local.h

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#ifndef __M32R_LOCAL_H
#define __M32R_LOCAL_H

/*
 *  linux/include/asm-m32r/local.h
 *
 *  M32R version:
 *    Copyright (C) 2001, 2002  Hitoshi Yamamoto
 *    Copyright (C) 2004  Hirokazu Takata <takata at linux-m32r.org>
 *    Copyright (C) 2007  Mathieu Desnoyers <[email protected]>
 */

#include <linux/percpu.h>
#include <asm/assembler.h>
#include <asm/local.h>

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

/*
 * Make sure gcc doesn't try to be clever and move things around
 * on us. We need to use _exactly_ the address the user gave us,
 * not some alias that contains the same information.
 */
typedef struct { volatile int counter; } local_t;

#define LOCAL_INIT(i)   { (i) }

#define local_read(l)   ((l)->counter)

#define local_set(l, i) (((l)->counter) = (i))

static inline long local_add_return(long i, local_t *l)
{
    unsigned long flags;
    long result;

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

    return result;
}

static inline long local_sub_return(long i, local_t *l)
{
    unsigned long flags;
    long result;

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

    return result;
}

#define local_add(i, l) ((void) local_add_return((i), (l)))

#define local_sub(i, l) ((void) local_sub_return((i), (l)))

#define local_sub_and_test(i, l) (local_sub_return((i), (l)) == 0)

static inline long local_inc_return(local_t *l)
{
    unsigned long flags;
    long result;

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

    return result;
}

static inline long local_dec_return(local_t *l)
{
    unsigned long flags;
    long result;

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

    return result;
}

#define local_inc(l) ((void)local_inc_return(l))

#define local_dec(l) ((void)local_dec_return(l))

#define local_inc_and_test(l) (local_inc_return(l) == 0)

#define local_dec_and_test(l) (local_dec_return(l) == 0)

#define local_add_negative(i, l) (local_add_return((i), (l)) < 0)

#define local_cmpxchg(l, o, n) (cmpxchg_local(&((l)->counter), (o), (n)))
#define local_xchg(v, new) (xchg_local(&((l)->counter), new))

static inline int local_add_unless(local_t *l, long a, long u)
{
    long c, old;
    c = local_read(l);
    for (;;) {
        if (unlikely(c == (u)))
            break;
        old = local_cmpxchg((l), c, c + (a));
        if (likely(old == c))
            break;
        c = old;
    }
    return c != (u);
}

#define local_inc_not_zero(l) local_add_unless((l), 1, 0)

static inline void local_clear_mask(unsigned long  mask, local_t *addr)
{
    unsigned long flags;
    unsigned long tmp;

    local_irq_save(flags);
    __asm__ __volatile__ (
        "# local_clear_mask     \n\t"
        DCACHE_CLEAR("%0", "r5", "%1")
        "ld %0, @%1;            \n\t"
        "and    %0, %2;         \n\t"
        "st %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 local_set_mask(unsigned long  mask, local_t *addr)
{
    unsigned long flags;
    unsigned long tmp;

    local_irq_save(flags);
    __asm__ __volatile__ (
        "# local_set_mask       \n\t"
        DCACHE_CLEAR("%0", "r5", "%1")
        "ld %0, @%1;            \n\t"
        "or %0, %2;         \n\t"
        "st %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_local_dec()  barrier()
#define smp_mb__after_local_dec()   barrier()
#define smp_mb__before_local_inc()  barrier()
#define smp_mb__after_local_inc()   barrier()

/* Use these for per-cpu local_t variables: on some archs they are
 * much more efficient than these naive implementations.  Note they take
 * a variable, not an address.
 */

#define __local_inc(l)      ((l)->a.counter++)
#define __local_dec(l)      ((l)->a.counter++)
#define __local_add(i, l)   ((l)->a.counter += (i))
#define __local_sub(i, l)   ((l)->a.counter -= (i))

/* Use these for per-cpu local_t variables: on some archs they are
 * much more efficient than these naive implementations.  Note they take
 * a variable, not an address.
 */

#endif /* __M32R_LOCAL_H */