ioctl.h

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/*
 * This file is part of the µOS++ distribution.
 *   (https://github.com/micro-os-plus)
 * Copyright (c) 2018 Liviu Ionescu.
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom
 * the Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */
 
#ifndef POSIX_SYS_IOCTL_H_
#define POSIX_SYS_IOCTL_H_
 
// ----------------------------------------------------------------------------
 
// Avoid warnings for _IOC* definitions.
#pragma GCC system_header
 
/*
 * From: https://github.com/torvalds/linux/blob/master/include/uapi/asm-generic/ioctl.h
 *
 * The following is for compatibility across the various Linux
 * platforms.  The generic ioctl numbering scheme doesn't really enforce
 * a type field.  De facto, however, the top 8 bits of the lower 16
 * bits are indeed used as a type field, so we might just as well make
 * this explicit here.  Please be sure to use the decoding macros
 * below from now on.
 */
#define _IOC_NRBITS 8
#define _IOC_TYPEBITS 8
 
#ifndef _IOC_SIZEBITS
# define _IOC_SIZEBITS  14
#endif
 
#ifndef _IOC_DIRBITS
# define _IOC_DIRBITS 2
#endif
 
#define _IOC_NRMASK ((1 << _IOC_NRBITS)-1)
#define _IOC_TYPEMASK ((1 << _IOC_TYPEBITS)-1)
#define _IOC_SIZEMASK ((1 << _IOC_SIZEBITS)-1)
#define _IOC_DIRMASK  ((1 << _IOC_DIRBITS)-1)
 
#define _IOC_NRSHIFT  0
#define _IOC_TYPESHIFT  (_IOC_NRSHIFT+_IOC_NRBITS)
#define _IOC_SIZESHIFT  (_IOC_TYPESHIFT+_IOC_TYPEBITS)
#define _IOC_DIRSHIFT (_IOC_SIZESHIFT+_IOC_SIZEBITS)
 
/*
 * Direction bits, which any architecture can choose to override
 * before including this file.
 *
 * NOTE: _IOC_WRITE means userland is writing and kernel is
 * reading. _IOC_READ means userland is reading and kernel is writing.
 */
 
#ifndef _IOC_NONE
# define _IOC_NONE  0U
#endif
 
#ifndef _IOC_WRITE
# define _IOC_WRITE 1U
#endif
 
#ifndef _IOC_READ
# define _IOC_READ  2U
#endif
 
#define _IOC(dir,type,nr,size) \
   (((dir)  << _IOC_DIRSHIFT) | \
   ((type) << _IOC_TYPESHIFT) | \
   ((nr)   << _IOC_NRSHIFT) | \
   ((size) << _IOC_SIZESHIFT))
 
#ifndef __KERNEL__
#define _IOC_TYPECHECK(t) (sizeof(t))
#endif
 
// ----------------------------------------------------------------------------
 
/*
 * From: https://github.com/torvalds/linux/blob/master/include/uapi/linux/fs.h
 *
 * Used to create numbers.
 *
 * NOTE: _IOW means userland is writing and kernel is reading. _IOR
 * means userland is reading and kernel is writing.
 */
#define _IO(type,nr)    _IOC(_IOC_NONE,(type),(nr),0)
#define _IOR(type,nr,size)  _IOC(_IOC_READ,(type),(nr),(_IOC_TYPECHECK(size)))
#define _IOW(type,nr,size)  _IOC(_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size)))
#define _IOWR(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size)))
 
/* 108-111 have been used for various private purposes. */
 
#define BLKSSZGET  _IO(0x12,104) /* get block logical device sector size */
#define BLKGETSIZE64 _IOR(0x12,114,size_t)  /* get device size in bytes (u64 *arg) */
#define BLKPBSZGET _IO(0x12,123) /* get block physical device sector size */
 
// ----------------------------------------------------------------------------
 
#endif /* POSIX_SYS_IOCTL_H_ */