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2015-07-07sim: Refactor the serialization base classAndreas Sandberg
Objects that are can be serialized are supposed to inherit from the Serializable class. This class is meant to provide a unified API for such objects. However, so far it has mainly been used by SimObjects due to some fundamental design limitations. This changeset redesigns to the serialization interface to make it more generic and hide the underlying checkpoint storage. Specifically: * Add a set of APIs to serialize into a subsection of the current object. Previously, objects that needed this functionality would use ad-hoc solutions using nameOut() and section name generation. In the new world, an object that implements the interface has the methods serializeSection() and unserializeSection() that serialize into a named /subsection/ of the current object. Calling serialize() serializes an object into the current section. * Move the name() method from Serializable to SimObject as it is no longer needed for serialization. The fully qualified section name is generated by the main serialization code on the fly as objects serialize sub-objects. * Add a scoped ScopedCheckpointSection helper class. Some objects need to serialize data structures, that are not deriving from Serializable, into subsections. Previously, this was done using nameOut() and manual section name generation. To simplify this, this changeset introduces a ScopedCheckpointSection() helper class. When this class is instantiated, it adds a new /subsection/ and subsequent serialization calls during the lifetime of this helper class happen inside this section (or a subsection in case of nested sections). * The serialize() call is now const which prevents accidental state manipulation during serialization. Objects that rely on modifying state can use the serializeOld() call instead. The default implementation simply calls serialize(). Note: The old-style calls need to be explicitly called using the serializeOld()/serializeSectionOld() style APIs. These are used by default when serializing SimObjects. * Both the input and output checkpoints now use their own named types. This hides underlying checkpoint implementation from objects that need checkpointing and makes it easier to change the underlying checkpoint storage code.
2015-05-05mem, cpu: Add a separate flag for strictly ordered memoryAndreas Sandberg
The Request::UNCACHEABLE flag currently has two different functions. The first, and obvious, function is to prevent the memory system from caching data in the request. The second function is to prevent reordering and speculation in CPU models. This changeset gives the order/speculation requirement a separate flag (Request::STRICT_ORDER). This flag prevents CPU models from doing the following optimizations: * Speculation: CPU models are not allowed to issue speculative loads. * Write combining: CPU models and caches are not allowed to merge writes to the same cache line. Note: The memory system may still reorder accesses unless the UNCACHEABLE flag is set. It is therefore expected that the STRICT_ORDER flag is combined with the UNCACHEABLE flag to prevent this behavior.
2014-11-23kvm, x86: Adding support for SE mode executionAlexandru Dutu
This patch adds methods in KvmCPU model to handle KVM exits caused by syscall instructions and page faults. These types of exits will be encountered if KvmCPU is run in SE mode.
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".
2013-10-15mem: Use a flag instead of address bit 63 for generic IPRsAndreas Sandberg
Using address bit 63 to identify generic IPRs caused problems on SPARC, where IPRs are heavily used. This changeset redefines how generic IPRs are identified. Instead of using bit 63, we now use a separate flag (GENERIC_IPR) a memory request.
2013-09-30x86: Add support for m5ops through a memory mapped interfaceAndreas Sandberg
In order to support m5ops in virtualized environments, we need to use a memory mapped interface. This changeset adds support for that by reserving 0xFFFF0000-0xFFFFFFFF and mapping those to the generic IPR interface for m5ops. The mapping is done in the X86ISA::TLB::finalizePhysical() which means that it just works for all of the CPU models, including virtualized ones.
2013-08-07x86: add tlb checkpointingNilay Vaish
This patch adds checkpointing support to x86 tlb. It upgrades the cpt_upgrader.py script so that previously created checkpoints can be updated. It moves the checkpoint version to 6.
2013-06-03arch: Create a method to finalize physical addressesAndreas Sandberg
in the TLB Some architectures (currently only x86) require some fixing-up of physical addresses after a normal address translation. This is usually to remap devices such as the APIC, but could be used for other memory mapped devices as well. When running the CPU in a using hardware virtualization, we still need to do these address fix-ups before inserting the request into the memory system. This patch moves this patch allows that code to be used by such CPUs without doing full address translations.
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.
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.
2012-06-07X86 TLB: Add a missing = signNilay Vaish
2012-06-07X86 TLB: Fix for gcc 4.4.3Jayneel Gandhi
Due to recent changes to X86 TLB, gem5 stopped compiling on gcc version 4.4.3. This patch provides the fix for that problem. The patch is tested on gcc 4.4.3. The change is not required for more recent versions of gcc (like on 4.6.3).
2012-05-28X86: Use the HandyM5Reg to avoid a register read and some logic in the TLB.Gabe Black
2012-05-27X86: Truncate addresses to 32 bits except in 64 bit mode, not long mode.Gabe Black
A small change was added a while ago to keep addresses from overflowing 32 bits when larger addresses shouldn't be accessible to software. That change truncated when not in long mode, but really it should have truncated when not in 64 bit mode. The difference is whether compatibility mode is included, a mode that's supposed to act like a legacy 32 bit mode.
2012-04-24X86: Clear out duplicate TLB entries when adding a new one.Gabe Black
It's possible for two page table walks to overlap which will go in the same place in the TLB's trie. They would land on top of each other, so this change adds some code which detects if an address already matches an entry and if so throws away the new one.
2012-04-14X86: Use the AddrTrie class to implement the TLB.Gabe Black
This change also adjusts the TlbEntry class so that it stores the number of address bits wide a page is rather than its size in bytes. In other words, instead of storing 4K for a 4K page, it stores 12. 12 is easy to turn into 4K, but it's a little harder going the other way.
2012-03-31X86: Fix address size handling so real mode works properly.Gabe Black
Virtual (pre-segmentation) addresses are truncated based on address size, and any non-64 bit linear address is truncated to 32 bits. This means that real mode addresses aren't truncated down to 16 bits after their segment bases are added in.
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.
2012-03-19gcc: Clean-up of non-C++0x compliant code, first stepsAndreas Hansson
This patch cleans up a number of minor issues aiming to get closer to compliance with the C++0x standard as interpreted by gcc and clang (compile with std=c++0x and -pedantic-errors). In particular, the patch cleans up enums where the last item was succeded by a comma, namespaces closed by a curcly brace followed by a semi-colon, and the use of the GNU-extension typeof (replaced by templated functions). It does not address variable-length arrays, zero-size arrays, anonymous structs, range expressions in switch statements, and the use of long long. The generated CPU code also has a large number of issues that remain to be fixed, mainly related to overflows in implicit constant conversion (due to shifts).
2012-03-09CheckerCPU: Add function stubs to non-ARM ISA source to compile with CheckerCPUGeoffrey Blake
Making the CheckerCPU a runtime time option requires the code to be compatible with ISAs other than ARM. This patch adds the appropriate function stubs to allow compilation.
2012-03-01x86: Fix x86 TLB and WalkerNilay Vaish
This patch adds a function to X86 tlb that returns the walker port. This port is required for correctly connecting the walker ports for the cpu just switched in
2012-01-07Another merge with the main repository.Gabe Black
2012-01-05X86 TLB: Move a DPRINTF to its correct placeNilay Vaish
The DPRINTF for doing protection checks appears after the checks have been carried out. It is possible that the function returns while the checks are being carried, in which case the printf is missed out. This patch moves the DPRINTF before the checks. --HG-- extra : rebase_source : 172896057e593022444d882ea93323a5d9f77a89
2011-10-30X86: Get rid of more uses of FULL_SYSTEM.Gabe Black
2011-10-30SE/FS: Make getProcessPtr available in both modes, and get rid of FULL_SYSTEMs.Gabe Black
2011-10-13X86: Turn on the page table walker in SE mode.Gabe Black
2011-09-23X86: Move the MSR lookup table out of the TLB and into its own file.Gabe Black
Translating MSR addresses into MSR register indices took a lot of space in the TLB source and made looking around in that file awkward. This change moves the lookup into its own file to get it out of the way. It also changes it from a switch statement to a hash map which should hopefully be a little more efficient.
2011-09-09Stack: Tidy up some comments, a warning, and make stack extension consistent.Gabe Black
Do some minor cleanup of some recently added comments, a warning, and change other instances of stack extension to be like what's now being done for x86.
2011-09-05X86,TLB: Make sure the "delayedResponse" variable is always set.Gabe Black
When an instruction is translated in the x86 TLB, a variable called delayedResponse is passed back and forth which tracks whether a translation could be completed immediately, or if there's going to be callback that will finish things up. If a read was to the internal memory space, memory mapped registers used to implement things like MSRs, the function hadn't yet gotten to where delayedResponse was set to false, it's default. That meant that the value was never set, and the TLB could start waiting for a callback that would never come. This change simply moves the assignment to above where control can divert to translateInt().
2011-09-02TLB: comments and a helpful warning.Lisa Hsu
Nothing big here, but when you have an address that is not in the page table request to be allocated, if it falls outside of the maximum stack range all you get is a page fault and you don't know why. Add a little warn() to explain it a bit. Also add some comments and alter logic a little so that you don't totally ignore the return value of checkAndAllocNextPage().
2011-04-15trace: reimplement the DTRACE function so it doesn't use a vectorNathan Binkert
At the same time, rename the trace flags to debug flags since they have broader usage than simply tracing. This means that --trace-flags is now --debug-flags and --trace-help is now --debug-help
2011-04-15includes: sort all includesNathan Binkert
2011-03-01Spelling: Fix the a spelling error by changing mmaped to mmapped.Gabe Black
There may not be a formally correct spelling for the past tense of mmap, but mmapped is the spelling Google doesn't try to autocorrect. This makes sense because it mirrors the past tense of map->mapped and not the past tense of cape->caped. --HG-- rename : src/arch/alpha/mmaped_ipr.hh => src/arch/alpha/mmapped_ipr.hh rename : src/arch/arm/mmaped_ipr.hh => src/arch/arm/mmapped_ipr.hh rename : src/arch/mips/mmaped_ipr.hh => src/arch/mips/mmapped_ipr.hh rename : src/arch/power/mmaped_ipr.hh => src/arch/power/mmapped_ipr.hh rename : src/arch/sparc/mmaped_ipr.hh => src/arch/sparc/mmapped_ipr.hh rename : src/arch/x86/mmaped_ipr.hh => src/arch/x86/mmapped_ipr.hh
2011-02-27X86: If PCI config space is disabled, pass through to regular IO addresses.Gabe Black
2011-02-07X86: Obey the wp bit of CR0.Tim Harris
If cr0.wp ("write protect" bit) is clear then do not generate page faults when writing to write-protected pages in kernel mode.
2011-02-06x86: Timing support for pagetable walkerJoel Hestness
Move page table walker state to its own object type, and make the walker instantiate state for each outstanding walk. By storing the states in a queue, the walker is able to handle multiple outstanding timing requests. Note that functional walks use separate state elements.
2011-01-03Make commenting on close namespace brackets consistent.Steve Reinhardt
Ran all the source files through 'perl -pi' with this script: s|\s*(};?\s*)?/\*\s*(end\s*)?namespace\s*(\S+)\s*\*/(\s*})?|} // namespace $3|; s|\s*};?\s*//\s*(end\s*)?namespace\s*(\S+)\s*|} // namespace $2\n|; s|\s*};?\s*//\s*(\S+)\s*namespace\s*|} // namespace $1\n|; Also did a little manual editing on some of the arch/*/isa_traits.hh files and src/SConscript.
2010-11-23X86: Obey the PCD (cache disable) bit in the page tables.Gabe Black
2010-11-22X86: Mark IO space accesses as uncachable.Gabe Black
2010-10-31ISA,CPU,etc: Create an ISA defined PC type that abstracts out ISA behaviors.Gabe Black
This change is a low level and pervasive reorganization of how PCs are managed in M5. Back when Alpha was the only ISA, there were only 2 PCs to worry about, the PC and the NPC, and the lsb of the PC signaled whether or not you were in PAL mode. As other ISAs were added, we had to add an NNPC, micro PC and next micropc, x86 and ARM introduced variable length instruction sets, and ARM started to keep track of mode bits in the PC. Each CPU model handled PCs in its own custom way that needed to be updated individually to handle the new dimensions of variability, or, in the case of ARMs mode-bit-in-the-pc hack, the complexity could be hidden in the ISA at the ISA implementation's expense. Areas like the branch predictor hadn't been updated to handle branch delay slots or micropcs, and it turns out that had introduced a significant (10s of percent) performance bug in SPARC and to a lesser extend MIPS. Rather than perpetuate the problem by reworking O3 again to handle the PC features needed by x86, this change was introduced to rework PC handling in a more modular, transparent, and hopefully efficient way. PC type: Rather than having the superset of all possible elements of PC state declared in each of the CPU models, each ISA defines its own PCState type which has exactly the elements it needs. A cross product of canned PCState classes are defined in the new "generic" ISA directory for ISAs with/without delay slots and microcode. These are either typedef-ed or subclassed by each ISA. To read or write this structure through a *Context, you use the new pcState() accessor which reads or writes depending on whether it has an argument. If you just want the address of the current or next instruction or the current micro PC, you can get those through read-only accessors on either the PCState type or the *Contexts. These are instAddr(), nextInstAddr(), and microPC(). Note the move away from readPC. That name is ambiguous since it's not clear whether or not it should be the actual address to fetch from, or if it should have extra bits in it like the PAL mode bit. Each class is free to define its own functions to get at whatever values it needs however it needs to to be used in ISA specific code. Eventually Alpha's PAL mode bit could be moved out of the PC and into a separate field like ARM. These types can be reset to a particular pc (where npc = pc + sizeof(MachInst), nnpc = npc + sizeof(MachInst), upc = 0, nupc = 1 as appropriate), printed, serialized, and compared. There is a branching() function which encapsulates code in the CPU models that checked if an instruction branched or not. Exactly what that means in the context of branch delay slots which can skip an instruction when not taken is ambiguous, and ideally this function and its uses can be eliminated. PCStates also generally know how to advance themselves in various ways depending on if they point at an instruction, a microop, or the last microop of a macroop. More on that later. Ideally, accessing all the PCs at once when setting them will improve performance of M5 even though more data needs to be moved around. This is because often all the PCs need to be manipulated together, and by getting them all at once you avoid multiple function calls. Also, the PCs of a particular thread will have spatial locality in the cache. Previously they were grouped by element in arrays which spread out accesses. Advancing the PC: The PCs were previously managed entirely by the CPU which had to know about PC semantics, try to figure out which dimension to increment the PC in, what to set NPC/NNPC, etc. These decisions are best left to the ISA in conjunction with the PC type itself. Because most of the information about how to increment the PC (mainly what type of instruction it refers to) is contained in the instruction object, a new advancePC virtual function was added to the StaticInst class. Subclasses provide an implementation that moves around the right element of the PC with a minimal amount of decision making. In ISAs like Alpha, the instructions always simply assign NPC to PC without having to worry about micropcs, nnpcs, etc. The added cost of a virtual function call should be outweighed by not having to figure out as much about what to do with the PCs and mucking around with the extra elements. One drawback of making the StaticInsts advance the PC is that you have to actually have one to advance the PC. This would, superficially, seem to require decoding an instruction before fetch could advance. This is, as far as I can tell, realistic. fetch would advance through memory addresses, not PCs, perhaps predicting new memory addresses using existing ones. More sophisticated decisions about control flow would be made later on, after the instruction was decoded, and handed back to fetch. If branching needs to happen, some amount of decoding needs to happen to see that it's a branch, what the target is, etc. This could get a little more complicated if that gets done by the predecoder, but I'm choosing to ignore that for now. Variable length instructions: To handle variable length instructions in x86 and ARM, the predecoder now takes in the current PC by reference to the getExtMachInst function. It can modify the PC however it needs to (by setting NPC to be the PC + instruction length, for instance). This could be improved since the CPU doesn't know if the PC was modified and always has to write it back. ISA parser: To support the new API, all PC related operand types were removed from the parser and replaced with a PCState type. There are two warts on this implementation. First, as with all the other operand types, the PCState still has to have a valid operand type even though it doesn't use it. Second, using syntax like PCS.npc(target) doesn't work for two reasons, this looks like the syntax for operand type overriding, and the parser can't figure out if you're reading or writing. Instructions that use the PCS operand (which I've consistently called it) need to first read it into a local variable, manipulate it, and then write it back out. Return address stack: The return address stack needed a little extra help because, in the presence of branch delay slots, it has to merge together elements of the return PC and the call PC. To handle that, a buildRetPC utility function was added. There are basically only two versions in all the ISAs, but it didn't seem short enough to put into the generic ISA directory. Also, the branch predictor code in O3 and InOrder were adjusted so that they always store the PC of the actual call instruction in the RAS, not the next PC. If the call instruction is a microop, the next PC refers to the next microop in the same macroop which is probably not desirable. The buildRetPC function advances the PC intelligently to the next macroop (in an ISA specific way) so that that case works. Change in stats: There were no change in stats except in MIPS and SPARC in the O3 model. MIPS runs in about 9% fewer ticks. SPARC runs with 30%-50% fewer ticks, which could likely be improved further by setting call/return instruction flags and taking advantage of the RAS. TODO: Add != operators to the PCState classes, defined trivially to be !(a==b). Smooth out places where PCs are split apart, passed around, and put back together later. I think this might happen in SPARC's fault code. Add ISA specific constructors that allow setting PC elements without calling a bunch of accessors. Try to eliminate the need for the branching() function. Factor out Alpha's PAL mode pc bit into a separate flag field, and eliminate places where it's blindly masked out or tested in the PC.
2010-08-23X86: Create a directory for files that define register indexes.Gabe Black
This is to help tidy up arch/x86. These files should not be used external to the ISA. --HG-- rename : src/arch/x86/apicregs.hh => src/arch/x86/regs/apic.hh rename : src/arch/x86/floatregs.hh => src/arch/x86/regs/float.hh rename : src/arch/x86/intregs.hh => src/arch/x86/regs/int.hh rename : src/arch/x86/miscregs.hh => src/arch/x86/regs/misc.hh rename : src/arch/x86/segmentregs.hh => src/arch/x86/regs/segment.hh
2010-08-23X86: Make the TLB fault instead of panic when something is unmapped in SE mode.Gabe Black
The fault object, if invoked, would then panic. This is a bit less direct, but it means speculative execution won't panic the simulator.
2010-05-23copyright: Change HP copyright on x86 code to be more friendlyNathan Binkert
2009-11-08X86: Don't panic on faults on prefetches in SE mode.Gabe Black
2009-11-08X86: Explain what really didn't work with unmapped addresses in SE mode.Gabe Black
2009-08-01Clean up some inconsistencies with Request flags.Steve Reinhardt
2009-07-08Registers: Eliminate the ISA defined floating point register file.Gabe Black
2009-07-08Registers: Add an ISA object which replaces the MiscRegFile.Gabe Black
This object encapsulates (or will eventually) the identity and characteristics of the ISA in the CPU.
2009-04-26X86: Split out the internal memory space from the regular translate() and ↵Gabe Black
precompute mode.
2009-04-23X86: Put the StoreCheck flag with the others, and don't collide with other ↵Gabe Black
flags.