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+/*
+ * Copyright (c) 2003-2005 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: Erik Hallnor
+ */
+
+/**
+ * @file
+ * Declaration of a simple buffer for a blocking cache.
+ */
+
+#ifndef __BLOCKING_BUFFER_HH__
+#define __BLOCKING_BUFFER_HH__
+
+#include <vector>
+
+#include "mem/cache/miss/mshr.hh"
+#include "base/statistics.hh"
+
+class BaseCache;
+class BasePrefetcher;
+
+/**
+ * Miss and writeback storage for a blocking cache.
+ */
+class BlockingBuffer
+{
+protected:
+ /** Miss storage. */
+ MSHR miss;
+ /** WB storage. */
+ MSHR wb;
+
+ //Params
+
+ /** Allocate on write misses. */
+ const bool writeAllocate;
+
+ /** Pointer to the parent cache. */
+ BaseCache* cache;
+
+ BasePrefetcher* prefetcher;
+
+ /** Block size of the parent cache. */
+ int blkSize;
+
+ // Statistics
+ /**
+ * @addtogroup CacheStatistics
+ * @{
+ */
+ /** Number of blocks written back per thread. */
+ Stats::Vector<> writebacks;
+
+ /**
+ * @}
+ */
+
+public:
+ /**
+ * Builds and initializes this buffer.
+ * @param write_allocate If true, treat write misses the same as reads.
+ */
+ BlockingBuffer(bool write_allocate)
+ : writeAllocate(write_allocate)
+ {
+ }
+
+ /**
+ * Register statistics for this object.
+ * @param name The name of the parent cache.
+ */
+ void regStats(const std::string &name);
+
+ /**
+ * 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);
+
+ /**
+ * Handle a cache miss properly. Requests the bus and marks the cache as
+ * blocked.
+ * @param req The request that missed in the cache.
+ * @param blk_size The block size of the cache.
+ * @param time The time the miss is detected.
+ */
+ void handleMiss(Packet * &pkt, int blk_size, Tick time);
+
+ /**
+ * 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.
+ */
+ MSHR* fetchBlock(Addr addr, int asid, int blk_size, Tick time,
+ Packet * &target)
+ {
+ fatal("Unimplemented");
+ }
+
+ /**
+ * Selects a outstanding request to service.
+ * @return The request to service, NULL if none found.
+ */
+ Packet * getPacket();
+
+ /**
+ * Set the command to the given bus command.
+ * @param req The request to update.
+ * @param cmd The bus command to use.
+ */
+ void setBusCmd(Packet * &pkt, Packet::Command cmd);
+
+ /**
+ * Restore the original command in case of a bus transmission error.
+ * @param req The request to reset.
+ */
+ void restoreOrigCmd(Packet * &pkt);
+
+ /**
+ * 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 req The request that was sent on the bus.
+ */
+ void markInService(Packet * &pkt);
+
+ /**
+ * Frees the resources of the request and unblock the cache.
+ * @param req The request that has been satisfied.
+ * @param time The time when the request is satisfied.
+ */
+ void handleResponse(Packet * &pkt, Tick time);
+
+ /**
+ * 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 thread_number The thread number of the requests to squash.
+ */
+ void squash(int thread_number);
+
+ /**
+ * Return the current number of outstanding misses.
+ * @return the number of outstanding misses.
+ */
+ int getMisses()
+ {
+ return miss.getNumTargets();
+ }
+
+ /**
+ * Searches for the supplied address in the miss "queue".
+ * @param addr The address to look for.
+ * @param asid The address space id.
+ * @return A pointer to miss if it matches.
+ */
+ MSHR* findMSHR(Addr addr, int asid)
+ {
+ if (miss.addr == addr && miss.pkt)
+ return &miss;
+ return NULL;
+ }
+
+ /**
+ * Searches for the supplied address in the write buffer.
+ * @param addr The address to look for.
+ * @param asid The address space id.
+ * @param writes List of pointers to the matching writes.
+ * @return True if there is a matching write.
+ */
+ bool findWrites(Addr addr, int asid, std::vector<MSHR*>& writes)
+ {
+ if (wb.addr == addr && wb.pkt) {
+ writes.push_back(&wb);
+ return true;
+ }
+ return false;
+ }
+
+
+
+ /**
+ * 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.
+ */
+ void doWriteback(Addr addr, int asid, ExecContext *xc,
+ int size, uint8_t *data, bool compressed);
+
+ /**
+ * Perform a writeback request.
+ * @param req The writeback request.
+ */
+ void doWriteback(Packet * &pkt);
+
+ /**
+ * Returns true if there are outstanding requests.
+ * @return True if there are outstanding requests.
+ */
+ bool havePending()
+ {
+ return !miss.inService || !wb.inService;
+ }
+
+ /**
+ * 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 req The target to add.
+ */
+ void addTarget(MSHR *mshr, Packet * &pkt)
+ {
+ fatal("Shouldn't call this on a blocking buffer.");
+ }
+
+ /**
+ * Dummy implmentation.
+ */
+ MSHR* allocateTargetList(Addr addr, int asid)
+ {
+ fatal("Unimplemented");
+ }
+};
+
+#endif // __BLOCKING_BUFFER_HH__