1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2*4882a593Smuzhiyun #ifndef _UAPI_ASM_GENERIC_IOCTL_H 3*4882a593Smuzhiyun #define _UAPI_ASM_GENERIC_IOCTL_H 4*4882a593Smuzhiyun 5*4882a593Smuzhiyun /* ioctl command encoding: 32 bits total, command in lower 16 bits, 6*4882a593Smuzhiyun * size of the parameter structure in the lower 14 bits of the 7*4882a593Smuzhiyun * upper 16 bits. 8*4882a593Smuzhiyun * Encoding the size of the parameter structure in the ioctl request 9*4882a593Smuzhiyun * is useful for catching programs compiled with old versions 10*4882a593Smuzhiyun * and to avoid overwriting user space outside the user buffer area. 11*4882a593Smuzhiyun * The highest 2 bits are reserved for indicating the ``access mode''. 12*4882a593Smuzhiyun * NOTE: This limits the max parameter size to 16kB -1 ! 13*4882a593Smuzhiyun */ 14*4882a593Smuzhiyun 15*4882a593Smuzhiyun /* 16*4882a593Smuzhiyun * The following is for compatibility across the various Linux 17*4882a593Smuzhiyun * platforms. The generic ioctl numbering scheme doesn't really enforce 18*4882a593Smuzhiyun * a type field. De facto, however, the top 8 bits of the lower 16 19*4882a593Smuzhiyun * bits are indeed used as a type field, so we might just as well make 20*4882a593Smuzhiyun * this explicit here. Please be sure to use the decoding macros 21*4882a593Smuzhiyun * below from now on. 22*4882a593Smuzhiyun */ 23*4882a593Smuzhiyun #define _IOC_NRBITS 8 24*4882a593Smuzhiyun #define _IOC_TYPEBITS 8 25*4882a593Smuzhiyun 26*4882a593Smuzhiyun /* 27*4882a593Smuzhiyun * Let any architecture override either of the following before 28*4882a593Smuzhiyun * including this file. 29*4882a593Smuzhiyun */ 30*4882a593Smuzhiyun 31*4882a593Smuzhiyun #ifndef _IOC_SIZEBITS 32*4882a593Smuzhiyun # define _IOC_SIZEBITS 14 33*4882a593Smuzhiyun #endif 34*4882a593Smuzhiyun 35*4882a593Smuzhiyun #ifndef _IOC_DIRBITS 36*4882a593Smuzhiyun # define _IOC_DIRBITS 2 37*4882a593Smuzhiyun #endif 38*4882a593Smuzhiyun 39*4882a593Smuzhiyun #define _IOC_NRMASK ((1 << _IOC_NRBITS)-1) 40*4882a593Smuzhiyun #define _IOC_TYPEMASK ((1 << _IOC_TYPEBITS)-1) 41*4882a593Smuzhiyun #define _IOC_SIZEMASK ((1 << _IOC_SIZEBITS)-1) 42*4882a593Smuzhiyun #define _IOC_DIRMASK ((1 << _IOC_DIRBITS)-1) 43*4882a593Smuzhiyun 44*4882a593Smuzhiyun #define _IOC_NRSHIFT 0 45*4882a593Smuzhiyun #define _IOC_TYPESHIFT (_IOC_NRSHIFT+_IOC_NRBITS) 46*4882a593Smuzhiyun #define _IOC_SIZESHIFT (_IOC_TYPESHIFT+_IOC_TYPEBITS) 47*4882a593Smuzhiyun #define _IOC_DIRSHIFT (_IOC_SIZESHIFT+_IOC_SIZEBITS) 48*4882a593Smuzhiyun 49*4882a593Smuzhiyun /* 50*4882a593Smuzhiyun * Direction bits, which any architecture can choose to override 51*4882a593Smuzhiyun * before including this file. 52*4882a593Smuzhiyun * 53*4882a593Smuzhiyun * NOTE: _IOC_WRITE means userland is writing and kernel is 54*4882a593Smuzhiyun * reading. _IOC_READ means userland is reading and kernel is writing. 55*4882a593Smuzhiyun */ 56*4882a593Smuzhiyun 57*4882a593Smuzhiyun #ifndef _IOC_NONE 58*4882a593Smuzhiyun # define _IOC_NONE 0U 59*4882a593Smuzhiyun #endif 60*4882a593Smuzhiyun 61*4882a593Smuzhiyun #ifndef _IOC_WRITE 62*4882a593Smuzhiyun # define _IOC_WRITE 1U 63*4882a593Smuzhiyun #endif 64*4882a593Smuzhiyun 65*4882a593Smuzhiyun #ifndef _IOC_READ 66*4882a593Smuzhiyun # define _IOC_READ 2U 67*4882a593Smuzhiyun #endif 68*4882a593Smuzhiyun 69*4882a593Smuzhiyun #define _IOC(dir,type,nr,size) \ 70*4882a593Smuzhiyun (((dir) << _IOC_DIRSHIFT) | \ 71*4882a593Smuzhiyun ((type) << _IOC_TYPESHIFT) | \ 72*4882a593Smuzhiyun ((nr) << _IOC_NRSHIFT) | \ 73*4882a593Smuzhiyun ((size) << _IOC_SIZESHIFT)) 74*4882a593Smuzhiyun 75*4882a593Smuzhiyun #ifndef __KERNEL__ 76*4882a593Smuzhiyun #define _IOC_TYPECHECK(t) (sizeof(t)) 77*4882a593Smuzhiyun #endif 78*4882a593Smuzhiyun 79*4882a593Smuzhiyun /* 80*4882a593Smuzhiyun * Used to create numbers. 81*4882a593Smuzhiyun * 82*4882a593Smuzhiyun * NOTE: _IOW means userland is writing and kernel is reading. _IOR 83*4882a593Smuzhiyun * means userland is reading and kernel is writing. 84*4882a593Smuzhiyun */ 85*4882a593Smuzhiyun #define _IO(type,nr) _IOC(_IOC_NONE,(type),(nr),0) 86*4882a593Smuzhiyun #define _IOR(type,nr,size) _IOC(_IOC_READ,(type),(nr),(_IOC_TYPECHECK(size))) 87*4882a593Smuzhiyun #define _IOW(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size))) 88*4882a593Smuzhiyun #define _IOWR(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size))) 89*4882a593Smuzhiyun #define _IOR_BAD(type,nr,size) _IOC(_IOC_READ,(type),(nr),sizeof(size)) 90*4882a593Smuzhiyun #define _IOW_BAD(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),sizeof(size)) 91*4882a593Smuzhiyun #define _IOWR_BAD(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size)) 92*4882a593Smuzhiyun 93*4882a593Smuzhiyun /* used to decode ioctl numbers.. */ 94*4882a593Smuzhiyun #define _IOC_DIR(nr) (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK) 95*4882a593Smuzhiyun #define _IOC_TYPE(nr) (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK) 96*4882a593Smuzhiyun #define _IOC_NR(nr) (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK) 97*4882a593Smuzhiyun #define _IOC_SIZE(nr) (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK) 98*4882a593Smuzhiyun 99*4882a593Smuzhiyun /* ...and for the drivers/sound files... */ 100*4882a593Smuzhiyun 101*4882a593Smuzhiyun #define IOC_IN (_IOC_WRITE << _IOC_DIRSHIFT) 102*4882a593Smuzhiyun #define IOC_OUT (_IOC_READ << _IOC_DIRSHIFT) 103*4882a593Smuzhiyun #define IOC_INOUT ((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT) 104*4882a593Smuzhiyun #define IOCSIZE_MASK (_IOC_SIZEMASK << _IOC_SIZESHIFT) 105*4882a593Smuzhiyun #define IOCSIZE_SHIFT (_IOC_SIZESHIFT) 106*4882a593Smuzhiyun 107*4882a593Smuzhiyun #endif /* _UAPI_ASM_GENERIC_IOCTL_H */ 108