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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.
2010-09-13CPU: Get rid of the now unnecessary getInst/setInst family of functions.Gabe Black
This code is no longer needed because of the preceeding change which adds a StaticInstPtr parameter to the fault's invoke method, obviating the only use for this pair of functions.
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.
2010-08-31CPU: Get rid of the unused ev5_trap function on the simple and checker CPUs.Gabe Black
2010-06-03Minor remote GDB cleanup.Steve Reinhardt
Expand the help text on the --remote-gdb-port option so people know you can use it to disable remote gdb without reading the source code, and thus don't waste any time trying to add a separate option to do that. Clean up some gdb-related cruft I found while looking for where one would add a gdb disable option, before I found the comment that told me that I didn't need to do that.
2010-02-26cpu_models: get rid of cpu_models.py and move the stuff into SConsNathan Binkert
2009-11-10Mem: Eliminate the NO_FAULT request flag.Gabe Black
2009-09-23arch: nuke arch/isa_specific.hh and move stuff to generated config/the_isa.hhNathan Binkert
2009-07-08Get rid of the unused get(Data|Inst)Asid and (inst|data)Asid functions.Gabe Black
2009-07-08Registers: Get rid of the float register width parameter.Gabe Black
2009-04-19Mem: Change isLlsc to isLLSC.Gabe Black
2009-04-19Memory: Rename LOCKED for load locked store conditional to LLSC.Gabe Black
2009-04-15ThreadState: initialize status to Halted in constructor.Steve Reinhardt
This provides a common initial status for all threads independent of CPU model (unlike the prior situation where CPUs initialized threads to inconsistent states). This mostly matters for SE mode; in FS mode, ISA-specific startupCPU() methods generally handle boot-time initialization of thread contexts (since the right thing to do is ISA-dependent).
2009-04-15Get rid of the Unallocated thread context state.Steve Reinhardt
Basically merge it in with Halted. Also had to get rid of a few other functions that called ThreadContext::deallocate(), including: - InOrderCPU's setThreadRescheduleCondition. - ThreadContext::exit(). This function was there to avoid terminating simulation when one thread out of a multi-thread workload exits, but we need to find a better (non-cpu-centric) way.
2009-04-08tlb: Don't separate the TLB classes into an instruction TLB and a data TLBGabe Black
2009-02-27Processes: Make getting and setting system call arguments part of a process ↵Gabe Black
object.
2009-02-25ISA: Replace the translate functions in the TLBs with translateAtomic.Gabe Black
2009-02-25CPU: Get rid of translate... functions from various interface classes.Gabe Black
2008-11-04get rid of all instances of readTid() and getThreadNum(). Unify and eliminateLisa Hsu
redundancies with threadId() as their replacement.
2008-11-02Add in Context IDs to the simulator. From now on, cpuId is almost never used,Lisa Hsu
the primary identifier for a hardware context should be contextId(). The concept of threads within a CPU remains, in the form of threadId() because sometimes you need to know which context within a cpu to manipulate.
2008-11-02make BaseCPU the provider of _cpuId, and cpuId() instead of being scatteredLisa Hsu
across the subclasses. generally make it so that member data is _cpuId and accessor functions are cpuId(). The ID val comes from the python (default -1 if none provided), and if it is -1, the index of cpuList will be given. this has passed util/regress quick and se.py -n4 and fs.py -n4 as well as standard switch.
2008-10-20O3CPU: Undo Gabe's changes to remove hwrei and simpalcheck from O3 CPU. ↵Ali Saidi
Removing hwrei causes the instruction after the hwrei to be fetched before the ITB/DTB_CM register is updated in a call pal call sys and thus the translation fails because the user is attempting to access a super page address. Minimally, it seems as though some sort of fetch stall or refetch after a hwrei is required. I think this works currently because the hwrei uses the exec context interface, and the o3 stalls when that occurs. Additionally, these changes don't update the LOCK register and probably break ll/sc. Both o3 changes were removed since a great deal of manual patching would be required to only remove the hwrei change.
2008-10-12Get rid of old RegContext code.Gabe Black
2008-10-11CPU: Eliminate the simPalCheck funciton.Gabe Black
2008-10-11CPU: Eliminate the hwrei function.Gabe Black
2008-09-10style: Remove non-leading tabs everywhere they shouldn't be. Developers ↵Ali Saidi
should configure their editors to not insert tabs
2008-08-11params: Convert the CPU objects to use the auto generated param structs.Nathan Binkert
A whole bunch of stuff has been converted to use the new params stuff, but the CPU wasn't one of them. While we're at it, make some things a bit more stylish. Most of the work was done by Gabe, I just cleaned stuff up a bit more at the end.
2008-07-01Remove delVirtPort() and make getVirtPort() only return cached version.Ali Saidi
2008-02-26TLB: Make a TLB base class and put a virtual demapPage function in it.Gabe Black
--HG-- extra : convert_revision : cc0e62a5a337fd5bf332ad33bed61c0d505a936f
2007-08-26Address Translation: Make SE mode use an actual TLB/MMU for translation like FS.Gabe Black
--HG-- extra : convert_revision : a04a30df0b6246e877a1cea35420dbac94b506b1
2007-03-07*MiscReg->*MiscRegNoEffect, *MiscRegWithEffect->*MiscRegAli Saidi
--HG-- extra : convert_revision : f799b65f1b2a6bf43605e6870b0f39b473dc492b
2007-02-12some forgotten commitsAli Saidi
--HG-- extra : convert_revision : 213440066c700ed5891a6d4568928b7f3f2fe750
2006-12-12Rename the StaticInst-based (read|set)(Int|Float)Reg methods to ↵Steve Reinhardt
(read|set)(Int|Float)RegOperand to distinguish from non-StaticInst version. --HG-- extra : convert_revision : b33ce0ebe2fee86cc791c00a35d8c6e395e1380c
2006-11-07Put kernel_stats back into arch.Gabe Black
--HG-- rename : src/kern/alpha/idle_event.cc => src/arch/alpha/idle_event.cc rename : src/kern/alpha/idle_event.hh => src/arch/alpha/idle_event.hh rename : src/kern/alpha/kernel_stats.cc => src/arch/alpha/kernel_stats.cc rename : src/kern/alpha/kernel_stats.hh => src/arch/alpha/kernel_stats.hh rename : src/kern/sparc/kernel_stats.hh => src/arch/sparc/kernel_stats.hh rename : src/kern/base_kernel_stats.cc => src/kern/kernel_stats.cc rename : src/kern/base_kernel_stats.hh => src/kern/kernel_stats.hh extra : convert_revision : 42bd3e36b407edbd19b912c9218f4e5923a15966
2006-11-07Moved the switched version of kernel_stats.hh back to kern, and moved the ↵Gabe Black
base kernel_stats to base_kernel_stats --HG-- extra : convert_revision : 2a010d2eb7ea2586ff063b99b8bcde6eb1e8e017
2006-11-03Got rid of "inPalMode". Some places are still effectively checking if they ↵Gabe Black
are in PAL mode, however. --HG-- extra : convert_revision : b52d9642efc474eaf97437fa2df879efefa0062b
2006-11-02Merge ktlim@zizzer:/bk/newmemKevin Lim
into zamp.eecs.umich.edu:/z/ktlim2/clean/newmem-busfix --HG-- extra : convert_revision : a9a41e2c292bd95aa148e1cf4d9a77c0622a462b
2006-11-02Use ISA specific makeExtMI.Kevin Lim
src/arch/alpha/utility.hh: For now makeExtMI will be specific to the ISA. --HG-- extra : convert_revision : 89959c6499efcc3df9301ad8ea039580764a1496
2006-11-01Merge zizzer.eecs.umich.edu:/bk/newmem/Gabe Black
into zeep.eecs.umich.edu:/home/gblack/m5/newmemmemops --HG-- extra : convert_revision : c2f7398a0d14dd11108579bb243ada7420285a22
2006-11-01Adjustments for the AlphaTLB changing to AlphaISA::TLB and changing register ↵Gabe Black
file functions to not take faults --HG-- extra : convert_revision : 1cef0734462ee2e4db12482462c2ab3c134d3675
2006-10-31Remove mem parameter. Now the translating port asks the CPU's dcache's peer ↵Kevin Lim
for its MemObject instead of having to have a paramter for the MemObject. configs/example/fs.py: configs/example/se.py: src/cpu/simple/base.cc: src/cpu/simple/base.hh: src/cpu/simple/timing.cc: src/cpu/simple_thread.cc: src/cpu/simple_thread.hh: src/cpu/thread_state.cc: src/cpu/thread_state.hh: tests/configs/o3-timing-mp.py: tests/configs/o3-timing.py: tests/configs/simple-atomic-mp.py: tests/configs/simple-atomic.py: tests/configs/simple-timing-mp.py: tests/configs/simple-timing.py: tests/configs/tsunami-simple-atomic-dual.py: tests/configs/tsunami-simple-atomic.py: tests/configs/tsunami-simple-timing-dual.py: tests/configs/tsunami-simple-timing.py: No need for mem parameter any more. src/cpu/checker/cpu.cc: Use new constructor for simple thread (no more MemObject parameter). src/cpu/checker/cpu.hh: Remove MemObject parameter. src/cpu/memtest/memtest.hh: Ports now take in their MemObject owner. src/cpu/o3/alpha/cpu_builder.cc: Remove mem parameter. src/cpu/o3/alpha/cpu_impl.hh: Remove memory parameter and clean up handling of TranslatingPort. src/cpu/o3/cpu.cc: src/cpu/o3/cpu.hh: src/cpu/o3/fetch.hh: src/cpu/o3/fetch_impl.hh: src/cpu/o3/mips/cpu_builder.cc: src/cpu/o3/mips/cpu_impl.hh: src/cpu/o3/params.hh: src/cpu/o3/thread_state.hh: src/cpu/ozone/cpu.hh: src/cpu/ozone/cpu_builder.cc: src/cpu/ozone/cpu_impl.hh: src/cpu/ozone/front_end.hh: src/cpu/ozone/front_end_impl.hh: src/cpu/ozone/lw_lsq.hh: src/cpu/ozone/lw_lsq_impl.hh: src/cpu/ozone/simple_params.hh: src/cpu/ozone/thread_state.hh: src/cpu/simple/atomic.cc: Remove memory parameter. --HG-- extra : convert_revision : 43cb44a33b31320d44b69679dcf646c0380d07d3
2006-10-31Move IntrFlag into the MiscRegFile and get rid of specialized accessor ↵Gabe Black
functions. --HG-- extra : convert_revision : e0d12a150b01d05de9bc02bcbc7c22797975a5b9
2006-10-20Merge zizzer.eecs.umich.edu:/bk/newmemGabe Black
into zeep.eecs.umich.edu:/home/gblack/m5/newmem --HG-- extra : convert_revision : 2711fec2bf72801999b060e65f0bf744c18734fb
2006-10-20Use PacketPtr everywhereNathan Binkert
--HG-- extra : convert_revision : d9eb83ab77ffd2d725961f295b1733137e187711
2006-10-19refactor code for the packet, get rid of packet_impl.hhNathan Binkert
and call it packet_access.hh and fix the #includes so things compile right. --HG-- extra : convert_revision : d3626c9715b9f7e51bb3ab8d97e971fad4e0b724
2006-10-12Merge zizzer.eecs.umich.edu:/bk/newmemGabe Black
into zeep.eecs.umich.edu:/home/gblack/m5/newmem --HG-- extra : convert_revision : 30b2475ba034550376455e1bc0e52e19a200fd5a
2006-10-09Merge ktlim@zizzer:/bk/newmemKevin Lim
into zamp.eecs.umich.edu:/z/ktlim2/clean/o3-merge/newmem src/cpu/memtest/memtest.cc: src/cpu/memtest/memtest.hh: src/cpu/simple/timing.hh: tests/configs/o3-timing-mp.py: Hand merge. --HG-- extra : convert_revision : a58cc439eb5e8f900d175ed8b5a85b6c8723e558
2006-10-09Fix checker bug.Kevin Lim
src/cpu/checker/thread_context.hh: Checker's TC should only copy state, and not fully take over from the old context (prevents it from accidentally stealing the quiesce event). --HG-- extra : convert_revision : 5760f9c5bae749f8d1df35e4c898df13e41b0224
2006-10-08Replace tests of LOCKED/UNCACHEABLE flags with isLocked()/isUncacheable().Steve Reinhardt
--HG-- extra : convert_revision : f22ce3221d270ecf8631d3dcaed05753accd5461
2006-10-02Merge zizzer.eecs.umich.edu:/bk/newmemGabe Black
into zeep.eecs.umich.edu:/home/gblack/m5/newmem src/cpu/ozone/cpu_impl.hh: Hand merged --HG-- extra : convert_revision : f8a5b0205bcb78c8f5e109f456fe7bca80a7abac