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Diffstat (limited to 'src/mem/cache/miss/miss_buffer.hh')
| -rw-r--r-- | src/mem/cache/miss/miss_buffer.hh | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/src/mem/cache/miss/miss_buffer.hh b/src/mem/cache/miss/miss_buffer.hh new file mode 100644 index 000000000..3e3080578 --- /dev/null +++ b/src/mem/cache/miss/miss_buffer.hh @@ -0,0 +1,223 @@ +/* + * Copyright (c) 2003-2006 The Regents of The University of Michigan + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * 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: Steve Reinhardt + */ + +/** + * @file + * MissBuffer declaration. + */ + +#ifndef __MISS_BUFFER_HH__ +#define __MISS_BUFFER_HH__ + +class BaseCache; +class BasePrefetcher; +class MSHR; + +/** + * Abstract base class for cache miss buffering. + */ +class MissBuffer +{ + protected: + /** True if the cache should allocate on a write miss. */ + const bool writeAllocate; + + /** Pointer to the parent cache. */ + BaseCache *cache; + + /** The Prefetcher */ + BasePrefetcher *prefetcher; + + /** Block size of the parent cache. */ + int blkSize; + + // Statistics + /** + * @addtogroup CacheStatistics + * @{ + */ + /** Number of blocks written back per thread. */ + Stats::Vector<> writebacks; + + /** + * @} + */ + + public: + MissBuffer(bool write_allocate) + : writeAllocate(write_allocate) + { + } + + virtual ~MissBuffer() {} + + /** + * Called by the parent cache to set the back pointer. + * @param _cache A pointer to the parent cache. + */ + void setCache(BaseCache *_cache); + + void setPrefetcher(BasePrefetcher *_prefetcher); + + /** + * Register statistics for this object. + * @param name The name of the parent cache. + */ + virtual void regStats(const std::string &name); + + /** + * Handle a cache miss properly. Either allocate an MSHR for the request, + * or forward it through the write buffer. + * @param pkt The request that missed in the cache. + * @param blk_size The block size of the cache. + * @param time The time the miss is detected. + */ + virtual void handleMiss(PacketPtr &pkt, int blk_size, Tick time) = 0; + + /** + * Fetch the block for the given address and buffer the given target. + * @param addr The address to fetch. + * @param asid The address space of the address. + * @param blk_size The block size of the cache. + * @param time The time the miss is detected. + * @param target The target for the fetch. + */ + virtual MSHR *fetchBlock(Addr addr, int blk_size, Tick time, + PacketPtr &target) = 0; + + /** + * Selects a outstanding request to service. + * @return The request to service, NULL if none found. + */ + virtual PacketPtr getPacket() = 0; + + /** + * Set the command to the given bus command. + * @param pkt The request to update. + * @param cmd The bus command to use. + */ + virtual void setBusCmd(PacketPtr &pkt, Packet::Command cmd) = 0; + + /** + * Restore the original command in case of a bus transmission error. + * @param pkt The request to reset. + */ + virtual void restoreOrigCmd(PacketPtr &pkt) = 0; + + /** + * Marks a request as in service (sent on the bus). This can have side + * effect since storage for no response commands is deallocated once they + * are successfully sent. + * @param pkt The request that was sent on the bus. + */ + virtual void markInService(PacketPtr &pkt, MSHR* mshr) = 0; + + /** + * Collect statistics and free resources of a satisfied request. + * @param pkt The request that has been satisfied. + * @param time The time when the request is satisfied. + */ + virtual void handleResponse(PacketPtr &pkt, Tick time) = 0; + + /** + * Removes all outstanding requests for a given thread number. If a request + * has been sent to the bus, this function removes all of its targets. + * @param threadNum The thread number of the requests to squash. + */ + virtual void squash(int threadNum) = 0; + + /** + * Return the current number of outstanding misses. + * @return the number of outstanding misses. + */ + virtual int getMisses() = 0; + + /** + * Searches for the supplied address in the miss queue. + * @param addr The address to look for. + * @param asid The address space id. + * @return The MSHR that contains the address, NULL if not found. + * @warning Currently only searches the miss queue. If non write allocate + * might need to search the write buffer for coherence. + */ + virtual MSHR* findMSHR(Addr addr) = 0; + + /** + * Searches for the supplied address in the write buffer. + * @param addr The address to look for. + * @param asid The address space id. + * @param writes The list of writes that match the address. + * @return True if any writes are found + */ + virtual bool findWrites(Addr addr, std::vector<MSHR*>& writes) = 0; + + /** + * Perform a writeback of dirty data to the given address. + * @param addr The address to write to. + * @param asid The address space id. + * @param xc The execution context of the address space. + * @param size The number of bytes to write. + * @param data The data to write, can be NULL. + * @param compressed True if the data is compressed. + */ + virtual void doWriteback(Addr addr, int size, uint8_t *data, + bool compressed) = 0; + + /** + * Perform the given writeback request. + * @param pkt The writeback request. + */ + virtual void doWriteback(PacketPtr &pkt) = 0; + + /** + * Returns true if there are outstanding requests. + * @return True if there are outstanding requests. + */ + virtual bool havePending() = 0; + + /** + * Add a target to the given MSHR. This assumes it is in the miss queue. + * @param mshr The mshr to add a target to. + * @param pkt The target to add. + */ + virtual void addTarget(MSHR *mshr, PacketPtr &pkt) = 0; + + /** + * Allocate a MSHR to hold a list of targets to a block involved in a copy. + * If the block is marked done then the MSHR already holds the data to + * fill the block. Otherwise the block needs to be fetched. + * @param addr The address to buffer. + * @param asid The address space ID. + * @return A pointer to the allocated MSHR. + */ + virtual MSHR* allocateTargetList(Addr addr) = 0; +}; + +#endif //__MISS_BUFFER_HH__ |