* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Ron Dreslinski
+ * Ali Saidi
*/
/**
- * @file Decleration of a bus object.
+ * @file
+ * Declaration of a bus object.
*/
#ifndef __MEM_BUS_HH__
#include "mem/packet.hh"
#include "mem/port.hh"
#include "mem/request.hh"
+#include "sim/eventq.hh"
class Bus : public MemObject
{
/** a globally unique id for this bus. */
int busId;
+ /** the clock speed for the bus */
+ int clock;
+ /** the width of the bus in bytes */
+ int width;
+ /** the next tick at which the bus will be idle */
+ Tick tickNextIdle;
+
+ static const int defaultId = -1;
struct DevMap {
int portId;
Range<Addr> range;
};
std::vector<DevMap> portList;
-
+ AddrRangeList defaultRange;
+ std::vector<DevMap> portSnoopList;
/** Function called by the port when the bus is recieving a Timing
- transaction.*/
+ transaction.*/
bool recvTiming(Packet *pkt);
/** Function called by the port when the bus is recieving a Atomic
- transaction.*/
+ transaction.*/
Tick recvAtomic(Packet *pkt);
/** Function called by the port when the bus is recieving a Functional
transaction.*/
void recvFunctional(Packet *pkt);
+ /** Timing function called by port when it is once again able to process
+ * requests. */
+ void recvRetry(int id);
+
/** Function called by the port when the bus is recieving a status change.*/
void recvStatusChange(Port::Status status, int id);
*/
Port *findPort(Addr addr, int id);
+ /** Find all ports with a matching snoop range, except src port. Keep in mind
+ * that the ranges shouldn't overlap or you will get a double snoop to the same
+ * interface.and the cache will assert out.
+ * @param addr Address to find snoop prts for.
+ * @param id Id of the src port of the request to avoid calling snoop on src
+ * @return vector of IDs to snoop on
+ */
+ std::vector<int> findSnoopPorts(Addr addr, int id);
+
+ /** Snoop all relevant ports atomicly. */
+ Tick atomicSnoop(Packet *pkt);
+
+ /** Snoop all relevant ports functionally. */
+ void functionalSnoop(Packet *pkt);
+
+ /** Call snoop on caches, be sure to set SNOOP_COMMIT bit if you want
+ * the snoop to happen
+ * @return True if succeds.
+ */
+ bool timingSnoop(Packet *pkt);
+
/** Process address range request.
* @param resp addresses that we can respond to
* @param snoop addresses that we would like to snoop
*/
void addressRanges(AddrRangeList &resp, AddrRangeList &snoop, int id);
+ /** Occupy the bus with transmitting the packet pkt */
+ void occupyBus(PacketPtr pkt);
- /** Decleration of the buses port type, one will be instantiated for each
+ /** Declaration of the buses port type, one will be instantiated for each
of the interfaces connecting to the bus. */
class BusPort : public Port
{
+ bool _onRetryList;
+
/** A pointer to the bus to which this port belongs. */
Bus *bus;
public:
/** Constructor for the BusPort.*/
- BusPort(Bus *_bus, int _id)
- : bus(_bus), id(_id)
+ BusPort(const std::string &_name, Bus *_bus, int _id)
+ : Port(_name), _onRetryList(false), bus(_bus), id(_id)
{ }
+ bool onRetryList()
+ { return _onRetryList; }
+
+ void onRetryList(bool newVal)
+ { _onRetryList = newVal; }
+
protected:
/** When reciving a timing request from the peer port (at id),
pass it to the bus. */
virtual bool recvTiming(Packet *pkt)
- { pkt->src = id; return bus->recvTiming(pkt); }
+ { pkt->setSrc(id); return bus->recvTiming(pkt); }
/** When reciving a Atomic requestfrom the peer port (at id),
pass it to the bus. */
virtual Tick recvAtomic(Packet *pkt)
- { pkt->src = id; return bus->recvAtomic(pkt); }
+ { pkt->setSrc(id); return bus->recvAtomic(pkt); }
/** When reciving a Functional requestfrom the peer port (at id),
pass it to the bus. */
virtual void recvFunctional(Packet *pkt)
- { pkt->src = id; bus->recvFunctional(pkt); }
+ { pkt->setSrc(id); bus->recvFunctional(pkt); }
/** When reciving a status changefrom the peer port (at id),
pass it to the bus. */
virtual void recvStatusChange(Status status)
{ bus->recvStatusChange(status, id); }
+ /** When reciving a retry from the peer port (at id),
+ pass it to the bus. */
+ virtual void recvRetry()
+ { bus->recvRetry(id); }
+
// This should return all the 'owned' addresses that are
// downstream from this bus, yes? That is, the union of all
// the 'owned' address ranges of all the other interfaces on
};
+ class BusFreeEvent : public Event
+ {
+ Bus * bus;
+
+ public:
+ BusFreeEvent(Bus * _bus);
+ void process();
+ const char *description();
+ };
+
+ BusFreeEvent busIdle;
+
+ bool inRetry;
+
/** An array of pointers to the peer port interfaces
connected to this bus.*/
- std::vector<Port*> interfaces;
+ std::vector<BusPort*> interfaces;
- public:
+ /** An array of pointers to ports that retry should be called on because the
+ * original send failed for whatever reason.*/
+ std::list<BusPort*> retryList;
- /** A function used to return the port associated with this bus object. */
- virtual Port *getPort(const std::string &if_name)
+ void addToRetryList(BusPort * port)
{
- // if_name ignored? forced to be empty?
- int id = interfaces.size();
- interfaces.push_back(new BusPort(this, id));
- return interfaces.back();
+ if (!inRetry) {
+ // The device wasn't retrying a packet, or wasn't at an appropriate
+ // time.
+ assert(!port->onRetryList());
+ port->onRetryList(true);
+ retryList.push_back(port);
+ } else {
+ if (port->onRetryList()) {
+ // The device was retrying a packet. It didn't work, so we'll leave
+ // it at the head of the retry list.
+ assert(port == retryList.front());
+ inRetry = false;
+ }
+ else {
+ retryList.push_back(port);
+ }
+ }
}
+ /** Port that handles requests that don't match any of the interfaces.*/
+ Port *defaultPort;
+
+ public:
+
+ /** A function used to return the port associated with this bus object. */
+ virtual Port *getPort(const std::string &if_name, int idx = -1);
+
virtual void init();
- Bus(const std::string &n, int bus_id)
- : MemObject(n), busId(bus_id) {}
+ Bus(const std::string &n, int bus_id, int _clock, int _width)
+ : MemObject(n), busId(bus_id), clock(_clock), width(_width),
+ tickNextIdle(0), busIdle(this), inRetry(false), defaultPort(NULL)
+ {
+ //Both the width and clock period must be positive
+ if (width <= 0)
+ fatal("Bus width must be positive\n");
+ if (clock <= 0)
+ fatal("Bus clock period must be positive\n");
+ }
};
projects / gem5.git / blobdiff