| Age | Commit message (Collapse) | Author |
|---|
|
This patch simplifies the packet by removing the broadcast flag and
instead more firmly relying on (and enforcing) the semantics of
transactions in the classic memory system, i.e. request packets are
routed from a master to a slave based on the address, and when they
are created they have neither a valid source, nor destination. On
their way to the slave, the request packet is updated with a source
field for all modules that multiplex packets from multiple master
(e.g. a bus). When a request packet is turned into a response packet
(at the final slave), it moves the potentially populated source field
to the destination field, and the response packet is routed through
any multiplexing components back to the master based on the
destination field.
Modules that connect multiplexing components, such as caches and
bridges store any existing source and destination field in the sender
state as a stack (just as before).
The packet constructor is simplified in that there is no longer a need
to pass the Packet::Broadcast as the destination (this was always the
case for the classic memory system). In the case of Ruby, rather than
using the parameter to the constructor we now rely on setDest, as
there is already another three-argument constructor in the packet
class.
In many places where the packet information was printed as part of
DPRINTFs, request packets would be printed with a numeric "dest" that
would always be -1 (Broadcast) and that field is now removed from the
printing.
|
|
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 moves the readBlob/writeBlob/memsetBlob from the Port class
to the PortProxy class, thus making a clear separation of the basic
port functionality (recv/send functional/atomic/timing), and the
higher-level functional accessors available on the port proxies.
There are only a few places in the code base where the blob functions
were used on ports, and they are all for peeking into the memory
system without making a normal memory access (in the memtest, and the
malta and tsunami pchip). The memtest also exemplifies how easy it is
to create a non-translating proxy if desired. The malta and tsunami
pchip used a slave port to perform a functional read, and this is now
changed to rely on the physProxy of the system (to which they already
have a pointer).
|
|
This patch classifies all ports in Python as either Master or Slave
and enforces a binding of master to slave. Conceptually, a master (such
as a CPU or DMA port) issues requests, and receives responses, and
conversely, a slave (such as a memory or a PIO device) receives
requests and sends back responses. Currently there is no
differentiation between coherent and non-coherent masters and slaves.
The classification as master/slave also involves splitting the dual
role port of the bus into a master and slave port and updating all the
system assembly scripts to use the appropriate port. Similarly, the
interrupt devices have to have their int_port split into a master and
slave port. The intdev and its children have minimal changes to
facilitate the extra port.
Note that this patch does not enforce any port typing in the C++
world, it merely ensures that the Python objects have a notion of the
port roles and are connected in an appropriate manner. This check is
carried when two ports are connected, e.g. bus.master =
memory.port. The following patches will make use of the
classifications and specialise the C++ ports into masters and slaves.
|
|
This change adds a master id to each request object which can be
used identify every device in the system that is capable of issuing a request.
This is part of the way to removing the numCpus+1 stats in the cache and
replacing them with the master ids. This is one of a series of changes
that make way for the stats output to be changed to python.
|
|
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.
|
|
This patch rpovides functional access support in Ruby. Currently only
the M5Port of RubyPort supports functional accesses. The support for
functional through the PioPort will be added as a separate patch.
|
|
|
|
At the same time, rename the trace flags to debug flags since they
have broader usage than simply tracing. This means that
--trace-flags is now --debug-flags and --trace-help is now --debug-help
|
|
|
|
This step makes it easy to replace the accessor functions
(which still access a global variable) with ones that access
per-thread curTick values.
|
|
|
|
Don't assert that the response packet is marked as a response
since it won't always be so for functional accesses.
Also cleanup code to refer to functional accesses rather
than "probes" (old terminology), and mention in the
DPRINTF which type of access we're doing.
|
|
This patch moves the testers to a new subdirectory under src/cpu and includes
the necessary fixes to work with latest m5 initialization patches.
--HG--
rename : configs/example/determ_test.py => configs/example/ruby_direct_test.py
rename : src/cpu/directedtest/DirectedGenerator.cc => src/cpu/testers/directedtest/DirectedGenerator.cc
rename : src/cpu/directedtest/DirectedGenerator.hh => src/cpu/testers/directedtest/DirectedGenerator.hh
rename : src/cpu/directedtest/InvalidateGenerator.cc => src/cpu/testers/directedtest/InvalidateGenerator.cc
rename : src/cpu/directedtest/InvalidateGenerator.hh => src/cpu/testers/directedtest/InvalidateGenerator.hh
rename : src/cpu/directedtest/RubyDirectedTester.cc => src/cpu/testers/directedtest/RubyDirectedTester.cc
rename : src/cpu/directedtest/RubyDirectedTester.hh => src/cpu/testers/directedtest/RubyDirectedTester.hh
rename : src/cpu/directedtest/RubyDirectedTester.py => src/cpu/testers/directedtest/RubyDirectedTester.py
rename : src/cpu/directedtest/SConscript => src/cpu/testers/directedtest/SConscript
rename : src/cpu/directedtest/SeriesRequestGenerator.cc => src/cpu/testers/directedtest/SeriesRequestGenerator.cc
rename : src/cpu/directedtest/SeriesRequestGenerator.hh => src/cpu/testers/directedtest/SeriesRequestGenerator.hh
rename : src/cpu/memtest/MemTest.py => src/cpu/testers/memtest/MemTest.py
rename : src/cpu/memtest/SConscript => src/cpu/testers/memtest/SConscript
rename : src/cpu/memtest/memtest.cc => src/cpu/testers/memtest/memtest.cc
rename : src/cpu/memtest/memtest.hh => src/cpu/testers/memtest/memtest.hh
rename : src/cpu/rubytest/Check.cc => src/cpu/testers/rubytest/Check.cc
rename : src/cpu/rubytest/Check.hh => src/cpu/testers/rubytest/Check.hh
rename : src/cpu/rubytest/CheckTable.cc => src/cpu/testers/rubytest/CheckTable.cc
rename : src/cpu/rubytest/CheckTable.hh => src/cpu/testers/rubytest/CheckTable.hh
rename : src/cpu/rubytest/RubyTester.cc => src/cpu/testers/rubytest/RubyTester.cc
rename : src/cpu/rubytest/RubyTester.hh => src/cpu/testers/rubytest/RubyTester.hh
rename : src/cpu/rubytest/RubyTester.py => src/cpu/testers/rubytest/RubyTester.py
rename : src/cpu/rubytest/SConscript => src/cpu/testers/rubytest/SConscript
|
