kernel/power/power.h

   1 #include <linux/suspend.h>
   2 #include <linux/utsname.h>
   3
   4 struct swsusp_info {
   5         struct new_utsname      uts;
   6         u32                     version_code;
   7         unsigned long           num_physpages;
   8         int                     cpus;
   9         unsigned long           image_pages;
  10         unsigned long           pages;
  11         unsigned long           size;
  12 } __attribute__((aligned(PAGE_SIZE)));
  13
  14
  15
  16 #ifdef CONFIG_SOFTWARE_SUSPEND
  17 extern int pm_suspend_disk(void);
  18
  19 #else
  20 static inline int pm_suspend_disk(void)
  21 {
  22         return -EPERM;
  23 }
  24 #endif
  25 extern struct semaphore pm_sem;
  26 #define power_attr(_name) \
  27 static struct subsys_attribute _name##_attr = { \
  28         .attr   = {                             \
  29                 .name = __stringify(_name),     \
  30                 .mode = 0644,                   \
  31         },                                      \
  32         .show   = _name##_show,                 \
  33         .store  = _name##_store,                \
  34 }
  35
  36 extern struct subsystem power_subsys;
  37
  38 /* References to section boundaries */
  39 extern const void __nosave_begin, __nosave_end;
  40
  41 /* Preferred image size in bytes (default 500 MB) */
  42 extern unsigned long image_size;
  43 extern int in_suspend;
  44 extern dev_t swsusp_resume_device;
  45
  46 extern asmlinkage int swsusp_arch_suspend(void);
  47 extern asmlinkage int swsusp_arch_resume(void);
  48
  49 extern unsigned int count_data_pages(void);
  50
  51 /**
  52  *      Auxiliary structure used for reading the snapshot image data and
  53  *      metadata from and writing them to the list of page backup entries
  54  *      (PBEs) which is the main data structure of swsusp.
  55  *
  56  *      Using struct snapshot_handle we can transfer the image, including its
  57  *      metadata, as a continuous sequence of bytes with the help of
  58  *      snapshot_read_next() and snapshot_write_next().
  59  *
  60  *      The code that writes the image to a storage or transfers it to
  61  *      the user land is required to use snapshot_read_next() for this
  62  *      purpose and it should not make any assumptions regarding the internal
  63  *      structure of the image.  Similarly, the code that reads the image from
  64  *      a storage or transfers it from the user land is required to use
  65  *      snapshot_write_next().
  66  *
  67  *      This may allow us to change the internal structure of the image
  68  *      in the future with considerably less effort.
  69  */
  70
  71 struct snapshot_handle {
  72         loff_t          offset; /* number of the last byte ready for reading
  73                                  * or writing in the sequence
  74                                  */
  75         unsigned int    cur;    /* number of the block of PAGE_SIZE bytes the
  76                                  * next operation will refer to (ie. current)
  77                                  */
  78         unsigned int    cur_offset;     /* offset with respect to the current
  79                                          * block (for the next operation)
  80                                          */
  81         unsigned int    prev;   /* number of the block of PAGE_SIZE bytes that
  82                                  * was the current one previously
  83                                  */
  84         struct pbe      *pbe;   /* PBE that corresponds to 'buffer' */
  85         struct pbe      *last_pbe;      /* When the image is restored (eg. read
  86                                          * from disk) we can store some image
  87                                          * data directly in the page frames
  88                                          * in which they were before suspend.
  89                                          * In such a case the PBEs that
  90                                          * correspond to them will be unused.
  91                                          * This is the last PBE, so far, that
  92                                          * does not correspond to such data.
  93                                          */
  94         void            *buffer;        /* address of the block to read from
  95                                          * or write to
  96                                          */
  97         unsigned int    buf_offset;     /* location to read from or write to,
  98                                          * given as a displacement from 'buffer'
  99                                          */
 100         int             sync_read;      /* Set to one to notify the caller of
 101                                          * snapshot_write_next() that it may
 102                                          * need to call wait_on_bio_chain()
 103                                          */
 104 };
 105
 106 /* This macro returns the address from/to which the caller of
 107  * snapshot_read_next()/snapshot_write_next() is allowed to
 108  * read/write data after the function returns
 109  */
 110 #define data_of(handle) ((handle).buffer + (handle).buf_offset)
 111
 112 extern unsigned int snapshot_additional_pages(struct zone *zone);
 113 extern int snapshot_read_next(struct snapshot_handle *handle, size_t count);
 114 extern int snapshot_write_next(struct snapshot_handle *handle, size_t count);
 115 extern int snapshot_image_loaded(struct snapshot_handle *handle);
 116
 117 #define SNAPSHOT_IOC_MAGIC      '3'
 118 #define SNAPSHOT_FREEZE                 _IO(SNAPSHOT_IOC_MAGIC, 1)
 119 #define SNAPSHOT_UNFREEZE               _IO(SNAPSHOT_IOC_MAGIC, 2)
 120 #define SNAPSHOT_ATOMIC_SNAPSHOT        _IOW(SNAPSHOT_IOC_MAGIC, 3, void *)
 121 #define SNAPSHOT_ATOMIC_RESTORE         _IO(SNAPSHOT_IOC_MAGIC, 4)
 122 #define SNAPSHOT_FREE                   _IO(SNAPSHOT_IOC_MAGIC, 5)
 123 #define SNAPSHOT_SET_IMAGE_SIZE         _IOW(SNAPSHOT_IOC_MAGIC, 6, unsigned long)
 124 #define SNAPSHOT_AVAIL_SWAP             _IOR(SNAPSHOT_IOC_MAGIC, 7, void *)
 125 #define SNAPSHOT_GET_SWAP_PAGE          _IOR(SNAPSHOT_IOC_MAGIC, 8, void *)
 126 #define SNAPSHOT_FREE_SWAP_PAGES        _IO(SNAPSHOT_IOC_MAGIC, 9)
 127 #define SNAPSHOT_SET_SWAP_FILE          _IOW(SNAPSHOT_IOC_MAGIC, 10, unsigned int)
 128 #define SNAPSHOT_S2RAM                  _IO(SNAPSHOT_IOC_MAGIC, 11)
 129 #define SNAPSHOT_IOC_MAXNR      11
 130
 131 /**
 132  *      The bitmap is used for tracing allocated swap pages
 133  *
 134  *      The entire bitmap consists of a number of bitmap_page
 135  *      structures linked with the help of the .next member.
 136  *      Thus each page can be allocated individually, so we only
 137  *      need to make 0-order memory allocations to create
 138  *      the bitmap.
 139  */
 140
 141 #define BITMAP_PAGE_SIZE        (PAGE_SIZE - sizeof(void *))
 142 #define BITMAP_PAGE_CHUNKS      (BITMAP_PAGE_SIZE / sizeof(long))
 143 #define BITS_PER_CHUNK          (sizeof(long) * 8)
 144 #define BITMAP_PAGE_BITS        (BITMAP_PAGE_CHUNKS * BITS_PER_CHUNK)
 145
 146 struct bitmap_page {
 147         unsigned long           chunks[BITMAP_PAGE_CHUNKS];
 148         struct bitmap_page      *next;
 149 };
 150
 151 extern void free_bitmap(struct bitmap_page *bitmap);
 152 extern struct bitmap_page *alloc_bitmap(unsigned int nr_bits);
 153 extern unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap);
 154 extern void free_all_swap_pages(int swap, struct bitmap_page *bitmap);
 155
 156 extern int swsusp_check(void);
 157 extern int swsusp_shrink_memory(void);
 158 extern void swsusp_free(void);
 159 extern int swsusp_suspend(void);
 160 extern int swsusp_resume(void);
 161 extern int swsusp_read(void);
 162 extern int swsusp_write(void);
 163 extern void swsusp_close(void);
 164 extern int suspend_enter(suspend_state_t state);