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+Copyright 2004 Linus Torvalds
+Copyright 2004 Pavel Machek <pavel@suse.cz>
+Copyright 2006 Bob Copeland <me@bobcopeland.com>
+
+Using sparse for typechecking
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+"__bitwise" is a type attribute, so you have to do something like this:
+
+        typedef int __bitwise pm_request_t;
+
+        enum pm_request {
+                PM_SUSPEND = (__force pm_request_t) 1,
+                PM_RESUME = (__force pm_request_t) 2
+        };
+
+which makes PM_SUSPEND and PM_RESUME "bitwise" integers (the "__force" is
+there because sparse will complain about casting to/from a bitwise type,
+but in this case we really _do_ want to force the conversion). And because
+the enum values are all the same type, now "enum pm_request" will be that
+type too.
+
+And with gcc, all the __bitwise/__force stuff goes away, and it all ends
+up looking just like integers to gcc.
+
+Quite frankly, you don't need the enum there. The above all really just
+boils down to one special "int __bitwise" type.
+
+So the simpler way is to just do
+
+        typedef int __bitwise pm_request_t;
+
+        #define PM_SUSPEND ((__force pm_request_t) 1)
+        #define PM_RESUME ((__force pm_request_t) 2)
+
+and you now have all the infrastructure needed for strict typechecking.
+
+One small note: the constant integer "0" is special. You can use a
+constant zero as a bitwise integer type without sparse ever complaining.
+This is because "bitwise" (as the name implies) was designed for making
+sure that bitwise types don't get mixed up (little-endian vs big-endian
+vs cpu-endian vs whatever), and there the constant "0" really _is_
+special.
+
+Getting sparse
+~~~~~~~~~~~~~~
+
+You can get latest released versions from the Sparse homepage at
+http://www.kernel.org/pub/linux/kernel/people/josh/sparse/
+
+Alternatively, you can get snapshots of the latest development version
+of sparse using git to clone..
+
+        git://git.kernel.org/pub/scm/linux/kernel/git/josh/sparse.git
+
+DaveJ has hourly generated tarballs of the git tree available at..
+
+        http://www.codemonkey.org.uk/projects/git-snapshots/sparse/
+
+
+Once you have it, just do
+
+        make
+        make install
+
+as a regular user, and it will install sparse in your ~/bin directory.
+
+Using sparse
+~~~~~~~~~~~~
+
+Do a kernel make with "make C=1" to run sparse on all the C files that get
+recompiled, or use "make C=2" to run sparse on the files whether they need to
+be recompiled or not.  The latter is a fast way to check the whole tree if you
+have already built it.
+
+The optional make variable CF can be used to pass arguments to sparse.  The
+build system passes -Wbitwise to sparse automatically.  To perform endianness
+checks, you may define __CHECK_ENDIAN__:
+
+        make C=2 CF="-D__CHECK_ENDIAN__"
+
+These checks are disabled by default as they generate a host of warnings.