Thread (48 messages) 48 messages, 8 authors, 2016-06-16

Re: [PATCH -v2 19/33] locking,powerpc: Implement atomic{,64}_fetch_{add,sub,and,or,xor}{,_relaxed,_acquire,_release}()

From: Boqun Feng <hidden>
Date: 2016-06-01 03:08:11
Also in: lkml

Hi Peter,

On Tue, May 31, 2016 at 12:19:44PM +0200, Peter Zijlstra wrote:
[snip]
quoted hunk ↗ jump to hunk
 
@@ -329,20 +361,53 @@ atomic64_##op##_return_relaxed(long a, a
 	return t;							\
 }
 
+#define ATOMIC64_FETCH_OP_RELAXED(op, asm_op)				\
+static inline long							\
+atomic64_fetch_##op##_relaxed(long a, atomic64_t *v)			\
+{									\
+	long res, t;							\
+									\
+	__asm__ __volatile__(						\
+"1:	ldarx	%0,0,%4		# atomic64_fetch_" #op "_relaxed\n"	\
+	#asm_op " %1,%3,%0\n"						\
+"	stdcx.	%1,0,%4\n"						\
+"	bne-	1b\n"							\
+	: "=&r" (res), "=&r" (t), "+m" (v->counter)			\
+	: "r" (a), "r" (&v->counter)					\
+	: "cc");							\
+									\
+	return t;							\
Looks like I missed this one in v1, it should be
	
	return res;

because the primitives will return the values before modified by the
operations.

Regards,
Boqun
+}
+

Attachments

Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help