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linux-next/arch/sh/include/asm/atomic-grb.h
Peter Zijlstra 7d9794e752 locking/atomic, arch/sh: Implement atomic_fetch_{add,sub,and,or,xor}()
Implement FETCH-OP atomic primitives, these are very similar to the
existing OP-RETURN primitives we already have, except they return the
value of the atomic variable _before_ modification.

This is especially useful for irreversible operations -- such as
bitops (because it becomes impossible to reconstruct the state prior
to modification).

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-16 10:48:29 +02:00

86 lines
2.6 KiB
C

#ifndef __ASM_SH_ATOMIC_GRB_H
#define __ASM_SH_ATOMIC_GRB_H
#define ATOMIC_OP(op) \
static inline void atomic_##op(int i, atomic_t *v) \
{ \
int tmp; \
\
__asm__ __volatile__ ( \
" .align 2 \n\t" \
" mova 1f, r0 \n\t" /* r0 = end point */ \
" mov r15, r1 \n\t" /* r1 = saved sp */ \
" mov #-6, r15 \n\t" /* LOGIN: r15 = size */ \
" mov.l @%1, %0 \n\t" /* load old value */ \
" " #op " %2, %0 \n\t" /* $op */ \
" mov.l %0, @%1 \n\t" /* store new value */ \
"1: mov r1, r15 \n\t" /* LOGOUT */ \
: "=&r" (tmp), \
"+r" (v) \
: "r" (i) \
: "memory" , "r0", "r1"); \
} \
#define ATOMIC_OP_RETURN(op) \
static inline int atomic_##op##_return(int i, atomic_t *v) \
{ \
int tmp; \
\
__asm__ __volatile__ ( \
" .align 2 \n\t" \
" mova 1f, r0 \n\t" /* r0 = end point */ \
" mov r15, r1 \n\t" /* r1 = saved sp */ \
" mov #-6, r15 \n\t" /* LOGIN: r15 = size */ \
" mov.l @%1, %0 \n\t" /* load old value */ \
" " #op " %2, %0 \n\t" /* $op */ \
" mov.l %0, @%1 \n\t" /* store new value */ \
"1: mov r1, r15 \n\t" /* LOGOUT */ \
: "=&r" (tmp), \
"+r" (v) \
: "r" (i) \
: "memory" , "r0", "r1"); \
\
return tmp; \
}
#define ATOMIC_FETCH_OP(op) \
static inline int atomic_fetch_##op(int i, atomic_t *v) \
{ \
int res, tmp; \
\
__asm__ __volatile__ ( \
" .align 2 \n\t" \
" mova 1f, r0 \n\t" /* r0 = end point */ \
" mov r15, r1 \n\t" /* r1 = saved sp */ \
" mov #-6, r15 \n\t" /* LOGIN: r15 = size */ \
" mov.l @%2, %0 \n\t" /* load old value */ \
" mov %0, %1 \n\t" /* save old value */ \
" " #op " %3, %0 \n\t" /* $op */ \
" mov.l %0, @%2 \n\t" /* store new value */ \
"1: mov r1, r15 \n\t" /* LOGOUT */ \
: "=&r" (tmp), "=&r" (res), "+r" (v) \
: "r" (i) \
: "memory" , "r0", "r1"); \
\
return res; \
}
#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op) ATOMIC_FETCH_OP(op)
ATOMIC_OPS(add)
ATOMIC_OPS(sub)
#undef ATOMIC_OPS
#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_FETCH_OP(op)
ATOMIC_OPS(and)
ATOMIC_OPS(or)
ATOMIC_OPS(xor)
#undef ATOMIC_OPS
#undef ATOMIC_FETCH_OP
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP
#endif /* __ASM_SH_ATOMIC_GRB_H */