locking/atomic/x86: Un-macro-ify atomic ops implementation

CPP turns perfectly readable code into a much harder to read syntactic soup.

Ingo suggested to write them out as-is in C and ignore the higher linecount.

Do this.

(As a side effect, plain C functions will be easier to KASAN-instrument as well.)

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kasan-dev@googlegroups.com
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/a35b983dd3be937a3cf63c4e2db487de2cdc7b8f.1497690003.git.dvyukov@google.com
[ Beautified the C code some more and twiddled the changelog
  to mention the linecount increase and the KASAN benefit. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 57 insertions, 24 deletions

diff --git a/arch/x86/include/asm/atomic64_32.h b/arch/x86/include/asm/atomic64_32.h
index 71d7705fb303b..9e206f31ce2a6 100644
--- a/arch/x86/include/asm/atomic64_32.h
+++ b/arch/x86/include/asm/atomic64_32.h
@@ -312,37 +312,70 @@ static inline long long atomic64_dec_if_positive(atomic64_t *v)
 #undef alternative_atomic64
 #undef __alternative_atomic64
 
-#define ATOMIC64_OP(op, c_op)						\
-static inline void atomic64_##op(long long i, atomic64_t *v)		\
-{									\
-	long long old, c = 0;						\
-	while ((old = atomic64_cmpxchg(v, c, c c_op i)) != c)		\
-		c = old;						\
+static inline void atomic64_and(long long i, atomic64_t *v)
+{
+	long long old, c = 0;
+
+	while ((old = atomic64_cmpxchg(v, c, c & i)) != c)
+		c = old;
 }
 
-#define ATOMIC64_FETCH_OP(op, c_op)					\
-static inline long long atomic64_fetch_##op(long long i, atomic64_t *v)	\
-{									\
-	long long old, c = 0;						\
-	while ((old = atomic64_cmpxchg(v, c, c c_op i)) != c)		\
-		c = old;						\
-	return old;							\
+static inline long long atomic64_fetch_and(long long i, atomic64_t *v)
+{
+	long long old, c = 0;
+
+	while ((old = atomic64_cmpxchg(v, c, c & i)) != c)
+		c = old;
+
+	return old;
 }
 
-ATOMIC64_FETCH_OP(add, +)
+static inline void atomic64_or(long long i, atomic64_t *v)
+{
+	long long old, c = 0;
 
-#define atomic64_fetch_sub(i, v)	atomic64_fetch_add(-(i), (v))
+	while ((old = atomic64_cmpxchg(v, c, c | i)) != c)
+		c = old;
+}
+
+static inline long long atomic64_fetch_or(long long i, atomic64_t *v)
+{
+	long long old, c = 0;
+
+	while ((old = atomic64_cmpxchg(v, c, c | i)) != c)
+		c = old;
+
+	return old;
+}
 
-#define ATOMIC64_OPS(op, c_op)						\
-	ATOMIC64_OP(op, c_op)						\
-	ATOMIC64_FETCH_OP(op, c_op)
+static inline void atomic64_xor(long long i, atomic64_t *v)
+{
+	long long old, c = 0;
+
+	while ((old = atomic64_cmpxchg(v, c, c ^ i)) != c)
+		c = old;
+}
 
-ATOMIC64_OPS(and, &)
-ATOMIC64_OPS(or, |)
-ATOMIC64_OPS(xor, ^)
+static inline long long atomic64_fetch_xor(long long i, atomic64_t *v)
+{
+	long long old, c = 0;
+
+	while ((old = atomic64_cmpxchg(v, c, c ^ i)) != c)
+		c = old;
+
+	return old;
+}
 
-#undef ATOMIC64_OPS
-#undef ATOMIC64_FETCH_OP
-#undef ATOMIC64_OP
+static inline long long atomic64_fetch_add(long long i, atomic64_t *v)
+{
+	long long old, c = 0;
+
+	while ((old = atomic64_cmpxchg(v, c, c + i)) != c)
+		c = old;
+
+	return old;
+}
+
+#define atomic64_fetch_sub(i, v)	atomic64_fetch_add(-(i), (v))
 
 #endif /* _ASM_X86_ATOMIC64_32_H */