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