include/linux/mm.h

/* */
This source file includes following definitions.
get_free_page
expand_stack
find_vma
find_vma_intersection
   1 #ifndef _LINUX_MM_H
   2 #define _LINUX_MM_H
   3 
   4 #include <linux/sched.h>
   5 #include <linux/errno.h>
   6 #include <linux/kernel.h>
   7 #include <linux/string.h>
   8 
   9 extern unsigned long high_memory;
  10 
  11 #include <asm/page.h>
  12 
  13 #ifdef __KERNEL__
  14 
  15 #define VERIFY_READ 0
  16 #define VERIFY_WRITE 1
  17 
  18 extern int verify_area(int, const void *, unsigned long);
  19 
  20 /*
  21  * Linux kernel virtual memory manager primitives.
  22  * The idea being to have a "virtual" mm in the same way
  23  * we have a virtual fs - giving a cleaner interface to the
  24  * mm details, and allowing different kinds of memory mappings
  25  * (from shared memory to executable loading to arbitrary
  26  * mmap() functions).
  27  */
  28 
  29 /*
  30  * This struct defines a memory VMM memory area. There is one of these
  31  * per VM-area/task.  A VM area is any part of the process virtual memory
  32  * space that has a special rule for the page-fault handlers (ie a shared
  33  * library, the executable area etc).
  34  */
  35 struct vm_area_struct {
  36         struct mm_struct * vm_mm;       /* VM area parameters */
  37         unsigned long vm_start;
  38         unsigned long vm_end;
  39         pgprot_t vm_page_prot;
  40         unsigned short vm_flags;
  41 /* AVL tree of VM areas per task, sorted by address */
  42         short vm_avl_height;
  43         struct vm_area_struct * vm_avl_left;
  44         struct vm_area_struct * vm_avl_right;
  45 /* linked list of VM areas per task, sorted by address */
  46         struct vm_area_struct * vm_next;
  47 /* for areas with inode, the circular list inode->i_mmap */
  48 /* for shm areas, the circular list of attaches */
  49 /* otherwise unused */
  50         struct vm_area_struct * vm_next_share;
  51         struct vm_area_struct * vm_prev_share;
  52 /* more */
  53         struct vm_operations_struct * vm_ops;
  54         unsigned long vm_offset;
  55         struct inode * vm_inode;
  56         unsigned long vm_pte;                   /* shared mem */
  57 };
  58 
  59 /*
  60  * vm_flags..
  61  */
  62 #define VM_READ         0x0001  /* currently active flags */
  63 #define VM_WRITE        0x0002
  64 #define VM_EXEC         0x0004
  65 #define VM_SHARED       0x0008
  66 
  67 #define VM_MAYREAD      0x0010  /* limits for mprotect() etc */
  68 #define VM_MAYWRITE     0x0020
  69 #define VM_MAYEXEC      0x0040
  70 #define VM_MAYSHARE     0x0080
  71 
  72 #define VM_GROWSDOWN    0x0100  /* general info on the segment */
  73 #define VM_GROWSUP      0x0200
  74 #define VM_SHM          0x0400  /* shared memory area, don't swap out */
  75 #define VM_DENYWRITE    0x0800  /* ETXTBSY on write attempts.. */
  76 
  77 #define VM_EXECUTABLE   0x1000
  78 #define VM_LOCKED       0x2000
  79 
  80 #define VM_STACK_FLAGS  0x0177
  81 
  82 /*
  83  * mapping from the currently active vm_flags protection bits (the
  84  * low four bits) to a page protection mask..
  85  */
  86 extern pgprot_t protection_map[16];
  87 
  88 
  89 /*
  90  * These are the virtual MM functions - opening of an area, closing and
  91  * unmapping it (needed to keep files on disk up-to-date etc), pointer
  92  * to the functions called when a no-page or a wp-page exception occurs. 
  93  */
  94 struct vm_operations_struct {
  95         void (*open)(struct vm_area_struct * area);
  96         void (*close)(struct vm_area_struct * area);
  97         void (*unmap)(struct vm_area_struct *area, unsigned long, size_t);
  98         void (*protect)(struct vm_area_struct *area, unsigned long, size_t, unsigned int newprot);
  99         int (*sync)(struct vm_area_struct *area, unsigned long, size_t, unsigned int flags);
 100         void (*advise)(struct vm_area_struct *area, unsigned long, size_t, unsigned int advise);
 101         unsigned long (*nopage)(struct vm_area_struct * area, unsigned long address, int write_access);
 102         unsigned long (*wppage)(struct vm_area_struct * area, unsigned long address,
 103                 unsigned long page);
 104         int (*swapout)(struct vm_area_struct *,  unsigned long, pte_t *);
 105         pte_t (*swapin)(struct vm_area_struct *, unsigned long, unsigned long);
 106 };
 107 
 108 /*
 109  * Try to keep the most commonly accessed fields in single cache lines
 110  * here (16 bytes or greater).  This ordering should be particularly
 111  * beneficial on 32-bit processors.
 112  *
 113  * The first line is data used in linear searches (eg. clock algorithm
 114  * scans).  The second line is data used in page searches through the
 115  * page-cache.  -- sct 
 116  */
 117 typedef struct page {
 118         unsigned int count;
 119         unsigned dirty:16,
 120                  age:8,
 121                  uptodate:1,
 122                  error:1,
 123                  referenced:1,
 124                  locked:1,
 125                  free_after:1,
 126                  unused:2,
 127                  reserved:1;
 128         struct wait_queue *wait;
 129         struct page *next;
 130 
 131         struct page *next_hash;
 132         unsigned long offset;
 133         struct inode *inode;
 134         struct page *write_list;
 135 
 136         struct page *prev;
 137         struct page *prev_hash;
 138 } mem_map_t;
 139 
 140 extern mem_map_t * mem_map;
 141 
 142 /*
 143  * Free area management
 144  */
 145 
 146 #define NR_MEM_LISTS 6
 147 
 148 struct mem_list {
 149         struct mem_list * next;
 150         struct mem_list * prev;
 151 };
 152 
 153 extern struct mem_list free_area_list[NR_MEM_LISTS];
 154 extern unsigned int * free_area_map[NR_MEM_LISTS];
 155 
 156 /*
 157  * This is timing-critical - most of the time in getting a new page
 158  * goes to clearing the page. If you want a page without the clearing
 159  * overhead, just use __get_free_page() directly..
 160  */
 161 #define __get_free_page(priority) __get_free_pages((priority),0,~0UL)
 162 #define __get_dma_pages(priority, order) __get_free_pages((priority),(order),MAX_DMA_ADDRESS)
 163 extern unsigned long __get_free_pages(int priority, unsigned long gfporder, unsigned long max_addr);
 164 
 165 extern inline unsigned long get_free_page(int priority)
     /*  */
 166 {
 167         unsigned long page;
 168 
 169         page = __get_free_page(priority);
 170         if (page)
 171                 memset((void *) page, 0, PAGE_SIZE);
 172         return page;
 173 }
 174 
 175 /* memory.c & swap.c*/
 176 
 177 #define free_page(addr) free_pages((addr),0)
 178 extern void free_pages(unsigned long addr, unsigned long order);
 179 
 180 extern void show_free_areas(void);
 181 extern unsigned long put_dirty_page(struct task_struct * tsk,unsigned long page,
 182         unsigned long address);
 183 
 184 extern void free_page_tables(struct task_struct * tsk);
 185 extern void clear_page_tables(struct task_struct * tsk);
 186 extern int new_page_tables(struct task_struct * tsk);
 187 extern int copy_page_tables(struct task_struct * to);
 188 
 189 extern int zap_page_range(struct mm_struct *mm, unsigned long address, unsigned long size);
 190 extern int copy_page_range(struct mm_struct *dst, struct mm_struct *src, struct vm_area_struct *vma);
 191 extern int remap_page_range(unsigned long from, unsigned long to, unsigned long size, pgprot_t prot);
 192 extern int zeromap_page_range(unsigned long from, unsigned long size, pgprot_t prot);
 193 
 194 extern void vmtruncate(struct inode * inode, unsigned long offset);
 195 extern void handle_mm_fault(struct vm_area_struct *vma, unsigned long address, int write_access);
 196 extern void do_wp_page(struct task_struct * tsk, struct vm_area_struct * vma, unsigned long address, int write_access);
 197 extern void do_no_page(struct task_struct * tsk, struct vm_area_struct * vma, unsigned long address, int write_access);
 198 
 199 extern unsigned long paging_init(unsigned long start_mem, unsigned long end_mem);
 200 extern void mem_init(unsigned long start_mem, unsigned long end_mem);
 201 extern void show_mem(void);
 202 extern void oom(struct task_struct * tsk);
 203 extern void si_meminfo(struct sysinfo * val);
 204 
 205 /* vmalloc.c */
 206 
 207 extern void * vmalloc(unsigned long size);
 208 extern void * vremap(unsigned long offset, unsigned long size);
 209 extern void vfree(void * addr);
 210 extern int vread(char *buf, char *addr, int count);
 211 
 212 /* mmap.c */
 213 extern unsigned long do_mmap(struct file * file, unsigned long addr, unsigned long len,
 214         unsigned long prot, unsigned long flags, unsigned long off);
 215 extern void merge_segments(struct task_struct *, unsigned long, unsigned long);
 216 extern void insert_vm_struct(struct task_struct *, struct vm_area_struct *);
 217 extern void remove_shared_vm_struct(struct vm_area_struct *);
 218 extern void build_mmap_avl(struct mm_struct *);
 219 extern void exit_mmap(struct mm_struct *);
 220 extern int do_munmap(unsigned long, size_t);
 221 extern unsigned long get_unmapped_area(unsigned long, unsigned long);
 222 
 223 /* filemap.c */
 224 extern unsigned long page_unuse(unsigned long);
 225 extern int shrink_mmap(int, unsigned long);
 226 extern void truncate_inode_pages(struct inode *, unsigned long);
 227 
 228 #define GFP_BUFFER      0x00
 229 #define GFP_ATOMIC      0x01
 230 #define GFP_USER        0x02
 231 #define GFP_KERNEL      0x03
 232 #define GFP_NOBUFFER    0x04
 233 #define GFP_NFS         0x05
 234 
 235 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
 236    platforms, used as appropriate on others */
 237 
 238 #define GFP_DMA         0x80
 239 
 240 #define GFP_LEVEL_MASK 0xf
 241 
 242 /* vma is the first one with  address < vma->vm_end,
 243  * and even  address < vma->vm_start. Have to extend vma. */
 244 static inline int expand_stack(struct vm_area_struct * vma, unsigned long address)
     /*  */
 245 {
 246         unsigned long grow;
 247 
 248         address &= PAGE_MASK;
 249         if (vma->vm_end - address > current->rlim[RLIMIT_STACK].rlim_cur)
 250                 return -ENOMEM;
 251         grow = vma->vm_start - address;
 252         vma->vm_start = address;
 253         vma->vm_offset -= grow;
 254         vma->vm_mm->total_vm += grow >> PAGE_SHIFT;
 255         if (vma->vm_flags & VM_LOCKED)
 256                 vma->vm_mm->locked_vm += grow >> PAGE_SHIFT;
 257         return 0;
 258 }
 259 
 260 #define avl_empty       (struct vm_area_struct *) NULL
 261 
 262 /* Look up the first VMA which satisfies  addr < vm_end,  NULL if none. */
 263 static inline struct vm_area_struct * find_vma (struct task_struct * task, unsigned long addr)
     /*  */
 264 {
 265         struct vm_area_struct * result = NULL;
 266         struct vm_area_struct * tree;
 267 
 268         if (!task->mm)
 269                 return NULL;
 270         for (tree = task->mm->mmap_avl ; ; ) {
 271                 if (tree == avl_empty)
 272                         return result;
 273                 if (tree->vm_end > addr) {
 274                         if (tree->vm_start <= addr)
 275                                 return tree;
 276                         result = tree;
 277                         tree = tree->vm_avl_left;
 278                 } else
 279                         tree = tree->vm_avl_right;
 280         }
 281 }
 282 
 283 /* Look up the first VMA which intersects the interval start_addr..end_addr-1,
 284    NULL if none.  Assume start_addr < end_addr. */
 285 static inline struct vm_area_struct * find_vma_intersection (struct task_struct * task, unsigned long start_addr, unsigned long end_addr)
     /*  */
 286 {
 287         struct vm_area_struct * vma;
 288 
 289         vma = find_vma(task,start_addr);
 290         if (!vma || end_addr <= vma->vm_start)
 291                 return NULL;
 292         return vma;
 293 }
 294 
 295 #endif /* __KERNEL__ */
 296 
 297 #endif
/* */
root/include/linux/mm.h

INCLUDED FROM

DEFINITIONS
