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[PATCH 09/09] atomic.h : Add atomic64 cmpxchg, xchg and add_unless to x86_64
- From: Mathieu Desnoyers <mathieu dot desnoyers at polymtl dot ca>
- To: linux-kernel at vger dot kernel dot org
- Cc: Linus Torvalds <torvalds at osdl dot org>, Andrew Morton <akpm at osdl dot org>, Ingo Molnar <mingo at redhat dot com>, Greg Kroah-Hartman <gregkh at suse dot de>, Christoph Hellwig <hch at infradead dot org>, ltt-dev at shafik dot org, systemtap at sources dot redhat dot com, Douglas Niehaus <niehaus at eecs dot ku dot edu>, "Martin J. Bligh" <mbligh at mbligh dot org>, Thomas Gleixner <tglx at linutronix dot de>, Paul Mackerras <paulus at samba dot org>, Mathieu Desnoyers <mathieu dot desnoyers at polymtl dot ca>
- Date: Thu, 25 Jan 2007 11:15:54 -0500
- Subject: [PATCH 09/09] atomic.h : Add atomic64 cmpxchg, xchg and add_unless to x86_64
- References: <11697417541743-git-send-email-mathieu.desnoyers@polymtl.ca>
atomic.h : Add atomic64 cmpxchg, xchg and add_unless to x86_64
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
--- a/include/asm-x86_64/atomic.h
+++ b/include/asm-x86_64/atomic.h
@@ -375,8 +375,8 @@ static __inline__ long atomic64_add_return(long i, atomic64_t *v)
long __i = i;
__asm__ __volatile__(
LOCK_PREFIX "xaddq %0, %1;"
- :"=r"(i)
- :"m"(v->counter), "0"(i));
+ :"+r" (i), "+m" (v->counter)
+ : : "memory");
return i + __i;
}
@@ -388,7 +388,12 @@ static __inline__ long atomic64_sub_return(long i, atomic64_t *v)
#define atomic64_inc_return(v) (atomic64_add_return(1,v))
#define atomic64_dec_return(v) (atomic64_sub_return(1,v))
-#define atomic_cmpxchg(v, old, new) ((int)cmpxchg(&((v)->counter), old, new))
+#define atomic64_cmpxchg(v, old, new) \
+ ((__typeof__((v)->counter))cmpxchg(&((v)->counter), old, new))
+#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
+
+#define atomic_cmpxchg(v, old, new) \
+ ((__typeof__((v)->counter))cmpxchg(&((v)->counter), old, new))
#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
/**
@@ -402,7 +407,7 @@ static __inline__ long atomic64_sub_return(long i, atomic64_t *v)
*/
#define atomic_add_unless(v, a, u) \
({ \
- int c, old; \
+ __typeof__((v)->counter) c, old; \
c = atomic_read(v); \
for (;;) { \
if (unlikely(c == (u))) \
@@ -416,6 +421,31 @@ static __inline__ long atomic64_sub_return(long i, atomic64_t *v)
})
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
+/**
+ * atomic64_add_unless - add unless the number is a given value
+ * @v: pointer of type atomic64_t
+ * @a: the amount to add to v...
+ * @u: ...unless v is equal to u.
+ *
+ * Atomically adds @a to @v, so long as it was not @u.
+ * Returns non-zero if @v was not @u, and zero otherwise.
+ */
+#define atomic64_add_unless(v, a, u) \
+({ \
+ __typeof__((v)->counter) c, old; \
+ c = atomic64_read(v); \
+ for (;;) { \
+ if (unlikely(c == (u))) \
+ break; \
+ old = atomic64_cmpxchg((v), c, c + (a)); \
+ if (likely(old == c)) \
+ break; \
+ c = old; \
+ } \
+ c != (u); \
+})
+#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
+
/* These are x86-specific, used by some header files */
#define atomic_clear_mask(mask, addr) \
__asm__ __volatile__(LOCK_PREFIX "andl %0,%1" \