locking/x86: Define arch_try_cmpxchg_local()

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().

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230405141710.3551-5-ubizjak@gmail.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/x86/include/asm/cmpxchg.h b/arch/x86/include/asm/cmpxchg.h
index 94fbe6a..540573f 100644 (file)
--- 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".