sim/vptr.hh

   1 /*
   2  * Copyright (c) 2004-2005 The Regents of The University of Michigan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #ifndef __ARCH_ALPHA_VPTR_HH__
  30 #define __ARCH_ALPHA_VPTR_HH__
  31
  32 #include "targetarch/vtophys.hh"
  33 #include "arch/isa_traits.hh"
  34
  35 class ExecContext;
  36
  37 template <class T>
  38 class VPtr
  39 {
  40   public:
  41     typedef T Type;
  42
  43   private:
  44     ExecContext *xc;
  45     Addr ptr;
  46
  47   public:
  48     ExecContext *GetXC() const { return xc; }
  49     Addr GetPointer() const { return ptr; }
  50
  51   public:
  52     explicit VPtr(ExecContext *_xc, Addr p = 0) : xc(_xc), ptr(p) { }
  53     template <class U>
  54     VPtr(const VPtr<U> &vp) : xc(vp.GetXC()), ptr(vp.GetPointer()) {}
  55     ~VPtr() {}
  56
  57     bool operator!() const
  58     {
  59         return ptr == 0;
  60     }
  61
  62     VPtr<T> operator+(int offset)
  63     {
  64         VPtr<T> ptr(*this);
  65         ptr += offset;
  66
  67         return ptr;
  68     }
  69
  70     const VPtr<T> &operator+=(int offset)
  71     {
  72         ptr += offset;
  73         assert((ptr & (TheISA::PageBytes - 1)) + sizeof(T)
  74                < TheISA::PageBytes);
  75
  76         return *this;
  77     }
  78
  79     const VPtr<T> &operator=(Addr p)
  80     {
  81         assert((p & (TheISA::PageBytes - 1)) + sizeof(T)
  82                < TheISA::PageBytes);
  83         ptr = p;
  84
  85         return *this;
  86     }
  87
  88     template <class U>
  89     const VPtr<T> &operator=(const VPtr<U> &vp)
  90     {
  91         xc = vp.GetXC();
  92         ptr = vp.GetPointer();
  93
  94         return *this;
  95     }
  96
  97     operator T *()
  98     {
  99         void *addr = vtomem(xc, ptr, sizeof(T));
 100         return (T *)addr;
 101     }
 102
 103     T *operator->()
 104     {
 105         void *addr = vtomem(xc, ptr, sizeof(T));
 106         return (T *)addr;
 107     }
 108
 109     T &operator*()
 110     {
 111         void *addr = vtomem(xc, ptr, sizeof(T));
 112         return *(T *)addr;
 113     }
 114 };
 115
 116 #endif // __ARCH_ALPHA_VPTR_HH__