2006-02-21 17:27:53 +01:00
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/*
|
MEM: Introduce the master/slave port sub-classes in C++
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.
2012-03-30 15:40:11 +02:00
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* Copyright (c) 2012 ARM Limited
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* All rights reserved
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*
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* The license below extends only to copyright in the software and shall
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* not be construed as granting a license to any other intellectual
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* property including but not limited to intellectual property relating
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* to a hardware implementation of the functionality of the software
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* licensed hereunder. You may use the software subject to the license
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* terms below provided that you ensure that this notice is replicated
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* unmodified and in its entirety in all distributions of the software,
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* modified or unmodified, in source code or in binary form.
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*
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2006-02-21 17:27:53 +01:00
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* Copyright (c) 2002-2005 The Regents of The University of Michigan
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are
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* met: redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer;
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* redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution;
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* neither the name of the copyright holders nor the names of its
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* contributors may be used to endorse or promote products derived from
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* this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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2006-06-01 01:26:56 +02:00
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*
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* Authors: Steve Reinhardt
|
MEM: Introduce the master/slave port sub-classes in C++
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.
2012-03-30 15:40:11 +02:00
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* Andreas Hansson
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* William Wang
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2006-02-21 17:27:53 +01:00
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*/
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/**
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2006-08-15 01:25:07 +02:00
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* @file
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* Port object definitions.
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2006-02-21 17:27:53 +01:00
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*/
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2006-05-26 20:24:46 +02:00
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#include "base/trace.hh"
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2007-03-09 00:57:15 +01:00
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#include "mem/mem_object.hh"
|
2006-02-21 17:27:53 +01:00
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|
#include "mem/port.hh"
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|
|
|
|
MEM: Introduce the master/slave port sub-classes in C++
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.
2012-03-30 15:40:11 +02:00
|
|
|
Port::Port(const std::string &_name, MemObject& _owner)
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2012-01-17 19:55:09 +01:00
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: portName(_name), peer(NULL), owner(_owner)
|
2008-06-16 06:34:32 +02:00
|
|
|
{
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}
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|
2008-06-28 19:19:38 +02:00
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Port::~Port()
|
2007-11-28 23:39:19 +01:00
|
|
|
{
|
|
|
|
}
|
|
|
|
|
MEM: Introduce the master/slave port sub-classes in C++
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.
2012-03-30 15:40:11 +02:00
|
|
|
/**
|
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* Master port
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*/
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MasterPort::MasterPort(const std::string& name, MemObject* owner)
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: Port(name, *owner), _slavePort(NULL)
|
2006-05-26 20:24:46 +02:00
|
|
|
{
|
MEM: Introduce the master/slave port sub-classes in C++
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.
2012-03-30 15:40:11 +02:00
|
|
|
}
|
2008-06-28 19:19:38 +02:00
|
|
|
|
MEM: Introduce the master/slave port sub-classes in C++
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.
2012-03-30 15:40:11 +02:00
|
|
|
MasterPort::~MasterPort()
|
|
|
|
{
|
2006-05-26 20:24:46 +02:00
|
|
|
}
|
|
|
|
|
MEM: Introduce the master/slave port sub-classes in C++
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.
2012-03-30 15:40:11 +02:00
|
|
|
SlavePort&
|
|
|
|
MasterPort::getSlavePort() const
|
eventq: Major API change for the Event and EventQueue structures.
Since the early days of M5, an event needed to know which event queue
it was on, and that data was required at the time of construction of
the event object. In the future parallelized M5, this sort of
requirement does not work well since the proper event queue will not
always be known at the time of construction of an event. Now, events
are created, and the EventQueue itself has the schedule function,
e.g. eventq->schedule(event, when). To simplify the syntax, I created
a class called EventManager which holds a pointer to an EventQueue and
provides the schedule interface that is a proxy for the EventQueue.
The intent is that objects that frequently schedule events can be
derived from EventManager and then they have the schedule interface.
SimObject and Port are examples of objects that will become
EventManagers. The end result is that any SimObject can just call
schedule(event, when) and it will just call that SimObject's
eventq->schedule function. Of course, some objects may have more than
one EventQueue, so this interface might not be perfect for those, but
they should be relatively few.
2008-10-09 13:58:23 +02:00
|
|
|
{
|
MEM: Introduce the master/slave port sub-classes in C++
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.
2012-03-30 15:40:11 +02:00
|
|
|
if(_slavePort == NULL)
|
|
|
|
panic("Cannot getSlavePort on master port %s that is not connected\n",
|
|
|
|
name());
|
|
|
|
|
|
|
|
return *_slavePort;
|
eventq: Major API change for the Event and EventQueue structures.
Since the early days of M5, an event needed to know which event queue
it was on, and that data was required at the time of construction of
the event object. In the future parallelized M5, this sort of
requirement does not work well since the proper event queue will not
always be known at the time of construction of an event. Now, events
are created, and the EventQueue itself has the schedule function,
e.g. eventq->schedule(event, when). To simplify the syntax, I created
a class called EventManager which holds a pointer to an EventQueue and
provides the schedule interface that is a proxy for the EventQueue.
The intent is that objects that frequently schedule events can be
derived from EventManager and then they have the schedule interface.
SimObject and Port are examples of objects that will become
EventManagers. The end result is that any SimObject can just call
schedule(event, when) and it will just call that SimObject's
eventq->schedule function. Of course, some objects may have more than
one EventQueue, so this interface might not be perfect for those, but
they should be relatively few.
2008-10-09 13:58:23 +02:00
|
|
|
}
|
|
|
|
|
2008-01-02 21:20:15 +01:00
|
|
|
void
|
MEM: Introduce the master/slave port sub-classes in C++
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.
2012-03-30 15:40:11 +02:00
|
|
|
MasterPort::bind(SlavePort& slave_port)
|
|
|
|
{
|
|
|
|
// master port keeps track of the slave port
|
|
|
|
_slavePort = &slave_port;
|
|
|
|
peer = &slave_port;
|
|
|
|
|
|
|
|
// slave port also keeps track of master port
|
|
|
|
_slavePort->bind(*this);
|
|
|
|
}
|
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|
|
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bool
|
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|
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MasterPort::isConnected() const
|
|
|
|
{
|
|
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|
return _slavePort != NULL;
|
|
|
|
}
|
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unsigned
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MasterPort::peerBlockSize() const
|
|
|
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{
|
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return _slavePort->deviceBlockSize();
|
|
|
|
}
|
|
|
|
|
MEM: Separate snoops and normal memory requests/responses
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.
2012-04-14 11:45:07 +02:00
|
|
|
Tick
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MasterPort::sendAtomic(PacketPtr pkt)
|
|
|
|
{
|
|
|
|
return _slavePort->recvAtomic(pkt);
|
|
|
|
}
|
|
|
|
|
|
|
|
void
|
|
|
|
MasterPort::sendFunctional(PacketPtr pkt)
|
|
|
|
{
|
|
|
|
return _slavePort->recvFunctional(pkt);
|
|
|
|
}
|
|
|
|
|
|
|
|
void
|
MEM: Introduce the master/slave port sub-classes in C++
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.
2012-03-30 15:40:11 +02:00
|
|
|
MasterPort::printAddr(Addr a)
|
2008-01-02 21:20:15 +01:00
|
|
|
{
|
2012-02-12 23:07:38 +01:00
|
|
|
Request req(a, 1, 0, Request::funcMasterId);
|
MEM: Remove the Broadcast destination from the packet
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.
2012-04-14 11:45:55 +02:00
|
|
|
Packet pkt(&req, MemCmd::PrintReq);
|
2008-01-02 21:20:15 +01:00
|
|
|
Packet::PrintReqState prs(std::cerr);
|
|
|
|
pkt.senderState = &prs;
|
|
|
|
|
|
|
|
sendFunctional(&pkt);
|
|
|
|
}
|
MEM: Introduce the master/slave port sub-classes in C++
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.
2012-03-30 15:40:11 +02:00
|
|
|
|
|
|
|
/**
|
|
|
|
* Slave port
|
|
|
|
*/
|
|
|
|
SlavePort::SlavePort(const std::string& name, MemObject* owner)
|
|
|
|
: Port(name, *owner), _masterPort(NULL)
|
|
|
|
{
|
|
|
|
}
|
|
|
|
|
|
|
|
SlavePort::~SlavePort()
|
|
|
|
{
|
|
|
|
}
|
|
|
|
|
|
|
|
void
|
|
|
|
SlavePort::bind(MasterPort& master_port)
|
|
|
|
{
|
|
|
|
_masterPort = &master_port;
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|
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|
peer = &master_port;
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}
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MasterPort&
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SlavePort::getMasterPort() const
|
|
|
|
{
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|
|
|
if (_masterPort == NULL)
|
|
|
|
panic("Cannot getMasterPort on slave port %s that is not connected\n",
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|
|
|
name());
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|
|
|
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|
return *_masterPort;
|
|
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|
}
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|
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|
|
|
|
|
unsigned
|
|
|
|
SlavePort::peerBlockSize() const
|
|
|
|
{
|
|
|
|
return _masterPort->deviceBlockSize();
|
|
|
|
}
|
|
|
|
|
|
|
|
bool
|
|
|
|
SlavePort::isConnected() const
|
|
|
|
{
|
|
|
|
return _masterPort != NULL;
|
|
|
|
}
|
MEM: Separate snoops and normal memory requests/responses
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.
2012-04-14 11:45:07 +02:00
|
|
|
|
|
|
|
Tick
|
|
|
|
SlavePort::sendAtomicSnoop(PacketPtr pkt)
|
|
|
|
{
|
|
|
|
return _masterPort->recvAtomicSnoop(pkt);
|
|
|
|
}
|
|
|
|
|
|
|
|
void
|
|
|
|
SlavePort::sendFunctionalSnoop(PacketPtr pkt)
|
|
|
|
{
|
|
|
|
return _masterPort->recvFunctionalSnoop(pkt);
|
|
|
|
}
|