Quelle  atomic-llsc.h   Sprache: C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_SH_ATOMIC_LLSC_H
#define __ASM_SH_ATOMIC_LLSC_H

/*
 * 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.
 */
/*
 * 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.
 */

#define ATOMIC_OP(op)       \
static inline void arch_atomic_##op(int i, atomic_t *v)   \
{         \
 unsigned long tmp;      \
         \
 __asm__ __volatile__ (      \
"1: movli.l @%2, %0 ! atomic_" #op "\n"   \
" " #op " %1, %0 \n"   \
" movco.l %0, @%2 \n"   \
" bf 1b \n"   \
 : "=&z" (tmp)       \
 : "r" (i), "r" (&v->counter)     \
 : "t");        \
}

#define ATOMIC_OP_RETURN(op)      \
static inline int arch_atomic_##op##_return(int i, atomic_t *v)  \
{         \
 unsigned long temp;      \
         \
 __asm__ __volatile__ (      \
"1: movli.l @%2, %0 ! atomic_" #op "_return \n"  \
" " #op " %1, %0 \n"  \
" movco.l %0, @%2 \n"  \
" bf 1b \n"  \
" synco \n"  \
 : "=&z" (temp)       \
 : "r" (i), "r" (&v->counter)     \
 : "t");        \
         \
 return temp;       \
}

#define ATOMIC_FETCH_OP(op)      \
static inline int arch_atomic_fetch_##op(int i, atomic_t *v)  \
{         \
 unsigned long res, temp;     \
         \
 __asm__ __volatile__ (      \
"1: movli.l @%3, %0 ! atomic_fetch_" #op " \n"  \
" mov %0, %1 \n"  \
" " #op " %2, %0 \n"  \
" movco.l %0, @%3 \n"  \
" bf 1b \n"  \
" synco \n"  \
 : "=&z" (temp), "=&r" (res)     \
 : "r" (i), "r" (&v->counter)     \
 : "t");        \
         \
 return res;       \
}

#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op) ATOMIC_FETCH_OP(op)

ATOMIC_OPS(add)
ATOMIC_OPS(sub)

#define arch_atomic_add_return arch_atomic_add_return
#define arch_atomic_sub_return arch_atomic_sub_return
#define arch_atomic_fetch_add arch_atomic_fetch_add
#define arch_atomic_fetch_sub arch_atomic_fetch_sub

#undef ATOMIC_OPS
#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_FETCH_OP(op)

ATOMIC_OPS(and)
ATOMIC_OPS(or)
ATOMIC_OPS(xor)

#define arch_atomic_fetch_and arch_atomic_fetch_and
#define arch_atomic_fetch_or arch_atomic_fetch_or
#define arch_atomic_fetch_xor arch_atomic_fetch_xor

#undef ATOMIC_OPS
#undef ATOMIC_FETCH_OP
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP

#endif /* __ASM_SH_ATOMIC_LLSC_H */