src/mem/ruby/system/MemoryVector.hh

/*
 * Copyright (c) 2009 Mark D. Hill and David A. Wood
 * 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.
 */

#ifndef __MEM_RUBY_SYSTEM_MEMORYVECTOR_HH__
#define __MEM_RUBY_SYSTEM_MEMORYVECTOR_HH__

#include "mem/ruby/common/Address.hh"

class DirectoryMemory;

/**
 *  MemoryVector holds memory data (DRAM only)
 */
class MemoryVector
{
  public:
    MemoryVector();
    MemoryVector(uint32 size);
    ~MemoryVector();
    friend class DirectoryMemory;

    void resize(uint32 size);  // destructive

    void write(const Address & paddr, uint8* data, int len);
    uint8* read(const Address & paddr, uint8* data, int len);

  private:
    uint8* getBlockPtr(const PhysAddress & addr);

    uint32 m_size;
    uint8** m_pages;
    uint32 m_num_pages;
    const uint32 m_page_offset_mask;
};

inline
MemoryVector::MemoryVector()
    : m_page_offset_mask(4095)
{
    m_size = 0;
    m_num_pages = 0;
    m_pages = NULL;
}

inline
MemoryVector::MemoryVector(uint32 size)
    : m_page_offset_mask(4095)
{
    resize(size);
}

inline
MemoryVector::~MemoryVector()
{
    for (int i = 0; i < m_num_pages; i++) {
        if (m_pages[i] != 0) {
            delete [] m_pages[i];
        }
    }
    delete [] m_pages;
}

inline void
MemoryVector::resize(uint32 size)
{
    if (m_pages != NULL){
        for (int i = 0; i < m_num_pages; i++) {
            if (m_pages[i] != 0) {
                delete [] m_pages[i];
            }
        }
        delete [] m_pages;
    }
    m_size = size;
    assert(size%4096 == 0);
    m_num_pages = size >> 12;
    m_pages = new uint8*[m_num_pages];
    memset(m_pages, 0, m_num_pages * sizeof(uint8*));
}

inline void
MemoryVector::write(const Address & paddr, uint8* data, int len)
{
    assert(paddr.getAddress() + len <= m_size);
    uint32 page_num = paddr.getAddress() >> 12;
    if (m_pages[page_num] == 0) {
        bool all_zeros = true;
        for (int i = 0; i < len;i++) {
            if (data[i] != 0) {
                all_zeros = false;
                break;
            }
        }
        if (all_zeros)
            return;
        m_pages[page_num] = new uint8[4096];
        memset(m_pages[page_num], 0, 4096);
        uint32 offset = paddr.getAddress() & m_page_offset_mask;
        memcpy(&m_pages[page_num][offset], data, len);
    } else {
        memcpy(&m_pages[page_num][paddr.getAddress()&m_page_offset_mask],
               data, len);
    }
}

inline uint8*
MemoryVector::read(const Address & paddr, uint8* data, int len)
{
    assert(paddr.getAddress() + len <= m_size);
    uint32 page_num = paddr.getAddress() >> 12;
    if (m_pages[page_num] == 0) {
        memset(data, 0, len);
    } else {
        memcpy(data, &m_pages[page_num][paddr.getAddress()&m_page_offset_mask],
               len);
    }
    return data;
}

inline uint8*
MemoryVector::getBlockPtr(const PhysAddress & paddr)
{
    uint32 page_num = paddr.getAddress() >> 12;
    if (m_pages[page_num] == 0) {
        m_pages[page_num] = new uint8[4096];
        memset(m_pages[page_num], 0, 4096);
    }
    return &m_pages[page_num][paddr.getAddress()&m_page_offset_mask];
}

#endif // __MEM_RUBY_SYSTEM_MEMORYVECTOR_HH__