[PATCH] swsusp: update userland interface documentation
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / kernel / power / power.h
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1#include <linux/suspend.h>
2#include <linux/utsname.h>
3
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4struct swsusp_info {
5 struct new_utsname uts;
6 u32 version_code;
7 unsigned long num_physpages;
8 int cpus;
9 unsigned long image_pages;
7088a5c0 10 unsigned long pages;
6e1819d6 11 unsigned long size;
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12} __attribute__((aligned(PAGE_SIZE)));
13
14
15
16#ifdef CONFIG_SOFTWARE_SUSPEND
17extern int pm_suspend_disk(void);
18
19#else
20static inline int pm_suspend_disk(void)
21{
22 return -EPERM;
23}
24#endif
25extern struct semaphore pm_sem;
26#define power_attr(_name) \
27static 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
36extern struct subsystem power_subsys;
37
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38/* References to section boundaries */
39extern const void __nosave_begin, __nosave_end;
40
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41/* Preferred image size in bytes (default 500 MB) */
42extern unsigned long image_size;
f577eb30 43extern int in_suspend;
61159a31 44extern dev_t swsusp_resume_device;
9a154d9d 45extern sector_t swsusp_resume_block;
f577eb30 46
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47extern asmlinkage int swsusp_arch_suspend(void);
48extern asmlinkage int swsusp_arch_resume(void);
49
72a97e08 50extern unsigned int count_data_pages(void);
f577eb30 51
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52/**
53 * Auxiliary structure used for reading the snapshot image data and
54 * metadata from and writing them to the list of page backup entries
55 * (PBEs) which is the main data structure of swsusp.
56 *
57 * Using struct snapshot_handle we can transfer the image, including its
58 * metadata, as a continuous sequence of bytes with the help of
59 * snapshot_read_next() and snapshot_write_next().
60 *
61 * The code that writes the image to a storage or transfers it to
62 * the user land is required to use snapshot_read_next() for this
63 * purpose and it should not make any assumptions regarding the internal
64 * structure of the image. Similarly, the code that reads the image from
65 * a storage or transfers it from the user land is required to use
66 * snapshot_write_next().
67 *
68 * This may allow us to change the internal structure of the image
69 * in the future with considerably less effort.
70 */
71
f577eb30 72struct snapshot_handle {
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73 loff_t offset; /* number of the last byte ready for reading
74 * or writing in the sequence
75 */
76 unsigned int cur; /* number of the block of PAGE_SIZE bytes the
77 * next operation will refer to (ie. current)
78 */
79 unsigned int cur_offset; /* offset with respect to the current
80 * block (for the next operation)
81 */
82 unsigned int prev; /* number of the block of PAGE_SIZE bytes that
83 * was the current one previously
84 */
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85 void *buffer; /* address of the block to read from
86 * or write to
87 */
88 unsigned int buf_offset; /* location to read from or write to,
89 * given as a displacement from 'buffer'
90 */
91 int sync_read; /* Set to one to notify the caller of
92 * snapshot_write_next() that it may
93 * need to call wait_on_bio_chain()
94 */
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95};
96
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97/* This macro returns the address from/to which the caller of
98 * snapshot_read_next()/snapshot_write_next() is allowed to
99 * read/write data after the function returns
100 */
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101#define data_of(handle) ((handle).buffer + (handle).buf_offset)
102
b788db79 103extern unsigned int snapshot_additional_pages(struct zone *zone);
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104extern int snapshot_read_next(struct snapshot_handle *handle, size_t count);
105extern int snapshot_write_next(struct snapshot_handle *handle, size_t count);
b788db79 106extern int snapshot_image_loaded(struct snapshot_handle *handle);
940864dd 107extern void snapshot_free_unused_memory(struct snapshot_handle *handle);
61159a31 108
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109/*
110 * This structure is used to pass the values needed for the identification
111 * of the resume swap area from a user space to the kernel via the
112 * SNAPSHOT_SET_SWAP_AREA ioctl
113 */
114struct resume_swap_area {
115 loff_t offset;
116 u_int32_t dev;
117} __attribute__((packed));
118
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119#define SNAPSHOT_IOC_MAGIC '3'
120#define SNAPSHOT_FREEZE _IO(SNAPSHOT_IOC_MAGIC, 1)
121#define SNAPSHOT_UNFREEZE _IO(SNAPSHOT_IOC_MAGIC, 2)
122#define SNAPSHOT_ATOMIC_SNAPSHOT _IOW(SNAPSHOT_IOC_MAGIC, 3, void *)
123#define SNAPSHOT_ATOMIC_RESTORE _IO(SNAPSHOT_IOC_MAGIC, 4)
124#define SNAPSHOT_FREE _IO(SNAPSHOT_IOC_MAGIC, 5)
125#define SNAPSHOT_SET_IMAGE_SIZE _IOW(SNAPSHOT_IOC_MAGIC, 6, unsigned long)
126#define SNAPSHOT_AVAIL_SWAP _IOR(SNAPSHOT_IOC_MAGIC, 7, void *)
127#define SNAPSHOT_GET_SWAP_PAGE _IOR(SNAPSHOT_IOC_MAGIC, 8, void *)
128#define SNAPSHOT_FREE_SWAP_PAGES _IO(SNAPSHOT_IOC_MAGIC, 9)
129#define SNAPSHOT_SET_SWAP_FILE _IOW(SNAPSHOT_IOC_MAGIC, 10, unsigned int)
9b238205 130#define SNAPSHOT_S2RAM _IO(SNAPSHOT_IOC_MAGIC, 11)
3592695c 131#define SNAPSHOT_PMOPS _IOW(SNAPSHOT_IOC_MAGIC, 12, unsigned int)
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132#define SNAPSHOT_SET_SWAP_AREA _IOW(SNAPSHOT_IOC_MAGIC, 13, \
133 struct resume_swap_area)
134#define SNAPSHOT_IOC_MAXNR 13
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135
136#define PMOPS_PREPARE 1
137#define PMOPS_ENTER 2
138#define PMOPS_FINISH 3
6e1819d6 139
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140/**
141 * The bitmap is used for tracing allocated swap pages
142 *
143 * The entire bitmap consists of a number of bitmap_page
144 * structures linked with the help of the .next member.
145 * Thus each page can be allocated individually, so we only
146 * need to make 0-order memory allocations to create
147 * the bitmap.
148 */
149
150#define BITMAP_PAGE_SIZE (PAGE_SIZE - sizeof(void *))
151#define BITMAP_PAGE_CHUNKS (BITMAP_PAGE_SIZE / sizeof(long))
152#define BITS_PER_CHUNK (sizeof(long) * 8)
153#define BITMAP_PAGE_BITS (BITMAP_PAGE_CHUNKS * BITS_PER_CHUNK)
154
155struct bitmap_page {
156 unsigned long chunks[BITMAP_PAGE_CHUNKS];
157 struct bitmap_page *next;
158};
159
160extern void free_bitmap(struct bitmap_page *bitmap);
161extern struct bitmap_page *alloc_bitmap(unsigned int nr_bits);
3aef83e0 162extern sector_t alloc_swapdev_block(int swap, struct bitmap_page *bitmap);
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163extern void free_all_swap_pages(int swap, struct bitmap_page *bitmap);
164
74c7e2ef 165extern int swsusp_check(void);
61159a31 166extern int swsusp_shrink_memory(void);
74c7e2ef 167extern void swsusp_free(void);
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168extern int swsusp_suspend(void);
169extern int swsusp_resume(void);
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170extern int swsusp_read(void);
171extern int swsusp_write(void);
172extern void swsusp_close(void);
9b238205 173extern int suspend_enter(suspend_state_t state);