jump_label: Allow jump labels to be used in assembly

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 <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
iegor · Apr 9, 2015 · c0ccf6f · c0ccf6f
1 parent 55dd0df
commit c0ccf6f
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Showing 2 changed files with 18 additions and 4 deletions.
diff --git a/Makefile b/Makefile
@@ -779,6 +779,7 @@ 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.kasan

diff --git 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,
@@ -203,3 +214,5 @@ static inline bool static_key_enabled(struct static_key *key)
 }
 
 #endif	/* _LINUX_JUMP_LABEL_H */
+
+#endif /* __ASSEMBLY__ */