diff options
Diffstat (limited to 'include/arch/x86_64/asm-generic/ioctl.h')
| -rw-r--r-- | include/arch/x86_64/asm-generic/ioctl.h | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/include/arch/x86_64/asm-generic/ioctl.h b/include/arch/x86_64/asm-generic/ioctl.h new file mode 100644 index 00000000..a512641b --- /dev/null +++ b/include/arch/x86_64/asm-generic/ioctl.h @@ -0,0 +1,109 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef _ASM_GENERIC_IOCTL_H +#define _ASM_GENERIC_IOCTL_H + +/* ioctl command encoding: 32 bits total, command in lower 16 bits, + * size of the parameter structure in the lower 14 bits of the + * upper 16 bits. + * Encoding the size of the parameter structure in the ioctl request + * is useful for catching programs compiled with old versions + * and to avoid overwriting user space outside the user buffer area. + * The highest 2 bits are reserved for indicating the ``access mode''. + * NOTE: This limits the max parameter size to 16kB -1 ! + */ + +/* + * The following is for compatibility across the various Linux + * platforms. The generic ioctl numbering scheme doesn't really enforce + * a type field. De facto, however, the top 8 bits of the lower 16 + * bits are indeed used as a type field, so we might just as well make + * this explicit here. Please be sure to use the decoding macros + * below from now on. + */ +#define _IOC_NRBITS 8 +#define _IOC_TYPEBITS 8 + +/* + * Let any architecture override either of the following before + * including this file. + */ + +#ifndef _IOC_SIZEBITS +#define _IOC_SIZEBITS 14 +#endif + +#ifndef _IOC_DIRBITS +#define _IOC_DIRBITS 2 +#endif + +#define _IOC_NRMASK ((1 << _IOC_NRBITS) - 1) +#define _IOC_TYPEMASK ((1 << _IOC_TYPEBITS) - 1) +#define _IOC_SIZEMASK ((1 << _IOC_SIZEBITS) - 1) +#define _IOC_DIRMASK ((1 << _IOC_DIRBITS) - 1) + +#define _IOC_NRSHIFT 0 +#define _IOC_TYPESHIFT (_IOC_NRSHIFT + _IOC_NRBITS) +#define _IOC_SIZESHIFT (_IOC_TYPESHIFT + _IOC_TYPEBITS) +#define _IOC_DIRSHIFT (_IOC_SIZESHIFT + _IOC_SIZEBITS) + +/* + * Direction bits, which any architecture can choose to override + * before including this file. + * + * NOTE: _IOC_WRITE means userland is writing and kernel is + * reading. _IOC_READ means userland is reading and kernel is writing. + */ + +#ifndef _IOC_NONE +#define _IOC_NONE 0U +#endif + +#ifndef _IOC_WRITE +#define _IOC_WRITE 1U +#endif + +#ifndef _IOC_READ +#define _IOC_READ 2U +#endif + +#define _IOC(dir, type, nr, size) \ + (((dir) << _IOC_DIRSHIFT) | ((type) << _IOC_TYPESHIFT) | \ + ((nr) << _IOC_NRSHIFT) | ((size) << _IOC_SIZESHIFT)) + +#define _IOC_TYPECHECK(t) (sizeof(t)) + +/* + * Used to create numbers. + * + * NOTE: _IOW means userland is writing and kernel is reading. _IOR + * means userland is reading and kernel is writing. + */ +#define _IO(type, nr) _IOC(_IOC_NONE, (type), (nr), 0) +#define _IOR(type, nr, argtype) \ + _IOC(_IOC_READ, (type), (nr), (_IOC_TYPECHECK(argtype))) +#define _IOW(type, nr, argtype) \ + _IOC(_IOC_WRITE, (type), (nr), (_IOC_TYPECHECK(argtype))) +#define _IOWR(type, nr, argtype) \ + _IOC(_IOC_READ | _IOC_WRITE, (type), (nr), (_IOC_TYPECHECK(argtype))) +#define _IOR_BAD(type, nr, argtype) \ + _IOC(_IOC_READ, (type), (nr), sizeof(argtype)) +#define _IOW_BAD(type, nr, argtype) \ + _IOC(_IOC_WRITE, (type), (nr), sizeof(argtype)) +#define _IOWR_BAD(type, nr, argtype) \ + _IOC(_IOC_READ | _IOC_WRITE, (type), (nr), sizeof(argtype)) + +/* used to decode ioctl numbers.. */ +#define _IOC_DIR(nr) (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK) +#define _IOC_TYPE(nr) (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK) +#define _IOC_NR(nr) (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK) +#define _IOC_SIZE(nr) (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK) + +/* ...and for the drivers/sound files... */ + +#define IOC_IN (_IOC_WRITE << _IOC_DIRSHIFT) +#define IOC_OUT (_IOC_READ << _IOC_DIRSHIFT) +#define IOC_INOUT ((_IOC_WRITE | _IOC_READ) << _IOC_DIRSHIFT) +#define IOCSIZE_MASK (_IOC_SIZEMASK << _IOC_SIZESHIFT) +#define IOCSIZE_SHIFT (_IOC_SIZESHIFT) + +#endif /* _ASM_GENERIC_IOCTL_H */ |
