arch/alpha/vptr.hh

   1 /*
   2  * Copyright (c) 2004 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 "arch/alpha/vtophys.hh"
  33
  34 class ExecContext;
  35
  36 template <class T>
  37 class VPtr
  38 {
  39   public:
  40     typedef T Type;
  41
  42   private:
  43     ExecContext *xc;
  44     Addr ptr;
  45
  46   public:
  47     ExecContext *GetXC() const { return xc; }
  48     Addr GetPointer() const { return ptr; }
  49
  50   public:
  51     explicit VPtr(ExecContext *_xc, Addr p = 0) : xc(_xc), ptr(p) { }
  52     template <class U>
  53     VPtr(const VPtr<U> &vp) : xc(vp.GetXC()), ptr(vp.GetPointer()) {}
  54     ~VPtr() {}
  55
  56     bool operator!() const
  57     {
  58         return ptr == 0;
  59     }
  60
  61     VPtr<T> operator+(int offset)
  62     {
  63         VPtr<T> ptr(*this);
  64         ptr += offset;
  65
  66         return ptr;
  67     }
  68
  69     const VPtr<T> &operator+=(int offset)
  70     {
  71         ptr += offset;
  72         assert((ptr & (AlphaISA::PageBytes - 1)) + sizeof(T)
  73                < AlphaISA::PageBytes);
  74
  75         return *this;
  76     }
  77
  78     const VPtr<T> &operator=(Addr p)
  79     {
  80         assert((p & (AlphaISA::PageBytes)) + sizeof(T) < AlphaISA::PageBytes);
  81         ptr = p;
  82
  83         return *this;
  84     }
  85
  86     template <class U>
  87     const VPtr<T> &operator=(const VPtr<U> &vp)
  88     {
  89         xc = vp.GetXC();
  90         ptr = vp.GetPointer();
  91
  92         return *this;
  93     }
  94
  95     operator T *()
  96     {
  97         void *addr = vtomem(xc, ptr, sizeof(T));
  98         return (T *)addr;
  99     }
 100
 101     T *operator->()
 102     {
 103         void *addr = vtomem(xc, ptr, sizeof(T));
 104         return (T *)addr;
 105     }
 106
 107     T &operator*()
 108     {
 109         void *addr = vtomem(xc, ptr, sizeof(T));
 110         return *(T *)addr;
 111     }
 112 };
 113
 114 #endif // __ARCH_ALPHA_VPTR_HH__