1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2 #ifndef _ALPHA_IOCTL_H 3 #define _ALPHA_IOCTL_H 4 5 /* 6 * The original linux ioctl numbering scheme was just a general 7 * "anything goes" setup, where more or less random numbers were 8 * assigned. Sorry, I was clueless when I started out on this. 9 * 10 * On the alpha, we'll try to clean it up a bit, using a more sane 11 * ioctl numbering, and also trying to be compatible with OSF/1 in 12 * the process. I'd like to clean it up for the i386 as well, but 13 * it's so painful recognizing both the new and the old numbers.. 14 */ 15 16 #define _IOC_NRBITS 8 17 #define _IOC_TYPEBITS 8 18 #define _IOC_SIZEBITS 13 19 #define _IOC_DIRBITS 3 20 21 #define _IOC_NRMASK ((1 << _IOC_NRBITS)-1) 22 #define _IOC_TYPEMASK ((1 << _IOC_TYPEBITS)-1) 23 #define _IOC_SIZEMASK ((1 << _IOC_SIZEBITS)-1) 24 #define _IOC_DIRMASK ((1 << _IOC_DIRBITS)-1) 25 26 #define _IOC_NRSHIFT 0 27 #define _IOC_TYPESHIFT (_IOC_NRSHIFT+_IOC_NRBITS) 28 #define _IOC_SIZESHIFT (_IOC_TYPESHIFT+_IOC_TYPEBITS) 29 #define _IOC_DIRSHIFT (_IOC_SIZESHIFT+_IOC_SIZEBITS) 30 31 /* 32 * Direction bits _IOC_NONE could be 0, but OSF/1 gives it a bit. 33 * And this turns out useful to catch old ioctl numbers in header 34 * files for us. 35 */ 36 #define _IOC_NONE 1U 37 #define _IOC_READ 2U 38 #define _IOC_WRITE 4U 39 40 #define _IOC(dir,type,nr,size) \ 41 ((unsigned int) \ 42 (((dir) << _IOC_DIRSHIFT) | \ 43 ((type) << _IOC_TYPESHIFT) | \ 44 ((nr) << _IOC_NRSHIFT) | \ 45 ((size) << _IOC_SIZESHIFT))) 46 47 /* used to create numbers */ 48 #define _IO(type,nr) _IOC(_IOC_NONE,(type),(nr),0) 49 #define _IOR(type,nr,size) _IOC(_IOC_READ,(type),(nr),sizeof(size)) 50 #define _IOW(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),sizeof(size)) 51 #define _IOWR(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size)) 52 53 /* used to decode them.. */ 54 #define _IOC_DIR(nr) (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK) 55 #define _IOC_TYPE(nr) (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK) 56 #define _IOC_NR(nr) (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK) 57 #define _IOC_SIZE(nr) (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK) 58 59 /* ...and for the drivers/sound files... */ 60 61 #define IOC_IN (_IOC_WRITE << _IOC_DIRSHIFT) 62 #define IOC_OUT (_IOC_READ << _IOC_DIRSHIFT) 63 #define IOC_INOUT ((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT) 64 #define IOCSIZE_MASK (_IOC_SIZEMASK << _IOC_SIZESHIFT) 65 #define IOCSIZE_SHIFT (_IOC_SIZESHIFT) 66 67 #endif /* _ALPHA_IOCTL_H */ 68