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 */ 64 extern 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
