| /* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org> |
| * Copyright (C) 2006 Kyle McMartin <kyle@parisc-linux.org> |
| */ |
| |
| #ifndef _ASM_PARISC_ATOMIC_H_ |
| #define _ASM_PARISC_ATOMIC_H_ |
| |
| #include <linux/types.h> |
| #include <asm/cmpxchg.h> |
| |
| /* |
| * Atomic operations that C can't guarantee us. Useful for |
| * resource counting etc.. |
| * |
| * And probably incredibly slow on parisc. OTOH, we don't |
| * have to write any serious assembly. prumpf |
| */ |
| |
| #ifdef CONFIG_SMP |
| #include <asm/spinlock.h> |
| #include <asm/cache.h> /* we use L1_CACHE_BYTES */ |
| |
| /* Use an array of spinlocks for our atomic_ts. |
| * Hash function to index into a different SPINLOCK. |
| * Since "a" is usually an address, use one spinlock per cacheline. |
| */ |
| # define ATOMIC_HASH_SIZE 4 |
| # define ATOMIC_HASH(a) (&(__atomic_hash[ (((unsigned long) (a))/L1_CACHE_BYTES) & (ATOMIC_HASH_SIZE-1) ])) |
| |
| extern arch_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned; |
| |
| /* Can't use raw_spin_lock_irq because of #include problems, so |
| * this is the substitute */ |
| #define _atomic_spin_lock_irqsave(l,f) do { \ |
| arch_spinlock_t *s = ATOMIC_HASH(l); \ |
| local_irq_save(f); \ |
| arch_spin_lock(s); \ |
| } while(0) |
| |
| #define _atomic_spin_unlock_irqrestore(l,f) do { \ |
| arch_spinlock_t *s = ATOMIC_HASH(l); \ |
| arch_spin_unlock(s); \ |
| local_irq_restore(f); \ |
| } while(0) |
| |
| |
| #else |
| # define _atomic_spin_lock_irqsave(l,f) do { local_irq_save(f); } while (0) |
| # define _atomic_spin_unlock_irqrestore(l,f) do { local_irq_restore(f); } while (0) |
| #endif |
| |
| /* |
| * Note that we need not lock read accesses - aligned word writes/reads |
| * are atomic, so a reader never sees inconsistent values. |
| */ |
| |
| /* It's possible to reduce all atomic operations to either |
| * __atomic_add_return, atomic_set and atomic_read (the latter |
| * is there only for consistency). |
| */ |
| |
| static __inline__ int __atomic_add_return(int i, atomic_t *v) |
| { |
| int ret; |
| unsigned long flags; |
| _atomic_spin_lock_irqsave(v, flags); |
| |
| ret = (v->counter += i); |
| |
| _atomic_spin_unlock_irqrestore(v, flags); |
| return ret; |
| } |
| |
| static __inline__ void atomic_set(atomic_t *v, int i) |
| { |
| unsigned long flags; |
| _atomic_spin_lock_irqsave(v, flags); |
| |
| v->counter = i; |
| |
| _atomic_spin_unlock_irqrestore(v, flags); |
| } |
| |
| static __inline__ int atomic_read(const atomic_t *v) |
| { |
| return (*(volatile int *)&(v)->counter); |
| } |
| |
| /* exported interface */ |
| #define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n))) |
| #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) |
| |
| /** |
| * __atomic_add_unless - add unless the number is a given value |
| * @v: pointer of type atomic_t |
| * @a: the amount to add to v... |
| * @u: ...unless v is equal to u. |
| * |
| * Atomically adds @a to @v, so long as it was not @u. |
| * Returns the old value of @v. |
| */ |
| 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; |
| } |
| |
| |
| #define atomic_add(i,v) ((void)(__atomic_add_return( (i),(v)))) |
| #define atomic_sub(i,v) ((void)(__atomic_add_return(-((int) (i)),(v)))) |
| #define atomic_inc(v) ((void)(__atomic_add_return( 1,(v)))) |
| #define atomic_dec(v) ((void)(__atomic_add_return( -1,(v)))) |
| |
| #define atomic_add_return(i,v) (__atomic_add_return( (i),(v))) |
| #define atomic_sub_return(i,v) (__atomic_add_return(-(i),(v))) |
| #define atomic_inc_return(v) (__atomic_add_return( 1,(v))) |
| #define atomic_dec_return(v) (__atomic_add_return( -1,(v))) |
| |
| #define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0) |
| |
| /* |
| * atomic_inc_and_test - increment and test |
| * @v: pointer of type atomic_t |
| * |
| * Atomically increments @v by 1 |
| * and returns true if the result is zero, or false for all |
| * other cases. |
| */ |
| #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0) |
| |
| #define atomic_dec_and_test(v) (atomic_dec_return(v) == 0) |
| |
| #define atomic_sub_and_test(i,v) (atomic_sub_return((i),(v)) == 0) |
| |
| #define ATOMIC_INIT(i) { (i) } |
| |
| #define smp_mb__before_atomic_dec() smp_mb() |
| #define smp_mb__after_atomic_dec() smp_mb() |
| #define smp_mb__before_atomic_inc() smp_mb() |
| #define smp_mb__after_atomic_inc() smp_mb() |
| |
| #ifdef CONFIG_64BIT |
| |
| #define ATOMIC64_INIT(i) { (i) } |
| |
| static __inline__ s64 |
| __atomic64_add_return(s64 i, atomic64_t *v) |
| { |
| s64 ret; |
| unsigned long flags; |
| _atomic_spin_lock_irqsave(v, flags); |
| |
| ret = (v->counter += i); |
| |
| _atomic_spin_unlock_irqrestore(v, flags); |
| return ret; |
| } |
| |
| static __inline__ void |
| atomic64_set(atomic64_t *v, s64 i) |
| { |
| unsigned long flags; |
| _atomic_spin_lock_irqsave(v, flags); |
| |
| v->counter = i; |
| |
| _atomic_spin_unlock_irqrestore(v, flags); |
| } |
| |
| static __inline__ s64 |
| atomic64_read(const atomic64_t *v) |
| { |
| return (*(volatile long *)&(v)->counter); |
| } |
| |
| #define atomic64_add(i,v) ((void)(__atomic64_add_return( ((s64)(i)),(v)))) |
| #define atomic64_sub(i,v) ((void)(__atomic64_add_return(-((s64)(i)),(v)))) |
| #define atomic64_inc(v) ((void)(__atomic64_add_return( 1,(v)))) |
| #define atomic64_dec(v) ((void)(__atomic64_add_return( -1,(v)))) |
| |
| #define atomic64_add_return(i,v) (__atomic64_add_return( ((s64)(i)),(v))) |
| #define atomic64_sub_return(i,v) (__atomic64_add_return(-((s64)(i)),(v))) |
| #define atomic64_inc_return(v) (__atomic64_add_return( 1,(v))) |
| #define atomic64_dec_return(v) (__atomic64_add_return( -1,(v))) |
| |
| #define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0) |
| |
| #define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0) |
| #define atomic64_dec_and_test(v) (atomic64_dec_return(v) == 0) |
| #define atomic64_sub_and_test(i,v) (atomic64_sub_return((i),(v)) == 0) |
| |
| /* exported interface */ |
| #define atomic64_cmpxchg(v, o, n) \ |
| ((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n))) |
| #define atomic64_xchg(v, new) (xchg(&((v)->counter), new)) |
| |
| /** |
| * atomic64_add_unless - add unless the number is a given value |
| * @v: pointer of type atomic64_t |
| * @a: the amount to add to v... |
| * @u: ...unless v is equal to u. |
| * |
| * Atomically adds @a to @v, so long as it was not @u. |
| * Returns the old value of @v. |
| */ |
| static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u) |
| { |
| long c, old; |
| c = atomic64_read(v); |
| for (;;) { |
| if (unlikely(c == (u))) |
| break; |
| old = atomic64_cmpxchg((v), c, c + (a)); |
| if (likely(old == c)) |
| break; |
| c = old; |
| } |
| return c != (u); |
| } |
| |
| #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0) |
| |
| #endif /* !CONFIG_64BIT */ |
| |
| |
| #endif /* _ASM_PARISC_ATOMIC_H_ */ |