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#ifndef _ASM_PARISC_ATOMIC_H_

#define _ASM_PARISC_ATOMIC_H_

#include <linux/config.h>

#include <asm/system.h>

/* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>.  */

/*

 * 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_t.h>

/* Use an array of spinlocks for our atomic_ts.

** Hash function to index into a different SPINLOCK.

** Since "a" is usually an address, ">>8" makes one spinlock per 64-bytes.

*/

#  define ATOMIC_HASH_SIZE 4

#  define ATOMIC_HASH(a) (&__atomic_hash[(((unsigned long) a)>>8)&(ATOMIC_HASH_SIZE-1)])

extern spinlock_t __atomic_hash[ATOMIC_HASH_SIZE];

/* copied from <asm/spinlock.h> and modified.

 * No CONFIG_DEBUG_SPINLOCK support.

 *

 * XXX REVISIT these could be renamed and moved to spinlock_t.h as well

 */

#define SPIN_LOCK(x)    do { while(__ldcw(&(x)->lock) == 0); } while(0)

#define SPIN_UNLOCK(x)  do { (x)->lock = 1; } while(0)

#else   /* CONFIG_SMP */

#define ATOMIC_HASH_SIZE 1

#define ATOMIC_HASH(a)  (0)

#define SPIN_LOCK(x) (void)(x)

#define SPIN_UNLOCK(x) do { } while(0)

#endif  /* CONFIG_SMP */

/* copied from <linux/spinlock.h> and modified */

#define SPIN_LOCK_IRQSAVE(lock, flags)  do { \

        local_irq_save(flags);  SPIN_LOCK(lock); \

} while (0)

#define SPIN_UNLOCK_IRQRESTORE(lock, flags) do { \

        SPIN_UNLOCK(lock);  local_irq_restore(flags); \

} while (0)

/* Note that we need not lock read accesses - aligned word writes/reads

 * are atomic, so a reader never sees unconsistent values.

 *

 * Cache-line alignment would conflict with, for example, linux/module.h

 */

typedef struct {

        volatile int counter;

} atomic_t;

/* This should get optimized out since it's never called.

** Or get a link error if xchg is used "wrong".

*/

extern void __xchg_called_with_bad_pointer(void);

/* __xchg32/64 defined in arch/parisc/lib/bitops.c */

extern unsigned long __xchg8(char, char *);

extern unsigned long __xchg32(int, int *);

#ifdef __LP64__

extern unsigned long __xchg64(unsigned long, unsigned long *);

#endif

/* optimizer better get rid of switch since size is a constant */

static __inline__ unsigned long __xchg(unsigned long x, __volatile__ void * ptr,

                                       int size)

{

        switch(size) {

#ifdef __LP64__

        case 8: return __xchg64(x,(unsigned long *) ptr);

#endif

        case 4: return __xchg32((int) x, (int *) ptr);

        case 1: return __xchg8((char) x, (char *) ptr);

        }

        __xchg_called_with_bad_pointer();

        return x;

}

/*

** REVISIT - Abandoned use of LDCW in xchg() for now:

** o need to test sizeof(*ptr) to avoid clearing adjacent bytes

** o and while we are at it, could 64-bit code use LDCD too?

**

**      if (__builtin_constant_p(x) && (x == NULL))

**              if (((unsigned long)p & 0xf) == 0)

**                      return __ldcw(p);

*/

#define xchg(ptr,x) \

        ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))

#define __HAVE_ARCH_CMPXCHG     1

/* bug catcher for when unsupported size is used - won't link */

extern void __cmpxchg_called_with_bad_pointer(void);

/* __cmpxchg_u32/u64 defined in arch/parisc/lib/bitops.c */

extern unsigned long __cmpxchg_u32(volatile unsigned int *m, unsigned int old, unsigned int new_);

extern unsigned long __cmpxchg_u64(volatile unsigned long *ptr, unsigned long old, unsigned long new_);

/* don't worry...optimizer will get rid of most of this */

static __inline__ unsigned long

__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size)

{

        switch(size) {

#ifdef __LP64__

        case 8: return __cmpxchg_u64((unsigned long *)ptr, old, new_);

#endif

        case 4: return __cmpxchg_u32((unsigned int *)ptr, (unsigned int) old, (unsigned int) new_);

        }

        __cmpxchg_called_with_bad_pointer();

        return old;

}

#define cmpxchg(ptr,o,n)                                                 \

  ({                                                                     \

     __typeof__(*(ptr)) _o_ = (o);                                       \

     __typeof__(*(ptr)) _n_ = (n);                                       \

     (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,           \

                                    (unsigned long)_n_, sizeof(*(ptr))); \

  })

/* It's possible to reduce all atomic operations to either

 * __atomic_add_return, __atomic_set and __atomic_ret (the latter

 * is there only for consistency). */

static __inline__ int __atomic_add_return(int i, atomic_t *v)

{

        int ret;

        unsigned long flags;

        SPIN_LOCK_IRQSAVE(ATOMIC_HASH(v), flags);

        ret = (v->counter += i);

        SPIN_UNLOCK_IRQRESTORE(ATOMIC_HASH(v), flags);

        return ret;

}

static __inline__ void __atomic_set(atomic_t *v, int i)

{

        unsigned long flags;

        SPIN_LOCK_IRQSAVE(ATOMIC_HASH(v), flags);

        v->counter = i;

        SPIN_UNLOCK_IRQRESTORE(ATOMIC_HASH(v), flags);

}

static __inline__ int __atomic_read(atomic_t *v)

{

        return v->counter;

}

/* exported interface */

#define atomic_add(i,v)         ((void)(__atomic_add_return( (i),(v))))

#define atomic_sub(i,v)         ((void)(__atomic_add_return(-(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_dec_and_test(v)  (atomic_dec_return(v) == 0)

#define atomic_set(v,i)         (__atomic_set((v),i))

#define atomic_read(v)          (__atomic_read(v))

#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()

#endif