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Diffstat (limited to 'arch/m68k/include/asm/atomic.h')
| -rw-r--r-- | arch/m68k/include/asm/atomic.h | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/arch/m68k/include/asm/atomic.h b/arch/m68k/include/asm/atomic.h new file mode 100644 index 000000000..e85f047fb --- /dev/null +++ b/arch/m68k/include/asm/atomic.h @@ -0,0 +1,198 @@ +#ifndef __ARCH_M68K_ATOMIC__ +#define __ARCH_M68K_ATOMIC__ + +#include <linux/types.h> +#include <linux/irqflags.h> +#include <asm/cmpxchg.h> +#include <asm/barrier.h> + +/* + * Atomic operations that C can't guarantee us. Useful for + * resource counting etc.. + */ + +/* + * We do not have SMP m68k systems, so we don't have to deal with that. + */ + +#define ATOMIC_INIT(i) { (i) } + +#define atomic_read(v) ACCESS_ONCE((v)->counter) +#define atomic_set(v, i) (((v)->counter) = i) + +/* + * The ColdFire parts cannot do some immediate to memory operations, + * so for them we do not specify the "i" asm constraint. + */ +#ifdef CONFIG_COLDFIRE +#define ASM_DI "d" +#else +#define ASM_DI "di" +#endif + +#define ATOMIC_OP(op, c_op, asm_op) \ +static inline void atomic_##op(int i, atomic_t *v) \ +{ \ + __asm__ __volatile__(#asm_op "l %1,%0" : "+m" (*v) : ASM_DI (i));\ +} \ + +#ifdef CONFIG_RMW_INSNS + +#define ATOMIC_OP_RETURN(op, c_op, asm_op) \ +static inline int atomic_##op##_return(int i, atomic_t *v) \ +{ \ + int t, tmp; \ + \ + __asm__ __volatile__( \ + "1: movel %2,%1\n" \ + " " #asm_op "l %3,%1\n" \ + " casl %2,%1,%0\n" \ + " jne 1b" \ + : "+m" (*v), "=&d" (t), "=&d" (tmp) \ + : "g" (i), "2" (atomic_read(v))); \ + return t; \ +} + +#else + +#define ATOMIC_OP_RETURN(op, c_op, asm_op) \ +static inline int atomic_##op##_return(int i, atomic_t * v) \ +{ \ + unsigned long flags; \ + int t; \ + \ + local_irq_save(flags); \ + t = (v->counter c_op i); \ + local_irq_restore(flags); \ + \ + return t; \ +} + +#endif /* CONFIG_RMW_INSNS */ + +#define ATOMIC_OPS(op, c_op, asm_op) \ + ATOMIC_OP(op, c_op, asm_op) \ + ATOMIC_OP_RETURN(op, c_op, asm_op) + +ATOMIC_OPS(add, +=, add) +ATOMIC_OPS(sub, -=, sub) + +#undef ATOMIC_OPS +#undef ATOMIC_OP_RETURN +#undef ATOMIC_OP + +static inline void atomic_inc(atomic_t *v) +{ + __asm__ __volatile__("addql #1,%0" : "+m" (*v)); +} + +static inline void atomic_dec(atomic_t *v) +{ + __asm__ __volatile__("subql #1,%0" : "+m" (*v)); +} + +static inline int atomic_dec_and_test(atomic_t *v) +{ + char c; + __asm__ __volatile__("subql #1,%1; seq %0" : "=d" (c), "+m" (*v)); + return c != 0; +} + +static inline int atomic_dec_and_test_lt(atomic_t *v) +{ + char c; + __asm__ __volatile__( + "subql #1,%1; slt %0" + : "=d" (c), "=m" (*v) + : "m" (*v)); + return c != 0; +} + +static inline int atomic_inc_and_test(atomic_t *v) +{ + char c; + __asm__ __volatile__("addql #1,%1; seq %0" : "=d" (c), "+m" (*v)); + return c != 0; +} + +#ifdef CONFIG_RMW_INSNS + +#define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n))) +#define atomic_xchg(v, new) (xchg(&((v)->counter), new)) + +#else /* !CONFIG_RMW_INSNS */ + +static inline int atomic_cmpxchg(atomic_t *v, int old, int new) +{ + unsigned long flags; + int prev; + + local_irq_save(flags); + prev = atomic_read(v); + if (prev == old) + atomic_set(v, new); + local_irq_restore(flags); + return prev; +} + +static inline int atomic_xchg(atomic_t *v, int new) +{ + unsigned long flags; + int prev; + + local_irq_save(flags); + prev = atomic_read(v); + atomic_set(v, new); + local_irq_restore(flags); + return prev; +} + +#endif /* !CONFIG_RMW_INSNS */ + +#define atomic_dec_return(v) atomic_sub_return(1, (v)) +#define atomic_inc_return(v) atomic_add_return(1, (v)) + +static inline int atomic_sub_and_test(int i, atomic_t *v) +{ + char c; + __asm__ __volatile__("subl %2,%1; seq %0" + : "=d" (c), "+m" (*v) + : ASM_DI (i)); + return c != 0; +} + +static inline int atomic_add_negative(int i, atomic_t *v) +{ + char c; + __asm__ __volatile__("addl %2,%1; smi %0" + : "=d" (c), "+m" (*v) + : ASM_DI (i)); + return c != 0; +} + +static inline void atomic_clear_mask(unsigned long mask, unsigned long *v) +{ + __asm__ __volatile__("andl %1,%0" : "+m" (*v) : ASM_DI (~(mask))); +} + +static inline void atomic_set_mask(unsigned long mask, unsigned long *v) +{ + __asm__ __volatile__("orl %1,%0" : "+m" (*v) : ASM_DI (mask)); +} + +static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u) +{ + int c, old; + c = atomic_read(v); + for (;;) { + if (unlikely(c == (u))) + break; + old = atomic_cmpxchg((v), c, c + (a)); + if (likely(old == c)) + break; + c = old; + } + return c; +} + +#endif /* __ARCH_M68K_ATOMIC __ */ |