git.libre-soc.org Git - gem5.git/log

arch-arm: Don't change PSTATE in Illegal Exception return

This patch fixes the Illegal Exception return handler. According to the
armarm documentation, when PSTATE.IL is set to one because of an illegal
exception return, PSTATE.{EL, nRW, SP} are unchanged. This means the
Exception level, Execution state, and stack pointer selection do not
change as a result of the return.

Change-Id: I35f2fe68fb2822a54fc4a21930871eab7a1aaab4
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/8021
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arch-arm: Handle route to EL2 in Supervisor Trap

Supervisor Trap is supposed to be able to handle exceptions routed
to EL2, which is enabled by HCR_EL2.TGE. This fix adds routeToHyp()
function to Supervisor Trap to handle this, similar to that in
UndefinedFault, DataAbort, etc.

Change-Id: I1fcf9f2d445ecbc13c8f6d3b7d599728b0250ab7
Reviewed-by: Jack Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7961
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arch-arm: Change the type of fault for dc ivac instructions

Change-Id: I00f957a3bc4721a66db62b1257f10e9019a94608
Reviewed-by: Jack Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7829
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>

arch-arm: Unify permission checks for dc * instructions

Change-Id: Ib47f4134e3f0a580e5356d384a5d3b293c1af7be
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7828
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arch-arm: Check cache maintenance insts for permission faults

In AArch32, data cache maintenance instructions that operate by VA do
not generate permission faults.

In AArch64, a data cache invalidate instruction can generate a
permission fault when there are no write permissions to the specified
VA. Data cache clean and data cache clean and invalidate instructions
do not generate permission faults.

Checks for external aborts are also bypassed for data cache
maintenance instructions.

Change-Id: Iea5bc665e4cf66d528e36b671535b66637c4b224
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7827
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arch-arm: Turn dc ivac to dc civac when some conditions are met

The Arm ARM defines that at EL1 a data cache invalidate instruction
performs a data cache clean and invalidate operation if all of the
following apply:
* EL2 is implemented,
* HCR_EL2.VM is set to 1,
* SCR_EL3.NS is set to 1 or EL3 is not implemented.
This changeset implements this behavior.

Change-Id: I6b6aef2f4b1e7eb107c069fdb0a10f4aa8e6b196
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7826
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arch-arm: Fix printing of the data cache maintenance instructions

Change-Id: I2322c7bf65b38cb07a1ea2b5dc25dfc5a0496cf0
Reviewed-by: Jack Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7825
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>

arch-arm: Fix cache line size for cache maintenace inst

Cache maintenance operations operate on whole cache blocks. This
changeset uses the system cache line size as the size of the cache
maintenance requests and masks the lower bits of the effective
address.

Change-Id: I6e7aefff51670c8cac39e4e73db21a0c5a0b7aef
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7824
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arch-arm: Fault when dc ivac is executed from EL0

A previous change enabled execution of dc ivac from EL0 when
SCTLR_EL1.UCI=1. The Arm ARM specifies that dc ivac is the only data
cache maintenance operation by VA that cannot be executed from
EL0. This changeset essential reverts the change:
8d43922 arch-arm: Allow dc ivac from EL0 when SCTLR_EL1.UCI=1

Change-Id: Ia25fab13846a151f548e649a16067feb1ff65c9c
Reviewed-by: Jack Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7823
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

mem-cache: Only pendingModified MSHRs can satisfy CMO snoops

We set the satisfied flag when a cache clean request encounters:
1) a block with the dirty bit set, or
2) a pending modified MSHR which means that the cache will get copy of
the block that will be soon modified.

This changeset fixes a previous bug that set the satisfied flag on
snooping MSHR hits even the pendingModified flags was not set.

Change-Id: I4968c4820997be5cc1238148eea12a1ba39837d4
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Sudhanshu Jha <sudhanshu.jha@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7822
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-cache: Cleaned blocks should be marked as not writable

A writeclean packet writes a dirty block to the memory below and
therefore sets the dirty flag for the block when the memory below is a
cache. If the block was also marked as writable it can satisfy future
write requests without further requests/snoops. This can lead to
multiple copies of the same block marked as dirty which is not
allowed. This changeset clears the writable flag from the cleaned
block to prevent the cache from satisfying future write requests
without sending a downstream request.

Change-Id: I14d3c62fd33f81b1a8ba62374c8565ccab00a6fe
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7821
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

arch-arm: Change function name for banked miscregs

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>

arch-arm: Fix AArch32 SETEND Instruction

This patch fixes AArch32 SETEND instruction, which was previously
executed unconditionally without checking (H)SCTLR.SED field. This bit
enables/disables the trapping of the instruction.

Change-Id: Ib3d2194c8d16c34ec2a9ab3e8090081900c1e42e
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7981
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arch-arm: Correct Illegal Exception Return detection

Fixed Illegal Exception Return detection, which was not
covering all the documented cases.

Change-Id: If08ddc1490d1c0a1fccee1489d116384770ce0a5
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7223
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arch-arm: ELUsingAArch32K from armarm pseudocode

This patch implements the ELUsingAArch32K pseudocode, which is returning
true if the provided Exception Level is using A32 ISA, but it is not
panicking (quitting simulation) if the information is unknown (see
documentation).
The panicking is the current behaviour of the ELIs32 utility in gem5.

Change-Id: Iad7b56077d7e0f8ee223b5b9593cb8097f26bb29
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7222
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arch-arm: isSecureBelow from armarm pseudocode

This patch introduces the inSecureBelow pseudocode function
defined in the armarm documentation. It also replaces the
inSecureState function call which was improperly used in
ELIs32: we might be in secure state (EL3), but with non-secure
lower ELs (SCR.NS = 1).

Change-Id: I01febcb54392ad4e51e785b4d5153aeb3437c778
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Chuan Zhu <chuan.zhu@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7221
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arch-arm: Fix incorrect assumptions in ELIs64

The state of EL1 wasn't determined correctly when running in secure
mode if virtualisation was enabled. This changset updates the
implementation to match the canonical behavior from the ARM ARM.

Change-Id: I7ed6f5c003617773603f678667aac069d73b6f62
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7141
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>

mem-cache: Remove extra numSets zero check.

numSets is unsigned, so it cannot be lower than 0. Besides, isPowerOf2(0)
is false by definition (and implemmentation*), so there is no need for the
double check.

* As presented in base/intmath.hh

Change-Id: I3f6296694a937434feddc7ed21f11c2a6fdfc5a9
Reviewed-on: https://gem5-review.googlesource.com/7901
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

mem: Standardize mem folder header guards

Standardize all header guards in the mem directory according to the most
frequent patterns. In general they have the form:
mem: __FOLDER_TREE_FILE_NAME_HH__
ruby: __FOLDER_TREE_FILENAME_HH__

Change-Id: I983853e292deb302becf151bf0e970057dc24774
Reviewed-on: https://gem5-review.googlesource.com/7881
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

base: Update #includes for bitunion.hh.

<iostream> isn't actually used anywhere in bitunion.hh. The templated
hash struct type is defined in <functional> and should be included
explicitly.

Change-Id: I8691ccb2f9e28a01610ae8bb4d9591b07cb7320b
Reviewed-on: https://gem5-review.googlesource.com/7781
Reviewed-by: Matthias Jung <jungma@eit.uni-kl.de>
Maintainer: Gabe Black <gabeblack@google.com>

config: remove dead code in fs.py

We have not added the --generate-dtb option for non-ARM systems and
hence this case becomes dead code. It also leads to error on non-ARM
systems as is tries to access a non existent field.

Change-Id: Ia926bd0c61efa275bc5e3864b8a9c3ffb7aa3cb5
Signed-off-by: Nayan Deshmukh <nayan26deshmukh@gmail.com>
Reviewed-on: https://gem5-review.googlesource.com/7801
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

cpu: MinorCPU handling IsSquashAfter flag

MinorCPU was not handling IsSquashAfter flagged instructions. The
behaviour was to force a branch (hence enforcing refetching) for
SerializeAfter instructions only. This has now been extended to
SquashAfter in order to correctly support ISB barrier instruction
behaviour.

Change-Id: Ie525b23350b0de121372d3b98b433e36b097d5c4
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/5702
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arch-arm: Removing Serializing flag from ISB

ISB Serializing behaviour is guaranteed by IsSquashAfter,
which is inherently serializing; when instruction is commited,
consecutive instructions are flushed and refetched.

Change-Id: I05e61b4cf9f01113d95b1502c996d04cbd69b759
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/5701
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

base: Fix unused function warning

After refactoring the remote gdb interface, break_type is declared as
const function and is only used as a parameter to DPRINTF function
calls. This means that it is seen as unused when compiling
gem5.fast. This changeset fixes the warning.

Change-Id: Iea89b66c53c62341c043d8bd3838ebc27ee333bc
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7741
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

alpha: fix for no 'break' in the case statement

gem5 won't compile correctly since g++ will throw a warning (error)
that the next case statement below this one is reachable since there is
no 'break' statement.

Signed-off-by: Sujay Phadke
Change-Id: Icab646ee5abcfeb6ba3e690909042927b4003eba
Reviewed-on: https://gem5-review.googlesource.com/7521
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

scons: Resolve backtrace implementation existence testing failure

Change backtrace implementation testing code not to have NULL pointer.

SCons fails to find backtrace implementation even if it exists.
The implementation testing code contains NULL pointers as a backtrace
buffer argument. Some compilers check the buffer is NULL pointed
or not, and generate a compilation error.

Change-Id: Icc5bc9a887b7a6bbc804b5b8a5a35a935c78a922
Reviewed-on: https://gem5-review.googlesource.com/7681
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

arch-x86: consistent style of comments in system files

Change-Id: I9f208819b8c1a5c46a77262eb533bb47adb2b905
Reviewed-on: https://gem5-review.googlesource.com/7701
Reviewed-by: Gabe Black <gabeblack@google.com>
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Gabe Black <gabeblack@google.com>

arch-x86: Granularity bit and segment limit

If set, the granularity bit indicates that the segment limit of segment
descriptors shall be interpreted as number of 4K blocks rather than
bytes.

The high part (bit 48 to 51) of segment descriptor limits is only 4 bits
wide while the low part (bit 0 to 15) spans 16 bits.

Change-Id: Ie386224ca815275fdb31498fe68310ed9c62cc87
Reviewed-on: https://gem5-review.googlesource.com/7601
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

riscv: Add overrides to various StaticInst methods.

This makes riscv compile with the version of clang(++) I have on my
workstation.

Change-Id: I0478616810fbc8a715fd61323b7e0f73676c8328
Reviewed-on: https://gem5-review.googlesource.com/7643
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>

base: Remove the ability to cprintf stringstreams directly.

The cprintf functions don't know ahead of time what format characters
are going to be used with what underlying data types, and so any
type must be minimally usable with the default specialization of
format_integer, format_char, format_float and format_string. All of
those functions ultimately print their parameter with out << data
except the one which prints stringstreams. That function accesses the
buffer of the string stream with .str(), and then prints that instead.

That should technically work out ok as long as stringstreams are only
printed using %s, but there's no way to guarantee that ahead of time.
To avoid that problem, and because gem5 doesn't ever actually use the
ability to print stringstreams directly, this change removes that
feature and modifies the corresponding part of the unit test.

If we ever do want to print the contents of a string stream, it won't
be difficult to add a .str() to it.

Change-Id: Id902eaff042b96b374efe0183e5e3be9626e8c88
Reviewed-on: https://gem5-review.googlesource.com/7642
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>

base: Delete commented out versions of the format_integer function.

If they're needed, they'd be fairly easy to recreate and are also
available in the revision history.

Change-Id: I5cf5e4b1271ce488016464048de69bc643dee4d9
Reviewed-on: https://gem5-review.googlesource.com/7641
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>

arch-arm: understandably initialize register permissions

Move massive initialization routine to the bottom of miscregs.cc.
Additionally, share register metadata across ISA instances by
making lookUpMiscReg a static member of the ISA and only
initializing it once.

Change-Id: I6d6ab26200c4e781151cc6efd97ce2420e2bf4cc
Signed-off-by: Curtis Dunham <Curtis.Dunham@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jack Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/6803
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arm: extend MiscReg metadata structures

Implement proper handling of RES0/RES1 and RAZ/RAO bitfields.

Change-Id: I344c32c3fb1d142acfb0521ba3590ddd2b1f5360
Signed-off-by: Curtis Dunham <Curtis.Dunham@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jack Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/6802
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arch-arm: understandably initialize register mappings

The mappings for sharing a backing store between AArch32
and AArch64 system registers are made clearer using an
initializer object.

Change-Id: I29dcfab2797b4d36b3182342997edffde334a291
Signed-off-by: Curtis Dunham <Curtis.Dunham@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jack Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/6801
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

config, arm: enable device tree autogeneration for bigLITTLE

Change-Id: Iaa5eeb3504b3ff9e46b6f592a06d6b833c830d83
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/5969
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

config: Embed Device Tree generation in fs.py config

Equips the fs.py config routine with an extra commandline option
--generate-dtb that will generate a dtb file automatically before
running the simulation. Only works with ARM systems and gives a warning
if the simulated system is not of --machine-type VExpress_GEM5_V1.

Change-Id: I7766e5459fd9bec2245de83cef103091ebaf7229
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/5968
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arm: DT autogeneration - generate PCI node

Enables automatic generation of Device Trees for RealView PCI host
controllers. Note that some parts are more hard coded than you'd want,
but this is due to the limited understanding the PCI host has of its
configuration (i.e. it doesn't know all memory ranges). Fixing this,
for now at least, went beyond the scope and intentions of the
Device Tree generating code: use with care!

Change-Id: I2041871e0eb4d04fb5191257c47dd38649d1c0cc
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/5967
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arm: DT autogeneration - Generate energy controller node

Adds Device Tree methods for the energy controller to allow for
DVFS simulations with automatically generated DTB files

Change-Id: Id8682f07dff1bbe63987e757faa0694e03ee86ab
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/5966
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arm: DT autogeneration - autogenerate RealView Platform devices

Implements the Device Tree generating code for devices required by the
RealView VExpress_GEM5_V1 platform

Change-Id: I14244b2f3c028cbddba3c23ce7433fe3b301a0e8
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/5965
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arm: DT autogeneration - Generate memory node

Implements a high level method for generating a Device Tree node for
an AbstractMemory object.

Change-Id: I544ec642f182f103df26de535fdfaf03b3787a08
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/5964
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arm: DT autogeneration - Generate cpus node

Equips cpu models with a method to generate the cpu node.

Note: even though official documentation requires that CPU ids start
counting from 0 in every cluster, GEM5 requires a globally unique cpu_id.

Change-Id: Ida3e17af3124a68ef7dbf2449cd034dfc3ec39df
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/5963
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arm: DT autogeneration - Device Tree generation methods

This patch adds an extra layer to the pyfdt library such that usage
gets easier and device tree nodes can be specified in less code,
without limiting original usage. Note to not import both the pyfdt
and fdthelper in the same namespace (but generally fdthelper is all
you need, because it supplies the same classes even when they are not
extended in any way)

Also, this patch lays out the primary functionality for generating a
device tree, where every SimObject gets an empty generateDeviceTree
method and ArmSystems loop over their children in an effort to merge
all the nodes. Devices are implemented in other patches.

Change-Id: I4d0a0666827287fe42e18447f19acab4dc80cc49
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/5962
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

ext: DT autogeneration - Add PyFtd to m5 space

This patch adds pyfdt.py to the m5.ext module. This is used in
succeeding patches for generating and editing dtb files and flat
device trees for DT autogeneration.

The file is in the m5_root/src/python/m5/ext directory, as opposed to
the m5_root/ext, because this library is part of the m5 object space
and linking to the m5_root/ext directory from the SConscript file
in src/python can not be done reliably. Linking from the root level
SConscript is also not an option, because it doesn't have the PySource
method defined.

Cloned from: https://github.com/superna9999/pyfdt
Commit: accbcd254584c9295a18878d32999d0c7c156f8e
Version: 0.3

Change-Id: I928bdc912a9507d1f8a3290acf445c7cae496552
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/5961
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arm: make Arm GenericTimer a ClockedObject

Within a device tree, the GenericTimer device needs to point (via phandle)
to a clock domain which is itself also an object in the device tree. Within
gem5, clock domains are managed by making all clocked SimObjects inherit
from ClockedObject rather than SimObject.

Without this change, the GenericTimer is unable to generate the appropriate
clock domain phandle, and will crash during DTB autogeneration.

Change-Id: I6d3fb6362847c6a01720b2f14b3d595d1e59f01f
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/4960
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

base: Add an "override" to name() in the HardBreakpoint class.

clang reports an error otherwise and fails to compile.

Change-Id: I3603d6c710641f1289e35c67f89a49f5cb71e95e
Reviewed-on: https://gem5-review.googlesource.com/7582
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

base: Get bitunions to compile on clang 3.8.

clang was getting very upset and interpretting a member function
pointer as a call to the actual underlying function, and then
complaining that it was a non-static function call without an instance.

It seems what it was really upset about was that the class who's scope
the member function pointer belonged to (the current class) wasn't done
being defined. This *should* be ok as far as I can tell, but clang was
having none of it.

This change reworks how the type of the setter function arguments are
determined to work around that limitation. The bitunion test was run
with clang++ and g++ and both pass, and I've built gem5.opt for ARM
successfully.

Change-Id: Ib9351784a897af4867fe08045577e0247334ea11
Reviewed-on: https://gem5-review.googlesource.com/7581
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>

util: Implement Lua module for m5ops.

This module allows m5ops to be executed in Lua programs.
To compile it (in util/m5):
    The following command generates Lua moduel, gem5OpLua.so.

    make -f Makefile.<arch> gem5OpLua.so

To use it:
    First, put gem5OpLua.so in Lua library search path.
    Then, import the module and execute the m5op function.

Example usage, creating a checkpoint.

    m5 = require("gem5OpLua")
    m5.do_checkpoint(0, 0)

Change-Id: Icc18a1fb6c050afeb1cf4558fbdc724fb26a90e2
Reviewed-on: https://gem5-review.googlesource.com/6541
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arch-x86: Adding clflush, clflushopt, clwb instructions

This patch adds support for cache flushing instructions in x86.
It piggybacks on support for similar instructions in arm ISA
added by Nikos Nikoleris. I have tested each instruction using
microbenchmarks.

Change-Id: I72b6b8dc30c236a21eff7958fa231f0663532d7d
Reviewed-on: https://gem5-review.googlesource.com/7401
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

arch: Remove the "arch/tlb.hh" switching header.

This header is no longer used.

Change-Id: I8da7f8618d647dd11c581818c13855c4e20d32d2
Reviewed-on: https://gem5-review.googlesource.com/7351
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

tarch, mem: Abstract the data stored in the SE page tables.

Rather than store the actual TLB entry that corresponds to a mapping,
we can just store some abstracted information (address, a few flags)
and then let the caller turn that into the appropriate entry. There
could potentially be some small amount of overhead from creating
entries vs. storing them and just installing them, but it's likely
pretty minimal since that only happens on a TLB miss (ideally rare),
and, if it is problematic, there could be some preallocated TLB
entries which are just minimally filled in as necessary.

This has the nice effect of finally making the page tables ISA
agnostic.

Change-Id: I11e630f60682f0a0029b0683eb8ff0135fbd4317
Reviewed-on: https://gem5-review.googlesource.com/7350
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

x86, mem: Rewrite the multilevel page table class.

The new version extracts all the x86 specific aspects of the class,
and builds the interface around a variable collection of template
arguments which are classes that represent the different levels of the
page table. The multilevel page table class is now much more ISA
independent.

Change-Id: Id42e168a78d0e70f80ab2438480cb6e00a3aa636
Reviewed-on: https://gem5-review.googlesource.com/7347
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Gabe Black <gabeblack@google.com>

util: Implement PIC version of m5ops for X86.

Using m5ops for X86 in shared objects requires PIC for the m5ops.
Typically, the PIC version is used to make m5op interfaces to other
languages like python and lua.

Change-Id: I2463904c13ea8b839d0386d3c743d8dad1e1e6bc
Reviewed-on: https://gem5-review.googlesource.com/7261
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

x86, mem: Don't try to force physical addresses on the system.

Use the system object to allocate physical memory instead of manually
placing certain structures and then forcing the system to start other
allocations after them in physical memory.

Change-Id: Ie18c81645c3b648c64a6d7a649a0e50f7028f344
Reviewed-on: https://gem5-review.googlesource.com/7346
Maintainer: Gabe Black <gabeblack@google.com>
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>

x86, mem: Get rid of PageTableOps::getBasePtr.

Pass this constant into the page table constructor.

Change-Id: Icbf730f18d9dfcfebd10a196f7f799514728b0fb
Reviewed-on: https://gem5-review.googlesource.com/7345
Maintainer: Gabe Black <gabeblack@google.com>
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>

x86, mem: Pass the multi level page table layout in as a parameter.

Don't get it from a global constant declared in an ISA header file.

Change-Id: Ie19440abdd76500a5e12e6791e6f755ad9e95af3
Reviewed-on: https://gem5-review.googlesource.com/7344
Maintainer: Gabe Black <gabeblack@google.com>
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Reviewed-by: Alexandru Duțu <alexandru.dutu@amd.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

arch, mem: Make the page table lookup function return a pointer.

This avoids having a copy in the lookup function itself, and the
declaration of a lot of temporary TLB entry pointers in callers. The
gpu TLB seems to have had the most dependence on the original signature
of the lookup function, partially because it was relying on a somewhat
unsafe copy to a TLB entry using a base class pointer type.

Change-Id: I8b1cf494468163deee000002d243541657faf57f
Reviewed-on: https://gem5-review.googlesource.com/7343
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

base: Hide the BitUnion::__StorageType type.

Since this type is now accessible through a clean interface, hide it
from anybody that tries to peak around the curtain.

Change-Id: I1257b6675a45b8648be459ad8e8d0f27a6feee6b
Reviewed-on: https://gem5-review.googlesource.com/7205
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

arm, base: Generalize and move the BitUnion hash struct.

The ARM types.hh file defined an STL style hash structure to operate
on the ExtMachInst, but it referred to the underlying storage type
using internal typedefs in the BitUnion types. To avoid having to do
that, this change adds a hash structure to bitunion.hh which will work
on any BitUnion, and gets rid of the ARM ExtMachInst version.

Change-Id: I7c1c84d61b59061fec98abaaeab6becd06537dee
Reviewed-on: https://gem5-review.googlesource.com/7204
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>

sim: Use the new BitUnion templates in serialize.hh.

serialize.hh should not reference internal implementation details in
the underlying BitUnion types.

Change-Id: I1ce29243db63801b7788f037fdc54811bdab889c
Reviewed-on: https://gem5-review.googlesource.com/7203
Maintainer: Gabe Black <gabeblack@google.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

base: Enable specializing templates on BitUnion types.

Previously these relied on reaching into private internal definitions
in the BitUnion types.

Change-Id: Ia6c94de92986b85ec9e5fcb197459d450111fb36
Reviewed-on: https://gem5-review.googlesource.com/7202
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>

base: Rework bitunions so they can be more flexible.

They are now oriented around a class which makes it easy to provide
custom setter/getter functions which let you set or read bits in an
arbitrary way.

Future additions may add the ability to add custom bitfield methods,
and index-able bitfields.

Change-Id: Ibd6d4d9e49107490f6dad30a4379a8c93bda9333
Reviewed-on: https://gem5-review.googlesource.com/7201
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>

sim, arch, base: Refactor the base remote GDB class.

Fold the GDBListener class into the main BaseRemoteGDB class, move
around a bunch of functions, convert a lot of internal functions to
be private, move some functions into the .cc, make some functions
non-virtual which didn't really need to be overridden.

Change-Id: Id0832b730b0fdfb2eababa5067e72c66de1c147d
Reviewed-on: https://gem5-review.googlesource.com/7422
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

arch, mem, sim: Consolidate and rename the SE mode page table classes.

Now that Nothing inherits from PageTableBase directly, it can be
merged into FuncPageTable. This change also takes the opportunity to
rename the combined class to EmulationPageTable which lets you know
that it's specifically for SE mode.

Also remove the page table entry cache since it doesn't seem to
actually improve performance. The TLBs likely absorb the majority of
the locality, essentially acting like a cache like they would in real
hardware.

Change-Id: If1bcb91aed08686603bf7bee37298c0eee826e13
Reviewed-on: https://gem5-review.googlesource.com/7342
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Gabe Black <gabeblack@google.com>

util: Add an option to specify paths in list_changes.py

Add an option to restrict change lists to changes that touch one or
more subdirectories in the source tree.

Change-Id: Id4e34fe300fdc3657505e2e188c727e583bcf611
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Sudhanshu Jha <sudhanshu.jha@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7461
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>

mem: Change the multilevel page table to inherit from FuncPageTable.

KVM looks up translations using the image of the page table in the
guest's memory, but we don't have to. By maintaining that image in
addition to rather than instead of maintaining an abstract copy makes
our lookups faster, and ironically avoids duplicate implementation.

Change-Id: I9ff4cae6f7cf4027c3738b75f74eae50dde2fda1
Reviewed-on: https://gem5-review.googlesource.com/7341
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Gabe Black <gabeblack@google.com>

arch-riscv: Fix floating-poing op classes

This patch applies correct miscellaneous or multiply-accumulate op
classes to floating point instructions which had previously been
incorrectly classed as add or multiply instructions.

Change-Id: I959dd8d3152aa341e0f060b003ce1da8c4d688fb
Reviewed-on: https://gem5-review.googlesource.com/6521
Reviewed-by: Alec Roelke <ar4jc@virginia.edu>
Maintainer: Alec Roelke <ar4jc@virginia.edu>

arch-riscv: Fix floating-point conversion bugs

Using the fetestexcept function to check for specific types of floating
point exceptions is unreliable for some kinds of
floating-point-to-integer conversion operations. RISC-V code used to
make use of them to check for some exceptional cases like overflow and
underflow, which caused incorrect output when compiler optimization is
turned on. This patch changes the use of fetestexcept to explicit checks
for those exceptional cases.

Change-Id: Id983906ea0664dc246e115a9e470d9ab7733bde1
Reviewed-on: https://gem5-review.googlesource.com/6402
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Alec Roelke <ar4jc@virginia.edu>

sim: Simplify registerThreadContext a little bit.

The code in this function was a little convoluted. This change attempts
to simplify it a little bit to make it easier to read.

Change-Id: I1ae557b9fede47fa89a9ea550bd0af8ad242449f
Reviewed-on: https://gem5-review.googlesource.com/7421
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

mem: Track TLB entries in the lookup cache as pointers.

Using the architectural page table on x86 and the functional page table
on ARM, both with the twolf benchmark in SE mode, there was no
performance penalty for doing so, and again possibly a performance
improvement. By using a pointer instead of an inline instance, it's
possible for the actual type of the TLB entry to be hidden somewhat,
taking a step towards abstracting away another aspect of the ISAs.

Since the TLB entries are no longer overwritten and now need to be
allocated and freed, this change introduces return types from the
updateCache and eraseCacheEntry functions. These functions will return
the pointer to any entry which has been displaced from the cache which
the caller can either free or ignore, depending on whether the entry
has a purpose outside of the cache.

Because the functional page table stores its entries over a longer time
period, it will generally not delete the pointer returned from those
functions. The "architechtural" page table, ie the one which is backed
by memory, doesn't have any other use for the TlbEntrys and will delete
them. That leads to more news and deletes than there used to be.

To address that, and also to speed up the architectural page table in
general, it would be a good idea to augment the functional page table
with an image of the table in memory, instead of replacing it with one.
The functional page table would provide quick lookups and also avoid
having to translate page table entries to TLB entries, making
performance essentially equivalent to the functional case. The backing
page tables, which are primarily for consumption by the physical
hardware when in KVM, can be updated when mappings change but otherwise
left alone.

If we end up doing that, we could just let the ISA specific process
classes enable whatever additional TLB machinery they need, likely
a backing copy in memory, without any knowledge or involvement from
the ISA agnostic class. We would be able to get rid of the useArchPT
setting and the bits of code in the configs which set it.

Change-Id: I2e21945cd852bb1b3d0740fe6a4c5acbfd9548c5
Reviewed-on: https://gem5-review.googlesource.com/6983
Maintainer: Gabe Black <gabeblack@google.com>
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>

arch: Fix a fatal_if in most of the arch's process classes.

When switching an assert to a fatal while addressing recent review
feedback, I forgot to reverse the polarity of the condition, making
the fatal fire in exactly the opposite of the conditions it was meant
to.

Change-Id: Icf49864ef449052bbb0d427dca786006166575c4
Reviewed-on: https://gem5-review.googlesource.com/7381
Reviewed-by: Matthias Jung <jungma@eit.uni-kl.de>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

sim: Allow passing a user-defined L2XBar to addTwoLevelCacheHierarchy().

Before this CL, the addTwoLevelCacheHierarchy() function uses the
default L2XBar class as the interconnect between CPU L1 caches and
L2. This CL allows passing a user-defined bus to overwrite the
default L2XBar by adding an optional argument to the function.

Change-Id: I917657272fd4924ee0bed882a226851afba26847
Reviewed-on: https://gem5-review.googlesource.com/7364
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

util/m5: add Android.mk

Add Android.mk so we can build m5 tool in Android tree.

Change-Id: I7023130bd3ce5e015b8f7c41941eafb4611da8cb
Reviewed-on: https://gem5-review.googlesource.com/7363
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>

arch-riscv: Don't crash when printing unknown CSRs

This patch fixes a potential crash if an unnamed CSR is accessed and
debug flags are enabled that print disassembly. Unknown CSRs will be
identified as "??" followed by the address that was used.

Change-Id: If5ac57f1422bd59c72a1a06206fa9d9dc05d21ef
Reviewed-on: https://gem5-review.googlesource.com/7321
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Alec Roelke <ar4jc@virginia.edu>

mem-ruby: Fix wakeup timeouts for the MOESI_CMP_token protocol

This changeset fixes a bug that was affecting the MOESI_CMP_token
protocol where setting the next timeout required an absolute tick in
the future.

Change-Id: Ibfdb59354e13c7e552cb3389e71bda010f333249
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7163
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-ruby: Remove function that maps responses to a DMA engine

The function map_Address_to_DMA was used to route responses to the
first (and assumed to be the only) DMA engine in the system. This
function is now unused as protocols handle responses and route them to
the right DMA engine.

Change-Id: I2fba913cf2f12321d1a1e38e7ee85bdf26b8a47a
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7162
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-ruby: Add support for multiple DMA engines in MESI_Two_Level

Previously the MESI_Two_Level protocol supported systems with a single
DMA engine and responses from the directory to DMA requests were
routed back to the only DMA engine. This changeset adds support for
multiple DMA engines in the system by routing the response to the DMA
engine that originally sent the request.

Change-Id: I10ceda682ea29746636862ec8ef2a9c4220ca045
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/7161
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

cpu: Make the CPU's TLB parameter a BaseTLB.

This is instead of the architecture specific version.

Change-Id: I906ec16eee1f65f0e9b9c24b401430f9ea01637b
Reviewed-on: https://gem5-review.googlesource.com/7349
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arm, power: Make the python TLB simobjects inherit from BaseTLB.

These were still inheriting from SimObject instead of BaseTLB, making
them incompatible with parameters which expect a BaseTLB.

Change-Id: I05115cc5515f745fdeb85e4dea8eded613647e40
Reviewed-on: https://gem5-review.googlesource.com/7348
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arch,mem: Remove the default value for page size.

This breaks one more architecture dependence outside of the ISAs.

Change-Id: I071f9ed73aef78e1cd1752247c183e30854b2d28
Reviewed-on: https://gem5-review.googlesource.com/6982
Maintainer: Gabe Black <gabeblack@google.com>
Reviewed-by: Alexandru Duțu <alexandru.dutu@amd.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>

arch,mem: Move page table construction into the arch classes.

This gets rid of an awkward NoArchPageTable class, and also gives the
arch a place to inject ISA specific parameters (specifically page size)
without having to have TheISA:: in the generic version of these types.

Change-Id: I1412f303460d5c43dafdb9b3cd07af81c908a441
Reviewed-on: https://gem5-review.googlesource.com/6981
Reviewed-by: Alexandru Duțu <alexandru.dutu@amd.com>
Maintainer: Gabe Black <gabeblack@google.com>

configs: Fill in the cpu.isa field in etrace_replay.py since no default are provided now

Change-Id: I5f337b9969820bd74ed67e576e2d1a8e4666ecdb
Reviewed-on: https://gem5-review.googlesource.com/7021
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

style: change C/C++ source permissions to noexec

Several files in the repository were tracked with execute permissions
even though the files are just normal C/C++ files (and the one .isa).

Change-Id: I976b096acab4a1fc74c5699ef1f9b222c1e635c2
Reviewed-on: https://gem5-review.googlesource.com/7241
Reviewed-by: Gabe Black <gabeblack@google.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arch-riscv: Make use of ImmOp's polymorphism

This patch makes use of ImmOp's polymorphism to remove unnecessary
casting from the implementations of arithmetic instructions with
immediate operands and to remove the CUIOp format by combining it with
the CIOp format (compressed arithmetic instructions with immediate
operands). Interestingly, RISC-V specifies that instructions with
unsigned immediate operands still need to sign-extend the immediates
from 12 (or 20) bits to 64 bits, so that is left alone.

Change-Id: If20d70c1e90f379b9ed8a4155b2b9222b6defe16
Reviewed-on: https://gem5-review.googlesource.com/6401
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Tuan Ta <qtt2@cornell.edu>
Maintainer: Alec Roelke <ar4jc@virginia.edu>

alpha,arm,mips,power,riscv,sparc,x86,cpu: Get rid of ISA_HAS_DELAY_SLOT.

This constant is, first, a #define, and second only used in one place.

In that one place, it appears that the code it guards is no longer
necessary in general. It was originally written to avoid refetching a
block of data that you're still in, even if you've moved slightly
farther in it because you're skipping the next instruction due to an
annulled branch delay slot. In reality however, in SPARC, the one ISA
I'm aware of which has this sort of branching behavior, the PC state
object will correctly determine that no branch is happening in these
cases. Code lower down in the loop will then recompute where fetching
should continue based on the next PC, automatically skipping the
annulled branch slot without misinterpretting the gap as a branch.

This change therefore also removes this block of code.

Change-Id: I820ebc9df10aeb4fcb69c12f6a784e9ec616743c
Reviewed-on: https://gem5-review.googlesource.com/6821
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arch-riscv,sim: Support clone syscall in RISC-V

(1) This patch sets a correct order of clone syscall's arguments for
RISC-V. Linux kernel 4.15 uses CLONE_BACKWARDS flag by default for
RISC-V. The flag in the Linux kernel defines the list of clone syscall's
arguments in the following order:

  clone_flags   (flags)
  newsp         (newStack)
  parent_tidptr (ptidPtr)
  tls           (tlsPtr)
  child_tidptr  (ctidPtr)

Code reference:
  https://github.com/riscv/riscv-linux/blob/master/kernel/fork.c
  https://github.com/riscv/riscv-linux/blob/master/arch/riscv/Kconfig

(2) This patch copies a parent thread's register values to its child
thread in clone syscall.

Change-Id: I2eb1c8e80990861080ce7153503ed784fb2c7bdf
Reviewed-on: https://gem5-review.googlesource.com/6904
Maintainer: Brandon Potter <Brandon.Potter@amd.com>
Reviewed-by: Alec Roelke <ar4jc@virginia.edu>

mem-cache: Prune unnecessary writebacks in exclusive caches

Exclusive caches use the tempBlock to fill for responses from a
downstream cache. The reason for this is that they only pass the block
to the cache above without keeping a copy. When all requests are
serviced the block is immediately invalidated unless it is dirty, in
which case it has to be written back to the memory below.

To avoid unnecessary writebacks, this changeset forces mostly
exclusive caches to issuse requests that can only fetch clean data
when possible.

Reported-by: Quereshi Muhammad Avais <avais@kaist.ac.kr>
Change-Id: I01b377563f5aa3e12d22f425a04db7c023071849
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/5061
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

util: Add the missing wakecpu m5op in X86.

Change-Id: I74876a4638ad37308ecdb0ef68513a968fac8787
Reviewed-on: https://gem5-review.googlesource.com/6501
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>

util: resolve m5op name mismatching in m5op headers.

Two m5op, load_symbol and dist_toggle_sync are defined with
different name in C and asm version headers 'm5ops.h'
The m5ops are named to m5_load_symbol() and m5_dist_toggle_sync().

Change-Id: I9630d74f3fb95bc3dc5fa082778d8f6eaa49b3cb
Reviewed-on: https://gem5-review.googlesource.com/6481
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

cpu: Use the NotAnInst flag to avoid passing an inst to fetch faults.

When a fault happens in fetch in O3, a dummy inst is created to carry
the fault through the pipeline to commit, but conceptually there isn't
actually any instruction since we failed to fetch one.

This change marks the dummy instruction as NotAnInst, and when any
such instruction gets to commit, the fault object associated with it
is invoked and passed a null static inst pointer instead of a pointer
to the dummy inst.

Change-Id: I18d993083406deb625402e06af4ba0d4772ca5a3
Reviewed-on: https://gem5-review.googlesource.com/7124
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>

cpu: Add a NotAnInst flag to the BaseDynInst class.

This flag means that the instruction isn't an actual instruction, it's
just a placeholder to carry a fault down a pipeline, for instance.

Change-Id: I1cc12b068662dbd3d3b089c9941a07b6e88b57e3
Reviewed-on: https://gem5-review.googlesource.com/7123
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>

cpu, power: Get rid of the remnants of the EA computation insts.

Get rid of some remnants of a system which was intended to separate
address computation into its own instruction object.

Change-Id: I23f9ffd70fcb89a8ea5bbb934507fb00da9a0b7f
Reviewed-on: https://gem5-review.googlesource.com/7122
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>

arm: Make translateFunctional override the base implementation.

Now that translateFunctional is a virtual function, having an extra
parameter with a default value makes the compiler fall through to the
base implementation instead of overriding it. This change removes the
default value for the extra parameter, and adds a small wrapper with
the correct signature which overrides the base implementation and calls
the full version with the previously default value for the extra
parameter. To callers this will look like the same thing, but the
the right function will get called.

This was what was already being done for transateAtomic and
translateTiming.

Change-Id: I0b71adf34fd6f326005edbb8eaac93275b437c55
Reviewed-on: https://gem5-review.googlesource.com/7121
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>

gpu-compute: call createThreads() on cpu objs in apu_se.py

commit 8ad26e2688b8736f9290086bb4026cc7500429e9
cpu: Don't override ISA if provided by user

removed the default ISA from the BaseCPU, and instead relies on
createThreads() to initiate a default ISA if none is specified. the apu_se.py
script, however does not call creatThreads() leading to a fatal when
constructing CPU objects. this patch adds the appropriate calls to
createThreads() inside apu_se.py.

Change-Id: I16a5929454c59d68a3f1b7b3858c48a70cb76412
Reviewed-on: https://gem5-review.googlesource.com/7101
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Michael LeBeane <Michael.Lebeane@amd.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>

arch-riscv: Ignore sched_yield syscall in SE mode

Change-Id: I14f22c06eb8fdbe063980b4cd0a49387b9113a97
Reviewed-on: https://gem5-review.googlesource.com/6961
Maintainer: Brandon Potter <Brandon.Potter@amd.com>
Reviewed-by: Alec Roelke <ar4jc@virginia.edu>

sim: Fix a bug in prlimit syscall in SE mode

The old_limit pointer is supposed to be the 4th argument (index 3) of
the prlimit syscall. This patch sets old_limit pointer to the correct
argument.

Change-Id: I97808f7234cd2622cb3eb2f1e0beb7fc8cf492c1
Reviewed-on: https://gem5-review.googlesource.com/6903
Reviewed-by: Alec Roelke <ar4jc@virginia.edu>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>

arch-riscv: Ignore set_robust_list and get_robust_list syscalls

Change-Id: I5a4744e5aed07337144af9f07978b83405b6695b
Reviewed-on: https://gem5-review.googlesource.com/6902
Reviewed-by: Alec Roelke <ar4jc@virginia.edu>
Maintainer: Alec Roelke <ar4jc@virginia.edu>

arch-riscv: Add an implementation of set_tid_address syscall in RISCV

Change-Id: Ida29ea6f6a9c3efe00aaebbfcb6b537fc62f6d06
Reviewed-on: https://gem5-review.googlesource.com/6901
Reviewed-by: Alec Roelke <ar4jc@virginia.edu>
Maintainer: Alec Roelke <ar4jc@virginia.edu>

arch-riscv: Correct syscall argument reg count

As per the discussion in patch #6904 and the Linux 4.15 kernel code for
RISC-V, RISC-V has 7 system call argument registers, x10 through x16 (a0
through a6), with x17 (a7) being used for the system call number.

Change-Id: I0080eca78ffa844b322bb2cff2a51ab2815f3809
Reviewed-on: https://gem5-review.googlesource.com/7081
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Tuan Ta <qtt2@cornell.edu>
Maintainer: Alec Roelke <ar4jc@virginia.edu>

arch-riscv: Remove "magic" syscall number constant

getSyscallArg() in RISC-V has an explicit check to make sure that the
register index is within the bounds of the system call register indices
vector. This patch fixes it so that it uses SyscallArgumentRegs.size()
rather than a "magic" constant that has to be updated every time
SyscallArgumentRegs is changed.

Change-Id: I2935d811177dc8028cb3df64b250ba997bc970d8
Reviewed-on: https://gem5-review.googlesource.com/7061
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Alec Roelke <ar4jc@virginia.edu>