Add kbuild.h that contains common definitions for kbuild users

The same definitions are used for the bounds logic and the asm-offsets.h
generation by kbuild.  Put them into include/linux/kbuild.h file.

Also add a new feature

	COMMENT("text")

which can be used to insert lines of ocmments into asm-offsets.h and
bounds.h.

Cc: Sam Ravnborg <[email protected]>
Signed-off-by: Christoph Lameter <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ralf Baechle <[email protected]>
Cc: Jay Estabrook <[email protected]>
Cc: Ivan Kokshaysky <[email protected]>
Cc: Richard Henderson <[email protected]>
Cc: "Luck, Tony" <[email protected]>
Cc: Russell King <[email protected]>
Cc: Chris Zankel <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Haavard Skinnemoen <[email protected]>
Cc: Bryan Wu <[email protected]>
Cc: Mike Frysinger <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Roman Zippel <[email protected]>
Cc: Greg Ungerer <[email protected]>
Cc: David Howells <[email protected]>
Cc: Kyle McMartin <[email protected]>
Cc: Grant Grundler <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Paul Mundt <[email protected]>
Cc: Miles Bader <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

include/linux/kbuild.h

@@ -0,0 +1,15 @@
+#ifndef __LINUX_KBUILD_H
+#define __LINUX_KBUILD_H
+
+#define DEFINE(sym, val) \
+        asm volatile("\n->" #sym " %0 " #val : : "i" (val))
+
+#define BLANK() asm volatile("\n->" : : )
+
+#define OFFSET(sym, str, mem) \
+	DEFINE(sym, offsetof(struct str, mem))
+
+#define COMMENT(x) \
+	asm volatile("\n->#" x)
+
+#endif

kernel/bounds.c

@@ -8,11 +8,7 @@
 /* Include headers that define the enum constants of interest */
 #include <linux/page-flags.h>
 #include <linux/mmzone.h>
-
-#define DEFINE(sym, val) \
-        asm volatile("\n->" #sym " %0 " #val : : "i" (val))
-
-#define BLANK() asm volatile("\n->" : : )
+#include <linux/kbuild.h>
 
 void foo(void)
 {