[PATCH 3.16 09/86] jump_label: Allow jump labels to be used in assembly

[Ben Hutchings]

3.16.68-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Anton Blanchard <anton at samba.org>

commit c0ccf6f99e3a43b87980c9df7da48427885206d0 upstream.

To use jump labels in assembly we need the HAVE_JUMP_LABEL
define, so we select a fallback version if the toolchain does
not support them.

Modify linux/jump_label.h so it can be included by assembly
files. We also need to add -DCC_HAVE_ASM_GOTO to KBUILD_AFLAGS.

Signed-off-by: Anton Blanchard <anton at samba.org>
Acked-by: Peter Zijlstra (Intel) <peterz at infradead.org>
Cc: Andrew Morton <akpm at linux-foundation.org>
Cc: Linus Torvalds <torvalds at linux-foundation.org>
Cc: Paul E. McKenney <paulmck at linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz at infradead.org>
Cc: Thomas Gleixner <tglx at linutronix.de>
Cc: benh at kernel.crashing.org
Cc: catalin.marinas at arm.com
Cc: davem at davemloft.net
Cc: heiko.carstens at de.ibm.com
Cc: jbaron at akamai.com
Cc: linux at arm.linux.org.uk
Cc: linuxppc-dev at lists.ozlabs.org
Cc: liuj97 at gmail.com
Cc: mgorman at suse.de
Cc: mmarek at suse.cz
Cc: mpe at ellerman.id.au
Cc: paulus at samba.org
Cc: ralf at linux-mips.org
Cc: rostedt at goodmis.org
Cc: schwidefsky at de.ibm.com
Cc: will.deacon at arm.com
Link: http://lkml.kernel.org/r/1428551492-21977-2-git-send-email-anton@samba.org
Signed-off-by: Ingo Molnar <mingo at kernel.org>
Signed-off-by: Ben Hutchings <ben at decadent.org.uk>
---
 Makefile                   |  1 +
 include/linux/jump_label.h | 21 +++++++++++++++++----
 2 files changed, 18 insertions(+), 4 deletions(-)

--- a/Makefile
+++ b/Makefile
@@ -761,6 +761,7 @@ KBUILD_ARFLAGS := $(call ar-option,D)
 # check for 'asm goto'
 ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC)), y)
 	KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
+	KBUILD_AFLAGS += -DCC_HAVE_ASM_GOTO
 endif
 
 include $(srctree)/scripts/Makefile.extrawarn
--- a/include/linux/jump_label.h
+++ b/include/linux/jump_label.h
@@ -45,6 +45,12 @@
  * same as using STATIC_KEY_INIT_FALSE.
  */
 
+#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
+# define HAVE_JUMP_LABEL
+#endif
+
+#ifndef __ASSEMBLY__
+
 #include <linux/types.h>
 #include <linux/compiler.h>
 #include <linux/bug.h>
@@ -55,7 +61,7 @@ extern bool static_key_initialized;
 				    "%s used before call to jump_label_init", \
 				    __func__)
 
-#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
+#ifdef HAVE_JUMP_LABEL
 
 struct static_key {
 	atomic_t enabled;
@@ -66,13 +72,18 @@ struct static_key {
 #endif
 };
 
-# include <asm/jump_label.h>
-# define HAVE_JUMP_LABEL
 #else
 struct static_key {
 	atomic_t enabled;
 };
-#endif	/* CC_HAVE_ASM_GOTO && CONFIG_JUMP_LABEL */
+#endif	/* HAVE_JUMP_LABEL */
+#endif /* __ASSEMBLY__ */
+
+#ifdef HAVE_JUMP_LABEL
+#include <asm/jump_label.h>
+#endif
+
+#ifndef __ASSEMBLY__
 
 enum jump_label_type {
 	JUMP_LABEL_DISABLE = 0,
@@ -223,3 +234,5 @@ static inline void static_key_disable(st
 }
 
 #endif	/* _LINUX_JUMP_LABEL_H */
+
+#endif /* __ASSEMBLY__ */