This is the final step in the transformation process.
We limit the use of the "managing Exception Level" for
a translation in favour of the more standard "Translation
Regime"
This greatly simplifies our code, especially with VHE
where the managing el (EL2) could handle to different
translation regimes (EL and EL2&0).
We can therefore remove the isHost flag wherever it got
used. That case is automatically handled by the proper
regime value (EL2&0)
Change-Id: Iafd1d2ce4757cfa6598656759694e5e7b05267ad
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
We should stop using isHyp.. An hypervisor entry is flagged
already by the EL of the entry (el == EL2)
Change-Id: I20c3d06fa2b04e0b938a380ca917d0b596eddcf2
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Most of the invalidation methods in the TLB class are
doing the same thing: looping over all entries, checking if
the entry matches a certain criteria, and invalidating it
in case it does.
The only specific bit is the matching function, therefore
we add a virtual TLBIOp::match method which allows us
to specialize different TLBIs and to provide a single
flush method in the TLB class
Change-Id: I0672ff958742ac7ebff8d30218f75127343f1a58
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/61753
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Richard Cooper <richard.cooper@arm.com>
The method is no longer calling the lookup method which
had been complicated by the introduction of partial translations.
(which is now called during address translation only)
The lookup method is iterating over all TLB Entries until a non
partial translation is found. Using lookup in flushMva makes it
O(n^2). With this patch we iterate over the TLB entries only once
(making flushMva O(n))
Change-Id: I8f2ae56192812cee231baf6943068abea4d7ef91
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/61752
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Richard Cooper <richard.cooper@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
We shouldn't print all TLB stats regardless of their value
For example there is no need to print the number of
read/write hits/misses/accesses in a instruction only TLB as
it will always inevitably be zero
With this patch we are flagging them as nozero, in order
to suppress their printing in the final stats file.
We are still printing them (regardless of their value) in the
unified TLB type
Change-Id: I54e57d856ceb451f6bacdd175a61768d030862aa
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/51667
Tested-by: kokoro <noreply+kokoro@google.com>
At the moment the ITLBI and DTLBI operations where implicitly
implemented as generic TLBIs
e.g:
* DTLBIASID, ITLBIASID = TLBIASID
This was possible as a single TLB was either an instruction TLB
or a data TLB and no generic/shared TLB option was available.
In other words, an ITLBI Op to an ITB was invalidating all entries
as we were sure the ITB was not containing data entries.
With shared TLBs, this doesn't hold true and we need to explicitly
implement I/DTLBIs
JIRA: https://gem5.atlassian.net/browse/GEM5-790
Change-Id: I39a4add7674f6008dacaedfd1fd90560d264048e
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/48148
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This patch is moving most of the TLB code to the MMU.
In this way the TLB stops being the main translating agent and becomes a
simple "passive" translation cache.
All the logic behind virtual memory translation, like
* Checking permission/alignment
* Issuing page table walks
* etc
Is now embedded in the MMU model. This will allow us to stack multiple
TLBs and to compose arbitrary hierarchies as their sole purpose now is
to cache translations
JIRA: https://gem5.atlassian.net/browse/GEM5-790
Change-Id: I687c639a56263d5e3bb6633dd8c9666c85edba3a
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/48141
Tested-by: kokoro <noreply+kokoro@google.com>
Apply the gem5 namespace to the codebase.
Some anonymous namespaces could theoretically be removed,
but since this change's main goal was to keep conflicts
at a minimum, it was decided not to modify much the
general shape of the files.
A few missing comments of the form "// namespace X" that
occurred before the newly added "} // namespace gem5"
have been added for consistency.
std out should not be included in the gem5 namespace, so
they weren't.
ProtoMessage has not been included in the gem5 namespace,
since I'm not familiar with how proto works.
Regarding the SystemC files, although they belong to gem5,
they actually perform integration between gem5 and SystemC;
therefore, it deserved its own separate namespace.
Files that are automatically generated have been included
in the gem5 namespace.
The .isa files currently are limited to a single namespace.
This limitation should be later removed to make it easier
to accomodate a better API.
Regarding the files in util, gem5:: was prepended where
suitable. Notice that this patch was tested as much as
possible given that most of these were already not
previously compiling.
Change-Id: Ia53d404ec79c46edaa98f654e23bc3b0e179fe2d
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/46323
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Matthew Poremba <matthew.poremba@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The class was adding some complexity on the python/C++ front:
The Stage2MMU was a child of the ArmTLB and parent of the Stage2TLB
However, it's C++ implementation was solely issuing stage2 table walks
and was not handling the stage2 translation logic in general.
We are removing the class and moving its implemetation structures
within the table walker.
This simplifies the code: the nested Stage2Translation class has
been renamed to Stage2Walk to make its purpose more explicit
The MMU has now a centralized view of all TLBs and Table Walkers in the
system
Change-Id: I8a13a5b793abb7e602e9a05a908e7e0ec3c37247
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/45780
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
As part of recent decisions regarding namespace
naming conventions, all namespaces will be changed
to snake case.
::Stats became ::statistics.
"statistics" was chosen over "stats" to avoid generating
conflicts with the already existing variables (there are
way too many "stats" in the codebase), which would make
this patch even more disturbing for the users.
Change-Id: If877b12d7dac356f86e3b3d941bf7558a4fd8719
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/45421
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
As part of recent decisions regarding namespace
naming conventions, all namespaces will be changed
to snake case.
::ProbePoints became ::probing.
"probing" was chosen over "probe_points" because the
namespace contains more than solely probe points; it
contains all classes related to the act of probing.
Change-Id: I44567974a521707593739a2bd5933391803e5b51
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/45412
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Hoa Nguyen <hoanguyen@ucdavis.edu>
While a TLB hit caused by a prefetching operation is visible in terms
of TLB stats update, this is not the case for a TLB miss, which is
invisible to the stats as it is now.
This patch is realigning the behaviour to be more consistent: we will
always update the stats regardless of whether the access caused a
TLB hit/miss
Change-Id: I161e04fc09a0dbba7468a52848aa7710d1476e19
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/37955
Reviewed-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-by: Richard Cooper <richard.cooper@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Several TLB invalidation instructions rely on VMID matching. This is
only applicable is EL2 is implemented and enabled in the current state.
The code prior to this patch was making the now invalid assumption that
we shouldn't consider the VMID if we are doing a secure lookup. This is
because in the past if we were in secure mode we were sure EL2 was not
enabled.
This is fishy and not valid anymore anyway after the introduction of
secure EL2.
Change-Id: I9a1368f8ed19279ed3c4b2da9fcdf0db799bc514
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35242
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The TLBIALL op in gem5 was designed after the AArch32 TLBIALL instruction.
and was reused by the TLBI ALLEL1, ALLE2, ALLE3 logic.
This is not correct for the following reasons:
- TLBI ALLEx invalidates regardless of the VMID
- TLBI ALLEx (AArch64) is "target regime" oriented, whereas TLBIALL
(AArch32) is "current regime" oriented
TLBIALL has a different behaviour depending on the current exception
level: if issued at EL1 it will invalidate stage1 translations only; if
at EL2, it will invalidate stage2 translations as well.
TLBI ALLEx is more standard; every TLBI ALLE1 will invalidate stage1 and
stage2 translations. This is because the instruction is not executable
from the guest (EL1)
So for TLBIALL the condition for stage2 forwarding will be:
if (!isStage2 && isHyp) {
Whereas for TLBI ALLEx will be:
if (!isStage2 && target_el == EL1) {
Change-Id: I282f2cfaecbfc883e173770e5d2578b41055bb7a
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35241
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The create() method on Params structs usually instantiate SimObjects
using a constructor which takes the Params struct as a parameter
somehow. There has been a lot of needless variation in how that was
done, making it annoying to pass Params down to base classes. Some of
the different forms were:
const Params &
Params &
Params *
const Params *
Params const*
This change goes through and fixes up every constructor and every
create() method to use the const Params & form. We use a reference
because the Params struct should never be null. We use const because
neither the create method nor the consuming object should modify the
record of the parameters as they came in from the config. That would
make consuming them not idempotent, and make it impossible to tell what
the actual simulation configuration was since it would change from any
user visible form (config script, config.ini, dot pdf output).
Change-Id: I77453cba52fdcfd5f4eec92dfb0bddb5a9945f31
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35938
Reviewed-by: Gabe Black <gabeblack@google.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This change replaces the __attribute__ syntax with the now standard [[]]
syntax. It also reorganizes compiler.hh so that all special macros have
some explanatory text saying what they do, and each attribute which has a
standard version can use that if available and what version of c++ it's
standard in is put in a comment.
Also, the requirements as far as where you put [[]] style attributes are
a little more strict than the old school __attribute__ style. The use of
the attribute macros was updated to fit these new, more strict
requirements.
Change-Id: Iace44306a534111f1c38b9856dc9e88cd9b49d2a
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35219
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
