[PATCH] swsusp: userland interface
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>
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 5d1abff..42c431c 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -8,6 +8,7 @@
int cpus;
unsigned long image_pages;
unsigned long pages;
+ unsigned long size;
} __attribute__((aligned(PAGE_SIZE)));
@@ -65,6 +66,19 @@
extern int snapshot_write_next(struct snapshot_handle *handle, size_t count);
int snapshot_image_loaded(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_IOC_MAXNR 10
+
/**
* The bitmap is used for tracing allocated swap pages
*