atomic-llsc.h

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#ifndef __ASM_SH_ATOMIC_LLSC_H
#define __ASM_SH_ATOMIC_LLSC_H

/*
 * To get proper branch prediction for the main line, we must branch
 * forward to code at the end of this object's .text section, then
 * branch back to restart the operation.
 */
static inline void atomic_add(int i, atomic_t *v)
{
    unsigned long tmp;

    __asm__ __volatile__ (
"1: movli.l @%2, %0     ! atomic_add    \n"
"   add %1, %0              \n"
"   movco.l %0, @%2             \n"
"   bf  1b              \n"
    : "=&z" (tmp)
    : "r" (i), "r" (&v->counter)
    : "t");
}

static inline void atomic_sub(int i, atomic_t *v)
{
    unsigned long tmp;

    __asm__ __volatile__ (
"1: movli.l @%2, %0     ! atomic_sub    \n"
"   sub %1, %0              \n"
"   movco.l %0, @%2             \n"
"   bf  1b              \n"
    : "=&z" (tmp)
    : "r" (i), "r" (&v->counter)
    : "t");
}

/*
 * SH-4A note:
 *
 * We basically get atomic_xxx_return() for free compared with
 * atomic_xxx(). movli.l/movco.l require r0 due to the instruction
 * encoding, so the retval is automatically set without having to
 * do any special work.
 */
static inline int atomic_add_return(int i, atomic_t *v)
{
    unsigned long temp;

    __asm__ __volatile__ (
"1: movli.l @%2, %0     ! atomic_add_return \n"
"   add %1, %0                  \n"
"   movco.l %0, @%2                 \n"
"   bf  1b                  \n"
"   synco                       \n"
    : "=&z" (temp)
    : "r" (i), "r" (&v->counter)
    : "t");

    return temp;
}

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

    __asm__ __volatile__ (
"1: movli.l @%2, %0     ! atomic_sub_return \n"
"   sub %1, %0                  \n"
"   movco.l %0, @%2                 \n"
"   bf  1b                  \n"
"   synco                       \n"
    : "=&z" (temp)
    : "r" (i), "r" (&v->counter)
    : "t");

    return temp;
}

static inline void atomic_clear_mask(unsigned int mask, atomic_t *v)
{
    unsigned long tmp;

    __asm__ __volatile__ (
"1: movli.l @%2, %0     ! atomic_clear_mask \n"
"   and %1, %0                  \n"
"   movco.l %0, @%2                 \n"
"   bf  1b                  \n"
    : "=&z" (tmp)
    : "r" (~mask), "r" (&v->counter)
    : "t");
}

static inline void atomic_set_mask(unsigned int mask, atomic_t *v)
{
    unsigned long tmp;

    __asm__ __volatile__ (
"1: movli.l @%2, %0     ! atomic_set_mask   \n"
"   or  %1, %0                  \n"
"   movco.l %0, @%2                 \n"
"   bf  1b                  \n"
    : "=&z" (tmp)
    : "r" (mask), "r" (&v->counter)
    : "t");
}

#endif /* __ASM_SH_ATOMIC_LLSC_H */