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Diffstat (limited to 'include/asm-s390/atomic.h')
| -rw-r--r-- | include/asm-s390/atomic.h | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/include/asm-s390/atomic.h b/include/asm-s390/atomic.h new file mode 100644 index 000000000..f1c1f3c5d --- /dev/null +++ b/include/asm-s390/atomic.h @@ -0,0 +1,215 @@ +#ifndef __ARCH_S390_ATOMIC__ +#define __ARCH_S390_ATOMIC__ + +/* + * include/asm-s390/atomic.h + * + * S390 version + * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation + * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), + * Denis Joseph Barrow + * + * Derived from "include/asm-i386/bitops.h" + * Copyright (C) 1992, Linus Torvalds + * + */ + +/* + * Atomic operations that C can't guarantee us. Useful for + * resource counting etc.. + * S390 uses 'Compare And Swap' for atomicity in SMP enviroment + */ + +typedef struct { volatile int counter; } atomic_t __attribute__ ((aligned (4))); +#define ATOMIC_INIT(i) { (i) } + +#define atomic_eieio() __asm__ __volatile__ ("BCR 15,0") + +static __inline__ int atomic_read(atomic_t *v) +{ + int retval; + __asm__ __volatile__("bcr 15,0\n\t" + "l %0,%1" + : "=d" (retval) : "m" (*v) ); + return retval; +} + +static __inline__ void atomic_set(atomic_t *v, int i) +{ + __asm__ __volatile__("st %1,%0\n\t" + "bcr 15,0" + : : "m" (*v), "d" (i) : "memory"); +} + +static __inline__ void atomic_add(int i, atomic_t *v) +{ + __asm__ __volatile__(" l 0,%0\n" + "0: lr 1,0\n" + " ar 1,%1\n" + " cs 0,1,%0\n" + " jl 0b" + : "+m" (*v) : "d" (i) : "0", "1" ); +} + +static __inline__ int atomic_add_return (int i, atomic_t *v) +{ + int newval; + __asm__ __volatile__(" l 0,%0\n" + "0: lr %1,0\n" + " ar %1,%2\n" + " cs 0,%1,%0\n" + " jl 0b" + : "+m" (*v), "=&d" (newval) + : "d" (i) : "0", "cc" ); + return newval; +} + +static __inline__ int atomic_add_negative(int i, atomic_t *v) +{ + int newval; + __asm__ __volatile__(" l 0,%0\n" + "0: lr %1,0\n" + " ar %1,%2\n" + " cs 0,%1,%0\n" + " jl 0b\n" + : "+m" (*v), "=&d" (newval) + : "d" (i) : "0", "cc" ); + return newval < 0; +} + +static __inline__ void atomic_sub(int i, atomic_t *v) +{ + __asm__ __volatile__(" l 0,%0\n" + "0: lr 1,0\n" + " sr 1,%1\n" + " cs 0,1,%0\n" + " jl 0b" + : "+m" (*v) : "d" (i) : "0", "1" ); +} + +static __inline__ void atomic_inc(volatile atomic_t *v) +{ + __asm__ __volatile__(" l 0,%0\n" + "0: lr 1,0\n" + " ahi 1,1\n" + " cs 0,1,%0\n" + " jl 0b" + : "+m" (*v) : : "0", "1" ); +} + +static __inline__ int atomic_inc_return(volatile atomic_t *v) +{ + int i; + __asm__ __volatile__(" l 0,%0\n" + "0: lr %1,0\n" + " ahi %1,1\n" + " cs 0,%1,%0\n" + " jl 0b" + : "+m" (*v), "=&d" (i) : : "0" ); + return i; +} + +static __inline__ int atomic_inc_and_test(volatile atomic_t *v) +{ + int i; + + __asm__ __volatile__(" l 0,%0\n" + "0: lr %1,0\n" + " ahi %1,1\n" + " cs 0,%1,%0\n" + " jl 0b" + : "+m" (*v), "=&d" (i) : : "0" ); + return i != 0; +} + +static __inline__ void atomic_dec(volatile atomic_t *v) +{ + __asm__ __volatile__(" l 0,%0\n" + "0: lr 1,0\n" + " ahi 1,-1\n" + " cs 0,1,%0\n" + " jl 0b" + : "+m" (*v) : : "0", "1" ); +} + +static __inline__ int atomic_dec_return(volatile atomic_t *v) +{ + int i; + __asm__ __volatile__(" l 0,%0\n" + "0: lr %1,0\n" + " ahi %1,-1\n" + " cs 0,%1,%0\n" + " jl 0b" + : "+m" (*v), "=&d" (i) : : "0" ); + return i; +} + +static __inline__ int atomic_dec_and_test(volatile atomic_t *v) +{ + int i; + __asm__ __volatile__(" l 0,%0\n" + "0: lr %1,0\n" + " ahi %1,-1\n" + " cs 0,%1,%0\n" + " jl 0b" + : "+m" (*v), "=&d" (i) : : "0"); + return i == 0; +} + +static __inline__ void atomic_clear_mask(unsigned long mask, atomic_t *v) +{ + __asm__ __volatile__(" l 0,%0\n" + "0: lr 1,0\n" + " nr 1,%1\n" + " cs 0,1,%0\n" + " jl 0b" + : "+m" (*v) : "d" (~(mask)) : "0", "1" ); +} + +static __inline__ void atomic_set_mask(unsigned long mask, atomic_t *v) +{ + __asm__ __volatile__(" l 0,%0\n" + "0: lr 1,0\n" + " or 1,%1\n" + " cs 0,1,%0\n" + " jl 0b" + : "+m" (*v) : "d" (mask) : "0", "1" ); +} + +/* + returns 0 if expected_oldval==value in *v ( swap was successful ) + returns 1 if unsuccessful. +*/ +static __inline__ int +atomic_compare_and_swap(int expected_oldval,int new_val,atomic_t *v) +{ + int retval; + + __asm__ __volatile__( + " cs %2,%3,%1\n" + " ipm %0\n" + " srl %0,28\n" + "0:" + : "=&r" (retval), "+m" (*v) + : "d" (expected_oldval) , "d" (new_val) + : "memory", "cc"); + return retval; +} + +/* + Spin till *v = expected_oldval then swap with newval. + */ +static __inline__ void +atomic_compare_and_swap_spin(int expected_oldval,int new_val,atomic_t *v) +{ + __asm__ __volatile__( + "0: lr 1,%1\n" + " cs 1,%2,%0\n" + " jl 0b\n" + : "+m" (*v) + : "d" (expected_oldval) , "d" (new_val) + : "memory", "cc", "1"); +} + +#endif /* __ARCH_S390_ATOMIC __ */ + |