/*-
 * Copyright (c) 2010 Isilon Systems, Inc.
 * Copyright (c) 2010 iX Systems, Inc.
 * Copyright (c) 2010 Panasas, Inc.
 * Copyright (c) 2013-2016 Mellanox Technologies, Ltd.
 * Copyright (c) 2015 François Tigeot
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice unmodified, this list of conditions, and the following
 *    disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef	_LINUXKPI_LINUX_UACCESS_H_
#define	_LINUXKPI_LINUX_UACCESS_H_

#include <sys/param.h>
#include <sys/lock.h>
#include <sys/proc.h>

#include <vm/vm.h>
#include <vm/vm_extern.h>

#include <linux/compiler.h>

#define	VERIFY_READ	VM_PROT_READ
#define	VERIFY_WRITE	VM_PROT_WRITE

#define	__get_user(_x, _p) ({					\
	int __err;						\
	__typeof(*(_p)) __x;					\
	__err = linux_copyin((_p), &(__x), sizeof(*(_p)));	\
	(_x) = __x;						\
	__err;							\
})

#define	__put_user(_x, _p) ({				\
	__typeof(*(_p)) __x = (_x);			\
	linux_copyout(&(__x), (_p), sizeof(*(_p)));	\
})
#define	get_user(_x, _p)	linux_copyin((_p), &(_x), sizeof(*(_p)))
#define	put_user(_x, _p)	__put_user(_x, _p)
#define	clear_user(...)		linux_clear_user(__VA_ARGS__)

#define	access_ok(a,b)		linux_access_ok(a,b)

extern int linux_copyin(const void *uaddr, void *kaddr, size_t len);
extern int linux_copyout(const void *kaddr, void *uaddr, size_t len);
extern size_t linux_clear_user(void *uaddr, size_t len);
extern int linux_access_ok(const void *uaddr, size_t len);

/*
 * NOTE: Each pagefault_disable() call must have a corresponding
 * pagefault_enable() call in the same scope. The former creates a new
 * block and defines a temporary variable, and the latter uses the
 * temporary variable and closes the block. Failure to balance the
 * calls will result in a compile-time error.
 */
#define	pagefault_disable(void) do {		\
	int __saved_pflags =			\
	    vm_fault_disable_pagefaults()

#define	pagefault_enable(void)				\
	vm_fault_enable_pagefaults(__saved_pflags);	\
} while (0)

static inline bool
pagefault_disabled(void)
{
	return ((curthread->td_pflags & TDP_NOFAULTING) != 0);
}

static inline int
__copy_to_user_inatomic(void __user *to, const void *from, unsigned n)
{

	return (copyout_nofault(from, to, n) != 0 ? n : 0);
}
#define	__copy_to_user_inatomic_nocache(to, from, n)	\
	__copy_to_user_inatomic((to), (from), (n))

static inline unsigned long
__copy_from_user_inatomic(void *to, const void __user *from,
    unsigned long n)
{
	/*
	 * XXXKIB.  Equivalent Linux function is implemented using
	 * MOVNTI for aligned moves.  For unaligned head and tail,
	 * normal move is performed.  As such, it is not incorrect, if
	 * only somewhat slower, to use normal copyin.  All uses
	 * except shmem_pwrite_fast() have the destination mapped WC.
	 */
	return ((copyin_nofault(__DECONST(void *, from), to, n) != 0 ? n : 0));
}
#define	__copy_from_user_inatomic_nocache(to, from, n)	\
	__copy_from_user_inatomic((to), (from), (n))

#endif					/* _LINUXKPI_LINUX_UACCESS_H_ */