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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_UM_FUTEX_H
#define _ASM_UM_FUTEX_H
#include <linux/futex.h>
#include <linux/uaccess.h>
#include <asm/errno.h>
#ifdef CONFIG_MMU
int arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval, u32 __user *uaddr);
int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
u32 oldval, u32 newval);
#else
#include <linux/atomic.h>
#include <asm-generic/futex.h>
#ifdef CONFIG_SMP
static inline int
arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval, u32 __user *uaddr)
{
u32 oldval, newval;
u32 *p = (u32 __force *)uaddr;
do {
oldval = READ_ONCE(*p);
switch (op) {
case FUTEX_OP_SET:
newval = oparg;
break;
case FUTEX_OP_ADD:
newval = oldval + oparg;
break;
case FUTEX_OP_OR:
newval = oldval | oparg;
break;
case FUTEX_OP_ANDN:
newval = oldval & ~oparg;
break;
case FUTEX_OP_XOR:
newval = oldval ^ oparg;
break;
default:
return -ENOSYS;
}
} while (!try_cmpxchg(p, &oldval, newval));
*oval = oldval;
return 0;
}
static inline int
futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
u32 oldval, u32 newval)
{
u32 *p = (u32 __force *)uaddr;
*uval = cmpxchg(p, oldval, newval);
return 0;
}
#endif /* CONFIG_SMP */
#endif /* CONFIG_MMU */
#endif
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