[tip: x86/cleanups] x86/asm: Simplify __smp_mb() definition

[tip-bot2 for Borislav Petkov]

The following commit has been merged into the x86/cleanups branch of tip:

Commit-ID:     1bc67873d401e6c2e6e30be7fef21337db07a042
Gitweb:        https://git.kernel.org/tip/1bc67873d401e6c2e6e30be7fef21337db07a042
Author:        Borislav Petkov <bp@xxxxxxx>
AuthorDate:    Wed, 12 May 2021 11:33:10 +02:00
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Wed, 12 May 2021 12:22:57 +02:00

x86/asm: Simplify __smp_mb() definition

Drop the bitness ifdeffery in favor of using _ASM_SP,
which is the helper macro for the rSP register specification
for 32 and 64 bit depending on the build.

No functional changes.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210512093310.5635-1-bp@xxxxxxxxx
---
 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 4819d5e..3ba772a 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)