arch: Fix all override related warnings.

Clang has started(?) reporting override related warnings, something gcc
apparently did before, but was disabled in the SConstruct. Rather than
disable the warnings in for clang as well, this change fixes the
warnings. A future change will re-enable the warnings for gcc.

Change-Id: I3cc79e45749b2ae0f9bebb1acadc56a3d3a942da
Reviewed-on: https://gem5-review.googlesource.com/9343
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Gabe Black <gabeblack@google.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>

arm: Add support for the mcr dc{ic,i,c}mvac, dccmvau instructions

This patch adds support for the ARMv7 cache maintenance
intructions:
* mcr dccmvac cleans a VA to the PoC
* mcr dcimvac invalidates a VA to the PoC
* mcr dccimvac cleans and invalidates a VA to the PoC
* mcr dccmvau cleans a VA to the PoU

Change-Id: I6511f203039ca145cc9128ddf61d09d6d7e40c10
Reviewed-by: Stephan Diestelhorst <stephan.diestelhorst@arm.com>
Reviewed-by: Anouk Van Laer <anouk.vanlaer@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/5059
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

alpha,arm,mips,power,riscv,sparc,x86: Merge exec decl templates.

In the ISA instruction definitions, some classes were declared with
execute, etc., functions outside of the main template because they
had CPU specific signatures and would need to be duplicated with
each CPU plugged into them. Now that the instructions always just
use an ExecContext, there's no reason for those templates to be
separate. This change folds those templates together.

Change-Id: I13bda247d3d1cc07c0ea06968e48aa5b4aace7fa
Reviewed-on: https://gem5-review.googlesource.com/5401
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Alec Roelke <ar4jc@virginia.edu>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

arm: More UBSan cleanups after additional full-system runs

Some incorrect casting to IntRegIndex, and a few uninitialized members
in the i8254xGBe device.

arm: Fixed undefined behaviours identified by gcc

This patch fixes the runtime errors highlighted by the undefined
behaviour sanitizer. In the end there were two issues. First, when
rotating an immediate, we ended up shifting an uint32_t by 32 in some
cases. This case is fixed by checking for a rotation by 0
positions. Second, the Mrc15 and Mcr15 are operating on an IntReg and
a MiscReg, but we used the type RegRegImmOp and passed a MiscRegIndex
as an IntRegIndex. This issue is resolved by introducing a
MiscRegRegImmOp and RegMiscRegImmOp with the appropriate types.

With these fixes there are no runtime errors identified for the full
ARM regressions.

arch: remove inline specifiers on all inst constrs, all ISAs

With (upcoming) separate compilation, they are useless. Only
link-time optimization could re-inline them, but ideally
feedback-directed optimization would choose to do so only for
profitable (i.e. common) instructions.

arm: Add support for ARMv8 (AArch64 & AArch32)

Note: AArch64 and AArch32 interworking is not supported. If you use an AArch64
kernel you are restricted to AArch64 user-mode binaries. This will be addressed
in a later patch.

Note: Virtualization is only supported in AArch32 mode. This will also be fixed
in a later patch.

Contributors:
Giacomo Gabrielli (TrustZone, LPAE, system-level AArch64, AArch64 NEON, validation)
Thomas Grocutt (AArch32 Virtualization, AArch64 FP, validation)
Mbou Eyole (AArch64 NEON, validation)
Ali Saidi (AArch64 Linux support, code integration, validation)
Edmund Grimley-Evans (AArch64 FP)
William Wang (AArch64 Linux support)
Rene De Jong (AArch64 Linux support, performance opt.)
Matt Horsnell (AArch64 MP, validation)
Matt Evans (device models, code integration, validation)
Chris Adeniyi-Jones (AArch64 syscall-emulation)
Prakash Ramrakhyani (validation)
Dam Sunwoo (validation)
Chander Sudanthi (validation)
Stephan Diestelhorst (validation)
Andreas Hansson (code integration, performance opt.)
Eric Van Hensbergen (performance opt.)
Gabe Black

ARM: Use CPU local lock before sending load to mem system.

This change uses the locked_mem.hh header to handle implementing CLREX. It
simplifies the current implementation greatly.

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.

ARM: Add support for moving predicated false dest operands from sources.

ISA: Simplify various implementations of completeAcc.

Mem: Change the CLREX flag to CLEAR_LL.

CLREX is the name of an ARM instruction, not a name for this generic flag.

MEM: Make CLREX a first class request operation and clear locks in caches when it in received

ARM: Implement CLREX init/complete acc methods

ARM: Add a new RegImmOp base class.

ARM: Add a RegRegImmOp base class.

ARM: Widen the immediate fields in the misc instruction classes.

ARM: Make a base class for instructions that use only an immediate.

ARM: Rename the RevOp base class to something more generic.

ARM: Add a register, immediate, immediate to register base for [su]bfx.

ARM: Add a base class to support usada8.

ARM: Add a base class for the sel instruction.

ARM: Add a base class for extend and add instructions.

ARM: Generalize the saturation instruction bases for use in other instructions.

ARM: Implement base classes for the saturation instructions.

ARM: Add base classes suitable for the REV* instructions.

ARM: Define versions of MSR and MRS outside the decoder.