diff options
Diffstat (limited to 'dev/io_device.hh')
| -rw-r--r-- | dev/io_device.hh | 125 |
1 files changed, 86 insertions, 39 deletions
diff --git a/dev/io_device.hh b/dev/io_device.hh index a79c3f20a..8e44a1c00 100644 --- a/dev/io_device.hh +++ b/dev/io_device.hh @@ -32,30 +32,56 @@ #include "base/chunk_generator.hh" #include "mem/port.hh" #include "sim/eventq.hh" +#include "sim/sim_object.hh" -class Bus; class Platform; class PioDevice; - +class DmaDevice; + +/** + * The PioPort class is a programmed i/o port that all devices that are + * sensitive to an address range use. The port takes all the memory + * access types and roles them into one read() and write() call that the device + * must respond to. The device must also provide the addressRanges() function + * with which it returns the address ranges it is interested in. An extra + * sendTiming() function is implemented which takes an delay. In this way the + * device can immediatly call sendTiming(pkt, time) after processing a request + * and the request will be handled by the port even if the port bus the device + * connects to is blocked. + */ class PioPort : public Port { protected: + /** The device that this port serves. */ PioDevice *device; + /** The platform that device/port are in. This is used to select which mode + * we are currently operating in. */ + Platfrom *platform; + + /** A list of outgoing timing response packets that haven't been serviced + * yet. */ + std::list<Packet*> transmitList; + + /** The current status of the peer(bus) that we are connected to. */ + Status peerStatus; + virtual bool recvTiming(Packet &pkt); - virtual Tick recvAtomic(Packet &pkt) - { return device->recvAtomic(pkt) }; + virtual Tick recvAtomic(Packet &pkt); - virtual void recvFunctional(Packet &pkt) - { device->recvAtomic(pkt) }; + virtual void recvFunctional(Packet &pkt) ; - virtual void getDeviceAddressRanges(AddrRangeList &range_list, bool &owner) - { device->addressRanges(range_list, owner); } + virtual void recvStatusChange(Status status) + { peerStatus = status; } - void sendTiming(Packet &pkt, Tick time) - { new SendEvent(this, pkt, time); } + virtual void getDeviceAddressRanges(AddrRangeList &range_list, bool &owner); + /** + * This class is used to implemented sendTiming() with a delay. When a delay + * is requested a new event is created. When the event time expires it + * attempts to send the packet. If it cannot, the packet is pushed onto the + * transmit list to be sent when recvRetry() is called. */ class SendEvent : public Event { PioPort *port; @@ -71,13 +97,19 @@ class PioPort : public Port { return "Future scheduled sendTiming event"; } friend class PioPort; - } + }; + + /** Schedule a sendTiming() event to be called in the future. */ + void sendTiming(Packet &pkt, Tick time) + { new PioPort::SendEvent(this, pkt, time); } + + /** This function pops the last element off the transmit list and sends it.*/ + virtual Packet *recvRetry(); public: - PioPort(PioDevice *dev) - : device(dev) - { } + PioPort(PioDevice *dev, Platform *p); + friend class PioPort::SendEvent; }; class DmaPort : public Port @@ -85,10 +117,10 @@ class DmaPort : public Port protected: PioDevice *device; std::list<Packet*> transmitList; + Event *completionEvent; - virtual bool recvTiming(Packet &pkt) - { completionEvent->schedule(curTick+1); completionEvent = NULL; } + virtual bool recvTiming(Packet &pkt); virtual Tick recvAtomic(Packet &pkt) { panic("dma port shouldn't be used for pio access."); } virtual void recvFunctional(Packet &pkt) @@ -97,23 +129,14 @@ class DmaPort : public Port virtual void recvStatusChange(Status status) { ; } - virtual Packet *recvRetry() - { return transmitList.pop_front(); } + virtual Packet *recvRetry() ; virtual void getDeviceAddressRanges(AddrRangeList &range_list, bool &owner) { range_list.clear(); owner = true; } - void dmaAction(Memory::Command cmd, DmaPort port, Addr addr, int size, - Event *event, uint8_t *data = NULL); - - void sendDma(Packet &pkt); - - virtual Packet *recvRetry() - { return transmitList.pop_front(); } - class SendEvent : public Event { - PioPort *port; + DmaPort *port; Packet packet; SendEvent(PioPort *p, Packet &pkt, Tick t) @@ -125,33 +148,55 @@ class DmaPort : public Port virtual const char *description() { return "Future scheduled sendTiming event"; } - friend class PioPort; - } + friend class DmaPort; + }; + + void dmaAction(Command cmd, DmaPort port, Addr addr, int size, + Event *event, uint8_t *data = NULL); + + void sendDma(Packet &pkt); + public: - DmaPort(DmaDevice *dev) - : device(dev) - { } + DmaPort(DmaDevice *dev); + friend class DmaPort::SendEvent; }; +/** + * This device is the base class which all devices senstive to an address range + * inherit from. There are three pure virtual functions which all devices must + * implement addressRanges(), read(), and write(). The magic do choose which + * mode we are in, etc is handled by the PioPort so the device doesn't have to + * bother. + */ class PioDevice : public SimObject { protected: + /** The platform we are in. This is used to decide what type of memory + * transaction we should perform. */ Platform *platform; + /** The pioPort that handles the requests for us and provides us requests + * that it sees. */ PioPort *pioPort; virtual void addressRanges(AddrRangeList &range_list, bool &owner) = 0; - virtual read(Packet &pkt) = 0; + /** As far as the devices are concerned they only accept atomic transactions + * which are converted to either a write or a read. */ + Tick recvAtomic(Packet &pkt) + { return pkt.cmd == Read ? this->read(pkt) : this->write(pkt); } - virtual write(Packet &pkt) = 0; + /** Pure virtual function that the device must implement. Called when a read + * command is recieved by the port. */ + virtual bool read(Packet &pkt) = 0; - Tick recvAtomic(Packet &pkt) - { return pkt->cmd == Read ? this->read(pkt) : this->write(pkt); } + /** Pure virtual function that the device must implement. Called when a + * write command is recieved by the port. */ + virtual bool write(Packet &pkt) = 0; public: PioDevice(const std::string &name, Platform *p); @@ -165,6 +210,8 @@ class PioDevice : public SimObject else return NULL; } + friend class PioPort; + }; class DmaDevice : public PioDevice @@ -180,14 +227,14 @@ class DmaDevice : public PioDevice { if (if_name == "pio") return pioPort; - else if (if_name = "dma") + else if (if_name == "dma") return dmaPort; else return NULL; } -}; - + friend class DmaPort; +}; #endif // __DEV_IO_DEVICE_HH__ |