projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
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 | * 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 | /* provoke compile error for invalid uses of size argument */ | |
| 69 | extern unsigned int __invalid_size_argument_for_IOC; | |
| 70 | #define _IOC_TYPECHECK(t) \ | |
| 71 | ((sizeof(t) == sizeof(t[1]) && \ | |
| 72 | sizeof(t) < (1 << _IOC_SIZEBITS)) ? \ | |
| 73 | sizeof(t) : __invalid_size_argument_for_IOC) | |
| 74 | ||
| 75 | /* used to create numbers */ | |
| 76 | #define _IO(type,nr) _IOC(_IOC_NONE,(type),(nr),0) | |
| 77 | #define _IOR(type,nr,size) _IOC(_IOC_READ,(type),(nr),(_IOC_TYPECHECK(size))) | |
| 78 | #define _IOW(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size))) | |
| 79 | #define _IOWR(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size))) | |
| 80 | #define _IOR_BAD(type,nr,size) _IOC(_IOC_READ,(type),(nr),sizeof(size)) | |
| 81 | #define _IOW_BAD(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),sizeof(size)) | |
| 82 | #define _IOWR_BAD(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size)) | |
| 83 | ||
| 84 | ||
| 85 | /* used to decode them.. */ | |
| 86 | #define _IOC_DIR(nr) (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK) | |
| 87 | #define _IOC_TYPE(nr) (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK) | |
| 88 | #define _IOC_NR(nr) (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK) | |
| 89 | #define _IOC_SIZE(nr) (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK) | |
| 90 | ||
| 91 | /* ...and for the drivers/sound files... */ | |
| 92 | ||
| 93 | #define IOC_IN (_IOC_WRITE << _IOC_DIRSHIFT) | |
| 94 | #define IOC_OUT (_IOC_READ << _IOC_DIRSHIFT) | |
| 95 | #define IOC_INOUT ((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT) | |
| 96 | #define IOCSIZE_MASK (_IOC_SIZEMASK << _IOC_SIZESHIFT) | |
| 97 | #define IOCSIZE_SHIFT (_IOC_SIZESHIFT) | |
| 98 | ||
| 99 | #endif /* _ASM_IOCTL_H */ |