tport.hh (3090:3cced9156352) tport.hh (3091:dba513d68c16)
1/*
2 * Copyright (c) 2006 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;

--- 14 unchanged lines hidden (view full) ---

23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Ali Saidi
29 */
30
1/*
2 * Copyright (c) 2006 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;

--- 14 unchanged lines hidden (view full) ---

23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Ali Saidi
29 */
30
31#ifndef __MEM_TPORT_HH__
32#define __MEM_TPORT_HH__
33
31/**
32 * @file
34/**
35 * @file
33 * Implement a port which adds simple support of a sendTiming() function that
34 * takes a delay. In this way the * device can immediatly call
35 * sendTiming(pkt, time) after processing a request and the request will be
36 * handled by the port even if the port bus the device connects to is blocked.
36 *
37 * Declaration of SimpleTimingPort.
37 */
38
38 */
39
39/** recvTiming and drain should be implemented something like this when this
40 * class is used.
41
42bool
43PioPort::recvTiming(Packet *pkt)
44{
45 if (pkt->result == Packet::Nacked) {
46 resendNacked(pkt);
47 } else {
48 Tick latency = device->recvAtomic(pkt);
49 // turn packet around to go back to requester
50 pkt->makeTimingResponse();
51 sendTiming(pkt, latency);
52 }
53 return true;
54}
55
56PioDevice::drain(Event *de)
57{
58 unsigned int count;
59 count = SimpleTimingPort->drain(de);
60 if (count)
61 changeState(Draining);
62 else
63 changeState(Drained);
64 return count;
65}
66*/
67
68#ifndef __MEM_TPORT_HH__
69#define __MEM_TPORT_HH__
70
71#include "mem/port.hh"
72#include "sim/eventq.hh"
73#include <list>
74#include <string>
75
40#include "mem/port.hh"
41#include "sim/eventq.hh"
42#include <list>
43#include <string>
44
45/**
46 * A simple port for interfacing objects that basically have only
47 * functional memory behavior (e.g. I/O devices) to the memory system.
48 * Both timing and functional accesses are implemented in terms of
49 * atomic accesses. A derived port class thus only needs to provide
50 * recvAtomic() to support all memory access modes.
51 *
52 * The tricky part is handling recvTiming(), where the response must
53 * be scheduled separately via a later call to sendTiming(). This
54 * feature is handled by scheduling an internal event that calls
55 * sendTiming() after a delay, and optionally rescheduling the
56 * response if it is nacked.
57 */
76class SimpleTimingPort : public Port
77{
78 protected:
79 /** A list of outgoing timing response packets that haven't been
80 * serviced yet. */
81 std::list<Packet*> transmitList;
58class SimpleTimingPort : public Port
59{
60 protected:
61 /** A list of outgoing timing response packets that haven't been
62 * serviced yet. */
63 std::list<Packet*> transmitList;
64
82 /**
83 * This class is used to implemented sendTiming() with a delay. When
84 * a delay is requested a new event is created. When the event time
85 * expires it attempts to send the packet. If it cannot, the packet
86 * is pushed onto the transmit list to be sent when recvRetry() is
87 * called. */
88 class SendEvent : public Event
89 {

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107 */
108 int outTiming;
109
110 /** If we need to drain, keep the drain event around until we're done
111 * here.*/
112 Event *drainEvent;
113
114 /** Schedule a sendTiming() event to be called in the future. */
65 /**
66 * This class is used to implemented sendTiming() with a delay. When
67 * a delay is requested a new event is created. When the event time
68 * expires it attempts to send the packet. If it cannot, the packet
69 * is pushed onto the transmit list to be sent when recvRetry() is
70 * called. */
71 class SendEvent : public Event
72 {

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90 */
91 int outTiming;
92
93 /** If we need to drain, keep the drain event around until we're done
94 * here.*/
95 Event *drainEvent;
96
97 /** Schedule a sendTiming() event to be called in the future. */
115 void sendTiming(Packet *pkt, Tick time)
116 { outTiming++; new SimpleTimingPort::SendEvent(this, pkt, time); }
98 void sendTimingLater(Packet *pkt, Tick time)
99 { outTiming++; new SendEvent(this, pkt, time); }
117
118 /** This function is notification that the device should attempt to send a
119 * packet again. */
120 virtual void recvRetry();
121
100
101 /** This function is notification that the device should attempt to send a
102 * packet again. */
103 virtual void recvRetry();
104
122 void resendNacked(Packet *pkt);
105 /** Implemented using recvAtomic(). */
106 void recvFunctional(Packet *pkt);
107
108 /** Implemented using recvAtomic(). */
109 bool recvTiming(Packet *pkt);
110
111 /**
112 * Simple ports generally don't care about any status
113 * changes... can always override this in cases where that's not
114 * true. */
115 virtual void recvStatusChange(Status status) { }
116
117
123 public:
124
125 SimpleTimingPort(std::string pname)
126 : Port(pname), outTiming(0), drainEvent(NULL)
127 {}
128
118 public:
119
120 SimpleTimingPort(std::string pname)
121 : Port(pname), outTiming(0), drainEvent(NULL)
122 {}
123
124 /** Hook for draining timing accesses from the system. The
125 * associated SimObject's drain() functions should be implemented
126 * something like this when this class is used:
127 \code
128 PioDevice::drain(Event *de)
129 {
130 unsigned int count;
131 count = SimpleTimingPort->drain(de);
132 if (count)
133 changeState(Draining);
134 else
135 changeState(Drained);
136 return count;
137 }
138 \endcode
139 */
129 unsigned int drain(Event *de);
130};
131
132#endif // __MEM_TPORT_HH__
140 unsigned int drain(Event *de);
141};
142
143#endif // __MEM_TPORT_HH__