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, 96, 99, 2001 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 * Direction bits _IOC_NONE could be 0, but OSF/1 gives it a bit. 42 * And this turns out useful to catch old ioctl numbers in header 43 * files for us. 44 */ 45#define _IOC_NONE 1U 46#define _IOC_READ 2U 47#define _IOC_WRITE 4U 48 49/* 50 * The following are included for compatibility 51 */ 52#define _IOC_VOID 0x20000000 53#define _IOC_OUT 0x40000000 54#define _IOC_IN 0x80000000 55#define _IOC_INOUT (IOC_IN|IOC_OUT) 56 57#define _IOC(dir,type,nr,size) \ 58 (((dir) << _IOC_DIRSHIFT) | \ 59 ((type) << _IOC_TYPESHIFT) | \ 60 ((nr) << _IOC_NRSHIFT) | \ 61 ((size) << _IOC_SIZESHIFT)) 62 63/* provoke compile error for invalid uses of size argument */ 64extern unsigned int __invalid_size_argument_for_IOC; 65#define _IOC_TYPECHECK(t) \ 66 ((sizeof(t) == sizeof(t[1]) && \ 67 sizeof(t) < (1 << _IOC_SIZEBITS)) ? \ 68 sizeof(t) : __invalid_size_argument_for_IOC) 69 70/* used to create numbers */ 71#define _IO(type,nr) _IOC(_IOC_NONE,(type),(nr),0) 72#define _IOR(type,nr,size) _IOC(_IOC_READ,(type),(nr),(_IOC_TYPECHECK(size))) 73#define _IOW(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size))) 74#define _IOWR(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size))) 75#define _IOR_BAD(type,nr,size) _IOC(_IOC_READ,(type),(nr),sizeof(size)) 76#define _IOW_BAD(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),sizeof(size)) 77#define _IOWR_BAD(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size)) 78 79 80/* used to decode them.. */ 81#define _IOC_DIR(nr) (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK) 82#define _IOC_TYPE(nr) (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK) 83#define _IOC_NR(nr) (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK) 84#define _IOC_SIZE(nr) (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK) 85 86/* ...and for the drivers/sound files... */ 87 88#define IOC_IN (_IOC_WRITE << _IOC_DIRSHIFT) 89#define IOC_OUT (_IOC_READ << _IOC_DIRSHIFT) 90#define IOC_INOUT ((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT) 91#define IOCSIZE_MASK (_IOC_SIZEMASK << _IOC_SIZESHIFT) 92#define IOCSIZE_SHIFT (_IOC_SIZESHIFT) 93 94#endif /* _ASM_IOCTL_H */ 95