[PATCH v2 4/5] locking/x86: Define arch_try_cmpxchg_local

From: Uros Bizjak
Date: Wed Apr 05 2023 - 10:19:15 EST


Define target specific arch_try_cmpxchg_local. This
definition overrides the generic arch_try_cmpxchg_local
fallback definition and enables target-specific
implementation of try_cmpxchg_local.

Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx>
---
arch/x86/include/asm/cmpxchg.h | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/arch/x86/include/asm/cmpxchg.h b/arch/x86/include/asm/cmpxchg.h
index 94fbe6ae7431..540573f515b7 100644
--- a/arch/x86/include/asm/cmpxchg.h
+++ b/arch/x86/include/asm/cmpxchg.h
@@ -221,9 +221,15 @@ extern void __add_wrong_size(void)
#define __try_cmpxchg(ptr, pold, new, size) \
__raw_try_cmpxchg((ptr), (pold), (new), (size), LOCK_PREFIX)

+#define __try_cmpxchg_local(ptr, pold, new, size) \
+ __raw_try_cmpxchg((ptr), (pold), (new), (size), "")
+
#define arch_try_cmpxchg(ptr, pold, new) \
__try_cmpxchg((ptr), (pold), (new), sizeof(*(ptr)))

+#define arch_try_cmpxchg_local(ptr, pold, new) \
+ __try_cmpxchg_local((ptr), (pold), (new), sizeof(*(ptr)))
+
/*
* xadd() adds "inc" to "*ptr" and atomically returns the previous
* value of "*ptr".
--
2.39.2