RubyPrefetcher.hh

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 * to a hardware implementation of the functionality of the software
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 * modified or unmodified, in source code or in binary form.
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 * Copyright (c) 1999-2012 Mark D. Hill and David A. Wood
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#ifndef __MEM_RUBY_STRUCTURES_PREFETCHER_HH__
#define __MEM_RUBY_STRUCTURES_PREFETCHER_HH__
 
// Implements Power 4 like prefetching
 
#include <bitset>
 
#include "base/statistics.hh"
#include "mem/ruby/common/Address.hh"
#include "mem/ruby/network/MessageBuffer.hh"
#include "mem/ruby/slicc_interface/AbstractController.hh"
#include "mem/ruby/slicc_interface/RubyRequest.hh"
#include "mem/ruby/system/RubySystem.hh"
#include "params/RubyPrefetcher.hh"
#include "sim/sim_object.hh"
#include "sim/system.hh"
 
#define MAX_PF_INFLIGHT 8
 
class PrefetchEntry
{
    public:
        PrefetchEntry()
        {
            // default: 1 cache-line stride
            m_stride   = (1 << RubySystem::getBlockSizeBits());
            m_use_time = Cycles(0);
            m_is_valid = false;
        }
 
        Addr m_address;
 
        int m_stride;
 
        Cycles m_use_time;
 
        bool m_is_valid;
 
        RubyRequestType m_type;
 
        std::bitset<MAX_PF_INFLIGHT> requestIssued;
        std::bitset<MAX_PF_INFLIGHT> requestCompleted;
};
 
class RubyPrefetcher : public SimObject
{
    public:
        typedef RubyPrefetcherParams Params;
        RubyPrefetcher(const Params *p);
        ~RubyPrefetcher();
 
        void issueNextPrefetch(Addr address, PrefetchEntry *stream);
        void observePfHit(Addr address);
        void observePfMiss(Addr address);
 
        void observeMiss(Addr address, const RubyRequestType& type);
 
        void print(std::ostream& out) const;
        void setController(AbstractController *_ctrl)
        { m_controller = _ctrl; }
 
        void regStats();
 
    private:
        uint32_t getLRUindex(void);
 
        void clearNonunitEntry(uint32_t index);
 
        void initializeStream(Addr address, int stride,
            uint32_t index, const RubyRequestType& type);
 
        PrefetchEntry* getPrefetchEntry(Addr address,
            uint32_t &index);
 
        bool accessUnitFilter(std::vector<Addr>& filter_table,
            uint32_t *hit_table, uint32_t &index, Addr address,
            int stride, bool &alloc);
 
        bool accessNonunitFilter(Addr address, int *stride,
            bool &alloc);
 
        Addr pageAddress(Addr addr) const;
 
        uint32_t m_num_streams;
        std::vector<PrefetchEntry> m_array;
 
        uint32_t m_train_misses;
        uint32_t m_num_startup_pfs;
        uint32_t m_num_unit_filters;
        uint32_t m_num_nonunit_filters;
 
        std::vector<Addr> m_unit_filter;
        uint32_t m_unit_filter_index;
        uint32_t *m_unit_filter_hit;
 
        std::vector<Addr> m_negative_filter;
        uint32_t m_negative_filter_index;
        uint32_t *m_negative_filter_hit;
 
        std::vector<Addr> m_nonunit_filter;
        int *m_nonunit_stride;
        uint32_t *m_nonunit_hit;
        uint32_t m_nonunit_index;
 
        bool m_prefetch_cross_pages;
 
        AbstractController *m_controller;
 
        const Addr m_page_shift;
 
        Stats::Scalar numMissObserved;
        Stats::Scalar numAllocatedStreams;
        Stats::Scalar numPrefetchRequested;
        Stats::Scalar numHits;
        Stats::Scalar numPartialHits;
        Stats::Scalar numPagesCrossed;
        Stats::Scalar numMissedPrefetchedBlocks;
};
 
#endif // __MEM_RUBY_STRUCTURES_PREFETCHER_HH__