#define __MEM_BUS_HH__
#include <string>
+#include <set>
#include <list>
-#include <inttypes.h>
-#include "base/range.hh"
#include "base/hashmap.hh"
+#include "base/range.hh"
#include "base/range_map.hh"
+#include "base/types.hh"
#include "mem/mem_object.hh"
#include "mem/packet.hh"
#include "mem/port.hh"
#include "mem/request.hh"
+#include "params/Bus.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;
-
- Event * drainEvent;
-
- static const int defaultId = -3; //Make it unique from Broadcast
-
- struct DevMap {
- int portId;
- Range<Addr> range;
- };
- range_map<Addr, int> portMap;
- AddrRangeList defaultRange;
- std::vector<DevMap> portSnoopList;
-
- /** Function called by the port when the bus is recieving a Timing
- transaction.*/
- bool recvTiming(PacketPtr pkt);
-
- /** Function called by the port when the bus is recieving a Atomic
- transaction.*/
- Tick recvAtomic(PacketPtr pkt);
-
- /** Function called by the port when the bus is recieving a Functional
- transaction.*/
- void recvFunctional(PacketPtr 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);
-
- /** Find which port connected to this bus (if any) should be given a packet
- * with this address.
- * @param addr Address to find port for.
- * @param id Id of the port this packet was received from (to prevent
- * loops)
- * @return pointer to port that the packet should be sent out of.
- */
- 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(PacketPtr pkt, Port* responder);
-
- /** Snoop all relevant ports functionally. */
- void functionalSnoop(PacketPtr pkt, Port *responder);
-
- /** Call snoop on caches, be sure to set SNOOP_COMMIT bit if you want
- * the snoop to happen
- * @return True if succeds.
- */
- bool timingSnoop(PacketPtr pkt, Port *responder);
-
- /** Process address range request.
- * @param resp addresses that we can respond to
- * @param snoop addresses that we would like to snoop
- * @param id ide of the busport that made the request.
- */
- void addressRanges(AddrRangeList &resp, AddrRangeList &snoop, int id);
-
- /** Occupy the bus with transmitting the packet pkt */
- void occupyBus(PacketPtr pkt);
-
/** Declaration of the buses port type, one will be instantiated for each
of the interfaces connecting to the bus. */
class BusPort : public Port
// the 'owned' address ranges of all the other interfaces on
// this bus...
virtual void getDeviceAddressRanges(AddrRangeList &resp,
- AddrRangeList &snoop)
+ bool &snoop)
{ bus->addressRanges(resp, snoop, id); }
- // Hack to make translating port work without changes
- virtual int deviceBlockSize() { return 32; }
+ // Ask the bus to ask everyone on the bus what their block size is and
+ // take the max of it. This might need to be changed a bit if we ever
+ // support multiple block sizes.
+ virtual unsigned deviceBlockSize() const
+ { return bus->findBlockSize(id); }
};
public:
BusFreeEvent(Bus * _bus);
void process();
- const char *description();
+ const char *description() const;
};
+ /** a globally unique id for this bus. */
+ int busId;
+ /** the clock speed for the bus */
+ int clock;
+ /** cycles of overhead per transaction */
+ int headerCycles;
+ /** the width of the bus in bytes */
+ int width;
+ /** the next tick at which the bus will be idle */
+ Tick tickNextIdle;
+
+ Event * drainEvent;
+
+
+ static const int defaultId = -3; //Make it unique from Broadcast
+
+ typedef range_map<Addr,int>::iterator PortIter;
+ range_map<Addr, int> portMap;
+
+ AddrRangeList defaultRange;
+
+ typedef std::vector<BusPort*>::iterator SnoopIter;
+ std::vector<BusPort*> snoopPorts;
+
+ /** Function called by the port when the bus is recieving a Timing
+ transaction.*/
+ bool recvTiming(PacketPtr pkt);
+
+ /** Function called by the port when the bus is recieving a Atomic
+ transaction.*/
+ Tick recvAtomic(PacketPtr pkt);
+
+ /** Function called by the port when the bus is recieving a Functional
+ transaction.*/
+ void recvFunctional(PacketPtr 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);
+
+ /** Find which port connected to this bus (if any) should be given a packet
+ * with this address.
+ * @param addr Address to find port for.
+ * @return id of port that the packet should be sent out of.
+ */
+ int findPort(Addr addr);
+
+ // Cache for the findPort function storing recently used ports from portMap
+ struct PortCache {
+ bool valid;
+ int id;
+ Addr start;
+ Addr end;
+ };
+
+ PortCache portCache[3];
+
+ // Checks the cache and returns the id of the port that has the requested
+ // address within its range
+ inline int checkPortCache(Addr addr) {
+ if (portCache[0].valid && addr >= portCache[0].start &&
+ addr < portCache[0].end) {
+ return portCache[0].id;
+ }
+ if (portCache[1].valid && addr >= portCache[1].start &&
+ addr < portCache[1].end) {
+ return portCache[1].id;
+ }
+ if (portCache[2].valid && addr >= portCache[2].start &&
+ addr < portCache[2].end) {
+ return portCache[2].id;
+ }
+
+ return -1;
+ }
+
+ // Clears the earliest entry of the cache and inserts a new port entry
+ inline void updatePortCache(short id, Addr start, Addr end) {
+ portCache[2].valid = portCache[1].valid;
+ portCache[2].id = portCache[1].id;
+ portCache[2].start = portCache[1].start;
+ portCache[2].end = portCache[1].end;
+
+ portCache[1].valid = portCache[0].valid;
+ portCache[1].id = portCache[0].id;
+ portCache[1].start = portCache[0].start;
+ portCache[1].end = portCache[0].end;
+
+ portCache[0].valid = true;
+ portCache[0].id = id;
+ portCache[0].start = start;
+ portCache[0].end = end;
+ }
+
+ // Clears the cache. Needs to be called in constructor.
+ inline void clearPortCache() {
+ portCache[2].valid = false;
+ portCache[1].valid = false;
+ portCache[0].valid = false;
+ }
+
+ /** Process address range request.
+ * @param resp addresses that we can respond to
+ * @param snoop addresses that we would like to snoop
+ * @param id ide of the busport that made the request.
+ */
+ void addressRanges(AddrRangeList &resp, bool &snoop, int id);
+
+ /** Calculate the timing parameters for the packet. Updates the
+ * firstWordTime and finishTime fields of the packet object.
+ * Returns the tick at which the packet header is completed (which
+ * will be all that is sent if the target rejects the packet).
+ */
+ Tick calcPacketTiming(PacketPtr pkt);
+
+ /** Occupy the bus until until */
+ void occupyBus(Tick until);
+
+ /** Ask everyone on the bus what their size is
+ * @param id id of the busport that made the request
+ * @return the max of all the sizes
+ */
+ unsigned findBlockSize(int id);
+
BusFreeEvent busIdle;
bool inRetry;
+ std::set<int> inRecvStatusChange;
/** max number of bus ids we've handed out so far */
short maxId;
/** Port that handles requests that don't match any of the interfaces.*/
BusPort *defaultPort;
+ BusPort *funcPort;
+ int funcPortId;
+
/** Has the user specified their own default responder? */
bool responderSet;
+ unsigned defaultBlockSize;
+ unsigned cachedBlockSize;
+ bool cachedBlockSizeValid;
+
+ // Cache for the peer port interfaces
+ struct BusCache {
+ bool valid;
+ short id;
+ BusPort *port;
+ };
+
+ BusCache busCache[3];
+
+ // Checks the peer port interfaces cache for the port id and returns
+ // a pointer to the matching port
+ inline BusPort* checkBusCache(short id) {
+ if (busCache[0].valid && id == busCache[0].id) {
+ return busCache[0].port;
+ }
+ if (busCache[1].valid && id == busCache[1].id) {
+ return busCache[1].port;
+ }
+ if (busCache[2].valid && id == busCache[2].id) {
+ return busCache[2].port;
+ }
+
+ return NULL;
+ }
+
+ // Replaces the earliest entry in the cache with a new entry
+ inline void updateBusCache(short id, BusPort *port) {
+ busCache[2].valid = busCache[1].valid;
+ busCache[2].id = busCache[1].id;
+ busCache[2].port = busCache[1].port;
+
+ busCache[1].valid = busCache[0].valid;
+ busCache[1].id = busCache[0].id;
+ busCache[1].port = busCache[0].port;
+
+ busCache[0].valid = true;
+ busCache[0].id = id;
+ busCache[0].port = port;
+ }
+
+ // Invalidates the cache. Needs to be called in constructor.
+ inline void clearBusCache() {
+ busCache[2].valid = false;
+ busCache[1].valid = false;
+ busCache[0].valid = false;
+ }
+
+
public:
/** A function used to return the port associated with this bus object. */
virtual void deletePortRefs(Port *p);
virtual void init();
+ virtual void startup();
unsigned int drain(Event *de);
- Bus(const std::string &n, int bus_id, int _clock, int _width,
- bool responder_set)
- : MemObject(n), busId(bus_id), clock(_clock), width(_width),
- tickNextIdle(0), drainEvent(NULL), busIdle(this), inRetry(false),
- maxId(0), defaultPort(NULL), responderSet(responder_set)
+ Bus(const BusParams *p)
+ : MemObject(p), busId(p->bus_id), clock(p->clock),
+ headerCycles(p->header_cycles), width(p->width), tickNextIdle(0),
+ drainEvent(NULL), busIdle(this), inRetry(false), maxId(0),
+ defaultPort(NULL), funcPort(NULL), funcPortId(-4),
+ responderSet(p->responder_set), defaultBlockSize(p->block_size),
+ cachedBlockSize(0), cachedBlockSizeValid(false)
{
- //Both the width and clock period must be positive
+ //width, clock period, and header cycles must be positive
if (width <= 0)
fatal("Bus width must be positive\n");
if (clock <= 0)
fatal("Bus clock period must be positive\n");
+ if (headerCycles <= 0)
+ fatal("Number of header cycles must be positive\n");
+ clearBusCache();
+ clearPortCache();
}
};
projects / gem5.git / blobdiff