[PATCH] swsusp: use block device offsets to identify swap locations

[safe/jmp/linux-2.6] / kernel / power / power.h

diff --git a/kernel/power/power.h b/kernel/power/power.h
index 42c431c..210ebba 100644 (file)
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -38,8 +38,6 @@ extern struct subsystem power_subsys;
 /* References to section boundaries */
 extern const void __nosave_begin, __nosave_end;
 
-extern struct pbe *pagedir_nosave;
-
 /* Preferred image size in bytes (default 500 MB) */
 extern unsigned long image_size;
 extern int in_suspend;
@@ -50,21 +48,62 @@ 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;
-       unsigned int    page;
-       unsigned int    page_offset;
-       unsigned int    prev;
-       struct pbe      *pbe;
-       void            *buffer;
-       unsigned int    buf_offset;
+       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);
-int snapshot_image_loaded(struct snapshot_handle *handle);
+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)
@@ -77,7 +116,13 @@ int snapshot_image_loaded(struct snapshot_handle *handle);
 #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_IOC_MAXNR     10
+#define SNAPSHOT_S2RAM                 _IO(SNAPSHOT_IOC_MAGIC, 11)
+#define SNAPSHOT_PMOPS                 _IOW(SNAPSHOT_IOC_MAGIC, 12, unsigned int)
+#define SNAPSHOT_IOC_MAXNR     12
+
+#define PMOPS_PREPARE  1
+#define PMOPS_ENTER    2
+#define PMOPS_FINISH   3
 
 /**
  *     The bitmap is used for tracing allocated swap pages
@@ -101,7 +146,7 @@ struct bitmap_page {
 
 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 sector_t alloc_swapdev_block(int swap, struct bitmap_page *bitmap);
 extern void free_all_swap_pages(int swap, struct bitmap_page *bitmap);
 
 extern int swsusp_check(void);
@@ -112,3 +157,4 @@ 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);