the protocol-specific and protocl-agnostic parts. All the functionality related to the binding of ports is now confined to use BaseMaster/BaseSlavePorts, and all the protocol-specific parts stay in the Master/SlavePort. In the future it will be possible to add other protocol-specific implementations. The functions used in the binding of ports, i.e. getMaster/SlavePort now use the base classes, and the index parameter is updated to use the PortID typedef with the symbolic InvalidPortID as the default.
2012-09-25ARM: Squash outstanding walks when instructions are squashed.Ali Saidi
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.
2012-08-22Packet: Remove NACKs from packet and its use in endpointsAndreas Hansson
This patch removes the NACK frrom the packet as there is no longer any module in the system that issues them (the bridge was the only one and the previous patch removes that). The handling of NACKs was mostly avoided throughout the code base, by using e.g. panic or assert false, but in a few locations the NACKs were actually dealt with (although NACKs never occured in any of the regressions). Most notably, the DMA port will now never receive a NACK and the backoff time is thus never changed. As a consequence, the entire backoff mechanism (similar to a PCI bus) is now removed and the DMA port entirely relies on the bus performing the arbitration and issuing a retry when appropriate. This is more in line with e.g. PCIe. Surprisingly, this patch has no impact on any of the regressions. As mentioned in the patch that removes the NACK from the bridge, a follow-up patch should change the request and response buffer size for at least one regression to also verify that the system behaves as expected when the bridge fills up.
2012-08-15O3,ARM: fix some problems with drain/switchout functionality and add Drain ↵Anthony Gutierrez
DPRINTFs This patch fixes some problems with the drain/switchout functionality for the O3 cpu and for the ARM ISA and adds some useful debug print statements. This is an incremental fix as there are still a few bugs/mem leaks with the switchout code. Particularly when switching from an O3CPU to a TimingSimpleCPU. However, when switching from O3 to O3 cores with the ARM ISA I haven't encountered any more assertion failures; now the kernel will typically panic inside of simulation.
2012-05-23MEM: Add a snooping DMA port subclass for table walkerAndreas Hansson
This patch makes the (device) DmaPort non-snooping and removes the recvSnoop constructor parameter and instead introduces a SnoopingDmaPort subclass for the ARM table walker. Functionality is unchanged, as are the stats, and the patch merely clarifies that the normal DMA ports are not snooping (although they may issue requests that are snooped by others, as done with PCI, PCIe, AMBA4 ACE etc). Currently this port is declared in the ARM table walker as it is not used anywhere else. If other ports were to have similar behaviour it could be moved in a future patch.
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.
2012-03-30MEM: 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.
2012-02-24MEM: Move port creation to the memory object(s) constructionAndreas Hansson
This patch moves all port creation from the getPort method to be consistently done in the MemObject's constructor. This is possible thanks to the Swig interface passing the length of the vector ports. Previously there was a mix of: 1) creating the ports as members (at object construction time) and using getPort for the name resolution, or 2) dynamically creating the ports in the getPort call. This is now uniform. Furthermore, objects that would not be complete without a port have these ports as members rather than having pointers to dynamically allocated ports. This patch also enables an elaboration-time enumeration of all the ports in the system which can be used to determine the masterId.
2012-02-12mem: Add a master ID to each request object.Ali Saidi
This change adds a master id to each request object which can be used identify every device in the system that is capable of issuing a request. This is part of the way to removing the numCpus+1 stats in the cache and replacing them with the master ids. This is one of a series of changes that make way for the stats output to be changed to python.
2012-01-31CheckerCPU: Re-factor CheckerCPU to be compatible with current gem5Geoffrey Blake
Brings the CheckerCPU back to life to allow FS and SE checking of the O3CPU. These changes have only been tested with the ARM ISA. Other ISAs potentially require modification.
2011-12-01Device: Make changes necessary to support a coherent page walker cache.Mitchell Hayenga
Adds the flag 'recvSnoops' which enables pagewalkers using DmaPorts, to properly configure snoops. --HG-- extra : rebase_source : 64207bef62c3268ddff2236ee4adae873812325f