The only difference between the TaggedEntry and the newly defined
CacheEntry is the presence of the secure flag in the first case. The
need to tag a cache entry according to the security bit required the
overloading of the matching methods in the TaggedEntry class to take
security into account (See matchTag [1]), and the persistance after
PR #745 of the AssociativeSet class which is basically identical
to its AssociativeCache superclass, only it overrides its virtual
method to match the tag according to the secure bit as well.
The introduction of the KeyType parameter in the previous commit
will smoothe the differences and help unifying the interface.
Rather than overloading and overriding to account for a different
signature, we embody the difference in the KeyType class. A
CacheEntry will match with KeyType = Addr,
whereas a TaggedEntry will use the following lookup type proposed in this
patch:
struct KeyType {
Addr address;
bool secure;
}
This patch is partly reverting the changes in #745 which were
reimplementing TaggedEntry on top of the CacheEntry. Instead
we keep them separate as the plan is to allow different
entry types with templatization rather than polymorphism.
As a final note, I believe a separate commit will have to
change the naming of our entries; the CacheEntry should
probably be renamed into TaggedEntry and the current TaggedEntry
into something that reflect the presence of the security bit
alongside the traditional address tag
[1]: https://github.com/gem5/gem5/blob/stable/\
src/mem/cache/tags/tagged_entry.hh#L81
Change-Id: Ifc104c8d0c1d64509f612d87b80d442e0764f7ca
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
I noticed while using the stable branch that there were a few typos of
the word 'cache' and so I've corrected a few files where I found such
typos.
Change-Id: I7c7f64812039f34fe39d0c45c4f5ce921cba06d0
This change, https://github.com/gem5/gem5/pull/205, mistakenly
allocates write buffer for clflush instruction when there's a
cache miss. However, clflush in gem5 is not a write instruction.
Thus, the cache should allocate miss buffer in this case.
Change-Id: I9c1c9b841159c4420567e9c929e71e4aa27d5c28
Signed-off-by: Hoa Nguyen <hn@hnpl.org>
When a linux kernel changes a page property, it flushes the related cache
lines. The kernel might change the page property before flushing the
cache lines. This results in the clflush might occur in an uncacheable region.
Currently, an uncacheable request must be a read or a write. However,
clflush request is neither of them.
This change aims to allow clflush requests to work on uncacheable regions.
Since there is no straightforward way to check if a packet is from a clflush
instruction, this change permits all Clean Invalidate Requests, which is
the type of request produced by clflush, to work on uncacheable regions.
Change-Id: Ib3ec01d9281d3dfe565a0ced773ed912edb32b8f
Signed-off-by: Hoa Nguyen <hn@hnpl.org>
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 code in the body of a DPRINTF will always be compiled, even if it's
disabled. If TRACING_ON is false, the if around it will short circuit to
false without actually running any code to check the specified
condition, and the body of the if will be elided by the compiler as
unreachable code.
This creates a more consistent environment whether TRACING_ON is on or
not, so that variables which are only used in DPRINTF don't have to be
guarded by their own TRACING_ON #ifs at the call site. It also ensures
that the code inside DPRINTF is always checked to be valid code, even if
the DPRINTF itself will never go off. This helps avoid syntax errors,
etc, which aren't found because of the configuration of the build being
tested with.
Change-Id: Ia95ae229ebcd2fc9828f62e87f037f76b9279819
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/44988
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
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>
Encapsulate this variable to facilitate polymorphism.
- The status enum was renamed to CoherenceBits, since it
lists the coherence bits supported by the CacheBlk.
- status was made protected and renamed to coherence since
it contains the coherence bits.
- Functions to set, clear and get the coherence bits were
created.
- To set a status bit, the block must be validated first.
This guarantees a constant flow and helps catching bugs.
As a side effect, some of the modified files contained long
lines, which had to be split.
Change-Id: I558cc51ac685d30b6bf298c78f86a6e24ff06973
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/34960
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.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>
This addresses the issue described in
64687ee mem-cache: Mark block as dirty after a SWPrefetchEXResp.
Previous patch misses cases when the prefetch response is ReadExResp or
UpgradeResp. Also, marking the block as dirty in serviceMSHRTargets
instead of in handleFill covers cases when the prefetch is coalesced with
other requests.
Change-Id: I2b377fdd240eb0f09e720b6bb284dee6545925ce
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/19688
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This reverts commit bf0a722acd.
Reason for revert: This patch introduces a bug:
The problem here is that the insertion of block A may cause the
eviction of block B, which on the lower level may cause the
eviction of block A. Since A is not marked as present yet, A is
"safely" removed from the snoop filter
However, by reverting it, using atomic and a Tags sub-class that
can generate multiple evictions at once becomes broken when using
Atomic mode and shall be fixed in a future patch.
Change-Id: I5b27e54b54ae5b50255588835c1a2ebf3015f002
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/19088
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This changeset adds support for partial (or masked) loads/stores, i.e.
loads/stores that can disable accesses to individual bytes within the
target address range. In addition, this changeset extends the code to
crack memory accesses across most CPU models (TimingSimpleCPU still
TBD), so that arbitrarily wide memory accesses are supported. These
changes are required for supporting ISAs with wide vectors.
Additional authors:
- Gabor Dozsa <gabor.dozsa@arm.com>
- Tiago Muck <tiago.muck@arm.com>
Change-Id: Ibad33541c258ad72925c0b1d5abc3e5e8bf92d92
Signed-off-by: Giacomo Gabrielli <giacomo.gabrielli@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/13518
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Previously all atomic writebacks concerned a single block,
therefore, when a block was evicted, no other block would be
pending eviction. With sector tags (and compression),
however, a single replacement can generate many evictions.
This can cause problems, since a writeback that evicts a block
may evict blocks in the lower cache. If one of these conflict
with one of the blocks pending eviction in the higher level, the
snoop must inform it to the lower level. Since atomic mode does
not have a writebuffer, this kind of conflict wouldn't be noticed.
Therefore, instead of evicting multiple blocks at once, we
do it one by one.
Change-Id: I2fc2f9eb0f26248ddf91adbe987d158f5a2e592b
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18209
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Previously satisfied clean requests would not snoop in-service
MSHRs. This is a problem when a clean request is also invalidating, in
which case we have to post-invalidate or post-downgrade outstanding
requests. This changes fixes this bug.
Change-Id: I31e42aa94dd3637b2818e00fbaae68c810145eaf
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/17728
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
A cache that forwards a request to the memory below does not fill and
forwards the response with the data to cache above. This change
ensures that the flags of the original response are also preserved.
Change-Id: I244b20b073c31b976358816c5b14bba413b8271f
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/16182
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
A packet queue is typically used to hold on to packets that are
schedules to be sent in the future or when they need to queue behind
younger packets that have been sent out yet. Due to memory order
requirements, some MemObjects need to maintain the order for packet
(mostly responses) that reference the same cache block.
Prior to this patch the ordering requirements where determined when
the packet was scheduled to be sent. This patch moves the parameter to
the constructor.
Change-Id: Ieb4d94e86bc7514f5036b313ec23ea47dd653164
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/15555
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Requests, for which a cache has already committed to respond do not
perform any lookups. Previously in atomic mode the packet would pay
the lookup latency while in timing it wouldn't. This patch aligns
recvAtomic with recvTimingReq and removes the lookup latency from the
the handling of such requests.
Change-Id: I50a0631f8058e5086d94d55af0e1788a60e2883f
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/14175
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Jason Lowe-Power <jason@lowepower.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>
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>
"4976ff5 mem-cache: Refactor the recvAtomic function" introduced a bug
where if an atomic request that fills in using the tempBlock it will
not evict it when it finishes handling the request as it should. This
triggers an assertion. This change fixes this bug.
Change-Id: I73c808a7e15237eddb36b5448ef6728f7bcf7fd9
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/12644
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
While a cache clean operation is pending, all requests to the
corresponding block get deferred. When the response of a cache clean
operation is received, if the block is present and the response is not
invalidating, we can service all deferred targets that didn't require
writable. This change implements this functionality.
Change-Id: Ief47e74d07749a6a9736ab450eb46eefa53464a2
Reviewed-on: https://gem5-review.googlesource.com/11018
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
This patch is changing the underlying type for RequestPtr from Request*
to shared_ptr<Request>. Having memory requests being managed by smart
pointers will simplify the code; it will also prevent memory leakage and
dangling pointers.
Change-Id: I7749af38a11ac8eb4d53d8df1252951e0890fde3
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/10996
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
tempBlock has its member variables manually set in order to allow
it to be used in the block address regeneration function. This is
not necessary, and ti can be simply given the address, so it does
not need to be aware of set and tag. This will simplify
implementation of sector and skewed caches.
Change-Id: Iaffb10c323509722cd5589fe1030b818d43336d6
Reviewed-on: https://gem5-review.googlesource.com/9961
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Cache bypass is necessary for cpu models like the KvmCPU. Previously
the bypass would happen at the cache classes. With this change the
bypassing happens directly at the ports.
Change-Id: I34de9fc63383aee8590643e169501ea6060d2d62
Reviewed-on: https://gem5-review.googlesource.com/10432
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
This patch changes what goes into the BaseCache and what goes into the
Cache, to make it easier to add a NoncoherentCache with as much re-use
as possible. A number of redundant members and definitions are also
removed in the process.
This is a modified version of a changeset put together by Andreas
Hansson <andreas.hansson@arm.com>
Change-Id: Ie9dd73c4ec07732e778e7416b712dad8b4bd5d4b
Reviewed-on: https://gem5-review.googlesource.com/10431
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
