[PATCH] x86/asm: Simplify __smp_mb() definition

From: Borislav Petkov
Date: Wed May 12 2021 - 05:33:23 EST


From: Borislav Petkov <bp@xxxxxxx>

Drop the bitness ifdeffery in favor of using the rSP register
specification for 32 and 64 bit depending on the build.

No functional changes.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
---
arch/x86/include/asm/barrier.h | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h
index 4819d5e5a335..3ba772a69cc8 100644
--- a/arch/x86/include/asm/barrier.h
+++ b/arch/x86/include/asm/barrier.h
@@ -54,11 +54,8 @@ static inline unsigned long array_index_mask_nospec(unsigned long index,
#define dma_rmb() barrier()
#define dma_wmb() barrier()

-#ifdef CONFIG_X86_32
-#define __smp_mb() asm volatile("lock; addl $0,-4(%%esp)" ::: "memory", "cc")
-#else
-#define __smp_mb() asm volatile("lock; addl $0,-4(%%rsp)" ::: "memory", "cc")
-#endif
+#define __smp_mb() asm volatile("lock; addl $0,-4(%%" _ASM_SP ")" ::: "memory", "cc")
+
#define __smp_rmb() dma_rmb()
#define __smp_wmb() barrier()
#define __smp_store_mb(var, value) do { (void)xchg(&var, value); } while (0)
--
2.29.2