1/* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Copyright (C) 1995, 1996, 1999, 2001 by Ralf Baechle 7 */ 8#ifndef _ASM_IOCTL_H 9#define _ASM_IOCTL_H 10 11/* 12 * The original linux ioctl numbering scheme was just a general 13 * "anything goes" setup, where more or less random numbers were 14 * assigned. Sorry, I was clueless when I started out on this. 15 * 16 * On the alpha, we'll try to clean it up a bit, using a more sane 17 * ioctl numbering, and also trying to be compatible with OSF/1 in 18 * the process. I'd like to clean it up for the i386 as well, but 19 * it's so painful recognizing both the new and the old numbers.. 20 * 21 * The same applies for for the MIPS ABI; in fact even the macros 22 * from Linux/Alpha fit almost perfectly. 23 */ 24 25#define _IOC_NRBITS 8 26#define _IOC_TYPEBITS 8 27#define _IOC_SIZEBITS 13 28#define _IOC_DIRBITS 3 29 30#define _IOC_NRMASK ((1 << _IOC_NRBITS)-1) 31#define _IOC_TYPEMASK ((1 << _IOC_TYPEBITS)-1) 32#define _IOC_SIZEMASK ((1 << _IOC_SIZEBITS)-1) 33#define _IOC_DIRMASK ((1 << _IOC_DIRBITS)-1) 34 35#define _IOC_NRSHIFT 0 36#define _IOC_TYPESHIFT (_IOC_NRSHIFT+_IOC_NRBITS) 37#define _IOC_SIZESHIFT (_IOC_TYPESHIFT+_IOC_TYPEBITS) 38#define _IOC_DIRSHIFT (_IOC_SIZESHIFT+_IOC_SIZEBITS) 39 40/* 41 * We to additionally limit parameters to a maximum 255 bytes. 42 */ 43#define _IOC_SLMASK 0xff 44 45/* 46 * Direction bits _IOC_NONE could be 0, but OSF/1 gives it a bit. 47 * And this turns out useful to catch old ioctl numbers in header 48 * files for us. 49 */ 50#define _IOC_NONE 1U 51#define _IOC_READ 2U 52#define _IOC_WRITE 4U 53 54/* 55 * The following are included for compatibility 56 */ 57#define _IOC_VOID 0x20000000 58#define _IOC_OUT 0x40000000 59#define _IOC_IN 0x80000000 60#define _IOC_INOUT (IOC_IN|IOC_OUT) 61 62#define _IOC(dir,type,nr,size) \ 63 (((dir) << _IOC_DIRSHIFT) | \ 64 ((type) << _IOC_TYPESHIFT) | \ 65 ((nr) << _IOC_NRSHIFT) | \ 66 ((size) << _IOC_SIZESHIFT)) 67 68/* used to create numbers */ 69#define _IO(type,nr) _IOC(_IOC_NONE,(type),(nr),0) 70#define _IOR(type,nr,size) _IOC(_IOC_READ,(type),(nr),sizeof(size)) 71#define _IOW(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),sizeof(size)) 72#define _IOWR(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size)) 73 74/* used to decode them.. */ 75#define _IOC_DIR(nr) (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK) 76#define _IOC_TYPE(nr) (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK) 77#define _IOC_NR(nr) (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK) 78#define _IOC_SIZE(nr) (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK) 79 80/* ...and for the drivers/sound files... */ 81 82#define IOC_IN (_IOC_WRITE << _IOC_DIRSHIFT) 83#define IOC_OUT (_IOC_READ << _IOC_DIRSHIFT) 84#define IOC_INOUT ((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT) 85#define IOCSIZE_MASK (_IOC_SIZEMASK << _IOC_SIZESHIFT) 86#define IOCSIZE_SHIFT (_IOC_SIZESHIFT) 87 88#endif /* _ASM_IOCTL_H */ 89