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Message-Id: <d6775e129db48371cdf86e94ddfaa1d15617bb8f.1186773842.git.segher@kernel.crashing.org>
Date: Sat, 11 Aug 2007 02:15:30 +0200
From: Segher Boessenkool <segher@...nel.crashing.org>
To: linuxppc-dev@...abs.org
Cc: paulus@...ba.org, Segher Boessenkool <segher@...nel.crashing.org>,
linux-arch@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] powerpc: Implement atomic{,64}_{read,write}() without volatile
Instead, use asm() like all other atomic operations already do.
Also use inline functions instead of macros; this actually
improves code generation (some code becomes a little smaller,
probably because of improved alias information -- just a few
hundred bytes total on a default kernel build, nothing shocking).
Signed-off-by: Segher Boessenkool <segher@...nel.crashing.org>
---
include/asm-powerpc/atomic.h | 34 ++++++++++++++++++++++++++++------
1 files changed, 28 insertions(+), 6 deletions(-)
diff --git a/include/asm-powerpc/atomic.h b/include/asm-powerpc/atomic.h
index c44810b..bc17506 100644
--- a/include/asm-powerpc/atomic.h
+++ b/include/asm-powerpc/atomic.h
@@ -5,7 +5,7 @@
* PowerPC atomic operations
*/
-typedef struct { volatile int counter; } atomic_t;
+typedef struct { int counter; } atomic_t;
#ifdef __KERNEL__
#include <linux/compiler.h>
@@ -15,8 +15,19 @@ typedef struct { volatile int counter; } atomic_t;
#define ATOMIC_INIT(i) { (i) }
-#define atomic_read(v) ((v)->counter)
-#define atomic_set(v,i) (((v)->counter) = (i))
+static __inline__ int atomic_read(const atomic_t *v)
+{
+ int t;
+
+ __asm__ __volatile__("lwz%U1%X1 %0,%1" : "=r"(t) : "m"(v->counter));
+
+ return t;
+}
+
+static __inline__ void atomic_set(atomic_t *v, int i)
+{
+ __asm__ __volatile__("stw%U0%X0 %1,%0" : "=m"(v->counter) : "r"(i));
+}
static __inline__ void atomic_add(int a, atomic_t *v)
{
@@ -240,12 +251,23 @@ static __inline__ int atomic_dec_if_positive(atomic_t *v)
#ifdef __powerpc64__
-typedef struct { volatile long counter; } atomic64_t;
+typedef struct { long counter; } atomic64_t;
#define ATOMIC64_INIT(i) { (i) }
-#define atomic64_read(v) ((v)->counter)
-#define atomic64_set(v,i) (((v)->counter) = (i))
+static __inline__ long atomic64_read(const atomic_t *v)
+{
+ long t;
+
+ __asm__ __volatile__("ld%U1%X1 %0,%1" : "=r"(t) : "m"(v->counter));
+
+ return t;
+}
+
+static __inline__ void atomic64_set(atomic_t *v, long i)
+{
+ __asm__ __volatile__("std%U0%X0 %1,%0" : "=m"(v->counter) : "r"(i));
+}
static __inline__ void atomic64_add(long a, atomic64_t *v)
{
--
1.5.2.1.144.gabc40-dirty
-
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