reactos/include/internal/mm.h

   1 /*
   2  * Higher level memory managment definitions
   3  */
   4
   5 #ifndef __MM_H
   6 #define __MM_H
   7
   8 #define PAGE_SYSTEM (0x80000000)
   9
  10 #include <internal/linkage.h>
  11 #include <internal/kernel.h>
  12 #include <windows.h>
  13
  14 typedef struct _memory_area
  15 /*
  16  * PURPOSE: Describes an area of virtual memory
  17  */
  18 {
  19    /*
  20     * Access protection
  21     */
  22    unsigned int access;
  23
  24    /*
  25     * Memory region base
  26     */
  27    unsigned int base;
  28
  29    /*
  30     * Memory region length
  31     */
  32    unsigned int length;
  33
  34    /*
  35     * Memory type (Mapped file, mapped from an executable or private)
  36     */
  37    unsigned int type;
  38
  39    /*
  40     * Memory region state (committed, reserved or free)
  41     */
  42    unsigned int state;
  43
  44    /*
  45     * Original access protection
  46     */
  47    unsigned int initial_access;
  48
  49    /*
  50     * Used to maintain the linked list of memory areas
  51     */
  52    struct _memory_area* previous;
  53    struct _memory_area* next;
  54
  55    /*
  56     * True the region is locked
  57     */
  58    BOOL lock;
  59
  60    /*
  61     * FUNCTION: Decommits all the pages in the regions
  62     */
  63    void (*free)(struct _memory_area* marea);
  64
  65    /*
  66     * FUNCTION: Handles a page fault by loading the required page
  67     * RECEIVES:
  68     *           marea = the memory area
  69     *           address = the relative address of the page to load
  70     * RETURNS:
  71     *           TRUE = the access should be restarted
  72     *           FALSE = the access was illegal and an exception should
  73     *                   be generated
  74     * NOTES: This function is guarrented to be called within the context
  75     * of the thread which required a page to be loaded
  76     */
  77    BOOL (*load_page)(struct _memory_area* marea, unsigned int address);
  78 } memory_area;
  79
  80
  81 /*
  82  * FUNCTION: Gets a page with a restricted max physical address (i.e.
  83  * suitable for dma)
  84  * RETURNS:
  85  *      The physical address of the page if it succeeds
  86  *      NULL if it fails.
  87  * NOTES: This is very inefficent because the list isn't sorted. On the
  88  * other hand sorting the list would be quite expensive especially if dma
  89  * is only used infrequently. Perhaps a special cache of dma pages should
  90  * be maintained?
  91  */
  92 unsigned int get_dma_page(unsigned int max_address);
  93
  94 /*
  95  * FUNCTION: Allocate a page and return its physical address
  96  * RETURNS: The physical address of the page allocated
  97  */
  98 asmlinkage unsigned int get_free_page(void);
  99
 100 /*
 101  * FUNCTION: Adds pages to the free list
 102  * ARGUMENTS:
 103  *          physical_base = Physical address of the base of the region to
 104  *                          be freed
 105  *          nr = number of continuous pages to free
 106  */
 107 asmlinkage void free_page(unsigned int physical_base, unsigned int nr);
 108
 109 /*
 110  * FUNCTION: Returns the physical address mapped by a given virtual address
 111  * ARGUMENTS:
 112  *          vaddr = virtual address to query
 113  * RETURNS: The physical address if present in memory
 114  *          Zero if paged out or invalid
 115  * NOTE: This doesn't do any synchronization
 116  */
 117 unsigned int get_page_physical_address(unsigned int vaddr);
 118
 119 void mark_page_not_writable(unsigned int vaddr);
 120
 121 void VirtualInit(boot_param* bp);
 122
 123 /*
 124  * FUNCTION: Returns the first memory area starting in the region or the last
 125  *           one before the start of the region
 126  * ARGUMENTS:
 127  *           list_head = Head of the list of memory areas to search
 128  *           base = base address of the region
 129  *           length = length of the region
 130  * RETURNS: A pointer to the area found or
 131  *          NULL if the region was before the first region on the list
 132  */
 133 memory_area* find_first_marea(memory_area* list_head, unsigned int base,
 134                               unsigned int length);
 135
 136 /*
 137  * Head of the list of system memory areas
 138  */
 139 extern memory_area* system_memory_area_list_head;
 140
 141 /*
 142  * Head of the list of user memory areas (this should be per process)
 143  */
 144 extern memory_area* memory_area_list_head;
 145
 146 #endif