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atomic_mm.h

#ifndef __ARCH_M68K_ATOMIC__
#define __ARCH_M68K_ATOMIC__

#include <linux/types.h>
#include <asm/system.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)        ((v)->counter)
#define atomic_set(v, i)      (((v)->counter) = i)

static inline void atomic_add(int i, atomic_t *v)
{
      __asm__ __volatile__("addl %1,%0" : "+m" (*v) : "id" (i));
}

static inline void atomic_sub(int i, atomic_t *v)
{
      __asm__ __volatile__("subl %1,%0" : "+m" (*v) : "id" (i));
}

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_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

static inline int atomic_add_return(int i, atomic_t *v)
{
      int t, tmp;

      __asm__ __volatile__(
                  "1:   movel %2,%1\n"
                  "     addl %3,%1\n"
                  "     casl %2,%1,%0\n"
                  "     jne 1b"
                  : "+m" (*v), "=&d" (t), "=&d" (tmp)
                  : "g" (i), "2" (atomic_read(v)));
      return t;
}

static inline int atomic_sub_return(int i, atomic_t *v)
{
      int t, tmp;

      __asm__ __volatile__(
                  "1:   movel %2,%1\n"
                  "     subl %3,%1\n"
                  "     casl %2,%1,%0\n"
                  "     jne 1b"
                  : "+m" (*v), "=&d" (t), "=&d" (tmp)
                  : "g" (i), "2" (atomic_read(v)));
      return t;
}

#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_add_return(int i, atomic_t * v)
{
      unsigned long flags;
      int t;

      local_irq_save(flags);
      t = atomic_read(v);
      t += i;
      atomic_set(v, t);
      local_irq_restore(flags);

      return t;
}

static inline int atomic_sub_return(int i, atomic_t * v)
{
      unsigned long flags;
      int t;

      local_irq_save(flags);
      t = atomic_read(v);
      t -= i;
      atomic_set(v, t);
      local_irq_restore(flags);

      return t;
}

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): "g" (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): "g" (i));
      return c != 0;
}

static inline void atomic_clear_mask(unsigned long mask, unsigned long *v)
{
      __asm__ __volatile__("andl %1,%0" : "+m" (*v) : "id" (~(mask)));
}

static inline void atomic_set_mask(unsigned long mask, unsigned long *v)
{
      __asm__ __volatile__("orl %1,%0" : "+m" (*v) : "id" (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 != (u);
}

#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)

/* Atomic operations are already serializing */
#define smp_mb__before_atomic_dec() barrier()
#define smp_mb__after_atomic_dec()  barrier()
#define smp_mb__before_atomic_inc() barrier()
#define smp_mb__after_atomic_inc()  barrier()

#include <asm-generic/atomic-long.h>
#endif /* __ARCH_M68K_ATOMIC __ */

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