PM / Hibernate: Compress hibernation image with LZO

Compress hibernation image with LZO in order to save on I/O and
therefore time to hibernate/thaw.

[rjw: Added hibernate=nocompress command line option instead of just
 nocompress which would be confusing, fixed a couple of compiler
 warnings, fixed kerneldoc comments, minor cleanups.]

Signed-off-by: Bojan Smojver <bojan@rexursive.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 8dd7248..2c98b18 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2165,6 +2165,11 @@
 			in <PAGE_SIZE> units (needed only for swap files).
 			See  Documentation/power/swsusp-and-swap-files.txt
 
+	hibernate=	[HIBERNATION]
+		noresume	Don't check if there's a hibernation image
+				present during boot.
+		nocompress	Don't compress/decompress hibernation images.
+
 	retain_initrd	[RAM] Keep initrd memory after extraction
 
 	rhash_entries=	[KNL,NET]
diff --git a/Documentation/power/swsusp.txt b/Documentation/power/swsusp.txt
index 9d60ab7..ea71889 100644
--- a/Documentation/power/swsusp.txt
+++ b/Documentation/power/swsusp.txt
@@ -66,7 +66,8 @@
 powerdowns.  You must explicitly specify the swap partition to resume from with
 ``resume='' kernel option. If signature is found it loads and restores saved
 state. If the option ``noresume'' is specified as a boot parameter, it skips
-the resuming.
+the resuming.  If the option ``hibernate=nocompress'' is specified as a boot
+parameter, it saves hibernation image without compression.
 
 In the meantime while the system is suspended you should not add/remove any
 of the hardware, write to the filesystems, etc.