While there is a AArch32 class for instructions accessing implementation
defined registers, we are lacking for the AArch64 counterpart.
we were relying on FailUnimplemented, which is untrappable at EL2 (except
for HCR_EL2.TGE) since it is just raising Undefined Instruction.
Change-Id: I923cb914658ca958af031612cf005159707b0b4f
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/13779
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
This patch refactors AArch64 MSR/MRS trapping, by moving the trapping
helpers in arch/arm/utility and in the isa code into a MiscRegOp64
class.
This class is the Base class for a generic AArch64 instruction which is
making use of system registers (MiscReg), like MSR,MRS,SYS. The common
denominator or those instruction is the chance that the system register
access is trapped to an upper Exception level. MiscRegOp64 is providing
that feature.
What do we gain? Other "pseudo" instructions, like access to
implementation defined registers can inherit from this class to make use
of the trapping functionalities even if there is no data movement
between GPRs and system register.
Change-Id: I0924354db100de04f1079a1ab43d4fd32039e08d
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/13778
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
According to the arm arm, CPTR_EL3.TCPAC traps EL2 accesses to the
CPTR_EL2 or HCPTR, and EL2 and EL1 accesses to the CPACR_EL1 or CPACR,
are trapped to EL3, unless they are trapped by CPTR_EL2.TCPAC.
Change-Id: I637be35b29db39f044dda0c6cc4fe986c9620371
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/13775
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
The option allows to set SimObject params from the CLI.
The existing config scripts have a large number of options that simply set
a single SimObject parameter, and many still are not exposed.
This commit allows users to pass arbitrary parameters from the command
line to prevent the need for this kind of trivial option.
Change-Id: Ic4bd36948aca4998d2eaf6369c85d3668efa3944
Reviewed-on: https://gem5-review.googlesource.com/c/12985
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Add a utility method, SimObject.apply_config that can be used to
implement SimObject param overrides from the command line. This
function provides safe and convenient semantics for CLI assignment:
* The override expression is evaluated in a restricted environment. The
only global variables are the child objects and params from the root
object.
* Only params can be overridden. For example, calling methods or setting
attributes on SimObjects isn't possible.
* Vectors use non-standard list semantics which enable something similar
to glob expansion on the shell. For example, setting:
root.system.cpu[0:2].numThreads = 2
will override numThreads for cpu 0 and 1 and:
root.system.cpus[0,2].numThreads = 2
sets it for cpus 0 and 2.
The intention is that the helper method is called to override default
values before calling m5.instantiate.
Change-Id: I73f99da21d6d8ce1ff2ec8db2bb34338456f6799
Reviewed-on: https://gem5-review.googlesource.com/c/12984
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
This fixes:
- unallocated hints that have since been allocated
- unallocated and unimplemented hint instructions being treated as
Unknown instead of the correct NOP
- missing encoding for DBG on A32
Unallocated and unimplemented hints give a warning if executed.
The most important fix was for the CSDB Spectre mitigation
instruction, which was added recently and previously unallocated and
treated as Unknown.
The Linux kernel v4.18 ARMv7 uses CSDB it and boot would
fail with "undefined instruction" since Linux commit
1d4238c56f9816ce0f9c8dbe42d7f2ad81cb6613
Change-Id: I283da3f08a9af4148edc6fb3ca2930cbb97126b8
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/13475
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Enable the cache to detect contiguous writes and hold on to the MSHR
long enough to allow the entire line to be written. If the whole line
is written, the MSHR will be sent out as an invalidation requests, as
it is part of a whole-line write, i.e. no-fetch-on-write.
The cache is also able to switch to a write-no-allocate policy on the
actual completion of the writes, and instead use the tempBlock and
turn the write operation into a writeback.
These policies are all well-known, and described in works such as
Jouppi, Cache Write Policies and Performance, vol 21, no 2, ACM, 1993.
Change-Id: I19792f2970b3c6798c9b2b493acdd156897284ae
Reviewed-on: https://gem5-review.googlesource.com/c/12907
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
An MSHR is allocated and the computed latency determines when the MSHR
will be ready and can be serviced by the cache. This patch adds a
function that allows changing the time that an MSHR is ready and
adjusts the queue such that other MSHRs can be serviced first if they
are ready.
Change-Id: Ie908191fcb3c2d84d4c6f855c8b1e41ca5881bff
Reviewed-on: https://gem5-review.googlesource.com/c/12906
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
This patch changes how we deal with whole-line writes their
responses. With these changes, we use the MSHR tracking to determine
if a whole-line is written, and on a fill we simply handle the
invalidation response, with the actual writes taking place as part of
satisfying the CPU-side hit.
Change-Id: I9a18e41a95db3c20b97f8bca7d95ff33d35a578b
Reviewed-on: https://gem5-review.googlesource.com/c/12905
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
This patch adds support for determining whether the targets in an MSHR
are 1) only writes and 2) whether these writes are effectively a
whole-line write. This patch adds the necessary functions in the MSHR
to allow for write coalescing in the cache.
Change-Id: I2c9a9a83d2d9b506a491ba5b0b9ac1054bdb31b4
Reviewed-on: https://gem5-review.googlesource.com/c/12904
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
The NULL ISA doesn't really have an endianness. Now that the packet
accessors which consumed that endianness are gone, we can get rid of
that setting as well.
Change-Id: I8dd4c7b8236b07df4458fea377865f30141121d4
Reviewed-on: https://gem5-review.googlesource.com/c/13466
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
The accessors are used for debugging output. If we're using an ISA
where there's an endianness, we use that explicitly, falling back to a
binary dump if the size isn't supported. If not, then we just dump the
data without interpretation regardless of size.
Change-Id: Ib050c4c876ee41f17cfd14ad657150bf6ab1de39
Reviewed-on: https://gem5-review.googlesource.com/c/13464
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>
The gpu ISA doesn't have a well defined endianness, but it really
should. It seems that the GPU is only used with x86, and in that
context it would be little endian.
Change-Id: I1620906564a77f44553fbf6d788866e017b6054b
Reviewed-on: https://gem5-review.googlesource.com/c/13463
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
Generally speaking, the endianness of the data devices provide or
accept is dependent on the device and not the ISA the system
executes. This change makes the devices in dev pick an endianness
rather than using the guest's.
For the ISA bus and the UART, accesses are byte sized and so endianness
doesn't matter. The ISA and PCI busses and the devices which use them
are defined to be little endian.
Change-Id: Ib0aa70f192e1d6f3b886d9f3ad41ae03bddb583f
Reviewed-on: https://gem5-review.googlesource.com/c/13462
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
The only part of these devices which are incompatible with other ISAs,
with the possible exception of endianness transformation, is that
the dist_iface implementation refers to ThreadContext methods and
that class is heavily tied to the guest ISA. Only those few lines are
excluded in a NULL_ISA build.
Change-Id: Ic6d643fdbb792d0a996a37d75e027c5ce0ecd460
Reviewed-on: https://gem5-review.googlesource.com/c/13469
Reviewed-by: Gabor Dozsa <gabor.dozsa@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
There are some minor ISA dependencies in the PCI device models,
specifically that they use the set<> accessors on the packet objects.
This actually compiles fine because the NULL ISA claims to be little
endian, but really these accessors should be changed to use little
endian all the time since that's what PCI is defined to use, not
the guest endianness.
The other types of accessors, specifically the ones that default to
what the guest wants, should be excluded when building NULL_ISA, and,
pending other dependencies, the NULL_ISA should no longer have an
endianness associated with it.
Change-Id: I0739122dbf67d109e7959553a1eff0239b090ca4
Reviewed-on: https://gem5-review.googlesource.com/c/13468
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
GIC architecture specification says that writing EOIR with
a not active irq it is an unpredictable behavior.
So, just warn when it happens for a PPI case, like it is
already done in SPI case.
Change-Id: Icb1b8f5690d5e87b15c3b0fe2ca0d37fdd4085ee
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/13556
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
These warnings were removed when the functionality they warned about
was implemented, but there were some leftovers like unnecessary
includes and some helper functions which hid gem5 specific headers
from the ext directory.
Change-Id: Ic886ac0f1264687524e3a7b7eaab8836f318a5a2
Reviewed-on: https://gem5-review.googlesource.com/c/13398
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
The scheduler is an internal detail and shouldn't be exposed to the
headers in ext. It would transitively include more headers which are
not in ext, making it not self contained.
Change-Id: I8384cde9d19363953ffd0c91e7d8d27f8f79a570
Reviewed-on: https://gem5-review.googlesource.com/c/13336
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
This is to avoid having to expose the scheduler (which tracks the
current process) to header files which should be independent of gem5
and the underlying implementation.
Change-Id: I1b0810ab66c3ce52b5b94236d7df86da66a62472
Reviewed-on: https://gem5-review.googlesource.com/c/13335
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
STL containers may need to be constructed before they're used. Don't
count on being able to insert into them during a static initializer.
Change-Id: Icb05d5084a470e1ebd976ae6e1954b1a78aabd6a
Reviewed-on: https://gem5-review.googlesource.com/c/13329
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
