1 files changed, 150 insertions, 48 deletions

diff --git a/dev/io_device.hh b/dev/io_device.hh
index a79c3f20a..a43527b37 100644
--- a/dev/io_device.hh
+++ b/dev/io_device.hh
@@ -32,30 +32,57 @@
 #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;
+class System;
+
+/**
+ * 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. */
+    Platform *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 &resp, AddrRangeList &snoop);
 
+    /**
+     * 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 +98,19 @@ 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 +118,10 @@ 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 +130,14 @@ class DmaPort : public Port
     virtual void recvStatusChange(Status status)
     { ; }
 
-    virtual Packet *recvRetry()
-    { return transmitList.pop_front();  }
-
-    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() ;
 
-    virtual Packet *recvRetry()
-    { return transmitList.pop_front();  }
+    virtual void getDeviceAddressRanges(AddrRangeList &resp, AddrRangeList &snoop)
+    { resp.clear(); snoop.clear(); }
 
     class SendEvent : public Event
     {
-        PioPort *port;
+        DmaPort *port;
         Packet packet;
 
         SendEvent(PioPort *p, Packet &pkt, Tick t)
@@ -125,46 +149,124 @@ 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 void addressRanges(AddrRangeList &range_list) = 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); }
+
+    /** Pure virtual function that the device must implement. Called when a read
+     * command is recieved by the port.
+     * @param pkt Packet describing this request
+     * @return number of ticks it took to complete
+     */
+    virtual Tick read(Packet &pkt) = 0;
+
+    /** Pure virtual function that the device must implement. Called when a
+     * write command is recieved by the port.
+     * @param pkt Packet describing this request
+     * @return number of ticks it took to complete
+     */
+    virtual Tick write(Packet &pkt) = 0;
 
-    virtual write(Packet &pkt) = 0;
+  public:
+    /** Params struct which is extended through each device based on the
+     * parameters it needs. Since we are re-writing everything, we might as well
+     * start from the bottom this time. */
 
-    Tick recvAtomic(Packet &pkt)
-    { return pkt->cmd == Read ? this->read(pkt) : this->write(pkt); }
+    struct Params
+    {
+        std::string name;
+        Platform *platform;
+        System *system;
+    };
+
+  protected:
+    Params *_params;
 
   public:
-    PioDevice(const std::string &name, Platform *p);
+    const Params *params() const { return _params; }
+
+    PioDevice(Params *p)
+              : SimObject(params()->name), platform(p->platform), _params(p)
+              {}
 
     virtual ~PioDevice();
 
-    virtual Port *getPort(std::string if_name)
+    virtual Port *getPort(const std::string &if_name)
     {
-        if (if_name == "pio")
+        if (if_name == "pio") {
+            if (pioPort != NULL)
+                panic("pio port already connected to.");
+            pioPort = new PioPort(this, params()->platform);
             return pioPort;
-        else
+        } else
             return NULL;
     }
+    friend class PioPort;
+
+};
+
+class BasicPioDevice : public PioDevice
+{
+  public:
+    struct Params :  public PioDevice::Params
+    {
+        Addr pio_addr;
+        Tick pio_delay;
+    };
+
+  protected:
+    /** Address that the device listens to. */
+    Addr pioAddr;
+
+    /** Size that the device's address range. */
+    Addr pioSize;
+
+    /** Delay that the device experinces on an access. */
+    Tick pioDelay;
+
+  public:
+    BasicPioDevice(Params *p)
+        : PioDevice(p), pioAddr(p->pio_addr), pioSize(0), pioDelay(p->pio_delay)
+    {}
+
 };
 
 class DmaDevice : public PioDevice
@@ -173,21 +275,21 @@ class DmaDevice : public PioDevice
     DmaPort *dmaPort;
 
   public:
-    DmaDevice(const std::string &name, Platform *p);
+    DmaDevice(Params *p);
     virtual ~DmaDevice();
 
-    virtual Port *getPort(std::string if_name)
+    virtual Port *getPort(const std::string &if_name)
     {
         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__