/* SPDX-License-Identifier: GPL-2.0 */#ifndef _ASM_GENERIC_FUTEX_H#define _ASM_GENERIC_FUTEX_H #include <linux/futex.h>#include <linux/uaccess.h>#include <asm/errno.h> #ifndef CONFIG_SMP/* * The following implementation only for uniprocessor machines. * It relies on preempt_disable() ensuring mutual exclusion. * */ /** * arch_futex_atomic_op_inuser() - Atomic arithmetic operation with constant *			  argument and comparison of the previous *			  futex value with another constant. * * @encoded_op:	encoded operation to execute * @uaddr:	pointer to user space address * * Return: * 0 - On success * -EFAULT - User access resulted in a page fault * -EAGAIN - Atomic operation was unable to complete due to contention * -ENOSYS - Operation not supported */static inline intarch_futex_atomic_op_inuser(int op, u32 oparg, int *oval, u32 __user *uaddr){	int oldval, ret;	u32 tmp; 	preempt_disable(); 	ret = -EFAULT;	if (unlikely(get_user(oldval, uaddr) != 0))		goto out_pagefault_enable; 	ret = 0;	tmp = oldval; 	switch (op) {	case FUTEX_OP_SET:		tmp = oparg;		break;	case FUTEX_OP_ADD:		tmp += oparg;		break;	case FUTEX_OP_OR:		tmp |= oparg;		break;	case FUTEX_OP_ANDN:		tmp &= ~oparg;		break;	case FUTEX_OP_XOR:		tmp ^= oparg;		break;	default:		ret = -ENOSYS;	} 	if (ret == 0 && unlikely(put_user(tmp, uaddr) != 0))		ret = -EFAULT; out_pagefault_enable:	preempt_enable(); 	if (ret == 0)		*oval = oldval; 	return ret;} /** * futex_atomic_cmpxchg_inatomic() - Compare and exchange the content of the *				uaddr with newval if the current value is *				oldval. * @uval:	pointer to store content of @uaddr * @uaddr:	pointer to user space address * @oldval:	old value * @newval:	new value to store to @uaddr * * Return: * 0 - On success * -EFAULT - User access resulted in a page fault * -EAGAIN - Atomic operation was unable to complete due to contention * -ENOSYS - Function not implemented (only if !HAVE_FUTEX_CMPXCHG) */static inline intfutex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,			      u32 oldval, u32 newval){	u32 val; 	preempt_disable();	if (unlikely(get_user(val, uaddr) != 0)) {		preempt_enable();		return -EFAULT;	} 	if (val == oldval && unlikely(put_user(newval, uaddr) != 0)) {		preempt_enable();		return -EFAULT;	} 	*uval = val;	preempt_enable(); 	return 0;} #elsestatic inline intarch_futex_atomic_op_inuser(int op, u32 oparg, int *oval, u32 __user *uaddr){	return -ENOSYS;} static inline intfutex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,			      u32 oldval, u32 newval){	return -ENOSYS;} #endif /* CONFIG_SMP */#endif