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>
diff --git a/arch/x86/include/asm/atomic.h b/arch/x86/include/asm/atomic.h
index 33380b8..0874ebd 100644
--- a/arch/x86/include/asm/atomic.h
+++ b/arch/x86/include/asm/atomic.h
@@ -197,35 +197,56 @@ static inline int atomic_xchg(atomic_t *v, int new)
return xchg(&v->counter, new);
}
-#define ATOMIC_OP(op) \
-static inline void atomic_##op(int i, atomic_t *v) \
-{ \
- asm volatile(LOCK_PREFIX #op"l %1,%0" \
- : "+m" (v->counter) \
- : "ir" (i) \
- : "memory"); \
+static inline void atomic_and(int i, atomic_t *v)
+{
+ asm volatile(LOCK_PREFIX "andl %1,%0"
+ : "+m" (v->counter)
+ : "ir" (i)
+ : "memory");
}
-#define ATOMIC_FETCH_OP(op, c_op) \
-static inline int atomic_fetch_##op(int i, atomic_t *v) \
-{ \
- int val = atomic_read(v); \
- do { \
- } while (!atomic_try_cmpxchg(v, &val, val c_op i)); \
- return val; \
+static inline int atomic_fetch_and(int i, atomic_t *v)
+{
+ int val = atomic_read(v);
+
+ do { } while (!atomic_try_cmpxchg(v, &val, val & i));
+
+ return val;
}
-#define ATOMIC_OPS(op, c_op) \
- ATOMIC_OP(op) \
- ATOMIC_FETCH_OP(op, c_op)
+static inline void atomic_or(int i, atomic_t *v)
+{
+ asm volatile(LOCK_PREFIX "orl %1,%0"
+ : "+m" (v->counter)
+ : "ir" (i)
+ : "memory");
+}
-ATOMIC_OPS(and, &)
-ATOMIC_OPS(or , |)
-ATOMIC_OPS(xor, ^)
+static inline int atomic_fetch_or(int i, atomic_t *v)
+{
+ int val = atomic_read(v);
-#undef ATOMIC_OPS
-#undef ATOMIC_FETCH_OP
-#undef ATOMIC_OP
+ do { } while (!atomic_try_cmpxchg(v, &val, val | i));
+
+ return val;
+}
+
+static inline void atomic_xor(int i, atomic_t *v)
+{
+ asm volatile(LOCK_PREFIX "xorl %1,%0"
+ : "+m" (v->counter)
+ : "ir" (i)
+ : "memory");
+}
+
+static inline int atomic_fetch_xor(int i, atomic_t *v)
+{
+ int val = atomic_read(v);
+
+ do { } while (!atomic_try_cmpxchg(v, &val, val ^ i));
+
+ return val;
+}
/**
* __atomic_add_unless - add unless the number is already a given value
@@ -239,10 +260,12 @@ ATOMIC_OPS(xor, ^)
static __always_inline int __atomic_add_unless(atomic_t *v, int a, int u)
{
int c = atomic_read(v);
+
do {
if (unlikely(c == u))
break;
} while (!atomic_try_cmpxchg(v, &c, c + a));
+
return c;
}