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/page.h>
   5 #include <linux/sched.h>
   6 #include <linux/errno.h>
   7 #include <linux/kernel.h>
   8 
   9 #define VERIFY_READ 0
  10 #define VERIFY_WRITE 1
  11 
  12 extern int verify_area(int, const void *, unsigned long);
  13 
  14 /*
  15  * Linux kernel virtual memory manager primitives.
  16  * The idea being to have a "virtual" mm in the same way
  17  * we have a virtual fs - giving a cleaner interface to the
  18  * mm details, and allowing different kinds of memory mappings
  19  * (from shared memory to executable loading to arbitrary
  20  * mmap() functions).
  21  */
  22 
  23 /*
  24  * This struct defines a memory VMM memory area. There is one of these
  25  * per VM-area/task.  A VM area is any part of the process virtual memory
  26  * space that has a special rule for the page-fault handlers (ie a shared
  27  * library, the executable area etc).
  28  */
  29 struct vm_area_struct {
  30         struct task_struct * vm_task;           /* VM area parameters */
  31         unsigned long vm_start;
  32         unsigned long vm_end;
  33         unsigned short vm_page_prot;
  34         unsigned short vm_flags;
  35         struct vm_area_struct * vm_next;        /* linked list */
  36         struct vm_area_struct * vm_share;       /* linked list */
  37         struct vm_operations_struct * vm_ops;
  38         unsigned long vm_offset;
  39         struct inode * vm_inode;
  40         unsigned long vm_pte;                   /* shared mem */
  41 };
  42 
  43 /*
  44  * vm_flags..
  45  */
  46 #define VM_READ         0x0001  /* currently active flags */
  47 #define VM_WRITE        0x0002
  48 #define VM_EXEC         0x0004
  49 #define VM_SHARED       0x0008
  50 
  51 #define VM_MAYREAD      0x0010  /* limits for mprotect() etc */
  52 #define VM_MAYWRITE     0x0020
  53 #define VM_MAYEXEC      0x0040
  54 #define VM_MAYSHARE     0x0080
  55 
  56 #define VM_GROWSDOWN    0x0100  /* general info on the segment */
  57 #define VM_GROWSUP      0x0200
  58 #define VM_SHM          0x0400
  59 #define VM_DENYWRITE    0x0800  /* ETXTBSY on write attempts.. */
  60 
  61 #define VM_EXECUTABLE   0x1000
  62 
  63 #define VM_STACK_FLAGS  0x0177
  64 
  65 /*
  66  * These are the virtual MM functions - opening of an area, closing it (needed to
  67  * keep files on disk up-to-date etc), pointer to the functions called when a
  68  * no-page or a wp-page exception occurs, and the function which decides on sharing
  69  * of pages between different processes.
  70  */
  71 struct vm_operations_struct {
  72         void (*open)(struct vm_area_struct * area);
  73         void (*close)(struct vm_area_struct * area);
  74         unsigned long (*nopage)(struct vm_area_struct * area, unsigned long address,
  75                 unsigned long page, int error_code);
  76         unsigned long (*wppage)(struct vm_area_struct * area, unsigned long address,
  77                 unsigned long page);
  78         int (*share)(struct vm_area_struct * from, struct vm_area_struct * to, unsigned long address);
  79         int (*unmap)(struct vm_area_struct *area, unsigned long, size_t);
  80         void (*swapout)(struct vm_area_struct *,  unsigned long *);
  81         unsigned long (*swapin)(struct vm_area_struct *,  unsigned long);
  82 };
  83 
  84 extern unsigned long __bad_page(void);
  85 extern unsigned long __bad_pagetable(void);
  86 extern unsigned long __zero_page(void);
  87 
  88 #define BAD_PAGETABLE __bad_pagetable()
  89 #define BAD_PAGE __bad_page()
  90 #define ZERO_PAGE __zero_page()
  91 
  92 /* planning stage.. */
  93 #define P_DIRTY         0x0001
  94 #define P_LOCKED        0x0002
  95 #define P_UPTODATE      0x0004
  96 #define P_RESERVED      0x8000
  97 
  98 struct page_info {
  99         unsigned short flags;
 100         unsigned short count;
 101         struct inode * inode;
 102         unsigned long offset;
 103         struct page_info * next_same_inode;
 104         struct page_info * prev_same_inode;
 105         struct page_info * next_hash;
 106         struct page_info * prev_hash;
 107         struct wait_queue *wait;
 108 };
 109 /* end of planning stage */
 110 
 111 #ifdef __KERNEL__
 112 
 113 /*
 114  * Free area management
 115  */
 116 
 117 extern int nr_swap_pages;
 118 extern int nr_free_pages;
 119 
 120 #define NR_MEM_LISTS 6
 121 
 122 struct mem_list {
 123         struct mem_list * next;
 124         struct mem_list * prev;
 125 };
 126 
 127 extern struct mem_list free_area_list[NR_MEM_LISTS];
 128 extern unsigned char * free_area_map[NR_MEM_LISTS];
 129 
 130 /*
 131  * This is timing-critical - most of the time in getting a new page
 132  * goes to clearing the page. If you want a page without the clearing
 133  * overhead, just use __get_free_page() directly..
 134  */
 135 #define __get_free_page(priority) __get_free_pages((priority),0)
 136 extern unsigned long __get_free_pages(int priority, unsigned long gfporder);
 137 extern inline unsigned long get_free_page(int priority)
     /*  */
 138 {
 139         unsigned long page;
 140 
 141         page = __get_free_page(priority);
 142         if (page)
 143                 __asm__ __volatile__("rep ; stosl"
 144                         : /* no outputs */ \
 145                         :"a" (0),"c" (1024),"D" (page)
 146                         :"di","cx");
 147         return page;
 148 }
 149 
 150 /* memory.c & swap.c*/
 151 
 152 #define free_page(addr) free_pages((addr),0)
 153 extern void free_pages(unsigned long addr, unsigned long order);
 154 
 155 extern void show_free_areas(void);
 156 extern unsigned long put_dirty_page(struct task_struct * tsk,unsigned long page,
 157         unsigned long address);
 158 
 159 extern void free_page_tables(struct task_struct * tsk);
 160 extern void clear_page_tables(struct task_struct * tsk);
 161 extern int copy_page_tables(struct task_struct * to);
 162 extern int clone_page_tables(struct task_struct * to);
 163 extern int unmap_page_range(unsigned long from, unsigned long size);
 164 extern int remap_page_range(unsigned long from, unsigned long to, unsigned long size, int mask);
 165 extern int zeromap_page_range(unsigned long from, unsigned long size, int mask);
 166 
 167 extern void do_wp_page(struct vm_area_struct * vma, unsigned long address,
 168         unsigned long error_code);
 169 extern void do_no_page(struct vm_area_struct * vma, unsigned long address,
 170         unsigned long error_code);
 171 
 172 extern unsigned long paging_init(unsigned long start_mem, unsigned long end_mem);
 173 extern void mem_init(unsigned long low_start_mem,
 174                      unsigned long start_mem, unsigned long end_mem);
 175 extern void show_mem(void);
 176 extern void oom(struct task_struct * task);
 177 extern void si_meminfo(struct sysinfo * val);
 178 
 179 /* vmalloc.c */
 180 
 181 extern void * vmalloc(unsigned long size);
 182 extern void vfree(void * addr);
 183 extern int vread(char *buf, char *addr, int count);
 184 
 185 /* swap.c */
 186 
 187 extern void swap_free(unsigned long page_nr);
 188 extern unsigned long swap_duplicate(unsigned long page_nr);
 189 extern unsigned long swap_in(unsigned long entry);
 190 extern void si_swapinfo(struct sysinfo * val);
 191 extern void rw_swap_page(int rw, unsigned long nr, char * buf);
 192 
 193 /* mmap.c */
 194 extern int do_mmap(struct file * file, unsigned long addr, unsigned long len,
 195         unsigned long prot, unsigned long flags, unsigned long off);
 196 extern void merge_segments(struct vm_area_struct *);
 197 extern void insert_vm_struct(struct task_struct *, struct vm_area_struct *);
 198 extern int do_munmap(unsigned long, size_t);
 199 
 200 #define read_swap_page(nr,buf) \
 201         rw_swap_page(READ,(nr),(buf))
 202 #define write_swap_page(nr,buf) \
 203         rw_swap_page(WRITE,(nr),(buf))
 204 
 205 #define invalidate() \
 206 __asm__ __volatile__("movl %%cr3,%%eax\n\tmovl %%eax,%%cr3": : :"ax")
 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 
 236 
 237 /*
 238  * vm_ops not present page codes for shared memory.
 239  *
 240  * Will go away eventually..
 241  */
 242 #define SHM_SWP_TYPE 0x41
 243 extern void shm_no_page (ulong *);
 244 
 245 /*
 246  * swap cache stuff (in swap.c)
 247  */
 248 #define SWAP_CACHE_INFO
 249 
 250 extern unsigned long * swap_cache;
 251 
 252 #ifdef SWAP_CACHE_INFO
 253 extern unsigned long swap_cache_add_total;
 254 extern unsigned long swap_cache_add_success;
 255 extern unsigned long swap_cache_del_total;
 256 extern unsigned long swap_cache_del_success;
 257 extern unsigned long swap_cache_find_total;
 258 extern unsigned long swap_cache_find_success;
 259 #endif
 260 
 261 extern inline unsigned long in_swap_cache(unsigned long addr)
     /*  */
 262 {
 263         return swap_cache[addr >> PAGE_SHIFT]; 
 264 }
 265 
 266 extern inline long find_in_swap_cache (unsigned long addr)
     /*  */
 267 {
 268         unsigned long entry;
 269 
 270 #ifdef SWAP_CACHE_INFO
 271         swap_cache_find_total++;
 272 #endif
 273         __asm__ __volatile__("xchgl %0,%1"
 274                 :"=m" (swap_cache[addr >> PAGE_SHIFT]),
 275                  "=r" (entry)
 276                 :"0" (swap_cache[addr >> PAGE_SHIFT]),
 277                  "1" (0));
 278 #ifdef SWAP_CACHE_INFO
 279         if (entry)
 280                 swap_cache_find_success++;
 281 #endif  
 282         return entry;
 283 }
 284 
 285 extern inline int delete_from_swap_cache(unsigned long addr)
     /*  */
 286 {
 287         unsigned long entry;
 288         
 289 #ifdef SWAP_CACHE_INFO
 290         swap_cache_del_total++;
 291 #endif  
 292         __asm__ __volatile__("xchgl %0,%1"
 293                 :"=m" (swap_cache[addr >> PAGE_SHIFT]),
 294                  "=r" (entry)
 295                 :"0" (swap_cache[addr >> PAGE_SHIFT]),
 296                  "1" (0));
 297         if (entry)  {
 298 #ifdef SWAP_CACHE_INFO
 299                 swap_cache_del_success++;
 300 #endif
 301                 swap_free(entry);
 302                 return 1;
 303         }
 304         return 0;
 305 }
 306 
 307 #endif /* __KERNEL__ */
 308 
 309 #endif
/* */
root/include/linux/mm.h

INCLUDED FROM

DEFINITIONS
