mem-cache: Fix set and way of sub-entries

Set and way of sub-entries were not being set previously.
They must be set after the sub-blocks have been assigned
to the main block.

Change-Id: I7b6921b8437b29c472d691cd78cf20f2bb6c7e07
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/19669
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

mem-cache: Add block size to findVictim

Add block size to findVictim. For standard caches it
will not be used. Compressed caches, however, need to
know the size of the compressed block to decide whether
a block is co-allocatable or not.

Change-Id: Id07f79763687b29f75d707c080fa9bd978a408aa
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/11198
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Mohammad Seyedzadeh <sm.seyedzade@gmail.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>

mem-cache: Stub compression framework

Create a stub of a compression framework where we can have
multiple data blocks per tag entry. Only consecutive blocks
can share a tag as of now.

For each tag entry there can be multiple data blocks. We have
the same number of tags a conventional cache would have, but
we instantiate the maximum number of data blocks (according to
the compression ratio) per tag, to virtually implement
compression without increasing the complexity of the simulator.

Change-Id: I549940c7afb2f744ab293ff8bb283967e7551a11
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/10763
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>

mem-cache: Revert "mem-cache: Remove Packet dependency in Tags"

Reverting patch due to polymorphism limitations.

This reverts commit 86a54d91936b524c0ef0f282959f0fc29bafe7eb.

Change-Id: Ie032dcc5176448c62118c89732b3cc6b8efd5a13
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/17049
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

mem-cache: Add setters to validate and secure block

In order to allow polymorphism of the block these two
functions have been added, and all direct status
assignments to these bits have been substituted.

We also assert that the block has been invalidated
before insertion. Then the block is validated in
the insertion.

Change-Id: Ie7be42408721ad4c2c9dc880f82a62cb594f8668
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/14362
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

mem-cache: Remove Cache dependency from Tags

Tags do not need to be aware of caches.

Change-Id: Ib6a082b74dcd9b2f10852651634b59512732fb2a
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/14296
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

mem-cache: Move access latency calculation to Cache

Access latency was not being calculated properly, as it was
always assuming that for hits reads take as long as writes,
and that parallel accesses would produce the same latency
for read and write misses.

By moving the calculation to the Cache we can use the write/
read information, reduce latency variables duplication and
remove Cache dependency from Tags.

The tag lookup latency is still calculated by the Tags.

Change-Id: I71bc68fb5c3515b372c3bf002d61b6f048a45540
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/13697
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

mem-cache: Rename the tag class init function to tagsInit.

Since the tag classes are subclasses of SimObject, they inherit an
init function which does generic initialization at simulation startup
and which doesn't take any parameters. A new function was added which
does take a parameter, and which is just for doing tag specific
initialization as triggered by the base cache. These two names clashed,
and clang complained that the tag local name was hiding the SimObject
name (which it was).

Change-Id: I399775aceaf8f1a8e2646d434facef22e6d3e7d0
Reviewed-on: https://gem5-review.googlesource.com/c/13875
Reviewed-by: Gabe Black <gabeblack@google.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

mem-cache: Factor ReplaceableEntry out

ReplaceableEntry is referenced by many classes that do
not necessarily need access to the replacement policies.
Therefore, in order to allow better compilation units,
we factor it out to a new file.

Change-Id: I0823567bf1ca336ffcdf783682ef473e8878d7fd
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/13418
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

mem-cache: Virtualize block print

Encapsulate and virtualize block print, so that relevant
information can be easily printed anywhere.

Change-Id: I91109c29c126755183a0fd2b4446f5335e64076b
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/13415
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

mem-cache: Split Tags for indexing policies

Split indexing functionality from tags, so that code duplication
is reduced when adding new classes that use different indexing
policies, such as set associative, skewed associative or other
hash-based policies.

An indexing policy defines the mapping between an address' set
and its physical location. For example, a conventional set assoc
cache maps an address to all ways in a set using an immutable
function, that is, a set x is always mapped to set x. However,
skewed assoc caches map an address to a different set for each way,
using a skewing function.

FALRU has been left unmodified as it is a specialization with its
own complexity.

Change-Id: I0838b41663f21eba0aeab7aeb7839e3703ca3324
Reviewed-on: https://gem5-review.googlesource.com/c/8885
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-cache: Use set and way for ReplaceableEntry

Replaceable entries belong to table-like structures, and therefore
they should be indexable by combining a row and a column. These,
using conventional cache nomenclature translate to sets and ways.

Make these entries aware of their sets and ways. The idea is to
make indexing policies usable by other table-like structures. In
order to do so we move sets and ways to ReplaceableEntry, which
will be the common base among table entries.

Change-Id: If0e3dacf9ea2f523af9cface067469ccecf82648
Reviewed-on: https://gem5-review.googlesource.com/c/12764
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-cache: Use possible locations to find block

Use possible locations to find block to make it placement policy
independent.

Change-Id: I4c9d9e1e1ff91ce12e85ca1970f927d8f4f5a93b
Reviewed-on: https://gem5-review.googlesource.com/c/8884
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-cache: Create tags initialization function

Having the blocks initialized in the constructor makes it harder
to apply inheritance in the tags classes. This patch decouples
the block initialization functionality from the constructor by
using an init() function. It also sets the parent cache.

Change-Id: I0da7fdaae492b1177c7cc3bda8639f79921fbbeb
Reviewed-on: https://gem5-review.googlesource.com/c/11509
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-cache: Remove Packet dependency in Tags

Decouple Tags from Packets, only extracting the necessary
functionality for block insertion. As a side effect, create
a new function to update common insertion statistics.

Change-Id: I5c58f7c17de3255beee531f72a3fd25a30d74c90
Reviewed-on: https://gem5-review.googlesource.com/c/11098
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

mem-cache: Remove unnecessary cast in SectorTags::findVictim

Removes an uneccessary cast that also caused an unused variable
error (due to -Werror) when compiling .fast targets.

Change-Id: Ic043f462925e7eaa7b691455f1d9e08a1c101980
Reviewed-on: https://gem5-review.googlesource.com/11119
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

mem-cache: Make packet const in insertBlock

The packet should not be modified within insertBlock.

Change-Id: If7d2b01fe131f9923194efd155c9e85eeab24d5a
Reviewed-on: https://gem5-review.googlesource.com/10811
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

mem-cache: Create Sector Cache

Implementation of Sector Caches, i.e., a cache with multiple
sequential data entries per tag entry for Set Associtive
placement policies.

Change-Id: I8e1e9448fa44ba308ccb16cd5bcc5fd36c988feb
Reviewed-on: https://gem5-review.googlesource.com/9741
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>