io_device.hh revision 8922:17f037ad8918 
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 "base/fast_alloc.hh"
36#include "mem/mem_object.hh"
37#include "mem/packet.hh"
38#include "mem/tport.hh"
39#include "params/BasicPioDevice.hh"
40#include "params/DmaDevice.hh"
41#include "params/PioDevice.hh"
42#include "sim/sim_object.hh"
43
44class Event;
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 getAddrRanges() 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 AddrRangeList getAddrRanges();
65
66  public:
67
68    PioPort(PioDevice *dev);
69};
70
71
72class DmaPort : public MasterPort
73{
74  protected:
75    struct DmaReqState : public Packet::SenderState, public FastAlloc
76    {
77        /** Event to call on the device when this transaction (all packets)
78         * complete. */
79        Event *completionEvent;
80
81        /** Where we came from for some sanity checking. */
82        Port *outPort;
83
84        /** Total number of bytes that this transaction involves. */
85        Addr totBytes;
86
87        /** Number of bytes that have been acked for this transaction. */
88        Addr numBytes;
89
90        /** Amount to delay completion of dma by */
91        Tick delay;
92
93
94        DmaReqState(Event *ce, Port *p, Addr tb, Tick _delay)
95            : completionEvent(ce), outPort(p), totBytes(tb), numBytes(0),
96              delay(_delay)
97        {}
98    };
99
100    MemObject *device;
101    std::list<PacketPtr> transmitList;
102
103    /** The system that device/port are in. This is used to select which mode
104     * we are currently operating in. */
105    System *sys;
106
107    /** Id for all requests */
108    MasterID masterId;
109
110    /** Number of outstanding packets the dma port has. */
111    int pendingCount;
112
113    /** If a dmaAction is in progress. */
114    int actionInProgress;
115
116    /** If we need to drain, keep the drain event around until we're done
117     * here.*/
118    Event *drainEvent;
119
120    /** time to wait between sending another packet, increases as NACKs are
121     * recived, decreases as responses are recived. */
122    Tick backoffTime;
123
124    /** Minimum time that device should back off for after failed sendTiming */
125    Tick minBackoffDelay;
126
127    /** Maximum time that device should back off for after failed sendTiming */
128    Tick maxBackoffDelay;
129
130    /** If the port is currently waiting for a retry before it can send whatever
131     * it is that it's sending. */
132    bool inRetry;
133
134    /** Port accesses a cache which requires snooping */
135    bool recvSnoops;
136
137    virtual bool recvTiming(PacketPtr pkt);
138    virtual Tick recvAtomic(PacketPtr pkt)
139    {
140        if (recvSnoops) return 0;
141
142        panic("dma port shouldn't be used for pio access."); M5_DUMMY_RETURN
143    }
144    virtual void recvFunctional(PacketPtr pkt)
145    {
146        if (recvSnoops) return;
147
148        panic("dma port shouldn't be used for pio access.");
149    }
150
151    virtual void recvRetry() ;
152
153    virtual bool isSnooping() const { return recvSnoops; }
154
155    void queueDma(PacketPtr pkt, bool front = false);
156    void sendDma();
157
158    /** event to give us a kick every time we backoff time is reached. */
159    EventWrapper<DmaPort, &DmaPort::sendDma> backoffEvent;
160
161  public:
162    DmaPort(MemObject *dev, System *s, Tick min_backoff, Tick max_backoff,
163            bool recv_snoops = false);
164
165    void dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
166                   uint8_t *data, Tick delay, Request::Flags flag = 0);
167
168    bool dmaPending() { return pendingCount > 0; }
169
170    unsigned cacheBlockSize() const { return peerBlockSize(); }
171    unsigned int drain(Event *de);
172};
173
174/**
175 * This device is the base class which all devices senstive to an address range
176 * inherit from. There are three pure virtual functions which all devices must
177 * implement getAddrRanges(), read(), and write(). The magic do choose which
178 * mode we are in, etc is handled by the PioPort so the device doesn't have to
179 * bother.
180 */
181class PioDevice : public MemObject
182{
183  protected:
184    System *sys;
185
186    /** The pioPort that handles the requests for us and provides us requests
187     * that it sees. */
188    PioPort pioPort;
189
190    /**
191     * Every PIO device is obliged to provide an implementation that
192     * returns the address ranges the device responds to.
193     *
194     * @return a list of non-overlapping address ranges
195     */
196    virtual AddrRangeList getAddrRanges() = 0;
197
198    /** Pure virtual function that the device must implement. Called
199     * when a read command is recieved by the port.
200     * @param pkt Packet describing this request
201     * @return number of ticks it took to complete
202     */
203    virtual Tick read(PacketPtr pkt) = 0;
204
205    /** Pure virtual function that the device must implement. Called when a
206     * write command is recieved by the port.
207     * @param pkt Packet describing this request
208     * @return number of ticks it took to complete
209     */
210    virtual Tick write(PacketPtr pkt) = 0;
211
212  public:
213    typedef PioDeviceParams Params;
214    PioDevice(const Params *p);
215    virtual ~PioDevice();
216
217    const Params *
218    params() const
219    {
220        return dynamic_cast<const Params *>(_params);
221    }
222
223    virtual void init();
224
225    virtual unsigned int drain(Event *de);
226
227    virtual SlavePort &getSlavePort(const std::string &if_name, int idx = -1);
228
229    friend class PioPort;
230
231};
232
233class BasicPioDevice : public PioDevice
234{
235  protected:
236    /** Address that the device listens to. */
237    Addr pioAddr;
238
239    /** Size that the device's address range. */
240    Addr pioSize;
241
242    /** Delay that the device experinces on an access. */
243    Tick pioDelay;
244
245  public:
246    typedef BasicPioDeviceParams Params;
247    BasicPioDevice(const Params *p);
248
249    const Params *
250    params() const
251    {
252        return dynamic_cast<const Params *>(_params);
253    }
254
255    /**
256     * Determine the address ranges that this device responds to.
257     *
258     * @return a list of non-overlapping address ranges
259     */
260    virtual AddrRangeList getAddrRanges();
261
262};
263
264class DmaDevice : public PioDevice
265{
266   protected:
267    DmaPort dmaPort;
268
269  public:
270    typedef DmaDeviceParams Params;
271    DmaDevice(const Params *p);
272    virtual ~DmaDevice();
273
274    const Params *
275    params() const
276    {
277        return dynamic_cast<const Params *>(_params);
278    }
279
280    void dmaWrite(Addr addr, int size, Event *event, uint8_t *data,
281                  Tick delay = 0)
282    {
283        dmaPort.dmaAction(MemCmd::WriteReq, addr, size, event, data, delay);
284    }
285
286    void dmaRead(Addr addr, int size, Event *event, uint8_t *data,
287                 Tick delay = 0)
288    {
289        dmaPort.dmaAction(MemCmd::ReadReq, addr, size, event, data, delay);
290    }
291
292    bool dmaPending() { return dmaPort.dmaPending(); }
293
294    virtual void init();
295
296    virtual unsigned int drain(Event *de);
297
298    unsigned cacheBlockSize() const { return dmaPort.cacheBlockSize(); }
299
300    virtual MasterPort &getMasterPort(const std::string &if_name,
301                                      int idx = -1);
302
303    friend class DmaPort;
304};
305
306
307#endif // __DEV_IO_DEVICE_HH__
308