source: trunk/modules/vci_mem_cache/caba/source/include/mem_cache_directory.h @ 752

#ifndef SOCLIB_CABA_MEM_CACHE_DIRECTORY_H
#define SOCLIB_CABA_MEM_CACHE_DIRECTORY_H 

#include <inttypes.h>
#include <systemc>
#include <cassert>
#include "arithmetics.h"

//#define RANDOM_EVICTION

namespace soclib { namespace caba {

  using namespace sc_core;

  ////////////////////////////////////////////////////////////////////////
  //                    A LRU entry 
  ////////////////////////////////////////////////////////////////////////
  class LruEntry {

    public:

      bool recent;            

      void init()
      {
        recent=false;
      }

  }; // end class LruEntry

  ////////////////////////////////////////////////////////////////////////
  //                    An Owner
  ////////////////////////////////////////////////////////////////////////
  class Owner{
    
    public:
    // Fields
      bool      inst;       // Is the owner an ICache ?
      size_t    srcid;      // The SRCID of the owner

    ////////////////////////
    // Constructors
    ////////////////////////
      Owner(bool   i_inst,
            size_t i_srcid)
      {
        inst    = i_inst;
        srcid   = i_srcid;
      }

      Owner(const Owner &a)
      {
        inst    = a.inst;
        srcid   = a.srcid;
      }

      Owner()
      {
        inst    = false;
        srcid   = 0;
      }
      // end constructors

  }; // end class Owner


  ////////////////////////////////////////////////////////////////////////
  //                    A directory entry                               
  ////////////////////////////////////////////////////////////////////////
  class DirectoryEntry {

    typedef uint32_t tag_t;

    public:

    bool    valid;                  // entry valid
    bool    is_cnt;                 // directory entry is in counter mode
    bool    dirty;                  // entry dirty
    bool    lock;                   // entry locked
    tag_t   tag;                    // tag of the entry
    size_t  count;                  // number of copies
    Owner   owner;                  // an owner of the line 
    size_t  ptr;                    // pointer to the next owner

    DirectoryEntry()
    {
      valid         = false;
      is_cnt        = false;
      dirty         = false;
      lock          = false;
      tag           = 0;
      count         = 0;
      owner.inst    = 0;
      owner.srcid   = 0;
      ptr           = 0;
    }

    DirectoryEntry(const DirectoryEntry &source)
    {
      valid         = source.valid;
      is_cnt        = source.is_cnt;
      dirty         = source.dirty;
      lock          = source.lock;
      tag           = source.tag;
      count         = source.count;
      owner         = source.owner;
      ptr           = source.ptr;
    }          

    /////////////////////////////////////////////////////////////////////
    // The init() function initializes the entry 
    /////////////////////////////////////////////////////////////////////
    void init()
    {
      valid     = false;
      is_cnt    = false;
      dirty     = false;
      lock      = false;
      count     = 0;
    }

    /////////////////////////////////////////////////////////////////////
    // The copy() function copies an existing source entry to a target 
    /////////////////////////////////////////////////////////////////////
    void copy(const DirectoryEntry &source)
    {
      valid         = source.valid;
      is_cnt    = source.is_cnt;
      dirty         = source.dirty;
      lock          = source.lock;
      tag           = source.tag;
      count     = source.count;
      owner     = source.owner;
      ptr       = source.ptr;
    }

    ////////////////////////////////////////////////////////////////////
    // The print() function prints the entry 
    ////////////////////////////////////////////////////////////////////
    void print()
    {
      std::cout << "Valid = " << valid 
                << " ; IS COUNT = " << is_cnt 
                << " ; Dirty = " << dirty 
                << " ; Lock = " << lock 
                << " ; Tag = " << std::hex << tag << std::dec 
                << " ; Count = " << count 
                << " ; Owner = " << owner.srcid 
                << " " << owner.inst 
                << " ; Pointer = " << ptr << std::endl;
    }

  }; // end class DirectoryEntry

  ////////////////////////////////////////////////////////////////////////
  //                       The directory  
  ////////////////////////////////////////////////////////////////////////
  class CacheDirectory {

    typedef sc_dt::sc_uint<40> addr_t;
    typedef uint32_t data_t;
    typedef uint32_t tag_t;

    private:

    // Directory constants
    size_t                                      m_ways;
    size_t                                      m_sets;
    size_t                                      m_words;
    size_t                                      m_width;
    uint32_t                lfsr;

    // the directory & lru tables
    DirectoryEntry                              **m_dir_tab;
    LruEntry                                    **m_lru_tab;

    public:

    ////////////////////////
    // Constructor
    ////////////////////////
    CacheDirectory( size_t ways, size_t sets, size_t words, size_t address_width)        
    {
      m_ways  = ways; 
      m_sets  = sets;
      m_words = words;
      m_width = address_width;
      lfsr = -1;

      m_dir_tab = new DirectoryEntry*[sets];
      for ( size_t i=0; i<sets; i++ ) {
        m_dir_tab[i] = new DirectoryEntry[ways];
        for ( size_t j=0 ; j<ways ; j++) m_dir_tab[i][j].init();
      }
      m_lru_tab = new LruEntry*[sets];
      for ( size_t i=0; i<sets; i++ ) {
        m_lru_tab[i] = new LruEntry[ways];
        for ( size_t j=0 ; j<ways ; j++) m_lru_tab[i][j].init();
      }
    } // end constructor

    /////////////////
    // Destructor
    /////////////////
    ~CacheDirectory()
    {
      for(size_t i=0 ; i<m_sets ; i++){
        delete [] m_dir_tab[i];
        delete [] m_lru_tab[i];
      }
      delete [] m_dir_tab;
      delete [] m_lru_tab;
    } // end destructor

    /////////////////////////////////////////////////////////////////////
    // The read() function reads a directory entry. In case of hit, the
    // LRU is updated.
    // Arguments :
    // - address : the address of the entry 
    // - way : (return argument) the way of the entry in case of hit
    // The function returns a copy of a (valid or invalid) entry  
    /////////////////////////////////////////////////////////////////////
    DirectoryEntry read(const addr_t &address, size_t &way)
    {

#define L2 soclib::common::uint32_log2
        const size_t set = (size_t)(address >> (L2(m_words) + 2)) & (m_sets - 1);
        const tag_t  tag = (tag_t)(address >> (L2(m_sets) + L2(m_words) + 2));
#undef L2

        bool hit       = false;
        for ( size_t i=0 ; i<m_ways ; i++ ) 
        {
            bool equal = ( m_dir_tab[set][i].tag == tag );
            bool valid = m_dir_tab[set][i].valid;
            hit        = equal && valid;
            if ( hit ) 
            {                   
                way = i;
                break;
            } 
        }
        if ( hit ) 
        {
            m_lru_tab[set][way].recent = true;
            return DirectoryEntry(m_dir_tab[set][way]);
        } 
        else 
        {
            return DirectoryEntry();
        }
    } // end read()

    /////////////////////////////////////////////////////////////////////
    // The inval function invalidate an entry defined by the set and
    // way arguments. 
    /////////////////////////////////////////////////////////////////////
    void inval( const size_t &way, const size_t &set )
    {
        m_dir_tab[set][way].init();
    }

    /////////////////////////////////////////////////////////////////////
    // The read_neutral() function reads a directory entry, without
    // changing the LRU
    // Arguments :
    // - address : the address of the entry 
    // The function returns a copy of a (valid or invalid) entry  
    /////////////////////////////////////////////////////////////////////
    DirectoryEntry read_neutral( const addr_t &address, 
                                 size_t*      ret_way,
                                 size_t*      ret_set )
    {

#define L2 soclib::common::uint32_log2
        size_t set = (size_t)(address >> (L2(m_words) + 2)) & (m_sets - 1);
        tag_t  tag = (tag_t)(address >> (L2(m_sets) + L2(m_words) + 2));
#undef L2

        for ( size_t way = 0 ; way < m_ways ; way++ ) 
        {
            bool equal = ( m_dir_tab[set][way].tag == tag );
            bool valid = m_dir_tab[set][way].valid;
            if ( equal and valid )
            {
                *ret_set = set;
                *ret_way = way; 
                return DirectoryEntry(m_dir_tab[set][way]);
            }
        } 
        return DirectoryEntry();
    } // end read_neutral()

    /////////////////////////////////////////////////////////////////////
    // The write function writes a new entry, 
    // and updates the LRU bits if necessary.
    // Arguments :
    // - set : the set of the entry
    // - way : the way of the entry
    // - entry : the entry value
    /////////////////////////////////////////////////////////////////////
    void write( const size_t         &set, 
                const size_t         &way, 
                const DirectoryEntry &entry)
    {
      assert( (set<m_sets) 
          && "Cache Directory write : The set index is invalid");
      assert( (way<m_ways) 
          && "Cache Directory write : The way index is invalid");

      // update Directory
      m_dir_tab[set][way].copy(entry);

      // update LRU bits
      bool all_recent = true;
      for ( size_t i=0 ; i<m_ways ; i++ ) 
      {
          if ( i != way ) all_recent = m_lru_tab[set][i].recent && all_recent;
      }
      if ( all_recent ) 
      {
          for( size_t i=0 ; i<m_ways ; i++ ) m_lru_tab[set][i].recent = false;
      } 
      else 
      {
          m_lru_tab[set][way].recent = true;
      }
    } // end write()

    /////////////////////////////////////////////////////////////////////
    // The print() function prints a selected directory entry
    // Arguments :
    // - set : the set of the entry to print
    // - way : the way of the entry to print
    /////////////////////////////////////////////////////////////////////
    void print(const size_t &set, const size_t &way)
    {
      std::cout << std::dec << " set : " << set << " ; way : " << way << " ; " ;
      m_dir_tab[set][way].print();
    } // end print()

    /////////////////////////////////////////////////////////////////////
    // The select() function selects a directory entry to evince.
    // Arguments :
    // - set   : (input argument) the set to modify
    // - way   : (return argument) the way to evince
    /////////////////////////////////////////////////////////////////////
    DirectoryEntry select(const size_t &set, size_t &way)
    {
        assert( (set < m_sets) 
          && "Cache Directory : (select) The set index is invalid");

        // looking for an empty slot
        for(size_t i=0; i<m_ways; i++)
        {
            if( not m_dir_tab[set][i].valid )
            {
                way=i;
                return DirectoryEntry(m_dir_tab[set][way]);
            }
        }

#ifdef RANDOM_EVICTION
        lfsr = (lfsr >> 1) ^ ((-(lfsr & 1)) & 0xd0000001);
        way = lfsr % m_ways;
        return DirectoryEntry(m_dir_tab[set][way]);
#endif

        // looking for a not locked and not recently used entry
        for(size_t i=0; i<m_ways; i++)
        {
            if((not m_lru_tab[set][i].recent) && (not m_dir_tab[set][i].lock) )
            {
                way=i;
                return DirectoryEntry(m_dir_tab[set][way]);
            }
        }

        // looking for a locked not recently used entry
        for(size_t i=0; i<m_ways; i++)
        {
            if( (not m_lru_tab[set][i].recent) && (m_dir_tab[set][i].lock))
            {
                way=i;
                return DirectoryEntry(m_dir_tab[set][way]);
            }
        }

        // looking for a recently used entry not locked
        for(size_t i=0; i<m_ways; i++)
        {
            if( (m_lru_tab[set][i].recent) && (not m_dir_tab[set][i].lock))
            {
                way=i;
                return DirectoryEntry(m_dir_tab[set][way]);
            }
        }

        // select way 0 (even if entry is locked and recently used)
        way = 0;
        return DirectoryEntry(m_dir_tab[set][0]);
    } // end select()

    /////////////////////////////////////////////////////////////////////
    //          Global initialisation function
    /////////////////////////////////////////////////////////////////////
    void init()
    {
      for ( size_t set=0 ; set<m_sets ; set++ ) 
      {
        for ( size_t way=0 ; way<m_ways ; way++ ) 
        {
          m_dir_tab[set][way].init();
          m_lru_tab[set][way].init();
        }
      }
    } // end init()

  }; // end class CacheDirectory

  ///////////////////////////////////////////////////////////////////////
  //                    A Heap Entry
  ///////////////////////////////////////////////////////////////////////
  class HeapEntry{

    public:
    // Fields of the entry
      Owner     owner;
      size_t    next;

    ////////////////////////
    // Constructor
    ////////////////////////
      HeapEntry()
      :owner(false,0)
      {
        next = 0;
      } // end constructor

    ////////////////////////
    // Constructor
    ////////////////////////
      HeapEntry(const HeapEntry &entry)
      {
        owner.inst  = entry.owner.inst;
        owner.srcid = entry.owner.srcid;
        next           = entry.next;
      } // end constructor

    /////////////////////////////////////////////////////////////////////
    // The copy() function copies an existing source entry to a target 
    /////////////////////////////////////////////////////////////////////
      void copy(const HeapEntry &entry)
      {
        owner.inst     = entry.owner.inst;
        owner.srcid    = entry.owner.srcid;
        next           = entry.next;
      } // end copy()

    ////////////////////////////////////////////////////////////////////
    // The print() function prints the entry 
    ////////////////////////////////////////////////////////////////////
      void print(){
        std::cout 
        << " -- owner.inst     : " << std::dec << owner.inst << std::endl
        << " -- owner.srcid    : " << std::dec << owner.srcid << std::endl
        << " -- next           : " << std::dec << next << std::endl;

      } // end print()

  }; // end class HeapEntry

  ////////////////////////////////////////////////////////////////////////
  //                        The Heap 
  ////////////////////////////////////////////////////////////////////////
  class HeapDirectory{
    
    private:
    // Registers and the heap
      size_t    ptr_free;
      bool      full;
      HeapEntry *m_heap_tab;

    // Constants for debugging purpose
      size_t    tab_size;

    public:
    ////////////////////////
    // Constructor
    ////////////////////////
      HeapDirectory(uint32_t size){
        assert(size>0 && "Memory Cache, HeapDirectory constructor : invalid size");
        ptr_free    = 0;
        full        = false;
        m_heap_tab  = new HeapEntry[size];
        tab_size    = size;
      } // end constructor

    /////////////////
    // Destructor
    /////////////////
      ~HeapDirectory(){
        delete [] m_heap_tab;
      } // end destructor

    /////////////////////////////////////////////////////////////////////
    //          Global initialisation function
    /////////////////////////////////////////////////////////////////////
      void init(){
        ptr_free=0;
        full=false;
        for(size_t i=0; i< tab_size-1;i++){
          m_heap_tab[i].next = i+1;
        }
        m_heap_tab[tab_size-1].next = tab_size-1;
        return;
      }

    /////////////////////////////////////////////////////////////////////
    // The print() function prints a selected directory entry
    // Arguments :
    // - ptr : the pointer to the entry to print
    /////////////////////////////////////////////////////////////////////
      void print(const size_t &ptr){
        std::cout << "Heap, printing the entry : " << std::dec << ptr << std::endl;
        m_heap_tab[ptr].print();
      } // end print()

    /////////////////////////////////////////////////////////////////////
    // The print_list() function prints a list from selected directory entry
    // Arguments :
    // - ptr : the pointer to the first entry to print
    /////////////////////////////////////////////////////////////////////
      void print_list(const size_t &ptr){
        bool end = false;
        size_t ptr_temp = ptr;
        std::cout << "Heap, printing the list from : " << std::dec << ptr << std::endl;
        while(!end){
            m_heap_tab[ptr_temp].print();
            if(ptr_temp == m_heap_tab[ptr_temp].next) end = true;
            ptr_temp = m_heap_tab[ptr_temp].next;
        } 
      } // end print_list()

    /////////////////////////////////////////////////////////////////////
    // The is_full() function return true if the heap is full.
    /////////////////////////////////////////////////////////////////////
      bool is_full(){
        return full;
      } // end is_full()

    /////////////////////////////////////////////////////////////////////
    // The next_free_ptr() function returns the pointer 
    // to the next free entry.
    /////////////////////////////////////////////////////////////////////
      size_t next_free_ptr(){
        return ptr_free;
      } // end next_free_ptr()

    /////////////////////////////////////////////////////////////////////
    // The next_free_entry() function returns 
    // a copy of the next free entry.
    /////////////////////////////////////////////////////////////////////
      HeapEntry next_free_entry(){
        return HeapEntry(m_heap_tab[ptr_free]);
      } // end next_free_entry()
   
    /////////////////////////////////////////////////////////////////////
    // The write_free_entry() function modify the next free entry.
    // Arguments :
    // - entry : the entry to write
    /////////////////////////////////////////////////////////////////////
      void write_free_entry(const HeapEntry &entry){
        m_heap_tab[ptr_free].copy(entry);
      } // end write_free_entry()

    /////////////////////////////////////////////////////////////////////
    // The write_free_ptr() function writes the pointer
    // to the next free entry
    /////////////////////////////////////////////////////////////////////
      void write_free_ptr(const size_t &ptr){
        assert( (ptr<tab_size) && "HeapDirectory error : try to write a wrong free pointer");
        ptr_free = ptr;
      } // end write_free_ptr()

    /////////////////////////////////////////////////////////////////////
    // The set_full() function sets the full bit (to true).
    /////////////////////////////////////////////////////////////////////
      void set_full(){
        full = true;
      } // end set_full()

    /////////////////////////////////////////////////////////////////////
    // The unset_full() function unsets the full bit (to false).
    /////////////////////////////////////////////////////////////////////
      void unset_full(){
        full = false;
      } // end unset_full()

    /////////////////////////////////////////////////////////////////////
    // The read() function returns a copy of
    // the entry pointed by the argument
    // Arguments :
    //  - ptr : the pointer to the entry to read
    /////////////////////////////////////////////////////////////////////
      HeapEntry read(const size_t &ptr){
        assert( (ptr<tab_size) && "HeapDirectory error : try to write a wrong free pointer");
        return HeapEntry(m_heap_tab[ptr]);
      } // end read()

    /////////////////////////////////////////////////////////////////////
    // The write() function writes an entry in the heap
    // Arguments :
    //  - ptr : the pointer to the entry to replace
    //  - entry : the entry to write
    /////////////////////////////////////////////////////////////////////
      void write(const size_t &ptr, const HeapEntry &entry){
        assert( (ptr<tab_size) && "HeapDirectory error : try to write a wrong free pointer");
        m_heap_tab[ptr].copy(entry);
      } // end write()

  }; // end class HeapDirectory

  ////////////////////////////////////////////////////////////////////////
  //                        Cache Data 
  ////////////////////////////////////////////////////////////////////////
  class CacheData 
  {
    private:
      const uint32_t m_sets;
      const uint32_t m_ways;
      const uint32_t m_words;

      uint32_t *** m_cache_data;

    public:

      ///////////////////////////////////////////////////////
      CacheData(uint32_t ways, uint32_t sets, uint32_t words)
        : m_sets(sets), m_ways(ways), m_words(words) 
      {
          m_cache_data = new uint32_t ** [ways];
          for ( size_t i=0 ; i < ways ; i++ ) 
          {
              m_cache_data[i] = new uint32_t * [sets];
          }
          for ( size_t i=0; i<ways; i++ ) 
          {
              for ( size_t j=0; j<sets; j++ ) 
              {
                  m_cache_data[i][j] = new uint32_t [words];
                  // Init to avoid potential errors from memory checkers
                  std::memset(m_cache_data[i][j], 0, sizeof(uint32_t) * words);
              }
          }
      }
      ////////////
      ~CacheData() 
      {
          for(size_t i=0; i<m_ways ; i++)
          {
              for(size_t j=0; j<m_sets ; j++)
              {
                  delete [] m_cache_data[i][j];
              }
          }
          for(size_t i=0; i<m_ways ; i++)
          {
              delete [] m_cache_data[i];
          }
          delete [] m_cache_data;
      }
      //////////////////////////////////////////
      uint32_t read ( const uint32_t &way,
                      const uint32_t &set,
                      const uint32_t &word) const 
      {
          assert((set  < m_sets ) && "Cache data error: Trying to read a wrong set" );
          assert((way  < m_ways ) && "Cache data error: Trying to read a wrong way" );
          assert((word < m_words) && "Cache data error: Trying to read a wrong word");

          return m_cache_data[way][set][word];
      }
      //////////////////////////////////////////
      void read_line( const uint32_t &way,
                      const uint32_t &set,
                      sc_core::sc_signal<uint32_t> * cache_line)
      {
          assert((set < m_sets ) && "Cache data error: Trying to read a wrong set" );
          assert((way < m_ways ) && "Cache data error: Trying to read a wrong way" );

          for (uint32_t word=0; word<m_words; word++)
              cache_line[word].write(m_cache_data[way][set][word]);
      }
      /////////////////////////////////////////
      void write ( const uint32_t &way,
                   const uint32_t &set,
                   const uint32_t &word,
                   const uint32_t &data,
                   const uint32_t &be = 0xF) 
      {

          assert((set  < m_sets ) && "Cache data error: Trying to write a wrong set" );
          assert((way  < m_ways ) && "Cache data error: Trying to write a wrong way" );
          assert((word < m_words) && "Cache data error: Trying to write a wrong word");
          assert((be  <= 0xF    ) && "Cache data error: Trying to write a wrong be");

          if (be == 0x0) return;

          if (be == 0xF) 
          {
              m_cache_data[way][set][word] = data; 
              return;
          }

          uint32_t mask = 0;
          if  (be & 0x1) mask = mask | 0x000000FF;
          if  (be & 0x2) mask = mask | 0x0000FF00;
          if  (be & 0x4) mask = mask | 0x00FF0000;
          if  (be & 0x8) mask = mask | 0xFF000000;

          m_cache_data[way][set][word] = 
              (data & mask) | (m_cache_data[way][set][word] & ~mask);
      }
  }; // end class CacheData

}} // end namespaces

#endif

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// tab-width: 4
// c-basic-offset: 4
// c-file-offsets:((innamespace . 0)(inline-open . 0))
// indent-tabs-mode: nil
// End:

// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=4:softtabstop=4