io_device.hh revision 4965:ad0e792a5c78 
1/*
2 * Copyright (c) 2004-2005 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;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 *          Nathan Binkert
30 */
31
32#ifndef __DEV_IO_DEVICE_HH__
33#define __DEV_IO_DEVICE_HH__
34
35#include "mem/mem_object.hh"
36#include "mem/packet.hh"
37#include "mem/tport.hh"
38#include "params/BasicPioDevice.hh"
39#include "params/DmaDevice.hh"
40#include "params/PioDevice.hh"
41#include "sim/sim_object.hh"
42
43class Event;
44class Platform;
45class PioDevice;
46class DmaDevice;
47class System;
48
49/**
50 * The PioPort class is a programmed i/o port that all devices that are
51 * sensitive to an address range use. The port takes all the memory
52 * access types and roles them into one read() and write() call that the device
53 * must respond to. The device must also provide the addressRanges() function
54 * with which it returns the address ranges it is interested in.
55 */
56class PioPort : public SimpleTimingPort
57{
58  protected:
59    /** The device that this port serves. */
60    PioDevice *device;
61
62    virtual Tick recvAtomic(PacketPtr pkt);
63
64    virtual void getDeviceAddressRanges(AddrRangeList &resp,
65                                        bool &snoop);
66
67  public:
68
69    PioPort(PioDevice *dev, System *s, std::string pname = "-pioport");
70};
71
72
73class DmaPort : public Port
74{
75  protected:
76    struct DmaReqState : public Packet::SenderState
77    {
78        /** Event to call on the device when this transaction (all packets)
79         * complete. */
80        Event *completionEvent;
81
82        /** Where we came from for some sanity checking. */
83        Port *outPort;
84
85        /** Total number of bytes that this transaction involves. */
86        Addr totBytes;
87
88        /** Number of bytes that have been acked for this transaction. */
89        Addr numBytes;
90
91        DmaReqState(Event *ce, Port *p, Addr tb)
92            : completionEvent(ce), outPort(p), totBytes(tb), numBytes(0)
93        {}
94    };
95
96    DmaDevice *device;
97    std::list<PacketPtr> transmitList;
98
99    /** The system that device/port are in. This is used to select which mode
100     * we are currently operating in. */
101    System *sys;
102
103    /** Number of outstanding packets the dma port has. */
104    int pendingCount;
105
106    /** If a dmaAction is in progress. */
107    int actionInProgress;
108
109    /** If we need to drain, keep the drain event around until we're done
110     * here.*/
111    Event *drainEvent;
112
113    /** time to wait between sending another packet, increases as NACKs are
114     * recived, decreases as responses are recived. */
115    Tick backoffTime;
116
117    /** If the port is currently waiting for a retry before it can send whatever
118     * it is that it's sending. */
119    bool inRetry;
120
121    virtual bool recvTiming(PacketPtr pkt);
122    virtual Tick recvAtomic(PacketPtr pkt)
123    { panic("dma port shouldn't be used for pio access."); M5_DUMMY_RETURN }
124    virtual void recvFunctional(PacketPtr pkt)
125    { panic("dma port shouldn't be used for pio access."); }
126
127    virtual void recvStatusChange(Status status)
128    { ; }
129
130    virtual void recvRetry() ;
131
132    virtual void getDeviceAddressRanges(AddrRangeList &resp,
133                                        bool &snoop)
134    { resp.clear(); snoop = false; }
135
136    void queueDma(PacketPtr pkt, bool front = false);
137    void sendDma();
138
139    /** event to give us a kick every time we backoff time is reached. */
140    EventWrapper<DmaPort, &DmaPort::sendDma> backoffEvent;
141
142  public:
143    DmaPort(DmaDevice *dev, System *s);
144
145    void dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
146                   uint8_t *data = NULL);
147
148    bool dmaPending() { return pendingCount > 0; }
149
150    int cacheBlockSize() { return peerBlockSize(); }
151    unsigned int drain(Event *de);
152};
153
154/**
155 * This device is the base class which all devices senstive to an address range
156 * inherit from. There are three pure virtual functions which all devices must
157 * implement addressRanges(), read(), and write(). The magic do choose which
158 * mode we are in, etc is handled by the PioPort so the device doesn't have to
159 * bother.
160 */
161class PioDevice : public MemObject
162{
163  protected:
164
165    /** The platform we are in. This is used to decide what type of memory
166     * transaction we should perform. */
167    Platform *platform;
168
169    System *sys;
170
171    /** The pioPort that handles the requests for us and provides us requests
172     * that it sees. */
173    PioPort *pioPort;
174
175    virtual void addressRanges(AddrRangeList &range_list) = 0;
176
177    /** Pure virtual function that the device must implement. Called
178     * when a read command is recieved by the port.
179     * @param pkt Packet describing this request
180     * @return number of ticks it took to complete
181     */
182    virtual Tick read(PacketPtr pkt) = 0;
183
184    /** Pure virtual function that the device must implement. Called when a
185     * write command is recieved by the port.
186     * @param pkt Packet describing this request
187     * @return number of ticks it took to complete
188     */
189    virtual Tick write(PacketPtr pkt) = 0;
190
191  public:
192    typedef PioDeviceParams Params;
193    PioDevice(const Params *p);
194    virtual ~PioDevice();
195
196    const Params *
197    params() const
198    {
199        return dynamic_cast<const Params *>(_params);
200    }
201
202    virtual void init();
203
204    virtual unsigned int drain(Event *de);
205
206    virtual Port *getPort(const std::string &if_name, int idx = -1)
207    {
208        if (if_name == "pio") {
209            if (pioPort != NULL)
210                panic("pio port already connected to.");
211            pioPort = new PioPort(this, sys);
212            return pioPort;
213        } else
214            return NULL;
215    }
216    friend class PioPort;
217
218};
219
220class BasicPioDevice : public PioDevice
221{
222  protected:
223    /** Address that the device listens to. */
224    Addr pioAddr;
225
226    /** Size that the device's address range. */
227    Addr pioSize;
228
229    /** Delay that the device experinces on an access. */
230    Tick pioDelay;
231
232  public:
233    typedef BasicPioDeviceParams Params;
234    BasicPioDevice(const Params *p);
235
236    const Params *
237    params() const
238    {
239        return dynamic_cast<const Params *>(_params);
240    }
241
242    /** return the address ranges that this device responds to.
243     * @param range_list range list to populate with ranges
244     */
245    void addressRanges(AddrRangeList &range_list);
246
247};
248
249class DmaDevice : public PioDevice
250{
251   protected:
252    DmaPort *dmaPort;
253    Tick minBackoffDelay;
254    Tick maxBackoffDelay;
255
256  public:
257    typedef DmaDeviceParams Params;
258    DmaDevice(const Params *p);
259    virtual ~DmaDevice();
260
261    const Params *
262    params() const
263    {
264        return dynamic_cast<const Params *>(_params);
265    }
266
267    void dmaWrite(Addr addr, int size, Event *event, uint8_t *data)
268    {
269        dmaPort->dmaAction(MemCmd::WriteReq, addr, size, event, data);
270    }
271
272    void dmaRead(Addr addr, int size, Event *event, uint8_t *data)
273    {
274        dmaPort->dmaAction(MemCmd::ReadReq, addr, size, event, data);
275    }
276
277    bool dmaPending() { return dmaPort->dmaPending(); }
278
279    virtual unsigned int drain(Event *de);
280
281    int cacheBlockSize() { return dmaPort->cacheBlockSize(); }
282
283    virtual Port *getPort(const std::string &if_name, int idx = -1)
284    {
285        if (if_name == "pio") {
286            if (pioPort != NULL)
287                panic("pio port already connected to.");
288            pioPort = new PioPort(this, sys);
289            return pioPort;
290        } else if (if_name == "dma") {
291            if (dmaPort != NULL)
292                panic("dma port already connected to.");
293            dmaPort = new DmaPort(this, sys);
294            return dmaPort;
295        } else
296            return NULL;
297    }
298
299    friend class DmaPort;
300};
301
302
303#endif // __DEV_IO_DEVICE_HH__
304