atomic_add_return-sles9.patch

非常经典的一个分布式系统

Index: linux-2.6.5-7.283/include/asm-i386/atomic.h
===================================================================
--- linux-2.6.5-7.283.orig/include/asm-i386/atomic.h
+++ linux-2.6.5-7.283/include/asm-i386/atomic.h
@@ -2,6 +2,7 @@
 #define __ARCH_I386_ATOMIC__
 
 #include <linux/config.h>
+#include <linux/bitops.h>
 
 /*
  * Atomic operations that C can't guarantee us.  Useful for
@@ -176,6 +177,47 @@ static __inline__ int atomic_add_negativ
 	return c;
 }
 
+/**
+ * atomic_add_return - add and return
+ * @v: pointer of type atomic_t
+ * @i: integer value to add
+ *
+ * Atomically adds @i to @v and returns @i + @v
+ */
+static __inline__ int atomic_add_return(int i, atomic_t *v)
+{
+	int __i;
+#ifdef CONFIG_M386
+	unsigned long flags;
+	if(unlikely(boot_cpu_data.x86==3))
+		goto no_xadd;
+#endif
+	/* Modern 486+ processor */
+	__i = i;
+	__asm__ __volatile__(
+		LOCK_PREFIX "xaddl %0, %1"
+		:"+r" (i), "+m" (v->counter)
+		: : "memory");
+	return i + __i;
+
+#ifdef CONFIG_M386
+no_xadd: /* Legacy 386 processor */
+	local_irq_save(flags);
+	__i = atomic_read(v);
+	atomic_set(v, i + __i);
+	local_irq_restore(flags);
+	return i + __i;
+#endif
+}
+
+static __inline__ int atomic_sub_return(int i, atomic_t *v)
+{
+	return atomic_add_return(-i,v);
+}
+
+#define atomic_inc_return(v)  (atomic_add_return(1,v))
+#define atomic_dec_return(v)  (atomic_sub_return(1,v))
+
 /* These are x86-specific, used by some header files */
 #define atomic_clear_mask(mask, addr) \
 __asm__ __volatile__(LOCK "andl %0,%1" \
Index: linux-2.6.5-7.283/include/asm-x86_64/atomic.h
===================================================================
--- linux-2.6.5-7.283.orig/include/asm-x86_64/atomic.h
+++ linux-2.6.5-7.283/include/asm-x86_64/atomic.h
@@ -2,6 +2,7 @@
 #define __ARCH_X86_64_ATOMIC__
 
 #include <linux/config.h>
+#include <linux/bitops.h>
 
 /* atomic_t should be 32 bit signed type */
 
@@ -178,6 +179,31 @@ static __inline__ int atomic_add_negativ
 	return c;
 }
 
+/**
+ * atomic_add_return - add and return
+ * @i: integer value to add
+ * @v: pointer of type atomic_t
+ *
+ * Atomically adds @i to @v and returns @i + @v
+ */
+static __inline__ int atomic_add_return(int i, atomic_t *v)
+{
+	int __i = i;
+	__asm__ __volatile__(
+		LOCK_PREFIX "xaddl %0, %1"
+		:"+r" (i), "+m" (v->counter)
+		: : "memory");
+	return i + __i;
+}
+
+static __inline__ int atomic_sub_return(int i, atomic_t *v)
+{
+	return atomic_add_return(-i,v);
+}
+
+#define atomic_inc_return(v)  (atomic_add_return(1,v))
+#define atomic_dec_return(v)  (atomic_sub_return(1,v))
+
 /* These are x86-specific, used by some header files */
 #define atomic_clear_mask(mask, addr) \
 __asm__ __volatile__(LOCK "andl %0,%1" \