io_device.hh revision 8711 
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 Platform;
46class PioDevice;
47class DmaDevice;
48class System;
49
50/**
51 * The PioPort class is a programmed i/o port that all devices that are
52 * sensitive to an address range use. The port takes all the memory
53 * access types and roles them into one read() and write() call that the device
54 * must respond to. The device must also provide getAddrRanges() function
55 * with which it returns the address ranges it is interested in.
56 */
57class PioPort : public SimpleTimingPort
58{
59  protected:
60    /** The device that this port serves. */
61    PioDevice *device;
62
63    virtual Tick recvAtomic(PacketPtr pkt);
64
65    virtual AddrRangeList getAddrRanges();
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, public FastAlloc
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        /** Amount to delay completion of dma by */
92        Tick delay;
93
94
95        DmaReqState(Event *ce, Port *p, Addr tb, Tick _delay)
96            : completionEvent(ce), outPort(p), totBytes(tb), numBytes(0),
97              delay(_delay)
98        {}
99    };
100
101    MemObject *device;
102    std::list<PacketPtr> transmitList;
103
104    /** The system that device/port are in. This is used to select which mode
105     * we are currently operating in. */
106    System *sys;
107
108    /** Number of outstanding packets the dma port has. */
109    int pendingCount;
110
111    /** If a dmaAction is in progress. */
112    int actionInProgress;
113
114    /** If we need to drain, keep the drain event around until we're done
115     * here.*/
116    Event *drainEvent;
117
118    /** time to wait between sending another packet, increases as NACKs are
119     * recived, decreases as responses are recived. */
120    Tick backoffTime;
121
122    /** Minimum time that device should back off for after failed sendTiming */
123    Tick minBackoffDelay;
124
125    /** Maximum time that device should back off for after failed sendTiming */
126    Tick maxBackoffDelay;
127
128    /** If the port is currently waiting for a retry before it can send whatever
129     * it is that it's sending. */
130    bool inRetry;
131
132    /** Port accesses a cache which requires snooping */
133    bool recvSnoops;
134
135    virtual bool recvTiming(PacketPtr pkt);
136    virtual Tick recvAtomic(PacketPtr pkt)
137    {
138        if (recvSnoops) return 0;
139
140        panic("dma port shouldn't be used for pio access."); M5_DUMMY_RETURN
141    }
142    virtual void recvFunctional(PacketPtr pkt)
143    {
144        if (recvSnoops) return;
145
146        panic("dma port shouldn't be used for pio access.");
147    }
148
149    virtual void recvRangeChange()
150    {
151        // DMA port is a master with a single slave so there is no choice and
152        // thus no need to worry about any address changes
153    }
154
155    virtual void recvRetry() ;
156
157    virtual bool isSnooping()
158    { return recvSnoops; }
159
160    void queueDma(PacketPtr pkt, bool front = false);
161    void sendDma();
162
163    /** event to give us a kick every time we backoff time is reached. */
164    EventWrapper<DmaPort, &DmaPort::sendDma> backoffEvent;
165
166  public:
167    DmaPort(MemObject *dev, System *s, Tick min_backoff, Tick max_backoff,
168            bool recv_snoops = false);
169
170    void dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
171                   uint8_t *data, Tick delay, Request::Flags flag = 0);
172
173    bool dmaPending() { return pendingCount > 0; }
174
175    unsigned cacheBlockSize() const { return peerBlockSize(); }
176    unsigned int drain(Event *de);
177};
178
179/**
180 * This device is the base class which all devices senstive to an address range
181 * inherit from. There are three pure virtual functions which all devices must
182 * implement getAddrRanges(), read(), and write(). The magic do choose which
183 * mode we are in, etc is handled by the PioPort so the device doesn't have to
184 * bother.
185 */
186class PioDevice : public MemObject
187{
188  protected:
189
190    /** The platform we are in. This is used to decide what type of memory
191     * transaction we should perform. */
192    Platform *platform;
193
194    System *sys;
195
196    /** The pioPort that handles the requests for us and provides us requests
197     * that it sees. */
198    PioPort *pioPort;
199
200    /**
201     * Every PIO device is obliged to provide an implementation that
202     * returns the address ranges the device responds to.
203     *
204     * @return a list of non-overlapping address ranges
205     */
206    virtual AddrRangeList getAddrRanges() = 0;
207
208    /** Pure virtual function that the device must implement. Called
209     * when a read command is recieved by the port.
210     * @param pkt Packet describing this request
211     * @return number of ticks it took to complete
212     */
213    virtual Tick read(PacketPtr pkt) = 0;
214
215    /** Pure virtual function that the device must implement. Called when a
216     * write command is recieved by the port.
217     * @param pkt Packet describing this request
218     * @return number of ticks it took to complete
219     */
220    virtual Tick write(PacketPtr pkt) = 0;
221
222  public:
223    typedef PioDeviceParams Params;
224    PioDevice(const Params *p);
225    virtual ~PioDevice();
226
227    const Params *
228    params() const
229    {
230        return dynamic_cast<const Params *>(_params);
231    }
232
233    virtual void init();
234
235    virtual unsigned int drain(Event *de);
236
237    virtual Port *getPort(const std::string &if_name, int idx = -1);
238
239    friend class PioPort;
240
241};
242
243class BasicPioDevice : public PioDevice
244{
245  protected:
246    /** Address that the device listens to. */
247    Addr pioAddr;
248
249    /** Size that the device's address range. */
250    Addr pioSize;
251
252    /** Delay that the device experinces on an access. */
253    Tick pioDelay;
254
255  public:
256    typedef BasicPioDeviceParams Params;
257    BasicPioDevice(const Params *p);
258
259    const Params *
260    params() const
261    {
262        return dynamic_cast<const Params *>(_params);
263    }
264
265    /**
266     * Determine the address ranges that this device responds to.
267     *
268     * @return a list of non-overlapping address ranges
269     */
270    virtual AddrRangeList getAddrRanges();
271
272};
273
274class DmaDevice : public PioDevice
275{
276   protected:
277    DmaPort *dmaPort;
278
279  public:
280    typedef DmaDeviceParams Params;
281    DmaDevice(const Params *p);
282    virtual ~DmaDevice();
283
284    const Params *
285    params() const
286    {
287        return dynamic_cast<const Params *>(_params);
288    }
289
290    void dmaWrite(Addr addr, int size, Event *event, uint8_t *data, Tick delay = 0)
291    {
292        dmaPort->dmaAction(MemCmd::WriteReq, addr, size, event, data, delay);
293    }
294
295    void dmaRead(Addr addr, int size, Event *event, uint8_t *data, Tick delay = 0)
296    {
297        dmaPort->dmaAction(MemCmd::ReadReq, addr, size, event, data, delay);
298    }
299
300    bool dmaPending() { return dmaPort->dmaPending(); }
301
302    virtual unsigned int drain(Event *de);
303
304    unsigned cacheBlockSize() const { return dmaPort->cacheBlockSize(); }
305
306    virtual Port *getPort(const std::string &if_name, int idx = -1);
307
308    friend class DmaPort;
309};
310
311
312#endif // __DEV_IO_DEVICE_HH__
313