trunk/kernel/include/kernel/page_allocator.hpp

   1 /*
   2 lightOS kernel
   3 Copyright (C) 2006-2009 Jörg Pfähler
   4
   5 This program is free software; you can redistribute it and/or
   6 modify it under the terms of the GNU General Public License
   7 as published by the Free Software Foundation; either version 2
   8 of the License, or (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with this program; if not, write to the Free Software
  17 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  18 */
  19 #ifndef LIGHTOS_KERNEL_PAGEALLOCATOR_HPP
  20 #define LIGHTOS_KERNEL_PAGEALLOCATOR_HPP
  21
  22 /*! \addtogroup kernel kernel */
  23 /*@{*/
  24
  25 #include <cstddef>
  26 #include <cstdint>
  27 #include <kernel/utils/macros.hpp>
  28 #include <kernel/spinlock.hpp>
  29
  30 namespace kernel
  31 {
  32   /*! page_allocator class for the management of pages above the 16mb barrier
  33    *\note Not neccessarily every page above the 16mb barrier is manged by this allocator. The amount is calculated
  34    *      based on the total amount of RAM (see x86-shared/multiboot.cpp) */
  35   class page_allocator
  36   {
  37     SINGLETON(page_allocator);
  38
  39     public:
  40       /*! Allocate a new page
  41        *\return physical address of the page */
  42       void *allocate();
  43       /*! Free a previously allocated page
  44        *\param[in] physical address of the page */
  45       void free(void *page);
  46
  47       /*! Get the page size
  48        *\return the page size in byte */
  49       inline static size_t page_size(){return mPageSize;}
  50       /*! Number of free pages
  51        *\return the number of free pages */
  52       inline size_t size(){return mSize;}
  53       /*! Total number of pages (userfriendly version)
  54        *\return the total number of pages (userfriendly version) */
  55       inline size_t capacity(){return mPageCount;}
  56       /*! Set the total number of pages (userfriendly version)
  57        *\param[in] the number of pages (userfriendly version) */
  58       inline void capacity(size_t i){mPageCount = i;}
  59
  60     private:
  61       /*! Size of one page */
  62       static size_t mPageSize;
  63       /*! The number of pages */
  64       size_t mCapacity;
  65       /*! The number of free pages */
  66       size_t mSize;
  67       /*! The number of total pages (userfriendly version) */
  68       size_t mPageCount;
  69       /*! Pointer to the stack */
  70       uintptr_t *mStack;
  71       #ifdef _LIGHTOS_SMP
  72         /*! Spinlock to protect the page_allocator in a multiprocessor environment */
  73         lightOS::spinlock mLock;
  74       #endif
  75   };
  76 }
  77
  78 /*@}*/
  79
  80 #endif