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path: root/src/arch/arm/isa.cc
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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.
2013-01-07arm: 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.
2013-01-07arm: Make ID registers ISA parametersAndreas Sandberg
This patch makes the values of ID_ISARx, MIDR, and FPSID configurable as ISA parameter values. Additionally, setMiscReg now ignores writes to all of the ID registers. Note: This moves the MIDR parameter from ArmSystem to ArmISA for consistency.
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.
2013-01-04Decoder: 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>
2013-01-04ARM: Keep a copy of the fpscr len and stride fields in the decoder.Gabe Black
Avoid reading them every instruction, and also eliminate the last use of the thread context in the decoders. Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2012-07-27ARM: fix value of MISCREG_CTR returned by readMiscReg()Anthony Gutierrez
According to the A15 TRM the value of this register is as follows (assuming 16 word = 64 byte lines) [31:29] Format - b100 specifies v7 [28] RAZ - b0 [27:24] CWG log2(max writeback size #words) - 0x4 16 words [23:20] ERG log2(max reservation size #words) - 0x4 16 words [19:16] DminLine log2(smallest dcache line #words) - 0x4 16 words [15:14] L1Ip L1 index/tagging policy - b11 specifies PIPT [13:4] RAZ - b0000000000 [3:0] IminLine log2(smallest icache line #words) - 0x4 16 words
2012-06-05ARM: Fix MPIDR and MIDR register implementation.Chander Sudanthi
This change allows designating a system as MP capable or not as some bootloaders/kernels care that it's set right. You can have a single processor MP capable system, but you can't have a multi-processor UP only system. This change also fixes the initialization of the MIDR register.
2012-03-09CheckerCPU: Make CheckerCPU runtime selectable instead of compile selectableGeoffrey Blake
Enables the CheckerCPU to be selected at runtime with the --checker option from the configs/example/fs.py and configs/example/se.py configuration files. Also merges with the SE/FS changes.
2012-03-02ARM: FIx a bug preventing multiple cores booting a VExpress_EMM machine.Ali Saidi
New kernel code verifies that multi-processor extensions are available before booting secondary CPUs.
2012-03-01ARM: Add support for Versatile Express extended memory mapAli Saidi
Also clean up how we create boot loader memory a bit.
2012-03-01ARM: Add limited CP14 support.Matt Horsnell
New kernels attempt to read CP14 what debug architecture is available. These changes add the debug registers and return that none is currently available.
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.
2011-09-13ARM: Implement numcpus bits in L2CTLR register.Daniel Johnson
2011-08-19ARM: Mark some variables uncacheable until boot all CPUs are enabled.Ali Saidi
There are a set of locations is the linux kernel that are managed via cache maintence instructions until all processors enable their MMUs & TLBs. Writes to these locations are manually flushed from the cache to main memory when the occur so that cores operating without their MMU enabled and only issuing uncached accesses can receive the correct data. Unfortuantely, gem5 doesn't support any kind of software directed maintence of the cache. Until such time as that support exists this patch marks the specific cache blocks that need to be coherent as non-cacheable until all CPUs enable their MMU and thus allows gem5 to boot MP systems with caches enabled (a requirement for booting an O3 cpu and thus an O3 CPU regression).
2011-08-19ARM: Add support for DIV/SDIV instructions.Ali Saidi
2011-07-15ARM: Add two unimplemented miscellaneous registers.Wade Walker
Adds MISCREG_ID_MMFR2 and removes break on access to MISCREG_CLIDR. Both registers now return values that are consistent with current ARM implementations.
2011-05-13ARM: Remove the saturating (Q) condition code from the renamed register.Ali Saidi
Move the saturating bit (which is also saturating) from the renamed register that holds the flags to the CPSR miscreg and adds a allows setting it in a similar way to the FP saturating registers. This removes a dependency in instructions that don't write, but need to preserve the Q bit.
2011-05-13ARM: Better RealView/Versatile EB platform support.Chander Sudanthi
Add registers and components to better support the VersatileEB board. Made the MIDR and SYS_ID register parameters to ArmSystem and RealviewCtrl respectively.
2011-05-04ARM: Add support for MP misc regs and broadcast flushes.Ali Saidi
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
2011-04-04ARM: Fix checkpoint restoration into O3 CPU and the way O3 switchCpu works.Ali Saidi
This change fixes a small bug in the arm copyRegs() code where some registers wouldn't be copied if the processor was in a mode other than MODE_USER. Additionally, this change simplifies the way the O3 switchCpu code works by utilizing TheISA::copyRegs() to copy the required context information rather than the adhoc copying that goes on in the CPU model. The current code makes assumptions about the visibility of int and float registers that aren't true for all architectures in FS mode.
2011-04-04ARM: Cleanup and small fixes to some NEON ops to match the spec.William Wang
Only certain bits of the cpacr can be written, some must be equal. Mult instructions that write the same register should do something sane
2011-04-04ARM: Cleanup implementation of ITSTATE and put important code in PCState.Ali Saidi
Consolidate all code to handle ITSTATE in the PCState object rather than touching a variety of structures/objects.
2011-03-17ARM: Implement the Instruction Set Attribute Registers (ISAR).Ali Saidi
The ISAR registers describe which features the processor supports. Transcribe the values listed in section B5.2.5 of the ARM ARM into the registers as read-only values
2011-02-23ARM: Reset simulation statistics when pref counters are reset.Ali Saidi
The ARM performance counters are not currently supported by the model. This patch interprets a 'reset performance counters' command to mean 'reset the simulator statistics' instead.
2010-12-07O3: Make all instructions that write a misc. register not perform the write ↵Giacomo Gabrielli
until commit. ARM instructions updating cumulative flags (ARM FP exceptions and saturation flags) are not serialized. Added aliases for ARM FP exceptions and saturation flags in FPSCR. Removed write accesses to the FP condition codes for most ARM VFP instructions: only VCMP and VCMPE instructions update the FP condition codes. Removed a potential cause of seg. faults in the O3 model for NEON memory macro-ops (ARM).
2010-11-15ARM: Return an FailUnimp instruction when an unimplemented CP15 register is ↵Ali Saidi
accessed. Just panicing in readMiscReg() doesn't work because a speculative access in the o3 model can end the simulation.
2010-11-15ARM: Cache the misc regs at the TLB to limit readMiscReg() calls.Ali Saidi
2010-11-08ARM: Keep the warnings to a minimum.Ali Saidi
These warnings still need to be addresses, but pages of them is counterproductive.
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.
2010-10-01ARM: Clean up use of TBit and JBit.Ali Saidi
Rather tha constantly using ULL(1) << PcXBitShift define those directly. Additionally, add some helper functions to further clean up the code.
2010-09-13Faults: Pass the StaticInst involved, if any, to a Fault's invoke method.Gabe Black
Also move the "Fault" reference counted pointer type into a separate file, sim/fault.hh. It would be better to name this less similarly to sim/faults.hh to reduce confusion, but fault.hh matches the name of the type. We could change Fault to FaultPtr to match other pointer types, and then changing the name of the file would make more sense.
2010-08-25ARM: Set the high bits in the part number so it's considered new by some code.Ali Saidi
2010-08-25ARM: Fix VFP enabled checks for mem instructionsAli Saidi
2010-08-25ARM: Implement CPACR register and return Undefined Instruction when FP ↵Gabe Black
access is disabled.
2010-08-23ARM: Clean up flattening for SPSR addingMin Kyu Jeong
2010-08-23ARM: Get SCTLR TE bit from reset SCTLRGene Wu
2010-08-23ARM: We don't currently support ThumbEE exceptions, so don't report that we doAli Saidi
2010-08-23ARM: Implement some more misc registersAli Saidi
2010-06-03ARM: Fix issue with m5.fast and ARMAli Saidi
2010-06-02ARM: Added support for Access Flag and some CP15 regs (V2PCWPR, V2PCWPW, ↵Dam Sunwoo
V2PCWUR, V2PCWUW,...)
2010-06-02ARM: Move the ISA "clear" function into isa.cc.Gabe Black
2010-06-02ARM: Implement support for the IT instruction and the ITSTATE bits of CPSR.Gabe Black
2010-06-02ARM: Some TLB bug fixes.Ali Saidi
2010-06-02ARM: Move Miscreg functions out of isa.hhAli Saidi