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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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6e1819d615
This patch introduces a user space interface for swsusp. The interface is based on a special character device, called the snapshot device, that allows user space processes to perform suspend and resume-related operations with the help of some ioctls and the read()/write() functions. Additionally it allows these processes to allocate free swap pages from a selected swap partition, called the resume partition, so that they know which sectors of the resume partition are available to them. The interface uses the same low-level system memory snapshot-handling functions that are used by the built-it swap-writing/reading code of swsusp. The interface documentation is included in the patch. The patch assumes that the major and minor numbers of the snapshot device will be 10 (ie. misc device) and 231, the registration of which has already been requested. 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>
114 lines
3.3 KiB
C
114 lines
3.3 KiB
C
#include <linux/suspend.h>
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#include <linux/utsname.h>
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struct swsusp_info {
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struct new_utsname uts;
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u32 version_code;
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unsigned long num_physpages;
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int cpus;
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unsigned long image_pages;
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unsigned long pages;
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unsigned long size;
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} __attribute__((aligned(PAGE_SIZE)));
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#ifdef CONFIG_SOFTWARE_SUSPEND
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extern int pm_suspend_disk(void);
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#else
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static inline int pm_suspend_disk(void)
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{
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return -EPERM;
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}
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#endif
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extern struct semaphore pm_sem;
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#define power_attr(_name) \
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static struct subsys_attribute _name##_attr = { \
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.attr = { \
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.name = __stringify(_name), \
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.mode = 0644, \
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}, \
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.show = _name##_show, \
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.store = _name##_store, \
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}
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extern struct subsystem power_subsys;
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/* References to section boundaries */
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extern const void __nosave_begin, __nosave_end;
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extern struct pbe *pagedir_nosave;
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/* Preferred image size in bytes (default 500 MB) */
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extern unsigned long image_size;
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extern int in_suspend;
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extern dev_t swsusp_resume_device;
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extern asmlinkage int swsusp_arch_suspend(void);
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extern asmlinkage int swsusp_arch_resume(void);
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extern unsigned int count_data_pages(void);
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struct snapshot_handle {
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loff_t offset;
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unsigned int page;
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unsigned int page_offset;
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unsigned int prev;
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struct pbe *pbe;
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void *buffer;
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unsigned int buf_offset;
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};
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#define data_of(handle) ((handle).buffer + (handle).buf_offset)
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extern int snapshot_read_next(struct snapshot_handle *handle, size_t count);
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extern int snapshot_write_next(struct snapshot_handle *handle, size_t count);
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int snapshot_image_loaded(struct snapshot_handle *handle);
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#define SNAPSHOT_IOC_MAGIC '3'
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#define SNAPSHOT_FREEZE _IO(SNAPSHOT_IOC_MAGIC, 1)
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#define SNAPSHOT_UNFREEZE _IO(SNAPSHOT_IOC_MAGIC, 2)
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#define SNAPSHOT_ATOMIC_SNAPSHOT _IOW(SNAPSHOT_IOC_MAGIC, 3, void *)
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#define SNAPSHOT_ATOMIC_RESTORE _IO(SNAPSHOT_IOC_MAGIC, 4)
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#define SNAPSHOT_FREE _IO(SNAPSHOT_IOC_MAGIC, 5)
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#define SNAPSHOT_SET_IMAGE_SIZE _IOW(SNAPSHOT_IOC_MAGIC, 6, unsigned long)
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#define SNAPSHOT_AVAIL_SWAP _IOR(SNAPSHOT_IOC_MAGIC, 7, void *)
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#define SNAPSHOT_GET_SWAP_PAGE _IOR(SNAPSHOT_IOC_MAGIC, 8, void *)
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#define SNAPSHOT_FREE_SWAP_PAGES _IO(SNAPSHOT_IOC_MAGIC, 9)
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#define SNAPSHOT_SET_SWAP_FILE _IOW(SNAPSHOT_IOC_MAGIC, 10, unsigned int)
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#define SNAPSHOT_IOC_MAXNR 10
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/**
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* The bitmap is used for tracing allocated swap pages
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*
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* The entire bitmap consists of a number of bitmap_page
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* structures linked with the help of the .next member.
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* Thus each page can be allocated individually, so we only
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* need to make 0-order memory allocations to create
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* the bitmap.
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*/
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#define BITMAP_PAGE_SIZE (PAGE_SIZE - sizeof(void *))
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#define BITMAP_PAGE_CHUNKS (BITMAP_PAGE_SIZE / sizeof(long))
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#define BITS_PER_CHUNK (sizeof(long) * 8)
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#define BITMAP_PAGE_BITS (BITMAP_PAGE_CHUNKS * BITS_PER_CHUNK)
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struct bitmap_page {
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unsigned long chunks[BITMAP_PAGE_CHUNKS];
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struct bitmap_page *next;
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};
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extern void free_bitmap(struct bitmap_page *bitmap);
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extern struct bitmap_page *alloc_bitmap(unsigned int nr_bits);
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extern unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap);
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extern void free_all_swap_pages(int swap, struct bitmap_page *bitmap);
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extern int swsusp_check(void);
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extern int swsusp_shrink_memory(void);
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extern void swsusp_free(void);
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extern int swsusp_suspend(void);
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extern int swsusp_resume(void);
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extern int swsusp_read(void);
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extern int swsusp_write(void);
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extern void swsusp_close(void);
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