Commit graph

1000 commits

Author SHA1 Message Date
Nathan Binkert
eddac53ff6 trace: reimplement the DTRACE function so it doesn't use a vector
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
2011-04-15 10:44:32 -07:00
Nathan Binkert
39a055645f includes: sort all includes 2011-04-15 10:44:06 -07:00
Ali Saidi
a679cd917a ARM: Cleanup implementation of ITSTATE and put important code in PCState.
Consolidate all code to handle ITSTATE in the PCState object rather than
touching a variety of structures/objects.
2011-04-04 11:42:28 -05:00
Korey Sewell
e0fdd86fd9 mips: cleanup ISA-specific code
***
(1): get rid of expandForMT function
MIPS is the only ISA that cares about having a piece of ISA state integrate
multiple threads so add constants for MIPS and relieve the other ISAs from having
to define this. Also, InOrder was the only core that was actively calling
this function
* * *
(2): get rid of corespecific type
The CoreSpecific type was used as a proxy to pass in HW specific params to
a MIPS CPU, but since MIPS FS hasnt been touched for awhile, it makes sense
to not force every other ISA to use CoreSpecific as well use a special
reset function to set it. That probably should go in a PowerOn reset fault
 anyway.
2011-03-26 09:23:52 -04:00
Ali Saidi
799c3da8d0 O3: Send instruction back to fetch on squash to seed predecoder correctly. 2011-03-17 19:20:19 -05:00
Gabe Black
07b507d278 X86: Use the npc as the pc when doing a nativetrace, not what M5 considers the pc. 2011-03-02 00:41:44 -08:00
Gabe Black
8966312785 X86: Decode the mysterious and elusive ffreep x87 instruction.
The internet says this instruction was created by accident when an Intel CPU
failed to decode x87 instructions properly. It's been documented on a few rare
occasions and has generally worked to ensure backwards compatability. One
source claims that the gcc toolchain is basically the only thing that emits
it, and that emulators/binary translators like qemu and bochs implement it.

We won't actually implement it here since we're hardly implementing any other
x87 instructions either. If we were to implement it, it would behave the same
as ffree but then also pop the register stack.

http://www.pagetable.com/?p=16
2011-03-02 00:41:38 -08:00
Gabe Black
579c5f0b65 Spelling: Fix the a spelling error by changing mmaped to mmapped.
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
2011-03-01 23:18:47 -08:00
Gabe Black
2e4fb3f139 X86: Mark IO reads and writes as non-speculative. 2011-03-01 22:42:59 -08:00
Gabe Black
72d35701e9 X86: Mark prefetches as such in their instruction and request flags. 2011-03-01 22:42:18 -08:00
Gabe Black
d3214c5c5e X86: If PCI config space is disabled, pass through to regular IO addresses. 2011-02-27 16:25:06 -08:00
Gabe Black
0ce5d31159 X86: Use regular read requests in the walker instead of read exclusive. 2011-02-27 16:24:10 -08:00
Gabe Black
fde8b5c387 X86: Get rid of "inline" on the MicroPanic constructor in decoder.cc.
This was making certain versions of gcc omit the function from the object file
which would break the build.
2011-02-15 15:58:16 -08:00
Gabe Black
77b4a37067 X86: Detect branches taking into account instruction size.
The size of the current instruction determines what the npc should be if
there's no branching.
2011-02-13 17:45:47 -08:00
Gabe Black
bce2be525d X86: Put the result used for flags in an intermediate variable.
Using the destination register directly causes the ISA parser to treat it as a
source even if none of the original bits are used.
2011-02-13 17:45:12 -08:00
Gabe Black
4e1adf85f7 X86: Don't read in dest regs if all bits are replaced.
In x86, 32 and 64 bit writes to registers in which registers appear to be 32 or
64 bits wide overwrite all bits of the destination register. This change
removes false dependencies in these cases where the previous value of a
register doesn't need to be read to write a new value. New versions of most
microops are created that have a "Big" suffix which simply overwrite their
destination, and the right version to use is selected during microop
allocation based on the selected data size.

This does not change the performance of the O3 CPU model significantly, I
assume because there are other false dependencies from the condition code bits
in the flags register.
2011-02-13 17:44:24 -08:00
Gabe Black
399e095510 X86: On a bad microopc, return a microop that returns a fault that panics.
This way a bad micropc will have to get all the way to commit before killing
the simulation. This accounts for misspeculated branches.
2011-02-13 17:42:56 -08:00
Gabe Black
1aa9698fa0 X86: Define fault objects to carry debug messages.
These faults can panic/warn/warn_once, etc., instead of instructions doing
that themselves directly. That way, instructions can be speculatively
executed, and only if they're actually going to commit will their fault be
invoked and the panic, etc., happen.
2011-02-13 17:42:05 -08:00
Gabe Black
5ee94f4a3d X86: Only reset npc to reflect instruction length once.
When redirecting fetch to handle branches, the npc of the current pc state
needs to be left alone. This change makes the pc state record whether or not
the npc already reflects a real value by making it keep track of the current
instruction size, or if no size has been set.
2011-02-13 17:41:10 -08:00
Tim Harris
44e5e7e053 X86: Obey the wp bit of CR0.
If cr0.wp ("write protect" bit) is clear then do not generate page faults when
writing to write-protected pages in kernel mode.
2011-02-07 15:18:52 -08:00
Tim Harris
6da83b8a1b X86: Use all 64 bits of the lstar register in the SYSCALL_64 macroop.
During SYSCALL_64, use dataSize=8 when handling new rip (ref
http://www.intel.com/Assets/PDF/manual/253668.pdf 5.8.8 IA32_LSTAR is a 64-bit
address)
2011-02-07 15:16:27 -08:00
Tim Harris
2ea1aa8a4f X86: Fix JMP_FAR_I to unpack a far pointer correctly.
JMP_FAR_I was unpacking its far pointer operand using sll instead of srl like
it should, and also putting the components in the wrong registers for use by
other microcode.
2011-02-07 15:12:59 -08:00
Tim Harris
5810ab121c X86: Read the LDT/GDT at CPL0 when executing an iret.
During iret access LDT/GDT at CPL0 rather than after transition to user mode
(if I'm reading the Intel IA-64 architecture spec correctly, the contents of
the descriptor table are read before the CPL is updated).
2011-02-07 15:05:28 -08:00
Gabe Black
0c4b816d84 X86: Fix compiling vtophys.cc 2011-02-07 01:21:21 -08:00
Brad Beckmann
dfa8cbeb06 m5: added work completed monitoring support 2011-02-06 22:14:19 -08:00
Brad Beckmann
c41fc138e7 dev: fixed bugs to extend interrupt capability beyond 15 cores 2011-02-06 22:14:18 -08:00
Joel Hestness
3a2d2223e1 x86: Timing support for pagetable walker
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.
2011-02-06 22:14:18 -08:00
Joel Hestness
911ccef6c0 x86: Add checkpointing capability to arch components
Add checkpointing capability to the x86 interrupt device and the TLBs
2011-02-06 22:14:17 -08:00
Joel Hestness
38140b5519 x86: implements vtophys
Calls walker to look up virt. to phys. page mapping
2011-02-06 22:14:17 -08:00
Joel Hestness
eea78f968b IntDev: packet latency fix
The x86 local apic now includes a separate latency parameter for interrupts.
2011-02-06 22:14:17 -08:00
Joel Hestness
d9f0a8288e MessagePort: implement the virtual recvTiming function to avoid double pkt delete
Double packet delete problem is due to an interrupt device deleting a packet that the SimpleTimingPort also deletes. Since MessagePort descends from SimpleTimingPort, simply reimplement the failing code from SimpleTimingPort: recvTiming.
2011-02-06 22:14:17 -08:00
Brad Beckmann
afd754dc0d x86: set IsCondControl flag for the appropriate microops 2011-02-06 22:14:16 -08:00
Gabe Black
091a3e6cc0 Fault: Rename sim/fault.hh to fault_fwd.hh to distinguish it from faults.hh.
--HG--
rename : src/sim/fault.hh => src/sim/fault_fwd.hh
2011-02-03 21:47:58 -08:00
Gabe Black
cb22bead7d X86: Get rid of the stupd microop. 2011-02-02 19:57:12 -08:00
Gabe Black
eabbdbee63 X86: Replace the stupd microop with a store/update sequence. 2011-02-02 19:56:38 -08:00
Steve Reinhardt
6f1187943c Replace curTick global variable with accessor functions.
This step makes it easy to replace the accessor functions
(which still access a global variable) with ones that access
per-thread curTick values.
2011-01-07 21:50:29 -08:00
Steve Reinhardt
c69d48f007 Make commenting on close namespace brackets consistent.
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.
2011-01-03 14:35:43 -08:00
Gabe Black
672d6a4b98 Style: Replace some tabs with spaces. 2010-12-20 16:24:40 -05:00
Gabe Black
d3e021820e X86: Take advantage of new PCState syntax. 2010-12-08 00:27:23 -08:00
Gabe Black
3cd349f443 X86: Obey the PCD (cache disable) bit in the page tables. 2010-11-23 06:10:17 -05:00
Gabe Black
c8c921b9db X86: Mark IO space accesses as uncachable. 2010-11-22 05:49:03 -05:00
Gabe Black
388124492e X86: Fix X86_FS compilation. 2010-11-08 12:43:38 -08:00
Gabe Black
6f4bd2c1da ISA,CPU,etc: Create an ISA defined PC type that abstracts out ISA behaviors.
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.
2010-10-31 00:07:20 -07:00
Gabe Black
373154a25a X86: Fault on divide by zero instead of panicing. 2010-10-29 02:20:47 -07:00
Gabe Black
7378424b14 X86: Make syscalls also serialize after. 2010-10-29 02:20:46 -07:00
Gabe Black
2eae11be64 X86: Make nop a regular, non-microcoded instruction.
Code in the CPUs that need a nop to carry a fault can't easily deal with a
microcoded nop. This instruction format provides for one that isn't.

--HG--
rename : src/arch/x86/isa/formats/syscall.isa => src/arch/x86/isa/formats/nop.isa
2010-10-22 00:24:15 -07:00
Gabe Black
23f6196d61 X86: Implement genMachineCheckFault.
Even though this shouldn't ever be used, it might get called speculatively and
shouldn't panic.
2010-10-22 00:24:08 -07:00
Gabe Black
255685534a X86: Make syscall instructions non-speculative in SE. 2010-10-22 00:23:50 -07:00
Gabe Black
ab9f062166 GetArgument: Rework getArgument so that X86_FS compiles again.
When no size is specified for an argument, push the decision about what size
to use into the ISA by passing a size of -1.
2010-10-15 23:57:06 -07:00
Gabe Black
b273e0be33 X86: Detect attempts to load a 32 bit kernel and panic. 2010-10-10 20:39:26 -07:00