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author | Brian Gerst <bgerst@didntduck.org> | 2006-01-09 20:52:18 -0800 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-01-10 08:01:34 -0800 |
commit | af4cd3fe4cfa75ca74f8d8622867371289043a8d (patch) | |
tree | 70dc7836a98758578628a96dc609a0c67f78dffb /include/asm-generic/ioctl.h | |
parent | 7ff92053ddff48d9d7908a353bd85f893944463e (diff) | |
download | op-kernel-dev-af4cd3fe4cfa75ca74f8d8622867371289043a8d.zip op-kernel-dev-af4cd3fe4cfa75ca74f8d8622867371289043a8d.tar.gz |
[PATCH] Generic ioctl.h
Most arches copied the i386 ioctl.h. Combine them into a generic header.
Signed-off-by: Brian Gerst <bgerst@didntduck.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/asm-generic/ioctl.h')
-rw-r--r-- | include/asm-generic/ioctl.h | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/include/asm-generic/ioctl.h b/include/asm-generic/ioctl.h new file mode 100644 index 0000000..cd02729 --- /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 */ |