kernel-fxtec-pro1x/kernel/power/power.h
Rafael J. Wysocki 940864ddab [PATCH] swsusp: Use memory bitmaps during resume
Make swsusp use memory bitmaps to store its internal information during the
resume phase of the suspend-resume cycle.

If the pfns of saveable pages are saved during the suspend phase instead of
the kernel virtual addresses of these pages, we can use them during the resume
phase directly to set the corresponding bits in a memory bitmap.  Then, this
bitmap is used to mark the page frames corresponding to the pages that were
saveable before the suspend (aka "unsafe" page frames).

Next, we allocate as many page frames as needed to store the entire suspend
image and make sure that there will be some extra free "safe" page frames for
the list of PBEs constructed later.  Subsequently, the image is loaded and, if
possible, the data loaded from it are written into their "original" page
frames (ie.  the ones they had occupied before the suspend).

The image data that cannot be written into their "original" page frames are
loaded into "safe" page frames and their "original" kernel virtual addresses,
as well as the addresses of the "safe" pages containing their copies, are
stored in a list of PBEs.  Finally, the list of PBEs is used to copy the
remaining image data into their "original" page frames (this is done
atomically, by the architecture-dependent parts of swsusp).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:49:02 -07:00

155 lines
5.2 KiB
C

#include <linux/suspend.h>
#include <linux/utsname.h>
struct swsusp_info {
struct new_utsname uts;
u32 version_code;
unsigned long num_physpages;
int cpus;
unsigned long image_pages;
unsigned long pages;
unsigned long size;
} __attribute__((aligned(PAGE_SIZE)));
#ifdef CONFIG_SOFTWARE_SUSPEND
extern int pm_suspend_disk(void);
#else
static inline int pm_suspend_disk(void)
{
return -EPERM;
}
#endif
extern struct semaphore pm_sem;
#define power_attr(_name) \
static struct subsys_attribute _name##_attr = { \
.attr = { \
.name = __stringify(_name), \
.mode = 0644, \
}, \
.show = _name##_show, \
.store = _name##_store, \
}
extern struct subsystem power_subsys;
/* References to section boundaries */
extern const void __nosave_begin, __nosave_end;
/* Preferred image size in bytes (default 500 MB) */
extern unsigned long image_size;
extern int in_suspend;
extern dev_t swsusp_resume_device;
extern asmlinkage int swsusp_arch_suspend(void);
extern asmlinkage int swsusp_arch_resume(void);
extern unsigned int count_data_pages(void);
/**
* Auxiliary structure used for reading the snapshot image data and
* metadata from and writing them to the list of page backup entries
* (PBEs) which is the main data structure of swsusp.
*
* Using struct snapshot_handle we can transfer the image, including its
* metadata, as a continuous sequence of bytes with the help of
* snapshot_read_next() and snapshot_write_next().
*
* The code that writes the image to a storage or transfers it to
* the user land is required to use snapshot_read_next() for this
* purpose and it should not make any assumptions regarding the internal
* structure of the image. Similarly, the code that reads the image from
* a storage or transfers it from the user land is required to use
* snapshot_write_next().
*
* This may allow us to change the internal structure of the image
* in the future with considerably less effort.
*/
struct snapshot_handle {
loff_t offset; /* number of the last byte ready for reading
* or writing in the sequence
*/
unsigned int cur; /* number of the block of PAGE_SIZE bytes the
* next operation will refer to (ie. current)
*/
unsigned int cur_offset; /* offset with respect to the current
* block (for the next operation)
*/
unsigned int prev; /* number of the block of PAGE_SIZE bytes that
* was the current one previously
*/
void *buffer; /* address of the block to read from
* or write to
*/
unsigned int buf_offset; /* location to read from or write to,
* given as a displacement from 'buffer'
*/
int sync_read; /* Set to one to notify the caller of
* snapshot_write_next() that it may
* need to call wait_on_bio_chain()
*/
};
/* This macro returns the address from/to which the caller of
* snapshot_read_next()/snapshot_write_next() is allowed to
* read/write data after the function returns
*/
#define data_of(handle) ((handle).buffer + (handle).buf_offset)
extern unsigned int snapshot_additional_pages(struct zone *zone);
extern int snapshot_read_next(struct snapshot_handle *handle, size_t count);
extern int snapshot_write_next(struct snapshot_handle *handle, size_t count);
extern int snapshot_image_loaded(struct snapshot_handle *handle);
extern void snapshot_free_unused_memory(struct snapshot_handle *handle);
#define SNAPSHOT_IOC_MAGIC '3'
#define SNAPSHOT_FREEZE _IO(SNAPSHOT_IOC_MAGIC, 1)
#define SNAPSHOT_UNFREEZE _IO(SNAPSHOT_IOC_MAGIC, 2)
#define SNAPSHOT_ATOMIC_SNAPSHOT _IOW(SNAPSHOT_IOC_MAGIC, 3, void *)
#define SNAPSHOT_ATOMIC_RESTORE _IO(SNAPSHOT_IOC_MAGIC, 4)
#define SNAPSHOT_FREE _IO(SNAPSHOT_IOC_MAGIC, 5)
#define SNAPSHOT_SET_IMAGE_SIZE _IOW(SNAPSHOT_IOC_MAGIC, 6, unsigned long)
#define SNAPSHOT_AVAIL_SWAP _IOR(SNAPSHOT_IOC_MAGIC, 7, void *)
#define SNAPSHOT_GET_SWAP_PAGE _IOR(SNAPSHOT_IOC_MAGIC, 8, void *)
#define SNAPSHOT_FREE_SWAP_PAGES _IO(SNAPSHOT_IOC_MAGIC, 9)
#define SNAPSHOT_SET_SWAP_FILE _IOW(SNAPSHOT_IOC_MAGIC, 10, unsigned int)
#define SNAPSHOT_S2RAM _IO(SNAPSHOT_IOC_MAGIC, 11)
#define SNAPSHOT_IOC_MAXNR 11
/**
* The bitmap is used for tracing allocated swap pages
*
* The entire bitmap consists of a number of bitmap_page
* structures linked with the help of the .next member.
* Thus each page can be allocated individually, so we only
* need to make 0-order memory allocations to create
* the bitmap.
*/
#define BITMAP_PAGE_SIZE (PAGE_SIZE - sizeof(void *))
#define BITMAP_PAGE_CHUNKS (BITMAP_PAGE_SIZE / sizeof(long))
#define BITS_PER_CHUNK (sizeof(long) * 8)
#define BITMAP_PAGE_BITS (BITMAP_PAGE_CHUNKS * BITS_PER_CHUNK)
struct bitmap_page {
unsigned long chunks[BITMAP_PAGE_CHUNKS];
struct bitmap_page *next;
};
extern void free_bitmap(struct bitmap_page *bitmap);
extern struct bitmap_page *alloc_bitmap(unsigned int nr_bits);
extern unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap);
extern void free_all_swap_pages(int swap, struct bitmap_page *bitmap);
extern int swsusp_check(void);
extern int swsusp_shrink_memory(void);
extern void swsusp_free(void);
extern int swsusp_suspend(void);
extern int swsusp_resume(void);
extern int swsusp_read(void);
extern int swsusp_write(void);
extern void swsusp_close(void);
extern int suspend_enter(suspend_state_t state);