[PATCH 10/23] make atomic_read() and atomic_set() behavior consistent on ia64

From: Chris Snook
Date: Mon Aug 13 2007 - 10:22:22 EST


From: Chris Snook <csnook@xxxxxxxxxx>

Use volatile consistently in atomic.h on ia64.
This will do weird things without Andreas Schwab's fix:
http://lkml.org/lkml/2007/8/10/410

Signed-off-by: Chris Snook <csnook@xxxxxxxxxx>

--- linux-2.6.23-rc3-orig/include/asm-ia64/atomic.h 2007-07-08 19:32:17.000000000 -0400
+++ linux-2.6.23-rc3/include/asm-ia64/atomic.h 2007-08-13 05:38:27.000000000 -0400
@@ -19,19 +19,34 @@

/*
* On IA-64, counter must always be volatile to ensure that that the
- * memory accesses are ordered.
+ * memory accesses are ordered. This must be enforced each time that
+ * counter is read or written.
*/
-typedef struct { volatile __s32 counter; } atomic_t;
-typedef struct { volatile __s64 counter; } atomic64_t;
+typedef struct { __s32 counter; } atomic_t;
+typedef struct { __s64 counter; } atomic64_t;

#define ATOMIC_INIT(i) ((atomic_t) { (i) })
#define ATOMIC64_INIT(i) ((atomic64_t) { (i) })

-#define atomic_read(v) ((v)->counter)
-#define atomic64_read(v) ((v)->counter)
+static inline __s32 atomic_read(atomic_t *v)
+{
+ return *(volatile __s32 *)&v->counter;
+}
+
+static inline void atomic_set(atomic_t *v, __s32 i)
+{
+ *(volatile __s32 *)&v->counter = i;
+}

-#define atomic_set(v,i) (((v)->counter) = (i))
-#define atomic64_set(v,i) (((v)->counter) = (i))
+static inline __s64 atomic64_read(atomic64_t *v)
+{
+ return *(volatile __s64 *)&v->counter;
+}
+
+static inline void atomic64_set(atomic64_t *v, __s64 i)
+{
+ *(volatile __s64 *)&v->counter = i;
+}

static __inline__ int
ia64_atomic_add (int i, atomic_t *v)
-
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