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 */ 67