diff -Naru a/include/asm-i386/atomic.h b/include/asm-i386/atomic.h --- a/include/asm-i386/atomic.h 2006-03-17 03:50:30 -08:00 +++ b/include/asm-i386/atomic.h 2006-03-17 03:50:30 -08:00 @@ -2,6 +2,8 @@ #define __ARCH_I386_ATOMIC__ #include +#include +#include /* * Atomic operations that C can't guarantee us. Useful for @@ -175,6 +177,46 @@ :"ir" (i), "m" (v->counter) : "memory"); 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 + if(unlikely(boot_cpu_data.x86==3)) + goto no_xadd; +#endif + /* Modern 486+ processor */ + __i = i; + __asm__ __volatile__( + LOCK "xaddl %0, %1;" + :"=r"(i) + :"m"(v->counter), "0"(i)); + return i + __i; + +#ifdef CONFIG_M386 +no_xadd: /* Legacy 386 processor */ + local_irq_disable(); + __i = atomic_read(v); + atomic_set(v, i + __i); + local_irq_enable(); + 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) \ # This is a BitKeeper generated diff -Nru style patch. # # ChangeSet # 2004/10/20 08:13:14-07:00 kaigai@ak.jp.nec.com # [PATCH] atomic_inc_return() for i386 # # This patch implements atomic_inc_return() and so on for i386, and includes # runtime check whether CPU is legacy 386. # # Signed-off-by: KaiGai, Kohei # Signed-off-by: Andrew Morton # Signed-off-by: Linus Torvalds # # include/asm-i386/atomic.h # 2004/10/20 01:12:08-07:00 kaigai@ak.jp.nec.com +42 -0 # atomic_inc_return() for i386 # http://linux.bkbits.net:8080/linux-2.6/cset@1.1938.185.12