home *** CD-ROM | disk | FTP | other *** search
- /* $Id: atomic.h,v 1.18 1997/08/07 03:38:31 davem Exp $
- * atomic.h: Thankfully the V9 is at least reasonable for this
- * stuff.
- *
- * Copyright (C) 1996, 1997 David S. Miller (davem@caip.rutgers.edu)
- */
-
- #ifndef __ARCH_SPARC64_ATOMIC__
- #define __ARCH_SPARC64_ATOMIC__
-
- /* Make sure gcc doesn't try to be clever and move things around
- * on us. We need to use _exactly_ the address the user gave us,
- * not some alias that contains the same information.
- */
- #define __atomic_fool_gcc(x) ((struct { int a[100]; } *)x)
-
- typedef struct { int counter; } atomic_t;
- #define ATOMIC_INIT(i) { (i) }
-
- #define atomic_read(v) ((v)->counter)
- #define atomic_set(v, i) (((v)->counter) = i)
-
- extern __inline__ void atomic_add(int i, atomic_t *v)
- {
- __asm__ __volatile__("
- 1: lduw [%1], %%g5
- add %%g5, %0, %%g7
- cas [%1], %%g5, %%g7
- sub %%g5, %%g7, %%g5
- brnz,pn %%g5, 1b
- nop"
- : /* No outputs */
- : "HIr" (i), "r" (__atomic_fool_gcc(v))
- : "g5", "g7", "memory");
- }
-
- extern __inline__ void atomic_sub(int i, atomic_t *v)
- {
- __asm__ __volatile__("
- 1: lduw [%1], %%g5
- sub %%g5, %0, %%g7
- cas [%1], %%g5, %%g7
- sub %%g5, %%g7, %%g5
- brnz,pn %%g5, 1b
- nop"
- : /* No outputs */
- : "HIr" (i), "r" (__atomic_fool_gcc(v))
- : "g5", "g7", "memory");
- }
-
- /* Same as above, but return the result value. */
- extern __inline__ int atomic_add_return(int i, atomic_t *v)
- {
- unsigned long oldval;
- __asm__ __volatile__("
- 1: lduw [%2], %%g5
- add %%g5, %1, %%g7
- cas [%2], %%g5, %%g7
- sub %%g5, %%g7, %%g5
- brnz,pn %%g5, 1b
- add %%g7, %1, %0"
- : "=&r" (oldval)
- : "HIr" (i), "r" (__atomic_fool_gcc(v))
- : "g5", "g7", "memory");
- return (int)oldval;
- }
-
- extern __inline__ int atomic_sub_return(int i, atomic_t *v)
- {
- unsigned long oldval;
- __asm__ __volatile__("
- 1: lduw [%2], %%g5
- sub %%g5, %1, %%g7
- cas [%2], %%g5, %%g7
- sub %%g5, %%g7, %%g5
- brnz,pn %%g5, 1b
- sub %%g7, %1, %0"
- : "=&r" (oldval)
- : "HIr" (i), "r" (__atomic_fool_gcc(v))
- : "g5", "g7", "memory");
- return (int)oldval;
- }
-
- #define atomic_dec_return(v) atomic_sub_return(1,(v))
- #define atomic_inc_return(v) atomic_add_return(1,(v))
-
- #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
- #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
-
- #define atomic_inc(v) atomic_add(1,(v))
- #define atomic_dec(v) atomic_sub(1,(v))
-
- #endif /* !(__ARCH_SPARC64_ATOMIC__) */
-