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44 #ifndef __DEV_IO_DEVICE_HH__
45 #define __DEV_IO_DEVICE_HH__
47 #include "mem/tport.hh"
48 #include "params/BasicPioDevice.hh"
49 #include "params/PioDevice.hh"
50 #include "sim/clocked_object.hh"
56 * The PioPort class is a programmed i/o port that all devices that are
57 * sensitive to an address range use. The port takes all the memory
58 * access types and roles them into one read() and write() call that the device
59 * must respond to. The device must also provide getAddrRanges() function
60 * with which it returns the address ranges it is interested in.
62 template <class Device>
63 class PioPort : public SimpleTimingPort
66 /** The device that this port serves. */
70 recvAtomic(PacketPtr pkt) override
72 // Technically the packet only reaches us after the header delay,
73 // and typically we also need to deserialise any payload.
74 Tick receive_delay = pkt->headerDelay + pkt->payloadDelay;
75 pkt->headerDelay = pkt->payloadDelay = 0;
78 pkt->isRead() ? device->read(pkt) : device->write(pkt);
79 assert(pkt->isResponse() || pkt->isError());
80 return delay + receive_delay;
84 getAddrRanges() const override
86 return device->getAddrRanges();
90 PioPort(Device *dev) :
91 SimpleTimingPort(dev->name() + ".pio", dev), device(dev)
96 * This device is the base class which all devices senstive to an address range
97 * inherit from. There are three pure virtual functions which all devices must
98 * implement getAddrRanges(), read(), and write(). The magic do choose which
99 * mode we are in, etc is handled by the PioPort so the device doesn't have to
102 class PioDevice : public ClockedObject
107 /** The pioPort that handles the requests for us and provides us requests
109 PioPort<PioDevice> pioPort;
112 * Every PIO device is obliged to provide an implementation that
113 * returns the address ranges the device responds to.
115 * @return a list of non-overlapping address ranges
117 virtual AddrRangeList getAddrRanges() const = 0;
119 /** Pure virtual function that the device must implement. Called
120 * when a read command is recieved by the port.
121 * @param pkt Packet describing this request
122 * @return number of ticks it took to complete
124 virtual Tick read(PacketPtr pkt) = 0;
126 /** Pure virtual function that the device must implement. Called when a
127 * write command is recieved by the port.
128 * @param pkt Packet describing this request
129 * @return number of ticks it took to complete
131 virtual Tick write(PacketPtr pkt) = 0;
134 typedef PioDeviceParams Params;
135 PioDevice(const Params *p);
136 virtual ~PioDevice();
141 return dynamic_cast<const Params *>(_params);
144 void init() override;
146 Port &getPort(const std::string &if_name,
147 PortID idx=InvalidPortID) override;
149 friend class PioPort<PioDevice>;
153 class BasicPioDevice : public PioDevice
156 /** Address that the device listens to. */
159 /** Size that the device's address range. */
162 /** Delay that the device experinces on an access. */
166 typedef BasicPioDeviceParams Params;
167 BasicPioDevice(const Params *p, Addr size);
172 return dynamic_cast<const Params *>(_params);
176 * Determine the address ranges that this device responds to.
178 * @return a list of non-overlapping address ranges
180 AddrRangeList getAddrRanges() const override;
183 #endif // __DEV_IO_DEVICE_HH__