include/linux/mm.h

/* */
This source file includes following definitions.
get_free_page
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 task_struct * vm_task;           /* 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
  75 #define VM_DENYWRITE    0x0800  /* ETXTBSY on write attempts.. */
  76 
  77 #define VM_EXECUTABLE   0x1000
  78 
  79 #define VM_STACK_FLAGS  0x0177
  80 
  81 /*
  82  * mapping from the currently active vm_flags protection bits (the
  83  * low four bits) to a page protection mask..
  84  */
  85 extern pgprot_t protection_map[16];
  86 
  87 
  88 /*
  89  * These are the virtual MM functions - opening of an area, closing and
  90  * unmapping it (needed to keep files on disk up-to-date etc), pointer
  91  * to the functions called when a no-page or a wp-page exception occurs. 
  92  */
  93 struct vm_operations_struct {
  94         void (*open)(struct vm_area_struct * area);
  95         void (*close)(struct vm_area_struct * area);
  96         void (*unmap)(struct vm_area_struct *area, unsigned long, size_t);
  97         void (*protect)(struct vm_area_struct *area, unsigned long, size_t, unsigned int newprot);
  98         void (*sync)(struct vm_area_struct *area, unsigned long, size_t, unsigned int flags);
  99         void (*advise)(struct vm_area_struct *area, unsigned long, size_t, unsigned int advise);
 100         unsigned long (*nopage)(struct vm_area_struct * area, unsigned long address,
 101                 unsigned long page, int write_access);
 102         unsigned long (*wppage)(struct vm_area_struct * area, unsigned long address,
 103                 unsigned long page);
 104         void (*swapout)(struct vm_area_struct *,  unsigned long, pte_t *);
 105         pte_t (*swapin)(struct vm_area_struct *, unsigned long, unsigned long);
 106 };
 107 
 108 extern mem_map_t * mem_map;
 109 
 110 /* planning stage.. */
 111 #define P_DIRTY         0x0001
 112 #define P_LOCKED        0x0002
 113 #define P_UPTODATE      0x0004
 114 #define P_RESERVED      0x8000
 115 
 116 struct page_info {
 117         unsigned short flags;
 118         unsigned short count;
 119         struct inode * inode;
 120         unsigned long offset;
 121         struct page_info * next_same_inode;
 122         struct page_info * prev_same_inode;
 123         struct page_info * next_hash;
 124         struct page_info * prev_hash;
 125         struct wait_queue *wait;
 126 };
 127 /* end of planning stage */
 128 
 129 /*
 130  * Free area management
 131  */
 132 
 133 extern int nr_swap_pages;
 134 extern int nr_free_pages;
 135 extern int min_free_pages;
 136 
 137 #define NR_MEM_LISTS 6
 138 
 139 struct mem_list {
 140         struct mem_list * next;
 141         struct mem_list * prev;
 142 };
 143 
 144 extern struct mem_list free_area_list[NR_MEM_LISTS];
 145 extern unsigned char * free_area_map[NR_MEM_LISTS];
 146 
 147 /*
 148  * This is timing-critical - most of the time in getting a new page
 149  * goes to clearing the page. If you want a page without the clearing
 150  * overhead, just use __get_free_page() directly..
 151  */
 152 #define __get_free_page(priority) __get_free_pages((priority),0,~0UL)
 153 #define __get_dma_pages(priority, order) __get_free_pages((priority),(order),MAX_DMA_ADDRESS)
 154 extern unsigned long __get_free_pages(int priority, unsigned long gfporder, unsigned long max_addr);
 155 
 156 extern inline unsigned long get_free_page(int priority)
     /*  */
 157 {
 158         unsigned long page;
 159 
 160         page = __get_free_page(priority);
 161         if (page)
 162                 memset((void *) page, 0, PAGE_SIZE);
 163         return page;
 164 }
 165 
 166 /* memory.c & swap.c*/
 167 
 168 #define free_page(addr) free_pages((addr),0)
 169 extern void free_pages(unsigned long addr, unsigned long order);
 170 
 171 extern void show_free_areas(void);
 172 extern unsigned long put_dirty_page(struct task_struct * tsk,unsigned long page,
 173         unsigned long address);
 174 
 175 extern void free_page_tables(struct task_struct * tsk);
 176 extern void clear_page_tables(struct task_struct * tsk);
 177 extern int copy_page_tables(struct task_struct * to);
 178 extern int clone_page_tables(struct task_struct * to);
 179 extern int unmap_page_range(unsigned long from, unsigned long size);
 180 extern int remap_page_range(unsigned long from, unsigned long to, unsigned long size, pgprot_t prot);
 181 extern int zeromap_page_range(unsigned long from, unsigned long size, pgprot_t prot);
 182 
 183 extern void handle_mm_fault(struct vm_area_struct *vma, unsigned long address, int write_access);
 184 extern void do_wp_page(struct vm_area_struct * vma, unsigned long address, int write_access);
 185 extern void do_no_page(struct vm_area_struct * vma, unsigned long address, int write_access);
 186 
 187 extern unsigned long paging_init(unsigned long start_mem, unsigned long end_mem);
 188 extern void mem_init(unsigned long start_mem, unsigned long end_mem);
 189 extern void show_mem(void);
 190 extern void oom(struct task_struct * tsk);
 191 extern void si_meminfo(struct sysinfo * val);
 192 
 193 /* vmalloc.c */
 194 
 195 extern void * vmalloc(unsigned long size);
 196 extern void vfree(void * addr);
 197 extern int vread(char *buf, char *addr, int count);
 198 
 199 /* swap.c */
 200 
 201 extern void swap_free(unsigned long);
 202 extern void swap_duplicate(unsigned long);
 203 extern void swap_in(struct vm_area_struct *, pte_t *, unsigned long id, int write_access);
 204 
 205 extern void si_swapinfo(struct sysinfo * val);
 206 extern void rw_swap_page(int rw, unsigned long nr, char * buf);
 207 
 208 /* mmap.c */
 209 extern unsigned long do_mmap(struct file * file, unsigned long addr, unsigned long len,
 210         unsigned long prot, unsigned long flags, unsigned long off);
 211 extern struct vm_area_struct * find_vma (struct task_struct *, unsigned long);
 212 extern struct vm_area_struct * find_vma_intersection (struct task_struct *, unsigned long, unsigned long);
 213 extern void merge_segments(struct task_struct *, unsigned long, unsigned long);
 214 extern void insert_vm_struct(struct task_struct *, struct vm_area_struct *);
 215 extern void remove_shared_vm_struct(struct vm_area_struct *);
 216 extern void build_mmap_avl(struct task_struct *);
 217 extern void exit_mmap(struct task_struct *);
 218 extern int do_munmap(unsigned long, size_t);
 219 extern unsigned long get_unmapped_area(unsigned long, unsigned long);
 220 
 221 #define read_swap_page(nr,buf) \
 222         rw_swap_page(READ,(nr),(buf))
 223 #define write_swap_page(nr,buf) \
 224         rw_swap_page(WRITE,(nr),(buf))
 225 
 226 #define GFP_BUFFER      0x00
 227 #define GFP_ATOMIC      0x01
 228 #define GFP_USER        0x02
 229 #define GFP_KERNEL      0x03
 230 #define GFP_NOBUFFER    0x04
 231 #define GFP_NFS         0x05
 232 
 233 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
 234    platforms, used as appropriate on others */
 235 
 236 #define GFP_DMA         0x80
 237 
 238 #define GFP_LEVEL_MASK 0xf
 239 
 240 
 241 /*
 242  * vm_ops not present page codes for shared memory.
 243  *
 244  * Will go away eventually..
 245  */
 246 #define SHM_SWP_TYPE 0x40
 247 
 248 extern void shm_no_page (ulong *);
 249 
 250 /*
 251  * swap cache stuff (in swap.c)
 252  */
 253 #define SWAP_CACHE_INFO
 254 
 255 extern unsigned long * swap_cache;
 256 
 257 #ifdef SWAP_CACHE_INFO
 258 extern unsigned long swap_cache_add_total;
 259 extern unsigned long swap_cache_add_success;
 260 extern unsigned long swap_cache_del_total;
 261 extern unsigned long swap_cache_del_success;
 262 extern unsigned long swap_cache_find_total;
 263 extern unsigned long swap_cache_find_success;
 264 #endif
 265 
 266 extern inline unsigned long in_swap_cache(unsigned long addr)
     /*  */
 267 {
 268         return swap_cache[MAP_NR(addr)]; 
 269 }
 270 
 271 extern inline long find_in_swap_cache (unsigned long addr)
     /*  */
 272 {
 273         unsigned long entry;
 274 
 275 #ifdef SWAP_CACHE_INFO
 276         swap_cache_find_total++;
 277 #endif
 278         entry = (unsigned long) xchg_ptr(swap_cache + MAP_NR(addr), NULL);
 279 #ifdef SWAP_CACHE_INFO
 280         if (entry)
 281                 swap_cache_find_success++;
 282 #endif  
 283         return entry;
 284 }
 285 
 286 extern inline int delete_from_swap_cache(unsigned long addr)
     /*  */
 287 {
 288         unsigned long entry;
 289         
 290 #ifdef SWAP_CACHE_INFO
 291         swap_cache_del_total++;
 292 #endif  
 293         entry= (unsigned long) xchg_ptr(swap_cache + MAP_NR(addr), NULL);
 294         if (entry)  {
 295 #ifdef SWAP_CACHE_INFO
 296                 swap_cache_del_success++;
 297 #endif
 298                 swap_free(entry);
 299                 return 1;
 300         }
 301         return 0;
 302 }
 303 
 304 #endif /* __KERNEL__ */
 305 
 306 #endif
/* */
root/include/linux/mm.h

INCLUDED FROM

DEFINITIONS
