/*
- * Copyright (c) 2011-2012 ARM Limited
+ * Copyright (c) 2011-2012,2015,2017 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
*
* 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__
#define __MEM_PORT_HH__
-#include <list>
-
-#include "base/range.hh"
+#include "base/addr_range.hh"
#include "mem/packet.hh"
-/** 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.
- */
-
-typedef std::list<Range<Addr> > AddrRangeList;
-typedef std::list<Range<Addr> >::iterator AddrRangeIter;
-
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.
- *
- * 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.
+ * 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. Each port has a name, an owner, and an identifier.
*/
class Port
{
- protected:
+
+ 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 InvalidPortID in case this port is not part of a vector.
+ */
+ const PortID id;
+
+ /** 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, PortID _id);
+
+ /**
+ * Virtual destructor due to inheritance.
*/
- Port(const std::string &_name, MemObject *_owner);
+ 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; }
- void setName(const std::string &name)
- { portName = name; }
+};
- /** Function to set the pointer for the peer port. */
- virtual void setPeer(Port *port);
+/** Forward declaration */
+class BaseSlavePort;
- /** Function to get the pointer to the peer port. */
- Port *getPeer() { return peer; }
+/**
+ * A BaseMasterPort is a protocol-agnostic master port, responsible
+ * only for the structural connection to a slave port. The final
+ * master port that inherits from the base class must override the
+ * bind member function for the specific slave port class.
+ */
+class BaseMasterPort : public Port
+{
+
+ protected:
- /** Function to set the owner of this port. */
- void setOwner(MemObject *_owner);
+ BaseSlavePort* _baseSlavePort;
+
+ BaseMasterPort(const std::string& name, MemObject* owner,
+ PortID id = InvalidPortID);
+ virtual ~BaseMasterPort();
+
+ public:
- /** Function to return the owner of this port. */
- MemObject *getOwner() { return owner; }
+ virtual void bind(BaseSlavePort& slave_port) = 0;
+ virtual void unbind() = 0;
+ BaseSlavePort& getSlavePort() const;
+ bool isConnected() const;
- bool isConnected() { return peer != NULL; }
+};
+
+/**
+ * A BaseSlavePort is a protocol-agnostic slave port, responsible
+ * only for the structural connection to a master port.
+ */
+class BaseSlavePort : public Port
+{
protected:
- /** These functions are protected because they should only be
- * called by a peer port, never directly by any outside object. */
+ BaseMasterPort* _baseMasterPort;
- /** Called to recive a timing call from the peer port. */
- virtual bool recvTiming(PacketPtr pkt) = 0;
+ BaseSlavePort(const std::string& name, MemObject* owner,
+ PortID id = InvalidPortID);
+ virtual ~BaseSlavePort();
- /** Called to recive a atomic call from the peer port. */
- virtual Tick recvAtomic(PacketPtr pkt) = 0;
+ public:
- /** Called to recive a functional call from the peer port. */
- virtual void recvFunctional(PacketPtr pkt) = 0;
+ BaseMasterPort& getMasterPort() const;
+ bool isConnected() const;
- /** Called to recieve an address range change from the peer port. */
- virtual void recvRangeChange() = 0;
+};
- /** 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.
- */
- virtual void recvRetry() { panic("??"); }
+/** Forward declaration */
+class SlavePort;
- /** 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.
- */
- virtual unsigned deviceBlockSize() const { return 0; }
+/**
+ * A MasterPort is a specialisation of a BaseMasterPort, which
+ * implements the default protocol for the three different level of
+ * transport functions. In addition to the basic functionality of
+ * sending packets, it also has functions to receive range changes or
+ * determine if the port is snooping or not.
+ */
+class MasterPort : public BaseMasterPort
+{
+
+ friend class SlavePort;
+
+ private:
+
+ SlavePort* _slavePort;
public:
+ MasterPort(const std::string& name, MemObject* owner,
+ PortID id = InvalidPortID);
+ virtual ~MasterPort();
+
+ /**
+ * Bind this master port to a slave port. This also does the
+ * mirror action and binds the slave port to the master port.
+ */
+ void bind(BaseSlavePort& slave_port);
+
/**
- * Get a list of the non-overlapping address ranges we are
- * responsible for. The default implementation returns an empty
- * list and thus no address ranges. Any slave port must override
- * this function and return a populated list with at least one
- * item.
+ * Unbind this master port and the associated slave port.
+ */
+ void unbind();
+
+ /**
+ * Send an atomic request packet, where the data is moved and the
+ * state is updated in zero time, without interleaving with other
+ * memory accesses.
*
- * @return a list of ranges responded to
+ * @param pkt Packet to send.
+ *
+ * @return Estimated latency of access.
*/
- virtual AddrRangeList getAddrRanges()
- { AddrRangeList ranges; return ranges; }
+ Tick sendAtomic(PacketPtr pkt);
/**
- * Determine if this port is snooping or not. The default
- * implementation returns false and thus tells the neighbour we
- * are not snooping. Any port that is to snoop (e.g. a cache
- * connected to a bus) has to override this function.
+ * 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.
*
- * @return true if the port should be considered a snooper
+ * @param pkt Packet to send.
*/
- virtual bool isSnooping()
- { return false; }
-
- /** 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.
+ void sendFunctional(PacketPtr pkt);
+
+ /**
+ * 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 recvReqRetry at which point it can re-issue a
+ * sendTimingReq.
+ *
+ * @param pkt Packet to send.
+ *
+ * @return If the send was succesful or not.
*/
- bool sendTiming(PacketPtr pkt) { return peer->recvTiming(pkt); }
+ bool sendTimingReq(PacketPtr pkt);
- /** 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.
+ /**
+ * Check if the slave can handle a timing request.
+ *
+ * If the send cannot be handled at the moment, as indicated by
+ * the return value, then the sender will receive a recvReqRetry
+ * at which point it can re-issue a sendTimingReq.
+ *
+ * @param pkt Packet to send.
+ *
+ * @return If the send was succesful or not.
*/
- Tick sendAtomic(PacketPtr pkt)
- { return peer->recvAtomic(pkt); }
+ bool tryTiming(PacketPtr pkt) const;
- /** 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); }
+ /**
+ * 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 recvRetrySnoop at which point it can
+ * re-issue a sendTimingSnoopResp.
+ *
+ * @param pkt Packet to send.
+ */
+ bool sendTimingSnoopResp(PacketPtr pkt);
/**
- * Called by the associated device to send a status range to the
- * peer interface.
+ * Send a retry to the slave port that previously attempted a
+ * sendTimingResp to this master port and failed. Note that this
+ * is virtual so that the "fake" snoop response port in the
+ * coherent crossbar can override the behaviour.
*/
- void sendRangeChange() const { peer->recvRangeChange(); }
+ virtual void sendRetryResp();
- /** When a timing access doesn't return a success, some time later the
- Retry will be sent.
- */
- void sendRetry() { return peer->recvRetry(); }
+ /**
+ * 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 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(); }
+ /**
+ * Get the address ranges of the connected slave port.
+ */
+ AddrRangeList getAddrRanges() 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 by the slave port if sendTimingReq was called on this
+ * master port (causing recvTimingReq to be called on the slave
+ * port) and was unsuccesful.
+ */
+ virtual void recvReqRetry() = 0;
+
+ /**
+ * Called by the slave port if sendTimingSnoopResp was called on this
+ * master port (causing recvTimingSnoopResp to be called on the slave
+ * port) and was unsuccesful.
+ */
+ virtual void recvRetrySnoopResp()
+ {
+ panic("%s was not expecting a snoop retry\n", name());
+ }
+
+ /**
+ * Called to receive an address range change from the peer slave
+ * port. The default implementation ignores the change and does
+ * nothing. Override this function in a derived class if the owner
+ * needs to be aware of the address 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 BaseSlavePort
+{
+
+ friend class MasterPort;
+
+ private:
+
+ MasterPort* _masterPort;
+
+ public:
+
+ SlavePort(const std::string& name, MemObject* owner,
+ PortID id = InvalidPortID);
+ virtual ~SlavePort();
+
+ /**
+ * 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 sendAtomicSnoop(PacketPtr 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);
+
+ /**
+ * 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 recvRespRetry at which point it can re-issue a
+ * sendTimingResp.
+ *
+ * @param pkt Packet to send.
+ *
+ * @return If the send was succesful or not.
+ */
+ bool sendTimingResp(PacketPtr pkt);
+
+ /**
+ * 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);
+
+ /**
+ * Send a retry to the master port that previously attempted a
+ * sendTimingReq to this slave port and failed.
+ */
+ void sendRetryReq();
+
+ /**
+ * Send a retry to the master port that previously attempted a
+ * sendTimingSnoopResp to this slave port and failed.
+ */
+ void sendRetrySnoopResp();
+
+ /**
+ * Find out if the peer master port is snooping or not.
+ *
+ * @return true if the peer master port is snooping
+ */
+ bool isSnooping() const { return _masterPort->isSnooping(); }
+
+ /**
+ * Called by the owner to send a range change
+ */
+ void sendRangeChange() const {
+ if (!_masterPort)
+ fatal("%s cannot sendRangeChange() without master port", name());
+ _masterPort->recvRangeChange();
+ }
+
+ /**
+ * 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() const = 0;
+
+ protected:
+
+ /**
+ * Called by the master port to unbind. Should never be called
+ * directly.
+ */
+ void unbind();
+
+ /**
+ * Called by the master port to bind. Should never be called
+ * directly.
+ */
+ void bind(MasterPort& master_port);
+
+ /**
+ * Receive an atomic request packet from the master port.
+ */
+ virtual Tick recvAtomic(PacketPtr pkt) = 0;
+
+ /**
+ * Receive a functional request packet from the master port.
+ */
+ virtual void recvFunctional(PacketPtr pkt) = 0;
+
+ /**
+ * Receive a timing request from the master port.
+ */
+ virtual bool recvTimingReq(PacketPtr pkt) = 0;
+
+ /**
+ * Availability request from the master port.
+ */
+ virtual bool tryTiming(PacketPtr pkt) {
+ panic("%s was not expecting a %s\n", name(), __func__);
+ }
+
+ /**
+ * Receive a timing snoop response from the master port.
+ */
+ virtual bool recvTimingSnoopResp(PacketPtr pkt)
+ {
+ panic("%s was not expecting a timing snoop response\n", name());
+ }
+
+ /**
+ * Called by the master port if sendTimingResp was called on this
+ * slave port (causing recvTimingResp to be called on the master
+ * port) and was unsuccesful.
+ */
+ virtual void recvRespRetry() = 0;
+
};
#endif //__MEM_PORT_HH__