This patch makes some rather trivial simplifications to the bus in
that it changes the use of BusMasterPort and BusSlavePort pointers to
simply use MasterPort and SlavePort (iterators are also updated
accordingly).
This change is a step towards a future patch that introduces a
separation of the interface and the structural port itself.
This patch introduces the PortId type, moves the definition of
INVALID_PORT_ID to the Port class, and also gives every port an id to
reflect the fact that each element in a vector port has an
identifier/index.
Previously the bus and Ruby testers (and potentially other users of
the vector ports) added the id field in their port subclasses, and now
this functionality is always present as it is moved to the base class.
This patch introduces port access methods that separates snoop
request/responses from normal memory request/responses. The
differentiation is made for functional, atomic and timing accesses and
builds on the introduction of master and slave ports.
Before the introduction of this patch, the packets belonging to the
different phases of the protocol (request -> [forwarded snoop request
-> snoop response]* -> response) all use the same port access
functions, even though the snoop packets flow in the opposite
direction to the normal packet. That is, a coherent master sends
normal request and receives responses, but receives snoop requests and
sends snoop responses (vice versa for the slave). These two distinct
phases now use different access functions, as described below.
Starting with the functional access, a master sends a request to a
slave through sendFunctional, and the request packet is turned into a
response before the call returns. In a system without cache coherence,
this is all that is needed from the functional interface. For the
cache-coherent scenario, a slave also sends snoop requests to coherent
masters through sendFunctionalSnoop, with responses returned within
the same packet pointer. This is currently used by the bus and caches,
and the LSQ of the O3 CPU. The send/recvFunctional and
send/recvFunctionalSnoop are moved from the Port super class to the
appropriate subclass.
Atomic accesses follow the same flow as functional accesses, with
request being sent from master to slave through sendAtomic. In the
case of cache-coherent ports, a slave can send snoop requests to a
master through sendAtomicSnoop. Just as for the functional access
methods, the atomic send and receive member functions are moved to the
appropriate subclasses.
The timing access methods are different from the functional and atomic
in that requests and responses are separated in time and
send/recvTiming are used for both directions. Hence, a master uses
sendTiming to send a request to a slave, and a slave uses sendTiming
to send a response back to a master, at a later point in time. Snoop
requests and responses travel in the opposite direction, similar to
what happens in functional and atomic accesses. With the introduction
of this patch, it is possible to determine the direction of packets in
the bus, and no longer necessary to look for both a master and a slave
port with the requested port id.
In contrast to the normal recvFunctional, recvAtomic and recvTiming
that are pure virtual functions, the recvFunctionalSnoop,
recvAtomicSnoop and recvTimingSnoop have a default implementation that
calls panic. This is to allow non-coherent master and slave ports to
not implement these functions.
This patch introduces the notion of a master and slave port in the C++
code, thus bringing the previous classification from the Python
classes into the corresponding simulation objects and memory objects.
The patch enables us to classify behaviours into the two bins and add
assumptions and enfore compliance, also simplifying the two
interfaces. As a starting point, isSnooping is confined to a master
port, and getAddrRanges to slave ports. More of these specilisations
are to come in later patches.
The getPort function is not getMasterPort and getSlavePort, and
returns a port reference rather than a pointer as NULL would never be
a valid return value. The default implementation of these two
functions is placed in MemObject, and calls fatal.
The one drawback with this specific patch is that it requires some
code duplication, e.g. QueuedPort becomes QueuedMasterPort and
QueuedSlavePort, and BusPort becomes BusMasterPort and BusSlavePort
(avoiding multiple inheritance). With the later introduction of the
port interfaces, moving the functionality outside the port itself, a
lot of the duplicated code will disappear again.
This patch unifies the recvFunctional, recvAtomic and recvTiming to
all be based on a similar structure: 1) extract information about the
incoming packet, 2) send it out to the appropriate snoopers, 3)
determine where it is going, and 4) forward it to the right
destination. The naming of variables across the different access
functions is now consistent as well.
Additionally, the patch introduces the member functions releaseBus and
retryWaiting to better distinguish between the two cases when we
should tell a sender to retry. The first case is when the bus goes
from busy to idle, and the second case is when it receives a retry
from a destination that did not immediatelly accept a packet.
As a very minor change, the MMU debug flag is no longer used in the bus.
This patch moves all port creation from the getPort method to be
consistently done in the MemObject's constructor. This is possible
thanks to the Swig interface passing the length of the vector ports.
Previously there was a mix of: 1) creating the ports as members (at
object construction time) and using getPort for the name resolution,
or 2) dynamically creating the ports in the getPort call. This is now
uniform. Furthermore, objects that would not be complete without a
port have these ports as members rather than having pointers to
dynamically allocated ports.
This patch also enables an elaboration-time enumeration of all the
ports in the system which can be used to determine the masterId.
This patch adds a check in the findPort method to ensure that an
invalid port id is never returned. Previously this could happen if no
default port was set, and no address matched the request, in which
case -1 was returned causing a SEGFAULT when using the id to index in
the port array. To clean things up further a symbolic name is added
for the invalid port id.
This patch removes the onRetryList field from the BusPort class and
entirely relies on the retryList which holds all ports that are
waiting to retry. The onRetryList field and the retryList were
previously used with overloaded functionalities and only one is really
needed (there were also checks to assert they held the same
information). After this patch the bus ports will be split into master
and slave ports and this simplifies that transition.
This patch removes the idiosyncratic nature of the default bus port
and makes it yet another port in the list of interfaces. Rather than
having a specific pointer to the default port we merely track the
identifier of this port. This change makes future port diversification
easier and overall cleans up the bus code.
The functional ports are no longer used and this patch cleans up the
legacy that is still present in buses, memories, CPUs etc. Note that
this does not refer to the class FunctionalPort (already removed), but
rather ports with the name (and use) functional.
This patch simplifies the address-range determination mechanism and
also unifies the naming across ports and devices. It further splits
the queries for determining if a port is snooping and what address
ranges it responds to (aiming towards a separation of
cache-maintenance ports and pure memory-mapped ports). Default
behaviours are such that most ports do not have to define isSnooping,
and master ports need not implement getAddrRanges.
Clean up some minor things left over from the default responder
change in rev 9af6fb59752f. Mostly renaming the 'responder_set'
param to 'use_default_range' to actually reflect what it does...
old name wasn't that descriptive in the first place, but now
it really doesn't make sense at all.
Also got rid of the bogus obsolete assignment to 'bus.responder'
which used to be a parameter but now is interpreted as an
implicit child assignment, and which was giving me problems in
the config restructuring to come. (A good argument for not
allowing implicit child assignments, IMO, but that's water under
the bridge, I'm afraid.)
Also moved the Bus constructor to the .cc file since that's
where it should have been all along.
SimObjects not yet updated:
- Process and subclasses
- BaseCPU and subclasses
The SimObject(const std::string &name) constructor was removed. Subclasses
that still rely on that behavior must call the parent initializer as
: SimObject(makeParams(name))
--HG--
extra : convert_revision : d6faddde76e7c3361ebdbd0a7b372a40941c12ed
Move check for loops outside, since half the call sites
end up working around it anyway. Return integer port ID
instead of port object pointer.
--HG--
extra : convert_revision : 4c31fe9930f4d1aa4919e764efb7c50d43792ea3
into vm1.(none):/home/stever/bk/newmem-cache2
configs/example/memtest.py:
Hand merge redundant changes.
--HG--
extra : convert_revision : a2e36be254bf052024f37bcb23b5209f367d37e1
timing mode still broken.
configs/example/memtest.py:
Revamp options.
src/cpu/memtest/memtest.cc:
No need for memory initialization.
No need to make atomic response... memory system should do that now.
src/cpu/memtest/memtest.hh:
MemTest really doesn't want to snoop.
src/mem/bridge.cc:
checkFunctional() cleanup.
src/mem/bus.cc:
src/mem/bus.hh:
src/mem/cache/base_cache.cc:
src/mem/cache/base_cache.hh:
src/mem/cache/cache.cc:
src/mem/cache/cache.hh:
src/mem/cache/cache_blk.hh:
src/mem/cache/cache_builder.cc:
src/mem/cache/cache_impl.hh:
src/mem/cache/coherence/coherence_protocol.cc:
src/mem/cache/coherence/coherence_protocol.hh:
src/mem/cache/coherence/simple_coherence.hh:
src/mem/cache/miss/SConscript:
src/mem/cache/miss/mshr.cc:
src/mem/cache/miss/mshr.hh:
src/mem/cache/miss/mshr_queue.cc:
src/mem/cache/miss/mshr_queue.hh:
src/mem/cache/prefetch/base_prefetcher.cc:
src/mem/cache/tags/fa_lru.cc:
src/mem/cache/tags/fa_lru.hh:
src/mem/cache/tags/iic.cc:
src/mem/cache/tags/iic.hh:
src/mem/cache/tags/lru.cc:
src/mem/cache/tags/lru.hh:
src/mem/cache/tags/split.cc:
src/mem/cache/tags/split.hh:
src/mem/cache/tags/split_lifo.cc:
src/mem/cache/tags/split_lifo.hh:
src/mem/cache/tags/split_lru.cc:
src/mem/cache/tags/split_lru.hh:
src/mem/packet.cc:
src/mem/packet.hh:
src/mem/physical.cc:
src/mem/physical.hh:
src/mem/tport.cc:
More major reorg. Seems to work for atomic mode now,
timing mode still broken.
--HG--
extra : convert_revision : 7e70dfc4a752393b911880ff028271433855ae87
using a divide in order to not loop forever after resuming from a checkpoint
--HG--
extra : convert_revision : 4bbc70b1be4e5c4ed99d4f88418ab620d5ce475a
figure out the block size from devices attached to the bus otherwise use a default block size when no devices that care are attached
configs/common/FSConfig.py:
src/mem/bridge.cc:
src/mem/bridge.hh:
src/python/m5/objects/Bridge.py:
fix partial writes with a functional memory hack
src/mem/bus.cc:
src/mem/bus.hh:
src/python/m5/objects/Bus.py:
figure out the block size from devices attached to the bus otherwise use a default block size when no devices that care are attached
src/mem/packet.cc:
fix WriteInvalidateResp to not be a request that needs a response since it isn't
src/mem/port.hh:
by default return 0 for deviceBlockSize instead of panicing. This makes finding the block size the bus should use easier
--HG--
extra : convert_revision : 3fcfe95f9f392ef76f324ee8bd1d7f6de95c1a64
In this way a MemoryObject can keep a functional port around and give it to anyone who wants to do functional accesses rather
than creating a new one each time.
src/mem/bus.cc:
src/mem/bus.hh:
src/mem/cache/cache_impl.hh:
only keep around one func port we give to anyone who wants it. Otherwise we can run out of port ids reasonably quickly if
a lot of functional accesses are happening (e.g. remote debugging, dprintk, etc)
--HG--
extra : convert_revision : 6a9e3e96f51cedaab6de1b36cf317203899a3716
don't create a new physPort/virtPort every time activateContext() is called
add the ability to tell a memory object to delete it's reference to a port and a method to have a port call deletePortRefs()
on the port owner as well as delete it's peer
still need to stop calling connectMemoPorts() every time activateContext() is called or we'll overflow the bus id and panic
src/cpu/thread_state.cc:
if we hav ea (phys|virt)Port don't create a new on, have it delete it's peer and then reuse it
src/mem/bus.cc:
src/mem/bus.hh:
add ability to delete a port by usig a hash_map instead of an array to store port ids
add a function to do deleting
src/mem/cache/cache.hh:
src/mem/cache/cache_impl.hh:
src/mem/mem_object.cc:
src/mem/mem_object.hh:
adda function to delete port references from a memory object
src/mem/port.cc:
src/mem/port.hh:
add a removeConn function that tell the owener to delete any references to the port and then deletes its peer
--HG--
extra : convert_revision : 272f0c8f80e1cf1ab1750d8be5a6c9aa110b06a4
src/mem/bridge.cc:
Update brdiges, now that snoop addresses are properly forwarded.
Bus bridge should only handle snoops on the second phase (SNOOP_COMMIT)
src/mem/bus.cc:
src/mem/bus.hh:
Make sure if a busBridge has access to both things that snoop and things that respond it only takes the request once
--HG--
extra : convert_revision : 26cc9ee4429be45d4476fa435e0e9a54843c2509
src/mem/bus.cc:
Fix up draining to work properly.
src/mem/bus.hh:
Initialize drainEvent to NULL.
src/mem/cache/base_cache.cc:
src/mem/cache/base_cache.hh:
Add draining to the caches.
--HG--
extra : convert_revision : 3082220a75d50876f10909f9f99bec535889f818
src/mem/bus.cc:
src/mem/bus.hh:
Bus now will be setup with a default responder, unless the user overrides it. This default responder should return BadAddress if no matching port is found.
src/python/m5/objects/Bus.py:
Bus now has a default responder for FS mode if the user doesn't override it. It returns BadAddress if no matching port is found.
src/python/m5/objects/Tsunami.py:
Add bad address device. Also record when the user has specified their own default responder.
--HG--
extra : convert_revision : 59070477ae313ee711b2d59baa2369c9a91c5b85
src/cpu/simple/atomic.hh:
Port now takes in the MemObject that owns it.
src/cpu/simple/timing.hh:
Port now takes in MemObject that owns it.
src/dev/io_device.cc:
src/mem/bus.hh:
Ports now take in the MemObject that owns it.
src/mem/cache/base_cache.cc:
Ports now take in the MemObject that own it.
src/mem/port.hh:
src/mem/tport.hh:
Ports now optionally take in the MemObject that owns it.
--HG--
extra : convert_revision : 890a72a871795987c2236c65937e06973412d349
Fix a segfault associated with DefaultId
src/mem/bus.cc:
Handle a segfault in the bus when DefaultPort was being used
src/mem/bus.hh:
Make the Default ID more unique (it overlapped with Broadcast ID)
--HG--
extra : convert_revision : 9182805c5cf4d9fe004e6c5be8547a8f41ed7bfe
src/mem/bus.cc:
Add debugging statement
src/mem/bus.hh:
Fix implementation of bus for subsequent recvTimings while handling a retry request.
src/mem/tport.cc:
Rework timing port to retry properly
--HG--
extra : convert_revision : fbfb5e8b4a625e49c6cd764da1df46a4f336b1b2
