From af4cd3fe4cfa75ca74f8d8622867371289043a8d Mon Sep 17 00:00:00 2001 From: Brian Gerst Date: Mon, 9 Jan 2006 20:52:18 -0800 Subject: [PATCH] Generic ioctl.h Most arches copied the i386 ioctl.h. Combine them into a generic header. Signed-off-by: Brian Gerst Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-generic/ioctl.h | 80 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 include/asm-generic/ioctl.h (limited to 'include/asm-generic') diff --git a/include/asm-generic/ioctl.h b/include/asm-generic/ioctl.h new file mode 100644 index 00000000000..cd027298beb --- /dev/null +++ b/include/asm-generic/ioctl.h @@ -0,0 +1,80 @@ +#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 +#define _IOC_SIZEBITS 14 +#define _IOC_DIRBITS 2 + +#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. + */ +#define _IOC_NONE 0U +#define _IOC_WRITE 1U +#define _IOC_READ 2U + +#define _IOC(dir,type,nr,size) \ + (((dir) << _IOC_DIRSHIFT) | \ + ((type) << _IOC_TYPESHIFT) | \ + ((nr) << _IOC_NRSHIFT) | \ + ((size) << _IOC_SIZESHIFT)) + +/* provoke compile error for invalid uses of size argument */ +extern unsigned int __invalid_size_argument_for_IOC; +#define _IOC_TYPECHECK(t) \ + ((sizeof(t) == sizeof(t[1]) && \ + sizeof(t) < (1 << _IOC_SIZEBITS)) ? \ + sizeof(t) : __invalid_size_argument_for_IOC) + +/* used to create numbers */ +#define _IO(type,nr) _IOC(_IOC_NONE,(type),(nr),0) +#define _IOR(type,nr,size) _IOC(_IOC_READ,(type),(nr),(_IOC_TYPECHECK(size))) +#define _IOW(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size))) +#define _IOWR(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),(_IOC_TYPECHECK(size))) +#define _IOR_BAD(type,nr,size) _IOC(_IOC_READ,(type),(nr),sizeof(size)) +#define _IOW_BAD(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),sizeof(size)) +#define _IOWR_BAD(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size)) + +/* 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 */ -- cgit v1.2.3