Before, for historical reasons, the PCI host device was the default
responder on the IO bus, meaning that when there was any type of
transaction which didn't have a device to go to, it would end up
looking like a PCI config transaction. It's very unlikely that this is
what it actually was, and what would happen would be arbitrary and
probably not helpful.
Also, there was no device in place to respond to accesses in x86's IO
port address space. On a real system, these accesses just return junk
and are otherwise legal. On systems where there would be physical bus
wires they would probably return whatever the last data on the bus was.
This would have been helpful when the platform was first being set up
because it would make it obvious when the OS tried to access a device
that wasn't implemented, but there were a few cases where it would
purposefully fiddle with ports with nothing on them. These had one off
backing devices in the config which would handle the accesses
harmlessly, but if the OS changed and tried to access other ports, the
configs would need to be updated.
Now, the PCI host is just another device on the bus. It claims all of
the PCI config space addresses, so any config access, even ones which
don't go with a device, will go to it, and it can respond with all 1s
like it's supposed to.
In it's place, the default responder is now a bus. On that bus is
a device which responds to the entire IO port address range with 0s.
The default on *that* bus is a device which will mark any accesses
as bad.
With this setup, accesses which don't go to a device, including a
device on the IO port address space, will go to the IO bus's default
port. There, if the access was an IO access, it will go to the device
which replies successfully with all 0s. If not, it's marked as an
error.
The device which backs the entire IO address space doesn't conflict
with the actual IO devices, since the access will only go towards it
if it's otherwise unclaimed, and the devices on the default bus don't
participate in routing on the higher level IO bus.
Change-Id: Ie02ad7165dfad3ee6f4a762e2f01f7f1b8225168
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35515
Reviewed-by: Matthew Poremba <matthew.poremba@amd.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Global stats are currently exposed using the legacy stat system (i.e.,
without a parent group). This change moves global stats from
stat_control.cc to a group that gets exported from the Root object.
The implementation adds the Root::Stats class which has a single
global instance. This instance is exposed to the rest of the simulator
using the global rootStats symbol. The intention is that objects that
need global statistics in formulas access them through the rootStats
object.
The global names simSeconds, simTicks, simFreq, and hostSeconds are
now references to their respective members in the rootStats object.
Change-Id: I267b5244a0bcca93dd2dcf03388e7085bdd79c9e
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35616
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Ruby prefetcher's non-unit filter is a circular queue, so use the class
created for this functionality.
This changes the behavior, since previously iterating through the
filter was completely arbitrary, and now it iterates from the
beginning of the queue to the end when accessing and updating
the filter's contents.
Change-Id: I3148efcbef00da0c8f6cf2dee7fb86f6c2ddb27d
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24533
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Ruby prefetcher's unit filter is a circular queue, so use the class
created for this functionality.
This changes the behavior, since previously iterating through the
filter was completely arbitrary, and now it iterates from the
beginning of the queue to the end when accessing and updating
the filter's contents.
Change-Id: I834be88a33580d5857c38e9bae8b289c5a6250b9
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24532
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
These regular expressions search code snippets to find places where
operands are used. Rather than build them explicitly at the end of
processing the operands{{}} construct, wait until they're first going to
be used. That way, we'll be able to define operands in as many places as
we want, as long as we've done all we're going to do before the first
instructions are defined.
This will pave the way to defining operands in regular python in let
blocks, and then possibly outside of the parser altogether, perhaps into
scons where having lots of output files for individual instructions will
be easier to manage. For now, this just lets you define multiple
operands blocks which is not all that exciting on its own :)
Change-Id: I1179092316c1c0ac2613810bfd236a32235502fb
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35237
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Richard Cooper <richard.cooper@arm.com>
Reviewed-by: Steve Reinhardt <stever@gmail.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Messages may be enqueued and be ready in the same cycle.
Using this feature may introduce nondeterminism in the protocol and
should be used in specific cases. A case study is to avoid needing an
additional cycle for internal protocol triggers (e.g. the All_Acks
event in src/mem/ruby/protocol/MOESI_CMP_directory-L2cache.sm).
To mitigate modeling mistakes, the 'allow_zero_latency' parameter must
be set for a MessageBuffer where this behavior is acceptable.
This changes also updates the Consumer to schedule events according to
this new behavior. The original implementation would not schedule a new
wakeup event if the wakeup for the Consumer had already been executed
in that cycle.
Additional authors:
- Tuan Ta <tuan.ta2@arm.com>
Change-Id: Ib194e7b4b4ee4b06da1baea17c0eb743f650dfdd
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/31255
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.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>
The TaggedEntry class inherits from the ReplaceableEntry
class. Its purpose is to define a replaceable entry with
tagging attributes.
It has been created as a separate class because both the
replacement policies and the AbstractCacheEntry use
ReplaceableEntry, and do not need the tagging information
to perform their operations.
Change-Id: I24e87c865fc21c79dea7e488507a8cafc5223b39
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35698
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The stat system currently assumes that the decision to merge groups is
done at construction time. This makes it hard to implement global
statistics that live in a single global group.
This change adds some error checking to mergeStatGroup and marks it as
a public method.
Change-Id: I6a42f48545c5ccfcd0672bae66a5bc86bb042f13
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35615
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This includes the filterDoubles function which adds code to combine 32
bit values into doubles or 64 bit values for floating point, and the
splitOutImm function which detects if the code that implements an
instruction has a register and immediate variant, and generates code for
each.
Change-Id: I5524b9acd6e610b51fd91fe70276c34c23be9f85
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35235
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Encapsulate this variable to facilitate polymorphism.
- tickInserted was renamed to _tickInserted and was privatized.
- The insertion tick should always be set to the current tick,
and only on insertion; thus, its setter is not public and
does not take arguments.
- An additional function was created to get the age since of
the block relative to its insertion tick.
- There is no current need for a getter.
Change-Id: I81d4009abec5e9633e10f1e851e3a524553c98a4
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/34958
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Encapsulate this variable to facilitate polymorphism.
- refCount was renamed to _refCount and was privatized.
- The reference count should only be reset at invalidation;
thus, its setter is not public.
- An additional function was created to increment the number
of references by 1.
Change-Id: Ibc8799a8dcb7c53c651de3eb1c9b86118a297b9d
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/34957
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Make the tag variable private, so that every access to it must pass
through a getter and a setter. This protects it from being incorrectly
updated when there is no direct match between a tag and a data entry,
as is the case of sector, compressed, decoupled, and many other table
layouts.
As a side effect, a block matching function has been created, which
also depends directly on the mapping between tag and data entries.
Change-Id: I848a154404feb5cbcea8d0fd2509bf49e1d73bd0
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/34955
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
We saw some strange behavior when building scons without an interactive
TTY. This seems be caused by the control signal set from
curses.initscr() and endwin(). To avoid issues, we should avoid those
operation when running in non interactive situation.
Change-Id: I9cf8e48a786d47d567ba193f0b069f638e8db647
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35595
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Rather than just leaving some macros undefined if none of the scenarios
we checked for match, we should report an error so it's clear what
happened. Otherwise the places the macros are used will just not compile
properly, or worse will silently not work correctly.
Change-Id: Ie010d6b6d1b6a1496a45d9ebc0d75d1c804df12f
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35275
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The is a bug in the GPUCoalescer which occurs in the following
situation:
1) An instruction crosses a page boundary causing multiple TLB requests
to be sent.
2) The TLB responses arrive at different times, causing the vector
memory requests to be sent at different times.
3) The first vector memory request completes before the second vector
memory request arrives at the coalescer.
This caused the coalescer to consider the instruction sequence number
done and return its token. Then the second request would arrive and
complete sending back another token. Eventually this increases the token
count beyond the maximum tripping an assert.
This change keeps track of the number of per-lane requests which are
expected to be sent in the vector memory request by looking at the exec
mask of the instruction. The token is not returned until the expected
number of per-lane requests have been coalesced. This fixes "#7" in the
list of issues in JIRA-300. There are also style fixes for local
variables in code nearby the changes in this CL.
Change-Id: I152fd9397920ad82ba6079112908387e71ff3cce
JIRA: https://gem5.atlassian.net/browse/GEM5-300
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35176
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Reviewed-by: Kyle Roarty <kyleroarty1716@gmail.com>
Maintainer: Matt Sinclair <mattdsinclair@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
