include/linux/mm.h

/* */
This source file includes following definitions.
get_free_page
expand_stack
find_vma
find_vma_intersection
in_swap_cache
find_in_swap_cache
delete_from_swap_cache
   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,
 102                 unsigned long page, int write_access);
 103         unsigned long (*wppage)(struct vm_area_struct * area, unsigned long address,
 104                 unsigned long page);
 105         int (*swapout)(struct vm_area_struct *,  unsigned long, pte_t *);
 106         pte_t (*swapin)(struct vm_area_struct *, unsigned long, unsigned long);
 107 };
 108 
 109 typedef struct {
 110         unsigned count:24,
 111                  age:6,
 112                  dirty:1,
 113                  reserved:1;
 114 } mem_map_t;
 115 
 116 extern mem_map_t * mem_map;
 117 
 118 /*
 119  * Free area management
 120  */
 121 
 122 extern int nr_swap_pages;
 123 extern int nr_free_pages;
 124 extern int min_free_pages;
 125 
 126 #define NR_MEM_LISTS 6
 127 
 128 struct mem_list {
 129         struct mem_list * next;
 130         struct mem_list * prev;
 131 };
 132 
 133 extern struct mem_list free_area_list[NR_MEM_LISTS];
 134 extern unsigned char * free_area_map[NR_MEM_LISTS];
 135 
 136 /*
 137  * This is timing-critical - most of the time in getting a new page
 138  * goes to clearing the page. If you want a page without the clearing
 139  * overhead, just use __get_free_page() directly..
 140  */
 141 #define __get_free_page(priority) __get_free_pages((priority),0,~0UL)
 142 #define __get_dma_pages(priority, order) __get_free_pages((priority),(order),MAX_DMA_ADDRESS)
 143 extern unsigned long __get_free_pages(int priority, unsigned long gfporder, unsigned long max_addr);
 144 
 145 extern inline unsigned long get_free_page(int priority)
     /*  */
 146 {
 147         unsigned long page;
 148 
 149         page = __get_free_page(priority);
 150         if (page)
 151                 memset((void *) page, 0, PAGE_SIZE);
 152         return page;
 153 }
 154 
 155 /* memory.c & swap.c*/
 156 
 157 #define free_page(addr) free_pages((addr),0)
 158 extern void free_pages(unsigned long addr, unsigned long order);
 159 
 160 extern void show_free_areas(void);
 161 extern unsigned long put_dirty_page(struct task_struct * tsk,unsigned long page,
 162         unsigned long address);
 163 
 164 extern void free_page_tables(struct task_struct * tsk);
 165 extern void clear_page_tables(struct task_struct * tsk);
 166 extern int new_page_tables(struct task_struct * tsk);
 167 extern int copy_page_tables(struct task_struct * to);
 168 
 169 extern int zap_page_range(struct mm_struct *mm, unsigned long address, unsigned long size);
 170 extern int copy_page_range(struct mm_struct *dst, struct mm_struct *src, struct vm_area_struct *vma);
 171 extern int remap_page_range(unsigned long from, unsigned long to, unsigned long size, pgprot_t prot);
 172 extern int zeromap_page_range(unsigned long from, unsigned long size, pgprot_t prot);
 173 
 174 extern void vmtruncate(struct inode * inode, unsigned long offset);
 175 extern void handle_mm_fault(struct vm_area_struct *vma, unsigned long address, int write_access);
 176 extern void do_wp_page(struct task_struct * tsk, struct vm_area_struct * vma, unsigned long address, int write_access);
 177 extern void do_no_page(struct task_struct * tsk, struct vm_area_struct * vma, unsigned long address, int write_access);
 178 
 179 extern unsigned long paging_init(unsigned long start_mem, unsigned long end_mem);
 180 extern void mem_init(unsigned long start_mem, unsigned long end_mem);
 181 extern void show_mem(void);
 182 extern void oom(struct task_struct * tsk);
 183 extern void si_meminfo(struct sysinfo * val);
 184 
 185 /* vmalloc.c */
 186 
 187 extern void * vmalloc(unsigned long size);
 188 extern void * vremap(unsigned long offset, unsigned long size);
 189 extern void vfree(void * addr);
 190 extern int vread(char *buf, char *addr, int count);
 191 
 192 /* swap.c */
 193 
 194 extern void swap_free(unsigned long);
 195 extern void swap_duplicate(unsigned long);
 196 extern void swap_in(struct task_struct *, struct vm_area_struct *, pte_t *, unsigned long id, int write_access);
 197 
 198 extern void si_swapinfo(struct sysinfo * val);
 199 extern void rw_swap_page(int rw, unsigned long nr, char * buf);
 200 
 201 /* mmap.c */
 202 extern unsigned long do_mmap(struct file * file, unsigned long addr, unsigned long len,
 203         unsigned long prot, unsigned long flags, unsigned long off);
 204 extern void merge_segments(struct task_struct *, unsigned long, unsigned long);
 205 extern void insert_vm_struct(struct task_struct *, struct vm_area_struct *);
 206 extern void remove_shared_vm_struct(struct vm_area_struct *);
 207 extern void build_mmap_avl(struct mm_struct *);
 208 extern void exit_mmap(struct mm_struct *);
 209 extern int do_munmap(unsigned long, size_t);
 210 extern unsigned long get_unmapped_area(unsigned long, unsigned long);
 211 
 212 #define read_swap_page(nr,buf) \
 213         rw_swap_page(READ,(nr),(buf))
 214 #define write_swap_page(nr,buf) \
 215         rw_swap_page(WRITE,(nr),(buf))
 216 
 217 #define GFP_BUFFER      0x00
 218 #define GFP_ATOMIC      0x01
 219 #define GFP_USER        0x02
 220 #define GFP_KERNEL      0x03
 221 #define GFP_NOBUFFER    0x04
 222 #define GFP_NFS         0x05
 223 
 224 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
 225    platforms, used as appropriate on others */
 226 
 227 #define GFP_DMA         0x80
 228 
 229 #define GFP_LEVEL_MASK 0xf
 230 
 231 #define avl_empty       (struct vm_area_struct *) NULL
 232 
 233 static inline int expand_stack(struct vm_area_struct * vma, unsigned long address)
     /*  */
 234 {
 235         unsigned long grow;
 236 
 237         address &= PAGE_MASK;
 238         if (vma->vm_end - address > current->rlim[RLIMIT_STACK].rlim_cur)
 239                 return -ENOMEM;
 240         grow = vma->vm_start - address;
 241         vma->vm_start = address;
 242         vma->vm_offset -= grow;
 243         vma->vm_mm->total_vm += grow >> PAGE_SHIFT;
 244         if (vma->vm_flags & VM_LOCKED)
 245                 vma->vm_mm->locked_vm += grow >> PAGE_SHIFT;
 246         return 0;
 247 }
 248 
 249 /* Look up the first VMA which satisfies  addr < vm_end,  NULL if none. */
 250 static inline struct vm_area_struct * find_vma (struct task_struct * task, unsigned long addr)
     /*  */
 251 {
 252         struct vm_area_struct * result = NULL;
 253         struct vm_area_struct * tree;
 254 
 255         if (!task->mm)
 256                 return NULL;
 257         for (tree = task->mm->mmap_avl ; ; ) {
 258                 if (tree == avl_empty)
 259                         return result;
 260                 if (tree->vm_end > addr) {
 261                         if (tree->vm_start <= addr)
 262                                 return tree;
 263                         result = tree;
 264                         tree = tree->vm_avl_left;
 265                 } else
 266                         tree = tree->vm_avl_right;
 267         }
 268 }
 269 
 270 /* Look up the first VMA which intersects the interval start_addr..end_addr-1,
 271    NULL if none.  Assume start_addr < end_addr. */
 272 static inline struct vm_area_struct * find_vma_intersection (struct task_struct * task, unsigned long start_addr, unsigned long end_addr)
     /*  */
 273 {
 274         struct vm_area_struct * vma;
 275 
 276         vma = find_vma(task,start_addr);
 277         if (!vma || end_addr <= vma->vm_start)
 278                 return NULL;
 279         return vma;
 280 }
 281 
 282 /*
 283  * vm_ops not present page codes for shared memory.
 284  *
 285  * Will go away eventually..
 286  */
 287 #define SHM_SWP_TYPE 0x40
 288 
 289 extern void shm_no_page (ulong *);
 290 
 291 /*
 292  * swap cache stuff (in swap.c)
 293  */
 294 #define SWAP_CACHE_INFO
 295 
 296 extern unsigned long * swap_cache;
 297 
 298 #ifdef SWAP_CACHE_INFO
 299 extern unsigned long swap_cache_add_total;
 300 extern unsigned long swap_cache_add_success;
 301 extern unsigned long swap_cache_del_total;
 302 extern unsigned long swap_cache_del_success;
 303 extern unsigned long swap_cache_find_total;
 304 extern unsigned long swap_cache_find_success;
 305 #endif
 306 
 307 extern inline unsigned long in_swap_cache(unsigned long addr)
     /*  */
 308 {
 309         return swap_cache[MAP_NR(addr)]; 
 310 }
 311 
 312 extern inline long find_in_swap_cache (unsigned long addr)
     /*  */
 313 {
 314         unsigned long entry;
 315 
 316 #ifdef SWAP_CACHE_INFO
 317         swap_cache_find_total++;
 318 #endif
 319         entry = xchg(swap_cache + MAP_NR(addr), 0);
 320 #ifdef SWAP_CACHE_INFO
 321         if (entry)
 322                 swap_cache_find_success++;
 323 #endif  
 324         return entry;
 325 }
 326 
 327 extern inline int delete_from_swap_cache(unsigned long addr)
     /*  */
 328 {
 329         unsigned long entry;
 330         
 331 #ifdef SWAP_CACHE_INFO
 332         swap_cache_del_total++;
 333 #endif  
 334         entry= xchg(swap_cache + MAP_NR(addr), 0);
 335         if (entry)  {
 336 #ifdef SWAP_CACHE_INFO
 337                 swap_cache_del_success++;
 338 #endif
 339                 swap_free(entry);
 340                 return 1;
 341         }
 342         return 0;
 343 }
 344 
 345 #endif /* __KERNEL__ */
 346 
 347 #endif
/* */
root/include/linux/mm.h

INCLUDED FROM

DEFINITIONS
