1 /* $Id: ioctl.h,v 1.2 2001/07/04 09:08:13 ak Exp $ 2 * 3 * linux/ioctl.h for Linux by H.H. Bergman. 4 */ 5 6 #ifndef _ASMX8664_IOCTL_H 7 #define _ASMX8664_IOCTL_H 8 9 /* ioctl command encoding: 32 bits total, command in lower 16 bits, 10 * size of the parameter structure in the lower 14 bits of the 11 * upper 16 bits. 12 * Encoding the size of the parameter structure in the ioctl request 13 * is useful for catching programs compiled with old versions 14 * and to avoid overwriting user space outside the user buffer area. 15 * The highest 2 bits are reserved for indicating the ``access mode''. 16 * NOTE: This limits the max parameter size to 16kB -1 ! 17 */ 18 19 /* 20 * The following is for compatibility across the various Linux 21 * platforms. The i386 ioctl numbering scheme doesn't really enforce 22 * a type field. De facto, however, the top 8 bits of the lower 16 23 * bits are indeed used as a type field, so we might just as well make 24 * this explicit here. Please be sure to use the decoding macros 25 * below from now on. 26 */ 27 #define _IOC_NRBITS 8 28 #define _IOC_TYPEBITS 8 29 #define _IOC_SIZEBITS 14 30 #define _IOC_DIRBITS 2 31 32 #define _IOC_NRMASK ((1 << _IOC_NRBITS)-1) 33 #define _IOC_TYPEMASK ((1 << _IOC_TYPEBITS)-1) 34 #define _IOC_SIZEMASK ((1 << _IOC_SIZEBITS)-1) 35 #define _IOC_DIRMASK ((1 << _IOC_DIRBITS)-1) 36 37 #define _IOC_NRSHIFT 0 38 #define _IOC_TYPESHIFT (_IOC_NRSHIFT+_IOC_NRBITS) 39 #define _IOC_SIZESHIFT (_IOC_TYPESHIFT+_IOC_TYPEBITS) 40 #define _IOC_DIRSHIFT (_IOC_SIZESHIFT+_IOC_SIZEBITS) 41 42 /* 43 * Direction bits. 44 */ 45 #define _IOC_NONE 0U 46 #define _IOC_WRITE 1U 47 #define _IOC_READ 2U 48 49 #define _IOC(dir,type,nr,size) \ 50 (((dir) << _IOC_DIRSHIFT) | \ 51 ((type) << _IOC_TYPESHIFT) | \ 52 ((nr) << _IOC_NRSHIFT) | \ 53 ((size) << _IOC_SIZESHIFT)) 54 55 /* used to create numbers */ 56 #define _IO(type,nr) _IOC(_IOC_NONE,(type),(nr),0) 57 #define _IOR(type,nr,size) _IOC(_IOC_READ,(type),(nr),sizeof(size)) 58 #define _IOW(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),sizeof(size)) 59 #define _IOWR(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size)) 60 61 /* used to decode ioctl numbers.. */ 62 #define _IOC_DIR(nr) (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK) 63 #define _IOC_TYPE(nr) (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK) 64 #define _IOC_NR(nr) (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK) 65 #define _IOC_SIZE(nr) (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK) 66 67 /* ...and for the drivers/sound files... */ 68 69 #define IOC_IN (_IOC_WRITE << _IOC_DIRSHIFT) 70 #define IOC_OUT (_IOC_READ << _IOC_DIRSHIFT) 71 #define IOC_INOUT ((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT) 72 #define IOCSIZE_MASK (_IOC_SIZEMASK << _IOC_SIZESHIFT) 73 #define IOCSIZE_SHIFT (_IOC_SIZESHIFT) 74 75 #endif /* _ASMX8664_IOCTL_H */ 76