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 <asm/page.h>
   5 
   6 #include <linux/sched.h>
   7 #include <linux/errno.h>
   8 #include <linux/kernel.h>
   9 
  10 #define VERIFY_READ 0
  11 #define VERIFY_WRITE 1
  12 
  13 extern int verify_area(int, const void *, unsigned long);
  14 
  15 /*
  16  * Linux kernel virtual memory manager primitives.
  17  * The idea being to have a "virtual" mm in the same way
  18  * we have a virtual fs - giving a cleaner interface to the
  19  * mm details, and allowing different kinds of memory mappings
  20  * (from shared memory to executable loading to arbitrary
  21  * mmap() functions).
  22  */
  23 
  24 /*
  25  * This struct defines a memory VMM memory area. There is one of these
  26  * per VM-area/task.  A VM area is any part of the process virtual memory
  27  * space that has a special rule for the page-fault handlers (ie a shared
  28  * library, the executable area etc).
  29  */
  30 struct vm_area_struct {
  31         struct task_struct * vm_task;           /* VM area parameters */
  32         unsigned long vm_start;
  33         unsigned long vm_end;
  34         unsigned short vm_page_prot;
  35         unsigned short vm_flags;
  36         struct vm_area_struct * vm_next;        /* linked list */
  37         struct vm_area_struct * vm_share;       /* linked list */
  38         struct vm_operations_struct * vm_ops;
  39         unsigned long vm_offset;
  40         struct inode * vm_inode;
  41         unsigned long vm_pte;                   /* shared mem */
  42 };
  43 
  44 /*
  45  * vm_flags..
  46  */
  47 #define VM_READ         0x0001  /* currently active flags */
  48 #define VM_WRITE        0x0002
  49 #define VM_EXEC         0x0004
  50 #define VM_SHARED       0x0008
  51 
  52 #define VM_MAYREAD      0x0010  /* limits for mprotect() etc */
  53 #define VM_MAYWRITE     0x0020
  54 #define VM_MAYEXEC      0x0040
  55 #define VM_MAYSHARE     0x0080
  56 
  57 #define VM_GROWSDOWN    0x0100  /* general info on the segment */
  58 #define VM_GROWSUP      0x0200
  59 #define VM_SHM          0x0400
  60 #define VM_DENYWRITE    0x0800  /* ETXTBSY on write attempts.. */
  61 
  62 #define VM_EXECUTABLE   0x1000
  63 
  64 #define VM_STACK_FLAGS  0x0177
  65 
  66 /*
  67  * These are the virtual MM functions - opening of an area, closing it (needed to
  68  * keep files on disk up-to-date etc), pointer to the functions called when a
  69  * no-page or a wp-page exception occurs, and the function which decides on sharing
  70  * of pages between different processes.
  71  */
  72 struct vm_operations_struct {
  73         void (*open)(struct vm_area_struct * area);
  74         void (*close)(struct vm_area_struct * area);
  75         unsigned long (*nopage)(struct vm_area_struct * area, unsigned long address,
  76                 unsigned long page, int error_code);
  77         unsigned long (*wppage)(struct vm_area_struct * area, unsigned long address,
  78                 unsigned long page);
  79         int (*share)(struct vm_area_struct * from, struct vm_area_struct * to, unsigned long address);
  80         int (*unmap)(struct vm_area_struct *area, unsigned long, size_t);
  81         void (*swapout)(struct vm_area_struct *,  unsigned long *);
  82         unsigned long (*swapin)(struct vm_area_struct *,  unsigned long);
  83 };
  84 
  85 extern unsigned long __bad_page(void);
  86 extern unsigned long __bad_pagetable(void);
  87 extern unsigned long __zero_page(void);
  88 
  89 #define BAD_PAGETABLE __bad_pagetable()
  90 #define BAD_PAGE __bad_page()
  91 #define ZERO_PAGE __zero_page()
  92 
  93 /* planning stage.. */
  94 #define P_DIRTY         0x0001
  95 #define P_LOCKED        0x0002
  96 #define P_UPTODATE      0x0004
  97 #define P_RESERVED      0x8000
  98 
  99 struct page_info {
 100         unsigned short flags;
 101         unsigned short count;
 102         struct inode * inode;
 103         unsigned long offset;
 104         struct page_info * next_same_inode;
 105         struct page_info * prev_same_inode;
 106         struct page_info * next_hash;
 107         struct page_info * prev_hash;
 108         struct wait_queue *wait;
 109 };
 110 /* end of planning stage */
 111 
 112 #ifdef __KERNEL__
 113 
 114 /*
 115  * Free area management
 116  */
 117 
 118 extern int nr_swap_pages;
 119 extern int nr_free_pages;
 120 extern int min_free_pages;
 121 
 122 #define NR_MEM_LISTS 6
 123 
 124 struct mem_list {
 125         struct mem_list * next;
 126         struct mem_list * prev;
 127 };
 128 
 129 extern struct mem_list free_area_list[NR_MEM_LISTS];
 130 extern unsigned char * free_area_map[NR_MEM_LISTS];
 131 
 132 /*
 133  * This is timing-critical - most of the time in getting a new page
 134  * goes to clearing the page. If you want a page without the clearing
 135  * overhead, just use __get_free_page() directly..
 136  */
 137 #define __get_free_page(priority) __get_free_pages((priority),0)
 138 extern unsigned long __get_free_pages(int priority, unsigned long gfporder);
 139 extern inline unsigned long get_free_page(int priority)
     /*  */
 140 {
 141         unsigned long page;
 142 
 143         page = __get_free_page(priority);
 144         if (page)
 145                 __asm__ __volatile__("rep ; stosl"
 146                         : /* no outputs */ \
 147                         :"a" (0),"c" (1024),"D" (page)
 148                         :"di","cx");
 149         return page;
 150 }
 151 
 152 /* memory.c & swap.c*/
 153 
 154 #define free_page(addr) free_pages((addr),0)
 155 extern void free_pages(unsigned long addr, unsigned long order);
 156 
 157 extern void show_free_areas(void);
 158 extern unsigned long put_dirty_page(struct task_struct * tsk,unsigned long page,
 159         unsigned long address);
 160 
 161 extern void free_page_tables(struct task_struct * tsk);
 162 extern void clear_page_tables(struct task_struct * tsk);
 163 extern int copy_page_tables(struct task_struct * to);
 164 extern int clone_page_tables(struct task_struct * to);
 165 extern int unmap_page_range(unsigned long from, unsigned long size);
 166 extern int remap_page_range(unsigned long from, unsigned long to, unsigned long size, int mask);
 167 extern int zeromap_page_range(unsigned long from, unsigned long size, int mask);
 168 
 169 extern void do_wp_page(struct vm_area_struct * vma, unsigned long address,
 170         unsigned long error_code);
 171 extern void do_no_page(struct vm_area_struct * vma, unsigned long address,
 172         unsigned long error_code);
 173 
 174 extern unsigned long paging_init(unsigned long start_mem, unsigned long end_mem);
 175 extern void mem_init(unsigned long low_start_mem,
 176                      unsigned long start_mem, unsigned long end_mem);
 177 extern void show_mem(void);
 178 extern void oom(struct task_struct * task);
 179 extern void si_meminfo(struct sysinfo * val);
 180 
 181 /* vmalloc.c */
 182 
 183 extern void * vmalloc(unsigned long size);
 184 extern void vfree(void * addr);
 185 extern int vread(char *buf, char *addr, int count);
 186 
 187 /* swap.c */
 188 
 189 extern void swap_free(unsigned long page_nr);
 190 extern unsigned long swap_duplicate(unsigned long page_nr);
 191 extern unsigned long swap_in(unsigned long entry);
 192 extern void si_swapinfo(struct sysinfo * val);
 193 extern void rw_swap_page(int rw, unsigned long nr, char * buf);
 194 
 195 /* mmap.c */
 196 extern int do_mmap(struct file * file, unsigned long addr, unsigned long len,
 197         unsigned long prot, unsigned long flags, unsigned long off);
 198 extern void merge_segments(struct vm_area_struct *);
 199 extern void insert_vm_struct(struct task_struct *, struct vm_area_struct *);
 200 extern int do_munmap(unsigned long, size_t);
 201 extern unsigned long get_unmapped_area(unsigned long);
 202 
 203 #define read_swap_page(nr,buf) \
 204         rw_swap_page(READ,(nr),(buf))
 205 #define write_swap_page(nr,buf) \
 206         rw_swap_page(WRITE,(nr),(buf))
 207 
 208 extern unsigned long high_memory;
 209 
 210 #define MAP_NR(addr) ((addr) >> PAGE_SHIFT)
 211 #define MAP_PAGE_RESERVED (1<<15)
 212 
 213 extern unsigned short * mem_map;
 214 
 215 #define PAGE_PRESENT    0x001
 216 #define PAGE_RW         0x002
 217 #define PAGE_USER       0x004
 218 #define PAGE_PWT        0x008   /* 486 only - not used currently */
 219 #define PAGE_PCD        0x010   /* 486 only - not used currently */
 220 #define PAGE_ACCESSED   0x020
 221 #define PAGE_DIRTY      0x040
 222 #define PAGE_COW        0x200   /* implemented in software (one of the AVL bits) */
 223 
 224 #define PAGE_PRIVATE    (PAGE_PRESENT | PAGE_RW | PAGE_USER | PAGE_ACCESSED | PAGE_COW)
 225 #define PAGE_SHARED     (PAGE_PRESENT | PAGE_RW | PAGE_USER | PAGE_ACCESSED)
 226 #define PAGE_COPY       (PAGE_PRESENT | PAGE_USER | PAGE_ACCESSED | PAGE_COW)
 227 #define PAGE_READONLY   (PAGE_PRESENT | PAGE_USER | PAGE_ACCESSED)
 228 #define PAGE_TABLE      (PAGE_PRESENT | PAGE_RW | PAGE_USER | PAGE_ACCESSED)
 229 
 230 #define GFP_BUFFER      0x00
 231 #define GFP_ATOMIC      0x01
 232 #define GFP_USER        0x02
 233 #define GFP_KERNEL      0x03
 234 #define GFP_NOBUFFER    0x04
 235 #define GFP_NFS         0x05
 236 
 237 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
 238    platforms, used as appropriate on others */
 239 
 240 #define GFP_DMA         0x80
 241 
 242 /*
 243  * vm_ops not present page codes for shared memory.
 244  *
 245  * Will go away eventually..
 246  */
 247 #define SHM_SWP_TYPE 0x41
 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[addr >> PAGE_SHIFT]; 
 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         __asm__ __volatile__("xchgl %0,%1"
 279                 :"=m" (swap_cache[addr >> PAGE_SHIFT]),
 280                  "=r" (entry)
 281                 :"0" (swap_cache[addr >> PAGE_SHIFT]),
 282                  "1" (0));
 283 #ifdef SWAP_CACHE_INFO
 284         if (entry)
 285                 swap_cache_find_success++;
 286 #endif  
 287         return entry;
 288 }
 289 
 290 extern inline int delete_from_swap_cache(unsigned long addr)
     /*  */
 291 {
 292         unsigned long entry;
 293         
 294 #ifdef SWAP_CACHE_INFO
 295         swap_cache_del_total++;
 296 #endif  
 297         __asm__ __volatile__("xchgl %0,%1"
 298                 :"=m" (swap_cache[addr >> PAGE_SHIFT]),
 299                  "=r" (entry)
 300                 :"0" (swap_cache[addr >> PAGE_SHIFT]),
 301                  "1" (0));
 302         if (entry)  {
 303 #ifdef SWAP_CACHE_INFO
 304                 swap_cache_del_success++;
 305 #endif
 306                 swap_free(entry);
 307                 return 1;
 308         }
 309         return 0;
 310 }
 311 
 312 #endif /* __KERNEL__ */
 313 
 314 #endif
/* */
root/include/linux/mm.h

INCLUDED FROM

DEFINITIONS
