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

From: Ben Hutchings <ben@decadent.org.uk>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: akpm@linux-foundation.org, Denis Kirjanov <kda@linux-powerpc.org>,
	mpe@ellerman.id.au, mgorman@suse.de,
	"Ingo Molnar" <mingo@kernel.org>,
	catalin.marinas@arm.com, "Thomas Gleixner" <tglx@linutronix.de>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	paulus@samba.org, "Peter Zijlstra (Intel)" <peterz@infradead.org>,
	mmarek@suse.cz, davem@davemloft.net, will.deacon@arm.com,
	benh@kernel.crashing.org, "Anton Blanchard" <anton@samba.org>,
	schwidefsky@de.ibm.com, ralf@linux-mips.org,
	linux@arm.linux.org.uk, jbaron@akamai.com,
	"Linus Torvalds" <torvalds@linux-foundation.org>,
	heiko.carstens@de.ibm.com, linuxppc-dev@lists.ozlabs.org,
	rostedt@goodmis.org, liuj97@gmail.com
Subject: [PATCH 3.16 09/86] jump_label: Allow jump labels to be used in assembly
Date: Thu, 16 May 2019 16:55:32 +0100	[thread overview]
Message-ID: <lsq.1558022132.38146636@decadent.org.uk> (raw)
In-Reply-To: <lsq.1558022132.52852998@decadent.org.uk>

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

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

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

