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: 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: Move sector_blks to tags folder

Move sector_blks.hh and sector_blks.cc to the tags folder,
as its usage scope is restricted to the tags, and caches
should not be aware of them.

Change-Id: Ia7a71f51ec251d827872daf108c87da543a0ba57
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/13417
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 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: Forward declare ReplaceableEntry

Forward declare ReplaceableEntry where in classes where pointers
to it are used.

Change-Id: I49c08d36442a563d7a6b4c9bcd7eba3591d29b60
Reviewed-on: https://gem5-review.googlesource.com/11096
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
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>