/*
+ * Copyright (c) 2011-2012 ARM Limited
+ * All rights reserved
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder. You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
* Copyright (c) 2002-2005 The Regents of The University of Michigan
* All rights reserved.
*
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Ron Dreslinski
+ * Andreas Hansson
+ * William Wang
*/
/**
* @file
- * Port Object Declaration. Ports are used to interface memory objects to
- * each other. They will always come in pairs, and we refer to the other
- * port object as the peer. These are used to make the design more
- * modular so that a specific interface between every type of objcet doesn't
- * have to be created.
+ * Port Object Declaration.
*/
#ifndef __MEM_PORT_HH__
#include <list>
-#include "base/misc.hh"
#include "base/range.hh"
-#include "base/types.hh"
#include "mem/packet.hh"
-#include "mem/request.hh"
-/** This typedef is used to clean up the parameter list of
- * getDeviceAddressRanges() and getPeerAddressRanges(). It's declared
+/**
+ * This typedef is used to clean up getAddrRanges(). It's declared
* outside the Port object since it's also used by some mem objects.
* Eventually we should move this typedef to wherever Addr is
* defined.
class MemObject;
/**
- * Ports are used to interface memory objects to
- * each other. They will always come in pairs, and we refer to the other
- * port object as the peer. These are used to make the design more
- * modular so that a specific interface between every type of objcet doesn't
- * have to be created.
+ * Ports are used to interface memory objects to each other. A port is
+ * either a master or a slave and the connected peer is always of the
+ * opposite role.
*
- * Recv accesor functions are being called from the peer interface.
- * Send accessor functions are being called from the device the port is
- * associated with, and it will call the peer recv. accessor function.
+ * Each port has a name and an owner, and enables three basic types of
+ * accesses to the peer port: functional, atomic and timing.
*/
class Port
{
- protected:
+
+ public:
+
+ /** A type name for the port identifier. */
+ typedef int PortId;
+
+ /** A symbolic name for the absence of a port id. */
+ static const PortId INVALID_PORT_ID = -1;
+
+ private:
+
/** Descriptive name (for DPRINTF output) */
- mutable std::string portName;
+ std::string portName;
- /** A pointer to the peer port. Ports always come in pairs, that way they
- can use a standardized interface to communicate between different
- memory objects. */
- Port *peer;
+ protected:
- /** A pointer to the MemObject that owns this port. This may not be set. */
- MemObject *owner;
+ /**
+ * A numeric identifier to distinguish ports in a vector, and set
+ * to INVALID_PORT_ID in case this port is not part of a vector.
+ */
+ const PortId id;
+
+ /** A pointer to the peer port. */
+ Port* peer;
+
+ /** A reference to the MemObject that owns this port. */
+ MemObject& owner;
- public:
/**
- * Constructor.
+ * Abstract base class for ports
*
- * @param _name Port name for DPRINTF output. Should include name
- * of memory system object to which the port belongs.
- * @param _owner Pointer to the MemObject that owns this port.
- * Will not necessarily be set.
+ * @param _name Port name including the owners name
+ * @param _owner The MemObject that is the structural owner of this port
+ * @param _id A port identifier for vector ports
*/
- Port(const std::string &_name, MemObject *_owner);
+ Port(const std::string& _name, MemObject& _owner, PortId _id);
+
+ /**
+ * Virtual destructor due to inheritance.
+ */
+ virtual ~Port();
+
+ public:
/** Return port name (for DPRINTF). */
- const std::string &name() const { return portName; }
+ const std::string name() const { return portName; }
- virtual ~Port();
+ /** Get the port id. */
+ PortId getId() const { return id; }
- // mey be better to use subclasses & RTTI?
- /** Holds the ports status. Currently just that a range recomputation needs
- * to be done. */
- enum Status {
- RangeChange
- };
+ protected:
- void setName(const std::string &name)
- { portName = name; }
+ /**
+ * Called by a peer port if sendTimingReq, sendTimingResp or
+ * sendTimingSnoopResp was unsuccesful, and had to wait.
+ */
+ virtual void recvRetry() = 0;
- /** Function to set the pointer for the peer port. */
- virtual void setPeer(Port *port);
+ public:
- /** Function to get the pointer to the peer port. */
- Port *getPeer() { return peer; }
+ /**
+ * Send a retry to a peer port that previously attempted a
+ * sendTimingReq, sendTimingResp or sendTimingSnoopResp which was
+ * unsuccessful.
+ */
+ void sendRetry() { return peer->recvRetry(); }
- /** Function to set the owner of this port. */
- void setOwner(MemObject *_owner);
+};
- /** Function to return the owner of this port. */
- MemObject *getOwner() { return owner; }
+/** Forward declaration */
+class SlavePort;
- /** Inform the peer port to delete itself and notify it's owner about it's
- * demise. */
- void removeConn();
+/**
+ * A MasterPort is a specialisation of a port. In addition to the
+ * basic functionality of sending packets to its slave peer, it also
+ * has functions specific to a master, e.g. to receive range changes
+ * or determine if the port is snooping or not.
+ */
+class MasterPort : public Port
+{
- virtual bool isDefaultPort() const { return false; }
+ friend class SlavePort;
- bool isConnected() { return peer && !peer->isDefaultPort(); }
+ private:
- protected:
+ SlavePort* _slavePort;
- /** These functions are protected because they should only be
- * called by a peer port, never directly by any outside object. */
+ public:
- /** Called to recive a timing call from the peer port. */
- virtual bool recvTiming(PacketPtr pkt) = 0;
+ MasterPort(const std::string& name, MemObject* owner,
+ PortId id = INVALID_PORT_ID);
+ virtual ~MasterPort();
- /** Called to recive a atomic call from the peer port. */
- virtual Tick recvAtomic(PacketPtr pkt) = 0;
+ void bind(SlavePort& slave_port);
+ SlavePort& getSlavePort() const;
+ bool isConnected() const;
- /** Called to recive a functional call from the peer port. */
- virtual void recvFunctional(PacketPtr pkt) = 0;
+ /**
+ * Send an atomic request packet, where the data is moved and the
+ * state is updated in zero time, without interleaving with other
+ * memory accesses.
+ *
+ * @param pkt Packet to send.
+ *
+ * @return Estimated latency of access.
+ */
+ Tick sendAtomic(PacketPtr pkt);
- /** Called to recieve a status change from the peer port. */
- virtual void recvStatusChange(Status status) = 0;
+ /**
+ * Send a functional request packet, where the data is instantly
+ * updated everywhere in the memory system, without affecting the
+ * current state of any block or moving the block.
+ *
+ * @param pkt Packet to send.
+ */
+ void sendFunctional(PacketPtr pkt);
- /** Called by a peer port if the send was unsuccesful, and had to
- wait. This shouldn't be valid for response paths (IO Devices).
- so it is set to panic if it isn't already defined.
+ /**
+ * Attempt to send a timing request to the slave port by calling
+ * its corresponding receive function. If the send does not
+ * succeed, as indicated by the return value, then the sender must
+ * wait for a recvRetry at which point it can re-issue a
+ * sendTimingReq.
+ *
+ * @param pkt Packet to send.
+ *
+ * @return If the send was succesful or not.
*/
- virtual void recvRetry() { panic("??"); }
+ bool sendTimingReq(PacketPtr pkt);
- /** Called by a peer port in order to determine the block size of the
- device connected to this port. It sometimes doesn't make sense for
- this function to be called, so it just returns 0. Anytthing that is
- concerned with the size should just ignore that.
- */
+ /**
+ * Attempt to send a timing snoop response packet to the slave
+ * port by calling its corresponding receive function. If the send
+ * does not succeed, as indicated by the return value, then the
+ * sender must wait for a recvRetry at which point it can re-issue
+ * a sendTimingSnoopResp.
+ *
+ * @param pkt Packet to send.
+ */
+ bool sendTimingSnoopResp(PacketPtr pkt);
+
+ /**
+ * Determine if this master port is snooping or not. The default
+ * implementation returns false and thus tells the neighbour we
+ * are not snooping. Any master port that wants to receive snoop
+ * requests (e.g. a cache connected to a bus) has to override this
+ * function.
+ *
+ * @return true if the port should be considered a snooper
+ */
+ virtual bool isSnooping() const { return false; }
+
+ /**
+ * Called by a peer port in order to determine the block size of
+ * the owner of this port.
+ */
virtual unsigned deviceBlockSize() const { return 0; }
- /** The peer port is requesting us to reply with a list of the ranges we
- are responsible for.
- @param resp is a list of ranges responded to
- @param snoop is a list of ranges snooped
+ /** Called by the associated device if it wishes to find out the blocksize
+ of the device on attached to the peer port.
*/
- virtual void getDeviceAddressRanges(AddrRangeList &resp,
- bool &snoop)
- { panic("??"); }
+ unsigned peerBlockSize() const;
+
+ /** Inject a PrintReq for the given address to print the state of
+ * that address throughout the memory system. For debugging.
+ */
+ void printAddr(Addr a);
+
+ protected:
+
+ /**
+ * Receive an atomic snoop request packet from the slave port.
+ */
+ virtual Tick recvAtomicSnoop(PacketPtr pkt)
+ {
+ panic("%s was not expecting an atomic snoop request\n", name());
+ return 0;
+ }
+
+ /**
+ * Receive a functional snoop request packet from the slave port.
+ */
+ virtual void recvFunctionalSnoop(PacketPtr pkt)
+ {
+ panic("%s was not expecting a functional snoop request\n", name());
+ }
+
+ /**
+ * Receive a timing response from the slave port.
+ */
+ virtual bool recvTimingResp(PacketPtr pkt) = 0;
+
+ /**
+ * Receive a timing snoop request from the slave port.
+ */
+ virtual void recvTimingSnoopReq(PacketPtr pkt)
+ {
+ panic("%s was not expecting a timing snoop request\n", name());
+ }
+
+ /**
+ * Called to receive an address range change from the peer slave
+ * port. the default implementation ignored the change and does
+ * nothing. Override this function in a derived class if the owner
+ * needs to be aware of he laesddress ranges, e.g. in an
+ * interconnect component like a bus.
+ */
+ virtual void recvRangeChange() { }
+};
+
+/**
+ * A SlavePort is a specialisation of a port. In addition to the
+ * basic functionality of sending packets to its master peer, it also
+ * has functions specific to a slave, e.g. to send range changes
+ * and get the address ranges that the port responds to.
+ */
+class SlavePort : public Port
+{
+
+ friend class MasterPort;
+
+ private:
+
+ MasterPort* _masterPort;
public:
- /** Function called by associated memory device (cache, memory, iodevice)
- in order to send a timing request to the port. Simply calls the peer
- port receive function.
- @return This function returns if the send was succesful in it's
- recieve. If it was a failure, then the port will wait for a recvRetry
- at which point it can possibly issue a successful sendTiming. This is used in
- case a cache has a higher priority request come in while waiting for
- the bus to arbitrate.
- */
- bool sendTiming(PacketPtr pkt) { return peer->recvTiming(pkt); }
+ SlavePort(const std::string& name, MemObject* owner,
+ PortId id = INVALID_PORT_ID);
+ virtual ~SlavePort();
+
+ void bind(MasterPort& master_port);
+ MasterPort& getMasterPort() const;
+ bool isConnected() const;
- /** Function called by the associated device to send an atomic
- * access, an access in which the data is moved and the state is
- * updated in one cycle, without interleaving with other memory
- * accesses. Returns estimated latency of access.
+ /**
+ * Send an atomic snoop request packet, where the data is moved
+ * and the state is updated in zero time, without interleaving
+ * with other memory accesses.
+ *
+ * @param pkt Snoop packet to send.
+ *
+ * @return Estimated latency of access.
*/
- Tick sendAtomic(PacketPtr pkt)
- { return peer->recvAtomic(pkt); }
+ Tick sendAtomicSnoop(PacketPtr pkt);
- /** Function called by the associated device to send a functional access,
- an access in which the data is instantly updated everywhere in the
- memory system, without affecting the current state of any block or
- moving the block.
- */
- void sendFunctional(PacketPtr pkt)
- { return peer->recvFunctional(pkt); }
+ /**
+ * Send a functional snoop request packet, where the data is
+ * instantly updated everywhere in the memory system, without
+ * affecting the current state of any block or moving the block.
+ *
+ * @param pkt Snoop packet to send.
+ */
+ void sendFunctionalSnoop(PacketPtr pkt);
- /** Called by the associated device to send a status change to the device
- connected to the peer interface.
+ /**
+ * Attempt to send a timing response to the master port by calling
+ * its corresponding receive function. If the send does not
+ * succeed, as indicated by the return value, then the sender must
+ * wait for a recvRetry at which point it can re-issue a
+ * sendTimingResp.
+ *
+ * @param pkt Packet to send.
+ *
+ * @return If the send was succesful or not.
*/
- void sendStatusChange(Status status) {peer->recvStatusChange(status); }
+ bool sendTimingResp(PacketPtr pkt);
- /** When a timing access doesn't return a success, some time later the
- Retry will be sent.
- */
- void sendRetry() { return peer->recvRetry(); }
+ /**
+ * Attempt to send a timing snoop request packet to the master port
+ * by calling its corresponding receive function. Snoop requests
+ * always succeed and hence no return value is needed.
+ *
+ * @param pkt Packet to send.
+ */
+ void sendTimingSnoopReq(PacketPtr pkt);
+
+ /**
+ * Called by a peer port in order to determine the block size of
+ * the owner of this port.
+ */
+ virtual unsigned deviceBlockSize() const { return 0; }
/** Called by the associated device if it wishes to find out the blocksize
of the device on attached to the peer port.
*/
- unsigned peerBlockSize() const { return peer->deviceBlockSize(); }
+ unsigned peerBlockSize() const;
- /** Called by the associated device if it wishes to find out the address
- ranges connected to the peer ports devices.
- */
- void getPeerAddressRanges(AddrRangeList &resp, bool &snoop)
- { peer->getDeviceAddressRanges(resp, snoop); }
+ /**
+ * Called by the owner to send a range change
+ */
+ void sendRangeChange() const { _masterPort->recvRangeChange(); }
- /** This function is a wrapper around sendFunctional()
- that breaks a larger, arbitrarily aligned access into
- appropriate chunks. The default implementation can use
- getBlockSize() to determine the block size and go from there.
- */
- virtual void readBlob(Addr addr, uint8_t *p, int size);
+ /**
+ * Get a list of the non-overlapping address ranges the owner is
+ * responsible for. All slave ports must override this function
+ * and return a populated list with at least one item.
+ *
+ * @return a list of ranges responded to
+ */
+ virtual AddrRangeList getAddrRanges() = 0;
- /** This function is a wrapper around sendFunctional()
- that breaks a larger, arbitrarily aligned access into
- appropriate chunks. The default implementation can use
- getBlockSize() to determine the block size and go from there.
- */
- virtual void writeBlob(Addr addr, uint8_t *p, int size);
+ protected:
- /** Fill size bytes starting at addr with byte value val. This
- should not need to be virtual, since it can be implemented in
- terms of writeBlob(). However, it shouldn't be
- performance-critical either, so it could be if we wanted to.
- */
- virtual void memsetBlob(Addr addr, uint8_t val, int size);
+ /**
+ * Receive an atomic request packet from the master port.
+ */
+ virtual Tick recvAtomic(PacketPtr pkt) = 0;
- /** Inject a PrintReq for the given address to print the state of
- * that address throughout the memory system. For debugging.
+ /**
+ * Receive a functional request packet from the master port.
*/
- void printAddr(Addr a);
+ virtual void recvFunctional(PacketPtr pkt) = 0;
- private:
+ /**
+ * Receive a timing request from the master port.
+ */
+ virtual bool recvTimingReq(PacketPtr pkt) = 0;
- /** Internal helper function for read/writeBlob().
+ /**
+ * Receive a timing snoop response from the master port.
*/
- void blobHelper(Addr addr, uint8_t *p, int size, MemCmd cmd);
+ virtual bool recvTimingSnoopResp(PacketPtr pkt)
+ {
+ panic("%s was not expecting a timing snoop response\n", name());
+ }
+
};
#endif //__MEM_PORT_HH__