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28 * Authors: Erik Hallnor
32 * Declaration of a structure to manage MSHRs.
35 #ifndef __MEM__CACHE__MISS__MSHR_QUEUE_HH__
36 #define __MEM__CACHE__MISS__MSHR_QUEUE_HH__
40 #include "mem/cache/mshr.hh"
41 #include "mem/packet.hh"
44 * A Class for maintaining a list of pending and allocated memory requests.
49 /** Local label (for functional print requests) */
50 const std::string label;
54 /** Holds pointers to all allocated entries. */
55 MSHR::List allocatedList;
56 /** Holds pointers to entries that haven't been sent to the bus. */
58 /** Holds non allocated entries. */
63 * The total number of entries in this queue. This number is set as the
64 * number of entries requested plus (numReserve - 1). This allows for
65 * the same number of effective entries while still maintaining the reserve.
70 * The number of entries to hold in reserve. This is needed because copy
71 * operations can allocate upto 4 entries at one time.
75 MSHR::Iterator addToReadyList(MSHR *mshr);
79 /** The number of allocated entries. */
81 /** The number of entries that have been forwarded to the bus. */
83 /** The index of this queue within the cache (MSHR queue vs. write
88 * Create a queue with a given number of entries.
89 * @param num_entrys The number of entries in this queue.
90 * @param reserve The minimum number of entries needed to satisfy
93 MSHRQueue(const std::string &_label, int num_entries, int reserve,
100 * Find the first MSHR that matches the provided address.
101 * @param addr The address to find.
102 * @return Pointer to the matching MSHR, null if not found.
104 MSHR *findMatch(Addr addr) const;
107 * Find and return all the matching entries in the provided vector.
108 * @param addr The address to find.
109 * @param matches The vector to return pointers to the matching entries.
110 * @return True if any matches are found, false otherwise.
111 * @todo Typedef the vector??
113 bool findMatches(Addr addr, std::vector<MSHR*>& matches) const;
116 * Find any pending requests that overlap the given request.
117 * @param pkt The request to find.
118 * @return A pointer to the earliest matching MSHR.
120 MSHR *findPending(Addr addr, int size) const;
122 bool checkFunctional(PacketPtr pkt, Addr blk_addr);
125 * Allocates a new MSHR for the request and size. This places the request
126 * as the first target in the MSHR.
127 * @param pkt The request to handle.
128 * @param size The number in bytes to fetch from memory.
129 * @return The a pointer to the MSHR allocated.
131 * @pre There are free entries.
133 MSHR *allocate(Addr addr, int size, PacketPtr &pkt,
134 Tick when, Counter order);
137 * Removes the given MSHR from the queue. This places the MSHR on the
141 void deallocate(MSHR *mshr);
144 * Remove a MSHR from the queue. Returns an iterator into the
145 * allocatedList for faster squash implementation.
146 * @param mshr The MSHR to remove.
147 * @return An iterator to the next entry in the allocatedList.
149 MSHR::Iterator deallocateOne(MSHR *mshr);
152 * Moves the MSHR to the front of the pending list if it is not
154 * @param mshr The entry to move.
156 void moveToFront(MSHR *mshr);
159 * Mark the given MSHR as in service. This removes the MSHR from the
160 * readyList. Deallocates the MSHR if it does not expect a response.
161 * @param mshr The MSHR to mark in service.
163 void markInService(MSHR *mshr, PacketPtr pkt);
166 * Mark an in service entry as pending, used to resend a request.
167 * @param mshr The MSHR to resend.
169 void markPending(MSHR *mshr);
172 * Squash outstanding requests with the given thread number. If a request
173 * is in service, just squashes the targets.
174 * @param threadNum The thread to squash.
176 void squash(int threadNum);
179 * Returns true if the pending list is not empty.
180 * @return True if there are outstanding requests.
182 bool havePending() const
184 return !readyList.empty();
188 * Returns true if there are no free entries.
189 * @return True if this queue is full.
193 return (allocated > numEntries - numReserve);
197 * Returns the MSHR at the head of the readyList.
198 * @return The next request to service.
200 MSHR *getNextMSHR() const
202 if (readyList.empty() || readyList.front()->readyTime > curTick()) {
205 return readyList.front();
208 Tick nextMSHRReadyTime() const
210 return readyList.empty() ? MaxTick : readyList.front()->readyTime;
214 #endif //__MEM__CACHE__MISS__MSHR_QUEUE_HH__