PM / Hibernate: Improve comments in hibernate_preallocate_memory()
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / kernel / power / power.h
CommitLineData
1da177e4 1#include <linux/suspend.h>
3010f8ca 2#include <linux/suspend_ioctls.h>
1da177e4 3#include <linux/utsname.h>
b28f5081 4#include <linux/freezer.h>
1da177e4 5
1da177e4
LT
6struct swsusp_info {
7 struct new_utsname uts;
8 u32 version_code;
9 unsigned long num_physpages;
10 int cpus;
11 unsigned long image_pages;
7088a5c0 12 unsigned long pages;
6e1819d6 13 unsigned long size;
1da177e4
LT
14} __attribute__((aligned(PAGE_SIZE)));
15
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16#ifdef CONFIG_HIBERNATION
17#ifdef CONFIG_ARCH_HIBERNATION_HEADER
18/* Maximum size of architecture specific data in a hibernation header */
19#define MAX_ARCH_HEADER_SIZE (sizeof(struct new_utsname) + 4)
1da177e4 20
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21extern int arch_hibernation_header_save(void *addr, unsigned int max_size);
22extern int arch_hibernation_header_restore(void *addr);
23
24static inline int init_header_complete(struct swsusp_info *info)
25{
26 return arch_hibernation_header_save(info, MAX_ARCH_HEADER_SIZE);
27}
28
29static inline char *check_image_kernel(struct swsusp_info *info)
30{
31 return arch_hibernation_header_restore(info) ?
32 "architecture specific data" : NULL;
33}
34#endif /* CONFIG_ARCH_HIBERNATION_HEADER */
1da177e4 35
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RW
36/*
37 * Keep some memory free so that I/O operations can succeed without paging
38 * [Might this be more than 4 MB?]
39 */
40#define PAGES_FOR_IO ((4096 * 1024) >> PAGE_SHIFT)
d307c4a8 41
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RW
42/*
43 * Keep 1 MB of memory free so that device drivers can allocate some pages in
44 * their .suspend() routines without breaking the suspend to disk.
45 */
46#define SPARE_PAGES ((1024 * 1024) >> PAGE_SHIFT)
1da177e4 47
8b759b84 48/* kernel/power/hibernate.c */
7777fab9 49extern int hibernation_snapshot(int platform_mode);
a634cc10 50extern int hibernation_restore(int platform_mode);
7777fab9 51extern int hibernation_platform_enter(void);
1da177e4 52#endif
a6d70980 53
49c3df6a
VG
54extern int pfn_is_nosave(unsigned long);
55
1da177e4 56#define power_attr(_name) \
386f275f 57static struct kobj_attribute _name##_attr = { \
1da177e4
LT
58 .attr = { \
59 .name = __stringify(_name), \
60 .mode = 0644, \
61 }, \
62 .show = _name##_show, \
63 .store = _name##_store, \
64}
65
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RW
66/* Preferred image size in bytes (default 500 MB) */
67extern unsigned long image_size;
f577eb30 68extern int in_suspend;
61159a31 69extern dev_t swsusp_resume_device;
9a154d9d 70extern sector_t swsusp_resume_block;
f577eb30 71
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RW
72extern asmlinkage int swsusp_arch_suspend(void);
73extern asmlinkage int swsusp_arch_resume(void);
74
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RW
75extern int create_basic_memory_bitmaps(void);
76extern void free_basic_memory_bitmaps(void);
64a473cb 77extern int hibernate_preallocate_memory(void);
f577eb30 78
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79/**
80 * Auxiliary structure used for reading the snapshot image data and
81 * metadata from and writing them to the list of page backup entries
82 * (PBEs) which is the main data structure of swsusp.
83 *
84 * Using struct snapshot_handle we can transfer the image, including its
85 * metadata, as a continuous sequence of bytes with the help of
86 * snapshot_read_next() and snapshot_write_next().
87 *
88 * The code that writes the image to a storage or transfers it to
89 * the user land is required to use snapshot_read_next() for this
90 * purpose and it should not make any assumptions regarding the internal
91 * structure of the image. Similarly, the code that reads the image from
92 * a storage or transfers it from the user land is required to use
93 * snapshot_write_next().
94 *
95 * This may allow us to change the internal structure of the image
96 * in the future with considerably less effort.
97 */
98
f577eb30 99struct snapshot_handle {
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100 unsigned int cur; /* number of the block of PAGE_SIZE bytes the
101 * next operation will refer to (ie. current)
102 */
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103 void *buffer; /* address of the block to read from
104 * or write to
105 */
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106 int sync_read; /* Set to one to notify the caller of
107 * snapshot_write_next() that it may
108 * need to call wait_on_bio_chain()
109 */
f577eb30
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110};
111
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112/* This macro returns the address from/to which the caller of
113 * snapshot_read_next()/snapshot_write_next() is allowed to
114 * read/write data after the function returns
115 */
d3c1b24c 116#define data_of(handle) ((handle).buffer)
f577eb30 117
b788db79 118extern unsigned int snapshot_additional_pages(struct zone *zone);
af508b34 119extern unsigned long snapshot_get_image_size(void);
d3c1b24c
JS
120extern int snapshot_read_next(struct snapshot_handle *handle);
121extern int snapshot_write_next(struct snapshot_handle *handle);
8357376d 122extern void snapshot_write_finalize(struct snapshot_handle *handle);
b788db79 123extern int snapshot_image_loaded(struct snapshot_handle *handle);
61159a31 124
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125/* If unset, the snapshot device cannot be open. */
126extern atomic_t snapshot_device_available;
127
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128extern sector_t alloc_swapdev_block(int swap);
129extern void free_all_swap_pages(int swap);
130extern int swsusp_swap_in_use(void);
61159a31 131
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132/*
133 * Flags that can be passed from the hibernatig hernel to the "boot" kernel in
134 * the image header.
135 */
136#define SF_PLATFORM_MODE 1
f996fc96 137#define SF_NOCOMPRESS_MODE 2
a634cc10 138
8b759b84 139/* kernel/power/hibernate.c */
74c7e2ef 140extern int swsusp_check(void);
74c7e2ef 141extern void swsusp_free(void);
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RW
142extern int swsusp_read(unsigned int *flags_p);
143extern int swsusp_write(unsigned int flags);
c2dd0dae 144extern void swsusp_close(fmode_t);
0d3a9abe 145
8a0d613f
JS
146/* kernel/power/block_io.c */
147extern struct block_device *hib_resume_bdev;
148
149extern int hib_bio_read_page(pgoff_t page_off, void *addr,
150 struct bio **bio_chain);
151extern int hib_bio_write_page(pgoff_t page_off, void *addr,
152 struct bio **bio_chain);
153extern int hib_wait_on_bio_chain(struct bio **bio_chain);
154
0d3a9abe 155struct timeval;
b10d9117 156/* kernel/power/swsusp.c */
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157extern void swsusp_show_speed(struct timeval *, struct timeval *,
158 unsigned int, char *);
b10d9117 159
296699de 160#ifdef CONFIG_SUSPEND
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161/* kernel/power/suspend.c */
162extern const char *const pm_states[];
163
164extern bool valid_state(suspend_state_t state);
6c961dfb 165extern int suspend_devices_and_enter(suspend_state_t state);
a9d70523 166extern int enter_state(suspend_state_t state);
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167#else /* !CONFIG_SUSPEND */
168static inline int suspend_devices_and_enter(suspend_state_t state)
169{
170 return -ENOSYS;
171}
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172static inline int enter_state(suspend_state_t state) { return -ENOSYS; }
173static inline bool valid_state(suspend_state_t state) { return false; }
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174#endif /* !CONFIG_SUSPEND */
175
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176#ifdef CONFIG_PM_TEST_SUSPEND
177/* kernel/power/suspend_test.c */
178extern void suspend_test_start(void);
179extern void suspend_test_finish(const char *label);
180#else /* !CONFIG_PM_TEST_SUSPEND */
181static inline void suspend_test_start(void) {}
182static inline void suspend_test_finish(const char *label) {}
183#endif /* !CONFIG_PM_TEST_SUSPEND */
184
82525756
AS
185#ifdef CONFIG_PM_SLEEP
186/* kernel/power/main.c */
187extern int pm_notifier_call_chain(unsigned long val);
188#endif
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AB
189
190#ifdef CONFIG_HIGHMEM
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AB
191int restore_highmem(void);
192#else
193static inline unsigned int count_highmem_pages(void) { return 0; }
194static inline int restore_highmem(void) { return 0; }
195#endif
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RW
196
197/*
198 * Suspend test levels
199 */
200enum {
201 /* keep first */
202 TEST_NONE,
203 TEST_CORE,
204 TEST_CPUS,
205 TEST_PLATFORM,
206 TEST_DEVICES,
207 TEST_FREEZER,
208 /* keep last */
209 __TEST_AFTER_LAST
210};
211
212#define TEST_FIRST TEST_NONE
213#define TEST_MAX (__TEST_AFTER_LAST - 1)
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214
215extern int pm_test_level;
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JB
216
217#ifdef CONFIG_SUSPEND_FREEZER
218static inline int suspend_freeze_processes(void)
219{
220 return freeze_processes();
221}
222
223static inline void suspend_thaw_processes(void)
224{
225 thaw_processes();
226}
227#else
228static inline int suspend_freeze_processes(void)
229{
230 return 0;
231}
232
233static inline void suspend_thaw_processes(void)
234{
235}
236#endif