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atomic.h

#ifndef _ASM_M32R_ATOMIC_H
#define _ASM_M32R_ATOMIC_H

/*
 *  linux/include/asm-m32r/atomic.h
 *
 *  M32R version:
 *    Copyright (C) 2001, 2002  Hitoshi Yamamoto
 *    Copyright (C) 2004  Hirokazu Takata <takata at linux-m32r.org>
 */

#include <linux/types.h>
#include <asm/assembler.h>
#include <asm/system.h>

/*
 * Atomic operations that C can't guarantee us.  Useful for
 * resource counting etc..
 */

#define ATOMIC_INIT(i)  { (i) }

/**
 * atomic_read - read atomic variable
 * @v: pointer of type atomic_t
 *
 * Atomically reads the value of @v.
 */
#define atomic_read(v)  ((v)->counter)

/**
 * atomic_set - set atomic variable
 * @v: pointer of type atomic_t
 * @i: required value
 *
 * Atomically sets the value of @v to @i.
 */
#define atomic_set(v,i) (((v)->counter) = (i))

/**
 * atomic_add_return - add integer to atomic variable and return it
 * @i: integer value to add
 * @v: pointer of type atomic_t
 *
 * Atomically adds @i to @v and return (@i + @v).
 */
static __inline__ int atomic_add_return(int i, atomic_t *v)
{
      unsigned long flags;
      int result;

      local_irq_save(flags);
      __asm__ __volatile__ (
            "# atomic_add_return          \n\t"
            DCACHE_CLEAR("%0", "r4", "%1")
            M32R_LOCK" %0, @%1;           \n\t"
            "add  %0, %2;                 \n\t"
            M32R_UNLOCK" %0, @%1;         \n\t"
            : "=&r" (result)
            : "r" (&v->counter), "r" (i)
            : "memory"
#ifdef CONFIG_CHIP_M32700_TS1
            , "r4"
#endif      /* CONFIG_CHIP_M32700_TS1 */
      );
      local_irq_restore(flags);

      return result;
}

/**
 * atomic_sub_return - subtract integer from atomic variable and return it
 * @i: integer value to subtract
 * @v: pointer of type atomic_t
 *
 * Atomically subtracts @i from @v and return (@v - @i).
 */
static __inline__ int atomic_sub_return(int i, atomic_t *v)
{
      unsigned long flags;
      int result;

      local_irq_save(flags);
      __asm__ __volatile__ (
            "# atomic_sub_return          \n\t"
            DCACHE_CLEAR("%0", "r4", "%1")
            M32R_LOCK" %0, @%1;           \n\t"
            "sub  %0, %2;                 \n\t"
            M32R_UNLOCK" %0, @%1;         \n\t"
            : "=&r" (result)
            : "r" (&v->counter), "r" (i)
            : "memory"
#ifdef CONFIG_CHIP_M32700_TS1
            , "r4"
#endif      /* CONFIG_CHIP_M32700_TS1 */
      );
      local_irq_restore(flags);

      return result;
}

/**
 * atomic_add - add integer to atomic variable
 * @i: integer value to add
 * @v: pointer of type atomic_t
 *
 * Atomically adds @i to @v.
 */
#define atomic_add(i,v) ((void) atomic_add_return((i), (v)))

/**
 * atomic_sub - subtract the atomic variable
 * @i: integer value to subtract
 * @v: pointer of type atomic_t
 *
 * Atomically subtracts @i from @v.
 */
#define atomic_sub(i,v) ((void) atomic_sub_return((i), (v)))

/**
 * atomic_sub_and_test - subtract value from variable and test result
 * @i: integer value to subtract
 * @v: pointer of type atomic_t
 *
 * Atomically subtracts @i from @v and returns
 * true if the result is zero, or false for all
 * other cases.
 */
#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)

/**
 * atomic_inc_return - increment atomic variable and return it
 * @v: pointer of type atomic_t
 *
 * Atomically increments @v by 1 and returns the result.
 */
static __inline__ int atomic_inc_return(atomic_t *v)
{
      unsigned long flags;
      int result;

      local_irq_save(flags);
      __asm__ __volatile__ (
            "# atomic_inc_return          \n\t"
            DCACHE_CLEAR("%0", "r4", "%1")
            M32R_LOCK" %0, @%1;           \n\t"
            "addi %0, #1;                 \n\t"
            M32R_UNLOCK" %0, @%1;         \n\t"
            : "=&r" (result)
            : "r" (&v->counter)
            : "memory"
#ifdef CONFIG_CHIP_M32700_TS1
            , "r4"
#endif      /* CONFIG_CHIP_M32700_TS1 */
      );
      local_irq_restore(flags);

      return result;
}

/**
 * atomic_dec_return - decrement atomic variable and return it
 * @v: pointer of type atomic_t
 *
 * Atomically decrements @v by 1 and returns the result.
 */
static __inline__ int atomic_dec_return(atomic_t *v)
{
      unsigned long flags;
      int result;

      local_irq_save(flags);
      __asm__ __volatile__ (
            "# atomic_dec_return          \n\t"
            DCACHE_CLEAR("%0", "r4", "%1")
            M32R_LOCK" %0, @%1;           \n\t"
            "addi %0, #-1;          \n\t"
            M32R_UNLOCK" %0, @%1;         \n\t"
            : "=&r" (result)
            : "r" (&v->counter)
            : "memory"
#ifdef CONFIG_CHIP_M32700_TS1
            , "r4"
#endif      /* CONFIG_CHIP_M32700_TS1 */
      );
      local_irq_restore(flags);

      return result;
}

/**
 * atomic_inc - increment atomic variable
 * @v: pointer of type atomic_t
 *
 * Atomically increments @v by 1.
 */
#define atomic_inc(v) ((void)atomic_inc_return(v))

/**
 * atomic_dec - decrement atomic variable
 * @v: pointer of type atomic_t
 *
 * Atomically decrements @v by 1.
 */
#define atomic_dec(v) ((void)atomic_dec_return(v))

/**
 * 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)

/**
 * atomic_dec_and_test - decrement and test
 * @v: pointer of type atomic_t
 *
 * Atomically decrements @v by 1 and
 * returns true if the result is 0, or false for all
 * other cases.
 */
#define atomic_dec_and_test(v) (atomic_dec_return(v) == 0)

/**
 * atomic_add_negative - add and test if negative
 * @v: pointer of type atomic_t
 * @i: integer value to add
 *
 * Atomically adds @i to @v and returns true
 * if the result is negative, or false when
 * result is greater than or equal to zero.
 */
#define atomic_add_negative(i,v) (atomic_add_return((i), (v)) < 0)

#define atomic_cmpxchg(v, o, n) ((int)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 non-zero if @v was not @u, and zero otherwise.
 */
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)

static __inline__ void atomic_clear_mask(unsigned long  mask, atomic_t *addr)
{
      unsigned long flags;
      unsigned long tmp;

      local_irq_save(flags);
      __asm__ __volatile__ (
            "# atomic_clear_mask          \n\t"
            DCACHE_CLEAR("%0", "r5", "%1")
            M32R_LOCK" %0, @%1;           \n\t"
            "and  %0, %2;                 \n\t"
            M32R_UNLOCK" %0, @%1;         \n\t"
            : "=&r" (tmp)
            : "r" (addr), "r" (~mask)
            : "memory"
#ifdef CONFIG_CHIP_M32700_TS1
            , "r5"
#endif      /* CONFIG_CHIP_M32700_TS1 */
      );
      local_irq_restore(flags);
}

static __inline__ void atomic_set_mask(unsigned long  mask, atomic_t *addr)
{
      unsigned long flags;
      unsigned long tmp;

      local_irq_save(flags);
      __asm__ __volatile__ (
            "# atomic_set_mask            \n\t"
            DCACHE_CLEAR("%0", "r5", "%1")
            M32R_LOCK" %0, @%1;           \n\t"
            "or   %0, %2;                 \n\t"
            M32R_UNLOCK" %0, @%1;         \n\t"
            : "=&r" (tmp)
            : "r" (addr), "r" (mask)
            : "memory"
#ifdef CONFIG_CHIP_M32700_TS1
            , "r5"
#endif      /* CONFIG_CHIP_M32700_TS1 */
      );
      local_irq_restore(flags);
}

/* Atomic operations are already serializing on m32r */
#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      /* _ASM_M32R_ATOMIC_H */

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