X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=include%2Fasm-arm%2Fatomic.h;h=3d7283d84405e58b1249a562e4839570170928ec;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=257d32f099da205a53a5c984e389e597bd36f968;hpb=9213980e6a70d8473e0ffd4b39ab5b6caaba9ff5;p=linux-2.6.git

diff --git a/include/asm-arm/atomic.h b/include/asm-arm/atomic.h
index 257d32f09..3d7283d84 100644
--- a/include/asm-arm/atomic.h
+++ b/include/asm-arm/atomic.h
@@ -12,6 +12,7 @@
 #define __ASM_ARM_ATOMIC_H
 
 #include <linux/config.h>
+#include <linux/compiler.h>
 
 typedef struct { volatile int counter; } atomic_t;
 
@@ -44,21 +45,6 @@ static inline void atomic_set(atomic_t *v, int i)
 	: "cc");
 }
 
-static inline void atomic_add(int i, atomic_t *v)
-{
-	unsigned long tmp, tmp2;
-
-	__asm__ __volatile__("@ atomic_add\n"
-"1:	ldrex	%0, [%2]\n"
-"	add	%0, %0, %3\n"
-"	strex	%1, %0, [%2]\n"
-"	teq	%1, #0\n"
-"	bne	1b"
-	: "=&r" (tmp), "=&r" (tmp2)
-	: "r" (&v->counter), "Ir" (i)
-	: "cc");
-}
-
 static inline int atomic_add_return(int i, atomic_t *v)
 {
 	unsigned long tmp;
@@ -77,21 +63,6 @@ static inline int atomic_add_return(int i, atomic_t *v)
 	return result;
 }
 
-static inline void atomic_sub(int i, atomic_t *v)
-{
-	unsigned long tmp, tmp2;
-
-	__asm__ __volatile__("@ atomic_sub\n"
-"1:	ldrex	%0, [%2]\n"
-"	sub	%0, %0, %3\n"
-"	strex	%1, %0, [%2]\n"
-"	teq	%1, #0\n"
-"	bne	1b"
-	: "=&r" (tmp), "=&r" (tmp2)
-	: "r" (&v->counter), "Ir" (i)
-	: "cc");
-}
-
 static inline int atomic_sub_return(int i, atomic_t *v)
 {
 	unsigned long tmp;
@@ -110,6 +81,24 @@ static inline int atomic_sub_return(int i, atomic_t *v)
 	return result;
 }
 
+static inline int atomic_cmpxchg(atomic_t *ptr, int old, int new)
+{
+	unsigned long oldval, res;
+
+	do {
+		__asm__ __volatile__("@ atomic_cmpxchg\n"
+		"ldrex	%1, [%2]\n"
+		"mov	%0, #0\n"
+		"teq	%1, %3\n"
+		"strexeq %0, %4, [%2]\n"
+		    : "=&r" (res), "=&r" (oldval)
+		    : "r" (&ptr->counter), "Ir" (old), "r" (new)
+		    : "cc");
+	} while (res);
+
+	return oldval;
+}
+
 static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
 {
 	unsigned long tmp, tmp2;
@@ -135,15 +124,6 @@ static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
 
 #define atomic_set(v,i)	(((v)->counter) = (i))
 
-static inline void atomic_add(int i, atomic_t *v)
-{
-	unsigned long flags;
-
-	local_irq_save(flags);
-	v->counter += i;
-	local_irq_restore(flags);
-}
-
 static inline int atomic_add_return(int i, atomic_t *v)
 {
 	unsigned long flags;
@@ -157,26 +137,31 @@ static inline int atomic_add_return(int i, atomic_t *v)
 	return val;
 }
 
-static inline void atomic_sub(int i, atomic_t *v)
+static inline int atomic_sub_return(int i, atomic_t *v)
 {
 	unsigned long flags;
+	int val;
 
 	local_irq_save(flags);
-	v->counter -= i;
+	val = v->counter;
+	v->counter = val -= i;
 	local_irq_restore(flags);
+
+	return val;
 }
 
-static inline int atomic_sub_return(int i, atomic_t *v)
+static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
 {
+	int ret;
 	unsigned long flags;
-	int val;
 
 	local_irq_save(flags);
-	val = v->counter;
-	v->counter = val -= i;
+	ret = v->counter;
+	if (likely(ret == old))
+		v->counter = new;
 	local_irq_restore(flags);
 
-	return val;
+	return ret;
 }
 
 static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
@@ -190,11 +175,29 @@ static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
 
 #endif /* __LINUX_ARM_ARCH__ */
 
-#define atomic_inc(v)		atomic_add(1, v)
-#define atomic_dec(v)		atomic_sub(1, v)
+#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
+
+static inline int atomic_add_unless(atomic_t *v, int a, int u)
+{
+	int c, old;
+
+	c = atomic_read(v);
+	while (c != u && (old = atomic_cmpxchg((v), c, c + a)) != c)
+		c = old;
+	return c != u;
+}
+#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
+
+#define atomic_add(i, v)	(void) atomic_add_return(i, v)
+#define atomic_inc(v)		(void) atomic_add_return(1, v)
+#define atomic_sub(i, v)	(void) atomic_sub_return(i, v)
+#define atomic_dec(v)		(void) atomic_sub_return(1, v)
 
 #define atomic_inc_and_test(v)	(atomic_add_return(1, v) == 0)
 #define atomic_dec_and_test(v)	(atomic_sub_return(1, v) == 0)
+#define atomic_inc_return(v)    (atomic_add_return(1, v))
+#define atomic_dec_return(v)    (atomic_sub_return(1, v))
+#define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0)
 
 #define atomic_add_negative(i,v) (atomic_add_return(i, v) < 0)
 
@@ -204,5 +207,6 @@ static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
 #define smp_mb__before_atomic_inc()	barrier()
 #define smp_mb__after_atomic_inc()	barrier()
 
+#include <asm-generic/atomic.h>
 #endif
 #endif