locking/atomic/x86: Define arch_atomic_sub() family using arch_atomic_add() functions

There is no need to implement arch_atomic_sub() family of inline
functions, corresponding macros can be directly implemented using
arch_atomic_add() inlines with negated argument.

No functional changes intended.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240410062957.322614-4-ubizjak@gmail.com

arch/x86/include/asm/atomic.h

@@ -86,11 +86,7 @@ static __always_inline int arch_atomic_add_return(int i, atomic_t *v)
 }
 #define arch_atomic_add_return arch_atomic_add_return
 
-static __always_inline int arch_atomic_sub_return(int i, atomic_t *v)
-{
-	return arch_atomic_add_return(-i, v);
-}
-#define arch_atomic_sub_return arch_atomic_sub_return
+#define arch_atomic_sub_return(i, v) arch_atomic_add_return(-(i), v)
 
 static __always_inline int arch_atomic_fetch_add(int i, atomic_t *v)
 {
@@ -98,11 +94,7 @@ static __always_inline int arch_atomic_fetch_add(int i, atomic_t *v)
 }
 #define arch_atomic_fetch_add arch_atomic_fetch_add
 
-static __always_inline int arch_atomic_fetch_sub(int i, atomic_t *v)
-{
-	return xadd(&v->counter, -i);
-}
-#define arch_atomic_fetch_sub arch_atomic_fetch_sub
+#define arch_atomic_fetch_sub(i, v) arch_atomic_fetch_add(-(i), v)
 
 static __always_inline int arch_atomic_cmpxchg(atomic_t *v, int old, int new)
 {

arch/x86/include/asm/atomic64_64.h

@@ -80,11 +80,7 @@ static __always_inline s64 arch_atomic64_add_return(s64 i, atomic64_t *v)
 }
 #define arch_atomic64_add_return arch_atomic64_add_return
 
-static __always_inline s64 arch_atomic64_sub_return(s64 i, atomic64_t *v)
-{
-	return arch_atomic64_add_return(-i, v);
-}
-#define arch_atomic64_sub_return arch_atomic64_sub_return
+#define arch_atomic64_sub_return(i, v) arch_atomic64_add_return(-(i), v)
 
 static __always_inline s64 arch_atomic64_fetch_add(s64 i, atomic64_t *v)
 {
@@ -92,11 +88,7 @@ static __always_inline s64 arch_atomic64_fetch_add(s64 i, atomic64_t *v)
 }
 #define arch_atomic64_fetch_add arch_atomic64_fetch_add
 
-static __always_inline s64 arch_atomic64_fetch_sub(s64 i, atomic64_t *v)
-{
-	return xadd(&v->counter, -i);
-}
-#define arch_atomic64_fetch_sub arch_atomic64_fetch_sub
+#define arch_atomic64_fetch_sub(i, v) arch_atomic64_fetch_add(-(i), v)
 
 static __always_inline s64 arch_atomic64_cmpxchg(atomic64_t *v, s64 old, s64 new)
 {