| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | #ifndef _ALPHA_IOCTL_H |
| 2 | #define _ALPHA_IOCTL_H |
| 3 | |
| 4 | /* |
| 5 | * The original linux ioctl numbering scheme was just a general |
| 6 | * "anything goes" setup, where more or less random numbers were |
| 7 | * assigned. Sorry, I was clueless when I started out on this. |
| 8 | * |
| 9 | * On the alpha, we'll try to clean it up a bit, using a more sane |
| 10 | * ioctl numbering, and also trying to be compatible with OSF/1 in |
| 11 | * the process. I'd like to clean it up for the i386 as well, but |
| 12 | * it's so painful recognizing both the new and the old numbers.. |
| 13 | */ |
| 14 | |
| 15 | #define _IOC_NRBITS 8 |
| 16 | #define _IOC_TYPEBITS 8 |
| 17 | #define _IOC_SIZEBITS 13 |
| 18 | #define _IOC_DIRBITS 3 |
| 19 | |
| 20 | #define _IOC_NRMASK ((1 << _IOC_NRBITS)-1) |
| 21 | #define _IOC_TYPEMASK ((1 << _IOC_TYPEBITS)-1) |
| 22 | #define _IOC_SIZEMASK ((1 << _IOC_SIZEBITS)-1) |
| 23 | #define _IOC_DIRMASK ((1 << _IOC_DIRBITS)-1) |
| 24 | |
| 25 | #define _IOC_NRSHIFT 0 |
| 26 | #define _IOC_TYPESHIFT (_IOC_NRSHIFT+_IOC_NRBITS) |
| 27 | #define _IOC_SIZESHIFT (_IOC_TYPESHIFT+_IOC_TYPEBITS) |
| 28 | #define _IOC_DIRSHIFT (_IOC_SIZESHIFT+_IOC_SIZEBITS) |
| 29 | |
| 30 | /* |
| 31 | * Direction bits _IOC_NONE could be 0, but OSF/1 gives it a bit. |
| 32 | * And this turns out useful to catch old ioctl numbers in header |
| 33 | * files for us. |
| 34 | */ |
| 35 | #define _IOC_NONE 1U |
| 36 | #define _IOC_READ 2U |
| 37 | #define _IOC_WRITE 4U |
| 38 | |
| 39 | #define _IOC(dir,type,nr,size) \ |
| 40 | ((unsigned int) \ |
| 41 | (((dir) << _IOC_DIRSHIFT) | \ |
| 42 | ((type) << _IOC_TYPESHIFT) | \ |
| 43 | ((nr) << _IOC_NRSHIFT) | \ |
| 44 | ((size) << _IOC_SIZESHIFT))) |
| 45 | |
| 46 | /* used to create numbers */ |
| 47 | #define _IO(type,nr) _IOC(_IOC_NONE,(type),(nr),0) |
| 48 | #define _IOR(type,nr,size) _IOC(_IOC_READ,(type),(nr),sizeof(size)) |
| 49 | #define _IOW(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),sizeof(size)) |
| 50 | #define _IOWR(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size)) |
| 51 | |
| 52 | /* used to decode them.. */ |
| 53 | #define _IOC_DIR(nr) (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK) |
| 54 | #define _IOC_TYPE(nr) (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK) |
| 55 | #define _IOC_NR(nr) (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK) |
| 56 | #define _IOC_SIZE(nr) (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK) |
| 57 | |
| 58 | /* ...and for the drivers/sound files... */ |
| 59 | |
| 60 | #define IOC_IN (_IOC_WRITE << _IOC_DIRSHIFT) |
| 61 | #define IOC_OUT (_IOC_READ << _IOC_DIRSHIFT) |
| 62 | #define IOC_INOUT ((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT) |
| 63 | #define IOCSIZE_MASK (_IOC_SIZEMASK << _IOC_SIZESHIFT) |
| 64 | #define IOCSIZE_SHIFT (_IOC_SIZESHIFT) |
| 65 | |
| 66 | #endif /* _ALPHA_IOCTL_H */ |