[PATCH 14/20] x86/barrier: Use alternative_io() in 32-bit barrier functions

From: Josh Poimboeuf
Date: Fri Mar 14 2025 - 17:50:13 EST


Use the standard alternative_io() interface.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
arch/x86/include/asm/barrier.h | 23 +++++++++++++++++------
1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h
index db70832232d4..489a7ea76384 100644
--- a/arch/x86/include/asm/barrier.h
+++ b/arch/x86/include/asm/barrier.h
@@ -12,12 +12,23 @@
*/

#ifdef CONFIG_X86_32
-#define mb() asm volatile(ALTERNATIVE("lock addl $0,-4(%%esp)", "mfence", \
- X86_FEATURE_XMM2) ::: "memory", "cc")
-#define rmb() asm volatile(ALTERNATIVE("lock addl $0,-4(%%esp)", "lfence", \
- X86_FEATURE_XMM2) ::: "memory", "cc")
-#define wmb() asm volatile(ALTERNATIVE("lock addl $0,-4(%%esp)", "sfence", \
- X86_FEATURE_XMM2) ::: "memory", "cc")
+#define mb() alternative_io("lock addl $0,-4(%%esp)", \
+ "mfence", X86_FEATURE_XMM2, \
+ ARG(), \
+ ARG(), \
+ ARG("memory", "cc"))
+
+#define rmb() alternative_io("lock addl $0, -4(%%esp)", \
+ "lfence", X86_FEATURE_XMM2, \
+ ARG(), \
+ ARG(), \
+ ARG("memory", "cc"))
+
+#define wmb() alternative_io("lock addl $0, -4(%%esp)", \
+ "sfence", X86_FEATURE_XMM2, \
+ ARG(), \
+ ARG(), \
+ ARG("memory", "cc"))
#else
#define __mb() asm volatile("mfence":::"memory")
#define __rmb() asm volatile("lfence":::"memory")
--
2.48.1